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Hydraulic solenoid valve coil working principle introduction

Solenoid valves are industrial devices that are controlled by electromagnetics. They are the basic components of automation used to control fluids. They are attributed to actuators and are not limited to hydraulics and pneumatics. Used in industrial control systems to adjust the direction, flow, speed and other parameters of the medium to ensure control accuracy and flexibility, the solenoid valve coil between the solenoid valve plays a key role. There are many kinds of solenoid valves, and different solenoid valves play a role in different directions of the control system. The most common ones are check valves, safety valves, directional control valves, speed dispatch valves, and are not limited to hydraulic solenoid valves.
Hydraulic solenoid valves are an automated base component used to control fluids and are attributed to the actuator. Hydraulic solenoid valves are used to control the direction of hydraulic activity. The mechanical equipment of the factory is generally controlled by hydraulic cylinders, so hydraulic solenoid valves are used.
There are closed chambers in the solenoid valve, and there are through holes in different directions. Each hole is connected with a different oil pipe. The cavity base is a piston, and the two sides are two electromagnetic valve electromagnetic coils. The magnet coil energizes the valve body to control the electric signal. Acting on each other, by controlling the movement of the valve body to open or close different oil drain holes, and the oil inlet hole is normally open, the hydraulic oil will enter a different oil drain pipe, and then push the piston of the oil cylinder through the pressure of the oil. The piston also moves the piston rod, and the piston rod moves the mechanical gear. This controls the mechanical motion by controlling the current through and off of the electromagnet.

Solenoid valves are divided into three main categories in principle:
Direct acting solenoid valve

Principle: When energized, the electromagnetic coil exerts electromagnetic force to lift the closing member from the valve seat, and the valve is opened; when the power is off, the electromagnetic force is not seen, the spring presses the closing member against the valve seat, and the valve is closed.
Features: It can work normally under vacuum, negative pressure and zero pressure, but the diameter generally does not exceed 25mm.

Step-by-step direct-acting solenoid valve

Principle: It is a combination of direct motion and pilot type. When there is no pressure difference between the inlet and the outlet, after the power is applied, the electromagnetic force directly lifts the pilot small valve and the main valve closing member upward, and the valve is opened. When the inlet and outlet reach the starting pressure difference, after the energization, the electromagnetic force leads the small valve, the pressure of the lower chamber of the main valve rises, the pressure of the upper chamber drops, and then the differential pressure is used to push the main valve upward; when the power is off, the pilot valve uses the spring. The force or medium pressure pushes the closure and moves down to close the valve.
Features: It can also be operated at zero differential pressure or vacuum or high pressure, but the power is large and necessary level equipment is required.

Pilot solenoid valve

Principle: When energized, the electromagnetic force turns the pilot hole open, the pressure of the upper chamber is sensitively lowered, and the pressure difference between the lower and lower parts is formed around the closing member. The fluid pressure pushes the closing member upward to move the valve, and the valve opens; when the power is off, the spring force The pilot hole is closed, and the inlet pressure passes through the bypass hole sensitive chamber to form a lower high and high pressure difference around the valve closing member, and the fluid pressure pushes the closing member downward to close the valve.
Features: The upper limit of fluid pressure planning is higher, and it can be any equipment (customized), but it is necessary to satisfy the condition of fluid pressure difference.

2, solenoid valve from the valve structure and material differences and principle differences, divided into six sub-categories: direct-moving diaphragm structure, step-by-step direct diaphragm structure, pilot diaphragm structure, direct-acting piston structure , step-by-step direct-acting piston structure, pilot piston structure.

3. Solenoid valves are classified according to their functions: water solenoid valve, steam solenoid valve, refrigeration solenoid valve, low temperature solenoid valve, gas solenoid valve, fire solenoid valve, ammonia solenoid valve, gas solenoid valve, liquid solenoid valve, miniature solenoid valve, Pulse solenoid valve, hydraulic solenoid valve normally open solenoid valve, oil solenoid valve, DC solenoid valve, high pressure solenoid valve, explosion-proof solenoid valve, etc.

Regarding the type of hydraulic solenoid valve, different manufacturers have different types of arrangement, such as 34BYM-L20H-T, 34 is marked with 3 position 4, B is AC type, Y is hydraulic, M is slide valve Function, L indicates the thread connection method, 20 is the nominal diameter, H is the nominal pressure, H is marked as the high pressure 31.5MPA, and T indicates the spring to medium code. For more detailed type meaning, please consult the relevant manufacturer.

1. The pressure control valve can be divided into an overflow valve, a pressure reducing valve and a secondary valve according to the application.

(1) Overflow valve: It can control the hydraulic system to maintain a constant condition when it reaches the set pressure. The relief valve used for overload maintenance is called a safety valve. When the system has a shortcoming and the pressure increases to a limit value that may constitute damage, the valve port will open the overflow to ensure the safety of the system.
(2) Pressure reducing valve: It can control the branch circuit to obtain a stable pressure lower than the oil pressure of the main circuit. The pressure reducing valve has different functions according to the pressure it controls, and can be divided into fixed value pressure reducing valve, differential pressure reducing valve and proportional pressure reducing valve.
(3) The second valve: can make one of the implementation components move backwards, and then press the other to make the other components operate.

2. The flow control valve uses the orifice area between the dispatching spool and the valve body and the partial resistance of the valve to schedule the flow, and then controls the movement speed of the component. Flow control valves are classified into five types according to their purposes.

(1) Saving valve: After adjusting the saving port area, the saving valve can make the moving pressure of the component without changing the load pressure and the movement uniformity is basically high.
(2) Speed control valve: When the load pressure is changed, the pressure difference between the inlet and outlet of the saving valve can be maintained as a fixed value.
(3) Diverter valve: Regardless of the size of the load, the two operating elements of the same oil source can be equal flow valves or equalizing valves; and the proportionally distributed flow rate is proportional to the diverter valve.
(4) Collecting valve: It is to distribute the flow into the collecting valve proportionally, which acts opposite to the diverter valve.
(5) Diverting manifold: It has the functions of diverter valve and collector valve.

3. The directional control valve is divided into a check valve and a reversing valve according to the purpose.
(1) Check valve: Only the fluid can be connected in one direction in the pipeline, and the reverse direction is blocked.
(2) Reversing valve: change the connection between the pipelines, according to the working direction of the valve core in the valve body, two, three, etc.; according to the number of channels controlled, two-way, three-way, Four-way, five-way, etc.; according to the spool drive method, manual, motorized, electric, hydraulic, etc.

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