There are many varieties of electromagnetic reversing valves, which can be divided into two three-way, two four-way, three four-way, etc., according to the number of working positions and the number of channels; According to its return and positioning form can be divided into spring return type, steel ball positioning type, no return spring type; According to the connection form of the valve body and the electromagnet, it can be divided into flange connection and thread connection; According to the structure of the distribution magnet can be divided into dry type and wet type, each type has AC, DC, the whole form, and there are many kinds of power supply voltage required, so there are many differences in its structure.
Electromagnetic directional valve: The use of electromagnet on, off and directly push the valve core to control the connectivity of the oil port
Electromagnetic directional valve in the normal use of the process of loss, loss to a certain extent will cause failure can not work. This article shares the fault prone parts and solutions of electromagnetic directional valve.
1, electromagnet damage (burned)
Electromagnet burnout is also one of the common faults of electromagnetic directional valve. One of the main reasons is quality problems, such as poor processing of the iron core, the wire material diameter standard is too low and easy to overheat.
The failure caused by quality reasons is usually obvious within a few hours of the electromagnetic reversing valve being energized. For coil failures after working for a period of time, most are caused by the use of environmental reasons.
2. The reset spring is tired or broken
This kind of failure is related to the material selection of the spring. The electromagnetic directional valve uses the steel wire spring of the harmonica, the surface is dyed black, and it has good elasticity and fatigue resistance.
The strengthening of the surface treatment process can effectively prevent the spring from being corroded and has a long service life. In the event of such a failure, the springs on both sides must be replaced at the same time, and pay attention to the length matching the design value of the electromagnetic reversing valve.
3, spool outer diameter wear
This is the same as the wear of the bore in the valve body. Especially for the oil containing too much, too large impurities, will aggravate the wear of the solenoid valve spool.
Although such wear cannot be completely avoided, in order to extend the service life of the solenoid directional valve and maintain good working condition, the cleanliness of the hydraulic oil should be checked regularly and the excessive pollution of the hydraulic oil should be dealt with in a timely manner.
Three-wing solenoid directional valve spool unique material, hardness up to HRC60 or more, compared with ordinary solenoid directional valve spool has better wear resistance, so the life is also greatly enhanced.
4, valve body inner hole wear
The frequent round-trip movement between the spool and the valve body hole, although the solenoid valve spool design has an oil groove, can maximize the contact surface filled with oil, reduce friction, but according to the working nature of the solenoid valve, the wear of the solenoid valve body hole is still not completely avoidable. The solenoid valve body is made of ductile iron material, which is different from the ordinary electromagnetic directional valve. The three wings use a unique raw material ratio to strengthen the hardness of the valve body, which delays the wear and deformation of the hole in the valve body to a certain extent.
Wear in the body holes can be repaired or replaced as needed. When replacing, it is necessary to pay attention to whether the new valve body can match the relevant components of the original electromagnetic reversing valve, such as electromagnetic tubes, sealing rings, etc.
5, electromagnetic tube push rod wear shorter
The role of the push rod in the solenoid tube is to push the valve core to make it move when the armature moves. The push rod and the spool are not integrated. Therefore, in constant contact, wear is bound to occur.
After a long period of high frequency commutation, it may wear out and become significantly shorter. At this time, the spool reversing is not in place, affecting the normal work of the electromagnetic reversing valve, and the fault can be solved only by replacing the push rod. Note that the size of the new push rod should be consistent with the original parts.
6. Uncommon problems cause
The above are the five most common problems of electromagnetic directional valves, and may also be some other uncommon problems, such as voltage, current instability, and large impact fluctuations, resulting in burnout.
According to the working principle of electromagnet, when the solenoid valve core is stuck, and the armature can not move in place after the electromagnet is energized, the coil temperature will rise sharply, and it is easy to burn in a short time, such failures account for most of the solenoid valve coil failures.
Therefore, in the actual maintenance, the coil burn should first check whether the work of the solenoid valve is smooth, after eliminating the spool blockage and other faults, replace the new coil, otherwise the coil may still burn after replacement.
Solenoid valve 02 diameter coil diameter is 20mm, different manufacturers of coil this value may be different, the replacement of the coil diameter and length must be consistent with the original product, otherwise it cannot be used.
The following attached solenoid valve does not operate troubleshooting
The failure of the solenoid valve will directly affect the action of the switching valve and the regulating valve, and the common faults are that the solenoid valve does not operate, which should be investigated from the following aspects:
1. The solenoid valve connector is loose or the wire connector is off, the solenoid valve is not electric, and the wire connector can be tightened.
2, the solenoid coil is burned out, you can remove the solenoid valve wiring, measurement with a multimeter, if open, the solenoid coil is burned out. The reason is that the coil is damp, causing poor insulation and magnetic leakage, causing the current in the coil to be too large and burned, so it is necessary to prevent rain from entering the solenoid valve. In addition, the spring is too strong, the reaction force is too large, the coil turns are too few, and the suction is not enough can also make the coil burn. In case of emergency, the manual button on the coil can be pressed from the "0" position in normal operation to the "1" position to make the valve open.
3, the solenoid valve stuck: the solenoid valve sleeve and the spool with a small gap (less than 0.008mm), generally a single assembly, when there are mechanical impurities or too little oil, it is easy to get stuck. The treatment method can be steel wire through the small hole of the head to make it spring back. The fundamental solution is to remove the solenoid valve, take out the spool and spool sleeve, and clean it with CCI4, so that the spool is flexible in the valve sleeve. When disassembling, attention should be paid to the assembly sequence and external wiring position of each component, so as to reassemble and wire correctly, and check whether the oil spray hole is blocked and whether the lubricating oil is enough.
4, air leakage: air leakage will cause insufficient air pressure, making it difficult to open and close the forced valve, because the sealing gasket is damaged or the slide valve is worn and several cavities are channeling. When dealing with the failure of the solenoid valve of the switching system, the appropriate time should be selected to deal with the solenoid valve when it is out of power. If the processing cannot be completed within a switching gap, the switching system can be suspended and handled calmly.