共查询到17条相似文献,搜索用时 188 毫秒
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《液压气动与密封》2016,(11)
阐述了一种新型本安型电液换向阀的工作原理,采用了2D阀的技术,在本安型双向电磁铁与双自由度阀芯之间引入双向压扭联轴器。正常压力情况下,电磁铁输出的推(吸)力通过压扭联轴器使阀芯转动,由液压力差推动阀芯轴向移动,实现换向功能。本质安全技术作为低功率的设计技术,限制了本安型电磁铁的输出的推力,而压扭联轴器不仅可以实现位移-旋转的运动转换,还可以将电磁铁的驱动力放大,使其能有效、可靠地驱动阀芯运动,从而提高本安型换向阀的可靠性。通过对本安型二维(2D)电液换向阀实验研究,测得其启、闭特性,表明在一定压力范围内,本安型2D电液换向阀不仅可以克服液动力和摩擦力的不利影响,还具有较快的响应速度和稳定性。 相似文献
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提出了一种滚珠丝杠型压扭联轴器,该联轴器能将输出力放大约20倍,有效地解决了因比例电磁铁磁饱和造成直动比例方向阀无法实现大流量的问题。该联轴器将2D方向阀和比例电磁铁相连接,利用压扭放大驱动技术,将电磁力转化为阀芯左右两端不平衡的液压力,以克服摩擦力、卡紧力和液动力等非线性因素的影响。对主阀P-A处与导控级的压力分布和流场分布进行了仿真分析,理论与实验研究表明:压扭联轴器有效地放大了电磁力,在流量约为210L/min的情况下,阀的阶跃响应约为0.35s,该阀-90°频率为4Hz左右。叠加一定颤振对改善阀的阶跃响应不明显,但能较好保证阀芯位移与电磁铁位移之间的跟随性。 相似文献
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针对2D电液比例换向阀阀芯卡滞现象,应用缝隙流动原理,对2D阀芯有无偏心情况下的径向卡紧力进行系统理论分析,得到2D阀芯液压卡紧力计算方法;运用MATLAB软件进行数值计算,得出2D阀芯径向卡紧力与偏心量和高低压孔夹角间的关系;根据2D阀特性,提出2D电液比例换向阀阀芯改进措施,应用Fluent 软件对阀芯表面的流场进行CFD仿真分析,比较了改进前后的流速矢量和压力分布情况,验证了改进措施的正确性。改进后的2D电液比例换向阀在中高压实验中无“卡滞”现象出现,实现了高压大流量的比例控制。 相似文献
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1 电液比例复合阀图1为电液比例复合阀的结构示意图。它由作为先导阀的电液比例双向减压阀和作为主阀的弹簧对中液动换向阀组成。 相似文献
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电液控制元件的插装化是目前移动式液压控制系统的主流发展趋势。现有的2D比例阀面向传统工业液压领域,其受到液压桥路以及压扭联轴节结构限制,无法实现插装化。提出一种新型插装式2D电液比例流量阀的结构原理,在电-机械转换器与半桥式2D阀本体之间引入双向滚子联轴节,以此实现力传递、阀芯位置反馈和阀芯直线-旋转运动的转换功能。基于线性理论推导了阀的特性方程,并利用Nyquist判据判定了阀的工作稳定性;为实现优化设计,建立基于AMESim、ADAMS和Matlab/Simulink平台的联合仿真模型,研究诸关键结构参数对动态特性的影响。最后设计并制造了样机,搭建了滚子联轴节和插装式2D阀的试验台架,研究联轴节的静动态特性及阀样机的空载流量特性、负载流量特性、泄漏特性以及频响和阶跃特性等。试验结果表明样机具有良好的工作性能。当预载荷为40 N时,联轴节的最大输出扭矩为2.3 N·m,输出角位移为0.42°,滞环为5.25%,响应时间为32.5 ms;当供油压力为12 MPa时,阀样机的空载流量为61.5 L/min,滞环为6.32%,阶跃时间为68.5 ms,幅频频宽为19.7 Hz,相频频宽为22.1 Hz。研究表明,插装式2D阀具有较好的静动态特性,是移动式电液控制系统流量控制阀的一种较理想解决方案。 相似文献
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The pilot operated proportional directional valves (POPDVs) with a flow rate ranging from 100 to 1000 L/min are widely used in electro-hydraulic systems (EHSs). The deadzone of the pilot stage valve and its control compensation could significantly affect the position control performance for the main stage valve that could directly affect dynamics of EHSs In this paper, it is concluded that micro flow rates exist at the intermediate position of the valve based on the analysis of the continuity equation of the flow in the control chamber of the pilot stage. The micro flow rate is helpful to eliminate the discontinuity and unsmooth domain in the previous inverse deadzone compensation function. An improved deadzone detection method is proposed to calibrate the pilot valve flow characteristics which include the micro flow rate. This new method avoids the threshold selection of the main valve spool displacement which affects the detected deadzone values. Its detection processes are realized based on the pilot flow rate characterized by the speed of the main valve spool and the pilot valve displacement characterized by the solenoid current. The deadzone compensation control strategy based on the improved deadzone detection method is also designed. The experimental results using the steady-state position tracking and sinusoidal position tracking methods are verified. It is concluded that the tracking accuracy of the main valve spool position is effectively improved with this control strategy. 相似文献
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为了提高液压支架的机械控制能力,利用电液换向阀完成支架控制箱动作控制。该文采用流体动力学仿真了电液换向阀的动态特征及流场特性。研究结果表明:当时间到达0.14 s时二级阀芯发生运动,出口流量快速增大至一个峰值状态;随着阀芯到达一个稳定运动状态后,换向阀也达到1013 L/min的稳定出口流量。换向阀在高压大流量系统内工作时将会快速到达峰值压力,产生液压冲击作用并使支架立柱受到破坏。当流体由阀套流至阀芯时因为过流断面的面积会迅速降低,使压力下降4.1 MPa,形成压力集中损失的区域,同时在阀芯的主流道区域还会形成均匀的压力分布状态。从阀口的下游最初进入阀芯的主通道位置时将达到最大流速,等于109 m/s,表明该部位形成了最小的过流面积。 相似文献
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严恺;阮健;傅莹龙;李朋 《流体传动与控制》2013,(6):17-21
介绍了一种专门用于控制全桥式2D电液比例换向阀的比例控制器,叙述了其电源电路、模拟量输入接口电路、数字量输入接口电路、PWM功率放大电路及电流检测电路等硬件电路的设计,论述了其软件系统的主要工作流程,并对该比例控制器的输入输出特性进行了测试。测试结果表明,该比例控制器具有良好的稳态控制性能。 相似文献
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A 2D high-frequency rotary directional control valve with a spool having two degrees of freedom for axial linear motion and circumferential rotation is proposed in this paper. The axial linear motion decides the maximum orifice area, and the circumferential rotation lets the orifice area change continuously. One of the known elements impacting valve function is the flow force. This paper systematically analyzes the steady and transient flow torques subjected to the valve through theoretical analysis, AMESim-Fluent joint simulation and experimental tests. The results show that: under a single variable, the flow torques of the 2D high-frequency rotary directional control valve initially increase and then decrease like the sinusoid curve with the rotation of the spool and reach the maximum when the orifice opening is 1/2, and the flow torques are always in the direction of orifice closing and want to close the orifice. When the orifice area increases, the flow torques are the resistance, preventing the spool from opening; when the orifice area decreases, the flow torques are the power, pushing the spool to close. The steady flow torques are proportional to the pressure drop. The direction of the transient flow torque is independent of the relative position of the spool groove and sleeve window, which proportional to the square root of the pressure drop, orifice area and rotational speed. The flow torques are so important in the control of valve and can not be negligible. 相似文献