JP2001150349A - Grinding and polishing wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding and polishing wheel, for preventing flaws and deep cracks from being produced on a workpiece by easily separating abrasive grains. SOLUTION: A solid kneaded material of abrasive grains and bond materials are crushed, the crushed kneaded materials are solidified into a desired shape by being compressed, molded and burnt, and a grinding and polishing wheel is constituted. At this time, the kneaded material is fine crushed into the mean grain diameter of not more than 50 μm. Therefore, pores are generated between the kneaded materials, and abrasive grains are easily separated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding wheel for grinding and polishing, and more particularly, to a grinding wheel for grinding and polishing in which abrasive grains are fixed with a bonding material.

[0002]

2. Description of the Related Art Conventionally, a grindstone for grinding and polishing in which abrasive grains are fixed by a bonding material is disclosed in Japanese Patent Application Laid-Open No. Sho 59-134647.

[0003] The grinding wheel for grinding and polishing is formed by the manufacturing process shown in FIG. In other words, this grinding and polishing whetstone is prepared by dissolving a phenolic resin serving as a bonding material in an organic solvent, adding abrasive particles and a hardening agent, mixing the mixture, and forcibly drying the mixture to form a solid kneading of the abrasive particles and the bonding material. A product is obtained, crushed and solidified by hot pressing.

[0004]

In the above-mentioned conventional grinding and polishing grindstone, a solid kneaded product of a bonding material and abrasive grains is coarsely crushed and solidified. That is, the solid kneaded material was pulverized so as to have a particle size of 2 mm or less. Therefore, when the pulverized kneaded material is solidified, the whetstone 10 is formed in a state in which the kneaded material A having a large particle size and the kneaded material B having a small particle size are mixed in the grindstone 10 as shown in FIG. That is, the solid kneaded material is added to the solution of the bonding material 12 with the abrasive grains 11.
Is obtained by kneading and drying, the solid kneaded material has few pores, and the abrasive grains 11 are firmly held by the bonding material 12.

[0005] For this reason, the abrasive grains 11 held by the small kneaded material B are crushed together with the kneaded material B when a large working resistance is applied to the abrasive grains 11 because the pores 13 exist around the kneaded material B. However, the large kneaded material A is hard to fall off, and when held, the abrasive grains 11 are also firmly held by the bonding material 12. Causes deep scratches. Therefore, when grinding and polishing are performed using the conventional grindstone 10, there is a problem in that the workpiece is scratched and deep cracks are generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to prevent the kneaded material from falling off by minimizing the particle size of the pulverized solid kneaded material comprising abrasive grains and a bonding material before molding. An object of the present invention is to provide a grindstone for grinding and polishing which facilitates and does not have firmly held abrasive grains that cause scratches and deep cracks.

[0007]

Means for Solving the Problems To achieve the above object, the present invention is to pulverize a solid kneaded material comprising abrasive grains and a bonding material according to the purpose of working, and to pulverize the pulverized solid kneaded material. In a grinding / polishing whetstone solidified by being formed into a desired shape and firing, the average particle size of the pulverized solid kneaded material before molding is determined by a laser diffraction / scattering method. Was solidified by using one having a particle size of 50 μm or less.

[0008]

According to the above grinding and polishing whetstone, a portion having a large particle size, that is, a portion in which the abrasive grains are firmly held by the bond material, is contained in the pulverized solid kneaded product of the abrasive grains and the bond material before molding. Since it does not exist, the particle diameter is easily dropped, and the generation of scratches and cracks on the workpiece can be reduced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

[0010]

Embodiment 1 A grinding wheel for grinding and polishing according to Embodiment 1 is
Synthetic diamond (# 2000, average particle size 6.3)
μm) and a phenolic resin as a bonding material. Hereinafter, description will be made with reference to FIGS.

FIG. 1 is a flow chart showing a manufacturing process of the grinding wheel for grinding and polishing according to the first embodiment. An appropriate amount of a phenolic resin to be used as the bonding material 2 is weighed, and an organic solvent is gradually added thereto and completely dissolved with stirring. Next, an appropriate amount of synthetic diamond 1 and a hardener are weighed in advance and uniformly mixed with the solution. Then, the kneaded material is placed in a drying furnace and heated to evaporate and remove the organic solvent, followed by forced drying.
As a result, a solid kneaded mass is obtained. This lump is crushed by a cutter mixer to a particle size of about 900 μm.
Further, the coarsely crushed powder is finely pulverized by a wet hole mill using zirconia balls having a diameter of 7 mm to reduce the average particle diameter to 50 μm or less as shown in FIG. Then, the finely pulverized solid kneaded material is cold-compressed under desired conditions, and
By firing at 50 ° C., the grinding and polishing grindstone of the first embodiment is obtained.

According to the grinding / polishing whetstone of the first embodiment, the solid kneaded material before cold compression and firing is finely pulverized to an average particle size of 50 μm or less. Since the portion where the abrasive grains 1 are firmly held by the bond material, that is, the bond material 2, does not exist in the grindstone, the abrasive grains 1
Can easily fall off, and the occurrence of deep cracks in the workpiece can be reduced.

Next, in order to compare and evaluate the grinding / polishing grindstone of the first embodiment, the grinding / grinding grindstone having a different particle size is omitted by omitting or performing the fine grinding step in the manufacturing process in a short time. Was formed, and when the optical glass BSL7 was ground using this grinding and polishing whetstone and the case of the present embodiment, the crack depth generated in the workpiece was measured. The average particle size of the kneaded material is measured by a laser diffraction / scattering method, and the crack depth is determined by polishing the ground surface after grinding, and the amount of shaving until cracks generated by grinding cannot be observed. Substitution was measured. Table 1 shows the measurement results, and FIG. 3 is a graph showing the relationship between the average particle size of the kneaded material and the crack depth.

[0014]

[Table 1]

As shown in Table 1 and FIG. 3, the crack depth decreases until the average particle size of the kneaded material reaches 50 μm, but when the average particle size is smaller than 50 μm, the rate of the decrease becomes small. You can see that. From this, it can be seen that according to the grinding and polishing whetstone of the first embodiment, when the kneaded body is finely pulverized to 50 μm or less, the grinding and polishing can be realized with a small crack depth.

[0016]

Embodiment 2 A grinding wheel for grinding and polishing according to Embodiment 2 is
Cerium oxide (average particle size: 1.6 μm) was used for the abrasive grains, and polyimide resin was used for the bonding material. Hereinafter, description will be made with reference to FIG. 2 and FIGS. 4 to 6. FIG. 4 is a flowchart showing a manufacturing process of the grinding and polishing grindstone of the second embodiment.

An appropriate amount of the polyimide resin as the bonding material 2 is weighed, and an organic solvent is gradually added thereto and completely dissolved with stirring. Next, cerium oxide 1 weighed in advance in an appropriate amount is added to this solution and mixed uniformly. Then, as shown in FIG. 5, the liquid kneaded material 3 is sprayed into an air tank 5 heated by a heater 4 by a spraying device 6 and forcedly dried. The powder 7 having an average particle diameter of about 550 μm obtained here is finely pulverized by a wet ball mill using zirconium balls of φ5 mm to reduce the kneaded body to an average particle diameter of 50 μm or less. Then, the finely pulverized material is cold-compressed and baked at 200 ° C. to obtain a grinding wheel for grinding and polishing according to the second embodiment.

According to the grinding and polishing whetstone of the second embodiment, the solid kneaded material before cold compression and firing is finely pulverized to an average particle size of 50 μm or less. Similarly, since there is no portion in the grindstone where the holding force of the abrasive grains is strong, the workpiece is not scratched.

Next, in order to compare and evaluate the grinding / polishing grindstone of the second embodiment, the grinding / grinding grindstone having different particle sizes is omitted by omitting the fine pulverizing step in the manufacturing process or performing it in a short time. Was formed, and the appearance pass rate when the optical glass PBH6 was polished using this grindstone and the grindstone for grinding and polishing the present paper was evaluated. Here, the index of the appearance pass is a level at which the lens is visually observed with a 60 W incandescent lamp after double-side polishing, and no scratches more than scratches are visually observed. Also, the term “scratch” refers to an extremely thin scratch that is visible or invisible when the lens is turned (Optical Component Processing Glossary, published by the Optical Industrial Technology Association). The average particle size of the kneaded material was measured by a laser diffraction / scattering method, and the appearance inspection was visually performed as described above. Table 2 shows the appearance pass rate, and FIG. 6 is a graph showing the relationship between the average particle size of the kneaded material and the appearance pass rate.

[0020]

[Table 2]

As shown in Table 2 and FIG.
It can be seen that the appearance pass rate increases up to 0 μm, but the rate of increase becomes small when the average particle size is smaller than 50 μm. This indicates that the grinding wheel for grinding and polishing according to the second embodiment can achieve high appearance quality.

[0022]

As described above, according to the present invention, the kneaded material having an average particle size of 50 μm or less is used.
Abrasive grains easily fall off, and it is possible to reduce the crack depth generated in the workpiece in the grinding process and to improve the appearance quality of the workpiece in the polishing process.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a process of manufacturing a grinding wheel for grinding and polishing according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a unit of a finely ground kneaded material in each embodiment of the present invention.

FIG. 3 is a graph showing a relationship between an average particle size of a kneaded material and a crack depth generated in a workpiece.

FIG. 4 is a flowchart showing a process of manufacturing a grinding wheel for grinding and polishing according to a second embodiment of the present invention.

FIG. 5 is a schematic view showing an apparatus for forcibly drying a liquid kneaded material when manufacturing a grinding and polishing grindstone according to a second embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the average particle size of the kneaded material and the appearance pass rate of the workpiece.

FIG. 7 is a flowchart showing a manufacturing process of a conventional grinding / polishing whetstone.

FIG. 8 is a cross-sectional view showing a conventional grindstone for grinding and polishing.

[Explanation of symbols]

 1 abrasive grains 2 bond material 3 liquid kneaded material

Claims (1)

[Claims] 1. A solid kneaded product of abrasive grains and a bonding material is pulverized, and the pulverized solid kneaded material is formed into a desired shape and fired to be solidified, and the abrasive particles are fixed with the bonding material. When the average particle size of the crushed solid kneaded material before molding is 5 measured by a laser diffraction / scattering method in the crushed grinding / polishing whetstone before molding.
A grinding wheel for grinding and polishing, which is not more than 0 μm.