Study On A Full Automatic Grafting Machine For Solanaceae Vegetable Seedlings

China is one of the world's largest countries on facility cultivation.More than 2.7 million hm2 areas are used for facility vegetable cultivation.However,continuous cropping obstacle severely affects facility vegetable cultivation.It has been proved by domestic and foreign research and practice that grafting technique is the most effective way to deal with the continuous cropping obstacle.Since domestic vegetable grafting machines are mainly semi-automatic and inefficient in grafting individual seedling,this research aimed to design a full-automatic grafting machine for cell tray solanaceae seedlings,which can greatly improve grafting efficiency and successful rate.The machine can finish the grafting of a row of seedlings(5 strains)synchronously in a grafting working circle.The main research contents and results are as follows:1.The research focused on the applicable grafting method for the solanaceae plants.Splice grafting method was adopted by the full-automatic grafting machine.The geometric features and the mechanical properties of the optimum stock and scion have been measured.The parameters obtained provided scientific basis for the research and design of the grafting machine.2.The overall design scheme of grafting machine was studied to confirm the design requirements and technical indicators,and to analyze the main problems to be solved.The overall structure and layout of grafting machine have been studied to determine the work flow of the grafting machine.3.Cell tray transporting mechanism was designed to realize the feeding and replanting of the whole row of seedlings for the stock and scion.At the same time,a seedling supporting mechanism was designed to improve the consistency of the whole row of seedlings,which would guarantee the gripping and positioning of the stock and scion for the next step.4.The seedling gripping principles and positioning principles were analyzed.A new type of stock and scion gripping mechanism was designed,which could realize gripping and positioning for the whole row of seedlings synchronously.Main parameters of the gripping mechanism were designed.It has been proved that the stock and scion would not suffer damage when the opening size of the stock gripper was 2.55 mm,and the opening size of the scion gripper was 2.45 mm.An anti-falling plate was added to the gripping mechanism,which could avoid the bending of the seedlings and improve the cutting precision in the process.In addition,the gripping mechanism was driven by servo motor and ball screw,which could improve the moving speed and ensure the positioning accuracy of+/-0.2 mm.5.Synchronous cutting mechanism for a whole row of seedlings was designed.The cutting tool adopted 23#sculpting knife blade with the thickness of 0.4 mm and the length of the cutting edge of 20 mm.Based on the structure of the blade,special blade base and fixed elements were designed,which had the advantages of simple structure and convenient installation and disassembly.6.The automatic transmission mechanism of grafting clips was designed.The mechanism could complete the automatic sorting and feeding of the clips.It could grip five grafting clips at a time and automatically control the opening size of the clips,so as to realize the synchronous gripping and fixing for five grafting seedlings.7.The automatic control system of the grafting machine chose Omron CP1H PLC as the main controller.Modular programming technology was utilized to design the control program,so as to realize the automation of the grafting process.8.The entire work flow of the grafting machine has been tested.The whole process of the gripping,cutting,splice and fixation of the scion and stock was monitored.It has been tested that the productivity of the grafting machine was 1003 strains/h,and the successful grafting rate was 90%.