Development of CAPP system for removal operation of 3D free surfaces

The authors deal with the development of a computer aided process planning system (CAPP) for manufacturing products having 3D free-form surfaces. It is difficult to perform a form feature modeling of free-form surfaces, and to clear the relationship between the removal form and cutting tool form. To solve these problems, the authors extract the concavity of the product model by paying attention to the product concavity. Considering that the concavity is the most important part in the machining of the free surface, a local concavity model is produced by judging concavo-convex. This model is analyzed and characterized with geometric shape and machining conditions. The connection relationship between each area is represented as graphs. The authors carried out the process planning using the form feature model