Study On The Preposed Subsoiler On The New Type Tillage Machine

As an important part of the farming technology,subsoiling can break down the plough layer which produced by long-term use of traditional tillage,and subsoiling can improve soil structure and promote crop growth.At present,most of the deep loosening machines are matched with the large and medium-sized tractors,working with rear suspension.In hilly and mountainous area of our country,land area accounted for more than 2/3,but because of the uneven topography and other factors,large and medium-sized tractors are not suitable,therefore,it is very difficult to complete subsoiling in the hilly area.In order to solve this problem,this paper analytically study on the preposed subsoiler based on the new type tillage machine.This paper mainly includes the following contents:(1)The study on the front subsoiler componentsSelect the interval subsoiling as the subsoiling pattern.After analyzing the requirements of subsoiling,this paper determines the tillage width of 1.2m,subsoiling depth of 40 cm,the configuration of two subsoiling shovel,shovel spacing of 60 cm.Through the comparison of three common subsoiler models,the self-excited vibration subsoiler is chosen.After analyzing the rear subsoiling shovel's trajectory when it is lifted up and putted down,the parallel quadrilateral front suspension frame with the same motion trajectory is designed,and the size of the bar is determined.According to the principle of self-excited vibration,self-excited vibration component is designed.According to the size of frame installation and subsoiling requirements,the corresponding subsoiling shovel is designed.Finally,the 3D model of the front suspension frame,the self-excited vibration components and the subsoiling shovel are established and assembled by UG,and the preliminary design of the front subsoiler components is completed.(2)Theoretical analysis of subsoiling with front suspensionThe resistance of the subsoiling shovel and the front frame is calculated by theoretical analysis.According to the design requirements and check criteria of the suspension,the entry performance,tillage-depth stability and longitudinal stability of the subsoiler are checked.The results show that the front suspension components designed in this paper meet the above requirements.The subsoiling components of the front suspension makes the cultivator to move the focus of 118.23 mm by calculating,the cultivator can obtain a greater pressure center displacement allowable value through front and rear suspension working together.Based on the force analysis of subsoiler and rotary joint operation,preposing the subsoiling components can increase the adhesion of the tractor,thereby improving the tangent driving force,to further improve the traction,traction and traction power efficiency.Through the theoretical analysis,the rationality of the design for the subsoiler components is verified,and the foundation for the subsequent numerical simulation and static analysis is established.(3)Numerical simulation analysis for the operation of subsoilingTake the upland soil in the farm of Southwestern University as samples,the basic parameters of soil was measured.Based on Smoothed Particle Hydrodynamics(SPH)method,an ideal model of subsoiling is established.Take the numerical simulation of this model by using the ANSYS/LS-DYNA and LS-PREPOST,obtained the maximum resistance of subsoiling is 2560 N,the average power consumption is 13 kW,the disturbance of surface soil is less.Through the numerical simulation,it can be used to judge the operation effect and the power consumption of subsoiling,and make the foundation of the static analysis behind.(4)Static analysis of front suspension frameThe force of the front suspension frame is obtained by using the numerical simulation method.Through the static analysis and modal analysis for the front suspension frame by Workbench,get the maximum displacement of front suspension frame in subsoiling for 3.3904 mm,the maximum stress is 96.63 MPa,the first six order natural frequency distribution between 30~170Hz.Through the static analysis,it can be seen that the weak part of the frame is the bolt connecting part of the machine frame and the machine head,which will be changed into the U type screw connection,and the parallel four bar mechanism can be strengthened by ribs to improve the design of the front subsoiler components.