JPH01115575A - Lapping grinding wheel - Google Patents

Abstract

PURPOSE:To enable repetitive mirror surface working without loading by molding and baking a granular whetstones consisting of fine grain whetstones bound by first relatively hard bond together with second soft bond. CONSTITUTION:Granular whetstones are prepared by binding fine grain whetstones with first bond consisting of first resin such as relatively hard phenole system or epoxy system resin. Next, these granular whetstones are molded and baked by the use of second perforated elastic bond consisting of second resin such as urethane system resin softer than the first resin to provide a desired lapping grinding wheel. This grinding wheel does not vary the working amount (lapping rate) even after continuous lot working to enable repetitive mirror surface working without loading.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a lap grindstone, and more particularly to a lap grindstone for mirror finishing.

[Prior Art] Generally, this type of lap grinding wheel is manufactured by bonding fine grain grinding wheels together with a bond, but conventionally, only one type of bond has been used for bonding the fine grain grinding wheels together. For example, phenolic resin or epoxy resin is used for this bond.

[Problem to be solved by the invention 1 However, in the case of lap grindstones using phenolic resin or epoxy resin as bond, clogging occurs easily during use.The reason for this is the unevenness of the blade that acts on grinding. Since there are few holes and the holes are small, there is no way for Kiri to escape.
This is because it is difficult for the cooling water to sufficiently penetrate around the grindstone.

An object of the present invention is to provide a lap grindstone that can repeatedly perform mirror polishing without clogging.

[Means for Solving the Problems] The lap grindstone according to the present invention is obtained by bonding a fine grain grindstone using a first bond made of a relatively hard first resin such as a phenolic resin or an epoxy resin. The resulting granular grindstone is molded and fired using a second bond made of a second resin, such as a urethane resin, which is softer than the first resin.

[Function] In the present invention, two types of bonds, hard and soft, are used in one lap grindstone. First, a particulate grindstone is bonded with a first bond made of a relatively hard first resin such as a phenolic resin or an epoxy resin to produce a granular grindstone. This manufacturing method involves making a whetstone using a normal whetstone manufacturing method, crushing this whetstone and passing it through a sieve to make granules. Using the second bond made of the resin No. 2, a lap whetstone is further manufactured in the same manner as a normal whetstone.

-a, in the case of phenolic resin or epoxy resin bonds, it is fired at about 200°C, and in the case of urethane resin bonds, it is processed at a lower temperature of about 150°C, so in the latter process, the first The resin will not change in quality.

A lap grindstone with such a configuration is made of urethane resin (PV
The porosity and elasticity of the bond in A) compensates for the lack of porosity and rigidity of grinding wheels that use only phenolic resin or epoxy resin bonds, and allows repeated mirror polishing without clogging without a dresser. . Here, the finished surface of the workpiece is determined by the grain size of the fine grain grindstone, and has little effect on the size of the granules.

[Example] Examples of the present invention will be described below.

Cerium oxide with an average particle size of 2 μm is used as a fine-grain grindstone, and after uniformly coating this cerium oxide with phenol resin as the first resin, it is granulated to a diameter of 0.1 to 0.5 and fired. A granular whetstone was obtained.

This granular whetstone was bonded with polyvinyl alcohol (PVA), which is a urethane resin as a second resin, to produce a lap whetstone having an outer diameter of 300mm and a thickness of 15mm. This lap grinding wheel was used in the well-known Lap Master type single-sided lap surface plate.

The present inventor has compared the grinding and lapping process between this lap whetstone and a conventional lap whetstone manufactured by a well-known method using the same fine-grain whetstone and the same abrasive grain ratio and using phenolic resin as a bond. The test was conducted. Here, as the lapping processing conditions, glass (BK-7> is used as the workpiece, and the number of rotations of the surface plate (lap grindstone) is 100 r, p, i.
,,The load was 600 gr/-1 and only water was dropped and processed. As the workpiece, a glass plate having a size of φ10 x t5 is used, and as shown in FIG. 1, four of the glass plates 1 are pasted radially on a mounting table and weight 2 with an adhesive 3.

The amount of processing was determined by measuring the wear of the glass plate 1 using the surface of the attachment table and weight 2 as a reference.

As a test piece (glass plate 1), 50 pieces (4X5=2
0 pieces) were used. The specimens were pre-processed using GC' 200(1) free abrasive.

Figure 2 shows the test results. In the figure, the solid line denoted by 4 represents the amount of machining using the lap grindstone of the present invention, and the broken line denoted by 5 represents the amount of machining using the conventional lap whetstone. As is clear from FIG. 2, the amount of processing (lapping rate) of the lapping grindstone of the present invention does not change even after 50 continuous processings, that is, no clogging occurs. On the other hand, with the conventional lap grindstone, the amount of machining gradually decreases after 20 points, indicating that the grindstone is becoming clogged. In addition, the surface roughness Ra of the machined surfaces is 0.02.
A material with a surface of less than μ was obtained.

In addition, in the above embodiment, a phenol resin is used as the first resin, but an epoxy resin may also be used.

[Effects of the Invention] As is clear from the above explanation, the present invention has the effect of repeatedly performing mirror finishing without clogging.

[Brief explanation of the drawing]

Figure 1 is a diagram showing how to hold a sample (workpiece 'h>) when lapped using the present invention and a conventional lapping grindstone, and Figure 2 is a sample held in the state shown in Figure 1. The cumulative machining time (minutes) and the machining amount of each rod (μ
) is a diagram showing the relationship between 1... Workpiece (glass plate), 2... Pasting stand and weight,
3... Adhesive, 4... Processing amount using the lap grindstone of the present invention, 5... Processing amount using the conventional lap grindstone. Figure 1 Figure 2 Sheet processing inspection

Claims (1)

[Scope of Claims] 1. A granular grindstone obtained by bonding a fine-grain grindstone using a first bond made of a relatively hard first resin is bonded to a second resin that is softer than the first resin. A lap whetstone formed by molding and firing using a second bond consisting of. 2. The lap grindstone according to claim 1, wherein the first resin is a phenolic resin and the second resin is a urethane resin. 3. The lap grindstone according to claim 1, wherein the first resin is an epoxy resin and the second resin is a urethane resin.