Research On Thread Axis Measurement Technology Based On Three Coordinate Measuring Machine

In this paper,in the process of aviation equipment maintenance,it is difficult to actually measure the shape and position errors of the self-made mechanical parts and the thread axis.The method of measuring the thread axis based on three coordinates is proposed,and the system research and test are carried out.The comprehensive results are in line with expectations,can meet the inspection and testing requirements in the processing of aerospace parts,and solve the technical problem of shape position tolerance measurement related to the thread axis..The main research contents include:1.The basic principle of measuring the diameter of the external thread and the axis of the thread by three-coordinate measurement is studied.A multi-point fitting based on the measurement of the three-coordinate thread diameter is proposed to form a medium-diameter cylinder,and then the thread axis is extracted.Through analysis,the basic mathematical model of the three-coordinate measurement of the intermediate diameter of the external thread is given.2.The main problems and key technologies for measuring the existence of threads based on CMM are analyzed,Including the selection and implementation of the stylus,the accurate detection of the measuring point in the middle diameter position,the measurement strategy of the threaded cylinder,and the automatic measurement programming method and steps,At the same time,detailed measurement procedures and precautions are given.The innovative use of the internal measuring thread of the measuring machine to measure the combination of the T-type double-ball stylus and the three-coordinate stylus solves the stylus problem.3.Taking the actual parts as the starting point and fully considering the practical application of the research results,the experimental verification scheme and experimental verification samples were designed.A thorough measurement verification work was carried out.Based on the data of the measurement experiment,a comprehensive,in-depth and systematic analysis was carried out,and the uncertainty of the measurement results was evaluated.The accuracy and reliability of the measurement are verified by the detection capability index MCP,which can meet the detection requirements.