Cutting inserts and indexable insert type rotary cutting tools

Abstract

The cutting insert of the present invention has a rake face, a flank face, and a cutting edge, and the cutting edge has: a convex arc-shaped bottom cutting edge located at the front end in the direction of the central axis; The outer ends are connected and have a convex arc-shaped peripheral cutting edge whose curvature radius is larger than that of the bottom cutting edge, and the tangent line formed at the boundary point between the bottom cutting edge and the peripheral cutting edge and the central axis The angle between them is less than 45°, the radius of curvature R1 of the bottom cutting edge is 0.3-10 mm, and the ratio (R2 / R1) of the radius of curvature R2 of the outer peripheral cutting edge to the radius of curvature R1 of the bottom cutting edge is 3.6 ~333.

Description

technical field [0001] The present invention relates to a cutting insert suitable for cutting metal parts, etc., and an indexable insert type rotary cutting tool using the cutting insert. [0002] This application claims priority based on Patent Application No. 2016-165904 for which it applied in Japan on August 26, 2016, and uses the content here. Background technique [0003] Conventionally, an indexable insert type ball end mill as described in, for example, the following Patent Document 1 is known. An indexable insert type ball nose end mill is used, for example, when machining a curved surface of a vertical wall portion (vertical wall surface processing) or the like on a workpiece. [0004] Patent Document 1: Japanese Patent Laid-Open No. H10-315031 [0005] However, the existing indexable insert type ball end mills have the following problems. [0006] When performing vertical wall surface processing on a workpiece, it is difficult to improve processing efficiency w...

AI Technical Summary

Problems solved by technology

In detail, using Figure 11 In the cross-sectional observation of the machined surface of the workpiece W after being cut by the conventional ball nose end mill shown in (b), it is difficult to control the tip height CH of the machined mark on the machined surface to a predetermined value or less. Increase the periodic feed pitch P

[0007] In addition, it is impossible to finish the concave corner portion (vertical wall bottom corner portion) formed on the connection portion between the vertical wall surface and the bottom wall surface of the workpiece.

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