Presented in this thesis is a Computer Automated Process Planning/Computer Aided Manufacturing(CAPP/CAM) integration scheme for die machining. Die surfaces usually have free-formed geometry of complex shapes. It takes tens of hours to machine a die from a solid block and, in many cases, the same amount of time is required for preparing NC tool paths for the die machining. Another difficulty with NC machining of die is that it is easy to overcut the die surface and to overload the cutting tools.
The proposed CAPP/CAM integration scheme consists of three phases: 1) preprocessing via CAD interface, 2) process planning, and 3) NC data generation. Input to the system are a die surface geometry to be generated, the shapes of solid block, a set of available cutting tools(eg, drills, ball endmills, and flat endmills), machinability data, etc. In the preprocessing stage, the input geometry (from a CAD system) is converted to the so called Z-map form. Especially efficient NURB data conversion method is proposed. In the second stage, a sequence of machining operations together with cutting tools to be used is generated by using a backward recursion method. Actual NC cutter paths and machining parameters are generated in the final stage. A prototype CAPP/CAM integration system has been implimented in workstation environment using C language.
Also the proposed method of CAPP/CAM integration scheme is applied to concurrent engineering of die machining. The proposed scheme is found to be quite effective and useful to concurrent manufacture of die.
