Research On Calculation Model Of Forming Force In Medium-thick Sheet Metal Extrusion Process

In the field of medium-thick sheet metal production, fineblanking as one of the precision metal forming technologies has been a very important method. Compound fineblanking-forming process has been a significant trend of fineblanking technology, which is widely used in different areas, such as automotive and general machinery. In this paper, the medium-thick sheet metal extrusion process is selected for the research of medium-thick sheet metal bulk forming processes. The numerical simulation technology as well as physical experiments has been studied. The main research findings are as follows.1. A series of sheet metal extrusion process simulations were conducted under different combination of process parameters, which were arranged by the orthogonal experiments method. The results show that the key factors which affect the forming force in different phase of the extrusion process are extrusion ratio and material type; the original sheet thickness、die radius and friction factor affect the forming force a lot as well; punch radius has little effect on the forming force. Furthermore, friction factor affects the forming force significantly with the increase of the punch penetration depth.2. Experimental extrusion die was designed and physical experiments were carried out. A series of force-displacement curve of different process parameters were obtained which can be used to validate the calculation model.3. A new calculation model based on the research of C15 steel has been established which is weighted superposition of shearing force and extrusion force. The parameters in the model are determined by analyzing the influence of reduction, punch penetration depth, etc. Validated by the experiments, the proposed model is acceptable for engineering calculation.