JPH01188263A - Grindstone polisher for mirror grinding - Google Patents

Abstract

PURPOSE:To improve the working performance by using a lapping machine and a polisher by reducing the elastic modulus of a deformable elastic particle in comparison with that of a binder and increasing the particle diameter than the dimension of abrasive grains. CONSTITUTION:In the high load.low speed working, a pressure acting onto an elastic particle 3 increases, are said elastic particle 3 is deformed, and a workpiece and a grindstone matrix directly contact, and the grinding resistance which acts onto an individual abrasive grain 1 increases excessively, and the self dressing is accelerated. Therefore, the clogging of a grindstone is prevented, and a material can be lapping-worked efficiently. In the low load.high speed working, the deformation of the elastic particle 3 is reduced, and the workpiece and the grindstone particle do not contact directly, and mirror like surface working is carried out by the polishing action of the abrasive grains 1 embedded into the surface of the elastic particle 3. Therefore, all the works ranging from the lapping work to the mirror grinding can be carried out by one grindstone polisher, and clogging of the grindstone is prevented, and efficient work is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grindstone polisher for mirror finishing used for lapping and boring.

[Prior Art] Generally, when obtaining a mirror surface, a lapping process is performed, followed by a boring process. In this case, in the boring process, since an elastic polisher is used, a reduction in surface accuracy (surface sagging) such as rounded edges of the surface becomes a problem. Therefore, the wrapping process, which is the pre-processing process, is usually performed in the fourth process.
As shown in the figure, in a grinding wheel containing abrasive grains 21 dispersed in a matrix 22 of resin binder, the abrasive grains are divided into several stages from coarse grains to fine grains to reduce the removal allowance for boring as much as possible and prevent surface sagging. Measures are taken to prevent it.

[Problems to be Solved by the Invention] However, the above-mentioned finishing methods of lapping and boring in several steps significantly reduce processing efficiency and workability, and are a contributing factor to increased processing costs for mirror finishing. There is.

In view of the above-mentioned drawbacks, the technical problem of the present invention is to use the present invention as a polisher in lapping and borizing to enable processing from lapping to mirror finishing with high efficiency and no surface roughening. An object of the present invention is to provide a grindstone polisher for mirror finishing.

[Means for Solving the Problems] According to the present invention, abrasive grains that grind the surface to be machined, elastic grains that deform in response to pressure from the surface to be machined, and the surface are worn out as chips move. a resin-based binder, and the abrasive grains and elastic grains are scattered on the surface and inside of the binder,
These elastic grains have a smaller elastic modulus than the binder and a larger grain size than the abrasive grains, and these elastic grains can be used as a grinding wheel polisher for mirror finishing, which is characterized by adjusting the contact of the abrasive grains with the workpiece surface. It will be done.

Here, the polisher for mirror finishing of the present invention is used.

In this method, if the abrasive grains are formed into a flat surface by truing in advance, the elastic grains will be in a state of being raised in billions in so-called self-dressing, in which the micro-destruction of the abrasive grains 1 and the removal of the binder by the chips occur. As shown in Figure 1, high load,
During low-speed machining, the pressure acting on the elastic grains 3 is large, so that the elastic grains 3 are deformed and the workpiece and the grinding wheel matrix 2 come into direct contact. Furthermore, due to low-speed machining, the grinding resistance acting on each abrasive grain 1 becomes excessive and self-dressing is promoted, so material removal is performed efficiently without clogging the grindstone. Furthermore, as shown in FIG. 2, during low-load, high-speed machining, the deformation of the elastic grains is small, so the workpiece and the grinding wheel matrix 2 do not come into direct contact, and the abrasive grains 1 embedded in the surface of the elastic grains 3 A mirror surface is obtained by the borizing effect. Therefore, according to the present invention, it is possible to perform from semi-finishing to mirror polishing with one grindstone polisher, and it is possible to perform processing with less clogging and high processing efficiency.As the binder of the present invention, conventional phenolic Although epoxy, polyvinyl, and epoxy resins can be used, cashew-modified phenolic resin (manufactured by Tohoku Kako Co., Ltd.) has better self-dressing properties and is therefore preferable. As the abrasive grains of the present invention, diamond, alumina, GC, etc. can be used in addition to cerium oxide.

In addition to PVA, the elastic particles of the present invention include natural rubber, synthetic rubber,
The same material, such as PVA and softened PVA, can be used as long as it has a lower elastic modulus than the binder, such as wax or pitch.

[Example] Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the surface condition of a polisher for mirror finishing according to an embodiment of the present invention during high load and low speed machining. In this figure, the polisher for mirror finishing includes abrasive grains 1 and elastic grains 2 having a larger grain size than the abrasive grains 1 in its binder 3. Due to the high load, the elastic grains 2 are deformed and pressed into the binder from the surface, so that only abrasive grains are scattered on the surface of the mirror polisher.

FIG. 2 shows the surface condition of the polisher for mirror finishing according to the embodiment of the present invention during low-load, high-speed processing. In this figure, since the polisher for mirror finishing has a low load, the elastic grains 2 protrude from the surface.

FIG. 3 shows the relationship between machining allowance and machining time of the grindstone polisher for mirror polishing according to the embodiment of the present invention. In this figure, curve 11 is the machining allowance for a machining time of 10 minutes, and curve 12 is the machining allowance for 10 minutes.
The processing tool used for this measurement, which shows the change in machining allowance over 20 minutes, was a lap master one-type lapping machine, and the grinding wheel polisher for mirror finishing was an elastic grinding wheel (Tohoku Co., Ltd.) with a binder made of cashew-modified phenolic resin. (manufactured by Kako Co., Ltd.) was used. The abrasive grains of this grindstone were made of cerium oxide with an average grain size of 2 μm, and the elastic grains were made of PVA and had an average grain size of 10 μm.

The machining conditions were as follows: using a surface plate with an outer diameter of 30 cn, the rotation speed was initially 60 rpm and the load was 2000 r/-, and midway (after 10 minutes), the rotation speed of the surface plate was increased from 60 rpm to 300 ron.
At the same time, the load was changed from 600 gr/d to 100 gr/ci, and the flatness of the surface plate was adjusted using a correction ring for 20 minutes. The outer diameter of the lapping workpiece is 20
A glass plate (BK7) of II11 and a thickness of 5111 m was used.

For comparison, commercially available abrasive grains with an average particle size of 2 μl are used.
An elastic whetstone containing cerium and having a binder of polyurethane was used.

The processing conditions were to use a surface plate (grinding wheel) with an outer diameter of 30C1, a rotation speed of 60 rpm, a load of 200 gr/-, the flatness of the surface plate was adjusted in advance with a correction ring, an outer diameter of 201111, and a thickness of 511.
The glass No. 1 (BK7) was wrapped for 20 minutes.

The zero curve 30, the result of which is shown in FIG. 5, shows the change in machining allowance over 20 minutes.

Comparing the roughness of the finished surface obtained as shown in Fig. 3 and Fig. 5, the finished surface roughness of the workpiece by the grinding wheel polisher of the example is much more than the average roughness of 0.2 μl of the conventional grinding wheel. The average roughness is 0.03 μl. Also, at this time, the machining speed (lapping rate) is also the average machining rate of the conventional grindstone: 0, 25. It can be seen that the distance in the example is 0.5 μll/ll1n, which is twice as far as tl/nin.

In order to further clarify the polisher characteristics of the grinding wheel according to the present invention, an example was prepared in which a cashew-modified resin having the same components as the grinding wheel polisher of the example was processed under the same conditions as the above-mentioned example without dispersing the elastic resin branch number. As shown in Figure 6, the result is curve 3 in Figure 6.
1. As shown by curve 32, the processing speed (lapping rate) is a little faster at 0.6μII/1in,
It was confirmed that the surface roughness was as rough as an average roughness of 0.1 μm, which was significantly inferior to the surface finished by the grindstone polisher of the example.

Here, the machining allowance refers to the amount of reduction (μm) due to lapping in the direction perpendicular to the surface of the workpiece.

[Effects of the Invention] As described above, according to the present invention, there is no need to replace the grindstone in multiple stages during the intermediate finishing of the lapping process.
A grindstone polisher for mirror finishing with good workability can be obtained, which can be used as a lap as it is, and can also be used as a polisher during boring.

According to the present invention, due to the inherent properties of the binder, there is extremely little clogging during lapping processing, no sagging of the surface to be processed occurs, and the number of times of dressing can be reduced.

Furthermore, according to the present invention, the machining speed of the workpiece surface is high during lapping processing, and the elastic grains in the grindstone matrix make it possible to obtain a precise workpiece surface, that is, a mirror surface, with a small machining allowance during boring. A grindstone polisher for mirror finishing with good processing efficiency can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the surface condition of the grinding wheel polisher for mirror finishing according to the present invention under high load and low speed rotation, and Fig. 2 is an explanatory diagram of the surface condition of the grinding wheel polisher for mirror finishing according to the present invention under low load and high speed rotation. An explanatory diagram is shown. FIG. 3 is a diagram showing the relationship between machining time and machining allowance using an elastic grindstone according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a conventional elastic grindstone. FIG. 5 is a diagram showing the relationship between machining time and machining allowance using an elastic grindstone according to a conventional example. FIG. 6 shows the relationship between machining time and machining allowance using a conventional grindstone for cashew modified resin bond. 1 is an abrasive grain, 2 is a binder, and 3 is an elastic grain. Figure 1 Figure 2 Figure 4 F1 Figure 3 ε Processing time Figure 5 ε Processing time Figure 6 ε Processing time

Claims (1)

[Claims] 1. Abrasive grains for grinding a processed surface, deformable elastic grains,
The elastic grains are mixed with an abradable binder, and the elastic grains have a smaller elastic modulus than the binder and a grain size larger than the abrasive grains, and adjust the contact of the abrasive grains to the workpiece surface. A unique grindstone polisher for mirror finishing. 2. The grindstone polisher for mirror finishing as set forth in claim 1, wherein the binder is a cashew-modified phenolic resin. 3. A grindstone polisher for mirror finishing as set forth in claim 1 or 2, wherein the abrasive grains are made of cerium oxide. 4. A grindstone polisher for mirror finishing as set forth in any one of claims 1 to 3, wherein the elastic grains are made of polyvinyl alcohol resin.