Structure and working principle of one-way throttle valve

Structure and working principle of one-way throttle valve

The one-way throttle valve is composed of a one-way valve and a throttle valve in parallel. It is used in the circuit where the flow needs to be controlled in one direction and the oil flow needs to be unblocked in the other direction (reverse), so as to realize the speed regulation of the actuator in the forward direction and the rapid return in the reverse direction.

Figure 98 shows the slide valve differential pressure type one-way throttle valve. When the oil flows from P1 to P2, the valve acts as a throttle valve and a check valve in reverse. The lower end and upper end of valve element 4 are respectively affected by the pressure oil in and out of the oil chamber. Under the action of the pressure difference in and out of the oil chamber and the return spring 6, the valve element is tightly pressed on the adjusting screw 2 to maintain the original adjusted throttle opening.

Figure 99 shows a one-way throttle valve that can be directly installed on the pipeline. The throttle port is an axial triangular groove structure. Rotating the adjusting sleeve 3 can change the flow area of the throttle port and realize flow regulation. In case of forward flow (B → a), it acts as a throttle valve; During reverse flow (a → b), it acts as a one-way valve. Because some oil can flow in the annular gap, the sediment on the orifice can be removed. The left end of the valve core is provided with a scale groove, and the regulating sleeve is provided with a scale ring to mark the size of the regulated flow. The flow regulation of the valve must be carried out without pressure. Dr series MK type one-way throttle valve is of this structure.

There are two kinds of one-way throttle valve in structure. One is that the one-way valve and the throttle valve share a valve core, and the other is that the two valve cores of the one-way valve and the throttle valve are separated. For example: medium and low pressure one-way throttle valve (Li type), the throttle valve and the one-way valve share one valve core, and the two valve cores of medium and high pressure one-way throttle valve (LDF type) are separated, and their pressure and flow series are the same as the throttle valve. Their structures are shown in figures 100 to 102.