Application and principle of solenoid valve in factory

As the most common external drive unit, solenoid valves are widely used in industry. So what is the principle of solenoid valves? 

What are the classifications of solenoid valve?

The solenoid valve is composed of a solenoid coil and a magnetic core, and contains a valve body with one or more holes. When the coil is energized or de-energized, the operation of the magnetic core will cause the fluid to pass through the valve body or be cut off to achieve the purpose of changing the direction of the fluid. The electromagnetic part of the solenoid valve is composed of fixed iron core, moving iron core, coil and other parts; the valve body part is composed of spool valve core, spool valve sleeve, spring base and so on. The solenoid coil is directly installed on the valve body, and the valve body is enclosed in a sealed tube, forming a simple and compact combination.

The most commonly used solenoid valves in factories are two-position two-way solenoid valves, two-position three-way solenoid valves and three-position four-way solenoid valves;

1.The two-position two-way solenoid valve contains a coil. An output point of the PLC or other system controls the coil, that is, it opens or closes when it is energized, and has no action when it is powered off. This kind of solenoid valve has only one movement in control, and the other This kind of movement requires the coordination of mechanical conditions, so two-position two-way solenoid valves are mostly common in safety valve systems.

2.The two-position three-way solenoid valve also contains a coil, which is controlled by an output point of PLC or other system, that is, it opens or closes when it is energized, and the action is the opposite when it is powered off; this solenoid valve is suitable for mechanical structures with simple actions and repeated motions. For example, a single-coil controlled cylinder, etc.

3.     The three-position four-way solenoid valve contains two coils. The two output points of the PLC or other systems control the two coils, that is, one coil opens or closes when energized, and the other coil acts in the opposite direction when energized. If there is no solenoid valve output, it remains the same. The two coils cannot be energized at the same time; this solenoid valve is suitable for mechanical structures with large strokes and requires the use of position sensors.

The most common solenoid valves in factories are the above types, in addition to some special solenoid valves, such as four-way valves, five-way valves, etc., they all have their ownapplication.

In summary: there are several positions on the spool, which are several-position valves; the several outlets on the valve body are several-way valves, which is very convenient to understand.