Sequential Forming of Sheet Metal Parts.

摘要

The objective of this program was to investigate the possibility of radically improving the productivity of sheet metal forming processes through innovative mechanistic and control system designs. Two prototype forming machines were designed, constructed and evaluated. An adaptive brakeforming system was designed and constructed. This computer-controlled brakeforming system uses direct measurement of the sheet angle to automatically compensate for springback of material. Potential benefits from adaptive brakeforming include reduced setup time, improved quality control, insensitivity to material property variations and improved operator safety. Cost reductions from reduced setup time alone were estimated at $500,000 per year or 18%. A prototype discrete die surface (DDS) was also designed and constructed. The device consists of an array of die elements or rods which are free to slide in a housing. The die elements can be positioned to preprogrammed locations under computer control. The device can also measure the positions of individual die elements. A computer program was developed to calculate pin locations which would produce a desired unloaded shape. Forming experiments on 6061 T3 aluminum were performed in which specimens were formed to circular shape using the discrete die surface.