Patent ID: 11925978
Assignee: KABUSHIKI KAISHA F.C.C.
Field: Machine tools (Mechanical engineering)
Classification: CPC B  F  C | IPC B  C  F

Claim 3:
4. An aluminum casting comprising:
an aluminum casting with at least two projections that extend in an axial direction away from one another and the at least two projections are continuously arranged in a circumferential direction forming first and second cylindrical walls;
projecting end portions on the first cylindrical wall are cut along a processing line with a predetermined processing diameter to obtain splines of predetermined dimensions, forming splines of predetermined dimensions on an inner wall portion of the first cylindrical wall and forming splines of predetermined dimensions on a wall portion of the second cylindrical wall; and each projection is formed with side surfaces tapered in a direction from a base end to a projecting end;
a portion of each side surface that is cut adjacent to the projecting end and that is cut in the cutting step is either an inclined surface or a rounded portion; the adjacent projecting end surface having an inclination angle less than an inclination angle of a portion of the side surface that is adjacent to the base end, and
each projection is formed such that a projecting end surface is inclined with respect to the axial direction and that the adjacent projecting end surface or the rounded portion has a width, along the axial direction, that is greater in a region where the projecting end surface, furthest from the base, is high, than in a region where the projecting end surface is low.