Ball end mill

Abstract

In the tip section of an end mill body which is rotated about the axis thereof, a plurality of end cutting edges are formed in such a way as to extend from the inside of the front end of the tip section to the outside of the rear end thereof. In the outer periphery section of the end mill body, there are formed a plurality of peripheral cutting edges which extend to the rear end in such a way as to string out along the outer ends of the end cutting edges. Some of the plurality of end cutting edges are long end cutting edges extending from near that portion of the axis of the end mill body which is in the tip section. The angle which is formed, in an arbitrary cross section intersecting the axis at right angles, by the straight line that connects the axis to a peripheral cutting edge stringing out along a long end cutting edge and by the straight line that connects the axis to a peripheral cutting edge stringing out along the nearest end cutting edge positioned forward of the long end cutting edge in the rotation direction of the end mill, is larger than the angle which is formed, in a view looking at the tip section in the direction of the axis, by the tangent line at the inner end of the aforementioned long end cutting edge and the tangent line at the inner end of the nearest end cutting edge positioned forward of the long end cutting edge in the rotation direction of the end mill.

Description

technical field [0001] this application claims priority based on Japanese Patent Application No. 2009-212128 for which it applied on September 14, 2009, and uses the content here. [0002] The present invention relates to a ball end mill, in which a plurality of hemispherical hemispherical bottom edges are formed at different intervals in the circumferential direction on the front end of the end mill body rotating around the axis . Background technique [0003] As such a ball end mill having cutting edges formed at unequal intervals in the circumferential direction, for example, Patent Document 1 proposes a ball end mill in which a plurality of peripheral cutting edges formed on the outer periphery of the end mill body Among them, the helix angle of at least one peripheral cutting edge is different from that of the other peripheral cutting edges, and an arc-shaped bottom cutting edge whose rotation trajectory forms a hemispherical shape is formed at the front end of the per...

AI Technical Summary

Problems solved by technology

Therefore, chips that are compressed and flow into the chip flutes as described above may be further compressed and cause chip clogging

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