What are the common faults of solenoid valves?
The solenoid valve is composed of a solenoid coil and a magnetic core, and is a valve body containing one or several holes. When the coil is energized or de-energized, the operation of the magnetic core will cause the fluid to pass through the valve body or be cut off to achieve the purpose of changing the direction of the fluid. The electromagnetic components of the solenoid valve are composed of fixed iron core, moving iron core, coil and other components; the valve body part is composed of sliding valve core, sliding valve sleeve, spring base and so on. The solenoid coil is directly mounted on the valve body, which is enclosed in a sealed tube, forming a compact and compact combination. The solenoid valves commonly used in our production include two-position three-way, two-position four-way, two-position five-way and so on. Let’s talk about the meaning of the two positions first: for the solenoid valve, it is energized and de-energized, and for the controlled valve, it is on and off.
The failure of the solenoid valve will directly affect the action of the switching valve and the regulating valve. The common failure is that the solenoid valve does not work, and should be checked from the following aspects:
1. If the solenoid valve wiring head is loose or the wire head is falling off, the solenoid valve should not be energized, and the wire head can be tightened.
2. If the solenoid valve coil is burned out, the wiring of the solenoid valve can be removed and measured with a multimeter. If the circuit is open, the solenoid valve coil will be burned out. The reason is that the coil is damp, causing poor insulation and magnetic leakage, resulting in excessive current in the coil and burning, so it is necessary to prevent rainwater from entering the solenoid valve. In addition, the spring is too hard, the reaction force is too large, the number of coil turns is too small, and the suction force is not enough, which can also cause the coil to burn out. In emergency treatment, the manual button on the coil can be turned from the "0" position during normal operation to the "1" position to make the valve open.
3. The solenoid valve is stuck: the fitting gap between the spool valve sleeve and the valve core of the solenoid valve is very small (less than 0.008mm), and it is generally assembled in a single piece. When mechanical impurities are brought in or there is too little lubricating oil, it is easy to get stuck. . The treatment method can be used to poke the wire through the small hole in the head to make it spring back. The fundamental solution is to remove the solenoid valve, take out the valve core and the valve core sleeve, and clean it with CCI4, so that the valve core can move flexibly in the valve sleeve. When disassembling, pay attention to the assembly order of each component and the external wiring position, so as to reassemble and connect correctly, and also check whether the oil spray hole of the lubricator is blocked and whether the lubricating oil is sufficient.
4. Air leakage: Air leakage will cause insufficient air pressure, making it difficult to open and close the forced valve. When dealing with the failure of the solenoid valve of the switching system, an appropriate time should be selected, and the solenoid valve should be processed when the power is lost. If the processing cannot be completed within a switching gap, the switching system can be suspended and dealt with calmly.
Source of this article: 360 Encyclopedia
Solenoid valves can be divided into on-off solenoid valves and proportional solenoid valves according to their functions. 1) The on-off solenoid valve acts as a switch. When there is current flowing, the solenoid valve controls the circuit or the oil circuit to be on and off. 2) Proportional solenoid valve, that is, according to the input current, the output pressure is different. When the input current is changed, the output pressure of the solenoid valve can be changed, which is mostly used in hydraulic systems.