Study On Design And Optimization Of Stamping Force And Pressure Center For Progressive Die

Multi-station progressive die is the most efficient, the most suitable for volume-produce of stamping die at present. It is a kind of high-effect, high speed, high quality, long-lived pragmatic die, more and more widely used in many enterprises. To insure the gap of die is uniform, reduce wear of cutting edge and guide parts, improve the life of die, we all hope that die pressure center is in accordance with the center of press slide at utmost. The method in common use for locating pressure center of die is to compute the maximal punching force of all station firstly, then compute action spot of the composite force of all station. The action spot is the pressure center of die. There are two problems to use experience formula to compute the maximal punching force. Firstly, the punch force of continuous strip is greater than the punch force of lump material. Secondly, we can not get the variation of stamping force. The location of pressure center which use stamping force computing from experience formula is not the actual pressure center position and can not get the variation value for pressure center. Besides we must compute punch force before we select press machine. Also must insure that the punch force curve is underneath the pressure curve of press machine. That is to say, the maximum value of stamping force must be less than the press machine can bear. The maximum value of stamping force computing from experience formula is not the right value for selecting press machine.This paper gets the curve of stamping force and pressure center with finite element method, also optimizes stamping force and pressure center, to make die pressure center coincidence with the center of press slide. The researches mainly include:1) Represents the basic theory of sheet forming, discusses the key techniques of numerical simulation of multi-stamping, concludes the multi-stamping finite element numerical simulation method for progressive die.2) Introduces the pressure center locating method with drawing software in detail, gets the offset direction and offset gap used in the method. In order to get the variation of stamping force, numerical simulation is used in this paper. Then we can get the variation of pressure center.3) The optimization method for stamping force and pressure center of progressive die is discussed. Specially discussed the effect of drawing height, model figure, sheet thickness, die round corner radius on the figure of stamping force curve. The center offset optimization method make pressure center and slide center nearer.