What is a pneumatic solenoid valve?
The solenoid valve is an electromagnetically controlled industrial device. It is an automatic basic component used to control fluids. It is an actuator, and a pneumatic solenoid valve is one of them. It controls the movement of the valve body to block or leak different oil discharges. Hole, and the oil inlet hole is normally open, the hydraulic oil will enter different oil drain pipes, and then the piston of the oil cylinder is pushed by the pressure of the oil of the pneumatic solenoid valve, so that the current of the electromagnet controlling the pneumatic solenoid valve is controlled. Mechanical movement of the entire solenoid valve.
Pneumatic solenoid valve features
It can work normally under vacuum, negative pressure and zero pressure, but the diameter is generally no more than 25 mm.
It can also be operated at zero differential pressure or vacuum or high pressure, but the power is large and requires horizontal installation.
The upper limit of the fluid pressure range is high and can be installed arbitrarily (customized) but the fluid pressure difference must be met.
Pneumatic solenoid valve working principle
There are closed chambers in the pneumatic solenoid valve. There are through holes in different positions. Each hole of the pneumatic solenoid valve leads to different oil pipes. The middle of the cavity is a valve. On both sides are two electromagnets. Which side of the magnet coil is energized. The valve body will be attracted to which side; the pneumatic solenoid valve will block or leak different oil drain holes by controlling the movement of the valve body, and the oil inlet hole is normally open, and the hydraulic oil will enter different oil discharge pipes. Then, the oil piston is pushed by the pressure of the oil of the pneumatic solenoid valve, so that the mechanical movement of the entire solenoid valve is controlled by controlling the current of the electromagnet of the pneumatic solenoid valve.
In the pneumatic circuit, the function of the electromagnetically controlled reversing valve is to control the opening and closing of the air flow passage or to change the flow direction of the compressed air. The main working principle is to use the electromagnetic force generated by the electromagnetic coil to push the spool to switch and realize the commutation of the airflow. According to the difference of the way the electromagnetic control part pushes the reversing valve, it can be divided into a direct-acting solenoid valve and a pilot-operated solenoid valve. The direct-acting solenoid valve directly uses the electromagnetic force to push the spool reversing, while the pilot-operated directional valve uses the pilot air pressure output from the electromagnetic pilot valve to push the spool to reverse.
Classification of pneumatic solenoid valves
Direct acting solenoid valve:
When energized, the electromagnetic coil generates electromagnetic force to lift the closing member from the valve seat, and the valve is opened; when the power is off, the electromagnetic force disappears, the spring presses the closing member against the valve seat, and the valve is closed. It is characterized by normal operation under vacuum, negative pressure and zero pressure, but the diameter is generally not more than 25mm.
Distributed direct-acting solenoid valve:
It is a combination of direct motion and pilot type. When there is no pressure difference between the inlet and the outlet, after energization, the electromagnetic force directly lifts the pilot small valve and the main valve closing member upward, and the valve opens. When the inlet and outlet reach the starting pressure difference, after the energization, the electromagnetic force leads the small valve, the pressure of the lower chamber of the main valve rises, and the pressure of the upper chamber drops, so that the main valve is pushed upward by the pressure difference; when the power is off, the pilot valve uses the spring The force or medium pressure pushes the closure and moves down to close the valve.
Pilot solenoid valve:
When energized, the electromagnetic force opens the pilot hole, the pressure in the upper chamber drops rapidly, and a pressure difference between the lower part and the lower part is formed around the closing member. The fluid pressure pushes the closing member upward to move the valve to
open; when the power is off, the spring force closes the pilot hole. The inlet pressure through the bypass hole rapidly forms a lower low and high pressure difference around the valve member, and the fluid pressure pushes the closing member downward to close the valve.