JPS61274863A - Grinding apparatus - Google Patents

Abstract

PURPOSE:To provide high accuracy polishing without producing stepped material to be polished in a device for polishing an optical element by changing freely the feeding speed of a tool and the rotational speed of the material to be polished in synchronization with the position of the tool. CONSTITUTION:A drive motor 26 feeds circumferentially the surface of a material 12 to be polished. A tool rotating motor 30 rotates a polishing tool 28. A feed motor 34 rotates a feed screw 35 to slide a feed column 32 in a slide guide 36. When a feed position detecting unit 37 generates the signal according to the detected position, a calculation process controller 39 reverses the motor 34 to give reciprocating motion to the tool 28. Here, the rotation of the material 12 and the food of the feed column 32 are calculatively processed to have predetermined speed preset as working requirements in said controller 39 according to the feed position sent to the input of said controller 39 by a feed position detecting unit 37 so that the speed of the motor 34 is controlled while the speed the motor 26 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] "Industrial Application Field" The present invention relates to a polishing apparatus, and particularly to a polishing apparatus suitable for polishing optical elements with high precision.

"Prior Art" Conventionally, in order to finish the surface of optical elements such as lenses, prisms, or reflectors to extremely high precision, the surface, which has been polished to a certain degree of precision, is partially corrected and polished using a small-diameter polishing pad. things will be done.

FIG. 3 is a schematic perspective view for explaining a specific example of such corrective polishing. In the figure, 1 is an optical glass parallel plane plate which is a material to be polished, and the material to be polished 12 is disk-shaped. The bottom surface of the material to be polished is the workpiece support/41
(It is fixedly supported by being glued to the workpiece support 14.
! is rotatably supported by the work rotation shaft 2s-,
The material to be polished 12 is the shaft! It is fixed to the work support body /41 so as to be rotationally symmetrical with respect to the workpiece support body /41. The upper surface of the material to be polished has been mirror-polished in advance by pre-processing. However, it is assumed that the illustrated ring zone Y has become convex due to this pre-processing.

In corrective polishing, a polishing pad 16 that is smaller than the size of the workpiece to be polished is used.

The polishing pad 6 is fixedly supported by being bonded to the tool support 14, and one end of the rod 20 is abutted against a recess formed in the center of the upper surface of the tool support 14. The rod -O is swingable with an appropriate width in the radial direction of the material to be polished /2. Here is an abrasive supply means.

While supplying abrasive from the abrasive supply means 22 to the upper surface of the workpiece to be polished, the work support 14! Correct polishing is performed by rotating the tool in the direction of arrow B and simultaneously swinging the tool support /g in the radial direction of arrow A.

``Problems to be solved by the invention'' However, in conventional corrective polishing, polishing pads/
6 performs the polishing process while contacting the material to be polished /- with uniform pressure over the entire surface, the problem is that a difference in level is likely to occur between the part that has undergone correction polishing and the part that has not received correction polishing on the upper surface of the material to be polished /-. was there.

Figures (a) and (1)) are cross-sectional views of the material to be polished 12 corresponding to the I-1 cross section in Figure 3. Figure D (a)
Figure 7('b) shows the state before corrective polishing, and Fig. 7('b) shows the state after corrective polishing. From an optical point of view, a fairly large step height is formed.

For this reason, it has been proposed to prevent the occurrence of steps by gradually changing the swing width of the polishing pad 16 instead of fixing it.

However, such a change in only the swing width has the disadvantage that it is very difficult to eliminate the level difference and the control method is complicated and expensive.

The present invention eliminates the drawbacks of the above-mentioned conventional polishing devices, and makes it possible to easily obtain a highly accurate polished surface of an optical element using a small-diameter tool without creating difficult differences in level on the surface of the material to be polished. The purpose is to provide a polishing device.

[Structure of the invention]

"Means for Solving the Problems" The present invention provides a drive means for rotating a material to be polished, a drive means for rotating a polishing tool that is in pressure contact with the material to be polished, and a drive means for rotating the polishing tool in the radial direction of the material to be polished. In a polishing apparatus having a moving feeding means and a means for detecting the position of the workpiece of the polishing tool in the radial direction, the feed speed of the workpiece of the polishing tool in the radial direction and the position of the workpiece being polished are determined by the signal from the position detection means of the polishing tool. This polishing device is characterized by being equipped with an arithmetic processing device that changes the rotational speed of the material.

"Operation" Based on the signal from the position detection means of the polishing tool, the processing unit changes the feed speed of the polishing tool and the rotational speed of the material to be polished, adjusts the polishing action time of the polishing tool at each position of the material to be polished, Shape the surface of the material into the desired shape.

"Embodiments" Hereinafter, embodiments of the polishing apparatus of the present invention will be described with reference to the drawings.

FIG. 1 (IL) is a longitudinal sectional view showing an embodiment of the polishing apparatus of the present invention. FIG. 1(1)) is a plan view taken along the arrow 1--■ in FIG. 1(a).

In the figure, 1 is a flat glass plate which is the material to be polished, and the lower surface of the material to be polished /2 is adhesively fixed to the workpiece support 1. The work support body/da is rigidly fitted in the rotational direction to a work rotation shaft 25 supported on the machine frame 10.

The work rotation axis 2j is a drive motor 2 fixed to the machine frame 10.
It is connected so that rotation can be applied from the wheel via a pair of gears. Cot t is a polishing tool, and is connected to a tool rotating shaft knob which is supported by an arm 31 and connected to a motor 30 fixed to the head of an arm 37. The arm 31 is rotatably connected to the feed column J2 via a shaft 33, and the opposite end with the shaft J3 in between can be locked by a hook 21 pivotally connected to the feed column 3, so that the arm 31 connects to the shaft J3. It is rotated clockwise from FIG. 1 (&) around , and is held in an oblique position. Feed column 32
is slidably fitted to a slide guide 36 fixed to the machine frame 10, and a feed motor J'l fixed to the machine frame 10 and a feed screw 3 connected to the motor 3da and journalled to the machine frame 10 are connected to the slide guide 36 fixed to the machine frame 10.
5 and the feed screw 33 are screwed into the feed column 3 by a nut (not shown) fixed to the feed column 3, and the feed screw 33 is fed in the direction A in FIG. 1 (1). A feed position detection unit 37, such as an optical or magnetic linear scale or inductosin, is fixed to the slide guide 36 and the feed column J-. -1 is an abrasive supply means, and 3t is an abrasive layer pan fixed to the machine frame 1O for preventing and collecting the abrasive applied to the material to be polished 7.2 from scattering; the abrasive supply means] It has an outlet for discharging the abrasive into an abrasive tank (both not shown) equipped with a λ pump. The arithmetic processing control device 39 includes motor tacho &, 3117. Feed motor? 1I and a signal from the position detection unit 37 is inputted to control these components.

Next, its operation will be explained. The arm 31 is rotated clockwise around the shaft 33 and lifted up, and the end protruding in the opposite direction from the position pivoted to the shaft 33 is pulled down by the hook U/ pivoted to the three feed columns. It is supported by

First, the material to be polished /J is adhesively fixed onto the workpiece support /41 and fitted onto the workpiece rotation shaft J. Next, the polishing tool g is attached to the tool rotation axis 9. At this point, abrasive is supplied from the abrasive supply means 1, and then the arithmetic processing control unit 39 supplies each motor tach &, , 717, . 7II is energized. The drive motor 6 connects the workpiece rotation axis through a pair of gears! Rotate the workpiece support / Rotate the da to support the workpiece /
2. Send the surface to be polished in the direction of the polishing. Tool rotation motor 30
rotates the tool rotating shaft 29, and the polishing tool t rotates.

The feed motor 31I is the feed screw 3! is rotated to slide the feed column jJ through the slide guide 36. When the feed position detection unit 3 outputs a signal based on the detected position, the arithmetic processing control unit 39 receives the signal and reverses the feed motor 3, causing the feed column 3 to go back and move the tool 2.
A reciprocating feed is given to g.

At this point, remove the hook 1, rotate the arm 3/ counterclockwise around the shaft 3J, and place the polishing tool t on the octopus of the material to be polished. The incision of the polishing tool t into the octopus of the material to be polished is given by the weight I of other objects carried by the arm 31 and the arm J/.

Thus, while the polishing tool-t rotates, it swings in the radial direction and is fed in the radial direction, and at the same time the octopus of the material to be polished is rotated and fed in the circumferential direction to perform polishing.

Here, the rotation of the material to be polished 12 and the feed of the three feed columns are set in advance as machining conditions in the arithmetic processing control device 3D based on the feed position input to the arithmetic processing control device 3D from the feed position detection unit J7. The rotational speed of the feed motor 31I is controlled so as to achieve a predetermined speed, and the speed of the drive motor 2B is also controlled. The corrective polishing of the convex part octopus a of the octopus of the material to be polished illustrated in Fig. 2(+!L)t(1)) is different from that in Fig. 1(1)) in the case of Fig. 2(a). Polishing tool at protrusion/core a position-g
The feed speed of the material to be polished is increased, and the rotation speed of the material to be polished l- is slowed down. Actual processing amount per hour of the polished material octopus (5toc
kRemove ) has decreased compared to Figure 1 (1)), and the low convex part / in Figure 2 (a) has been corrected, and Figure 1 (0)
After the corrective polishing, the processed surface without undulations is shown in Figure 2b. In the case of FIG. 2(1)), the feeding speed of the polishing tool t is slow and the rotational speed of the material to be polished /2 is fast, compared to FIG. 2(a). The shape of the polished surface is also shown in Figure 1 (Q).
become.

As mentioned above, although the present embodiment has been explained by taking corrective polishing as an example, it goes without saying that the polishing apparatus of the present invention can also be used for other ordinary polishing.

Furthermore, the polishing apparatus of the present invention can also be used to create and polish axisymmetric aspheric surfaces with a small amount of aspheric surface by adjusting the usage method as described in the above embodiment and setting the polishing time appropriately. can.

〔Effect of the invention〕

As explained above, the present invention includes a driving means for rotating a material to be polished, a driving means for rotating a polishing tool that is in pressure contact with the material to be polished, and a feeding means for swinging the polishing tool in the radial direction of the material to be polished. In a polishing device having means for detecting the position of the workpiece of the polishing tool in the radial direction, the feed speed of the workpiece of the polishing tool in the radial direction and the rotational speed of the workpiece are determined based on the signal from the position detection means of the polishing tool. Since the polishing device is equipped with a processing unit that changes the speed, the feed speed of the tool and the rotational speed of the material to be polished can be freely changed in synchronization with the tool position, thereby achieving high speeds without creating a step on the material to be polished. Accurate polishing can be performed.

[Brief explanation of drawings]

FIG. 1(a) is a vertical cross-sectional view of an embodiment of the present invention, FIG.
)) in Figure 1(a)! -! Arrow view plan view, Figure 2 (a)
. (b) and (C) are longitudinal cross-sectional views of the material to be polished, Figure 3 is a perspective view showing the polishing method, and Figure 9 (IL)t(1)) is a longitudinal cross-sectional view of the conventional material to be polished. be. 24.30, J4 (...Motor 3...Position detection unit 3D...Arithmetic processing control unit.

Claims (1)

[Claims] 1. A drive means for rotating a material to be polished, a drive means for rotating a polishing tool that is in pressure contact with the material to be polished, a feeding means for swinging the polishing tool in the radial direction of the material to be polished, and a drive means for rotating the polishing tool to be polished. In a polishing device having a position detection means in the radial direction of the material, a calculation processing device is provided which changes the feed speed of the material to be polished of the polishing tool in the radial direction and the rotational speed of the material to be polished based on the signal from the position detection means of the polishing tool. A polishing device characterized by: