An Experimental Study on the Clearance Design of Fine Blanking Tool for High-Strength Steel Special Parts with Various Inner Corner Shapes

Abstract

The clearance between the punch and die of a fine blanking tool is an important design factor that affects the sheared surface of a product. In a fine blanking process, the clearance is typically assigned a 0.5% material thickness. If the clearance is too big, a fractured surface would occur in the product while if it is too small, bulging would occur.In this study, a setting for optimum clearance was proposed for inner corner shapes by checking shear characteristics and bulging effects according to various clearances. After designing a special part with various corner shapes possessing SPFH590 (thickness: 4 mm), a high-strength steel material, a fine blanking tool was constructed and fine blanking experiments were conducted. The result could be usefully applied in fine blanking processes for high-strength steel automobile parts with corner shapes in the future.