Common faults of Manifold Block solenoid directional valve and their handling methods
Manifold Block electromagnetic directional valve is widely used in hydraulic system, but there are many faults, such as directional failure, burning of electromagnet, oil seepage of valve body, slow electromagnetic drawing and releasing and slow motion speed of actuator, which affect the normal operation of the whole hydraulic system. Through several years of exploration and practice, summed up the electromagnetic directional valve common fault causes and handling methods, are described as follows.
Causes and handling methods of common faults
(1) Causes and treatment methods of Manifold Block solenoid valve failure:
The input voltage of the electromagnet is too low. Adjust the input voltage of the electromagnet.
② The return spring is broken or stuck. Re-adjust or replace the return spring to meet the original design requirements.
③ The surface of the spool is not smooth or has burrs. Gently grind with fine phase sandpaper to make it slide flexibly, and the grinding amount should not be too large to avoid causing large internal leakage and affecting the pressure of the whole system.
(4) There are metal or non-metal foreign bodies inside the valve body. Filter hydraulic oil and remove foreign matter in valve.
(2) Causes and treatment methods of electromagnet burning:
The input voltage of electromagnet is too high or the frequency is wrong. According to the electromagnet type and voltage requirements, adjust the input voltage or replace the power supply.
The commutation frequency of electromagnet is too high. According to the actual working frequency of production, the electromagnet suitable for the frequency is selected.
The push rod is too long, and the stroke is not matched properly, resulting in the electromagnetic coil current is too large. Before replacing the electromagnet, the extension length of the push rod and the stroke of the armature are measured to make the match suitable.
(3) Causes and treatment methods for oil seepage of Manifold Block valve body:
① The pressure of oil drainage and oil return chamber is too high. Adjust the height of drainage pipe or oil return to reduce the pressure drop of drainage and oil return, so as to achieve smooth drainage and oil return.
② Push stem and O-ring wear is excessive. Replace the O-ring regularly according to the frequency of use of the valve and the life of the O-ring.
③ The screws for installing the base plate are loose or dirty. Installation personnel should pay attention to the installation surface cleaning and use the correct installation sequence.
(4) There is air in the oil cavity where the wet electromagnet pulls and releases the armature, which is the fundamental cause of the fault. At this time, the exhaust screw at the rear end of the wet electromagnet can be used to exclude air until the oil can be excluded, and then the screw is tightened to seal it.
(5) The speed of the actuator slows down after the long-term use of the electromagnetic directional valve, resulting in the wear or deformation of the push rod, so that the spool stroke is insufficient, causing the valve opening to reduce the flow rate is small, then the push rod or electromagnet should be replaced.
According to the causes of common faults, the above treatment methods can shorten the maintenance time and improve the quality of maintenance.