RU2466812C2 - Method and device for jointing metal sheets - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: pair of top and bottom pressure rollers 3, 4 is arranged to allow turning their axles 15, 16 in horizontal plane relative to straight line Y perpendicular to line X of connection part I. Pressure rollers 3, 4 are driven hardly by appropriate motors 63, 64 to roll ledge flat in connection part. Appropriate parts 3A, 4A of pressure rollers 3, 4 are directed in horizontal plane opposite the metal sheet path relative to metal material pressure rollers 3, 4 get in contact with first. Ledges in connection part are rolled flat to reduce stepped gradient so that higher joint strength is ensured.

EFFECT: higher quality of joint due to reduced strain concentration.

8 cl, 16 dwg

Description

FIELD OF THE INVENTION

The invention relates to a method and device for connecting metal sheets, which allow you to align the ledge specified in the connecting part of the two metal sheets, and to reduce the stepwise gradient of the connecting part.

State of the art

An edge crush roller welding machine uses the welding method explained below. Two metal sheets are placed so as to overlap each other at their edges. The overlapping parts are pressed by a pair of welding rollers and continuously welded together by applying a welding current to them. However, the connecting part, softened by heating to a high temperature, is rolled by means of welding rollers in order to reduce the thickness of the connecting part. However, this welding method does not allow rolling the connecting part to a level corresponding to the thickness of the base material. The problem is that the thickness of the connecting part increases to approximately 120-160% of the thickness of the base material (metal sheet), which forms a ledge between the connecting part and the main material.

The following method is proposed as a method of reducing the thickness of the connecting part. A pair of pinch rollers is mounted side by side and on one side of a pair of upper and lower welding rollers. Before roller welding with crushing of the edges, the overlapping parts of the metal sheets are rolled by means of pressure rollers by moving the support frame supporting the welding rollers and pressure rollers in the previous direction of the pressure rollers. After rolling, the metal sheets overlapping each other are located at a small distance from each other to reduce the thickness of the connecting part. After that, the overlapping part is pressed by means of welding rollers by moving the carrier frame in the opposite direction and is continuously subjected to roller welding with crushing of the edges by applying a welding current to it. Additionally, the connecting part is rolled by means of pressure rollers in order to reduce its thickness. See Patent Documents 1 and 2.

To reduce the thickness of the connecting part subjected to roller welding with crushing edges, and to reduce the cycle time, a method and device are described below. The first and second pairs of upper and lower pinch rollers are mounted side by side and on both sides of the pair of upper and lower welding rollers. The overlapping portions of the metal sheets are rolled by means of the first pressure rollers by moving the support frame supporting the welding rollers and pressure rollers in the previous direction of the first first roller. After that, the rolled part is pressed by a pair of welding rollers after the pressure rollers and is continuously subjected to roller welding with crushing of the edges by applying a welding current to it. Additionally, the connecting part is rolled by means of second pressure rollers after the welding rollers in order to reduce its thickness. See Patent Document 1 and Patent Document 2.

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

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

SUMMARY OF THE INVENTION

The problem solved by the invention

An edge crush roller welding machine uses the welding method explained below. Two metal sheets are installed so as to overlap each other. The overlapping parts are pressed by a pair of welding rollers and continuously welded together by applying a welding current to them. At the same time, the connecting part, which must be softened, heated to a high temperature, is rolled by means of welding rollers in order to reduce its thickness. Therefore, the welding rollers perform, through rolling, most of the pressure treatment used to reduce the thickness of the materials to be joined. The plastic flow of the connecting part, reduced in thickness, prevails in the rolling direction of the welding rollers. However, the connecting part has a relationship of the continuous body with the main material of the metal sheet adjacent to it. Therefore, the plastic flow in the rolling direction is limited by the base material. Therefore, the connecting part cannot be rolled to the thickness of the base material. The thickness of the connecting part based on the method of roller welding with crushing edges increases to approximately 120-160% of the thickness of the base material (metal sheet). Since the connecting part and the base material differ in thickness from each other, a ledge having a high stress concentration coefficient is formed in the connecting part. If a voltage is applied to the connecting part, then the connecting part disadvantageously has a significantly reduced strength. In other words, there is a problem in that this bottleneck limits the range of application of roller welding with crushing edges. In addition, there are problems in that a steep ledge scratches the work roll on the production line of plate steel, and productivity and yield are reduced.

For example, the connecting part of an edge-splitting roller welding machine increases stepwise in thickness to approximately 120-160% of the base material. If an edge-crushing roller welding machine is applied to cold rolling equipment having a large overall reduction in rolling, as is, therefore, a portion of the shoulder of the connecting portion is embedded in the base material with cracks. Accordingly, the useful cross-sectional area is reduced in the connecting part, called the strip, of the metal sheet. This increases the tensile stress relative to the tensile force used during cold rolling. In addition, the front end of the ledge, embedded with cracks, becomes a singular stress field, which significantly increases the likelihood of breakage. This leads to the problem explained below. Since a low-cost small-sized edge-splitting roller welding machine cannot be applied to cold rolling equipment having a large overall reduction in rolling, cold rolling equipment should use a flash butt welding machine or laser welding machine, which is expensive and bulky.

A machine for roller welding with crushing edges, which can inexpensively connect sheets of plate steel having different thicknesses and strengths of the material, is applied to workpieces with desired properties. However, an edge-crushing roller welding machine cannot be applied to joining a part in which a joining part increased in thickness leads to a problem with forming performance and a part in which a stress concentration problem arises from a step defined in connecting part. Therefore, an expensive laser welding machine should be applied to workpieces with desired properties.

An inexpensive machine for roller welding with crushing edges is used as a connecting machine to set the production processes continuous to technological lines, such as a continuous annealing line, galvanizing line, etc. in the production of steel in order to increase the yield of products and productivity. However, as described above, the edge-crush roller welding increases the thickness of the connecting portion so that a steep ledge is formed. When the connecting part passes through a training rolling mill, respectively, the following method of operation is used in order to prevent scratching of the work roll and to prevent transfer of the fingerprint of the step defined in the connecting part to the work roll. The line speed decreases before and after the training rolling mill, and the work roll of the rolling mill opens or the force on the rolls decreases. This leads to the problem of reducing productivity and yield.

Of the traditional methods described in Patent Document 1 and Patent Document 2, the first method allows to reduce the thickness of the connecting part to approximately 110% of the thickness of the base material. In the first method, after the completion of rolling, the metal sheets, set so as to overlap each other, are located at a small distance from each other to reduce the thickness of the connecting part. After that, the connecting part is subjected to roller welding with crushing edges and is additionally rolled by means of pressure rollers. However, if the distance between the ends of the metal sheets placed far from each other is too large, a recess near the connecting part is formed due to rolling of the pressure rollers before welding. If the distance is insufficient, the thickness of the connecting part increases. As a result, the optimum range of setpoints for distance exists only in a precisely defined place. Therefore, reliability is poor. Therefore, it is difficult to stably provide high quality bond strength.

Of the traditional methods described in Patent Document 1 and Patent Document 2, the method in which the pinch rollers are mounted on both sides of the welding rollers and rolling before welding, welding and rolling after welding is continuously performed by moving the carrier frame in one direction, has a problem in the fact that the thickness of the connecting part cannot be sufficiently reduced. In particular, the metal sheets are gripped by means of fixing devices 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 by means of fixing devices. Therefore, rolling by means of pressure rollers after welding has a limitation on the volume of plastic flow in a direction perpendicular to the welding line, and mainly allows the metal to flow plastic in the direction of passage of the roller. Similar to rolling by means of welding rollers during the roll crushing welding described above, the plastic flow of the rolled part by means of pressure rollers is limited by the base material so that stretching is substantially limited. Therefore, the connecting part cannot be reduced in thickness to the thickness of the base material. When rolling by means of pressure rollers, the volume of the connecting part, the thickness of which is reduced by rolling, is absorbed by setting so as to flow plasticly in the longitudinal direction of the connecting part, which increases the length of the connecting part. This leads to a difference in stretching between the base material and the connecting part, which is increased due to the pinch rollers, which leads to such a problem that the connecting part bends or deforms in waves.

Due to these situations, it is believed that for the traditional method of roller welding with crushing edges, it is difficult to perform the connection along while suppressing the increase in the thickness of the connecting part, so as not to form a ledge between the connecting part and the main material. Therefore, an edge-crushing roller welding method is required that stably reduces the increased thickness value and the stepped gradient of the connecting part and provides a high degree of bond strength.

Also, if metal sheets having different thicknesses are interconnected by flash butt welding, laser welding or friction stir welding, a step arises in the connecting part, which leads to an identical problem.

The purpose of the present invention is to provide a method and device for joining metal sheets that allow you to align the ledge defined in the connecting part of the two metal sheets, and to reduce the stepwise gradient of the connecting part, to provide a high degree of strength of the connection.

Problem Solver

First Embodiment

The first embodiment of the invention, in order to solve the above problems, is characterized in that in the method for joining metal sheets, in which, after two metal sheets are connected together, the connecting part of the metal sheets is rolled by a pair of upper and lower pressure rollers corresponding to the axis of the pair pinch rollers rotate in a horizontal plane relative to a straight line perpendicular to the connection line of the connecting part, and then a pair of pinch rollers gesture to set in motion, thereby laminating step specified in the connection part in the direction of movement of the pressure rollers.

As described above, the corresponding axis of the pair of upper and lower pinch rollers is rotated, and then the pair of pinch rollers is rigidly driven to thereby roll the connecting portion. Therefore, in the case of roller welding with crushing edges, the shear force is applied in the direction perpendicular to the connection line of the connecting part. Shear deformation due to shear force allows to reduce the increased value of the thickness of the connecting part. This allows you to align the ledge and reduce the step gradient. Also, if metal sheets having different thicknesses are interconnected by laser welding, butt fusion welding or friction welding with stirring, similar shear deformation allows you to align the ledge and reduce the step gradient. In each case, the step defined in the connecting part may be aligned, and the step gradient may decrease. Thus, the stress concentration coefficient of the connecting part can be reduced, which provides a high degree of joint strength.

Second Embodiment

The second embodiment of the invention, in order to solve the above problems, is characterized in that in the method for joining metal sheets according to the first embodiment of the invention, the corresponding axes of the pair of pressure rollers are rotated relative to a straight line perpendicular to the connection line, so that the corresponding parts in the direction of movement of the pressure rollers face horizontal plane in the direction opposite to the direction of passage of the metal sheet relative to the metal material the shaft with which the pinch rollers first come into contact, and the ledge defined in the connecting part is rolled in the direction of movement.

As a result of this, it is possible to prevent a part of the step from being inserted into the base material of the metal sheets. Therefore, it is possible to prevent a defect, similar to a crack (defect in the impossibility of welding), formed when part of the step is embedded in the main material, which improves the quality of the connecting part.

Third Embodiment

A third embodiment of the invention, in order to solve the above problems, is characterized in that in the method of joining metal sheets according to the first or second embodiment of the invention, the corresponding rotation angles of the pair of pressure rollers are set according to the step size of the connecting part, and the connecting part is rolled in the direction of movement.

As a result of this, appropriate shear deformation can be applied in accordance with the thicknesses of the metal sheets to be interconnected. This minimizes the stepped gradient of the connecting part. Materials having different thicknesses can be interconnected, and the size of the step that must be formed can be different depending on the front and rear surfaces of the connecting part. Also in this case, the rotation angles of the pair of pressure rollers are set according to the step size of the connecting part, and the connecting part is rolled. This allows you to adjust the magnitude of the shear strain and minimize the stepwise gradient of the connecting part.

Fourth Embodiment

A fourth embodiment of the invention, in order to solve the above problems, is characterized in that in the method for joining metal sheets according to any one of the first to third embodiments of the invention, the temperature of the connecting part rises to 300 ° C or higher by the residual heat of the connecting part resulting from the welding of two metal sheets, and the connecting part is rolled in the direction of movement by means of pressure rollers.

As a result of this, the value of the resistance to deformation of the connecting part can be reduced in order to reduce the axial force that must be generated. Thus, the installation can be reduced in size. Due to the reduced axial force, the life of the pinch roller bearing can be extended, and the wear of the pinch roller can be suppressed, whereby operating costs can be reduced.

Fifth Embodiment

A fifth embodiment of the invention, in order to solve the above problems, is characterized in that in the method for joining metal sheets according to any one of the first to fourth embodiments of the invention, at least one of the processes selects a first position before rolling the connecting part and after completing the rolling of the connecting part in which a pair of pinch rollers is brought into contact with each other, or a second position in which a pair of pinch rollers is not brought into contact with each other or rivoditsya in contact with each other at partial load compared with the pressing force during the rolling, and in the first position the pair of pinch rollers are not driven and in the second position, the pair of pinch rollers are driven.

As a result of this, it is possible to prevent the application of excessive axial force to the upper and lower pressure rollers. This allows you to extend the life of the bearings for the upper and lower pinch rollers and additionally prevents wear of the upper and lower pinch rollers, whereby operating costs can be reduced.

Sixth Embodiment

A sixth embodiment of the invention, in order to solve the above problems, is characterized in that in the method of joining metal sheets according to any one of the first to fifth embodiments of the invention, two metal sheets are interconnected by means of any of the edge weld roller welding, laser welding, flash butt welding and friction stir welding.

As a result, the connecting part can be rolled by means of pressure rollers with the residual heat of the connecting part. Therefore, a connecting part having high strength and high quality can have high efficiency.

Seventh Embodiment

A seventh embodiment of the invention, in order to solve the above problems, is characterized in that the sheet metal joining device includes: heat joining means for joining two metal sheets together; and a pair of upper and lower pinch rollers for rolling the connecting part of the metal sheets; in which a pair of pinch rollers is installed so that the corresponding axis of the pinch rollers rotate in a horizontal plane relative to a straight line perpendicular to the connection line of the connecting part.

As a result of this, in the method for joining metal sheets regarding the first embodiment of the invention, production capacities can be provided that make it possible to align the step defined in the joining part of the metal sheets, reduce the step gradient and provide a joining part having high strength and high quality.

Eighth Embodiment

The eighth embodiment of the invention, in order to solve the above problems, is characterized in that the sheet metal joining device according to the seventh embodiment of the invention further includes a mechanism for independently rotating in the horizontal plane of each of the axes of the pinch rollers with respect to a straight line perpendicular to the connection line.

As a result of this, a connection device can be provided that makes it easy to properly set the optimum angle of rotation in accordance with the step size and has a wide range of difference thicknesses for the thickness of the metal sheets.

Advantage of the invention

According to the present invention, the corresponding axis of the pair of upper and lower pinch rollers is rotated in a horizontal plane with respect to a straight line perpendicular to the connection line, and then the pair of pinch rollers is rigidly driven to thereby roll the ledge defined in the connecting part after welding. Therefore, shear deformation in the direction perpendicular to the connection line allows you to reduce the increased value of the thickness of the connecting part, to align the ledge and to reduce the step gradient. Thus, a high degree of bond strength can be achieved.

According to the present invention, the step defined in the connecting part of the metal sheets is aligned, and the step gradient can be reduced. Therefore, the stress concentration coefficient of the connecting part can be reduced, which provides a high degree of joint strength. Thus, the following results may be obtained. The range of application of roller welding with crushing edges can expand. You can avoid scratching the work roll on the steel production line. Productivity and yield may increase.

Thus, in the present invention, the ledge defined in the connecting part subjected to roller welding with crushing edges can be aligned. Therefore, in the cold rolling process for steel production, it is possible to prevent scratching of the work roll during cold rolling, since the performance of the next process and the resistance to tension can increase. In this way, roll crush welding can be applied to the cold rolling process to which roll crush welding has not previously been applied.

Also in workpieces with desired properties due to stress concentration on the ledge specified in the connecting part, the use of roller welding with crushing edges to the part requiring fatigue strength is excluded. However, due to the aligned shoulder, the stress concentration decreases, and the suitability for pressing increases. Therefore, an expensive laser welding machine can be replaced with an inexpensive edge-splitting roller welding machine.

In a continuous annealing line and in a technological line including production facilities for manufacturing galvanized iron sheets and the like, the contact angle (stress concentration coefficient) between each of the work rolls of the temper rolling mill and the connecting part may decrease. Therefore, the pressure of the contact surface between the work roll and the material may decrease. Therefore, it is possible to prevent scratching of the work roll and transfer of the imprint of the connecting part without reducing the line speed. Thus, productivity and yield can increase.

Also, if metal sheets having different thicknesses are interconnected by laser welding, butt fusion welding or friction welding with stirring, similarly, shear deformation allows you to align the ledges and reduce the step gradient. Accordingly, the following results can be obtained. Laser welding, flash butt welding and friction stir welding can be widely applied to the cold rolling process or workpieces with desired properties to which they were not applied. You can avoid scratching the work roll on the steel production line. Productivity and yield may increase.

Additionally, according to the present invention, if the corresponding axis of the pair of upper and lower pressure rollers is rotated in respective directions opposite to each other in the horizontal plane during rolling by pressure rollers, a shear force is applied to the upper surface side and the lower surface side of the connecting part in opposite directions . The upper and lower forces transmitted to the locking devices suppress each other. Thus, it is possible to prevent the bending of a part of the metal sheet between the fixing device and the connecting part during the joining of thin metal sheets without the location of the fixing devices in close proximity to the connecting part. As a result, a relatively wide gap can be provided between the locking devices and the connecting part. This allows you to reduce the layout constraint of welding rollers, pinch rollers and related installations.

Brief Description of the Drawings

FIG. 1 is a schematic view of a sheet metal joining device according to an embodiment of the present invention in the case where the present invention is applied to an edge-crushing roller welding machine.

Figure 2 illustrates the shape of the connecting part having formed ledges immediately after two metal sheets are connected to each other by roller welding with crushing edges using welding rollers.

Fig. 3A illustrates the initial state of rolling performed by the pinch rollers when the respective axes of the pinch roller pair are rotated with respect to a straight line perpendicular to the welding line for rolling, so that the corresponding parts in the direction of travel of the pinch roller pair are turned in the horizontal plane in the opposite direction the direction of passage of the metal sheet relative to the metal material with which the pinch rollers first come into contact.

Fig. 3B illustrates a rolling completion state performed by the pinch rollers in the case of rolling, as shown in Fig. 3A.

Fig. 4A illustrates the initial state of rolling performed by the pinch rollers in the event that the pinch rollers are rotated in opposite directions compared to Fig. 3A, i.e. if the corresponding axis of the pair of pinch rollers is rotated relative to a straight line perpendicular to the welding line for rolling, so that the corresponding parts in the direction of movement of the pinch rollers face in a horizontal plane in the direction of passage of the metal sheet relative to the metal material with which the pinch rollers first come into contact .

Fig. 4B illustrates a rolling completion state performed by the pinch rollers in the case of rolling, as shown in Fig. 4A.

Figure 5 illustrates the flow of metal along the length of the contact arc in the case where the connecting part is rolled with the corresponding axes of the pinch rollers turned, in the case of considering the upper pinch roller as an example.

6 illustrates the correlation between the temperatures of materials and the resistance to deformation in the case when the metal sheet is ordinary steel.

Fig. 7, similarly to Fig. 1, illustrates a state in which the upper and lower welding rollers are pressed against each other before the start of edge-welding, and a state in which the upper and lower pressure rollers are pressed against each other with the axes turned.

Fig. 8 illustrates the velocity vectors and the relative sliding speed of the upper and lower pinch rollers that occur when the upper and lower pinch rollers are pressed and driven with the axes turned.

FIG. 9 schematically illustrates a control system for the sheet metal joining apparatus shown in FIG. 1.

Figure 10 illustrates the rotation mechanism of the pinch roller, which allows you to vary the angle of rotation of the axis of the pinch roller to any angle.

11 illustrates stress concentration points in a state where steps are present in the connecting portion.

12A illustrates the state of contact between the conventional part after roll welding with crushing edges and each of the work rolls for the rolling mill.

12B illustrates the state of contact between the part after roll-welding with crushing of the edges and the work rolls for the rolling mill in case the connecting part is rolled with the rotated axes of the pinch rollers, and the ledges defined in the connecting part are aligned.

13 is a schematic view of a sheet metal joining apparatus according to an embodiment in which the present invention is applied to the case where the welding machine is a laser welding machine.

Fig. 14 illustrates a state in which when two metal sheets having different thicknesses undergo laser welding or flash butt welding, the steps S defined in the connecting part J formed thereafter are not symmetrical with respect to the point.

Fig. 15 illustrates a state where, in the state of Fig. 14, after welding, the pinch rollers are rotated in one direction for pressing so that the ledges are not embedded in the base material.

Figa illustrates the state of contact between the part after laser welding or part after butt welding with fusion and each of the work rolls for the rolling mill.

16B illustrates the state of contact between the part after laser welding or the part after butt welding with reflow and each of the work rolls for the rolling mill in case the connecting part is rolled with the rotated axes of the pinch rollers in order to reduce the stepwise gradient of the connecting part.

Description of Reference Numbers

1 - upper welding roller

2 - lower welding roller

3 - upper pinch roller

4 - lower pressure roller

5 - metal sheet

6 - metal sheet

7 - locking device on the input side

8 - locking device on the receiving and output side

9 - supporting frame

10 - clamping device of the welding roller

11 - pressure device of the pressure roller

13 - axial force

14 - shear force

15 - axis of the upper pinch roller

16 - axis of the lower pinch roller

22 - upper work roll

23 - lower work roll

24 - the vector of the speed of the upper pinch roller

25 is the vector of the speed of the lower pinch roller

26 - relative sliding speed

27 - the mechanism of rotation of the pressure roller

28 - laser welding machine

45 - straight line perpendicular to the axis of the pinch roller

46 - part of the length of the contact arc

51, 52 - mounting blocks

54 - support roller

55 - base plate

57 is a cylindrical device for driving a supporting frame

61, 62 - electric motors

63, 64 - electric motors

67, 68 - chain transmission mechanisms

71 - upper controller

72 - controller drive the base frame

73 - the controller of the machine for roller welding with crushing edges

74 - pinch roller controller

75 - laser range finder

81 - rotational shaft

82, 83 - gears

84 - electric motor

85 - rotation angle controller

86 - angle sensor

J - connecting part

S - ledge

A - direction of movement (rolling direction)

X - welding line (connection line)

Y - direction perpendicular to the welding line

R is the pressure vector of the pinch roller in the part of the contact arc

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

R2 is a component of the velocity vector R in the direction perpendicular to the welding line X of the velocity vector R

α - angle of rotation

The optimal mode of carrying out the invention

Embodiments of the present invention are described below with reference to the drawings. A metal sheet according to embodiments is described with reference to cold rolling in a steel plant as an example.

1 is a schematic view of a sheet metal joining device according to an embodiment of the present invention. The present embodiment corresponds to the case where the present invention is applied to an edge-crushing roller welding machine.

Referring to FIG. 1, a sheet metal joining device according to an embodiment includes a pair of upper and lower welding rollers 1, 2, a pair of upper and lower pressure rollers 3, 4, fixing devices 7, 8 on the input side, as well as the receiving and an output supporting the frame 9, the pressure roller 10 of the welding roller and the pressure device 11 of the pressure roller. The pressure device 10 of the welding roller and the pressure device 11 of the pressure roller are, for example, hydraulic cylinders. The upper welding roller 1 and the upper pressure roller 3 are supported by the upper horizontal frame 9a of the support frame 9 through the pressure device 10 of the welding roller and the pressure device 11 of the pressure roller, respectively. In addition, the lower welding roller 2 and the lower pinch roller 4 are supported by the lower horizontal frame 9b of the supporting frame 9 through the mounting blocks 51 and 52, respectively. A pair of upper and lower pinch rollers 3, 4 is placed next to a pair of upper and lower welding rollers 1, 2 in the supporting frame 9.

The carrier frame 9 comprises support rollers 54 in its lower part. In addition, the supporting frame 9 can be shifted on the base plate 55 through the support rollers 54 in the direction (welding direction) perpendicular to the two metal sheets 5, 6, which must be interconnected. The locking device 7 on the inlet side includes a pair of upper and lower locking elements 7a, 7b, upper and lower pressing cylindrical devices 7c, 7d and a supporting frame 7e. The locking elements 7a and 7b are supported by the upper and lower pressing cylindrical devices 7c and 7d, respectively, in the support frame 7e. The locking device 8 on the receiving and output side includes a pair of upper and lower locking elements 8a, 8b, upper and lower pressing cylindrical devices 8c, 8d and a supporting frame 8e. The locking elements 8a and 8b are supported by the upper and lower pressing cylindrical devices 8c and 8d, respectively, in the support frame 8e. Support frames 7e, 8e are supported on the base plate 55.

The metal sheet connecting device includes electric motors 61, 62 for driving rotation of a pair of respective upper and lower welding rollers; and electric motors 63, 64 for driving rotation of a pair of respective upper and lower pinch rollers. The electric motors 61, 62 are mounted on the respective side surfaces of the pressure device 10 of the welding roller and the mounting block 51. The electric motors 61, 62 are connected to the respective rotational shafts of the welding rollers 1, 2, for example, through the corresponding chain transmission mechanisms 67. Thus, the rotation power of the electric motors 61, 62 is transmitted to the respective welding rollers 1, 2. Similarly, the electric motors 63, 64 are also mounted on the respective side surfaces of the pressure device 11 of the pressure roller and the mounting unit 52. The electric motors 63, 64 are connected to the respective rotational shafts of the pressure rollers 3, 4, for example, through corresponding chain transmission mechanisms 68. Thus, the rotation power of the electric motors 63, 64 is transmitted to the respective pinch rollers 3, 4.

Figure 2 illustrates the shape of the connecting part having formed ledges immediately after two metal sheets 5, 6 having the same thickness are connected to each other by roller welding with crushing edges using welding rollers 1, 2. Figure 3A, 3B, 4A and 4B illustrate the states where the connecting part after the roll welding with crushing edges is rolled by means of a pair of upper and lower pinch rollers 3, 4.

In the present embodiment, as illustrated in FIGS. 3A and 3B, or in FIGS. 4A and 4B, a pair of upper and lower pinch rollers 3, 4 are mounted so that their axes 15, 16 are rotated in a horizontal plane in respective opposite directions to each other, with respect to a straight line Y (see Figure 5), perpendicular to the welding line or connection line X (see Figure 5) of the connecting part (part of the roller welding with crushing edges) J (shaded part in Figure 2) of two metal sheets 5, 6. In addition, pinch rollers 3, 4 precisely driven by the respective electric motors 63, 64, thereby rolling the steps S defined in the connecting part J. The pressure device 11 of the pressure roller comprises a rotation mechanism 27 (FIG. 10) for adjusting the rotation angle of each of the respective axes of the pressure rollers 3, four.

When the metal sheets 5, 6 must be connected to each other, the corresponding ends of the metal sheets 5, 6 are placed so as to overlap each other. In this state, the metal sheets 5, 6 are gripped and positionally fixed by means of corresponding fixing elements 7a, 7b; 8a, 8b of the fixing devices 7, 8 on the input side, as well as on the receiving and output side. Then, the carrier frame 9 is shifted in the welding direction by means of a drive device, such as a cylindrical device 57 or the like, mounted on the base plate 55. This relatively moves the pair of the upper and lower welding rollers 1, 2 and the pair of upper and lower pinch rollers 3, 4 supported by the supporting frame 9 with respect to the metal sheets 5, 6. Thus, the joining and pressing are continuously performed. In this case, the overlapping parts of the metal sheets 5, 6 are gripped by the welding rollers 1, 2, and the welding rollers 1, 2 are pressed against the overlapping parts of the metal sheets 5, 6 by the pressure device 10 of the welding roller. Although the welding rollers 1, 2 rotate on the basis of a hard drive by means of the corresponding electric motors 61, 62, the welding current is allowed to flow into the welding rollers 1, 2 to form ohmic heating. Thus, welding (roller welding with crushing edges) is performed. Immediately after the overlapping parts are welded by means of welding rollers 1, 2, the connecting part (welded part) J is gripped and pressed by a pair of upper and lower pressure rollers 3, 4 by means of pressure device 11 of the pressure roller. Thus, the pinch rollers 3, 4 rotate on the basis of a hard drive by means of the respective motors 63, 64 to press and roll the connecting part of the metal sheets 5, 6.

Referring to FIG. 2, if roll crushing welding is performed using welding rollers 1, 2, the thickness of the connecting part J increases to approximately 120-160% of the thickness of the base material, i.e. metal sheets 5, 6. This creates ledges S between the connecting part J and the base material (metal sheets 5, 6). In traditional technology, as a method, when the connecting part subjected to roller welding with crushing edges is rolled by means of upper and lower pressure rollers rotating approximately around two axes parallel to each other, the volume of plastic flow in the direction perpendicular to the welding line is limited. In addition, the plastic flow in the direction of movement of the roller is limited by the base material adjacent to it; therefore, the thickness of the connecting part cannot be reduced by welding rollers 1, 2 to the thickness of the base material.

In the present embodiment, as described above, a pair of upper and lower pinch rollers 3, 4 is positioned so that their axes 15, 16 are rotated in a horizontal plane in respective directions opposite to each other, with respect to a straight line Y, perpendicular to the welding line X (connection lines) of the connecting part J. The pressure rollers 3, 4 are rigidly driven by the respective motors 63, 64, thereby rolling the steps S defined in the connecting part J. Thus, the shear force 14 fits to the connecting part J not only in the rolling direction (the direction of movement of the welding rollers 1, 2 and the pressure rollers 3, 4), but also in the direction of the straight line Y, perpendicular to the welding line X, i.e. in the direction perpendicular to the welding line. Shear deformation due to the shear force 14 supports the plastic flow in the direction perpendicular to the welding line. This makes it possible to reduce the increased thickness of the connecting part J in order to align the steps S and to reduce the step gradient. Since the steps S defined in the connecting part J are aligned and the step gradient decreases, the stress concentration coefficient of the connecting part is reduced, which provides a high degree of joint strength.

When rolling the connecting part by means of traditional pressure rollers whose axes are not rotated, the plastic flow in the direction perpendicular to the welding line is limited by fixing devices. In this case, there is a force transmitted from the connecting part to the capture part of the locking devices. Therefore, if metal sheets having small thicknesses are joined together, there is a possibility that there is a deflection in the connecting part and in the part of the metal material in the gripping part. In order to prevent bending, the locking device should only be located in close proximity to the connecting part. In this case, the gap between the locking device and the connecting part narrows, which leads to the problem explained below. The layout of the welding rollers, pinch rollers and their associated installations is limited. This reduces installation flexibility.

In the present embodiment, the respective axes 15, 16 of the pair of upper and lower pinch rollers 3, 4 are rotated in opposite directions to each other in the horizontal plane. Therefore, during rolling by the pinch rollers 3, 4, a shear force 14 is applied to the upper surface side and the lower surface side of the connecting part J in opposite directions. The upper and lower forces transmitted to the locking device 7, 8, suppress each other. Therefore, even if the locking devices 7, 8 are not located in close proximity to the connecting part J, it is possible to prevent the bending of the metal sheet during the joining of thin metal sheets. Consequently, a relatively wide gap can be provided between the fixing devices 7, 8 and the connecting part J. Thus, it is possible to reduce the layout restriction of the welding rollers 1, 2, the pressure rollers 3, 4 and related installations (for example, electric motors 61-64 , chain transmission mechanisms 67, 68, rotation devices 27, which will be described later, etc.).

The details of the action in which the plastic flow (metal flow) in the direction perpendicular to the welding line is supported by turning the corresponding axes 15, 16 of the pair of upper and lower pressure rollers 3, 4, are described in Fig.5.

Figure 5 illustrates the flow of metal along the length of the contact arc in case the connecting part J is rolled with the respective axes 15, 16 of the pinch rollers 3, 4 rotated. In addition, Figure 5 illustrates the case of the upper pinch roller 3 as an example.

In the drawing, the symbol A is an arrow indicating the direction of movement (rolling direction) of the pressure roller 3. The symbol X is a straight line, imaginatively indicating the welding line (connection line) of the connecting part J formed in the direction A of movement. The symbol Y indicates a straight line perpendicular to the welding line X. Reference number 45 denotes a straight line intersecting the width-central part of the pinch roller 3 in a direction perpendicular to the axis of the pinch roller 3. The symbol α denotes the angle of rotation of the pinch roller 3 (the angle between the welding line X and the straight line 45 going in the direction perpendicular to the axis top pinch roller 3). Additionally, reference numeral 46 denotes a portion of the length of the contact arc in which the pinch roller 3 is in contact with the connecting part J. The symbol R denotes the velocity vector of the pinch roller 3 in terms of the length of the arc of contact 46. The symbol R1 denotes the component of the velocity vector R in the direction of the X welding, and R2 denotes the component of the velocity vector R in the direction perpendicular to the welding line X.

Referring to Figure 5, the pinch roller 3 rotates on the basis of a hard cast while pressing against the connecting part J with the axis 15 of the pinch roller 3 turned in a horizontal plane relative to a straight line Y perpendicular to the welding line X. Due to the clamping force and the coefficient of friction between the pinch roller 3 and the connecting part J, the friction force corresponding to the component R2 of the velocity vector in the direction perpendicular to the welding line X is applied to the arc length part of the contact 46 due to the connecting part J. The shear force 14 (see FIG. .3A to 4B), corresponding to the friction force in the direction perpendicular to the welding line X, is applied to the connecting part J. Not only the metal flow in the direction (direction parallel to the welding line X) of the velocity vector component R1 Ti, but also the metal flow in the direction (direction perpendicular to the welding line X) of the component R2 of the velocity vector occurs in the connecting part J. In other words, plastic flow in the direction perpendicular to the welding line X, due to shear deformation by the shear force 14 occurs in the connecting part J. Thus, shear deformation or plastic flow in the direction perpendicular to the welding line X allows alignment of steps S defined in the connecting part J.

The direction of the angle α of rotation of the pair of upper and lower pressure rollers 3, 4 can be specified in two ways.

The installation method in the first position is explained below. 3A and 3B, the respective axes 15, 16 of the pair of pinch rollers 3, 4 are rotated relative to a straight line Y perpendicular to the welding line X, so that the corresponding parts 3A, 4A in the direction of movement of the pair of pinch rollers 3, 4 are turned horizontally planes in corresponding directions opposite to the directions of passage of the metal sheets 5, 6 with respect to the metal material with which the pinch rollers 3, 4 first come into contact. In other words, the corresponding axes 15, 16 of the pressure rollers 3, 4 are rotated so that the corresponding axial ends of the pressure rollers 3, 4 located in the connecting part J of the metal sheets 5, 6, on the side where the thickness is larger, with the steps S specified in of the connecting part J, considered as starting points (the material part of the connecting part J, with which the pinch rollers 3, 4 first come into contact), faces in the rolling direction A of the connecting part J. In this case, the shear force 14 corresponding to the above component R2 of the velocity vector is applied from the steps S defined in the connecting part J of the metal sheets 5, 6, in the direction of passage of the metal sheets 5, 6 with respect to the metal material with which the pressure rollers 3, 4 first come into contact. Thus, parts of the ledges are rolled and leveled while applying shear deformation in one direction, i.e. in the direction perpendicular to the welding line. In this regard, at this time, a force in the opposite direction to the shear force 14 is applied as an axial force 13 from the connecting part J to the pinch rollers 3, 4. In other words, a reactive axial force 13 is applied as a shear force 14 to the connecting part J.

The installation method in the second position consists in the fact that the pressure rollers 3, 4 are rotated in the opposite direction relative to the pressure rollers of the installation method in the first position, as illustrated in FIGS. 4A and 4B. In particular, the corresponding axes 15, 16 of the pair of pinch rollers 3, 4 are rotated relative to a straight line Y perpendicular to the welding line X, so that the corresponding parts 3A, 4A in the direction of movement of the pair of pinch rollers 3, 4 are turned in a horizontal plane in the respective directions of passage of the metal sheets 5, 6 with respect to the metal material with which the pinch rollers 3, 4 first come into contact. In other words, the corresponding axis 15, 16 of the pressure rollers 3, 4 are rotated so that the corresponding axial ends of the pressure rollers 3, 4 located in the connecting part (part of the roller welding with crushing edges) J metal sheets 5, 6, on the side where the thickness less, with the steps S defined in the connecting part J, considered as starting points (the part of the material of the connecting part J, with which the pressure rollers 3, 4 do not come into contact at first), are facing in the rolling direction A of the connecting part J. In this case , sdv the suction force 14 corresponding to the aforementioned component R2 of the velocity vector is applied from the steps S defined in the connecting part J of the metal sheets 5, 6 in the direction opposite to the direction of passage of the metal sheets 5, 6 with respect to the metal material with which the pressure rollers 3, 4 are first come in contact. Thus, parts of the ledges are rolled and leveled while applying shear deformation in one direction, i.e. in the direction perpendicular to the welding line. Also at this time, a force in the direction opposite to the shear force 14 is applied as the axial force 13 of the connecting part J to the pressure rollers 3, 4.

The present embodiment uses a first position setting method. The reason is explained below.

Even if the pair of the upper and lower pinch rollers 3, 4 is rotated by the installation method in the second position, the steps S are subjected to plastic flow due to the shear force 14, so that they can be aligned. However, this case leads to another problem, explained below. As illustrated in FIG. 4B, the steps S are embedded in the base material and immersed in the base material with cracks. There is no problem if you just need the texture of the smooth surface of the connecting part J, and the installation method in the second position is applied to the part that does not need strength. However, if the installation method in the second position is applied to the part subjected to stress, or the application is pressure treatment, such as pressing, including workpieces with desired properties, the end of the submerged step becomes a singular stress field, which causes breakage. Therefore, as illustrated in FIGS. 3A and 3B, the respective rotation directions of the pinch rollers 3, 4 are preferably the directions in which the corresponding axes 15, 16 of the pair of pinch rollers 3, 4 are rotated with respect to a straight line Y perpendicular to the welding line X, so that the corresponding parts 3A, 4A in the direction of movement of the pressure rollers 3, 4 are turned in a horizontal plane in directions opposite to the directions of passage of the metal sheets 5, 6 relative to the metal material with which the pressure Olika 3, 4 first come into contact. In this case, as illustrated in FIG. 3B, the steps S defined in the connecting part can be aligned without immersion in the base material with cracks, whereby the quality of the connecting part can be improved.

The rotation angle α of the axes 15, 16 of the pressure rollers 3, 4 is set according to the absolute value (step size) of the step S. Qualitatively, the rotation angle α is set to a small value if the step size is small; the angle of rotation α is set equal to a larger value as the magnitude of the step increases. As illustrated in FIG. 5, shear deformation due to rotation of the axis 15 of the upper pinch roller 3 is mainly due to the angle of rotation α in terms of the arc length of the contact 46 between the upper pinch roller 3 and the material. Therefore, the angle of rotation α, which must be set, is properly adjusted according to the size of the step, which must be aligned. If the metal sheets 5, 6, made of materials that differ in thickness from each other, are interconnected, the step sizes of the part J of roller welding with crushing edges are different depending on the front and rear surfaces. However, if the angle of rotation α of the upper pinch roller 3 is set according to the size of the step, as described above, the step can be aligned. Although not shown in the drawing, this is applicable to the rolled state from the lower pinch roller 4 having an angle of rotation α. The rotation angle α of the lower pinch roller 4 is set according to a lower step size.

As described above, the axes 15, 16 of the pair of pinch rollers 3, 4 are rotated with respect to a straight line Y perpendicular to the welding line X. The pressure rollers 3, 4 are rigidly driven by the respective electric motors 63, 64, thereby rolling the steps S defined in the connecting part J. Thus, a shear force in the direction perpendicular to the welding line is applied to the connecting part J to align the ledges S. The shear force depends on the resistance to deformation of the material. Therefore, the higher the resistance to deformation, the greater the increase in the axial force 13 applied to the pressure rollers 3, 4 from the metal sheets 5, 6. If the axial force 13 increases, as described above, the service life of the pressure rollers 3, 4 and their bearings are reduced, and the holding force for the axial force 13 is set, which leads to a problem in that the entire device increases in size.

6 illustrates the correlation between the temperatures of materials and the resistance to deformation in the case when the metal sheet is ordinary steel. The deformation resistance of the metal sheets 5, 6 depends on the temperature of the material and has the temperature characteristics shown in Fig.6, if the metal sheets 5, 6 are ordinary steel. In order to reduce the axial force 13, the temperature of the connecting part J is preferably set to 300 ° C or higher, further preferably equal to 500 ° C or higher. This allows you to reduce the value of the resistance to deformation of the metal sheets 5, 6 in order to suppress the increase in axial force 13. Thus, the installation can be reduced in size.

In the present embodiment, a pair of upper and lower pressure rollers 3, 4 is located next to a pair of upper and lower welding rollers 1, 2 in the carrier frame 9. Connection and pressing are continuously performed by moving the carrier frame 9 in the welding direction. Although depending on the thickness of the metal sheets 5, 6, the temperature near the connecting part rises to approximately 1000-1400 ° C. Thus, it is assumed that the temperature of the connecting part J rises to a level exceeding such temperatures. Since the connection and pressing are continuously performed, the temperature of the connecting part J during pressing by the pressure rollers 3, 4 can easily increase to approximately 300 ° C or higher or to 500 ° C or higher by the residual heat of the connecting part J formed by welding. Thus, the installation can be reduced in size.

FIG. 7, similarly to FIG. 1, illustrates a state in which the upper and lower welding rollers are pressed before crushing of the edges by crushing, and a state in which the upper and lower pressure rollers are pressed with the rotated axes.

Fig. 8 illustrates the velocity vector and the relative sliding speed of the upper and lower pinch rollers that occur when the upper and lower pinch rollers are pressed and driven with the axes turned.

The pressing processing was previously performed by means of pressure rollers 3, 4, rolling the connecting part from its end. In this case, as illustrated in FIG. 7, the pinch rollers 3, 4 are pressed against each other and rotated in the state before starting the connection. After the pinch rollers 3, 4 reach the end of the connecting part J, they begin to align the connecting part J as is. If the upper and lower pinch rollers 3, 4 are pressed and rotated with the rotated axes 15, 16, as illustrated in Fig. 8, the corresponding roller speed vectors 24, 25 for the upper and lower pinch rollers 3, 4 do not correspond to each other, so that the relative a sliding speed 26 is formed in the axial direction of the pressure rollers 3, 4. This relative sliding speed 26 generates an axial force in the axial direction of the upper and lower pressure rollers 3, 4 due to the pressing force and the coefficient of friction between the pressure rollers. The axial force reduces the life of the pinch roller and contributes to the wear of the pinch rollers 3, 4. For this reason, at least one, preferably both processes, before starting rolling of the connecting part J and after completing the rolling of the connecting part J, select the first position or the second position. In the first position, the upper and lower pinch rollers 3, 4 are brought into contact with each other. In the second position, 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 an incomplete load compared to the pressing force during rolling. In the initial, i.e. in the first position, the rotation of the upper and lower pinch rollers 3, 4 by means of the respective motors 63, 64 is not performed. In the end, i.e. in the second position, the rotation of the upper and lower pinch rollers 3, 4 by means of the respective motors 63, 64 is performed. In the first position, after the upper and lower pinch rollers 3, 4 reach the lateral end of the connecting part J, the motors 63, 64 immediately begin to rotate to rotate the upper and lower pinch rollers 3, 4 based on the hard drive. In the second position, after the upper and lower pressure rollers 3, 4 reach the lateral end of the connecting part J, the reduction of the pressure device 11 of the pressure roller immediately switches to the position for pressure welding to apply pressure to the upper and lower pressure olive with the rollers 3, 4. Thus, the formation of excessive axial forces can not be allowed to extend the life of the bearing and also to suppress the wear of the upper and lower pressure rollers.

FIG. 9 schematically illustrates a control system for the sheet metal joining apparatus shown in FIG. 1. The control system for the sheet metal joining device includes an upper controller 71, a carrier frame driving controller 72, an edge crushing machine controller 73, and a pinch roller controller 74. The upper controller 71 unifies the control for the controller 72 bring the supporting frame, the controller 73 of the machine for welding with crushing edges and the controller 74 of the pinch roller. The carrier frame driving controller 72 provides operation instructions to the hydraulic circuit (not shown) of the cylinder device 57 for driving the carrier frame 9 to control the driving of the cylindrical device 57. The edge-crushing machine for welding rollers gives operation instructions to the hydraulic circuit (not shown) of the presser welding roller devices 10 and electric motors 61, 62 to control their casting. The pinch roller controller provides operating instructions to the hydraulic circuit (not shown) of the pinch roller presser device 11 and the electric motors 63, 64 to control their driving. The laser range finder 75 is mounted on the upper horizontal frame 9a of the supporting frame 9 and next to the upper welding roller 1. The controller 73 of the edge-splitting roller welding machine and the pressure roller controller 74 receive the laser range finder 75 detection signal and determine, based on the signal, the time when the ends of the overlapping parts of the metal sheets 5, 6 reach a place directly below the laser range finder 75. The controller 73 of the edge-welding roller welding machine and the pressure roller controller 74 are stored in advance the distance between the laser range finder 75 and each of the welding rollers 1, 2 and between the laser range finder 75 and each of the pressure rollers 3, 4 and the speed of the carrier frame 9. The time when the ends of the overlapping parts of the metal sheets 5, 6 reach a place directly under the laser range finder 75, and the time when the welding rollers 1, 2 and pinch rollers 3, 4 grab the ends of the overlapping parts of the metal sheets 5, 6, is calculated based on the distances and speed. Before or after this time, the control of the pinch device 10 of the welding roller and the electric motors 61, 62 and the control of the pinch device 11 of the pinch roller and the electric motors 63, 64 are appropriately set different according to the above set state (first or second position) with respect to the contact between the upper and lower pinch rollers 3, 4.

The rotation angles of the axes of the pressure rollers 3, 4 can be fixed. However, it is preferable that the rotation angles vary to any angle. 10 illustrates a rotation mechanism for a pinch roller in such a case. In this regard, in order to prevent the complexity of the illustration, the electric motor and the chain transmission mechanism for driving rotation of the pinch roller are omitted from the drawing.

Referring to FIG. 10, the pinch roller presser device 11 includes a pivot mechanism 27. The rotation angle of the axis of the pinch roller 3 can be set equal to any angle in the horizontal plane by actuating the rotation mechanism 27. The rotation mechanism 27 may use various methods; however, it uses the type of electric drive as an example in the drawing. More specifically, the rotation mechanism 27 is mounted on the upper end of the pressure roller device 11 of the pressure roller. In addition, the rotation mechanism 27 includes a rotating shaft 81 provided at the upper end of the pressing device 11 of the pressure roller and inserted rotatably into the upper horizontal frame 9a of the supporting frame 9, and an electric motor 84 rotating the rotating shaft 81 through gears 82, 83. The electric motor 84 is controlled by a rotation angle controller 85. Although not illustrated, the rotation mechanism 27 includes a locking device for maintaining the angle of rotation after installation in the desired position.

Additionally, the rotation mechanism 27 includes an angle sensor 86 for detecting the rotation angle of the pressure roller 3. Before starting the connection, the rotation angle controller 85 receives angle information corresponding to the step size to be aligned from the upper controller 71 and sets the rotation angle. In addition, the rotation angle controller 85 controls the driving of the electric motor 84 by means of the signal from the angle sensor 86, in order to enable the rotation angle of the pressure roller 3 to be adjusted to the installation angle. In this case, the control model is prepared in advance with respect to the relationship between the step size and the rotation angle of the pinch rollers 3, 4 based on the thickness of the materials to be joined. The upper controller 71 collects a database based on the control model and provides the angle to be set to the rotation angle controller 85 as necessary. Thus, a joining device can be provided that can appropriately easily set the optimum angle of rotation in accordance with the step size and has a wide range of difference thicknesses of the materials to be joined. The angle sensor 86 may be a sensor that determines the angle of rotation of the rotational shaft 81, as shown in the drawing, and may be a position sensor that determines the angle of rotation of the electric motor 84.

Alternatively, the step size can be measured by means of determination means, such as a laser range finder 75 and the like described above, after welding by means of the welding rollers 1, 2. The angle to be set is provided to the rotation angle controller 85 based on position information in the database of measured values. Thus, the rotation angle is controlled in real time.

11 illustrates stress concentration points in a state in which steps are present in the connecting portion.

During cold rolling for steel production and during pressing, which includes billets with desired properties, high voltage is applied to the connecting part at the processing stage after connection. In particular, if the steps S exist in the connecting part J between the metal sheets 5, 6, as illustrated in FIG. 11, such parts of the steps correspond to stress concentration points. The connecting part J is rolled with the rotated axes 15, 16 of the pinch rollers 3, 4 to align the steps S defined in the connecting part J. Thus, the stress concentration coefficient can be reduced in order to increase the long-term strength of the connecting part. Therefore, the connection device can be applied to a working application for cold rolling for steel production and pressing.

12A illustrates the state of contact between the part after roll welding with crushing edges and work rolls for the rolling mill. 12B illustrates the state of contact between the part after roll-welding with crushing of the edges and the work rolls for the rolling mill in the case that the corresponding axis of the pinch rollers are rotated and the connecting part is rolled to align the ledges defined in the connecting part.

In the training process, for example, the connecting part connected in the joining process, which is the process prior to rolling, was previously rolled by means of a training rolling mill. In such a case, as illustrated in FIG. 12A, if the connecting portion extends between the work rolls as is, the steep ledge S of the connecting part touches and scratches the upper work roll 22. In addition, fingerprint of the connecting part occurs in the upper and lower work rolls 22, 23. In order to prevent such problems, the connecting part is passed between the upper and lower work rolls 22, 23, while the rolling load is set less than the load of the normal rolling part, or the upper and lower work rolls 22, 23 open i. Thus, scratching of the work roll 22 and transfer of the print of the connecting part to the work rolls 22, 23 are prevented. In contrast, in the present embodiment, the axles 15, 16 of the pinch rollers 3, 4 are rotated, and the ledge defined in the connecting part is aligned, as illustrated in Fig. 12B. This allows you to reduce the contact angle (stress concentration coefficient) between each of the work rolls 22, 23 and the connecting part. The pressure of the contact surface between each of the work rolls 22, 23 and the material may therefore decrease. Thus, the scratching of the work rolls 22, 23 and the transfer of the imprint of the connecting part to the work rolls 22, 23 can be prevented without reducing the line speed, which allows to increase productivity and yield.

The embodiment described above applies if the connecting machine is an edge-crushing roller welding machine. However, the present invention can similarly be applied to the case where the connecting machine is a laser welding machine, a flash butt welding machine or a friction stir welding machine. 13 is a schematic view of a sheet metal connecting machine according to an embodiment in which the present invention is applied to the case where the welding machine is a laser welding machine.

Referring to FIG. 13, the sheet metal joining device comprises a laser welding machine 28 instead of an edge-crushing roller welding machine including welding rollers 1, 2, a welding roller pressing device 10, and electric motors 61, 62. The connection device comprises a pair of upper and lower pinch rollers 3, 4, the axes of which are rotated, the pinch device 11 of the pinch roller and electric motors 63, 64 next to the laser welding machine 28. Also in this case, the axis of the pair of upper and lower pinch rollers 3, 4 is rotated vayutsya, and then the pressure rollers 3, 4 are pressed against the metal sheets by the pressing device 11 and the pressure roller are rotated by driving means of respective rigid motors 63, 64 to roll the metal plates. Thus, if two welded metal sheets have different thicknesses, the parts of the steps after welding are aligned so as to make their gradients flat. This allows you to reduce the stress concentration coefficient of the connecting part and to provide a high degree of joint strength. Although not illustrated, the case where the connecting machine is a flash butt welding machine or a friction stir welding machine has an identical configuration.

Fig. 14 illustrates a state in which if two metal sheets having different thicknesses are laser welded or butt flash welded, the steps S defined in the joint portion J formed thereafter are not symmetrical with respect to the point. Fig. 15 illustrates a state where, in the state of Fig. 14, the pinch rollers are turned in one direction and press the metal sheets after welding so that the ledges may not be embedded in the base material.

The steps defined in the joint portion subjected to roll-welding with crushing of the edges have a vertex-symmetric structure with respect to the center of the joint part J, as illustrated in FIG. However, if the metal sheets 5, 6 having different thicknesses are interconnected by laser welding and flash butt welding, the steps S defined in the connecting part J (shaded part) are not symmetrical with respect to the point, as illustrated in FIG. 14 due to the butt joint. Therefore, in order to align the steps S corresponding to the axis 15, 16 of the upper and lower pinch rollers 3, 4 are rotated in one direction, as illustrated in FIG. 15, so that steps S can not be embedded in the base material, as described above. The reactive force of the shear force due to the rotation of the axes of the pressure rollers 3, 4 in one direction is restrained by means of fixing devices 7, 8 for materials that must be interconnected. The step angle of the connecting part J is set flat by shear deformation due to the rotation of the upper and lower pressure rollers 3, 4. This can significantly reduce the stress concentration coefficient that occurs when tension is applied during rolling during pressing in workpieces with desired properties and cold rolling. Thus, the quality of the joint can be improved, and the value of the differential thickness can be increased. Additionally, it is possible to prevent scratching of the work roll during training and during cold rolling.

Figures 16A and 16B, similarly to Figures 12A and 12B, illustrate the effect of preventing scratching of work rolls during the training process by aligning the steps set in the part after laser welding or the part of butt welding by fusion.

The metal sheets 5, 6, having different thicknesses, are interconnected by laser welding and flash butt welding. In this case, similarly to the case of roller welding with crushing edges, if the connecting part J (shaded part) passes between the work rolls as is, for example, during the training process, as illustrated in Fig. 16A, the steep ledge defined in the connecting part touches and scratches the upper work roll 22, or the transfer of the fingerprint of the connecting part J occurs in the upper and lower work rolls 22, 23. Therefore, it is necessary to prevent scratching the work roll 22 and transfer the fingerprint of the connecting part J to the working shaft ki 22, 23 by allowing the connecting part J to pass between the work rolls at a reduced rolling load compared to the load of the conventional rolling part or by opening the upper and lower work rolls 22, 23. In contrast, in the present embodiment, the pinch rollers 3, 4 are rotated, and the steps S are aligned so as to have the desired step gradients, as illustrated in FIG. 16B. This allows to reduce the contact angle (stress concentration coefficient) between each of the work rolls 22, 23 and the connecting part J. Therefore, the pressure of the contact surface between each of the work rolls 22, 23 and the material can be reduced so as to prevent scratching of the work rolls 22, 23 and transferring the imprint of the connecting part to the work rolls 22, 23.

In this regard, in the connection devices of FIGS. 1 and 10, in which the present invention is applied to an edge-crushing roller welding machine, the pressure roller of the welding roller 10 and the pressure device 11 of the pressure roller having a rotation mechanism 27 are housed in one carrier frame 9. However, even if they are placed in separate frames, the functions of the present invention are not violated.

Also in the embodiment illustrated in FIG. 13, in which the present invention is applied to a laser welding machine, a flash butt welding machine, or a friction stir welding machine, a laser welding machine and a pinch roller pressing device 11 having a pivoting mechanism 27 are arranged in one carrier frame 9. However, even if they are placed in separate frames, the functions of the present invention are not violated.

The embodiments described above may produce the following results.

1-A. The axes 15, 16 of the pair of upper and lower pinch rollers 3, 4 are rotated, and then the pair of pinch rollers 3, 4 is rigidly driven by the corresponding electric motors 63, 64, thereby rolling the ledges S defined in the connecting part J. Therefore, in the case of roller crush welding, a shear force in the direction perpendicular to the weld line X is applied to the joint part J. Not only shear deformation due to this shear force reduces the increased value of the joint thickness th portion J, but also ledges S can be aligned, and a step gradient can be reduced in the compound of the metal sheets 5, 6 having the same thickness. In addition, the steps S can be aligned, and the step gradient can decrease in the connection of metal sheets 5, 6 having different thicknesses. Also, if metal sheets having different thicknesses are interconnected by laser welding, butt fusion welding or friction welding with stirring, similarly, shear deformation allows alignment of steps S and reduce the step gradient. Also, in each case, the steps S defined in the connecting part J are aligned and the step gradient decreases, which allows reducing the stress concentration coefficient of the connecting part J to provide a high degree of joint strength.

The steps S defined in the connecting part J of the metal sheets 5, 6 can be aligned and the step gradient can be reduced, whereby a high degree of bond strength can be achieved. Accordingly, the following results can be obtained. Edge crushing roller welding can be widely applied to the cold rolling process and workpieces with predetermined properties to which it has not previously been applied. You can avoid scratching the work roll on the steel production line. Productivity and yield may increase.

In other words, in the present embodiment, the ledges defined in the connecting part subjected to roller welding with crushing edges, which cannot align the ledges specified in the connecting part earlier, can be aligned. Therefore, during the cold rolling process for the steel production line, scratching of the work roll during cold rolling is not allowed, since the productivity of the next process and the resistance to tension are increased. In this way, roll crush welding can be applied to a cold rolling process to which it has not previously been applied.

It is also impossible in workpieces with desired properties to apply roller welding with crushing edges to the part requiring fatigue strength due to the concentration of stresses of the steps set in the connecting part. However, the smoothness of the steps reduces the stress concentration, which increases the suitability for pressing. Therefore, an expensive laser welding machine can be replaced with an inexpensive edge-splitting roller welding machine.

In a continuous annealing line and in a production line including a galvanizing line and the like, the contact angle (stress concentration coefficient) between each of the work rolls of the temper rolling mill and the connecting part can decrease. Therefore, the pressure of the contact surface between the work roll and the material may decrease. Therefore, it is possible to prevent scratching of the work roll and transfer of the imprint of the connecting part to the work roll without reducing the line speed. Thus, productivity and yield can increase.

1-B. The corresponding axis 15, 16 pairs of the upper and lower pressure rollers 3, 4 are rotated in the respective directions, opposite each other in the horizontal plane. During rolling by the pressure rollers 3, 4, a shear force 14 is applied to the upper surface side and the lower surface side of the connecting part J in opposite directions. The upper and lower forces transmitted to the locking device 7, 8, suppress each other. Thus, it is possible to prevent bending of the metal sheet during the joining of thin metal sheets without arranging the fixing devices 7, 8 in close proximity to the connecting part J. As a result, a relatively wide gap can be provided between the fixing devices 7, 8 and the connecting part J. This allows you to reduce the constraint on the layout of the welding rollers 1, 2, pinch rollers 3, 4 and related installations (for example, electric motors 61-64, chain transmission mechanisms 67, 68, rotation mechanisms 27 ota, etc.).

2. The corresponding axis 15, 16 of the pair of pinch rollers 3, 4 are rotated relative to a straight line Y perpendicular to the welding line X, so that the corresponding parts 3A, 4A in the direction of movement of the pair of pinch rollers 3, 4 are turned in a horizontal plane in the corresponding directions, opposite directions the passage of metal sheets 5, 6 with respect to the metal material with which the pinch rollers 3, 4 first come into contact. In addition, the connecting part is rolled while applying a shear force from the steps S defined in the connecting part J of the metal sheets 5, 6, in the directions of passage of the metal sheets 5, 6 relative to the metal material with which the pressure rollers 3, 4 first come into contact. Therefore, it is possible to prevent a part of the step from being inserted into the base material of the metal sheets 5, 6. This allows to prevent the occurrence of defects like a crack (defects of inability to weld) when a part of the step is inserted into the main material. Thus, the quality of the connecting part is improved.

3. The rotation angles of the pair of pressure rollers 3, 4 are set according to the step size of the connecting part J, and the connecting part is rolled. Therefore, the corresponding shear deformation is applied according to the thicknesses of the metal sheets 5, 6, which should be interconnected, thereby minimizing the stepwise gradient of the connecting part J. Materials having different thicknesses can be interconnected, and the values of the steps that must be formed may be different between the front and rear surfaces of the connecting part. Also, even in such a case, the corresponding rotation angles of the pair of pressure rollers 3, 4 are set according to the corresponding step sizes of the connecting part J, and the connecting part is rolled. This allows you to adjust the magnitude of the shear strain and minimize the stepwise gradient of the connecting part.

4. The temperature of the connecting part J rises to 300 ° C or higher with the residual heat of the connecting part J caused by welding two metal sheets 5, 6, and the connecting part J is rolled by means of pressure rollers 3, 4. Therefore, the value of the resistance to deformation of the connecting part J may decrease to reduce the axial force that must be formed. Thus, the installation can be reduced in size. Further, due to the reduced axial force, the service lives of the bearings of the pinch rollers 3, 4 can be extended, and the wear of the pinch rollers 3, 4 can be suppressed, whereby operating costs can be reduced.

5. At least one of the processes before starting rolling of the connecting part J and after completing rolling of the connecting part J selects a first position or a second position. In the first position, a pair of pinch rollers 3, 4 is brought into contact with each other. In the second position, the pair of pinch rollers 3, 4 is not brought into contact with each other, or pinch rollers 3, 4 are brought into contact with each other at an incomplete load compared to the pressing force during rolling. In the first position, a pair of pinch rollers 3, 4 is not provided, and in the second position, a pair of pinch rollers 3, 4 is driven. Therefore, it is possible to prevent the application of excessive axial force to the upper and lower pinch rollers 3, 4. Thus, the service life of the bearings for the upper and lower pinch rollers 3, 4 can be extended, and, in addition, wear of the upper and lower pinch rollers 3, 4 can be suppressed, whereby operating costs can be reduced.

6. Also in the present embodiment, in which the present invention is applied to a laser welding machine, a flash butt welding machine or a friction stir welding machine, metal sheets having different thicknesses can be joined together by laser welding, flash butt welding or friction stir welding. In this case, similarly to the case of roller welding with crushing edges, the connecting part can be rolled by means of pressure rollers using the residual heat of the connecting part. This allows you to effectively provide a connecting part having high strength and high quality. Also, if metal sheets having different thicknesses are interconnected by laser welding, butt fusion welding or friction welding with stirring, similarly, shear deformation allows alignment of steps S and reduce the step gradient. Thus, the following results may be obtained. A laser welding machine, a flash butt welding machine or a friction stir welding machine can be widely applied to the cold rolling process and workpieces with predetermined properties to which they have not previously been applied. You can avoid scratching the work roll on the steel production line. Productivity and yield may increase.

7. Heating means 1, 2 or 28 for connecting two metal sheets 5, 6 together and a pair of upper and lower pressure rollers 3, 4 for rolling the connecting part J of metal sheets 5, 6 are installed. In addition, a pair of pinch rollers 3, 4 is installed in such a way that their axes 15, 16 are rotated in a horizontal plane relative to a straight line Y perpendicular to the welding line X of the connecting part J. Consequently, production capacities can be provided that allow alignment of the steps S given in the connecting part J of the metal sheets 5, 6, and reduce the step gradient as described above, thereby providing a connecting part having high strength and high quality.

8. The mechanism 27 is installed, which independently rotates in a horizontal plane the corresponding axis 15, 16 of the pair of pinch rollers 3, 4 with respect to a straight line Y, perpendicular to the welding line X. Therefore, a coupling device can be provided that makes it easy to set the optimum angle of rotation appropriately according to the step size and has a wide range of difference thicknesses for the thickness of the metal sheets 5, 6.

Claims (8)

1. A method of joining metal sheets, in which, after two metal sheets (5, 6) are interconnected, a pair of upper and lower pressure rollers (3, 4) moves in a direction (A) identical to the direction of the connection line (X) the connecting part (J) of the metal sheets, and the connecting part (J) of the metal sheets is rolled by means of a pair of upper and lower pressure rollers (3, 4),
while the corresponding axis (15, 16) of the pair of pinch rollers (3, 4) are rotated in a horizontal plane with respect to a straight line (Y) perpendicular to the line (X) of the connection of the connecting part (J), and then the pair of pinch rollers is rigidly set in motion, in order to thereby roll the step (S) defined in the connecting part in the direction (A) of the movement of the pressure rollers (3, 4). 2. The method according to claim 1, in which the corresponding axis (15, 16) of the pair of pressure rollers (3, 4) are rotated relative to a straight line (Y) perpendicular to the connection line (X), so that the corresponding parts in the direction of movement (3A 4A) the pairs of pressure rollers (3, 4) are turned in a horizontal plane in the direction opposite to the direction of passage of the metal sheet relative to the metal material with which the pressure rollers (3, 4) first come into contact, and the ledge defined in the connecting part is rolled in the direction (A) of movement. 3. The method according to claim 1 or 2, in which the corresponding rotation angles of the pair of pressure rollers (3, 4) are set according to the step size of the connecting part (J) and the connecting part is rolled in the direction (A) of movement. 4. The method according to claim 1 or 2, in which the temperature of the connecting part rises to 300 ° C or higher by the residual heat of the connecting part (J) resulting from the welding of two metal sheets (5, 6), and the connecting part is rolled in the direction (A) movement by means of pressure rollers (3, 4). 5. The method according to claim 1 or 2, in which at least one of the processes before starting rolling the connecting part (J) and after completing the rolling of the connecting part (J) selects a first position in which a pair of pressure rollers (3, 4 ) is brought into contact with each other, or a second position in which a pair of pinch rollers is not brought into contact with each other or is brought into contact with each other at an incomplete load compared to the pressing force during rolling, and in the first position is a pair of pinch rollers not set in motion, but in the WTO position are a pair of pinch rollers is driven. 6. The method according to claim 1 or 2, in which two metal sheets (5, 6) are interconnected by any of the roller weld with crushing edges, laser welding, flash butt welding and friction stir welding. 7. A device for connecting metal sheets, containing:
- means (1, 2) for connecting by heating to connect two metal sheets (5, 6) with each other and
- a pair of upper and lower pinch rollers (3, 4) moving in a direction (A) identical to the direction of the line (X) of the connection of the connecting part (J) of the metal sheets, for rolling the connecting part (J) of the metal sheets,
however, a pair of pinch rollers (3, 4) is installed so that the corresponding axis (15, 16) of the pinch rollers are rotated in a horizontal plane relative to a straight line (Y), perpendicular to the line (X) of the connection of the connecting part (J). 8. The device according to claim 7, further comprising a mechanism (27) for independently turning in the horizontal plane of each of the axes (15, 16) a pair of pinch rollers (3, 4) with respect to a straight line (Y) perpendicular to the connection line (X).

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