Design And Experimental Research On Vegetable Refined Combined Tillage Machine

China is the world’s largest producer and consumer of vegetables, the planting area and total output respectively account for 40% and 50% of the world’s in 2013. But the disadvantage effect of low efficiency, large amount of labor and high labor cost in vegetable cultivation on vegetable industry development is more and more obvious, vegetable mechanization becomes increasingly urgent and will be the trend of vegetable industry. Soil tillage machines occupy an important position in the mechanization process of vegetable cultivation.Land levelling is the prerequis ites to assure the consistent of vegetable growth, which is the precondition of ensuring the quality of transplanting, harvesting mechanization, and the quality directly affects the yield of vegetables. However, specialized soil preparation machines for vegetable in China are also lack, the operation quality of existing tillage implement is not up to the requirements for vegetable cultivation, there are some serious problems, such as, not refined enough, not smooth enough, tillage depth is unstable and crushing roller is coated with clay. In order to solve the above problems, a combined tillage machine specially used for soil preparation of vegetable was designed, compared to the existing general tillage machines; the machine could improve the smoothness and the degree of soil crushing rate, the working quality and efficiency, and achieve the intensive requirements of vegetables cultivation. The main contents include the followings:(1) Vegetable refined combined tillage machine was designed. Based on the design concept of general combined tillage machinery, according to vegetable cultivation patterns, the composite structure of deep tillage- surface soil crushing- ridge repression, and the principle of double knife shafts joint operation were adopted, the front knife shaft and rear soil crushing roller shaft did the opposite movement. The structural parameters and performance parameters of the machine were determined, at the same time, through calculation and analysis, the scheme of transmission system and the appropriate gears for transmission system were selected.(2) The key components of the vegetable refined combined tillage machine were designed. the main structure of the rotary tillage components, the soil crushing roller components and suppression components were determined, the key structure parameters affected the performance of key components were analyzed. The cutter spacing, arrangement of the rotary blade, parameter of knife shaft, the diameter of roller and the parameter of end dish were determined. The innovative design of an arc soil crushing cutter blade and two kinds of different soil crushing roller were launched, and parameters of the intensive soil crushing roller were focused on.(3) The mechanical performance of the frame on working was studied. The stress and strain of the frame under two different working conditions and the maximum stress and the maximal deformation displacement were analyzed by Pro/E and ANSYS Workbench. Simulation results showed that the performance of the frame material had not been brought into full play, so the structure of frame by reducing the thickness of frame drawing rod and the two bars was optimized. After optimization, the maximum stress was slightly lower than the material allowable stress, the stiffness characteristics barely changed, which showed that the optimization effect was good, the amount of material used in frame was effectively reduced.(4) Experimental research on working performance of vegetable refined combined tillage machine was carried on. The soil crushing rate and soil roughness as the response index, traction speed, and soil roller speed and soil moisture content as experimental factors, with the single factor analys is of variance to explore the effects of traction speed, roller speed and soil moisture content on soil crushing rate and index of soil roughness by software SAS; the primary and secondary order impact of the factors on response index was explored with multiple factor analysis; the fitting test regression model between the factors and response was founded with the quadratic response surface analys is. By software MAT LAB, the optimum combination parameters under optimal condition that get the best soil crushing rate and soil roughness was obtained with multi-objective optimization analys is. Finally, the verif ication test was carried out on the optimization results; test results showed a good match between them.