JPH11277329A - Tip saw for power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of an usual cutter and obtain the tip saw for a power tool suitable for the cutting of a ceramic system siding board. SOLUTION: In the tip saw for a power tool, on whose outer periphery surface of a disc shape base body 3, plural tips 1 having an edge formed by a diamond sintered body and plural tips 2 having an edge formed by a cemented carbide are arranged respectively, the rake angle and escape angle of the edge formed by the diamond sintered body are made to less than the rake angle and escape angle of the edge formed by the cemented carbide respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip saw for use by attaching to a power tool, and more particularly to a power tool tip saw suitable for cutting ceramic siding boards.

[0002]

2. Description of the Related Art For cutting a ceramic siding board made of fiber-mixed cement calcium silicate material,
The cutter to be used is required to have excellent sharpness and long life characteristics, but conventionally, a carbide tip saw provided with a WC-Co-based cemented carbide tip as a cutting edge, and a diamond segment attached to an outer peripheral portion. A diamond segment cutter, an electrodeposition cutter in which diamond abrasive grains are electrodeposited on the outer periphery of the substrate, and the like are used.

However, each of the above-mentioned tip saws or cutters has the following disadvantages.

[0004] That is, the carbide tip saw has a good initial sharpness, but is inferior in abrasion resistance, so that the wear sharply progresses with use and the cutting ability rapidly deteriorates. In addition, the diamond segment cutter has a small number of working abrasive grains and therefore has little wear and a long life, but is inferior in sharpness because the projection amount of the abrasive grains is small. The electrodeposition cutter has a good sharpness at the beginning of mounting because of a large number of working abrasive grains and a large amount of projection of the abrasive grains, but the clogging occurs immediately and the cutting becomes impossible.

Japanese Unexamined Patent Publication No. 57-138522 discloses a rotary cutter provided with a cutting edge having a cutting edge made of sintered diamond and a cutting edge made of high-speed steel or cemented carbide. In the rake angle of the cutting edge having a cutting edge made of the sintered diamond is zero or negative,
On the other hand, although the rake angle of the cutting edge made of the high-speed steel or the cemented carbide is set to zero or positive, it has not yet reached a region where cutting processing of a strong ceramic siding board can be favorably performed.

Further, Japanese Utility Model Laid-Open No. 57-113912 describes a rotary cutter in which a cemented carbide tip and a sintered diamond tip are arranged on the outer peripheral surface.
Although the rake angle of the cemented carbide tip is set smaller than the rake angle of the sintered diamond tip,
There is a problem similar to the rotary cutter described in No. 38522.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to solve the above-mentioned problems of the conventional cutter and to obtain a power tool tip saw having a high cutting ability suitable for cutting a ceramic siding board.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a method in which a chip having a cutting edge formed of a diamond sintered body and a chip having a cutting edge formed of a cemented carbide are provided on the outer periphery of a disk-shaped substrate. In the power tool tip saws respectively arranged on a plurality of surfaces, the angle of the rake angle and the angle of relief of the cutting edge formed by the diamond sintered body are respectively less than the angle of the rake angle and the angle of relief of the cutting edge formed by the cemented carbide. It is characterized by having done.

It is preferable that the rake angle θ ₁ of the cutting edge formed by the diamond sintered body is 0 ° <θ ₁ ≦ 10 °, and the clearance angle θ ₂ is 5 ° ≦ θ ₂ ≦ 15 °.

[0010] Examples of the cemented carbide used in the present invention include WC-Co based cemented carbides.
In addition, a material such as cermet or ceramic may be used as a constituent material of the cutting edge as needed.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power tool tip saw having a basic structure comprising a cemented carbide tip having a cutting edge and a substrate having a tip having a cutting edge formed of a diamond sintered body. 57-1385
In addition to defining the rake angle of the cutting edge formed by a diamond sintered body as in the rotary cutter described in Japanese Patent Publication No. 22 and 57-113912, the value of the clearance angle is also defined in a specific range. As a result, a long-life cutter suitable for cutting ceramic siding boards is to be obtained.

As the diamond sintered body used in the present invention, a sintered body using 0.5 to 30 micron particles as diamond particles is preferable from the viewpoint of ease of cutter production and tool life.

If all the cutting edges of the chip are formed of a diamond sintered body alone, there is a problem in terms of manufacturing cost. Therefore, as in the present invention, a chip having a cutting edge formed of a diamond sintered body and a cemented carbide are used. It is preferable in terms of cost to combine chips having a cutting edge formed of an alloy and arrange them on the outer peripheral surface of the disk-shaped substrate. In addition, the combined use with the cutting edge made of cemented carbide makes it possible to increase the fracture resistance of the diamond toughness having low toughness, thereby preventing the occurrence of chipping. As a result, the life of the tip saw can be improved.

The sintered diamond and the cemented carbide have different toughness and wear resistance. Therefore, when various types of chips are used in combination as in the present invention, the rake angle and the clearance angle of the cutting edge made of a sintered diamond body are respectively changed to perform cutting, and the cutting edge made of a cemented carbide is used. It is necessary to make the angles smaller than the rake angle and the clearance angle.

An embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the illustrated embodiment. FIG. 1 is a side view of the tip saw of the present invention.

As shown in FIG. 1, the tip saw of the present invention has a structure in which a plurality of tips each having a cutting edge on the outer periphery of a disk-shaped substrate 3 formed of steel or the like are projected outward in the radial direction. At the center thereof, a hole is formed through which a drive shaft of an electric tool such as an electric motor is fitted.

In the embodiment shown in FIG. 1, a first chip 1 having a cutting edge formed of a diamond sintered body on an outer periphery of a substrate 3 is attached to an outer peripheral surface of the substrate 3 at a predetermined interval, and WC- between the first chips 1
Second insert 2 having a cutting edge made of Co-based cemented carbide
Are continuously attached to the outer peripheral surface of the substrate 3. In order to obtain an even cutting effect at each part of the outer peripheral surface of the substrate 3, as in the embodiment shown in FIG.
It is preferable that the arrangement interval between the first and second chips 2 and the arrangement interval between the second cutting blades 2 are set to be equal to each other. The combination ratio of the first chip 1 and the second chip 2 can be appropriately changed according to the physical properties of the object to be cut.

In the embodiment shown in FIG. 1, the rake angle θ ₁ of the cutting edge made of a diamond sintered body of the first chip 1 is shown.
Is 0 °, the clearance angle θ ₂ is 10 °, the rake angle θ ₃ of the cemented carbide cutting edge of the second chip 2 is 14 °, and the clearance angle θ ₄ is 14 °. Here, the “rake angle” is, as is apparent from FIG. 1, an angle formed between a radial line of the substrate 3 connecting the cutting edge of the tip end and the center of the substrate 3 with the front surface of the chip. The “relief angle” is the angle between the normal line perpendicular to the radial line of the substrate 3 connecting the cutting edge at the tip of the chip and the center of the substrate 3 and the back surface of the cutting edge. It is set so that it does not touch the object.

In the present embodiment, the first chip 1
The rake angle and relief angle of the cutting edge made of diamond sintered body of
Each is set to be smaller than the rake angle and relief angle of the cemented carbide cutting edge of the second chip 2. By doing so, the apparent toughness and wear resistance of the cutting edges of the first chip 1 and the second chip having the cutting edges made of materials having different toughness and wear resistance can be made equal, and the cutting operation can be performed. Can be performed well.

[0020]

EXAMPLE A ceramic siding board was cut at a cutting speed of about 14 m / min using the tip saw shown in FIG. As a result, it was possible to continue using the tip saw even after cutting 200 m.

Comparative Example: When a tip saw having both a clearance angle and a rake angle of 14 ° for the cutting edges of the first cutting edge 1 and the second cutting edge 2 was used under the same conditions as those of the embodiment,
Although 80 m could be cut, chipping occurred at the cutting edge at that stage, and further use was impossible.

[0022]

According to the present invention, it is possible to obtain a power tool tip saw suitable for cutting ceramic siding boards, which require particularly excellent sharpness and long life.

Since a chip having a cutting edge formed of a diamond sintered body and a chip having a cutting edge formed of a cemented carbide are used in combination, it is advantageous in terms of the manufacturing cost of a chip saw. In addition, the combined use with the cutting edge made of cemented carbide makes it possible to increase the fracture resistance of the diamond sintered body having low toughness, thereby preventing the occurrence of chipping. Therefore, the life of the tip saw can be improved.

Further, the life of the tip saw is further extended by making the angle of the rake angle and the angle of clearance of the cutting edge made of the diamond sintered body smaller than the angle of the rake angle and the angle of clearance of the cutting edge made of cemented carbide, respectively. be able to.

[Brief description of the drawings]

FIG. 1 is a side view of a cutting blade saw for a power tool according to the present invention.

[Explanation of symbols]

 1: first chip, 2: second chip, 3: substrate

Claims (2)

[Claims] 1. A power tool tip saw in which a plurality of chips each having a cutting edge formed of a diamond sintered body and a plurality of chips each having a cutting edge formed of a cemented carbide are arranged on an outer peripheral surface of a disk-shaped substrate. A rake angle and a clearance angle of the cutting edge formed by the cemented carbide are smaller than a rake angle and a clearance angle of the cutting edge formed by cemented carbide, respectively. 2. The rake angle θ ₁ of the cutting edge formed of a diamond sintered body is 0 ° <θ ₁ ≦ 10 °, and the clearance angle θ ₂ is 5 ° ≦ θ ₂ ≦ 15 °. The power tool tip saw according to claim 1.