The role and working principle of pneumatic valve solenoid valve

The role of pneumatic valve solenoid valve

Pneumatic valves are the most common fluid control equipment in industrial pipelines. They are mainly composed of pneumatic actuators and valves. The valves are driven by compressing clean air to control the flow and shut-off of pipeline media, and the execution speed is very fast. For quick cut use.

Pneumatic valves are usually equipped with various accessories, such as solenoid valves, air source processing triples, limit switches, positioners, control boxes, etc., to achieve local control and long-distance centralized control.

If the two-position valve only needs to be opened and closed, the solenoid valve is a necessary configuration, and the solenoid valve can control the opening/closing of the pneumatic valve through excitation/demagnetization.

In terms of the gas circuit (or liquid circuit), the two-position three-way solenoid valve has 1 air inlet hole (connected to the air intake air source), 1 air outlet hole (provided to the target equipment air source), 1 exhaust hole ( Generally install a muffler, if you are not afraid of noise, you can not install it.

The two-position five-way solenoid valve has 1 air intake hole (connected to the air intake air source), 1 positive action air outlet and 1 reverse action air outlet (respectively provided to the target equipment for one positive and one negative action air source), 1 1 positive action vent and 1 reverse action vent (with muffler installed).

For small automatic control equipment, the trachea generally uses 8~12mm industrial rubber trachea.

SCTC Series Standard Cylinder

Pneumatic valve solenoid valve working principle

Electrically speaking, the two-position three-way solenoid valve is generally a single electric control (ie, a single coil), and the two-position five-way solenoid valve is generally a double electric control (ie, a double coil).

The coil voltage level generally adopts DC24V, AC220V and so on. The two-position three-way solenoid valve is divided into two types: normally closed and normally open. Normally closed means that the gas circuit is broken when the coil is not energized, and normally open means that the gas circuit is open when the coil is not energized.

1. The action principle of the normally closed two-position three-way solenoid valve: energize the coil, and the gas circuit is connected. Once the coil is powered off, the gas circuit will be disconnected, which is equivalent to "jogging".

2. The action principle of the normally open two-position three-way single solenoid valve: when the coil is energized, the gas circuit is disconnected. Once the coil is powered off, the gas circuit will be connected, which is also "jogging".

Action principle of the two-position, five-way, double-electrically controlled solenoid valve: energize the positive-action coil, the positive-action air circuit is connected (the positive-action air outlet has air), and the positive-action air circuit is still connected even after the positive-action coil is powered off. , will be maintained until the reaction coil is energized.

Energize the reverse action coil, the reaction air circuit will be connected (the air outlet of the reaction action has air), even if the reverse action coil is powered off, the reaction air circuit will still be connected, and it will be maintained until the positive action coil is energized. . This is equivalent to "self-locking" (the so-called memory function).

Based on the characteristics of the two-position, five-way, double-electrically controlled solenoid valve, when designing an electromechanical control circuit or compiling a PLC program, the solenoid valve coil can be operated for 1~2 seconds, which can protect the solenoid valve coil from being damaged easily. .