Researches And Development On Commerical Five-axis NC Machining Post Processing Software

Generally, the complete information of tool path can been acquired with calculation functions provided by the common CAD/CAM software. However, in order to meet the processing requirement of NC machine, post-processing of the product model data is needed to acquire NC code, which can be applied to the specific type of NC machine. Such post processing is to translates cutter-location files generated by various CAD software into NC processing programs that corresponding NC machine can identify. The quality of post-processing directly affects the machining quality of parts, the efficiency and the reliable operation of the machine.China does not own any independent intellectual property rights of commercial post processing software, which relies heavily on import of commercial CAD/CAM software and other post processing software. The research and development work of this dissertation tries to make up for this gap in our country. The details of the work are as follows:1) Motions of three major categories of five-axis NC machines, which include twelve typical structures, are studied first. And then take the five-axis NC machine with the type of A-C axis as an example, detail study is conducted on the motion model. The coordinate transformation formula are derived for the case of which the axis of rotation and clamping of work-pieces are off-center. the formula is then applied in the software developed. The developed post-processing algorithm is validated by computer simulation as well as the actual machining of the parts.2) The calculation model of nonlinear motion error is analyzed in detail in the work, and the calculation of the maximum error of the nonlinear motion representaion was deduced. Two kinds of control methods for nonlinear error are analyzed:first, during the post-process, using the adaptive linear method for nonlinear error checking control; second, activate the RTCP function of NC system, which can control the non-linear motion error effectively.3) A generation scheme for post processing system is designed. The scheme requires input of cutter location files and the NC system properties files to generate NC codes. In order to make the post processing system has a robust adaptability for future demand, a script compiling system is designed and implemented in the post-processing system. The design and development process of the compiler for NC system characteristics files is analyzed, including lexical analysis, syntax analysis, executable code generation, etc.Last but not the least, the research results in this work are integrated into the domestic ZW3D CAD/CAM software, thus improve the native software with independent intellectual property rights for integration of three-dimensional design and processing.