Ball end mill
AssigneeMitsubishi Materials Corporation
InventorsHidehisa Shiratori, Tatsuo Arai, Masayuki Okawa
Life of this patent
Estimating the term…
Abstract
There is disclosed a ball end mill which has a hemishepherical portion formed at a front end of an end mill body. A pair of tip mounting seats are formed at the hemishepherical portion. A main throw-away tip and a second throw-away tip are secured on the tip mounting seat respectively such that the axial rake angle of the main tip is set at a negative angle and the axial rake angle of the second tip is set at a positive angle. There is also disclosed a second ball end mill. In the second ball end mill, only a main throw-away tip is secured on a tip mounting seat. The axial rake angle of the main tip is set at a negative angle. One or more chip breaker grooves are formed on a rake face of the tip.
Claims13
A ball end mill comprising:
- a tool body rotatable about an axis,
- said tool body having a plurality of tip mounting seats,
- a first throw-away tip and a second throw-away tip being removably mounted in said tip mounting seats,
- said first throw-away tip having a front face and a rear face being parallel to each other,
- one of said front face and said rear face being employed as a cutting face having a main cutting edge disposed at radially outward edge lines thereof,
- said second throw-away tip having a front face and a rear face parallel to each other,
- one of said front face and said rear face of said second tip being employed as a cutting face having a second cutting edge disposed at radially outward edge lines thereof,
- the axial rake angle of said main cutting edge being set at a negative angle,
- said main cutting edge having a forward portion and a rearward portion, at least the forward portion being substantially arcuately shaped when viewed from the rotational direction of said tool body and extending so as to intersect with said axis,
- said second cutting edge having a positive axial rake angle and a forward end, and being disposed circumferentially remote from said main cutting edge, the forward end being disposed radially outwardly remote from said axis.
A single edged ball end mill comprising:
- a tool body rotatable about an axis,
- said tool body having a tip mounting seat,
- a throw-away tip being removably mounted in said tip mounting seat,
- said throw-away tip having a front end face and a rear face parallel to each other, and having side faces peripherally lying between the front face and the rear face,
- said side faces intersecting with the front face in an acute angle, so that only said front face is employed as a cutting face having as main cutting edge disposed at radially outward edge lines thereof,
- said cutting face being inclined with respect to said axis so that the axial rake angle of said main cutting edge is set at a negative angle,
- said main cutting edge having a forward portion and a rearward portion, at least the forward portion being substantially arcuately shaped when viewed from a rotational direction of said tool body and extending so as to intersect with said axis, and
- at least one chip breaker groove extending along the main cutting edge being formed on said cutting face, the width of a land between the main cutting edge and the chip breaker groove being in the range of 0.01 through 0.05 mm, so that the actual axial rake angle defined by the wall of the chip breaker groove is substantially increased.
Dependencies are inferred from the claim text.