数字型比例阀的仿真与试验研究

发布时间：2018-12-29 15:24

【摘要】：电液比例阀是电液控制系统中的核心控制元件，广泛应用于工业领域。电-机械转换器作为电液比例控制元件中的关键部分，其性能直接影响电液比例控制元件的性能。传统电液比例阀的电-机械转换器为比例电磁铁，虽然其价格低廉、结构简单坚固，但也有线性度差、滞环大、控制精度低等缺点。近年来，随着电力电子技术、控制理论的快速发展，交流伺服电机技术得到了很好的发展，其具有控制精度高、响应速度快等特点。论文采用交流伺服电机取代比例电磁铁，作为电液比例阀的电-机械转换器，，解决了比例电磁铁存在的问题。论文采用永磁交流伺服电机驱动阀芯移动，控制阀口大小，实现对输出流量的控制。分析了数字型比例阀不同方案的特点，并完成方案设计。分析了不同结构的阀芯、阀体和节流槽的特点，并完成了阀芯、阀体及节流槽的结构设计。对阀芯进行受力分析，在此的基础上，设计了滚珠丝杠副并进行校验。建立了数字型比例阀的稳态数学模型。分别建立了伺服驱动系统和机械传动系统的数学模型及液压滑阀的运动方程，并在此基础上，建立了数字型比例阀的动态数学模型，为进一步的理论分析奠定了基础。利用MATLAB软件的仿真环境，建立数字型比例阀的稳态与动态仿真模型，并对其稳态特性与动态特性进行仿真分析。在同等条件下，对采用伺服电机驱动的数字型比例阀与传统的比例电磁铁式电液比例阀进行稳态流量特性试验对比。试验结果表明：在阀芯阀体结构相同的条件下，数字型比例阀与传统比例阀相比，其线性度更好，死区较小，线性区较大，流量控制范围也更大。
[Abstract]:The electro-hydraulic proportional valve is the core control element in the electro-hydraulic control system and is widely used in the industrial field. As a key part of electro-hydraulic proportional control element, the performance of electro-mechanical converter directly affects the performance of electro-hydraulic proportional control element. The electro-mechanical converter of the traditional electro-hydraulic proportional valve is a proportional electromagnet. Although its price is low and its structure is simple and firm, it also has the disadvantages of poor linearity, large hysteresis and low control precision. In recent years, with the rapid development of power electronics technology and control theory, AC servo motor technology has been well developed, which has the characteristics of high control precision and fast response speed. In this paper, AC servo motor is used to replace proportional electromagnet as electro-mechanical converter of electro-hydraulic proportional valve, which solves the problem of proportional electromagnet. In this paper, permanent magnet AC servo motor is used to drive the movement of valve core and control the size of valve opening to realize the control of output flow. The characteristics of different schemes of digital proportional valve are analyzed, and the scheme design is completed. The characteristics of spool, valve body and throttle are analyzed, and the structure design of spool, valve body and throttle is completed. On the basis of the stress analysis of the valve core, the ball screw pair is designed and checked. The steady mathematical model of digital proportional valve is established. The mathematical models of servo drive system and mechanical drive system and the equation of motion of hydraulic slide valve are established respectively. On this basis, the dynamic mathematical model of digital proportional valve is established, which lays a foundation for further theoretical analysis. The steady and dynamic simulation models of the digital proportional valve are established by using the simulation environment of MATLAB software, and the steady and dynamic characteristics of the digital proportional valve are simulated and analyzed. Under the same conditions, the steady flow characteristics of the digital proportional valve driven by servo motor and the traditional proportional electrohydraulic proportional valve are compared. The experimental results show that the digital proportional valve has better linearity, smaller dead zone, larger linear zone and larger flow control range than the traditional proportional valve under the same structure of valve core valve body.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH137.52

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