Design And Experimental Study Of Boom Suspension For High Ground Clearance Sprayer

The high ground clearance self-propelled boom sprayer has the characteristics of high work efficiency and wide application range,and is widely used in plant protection operations at home and abroad.The boom suspension system is an important part of connecting the boom and the sprayer.Its structure and performance have an important influence on the stability of the boom during operation and the final spray quality.At present,the domestic research on boom suspension lacks a complete theoretical system,and in-depth research and exploration are needed.This paper analyzes the current situation of the current research on the structure and technology of spray booms at home and abroad.Taking the boom suspension of high ground clearance sprayer as the research object,a boom suspension with a width of 21 m is designed,and the boom suspension is mathematically studied.Modeling,motion analysis,finite element analysis and research,the main research work is as follows:(1)Aiming at the problems that the sprayer body is susceptible to deflection,rotation,and shaking when the sprayer is operated,a double-link trapezoid that can achieve passive vibration reduction,active balance and ground profiling is designed based on the 3WPYZ sprayer.For the spray boom suspension system,a kinematic model of the designed spray boom suspension was established using the D'Alembert principle and the principle of multi-body dynamics,and the mathematical model was analyzed to determine the influencing factors and the optimization model.(2)The three-dimensional model and virtual prototype model of the boom suspension were constructed,and the virtual kinematics simulation analysis of the boom suspension was carried out to verify the motion of the boom suspension under instantaneous excitation and normal excitation.Through the single factor test,the influence law of system damping and structural parameters on the performance of the boom suspension was obtained.The orthogonal test was carried out on the boom suspension.The simulation result data was analyzed by variance analysis using DesignExport.The analysis results showed that each Influencing factors have a relatively obvious impact on the maximum swing angle and natural frequency of the boom suspension;the best response factor combination of the boom suspension is obtained,and the simulation results of the model before and after optimization are compared to optimize the maximum swing angle of the rear boom suspension.It has dropped by 53.02%,and the optimization effect is very significant;the natural frequency has dropped from 1.3143rad/s to 1.1826rad/s,which meets the design requirements.(3)Use Ansys workbench finite element analysis software to analyze the improved boom suspension.The structure is partially optimized and improved.The stress at the end of the boom suspension joint is reduced from 161 MPa to 22 MPa,and the maximum displacement is reduced from 35 mm to 7mm.The maximum stress of the inner boom suspension was reduced from 128.36 MPa to 88.07 MPa,and the maximum stress of the inner and outer suspension connecting plates was reduced from 187.3 MPa to 57.41 MPa.The stress distribution and displacement reached an ideal effect;the overall boom suspension was simulated.State analysis shows that the sixth-order natural frequency of the boom suspension reasonably avoids the external excitation frequency range.(4)The dynamic characteristics test of the improved spray rod suspension was carried out.The test results showed that the dynamic results of the physical model of the spray rod suspension were basically consistent with the results of the virtual model simulation analysis.Field test analysis of the boom suspension was carried out.When the sprayer is excited by the environment to vibrate at-4?3.5 degrees,the spray boom suspension can guarantee the isolation of the body swing when the travel speed of the sprayer and the height of the boom suspension change.The impact of the vehicle body is reduced to a smaller range of values,and the stability of the boom is maintained to the greatest extent.In this paper,aiming at the problem that the boom is prone to deflection,rotation,shaking and other undesired motions during work,the double-link trapezoidal boom suspension is designed and optimized.The test verifies that the designed boom suspension can effectively reduce the undesired motion.Occurrence,maintain the stability of the spraying operation,and effectively improve the final effect of the spraying operation.