| 摘要 |
PURPOSE:To produce a die of high quality for press forming only one layer of padding as a whole quickly and inexpensively by working grooves on the top surface of a base metal only around the round corners of the contour of the inside diameter of the roughly worked base metal and performing padding only from the top surfaces of the grooves. CONSTITUTION:The top surface of a base metal is roughly worked according to need in order to remove oxidized films, etc., and the contour of its inside diameter is beforehand blanked by gas cutting, etc. Next, only the round corners of the contour of the inside diameter are worked with grooves 12 on the top surface of the metal 11 so that they are beforehand cut to the depth required for the longitudinal section suited for padding. Then, one or multiple layers of paddings 13 are applied from the top surface of the grooves 12 according to said depth. Thereafter, the inside surfaces of the parts near the corners are cut in consideration for the thickness of the padding on the inside surface of the metal 11 in the part except near the corner part. Finally, the padding of only one layer is executed on the required parts of the top surface of the metal 11 and down to the prescribed depth of the inside surface, after which these are finished by cutting, whereby the die for drawing of square cylinders is perfected. Here, 15 denotes the padded metal of the inside surface. Inexpensive, strong and tough steel materials such as SS41 are suited for the base metal, and copper-Al alloys, etc. of superior abrasion resistance and seizure resistance are suited for the padding metal. |
