Design and Testing Method of Geometric Tolerances for Deep Stepped Hole

Abstract

Effective process checking tool is an important means to control the first pass rate and machining quality of large-size and high-precision parts in precision manufacturing. Its testing method and testing precision directly affect the reliability of precision manufacturing process system. Aiming at the problems of high machining and assembling precision, many machining parts and difficult detection of large-scale parts, the precision detection method for complex parts with high precision and deep step hole design characteristics was studied. Based on the drilling-expanding-rough boring-fine boring process, the control factors of coaxiality error and the machining errors caused by the weight of larger cutting tools in high-speed machining process are analyzed. The position relationship of the measured coaxial stepped holes is studied. A special measuring tool is designed to measure the coaxial machining error quickly and accurately. The corresponding process measuring method is given. The method is applied to the precise manufacturing process of this feature. The testing results are verified by a three-coordinate measuring instrument. The comparative study shows that the tool can effectively measure the coaxiality error of two holes in long distance, and visually display the size and position of the coaxiality error of two holes, effectively improving the efficiency of coaxiality error detection with two holes in long distance.