Theoretical And Experimental Research On Ditching Blade Of Orchards Ditching Fertilization Combined Machine

Mechanized furrow fertilization can improve work efficiency,reduce labor intensity of labor,is the development trend of orchard fertilization homework.Trenching blade is the most important working parts of trenching machinery,It has many problems,such as large power consumption,trenching depth instability,can't meet the agronomic requirements orchard furrow fertilization.Based on the analysis on the basis of existing research results,through theoretical analysis,simulation and experimental research,designed a new type of furrowing blade.Discusses the blade shape structure,operation parameters and the mutual relationship between power consumption and quality of furrowing,reveals the microscopic mechanism of saving energy and reducing consumption,solving the problem of large power consumption and depth instability of trenching machinery.Basically have the following conclusion:(1)An analysis was performed regarding movement of trenching components and trenching mechanism of forward and backward rotating,through which the trenching means and movement parameters were initially determined.The mechanism of submerged up-cut trenching was studied;and a model was established for power consumption of sine-exponential curve trenching blade(the "sine blade"for short),which contained geometrical parameters,soil parameters and movement parameters of the blade.15 types of sine blades with different structures were designed and fabricated using 60Si2Mn as blade material and bending radius,bending angle and sliding-cutting angle as variables.(2)The effect of the sine blade's structure parameters on its power consumption and trenching quality was studied through soil trough tests in lab,which indicate that,under the premise of meeting operation quality,the effect level of the blade's structure parameters to power consumption in descending order is bending angle,soil-cutting angle and bending radius,and that to trench depth stability in descending order is soil-cutting angle,bending angle and bending radius.Using non-linear optimization calculation method,it was determined that the power consumption and trenching quality can reach the optimal value when the bending angle is 86.75°,bending radius 12 mm,soil-cutting angle 13.8°,advancing speed 1 m/s,and cutter RPM 200 r/min,and that cutter RPM of 200 r/min is the best RPM for trenching operation of such type of blade.(3)A 3D dynamic simulation model was established for "soil—trenching blade" using Smoothed Particle Hydrodynamics method to simulate soil cutting process of the blade and thereby analyze the microprocess of soil cutting by the blade.The results indicate that during trenching process,the power consumption of the blade increased with increase in contact area and time between the blade and the soil and gradually became stable with elapse of trenching time.Two representative scenarios were selected for simulation analysis,from which the dynamic curve of power consumption during trenching was derived to reveal the micromechanism of power consumption during soil cutting.A comparison was made between the simulation model and the soil trough tests;the power consumption error of both at trenching depth of 400mm and 500mm,respectively was within 5%and power consumption was the smallest when RPM is 200 r/min,proving validity of the simulation model.(4)Field experiments were performed taking trenching depth,cutter RPM and advancing speed as experiment factors and power consumption and trench depth stability as experiment indexes.The results indicate that trenching depth is the factor that has the most significant effect on power consumption and advancing speed is the one that affects trench depth stability the most.The sine blade showed better performance than normal blades under both trenching depths.The study in this paper not only provides theory basis for optimization design of trenching blades and the whole set of trenchers in regard to energy saving and consumption reducing,but also has profound meaning in promoting rapid development of our country's orchard management machinery.