Common faults of solenoid valves and common troubleshooting methods for non operation

Hydraulic electromagnetic directional valve is a hydraulic component that relies on the thrust generated by the electromagnetic iron when it is energized to make the valve core move relative to the valve body, controlling the flow, interruption or direction of the fluid. The common fault phenomena of solenoid valves during use are as follows:

(1) The valve core does not move or is obstructed by abnormal movement: mainly due to electromagnetic coil failure, valve core clamping, scratches on the mating surface between the valve core and the valve body causing increased friction, reset spring failure, changes in oil characteristics, etc.

(2) Leakage: mainly includes internal and external leakage faults.

(3) High pressure loss: mainly caused by excessive actual flow, dimensional errors between the valve core platform or valve body sink groove, and improper movement of the valve core.

(4) Excessive magnetic leakage or path loss: Defects on the surface of the electromagnetic coil or faults in the coil drive circuit can cause abnormal magnetic flux passing through the coil.

(5) Abnormal impact and vibration: Excessive movement speed of the valve core or loose screws fixing the solenoid valve, as well as oil circuit faults, can all cause abnormal impact and vibration.

Common faults include solenoid valve failure, which should be investigated from the following aspects:

(1) If the wiring head of the imported solenoid valve is loose or the wire head falls off, the solenoid valve cannot be powered, and the wire head can be tightened.

(2) The imported solenoid valve coil is burnt out. The wiring of the solenoid valve can be removed and measured with a multimeter. If there is an open circuit, the solenoid valve coil is burnt out. The reason is that the coil is damp, causing poor insulation and magnetic leakage, resulting in excessive current inside the coil and burning out. Therefore, it is necessary to prevent rainwater from entering the solenoid valve. In addition, if the spring is too hard, the reaction force is too large, the number of turns in the coil is too small, and the suction force is not enough, it can also cause the coil to burn out. When dealing with emergencies, the manual button on the coil can be moved from the "0" position during normal operation to the "1" position to open the valve.

(3) The solenoid valve is stuck. The clearance between the slide valve sleeve and the valve core of the solenoid valve is very small (less than 0.008mm), usually assembled as a single piece. When mechanical impurities are introduced or there is too little lubricating oil, it is easy to get stuck. The processing method can be to insert a steel wire through the small hole in the head and make it bounce back. The fundamental solution is to remove the solenoid valve, take out the valve core and core sleeve, clean them with CCI4, and make the valve core move flexibly inside the valve sleeve. When disassembling, attention should be paid to the assembly sequence and external wiring position of each component, in order to reassemble and wire correctly. It is also necessary to check whether the oil mist spray hole is blocked and whether the lubricating oil is sufficient.

(4) Leakage. Leakage can cause insufficient air pressure, making it difficult to open and close the forced valve. The reason is that the sealing gasket is damaged or the slide valve is worn, causing several cavities to blow air. When dealing with electromagnetic valve faults in the switching system, an appropriate timing should be chosen to handle them when the solenoid valve is in a power-off state. If the problem cannot be resolved within a switching gap, the switching system can be paused and handled calmly.