| 摘要 |
PURPOSE:To expand and contract the split end parts of a cam piece and forge the same to an undercut part of a predetermined shape by the impact thereof by making a half-finished product having a recess smaller than a predetermined shape, making the cam piece face the recess then vertically moving the punch of the inside surface. CONSTITUTION:A semi-finished product 1 provided with a recess 8 having an inside surface 7 which is smaller than a predetermined shape and is approximately staight is put into the recess 12 of a die 11. A cam piece 26 having an outside surface 30 of approximately the same shape as that of the spherical inside surface of the product is inserted into the recess 8. A punch 17 is lowered by lowering a press slide 16, and the cam piece 26 is expanded outward by the downward truncated hexagonal cone face 25 of the end part 17a thereof so that the outside surface 30 thereof makes press-contact with the inside surface 7 of the semifinished product. In this way, the outside surface 30 of the cam piece 26 is expanded and contracted by the vertical movement of the punch 17, and the inside surface 7 of the semifinished product is forged to the undercut of a predetermined shape. |
