| 摘要 |
PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a clutch cover having an opening. SOLUTION: This method is a method for forming the clutch cover 2 having side wall holes 24a, 24b, 24c by executing press working to a planar blank and piercing, 1st chipping-off, 2nd chipping-off and drawing are prepared. In this method, the opening is made by executing punching to the blank by piercing. Next, by the 1st and 2nd chipping-off, using a punch and die having smaller clearance than that at the time of piercing, punching is executed to the periphery of the openings made on the blank. By drawing, draw-forming is executed to the blank on which holes are made.
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