JP2529866Y2 - Cutting tools for brittle materials - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool for brittle materials used for cutting brittle materials such as graphite.

[0002]

2. Description of the Related Art When processing a graphite electrode,
Although a cutting tool such as an end mill is used, as shown in FIGS. 5 and 6, a conventional cutting tool 50 is an improved end mill for cutting a metal material. Degree, with cutting edges 51, 52 at the tip,
It is constructed using a wear-resistant material.

[0003]

However, when the graphite 53 is cut using the cutting tool 50 according to the conventional example, the cut material is discharged to the upper part, and a large force for cutting is applied to the exit side of the blade. As a result, chipping (hereinafter referred to as chipping) occurs on the upper and side surfaces of the graphite 53. If chipping occurs at the corners of the EDM graphite used in mold making, it is transferred to the surface of the mold to be manufactured, so it is necessary to avoid such chipping as much as possible. Cutting was performed with a very small feed per hit. For this reason, there was a problem that the processing efficiency was extremely poor. In addition, such problems occur not only in graphite but also in green processing of ceramics, pre-sintering of sintered materials, cutting of viscous products, or processing of settable goods having relatively machinability. Was a point. The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a cutting tool for brittle material that can perform cutting with high efficiency without causing chipping.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
The cutting tool for a brittle material according to the above is a cutting tool for a brittle material having a right edge and a left twist, and the right edge has a torsion angle of 75 degrees or more, and has a straight portion for cutting in a rotational direction at a tip portion. It has a cutting edge, and an air hole is formed in its axis. Further, the cutting tool for brittle material according to claim 2 is a cutting tool for brittle material having a left edge and a right twist, and the left edge has a torsion angle of 75 degrees or more, and a tip portion has a torsion angle in a rotational direction. It has a straight cutting edge for cutting, and an air hole is formed in its axis.

[0005]

In the cutting tool for brittle material according to the first aspect, the tool has a right edge, so that the tool is rotated clockwise in use, but the edge is twisted left in use. Is discharged downward, thereby eliminating chipping at the upper end, and since the torsion angle is 75 degrees or more, the force applied to the material in the direction perpendicular to the axis of the cutting tool during cutting is reduced. This eliminates chipping at the side edge of the material. The brittle material cutting tool according to the second aspect has the same effect as the cutting tool according to the first aspect, by turning left when using the cutting tool. And in the cutting tool for brittle materials according to claims 1 and 2, since the cutting edge is provided at the tip portion for cutting in the rotational direction, the cutting edge is formed despite the direction of the blade screw being reversed. The cutting tool can be used as an end mill. Moreover, in the cutting tool for a brittle material according to the first and second aspects, since the air hole is provided in the shaft center, powdery cutting chips fed down by cutting can be blown off by air.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings to facilitate understanding of the present invention. Here, FIG. 1 is a front view of a cutting tool for brittle material according to an embodiment of the present invention, FIG. 2 is an enlarged bottom view, FIG. 3 is a perspective view showing the same use state, and FIG. It is a graph which shows the influence of the feed per 1 tooth on the cutting edge amount of a tool and the cutting tool which concerns on a prior art example.

As shown in FIGS. 1 and 2, a cutting tool 10 for a brittle material according to an embodiment of the present invention is made of cemented carbide, and an upper holder 11 has a cylindrical shape. Below the middle part, two right-edge, left-twisted blade shapes 12, 13 are formed. The torsion angle of the blades 12, 13 is 75 degrees in this embodiment, but may be larger. Here, if the torsion angle is large, the chipping hardly occurs in cutting, but it becomes difficult to manufacture the cutting tool. In this embodiment, two blades 12 and 13 are used. However, one or three or more blades 12 and 13 can be used, and the present invention can be applied to both straight and tapered shapes.

As shown in FIG. 2, a cutting edge 14 is formed at the tip end of the cutting edge 12 on the side opposite to the screw end of the cutting edge 12, and when the cutting tool 10 for brittle material is rotated in the cutting direction a. The horizontal cutting can be performed by the cutting edge 14. In this embodiment, the cutting edges 14 are two opposed to each other, and the cutting tool 10 for the brittle material is used at the time of cutting.
The bending moment and the vibration are hardly generated at the same time, but depending on the case, one sheet per side is also possible.

An air hole 15 is provided in the axis of the cutting tool 10 for a brittle material. The air hole 15 is mounted on a tool holder having an air supply portion, so that air is released from the tip at the time of cutting, and cutting chips are discharged to the outside. I have to.

FIG. 3 shows a state in which graphite 16 is cut by using the brittle material cutting tool 10. As shown in FIG. 3, the brittle material cutting tool 10 is
While being supplied with air from 5, it is driven by a rotary drive source (not shown), rotated clockwise (b direction), and performs cutting while feeding in c direction. As a result, the graphite 16 is cut by the downward force and the horizontal force in the exit direction of the blade is small, so that there is an effect that the chipping at the upper end and the chipping at the side end can be reduced.

Further, since the cutting tool 10 for brittle material has a cutting edge 14 also at the bottom thereof, the graphite 16 can be flat-processed at the same time. The air is blown out to the outside by the air ejected from the, so that the cutting can be performed extremely smoothly. FIG. 4 shows the case where the cutting tool 10 for brittle material according to the embodiment is used and the case where the cutting tool 50 according to the conventional example as shown in FIGS. 5 and 6 is used. The relationship between the amount and the feed per blade (mm / blade) is shown. As shown in the figure, the brittle material cutting tool 10 has the effect of reducing the chipping amount.

[0012]

As is apparent from the above description, the cutting tool for brittle materials according to the first and second aspects is suitable for cutting brittle materials such as graphite when the upper and side edges are cut. Chipping becomes 1/3 or less of the conventional one. Therefore, machining accuracy of about three times or more can be obtained as compared with the conventional machining conditions, and if the chipping amount is the same, brittle material can be cut at a high speed of about three times or more. The conventional cutting process can be performed at high speed and with high precision.
Also, since the tip has a linear cutting edge for cutting in the rotational direction, it is possible to use the cutting tool as an end mill using the cutting edge, even though the direction of the blade screw is reversed. Since the cutting edge is formed in a straight line, it can be easily repaired and polished when the cutting edge is worn. And since the air hole is provided in the shaft center, the powdery cutting chips fed down by the cutting process can be blown off by the air, whereby smooth end milling can be performed.

[Brief description of the drawings]

FIG. 1 is a front view of a cutting tool for brittle material according to an embodiment of the present invention.

FIG. 2 is an enlarged bottom view of the same.

FIG. 3 is a perspective view showing the same use state.

FIG. 4 is a graph showing the amount of chipping and the feed per tooth of the cutting tool for brittle material and the cutting tool according to the conventional example.

FIG. 5 is a perspective view of a cutting tool according to a conventional example in use.

FIG. 6 is a bottom view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cutting tool for brittle materials 11 Holder part 12 Edge shape 13 Edge shape 14 Cutting edge 15 Air hole 16 Graphite

Claims (2)

(57) [Scope of request for utility model registration] 1. A cutting tool for brittle material having a right edge and a left helix, wherein the right edge has a helix angle of 75 degrees or more, and has a straight cutting edge for cutting in a rotational direction at a tip portion. A cutting tool for brittle materials, characterized in that an air hole is formed in the axis thereof. 2. A cutting tool for brittle material having a left edge and a right twist, wherein the left edge has a torsion angle of 75 degrees or more, and a straight cutting edge for cutting in a rotational direction at a front end. A cutting tool for brittle materials, characterized in that an air hole is formed in the axis thereof.