Abstract:

Large vibration noise, high thread-broken rate, even failure of mechanical drive system will arise when the speed of main spindle motor of chain stitch chenille embroidery machine made in China overpass 1000r/min. In order to overcome these problems, mechanical analysis of the existing embroidery machine was provided, and kinematics characteristics of the needle-bar-structure was analyzed. The reasons which cause the failure was analyzed. An optimal mechanical design was provided to solve these problems. The movement flexibility of needle-bar-structure was improved by optimizing the cam system. Force analysis of the  connecting rod of the needle-bar-structure were compared before and after optimization in ADAMS simulations. Simulation result shows that the maximum force reduces 50% after optimization. In the end, a vibration testing experiment was carried out. Result show that the vibration is far less than the allowable value after optimization, and the performance is improved obviously.

Key words: computerized embroidery machine, mechanical analysis, kinematics characteristic, optimal design