Volumetric Precision Modeling, Testing And Reliability Analysis Of Four Axis Horizontal Machining Center

Subject study comes from the major science and technology subject "high-end CNC machine tools and basic manufacturing equipment"-innovation platform of precision horizontal machining center technology, and it focuses on volumetric precision modeling and testing technology research of four axes high-precision horizontal machining center, main research contents are as follows:(1) Volumetric error modeling of four axes horizontal machining centerAccording to the characteristics of four axes horizontal machining center, twenty one geometric errors including position, straightness, angle and perpendicularity errors of three linear axes are gotten by tracing analysis, and volumetric error modeling of four axis horizontal machining center is built by considering the coupling effect of six geometric errors including position, angle errors of rotary axis based on multi-body system theory.(2) Volumetric error identification model and test of four axes horizontal machining centerVolumetric error identification model of four axes horizontal machining center is built based on nine-line method. Geometric errors of THM46100 four axes high-precision horizontal machining center three linear axes are tested by laser interferometer, and twenty one geometric errors are identified by volumetric error identification model. With six geometric errors of rotary axis identified by ballbar and rotary indexing device, volumetric precision of machine tool is tested and analyzed.(3) Volumetric precision optimization analysis of four axes horizontal machining centerWith geometric errors identification data of THM46100 four axes horizontal machining center, key errors are determined by geometric error sensitivity and importance analysis based on volumetric error model. The key error influencing the X, Y, Z three directions of machine tool volumetric precision is position error, position error and straightness error. Volumetric error field is optimized by compensating key error factors and the largest volumetric error is reduced from 0.0564 mm to 0.0278 mm.(4) Volumetric precision reliability evaluation methodVolumetric precision reliability model and evaluation method of four axes horizontal machining center are built. Error sample follows normal distribution by geometric error distribution characteristics analysis of THM46100 four axes horizontal machining center, and X, Y, Z direction and comprehensive error are all subject to normal distribution based on monte carlo simulation method. Volumetric precision reliability is also calculated by volumetric precision reliability model.Volumetric precision modeling and testing of four axes horizontal machining center are carried out in this subject, and the experimental results verify its correctness by applying to the precision test of THM46100 four axes high-precision horizontal machining center in engineering practice. It provides a theoretical guidance for this kind of machine tool volumetric precision design.