关于节流调速油路速度稳定性的探析

Exploration of Throttle Velocity Oil Speed Stability

节流调速油路主要是通过改变节流阀的节流口开口面积的大小来调节通过阀口的流量,从而调节执行机构的运动速度。由于通过节流阀的流量q=KA(ΔP)1/2,ΔP-节流阀的进出口压差。当节流阀开口一定时,由于液压缸的负载F的变化,必然引起ΔP变化,那么进入液压缸的流量q也必然变化,因此液压缸的运行速度也将发生变化。所以,这种油路的最大弊端就是:液压缸的运动速度随负载F的波动而波动。在实际工作中,人们常常用调速阀代替节流阀。但是调速阀相当于减速阀与节流阀组合使用,系统开始工作时,减压阀完全打开,系统的流量只由节流阀来控制;系统正常工作时,由于减压阀开口大小是靠复位弹簧来调节的,在节流口两端的压差始终不能精确恒定。本文在节流调速油路中增设一个压差稳定缸,并通过相应控制元件的控制保证节流阀进出口压差稳定,从而实现液压工作缸的速度稳定。

Throttle Velocity Oil Speed is mainly through changing throttle orifice of throttle valve＇s size of the opening area so as to adjust the flow of the valve orifice and adjust the speed of the actuator. As the flow through the valve is equal to q=KA （A P）l/2, A p- differential pressure of throttle inlet. When the throttle valve opens at the certain level, for the load of hydraulic cylinder F＇s change, it must cause the chang of A P, so the running speed of the hydraulic cylinder will also change. Therefore, the biggest drawback of this kind of oil way is that the moving speed of the hydraulic cylinder fluctuates with the fluctuation of the load F. In actual work condition, people often replace valve with speed control valve. However, the control valve is equivalent to the combination of deceleration valve and the throttle valve. When the system works, the deceleration valve is completely opened. The flow of the system is controlled only by throttle valves. When the system works normally, the size of the opening of the relief valve is regulated by the reset spring. The pressure difference at both ends of the throttle orifice can never be accurately determined. A differential pressure stabilizing cylinder is added to throttle speed regulating oil passage in the thesis, so as to realize the speed stability of hydraulic cylinder.