Computer-aided product design system

A system for designing a product having at least a computer, a display connected to the computer for displaying result of processing of the computer, an input device connected to the computer for allowing an engineer to enter data in accordance with a required specification of the product and an interactive program, stored in the computer, for aiding the engineer to design the product through the display and the input device, the program having a shape modelling function realized by 3-dimensional curves and surfaces and including at least:

• product design process for allowing the engineer to design a product model by modelling the product through the shape modelling function;
• and
• mold design process for allowing the engineer to design a mold for producing the product based on the designed product model;
• wherein the program of the product design process comprising;
• basic element constructing means for constructing a basic element that constitutes the product model;
• fillet applying means for applying a fillet on the constructed basic element;
• and
• release draft judging means for judging whether a release draft formed on the constructed basic element with the applied fillet is sufficient for releasing the product from the mold to be designed on the mold design process,
• wherein the release draft judging means includes;
• release draft forming means for forming the release draft on the constructed basic element, and
• wherein the release draft forming means removes the fillet while the release draft is being formed, and restores the fillet after the release draft has been formed.