JPH04269172A - Resin bond super abrasive grain grinding wheel - Google Patents

Abstract

PURPOSE:To improve the abrasive grain holding force of a resin bond and to prevent a super abrasive grain from falling at grinding time, in a resin bond super abrasive grain grinding wheel. CONSTITUTION:A resin bond super abrasive grain grinding wheel 10 is made with a coating super abrasive grain 14 that is a CBN grain or diamond grain 11 being coated by a hard resin and a soft resin particle 16 which is made by granulating a soft resin, being mixed/pressurizing sintered.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention relates to a resin-bonded superabrasive grindstone made of CBN grains or diamond grains hardened with a resin bond (binding material).

0002

[Prior Art] Grinding wheels using CBN (cubic boron nitride) grains or diamond grains as superabrasive grains have been known for a long time, and CBN grinding wheels using CBN grains are mainly used for metal processing and Diamond grinding wheels are mainly used for ceramic processing. These grindstones differ depending on the type of bond (binding material) that hardens the superabrasive grains.
It is classified into three types: metal bond whetstone, resin bond whetstone, and vitrified bond whetstone, but generally resin (
Resin-bonded whetstones using resin) are most commonly used.

[0003] A resin bond grinding wheel generally has a structure as shown in FIG. Retained. Note that the Ni coating layer 2
This is for improving the adhesion between the superabrasive grains 1 and the resin bond 3, and is not necessarily necessary.

The performance of such a resin bonded grinding wheel depends on the abrasive grain holding power of the resin bond 3, and the problem is whether the superabrasive grains 1 coated with the Ni coating layer 2 are difficult to fall off during grinding. Therefore, various resin-bonded superabrasive grindstones have been studied that increase the abrasive-holding power of the resin bond and suppress the shedding of the abrasive grains.

Conventionally, as shown in FIG. 3, after a Ni coating layer 2 is applied to the superabrasive grains 1, a hard resin layer 4 containing a large amount of SiC, for example, and a normal soft resin layer 5 are further applied around the hard resin layer 4. are coated to form coated superabrasive grains 6 (FIG. 3(A)), and the coated superabrasive grains 6 are filled and assembled in a mold 7 (FIG. 3(B)), and the resin is fired by applying a predetermined load. A bonded superabrasive grinding wheel 8 (FIG. 3(C)) is being considered.

[0006]

[Problems to be Solved by the Invention] As mentioned above, when the coated superabrasive grains 6 in which the superabrasive grains 1 are coated with two or more different types of resin layers are assembled and fired, the result shown in FIG. 3(C) As shown, in the resin-bonded superabrasive grinding wheel 8, the boundary between the hard resin and the soft resin becomes ambiguous, and the problem arises that the abrasive grain retention, which is the effect of the hard resin layer 4 coated on the inside, cannot be obtained sufficiently. be.

[0007] In view of the above circumstances, an object of the present invention is to provide a resin bonded superabrasive grindstone having a sufficiently large abrasive grain retention force.

[0008]

[Means for Solving the Problems] A resin bonded superabrasive grinding wheel according to the present invention that achieves the above object is a resin bonded superabrasive grinding wheel in which CBN grains or diamond grains are interspersed in a resin bond. It is characterized by being made by mixing coated superabrasive particles or diamond particles coated with hard resin and soft resin particles obtained by granulating soft resin and firing them under pressure.

[0009]

[Function] When coated superabrasive grains having a hard resin layer and soft resin particles made of soft resin are mixed and fired, they are combined with the soft resin particles inserted between the coated superabrasive grains, so the resin melts. The distance traveled by the superabrasive grains in this state is small, and the resin-bonded superabrasive grindstone has a hard resin layer retained around the superabrasive grains.

0010

EXAMPLES The present invention will be explained below based on examples.

FIG. 1 is an explanatory diagram showing a resin bonded superabrasive grindstone according to one embodiment. As shown in FIG. 1(A), in the resin bonded superabrasive grindstone 10 of this example, CB
The superabrasive grains 11 made of N grains or diamond grains are coated with a metal coating layer 12 such as nickel and a hard resin layer 13.
The coated superabrasive grains 14 are dispersed and bonded by soft resin bonds 15.

In order to manufacture this resin-bonded superabrasive grinding wheel 10, first, the superabrasive grains 11 made of, for example, CBN abrasive grains are coated with a metal coating layer 12, and then a hard resin layer 13 is coated to form a coating superabrasive. Abrasive grains 14 are formed (FIG. 1(B)). Here, the hard resin layer 13 is made by adding hard particles to a resin such as phenol resin, epoxy resin, or polyimide resin to improve wear resistance.
Examples include ceramic powders such as 3N4, B4C, WC, and TiN, CBN powder, and diamond powder. In this embodiment, the hard resin layer 13 was made of hard resin containing 20 vol% of SiC. Separately, a soft resin containing 8 vol% of SiC is granulated to form soft resin particles 16 (FIG. 1(B)). Then, the coated superabrasive grains 14 and soft resin particles 16 thus formed are mixed and filled into a mold 17, and fired by applying a predetermined load (FIG. 1(C)) to obtain a concentration level of 1.
The resin bonded superabrasive grindstone 10 has a grain size of 0.00 and a grain size of 140.

In the resin bonded superabrasive grinding wheel 10 manufactured in this manner, the soft resin particles 16 enter between the coated superabrasive grains 14 during mixing and aggregation, and the coated superabrasive grains 14 are bonded in a molten state during firing. There is not much movement, and the hard resin layer 13 and the soft resin particles 16 hardly mix, and the soft resin particles 16 form the soft resin bond 15. Therefore, the hard resin layer 13 is maintained around the superabrasive grains 11 after firing, and its abrasive grain retention ability is fully exhibited. Incidentally, when a hard resin layer and a soft resin layer are formed on superabrasive grains as explained in the prior art section, the particles become large and the gaps during aggregation are large, causing the abrasive grains to move in the molten state of the resin during firing. It is thought that the distance becomes larger. Therefore, it is considered that the resin bond is a mixture of the hard resin layer and the soft resin layer, resulting in a decrease in abrasive grain retention.

[0014]

As explained above, the resin-bonded superabrasive grinding wheel of the present invention has a large abrasive retention force because the superabrasive grains having a hard resin layer are bonded with a soft resin bond, and the grinding wheel has a high abrasive grain retention ability during grinding. Super abrasive grains are difficult to fall off.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a resin bonded superabrasive grindstone according to one embodiment.

FIG. 2 is a schematic diagram showing an example of a resin bond grindstone.

FIG. 3 is a schematic diagram illustrating a conventional resin bond grindstone.

[Explanation of symbols]

10 Resin bond super abrasive grindstone 11. Super abrasive grain 12 Metal coating layer 13 Hard resin layer 14 Coating super abrasive grain 15 Soft resin bond 16 Soft resin particles 17 Mold

Claims (1)

[Claims] [Claim 1] A resin-bonded superabrasive grindstone in which CBN grains or diamond grains are scattered in a resin bond, which is made by granulating coated superabrasive grains in which CBN grains or diamond grains are coated with a hard resin, and a soft resin. A resin-bonded super-abrasive grindstone characterized by being made by mixing soft resin particles and firing under pressure.