自传感驱动水压射流管伺服阀研究

发布时间：2018-05-14 13:57

本文选题：水压 + 射流管伺服阀　；参考：《北京工业大学》2013年硕士论文

【摘要】：水压伺服控制技术作为机电液一体化高度融合发展的现代液压技术，已成为当前国际流体传动与控制领域内一个重要的研究方向。水压电液伺服阀是水压伺服系统的核心控制元件，具有体积小、重量轻、响应速度快、控制精度高等突出优点。针对喷嘴挡板式电液伺服阀使用中存在的性能缺陷，基于射流管式伺服阀的优势及水压传动技术的特点，并结合超磁致伸缩自传感驱动技术，开展了自传感驱动水压射流管式伺服阀的工作机理、设计理论与方法及静动态性能仿真实验研究。在水压射流管伺服阀中，前置级射流放大器与接收器的结构尺寸直接影响伺服阀的整体性能，利用FLUENT软件，采用有限体积法，通过数值模拟与实验分析方法，系统研究喷嘴与接收器的垂直间隙、喷嘴孔直径、接收孔直径等结构尺寸以及喷嘴偏移等性能参数对接收器内流场的影响规律，得出优化尺寸组合，建立了射流放大器射流喷嘴偏移与接收器两接收孔内压力比之间的数学关系，揭示了射流管放大器的能量转换与分配机理。高速水流在流经射流管喷嘴时，极易在喷嘴及其下游产生空化现象；同时由于射流剪切层的存在以及射流喷嘴与接收器的间距狭小，水压射流管伺服阀易产生高频空化自激振荡，严重影响伺服阀的性能与使用。利用计算流体力学（CFD）软件，对射流管放大器内部空化流场特性进行仿真，系统研究了前置级射流管结构参数、压力与温度等操作参数对空化产生的影响规律，提出了抑制空化自激振荡产生的控制方法。以功率级滑阀阀芯为驱动对象，以阀芯位移为检测参量，建立了驱动器、射流管放大器、弹簧管组件、功率级滑阀以及反馈杆等伺服阀各环节的传递函数和方框图，系统分析和研究了驱动器输入电流/电压与阀芯位移之间的关系以及电-磁-机-液各环节之间的双向传递规律，最终建立了反映伺服阀整机控制特性的驱动控制信号（电压/电流）与传感检测信号（阀芯位移）的数学模型。借鉴现有油压电液伺服阀特性指标体系，建立水压射流管式电液伺服阀特性指标体系，，并运用AMESim软件对自传感驱动器及伺服阀整机进行了性能仿真研究及参数敏感性分析，主要研究了水压射流管式电液伺服阀特性变化趋势，以及阀芯阀套间隙、滑阀口遮盖量、阀芯质量等参数变化对伺服阀特性的影响。
[Abstract]:Hydraulic servo control technology, as a modern hydraulic technology with high integration of electromechanical and hydraulic, has become an important research direction in the field of fluid transmission and control in the world. Hydraulic electro-hydraulic servo valve is the core control element of hydraulic servo system, which has the advantages of small volume, light weight, fast response speed and high control precision. In view of the performance defects in the use of nozzle baffle electro-hydraulic servo valve, based on the advantages of jet tube servo valve and the characteristics of hydraulic transmission technology, combined with giant magnetostrictive self-sensing drive technology, The working mechanism, design theory and method of self-sensing driven water jet pipe servo valve and the simulation experiment of static and dynamic performance are studied. In the hydraulic jet tube servo valve, the structure size of the front stage jet amplifier and receiver directly affects the whole performance of the servo valve. By using FLUENT software and finite volume method, the numerical simulation and experimental analysis method are adopted. The effects of the vertical gap between the nozzle and the receiver, the diameter of the nozzle hole, the diameter of the receiving hole, and the nozzle deviation on the flow field in the receiver are systematically studied, and the optimal size combination is obtained. The mathematical relationship between jet nozzle offset and the pressure ratio in the receiver is established, and the energy transfer and distribution mechanism of the jet tube amplifier is revealed. When high speed water flows through the nozzle of the jet tube, it is easy to produce cavitation in the nozzle and its downstream, and because of the existence of the jet shear layer and the narrow distance between the jet nozzle and the receiver, High frequency cavitation self-excited oscillation is easy to be produced by water jet pipe servo valve, which seriously affects the performance and application of servo valve. By using computational fluid dynamics (CFD) software, the cavitation flow field characteristics in the fluidic tube amplifier are simulated. The influence of the structure parameters, pressure and temperature of the front stage jet tube on cavitation is systematically studied. A control method to suppress cavitation self-excited oscillation is proposed. The transmission function and block diagram of servo valve, such as driver, jet tube amplifier, spring tube assembly, power stage slide valve and feedback rod, are established by taking the valve core of power level slide valve as driving object and the displacement of valve core as testing parameter. The relationship between the input current / voltage of the driver and the displacement of the valve core and the two-way transfer between the electro-magneto-machine-liquid segments are systematically analyzed and studied. Finally, the mathematical models of driving control signal (voltage / current) and sensing detection signal (spool displacement) which reflect the control characteristics of servo valve are established. Based on the existing hydraulic electro-hydraulic servo valve characteristic index system, the characteristic index system of hydraulic jet tube electro-hydraulic servo valve is established, and the performance simulation research and parameter sensitivity analysis of self-sensing driver and servo valve whole machine are carried out by using AMESim software. The variation trend of hydraulic jet tube electro-hydraulic servo valve and the influence of valve core clearance, sliding valve cover, valve core quality and other parameters on servo valve characteristics are studied in this paper.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH137

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