JPH0122082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a composite hard sintered body consisting of a hard sintered body mainly composed of diamond or high-pressure phase boron nitride and a support member.

In recent years, hard sintered bodies mainly made of diamond or high-pressure phase boron nitride have been developed and are being used as cutting tools, wear-resistant tools, and the like.

There are two types of these hard sintered bodies: those consisting only of hard sintered bodies, and composite hard sintered bodies in which hard sintered bodies are combined with cemented carbide and other supporting members. Composite hard sintered bodies are generally shown in Figure 1,
A structure as shown in Fig. 2 is used.

Figure 1 shows the one used for cutting tools.
It has a structure in which a hard sintered body layer 1 mainly made of diamond or high-pressure phase boron nitride is fixed to the upper surface of a base metal 2 made of cemented carbide. The advantage of this structure is that the hard sintered body layer 1 is lined with a tough cemented carbide, resulting in a strong structure as a whole. While it is not possible to braze with ordinary brazing material, in a structure in which a cemented carbide base metal is fixed, it is possible to easily braze and secure the tool body to the tool body by using the cemented carbide base metal as a brazing surface.

The one shown in Fig. 2 is used for wire drawing dies, and in this case as well, by surrounding the hard sintered body 1 with a cemented carbide outer peripheral member 2, the hard sintered body is supported and reinforced. There is.

As mentioned above, composite hard sintered bodies with conventional structures are excellent in terms of toughness and brazing to tools, etc., but because they are hard sintered bodies or extremely difficult-to-process materials,
The drawback was that it was difficult to process, which is necessary when using a tool shape with a through hole in the center.

The present invention provides a composite hard sintered body that is convenient and economical to use by having a composite structure that is different from the conventional composite sintered body.

The present invention provides a cylindrical or prismatic composite hard sintered body formed by combining a hard sintered body mainly made of diamond, high-pressure phase boron nitride, or a mixture thereof and a support member, in which the hard sintered body has a center portion thereof. This composite hard sintered body has a through hole in the thickness direction, and an integrated support member is disposed on the upper and lower surfaces in the thickness direction of the hard sintered body and in the central through hole.

This structure makes machining easier and improves machining accuracy compared to conventional structures, and expensive hard sintered bodies are only used in functionally necessary areas, while other parts are replaced by inexpensive support members. It is also economical because it consists of

The present invention will be explained below with reference to Examples.

FIG. 3 is an example of a composite hard sintered body based on the present invention.

Fig. a is a front view, and Fig. b is a cross-sectional view taken from the side direction and passing through the central axis, in which a donut-shaped disk 2 made of a hard sintered body is held by a support member.

FIG. 4 shows an example of a tool using the composite hard sintered body of FIG. 3. FIG. 4 shows a wheel-type cutter for glass, in which a diamond hard sintered body 2 is supported by a support member 1 made of a superhard alloy. The outer periphery is chamfered to form a cutting edge 21 on the outer periphery of the diamond sintered body, and a through hole 11 is further formed in the central support.

This wheel cutter cuts a glass plate using the outer peripheral edge 21, and only this portion requires a hard sintered body. Also, the cutter is fixed through the through hole in the center through which a pin is inserted. If this cutter were to be made from a conventional hard sintered body, the sintered body material shown in Figure 1 would be used. It is made of hard metal.

This wheel cutter has tight dimensional tolerances for the through hole in the center and the overall thickness, and requires precision machining, but the shape shown in Figures 5 and 6 allows for precise machining of diamond sintered bodies, which are hard and difficult to machine. This results in high machining costs and expensive tools.

Furthermore, when I made a cutter with the shape shown in Figure 5 and actually used it, I found that during use, the cutter is pressed against the glass surface with a considerable load, so the inner diameter of the cutter is 1.
The drawback was that one part would chip, resulting in a short lifespan.

However, in the case of the shape of the embodiment shown in Fig. 4, the cutting edge on the outer periphery must be made by grinding a diamond sintered body, but the other parts, such as the central through hole and both sides, can be made by machining carbide supports. It is exactly the same as the conventional carbide wheel cutter and can perform high-precision machining at low cost. Furthermore, since the inner diameter part is also made of a strong carbide support, pitting of the inner diameter during use, which was a problem with conventional shapes, is eliminated. Furthermore, since the volume of the diamond sintered body is reduced, diamond raw materials can be saved.

Therefore, according to the present embodiment, a diamond sintered body is placed in the portion necessary as a cutting edge, and a wheel cutter that is easy to manufacture and causes no problems during use can be obtained.

FIG. 7 shows a second embodiment. The structure is the same as the first embodiment, and in this embodiment, grooves are formed on the circumference in the outer diamond sintered body portion for the rolling roll.
In this case as well, the roll is held and used by passing a pin through the through hole in the center. The effects obtained by this embodiment are exactly the same as those of the first embodiment.

In the embodiment, only a disk-shaped structure has been described, but it goes without saying that a prismatic structure may also be used.

The supporting member in the present invention is a carbide of a group 4a, 5a, or 6a element of the periodic table such as WC, TiC, or TaC;
Alternatively, cemented carbide made by bonding these mutual solid solution carbides with iron group metals is preferable because it has high strength and mechanical properties such as thermal expansion coefficient and rigidity are close to those of the hard sintered body on the outer periphery. . However, steel, other metals, or alloys are superior in terms of ease of processing, and these materials may be used if there are no problems in use.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are conceptual diagrams of a conventional composite hard sintered body. FIG. 3 shows an example of the present invention, in which a is a front view and b is a sectional view taken along the line A-A'. FIGS. 4 and 7 show an embodiment of the present invention obtained by further processing the composite hard sintered body obtained in FIG. 3, and a is a front view, and FIG.
b shows a side view. FIGS. 5 and 6 are comparative examples, in which a shows a front view and b shows a side view, respectively. 1: Hard sintered body, 2: Base metal, 11: Inner diameter part, 2
1: Cutting blade part.

Claims (1)

[Claims] 1. In a cylindrical or prismatic composite hard sintered body formed by combining a hard sintered body mainly made of diamond, high-pressure phase boron nitride, or a mixture thereof and a support member, the hard sintered body is What is claimed is: 1. A composite hard sintered body having a through hole in the thickness direction in the center thereof, and an integrated support member disposed on the upper and lower surfaces in the thickness direction of the hard sintered body and in the central through hole. 2. The composite hard sintered body according to claim 1, wherein the supporting member is a carbide of elements of groups 4a, 5a, and 6a of the periodic table, or a cemented carbide made by bonding mutual solid solution carbides of these elements with an iron group metal. 3. The composite hard sintered body according to claim 1, wherein the supporting member is a metal or an alloy. 4. The composite hard sintered body according to claim 1, wherein the supporting member is made of steel.