Abstract
A concept of machining features of 3D free surfaces for process planning of removal operation is proposed. A modeling method for the removal form model defined by considering the concavity as machining features is suggested. In the removal form model, areas are classified and characterized by geometric shape and machining conditions. The proposed judgement method and algorithm for each area are explained concretely, and the effectiveness of them is also shown by examples. The connection relationships between each area are represented as graphs. Information on process planning is obtained from the graphs.
