Principle of solenoid valve structure

Direct acting solenoid valve

There are two types of normally closed and normally open. The normally closed type is closed when the power is turned off. When the coil is energized, an electromagnetic force is generated, which causes the moving iron core to overcome the spring force and the static iron core is attracted to directly open the valve. The core is reset under the action of the spring force, and the valve port is directly closed without medium. The structure is simple, the action is reliable, and it works normally under zero pressure difference and micro vacuum. The normally open type is just the opposite. Such as a solenoid valve with a flow diameter of less than φ6. (Figure 1 is a typical structure diagram)

Step-by-step direct acting solenoid valve

The valve uses a primary valve opening and a secondary valve opening in one, the main valve and the pilot valve step by step enable the electromagnetic force and pressure difference to directly open the main valve port. When the coil is energized, an electromagnetic force is generated to attract the moving iron core and the static iron core, the pilot valve port is opened and the pilot valve port is set on the main valve port, and the moving iron core is connected with the main valve core. The pressure in the cavity is unloaded through the pilot valve port, and the main valve core is moved upward under the action of the pressure difference and the electromagnetic force to open the main valve medium circulation. When the coil is de-energized, the electromagnetic force disappears, the power iron core closes the main valve under the effect of self-weight, spring return and pressure, and the medium is cut off. The structure is reasonable, the action is reliable, the work is also reliable when there is zero pressure difference, and it is also reliable when working with zero pressure difference. Such as: ZQDF, ZS, 2W. (Figure 2 is a typical structure diagram)

Indirect pilot solenoid valve

This series of solenoid valve is composed of a combination of pilot valve and main spool to form a channel; normally closed type is closed when not energized. When the coil is running, the magnetic force generated causes the moving iron core and the static iron core to pull together, the pilot valve port opens, and the medium flows to the outlet. At this time, the pressure in the upper cavity of the main valve core decreases and is lower than the pressure on the inlet side, forming a pressure difference The resistance of the spring moves upward accordingly, so as to achieve the purpose of opening the main valve port, and the medium circulates. When the coil is de-energized, the magnetic force disappears, and the moving iron core moves downwards under the action of the spring force, closing the main valve port. The principle of normally open is just the opposite. Such as: SLA, DF (diameter above φ15), ZCZ, etc. (Figure 3 is a typical structural diagram)