摘要
在设计目前国内斗容和机重最大的矿用液压挖掘机液压控制系统中,为减小使用成本,采用交流电动机驱动变量液压泵组作为动力源。为满足工作效率要求,斗杆举升过程采用四台液压泵供油,通过四组比例多路阀(主控阀)阀外合流来满足斗杆的速度要求,为降低能耗,提出在斗杆下降过程依靠自重和专用的比例节流阀进行流量再生的控制方法,加快斗杆下降速度,提高系统工作效率。分析斗杆采用流量再生方法下降的前提条件,对斗杆液压缸在一个工作循环内的压力变化进行机电液一体化的联合仿真研究,按照仿真确定的参数设计并制造样机,试验测试表明,挖掘机加载最大试验负载25kN时,所设计的液压控制系统可以满足斗杆满载举升所需要的压力及速度要求,斗杆下降采用流量再生方法后,下降时间由32s缩短至18s,下降速度明显加快,且下降结束阶段无液压冲击。通过试验,验证了挖掘机液压控制方案的正确性,为今后国内设计和制造更大型的液压挖掘机积累了数据和经验。
During the course of designing the hydraulic control system of hydraulic excavators with the domestic largest bucket capacity and machine weight, electricity with AC motor driving hydraulic pumps is used as a power source to reduce the cost. To meet the efficiency requirements, four oil pumps are adopted while the arm is uplifting. Incorporation outside the valve through four groups of proportional multi-way valve(master valve) is carried out to meet speed requirements. In order to reduce energy consumption, the control method of flow regeneration is put forward which depends on the arm’s own weight and dedicated proportional throttle valve while the arm is declining to accelerate its declining speed and improve the efficiency of the system. In the article the prerequisite for the arm declining is analyzed, which adopts the method of flow regeneration, and hydromechatronics simulation study of pressure changes of excavator arm cylinder within a work cycle is carried out. The prototype excavator has been made according to the parameter design of the simulation. The experimental research of the excavator indicates that the designed hydraulic control system with maximum test load of 250 kN can fully meet pressure and speed the arm needs. The declining time shortened from 32 s to 18 s, speed clearly accelerated, and no hydraulic shock at the last stage of declining after flow regeneration circuit is adopted. Through the test, the correctness of the hydraulic control program of the excavator gets verified. And importantly data and experience have been accumulated for the future design and manufacture of larger hydraulic excavators.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2014年第20期180-187,共8页
Journal of Mechanical Engineering
基金
山西省科技攻关资助项目(20100321025-02)
关键词
液压挖掘机
斗杆
液压控制
再生回路
hydraulic excavator
arm
hydraulic control
hydraulic regeneration circuit