End mill and manufacturing method of same

Abstract

PROBLEM TO BE SOLVED: To provide an end mill having stable cutting performance even in a small diameter of 2 mm or less, and a manufacturing method therefor.SOLUTION: This end mill is formed with at least a pair of cutting edges 13 in chip part tips on the side opposite to each other with an axis 0 therebetween, in a tool tip part 12 of a chip part 11 rotated around the axis 0, wherein an outside diameter of the cutting edge 13 is 2 mm or less, the entire tool tip part 12 is shape-formed by laser machining, and a chamfer 19 is formed band-likely on a cutting face 16 side of the cutting edge 13 by laser machining.

Description

technical field [0001] The present invention relates to an end mill capable of stably performing milling with a small diameter of 2 mm or less and a method for manufacturing the same. Background technique [0002] In recent years, end mills using cemented carbide, sintered diamond, and cubic boron nitride (hereinafter referred to as cBN) sintered bodies have been provided as tools for processing molds used in manufacturing housings of mobile phones and the like. In particular, cBN has the hardness second only to diamond, and has low chemical reactivity with metals such as Fe, Co, and Ni, so it is the most suitable material for mold processing. Among the end mills using cBN, it is possible to perform long-life machining in the cutting of very hard hardened steel above 60HRC, which has been short-lived in the past, and to provide high-precision, long-life dies. , especially in small-diameter end mills with a diameter of 2mm or less, there is a prospect of increasing demand in...

AI Technical Summary

Problems solved by technology

[0011] In the above-mentioned conventional end mill processing method, the cutting edge is formed by cutting or grinding using a grinding wheel. chamfering, there are disadvantages such as not being able to form a stable chamfering

That is, when a mechanical load from the grinding wheel is applied to a small-diameter and thin end mill, the shape of the grinding wheel itself changes over time, and the surface roughness increases and the width of the chamfer also varies, which is difficult. Form a stable chamfer

It is especially difficult when it is a material with very high hardness such as cBN sintered body

For example, if Figure 12 As shown, when making a small-diameter ball nose end mill 1, when using a grinding wheel to form a chamfer 2, because the grinding wheel is in contact with the rake face 4 side of the curved blade 13 while cutting, so grinding Cutting resistance changes depending on the location, so the deflection of the end mill during processing changes, so that it cannot be processed uniformly, and a part with a narrow chamfer width is generated in the middle

In this way, if the deformed chamfer 2 is formed locally with a narrow chamfer width, the edge strength of the blade 2 is locally lowered to shorten the life, or the release of chips is deteriorated, and stable cutting performance cannot be obtained.

Therefore, in the past, it was not possible to form high-precision chamfers with small-diameter end mills with a diameter of 2mm or less, and it was difficult to perform stable cutting.

In addition, it is difficult to manufacture a small-diameter ball nose end mill with a diameter of 2 mm or less in the method of attaching a plate-shaped cBN insert or a diamond insert to the end mill body.

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