JPH07256B2 - Vacuum chuck - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum chuck which can be reliably held on a processing machine without giving an excessive deformation to a work to be cut or ground.

[0002]

2. Description of the Related Art A magnet chuck is effective as a holder for fixing a work piece whose bottom surface is relatively flat on a table such as a milling machine or a grinding machine, and for a non-magnetic work piece, Vacuum chucks, which have a large number of suction holes on a lithographic plate, are used. Since the suction surface of these chucks is naturally finished with good flatness, there is no problem if the flatness of the lower surface of the work piece is good, but if this is not so good, the suction holding force becomes weak or The object is curved, and the lower surface is forcibly brought into close contact with the chuck surface. Therefore, in the latter case, even if the upper machined surface is finished with good flatness, when the product is removed from the chuck after machining, the internal stress causes the workpiece to return to the shape it had before it was held, and the machined surface finished with a flat corner. Will be curved.

[0003]

In order to eliminate such a defect, the workpiece is securely held without deforming the shape of the lower surface of the workpiece, that is, the surface attracted to the chuck, and internal stress is applied to this. It is important not to generate it.

[0004]

Therefore, according to the present invention, a large number of suction blocks are arranged on the plate of the chuck, and each suction block is floatingly installed in the groove so that the inclination angle of the upper suction surface can be changed. Then, after once adsorbing the suction blocks to the lower surface of the work piece, each suction block is fixed in the vertical groove by the vacuum action of the second piping system, and as a result, the work piece is held on the plate. In this case, the work piece is not forcedly attached to the upper surface of the chuck.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an embodiment of the present invention. In the drawing, A is a plate of a chuck composed of an upper plate 1 and a lower plate 2 for processing, and has a plurality of vertical grooves 3 on its upper surface. The suction blocks B are arranged in rows and fitted in an equidistant arrangement so that they can slide in the vertical grooves 3, respectively. An upper surface concave portion 4 and a side surface concave portion 5 are formed on the suction block B, and the upper surface concave portion 4 is formed on the suction block B.
The first piping system C is communicated with the vertical hole 6 penetrating through the pipe and the joint 7 and the flexible tube 8 attached to the lower portion thereof. In addition, a ventilation passage 9 is bored in the plate A (upper plate 1 in the drawing), one side of which serves as an opening 10 in the vertical groove 3 corresponding to the side surface recess 5 of the suction block B, and the other side thereof. Are assembled as a second piping system D.

A weak spring 11 is provided under each suction block B.
, And the upper surface of the suction block B is the plate A as shown in Fig. 3.
Connected to the vertical hole 6 so that it protrudes slightly from the upper surface of the (the amount of protrusion is easy to adjust so that all suction blocks are uniform, for example, using a ball plunger as the spring 11). The flexible tubes 8 are gathered through the holes 12 in the lower part of the vertical groove and the groove portions 13 provided in the lower plate 2 and guided to the outside. If necessary, a leaf spring 14 or the like is attached to the other side surface of each suction block B to promote the side surface recess 5 to closely contact the inner surface of the vertical groove on the opening 10 side.

Since the embodiment of the present invention is configured as described above, when the lower surface of the work piece placed on the plate A is not flat, the upper surface of the plate A and the work piece are different at a specific place. Although they come into close contact with each other, a gap can be formed depending on the flatness of the attracted surface. Therefore, when the first piping system C is communicated with the vacuum device, a suction action occurs in the upper surface concave portion 4 of each suction block B, and the suction block B itself moves upward and adheres to the workpiece. At a portion where the attracted surface is not parallel to the upper surface of the plate A, the floating suction block B inclines as shown in FIG. 2 to bring the upper surface into close contact with the workpiece.

Such operation of the suction block B is carried out at various places on the lower surface of the workpiece, and the required number of suction blocks B floating in the vertical groove 3 are fixed to the lower surface of the workpiece.
When the pipe system D is placed in a vacuum state, the suction block B is fixed in the vertical groove 3 by the surface of the side surface recess 5 by the suction action from the opening 10. As a result, the workpiece can be reliably fixed to the plate A through the suction block B without changing the shape of the lower surface, and can be subjected to milling cutting or grinding.

The product whose upper surface is processed in this manner is removed from the chuck by vacuum breaking of the first piping system, but since the forced adsorption that deforms the held surface is not performed, the processed surface is removed even after the removal. The flatness of will not be out of order. Therefore, when processing a thin plate or the like that requires good parallelism between the upper and lower surfaces, first process one surface by the above method, then apply a vacuum breaking action to both the first piping system and the second piping system to process the workpiece. Remove. Next, a flat plate was placed on the plate A with the reference surface facing downward, and each suction block B was pushed down so that its upper surface was flush with the upper surface of the plate A, and then the vacuum was applied only to the second piping system. When the action is given, all the suction blocks B are fixed in the vertical groove 3 in this state. After removing the flat plate from here, place the workpiece on the plate A with the primary processing surface facing downward, and if the suction action is given to the first piping system again, the desired chucking is performed and this fixing is performed. By processing in the state,
Good flatness and parallelism can be achieved, and the flatness of the workpiece does not change even after the chuck is removed.

Further, when all the upper recesses 4 of each suction block B are communicated with each other, the suction block whose upper recess 4 is not covered by the work deteriorates the suction force of other blocks, but the first piping system is not used. It is possible to deal with the size of the workpiece and the mounting position on the plate by connecting it to a separate switching device for each suction block or dividing it into several circuits, but this device is outside the scope of the present invention. Therefore, the description is omitted.

[0011]

As described above, the vacuum of the present invention
In the chuck, suction blocks having separate suction surfaces on the upper surface and side surfaces are arranged in a row in the vertical groove of the slab so that each of them adheres to the surface of the workpiece to be floatingly adhered. The work piece is fixed to the plate through the suction block of
Unlike the conventional flat chuck, the lower surface of the work piece is forcibly adsorbed and is not deformed to generate internal stress, so that the restoring deformation action of the work surface does not occur during uncucking. Therefore, a thin plate-shaped workpiece or the like that requires double-sided processing requires repeated correction processing to obtain parallelism.

With the recent weight reduction of members, steel materials have become thinner, and lightweight metals such as aluminum and plastics have low rigidity, so a special jig is required to hold them during processing, and further tightening However, delicate adjustments were required, and it was not possible to do simple work. The vacuum chuck according to the present invention is particularly effective for the flat surface machining of such a low rigidity member,
It has a remarkable effect on the efficiency of setup work and the improvement of processing accuracy.

[Brief description of drawings]

FIG. 1 is a plan view in which only a top plate of a vacuum chuck according to the present invention is partially cut away.

FIG. 2 is a partial vertical cross-sectional view of a central portion of a vertical groove of a chuck showing a state in which a workpiece is adsorbed.

FIG. 3 is a partial cross-sectional view taken along line XX shown in FIG.

FIG. 4 is a plan view showing an example of a suction block.

5 is a side view on the arrow S side in FIG. 4. FIG.

[Explanation of symbols]

 A chuck base plate B suction block C first piping system D second piping system 1 top plate top plate 2 bottom plate bottom plate 3 vertical groove 4 suction block top recess 5 suction block side recess 8 flexible tube 10 Opening of the second piping system 13 Groove through which the first piping system passes

Claims (1)

[Claims] 1. Adsorption blocks each having an upper surface concave portion and a side surface concave portion are floated in a vertical groove arranged in a plate, and the upper surface concave portion is connected to a vertical hole of the adsorption block or a lower portion thereof. While communicating with the first piping system by the flexible tube and the like, the opening of the second piping system formed in the plate is
A vacuum chuck, characterized in that the suction chucks are respectively provided opposite to the side surface recesses.