关键词: 产品模型数据交换标准, AP203协议, 螺杆, 数控加工, 计算机辅助制造

Abstract: To adapt to the development trend of special-shaped screw's integrated manufacturing technology,a Numerical Control (NC) machining method based on STandard for the Exchange of Product model data (STEP) was proposed.The STEP data model of helical surfaces was identified and the extraction method of the geometric information was researched.An approach to obtain the helical surfaces'parameters was presented by using NURBS' model.The whirling process of helical surfaces and its tool path calculation were investigated.A Computer Aided Manufacturing (CAM) system aiming at special-shaped screws was proposed.The system consisted of information extraction and analysis,feature recognition,tool path calculation,tool path validation and post-processing modules,which realized the integration between design system of special-shaped screws and NC machining system.The main function of the system had been implemented and verified in the machining test.

Key words: standard for exchange of product model data, AP203 procotol, screw;numerical control machining, computer aided manufacturing