| Vegetable grafting can effectively overcome the obstacles of continuous cropping,improve the adaptability of grafted seedlings to the environment,and play a role in promoting growth and increasing yield.At present,most seedling factories in our country are artificially grafted.Due to the seasonal nature of vegetable grafting,the labor intensity of the grafters is high and the production efficiency is low.Mechanical grafting can greatly improve the grafting speed and improve the survival rate of grafted seedlings,which is conducive to intensive and standardized management of grafted seedlings.At present,the vegetable grafting machines at home and abroad are single plant or single row for grafting operation,which requires manual seedling or automatic grasping of seedlings,and the grafting efficiency is not significantly higher than that of manual work.In this paper,based on the actual needs,the key technologies of melon vegetable grafting technology and mechanical grafting are studied,and a full-tray synchronous grafting machine for melon plug seedlings is designed.The main research contents are as follows:(1)The grafting methods commonly used in grafting operations were analyzed.And according to the needs of the full-tray grafting,the splice grafting was selected as the starting point of this research,then carrying out the structure design of the full-tray grafting machine.The geometric parameters and mechanical properties of melon and pumpkin seedlings at the optimum grafting period were determined,which provided a theoretical basis for the design of related mechanical devices.(2)The overall plan of the full-tray grafting machine was designed.The technical requirements and performance indicators of the full-tray grafting machine were determined.And the work flow of the full-tray grafting and the overall layout of each device were determined.The mechanical part of the grafting machine was mainly composed of plug tray seedling clamping and positioning device,plug tray positioning device,cutting device,clamping device for the upper half of the rootstock,and scion clamping device,etc.,which could complete the automatic operation of all processes,to achieve the clamping,positioning,cutting,transfer,docking,pushing out plug tray and other functions of grafted seedlings.(3)Each device of the full-tray grafting machine was designed and optimized,including the multi-position cutting device,the plug tray positioning and transferring device,the clamping and transferring device of the upper half of the rootstock and the scion clamping and lifting device.Using ANSYS and ADAMS simulation software respectively,the statics and kinematics simulation analysis of the key components of the cutting device and the plug tray positioning device verified the rationality of the mechanism design.(4)Mitsubishi FX2N-64 MR PLC was selected as the main controller to research and design the control system of the full-tray grafting machine.According to the full-tray grafting process,the grafting operation was divided into four modules: rootstock processing,scion processing,cutting and grafting,and each module was designed.The program block diagram and the main program of the grafting machine were written,and the debugging was carried out through the operation of the empty machine,and the working sequence of the grafting machine was optimized.(5)Taking the cutting success rate,grafting success rate and production efficiency as the test indicators,the grafting performance test of the full-tray grafting machine was carried out.The experimental effects of each device in the grafting operation were tested from five links: plug trays positioning,seedlings clamping and positioning,synchronous cutting,rootstock transfer and docking of rootstock and scion.The experimental results showed that the grafting effect of rootstock and scion was good,which could meet the grafting requirements. |
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