Abstract:

In order to address the issues of cutting steps induced by the separated machining of corners and profiles of aircraft structural parts as well as the increase of the cutting force and vibration due to the sharp change of the feed angle at the corner and the contact cutting angle, an integrated machining process and its tool path generation method are proposed for machining the corners and profiles in aircraft structural parts. In the proposed method, profiles and corners in one pocket are machined in one machining operation. Firstly, the allowance is calculated for finish machining which can guarantee the uniform change of the cutting angle within limits. The machining area is also obtained for subsequent tool path. Then by using the combination principle of maximum and constant contact cutting angle in corner positions, the corner material is removed evenly by multiple passes. Therefore the cutting condition is improved. Clothoid curve segments are adopted so as to smoothen the transition of the tool path, ensure the continuous change of the curvature, as well as reduce the vibration of the machine tool. The cutting experiment results show that the proposed method can improve the conditions of the cutting force, reduce vibration during machining as well as improve the surface machining quality.

Key words: aircraft structural part, profile, corner, machining, cutting force