Hydraulic Directional Valve Types

The role of hydraulic directional valves in hydraulic systems is to change the direction of oil flow in the hydraulic circuit and control the execution

The start and stop of the element and the change of the direction of movement of the actuator. Hydraulic directional valves are classified according to the different functions of the valve core, the common ones are O type, H type, M type and Y type

Type O

1. Structural characteristics: P represents oil inlet, T represents oil return port, A and B represent working oil port. In the neutral position, each oil port is fully closed, and the oil does not flow.

2. Functional characteristics:

The inlet and return ports of the working device are closed, and the working mechanism can be fixed in any position and stand still, even if there is an external force, the working mechanism cannot be moved or rotated, so it cannot be used for the mechanism with hand crank.

From stopping to starting is relatively smooth, because the working mechanism return chamber is filled with oil, which can play a cushioning role, when

When the pressure oil pushes the working mechanism to start moving, its speed will not be too fast due to the influence of oil resistance, and the inertia of motion during braking causes a large hydraulic shock.

The hydraulic pump cannot be unloaded.

High commutation position accuracy.

Type H

1. Structural features: In the neutral position, each oil port is fully open, and the system has no oil pressure.

2. Functional characteristics:

The oil inlet P, oil return port T and the working oil port A and B are all connected, so that the working mechanism is in a floating state, which can be moved under the action of external force and can be used for the mechanism with hand crank.

The hydraulic pump can be unloaded.

There is a shock from stopping to starting. Because the oil in the oil return chamber has flowed back to the oil tank when the working mechanism stops, no oil plays a buffering role. The oil ports are interconnected during braking, so the braking is large and O-shaped and stable.

For horizontal bar double-acting cylinders, because the effective action area on both sides of the piston is not equal, the spool valve with this function cannot completely ensure that the piston is in a stop state.

Type M

1. Structural characteristics: in the neutral position, the working oil ports A and B are closed, and the oil inlet P and the oil return port T are directly connected.

2. Functional characteristics:

Since the working ports A and B are closed, the working mechanism can remain stationary.

The hydraulic pump can be unloaded.

Cannot be used on mechanisms with hand cranks.

The transition from stop to start is relatively smooth.

The inertia of motion during braking causes a large hydraulic shock.

It can be used in hydraulic circuits where the oil pump is unloaded and the hydraulic cylinder is locked.

Type Y

1. Structural characteristics: In the neutral position, the oil inlet P closes the working oil ports A and B and the oil return port T.

2. Functional characteristics:

Because the working oil ports A and B are connected to the oil return port T, the working mechanism is in a floating state, which can move with the action of external forces, and can be used for the mechanism with hand crank.

There is some shock from stopping to starting, from stationary to shock at start, braking performance between O type and H type.

The hydraulic pump cannot be unloaded.

The above is a few common hydraulic directional valve classification, these can be manufactured in Elephant Fluid Power, Elephant Fluid Power has three professional production lines, the introduction of German advanced equipment, and has a young and professional production and development team, will definitely make you not lose hope.

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