1. Introduction
Solenoid valve is an automation basic component used to control fluid, which belongs to the actuator; it is not limited to hydraulic and pneumatic. Solenoid valves are used to control the direction of hydraulic flow. Factory machinery is generally controlled by hydraulic cylinders, so solenoid valves are used.
2. Features
It can work normally under vacuum, negative pressure, and zero pressure, but the diameter generally does not exceed 25 mm. It can also be operated under zero pressure difference, vacuum, or high pressure, but the power is large, and it must be installed horizontally. The upper limit of the fluid pressure range is relatively high, and it can be installed arbitrarily (customization is required), but the fluid pressure difference condition must be met.
Three, principle
The pneumatic solenoid valve has a closed cavity with through holes at different positions. Each hole of the pneumatic solenoid valve leads to a different tubing. In the middle of the cavity is the valve. On both sides are two electromagnets. Which side of the magnet coil is energized Where will the valve body be attracted;
The pneumatic solenoid valve blocks or leaks different oil discharge holes by controlling the movement of the valve body, and the oil inlet hole is normally open, the hydraulic oil will enter the different oil discharge pipes, and then the pressure of the pneumatic solenoid valve oil Push the piston of Yugang so that the mechanical movement of the entire solenoid valve is controlled by controlling the current of the electromagnet of the pneumatic solenoid valve.
Fourth, the operating principle of pneumatic solenoid valve
The working position of the pneumatic solenoid valve (open or closed) actually refers to the position of the spool of the pneumatic solenoid valve.
The spool is in the A position when the coil is not energized, and in the B position when the coil is energized. When the spool of the pneumatic solenoid valve is in different positions, each interface on the valve body is connected or closed. For example, a two-position solenoid valve means that the spool of the solenoid valve has two different working positions (open or closed). For a pneumatic solenoid valve, it is the solenoid valve's electrified state and de-energized state; for the valve, it controls It is the opening and closing of the valve. Two-way and three-way solenoid valves mean that there are two or three passage ports on the valve body of the pneumatic solenoid valve. The two-position two-way solenoid valve has two channels, one in and one out, and is the most common pneumatic solenoid valve; the two-position three-way solenoid valve has three channels with one in and two out, two of which are corresponding The connection is normally open and normally closed. Similarly, three-way, four-way, and five-way all refer to the number of fluid channels on the valve body.
Six, the working principle of pneumatic solenoid valve
In the initial position, 1 is the air inlet, 2 is the air outlet (normally open), and 3 is the air outlet (normally closed). 3 and 5 are vent holes. When the solenoid valve coil is energized, the iron core gets the electromagnetic force to make the pilot valve act. Use the 2 and 4 holes to change direction, and discharge the gas in the 2 holes. The solenoid valve is used to control the automation of the fluid. The basic components belong to the actuator; they are not limited to hydraulic and pneumatic. Solenoid valves are used to control the direction of hydraulic flow. Factory machinery is generally controlled by hydraulic steel, so solenoid valves are used.
The working principle of the solenoid valve, the solenoid valve has a closed cavity with through holes at different positions, and each hole leads to a different tubing. In the middle of the cavity is the valve. On both sides are two electromagnets, which side is the magnet coil The energized valve body will be attracted to which side, by controlling the movement of the valve body to block or leak out the different drain holes, and the oil inlet hole is normally open, the hydraulic oil will enter the different drain pipes and then pass The oil pressure pushes the oily piston, the piston drives the piston rod, and the piston rod drives the mechanical device to move. In this way, the mechanical movement is controlled by controlling the current of the electromagnet.
Tracing the development history of solenoid valves, so far, solenoid valves at home and abroad are divided into three major categories in principle, and the differences in the structure and material of the valve disc and the differences in principle are divided into six sub-categories ( Direct-acting diaphragm structure, step-by-step structure, pilot diaphragm structure, direct-acting piston structure, step-by-step direct-acting piston structure, pilot piston structure).
Pneumatic solenoid valve, as one of the common accessories of the pneumatic valve, plays a very important role, mainly used for the problem of air source reversal of pneumatic valve.
Among them (2/5) two-position five-way solenoid valve is used in conjunction with double-acting pneumatic valves, (2/3) two-position three-way solenoid valve is used in conjunction with single-acting pneumatic valves, and explosion-proof coils can be selected according to the working conditions, To achieve the effect of explosion-proof, the explosion-proof grade of this coil is encapsulated type: EX m II T4, which can work normally at an ambient temperature of -20~60℃. Pneumatic reversing solenoid valves can be mounted on a mount or tube according to actual conditions and valve needs. The installation complies with NAMUR standard and VDI/VDE3845 double hole, the medium is filtered 50 microns, lubricated, or non-lubricated compressed air. The gas source interface is a G1/4 pipe.
