Research Of Sheet Metal Multi-pass Numerical Control Incremental Forming

In the early 1990 s, Japanese scholars proposed a flexible manufacturing technology: Numerical Control Incremental Forming(NCIF). Compared with the traditional sheet metal forming techniques such as stamping, deep drawing, IF is a dieless-forming technology. IF eliminates the complexity of the production process and the high production cost of the mold, and it is processed directly on the blank to obtain the components. It has the characteristics of short production cycle and responsive to market changes, which is very suitable for the preparation and production of small quantities of components.By the finite element simulation of the frustum-shaped member and the analysis of some process parameters such as: the initial forming angle, the incremental depth, the forming rate, the dimension of tool, the interval between the tool and mold, lubricating and so on, we can get some conclusions. The wall thickness after molding equal to the product of the wall thickness before molding and the cosine of forming angle. With the increase of the forming angle, the wall thickness will reduce. And with the reduce of the initial forming angle, incremental depth and forming rate, the quality of sheet metal forming will improve a lot.This paper analyzes the defects that may occur in NCIF process, including forming accuracy, crack, material accumulation, scratches and wrinkles. By setting reasonable processing parameters and traditional multi-pass IF, a vertical-walled cylindrical component was processed successfully. The variation of wall thickness and thickness reduction were analyzed in each pass of multi-pass incremental forming. And mathematical models have been established based on strain and principle of constant volume. A vertical-walled cylindrical component can't be formed by one-pass IF, and multi-pass incremental forming must be used.NCIF was used in production practice. This paper introduced the build of 3D model,generation and optimization of track, and a car light-seat was processed successfully.