JPH10118804A - Throwaway tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To diffuse the heat near a blade directly from the blade through a pedestal tip in cutting by waxing a base board of an extra high pressure sintered body to the bottom and side face of a fitting groove and a blade tip to the side face of the fitting groove respectively. SOLUTION: A base board 5 which constitutes the bottom layer of an extra high pressure sintered body 4 and is composed of cemented carbide has its bottom face 5a waxed to the bottom face 3a of a fitting groove 3 of a throw-away chip 1 and its side face 5b waxed to the bottom part, of the side face 3b of the fitting groove 3. A blade tip 6 which constitutes the top layer and is composed of a hard sintered body such as CBN or PCD has its side face 6b directly waxed to the top of the side face 3b of the fitting groove 3. When a various kinds of materials to be cut are cut, the circumference of the blade 6a of the blade tip 6 generates heat and becomes high temperature, however, the heat is diffused not only in the base board 5 direction but directly from the side face 6b of the blade tip 6 to a pedestal 2 so that the temperature rise around the blade 6a can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away insert obtained by brazing an ultra-high pressure sintered body including a cutting edge tip to a base metal.

[0002]

2. Description of the Related Art Conventionally, as this kind of indexable insert, for example, there is one as shown in FIG. In this throw-away chip 1, a mounting groove 3 for mounting a chip is formed in a concave shape at one end such as a corner portion of a base metal 2 made of cemented carbide, and an ultra-high-pressure sintered body 4 is formed in the mounting groove 3. Be brazed. The ultrahigh-pressure sintered body 4 has a two-layer structure, for example, the lower layer is a substrate 5 made of cemented carbide, and the upper layer is CBN.
(Cubic boron nitride sintered body) or PCD (diamond sintered body). And
When brazing, for example, an Ag alloy brazing material is used as the brazing material 7, and the bottom surface 5 a of the substrate 5 is formed on the bottom surface 3 a of the mounting groove 3.
The side surface 5b of the substrate 5 is brazed to the side surface 3b of the mounting groove 3, respectively. Cutting blade tip 6 is CB
Since it is a hard sintered body such as N or PCD, the wettability with the brazing material is poor, so that brazing with the base metal 2 is not performed.

[0003]

When a workpiece is cut using such a throw-away tip 1, the temperature near the cutting edge 6a of the cutting tip 6 becomes high due to the cutting. 2 are not in direct contact with each other, and a small gap c is formed between the base metal 2 and the mounting groove side surface 3b. For this reason, there is a problem that the heat is not sufficiently diffused at the cutting edge 6a, the temperature near the cutting edge of the cutting tip 6 increases, and the cutting ability decreases. Also, the cutting blade tip 6
There is a disadvantage that the brazing strength of the ultrahigh-pressure sintered body is not very high because the brazing itself is not directly brazed to the base metal 2 but brazed only at the portion of the substrate 5.

SUMMARY OF THE INVENTION [0004] In view of such circumstances, an object of the present invention is to provide a throw-away insert capable of improving the cutting ability by promoting the heat diffusion of the cutting insert.

[0005]

According to the present invention, there is provided a throw-away chip comprising: a mounting groove of an ultra-high pressure sintered body comprising a substrate and a cutting edge brazed to a mounting groove of a base metal; The substrate is brazed to the bottom surface and the side surface, and the cutting tip is brazed to the side surface of the mounting groove. According to the present invention, not only the substrate but also the cutting edge chip is directly brazed to the base metal, so that the brazing strength is improved, and even if the temperature near the cutting edge of the cutting edge chip becomes high due to the cutting, the cutting edge chip is cut. Therefore, the heat is diffused not only in the direction of the substrate but also in the direction of the base metal, so that the temperature rise at the cutting edge can be suppressed, and the cutting ability does not decrease.

The base metal and the substrate are made of a cemented carbide, and the cutting tip is made of a hard sintered body such as CBN or PCD. In addition, an active silver brazing material may be used as the brazing material, and atmosphere brazing with an inert gas may be performed.

[0007]

FIG. 1 is a block diagram showing an embodiment of the present invention.
However, the same reference numerals are used for the same parts or members as those in the above-described related art, and the description is omitted. FIG. 1 is a longitudinal sectional view of a throw-away tip according to an embodiment. In FIG. 1, the ultrahigh-pressure sintered body 4 is brazed by an active silver brazing material 9 when brazing to the mounting groove 3 of the throw-away tip 1. That is, the substrate 5 made of a cemented carbide as a lower layer of the ultrahigh-pressure sintered body 4 has its bottom surface 5a brazed to the bottom surface 3a of the mounting groove 3 and its side surface 5b brazed below the side surface 3b of the mounting groove 3. Have been. In addition, the upper side of the cutting edge chip 6 made of a hard sintered body such as CBN or PCD has its side surface 6b directly brazed to the upper portion of the side surface 3b of the mounting groove 3.

Here, the active silver brazing material 9 will be described. This brazing material has a Cu content of 10 to 40% (preferably 20 to 30%) and a Ti content of 1 to 20% (preferably 1 to 5%). ), And the remainder is made of an Ag alloy having a composition consisting of Ag and unavoidable impurities (see JP-A-7-124804). Then, using the active silver brazing material 9, for example, 800 to 11 in an inert gas atmosphere such as argon gas.
By brazing the atmosphere at a temperature of 00 ° C., the base metal 2 and the ultrahigh-pressure sintered body 4 can be joined by brazing. Since this brazing material has good wettability with a hard sintered body such as CBN or PCD, not only the base metal 2 and the substrate 5 made of cemented carbide, but also the base metal 2 made of cemented carbide and CBN or PCD etc. The cutting blade tip 6 made of a hard sintered body can be brazed with high joining strength.

Since the indexable insert 1 according to the present embodiment has the above-described configuration, when cutting various materials using the indexable insert 1, the vicinity of the cutting edge 6a of the cutting edge tip 6 can be obtained. Generates heat and becomes high temperature. This heat is conducted not only in the direction of the substrate 5 but also from the side surface 6b of the cutting edge chip 6 to the base metal 2 and is thermally diffused, thereby suppressing a rise in temperature around the cutting edge 6a. be able to.

As described above, according to the present embodiment, not only the substrate 5 which is the lower layer of the ultrahigh-pressure sintered body 4 but also the cutting edge chip 6 which is the upper layer is directly brazed. In addition to the above, the heat generated in the vicinity of the cutting edge 6a during cutting can be diffused directly through the base metal 2, and
The temperature rise near a can be suppressed, and a decrease in cutting ability can be prevented.

[0011]

As described above, the indexable insert according to the present invention is obtained by brazing the substrate of the ultra-high pressure sintered body on the bottom and side surfaces of the mounting groove and brazing the cutting edge chip on the side surface of the mounting groove. Therefore, not only can the brazing strength be improved, but also the heat near the cutting edge can be diffused directly from the cutting edge tip through the base during cutting, and the temperature rise near the cutting edge can be suppressed, reducing the cutting ability. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cutting edge portion of a throw-away insert according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a cutting edge portion of a conventional indexable insert.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Throw-away tip 2 Base metal 4 Ultra-high pressure sintered compact 5 Substrate 6 Cutting edge tip

Claims (1)

[Claims] 1. A throw-away chip obtained by brazing an ultra-high pressure sintered body comprising a substrate and a cutting edge chip to a mounting groove of a base metal, wherein the substrate is provided on the bottom and side surfaces of the mounting groove, and A throwaway tip, wherein the cutting edge tip is brazed to a side surface of a mounting groove.