| Rape is widely used in edible oil industry,landscape tourism and industrial material industry.The middle and lower reaches of the Yangtze River,as the main production areas of winter rape in China,mainly two or three crops a year,crop rotation is tight.Mechanized transplanting is one of the main planting methods of rapeseed.In view of the soil clay weight in the middle and lower reaches of the Yangtze River,the seedling bowl did not level the bottom layer of the seedling bed,the vertical degree could not be guaranteed,and it was difficult to match the seedling raising technology with the transplanting equipment.This subject combines the domestic and foreign transplanting technology and the soil tillage machinery,especially the transplanting machine bowl seedling bed finishing related equipment,carries out the vertical rotary tillage blade and the opening trench.Combined design of soil cover device and optimum selection of working parameters of pneumatic seedling extraction device.According to the theoretical basis of the design of vertical blade geometry size,using Adams MATLAB simulation software to optimize the blade structure parameters,trench overburden device working parameters combined with the method.In order to reduce the impact load of transplanter and ensure the upright degree of potted seedling,a reasonable groove type was developed for the transplanter planting device by means of the simulation analysis of the groove type in order to reduce the impact load of the transplanter and to ensure the vertical degree of seedling planting.A prototype of transplanting machine is designed,including pneumatic seedling picking,seedling bed finishing device,soil covering device and other auxiliary systems.This project provides some reference for the research of seedling bed finishing and matching device design of rape pot seedling transplanter,and has guiding significance for the development of rape transplanter.The main contents and results are as follows:(1)The analysis of rotary tillage performance of seedling bed finishing device,the research of cutting soil and throwing soil model of rotary tillage blade,the comparison of different types of auxiliary trench opening methods,combined with the geometric size of seedling bowl were carried out.In this paper,the authors put forward a method of seedling bed arrangement of rapeseed bowl with dynamic driving rake vertical rotary tillage device and boat shovel furrow plough,and determined its working principle and working process.The corresponding seedling bed finishing device was developed.Combined with pneumatic seedling extraction device,a transplanting frame of rape seedling was designed,and the main structure and working parameters of vertical rotary tilling blade were analyzed and determined.It is concluded that the cutting edge of the blade is designed on the basis of the constant speed spiral curve,the curve equation is R= 2.10 * θ,the tangent edge is designed at the end of the blade,the overall length of the blade is 200 mm,and the bending angle is 90°,the distance between two blade is 140 mm.(2)ADAMS is used for Kinematic Simulation of blade.It describes the trajectory of blade edge,obtains track coordinate parameters,and imports MATLAB to match parameters.The groove profile of blade is obtained,combined with the size of rape seedling bowl.It was determined that the upper edge of the shovel plough was 140 mm wide,the lower side was 80 mm wide,the height was 120 mm,and the length of the rear side plate was 100 mm.At the same time,a series of field experiments of vertical rotary ploughing blade and boat shovel type furrow plough combination and the measurement of field furrow section were carried out.The curved surface fitting with MATLAB showed that.Seedling bed finishing device can meet the requirement of transplanting seedling bed in rape bowl.(3)According to the requirement of pneumatic seedling extraction device,mechanical analysis was carried out on the three stages of seedling extraction,seedling sending and seedling removal.The theoretical basis that the seedling extraction device can effectively carry out the seedling extraction function is obtained,and the main factors influencing the success rate of seedling extraction are the friction force f between the seedling needle and the seedling bowl matrix,the height L of seedling bowl falling off.Friction force fb between seedling bowl and seedling bowl,friction force fp between seedling bowl and seedling tray,expansion speed v of cylinders.(4)According to the factors affecting the success rate of seedling extraction by pneumatic seedling extraction device,the friction factors of seedling bowl,the friction force between seedling needle and seedling bowl matrix,the drop damage rate of seedling bowl substrate and the optimal selection parameters were tested on a bench.The results showed that when the friction between the seedling needle and the seedling bowl substrate was not less than 3.67 N,the seeding device could effectively carry out the seedling removal function.In the seedling pot average moisture content is 35.6%,the seedling needle is made of stainless steel,the diameter of 4mm,the insertion depth of 20 mm matrix seedling pot,bowl seedling height is taken off 340 mm as the optimum parameter combination;bench test shows that the optimum parameter combination as parameters,seedling frequency of 20 plants / min,seedling the success rate of 92%.(5)A prototype of transplanter was developed by integrating seedbed finishing device,pneumatic seedling collecting device,mechanical transmission system and electronic control system,and field experiments of transplanter were carried out.The results showed that the success rate of seedling picking was 90%,the qualified rate of planting depth of seedling bowl was 78.75%,and the average erection degree was 70.71%. |
