(1)Inside and outside the leaks endanger the safety factor. Other automatic control valve will usually stem extends from the electric, pneumatic, hydraulic actuator control spool to rotate or move. This should solve the long-term actions stem outside the dynamic seal leakage problem; only the solenoid valve is used to seal in the casing of the electric control valve separated from the magnetic core of electromagnetic masterpiece completed, there is no dynamic seal leakage so easy to block must .
(2) The system is simple, they take the computer, the price is low and modest. Solenoid valve structure is simple, low price, easy installation and maintenance compared to other types of control valves and other actuators. More significant is the automatic control system is much simpler and a much lower price. As the solenoid valve switching signal control and industrial computer connection is very convenient. Popular in today's computer prices an era of declining, the solenoid valve is even more obvious advantages.
(3) action express, power tiny, lightweight shape. Solenoid valve response time can be as short as a few milliseconds, even if the pilot solenoid valve can be controlled within tens of milliseconds. Forming the circuit, and more responsive than the other automatic control valve. Properly designed solenoid valve coil power consumption is very low, the case of energy-saving products; can also be done simply trigger movement, and automatically maintain valve position, and usually is not power consumption. Solenoid valve small size, saving space and lightweight appearance.
(4) regulation accuracy is limited for the media is limited. The solenoid valve is usually only switch the two states, the spool only in the two extreme positions can not be adjusted continuously, (trying to breakthrough a lot of new ideas, but also in the experimental trial stage) regulation accuracy also subject to certain restrictions. Solenoid valves have a higher requirement for media cleanliness, containing granular media can not be applied, in the case must first filter out impurities. In addition, the viscous media can not be applied, and a relatively narrow range of a particular product is suitable for medium viscosity.
(5) model and diverse, and versatile. Although the solenoid valve deficiencies, the advantage is still very prominent, so we designed a wide variety of products to meet the various needs and used widely. Solenoid valve technology advances are around how to overcome the deficiencies, how to better play to the inherent advantages commence.
FESTO solenoid valve automation infrastructure components used to control the flow direction, belonging to the actuator; normally used for machine control and industrial valves above, control the direction of the medium, so as to achieve control of the valve switch.
Working principle of the solenoid valve closed chamber with holes in different locations, each hole leads to a different pipeline, cavity intermediate valve, on both sides of the two electromagnets, which surface of the magnet coil is energized the valve body will be are attracted to which side, through the control valve body moves to block or leak oil discharge hole, and into the hole is always open, the hydraulic oil into the drain line, and then to push the oil through the oil pressure cylinder piston, piston driven piston rod, piston rod driven by a mechanical device to move. So that the electrical current through the control of the electromagnet off on the control of mechanical motion.
FESTO FESTO solenoid valve from the principle is divided into three categories:
1) direct-acting solenoid valves: principle: power, the electromagnetic coil to produce the electromagnetic force to turn off the pieces brought from the seat, the valve opens; power, the electromagnetic force disappears, the spring off pieces of pressure on the seat, the valve The door is closed. Characteristics: in vacuum, negative pressure, zero pressure can work, but the path is generally not more than 25mm.
2) step-by-step direct-acting solenoid valves: Principles: It is a direct acting and pilot-style combination of theory, when no pressure difference between inlet and outlet, the power, the electromagnetic force directly to the pilot valve and main valve to turn off parts in turn lift the valve opens. When the inlet and outlet reaches the start pressure, electricity, electromagnetic force pilot valve, main valve cavity pressure rise on chamber pressure drop, which use differential pressure to the main valve is pushed upwards; power failure, the pilot valve with a spring force or medium pressure to promote off, move down, so that the valve is closed. Features: * action also in the zero pressure or vacuum, high pressure, but the power is larger, the requirements must be mounted horizontally.
3) Pilot solenoid valve: Principle: power, electromagnetic force pilot hole open on the chamber pressure decline rapidly close the pieces around the formation of low pressure, fluid pressure to promote the closure of parts to move up, the valve opens; energized, the spring force to the pilot hole Close the inlet pressure through the bypass hole quickly chamber off valve formed around a high pressure differential, the fluid pressure to promote the closure of parts moving down, close the valve. Features: higher maximum fluid pressure range can be freely installed (to be customized) but must meet the fluid pressure conditions.
Solenoid valve from the valve structure and materials of different and the difference principle, be divided into six branch subclasses: straight diaphragm structure, step straight diaphragm structure, the pilot diaphragm structure, direct acting piston structure, step-by-step direct acting piston structure, the pilot piston structure.