| 摘要 |
PURPOSE:To simultaneously manufacture a cylinder of an excellent shape at high working speed by forming a slit having circular holes at both ends at the intermediate position of plural cylinders to be drawn, in the case of drawing plural cylinders simultaneously by deep drawing from a sheet of blank. CONSTITUTION:A slit 10 is formed along the width direction (P direction) at the center part in the length direction (L direction) of a rectangular steel plate blank 4 and round holes 11A, 11B in about 5mmphi are formed at both ends thereof. In this case, the length S of the slit 10 is taken at about 85% of the diameter of the cylinder to be drawn. Two cylindrical bodies 5A, 5B are manufactured by performing a deep drawing by the die 2 having punches 1A, 1B and die holes 2A, 2B by using this steel plate blank 4. In this case the material at the intermediate part of the drawn cylinders 5A, 5B is flowed into the cylinders 5A, 5B and the generation of a crack 6 at the inner side of the cylinders 5A, 5B is prevented with the slit 10 being spread. |
