| Rice is China's main food crop.China's rice planting area is more than 30 million hectares,accounting for more than 30%of the country's total planted area.The annual output of rice is close to 200 million tons,accounting for more than 40%of China's total grain output.Therefore,achieving mechanized production of rice is of great significance to China's agricultural development.The sowing line of rice generally includes the steps of feeding,soiling,compacting,sowing,sprinkling,stacking,etc.,and ordinary rice seedling trays cannot achieve the steps of stacking due to the hardness of it.In order to solve this problem,it is necessary to insert the tray into a hard one.Therefore,the development of a set of automatic tray embeding device can effectively save labor and improve the sowing efficiency of the seeding line.Based on this,this paper studies and designs a rice seedling tray automatic separation and embedding machine.The main contents of the thesis are as follows:(1)Starting from the design requirements of the embeding machine,it is determined that the overall design of the mechanism is to separate the trays by vacuum adsorption,and the Pneumatic transmission is used for the embeding mechanism.The measurement of the size,quality and the peak parameters of separation force of rice seedling trays is provided for the subsequent mechanism design(2)According to the design requirements,the vacuum system is designed and the selection of important components is carried out.The adsorption point of the vacuum chuck was determined as the outer wall surface of the hole at the edge of the tray,and the hole dameter of the vacuum chuck is 6mm.The number of it is determined to be 8 by calculation.The pneumatic circuit is designed,and the vacuum generator is selected as the vacuum generating device.The model is ZH05BS and the response time is calculated to be 0.108 s.Finally,according to the selection design of the pneumatic circuit,the model of the air compressor is determined.(3)The overall structural design of rice seedling trays automatic separation and embeding machine.The main mechanism includes a tray loading rack,a vacuum chuck clamping mechanism,a lifting mechanism,a tray turning mechanism and a tray embeding mechanism.The positioning block is used to locate the seedling tray.The vacuum chuck is fixed by a clamping mechanism,and the drive unit of the clamping mechanism is an electric push rod.The transmission mechanism of the lifting mechanism is screw drive.The stepping motor model is 57HS22,the torque is 2.3N,and the step angle is 1.8°.The tray turning mechanism uses the MHZ2-20D double-acting gripper,and the rotating motor uses the DH-3X steering gear.The embeding mechanism use MHZL2-10D double-acting gripper,and the cylinder diameter of vertical cylinders is 10mm.The hard trays conveying line is provided with a guiding mechanism and a tray blocking mechanism.(4)Design and selection of hardware and software for the control system.Determine the overall control proposal,the controller selects BE-2017PLC,and the stepper motor driver uses TB6600.The stroke switch adopts the micro-motion type and the photoelectric switch selects the opposite type to meet the requirements of the mechanism.Finally,plan the flow chart of the control system and write the corresponding control program.(5)The overall structure of the machine was designed by the 3D modeling software SolidWorks,and the prototype was built according to it.The experiments were carried out on the seedling trays simulated in different environments. |
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