| Research topics come from industrial sewing machine feed mechanism improvement project of the internship unit, aimed to develop a new feed mechanism can sew thick fabric, and to improve the instability stitches of the company existing sewing machine. At the same time to study the dynamic characteristics of the feed mechanism, improve its sewing performance.Industrial flat sewing machine contains four basic institutions: pick line institutions, thorn cloth institutions, hook line institutions and feed mechanism, feed mechanism is one of the most important institutions in sewing machine. The feed mechanism is the role of institutions with thorn cloth institutions, hook line institutions and pick line institutions, according to certain rules transfer cloth to form the required stitches. If the movement of feed mechanism is too fast, the wear loop will be pressed between cloth and needle plate, causing float. If the movement of feed mechanism is too slow to stop feed before needle thorn cloth, the needle will break. It means that the performance of feed mechanism directly affect the quality of the sewing quality.In order to solve the feed mechanism in the elastic deformation, by comparing two feed mechanism, we find the cause of excessive elastic deformation. Elastic dynamic analysis confirmed this reason. Analysis and optimization procedure is as follows:1) Measure the existing feed mechanism to measure the size of each component. Run body dynamics analysis, we will get the movement of each component, including the corner, angular velocity, angular acceleration, hinge between the forces and elements deform under force. Run the same analysis on another mechanism at the same time, then find the difference between them,compare the size of the elastic deformation.2) set machines trajectory abroad as optimization target, to optimize the length of the existing component. Calculated related components optimal length by using the penalty function. Trajectory optimized makes the impact force of feed mechanism reduce during operation, at the same time, reducing the elastic deformation.3) Run elastic dynamic analysis on industrial sewing machine’s feed mechanism to get its frequency and response to periodic excitation.4) Simplify the elastic dynamics calculations with neural network. Then use MATLAB optimization toolbox to optimize the feed mechanism. At the same time reduce vibration, reduce its weight.5) Reform the feed mechanism with optimal results. |
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