Radius end mill, ball end mill, and end mill

Abstract

The present invention is provided with: a ceramic end mill main body (2); chip discharge grooves (4) formed in an outer periphery of the end mill main body (2); outer peripheral cutting edges (6) formed at intersecting ridge lines between wall surfaces which face in a tool rotation direction (T), in the chip discharge grooves (4), and an outer peripheral surface of the end mill main body (2); base cutting edges formed at intersecting ridge lines between the wall surfaces in the chip discharge grooves (4) and a tip end surface of the end mill main body (2); and corner cutting edges which are located in tip end outer peripheral portions of the end mill main body (2), connect the outer ends of the base cutting edges with the tip ends of the outer peripheral cutting edges (6), and are formed in the shape of convex curved lines which have a convexity facing toward the tip end outer peripheral side of the end mill main body (2). From among the outer peripheral cutting edges (6), the base cutting edges and the corner cutting edges, a radial rake angle (angle alpha) of at least the outer peripheral cutting edges (6) is set to a negative angle. The radial rake angle (angle alpha) of the outer peripheral cutting edges (6) is between -20 deg and -10 deg.

Description

technical field [0001] The invention relates to a circular arc head end mill made of ceramics. [0002] This application claims priority based on Patent Application No. 2015-038218 filed in Japan on February 27, 2015 and Patent Application No. 2015-038219 filed in Japan on February 27, 2015, and the contents thereof are incorporated herein. Background technique [0003] Conventionally, for example, a circular arc end mill made of ceramics as disclosed in Patent Document 1 is known. [0004] This arcuate end mill has a shaft-shaped end mill body, and chip flutes, peripheral cutting edges, bottom cutting edges (tip cutting edges), and edge corners are formed on the end mill cutting body. [0005] During the cutting process, the arc nose end mill is rotated toward the tool rotation direction in the circumferential direction around the axis of the end mill body and is fed (feed) toward the direction intersecting the axis, thereby cutting into the workpiece material. [0006] S...

AI Technical Summary

Problems solved by technology

[0027] However, when the ball end mill is made of ceramics, if the radial rake angle of the outer peripheral cutting edge is increased toward the positive angle side, as described above, the tool angle becomes small and the edge strength cannot be ensured.

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