JPS61103768A - Polishing and grinding tool - Google Patents

Abstract

PURPOSE:To permit the work with high precision by permitting the uniform abrasion of grindstone and suppressing the change of the shape of the polishing surface of a tool by using the abrasive material, as polishing and grinding tool, in which regions having the different constitution of the content of gas foams in the abrasive material and said regions are arranged in concentric and annular form around the revolution shaft to the tool. CONSTITUTION:A tool 11 is constituted of the regions 12-14 of the polishing material having the different density of gas foams whose volume is nearly equal, and the regions 12-14 are joined integrally into concentric annular form around the revolution shaft O of the tool, and when the gas-foam density C in each region is 12a-14a, the relation 12a>13a>14a is established. The magnitude of the gas-foam density exerts an influence onto the magnitude of the polishing area of the polishing material, and the abrasion amount of the polishing tool can be controlled. In other words, since the region 12 as the center part of the polishing surface of the tool 11 has the highest gas-foam density C, the degree of abrasion at the upper edge is large, and since the region 14 as the abrasion surface of the peripheral part has the lowest gas-foam density C, the degree of abrasion is little. Therefore, each abrasion amount of the peripheral part and the center part can be made equal by setting the distribution of gas-foam density, and the precision can be improved.

Description

[Detailed description of the invention] Technical field The present invention relates to a polishing/grinding tool for a member having a curved surface.
Polishing and grinding of optical members C is a series of two steps.

Prior Art Conventionally, this type of polishing tool has been used, an example of which is shown in FIG. FIG. 6 shows an outline of the main parts of a polishing machine for polishing an optical lens using the polishing tool described above. In FIG. 42, reference numeral 1 denotes a conventional polishing tool, and as is well known, L: consists of a hemispherical body in which polishing abrasive material is uniformly combined, and is integrally supported by the upper end C of the tool rotation shaft 7. . The concave lens 2 to be polished by the tool 1 is held by a lens holder 3. A hairpin bulb 4a provided at the lower end of the hairpin 4 fits into a recess 3a provided on the upper surface of the holder 3, and the hairpin 4 is inserted into the lens holder 3 while applying an appropriate load. The swinging mechanism swings in the direction of the arrow (= swinging. In this way, the surface to be polished of the lens 2 is pressed and slid on the polished surface C of the tool 1 rotating on the rotation shaft 7 via the lens holder 3. At this time, the lens 2 rotates according to the rotation I of the tool 1 while swinging on the polishing surface of the tool 1, and a predetermined polishing is performed. Reference numeral 5 indicates a well-known coolant (cutting oil) supply. 1, and the coolant 6 is poured onto the exposed abrasive surface 1 of the abrasive tool 1.

By the way, in such conventional lens polishing/grinding processing, the polished surface of the polishing tool 1 does not come into even contact with the polished/grinded surface of the lens 2 to be processed, and moreover, the swinging of the hairpin 4 The pressing force is not necessarily equal depending on the mechanism. Therefore, the amount of wear due to polishing/grinding of conventional polishing/grinding tools is not uniform and differs from the expected amount.

For example, as shown in FIG. 7, if the wear amount of the central portion 1B of the polishing surface of the polishing tool 1 is tb1, and the wear amount of the peripheral portion 1a is ta, then tb\t=. In this way, the polished surface of the polishing tool 1 is evenly 1: no dust wear, tb>'t, or t
Corresponding to b<t@, the radius of curvature R of the polishing surface of the polishing tool increases or decreases depending on the length of polishing time t, as shown in No. 8 IAC, and the lens 2 is polished to a predetermined radius of curvature. It becomes difficult to do so.

Therefore, in order to equalize the amount of polishing compared to the conventional amount of polishing A1, the center axis A-X of the rotation rate dynamic axis 1 of the tool 1 and the state of the upright hairpin 4 (see Fig. 6) 1 and the two lenses 2 Means has been taken to moderately change the angle θ between the optical axis B-B' and the optical axis B-B'. In other words, it utilized the fact that, for example, if j θ is increased, tl>tb, and if j(b)-H-1 θ is decreased, ta <tb.

However, the processing diameter of the lens to be polished is 1, and the radius of curvature is R.
In this case, the half angle (lens half angle) α of the angle of the lens spherical surface viewed from the center of curvature, that is, Sin” (D/2R) is 9
0'' (hemispherical lens), the surface area of the polishing tool and the relative angle θ are subject to geometrical constraints, and the surface area of the tool cannot be made larger than the lens surface area.
Since the tool wears out quickly and the above relative angle θ cannot be made small, t, > tb, and ta and tb
It becomes impossible to make them equal. Therefore, 88Figure 1=
As shown, for example, in the case of a concave lens, the polishing time I: changes in the direction in which the radius of curvature becomes smaller proportionally, and in the case of a convex lens, the opposite 1 changes in the direction in which the radius of curvature becomes larger.

For this reason, conventional tools have the disadvantage that the radius of curvature changes unilaterally, making it impossible to perform machining with a stable radius of curvature.

Purpose of the Invention The present invention provides a polishing/grinding tool with regions with different air vesicle content compositions, thereby making the amount of wear on the polished/grinding surface of the tool uniform over the entire surface. The purpose is to resolve the shortcomings of polishing and grinding tools.

Summary of the Invention The abrasive material in which the abrasive material has different compositions of air cells is arranged in a concentric ring shape 6 around the tool rotation axis; the abrasive material arranged can also be used as a polishing/grinding tool; By changing the area ratio in the radial direction, the abrasion property is changed along the radial direction I:.

The difference in the composition of air spores can be caused by the difference I: in air spore density (number of air spores per unit volume) formed in the abrasive material. It can also occur due to a difference in the volume or shape of air cells contained in a unit volume of the abrasive material.

A region with a different air vesicle content structure is a distribution in which the air spore content structure, such as air vesicle density, air vesicle volume, or shape, changes stepwise in the radial direction around the tool rotation axis, or a continuous C two-dimensional distribution. WIm or has a curved distribution.

Also, for polishing and grinding curved surfaces with special shapes.
For the i'iJ distribution, in addition to the distribution that increases or decreases to a single W4, a distribution that changes in a high-order function having one or more extreme values can also be adopted.

In this way, the distribution of air spores in the regions having different air spore content compositions can be experimentally determined according to the shape of the surface to be processed so that the polished and ground edges are uniform.

EXAMPLES The present invention will be explained below based on illustrated examples. 1st
Figure 1 (Bl is tool 1 showing the first embodiment of the present invention)
A vertical section and a transverse section of 1 are shown, respectively.

This polishing tool 11 has the same external shape and material as the conventional polishing tool, but contains air cells (small circles in the figure) inside. The areas 12, 13 and 14 of the abrasive material have approximately the same volume and different vesicle densities expressed in terms of the number of vesicles per unit volume.
1 is configured.

Regions 12, 13, and 14 are integrally connected in a concentric ring shape around the tool rotation axis 0, and have the relationship 12a > 13m > 14a when the air cell density C of each region is +2a, 13m, and 14a, respectively. . The size of the bubble density affects the size of the polishing area (contact area with the corrugated polishing surface) of the abrasive material, and the amount of wear of the polishing tool can be controlled. That is, 9AFi! which constitutes the center of the polishing surface of the polishing tool 11! At t, 12, the air cell density 1i (is the highest (12a)), so the degree of wear at the upper end is large, and the area 14, which is the polished surface at the periphery, has an air cell density C.
is the minimum (14a), so the degree of wear is small. Therefore, even if the half-angle α of the lens is close to 90°, whereas polishing is a single pyramidal shape with conventional tools, by setting the distribution of the air bubble densities 12a to 14m through experiments, it is possible to polish the peripheral part of the polishing tool 11. It is possible to make Kjtta equal to the amount of wear tb at the center of the tool. Fig. 1 (C1 shows the distribution of the Ailian air encapsulation density C, and the air vesicle density C is expressed as % on the vertical side of the tool of the polishing tool 11.
・Second figure), (B) i1 The vertical cross section and the first horizontal cross section of the research tool showing the second embodiment of the present invention are shown. In this case as well, the fact that there are air cells in the abrasive material that makes up the tool is second to none.
Although the strain is the same as that of the example, in the case of the example, it is caused by the difference in the movement of the air follicles and the volume or shape of each air follicle. 15. Ki 1 + own size in Ken 1 M Li 1 E material differs in size. 16 and 17 constitute a polisher tool, and a filling area 15. lb and ear are integrally attached in a concentric ring shape with the tool rotation axis σ as the center. When the volumes σ of the air cells in the prisons south of 15, 16 and 1 are respectively 1 core a, 1 tia, and 17 a, there is a relationship of 15 a > 16 a > 17 a.

Due to the distribution of the volume C' of the t-vesicles, the upper end surface of the area 15, which is the central part of the polished surface, becomes the most abrasive base, and the upper end surface of the chain acid, which is the peripheral part, is the most abrasive. The size is small. Therefore, with the rice cake shop tool according to the third embodiment as well, it is possible to polish a lens whose half angle α of h/z is close to 90” by appropriately selecting the distribution of the bubble volume σ.

In the first and second embodiments, the air vesicle density C or the air spore volume C' changes stepwise in the radial direction around the construction method rotation axis, but the air spore density C or volume σ is It may be changed continuously and smoothly. 3rd place,
(Fl) and (C) show an example in which the air pore density 2c is continuously changed, and show the distribution of the air pore density C centered on the longitudinal section, cross section, and tool rotation axis σ of the tool, respectively. Example). In this case, since the distribution is continuous, more precise processing is possible.

In the above embodiment, in order to polish a nearly hemispherical lens as a polishing pair, as shown in FIG. 4 (5) and (B), the air cell density C or Although the volume C' of the bubble is increased, when polishing a so-called shallow lens where the half angle of the lens is close to σ, the bubble density C
Or the body of the air sac fi C' (containing composition of the air sac) is the fourth
As shown in Figures (C1 and (Di), a distribution that increases stepwise or continuously in the radial direction is used (fourth embodiment)
.

In the previous examples, the composition of the air vesicles changed monotonically along the radial direction, but due to the constraints of processing conditions such as mechanical conditions, the irregularity of the Newton's ring (NR habit) changed in the radial direction. If it occurs, the composition of the air spores (C
Or c') is radial direction ζ double, as shown in Figure 5, CB+ (: It is possible to set a distribution according to the NR habit in the form of a high-order function with an extreme value of 1 or more ( Fifth Example)
.

In addition, similar effects can be obtained by applying the regions with different bubble content structures described above to a balloon polisher using free abrasive grains such as a polyurethane sheet or a pitch plate (@6 Example).

In the above example, the purpose was polishing, but it can also be applied to a diamond cup grinding wheel in the grinding process of lenses etc. (curve generation process), and it can easily create a spherical surface even for a lens with a large half-angle that is close to a hemisphere. (Seventh Example)

Furthermore, when applied to grinding tools such as metal diamond grindstones and resinoid grindstones, the same effects as in the polishing process can be obtained even in the precision grinding process.

Effects of the invention 1: Even when processing conditions are more restricted such as the shape of the workpiece and general grinding wheels do not wear uniformly in one stroke, it is possible to appropriately adjust the composition of air cells in the grinding wheel. By distributing the grinding wheel, the wear of the grindstone can be made uniform, so that the shape of the polished part of the tool does not change over time, and stable machining with extremely high precision can be performed.

In addition, if a polishing/grinding tool with an appropriate distribution of air vesicle-containing structure (C or C') is prepared in advance for each shape to be machined according to the shape of the workpiece, conventional machining would be difficult. Also for members with shapes that were.

Machining can be performed efficiently in a short period of time simply by changing tools without complicated manipulation of mechanical processing conditions. J

[Brief explanation of the drawing]

11g(n, CB+ is a longitudinal cross-sectional view and a cross-sectional view showing the structure of the abrasive tool of the first embodiment of the present invention, FIG. 1(C) is the abrasive tool shown in FIG. 1(At, (B)im) Radial direction?
= distribution diagram showing the air cell density IC along the 2nd round), old) is a longitudinal cross-sectional view and a cross-sectional view showing the configuration of the polishing tool of the fifth embodiment of the present invention, s3 diagram (Al, (B) , tc) is a longitudinal sectional view showing the configuration of a polishing tool according to a third embodiment of the present invention,
Cross-sectional view and distribution map of air cell charge, Figure 4), T1,
fc), (Dl is a distribution diagram of the bubble-containing structure (C or σ) along the radial direction of the polishing tool of the fourth embodiment of the present invention, and CB+ is the distribution diagram of the bubble-containing structure (C or σ) along the radial direction of the polishing tool of the fourth embodiment of the present invention. A distribution diagram of the air vesicle content structure a (C or σ) of an abrasive tool is shown. In addition, Fig. 6 is a main part configuration diagram showing an example of an abrasive processing machine to which a conventional abrasive tool is applied, and Fig. 7 is a diagram of a conventional abrasive tool. A sectional view of the right half of the polishing tool showing the polishing mode, and FIG. 8 is a characteristic diagram showing the change in tool curvature radius depending on the polishing time of a conventional polishing tool. The details are as follows: 1.11...Grinding L2...Concave lens 3...Lens holding stem 4...Kanzashi 7...・Tool rotation axis 12.13, 14, 15, 16.17... River area 11
314 Fig. 3 1. (B) (C) Fig. 4 Fig. 7 ∆ Fig. 8 vr Koichi effort I Procedural amendment voluntarily) 1985 lθ Month 9, 1988 Patent Application No. 224699 2. Name of the invention Polishing/grinding tool 3. Relationship with the amended person case Patent applicant address 2-43-2 Hatagaya, Shibuya-ku, Tokyo Name (037) Satoshi Shimoyama, President and Director of Olympus Optical Industries Co., Ltd. Part 4, Agent 6, Subject of amendment
. 7. Contents of oil stopper (1) “Part 16 yo” written on page 4 or line 8 of the specification
Part 1b is corrected. (2) The statement from page 4, line 11 of the specification to line 13 of the same page is deleted, and the following statement is added. The same effect can be obtained by applying it to a prepared polishing plate or a balloon polisher, and using free abrasive grains (Sixth Example). Do it.
(Eighth Example). Yo and Ura 1: “I will.

Claims (6)

[Claims] (1) A polishing/grinding tool characterized by using a member that includes regions with different gas vesicle content compositions in the abrasive material and arranges the regions in a concentric ring shape around the tool rotation axis. (2) The polishing/grinding tool according to claim 1, wherein the difference in the composition of the gas vesicles is caused by a difference in the density of the gas sacs formed in the abrasive material. (3) The polishing/grinding tool according to claim 1, wherein the difference in the composition of the gas vesicles is caused by a difference in the volume or shape of the gas sacs formed in the abrasive material. (4) The region having a different gas vesicle content structure has a distribution in which the gas vesicle content structure changes stepwise in the radial direction around the tool rotation axis.
The polishing/grinding tool according to item 2 or 3. (5) The region having a different gas vesicle content structure has a distribution in which the gas vesicle content structure changes continuously in a radial direction centering on the tool rotation axis.
The polishing/grinding tool according to item 2 or 3. (6) The abrasive/grinding tool according to claim 5, wherein the composition of the gas vesicles does not change monotonically, but changes according to a distribution having one or more extreme values.