| 摘要 |
PURPOSE:To elevate productivity and to reduce a cost by forming a cross groove on the inner periphery of a blank material with overlaying a cylindrical blank material by a drawing and ironing works. CONSTITUTION:A cylindrical blank material 31 is fitted to the tip of a mandrel 13 and groove forming punch 19. With the descent of a upper die 3 a presser die 28 presses to lower part against the cushion action of each cylinder mechanisms 7, 17 the mandrel 13 and groove forming punch 19 via the blank material 31. The cylindrical part 31b is worked with drawing with ironing by a die 27 due to the displacement of the shaft 31a of the blank shape material 31 toward the lower part with its being formed by the pressser die 28 accordingly. The wall of the cylindrical part 31b is therefore approached to the mandrel 13 and groove forming punch 19 and plural cross grooves are formed at one time on the inner periphery of the cylindrical part 31b and a forming article is formed. |
