| 摘要 |
PURPOSE:To enable the forming of a circular formings without the use of binders and without the generation of cracks in press dies for said forming which defines the space of a circular shape on the inner side, by providing the contour of a circular shape by means of plural pieces of die members. CONSTITUTION:Press dies are provided with a pair of side plates 16, 16' and a pair of lateral plates 17, 17', and the internal space for pressing are defined by the inside circumferential surfaces of the plates 16, 6' and the plates 17, 17'. More specifically, the internal contour of a circular shape is divided by plural pieces of members for dies. The hindrance of expansion not only in vertical directions but also in a diametral direction by spring back in the stage of releasing the pressure is obviated, and no cracks are generated. |
