A Direct Engineering Approach to Draw Die Binder Development Design

A method of designing the binder developments of draw dies for sheet metal stampings that integrates the mathematics of formability, kinematics and friction into the design (i.e. synthesis) process is described. The method is in four phases: (1) Forming feasibility of the product design, (2) 3D wireframe design of the addendum, (3) Surfacing of the addendum, and (4) Productionizing the design. The objectives (e.g., splits, wrinkles, spring-back, etc) are converted to strains and displacements that must be imposed at strategic locations and then a 3D wireframe of true arcs is constructed to approximate the product geometry. The forming feasibility is then calculated for each arc of the wireframe outward in sequence from the defined strategic conditions quantifying the force-displacement energy continuum that must be imposed at the edge-of-part. The construction of the wire frame is then continued outward arc-by-arc to create the die addendum shape that will impose the required energy onto the edge-of-part, the length of line required in the wrap surface and the blank size. The design is then surfaced and checked with simulation and finally the actual die surfaces are extracted and offset as needed for the production die. The method minimizes redundant simulation-design iterations for both product and die, can be applied when the vehicle is in the architecture stage of development, identifies the location of root causes and reduced total lead time.