In the daily maintenance of the trouble car, the maintenance of the multi-way valve of the trouble car is particularly important, which is the core part of the operation. The function of the multi-way reversing valve of the trouble car is to use the change of the relative position between the valve core and the valve body to control the flow direction of the oil night, connect or close the oil road, so as to change the working state of the hydraulic system. Therefore, the various reversing valves of the repair vehicle need more maintenance and maintenance at ordinary times to ensure that it can operate normally.

maintenance

A. unscrew the overflow valve with A 30 opening or spanner.

B. block the mouth with clean gauze to prevent a large amount of oil spill.

C. clean the debris pointed by the arrow. Use the cross to top the part indicated by the pressure tip (inner spool), reciprocate for many times, and add a little hydraulic oil, until the impurities are discharged from the small hole, at this time with the mouth blowing end, should not leak.

The pressure of the multi-way reversing valve of the repair car is normal between 15 and 18. If the pressure is too high or too low, the big screw needs to be adjusted to reach the standard pressure. The multi-way reversing valve needs to be cleaned frequently. It can be cleaned with gasoline, special cleaning agent or high-pressure gas.

Fault of multi-way manual reversing valve:

A. Internal and external leakage caused by casting and forging defects.

B. damage and aging of the valve body end cover seals, leakage caused by damage and aging of the seals of the split (union) type multiplex valve pieces and the joint part of the pieces.

C. The linkage mechanism of the cylinder is not flexible, the oil is not clean, causing scratches and burr on the valve core and valve body, and the valve core is not moving properly due to the loosening or loosening of the installation screw on the valve body end cover, which causes the valve core to get stuck or the stroke is not in place.

D. Internal leakage of valve core and valve body caused by excessive sealing clearance caused by serious drawing and scratch caused by foreign matter and dirt.

E. overflow valve failure.

Fault site maintenance of multi-channel manual reversing valve:

The spool is stuck and the stroke is not in place:

A. Clean valve core and valve body. Check the surface finish of valve core and valve body.

B. Check linkage mechanism.

C. Check whether the valve body end cover screw is loose and aligned.

D. In practice, the valve body may be deformed due to thermal expansion and cold contraction, resulting in the change of the fit gap between the valve core and the valve body.

(1) the valve core or body daub grinding sand directly grind to flexibility.

(2) the use of low speed lathe rotation with fine sandpaper or water sandpaper on the valve core grinding, grinding amount control in the original size of the valve core -4 to 8 seconds. Note that the measuring tool used in grinding is a micrometer, not a vernier caliper.

(3) valve spool and valve body clearance size:

Small diameter 6 to 10 seconds, large diameter 8 to 16 seconds. 1 mm =100 threads =1000 seconds.

E. the connecting rod connected with the valve core and the joystick is out of shape, and the ball head at the connecting rod and the valve core is seriously worn, resulting in a gap.