| Rice planting is mainly divided into potted seedlings and blanket seedlings,among which potted seedlings are suitable for precision sowing lines,which have the unique advantages of saving seeds and increasing yields,but require multiple layers of stacked seedling trays and then sent to the dark room for seedling emergence.Therefore,it is necessary to embed the injection-molded potted-seedling tray and pallets together to form a combined type potted-seedling tray and provide them to the precision sowing line for seeding operation.In order to achieve full automation on the precision sowing line,especially the separation and supply of potted-seedling trays,reduce labor force and labor costs,an automatic separating and embedding machine was proposed.The machine includes a separation mechanism for injection-molded potted-seedling trays based on finger-clamp vacuum suction cup and a separation mechanism for pallets based on linkage mechanism combined with a lifting platform,and by combining them to form an embedding mechanism.It is used to realize the separation and embedding of the injection-molded potted-seedling tray and its supporting pallet one by one to meet the automatic supply process of the front end of the seedling production line.The main research contents are as follows:（1）A 3D printing straw vacuum suction cup was designed to simulate the grasping action of human fingers.The vacuum adsorption method is used to clamp the injection-molded potted-seedling tray flexibly,which will not damage the surface of the injection-molded potted-seedling tray.The diameter of vacuum suction cup was determined to be 8 mm after calculation and selection.ANSYS was used to analyze the horizontal deformation of the injection-molded potted-seedling tray when it is adsorbed and lifted.8 groups of vacuum suction cups were determined and reasonably arranged.Simulation and actual test results verify the feasibility of the design.（2）A lifting linkage type tray separating mechanism and a double cam type pallet separating mechanism were designed.The three-dimensional model of the pallet separation mechanism was established,the kinematic sketch was drawn for kinematic analysis,and the stroke of the required power source was determined.ADAMS was used to simulate the kinematics of the lifting linkage mechanism,and the correctness of the calculation results was verified.The optimal lifting height of the lifting platform and the opening and closing angle of the linkage were determined,and the stroke of the power source cylinder was selected as 30 mm.The double cam pallet separation mechanism was designed by analytical method and graphic method.The contour curve of the cams and their combination forms were obtained.The cylinder with a stroke of125 mm was selected as the power source.（3）The control system of the whole machine was designed,and the motion of the whole machine was realized by combining the stepper motor and the cylinder.By analyzing the motion flow and timing,the stroke switch was selected as the common signal for both parts of the mechanism,and proper timing allocation was made to ensure maximum efficiency.（4）The three-dimensional modeling of the whole machine was carried out by Solid Works,and the prototype was made.A three-factor,three-level orthogonal test of injection-molded potted-seedling tray separation was carried out by the prototype,and the effect of these factors on the successful rate of injection-molded potted-seedling tray separation was verified by setting the vertical cylinder speed V1,horizontal cylinder speed V2 and buffer absorbed energy N as the test factors.The test of separating and embedding tray was also conducted.The test results show that the success rate of pallet separation mechanism is 97%and the separation efficiency is 1200 trays/h;the success rate of separation mechanism for injection-molded potted-seedling tray is 94.25%and the efficiency is 600 trays/h.When the speed of separating and embedding is 600 trays/h,the success rate is 93.25%.The machine runs smoothly and has no cumulative deviation in multiple tests,which can be applied to the rice precision sowing line. |
