Abstract:Compared with the conventional horizontal conveyor chain type plastic film picking device, the longitudinal nail-tooth-chain plate type plastic film picking device developed by our team in the early stage has little tearing effect on the residual film, and the separation effect of the residual film and the impurity is better. In order to further improve the performance of the plastic film pickup device, a friction type nail-tooth-chain plate plastic film pickup chain that can not only overload and slip, but also facilitate the installation of functional components was optimized and designed. The kinematic analysis of the picking nail teeth on the film picking chain was carried out, and the motion equation and trajectory of the picking nail teeth during the operation were determined, as well as the conditions for the nail teeth to complete the film picking. The key parameters of the plastic film picking system were determined by analyzing the condition of no leakage of residual film and the force of the film. At the same time, the structural design and key parameters of the shovel type film lifting device were determined. The force of residual film and impurities in the film lifting process was analyzed, and the film lifting device was optimized. According to the design results, a prototype was developed and a multi-factor test of operating parameters was carried out. The operating speed, the spacing of pickup nail teeth, the depth of the film shovel into the soil, and the distance between the tip of the film shovel and the center of the picking drum were used as test factors. The residual film picking rate, impurity rate of recovered residual film and traction resistance were used as test indicators. The central composite design (CCD) method was used to carry out a four-factor five-level quadratic regression orthogonal combination test. The influence of each test factor on the test index of the residual film picking system was analyzed, the regression models were established, and the optimal parameter combination was obtained by using the multi-objective optimization method. When the operating speed was 6 km/h, the pickup nail tooth spacing was 228.6 mm, the depth of the film shovel into the soil was 37 mm, and the distance between the tip of the film shovel and the center of the pickup drum was 130 mm, the field test showed that the residual film pickup rate was 90.12%, the impurity rate of the recovered residual film was 8.96%, and the traction resistance was 19.905 kN. The relative errors between the experimental results and the predicted values of the regression models were no more than 4.55%, indicating that the parameter optimization regression models were reliable, and the designed friction type nail-tooth-chain plate plastic film picking system met the technical requirements of residual film recovery. The research results can provide technical reference for the development of residual film recycling machines.