Study On Calibration Method Of On-line Measurement System For CNC Machine Tools

With the rapid development of aviation,aerospace and other manufacturing industries,high precision and complex large parts processing and precision evaluation have become a prominent problem in the industry.Aero-engine is regarded as the heart of aircraft,and its quality and performance directly affect the flight safety of aircraft.The accurate detection of aeroengine parts is one of the important means to ensure its quality.Accurate and efficient measurement and detection has been the direction of metrology personnel.On-line measurement system is widely used in the field of machining.Compared with the traditional off-line workpiece measurement method,the on-line measurement has the characteristics of fast sampling speed and high precision,and realizes the digital data acquisition of workpiece measurement.Analysis and accuracy evaluation.Because of the diversity of design structure and complex environment of CNC machine tool,the calibration of on-line measurement system lacks clear measurement standard and calibration method,and its precision calibration is very difficult.In order to make the data of on-line measurement accurate,The measurement value is stable and reliable,so it has important application value in the research of precision calibration technology of online measurement system.In this paper,aiming at the problem of measuring precision of the on-line measuring system of trigger probe,on the basis of the research on the composition and working principle of the on-line measuring system of CNC machine tool,the systematic error structure is analyzed and studied in detail.The main error sources of machine tool error and probe error are analyzed and compensated respectively.According to the research on the working principle of the on-line measurement system and the error affecting its precision,combined with the research of the commonly used geometric parameter detection method,the four-coordinate machining center in our company is taken as the object.A feasible precision calibration scheme of online measurement system is designed,which solves the problem of accuracy calibration of online measurement system.The calibration scheme includes: calibration of main parameters The establishment of the project and the selection and demonstration of the specific calibration methods for each calibration item,the selection of the standard instrument for the use of each calibration item,the limitation of the calibration environment conditions and the regulations of the surveyors.Through this calibration scheme,the error of probe detection,axial length measurement,spatial length measurement and rotation axis error of the on-line measuring system of NC machine tools are calibrated.In this paper,the measurement uncertainty of axial length and space length measurement is analyzed and evaluated to determine whether the calibration method meets the requirements of measurement.Through the research on the calibration method of on-line measurement system,the problem that the on-line measurement part of similar equipment in our enterprise can not be calibrated is solved,and the experience of on-line measurement and calibration of non-contact measurement is provided.The research results provide reliable data support and quality assurance for parts processing and measurement in enterprises.