| 摘要 |
PROBLEM TO BE SOLVED: To provide a precision blanking method capable of surpassing the traditional fine blanking and the opposed dies process in addition to the inexpensive and maintenance-free precision blanking method. SOLUTION: Ramming juts 12, 17 on the top die 10 and bottom die 16 are pushed into the two sides surface of a stock 20 by the hydraulic press to form deep ramming grooves, by which a metal flow-inhibiting wall is constituted in the opposed position of the two sides surface of the stock. Blanking is performed by the punch 18 in the forming condition of the metal flow-inhibiting wall. When an outer vertical pressing force for blanking is impressed on the stock, side runout component force generated is caught by the metal flow- inhibiting wall, and an internal secondary fresh water pressure occurs and under the addition of the internal secondary fresh water pressure against the primary outer vertical pressing force, stock 20 is blanked by the punch 18. |
