JPH0621909U - Cutting tools for brittle materials - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cutting tool for brittle materials, which can be cut with high efficiency without causing chipping. [Structure] A cutting tool 1 for a brittle material having a right-handed left-handed or left-handed right-handed helix having a helix angle of at least 60 degrees or more.
The cutting edge 14 is 0, and the cutting edge 14 is formed in the tip portion as needed, and the air hole 15 is formed in the axial center.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a brittle material cutting tool used when cutting brittle materials such as graphite.

[0002]

[Prior art]

 Although a cutting tool such as an end mill is used when processing a graphite electrode, as shown in FIGS. 5 and 6, the conventional cutting tool 50 is an improved end mill for cutting a metal material. The shape of the blade is a right blade with a right helix angle of about 30 degrees, and has cutting blades 51 and 52 at its tip end, and is made of an abrasion resistant material.

[0003]

[Problems to be solved by the device]

 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 portion, and further, a large force is applied to the outlet side of the blade for cutting, so that the upper portion of the graphite 53 is cut. And the side surface will be chipped (hereinafter referred to as “koba chip”). If chips are generated at the corners of the electrical discharge machining graphite used for mold making, they are transferred to the surface of the mold to be manufactured, so it is necessary to avoid such chipping as much as possible. The amount of feed per hit was extremely small for cutting. Therefore, there is a problem that the processing efficiency is extremely poor. Moreover, such problems are not limited to graphite, but commonly occur in ceramic green body processing, sintering material pre-sintering processing, cutting of viscous products, or processing of crockery products with relatively machinability. It was a point. The present invention has been made in view of the above circumstances, and an object thereof is to provide a cutting tool for brittle materials that can be cut with high efficiency without causing chipping.

[0004]

[Means for Solving the Problems]

 The cutting tool for brittle materials according to the first aspect of the present invention is a cutting tool having a right-handed and left-handed helix having a helix angle of at least 60 degrees or more. A cutting tool for brittle materials according to a second aspect of the present invention is constituted by a left-handed and right-handed cutting tool having a helix angle of at least 60 degrees or more. A cutting tool for brittle materials according to a third aspect of the present invention is the cutting tool according to the first or second aspect of the present invention, which is configured such that a tip portion is provided with a cutting edge for cutting in a rotational direction. The cutting tool for brittle materials according to a fourth aspect is the cutting tool according to the third aspect, wherein an air hole is formed in the shaft center.

[0005]

[Action]

 In the brittle material cutting tool according to claim 1, since the tool has a right blade, the tool is rotated to the right in use, but since the blade has a left twist, the cutting material is moved downward. To eliminate the chipping of the top edge, and because the twist angle is more than 60 degrees, the force on the material in the direction orthogonal to the axis of the cutting tool during cutting is reduced, which results in There is no side edge chipping. The cutting tool for brittle materials according to the second aspect has the same action as the cutting tool according to the first aspect by rotating the cutting tool counterclockwise when the cutting tool is used. In the brittle material cutting tool according to claim 3, since the cutting edge for cutting in the rotational direction is provided at the tip, the cutting edge is used even though the direction of the blade screw is reversed. The cutting tool can be used as an end mill. In the brittle material cutting tool according to the fourth aspect, since the air hole is provided in the shaft center, it is possible to blow off the powdery cutting chips fed downward by the cutting process with air.

[0006]

【Example】

 Next, an embodiment of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. FIG. 1 is a front view of a brittle material cutting tool 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 usage state, and FIG. 4 is the brittle material cutting tool. It is a graph which shows the influence of the feed per blade on the amount of chipping of the tool and the cutting tool according to the conventional example.

As shown in FIGS. 1 and 2, a brittle material cutting tool 10 according to an embodiment of the present invention is made of cemented carbide, and an upper holder portion 11 has a cylindrical shape. Below the middle portion, two right-handed and left-handed blade shapes 12 and 13 are formed. Although the twist angles of the blade shapes 12 and 13 are 75 degrees in this embodiment, they can be set to 60 degrees, for example, and other angles of 60 degrees or more are also possible. Here, if the helix angle is large, it is difficult for the chip to be produced during cutting, but it is difficult to manufacture the cutting tool. Therefore, the practical helix angle is set to 60 degrees or more. Further, in this embodiment, the two-edge blade shapes 12 and 13 are used, but it is also possible to have one or three or more edges, and either straight or tapered shape can be used.

Then, as shown in FIG. 2, when a cutting edge 14 is formed at the tip portion on the side opposite to the screw end of the blade shape 12, and the cutting tool 10 for brittle material is rotated in the cutting direction a. The cutting edge 14 can perform horizontal processing. In this embodiment, the two cutting edges 14 are opposed to each other so that the bending tool and the vibration are less likely to occur in the brittle material cutting tool 10 at the time of cutting, but in some cases, one cutting edge is also possible. Is.

An air hole 15 is provided in the shaft center of the brittle material cutting tool 10 and is attached to a tool holder having an air supply portion so that air is discharged from the tip during cutting and cutting chips are discharged to the outside. I have to.

FIG. 3 shows a state in which the graphite 16 is cut by using the brittle material cutting tool 10. As shown in FIG. While being supplied, it is driven by a rotary drive source (not shown), rotated in the clockwise direction (direction b), and cutting is performed while feeding in the direction c. As a result, the graphite 16 is cut by a force from the upper side to the lower side, and the horizontal force in the outlet 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 are small.

Further, since the cutting tool 10 for brittle material also has a cutting edge 14 at the bottom thereof, the planar processing of the graphite 16 can be performed at the same time, and the cutting waste generated by the above cutting operation is Air blown out from the holes blows the air to the outside, enabling extremely smooth cutting. FIG. 4 shows the chipping of the upper and side plates when the cutting tool for brittle material 10 according to the example is used and when 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 an effect of less chipping.

[0012]

[Effect of device]

 As is clear from the above description, the cutting tools for brittle materials according to claims 1 to 4 have no chipping at the upper and side edges when cutting brittle materials such as graphite. / 3 or less. Therefore, under the conventional processing conditions, it is possible to obtain a processing accuracy of about 3 times or more, and if the chipping amount is the same, it is possible to perform the cutting of brittle materials at a speed of about 3 times or more. As a result, conventional cutting can be performed at high speed and with high precision.

[Brief description of drawings]

FIG. 1 is a front view of a brittle material cutting tool 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 usage state.

FIG. 4 is a graph showing the amount of chipping and the feed per blade of the brittle material cutting tool and the conventional cutting tool.

FIG. 5 is a perspective view showing a usage state of a cutting tool according to a conventional example.

FIG. 6 is a bottom view of the same.

[Explanation of symbols]

 10 Cutting Tool for Brittle Materials 11 Holder 12 Flute 13 Flute 14 Cutting Edge 15 Air Hole 16 Graphite

Claims (4)

[Scope of utility model registration request] 1. A cutting tool for brittle materials with a right-handed and left-handed helix having a helix angle of at least 60 degrees or more. 2. A cutting tool for a left-handed and right-handed brittle material having a helix angle of at least 60 degrees or more. 3. The cutting tool for brittle material according to claim 1, wherein a cutting edge for cutting in a rotational direction is provided on a tip portion. 4. The cutting tool for brittle materials according to claim 3, wherein air holes are formed in the shaft center.