Traction Force Test Of Air-blown Subsoiler And Finite Element Analysis Of Subsoiler

Subsoiling breaks the solid plough formation formed by long-term cultivation and effectively regulates the solid-liquid-gas ratio of soil.At the same time,the water storage capacity of soil was improved,and the drought and lodging resistance of crops were greatly enhanced.Existing subsoiling machines generally have such problems as high traction resistance,high energy consumption,shallow subsoiling depth and narrow subsoiling range.In this paper,the drag reduction principle of air-blown subsoiling is studied;the force analysis of subsoiling shovel is carried out;the three-dimensional model of subsoiling shovel is established;the traction force test in the field is carried out to obtain the test parameters;the static and dynamic simulation analysis of subsoiling shovel is carried out;and the effects before and after subsoiling are compared comprehensively.The research contents are as follows:(1)To study the principle of air-blown subsoiling and provide theoretical support for drag reduction optimization of air-blown subsoiler,the force analysis of air-blown subsoiling shovel was carried out,and the three-dimensional model of the subsoiling shovel was established.(2)The traction field test was carried out.The tractor average forward speed,pressure state and subsoiling depth were selected as three factors in the test,and the traction resistance of air-blown subsoiler was taken as the evaluation index.The test results show that with the increase of the average forward speed of the tractor,the traction resistance of air-blown subsoiler tends to increase;when the forward speed of the tractor is 0.4m/s,the traction resistance of the subsoiler is 24.86kN.With the increase of pressure,the traction resistance of air-blown subsoiler tends to increase;when the pressure reaches 4 MPa,the traction resistance of air-blown subsoiler is 29.14 kN.With the increase of subsoiling depth,the traction resistance of air-blown subsoiler shows an increasing trend;when the subsoiling depth is 45 cm,the traction resistance of subsoiler is 33.23 kN.(3)By testing the traction force of the subsoiler,the boundary conditions of the simulation analysis of the subsoiler are determined.The equivalent strain,stress and total deformation cloud of the air-blown subsoiler are obtained by static analysis.At the same time,the structural dynamics analysis is carried out to obtain the first six vibration modes of the air-blown subsoiler.Static and dynamic analysis shows that the main deformation of air-blown subsoiling shovel occurs at the first screw opening at the left end of the fixed connection plate of the subsoiling shovel handle.The maximum displacement deformation value is.11.47×10-4mm,and the stress point is concentrated at the head of the subsoiling shovel.Dynamics analysis shows that the main deformation of the first six modes occurs at the shovel head and shank of the subsoiling shovel.Therefore,long-term work will lead to wear and even deformation of subsoiler shovel,but also affect the service life of air-blown subsoiler.In order to solve these problems,the opening direction of high-pressure gas injected by the subsoiler is changed to vertical jet,and the stress area of the shovel surface and the angle of the subsoiler are changed.A three-dimensional model of the airfoil subsoiler is designed.(4)By comparing the soil bulk density porosity and water content before and after deep loosening,it is concluded that since the soil bulk density is very low during the freezing-thawing period,the change of soil bulk density is not obvious before and after deep loosening operation,and the soil moisture content has increased significantly.By acquiring these data,the direction of optimum design of air-blown subsoiler and subsoiler shovel is pointed out.