【作者】 黄勇；

【导师】 胡思节；

【作者基本信息】 湖南大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 电液比例阀是实现电液比例控制技术的关键控制器件。由于其较好的控制精度和稳定性,电液比例阀已开始逐渐代替传统控制阀。电液比例压力控制阀是电液比例阀中的一种,其功用是对液压系统中的油液压力进行比例控制,进而实现对执行器输出力或输出转矩的比例控制。论文在参照国内外成熟产品的基础上,运用现代设计方法和分析手段设计了一种新型比例压力阀的结构。首先,设计了十几种阀芯和阀腔的几何结构,根据计算流体力学的理论,对每一种阀的流道建立数学模型。其次,借助商业软件ANSYS/FLOTRAN和CFX求解流道中的速度、压力数值解,根据求解的数据,分析出阀内流道的几何形状对流场的影响。最后,根据所得结论优化出一种新型的阀芯和阀腔结构。在比例压力阀的控制电路设计中,以单片机控制系统、数字PID算法和PWM (脉冲宽度调制)技术为研究对象。根据电液比例阀的控制要求,编制了系统控制程序,设计了单片机控制系统的电路和功率放大电路,使控制电路的精度和可靠性大大提高。将阀的工作状态抽象成数学模型是研究现代液压系统的主要方法。论文运用运动学和动力学理论,建立了所设计的电液比例压力阀的稳态和动态数学模型,得到了系统的传递函数。另外,求解系统模型中的参数成为一个重要问题,论文中同样以计算流体力学为理论依据,通过有限元等数值方法,计算出流量系数等重要参数。为了研究阀的稳态、动态特性,将传递函数转换为MATLAB/SIMULINK软件包的方框图模型,利用计算机仿真技术得到阀的阶跃输入响应。然后,研究了不同结构对阀稳态与动态特性的影响,为进一步优化阀的结构提供了理论上的参考依据。更多还原

【Abstract】 Electro-hydraulic proportional valve is the key component of the Electro- hydraulic proportional control system . Because of it’s better accuracy and stability control. Electro-hydraulic proportional valve gradually replace the traditional control valve has become a trend。Electro-hydraulic Proportional Pressure Valve is one type of Electro-hydraulic proportional valve. Its function is controling the oil pressure of hydraulic system proportional . Further , control the force and torque of machine.Paper based referencing mature products at home and abroad, using modern design methods and analytical tools designe proportional relief valve structure。First, design a dozen spool and valve cavitys’geometric structure. According to the theory of computational fluid dynamics, establish Each valve flow mathematical model. Secondly using commercial software and CFX and ANSYS/FLOTRAN Solve velocity and pressure Numerical Solution in flow field of each valve .According to the data, Analyze the form of throttle impact on convective field.Finally according to the conclusions, Make the structure of spool and valve cavity optimization, and find a new type of structure.When design the Proportional valve control circuit ,reseach MCU to control systems, digital PID algorithm and PWM (Pulse Width Modulation).Under the electro-hydraulic proportional valve control requirements, develop a system control procedures and design the MCU control system and power amplifier circuit. This Make electro-hydraulic proportional valve control performance greatly improving.Abstracting Working conditions of Valve to mathematical model is main methord of Studying Hydraulic System. Using Kinematic and Kinetic theory establish static and dynamic mathematical model of electro-hydraulic proportional valve which was designed. Find the transfer function. In addition, Solving the model parameters become an important issue.The same, in paper CFD as a theoretical basis, using Finite element numerical method calculate pressure and flow coefficients and other important parameters .In order to study the dynamic and static characteristics of valve, Transfer function is converted into MATLAB/SIMULINK package Extender Model. Using computer simulation technology find dynamic response plan of Valve. Research into different structure of the valve impact on dynamic response of valve.It provides good conditions for further optimizing the structure of the valve.更多还原