| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of the twist caused by the difference in the lead width of a lead frame material to be punched, and the generation of the twist caused by the abrasion of a punch blade tip by providing a material holding projecting part and a sloping lever to adjust the height of the material holding projecting part on a stripper. SOLUTION: The height of a projecting part is increased when the lead width of a lead frame material 1 is small and the pressure must be increased, and also increased when a blade tip of a punch 3 is worn and its punching resistance is increased. The degree of the increase is appropriately adjusted according to the lead width and the material of the lead frame material 1. When the blade tip of the punch 3 is worn, its punching resistance is increased, and the twist is generated, a sloping lever 7 is adjusted, and the height of the projecting part is increased to eliminate the twist. Even when the blade tip of the punch 3 is worn, the punch can still be used by adjusting the height of the projecting part, and thus, the service life of a punching die can be improved. This means that the maintenance time of the punching die can be shortened.
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