The quality of solenoid directional valve

The quality of solenoid directional valve

 

As one of the commonly used standardized hydraulic components, the electromagnetic directional valve has no big difference in its basic structure. The quality of electromagnetic reversing valve is mainly determined by the following points:

 

1. Material

 

The electromagnetic reversing valve adopts a slide valve structure. When the electromagnet is energized, the cylindrical valve core moves back and forth inside the valve body, which inevitably generates friction with the valve body. At the same time, the electromagnetic reversing valve is subjected to high pressure during its operation, which intensifies wear. Therefore, the environment of high pressure and high frequency puts higher requirements on the durability of the electromagnetic directional valve. For ordinary electromagnetic directional valves with low valve core and valve body hardness, in this high-pressure and high-frequency work, the wear is faster, which increases the matching gap between the valve body and the valve core, and reaches a certain limit, which will cause The internal leakage of the electromagnetic reversing valve increases, ranging from a decrease in system efficiency due to flow loss, and at worst, malfunctions such as malfunction of the actuator due to internal leakage. The valve body is made of spheroidal graphite cast iron, and the hardness of the valve body can be increased through the proportioning process of raw materials.

 

The electromagnet used in the electromagnetic directional valve is also the key. In addition to the difference in performance and thrust, good electromagnets have relatively high material specifications for copper wires, silicon steel sheets, and white iron tubes. In addition to ensuring long-term pressure resistance and smooth operation in high-voltage environments, they can ensure high-voltage and high-frequency working temperature The lower the rise, it prolongs the life of the electromagnet. At the same time, it helps to control the temperature rise of the hydraulic oil. Excessive temperature of hydraulic oil can cause changes in oil quality, which can easily cause malfunctions of the hydraulic system and even component failures.

 

Other detailed materials, such as the hardness of the sealing O-ring, the material of the return spring, etc., will also affect the performance of the solenoid directional valve.

 

 

 

2. Process

 

Another difference in the quality of electromagnetic reversing valves lies in the processing technology and accuracy.

 

The fitting gap between the valve core and the valve body, because the valve core needs to move smoothly in the valve body, a certain gap between the two must be ensured. However, if the gap is too large, the seal between the oil ports cannot be achieved, and the internal leakage is too large. On the premise of smooth movement of the spool, the smaller the fit clearance, the more the solenoid directional valve can withstand high pressure and maintain a good seal. At the same time, the coaxiality of the valve core also has extremely high requirements. Poor coaxiality of the valve core, the force on each point of the valve core is not equal in a pressure environment, the pressure difference causes the valve core to be pushed to one side, close to the inner wall of the valve body, causing the valve to jam. Some inferior electromagnetic reversing valves are prone to valve jam after a certain period of operation, sometimes due to the low hardness of the spool and the deterioration of the coaxiality after wear.