JPH05293762A - Precision grinding polishing wheel - Google Patents

Abstract

PURPOSE:To provide a precision grinding polishing wheel which performs precision processing without forming a deep flaw. CONSTITUTION:Diamond grinding grains with a grain size of #1000 being a grinding grain and having Moh's hardness of 10 are used for grinding grains 1. A white alundum(WA) grinding grains with a grain size of #250 having hardness lower than that of the diamond grinding grains and Moh's hardness of 9.2-9.6 are used for a brittle powdery material 2. Phenol resin is used as binder 3 to constitute a precision grinding polishing wheel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision grinding and polishing whetstone in which abrasive grains are fixed with a binder.

[0002]

2. Description of the Related Art As a grindstone for precision grinding and polishing, which gives an excellent processing ability and a highly accurate finished surface, for example, Japanese Patent Publication No.
The one disclosed in Japanese Laid-Open Patent Publication No. 2-3148 is known.
That is, as shown in FIG. 3, this kind of precision grinding / polishing grindstone comprises abrasive grains 4 and an elastic composite abrasive grain mass that is fixed to a rubber-like elastic body particle 5 coarser than the abrasive grain 4 with a resin adhesive 6. , A structure having a structure that is formed by mutual bonding so as to have pores.

In the grindstone constructed as described above, the composite abrasive grain agglomerates act like coarse abrasive grains on a rough processed surface, exhibit a large grinding force, and at the same time avoid unnecessary wear of the grindstone. Since rubber-like elastic particles do not have bulk elasticity, they act like a rigid body against a large force. On the other hand, on the precision processed surface, the cushioning action by the deformation of the rubber-like elastic particles does not cause deep scratches, and a uniform finished surface and an elegant luster can be obtained. Since such deformation of the rubber-like elastic body is made possible by the existence of pores, the pores are indispensable in this kind of grinding and polishing grindstone.

[0004]

However, the above-mentioned conventional technique has the following problems. That is, when the grindstone was separated from the composite agglomerate by the grinding resistance generated during the grinding process, the rubber-like elastic body particles that were the core of the composite agglomerate protruding on the surface did not have the grinding and polishing ability.

The present invention has been made in view of the above-mentioned problems of the prior art, and the precision grinding and polishing having the grinding / polishing ability on the core of the complex grindstone while maintaining the effect of not giving the deep scratches of the prior art. The purpose is to provide a whetstone.

[0006]

A precision grinding / polishing grindstone of the present invention comprises abrasive grains, a brittle powder having a hardness lower than that of the abrasive grains, and a binder, and the abrasive grains are bonded to the brittle powder. It was decided that the composite abrasive grain lumps fixed by the agent had a bond-formed structure.

[0007]

According to the above-described precision grinding / polishing grindstone, the brittle powder is used as the core of the composite abrasive grains, so that the grinding / polishing action on the work can be achieved. Further, since the hardness of the brittle powder is set to be smaller than that of the abrasive grains, the surface to be processed is not deeply scratched by the abrasive grains. Further, even when a load larger than necessary is applied due to processing vibration or the like, the brittle powder is crushed to cause a buffering action, so that a deep scratch is not given to the surface to be processed. Moreover, it can be easily manufactured by known grinding and polishing whetstone manufacturing technology. For example, if abrasive grains coated with a binder are adhered and fixed to brittle powder, a complex abrasive grain mass is obtained. It can be easily manufactured by molding and firing according to the manufacturing method of the grindstone.

[0008]

[Embodiment 1] FIG. 1 is a cross-sectional view of a main part of a grinding and polishing grindstone of the present embodiment. Abrasive grain 1 has a grain size of # 100 as a grinding grain.
0 diamond abrasive grains (Mohs hardness 10) were used, and the brittle powder 2 had a particle size # smaller than the diamond abrasive grains.
250 white alundum (WA) abrasive grains (Mohs hardness 9.2 to 9.6) were used, and the binder 3 was manufactured using a phenol resin.

Next, the method of manufacturing the grindstone of this embodiment will be described. First, a solution of a phenol resin dissolved in acetone and white random abrasive grains of particle size # 250 are mixed,
Acetone is volatilized by heat drying. Next, the obtained dried product is pulverized to obtain a white random abrasive brittle powder coated with a phenol resin. White random abrasive brittle powder coated with phenolic resin and particle size # 10
00 diamond abrasive grains are mixed, compression-molded, and fired to obtain a desired grinding wheel.

Table 1 shows the results of comparison between the grinding wheel of the present embodiment manufactured as described above and the conventional grinding wheel using the rubber-like elastic body in the precision grinding of the glass lens. Regarding the processing capacity, the grinding amount per minute (μm / mi
n), and the deep scratch was evaluated by the processed surface roughness (Rmax / min) of the finished surface of the work piece.

[0011]

[Table 1]

From the results shown in Table 1, the grinding wheel of this embodiment has an improved grinding ability as compared with the conventional grinding wheel, and the machined surface roughness of the object to be ground is almost the same as the conventional machined surface roughness. Therefore, it was found that there is also an effect that deep scratches do not occur.

In this embodiment, the phenol resin is used as the binder, but other resin binders, metal binders, and vitrified binders can be used depending on the characteristics of the workpiece. Also, diamond abrasive grains were used as abrasive grains, but CB
Grinding abrasive grains represented by N, boron nitride, and silicon carbide can be used. Although white random abrasive grains were used as the brittle powder, other brittle powder having a hardness smaller than that of the abrasive grains can be used.

[0014]

[Embodiment 2] The grinding / polishing grindstone of this embodiment is the same as the embodiment 1 described above.
Since the materials are different, but the structures are the same, the description will be given with reference to FIG. 1 described above and based on FIG. A cerium oxide-based grinding grain (Mohs hardness 6) having an average grain size of 1.5 μm was used as the grain 1, and the average grain size was 0.5 in the core of the mass of the composite grain.
A brittle powder 2 obtained by sintering an aggregate of zinc oxide (Mohs hardness 5) having a size of 700 μm at 700 ° C. and crushing the obtained sintered product to have a particle size of # 600 (average particle size of 31 to 26 μm) The binder 3 was manufactured using a phenol resin.

In the grinding wheel of this example, mirror polishing can be performed by using cerium oxide-based polishing particles as polishing particles. Further, the brittle powder has a polishing ability because it is a sintered body of zinc oxide having a hardness smaller than that of the cerium oxide-based polishing abrasive grain, which is an abrasive grain. Despite its large diameter, it has the effect of preventing deep scratches.

In this embodiment, cerium oxide-based abrasive grains are used as the abrasive grains, but abrasive grains represented by zirconium oxide, red iron oxide, chromium oxide, and magnesium oxide can be used. A zinc oxide sintered body was used as the brittle powder, but a brittle powder having a hardness smaller than that of the abrasive grains can be used.

[0017]

[Embodiment 3] The grinding / polishing grindstone of this embodiment is the same as that of the above-mentioned Embodiment 1.
Since the materials are different, but the structures are the same, the description will be given with reference to FIG. 1 described above and based on FIG. A zirconium oxide-based grinding grain having an average grain size of 0.5 μm (Mohs hardness of 6 to 6.5) is used as the grain 1, and the brittle powder 2 has a grain size of # 600 (average grain size of 31 to 26 μm). The barium carbonate crystal (Mohs hardness 3) in (1) was used, and the binder 3 was manufactured using a polyvinyl alcohol resin.

In the grinding wheel of this example, the zirconium oxide-based abrasive grains, which are abrasive grains, were used as the abrasive grains, which enabled ultra-precision mirror polishing. Further, since the brittle powder is barium carbonate, which has a hardness smaller than that of the abrasive grains, it has polishing ability, and due to the buffering action shown in FIG. 2, deep scratches may occur even though the grain size is large. There is no effect. In addition, barium carbonate has a mechanochemical action on the Si component in the glass, and therefore is more effective in the polishing ability and the accuracy of the surface roughness of the workpiece than the brittle powder having no mechanochemical action.

[0016]

As described above, according to the precision grinding / polishing grindstone of the present invention, the brittle powder is used as the core of the composite abrasive grain agglomerates.
There is an effect that it is possible to obtain a precision grinding and polishing whetstone which does not give a deep scratch to the surface to be processed and in which the nucleus of the complex abrasive grain has grinding and polishing ability.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a precision grinding / polishing grindstone according to a first embodiment of the present invention.

FIG. 2 is a working state diagram of a precision grinding / polishing grindstone according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a conventional precision grinding wheel.

[Explanation of symbols]

 1 Abrasive grain 2 Brittle powder 3 Binder

Claims (1)

[Claims] 1. A precision grinding / polishing grindstone, which comprises abrasive grains, brittle powder having a hardness smaller than that of the abrasive grains, and a binder, and the abrasive grains are fixed to the brittle powder with the binder. A precision grinding and polishing whetstone having a structure in which composite abrasive particles are bonded and molded.