The Study Of Vertical-Single-Shaft Ditching-Fertilizing Machine For Orchards In Hilly And Mountainous Areas

The main way of fertilization in orchards is putting granular fertilizer into ditch,and it's also an important technique to improve the output and quality of fruits.At present,orchard ditching and fertilizing mainly rely on manual work in China's hilly and mountainous areas,and low mechanization level has became an important factor to restrict the development of fruit industry in china.To solve this problem,an orchard ditching-fertilizing machine is developed,which can suit for the operation in China's hilly and mountainous areas.The main contents of this paper are as follows:Considering the working environment and operating efficiency of orchard in the hilly and mountainous areas,operation mode of well shaped furrow is adopted,and ditching and fertilizing processes can be completed in one operation.According to agronomic requirements of orchard ditching and fertilizing,the agronomic parameters like ditching depth more than 250 mm and width less than 500 mm are put forward,and a vertical-single-shaft orchard ditching-fertilizing machine is preliminary developed.It combines blade-combined-rotary cutter and ditching plough to do the ditching operation,and the fertilizer apparatus is driven by a small motor of ZGB37 R.A 1WG6.3 type mini-tiller is selected as the power machine for ditching-fertilizing machine to improve machine's utilization efficiency.On the basis of satisfying the requirements agronomy,kinematics and dynamics model of soil particle on the blade are established by mathematical calculation and theoretical analysis for reducing the power consumption of the machine and improving the efficiency of the machine development.The numerical simulation of cutting process of the rotary cutter is carried out by using FEM-SPH numerical coupling method.The results show that the average cutting power consumption is 2.080 kW when the rotational speed is 26 rad/s and the blade bending angle is 22°.The test of cutting soil with rotary cutter is carried out by using torque speed measurement platform,the average cutting power consumption of the rotary cutter is 2.172 kW,and the relative error is 4.42%.It is feasible to use FEMSPH numerical coupling method to simulate the cutting soil in the range of error tolerance,which lays the foundation for the optimization design of rotary cutter.This paper designs the binary quadratic orthogonal regression test with rotational speed and blade bending angle as the test factors which obviously effect cutting soil power consumption.The numerical simulation of regression orthogonal combination experiment is carried out by using the FEM-SPH numerical coupling method,and the regression equation of cutting power consumption of the rotary cutter and the rotational speed of the cutter and the bending angle of the blade is established.The mathematical optimization model of regression equation is established by using MATLAB toolbox and the rotational speed of the cutter and the bending angle of the blade are optimized.The optimization results show that: when the rotational speed is 20.3 rad/s and the blade bending angle is 20.7°,the lowest cutting power consumption is 1.721 kW.Using FEM-SPH numerical coupling method for numerical simulation of the optimization rotary cutter cutting soil,the results show that the cutting power consumption is 1.684 kW,and the relative error is 2.15% compared with the optimization results.Using speed-torque measurement platform for the test of the optimization rotary cutter cutting soil,the results show that the cutting power consumption is 1.831 kW,and the relative error is 6.39% compared with the optimization results.The results of numerical simulation and test show that the optimization method has high accuracy in the range of error tolerance.Compared with the design of original rotary cutter,the cutting power consumption of the optimization rotary cutter is reduced by 15.70%.The optimization effect is remarkable.The finite element static analysis of rotary cutter's vertical shaft and blade is carried out by using Ansys-Workbench.The results show that the design of vertical shaft and blade can meet the operation requirements,having good reliability.This paper completes the design and optimization of vertical-single-shaft orchard ditchingfertilizing machine,make a prototype according to the optimization results,and carry out the field experiments by using 1WG6.3TG type mini-tiller as the power machine.The field test results show that: the vertical-single-shaft orchard ditching-fertilizing machine matches with 1WG6.3 type minitiller can meet the design requirements and agronomic requirements;the ditching-fertilizing machine can operate normally in the narrow orchard which is belong to hilly and mountainous areas,the average ditch depth is more than 250 mm and the maximum width of groove surface is less than 500 mm;the ditching and soil throwing effect is fine,the regolith in the bottom of ditch is few,and the distance of soil throwing is less than 700 mm;it can complete ditching operations more than 800 m every hour,and at the same time to complete the fertilization process.