Development of Fine Blanking Die with Fluid Chamber and its Application to Procuction of Circular Blanks in a Hydraulic Press

간이 파인 블랭킹 금형의 개발을 통한 범용 유압 프레스에서의 원형 정밀진단 가공성 연구

This paper is concered on the development of low-cost fine blanking die with two fluid chambers of which the pressure can be controlled by a hydraulic unit and its application to producting circular blanks in a conventional hydraulic press, not in a special triple-action press usually adopte in fine blanking operation. Four important working parameters affecting on the precision accuracy of products such as existence and position of Vee-ring, stripping force and counter punching force are primarily considered for experiments. Finite element analysis by suing ABAQUA software is approxi- mately made for blanking of circular specimen with a flat stripper plate and then compared with experimental measurements. The the theoretical prediction of camber height which represents deflection of a dish-shaped specimen after blanking seems to give a qualitatively good agreement. It is shown through experiments the the camber height decreases with decreasing stripping force and also with increasing counter punching force, but particularly depending on the latter much more than the former.