两种2D伺服阀导控阻力半桥的性能比较研究

发布时间：2018-10-09 12:40

【摘要】：电液伺服阀作为电液伺服控制系统中的核心元件,以及连接电气元件和液压元件的桥梁,在很大程度上决定了整个系统的性能。随着工业发展的需要,对电液伺服阀提出了大流量、响应快、频带宽、控制精度高、抗污染能力强以及价格低廉等要求。2D伺服阀具有可直接由计算机控制、不需要D/A转换器、线性重复性好外,还具有响应速度快、抗污染能力强、零位泄漏小以及转换精度高的优点,可应用于电液伺服系统中。本论文以圆孔型2D伺服阀与满弓型2D伺服阀为研究对象,分析两者在导控阻力半桥变化时,其动态响应性能方面的差异。分别建立了圆孔型2D伺服阀与满弓型2D阀的非线性模型,并对圆孔型2D阀作线性化处理;利用建立的非线性模型,采用仿真软件对圆孔型2D阀和满弓型2D阀进行比较研究,从仿真结果来看:敏感腔长度、阀芯半径、系统工作压力对满弓型2D阀阶跃过渡时间影响小,螺旋槽升角对满弓型2D阀的响应时间无影响;阀芯质量、小孔半径对满弓型2D阀的影响大;小孔初始弓高对两者影响均很大;满弓型在质量为21.58g时响应速度最快,达到0.7ms,圆孔型2D阀一般都在1ms左右。最后对圆孔型2D阀进行了实验研究,实验结果表明,圆孔型2D阀的零位泄漏量很小,动态响应性能基本符合仿真结果。本文各章内容如下: 第一章,详细介绍了2D伺服阀的结构组成与工作原理,并对电液数字控制元件进行分析,提出了2D阀采用混合式步进电机作为电—机械转换元件,并对步进电机采用连续跟踪算法; 第二章,分析2D伺服阀运动的基本方程,对圆孔型2D阀的小孔流量方程进行推导,建立高、低压小孔的连续性方程以及阀芯的力平衡方程等非线性模型,采用同样的方法建立了满弓型2D伺服阀的非线性模型,并对圆孔型2D伺服阀进行线性化处理,求出其传递函数。第三章,分别对圆孔型2D伺服阀与满弓型2D伺服阀进行仿真比较,分析两者在阀体结构参数改变时,阀芯轴向位移的阶跃响应特性存在差异,满弓型2D阀的响应速度快于圆孔型,如满弓型2D阀当质量为21.58g时,响应速度最快,达到0.7ms,圆孔型2D阀一般都在1ms左右。第四章,搭建2D伺服阀的实验测试平台,对圆孔型2D阀进行实验零位泄漏量进行理论与实验研究,测试了圆孔型2D阀的静态与动态响应特性,圆孔型2D阀具有良好的静态重复特性(重复精度与分辨率都在1%之内)、零位泄漏小(工作压力21MPa下其泄漏量为0.6L/min)以及阶跃响应过渡时间短(约8ms)等优点。
[Abstract]:The electro-hydraulic servo valve, as the key element in the electro-hydraulic servo control system, and the bridge connecting the electrical and hydraulic components, determine the performance of the whole system to a great extent. With the development of industry, the requirements of large flow rate, fast response, high frequency bandwidth, high control precision, strong anti-pollution ability and low price are put forward for the electro-hydraulic servo valve, which can be directly controlled by computer, and does not require a D / A converter. Besides good linear repeatability, it has the advantages of fast response speed, strong anti-pollution ability, small zero leakage and high conversion precision. It can be used in electro-hydraulic servo system. In this paper, the circular 2D servo valve and the full bow 2D servo valve are taken as the research objects, and the difference in dynamic response between them when the resistance half-bridge changes is analyzed. The nonlinear models of circular 2D servo valve and full bow 2D valve are established respectively, and the linear treatment of circular hole 2D valve is made, and the comparison between round hole 2D valve and full bow 2D valve is carried out by using the established nonlinear model and simulation software. The simulation results show that the length of the sensitive cavity, the radius of the valve core, the working pressure of the system have little effect on the step transition time of the full bow 2D valve, the spiral groove lift angle has no effect on the response time of the full bow 2D valve, the quality of the valve core, The radius of the hole has a great influence on the full arch 2D valve, the initial bow height of the small hole has a great influence on both of them, and the full arch type has the fastest response speed of 0.7 Ms when the mass is 21.58 g, and the circular hole type 2D valve is generally about 1ms. The experimental results show that the zero leakage of the circular 2D valve is very small and the dynamic response performance is basically consistent with the simulation results. The contents of each chapter are as follows: in the first chapter, the structure and working principle of 2D servo valve are introduced in detail, and the electro-hydraulic digital control element is analyzed, and the hybrid stepping motor is used as the electro-mechanical conversion element in 2D valve. In the second chapter, the basic equation of 2D servo valve motion is analyzed, and the flow equation of small hole of circular 2D valve is deduced. The nonlinear models such as continuity equation of low pressure orifice and force balance equation of valve core are used to establish the nonlinear model of full bow 2D servo valve, and linearization of circular hole 2D servo valve is carried out, and its transfer function is obtained. In the third chapter, the circular 2D servo valve and the full bow 2D servo valve are simulated and compared, and the step response characteristics of the spool axial displacement are analyzed when the valve body structure parameters are changed. The response speed of full bow 2D valve is faster than that of round hole type. For example, when the mass of full bow 2D valve is 21.58 g, the response speed is the fastest, up to 0.7 Ms, and the circular hole 2D valve is generally about 1ms. In the fourth chapter, the experimental test platform of 2D servo valve is built, and the experimental zero leakage of circular 2D valve is studied theoretically and experimentally, and the static and dynamic response characteristics of circular 2D valve are tested. The circular hole 2D valve has the advantages of good static repetition (within 1% repetition accuracy and resolution), small zero leakage (0.6L/min leakage under working pressure 21MPa) and short step response transition time (about 8ms).
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137.52

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