JPH031064B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a grinding wheel used in a high-speed grinding device,
In particular, it relates to a superhard grinding wheel made of ceramic material, which makes it possible to ultra-finely refine highly hard materials very rationally and economically.

[Conventional technology]

Recently, there has been a frequent need for ultra-fine graining of particularly hard materials, and there is a strong demand for a grindstone that can meet this demand. With the well-known vitrified grindstone, it has not been possible to cope with long-term stable production because the grindstone suffers significant wear and tear in ultrafine pulverization of materials with hardness equal to or higher than the abrasive grains. A solution to this problem is to use ultra-hard abrasive grains such as diamond or borazone (a trade name for boron nitride abrasives), but these abrasive grains are extremely expensive, so It is economically impossible to use it over the entire surface.

[Problems to be solved by the invention]

The purpose of the present invention is to rationally and economically make ultra-fine grains of high-hardness substances as described above, and to enable stable production over a long period of time. It was used effectively and appropriately.

[Means for solving problems]

In other words, the ultra-hard grinding wheel of the present invention is one in which ultra-hard abrasive grains are provided in layers only in the part of the grinding wheel that is subjected to the most load during grinding, and the outer periphery of the rotary grinding wheel and the fixed grinding wheel made of ceramic material are opposite to each other. It is characterized by re-sintering ultra-hard abrasive grains in the flat part of the grinding process.

It goes without saying that the ceramic material referred to in the present invention includes not only classical ceramics but also new ceramics and modern ceramics.

[Effect]

The carbide grinding wheel in the present invention is, for example,
It is obtained by carbide processing a grinding wheel made of zirconyl aceramic material or other ceramic material described in Japanese Patent No. 60-122052. The grinding wheel is a top view of the rotary grinding wheel shown in FIGS. 1A and 1B, and 1-
I line a1, b1, c1, b4, a4 sectional view, 2nd
As can be seen from the plan view of the fixed whetstone shown in Figures A and B and the cross-sectional view along the - lines a1', b1', c', b4', and a4', the rotary whetstone has a hole in the center for inserting the rotating shaft. The fixed grindstone has a structure in which a ceramic grinding surface is glued to a metal stand with a recess for tightening to the rotating shaft, and a fixed grindstone has a structure in which a ceramic grinding surface is glued to a metal stand with a hole for material supply in the center. rice cake,
In both cases, a flat part of a constant width (a part without grooves) is provided on the circumference, and a truncated cone-shaped part on the inside with a group of grinding grooves continuous to the flat part and attached to the inner side. is provided. The material of the whetstone for both rotary and fixed whetstones is, for example, zirconia ceramics, which has zirconium oxide as its main component, which is mixed with yttrium oxide and fired at high temperatures (1800~
2000℃).

The present invention was made based on the knowledge that during grinding, the load is applied to the flat part of the outer periphery of the grinding wheel. W in Figure 2 B and
The main idea is to re-sinter the ultra-hard abrasive grains (the part marked W'). As the ultra-hard abrasive grain, use diamond or borazone, for example, about 50~
100 meshes of these ultra-hard abrasive grains are resintered into the zirconia ceramic grinding wheel using a vitrified bonding agent. The bonding ratio is preferably in the range of 10 to 50 parts to 100 parts of abrasive grains. In addition, the width and thickness of the resintered layer are 5 to 30 mm and 0.1 to 5 mm, respectively.
is preferred. For this reason, when correcting the grindstone after primary firing (around 800℃), the flat part of the outer periphery should be cut to this thickness, or the settsukou mold for forming the grindstone should be adjusted to this thickness in advance to make it suitable for high-temperature firing. Therefore, after resintering, a predetermined size of the grindstone can be obtained. Note that when the thickness of the resintered layer is relatively thick, the resintered layer extends to a relatively inner side of the flat outer peripheral portion and near the outer peripheral end of the grinding groove group. The resintering thickness can be changed as appropriate between the rotary grindstone side and the fixed grindstone side.

〔Example〕

The present invention will be explained in more detail below using drawings instead of examples.

FIG. 3 is an explanatory cross-sectional view of a pair of cemented carbide grinding wheels made of, for example, zirconia ceramic material according to the present invention, in which 1 is a rotary grindstone and 2 is a fixed grindstone. The grinding surfaces 3, 3' of both grinding wheels are made of, for example, zirconia ceramics, and the mutually opposing outer peripheral grinding flat parts are resintered with ultra-hard abrasive grains, forming resintered layers 4, 4'. is provided.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, by using expensive ultra-hard abrasive grains only in a part of the grinding surface, that is, in the flat part of the outer periphery of the grinding wheel made of ceramic material, high hardness can be achieved. It is possible to rationally and extremely economically make ultra-fine particles of substances,
The industrial significance is enormous.

[Brief explanation of drawings]

FIGS. 1A and 1B are a plan view and a sectional view of a rotary grindstone made of ceramic material that is not subjected to carbide processing, and FIGS. 2A and 2B are a plan view and a sectional view of the fixed grindstone. FIG. 3 is an explanatory cross-sectional view of a pair of cemented carbide grinding wheels made of ceramic material according to the present invention. In the figure, 1... Rotating grindstone, 2... Fixed grindstone, 3, 3'...
...Ceramics material ground surface, 4,4'...Super hard abrasive grain re-sintered layer.

Claims (1)

[Scope of Claims] 1. A superhard grinding wheel made of a ceramic material, characterized in that superhard abrasive grains are resintered on the flat grinding portions of the outer peripheries of a rotary grindstone and a fixed grindstone that face each other. 2. A superhard grinding wheel made of a ceramic material according to claim 1, wherein the superhard abrasive grains are diamond. 3. A superhard grinding wheel made of a ceramic material according to claim 1, wherein the superhard abrasive grains are boron nitride.