JPH04240071A - Method and device for polishing ring-shaped grinder element - Google Patents

Abstract

PURPOSE:To generate a stable spherical accuracy even, when a ring-shaped grinding wheel wears quickly, without requiring correction of the rotary shaft of a cup wheel by using a disk-shaped polishing member formed in curved polishing surfaces, whose peripheries matche with the section configuration of the tip of the grinding wheel. CONSTITUTION:A cup wheel 30 to make spherical grinding of an optical member is equipped with a rotary shaft 31 fitted on a spindle and a ring-shaped grinding wheel 32 to make grinding of a work to be processed into a lens, wherein the section of the tip 33a assumes R form in symmetricity to the left and right about the center line 33. Below the grinding wheel 32, a polishing member 42 made of a super-hard material is installed on rotary shaft, and its curved grinding surfaces 47, 48, 49 match with the R-form section configuration of the tip 32a of the grinding wheel 32, wherein the curved surface 47 is designed for coarse polishing, the one 48 for medium polishing, and the other 49 for finish polishing. When the grinding wheel 32 has worn through spherical grinding, the curved surfaces of the polishing member 42 are contacted with the tip 32a of the grinding wheel, and the polishing member and grinding wheel are rotated to polish the tip of the grinding wheel. Thus the tip 32a is finished into a specified R-form.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing method and apparatus for polishing an annular grindstone for spherical grinding of optical members.

0002

[Prior Art] Conventionally, spherical grinding of optical members was performed as shown in Fig. 6.
As shown in FIG. 7, a cup wheel 2 equipped with an annular grindstone 1 having an R-shaped tip 1a is used, and the cup wheel 2 is rotated while rotating the lens 3 to be processed. The spherical surface grinding process of the processed lens 3 is performed.

By the way, the tip 1a of the annular grindstone 1 wears out during grinding, and the rounded shape of the tip 1a changes. When spherical grinding is performed using this worn annular grindstone 1, the radius of curvature of the spherical surface of the lens 3 to be processed differs from the design value, so the rotation axis 2a of the cup wheel 2
The inclination angle α is corrected.

0004

As described above, when processing the spherical surface of the lens 3 to be processed according to the designed value, the inclination angle of the rotating shaft 2a is corrected according to the amount of wear on the annular grindstone 1. However, the correction is very troublesome, and there is a problem in that it becomes difficult to obtain stable spherical accuracy, especially when the grindstone 1 is heavily worn.

The present invention was made in view of the above-mentioned problems, and its purpose is to create a stable spherical surface even when the grinding wheel is heavily worn, without requiring correction of the rotation axis of the cup wheel. An object of the present invention is to provide a method for polishing an annular grindstone and an apparatus for the same, which can achieve high precision.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a polishing method for polishing an annular grindstone for spherical grinding of an optical member, wherein the peripheral end is a cross section of the tip of the annular grindstone. A disc-shaped polishing member is formed with a polishing curved surface having a cross-sectional shape that matches the shape and is attached to a rotating shaft, and the polishing curved surface of the polishing member is brought into contact with the tip of the annular grindstone. The present invention is characterized in that the tip of the annular grindstone is polished by rotating the member and the annular grindstone.

[0007] The present invention also provides a polishing device for polishing an annular grindstone for performing spherical grinding of an optical member, comprising: a grindstone driving means for rotating the annular grindstone; a disc-shaped polishing member formed with a polishing curved surface having a cross-sectional shape that matches the shape of the polishing member; The present invention is characterized by comprising a polishing member driving means for polishing the tip of the annular grindstone.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an apparatus to which the annular grindstone polishing method according to the present invention is applied will be described with reference to the drawings.

FIG. 1 is a perspective view showing a grinding apparatus for grinding a spherical surface of a lens to be processed.

In FIG. 1, 11 is a base, and this base 1
1 is provided with a rotating base 12 that rotates around a B-axis 11a. The rotating base 12 is rotated by a drive motor 13. A substrate 14 is attached to the rotating base 12.
is attached, and this substrate 14 is provided with an X-axis moving plate 15 that moves in the X-axis direction. X-axis moving plate 15
is moved in the X-axis direction by an X-axis drive motor 16. The X-axis moving plate 15 is provided with a Z-axis moving plate 17 that moves in the Z-axis direction, which is the vertical direction, and the Z-axis moving plate 17 is moved in the Z-axis direction by a Z-axis drive motor 18. The Z-axis moving plate 17 has a Y moving in the Y-axis direction.
An axis moving plate 19 is provided, and movement of the Y-axis moving plate 19 is performed by operating a Y-axis handle 20. The Y-axis moving plate 19 includes a rotary drive motor (grinding wheel drive means).
A main shaft 22 is provided which rotates by a shaft 21, and a cup wheel 30 is removably mounted on this main shaft 22.

As shown in FIG. 2, the cup wheel 30 includes a rotating shaft 31 attached to the main shaft 22, and a ring-shaped grindstone 32 for spherically grinding a lens to be processed (not shown) is provided at the bottom thereof. ing. The cross section of the tip 32a of the annular grindstone 32 is rounded and symmetrical with respect to the center line 33.

As shown in FIG. 1, below the annular grindstone 32, a cylindrical rotating shaft 40 is provided which is rotated by a drive motor (polishing member driving means) 35, and the upper end of this rotating shaft 40 is As shown in FIG. 3, a flange 41 is formed, and a polishing member 42 made of a superhard material is screwed to the flange 41 and is detachable. As shown in FIG. 2, the polishing member 42 has three disc parts 44, 45, 4 whose diameter becomes smaller toward the upper stage on a disc base 43 whose diameter is smaller than the inner diameter of the annular grindstone 32.
6 is provided, and the circumferential ends of each of the disc parts 44 to 46 are formed into polishing curved surfaces 47, 48, 49 having a cross-sectional shape that matches the R-shaped cross-sectional shape of the tip end 32a of the annular grindstone 32. There is. The polishing curved surface 47 is for rough polishing, the polishing curved surface 48 is for medium polishing, and the polishing curved surface 49 is for fine polishing.

Next, the operation of the embodiment constructed as described above will be explained.

First, as shown in FIG. 4, when spherically grinding a lens, a lens holder 51 is attached to the rotating shaft 40, and a lens 52 to be processed is attracted to the lens holder 51. This suction is performed by creating a negative pressure inside the rotating shaft 40. Then, the rotation axis 31 of the cup wheel 30 is set at a predetermined angle (determined by the curvature of the lens to be processed) with respect to the optical axis 52a of the lens to be processed 52, and the annular grindstone 32 is set to the optical axis 52a of the lens to be processed 52.
2 (see Figure 6). These are performed by a drive motor 13, an X-axis drive motor 16, a Z-axis drive motor 18, and the like.

Then, the drive motor 35 rotates the rotating shaft 4.
The cup wheel 30 is rotated by the drive motor 2 while rotating the lens holder 51 and the lens to be processed 52 together with the
1 to perform spherical grinding of the lens 52 to be processed.

When the annular grindstone 32 is worn out due to the spherical grinding, the lens holder 51 attached to the rotating shaft 40
is removed, and a polishing member 41 is attached to its rotating shaft 40, as shown in FIG.

If the lens 52 to be processed is a convex lens, the inner side of the tip 32 of the annular grindstone 32 will wear out (see FIG. 6).
), as shown in FIG.
The cup wheel 30 is moved by the X-axis drive motor 16, the Z-axis drive motor 18, etc. so that the polishing curved surface 47 of the polishing member 41 is placed inside the tip 32a of the annular grindstone 32.
abut the inside of the Then, while the cup wheel 30 is rotated by the rotary drive motor 21, the rotary shaft 40 is rotated by the drive motor 35.
At the same time, the polishing member 41 is rotated to coarsely polish the annular grindstone 32. After this rough polishing is completed, the tip 32a of the annular grindstone 32 is
is brought into contact with the polishing curved surface 48 to perform medium polishing, and then the tip portion 32a is brought into contact with the polishing curved surface 49 to perform fine polishing. Through these polishing steps, the tip end 32a of the annular grindstone 32 has a predetermined R shape, so that when the next spherical grinding process is performed on the lens 52 to be processed, the rotation axis 31 of the cup wheel 30 and the light beam of the lens 52 to be processed will be The angle formed with the axis 52a may be the same as the previous predetermined angle. Therefore, it is very convenient because there is no need to make troublesome angle corrections every time there is wear. In addition, even if the abrasion is severe, the polishing member 41
By simply polishing the annular grindstone 32, the tip end 32a returns to its original rounded shape, so that the lens 52 to be processed can be finished with stable spherical precision.

If the outside of the tip 32a of the annular grindstone 32 is worn out, that is, when a concave lens is spherically ground as shown in FIG. 7, the annular grindstone 32 will wear from the tip to the outside. In this case, as shown in FIG. 2, the cup wheel 30 is moved by the X-axis drive motor 16, the Z-axis drive motor 18, etc. so that the rotating shaft 40 is located outside the polishing wheel 32, and the polishing member 41 is moved. The polishing curved surfaces 47 to 49 may be brought into contact with the inside of the polishing whetstone 32 to sequentially perform rough polishing, medium polishing, and fine polishing.

[0019]

As explained above, according to the present invention, when the annular grinding wheel is polished with the polishing member, the tip of the annular grinding wheel returns to its original rounded shape. The spherical precision of the processed lens can be stabilized without requiring axis correction, and even when the grindstone is severely worn.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a grinding device that performs spherical grinding of a lens to be processed;

FIG. 2 is an explanatory diagram showing a method of polishing the outside of the annular grindstone using the grinding device of FIG. 1;

[Fig. 3] An explanatory diagram showing a state in which the polishing member is attached to the rotating shaft,

[Fig. 4] An explanatory diagram showing a state in which the lens holder is attached to the rotating shaft,

FIG. 5 is an explanatory diagram showing a method of polishing the inside of the annular grindstone using the grinding device of FIG. 1;

[Figure 6] Explanatory diagram showing spherical grinding of a convex lens

[Figure 7
] It is an explanatory view showing spherical grinding of a concave lens.

[Explanation of symbols]

21 Rotary drive motor (grinding wheel driving means) 32 Annular grinding wheel 32a Tip portion 35 Drive motor (abrasive material driving means) 40 Rotating shaft 42 Polishing members 47 to 49 Polishing curved surface

Claims (3)

[Claims] 1. A polishing method for polishing an annular grindstone for performing spherical grinding of an optical member, wherein the peripheral end is formed into a curved polishing surface with a cross-sectional shape matching the cross-sectional shape of the tip of the annular grindstone, and , a disc-shaped polishing member attached to a rotating shaft is provided, the polishing curved surface of the polishing member is brought into contact with the tip of the annular grindstone, and the polishing member and the annular grindstone are rotated to polish the tip of the annular grindstone. A method for polishing an annular whetstone, characterized in that: 2. A polishing device for polishing an annular grindstone for performing spherical grinding of an optical member, comprising: a grindstone driving means for rotating the annular grindstone; and a grindstone drive means attached to a rotating shaft, the peripheral end surface having a cross-sectional shape of the annular grindstone. a disc-shaped polishing member formed with a polishing curved surface having a cross-sectional shape that matches the shape of the polishing member; A polishing device for an annular grindstone, comprising: a polishing member driving means for polishing the tip of the annular grindstone. 3. The polishing member is formed into a multi-stage shape consisting of a plurality of disk portions with different diameters, and a rough polishing curved surface for rough polishing to a fine polishing curved surface for fine polishing is formed in correspondence with each step portion. The annular grindstone polishing device according to claim 2, characterized in that: