Dynamic characteristics analysis and structureoptimization of high precision broaching machine
                                             CHEN Guojin1, LIN Lvgao2, GONG Youping1, CHEN Chang1, YUAN Yiming1
(1.School of Mechanic Engineering, Hangzhou Dianzi University, Hangzhou 310018, China;Zhejiang CHR Intelligent Equipment Co.,Ltd., Jinyun 321404, China)

Abstract: Aiming at the machining accuracy problems affected by dynamic load of broaching machine，the natural frequencies and corresponding vibration modes of broaching machine structure were determined，and the structure was optimized to improve the dynamic performance of the structure system and the broaching precision. Firstly, the digital simulation design model of the broaching machine was constructed, and the main order modes and transient responses of the broaching machine were obtained. The transient response was calculated by choosing three typical positions of the broaching machine, the top of the bed, the top of the main chute and the top of the hydraulic cylinder. The acceleration transient response caused by the impact load during broaching was calculated also. According to the results of modal analysis and transient analysis, the uniform method was selected to optimize the structure of broaching machine. Five structural topology optimization indexes were set up to optimize the broaching machine structure. Finally, the optimal design scheme of broaching machine was obtained. On this basis, the optimized broaching prototype system and experimental test platform were built, and the broaching machine was tested experimentally. The test results indicated that the quality of broaching machine is reduced by 15%, the displacement of broaching point is reduced from 0.168 mm to 0.152 mm, the displacement is reduced by 10%, and the machining precision is improved.

Key words: broaching machine; dynamic characteristics analysis; structural topology optimization