一种农具制动阀的设计与缓冲特性分析

Design and Cushion Characteristic Analysis of a New Brake Valve for Farm Tools

农业机具悬挂系统多采用液压缸控制的连杆机构。由于农用机械工况环境复杂,悬挂农具在制动定位过程中液压缸回油腔存在较大压力突变及波动,导致液压冲击及气穴的发生。通过采用并联阻尼泄荷部分高压油液补回到低压腔,完成了一种液压缓冲阀的结构及原理设计。根据某型农业机具悬挂液压系统参数,完成了该缓冲阀在农具下降制动工况下的数学建模。利用MATLAB/Simulink对该缓冲阀进行了液压缸制动缓冲特性仿真分析及关键参数的优化。结果表明,该缓冲阀在兼顾制动时间和距离的情况下,可以对液压缸制动突变压力超调及波动起到良好的抑制作用。

The hydraulic cylinder controlled linkage is wildly used in farm tools suspension system.For the complex working conditions of agricultural machinery,there is a great pressure mutation and fluctuation in the braking process of hydraulic cylinder,which cause hydraulic shock and cavitation.By using a parallel damping hole release a part of high pressure oil to the low pressure chamber,a new hydraulic buffer valve’s the principle and structure design are completed.Based on the parameters of a farm tools suspension hydraulic system,under the condition of hydraulic cylinder falling and braking,the mathematical model of the buffer system is completed.The cushion performance of the hydraulic cylinder is simulated and analyzed in MATLAB/Simulink and the key parameters are optimized.The simulation results show that the peak value of the braking pressure can be effectively reduced and within the limits of braking time and distance.