三腔液压缸驱动装载机动臂运行特性仿真研究

Simulation Research on Operation Characteristics of Loader Boom Driven by Three-chamber Cylinder

装载机外负载变化频繁且波动范围大,动臂举升时液压系统峰值功率大,动臂下降时举升装置重力势能经液压阀口以节流损失的形式转化为热能,导致液压油温度升高、系统能量效率低。提出基于三腔液压缸的装载机动臂自重液气平衡势能回收系统,在SimulationX仿真软件中建立了装载机机液联合仿真模型,通过试验结果验证了该模型的准确性。在此模型的基础上,采用已建立的三腔液压缸仿真模型代替原机动臂两腔液压缸,针对空载工况中动臂的举升下降过程进行了仿真研究,对比两腔液压缸与三腔液压缸的运行与能耗特性。研究结果表明:在蓄能器初始压力为6 MPa时,该系统具有与原机相同的运行特性,液压泵峰值功率降低57. 1%,能量消耗降低约39. 5%。

The load of the wheel loader changes frequently and fluctuates violently,the peak power of the hydraulic pump is large when the loader arm is lifting,and when the boom is falling the gravitational potential energy of the boom is dissipated by the hydraulic valve port. Then,the dissipated energy is converted into thermal energy,which increases temperature of the hydraulic oil and reduces the energy efficiency of hydraulic system. A potential energy recovery system that loader arm dead-weight hydraulic-gas balance based on three-chamber hydraulic cylinder was proposed. The co-simulation model of wheel loader was built in Simulation X,then the model was verified by experiments. The potential energy recovery and loader arm dead-weight hydraulic-gas balance system was stablished,in which the original two-chamber cylinder of boom hydraulic system was replaced by the three-chamber hydraulic cylinder. Operating characteristics and energy consumption were compared during the lifting and falling simulation process of boom system in no-load conditions. The results show that the proposed system has same operating characteristics with the original machine when the initial pressure of accumulator is 6 MPa,the peak power of pump can be reduced by 57. 1%,and the energy consumption can be decreased by about 39. 5%.