JPH06114738A - Precision grinding wheel and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the accuracy of truing and dressing by forming a diamond film or cubic boron nitride film on a grinding wheel base so as to provide irregularity in a surface of the film. CONSTITUTION:An Si-made disk 1b of thin plate, finishing the surface to a specified high accuracy, is pasted to one end face of a stainless steel-made disk 1a, to constitute a grinding wheel base 1. This grinding wheel base 1 is housed in a diamond film forming chamber 2 and secured to a rotary shaft 3a of a wheel spindle stock 3. Grinding wheel heating heaters 4, 5, gas supply port 6 and a gas discharge port 7 are provided in the chamber 2. A mixed gas of 2% hydrocarbon with 98% H2 is supplied at a 100 Torr pressure from the gas supply port 6, and an AC 10V power is applied to the heater 5, to heat the grinding wheel base 1 at about 700 deg.C. In this way, a diamond film having about 1mum irregularity in the surface is formed.

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 precision grinding,
Especially diamond wheels and CBN (cubic boron nitride)
It is useful when applied to a whetstone.

[0002]

2. Description of the Related Art In order to improve the precision of grinding, it is necessary not only to improve the precision of the grinder itself, but also to accurately truing and dressing a grindstone which is a tool. This truing / dressing is to correct the shape of the whetstone such as swinging and sharpening.

As a tool for precision grinding of this kind, a superabrasive grindstone in which abrasive grains are formed of diamond and CBN is mainly used. Further, in the truing / dressing of this kind of tool, conventionally, a method of grinding a grindstone with a tool having diamond grains on its outer surface (hereinafter referred to as a dresser) is adopted.

[0004]

In the truing dressing according to the prior art as described above, diamond and CBN abrasive grains having hardness close to diamond are ground by the dresser diamond grains, so that the dresser diamond grains are worn. Is hard, that is, the shape is severely deformed, and it is difficult to make highly accurate truing dressing. As described above, the difficulty of truing and dressing of the superabrasive grindstone having diamond and CBN as the abrasive grains is a major obstacle to the precision of grinding.

In view of the above-mentioned prior art, the present invention has a problem in that, when precision grinding is performed using a grindstone having diamond and CBN as abrasive grains, truing / dressing of the grindstone is difficult and there is a limit to high precision. It is an object of the present invention to provide a grinding wheel for precision grinding that can be solved at once.

[0006]

The structure of the present invention for achieving the above-mentioned object is to form a diamond film or a cubic boron nitride film on a grindstone base and to make the surface of the diamond film or the cubic boron nitride film It is characterized by having unevenness.

[0007]

According to the present invention having the above-described structure, since the diamond film or the cubic boron nitride film is provided with irregularities, it is possible to form a convex portion having a uniform height. Becomes

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing a mode of manufacturing a grindstone for precision grinding according to an embodiment of the present invention. As shown in FIG. 1, the grindstone base 1 has a structure in which a disc 1b made of Si, which is a thin plate whose surface is finished to a required high accuracy, is attached to one end surface of a disc 1a made of stainless steel which serves as a grindstone base member. It is housed in the chamber 2, and the other end surface is fixed to the grindstone shaft 3 a of the grindstone base 3.

The chamber 2 is for forming a diamond film on the surface of the disk 1b of the grindstone base 1 by the CVD method (chemical vapor deposition method). The chamber 2 is provided with a heater 4 and a heater 5 for heating the grindstone, as well as a gas supply port 6 and a gas exhaust port 7. In this chamber 2, the heater 4 for heating the grindstone heats the grindstone base 1 so that the disc 1b is heated. A diamond film is formed on the surface.

At this time, the conditions for forming the irregular diamond film are hydrocarbon (CnHm) 2% and H ₂ 98%.
The mixed gas of the above is supplied into the chamber 2 at a pressure of 100 Torr,
An alternating current of 10 V is applied to the heater 5. As a result, the grindstone base 1 is heated to 700 ° C. 1μ in about 1 hour treatment
A diamond film having many irregularities with a thickness of about m can be formed. By the way, when diamond is coated, it is not a smooth film, but a film having many irregularities.

Under the above conditions, if the working temperature of the grindstone base 1 is set to 300 ° C., a diamond-like carbon film having irregularities can be formed. In this case, the wear resistance of the grindstone is slightly inferior to the diamond film, but It can be included as an embodiment of the invention.

The grinding wheel for precision grinding obtained by the above manufacturing method has a diamond film having irregularities on the surface of the disk 1b of the grinding wheel base 1. With this grinding wheel for precision grinding, glass (material BK7) can be finished to have a surface roughness of 5 nm.

As shown in FIG. 1, the precision grinding wheel grinds a workpiece 8 disposed adjacent to the chamber 2. That is, the workpiece 8 is the chuck 1 of the workpiece headstock 9.
Grindstone base that is gripped by 0 and is movable on the workpiece guide surface 11 in the left-right direction in the figure, is formed on the grindstone guide surface 12 in the vertical direction in the figure, and rotates the grindstone base 1. Grinding in the state shown in FIG.

As shown in FIG. 3, the surface of the disk 1b serving as the vapor deposition surface of the grindstone base 1 may be previously processed by a diamond tip 14 fixed to a tool holder 13 fixed on the tool guide surface 11. Such diamond tip 14
With this, the surface of the disk 1b can be cut (self-cut) before coating to be finished with high accuracy.

In FIG. 4, instead of the disc 1b of the above embodiment,
This is another embodiment using a superhard disk 15b in which a diamond film is previously formed under the same conditions as described above by another coating device. In this embodiment, the grindstone base 15 is formed by pneumatically adsorbing the disk 15b to the stainless disk 15a which is the grindstone base member. At this time, the disk 15a is a vacuum chuck.

According to the present embodiment, since the coating on the grinder is unnecessary, the heating at the time of coating as in the case of the above embodiments is unnecessary. If the thickness of the disk 15b on which the diamond film is formed in advance is 0.5 mm or less, the entire surface can be adsorbed to the disk 15a, which is a vacuum chuck, without any gap.

The diamond film or the CBN film is formed on the irregularities by utilizing the fact that the irregularities are formed naturally as described above, and a smooth coating film may be formed on the irregularities later. For example, it is known that a CBN film can be formed into a smooth film by PVD method (physical vapor deposition method), and irregularities can be formed by, for example, Ar etching this film.

The fine grinding wheel according to the above-mentioned embodiment has a cutting edge (corresponding to an abrasive grain) having a substantially uniform height due to the unevenness of the diamond film or the CBN film, and therefore has a predetermined high precision processing. Can be realized.

[0020]

As described above in detail with reference to the embodiments, according to the present invention, it is not necessary to perform truing and dressing, and in grinding using a diamond grindstone or a CBN grindstone, the grinding is caused by the poor precision of the grindstone. The accuracy can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a mode at the time of tool grinding in the embodiment.

FIG. 3 is an explanatory diagram for processing a disk in the above-described embodiment.

FIG. 4 is an explanatory view showing another embodiment of the present invention.

[Explanation of symbols]

 1,15 Whetstone base 1a, 15a Disc 1b, 15b Disc

Front page continuation (72) Inventor Takeshi Tsuno 1-8-1 Koura, Kanazawa-ku, Yokohama-shi, Kanagawa Mitsubishi Heavy Industries, Ltd.

Claims (4)

[Claims] 1. A grindstone for precision grinding, wherein a diamond film or a cubic boron nitride film is formed on a grindstone base, and the diamond film or the cubic boron nitride film has irregularities on its surface. 2. A grindstone for precision grinding, wherein a thin plate having a diamond film or a cubic boron nitride film having irregularities on its surface is adsorbed or attached to a grindstone base member. 3. A method for manufacturing a grinding wheel for precision grinding, wherein the diamond film or the cubic boron nitride film is formed by a chemical vapor deposition method. 4. A method for producing a grinding wheel for precision grinding, characterized in that the diamond film or the cubic boron nitride film is formed by a physical vapor deposition method, and thereafter the surface of the film is provided with irregularities by etching or the like.