Diagnosis and maintenance of pneumatic solenoid valve

Release time:Jun. 09, 2015

1.Pneumatic control reversing valve
Air pressure control valve is used to make the main valve core move and change the flow of gas. According to the control mode, it can be divided into three kinds of pressure control, pressure relief control and differential pressure control. Pressure control means that the pressure of the added control signal is gradually increasing. When the pressure increases to the action pressure of the valve core, the main valve changes direction. Pressure relief control means that the pressure of the gas control signal is reduced, and when the pressure is reduced to a certain pressure value, the main valve changes direction. Differential pressure control is to make the main valve core under pressure difference at both ends.

The air controlled reversing valve is divided into two main types: cut-off and slide valve. The structure and working principle of the slide valve type pneumatic control valve are basically the same as that of the hydraulic change-over valve. The cut-off valve is mainly introduced here.

2.Precursor solenoid directional valve

Precursor solenoid directional valve is firstly controlled by the electromagnet, which leads to the pilot pressure, and then the pilot pressure is used to push the main valve core to change its direction, suitable for large size of occasion.

The precursor dual electric control two-bit four-pass solenoid valve consists of a pilot valve (DL, D2) and a main valve. The main valve also includes Valve body 1 and piston assembly 2 parts. The diagram shows that DL and D2 are in a state of power failure. Solenoid valve of the moving iron Core 5, 6 in the closed state. The wide cavity pushes the piston assembly 2 down to make the p with a pass, b through the spool center hole h with T Pass (exhaust). A has compressed air output at the same time, a part of the compressed air into the hole G, one of the way through the throttle hole D into the c cavity so that the seal plug 4 down to seal the exhaust hole B, the other way compressed air into the f cavity, the role of the upper part of the Piston Assembly 2. At this point, even if the DL power is off, the piston assembly 2 will not be bit that the valve has memory function.

Precursor dual electric control two-bit four-pass solenoid valve when the pilot valve D2 power, DL power off, moving iron core 6 is sucked up, c-cavity compressed air through the T1 mouth discharge. At this time from p to a compressed air acting on large and small pistons, due to large, small piston area difference and produce upward force, so that piston assembly 2 up. At the same time, the sealing plug 4 is also moved up and the valve opening 3 is opened, so that the compressed air at the upper end of the piston assembly 2 is discharged through the hole 6. The Piston assembly 2 is moved up, p and B pass, A and T pass (Exhaust). At this point even if the D2 power, due to the size of the piston area difference and produce upward force still exist, so the output status will not change, that is, with memory function. Pneumatic solenoid valve and hydraulic solenoid directional valve, there are many types with similar working principle.