JP2728841B2 - Grinding machine with grinding wheel at variable distance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine for grinding a mechanical workpiece, and more particularly to a grinding machine provided with a grinding wheel at a distance which can vary according to the position of the workpiece.

[0002] Grinding of a workpiece made of iron or ceramic, particularly for finishing, requires so-called "precision grinding" of a surface requiring high precision.

[0003] For this purpose, the "stock"
Remove a considerable amount of material, called its flatness,
Grinding machines are used which provide surfaces with parallelism and size errors in the thousands of millimeters.

[0004]

BACKGROUND OF THE INVENTION There are several types of grinders, among which are two cup wheels of the correct diameter and width, placed opposite each other and supported by a suitable wheel spindle. There are "double-headed" or "double" grinding machines fitted with. In these machines, the wheels are opposed but not necessarily coaxial, so in some cases the active surfaces of the wheels are not parallel,
Rather, they usually taper during the grinding operation in the direction in which the workpiece is inserted. These grinders also
Mechanisms are provided to secure the workpiece to the appropriate pedestal and guide the path between the wheels, and the movement of such paths and wheels is properly controlled.

[0005] In order to maintain the desired accuracy, it is necessary to keep the geometry of the active surface of the grinding wheel constant despite inevitable wear, which requires re-adjustment of the wheels and frequent activation of the active surface. This is done by reviewing

Particularly known grinding machines are basically of two types: "disks" or "rotary disks".
It operates according to two principles known as (Wendt).

Machines operating according to the "disk" principle have wheels in fixed positions, the active surfaces of which are tapered in the direction of workpiece insertion. The distance between the wheels can be set according to the thickness of the workpiece, and the workpiece is usually fed through the wheels by a rotary feed disc with a suitable pedestal.

The workpiece is guided along a fixed path, which is a circular arc from the point of entry of the normally widening wheel to the point of exit from the usually narrowing wheel, between which two points. The difference is usually equal to the stock to be removed.

Although these machines have a relatively short grinding cycle (grinding time) and can be operated on a relatively large workpiece, the surface of the grinding wheel is greatly deformed due to frequent reworking. I will be.

[0010] Conversely, machines operating according to the "turntable" principle have parallel grinding wheels in which the workpiece placed on a holding-feed plate is placed inside the surface of the grinding wheel. Or slightly outwardly by radial movement. One or both wheels are fed at an essentially constant feed rate and progressively grind the workpiece until the entire stock is removed.

[0011] Although this machine has a relatively long grinding cycle, the surface deformation of the grinding wheel is small, and the interval between redress cycles can be longer.

The above two types of grinders have good grinding accuracy according to the manner of movement of the grinding wheel and the manner of movement of the workpiece holding and feeding mechanism.

In the second case (rotary wheel), in particular, the wheel moves along its axis and the workpiece moves along the axis towards the wheel, while in the first case (disk), The object moves along the circumference of the feed disk that rotates along the axis.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to have a short working cycle, a long dressing interval, a minimum deformation of wheels, and to be able to process workpieces of any size with high precision. It is to provide a grinding machine.

The object is a grinding machine equipped with at least one grinding wheel (1, 2) and a unit suitable for controlling the movement of a mechanism for holding and feeding the workpiece (P). The at least one grinding wheel (1, 2) is rotated by a motor (M1, M2);
And a cup wheel movable along a first axis (A), wherein the mechanism for holding and feeding rotates about a second axis (B) parallel to the first axis (A). Possible and a third perpendicular to said first and second axes (A, B)
A feed disc (3) movable along an axis (C) of said three axes, said three axes (A, B, C) acting together to move simultaneously in relation to each other. And is achieved by a grinding machine.

The above object is also a grinding machine equipped with at least one grinding wheel (1, 2) and a suitable unit for controlling the movement of a mechanism for holding and feeding the workpiece (P). The at least one grinding wheel (1, 2) is a cup wheel rotated by a motor (M1, M2) and movable along a first axis (A); But,
Moveable along the first axis (A) according to a feed rate according to a predetermined rule regarding the movement of the mechanism for holding and feeding, that is, a feed amount as a function of the movement of the holding and feeding mechanism; The holding and feeding mechanism is mounted on a slide (4) or consists of a plate (5), the slide and the plate being parallel to the cup wheel and one in a plane tangent to the cup wheel. Suitable for moving along the axis (C) or two perpendicular axes (D, E), all these axes (C, D,
This is achieved by a grinding machine, characterized in that E) is perpendicular to said axis (A).

In a preferred embodiment, the grinding machine to which the variable distance wheel is mounted is of the double-head type,
The use of parallel wheels has the advantage of making the wear smaller and more constant.

According to the present invention, according to the manner of operation of the holding and feeding mechanism, the sophisticated orbit is controlled.
It offers another advantage of being able to send the workpiece according to the trajectory. this is,
This is made possible by controlling the feed operation on three axes simultaneously with the variable feed of the grinding wheel.

As a result, more accurate and complicated machining can be finally performed.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS The above and other advantages of the grinding machine according to the invention will become more apparent from the two preferred embodiments described in detail below with reference to the accompanying drawings.

FIG. 1 shows that a grinding machine according to the invention has two cup wheels 1, 2 (grinding wheels) mounted on a shaft A and driven by motors M1 and M2, respectively, via belts. Is shown. The cup wheels 1, 2 can be approached to each other by a known drive and are preferably operated by an electronic unit for numerical control (not shown).

The machine further comprises a feed disc 3 mounted on a slide 4 parallel to and partially inserted between the grinding wheels 1 and 2.
The feed disc rotates on an axis B parallel to the axis A, while the slide moves along a third axis C perpendicular to the axes A, B.
The feed disc 3 is placed on a suitable pedestal (not shown), and is moved between the wheels 1 and 2 according to a feed path resulting from the combination of the movement of the slide 4 and the rotational movement of the feed disc 3, which will be described in detail later. It is a holding fixture for the workpiece to be sent.

The rotation of the feed disc 3 and the movement of the slide 4 are well known and are controlled by a numerical control unit via a drive not shown here. The entire operation of the machine is therefore based on a combination of movements obtained by pre-entering the interrelationship between the feed disc 3 and slide 4 and the drive mechanism of the wheels 1, 2 into the numerical control unit.

FIG. 2 is a plan view of the same grinding machine showing the active surface of the cup wheel 2 overlapping the circumference of the rim or feed disc 3. Movement of the disc / slide assembly along axis C adjusts the overlap between the circumference of the feed disc on which the workpiece pedestal rests and the active edge of the wheel.

FIG. 3 is a plan view of another embodiment of the machine according to the invention. Also in this embodiment, the feed is a plate 5 mounted on a slide 4 ', shown in dotted lines, similar to that described in the previous case.

Such a slide is driven by a known system, is parallel to the wheel and translates along two orthogonal axes D and E on a plane intermediate the wheel and the wheel, or preferably Translates only along axis D, which corresponds to axis C in the case described above. The workpiece is mounted on a suitable pedestal (not shown) of the plate 5 in the overlap area, and the feed follows a path produced as a result of the combination of the two linear movements, Or run along a single axis.
The movement of the slide 4 'on one or two axes and the movement of the wheel on the axis A can be mutually performed by inputting the correlation of each movement on these axes into the above-mentioned numerical control unit in advance. Work together.

Referring to FIG. 4, the workpiece P, which rests on the pedestal on the circumference of the feed disc 3 according to FIG. 1, is predetermined by the combined movement of the feed disc and finally comes into contact with the workpiece. It can be seen that it travels along the path guided by the rolling wheel. The aforementioned combined movement of the feed disc results from a combination of linear and rotational movement centered on axis C. In the particular case shown, the workpiece P is moved between two predetermined positions, CR1 and CR2, with the twelve twelve shown as the disc rotates while the center of rotation of the feed disc moves. Follow the path indicated by the location. Such a movement is guided by a numerical control unit, the amplitude of which depends on the type of grinding of the workpiece P and the size and width of the active surfaces of the wheels 1,2.

FIG. 4 also shows at the top a diagram illustrating three possible ways of feeding the cup wheels 1, 2 by means of the numerical control unit (by means of the three characteristic lines CC1, CC2 and CC3). Wheel 1, 2
Occurs between a position X where contact between each wheel and the corresponding workpiece P begins and a final position Y where stock removal is completed. In the case of the characteristic line CC2, the ratio of the feed of the grinding wheels 1 and 2 to the feed of the workpiece is constant, and as a result, uniform stock removal can be obtained.

Conversely, to remove 3/4 of the stock in the first half of the wheel feed, increase the wheel feed in the first half of contact with the workpiece (characteristic line CC1),
Alternatively, in order to remove 3/4 of the stock in the latter half of the wheel stroke, the wheel feed can be increased in the latter half (characteristic line CC3).

If desired, the numerical control unit can be entered with rules governing the feed of various types of wheels. This flexibility of the grinder according to the invention offers the advantage of allowing more stock to be removed from the workpiece on the outer rim than on the inner rim of the cup wheel, which is more susceptible to wear and damage.

Referring finally to FIG. 5, there is seen an example of feed in the machine shown in FIG. 3 which is controlled on one axis (C). The workpiece P is placed on a suitable pedestal of the plate 5. , Plate 5 is mounted on the aforementioned slide and moves from position ES1 to position ES2 along machine axis C and back to ES1. This movement follows the illustrated continuous position of the workpiece.

In this case as well, the workpiece P is sent by numerical control of the movement defining only on the axis C. In the above case,
Although both the rotation axis B and the axis C are controlled, the same grinding can be performed by the feed control of the grinding wheels 1 and 2 also in the example of FIG.

By controlling the movement of the plate, preferably on two axes which are orthogonal to each other, it is also possible to obtain a path of the workpiece consisting of a combination of two linear movements.

FIG. 5 also shows a diagram D2 illustrating the main features of the grinding machine according to the invention. For example,
Wheels 1, 2 according to the characteristic lines shown in the diagram so that more than 3/4 of the stock is removed in the first half.
Feed can be programmed. Most of the required action is obtained on the outer rim of each wheel.

Also in this case, the movement of the plate 5 (on two axes in some cases) and the feed of the grinding wheel (axis A
The above relationship can be input to the numerical control unit for optimal operation.

Whatever the variable feed of the wheels depending on the position of the workpiece, the invention relates to any grinding machine with one or more grinding wheels, in particular one wheel on its axis. Applicable to a "double-head disc grinder" where the moving and other wheel is in a fixed position.

The mechanical components of the grinding machine according to the invention can be of any type known in the art, if appropriate, but the numerical control is, for example, a microcontroller which processes complex movements along three axes simultaneously. Performed by the processor. still,
Movement along the three axes can be performed in whole or in part by mechanical means.

Those skilled in the art can make various modifications to the grinder of the present invention without exceeding the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a side view of a grinding machine according to a first embodiment of the present invention.

FIG. 2 is a plan view of the machine according to FIG. 1;

FIG. 3 is a plan view similar to FIG. 2 for a machine according to a different embodiment;

FIG. 4 is a diagram illustrating the operating principle of the machine of FIGS. 1 and 2;

FIG. 5 is a diagram illustrating the operating principle of the machine of FIGS. 1 and 3;

[Explanation of symbols]

 1, 2 Cup wheel 3 Feed disc 4 Slide A, B, C axis M1, M2 Motor

Claims (3)

(57) [Claims] 1. A grinding machine equipped with at least one grinding wheel (1, 2) and a unit suitable for controlling the movement of a mechanism for holding and feeding a workpiece (P), The at least one grinding wheel (1, 2)
A cup wheel rotated by a motor (M1, M2) and movable along a first axis (A), wherein the mechanism for holding and feeding is a cup wheel parallel to the first axis (A); A feed disc (3) rotatable about a second axis (B) and movable along a third axis (C) perpendicular to said first and second axes (A, B). A grinding machine, characterized in that these three axes (A, B, C) interact with each other to move simultaneously in relation to each other. 2. A grinding machine equipped with at least one grinding wheel (1, 2) and a unit suitable for controlling the movement of a mechanism for holding and feeding a workpiece (P), The at least one grinding wheel (1, 2)
A cup wheel rotated by a motor (M1, M2) and movable along a first axis (A), wherein the at least one cup wheel is configured to move along the first axis (A); The feed amount according to a predetermined rule regarding the movement of the mechanism for holding and sending, that is, movable according to the feed amount as a function of the movement of the holding and sending mechanism,
The holding and feeding mechanism is mounted on a slide (4) or consists of a plate (5), wherein the slide and the plate are parallel to the cup wheel;
And one axis (C) in a plane tangent to the cup wheel
Or it is suitable to move along two perpendicular axes (D, E), characterized in that all these axes (C, D, E) are perpendicular to said axis (A) Grinder. 3. The grinding machine according to claim 1, comprising two grinding wheels which are two parallel and opposed cup wheels.