装载机电液混合流量匹配转向系统特性研究

Electro-hydraulic hybrid flow matching steering system of wheel loader

为提高传统装载机能量利用率,提出采用变转速定量泵独立供油的电液流量匹配转向原理,用于控制装载机转向,将装载机方向盘转向角速度与伺服电机转速进行合理匹配,使液压泵输出相应流量到转向系统中,当无转向信号时,转向动力源不输出流量。若电液流量匹配转向系统出现故障,则该液压转向系统经电磁阀自动切换到原有转向系统,继续完成转向作业。首先建立铰接式装载机机械结构动力学与电液混合系统联合仿真模型,利用该模型对电液流量匹配系统的转向过程进行仿真,进一步建立试验测试样机,对转向系统的动态及能耗特性进行测试,并与原有转向系统的转向特性进行对比。研究结果表明:采用电液混合流量匹配转向系统,可减少转向过程的节流损失并消除溢流损失,节能约16%,并可减小压力冲击和波动,系统的稳定性也得到明显提高。

In order to improve the energy efficiency of the traditional wheel loader,the electro-hydraulic flow matching steering principle was proposed to control the steering of the wheel loaders.In the steering system,and the hydraulic oil was supplied independently by the variable speed fixed displacement pump.And the steering angular velocity of the steering wheel was used to control the speed of servo motors,so that the hydraulic pump could output corresponding flow into the steering system.When there were no steering signals,the steering system did not work.Once the electro-hydraulic flow matching steering system broke down,the steering system would automatically switch to the original steering system to continue work via the magnetic valve.The co-simulation model of mechanical structure dynamic and electro hydraulic system of wheel loader was established,and the steering process of the electro-hydraulic flow matching steering system was simulated through the model.Then the test prototype was built to test the dynamic and the energy consumption characteristics of the steering system.Lastly,the characteristics of load sensing steering system and electro-hydraulic flow matching steering system were compared.The results show that by adopting the electro-hydraulic flow matching steering system,throttling losses can be reduced and overflow losses can be eliminated during the steering process,so that the energy consumption can be decreased by about 16%.Apart from that,the shock and fluctuation of pressure can also be reduced,which improves the system stability.