Characteristics and principle of solenoid valve

The valve driven directly or indirectly by electromagnetic force is called solenoid valve. According to its structure, it can be divided into:

1, Direct acting solenoid valve

There are two types: normally closed type and normally open type. The normally closed type is closed in case of power failure. When the coil is powered on, electromagnetic force is generated to make the moving iron core overcome the spring force and directly open the valve with the static iron core, and the medium is in a path; When the coil is powered off, the electromagnetic force disappears, the moving iron core is reset under the action of spring force, the valve port is directly closed, and the medium is blocked. The utility model has the advantages of simple structure, reliable action and normal operation under zero differential pressure and micro vacuum. Normally open type is just the opposite. If less than φ 6 solenoid valve for flow path.

2, Step by step direct acting solenoid valve

The valve is connected with the primary opening valve and the secondary opening valve. The main valve and the pilot valve step by step so that the electromagnetic force and differential pressure can directly open the main valve port. When the coil is energized, the electromagnetic force is generated to make the moving iron core and the static iron core pull in, 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. At this time, the pressure in the upper chamber of the main valve is unloaded through the pilot valve port, and the main valve core moves upward under the simultaneous action of pressure difference and electromagnetic force to open the medium flow of the main valve. When the coil is powered off, the electromagnetic force disappears. At this time, the moving iron core closes the pilot valve hole under the action of self weight and spring force. At this time, the medium enters the upper chamber of the main valve core in the balance hole to increase the pressure in the upper chamber. At this time, the main valve is closed under the action of spring return and pressure, and the medium is cut off. Reasonable structure, reliable action and reliable operation at zero differential pressure. Such as ZQDF, ZS, 2W, etc.

3, Indirect pilot solenoid valve

This series of solenoid valves are formed by connecting the pilot valve and the main valve core to form a channel combination; Normally closed type is closed when not powered on. When the coil is energized, the magnetic force generated makes the moving iron core and the static iron core pull in, the pilot valve port is opened, and the medium flows to the outlet. At this time, the pressure in the upper chamber of the main valve core is reduced, which is lower than the pressure on the inlet side, forming a pressure difference, overcoming the spring resistance and moving upward, so as to achieve the purpose of opening the main valve port, and the medium flows. When the coil is powered off, the magnetic force disappears, the moving iron core resets under the action of spring force and closes the pilot port. At this time, the medium flows from the balance hole, the pressure in the upper chamber of the main valve core increases, and moves downward under the action of spring force to close the main valve port. The principle of normally open is just the opposite.