Research On Deep Hole Cylindricity Measurement System Based On Spatial Straight Line-datum

High-end equipment puts forward more and more stringent geometric accuracy requirements for the required precision parts.Special structural parts with different manufacturing methods and different purposes require special precision measurement equipment,which promotes the continuous development of precision measurement equipment to high-end and specialization.For the cylindricity of special deep-hole parts,various manual measurement and evaluation methods or other geometric errors are used for simple replacement,and the consistency is poor and the accuracy cannot be guaranteed.Deep-hole parts have small space and long span.At present,there is an urgent need for automated measurement methods with high measurement accuracy and efficiency.This paper is oriented to the research on the precision measurement technology of cylindricity for deep hole parts with large aspect ratio.Based on the precision index and measurement requirements,a deep hole cylindricity measurement system is constructed based on the spatial datum-line of non-diffracting beam.It can adapt to the centering mechanism of different apertures and analyzes the centering error.The cross-sectional error mechanism of the measurement system is studied and an effective compensation method is proposed.A special interactive software for cylindricity measurement is written and related experiments are carried out.The main research contents are as follows:1 Construction of deep hole cylindricity measurement system.Starting from actual needs,a deep hole cylindricity measurement system was constructed,and the design of the system measurement principle,mechanical structure,electronic control components and interactive software was completed,and the data processing process was modeled to form an integrated measurement process.2 Structural design of the measurement system.For the centering mechanism,an ideal kinematic model is established and the accuracy of the model is verified through simulation.The multiple joint clearance of the mechanism are analyzed and the clearance error constraint model is established.The relationship between the joint clearance and the output position error is deduced and verified by simulation,which shows that the mechanism has good centering performance under actual process constraints.The design of other parts was carried out,and the deformation of the key parts was analyzed based on the finite element method,which verified the reliability of the structure.3 Cross-section error compensation based on pose path and cylindricity evaluation.Aiming at the problem of skew error in the cylindricity measurement,the cross-sectional skew error mechanism of the deep hole cylindricity measurement system is analyzed,and the error model is established and analyzed,and an error compensation method based on the pose path is proposed.Designed the cylindricity evaluation method for the imaging system in this paper,and compiled each method into the interactive software to improve the accuracy at the software level.4 Experiment and uncertainty analysis.The process of obtaining cylindricity data was analyzed in detail,a complete calibration scheme for each part of the system was designed and corresponding calibration experiments were carried out.The validity and reliability of the compensation method and cylindricity evaluation software are verified by the measured deep hole data.The uncertainty components of each influencing factor are determined,and the expanded uncertainty of the cylindricity measurement results is derived to meet the technical indicators and requirements of the subject.