JPH04348876A - Diamond grinding wheel - Google Patents

Abstract

PURPOSE:To provide a diamond grinding wheel having the height of diamond knifes with a submicroneous degree of accuracy by coating the outer peripheral surface of an end surface of the grind stone with a diamond film so as to align the tips of the diamond knifes with a high degree of accuracy. CONSTITUTION:A geometric shape 3a corresponding to a diamond knife is beforehand formed before a diamond layer is formed on a metal base 3. A diamond film 8 is formed on the geometric shape 3a so that the diamond knife is formed having a shape identical with the geometric shape 3a in order to form a diamond grinding wheel Thereby, the height of the diamond knife can be ensured with a submicroneous degree of accuracy, and accordingly, the sharpness is easily controlled. Thereby it is possible to obtain a diamond grind stone suitable for mirror-surface finishing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond grindstone, and more particularly to a diamond grindstone with uniform cutting edges.

0002

[Prior Art] Conventionally, the manufacturing method of diamond grinding wheels was as follows:
For example, as shown in the Diamond Tool Manual (Diamond Industry Association, published May 1974, pages 186 to 188), the sintering method and the electrodeposition method are known. The sintering method is generally a method in which a powdered bond material is mixed with abrasive diamond powder, placed in a mold, and solidified by applying heat and pressure. Therefore, as shown in FIG. 4, the diamond layer has diamond abrasive grains 1 dispersed in the bonding agent 2. On the other hand, in the electrodeposition method, as shown in FIG. 5, electroplating is performed with diamond abrasive grains 1 placed on a base metal 3, and the diamond abrasive grains 1 are placed on the base metal 3 using a plating metal 4 such as nickel. Hold. Therefore, in the electrodeposition method, diamond abrasive grains 1 are basically formed in only one layer on the base metal 3. The diamond abrasive grains used here have an average abrasive grain diameter of several micrometers to several tens of micrometers, and moreover, the abrasive grain diameters are not uniform but vary around the average abrasive grain diameter. For example, even fine abrasive grains with an average abrasive grain diameter of 4 μm actually have a diameter of 2 μm.
Abrasive grains with a diameter ranging from .mu.m to 6 .mu.m are used. The diamond abrasive grains present on the surface of the grinding wheel that interfere with the workpiece are called cutting edges, and in order to obtain a good machined surface during grinding using a diamond grinding wheel, it is necessary to control this abrasive cutting edge. is important. That is, a in FIG.
As shown in FIG. 5B, it is necessary to be able to control the alignment accuracy of the cutting edges in the height direction and the spacing of the abrasive grains in the plane. However, as mentioned above, with conventional sintering and electrodeposition methods, the alignment accuracy in the height direction of the cutting edge and the abrasive grain spacing vary depending on the variation in the abrasive grain diameter used and the state of abrasive grain dispersion. Controlling these values is very difficult. In principle, by decreasing the abrasive grain size, it is possible to reduce the alignment accuracy in the height direction of the cutting edge and the abrasive grain spacing, but as the abrasive grain size is decreased, the bond Since the abrasive retention force of the abrasive grains becomes small and it becomes difficult to disperse the abrasive grains during sintering, the practical limit is to use abrasive grains with a grain size on the micron order, and the above-mentioned cutting edge with submicron precision It is difficult to ensure accuracy.

0003

[Problem to be solved by the invention] Currently, in grinding using a diamond grinding wheel, it is difficult to realize mirror grinding that mainly produces ductile fracture instead of conventional brittle fracture, even for hard and brittle materials such as ceramics. It is strongly requested. For this purpose, it is necessary to control the amount of interference between the workpiece and the abrasive cutting edge with high precision to submicron or less. For this purpose, it is important to increase the number of abrasive cutting edges of the diamond whetstone.
As mentioned above, the height accuracy of the cutting edges is adjusted to submicron levels, and the intervals between the cutting edges are made close. That is, it is necessary to make the diamond grindstone uniform and small, and a method for manufacturing a diamond grindstone suitable for these needs is strongly desired.

0004

[Means for solving the problem] In order to control the abrasive cutting edge of a diamond grinding wheel, a predetermined geometric shape that will become the abrasive cutting edge is formed with high precision on the part of the base metal on which a conventional diamond layer has been formed. A method was used to form a diamond cutting edge as formed in the geometrical shape by forming a diamond thin film after forming the diamond.

[0005]

[Function] The predetermined geometric shape to be formed on the base metal can be formed with submicron precision by means such as machining or electrical processing, and the diamond thin film formed on this geometric shape is Since the diamond film can be formed to a thickness of about 5 μm, the diamond film can be formed while maintaining the precision of the geometric shape, so it becomes possible to easily obtain a diamond cutting edge with submicron precision.

[0006]

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a sectional view of a diamond grinding wheel showing an embodiment of the present invention, in which a predetermined geometrical shape 3a is formed on the diamond film forming surface of a base metal 3 having a mounting hole 7.
was applied to form a diamond film 8, and a diamond grindstone was produced. Hereinafter, the method for manufacturing a diamond grindstone of the present invention will be described in detail.

[0007] Outer diameter 100mm, diamond layer width 5m
A case will be described in which a cup-shaped diamond grindstone of size m is manufactured. For example, the outer shape of the base metal 3 made of cemented carbide is finished to these dimensions, and the mounting holes 7 are machined. Thereafter, a fine geometrical shape 3a that will become a diamond cutting edge is created on the upper surface of the cup-shaped grindstone that forms the diamond layer. For example, as shown in FIG. 2, this geometrical shape includes a circumferential spiral groove 5 having a V-shaped groove with a tip of 120°, and a sawtooth shape with a depth of 10 μm and a pitch of 35 μm. It is formed by mechanical grinding, electric discharge machining, etc. On the other hand, the depth of the cup-shaped whetstone with its flat tip toward the center is 1.
A radial groove 6 having a width of 0 μm and a width of 30 μm is formed in the same manner every time. Thereby, the height accuracy of the surface shape 3a on the base metal 3 is formed with submicron accuracy with respect to the reference surface 9 of the cup-shaped grindstone. Thereafter, a diamond thin film 8 is coated on the surface shape 3a of the base metal 3 to a thickness of, for example, about 5 μm. Coating methods for diamond thin films can be roughly divided into chemical vapor deposition and physical vapor deposition, but physical vapor deposition is preferable because it allows film formation at low temperatures and has strong adhesion to the base metal 3, but basically The method of forming the film does not matter. Therefore,
Since the shape of the fine unevenness 3a formed on the base metal 3 is directly formed on the upper surface on which the diamond film 8 is formed, the diamond film can be cut with submicron precision with respect to the reference surface 9 of the base metal 3. It becomes possible to manufacture a cup-shaped diamond grindstone with a blade formed thereon.

It should be noted that the geometrical shape of the surface shape 3a formed on the base metal 3 may be any shape other than those in the embodiments.
Since the shape becomes the diamond cutting edge after being coated with the diamond film, the spacing and alignment accuracy of the diamond cutting edge in the height direction can be arbitrarily determined in advance.

In the first embodiment, the surface shape 3a is formed on the base metal 3.
We have described an example in which a diamond film is directly formed on the base metal 3, but as shown in FIG. 3, a base material 9 is interposed between the base metal 3 and the diamond film 8. A surface shape 9a having an arbitrary geometric shape on the upper surface of the material 9
, and then the diamond film 8 may be formed thereon. The material of the base material 9 is, for example, SUS material, Si plate,
A SiC plate or the like may be considered, but it is effective to select the most suitable material in terms of adhesion to the diamond film and ease of creating the surface shape 9a.

Further, in the embodiment, a case of a cup-shaped diamond grindstone has been described, but it is clear that a peripheral grindstone having a diamond layer on the outer periphery can also be manufactured in the same manner.

[0011]

[Effects of the Invention] According to the present invention, it is possible to manufacture diamonds with submicron cutting edge height accuracy.
To obtain a diamond grinding wheel that does not require truing or dressing unlike conventional diamond grinding wheels, and is suitable for grinding with good surface roughness, since the cutting edge interval can be arbitrarily controlled. Can be done.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a diamond grinding wheel showing one embodiment of the present invention;

FIG. 2 is a partial plan view of the manufacturing process of the diamond grindstone of the present invention;

FIG. 3 is a cross-sectional view of a diamond grindstone showing another embodiment of the present invention;

[Fig. 4] Partial cross-sectional view of a diamond grinding wheel produced by the conventional sintering method.

FIG. 5 is a partial cross-sectional view of a diamond grindstone manufactured by a conventional electrodeposition method.

[Explanation of symbols]

1... Diamond abrasive grain, 2... Bond agent, 3... Base metal, 4...
Plated metal, 5... Spiral groove, 6... Radial groove, 7... Mounting hole, 8... Diamond film, 9... Base material.

Claims (1)

[Claims] Claim 1: A predetermined cutting edge corresponding to the abrasive cutting edge of a conventional diamond grinding wheel is preliminarily attached to a part of the base metal such as carbide, that is, the outer periphery or end face where the diamond layer of a conventional diamond grinding wheel is formed. A diamond whetstone characterized in that the tips of the diamond cutting blades are aligned with high precision by creating a geometric shape and coating the outer circumferential portion or the end face portion with a diamond film.