| 摘要 |
PURPOSE:To obtain a product of high quality by cold drawing of a blank in making the body of a cylinder by drawing a blank blanked from a steel plate by trimming the peripheral of opening in the course of working. CONSTITUTION:After annealing a blank 1 blanked from a steel plate, the blank is worked successively to a cylindrical body 2a-2c by drawing of the first - third processes. Then, the periphery of the flange part 3 of the cylindrical body 2c is removed by trimming and semimanufactured product 4 is formed. Thus, generation of cracks from the periphery of flange part is eradicated, and cracking of the part is prevented by succeeding drawing work. Works similar to the above are made on the semimanufactured product 4 by drawing works of the fifth - eighth processes to obtain a cylindrical body 5d. The outer periphery of the flange part 6 is trimmed for sizing and the second semimanufactured product 7 is obtained. Further, the spread of opening of the semimanufactured product 7 is corrected and a cylinder 8 in which the opening part is made linear is obtained. |
