基于新型旋转高速开关阀的内部流场分析及研究

发布时间：2018-04-24 19:29

本文选题：液压控制系统 + 高速开关阀　；参考：《广东工业大学》2012年硕士论文

【摘要】：在液压控制系统中,高速开关阀是20世纪80年代发展起来的一种新型数字电液转换控制元件,工作于开关两种状态,具有控制精度高、响应速度快、能量损失小以及提供数字接口便于计算机连接控制等特点,应用范围非常广泛。但是,由于高速开关阀自身的特点,存在大流量与快速响应两个性能之间存在矛盾,而无法满足大功率液压系统的需求。本文研究一种新型旋转高速开关阀,无需外加驱动,无需加速减速换向等操作,利用流体自身动能冲击阀芯夹心节螺旋叶片使阀芯获得动力旋转,随着阀芯旋转,螺旋叶片交织结构使得流体选择性的流向应用或流回油箱,通过改变阀芯的轴向位置调节PWM输出,PWM从0到100%可调,流量可达40L/M,开关速度3.4毫秒。轴向控制系统是由单片机、摆线泵和H桥电路组成,把阀一端的液压油抽到另一端来实现阀芯的轴向位移,从而实现流量输出PWM控制。通过分析新型旋转高速开关阀的原理,阀体参数之间的几何关系,分阀芯和阀套两个主要零件设计新型旋转高速开关阀,利用Proe软件参数化建模。阀套上有流体入口,三个喷嘴和四个孔特征。阀芯分夹心节和两个输出导向节(一个流向应用,一个流回油箱),夹心节上主要设计是六个螺旋叶片。通过对阀芯自旋转动力进行分析,在夹心节上设计阀芯螺旋叶片的轨道。为了提高开关响应速度,本文提出优化旋转高速开关阀提高阀芯旋转速度的两种方法,利用导向节开槽和减小喷嘴面积,结合ANSYS/WORKBENCH提供的Fluid Flow(Fluent)模型对阀内部流场进行仿真。仿真结果表明,可以利用在输出导向节的设计来增加阀芯的自旋转动力,利用流体自身动能提高阀芯自旋转速度,从而提高了阀的开关频率。优化后,在喷嘴上的压力损失为0.36Mpa,输出导向节的压力损失为0.2Mpa,增加了导向节的压力损失的同时,阀芯旋转速度由51HZ提升到81HZ,开关响应速度由5.4毫秒提升为3.4毫秒。根据仿真结果设计出新型旋转高速开关阀的虚拟变量泵系统,研究该系统的能量损失,结果表明,基于新型旋转高速开关阀的虚拟变量泵系统比比例阀节流控制系统更优越。
[Abstract]:In hydraulic control system, high speed switch valve is a new type of digital electro-hydraulic control element developed in 1980s. It works in two states of switch, and has high control precision and fast response speed. Energy loss is small and the digital interface is convenient for computer connection control, so it is widely used. However, because of the characteristics of the high speed switch valve, there is a contradiction between the high flow rate and the fast response, which can not meet the requirements of the high power hydraulic system. In this paper, a new type of rotary high speed switch valve is studied, which does not need to be driven by external force, does not need to speed up deceleration and commutates, and uses the kinetic energy of the fluid itself to impinge on the spiral blade of the core knob to make the valve core obtain dynamic rotation and rotate with the valve core. The spiral blade interleaving structure makes the fluid flow selectively applied or flowing back to the tank. The PWM output can be adjusted from 0 to 100% by changing the axial position of the valve core. The flow rate can reach 40 L / M and the switching speed is 3.4 milliseconds. The axial control system is composed of single chip microcomputer, cycloid pump and H-bridge circuit. The hydraulic oil at one end of the valve is drawn to the other end to realize the axial displacement of the valve core, thus the flow output PWM control is realized. Based on the analysis of the principle of the new rotary high speed switch valve and the geometric relationship between the valve body parameters, the new rotary high speed switch valve is designed by dividing the valve core and the valve sleeve into two main parts, and the parametric modeling is made by using Proe software. The valve sleeve has fluid inlet, three nozzles and four holes. The valve core is divided into sandwich joints and two output steering knots (one flow direction application, one flow back to the tank). The main design of the sandwich joint is six helical blades. By analyzing the self-rotating power of the spool, the track of the spool spiral blade is designed on the sandwich joint. In order to improve the switching response speed, this paper presents two methods to optimize the rotary high speed switch valve to increase the rotating speed of the valve core. The flow field inside the valve is simulated by using the slotted guide joint and reducing the area of the nozzle, combined with the Fluid flow flow model provided by ANSYS/WORKBENCH. The simulation results show that the self-rotating power of the valve core can be increased by the design of the output steering joint, and the self-rotating speed of the valve core can be increased by using the kinetic energy of the fluid itself, thus increasing the switching frequency of the valve. After optimization, the pressure loss on the nozzle is 0.36 Mpaand the pressure loss on the output steering joint is 0.2 Mpa. the pressure loss of the guide joint is increased, and the rotating speed of the valve core is increased from 51HZ to 81HZ, and the switching response speed is increased from 5.4 milliseconds to 3.4 milliseconds. According to the simulation results, the virtual variable pump system of the new rotary high speed switch valve is designed, and the energy loss of the system is studied. The results show that the virtual variable variable pump system based on the new rotary high speed switch valve is superior to the proportional valve throttle control system.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH137.52

【参考文献】