大流量高水基电液比例方向阀的研究

发布时间：2018-01-26 12:06

本文关键词： 电液比例方向阀流场分析液动力液压冲击　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前,电液控制系统的电液换向阀组都是采用开关阀,无法实现支架精确化的动作,同时高压大流量下,开关阀的快速启闭会产生液压冲击,这给系统元件带来较大的危害,而电液比例控制技术可以很好的解决这些问题。因此,大流量高水基电液比例方向阀的研究十分必要。本文首先对高水基开关阀及油介质比例阀的结构原理进行了分析,结合高水基阀和油介质比例阀设计理论,设计了一款大流量高水基电液比例方向阀。基于CFD技术对不同结构参数下的电液比例方向阀流场特性进行了模拟,得到了合适的结构参数;针对高压大流量工况下主阀进液阀芯液动力较大的问题,进行了液动力补偿研究,研究表明,通过合理设置主阀进液阀芯颈部尺寸以及主阀进液阀套孔锥角的大小均可以显著减小阀芯所受轴向稳态液动力。建立了电液比例方向阀的数学模型,对电液比例方向阀一些关键参数进行了理论分析。结果表明:固定阻尼孔R、主阀芯复位弹簧、主阀芯控制腔面积等重要参数对电液比例方向阀稳态及动态特性影响较大。基于AMESim建立了高水基电液比例方向阀控制系统模型,对其先导阀、主阀的稳态及动态特性进行了研究。结果表明:在输入电流信号中叠加颤振信号可以显著改善先导阀的控制特性(输入电流-输出压力特性);先导阀复位弹簧刚度越大,先导阀负载特性(压力-流量特性)越差;固定阻尼孔R直径越大,先导阀输出压力阶跃响应超调量越小,响应越平稳。主阀进液阀芯复位弹簧刚度越大,进液阀芯位移阶跃响应超调量越小,稳定性越好;直线电流信号输入方案下,进液阀芯开启时间越长,产生的液压冲击越小,在不影响系统响应时间时,抛物线电流信号输入方案与直线电流信号输入方案相比可以显著降低液压冲击。本文综合运用控制理论、计算流体动力学理论、计算机仿真,研究了高水基电液比例方向阀的流场特性、稳态及动态特性,并对高水基电液比例方向阀进行了结构设计与参数优化。本文的研究成果能够为煤矿液压支架用大流量高水基电液比例方向阀的设计提供参考。
[Abstract]:At present, the electro-hydraulic directional valve group of the electro-hydraulic control system adopts the switch valve, which can not realize the accurate action of the support. At the same time, under the high pressure and large flow rate, the quick opening and closing of the switch valve will produce the hydraulic impact. This brings great harm to system components, and electro-hydraulic proportional control technology can solve these problems very well. It is very necessary to study the high flow and high water base electro-hydraulic proportional directional valve. Firstly, the structure principle of high water base switch valve and oil medium proportional valve is analyzed, and the design theory of high water base valve and oil medium proportional valve is combined. A large flow rate and high water base electro-hydraulic proportional directional valve is designed. The flow field characteristics of the electro-hydraulic proportional directional valve with different structure parameters are simulated based on CFD technology and the appropriate structural parameters are obtained. In order to solve the problem of large fluid power in the main valve core under the condition of high pressure and large flow rate, the study of hydraulic power compensation is carried out, and the research shows that. By reasonably setting the neck size of the main valve inlet valve core and the cone angle of the main valve inlet valve sleeve, the axial steady hydraulic power of the valve core can be significantly reduced. The mathematical model of electro-hydraulic proportional directional valve is established. Some key parameters of electro-hydraulic proportional directional valve are theoretically analyzed. The results show that the fixed damping hole R, the main valve core reset spring. The main valve core control cavity area and other important parameters have great influence on the steady and dynamic characteristics of electro-hydraulic proportional directional valve. Based on AMESim, the control system model of high water base electro-hydraulic proportional directional valve is established, and the pilot valve is obtained. The steady and dynamic characteristics of the main valve are studied. The results show that the flutter signal in the input current signal can significantly improve the control characteristics of the pilot valve (input current-output pressure characteristic). The greater the spring stiffness of the pilot valve is, the worse the load characteristic (pressure-flow characteristic) of the pilot valve is. The larger the R diameter of the fixed damping hole, the smaller the output pressure step response overshoot of the pilot valve, and the more stable the response. The larger the spring stiffness of the main valve inlet valve is, the smaller the displacement step response overshoot quantity is. The better the stability; Under the linear current signal input scheme, the longer the valve core opening time, the smaller the hydraulic impact, when the system response time is not affected. Compared with the linear current signal input scheme, the parabolic current signal input scheme can significantly reduce the hydraulic shock. In this paper, the control theory, computational fluid dynamics theory and computer simulation are used synthetically. The characteristics of flow field, steady state and dynamic state of high water base electro-hydraulic proportional directional valve are studied. The structure design and parameter optimization of high water base electro-hydraulic proportional directional valve are carried out. The research results in this paper can provide a reference for the design of high flow and high water base electro-hydraulic proportional directional valve for coal mine hydraulic support.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137.52

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