Plastic working method and spinning machine used in the same

摘要

A spinning machine includes: a main shaft which includes a chuck holding a cylindrical material having a bottom and a regulation member; a mandrel which is inserted inside from an opening side end portion of the material; and a press roller which presses the opening side end portion of the material. The spinning machine molds a circumferential groove portion on the opening side end portion so that an inner diameter of the opening side end portion of the material is smaller than an inner diameter of a body of the material by pushing a press roller while rotating the material around the axial center of the main shaft, and at least a portion of the inserted mandrel is formed so that a gap is provided between the portion and an inner circumferential surface after the opening side end portion of the material is plastically deformed.

主权项

1. A plastic working method comprising:
securing a cylindrical material to a main shaft, the cylindrical material including a bottom wall and an opening side end portion adjacent an end surface; rotating the cylindrical material around an axis of the main shaft; moving a press roller in a direction toward the axial center to engage the cylindrical material and form a circumferential groove portion on an outer circumferential surface of the opening side end portion of the cylindrical material so that an inner diameter of the opening side end portion of the material is smaller than an inner diameter of a body of the material; moving a finishing roller toward an axis of rotation of the main shaft to simultaneously engage the outer circumferential surface and the end surface of the opening side end portion of the cylindrical material, wherein the cylindrical material is supported in an unrestricted state in which an inner circumferential surface of the opening side end portion of the material is freely deformable.