Due to the wide field of excavator operation, its frequency of use is relatively high. After a long period of work, there will be varying degrees of wear and failure problems.
Failure 1: Slow expansion and weakness of bucket cylinder
When the bucket cylinder of the long arm excavator is unable to expand slowly in the process of operation, we should do the following checks.
1. Check whether the seals are invalid. First loosen the tubing in the low pressure chamber, release the hydraulic oil in the chamber, and then start the engine to inject the pressure oil into the high pressure chamber. No hydraulic oil has flowed out of the tubing in the low pressure chamber, which indicates that the piston seal of the bucket rod cylinder is well sealed. If the seals fail, the hydraulic oil in the low pressure chamber and the high pressure chamber will run through each other due to internal leakage.
2. Check whether the safety oil suction valve is normal. Safety oil suction valve is a two-way protection valve, which is installed on the actuators such as hydraulic cylinder and motor. When a chamber of hydraulic cylinder or motor produces instantaneous high pressure, the high-pressure oil in the high-pressure chamber will open the relief valve in the safety oil suction valve for overflow. At the same time, the one-way valve of the safety oil suction valve in the negative pressure chamber opens and sucks oil from the tank to supplement the negative pressure and protect the oil circuit.
3. Check PPC valve and main control valve. PPC valve, also known as pilot control valve, is a proportional pressure control valve, which can output the corresponding control pressure and flow according to the size of the operation handle stroke, so that the main control valve core has a corresponding amount of movement.
So it can control the speed of the actuator. Each spool in the main control valve controls the opening and closing of an oil circuit. If one spool is worn, stuck or even blocked, the oil pressure and flow of the corresponding actuator will be reduced, resulting in slow or no action of the actuator.
Fault 2: Walking deviation
When there is running deviation fault in the long arm excavator, the combined valve of the excavator should be checked first. Remove the two tubing on the pressure limiting valve, plug the oil outlet with a plug, start the engine, pull the walking control handle extension arm excavator with the plug combination valve to check the normal oil pressure, and then remove the two tubing on the other side of the walking combination valve.
Start the engine again and observe whether there is oil outflow in the two oil holes of the pressure limiting valve. If there is no such phenomenon, troubleshooting of the combined valve will be eliminated.
The above information is organized and published by our extended arm excavator in the hope of helping everyone's life. Our website is http://www.rbaras.com!