Excavator solenoid valve 714-11-16840 proportional solenoid valve

1. System pressure fluctuation

The main causes of pressure fluctuations are:

① The screws adjusting the pressure cause the locking nut to loosen due to vibration, resulting in pressure fluctuation;

② Hydraulic oil is not clean, there is a small dust, so that the main spool sliding is not flexible. Resulting in irregular pressure changes. Sometimes the valve will jam;

③ The main valve spool is not smooth, causing the damping hole to be blocked when it is through;

(4) The conical surface of the main valve core is not in good contact with the cone of the valve seat, and it is not well grinded;

⑤ The damping hole of the main valve core is too large and does not play a damping role;

The pilot valve adjusting spring bending, resulting in poor contact between the spool and the cone seat, uneven wear.

The solution:

① Clean the oil tank and pipeline regularly, and filter the hydraulic oil entering the oil tank and pipeline system;

(2) If there is a filter in the pipeline, the secondary filter element should be added, or the filtration accuracy of the secondary component should be replaced; Disassemble and clean the valve components and replace the clean hydraulic oil;

③ Repair or replace unqualified parts;

④ Reduce the damping aperture appropriately.

2. System pressure can't go up at all

Reason 1:

① The main spool damping hole is blocked, such as the assembly of the main spool is not cleaned, the oil is too dirty or the assembly with debris;

② Poor assembly quality, poor assembly accuracy during assembly, poor adjustment of the gap between valves, the main spool stuck in the open position, poor assembly quality;

③ The main spool reset spring is broken or bent, so that the main spool can not be reset.

The solution:

① Disassemble the main valve cleaning damping hole and re-assemble;

② Filter or replace the oil;

③ Tighten the valve cap fastening screw to replace the broken spring.