| 摘要 |
<p>A ball end mill having on the front end of the main body of the end mill: arc shaped cutting edges extending from the tip to the outermost circumferential points curving in a S shape in front view; outer circumferential cutting edges with a spiral shape that connect smoothly to the arc shaped cutting edges; and convex curved cutting faces on the front sides of the arc shaped cutting edges in the rotation direction. Radial direction rake angles of the arc shaped cutting edges satisfy the condition that (ß) < (a) = (?) (provided (a) is the radial direction rake angle when the radial angle is 5° (ß) is the radial direction rake angle when the radial angle is 90° and (?) is the radial direction rake angle at the point of the arc shaped cutting edges that protrudes furthest in the rotation direction). The maximum values for the radial direction rake angle of the arc shaped cutting edges are for radial angles in the range of 12 40° and the radial direction rake angle decreases continuously from the points that protrude furthest in the rotation direction to the outermost circumferential points.</p> |
