电液激振控制的新方法

Hydraulic Vibration Excited by 2D Valve

传统的阀控液压缸或液压马达构成电液激振器的方案,其频宽在很大程度上受到伺服阀动态响应性能的限制。为提高工作频率至一较高水平,提出了2D电液伺服阀。这种2D伺服阀的阀芯的连续旋转运动使阀开口面积交替变化,而阀芯的直线滑动控制阀开口面积的最大值;2D伺服阀的工作频率正比于阀芯的旋转速度,同时阀芯处于液压油很好的润滑环境中,因而很容易通过提高阀芯的旋转速度来提高激振频率。在支架弹性负载的情况下对激振器进行了实验研究,同时测量液压缸活塞的激振输出波形。实验结果表明:激振输出波形近似为一正弦波;但由于弹性负载的方向变化,激振波形的上升和下降斜率存在不一致性;随着2D伺服阀轴向开口的减小,激振波形逐渐趋于一致。2D伺服阀控电液激振器是大幅度提高液压振动的激振频率的新途径。

The frequency bandwidth of the electrohydraulic vibrator conventionally constructed by a servo valve and a hydraulic cylinder or a motor is to a large extent limited to fairly narrow range by the dynamic response capability of the servo valve. A 2D electrohydraulic valve was developed to enhance the working frequency range. In this 2D valve, the continuous rotary motion of the spool is used to create alternated variation of the valve port areas, while the linear motion of the spool is to control the peak value of the valve port areas, The frequency excited by 2D valve is proportional to the rotary speed of the spool and thus the high-frequency can easily be achieved by increasing the rotary speed of the spool well lubricated in hydraulic oil. Experiments were carried out to the vibrator loaded by an elastic force coming from the deformation of a frame work and the wave forms of the cylinder piston was measured. It is demonstrated that the ascent and descent slopes of the wave form show some inconsistency because of the changing direction of the elastic force, which alleviates with the reduction of valve linear opening. Nevertheless, the wave from is close to a sinusoidal one. It is concluded the development of the 2D valve is an access to the high-frequency excitation of the hydraulic vibration.