Study On Pick-up And Unloading Device For Residual Plastic Film Of Bed Planting

With expand of the covering area and growth of age of plastic film, the residual plastic film left in fields caused serious pollution of the agriculture environment. Mechanical recycling plastic film can overcome shortcomings of the great labor intensity and low effective rate using artificial picking up. However the existing plastic film recycling equipments are generally design by experiences and have no precise theoretical researches for components, there are some issues including unreliable picking up performance and unloading film processes "back-carry" and serious wear of working parts. This paper researched deeply the key components of the pole-tooth residual film collecting machine by using theoretical analysis, the fuzzy optimization design, the virtual prototype simulation and experimental verification. Main research achievements include:1) The experiment and analysis about the changes of the mechanical properties of residual film have been carried on. Compared with the0.012mm residual film, the longitudinal tensile load of the0.006mm residual film decreases37.59%, the transverse tensile load decreases38.68%, the right angle tear load decreases29.60%, the longitudinal tensile fracture elongation decreases20.35%, the transverse tensile fracture elongation decreases26.27%, the right angle tear fracture elongation decreases35.09%. The longitudinal and transverse tensile strength of0.012mm residual plastic films used90days (without weather resistant agent) reduced by at least40.43%, the smallest fracture elongation reduced by at least43.01%.2) The deformation and stress distribution of the residual film and spring tooth were analyzed by nonlinear finite element method in the process of picking up film mulch. Using high speed camera system to test the deformation and stress distribution. Results show that the deformations of the film and spring tooth in the picked up process influence the residual film collecting rate of the spring-tooth, the deformations are related to the speed of the spring-tooth end and machine speed.3) The influencing factors of the lifting film shovel’s performance were researched in the paper. According to the working resistance model of the lifting film shovel, the strength and deformation of the shovel were analyzed by using the finite element method. The fuzzy comprehensive evaluation model of the lifting film shovel was established, the structure parameters and operating parameters were optimized by the experiment, the optimal entering soil angle of260and numbers of2bars of the lifting film shovel were gained.4) The kinematics and dynamics analysis of slide-way spring-tooth collecting residual film mechanism were done, and the kinematics and dynamics models were established. The spring tooth end trajectory model was received by using the curve fitting of Matlab software, and the mathematical model of the slide-way was obtained according to the structural relationship, it provided the conditions for the digital processing of slide way profile.5) By Multi-objective fuzzy optimization, the main structural parameters of the pick-up residual plastic film mechanism were identified:the slid-way minimum basic circle radius is55mm, the roller radius is15mm, the plate length is120mm, the pendulum length is70mm. Using ADM AS software, the kinematics and dynamics simulations of the fuzzy optimized collecting residual film mechanism were done, the results of simulation are consistent with the requirements of the picking up film. The working parameters were optimized by bench test of spring-tooth collecting residual film mechanism.6) The movement analyses of the raking and unloading plastic film mechanism were done, and the mathematical models of the components’ movement and stress were gained. According to the desired trajectory, the raking and unloading plastic film mechanism was optimized, and the parameters of parts were determined:the distance between crank and rocker is160mm, the crank length is80mm, the link length for scratching film is140mm, the rocker length is130mm, the tooth bar length is420mm, the angle between the frame and the x-axis positive direction is16°, the acute angle between the link length for scratching film and the tooth bar is26°.The kinematics and dynamics simulations of the optimized unloading residual film mechanism were done, the results of simulation are consistent with the requirements of the unloading film.7) The pole tooth physical prototype of the residual film recycling machine was made, the field experiment has proved that the work qualities of the physical prototype meet the technical requirements.