液压挖掘机合成式正流量节能控制研究

发布时间：2019-03-16 22:08

【摘要】：本文根据国内外挖掘机节能技术发展现状,在阐述挖掘机液压系统流量控制方式的基础上,对挖掘机正流量控制系统原理进行重点分析,主要研究正流量控制系统的节能效率问题。传统正流量控制系统采用梭阀组比较出各先导压力中的最高压力控制变量泵的排量,并没有根据各执行机构所需的实际流量控制变量泵的排量,导致变量泵的实际流量往往大于执行机构的所需流量,造成系统能量损失大、功率利用率低,而且使用一系列的梭阀组使系统结构复杂。为了进一步提高正流量控制系统的节能效率,提出一种新型合成式正流量控制系统,该系统利用各先导压力的合力综合控制变量泵排量,达到变量泵输出流量与执行机构所需流量相等的目的。在分析传统正流量控制系统和合成式正流量控制系统原理的基础上,建立两者的数学模型,利用Simulink软件对两种控制系统的阶跃响应情况加以分析,同时在AMESim环境中建立两者的工作机构模型,对两种系统在工作机构复合动作时变量泵输出的流量和功率进行对比分析。仿真结果表明,合成式正流量控制系统的响应速度较传统正流量控制系统要快,在对多个执行机构复合动作仿真过程中,合成式正流量控制系统的变量泵输出流量为传统正流量控制系统的78.13%,其变量泵输出功率为传统正流量控制系统的70.28%。仿真结果表明合成式正流量控制系统较传统正流量控制系统能量损失小、功率利用率高,节能效果好。
[Abstract]:According to the development of energy-saving technology of excavator at home and abroad, this paper mainly analyzes the principle of positive flow control system of excavator on the basis of expounding the flow control mode of hydraulic system of excavator. The energy saving efficiency of positive flow control system is studied in this paper. The traditional positive flow control system uses shuttle valve group to compare the displacement of the highest pressure control variable pump in each pilot pressure, and does not control the displacement of the variable pump according to the actual flow rate required by the actuators. As a result, the actual flow rate of variable pump is usually larger than that required by actuator, which results in large energy loss, low power utilization and complex system structure by using a series of shuttle valve groups. In order to further improve the energy saving efficiency of positive flow control system, a new type of composite positive flow control system is proposed. The system uses the force of each pilot pressure to control the displacement of variable pump. The output flow rate of the variable pump is equal to the flow rate required by the actuator. Based on the analysis of the principles of the traditional positive flow control system and the composite positive flow control system, the mathematical models of the two control systems are established, and the step response of the two control systems is analyzed by using Simulink software. At the same time, the working mechanism models of the two systems are established in the environment of AMESim, and the output flow and power of the variable pump under the combined action of the two systems are compared and analyzed. The simulation results show that the response speed of the composite positive flow control system is faster than that of the traditional positive flow control system. The output flow rate of the variable pump is 78.13% of that of the traditional positive flow control system, and the output power of the variable pump is 70.28% of that of the traditional positive flow control system. The simulation results show that the combined positive flow control system has lower energy loss, higher power utilization ratio and better energy saving effect than the traditional positive flow control system.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU621

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