JP2003220519A - Broaching tool for machining high hardness material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broaching tool for machining an inside diameter of a workpiece made of high hardness material and having a petal-like R shape tooth profile having a small radius of curvature, by which broaching tool each chip does not curl toward a center of an R shape tooth profile even in high speed broaching. <P>SOLUTION: In the broaching tools for machining an inside diameter of a workpiece made of high hardness material and having petal-like R shape tooth profiles 100 to 110 having a small radius of curvature, the R shape tooth profiles 100 to 110 are divided into polygons divided by radial lines 70, 71, 72, etc., so as to have corner portions 45, 55, 65, etc. Respective teeth (not shown) of the broach have polygon shape cutting edges, in which the widths of the respective cutting edges of the broach corresponding to the lengths of the sides of the respective polygons gradually increase so as to broach respective sides of the polygons, 41, 42, 43, etc., 51, 52, 53, etc., 61, 62, 63, etc. Consequently, in broaching, chips are separated one another at the corner portions 45, 55, 65, etc., of the polygons, and are discharged. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broaching tool for drilling an inner diameter hole of a high hardness material having a petal-like R shape with a small radius of curvature.

[0002]

2. Description of the Related Art As a broaching tool for processing a high hardness material having a hardness of HRC 35 to 55, for example, the cutting edge of the broaching tool is made of powder high speed steel or cemented carbide as disclosed in JP-A-7-195228. , A broaching tool for processing a hard material coated with a hard film is disclosed, and in JP-A-6-315820, a cutting edge shape of a rough cutting edge is corrugated, and in a cutting direction, a cutting edge is formed. On the other hand, there has been disclosed a broaching tool having a plurality of intermediate blades that shift the corrugated shape and that smooth the cutting surface of the rough cutting blade between the rough cutting blade and the intermediate finishing blade. However, there is no disclosure about petal-like inner diameter hole machining of a high hardness material having an R-shape with a small radius of curvature, and conventionally, such petal-like R-shape inner diameter hole machining with a small radius of curvature is as shown in FIG. An R-shaped cutting blade that is continuous in the axial direction and cuts a machining allowance along the R-shape has been used.

In such a conventional broach as shown in FIG. 4, when cutting at a high speed of 10 m / min or more, the chips to be cut by the R-shaped cutting edge try to wind toward each other in the center of the R-shaped cutting, The debris becomes smaller, making it difficult to wind. Especially when machining high hardness materials, the chips are hard, so
Like the chips 90 shown in Figure 1, the chips broke into a contracted state with a small degree of freedom, and chips that were difficult to flow were generated, shortening the life of the broach tool.

[0004] Further, as shown in Fig. 6, "Progressive Cutting" shown in Fig. 6 as a method of broaching the inner hole of a round hole of a forged or cast metal is shown in page 354 of "New Precision Machinery Handbook" edited by Corona Co. Method has been proposed. With this method, No.1 blade ~ No.1
Up to 8 blades, this is a broaching method in which even-numbered blades and odd-numbered blades have different cutting positions, and blades are arranged so as to alternately cut in the radial direction and the lateral direction. However, this method not only requires a very complicated and labor-intensive broach, but also cuts alternately in the radial direction and the lateral direction. There was a problem similar to that of the broach shown in FIG.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a broaching tool for machining an inner diameter hole of a hard material having a petal-like R shape with a small radius of curvature, and the chips are in the center of the R shape even in high speed cutting. The object is to provide a broaching tool that does not wind toward.

[0006]

Therefore, the present invention provides a petal-like broaching tool for machining an inner diameter hole of a high hardness material having an R shape with a small radius of curvature, wherein the broaching tool has the R shape and a corner portion. Each broach has a polygonal cutting edge in which the width of each broach blade corresponding to the length of the polygonal side gradually increases so that each side of the polygon is broached. The above-mentioned problems of the present invention have been solved by providing a broaching tool for high hardness material processing, characterized in that chips cut at the corners of the polygon are discharged during processing.

[0007]

With this structure, in the broaching process, the chips cut at the corners of the polygon are discharged, so that the hardness of the petals is RRC with a small radius of curvature HRC 40 or more. A broaching tool for drilling inner diameter holes of high hardness materials that does not wind chips toward each other even at high speeds of 10 m / min or more and is easy to wind corresponding to the cutting edge that processes each side. The present invention provides a broaching tool that generates scraps, and improves the life of the broaching tool.

Preferably, the polygonal cutting edge is a finishing cutting edge, the R-shaped cutting edge, and a cutting allowance of one blade.
By setting the thickness to 10 to 15 μm, chips can be easily wound and a clean finish can be obtained even at high speed cutting of 10 m / min or more. Further, the cutting edge of the broach tool is made of powdered high speed steel or cemented carbide, and by applying a hard coating, the life of the broach tool can be further improved.

[0009]

1 is a cross-sectional view of an inner diameter hole of a petal-shaped high-hardness material having an R shape with a small radius of curvature in which the present invention is used. FIG. 2 is an explanatory view showing a broach cutting situation of a single R-shaped processing portion of the inner diameter hole of FIG. 1 by the broach tool for processing a high hardness material according to the embodiment of the present invention. This hardness is a heat-treated steel having a hardness of around HRC 60. The broach tool of the present invention has a petal-like R shape with a small radius of curvature 100, ...
・ In the broaching tool for the inner diameter hole processing of the high hardness material having 110, the R shape 100, ...
Radial lines 70, 71, 72 with 55, 65 ...
・ Divided into polygons divided by, and each side of the polygon 41, 4
2, 43 ..., 51, 52, 53 ..., 61, 62, 63 ...
・ As for broaching, each broach blade (not shown) has a polygonal cutting edge in which the width of each broach blade gradually increases corresponding to the length of the polygonal side. The chips cut at 45, 55, 65, ... Are discharged.

With such a structure, in the broaching by the broaching tool for processing a high hardness material according to the embodiment of the present invention, the cutting chips as shown in FIG. 3 which are cut at the polygonal corner portions 45, 55, 65 ... Since 80 is discharged, a petal-like R shape with a small radius of curvature 100, ... 110
With a broaching tool for inner diameter hole machining of high hardness materials with hardness HRC of 40 or more, chips that process each side so that chips do not wind toward the center of the R shape even at high speed cutting of 10 m / min or more It provides a broaching tool that generates easily-wound chips corresponding to the blade, and improves the life of the broaching tool.

Preferably, the polygonal cutting edge of the broach tool is a round cutting edge (not shown) having the R shape 100, ...
··························· with 10 cutting blades and a cutting allowance of 10 to 15 μm, chips can easily be wound even at high speed cutting of 10 m / min or more, and a clean finish can be obtained. Further, the cutting edge of the broach tool is made of powder high speed steel or cemented carbide, and by applying a hard coating, the life of the broach tool can be further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a petal-shaped inner diameter hole of a high hardness material having an R shape with a small radius of curvature, and a hatched portion indicates a processed portion.

FIG. 2 is an explanatory view showing a broach cutting situation of a machining point having one R shape of the inner diameter hole of FIG. 1 by a broaching tool for machining a high hardness material according to an embodiment of the present invention.

3 is a perspective view of chips broached by the broach tool of FIG.

FIG. 4 is an explanatory view showing a broach cutting situation by a conventional broach tool.

FIG. 5 is a perspective view of chips broached by a conventional broach tool.

[Fig. 6] Corona Publishing Co., Ltd. "New Precision Machinery Handbook" edited by Seiki Society
Explanatory drawing which shows the internal surface broaching method "progressive type cutting method" described on page 354.

[Explanation of symbols]

41, 42, 43 ..., 51, 52, 53 ..., 61, 62,
63 ・ ・ ・ ・ Each side of the polygon 45, 55, 65 ・ ・ ・ ・ ・ Corner portion 100 ・ ・ ・ ・ ・ ・ 110 ・ ・ R-shape with a small radius of curvature like petals

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hidemichi Teranishi             1-1 1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture             Ceremony company Fujikoshinai (72) Inventor Hirotsugu Hirai             1-1 1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture             Ceremony company Fujikoshinai F term (reference) 3C050 BB01 BC01 BD03

Claims (3)

[Claims] 1. A broaching tool for inner diameter hole machining of a high hardness material having a petal-like R shape with a small radius of curvature, wherein the broaching tool divides the R shape into a polygon having a corner portion, Each broach blade has a polygonal cutting edge in which the width of each broach blade corresponding to the length of the polygonal side gradually increases so as to broach each side of the polygon. A broaching tool for processing high hardness materials, characterized in that chips cut at the part are discharged. 2. The polygonal cutting edge is a finishing cutting edge,
The broaching tool for processing high hardness material according to claim 1, wherein the R-shaped cutting edge is used and the machining allowance is 10 to 15 µm. 3. The high hardness material processing according to claim 1 or 2, wherein the cutting edge of the broaching tool is made of powder high speed steel or cemented carbide and is coated with a hard coating. Brooch tool.