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Reasons affecting the switching speed of the solenoid valve

- Jan 31, 2019 -

The response speed of the solenoid valve is a very important indicator affecting the performance of the solenoid valve. Especially in some occasions where the time and frequency are critical, the response speed of the solenoid valve must be controlled within 0.05s, which affects the switching speed of the solenoid valve. The three main factors of speed are the valve core, circuit and residual magnetism. The switching process of the solenoid valve is to drive the spool to move to achieve the opening and closing of the valve by the electromagnetic force and the return force of the spring.

(1) Movement delay of the spool

Due to the quality of the stainless steel solenoid valve spool, the valve core has inertial force during the movement, resulting in motion delay. The method of reducing the motion delay is to increase the driving force and reduce the spool quality.

(2) Circuit delay

According to the principle of electromagnetic induction, due to the existence of the coil inductance, the current of the coil cannot rise to the maximum value immediately, so that the electromagnetic force cannot be increased rapidly when the valve is opened, so that the friction force and the spring force cannot be overcome, and the valve core is quickly opened. When the valve is closed, the spring cannot immediately overcome the electromagnetic force that has not yet fallen, causing a current delay. The time parameter τ=L/R is related to the resistance of the coil, the voltage, the relative magnetic permeability of the magnetically permeable material, and the like.

(3) Hysteresis delay

Due to the residual magnetism formed by hysteresis and the existence of eddy currents in the magnetic circuit, the solenoid valve has losses in the working process and also affects the switching speed of the solenoid valve.