Design And Research Of A Parallel Hydraulic Control Shock-Absorbing Element For Agricultural Machinery

The hydraulic system is widely used in agricultural machinery.In baling machine,combine harvester rotary cultivator and other agricultural machine,the working element's suspension hoisting and angle swing adjustment are realized through the lifting hydraulic cylinder controled linkage mechanism.Under the working institution's braking and load abrupt condition,due to the complex working condition and high cost performance requirement for hydraulic components on agricultural machinery,there is a large hydraulic impact on the system,which cause the damage to the pipeline and sealing element,further more reducing the service life and reliability of the agricultural machinery and so on.Aiming at the problem of poor reliability and frequent failures in agricultural machinery caused by hydraulic impact.a shock-absorbing valve with parallel damping buffering scheme is put forward to reduce hydraulic impact and its theoretical analysis and simulation experiments are carried out in this papper.First,the paper analyzes the reasons for the poor reliability of the suspension hydraulic system in the agricultural machinery working institution.Through the analysis,several common solutions to the hydraulic impactin on engineering machinery are compared and the theoretical calculation of sudden impact of hydraulic impact pressure and dynamic simulation of braking process were completed in Matlab/Simulink.Then,According to the dynamic damping and steady state depressurization of the slender damping holes,combined with the working environment characteristics of agricultural machinery's working institution a hydraulic controled parallel damping hydraulic shock-absorbing element is proposed.With the parameters given by the working institution of the CF700 tractor's suspension hydraulic system.its structure design and mathematical model are completed.With the help of simulation software matlab,the shock-absorbing valve's dynamic characteristic and parameters are optimized in the braking process of agricultural machinery working institution.On this basis,the AMESim modeling and dynamic simulation analysis of shock-absorbing valve under all working conditions of the working institution are completed.The simulation analysis shows that under the limited security braking distance and time the shock-absorbing valve can effectively reduce the peak of pressure mutation and the gas negative pressure cavitation.Compared with the engineering mechanical shock-absorb scheme,the new shock-absorbing valve has the advantages of simple structure,convenient assembly and disassembly,the inhibitory effect of the pressure fluctuation significantly,by changing the damping hole diameter to achieve the best matching damping,because of its unique performance can be widely used in agricultural machinery hydraulic system buffer.It has a great practical significance to improve China's agricultural life and reliability...