Study On Optical Precision Measuring Principle And Technology Of Inner Diameter

With the rapid development of Chinese automobile industry, higher demands to the performance of the engine is needed, and the accuracy of between shaft and hole on the engine box has a direct impact on the overall performance of the engine, high precision and high intelligence inner diameter measuring system is an important foundation for achieving the ideal match. In this article, refer to the measurement method of pneumatic measuring instrument, adopted uniform distribution of multi-probe program, single probe basing on the laser triangulation principle, using position sensitive detector PSD as optoelectronic receiver, combining with calibration of measuring system, a new type of inner diameter precise measuring system and achieve the measurement of inner diameter is proposed. The measuring system researched in this paper has a large working space from the surface, it can achieve online automatic measurement functions, and it can fulfill the online measurement and quality control.This paper is organized as followed:1. advantages and disadvantages of optical inner diameter measuring method are analyzed, according to the actual measurement requirements of this subject, overall measurement program is proposed,2. according to the measuring requirements and environment of holes of the engine box, combined with current measuring technology, the whole designed program is studied out, and the principle adopted by the probe is deeply studied,3. mathematical model of measuring shaft is comparatively studied, the probes relationships among the position errors, assembly errors and measuring precision is built,4. reasonable choices of the optical imaging system components of the probe are made, and based on this, the mechanical structure of measuring system is designed,5. calibration method of this measuring system is designed, and errors on calibration and transmission are analyzed .