RU2466837C2 - Method and device for mash seam welding - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: two top and bottom rollers 1, 2 are arranged with their axes 17, 18 inclined in horizontal plane in opposite directions relative to straight line Y perpendicular to welding line X set for overlapping parts L of two metal plates 5, 6. Mash seam welding is carried out with hard driving of rollers 1, 2 by motors 61, 62. Metal plates 5, 6 are jointed together so that weld nugget N does not depart from joint interface. Axes 17, 18 of rollers 1, 2 are inclined in horizontal plane in direction of metal plate path with which rollers 1, 2 get in contact first.

EFFECT: ruled out spatter in welding.

10 cl, 26 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a method and apparatus for roll welding with crushing edges, in which two metal plates are arranged to overlap each other at their end parts, the overlapping parts are compressed using a pair of upper and lower roller electrodes and continuously welded to each other by applying current welding into overlapping parts with the subsequent connection of metal plates.

State of the art

In the device for roller welding with crushing edges, the following welding method is used. Two metal plates are arranged overlapping each other at their end parts. The overlapping parts are compressed using a pair of roller electrodes and continuously welded together by applying a welding current to them. At the same time, the joined part, softened by heating to a high temperature, is rolled with electrode rollers to reduce the thickness of the connected part. However, this welding method does not provide rolling of the connected part to a level corresponding to the thickness of the starting material. The problem is that the thickness of the joined part increases to approximately 120-160% of the thickness of the starting material (metal plate), so that a step is formed between the joined part and the starting material.

The following method was proposed as a method of reducing the thickness of the joined part. A pair of pinch rollers is installed near and on one side of the pair of upper and lower roller electrodes. Before roller welding with crushing of the edges, the overlapping parts of the metal plates are rolled using pressure rollers by moving the base frame supporting the roller electrodes and pressure rollers in the direction of the pressure rollers. After rolling, the overlapping metal plates are slightly pushed away from each other to reduce the thickness of the connected part. After that, the overlapping parts are compressed by means of roller electrodes by moving the base frame in the opposite direction and continuously subjected to roller welding with crushing of the edges by applying a welding current to them. Then the joined part is rolled using pressure rollers to reduce its thickness. See Patent Documents 1 and 2.

To reduce the thickness of the joined part, subjected to roller welding with crushing edges, and to reduce the connection time, the following method was proposed. The first and second pair of upper and lower pinch rollers are installed near and on both sides of the pair of upper and lower roller electrodes. The overlapping parts of the metal plates are rolled using the first pinch rollers by moving the base frame supporting the roller electrodes and pinch rollers in the direction preceding the first rollers. After that, the rolled part is compressed using a pair of roller electrodes following the pressure rollers, and continuously subjected to roller welding with crushing of the edges by applying a welding current to them. In addition, the part to be joined is rolled using second pressure rollers following the roller electrodes to reduce its thickness. See Patent Documents 1 and 2.

If two metal plates overlapping each other are connected to each other using the method of roller welding with crushing edges, then a molten and hardened part, called the core of the weld point, is formed on the central thickness part of metal plates captured by a pair of roller electrodes. The larger the difference in thickness between the metal plates, the farther the interface is from the central thickness of the part of the metal plates overlapping each other. Therefore, since there is a problem that the joint interface deviates from the core of the weld point and the joint thickness decreases, it is necessary to limit the ratio of the thicknesses of the metal plates to be connected to each other.

To mitigate the limitation of the thickness ratio between the metal plates to be connected to each other, the following means have been proposed. The contact zone between each of the roller electrodes and the material is set approximately equal to the thickness of the metal plates after roller welding with crushing edges, so that the core of the welding point is formed at the interface of the connection to increase the allowable ratio of the thickness of the connection. See Patent Document 3.

Patent Document 1: JP-2-15314-B.

Patent Document 2: JP-2-16191-B.

Patent Document 3: JP 3 350 933.

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

The device for roller welding with crushing edges uses the following method. Two metal plates are superimposed overlapping each other. The overlapping parts are compressed using a pair of roller electrodes and continuously welded to each other by applying a welding current to them. At the same time, the joined part, heated to a high temperature for softening, is rolled using electrode rollers to reduce its thickness. Therefore, the roller electrodes perform during rolling most of the pressure treatment to reduce the thickness of the joined materials. Plastic deformation of the joined part, reduced in thickness, prevails in the rolling direction of the roller electrodes. However, the joined part has a ratio of a continuous body with the source material of a metal plate adjacent to it. Therefore, plastic deformation in the rolling direction is limited by the starting material. Therefore, the joined part cannot be rolled to the thickness of the starting material. The thickness of the joined part based on the method of roller welding with crushing edges increases to approximately 120-160% of the thickness of the starting material (metal plate). Since the connected part and the starting material have a different thickness from each other, a step is formed in the connected part having a high stress concentration coefficient. When voltage is applied to the connected part, the strength of the connected part is significantly reduced. In other words, this limits the scope of application of roller welding with crushing edges. In addition, a steep step scratches the work roll on the steel plate processing line and reduces productivity.

For example, the joined part of the device for roller welding with crushing edges stepwise increases in thickness to approximately 120-160% of the source material. If the device for roller welding with crushing edges is used for equipment for cold rolling, having a large overall decrease in thickness during rolling, then the stepped part of the joined part is folded into the starting material with the formation of cracks. Therefore, the effective cross-sectional area decreases in the joined part, called the strip, of the metal plate. This increases the tensile stress relative to the tensile force applied during cold rolling. In addition, the front end of the step, rolled up with cracks, becomes a singular stress field, which sharply increases the probability of a fault. This leads to the following problem. Since an inexpensive, small-sized device for roller welding with crushing edges is not applicable for cold rolling equipment having a large overall degree of thickness reduction, it is necessary to use a flash welding device or a laser beam welding device with cold rolling equipment, which is expensive and has large sizes.

A device for roller welding with crushing edges, with which you can cheaply connect metal plates with different thicknesses and strengths of the material to each other, applicable to special workpieces. However, the device for roller welding with crushing edges cannot be used to connect the part when the joined part, increased in thickness, leads to a problem of formation characteristics, when there is a problem of stress concentration as a result of a step formed in the joined part. Therefore, for special blanks, it is necessary to use an expensive laser welding device.

An inexpensive device for roller welding with crushing edges is used as a connecting machine to ensure a continuous manufacturing process for production lines such as a continuous annealing line, galvanization line, etc. in steel production, with the goal of improving productivity. However, as mentioned above, edge-welded roller welding increases the thickness of the joined part to form a steep step. When the joined part passes through the pass in the training stand of the rolling mill, the following method of work is used to prevent scratches on the work roll and to prevent the impression of the step formed in the joined part from being transferred to the work roll. The line speed decreases before and after the passage in the training stand of the rolling mill, and the work roll of the rolling mill rises, or the rolling force decreases. This results in reduced performance.

Of the conventional methods described in Patent Document 1 and Patent Document 2, the first method can reduce the thickness of the part to be joined to approximately 110% of the thickness of the starting material. In the first method, after the completion of rolling, the metal plates are superimposed overlapping each other, slightly moved apart from each other to reduce the connected part. After that, the joined part is subjected to roller welding with crushing edges and additionally rolled using pressure rollers. However, if the distance between the ends of the metal plates moved apart from each other is too large, then a tooth is formed near the part to be joined by rolling with pressure rollers before welding. If the distance is not enough, then the excess of the thickness of the connected part increases. Due to this, there is only a small optimal range for setting the distance. That is, reliability is small. Therefore, it is difficult to provide stable bond strength with high quality.

Of the conventional methods described in Patent Document 1 and Patent Document 2, a method in which pressure rollers are mounted on both sides of the roller electrodes and rolling is carried out after welding, welding and rolling after welding are carried out continuously by moving the base frame in one direction, has the disadvantage that the thickness of the connected part cannot be significantly reduced. Namely, the metal plates are gripped by the clamping device, so that the amount of overlap during roller welding with crushing edges cannot be deflected and is limited in the direction perpendicular to the direction of welding with the clamping device. Therefore, rolling by means of pressure rollers after welding has a limitation of the magnitude of plastic deformation in the direction perpendicular to the welding line, and provides mainly plastic deformation of the metal in the direction of movement of the rollers. Similar to rolling by means of electrode rollers during roll crushing welding, as mentioned above, the plastic deformation of the part rolled by means of pressure rollers is limited by the starting material, so that the elongation is significantly limited. Therefore, the thickness of the joined part cannot be reduced to the thickness of the starting material. When rolling using pressure rollers, the volume of the joined part, the thickness of which decreases due to rolling, decreases due to plastic deformation in the longitudinal direction of the joined part with an increase in the length of the connected part. This causes a difference in elongation between the starting material and the joined part elongated by the pressure rollers, which leads to the disadvantage that the joined part bends or deforms in a wave-like fashion.

Due to this, as mentioned above, it is difficult to make the connection using the conventional method of roller welding with crushing the edges while simultaneously suppressing the increase in the thickness of the joined part, so that a step is not formed between the joined part and the source material. Therefore, it is desirable to create a method of roller welding with crushing edges, which stably provides a reduction in the increase in thickness and the formation of steps at the joined part, as well as a high degree of joint strength.

On the other hand, when welding with crushing edges, a core of the weld point is formed in the central part of the thickness of two metal plates, compressed using a pair of roller electrodes. If two metal plates have a large difference in thickness, then there is the disadvantage that the part where the core of the weld point is formed deviates from the interface of the joint, which reduces the strength of the joint. Indeed, the thickness ratio of the two metal plates to be joined is limited to about 1: 1.5 or less, and the edge-welding roller welding method is not applicable for thickness ratios greater than the specified thickness ratio.

To eliminate this drawback, the following method was proposed. As disclosed in Patent Document 3, a pair of roller electrodes is rotatably mounted about respective axes parallel to each other, and in such roller electrodes, the contact area on the side of the thick metal plate is smaller than that of the roller electrode on the side of the thin metal plate. This approximately equalizes the thickness of the metal plates after roller welding with crushing edges. However, to quantitatively control the difference in thickness between the metal plates, the overlapping parts of the metal plates must be located at the ends of the roller electrodes. For example, if a metal plate with a thickness of 2 mm is connected to a metal plate with a thickness of 3 mm, then the overlap of the metal plates generally corresponds to the thickness of the metal plate. Therefore, the contact width between the roller electrode and the material is approximately 2-3 mm. If the joined part is located at the end of the barrel of the roller electrode and the surface pressure between the roller electrode and the material is maintained with the required accuracy, the following problem arises. The gap between the vertical working frames of the roller electrodes, the gap between the bearings of the roller electrodes and the wear volume of the roller electrode must be controlled at a level of about 0.2-0.3 mm. Thus, it is necessary to increase the positioning accuracy in the direction of the joint width. In addition to this, higher rigidity and accuracy of the clamping device, which sets the position of the metal plates, which leads to an increase in the size and installation cost, are required. In addition, there is still the following problem. Even if the core of the weld point can be formed in the central part of the joint interface, the thickness of the joint part cannot be obtained equal to the thickness of the starting material. Therefore, there are limitations to the use of this edge-splitting roller welding for a part that requires fatigue strength.

The first objective of this invention is to provide a method and device for roller welding with crushing edges, which can reduce the stepwise gradient of the joined part of two metal plates and can provide high strength joints.

The second objective of the present invention is to provide a method and device for roller welding with crushing edges, which provide a core weld point using roller welding with crushing edges at the interface to improve the strength of the connection and allow you to increase the allowable ratio of the difference in thickness of the connection using a relatively simple and inexpensive configuration when metal plates having different thicknesses are connected to each other.

Means for solving the problem

First invention

The first invention for solving the above problems is characterized by the fact that in the method of roller welding with crushing edges, in which two metal plates are placed overlapping each other at their end parts and the overlapping parts are compressed using a pair of upper and lower roller electrodes and continuously welded to each other another by supplying a welding current to the overlapping parts with the connection of the metal plates, while the corresponding axis of the roller electrodes are inclined in a horizontal plane against directions opposite to each other with respect to a straight line perpendicular to the welding line defined on the overlapping parts of two metal plates, and then the roller electrodes are rigidly driven to connect the two metal plates.

As indicated above, the axes of the roller electrodes are tilted and two metal plates are connected to each other with a hard drive of the roller electrodes. A shear force in the direction perpendicular to the welding line is applied to the overlapping parts of the metal plates. This causes a shear strain in the same direction. Plastic deformation in the direction perpendicular to the welding line occurs in addition to plastic deformation in the direction of the welding line provided by rolling with conventional roller electrodes. Plastic deformation in the direction perpendicular to the welding line significantly reduces the magnitude of the increase in the thickness of the overlapping parts (the connected part) after joining. Therefore, immediately after this, the joined part is rolled using pressure rollers to further reduce the increase in thickness of the connected part, which significantly reduces the gradient of the step. By reducing the gradient of the step, the degree of stress concentration is reduced and a high bond strength can be provided.

If two metal plates have different thicknesses, then the angle of inclination of the axes of the roller electrodes is adjusted in accordance with the thicknesses of the metal plates. The reduction in thickness of each metal plate in the overlapping parts is controlled. The metal plates are connected to each other so that the core of the weld point does not deviate from the interface. Thus, the degree of stress concentration is reduced by reducing the gradient of the step, and in addition to this, a core of the weld point is formed at the interface, and this dramatically increases the strength of the joint of the joined part and allows you to increase the allowable thickness difference when joining, which increases the flexibility of the operation. In addition to this, only due to the implementation in which the pair of roller electrodes is tilted and rigidly set in motion, the method of roller welding with crushing edges can be implemented using a relatively simple and inexpensive implementation.

Second invention

The second invention for solving the above problems is characterized by the fact that in the method of roller welding with crushing edges according to the first invention, the corresponding axis of the roller electrodes are inclined relative to a straight line perpendicular to the welding line, so that the corresponding parts of the roller electrodes located in the direction of movement are turned in a horizontal plane in the direction passing a metal plate with which the roller electrodes first come into contact to connect two metal plates.

Due to this, it is possible to prevent the cutting of the ends of the metal plates at the overlapping parts into the roller electrodes and scratching them when the roller electrodes pass through the overlapping parts during the welding process. Therefore, it is possible to prevent spatter caused by such scratching during welding.

Third invention

The third embodiment for solving the above problems is characterized in that in the method of roller welding with crushing edges according to the first or second invention, two metal plates have different thicknesses and the angle of inclination of the axis of the roller electrode on the side of the metal plate with a greater thickness is set greater than the angle of inclination of the axis a roller electrode on the side of a metal plate with a smaller thickness.

As indicated above, the angle of inclination of the axis of the roller electrode on the side of the metal plate with a larger thickness is larger. This increases the decrease in the thickness of the metal plate on the side of a larger thickness and makes it approximately equal to the reduced thickness of the metal plate having a smaller thickness. Thus, the metal plates are connected to each other so that the core of the weld point is formed at the interface, which improves the strength of the connection.

Fourth invention

The fourth invention for solving the above problems is characterized in that in the method of roller welding with crushing edges according to the first or third invention, in at least one of the processes, before starting welding of overlapping parts and after welding of overlapping parts is completed, the first installation is selected in which a pair of roller electrodes is brought into contact with each other, or a second installation, in which a pair of roller electrodes is not brought into contact with each other or is brought into contact with each other gom a smaller load as compared with the pressing force during the welding, and are not driven, and at a second setting the pair of roller electrodes is driven at the first setting the pair of roller electrodes.

This can prevent the application of excessive thrust to the upper and lower roller electrodes, which extends the life of the roller electrode bearings. In addition, the wear of the upper and lower roller electrodes is reduced, which leads to lower operating costs.

Fifth invention

The fifth invention for solving the above problems is characterized in that in the method of roller welding with crushing the edges according to the first to fourth invention, after connecting two metal plates with each other using roller welding with crushing edges, the corresponding axis of the pair of pressure rollers are inclined in a horizontal plane relative to a straight line perpendicular to the welding line, and the step formed in the connected part is rolled in the direction of movement of the pressure rollers due to the gesture whom drive pinch rollers.

As mentioned above, the corresponding axis of the pair of upper and lower roller electrodes are tilted and the connected part is rolled with a simultaneous hard drive of a pair of pinch rollers. Therefore, similar to the case when the corresponding axis of the pair of upper and lower roller electrodes are tilted, a shear force in the direction perpendicular to the welding line is applied to the connected part. This causes a shear strain of the joined part. Shear deformation in the direction perpendicular to the welding line significantly reduces the magnitude of the increase in thickness of the connected part. Consequently, during both roll welding with crushing of the edges by means of roller electrodes and rolling by means of pressure rollers, the magnitude of the increase in thickness decreases due to shear deformation in the direction perpendicular to the welding line. When connecting metal plates having the same thickness, the joined part can be reliably rolled to a thickness corresponding to the thickness of the starting material of the metal plate, and thereby smooth the step. When connecting metal plates having different thicknesses, the step can be smoothed and the gradient of the step can be significantly reduced. Consequently, the degree of stress concentration can be reliably reduced to ensure high bond strength compared with the case when only the axis of the roller electrodes are inclined.

Sixth invention

The sixth invention for solving the above problems is characterized in that in the method of roller welding with crushing the edges according to the fifth invention, the corresponding axis of the pressure rollers are inclined, each, relative to a straight line, perpendicular to the welding line, so that the corresponding parts of the pressure rollers located in the direction of movement are turned in a horizontal plane in the direction opposite to the direction of passage of the metal plate, relative to the metal material with which the pressure p faces first come into contact, and the step formed at the connected part is rolled in the direction of movement.

This can prevent the step portion from folding into the metal plate starting material. Therefore, it is possible to prevent a defect similar to a crack (non-welding defect) that occurs when the stepped part is folded into the starting material. Thus, the quality of the connected part is improved.

Seventh invention

The seventh invention for solving the above problems is characterized in that in a device for roller welding with crushing edges, in which two metal plates are located overlapping each other at their end parts and the overlapping parts are compressed using a pair of upper and lower roller electrodes and continuously welded to each other with the other, by applying a welding current to the parts to be connected and then connecting the metal plates, the roller electrodes are mounted so that the axis of the roller electrodes inclined in a horizontal plane in respective directions opposite to each other, with respect to an axis perpendicular to the welding line defined on the connected parts of two metal plates.

Due to this, in the method of roller welding with crushing edges according to the first invention, it is possible to manufacture with the following results. The gradient of the step of the joined part of the two metal plates can be reduced. Therefore, the degree of stress concentration can be reduced and a high bond strength can be ensured. In addition, if two metal plates have different thicknesses, then using a relatively simple and cheap design, the core of the weld point formed during roller welding with crushing edges is located at the interface to increase the strength of the joint, thereby increasing the allowable difference in the thickness of the joint .

Eighth invention

The eighth invention for solving the above problems is characterized in that the device for roller welding with crushing edges according to the seventh invention provides a mechanism for independently tilting in the horizontal plane of each of the respective axes of the roller electrodes relative to the axis perpendicular to the welding line.

Due to this, a device for roller welding with crushing edges can be created in which you can simply set the correct angle of inclination in accordance with the thickness of each of the metal plates and cover a wide range of differences in the thickness of the metal plates.

Ninth invention

The ninth invention for solving the above problems is characterized in that the device for roller welding with crushing edges according to the eighth invention provides a pair of upper and lower pressure rollers for rolling the joined part of the metal plates connected by roller welding with crushing edges; while the pressure rollers are installed so that the axis of the pressure rollers are inclined in a horizontal plane relative to the axis perpendicular to the welding line of the connected part.

Due to this, in the method of roller welding with crushing edges according to the fifth invention, it is possible to manufacture with the following results. During both roll welding with crushing of the edges using roller electrodes and rolling using pressure rollers, the magnitude of the increase in the thickness of the connected part decreases due to shear deformation in the direction perpendicular to the welding line. In the joined part of the metal plates, the step can be smoothed and the step gradient can be significantly reduced. Therefore, it is possible to reliably reduce the degree of stress concentration and provide high strength joints.

Tenth invention

The tenth invention for solving the above problems is characterized in that the device for roller welding with crushing edges according to the ninth invention provides a mechanism for independently tilting in the horizontal plane of each of the respective axes of the pressure rollers relative to the axis perpendicular to the welding line.

Due to this, a device for roller welding with crushing edges can be created in which you can simply set the correct angle of inclination in accordance with the thickness of each of the metal plates.

Advantages of the Invention

According to the present invention, when metal plates are connected to each other using the edge-welding roller welding method, the corresponding axis of the pair of upper and lower roller electrodes are tilted and two metal plates are connected to each other during the hard drive of the roller electrodes. Therefore, the magnitude of the increase in the thickness of the connected part can be significantly reduced due to shear deformation in the direction perpendicular to the welding line, and the gradient of the step can be significantly reduced. Therefore, the degree of stress concentration can be reduced, and high bond strength can be ensured.

According to this invention, if two metal plates have different thicknesses, then the angles of inclination of the axes of the electrode rollers are set in accordance with the thicknesses of the metal plates. Therefore, the core of the weld point can be formed at the interface, which improves the strength of the connection and increases the allowable difference in thickness to increase the flexibility of work.

In addition, the above is achieved with a relatively simple and inexpensive implementation, in which only a pair of roller electrodes are tilted and rigidly driven.

According to this invention, the gradient of the step of the joined part of the metal plates is reduced and the step formed in the connected part is smoothed. Therefore, the degree of stress concentration can be reduced and a high bond strength can be ensured. This provides the following advantages: the range of application of roller welding with crushing edges is expanded, scratching of working rollers on the processing line of steel plates is prevented, and productivity and output are increased.

In particular, this invention makes it possible to reduce the gradient of the step and smooth the step formed in the joined part, which leads to a decrease in the concentration of stresses and provides high strength joints. Therefore, during cold rolling in a steel plate processing mill, scratching of work rolls during cold rolling can be prevented, and the following process can be improved and tension characteristics improved. Thus, roller welding with crushing edges can be used for the cold rolling process, which was not possible until now.

In addition, it was impossible to use roller welding with crushing edges with special workpieces in the part that requires fatigue strength, due to the stress concentration in the step formed in the joined part. However, as the gradient of the step decreases and the steps are smoothed out, the stress concentration softens and the shape changeability by pressure improves. Thus, an expensive laser beam welding apparatus can be replaced with an inexpensive edge-splitting roller welding apparatus.

On a production line, such as a continuous annealing line, galvanization line or the like, the contact angle (degree of stress concentration) between the pass rolls in the rolling mill stand and the joint part can be reduced. Therefore, the contact surface pressure between the work roll and the material can be reduced. Therefore, it is possible to prevent scratching of the work roll and transfer of the imprint of the connected part without reducing the line speed. Thus, it is possible to increase productivity and output.

In addition, according to this invention, the corresponding axis of the roller electrodes are inclined in directions opposite to each other in the horizontal plane. Therefore, during the connection by means of roller electrodes, a shear force applied to the part to be joined balances the force transmitted to the clamping devices. This can prevent a longitudinal bending of a part of the metal plate between the clamping device and the part to be joined during the joining of metal plates having a small thickness. Therefore, it is possible to provide a relatively wide space between the clamping device and the part to be connected, which can mitigate restrictions on the arrangement of roller electrodes, pressure rollers, and related equipment.

Brief Description of the Drawings

The drawings schematically depict:

figure 1 - device for roller welding with crushing edges according to one embodiment of the present invention;

figure 2 - state of the start of welding, when two metal plates having the same thickness are located overlapping each other and the overlapping part is compressed using a pair of upper and lower roller electrodes;

figure 3 - the shape of the connected part having steps formed immediately after connecting to each other metal plates having the same thickness using roller welding with crushing edges using conventional roller electrodes, the axes of which are not inclined;

figure 4 - the shape of the connected part having steps formed immediately after connecting to each other metal plates having the same thickness using roller welding with crushing edges using two roller electrodes according to this embodiment;

figure 5 - deformation of the metal along the length of the contact arc in the case when the overlapping parts are connected to each other using roller electrodes, the corresponding axis of which are tilted, for the upper roller electrode 1 as an example;

6 is a cross section of the connected part and the roller electrodes during welding in the view from the rear of the roller electrodes in the direction of their movement for the following case: the corresponding axis of the pair of roller electrodes are inclined, each, relative to a straight line, perpendicular to the welding line, so that the roller electrode located on the side in the direction of movement is turned in a horizontal plane in the direction opposite to the direction of passage of the metal plate with which the roller electrode comes in contact first;

figa - the upper roller electrode in a vertical view from above in the welding state shown in Fig.6, to illustrate the direction in which you want to tilt the upper roller electrode;

figv - lower roller electrode in a vertical view from above in the welding state shown in Fig.6, to illustrate the direction in which you want to tilt the lower roller electrode;

Fig. 8 is a cross-sectional view of the joined part and the roller electrodes during welding in a view from the rear of the roller electrodes in the direction of their movement for the following case: the corresponding axis of the pair of roller electrodes are inclined, each, with respect to a straight line, perpendicular to the welding line, so that the roller electrode located on the side in the direction of movement is turned in a horizontal plane in the direction opposite to the direction of passage of the metal plate with which the roller electrode comes in contact first;

figa - the upper roller electrode in a vertical view from above in the welding state shown in Fig, to illustrate the direction in which you want to tilt the upper roller electrode;

figv - lower roller electrode in a vertical view from above in the welding state shown in Fig.6, to illustrate the direction in which to lower the lower roller electrode;

figa is the part where the core of the weld point is formed in the case of joining with each other two metal plates having the same thickness, using roller welding with crushing edges using conventional roller electrodes, the axes of which are not tilted;

figv is the part where the core of the weld point is formed in the case of joining with each other two metal plates having different thicknesses, using roller welding with crushing edges using conventional roller electrodes, the axes of which are not inclined;

11 is a state of welding in the case where the angle of inclination of the axis of the roller electrode on the side of the thick metal plate is greater than the angle of inclination on the side of the thin metal plate, so that the corresponding thickness of the metal plates are equal to each other after connection;

figa - the upper roller electrode in a vertical view from above in the welding state shown in Fig.11, to illustrate the direction in which you want to tilt the upper roller electrode;

figv - lower roller electrode in a vertical view from above in the welding state shown in Fig.11, to illustrate the direction in which you should tilt the lower roller electrode;

Fig. 13 shows a state when the corresponding axes of the upper and lower roller electrodes are tilted before the start of the roll welding with crushing edges and the upper and lower roller electrodes are pressed against each other, and the state when the upper and lower pressure rollers are pressed against each other, in a view, similar to figure 1;

Fig. 14 shows the velocity vectors and the relative sliding coefficient of the upper and lower roller electrodes that occur when the upper and lower roller electrodes are pressed against each other and the drive when the corresponding axes of the upper and lower roller electrodes are tilted;

Fig. 15 is a diagram of a control system for a device for roller welding with crushing edges shown in Fig. 1;

Fig - the mechanism of the inclination of the roller electrode, with which you can change the angle of inclination of the roller electrode at any angle;

Fig - point stress concentration in the state when there are steps at the connected part;

figa - state of contact between the part welded using conventional roller welding with crushing edges, and the work rolls of the rolling mill;

figv - state of contact between the part welded by roller welding with crushing edges, and the work rolls of the rolling mill in the case when the metal plate is rolled using roller electrodes, the axes of which are inclined, and the step formed at the joined part is smoothed;

FIG. 19 is an illustration of a roll crushing device according to another embodiment of the present invention; FIG.

figa - the initial state of rolling performed using a pair of pinch rollers in the case when the corresponding axis of the pinch rollers are inclined relative to a straight line perpendicular to the welding line, so that the parts of the pinch rollers in the direction of movement are turned in a horizontal plane in the opposite direction to the metal plates relative to the metal material with which the pinch rollers come into contact first;

FIG. 20B is a state of completion of rolling performed by pressure rollers in the case of rolling according to FIG.

FIG. 21 is an initial state of rolling performed using a pair of pinch rollers in the case when the pinch rollers are tilted in the opposite direction as compared to FIG. 20A, i.e. in the case when the respective axes of the pressure rollers are tilted, each, with respect to a straight line, perpendicular to the welding line, so that the parts of the pressure rollers located in the direction of movement are turned in the horizontal plane in the direction of the metal plate passes through the metal material with which the pressure rollers first come into contact ;

figv - the state of completion of rolling performed using the pinch rollers, in the case of rolling according figa;

Fig - the relationship between the temperature of the material and the resistance to deformation in the case when the metal plate is ordinary steel.

List of items

1 - Upper roller electrode

1A — Part of the roller electrode located in the direction of travel

2 - Upper roller electrode

2A — Part of the roller electrode located in the direction of travel

3 - Upper pinch roller

4 - Lower pinch roller

5 - Metal plate

5A - End

6 - metal plate

6A - End

7 - Clamping device on the inlet side

8 - Clamping device on the supply side

9 - Support frame

10 - Device for pressing the roller electrode

11 - Presser pressure device

13 - Thrust force

14 - Shear force

15 - Axis of the upper pinch roller

16 - axis of the lower pinch roller

17 - Axis of the upper roller electrode

18 - Axis of the lower roller electrode

22 - Upper work roll

23 - Lower work roll

27 - Mechanism for tilting the roller electrode

28 - Speed vector of the upper roller electrode

29 - Speed vector of the lower roller electrode

30 - Relative slip coefficient

45 - Straight line in the direction perpendicular to the axis of the pinch roller

46 - Part of the length of the contact arc

51, 52 - Installation blocks

54 - Support roller

55 - Base plate

57 - Device with a cylinder for driving the supporting frame

61, 62 - Electric motors

63, 64 - Electric motors

67, 68 - Chain and sprocket mechanism

71 - Upper controller

72 - Carrier frame drive controller

73 - Crushed Edge Controller

74 - Pinch roller controller

75 - Laser Rangefinder

81 - Rotating shaft

82, 83 - Gears

84 - Electric motor

85 - Angle controller

86 - Angle Sensor

L - Overlapping part

J - Connecting part

S - Step

N - Weld Point Core

A - Direction of movement (rolling direction)

X - Welding line (connection line)

Y - Direction perpendicular to the welding line

R - Pinch roller speed vector in terms of contact length

R1 - Component of the velocity vector R in the direction of the welding line X

R2 - Component of the velocity vector R in the direction perpendicular to the welding line X

α, α1, α2 - Tilt Angle

Preferred Embodiments

The following is a description of embodiments of the present invention with reference to the drawings. A metal plate according to embodiments is intended as an example for a steel rolling mill.

1 schematically shows a device for roller welding with crushing edges according to one embodiment of the present invention.

As shown in figure 1, the device for roller welding with crushing edges according to one embodiment includes a pair of upper and lower roller electrodes 1, 2, a pair of upper and lower pinch rollers 3, 4, clamping devices 7, 8 on the input side and on the supply side, the supporting frame 9, the roller electrode pressing device 10 and the pressure roller pressing device 11. The roller electrode pressing device 10 and the pressing roller pressing device 11 are, for example, hydraulic cylinders. The upper roller electrode 1 and the upper pinch roller 3 are supported on the upper horizontal frame 9a of the supporting frame 9 through the roller electrode pressing device 10 and the pinch roller pressing device 11, respectively. In addition, the lower roller electrode 2 and the lower pinch roller 4 are supported on the lower horizontal frame 9b of the carrier frame 9 through the mounting blocks 51 and 52, respectively. A pair of upper and lower pinch rollers 3, 4 is located near a pair of upper and lower roller electrodes 1, 2 on the supporting frame 9.

The supporting frame 9 is provided on its lower part with support rollers 54. In addition, the supporting frame 9 can be shifted on the base plate 55 on the support rollers in the direction (welding direction) perpendicular to the two metal plates 5, 6 to be connected to each other. The clamping device 7 located on the input side includes a pair of upper and lower clamping elements 7a, 7b, upper and lower clamping cylinders 7c, 7d and a supporting frame 7e. The clamping elements 7a and 7b are supported on the upper and lower clamping cylinder devices 7c and 7d, respectively, on the support frame 7e. A clamping device 8 located on the supply side includes a pair of upper and lower clamping elements 8a, 8b, upper and lower clamping cylinders 8c, 8d, and a supporting frame 8e. The clamping elements 8a and 8b are supported on the upper and lower clamping cylinder devices 8c and 8d, respectively, on the support frame 8e. The supporting frames 7e, 8e are supported on the base plate 55.

The device for roller welding with crushing edges includes a pair of upper and lower electric motors 61, 62 for driving the rotation of the respective roller electrodes. A pair of upper and lower electric motors 61, 62 are mounted on the respective side surfaces of the device 10 for pressing the electrode rollers and the mounting unit 51. The electric motors 61, 62 are connected to the respective rotation shafts of the roller electrodes 1, 2, for example, through the corresponding chain and sprocket mechanisms 67. Thus, the rotation power of the electric motors 61, 62 is transmitted to the corresponding roller electrodes 1, 2.

The roller electrode pressing device 10 is provided with a tilt mechanism 27 (see FIG. 16) for tilting the axis of each of the roller electrode 1, 2.

Figure 2 shows the state of the start of welding when two metal plates 5, 6 having the same thickness are overlapping each other and their overlapping parts are compressed by a pair of upper and lower roller electrodes 1, 2 according to this invention. Figure 3 shows the shape of the part to be joined having steps formed immediately after the two metal plates 5, 6 having the same thickness are connected to each other by roller welding with crushing edges using conventional roller electrodes whose axes are not inclined. Figure 4 shows the shape of the part to be joined having steps formed immediately after the two metal plates 5, 6 having the same thickness are connected to each other by roller welding with crushing edges using roller electrodes according to this embodiment.

As shown in FIGS. 2 and 4, in this embodiment, the pair of upper and lower roller electrodes 1, 2 is mounted so that the axes 17, 18 of the roller electrodes 1, 2 are inclined in the horizontal plane in respective directions opposite to each other, relative to the Y axis (see FIG. 5) perpendicular to the welding line X (see FIG. 5) formed in the overlapping parts L (shaded parts in FIG. 2) of two metal plates 5, 6. In addition, the roller electrodes 1 and 2 are rigidly driven in motion using electric motors 61 and 62 respectively Twain for joining metal plates 5, 6. The device 10 is provided with a pressing roller electrodes tilting mechanism 27 (see. Figure 16) to regulate the inclination angle of each of the respective axes 17, 18 of roller electrodes 1, 2.

When the metal plates 5, 6 are to be connected to each other, the corresponding end parts of the metal plates 5, 6 are overlapped. In this state, the metal plates 5, 6 are captured and fixed in position using the respective clamping elements 7a, 7b; 8a, 8b located on the entry side and on the supply side of the clamping devices 7, 8. Then, the carrier frame 9 is shifted in the welding direction by a drive device, such as a cylinder device 57 or the like, mounted on the base plate 55. This causes a relative shift of the pair of upper and lower roller electrodes 1, 2 and the pairs of upper and lower pinch rollers 3, 4, supported on the supporting frame 9, relative to the metal plates 5, 6. Thus, the connection and compression are continuously performed. In this case, the overlapping parts L of the metal plates 5, 6 are captured by a pair of upper and lower roller electrodes 1, 2 and the roller electrodes 1, 2 are pressed against the overlapping parts L of the metal plates 5, 6 using the device 10 for pressing the roller electrodes. While the roller electrodes 1, 2 are rigidly driven into rotation by the corresponding electric motors 61, 62, a welding current is supplied to the roller electrodes 1, 2 to create resistive heating. Thus, welding is performed (roller welding with crushing edges). Then, the overlapping parts L are welded by means of roller electrodes 1, 2. Immediately after this, the joined part (welded part) J of the metal plates 5, 6 is captured by a pair of upper and lower pressure rollers 3, 4, and then the pressure rollers 3, 4 are pressed to the connected part J using the device 11 pressing the pressure rollers for rolling due to this connected part J of the metal plates 5, 6.

As shown in FIG. 3, if the edge-crushing roller welding is performed using conventional roller electrodes 1, 2 whose axes are not inclined, then the thickness of the joined part J (the shaded part in FIG. 3) increases to about 120-160% of the thickness source material, i.e. metal plates 5, 6. This creates steps S between the part to be joined and the starting material (metal plates 5, 6). In particular, in the conventional technology in which the roller electrodes 1, 2 are not inclined, the roller electrodes 1, 2 are pressed against the overlapping parts L of the metal plates 5, 6 with the aid of the device 10 for pressing the roller electrodes for rolling them during welding of the overlapping parts L. Even in this case, the thickness of the part to be joined cannot be reduced to the thickness of the starting material, i.e. metal plates using roller electrodes 1, 2. This is because plastic deformation in the direction perpendicular to the welding line is limited by limiting the coefficient of friction between the roller electrodes 1, 2 and the material. In addition to this, this is due to the fact that plastic deformation in the direction of movement of the roller electrodes 1, 2 is limited by the source material near them.

In the above embodiment, the pair of upper and lower roller electrodes 1, 2 is positioned so that their axes 17, 18 are inclined in a horizontal plane in respective directions opposite to each other, with respect to a straight line (straight line in a direction perpendicular to the welding line) perpendicular welding lines of the overlapping part L. Roller welding with crushing edges is performed during the hard drive of the roller electrodes 1, 2 using the corresponding electric motors 61, 62.

Thus, a shear force 14 is applied to the overlapping parts L in the direction of the straight line Y, perpendicular to the welding line X (connection line), i.e. in the direction perpendicular to the welding line, as well as in the rolling direction (in the direction of movement of the roller electrodes 1, 2 and pressure rollers 3, 4). Shear deformation due to the shear force 14 contributes to plastic deformation in the direction perpendicular to the welding line. This significantly reduces the thickness of the joined part (the amount of increase in the thickness of the joined part). Then, immediately after this, the joined part J is rolled with the help of pressure rollers 3, 4 to further reduce the increase in the thickness of the connected part J to a thickness corresponding to the thickness of the starting material, i.e. metal plates, which can significantly reduce the gradient of the steps. By decreasing the gradient of the step, the degree of stress concentration is reduced, which ensures high bond strength.

A description of the operation in which plastic deformation (metal flow) in the direction perpendicular to the welding line is facilitated by the inclination of the respective axes 17, 18 of the pair of upper and lower roller electrodes 1, 2 is given below with reference to FIG. 5.

Figure 5 shows the flow of metal in the case when the overlapping parts L are connected to each other by tilting the corresponding axes 17, 18 of the roller electrodes 1, 2. In addition, figure 5 shows the upper roller electrode 1 as an example. In the figure, an arrow A the direction of movement (welding direction) of the roller electrode 1 is indicated. The straight line X denotes the welding line formed in the overlapping part L lying in the welding direction A. Y denotes a straight line perpendicular to the X welding line. 45 denotes a straight line (a straight line in the direction perpendicular to the axis) perpendicular to the axis 17 of the roller electrode 1, while a straight line 45 runs along the width of the Central part of the roller electrode 1. The letter α denotes the angle of inclination of the roller electrode 1 (the angle between the welding line X and a straight line 45 extending in a direction perpendicular to the axis of the upper roller electrode 1). In addition, reference numeral 46 denotes a part of the length of the contact arc when the roller electrode 1 is in contact with the overlapping part L. The symbol R denotes the velocity vector of the roller electrode 1 in part 46 of the length of the contact arc. The symbol R1 denotes the component of the velocity vector R in the direction of the welding line X, and the symbol R2 denotes the component of the velocity vector R in the direction perpendicular to the welding line X.

As shown in FIG. 5, the roller electrode 1 is rigidly rotated while being pressed against the overlapping part L by tilting the axis 17 of the roller electrode 1 in a horizontal plane with respect to a straight line Y perpendicular to the welding line X. Due to the clamping force and the coefficient of friction between the roller electrode 1 and the overlapping part L, a shear force corresponding to the component R2 of the velocity vector in the direction perpendicular to the welding line X on part 46 of the length of the contact arc with the overlapping part L is applied to the overlapping part L. In the overlapping of part L, not only the metal flows in the direction of the component of the velocity vector component R1 (direction parallel to the welding line X), but also the metal flows in the direction of the component of the velocity vector R2 (direction perpendicular to the welding line X). In other words, in the overlapping part L, plastic deformation occurs in the direction perpendicular to the welding line X due to shear deformation caused by the shear force 14. Thus, shear deformation or plastic deformation in the direction perpendicular to the welding line X can reduce the thickness (thickness of the joint parts) after joining the overlapping part L.

As mentioned above, the pair of roller electrodes 1, 2 is rigidly driven by the corresponding electric motors 61, 62, while the corresponding axes 17, 18 of the roller electrodes 1, 2 are inclined relative to the straight line Y, perpendicular to the welding line X. At the same time, the overlapping parts L are welded while pressing against each other. A shear force 14 is applied to the overlapping portions L in a direction perpendicular to the welding line. Thus, the thickness of the joined part of the overlapping parts is reduced. The shear force 14 depends on the deformation resistance of the material; therefore, the higher the deformation resistance, the greater the stop force 13 is applied to the roller electrodes 1, 2 from the side of the respective metal plates 5, 6. When the stop force 13 is increased in the above manner, the problem arises that the life of the roller electrodes 1 is reduced, 2 and their bearings, and the entire device increases to ensure that the thrust force 13 is maintained.

In this embodiment, said stop force 13, caused by the tilting of the respective axes 17, 18 of the roller electrodes 1, 2, occurs during the heating of the overlapping parts L. up to about 1000-1400 ° C depending on the thickness of the metal plates. Thus, it can be assumed that the temperature of the joined part J rises to an even higher level. In contrast, if the deformation resistance of the metal plates 5, 6 depends on the temperature of the material and the temperature of the connected part J is approximately 1000-1400 ° C, then the deformation resistance is extremely low (see Fig. 22). Therefore, it is possible to reduce the size of the installation by suppressing an increase in the thrust force 13. Due to shear deformation at high temperature, the thickness of the joint part can be effectively reduced.

6, 7A and 7B; 8, 9A and 9B show two kinds of state of setting the angle of inclination α of the pair of upper and lower roller electrodes 1, 2.

The direction of installation of the angle α of the tilt of the pair of upper and lower roller electrodes 1, 2 can be twofold.

The first installation method is as follows. As shown in FIGS. 6, 7A and 7B, the respective axes 17, 18 of the pair of roller electrodes 1, 2 are inclined, each, with respect to a straight line Y, perpendicular to the welding line X, so that the parts 1A, 2A (called parts located in the direction of movement ) located on the side of the direction A of the movement of the roller electrodes 1, 2, are turned in the horizontal plane in the corresponding directions opposite to the directions of passage of the metal plates with which the corresponding roller electrodes 1, 2 come into contact first. Namely, the motion part 1A of the upper roller electrode 1 is inclined in the figure to the right metal plate 6, and the motion part 2A of the lower roller electrode 2 is inclined in the figure to the left metal plate 5. In this case, the shear force 14 corresponding to component of R1 of the velocity vector is applied from the roller electrodes 1, 2 to the corresponding metal plates 5, 6 in the direction from the corresponding ends 5A, 6A of the metal plates 5, 6 to the corresponding directions the passage of metal plates 5, 6. Thus, roller welding with crushing edges is performed when a shear strain is applied in the same direction, i.e. in the direction perpendicular to the welding line, which leads to a decrease in the thickness of the connected part. By the way, a force acting in the opposite direction to the action of the shear force 14 is applied as a stop force 13 from the overlapping parts L (the joined part J) to the roller electrodes 1, 2. In other words, the reactive force of the stop force 13 is applied to the overlapping parts L in quality of shear force 14.

As shown in FIGS. 8, 9A and 9B, the second installation method is that the roller electrodes 1, 2 are tilted opposite to the first installation method. Namely, the corresponding axes 17, 12 of the pair of roller electrodes 1, 2 are each inclined with respect to a straight line Y, perpendicular to the welding line X, so that the corresponding parts 1A, 2A of the roller electrodes 1, 2 located in the direction of movement are turned in the horizontal plane to the corresponding directions the passage of metal plates with which the corresponding roller electrodes 1, 2 come in contact first. Namely, the motion part 1A of the upper roller electrode 1 is inclined in the figure to the left metal plate 6, and the motion part 2A of the lower roller electrode 2 is inclined in the figure to the right metal plate 6. In this case, the shear force 14 corresponding to component R2 of the velocity vector is applied from the roller electrodes 1, 2 to the corresponding metal plates 5, 6 in the direction from the respective directions of passage of the metal plates 5, 6 to the corresponding uyuschim ends 5A, 6A of metal plates 5, 6. Thus, the mash seam welding edges is performed by applying a shear deformation in the same direction, i.e. in the direction perpendicular to the welding line, which leads to a decrease in the thickness of the connected part. In this case, also a force acting in the opposite direction to the action of the shear force 14 is applied as a stop force 13 from the overlapping parts L (the connected part J) to the roller electrodes 1, 2.

In this embodiment, the second installation method is used for the following reasons.

In general, the material of the roller electrodes 1, 2 is a copper-based material with high electrical conductivity. A copper-based material has the disadvantage that its strength is lower than the strength of the material being joined. The corresponding axes 17, 18 of the pair of roller electrodes 1, 2 can be tilted so that the respective sides 1A, 2A of the roller electrodes 1, 2 located in the direction of movement are turned in a horizontal plane in the respective directions opposite to the directions of passage of the metal plates with which the roller electrodes 1 , 2 come in contact first. In addition, a shear force 14 can be applied to the metal plates 5, 6 from the respective roller electrodes 1, 2 in the direction from the respective end parts 5A, 6A of the metal plates 5, 6 to the respective directions of the passage of the metal plates 5, 6. In this case, the roller electrodes 1, 2 move in the direction in which the surfaces of the roller electrodes cut into the corresponding angles of the end parts 5A, 6A of the metal plates 5, 6 during the welding process. This leads to a new problem, namely, that the surfaces of the roller electrodes are scratched by the corners of the material being joined. In this case, the current density is locally concentrated between the roller electrodes 1, 2 and the material, which leads to spatter and a significant reduction in the life of the roller electrode.

In contrast, the respective axes 17, 18 of the pair of roller electrodes 1, 2 can be tilted so that the respective sides 1A, 2A of the roller electrodes 1, 2 located in the direction of movement are turned in the horizontal plane to the respective directions of the passage of the metal plates with which the roller electrodes 1 , 2 come in contact first. In addition, a shear force 14 can be applied to the metal plates 5, 6 from the respective electrode rollers 1, 2 in the direction from the respective sides of the passage of the metal plates 5, 6 to the corresponding end parts 5A, 6A of the metal plates 5, 6. In this case, you can prevent scratching of the roller electrodes 1, 2 due to the insertion into the corners of the end parts 5A, 6A of the metal plates 1, 2 and the application of shear stress to the metal plates 5, 6.

The tilt angle α of the axes 17, 18 of the roller electrodes 1, 2 is set in accordance with the thickness of the metal plates 5, 6. Qualitatively, the tilt angle α is set to a smaller value if the thickness of the metal plates is less; the inclination angle α is set to a larger value if the thickness of the metal plates is greater. As shown in FIG. 5, shear deformation due to the inclination of the axis 17 of the upper roller electrode 1 is determined by the angle α of inclination in part 46 of the length of the contact arc between the upper roller electrode 1 and the material. Therefore, the inclination angle α set in accordance with the thickness of the metal plates 5, 6 is adjusted accordingly. If metal plates 5, 6 made of materials of different thicknesses are connected to each other, then the angle of inclination α of the upper roller electrode 1 is set in accordance with the thickness of the metal plate located on the upper side of the overlapping parts L and the angle α of inclination of the lower roller electrode 2 is set in accordance with the thickness of the metal plate located on the lower side of the overlapping parts L. Namely, if metal plates of different thickness are connected to each other, then the top lower and lower roller electrodes 1, 2 are installed with different angle α of inclination.

On figa and 10B shows the part in which the core of the weld point is formed in the case when the metal plates 5, 6 are connected to each other using roller welding with crushing edges using conventional roller electrodes, the axes of which are not inclined. FIG. 10A shows a case where metal plates with the same thickness are connected to each other, and FIG. 10B shows a case where metal plates of different thickness are connected to each other. 11, 12A and 12B show the part where the core of the weld point is formed, and the difference in the angle of inclination between the upper and lower roller electrodes 1, 2 in the case when metal plates 5, 6 having different thicknesses are connected to each other by roller welding with crushing edges using roller electrodes 1, 2 according to this embodiment.

When roller welding with crushing edges, as shown in figa, the core N of the weld point is formed in the Central thickness of the metal plates 5, 6, captured by the roller electrodes 1, 2. If the difference in thickness between the metal plates 5, 6 is small, then The core N of the weld point is formed in the central part of the joint interface. However, if the difference in thickness between the metal plates 5, 6 is large, then the core N of the weld point deviates from the Central part of the interface of the connection, as shown in figv. This limits the ratio of the thicknesses of the metal plates 5, 6 in the method of roller welding with crushing edges to approximately 1: 1.5 or less.

In the present invention, as shown in FIGS. 11, 12A and 12B, the respective axes 17, 18 of the roller electrodes 1, 2 are inclined with respect to a straight line Y perpendicular to the welding line X, so that the corresponding parts 1A, 2A of the roller electrodes 1 located in the direction of movement , 2 are turned in the horizontal plane to the corresponding directions of passage of the metal plates 5, 6, with which the roller electrodes 1, 2 come into contact first. Additionally, the angle of inclination α1 of the upper roller electrode 1 in contact with the metal plate 5, which is a thick metal plate, is greater than the angle of inclination α2 of the lower roller electrode 2 in contact with the metal plate 6, which is a thin metal plate. Thus, more shear deformation (shear stress) in the direction perpendicular to the welding line, as well as the compression force between the roller electrodes 1, 2 and the corresponding materials of the metal plates 5, 6, is applied to the material of the thick metal plate 5. Thus, it is possible to form a joint so that the corresponding thicknesses of the parts of the metal plates become approximately equal to each other after joining with the overlap.

The tilt angles α1, α2 are set in accordance with the thickness difference value for applying shear strain necessary to reduce the thickness difference. Due to this installation, the core N of the weld point can be formed at the interface. You can increase the ratio of various thicknesses without reducing the strength of the connection. The magnitude of the increase in the thickness of the overlapping joined part J can be reduced, which leads to a decrease in limitations in operation. You can improve the quality of connection with each other metal plates having different thicknesses.

In Fig.13, similarly to Fig.1, a state is shown in which the corresponding axes of the upper and lower roller electrodes are tilted before the beginning of the roller welding with crushing edges and the upper and lower roller electrodes are pressed against each other, and the state in which the upper and lower pinch rollers are pressed to each other.

On Fig shows the velocity vector and the relative slip coefficient of the upper and lower roller electrodes that occur when the upper and lower roller electrodes are pressed and driven when the corresponding axis of the upper and lower roller electrodes are tilted.

To date, conventional roller welding with crushing edges was performed during rolling of the roller electrodes 1, 2 of the overlapping parts from their end parts. In this case, as shown in FIG. 13, the roller electrodes 1, 2 are pressed against each other and rotated in the state before starting the connection. After the upper and lower roller electrodes 1, 2 reach the end parts of the overlapping parts L, they begin rolling and welding. If the upper and lower roller electrodes 1, 2 are pressed and rotated with the tilted axes 17, 18, as shown in Fig. 14, then the corresponding rolling speed vectors 28, 29 of the upper and lower roller electrodes 1, 2 are matched to each other, so that coefficient 30 relative slip in the axial direction of the roller electrodes 1, 2. This coefficient 30 relative slip creates a thrust force in the axial direction of the upper and lower electrode rollers 1, 2 due to the clamping force and the coefficient of friction between the roller elec dams 1, 2. The persistent force reduces the service life of the bearings of the roller electrodes and causes intermittent movement of the roller electrodes 1, 2. This contributes to abnormal vibration of the mechanical system and the wear of the roller electrodes 1, 2. Therefore, in this invention for at least one, preferably both processes before welding of the overlapping parts L and after welding of the overlapping parts L is completed, the first installation or the second installation is selected. During the first installation, the upper and lower roller electrodes 1, 2 are brought into contact with each other. In the second installation, the upper and lower roller electrodes 1, 2 are not brought into contact with each other or are brought into contact with each other with a small load compared to the pressing force during welding. During the first installation, the rotation of the upper and lower roller electrodes 1, 2 using the corresponding electric motors 61, 62 is carried out without a drive. In the second installation, the rotation of the upper and lower roller electrodes 1, 2 by means of the corresponding electric motors 61, 62 is carried out with a drive. At the first installation, after reaching the upper and lower roller electrodes 1, 2 of the lateral end parts of the overlapping parts L, the motors 61, 62 immediately turn on to rigidly rotate the upper and lower roller electrodes 1, 2. In the second installation, after reaching the upper and lower roller electrodes 1, 2 of the lateral end part of the joined part J, the drive of the electrode roller pressing device 10 is immediately turned on to perform welding with the application of a compressive force to the upper and lower roller electrodes 1, 2. Thus, it is possible to prevent the creation of a persistent force to extend the service life of the bearings, as well as to suppress the wear of the upper and lower roller electrodes 1, 2.

On Fig shows a diagram of a control system for a roller welding device with crushing edges shown in figure 1. The control system for the roll crushing device includes an upstream controller 71, a carrier frame drive controller 72, a crush roller welding controller 73, and a pinch roller controller 74. The upper controller 71 combines control for the controller 72 of the drive of the supporting frame, the controller 73 of the roller welding with crushing edges and the controller 74 of the pressure rollers. The carrier frame drive controller 72 issues operating commands to the hydraulic circuit (not shown) of the cylinder device 57 to drive the carrier frame 9 to control the drive of the cylinder device 57. An edge-crushing roller welding controller issues operating commands to the hydraulic circuit (not shown) of the roller electrode pressing device 10 and to the electric motors 61, 62 for controlling their drives. The pressure roller controller issues working commands to the hydraulic circuit (not shown) of the pressure roller pressure device 11 to control their drive. The laser range finder 75 is mounted on the upper horizontal frame 9a of the supporting frame 9 and near the upper roller electrode 1. The edge weld roller controller 73 and the pinch roller controller 74 receive the measurement signal of the laser range finder 75 and determine, based on the signal, the time when the ends of the overlapping parts of the metal plates 5, 6 pass directly under the laser range finder 75. Before that, the distance between the laser range finder 75 and each of the rollers is entered into the controller 73 and the controller 74 of the pressure rollers new electrodes 1, 2 and between the laser range finder 75 and each of the pressure rollers 3, 4 and the speed of movement of the supporting frame 9. The time when the ends of the overlapping parts of the metal plates 5, 6 pass directly under the laser range finder 75, and the time when the roller electrodes 1 , 2 and pinch rollers 3, 4 capture the ends of the overlapping parts of the metal plates 5, 6, calculated on the basis of distances and speed of movement. Before or after this time, the control of the device for pressing the electrode rollers 10 and the electric motors 61, 62 and the control of the device 11 for pressing the pressure rollers is performed differently in accordance with the above installation state (first or second installation) with respect to the contact between the upper and lower roller electrodes 1, 2.

The angles of inclination of the axes of the electrode rollers 1, 2 can be fixed. However, it is preferably provided that the tilt angles can be changed to any angle. On Fig shows the tilt mechanism for the roller electrode in this case. To simplify the illustration, the electric motor, chain mechanism, and sprockets for driving the roller electrode are not shown.

As shown in FIG. 16, the roller electrode pressing device 10 is provided with a tilt mechanism 27. The tilt angle of the axis of the upper roller electrode 1 can be set to any angle in the horizontal plane by actuating the tilt mechanism 27. Various methods can be used in tilt mechanism 27, however, it uses an electric drive as an example. In particular, the tilt mechanism 27 is mounted on the upper end of the roller electrode pressing device 10. In addition, the tilt mechanism 27 includes a rotary shaft 81 rotatably mounted in the upper horizontal frame 9a of the carrier frame 9, and an electric motor 84 driving the rotary shaft 81 through the gears 82, 83. The tilt angle controller 85 controls the electric motor 84. Although not shown, the tilt mechanism 27 is provided with a locking device for holding the tilt angle after installation.

In addition, the tilt mechanism 27 is provided with an angle sensor 86 for measuring the tilt angle of the upper roller electrode 1. Before starting the connection, the tilt angle controller 85 receives the angle information corresponding to the thicknesses of the metal plates 5, 6 from the upstream controller 71 and sets the tilt angle. In addition, the tilt angle controller 85 controls the drive of the electric motor 84 using the signal of the angle sensor 86 to match the tilt angle of the roller electrode 1 with the installation angle. In this case, a control model is preliminarily created with respect to the relationship between the respective thicknesses of the metal plates 5, 6 and the corresponding roller electrodes 1, 2. The upstream controller 71 collects a database based on the control model and provides the angle to be installed in the tilt angle controller 85. Thus, it is possible to simply set the required optimal angle of inclination in accordance with the thicknesses of the metal plates 5, 6. The allowable ratio of the difference in thickness of the materials to be joined can be increased. In addition, the core N of the weld point of the joined part of materials of different thicknesses can be reliably formed at the center of the joint interface. Therefore, a high-quality connecting part can be realized using an inexpensive device. The angle sensor 86 may be a sensor that measures the angle of rotation of the rotating shaft 81, as shown in the figure, and may be a position sensor measuring the angle of rotation of the electric motor 84.

Alternatively, the respective thicknesses of the metal plates 5, 6 are measured using measuring means, such as, for example, the laser range finder 75 described above, or the like, before welding with roller electrodes 1, 2. The angle to be installed, set by the controller 85 of the angle based on the installation information based on the database of measured thicknesses. Thus, the control of the angle is carried out in real time.

On Fig shows the point of concentration of stresses in a state when there are steps at the connected part.

During cold rolling of steel products and forming by pressure, including special billets, a large voltage is applied to the connected part in the working process after connection. In particular, if there is a step S at the joined part J between the metal plates 5, 6, as shown in FIG. 17, then such step parts correspond to stress concentration points. The metal plates 5, 6 are welded together when the axes 17, 18 of the roller electrodes 1, 2 are tilted. After that, the connected part is rolled using pressure rollers 3, 4 to significantly reduce the step gradient of the connected part J. Thus, the concentration coefficient can be reduced stresses to increase the long-term strength of the connected part. Consequently, roll crush welding can be used for cold rolling steel and forming pressure.

On figa shows the state of contact between the welded using conventional roller welding with crushing the edges of the part and the work rolls of the rolling mill. On figv shows the state of contact between the welded using roller welding with crushing the edges of the part and the work rolls of the rolling mill in the following case. Metal plates 5, 6 are welded together when the axes of the roller electrodes are tilted. After that, the welded joint part is rolled using pressure rollers to significantly reduce the increase in thickness and step gradient of the joint part.

Until now, for example, in the rolling step in the pass in the training stand, the joint part connected in the connecting step, which is the step prior to rolling, has been rolled using a pass mill in the training stand. In this case, as shown in FIG. 18A, if the joined part extends between the work rolls, then the steep step S of the connected part hits and scratches the upper work roll 22. In addition, the imprint of the connected part is transferred to the upper and lower work rolls 22, 23 To prevent these problems, the joint part extends between the upper and lower work rolls 22, 23 when the rolling load is reduced or when the upper and lower work rolls 22, 23 are opened. Thus, scratching of the work roll 22 and transfer of the imprint of the connected part to the work rolls 22, 23. In contrast, in the present invention, the connected part is welded by tilting the axes 17, 18 of the roller electrodes 1, 2, and then the connected part is rolled using pressure rollers 3, 4 to significantly reduce the gradient of the step of the joint parts as shown in FIG. Therefore, the contact angle (stress concentration coefficient) between the work rolls 22, 23 and the connected part can be reduced. Therefore, the contact surface pressure between the work rolls 22, 23 and the material can be reduced. Thus, scratching of the work rolls 22, 23 and transfer of the imprint of the connected part to the work rolls 22, 23 can be prevented without reducing the line speed, which leads to an increase in productivity.

The above embodiment provides the following effects.

1. A pair of roller electrodes 1, 2 is rigidly driven by the corresponding electric motors 61, 62 when the corresponding axes 17, 18 of the upper and lower roller electrodes 1, 2 are tilted to connect metal plates 5, 6 with them. Therefore, a shear force is applied in direction perpendicular to the welding line X, to the overlapping parts L of the two metal plates 5, 6. This causes shear strain in the same direction in the overlapping parts L. Plastic deformation in the direction perpendicular to the welding line X and, occurs in addition to plastic deformation in the direction of the weld line caused by conventional rolling by means of roller electrodes. Plastic deformation in the direction perpendicular to the welding line X significantly reduces the magnitude of the increase in the thickness of the overlapping parts (of the joining part J) after joining. Then, the joining part J is rolled using the pinch rollers 3, 4 to further reduce the increase in the thickness of the joining part to a level corresponding to the thickness of the starting material of the metal plates. Thus, the gradient of the step can be significantly reduced. As the gradient of the step decreases, the stress concentration coefficient can be reduced to ensure high bond strength.

If two metal plates 5, 6 differ in thickness from each other, then the angles of inclination of the axes of the roller electrodes 1, 2 are adjusted in accordance with the thicknesses of the metal plates 5, 6. This leads to adjustment of the reduction in thickness of each of the metal plates in the overlapping parts L. Therefore, the metal plates 5, 6 are connected to each other so that the core N of the weld point does not deviate from the interface of the connection. Thus, the formation of the core N of the weld point, in addition to reducing the stress concentration coefficient by reducing the step gradient, can significantly increase the strength of the connected part. The allowable difference in thickness can be increased to improve flexibility. In addition to this, since only a configuration is used in which a pair of roller electrodes 1, 2 are rigidly set in motion when their axes are tilted. Thus, an edge-crushing roller welding apparatus can be implemented with a relatively simple and inexpensive configuration.

The joined part J of the metal plates 5, 6 is rolled to a level corresponding to the thickness of the starting material of the metal plates to significantly reduce the gradient of the step. This can reduce the stress concentration coefficient of the connected part, which provides high strength of the connected part. Thus, the following effects can be provided. Edge welding can be widely used in cold rolling and for special workpieces where edge welding is not used to date. The work rolls of the steel rolling line can be prevented from scratching. Productivity and output can be improved. That is, in this embodiment, the gradient of the step of the joined part being subjected to roller welding with crushing of the edges is reduced to reduce the stress concentration coefficient of the joined part, which can provide high joint strength. Therefore, in the cold rolling process of the steel production line, scratching of the work rolls during cold rolling can be prevented as a next step and to improve tensile characteristics. Thus, the method of roller welding with crushing edges can be applied to the cold welding process, in which it has not been applied to date.

Also, with special blanks, due to the stress concentration in the step formed at the joined part, the use of roller welding with crushing edges was excluded for the part that requires fatigue strength. However, by decreasing the step gradient, the stress concentration is softened and the pressure forming characteristics are improved. Therefore, an expensive laser welding device can be replaced with an inexpensive edge-splitting roller welding device.

On the continuous annealing line and the production line, including the galvanization line or the like, the contact angle (stress concentration coefficient) between the work rolls of the rolling mill with a pass in the training stand and the connected part can be reduced. Therefore, the contact surface pressure between the work roll and the material can be reduced. Therefore, it is possible to prevent scratching of the work roll and transfer of the imprint of the connected part without reducing the line speed. Thus, productivity can be improved.

2. Two metal plates 5, 6 are connected to each other by tilting the respective axes 17, 18 of the pair of roller electrodes 1, 2 with respect to a straight line perpendicular to the welding line X, so that the corresponding pairs of roller electrodes 1, 1A, 2A located in the direction of travel, 2 are turned in the horizontal plane to the corresponding directions of the passage of the metal plates with which the roller electrodes 1, 2 come into contact. Therefore, when the roller electrodes 1, 2 move along the overlapping part L in the process of arches, it is possible to prevent the end parts 5A, 6A of the metal plates 5, 6 from overlapping parts L from being inserted into the corresponding roller electrodes 1, 2 and thereby scratching the roller electrodes 1, 2. As a result, such scratches during welding can be prevented due to such scratches .

3. If two metal plates 5, 6 have different thicknesses, then the angle of inclination of the axis of the roller electrode on the side where one of the metal plates 5, 6 has a larger thickness is set larger than the angle of inclination on the side where the other of the metal plates 5, 6 has a smaller thickness. Therefore, the amount of decrease in the thickness of the metal plate having a larger thickness can be increased to substantially match a metal plate having a smaller thickness. Thus, the core N of the weld point can be formed at the interface of the joint, and the allowable thickness difference for the joint can be increased.

4. In at least one of the processes, before starting welding of the overlapping parts L and after completion of welding of the overlapping parts L, a first installation or a second installation is selected. At the first installation, a pair of roller electrodes 1, 2 is brought into contact with each other. In the second installation, the pair of roller electrodes 1, 2 is not brought into contact with each other or the roller electrodes 1, 2 are brought into contact with each other at a lower load compared to the pressing force during welding. At the first installation, the pair of roller electrodes 1, 2 is not driven, and at the second installation it is driven. Therefore, the application of excessive persistent force to the upper and lower roller electrodes 1, 2 can be prevented. Thus, the life of the roller electrodes 1, 2 can be extended. In addition, the wear of the upper and lower roller electrodes 1, 2 can be reduced in order to reduce operating costs .

5. A pair of roller electrodes 1, 2 is mounted so that their axes 17, 18 are inclined in the horizontal plane in respective directions opposite to each other, with respect to the Y axis, perpendicular to the welding line X defined in the overlapping parts L of the two metal plates 5, 6. Therefore, the step gradient of the joint part of the two metal plates can be reduced, as indicated above, so that a high bond strength is ensured. In addition, the core N of the weld point, formed during roller welding with crushing edges, is formed at the interface of the connection using a relatively simple and inexpensive configuration to improve the strength of the connection. Thus, production facilities can be created for the increased allowable difference in the thickness of the joint.

6. A mechanism 27 is provided with which it is possible to independently tilt in the horizontal plane the corresponding axes 17, 18 of a pair of roller electrodes 1, 2 with respect to the Y axis perpendicular to the welding line X. Therefore, it is possible to correctly set the optimal angle of inclination in accordance with the thicknesses of the metal plates 5, 6. In addition to this, a roller welding device with crushing edges can be created, which has a wide range of differences in the thickness of the metal plates 5, 6.

The following is a description of another embodiment of the present invention with reference to FIGS. 19-22.

In the above embodiment, as in the past, the upper and lower pinch rollers 3 are pinch rollers that can rotate around respective axes parallel to each other. In addition, the joined part after roller welding with crushing the edges is rolled using pressure rollers 3, 4. Although the connected part is rolled flat, as mentioned above, the following effects can be created by performing roller welding with crushing edges when the corresponding axes 17, 18 are tilted roller electrodes 1, 2. The effect of reducing the thickness of the welded part (connected part) subjected to roller welding with crushing edges is large. The gradient of the step of the joined part J between the metal plates 5, 6 can be significantly reduced to reduce the stress concentration coefficient of the joined part, thereby ensuring high bond strength. In this embodiment, the connected part is rolled using a pair of upper and lower pressure rollers, the axes of which are inclined in addition to the pair of upper and lower electrode rollers. Thus, the joined part is reliably rolled to the thickness of the starting material of the metal plates, which makes it possible to smooth the step.

On Fig schematically shows a device for roller welding with crushing edges according to this variant implementation.

As shown in FIG. 19, an edge-crushing roller welding apparatus according to this embodiment is provided with electric motors 63, 64 for rotating the pairs of respective upper and lower pinch rollers. Similarly to electric motors 61, 62 for driving the pairs of respective upper and lower roller electrodes into rotation, the electric motors 63, 64 are also mounted on the respective side surfaces of the pinch roller pressing device 11 and the mounting unit 52. In addition, the electric motors 63, 64 are connected to the respective rotating shafts pinch rollers 3, 4 through, for example, the corresponding mechanism 68 with a chain and sprockets. The rotational power of the electric motors 63, 64 is transmitted to the corresponding pinch rollers 3, 4.

On figa, 20B, 21A and 21B shows the state when the joined part after roller welding with crushing edges is rolled using a pair of upper and lower pinch rollers 3, 4.

In this embodiment, a pair of upper and lower roller electrodes 1, 2 is installed as in the above embodiment, so that their axes 17, 18 are inclined in a horizontal plane in respective directions opposite to each other, with respect to a straight line, perpendicular to the line of welding of the overlapping parts L two metal plates 5, 6. Roller welding with crushing edges is performed with a hard drive of the roller electrodes 1, 2 using the corresponding electric motors 61, 62. As shown in figa and 20V or on figa and 21B, a pair of upper and lower pinch rollers 3, 4 is also installed so that their axis 15, 16 are inclined in the horizontal plane in corresponding directions opposite to each other, relative to a straight line perpendicular to the welding line X of the joint part J of two metal plates 5, 6. The pressure rollers 3, 4 are rigidly driven by the corresponding electric motors 63, 64 for rolling due to this connected part.

The corresponding axis 17, 18 of the pair of upper and lower roller electrodes 1, 2 and the corresponding axis 15, 16 of the pair of upper and lower pinch rollers 3, 4 are tilted in the above manner. Due to this, both roller welding with crushing edges using electrode rollers 1, 2, and rolling using pressure rollers 3, 4 provide the action of reducing thickness, contributing to plastic deformation in the direction perpendicular to the welding line. Thus, the steps S of the joining part J can be reliably rolled out with smoothing to a level corresponding to the thickness of the starting material.

When connected using conventional roller electrodes 1, 2, the axes of which are not inclined, plastic deformation in the direction perpendicular to the welding line is limited by clamping devices. In this case, there is a transfer of forces from the connected part to the gripping part of the clamping device. Therefore, if metal plates having a small thickness are connected to each other, then there is a possibility of waviness in the part to be connected and in the part of the metal material of the gripping part. To prevent corrugation, the clamping device must be positioned extremely close to the part to be connected. In this case, the space between the clamping device and the connected part narrows, which leads to the problem indicated below. The location of the roller electrodes, pinch rollers, and related equipment is limited. This adversely affects the flexibility of their location.

In this embodiment, the corresponding axes 17, 18 of the roller electrodes 1, 2 are inclined in the directions opposite to each other in the horizontal plane. Therefore, during the connection using the roller electrodes 1, 2, a shear force 14 applied to the joined part J balances the forces transmitted to the clamping devices 7, 8. Therefore, even if the clamping devices 7, 8 are not located directly adjacent to the connected part J, it is possible to prevent the waviness of the metal plate during the joining of metal plates having a small thickness. Therefore, it is possible to provide a relatively wide space between the clamping devices 7, 8 and the joining part J. Thus, it is possible to alleviate the restrictions on the arrangement of the roller electrodes 1, 2, the pinch rollers 3, 4 and related equipment (for example, electric motors 61-64, mechanisms 67, 68 with chain and sprockets, tilt devices, etc.).

The details of the action resulting in plastic deformation in the direction perpendicular to the welding line due to the inclination of the respective axes 15, 16 of the pair of upper and lower pressure rollers 3, 4 are the same as in the case of roller electrodes 1, 2, as explained above with reference to figure 5.

The corresponding directions of the tilt angles α of the pair of upper and lower pressure rollers 3, 4 can be set in two ways similarly to the case of roller electrodes 1, 2.

The following is the first installation method. As shown in FIGS. 20A and 20B, the respective axes 15, 16 of the pair of pinch rollers 3, 4 are inclined with respect to a straight line Y perpendicular to the welding line X, so that the corresponding pairs of pinch rollers 3, 4 located in the direction of travel are facing horizontal plane in a direction opposite to the direction of passage of the metal plate 5 relative to the metal material with which the pinch rollers 3, 4 come in contact. In other words, the corresponding axis 15, 16 of the pinch rollers 3, 4 are inclined so that о the corresponding axial ends of the pressure rollers 3, 4 located in the joined part J of the metal plates 5, 6, on the side where the thickness is greater, starting from the steps S of the joined part J as reference points (the material part of the connected part J with which the pressure rollers 3, 4 come into contact first), are facing in the rolling direction A of the joined part J. In this case, a shear force 14 corresponding to the above-mentioned component R2 of the velocity vector is applied from the steps S of the connected part J of the metal plates 5, 6 to the side lenii passage of the metal plate 5 concerning the metal material with which the pressure rollers 3, 4 first come into contact. Thus, the stepped parts are rolled and smoothed when a shear strain is applied in the same direction, i.e. in the direction perpendicular to the direction of welding. By the way, at the same time, a force in the direction opposite to the shear force 14 is applied as a stop force 13 from the joined part J to the pressure rollers 3, 4. In other words, the reaction force of the stop force 13 is applied as a shear force 14 to the joined part J .

The second installation method is such that the pinch rollers 3, 4 are tilted opposite to the first installation method, as shown in FIGS. 21A and 21B. Namely, the respective axes 15, 16 of the pair of pinch rollers 3, 4 are inclined with respect to a straight line Y perpendicular to the welding line X, so that the corresponding pairs of pinch rollers 3, 4 located in the direction of movement 3A, 4A are turned in a horizontal plane in the direction of passage metal plate 5 relative to the metal material with which the pinch rollers 3, 4 come into contact first. In other words, the corresponding axes 15, 16 of the pinch rollers 3, 4 are inclined so that the corresponding axial ends of the pinch role 3, 4, located in the joined part J of the metal plates 5, 6, on the side where the thickness is greater, starting from the steps S of the joined part J as starting points (the part of the material of the joined part J, with which the pressure rollers 3, 4 come first contact), facing in the rolling direction A of the joined part J. In this case, the shear force 14 corresponding to the above-mentioned component R2 of the velocity vector is applied from the steps S of the connected part J of the metal plates 5, 6 in the opposite direction a metal plate 5 with respect to a metal material with which the pinch rollers 3, 4 first come into contact. Thus, the stepped parts are rolled and smoothed when a shear strain is applied in the same direction, i.e. in the direction perpendicular to the direction of welding. At the same time, a force in the direction opposite to the shear force 14 is applied as a thrust force 13 from the joined part J to the pressure rollers 3, 4.

In this embodiment, the first installation method is used for the following reasons.

Even if the pair of upper and lower pinch rollers 3, 4 are tilted by the second installation method, the steps S undergo plastic deformation due to the shear force 14, so that they are smoothed. However, in this case, the following problem occurs. As shown in FIG. 21B, step S is folded into the starting material and immersed in the starting material to form cracks. The problem does not arise if a smooth surface texture of the joint part J is simply required, and the second installation method is applied to the part from which strength is not required. However, when applying the second installation method for the part subjected to stress, or when applying for plastic processing, such as pressure forming, including special blanks, the end of the immersed step becomes a singular stress field, which causes destruction. Therefore, as shown in FIGS. 20A and 20B, the corresponding tilt directions of the pinch rollers 3, 4 are preferably directions when the corresponding axes 15, 16 of the pair of pinch rollers 3, 4 are inclined with respect to a straight line Y perpendicular to the welding line X, so that the corresponding in the direction of movement of part 3A, 4A, the pairs of pinch rollers 3, 4 are turned in a horizontal plane in a direction opposite to the direction of passage of the metal plate 5 relative to the metal material with which the pinch rollers 3, 4 come into contact first. In this case, as shown in FIG. 20B, the steps of the joined part can be smoothed without immersion of the steps S in the starting material with the formation of cracks, whereby the quality of the joined part can be improved.

The inclination angle (corresponding to the inclination angle α in FIG. 5) of the axes 15, 16 of the pressure rollers 3, 4 is set in accordance with the height (step size) of the steps S of the connected part. Qualitatively, the angle of inclination is set small if the step size is small; the angle of inclination is set large if the step size is large. That is, similar to the case of the roller electrode shown in FIG. 5, shear deformation due to the inclination of the axis 15 of the upper pinch roller 3 is mainly determined by the angle of inclination on a part of the length of the arc contact (corresponding to part 46 of the length of the contact arc) between the upper pinch roller 3 and the material. Therefore, the angle of inclination to be set is accordingly adjusted in accordance with the size of the step to be smoothed. If metal plates 5, 6, made of materials of different thicknesses, are connected to each other, then the size of the steps welded by roller welding with crushing the edges of part J is different depending on the front or back surface. However, if the angle of inclination of the upper pinch roller 3 is set in accordance with the size of the step, as indicated above, then the step can be smoothed. The same is true for the rolling state with the lower pinch roller 4 having an angle of inclination. The angle of inclination of the lower pinch roller 4 is set in accordance with the size of the lower step.

As mentioned above, the axis 15, 16 of the pair of pinch rollers 3, 4 are inclined, each, relative to a straight line Y, perpendicular to the welding line X. A pair of pinch rollers 3, 4 is rigidly driven by the respective electric motors 63, 64 for rolling through this step S of the joint part J. Thus, a shear force in the direction perpendicular to the welding line is applied to the joint part J to smooth the steps S. The shear force depends on the deformation resistance of the material. Therefore, the higher the deformation resistance, the greater the thrust force 13 applied to the pressure rollers 3, 4 from the metal plates 5, 6. If the thrust force 13 increases, as mentioned above, the service life of the pressure rollers 3, 4 and their bearings is reduced and restraining force is set for the thrust force 13, which leads to an increase in the size of the entire device.

On Fig shows the relationship between the temperature of the material and the resistance to deformation in the case when the material is ordinary steel. The deformation resistance of the metal plates 5, 6 depends on the temperature of the material and has the temperature characteristics shown in FIG. 22 if the metal plates 5, 6 are made of ordinary steel. To reduce the thrust force 13, the temperature of the joint part J is preferably set to 300 ° C or higher, more preferably 500 ° C or higher. This can reduce the deformation resistance of the metal plates 5, 6 to suppress the increase in the thrust force 13. Thus, the dimensions of the installation can be reduced.

In this embodiment, a pair of upper and lower pinch rollers 3, 4 is located near a pair of upper and lower roller electrodes 1, 2 on the carrier frame 9. Connection and compression are performed continuously by moving the carrier frame 9 in the welding direction. Although the temperature depends on the thickness of the metal plates 5, 6, it near the joined part rises to approximately 1000-1400 ° C immediately after the passage of the joined part between the roller electrodes. Thus, it can be assumed that the temperature of the connected part J rises to a level exceeding these temperatures. Since the connection and compression are carried out continuously, the temperature of the joined part J during compression by the pressure rollers 3, 4 can easily increase to about 300 ° C or higher or 500 ° C or higher using the residual heat generated by the connected part J created by welding . Thus, it is possible to reduce the size of the installation.

The upper and lower pinch rollers 3, 4, having respectively inclined axes 15, 16, can have the same setting, as in the case of the electrode rollers in Fig. 13, before starting the roller welding with crushing edges. Namely, in at least one, preferably in both processes, the first installation or the second installation is selected before rolling the joined part J and after completing the rolling of the connected part J. During the first installation, the upper and lower pinch rollers 3, 4 are brought into contact with each other. In the second installation, the upper and lower pinch rollers 3, 4 are not brought into contact with each other, or are brought into contact with each other at a small load compared to the pressing force during rolling. At the first installation, the rotation of the upper and lower pinch rollers 3, 4 by means of the corresponding electric motors 63, 64 is carried out without a drive or stops. In the second installation, the rotation of the upper and lower pressure rollers 3, 4 by means of the corresponding electric motors 63, 64 is carried out with a drive. At the first installation, after the upper and lower drive rollers 3, 4 reach the lateral end parts of the joined part J, the motors 63, 64 immediately turn on to hard-drive the upper and lower pressure rollers 3, 4. In the second installation, after reaching the upper and lower pressure rollers 3, 4 of the lateral end part of the joined part J, the drive of the pressure roller pressing device 11 is immediately turned on to perform pressing and rolling with the application of compression force to the upper and lower pressure rollers 3, 4. So m, it is possible to prevent the creation of excessive thrust forces to extend the life of bearings, and also to suppress the wear of the upper and lower pressure rollers 3, 4.

In this embodiment, you can also use the same control system as in the previous embodiment, the description of which was given in relation to Fig.9. Namely, the control system, which includes a higher controller, a drive controller for the carrier frame, a roller welding controller with crushing edges, a pinch roller controller and a laser range finder. Before and after determining the time when the roller electrodes 1, 2 and pinch rollers 3, 4 capture the ends of the metal plates 5, 6, it is possible to control the device 57 with a cylinder for driving the supporting frame 9, the device 10 for pressing the roller electrodes, electric motors 61, 62, the device 11 pressing the pressure rollers and electric motors 63, 64 to ensure the next state of the drive. This state of the drive is different depending on the state of the installation (first installation or second installation) indicated above regarding the contact between the upper and lower roller electrodes 1, 2 and the above state of the installation (first installation or second installation) relative to the contact between the upper and lower pressure rollers 3, 4.

The same tilt device, as in the case of roller electrodes, the description of which is given above with reference to Fig. 10, can be provided for the upper and lower pinch rollers 3, 4, axis 15, 16 of which are tilted. Thus, a joining machine can be formed that is able to correctly set the optimal angle of inclination according to the size of the step and has a wide range of differences in the thickness of the materials being joined.

In particular, in the above embodiment, the roller electrode pressing device 10 having the tilt mechanism 27 and the pressure roller pressing device 11 having the tilt mechanism 27 are located on the same carrier frame 9. However, even if they are located on respective separate frames, the function of the present invention does not change.

The above embodiment may provide the following effects in addition to effects 1-6 in the previous embodiment.

1-A. A pair of pinch rollers 3, 4 is rigidly driven by the corresponding electric motors 63, 64 when the respective axes 15, 16 of the upper and lower pinch rollers 3, 4 are tilted for rolling using their metal plates 5, 6, similarly to the case when the corresponding axes 17, 18 pairs of upper and lower roller electrodes 1, 2 are inclined. Therefore, a shear force is applied in the direction perpendicular to the welding line X to the joined part J. This causes shear strain in the connected part J. Plastic deformation in the direction perpendicular to the welding line X significantly reduces the increase in thickness of the connected part J. Therefore, as during roller welding with crushing edges using roller electrodes 1, 2, and during rolling using pressure rollers 3, 4, shear deformation in the direction perpendicular to the welding line X, reducing ie the amount of increase of thickness of the connected portion J. In the case when joined together metal plates having the same thickness, the joining part can be reliably rolled up to a level corresponding to the thickness of the starting material of metal plates and the steps can be smoothed. In the joined part of the metal plates having different thicknesses, it is possible to smooth the steps or the gradient of the steps can be significantly reduced. As a result, the gradient of the step can be reduced more reliably to ensure high bond strength compared to the case when only the corresponding axis of the electrode rollers 1, 2 are inclined.

The gradient of the steps of the joined part J of the metal plates 5, 6 decreases, or the steps S of the connected part J are smoothed. This can reduce the stress concentration coefficient of the connected part, which can provide high bond strength. Thus, additional effects can be provided. Edge welding can be widely used in cold rolling and for special workpieces where edge welding is not used to date. Scratching of the work roll on the steel processing line can be prevented. Performance may be increased.

1-B. The corresponding axis 15, 16 of the pair of upper and lower pressure rollers 3, 4 are inclined in the directions opposite to each other in the horizontal plane. During rolling using the pinch rollers 3, 4, a shear force is applied to the upper side of the surface and the lower side of the surface of the joined part J in opposite directions. The upper and lower forces transmitted to the clamping devices 7, 8 are mutually balanced. Thus, the waviness of the metal plate can be prevented when connecting thin metal plates without positioning the clamping devices 7, 8 in close proximity to the joint part J. As a result, a relatively wide space can be provided between the clamping devices 7, 8 and the joint part J, which softens restrictions on the location of roller electrodes 1, 2, pressure rollers 3, 4 and related equipment (for example, electric motors 61-64, mechanisms 67, 68 with chain and sprockets, mechanisms 27 tilt, etc.).

2. The corresponding axes 15, 16 of the pair of pinch rollers 3, 4 are inclined, each, with respect to the straight line Y, perpendicular to the welding line X, so that the corresponding pairs of pinch rollers 3, 4 located in the direction of movement are facing in the horizontal plane in the respective directions opposite to the direction of passage of the metal plate 5 relative to the metal material with which the pinch rollers 3, 4 come into contact first. In addition, the joined part is rolled with a shear force from the steps S of the joined part J of the metal plates 5, 6 in the direction of passage of the metal plate 5 relative to the metal material with which the pressure rollers 3, 4 first come into contact. Therefore, it is possible to prevent the folding of the stepped part in the starting material of the metal plates 5, 6. This can prevent the occurrence of defects like cracks (not welding defects) when the stepped part is folded into the starting material.

3. In addition, a pair of pressure rollers 3, 4 is provided, which roll the joined part J of two metal plates 5, 6 connected by means of roller welding with crushing edges. In addition, the pinch rollers 3, 4 are mounted so that their axes 15, 16 are inclined in a horizontal plane with respect to a straight line Y perpendicular to the welding line X. Therefore, the gradient of the step of the joint part of the two metal plates 5, 6 can be reduced, so that a high bond strength can be achieved. In addition, the core N of the weld point formed by roller welding with crushing edges is formed at the interface of the connection using a relatively simple and inexpensive configuration to increase the strength of the connection. Thus, it is possible to create production plants that provide an increase in the difference in thickness of the connection.

4. There are mechanisms that independently tilt in the horizontal plane the corresponding axis 15, 16 of the pair of pinch rollers 3, 4 relative to the straight line Y, perpendicular to the welding line X. Therefore, a connecting device can be created in which you can simply set the correct angle of inclination in accordance with the size of the step and which has a wide range of differences in the thickness of the metal plates.

Claims (10)

1. The method of roller welding with crushing edges, in which two metal plates (5, 6) are placed with overlapping each other at their end parts and overlapping parts (L) are compressed using a pair of upper and lower roller electrodes (1, 2) and continuously welded to each other by supplying a welding current to the overlapping parts with the connection of metal plates,
while the corresponding axis (17, 18) of the roller electrodes (1, 2) are inclined in a horizontal plane in the respective directions opposite to each other, with respect to a straight line (Y) perpendicular to the welding line (X) defined on the overlapping parts (L) of the two metal plates (5, 6), and then the roller electrodes (1, 2) are rigidly set in motion to connect two metal plates due to this. 2. The method according to claim 1, in which the corresponding axis (17, 18) of the roller electrodes are inclined relative to a straight line (Y) perpendicular to the welding line (X), so that the corresponding parts (1A, 2A) of the roller electrodes located in the direction of movement ( 1, 2) are turned in a horizontal plane in the direction of passage of the metal plate (5 or 6) with which the roller electrodes first come into contact to connect two metal plates. 3. The method according to claim 1 or 2, in which two metal plates (5, 6) have different thicknesses and the angle of inclination of the axis (17 or 18) of the roller electrode (1 or 2) on the side of a metal plate with a greater thickness is set to greater than the angle of inclination of the axis of the roller electrode on the side of the metal plate with a smaller thickness. 4. The method according to claim 1 or 2, in which at least in one of the processes before starting welding of the overlapping parts (L) and after welding of the overlapping parts (L) is selected, the first installation, in which a pair of roller electrodes (1, 2) is brought into contact with each other, or a second installation, in which a pair of roller electrodes (1, 2) is not brought into contact with each other or is brought into contact with each other with a lower load than the pressing force during welding, and when do not drive the first pair of roller electrodes They are set in motion, and during the second installation a pair of roller electrodes is set in motion. 5. The method according to claim 1 or 2, in which, after connecting two metal plates (5, 6) to each other using roller welding with crushing edges, the corresponding axis (15, 16) of the pair of pressure rollers (3, 4) are tilted horizontally the plane relative to the straight line (Y), perpendicular to the welding line (X), and the step formed in the joined part is rolled in the direction (A) of the movement of the pressure rollers due to the hard drive of the pressure rollers. 6. The method according to claim 5, in which the corresponding axis (15, 16) of the pressure rollers (3, 4) are each inclined with respect to a straight line (Y) perpendicular to the welding line (X), so that the corresponding parts (3A) located in the direction of movement 4A) of the pressure rollers (3, 4) face in a horizontal plane in the opposite direction to the direction of passage of the metal plate (5 or 6), relative to the metal material with which the pressure rollers (3, 4) first come into contact, and the step formed in the connected part, rolled in the direction enii (A) of movement. 7. A device for roller welding with crushing edges, in which two metal plates (5, 6) are located overlapping each other at their end parts and the overlapping parts (L) are compressed using a pair of upper and lower roller electrodes (1, 2) and continuously welded to each other by applying a welding current to the overlapping parts, followed by the connection of metal plates,
wherein the roller electrodes (1, 2) are mounted so that the axes (17, 18) of the roller electrodes are inclined in a horizontal plane in respective directions opposite to each other, with respect to a straight line (Y), perpendicular to the welding line (X) formed on overlapping parts (L) of two metal plates (5, 6). 8. The device according to claim 7, containing:
a mechanism (27) for independent tilting in the horizontal plane of each of the corresponding axes (17, 18) of the roller electrodes (1, 2) with respect to the axis (Y) perpendicular to the welding line (X). 9. The device according to claim 7 or 8, further comprising:
a pair of upper and lower pinch rollers (3, 4) for rolling the joined part (J) of metal plates (5, 6), connected by roller welding with crushing edges; in this case, the pressure rollers (3, 4) are installed so that the axis (15, 16) of the pressure rollers are inclined in a horizontal plane with respect to a straight line (Y), perpendicular to the welding line (X) of the joined part (J). 10. The device according to claim 9, further comprising
a mechanism (27) for independent inclination in the horizontal plane of each of the corresponding axes (15, 16) of the pressure rollers (15, 16) with respect to a straight line (Y) perpendicular to the welding line (X).

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