Improvement Design Of Tobacco Transplanting Machine And Experimental Study On The Planting Components

The obacco,as an important economic crop,has a large proportion in agricultural production in China.The cultivation of tobacco has been developed from the initial artificial breeding,manual transplanting,hand covering soil,irrigation and film laying to mechanization.At present,the tobacco seedling has been mechanized seedling,but the mechanical production of tobacco transplanting still remain in a single step,for example,the hole machine,covering machine,and fertilizer machine can only work step by step.This will lead to a large number of labor costs,fuel costs,so that it is difficult to apply to large-scale agricultural production.Fortunately,the automatic transplanting machine,integrating seedling collection,seedling transportation,pit forming,fertilization,transplanting,water injection,soil covering and film spreading toghter,have been being researched and developed.Through summarizing the results of the physical and mechanical properties of previous tobacco seedlings and the experiment on the soil slot of the transplanting mechanism,and baseding on the field effect of transplanting machine,the improvement design of the frame and planting mechanism of the hanging cup transplanter are maked and stress situation of transplanting tobacco seedlings and system of sports forms are theoretical analyzed.Then the mechanical properties of the seedling bowl were tested.These provide the theoretical basis for the performance and quality of seedling transplanter.(1)The structure and working principle of the hanging cup transplanter and the problems found in the field experiment of the research groupare are described to put forward the improvement scheme,and the basic frame,planting mechanism,innovative design;(2)Through determining the physical and geometrical parameters of the greenhouse intensive seedling plug seedling in Northeast China,the distribution of the geometric parameters are analyzed and the mechanical properties of the bowl are tested.The results showed that The height of tobacco bowl was mainly distributed in [140180]mm,the mean value of leaf width was 96.7 mm,the coefficient of variation was 15.25,the mean value of soil bowl was 31.49 g,the coefficient of variation was 8.48%.It is found from the mechanical property test of the earthen bowl that the extrusion pressure and the displacement are nonlinear.When the displacement is about 4mm,the soil bowl will yield stress.When the extrusion pressure is 20 N,it will cause obvious damage to the earthen bowl.The loading site has a significant effect on the crushing failure force,and the moisture content of the earthen bowl has a significant effect on the crushing failure force.(3)Considering transplanting machine under different conditions,the maximum stress of the frame occurs in connection of the wheel height adjustment plate and the frame side beam in the normal operation,94.6MPa,less than the allowable stress of the material baseding on the static and modal analysis of transplanting machine frame.The results show that the whole structure meets the requirements of strength,and there is a large space in the frame;(4)The ratio of the radius of Seedling gyration and the radius of Planting seedlings rotation is determined and mathematical model of kinematics and dynamics of Seedling process is established through analyzing the process of transplanting,the movement curve of the seedling,the contact between the seedling and the planting mechanism,and the working principle of the planting mechanism.Matlab and Adams were used to simulate the motion state and the curve track,and the motion equation of the seedling in the hanging cup was obtained.The results showed that the seedling advance angle is 18 degrees,hanging cup release angle is 10 degrees,planting ring and planting rotary speed is proportional in planting tracks,and is inversely proportional to machine speed,and is no correlation with the distance from the point to the center of rotation,and the claw arm collision force is 3.34 N.(5)Through setting up the performance test bench of planting mechanism and simulating the field operation of planting mechanism,the performance of planting mechanism is Studied in the orthogonal test of three factors and three levels.Experiment showed that the best combination of planting are 16 r/min of planting turntable,5° of Cam angle and 25 mm of cup claw height.the rotation speed of the rotary table,the cam angle and the height of hanging cup have influence on the vertical degree of the seedling and the dropping position of the pot seedling.