As a key component for controlling fluid on and off in the automation control system, the core working principle of solenoid valve is based on the ingenious combination of electromagnetic induction and mechanical movement. Solenoid valve is mainly composed of electromagnetic coil, iron core, armature, valve core, valve body and other parts. When the electromagnetic coil is not energized, the valve core is tightly attached to the valve seat under the action of spring force or its own gravity, blocking the fluid channel and achieving a closed state. At this time, the fluid cannot pass through the solenoid valve, and the entire system is in a closed state. This initial closed state lays the foundation for the subsequent precise control of fluid on and off.
When the electromagnetic coil is powered on, a magnetic field is generated. Under the action of electromagnetic force, the iron core is magnetized, attracting the armature to drive the valve core to move. The displacement of the valve core directly changes the flow channel state in the valve body, the originally blocked channel is opened, and the fluid can pass through the solenoid valve smoothly. The magnitude of the electromagnetic force is closely related to the number of turns of the coil, the current intensity and the material of the iron core. By adjusting these parameters, the magnitude of the electromagnetic force can be accurately controlled, and then the displacement of the valve core can be accurately adjusted to control the flow of the fluid. This process converts electrical energy into mechanical energy, providing power for the on-off control of the fluid.
The precise control of the solenoid valve also depends on the feedback mechanism. In some high-precision application scenarios, the solenoid valve will be equipped with a position sensor or a pressure sensor. The position sensor can monitor the position of the valve core in real time and feed back the signal to the control system. The control system compares the difference between the actual valve core position and the target position according to the preset parameters, and fine-tunes the valve core position by adjusting the current of the electromagnetic coil to ensure that the fluid on-off state meets the requirements. The pressure sensor can monitor the fluid pressure in real time. When the pressure fluctuates abnormally, the control system will adjust the opening and closing state of the solenoid valve in time to maintain the system pressure stability and achieve precise control of the fluid on-off.
The sealing structure of the solenoid valve is also crucial for precise control of the fluid on-off. A good sealing structure can prevent the fluid from leaking when the solenoid valve is closed, ensuring the reliability of the closed state. Common sealing materials include rubber, polytetrafluoroethylene, etc., which have good corrosion resistance and sealing properties. The design of the sealing structure should not only consider the sealing effect, but also take into account the movement flexibility of the valve core. During the movement of the valve core, the sealing material needs to always maintain a good fit, while not generating too much resistance to the movement of the valve core, so as to ensure that the solenoid valve can quickly and accurately open and close, and avoid fluid leakage or control errors caused by poor sealing.
Different types of solenoid valves also have different working principles in details. For example, in the direct-acting solenoid valve, the electromagnetic force directly acts on the valve core. When powered on, the electromagnetic force overcomes the spring force to directly open the valve, which is suitable for small-caliber and low-pressure occasions; the pilot-operated solenoid valve controls the pilot valve through electromagnetic force, and uses the fluid pressure difference to drive the main valve core to move, which is suitable for large-caliber and high-pressure systems. During the opening process of the pilot-operated solenoid valve, the pilot valve is opened first to generate a pressure difference at both ends of the main valve. Under the action of the pressure difference, the main valve core opens. This working method can reduce the power required by the electromagnetic coil and improve the working efficiency and control accuracy of the solenoid valve.
The precise control of the solenoid valve is also closely related to the type and frequency of the control signal. Common control signals include voltage signals and current signals. By changing the size and frequency of the control signal, continuous regulation and pulse control of the solenoid valve can be achieved. In the continuous regulation mode, the size of the control signal is proportional to the opening of the solenoid valve, which can accurately control the flow of the fluid; in the pulse control mode, by adjusting the frequency and duty cycle of the pulse signal, the opening and closing time of the solenoid valve is controlled to achieve accurate measurement of the fluid flow. This diversified control method enables the solenoid valve to meet the precise requirements of fluid on-off and flow control in different application scenarios.
The solenoid valve generates power through electromagnetic induction, combined with feedback mechanism, sealing structure and diversified control methods, to achieve precise control of fluid on-off. From the electromagnetic coil energized to generate electromagnetic force to drive the valve core movement, to the sensor feedback and control system adjustment, to the unique working mode of different types of solenoid valves, each link cooperates with each other to ensure that the solenoid valve can accurately and reliably control the on-off and flow of the fluid under various complex working conditions, providing a strong guarantee for the stable operation of the automation control system.
