Ball end mill
AssigneeSumitomo Electric Hardmetal Corp.
InventorsKazuo Maeda, Kouji Tominaga
Life of this patent
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Abstract
A ball end mill in which a ball end cutting edge (3) has a convex shape in a tool rotation direction with respect to a line connecting a rotation center (O) and a radially outer end (3o) of the ball end cutting edge (3), in a front view of the tool. In the ball end mill, a rake angle (γ) of each portion of the ball end cutting edge (3) is set in a range from −10° to 0°, and the negative value of the rake angle (γ) is increased from a tip of the ball end cutting edge (3) and a radially outer end (3o) of the ball end cutting edge (3) toward a middle point in the radial direction, and is maximized at approximately the middle point in the radial direction.
Claims6
A ball end mill including a ball end cutting edge (3) having a shape of an arc of approximately a quarter circle, wherein:
- a rake angle γ of each of portions of the ball end cutting edge (3) is set in a range from −10° to 0°,
- the negative value of the rake angle γ is increased from a tip of the ball end cutting edge (3) and a radially outer end (3o) of the ball end cutting edge (3) toward a middle point of the quarter circle, and is maximized at approximately a middle point of the quarter circle,
- the ball end cutting edge (3) has a convex shape in a tool rotation direction with respect to a line (L1) connecting a rotation center (O) and the radially outer end (3o) of the ball end cutting edge in a front view of the tool, and
- the ball end cutting edge (3) has a rake face along the ball end cutting (3) having a convexly curved surface in a view along a direction vertical to a plane where the ball end cutting edge (3) appears as approximately a quarter circle.
Dependencies are inferred from the claim text.