JPH08118179A - Workpiece fixing device on electromagnetic chuck table - Google Patents

Abstract

PURPOSE: To dispense with strict control on the squareness of the corner angle of a fixing keep block. CONSTITUTION: A V-groove block 4 formed of magnetic material into almost rectangular hexahedron shape with one side face 41 provided with a V-groove 5 bored in longitudinally uniform sectional form almost parallelly with the bottom face is combined with a keep cylinder 6 formed of a cylindrical body to be fitted into the V-groove 5 in such a way that the peripheral surface of the cylindrical body is protruded from the V-groove bored face 41 of the V- groove block 4 at the fit-in time, thus forming a workpiece fixing device for an electromagnetic chuck table.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a workpiece fixing device for an electromagnetic chuck table.

[0002]

2. Description of the Related Art As shown in FIG. 4, when a relatively light weight work piece 1 in the form of a rectangular parallelepiped block is ground by a grinding wheel 3, the work piece 1 is placed on an electromagnetic chuck table 2. In some cases, a method of pressing and fixing the periphery thereof by four pressing blocks 101, 102, 103 and 104 arranged in a cross beam shape is used.

This work piece fixing method is a method which is relatively frequently used because the work piece 1 can be easily attached and detached at the time of working, and the holding block 101 having a rectangular parallelepiped shape and the like can also be used. There is a problem in that the corner angles of the workpieces 1 in contact with each other and the electromagnetic chuck table 2 are required to be exactly right angles.

That is, as shown in FIG. 5 (a), when the corner angles A, B, C, D of the pressing block 101 and the workpiece 1 which are in contact with the electromagnetic chuck table 2 are all exactly right angles, the workpiece is processed. When fixing 1, the bottom surface is held in close contact with the upper surface of the table 2 so that the upper surface to be polished can be held parallel to the upper surface of the electromagnetic chuck table 2. However, as shown in FIG. Corner A,
If some or all of B, C, and D do not form a right angle due to wear or dust adhesion, the work piece 1 cannot be accurately held on the chuck table.

[0005]

That is, FIG. 5 (b) shows that, for example, the corner angle A of the holding block 101 holding the workpiece 1 from one side is larger than the right angle and the holding block 102 holding the workpiece 1 from the other side. The case where the corner angle B is smaller than the right angle is shown, but in such a case, as is clear from the figure, the pressing blocks 101, 10 on both sides are shown.
2 does not contact the side surface of the work piece 1 entirely and presses it, but contacts linearly, and since the heights of the contacting points are different, the two pressing forces K _{1 with} different action lines ,
As a result of K ₂ acting on the work piece 1, a moment for rotating the work piece 1 is generated, and particularly, the work piece 1 is rotated.
Is a non-magnetic material, the electromagnetic force from the chuck table 2 does not work, and there is a drawback that it floats up from the upper surface. Similar results are obtained when the angle of the work piece 1 is not a right angle. As described above, in order to accurately hold the work piece on the electromagnetic chuck table, not only the pressing block but also the work piece itself must be machined at an extremely right angle in the corners. Is complicated in terms of work management.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a substantially rectangular parallelepiped shape made of a magnetic material, and one side surface thereof is substantially parallel to the bottom surface and is elongated. A V-shaped groove block having a V-shaped groove having a uniform cross-sectional shape in a direction, and a columnar body fitted into the V-shaped groove, and the outer peripheral surface of the columnar body at the time of fitting is the V-shaped groove. It is a device for fixing a workpiece in an electromagnetic chuck table, which is combined with a pressing columnar body that is projected from a V-shaped grooved surface of a block.

[0007]

The pressing cylinders, which are located on opposite sides of the work piece, come from the top surface of the V-shaped groove block, which holds them, regardless of whether or not the angle of the V-shaped groove block is perpendicular to the top surface of the electromagnetic chuck table. Since pressing force is applied from both sides to fix at the line of action at the same height, there is no moment to rotate the work piece, and the bottom surface is in close contact with the chuck table surface. Fixed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. A block having a rectangular parallelepiped shape as shown in FIGS. 1 and 2 is prepared by using an appropriate magnetic material such as iron and steel, and one side surface 41 thereof extends substantially parallel to the bottom surface V.
The groove 5 is formed. This becomes the V-shaped groove block 4.

The parallelism of the V-shaped groove 5 with respect to the bottom surface 42 need not be considered so strictly as will be seen later. It is more important that the dimensions such as the bottom angle, the width and the depth of the opening are uniform in the longitudinal direction of the groove.

Separately, a pressing column 6 to be fitted into the V-shaped groove 5 is provided. This may be a cylinder made of, for example, a ceramic material or a material such as hard steel that is hard and does not easily deform at room temperature. Of course, it is necessary that the diameter is a precise cylinder that is uniform in the longitudinal direction.

A particularly important requirement for the shapes and dimensions of the V-shaped groove 5 and the pressing column 6 is that the outer peripheral surface of the pressing column 6 is V when the pressing column 6 is fitted into the V-shaped groove 5 as shown in FIG.
That is, it projects beyond the surface of the V-shaped grooved surface 41 of the grooved block 4. As shown in FIGS. 3A, 3B and 3C, there is no particular limitation on the size of the bottom angle of the V-shaped groove 5. Further, as described above, the material of the pressing column 6 does not have to be a magnetic material, but if so, it would be convenient in that it can be handled together with being attached to the V-shaped groove block 4.

FIG. 2 shows a method of fixing the workpiece 1 on the electromagnetic chuck table 2 by combining the V-shaped groove block 4 and the pressing cylinder 6 of the present invention. That is, one generatrix of the pressing cylinder comes into line contact with the workpiece 1 and presses and fixes it.

Even if the parallelism of the V-shaped groove 5 with respect to the bottom surface 42 is somewhat low, it means that the generatrix in contact with the workpiece 1 is only slightly inclined with respect to the bottom surface, and the V-shaped groove blocks 4 on both sides. There is no particular hindrance to the action of the pressing force (to be exact, a reaction force against the force that the workpiece 1 moves along the upper surface of the chuck table 2 due to the polishing action of the polishing wheel 3).

Considering a case where the corner angle A of the portion of the V-shaped groove block 4 contacting the chuck table 2 is smaller than, for example, a right angle, in this case, the entire V-shaped groove block 4 descends to the right in FIG. The contact generatrix of the pressing cylinder 6 to the workpiece 1 only moves in the direction of P ′ along the outer circumference from that passing through the point P in the figure, and in this case as well, it is the same as the case examined in the previous section. In addition, there is no problem in clamping and fixing the work piece 1.

As can be seen from FIG. 2, the V-shaped groove block 4 does not have to be entirely made of a magnetic material. For example, a plate made of a magnetic material is arranged only at the bottom, and the V-shaped groove portion is formed as a synthetic resin molded product. A modified embodiment of the present invention is also possible in which these two are screwed together or joined by an adhesive or the like.

When the device of the present invention is used as described above,
It suffices to note that the top surface of the work piece 1 to be ground is parallel to the bottom surface, and it is not necessary to use much nerve in the squareness of the angle including the fixed blocks as in the prior art. Of.

[0017]

As is apparent from the above detailed description, according to the present invention, in the pressing cylinders which are located on opposite sides of the work piece, the corner angle of the V-shaped groove block for holding them is electromagnetic. Regardless of whether it is at right angles to the upper surface of the chuck table, pressing force is applied from both sides to fix it at the line of action at the same height position from the upper surface, so that it is rotated on the workpiece. Such a moment does not act, and there is an effect that the bottom surface of the work piece can be fixed so that it does not float up from the electromagnetic chuck table surface and closely contact it, and the squareness of the corner angle of the work piece and the holding block for fixing is There is an advantage that you do not have to manage it very strictly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing a usage state of the apparatus according to the embodiment of the present invention.

FIG. 3 is a side sectional view for explaining that the size of the bottom angle of the V-shaped groove of the V-shaped groove block of the device of the present invention is not related to the operation of the device of the present invention.

FIG. 4 is a perspective view showing a polishing machine using the device of the present invention and fixing a workpiece.

FIG. 5 is a side cross-sectional view for explaining a difference in a fixed state of a work piece when a corner angle of a conventional pressing block is both right angle and non-right angle.

[Explanation of symbols]

 1 Workpiece 2 Electromagnetic chuck table 3 Grinding wheel 4 V-shaped groove block 41 V-shaped groove drilling surface 42 Bottom surface 5 V-shaped groove 6 Holding cylinder

Claims (1)

[Claims] 1. A V-shaped groove (5) having a substantially rectangular parallelepiped shape made of a magnetic material, and having one side surface (41) substantially parallel to the bottom surface (42) and having a uniform cross-sectional shape in the longitudinal direction. The V-shaped groove block (4) and the V-shaped groove (5) are formed into a cylindrical body, and the outer peripheral surface of the cylindrical body at the time of fitting is the V-shaped groove drilling surface of the V-shaped groove block. (41) A device for fixing a workpiece on an electromagnetic chuck table, which is combined with a holding column (6) which is projected from (41).