Directional control valves , such as check valves and reversing valves , are used to control the direction of oil flow to achieve start, stop, forward and reverse of the actuator. Cartridge type, this type of valve has no separate valve body, and the inserting component consisting of valve core and valve sleeve is inserted into the prefabricated hole of the inserting block body, and the inserted block body functions as a valve body and a pipeline. By inserting several plug-in components together through the intra-block channel, a loop can be formed. There are usually on-off valves, proportional valves, servo valves and digital valves. After the switch valve is set, it can only work in the set state. The proportional valve and servo valve can control the parameters of the system in a connected or proportional manner according to the input signal. The digital valve side directly controls the action of the valve with a digital signal.

Actuators in hydraulic systems (such as hydraulic cylinders, hydraulic oil motors) need to constantly start, brake, reverse and adjust the speed of movement and adapt to changes in external loads during operation, so there is a set of mechanisms to control and Adjusted hydraulic components are usually completed with a control valve. It does not work externally and is only used to control the actuators to meet the performance requirements of the host.

1. Control valves are classified according to their functions

(1) Directional control valves, such as check valves and reversing valves, are used to control the direction of oil flow to achieve start, stop, forward and reverse of the actuator.

(2) Pressure control valves, such as relief valves, pressure relief valves, and sequence valves, are used to control the pressure in the hydraulic system to meet the force, torque, or operating program control required for the actuator.

(3) Flow control valves, such as throttle valves and speed control valves, are used to control the amount of oil flow in the hydraulic system to achieve the required speed of movement of the actuator.

2, the control valve is classified according to its connection method

(1) Pipe connection , the pipe valve is threaded, it is directly connected in series to the piping of the system, no special connection plate is required.

(2) Plate type connection , plate type valve requires special connecting plate, the valve is screwed on the connecting plate, the pipe is connected with the connecting plate, the valve is installed in front of the plate, and the oil pipe is connected behind the plate.

(3) Flange connection , when the flow rate is greater than 300L/min, use flange connection. The flange is welded at the end of the pipe and connected to the valve body with screws.

(4) Integrated block type , the integrated block is a generalized hexahedron with a pipe joint connected to the actuator on one side and valve components on the other three sides. The inner channel of the manifold is in communication with the valves to form different basic circuits. Below the block is the connection between the block and the block. Several blocks are stacked with long bolts to form the entire hydraulic system.

Its characteristics are: compact structure, less tubing, easy loading and unloading and maintenance.

(5) Stacking valve type, the stacking valve is a standardized hydraulic component, the valve body is stacked by bolts, and the stacking valves are directly connected to each other to form a hydraulic system. Each of the superposition valves functions as a control valve and functions as a passage body.

Its characteristics are: compact structure, less tubing, small size, light weight, no need for pipe connection, low pressure loss, and a large number of oil pipes and pipe joints.

(6) Cartridge type, this type of valve has no separate valve body, and the inserting component consisting of valve core and valve sleeve is inserted into the prefabricated hole of the inserting block body, and the plugging block body functions as the valve body and the tube. The role of the road, through the block channel to combine several components into a loop, you can loop.

Its characteristics are: very suitable for large traffic applications.

3, the control valve is classified according to its manipulation mode

General purpose is manual, pedal, motorized, pneumatic, electric and hydraulic, and sometimes in the form of several combinations.

4, classified by work pressure

Pressing the control valve in the hydraulic system is divided into: low pressure valve, medium pressure valve and high pressure valve.

5, according to the principle of control

There are usually on-off valves, proportional valves, servo valves and digital valves. After the switch valve is set, it can only work in the set state. The proportional valve and servo valve can control the parameters of the system in a connected or proportional manner according to the input signal. The digital valve side directly controls the action of the valve with a digital signal.