How to deal with emergency situations if hydraulic excavators used in coal mines malfunction（haoyun）

The editor of Shandong Haoyun Heavy Industry Machinery Co., Ltd. will provide the following information on how to handle emergency situations if hydraulic excavators used in coal mines malfunction.

Here are some emergency response methods from Haoyun Heavy Industry for hydraulic excavators used in coal mines when they malfunction:

1、 Engine malfunction

1. Engine “boiling”: Immediately stop the operation and let the engine idle for a few minutes. When the water temperature drops and no longer boils, wrap a towel around the radiator cap and carefully unscrew a part of the radiator cap to release water vapor. After the water vapor is released, unscrew all the radiator caps. When adding coolant, it is best to add the same type of coolant as the water radiator, using a gradual cooling method to allow the engine to slowly add while idling.
2. Engine cannot start: Check if the fuse in the cab is blown, if the fuse and relay in the battery compartment are intact, if the positive and negative battery terminals are securely fastened, loose, and corroded. If the battery is low and the dashboard brightness decreases, it can be started by powering on. After troubleshooting the electrical issue, if the engine still cannot be started, check if there is any wax buildup in the fuel, if the fuel filter has not been replaced or blocked for a long time, if the fuel pipe is leaking, and if necessary, remove the air inside the filter. For the malfunction of electronic fuel injection engine not starting, it is necessary to check the fault code and handle it according to the code prompt or contact the relevant company.

2、 Hydraulic system malfunction

1. No movement in the entire vehicle: Check if the fuse box and safety lock lever are in place, and if there is any melting or burning smell in the solenoid valve coil. Use a small iron tool to test the magnetism of the screw in the middle of the pilot valve locking solenoid valve. If there is no magnetism, it is an electrical fault, and if there is magnetism, it is a hydraulic fault. In terms of hydraulic system, the main issues are the stuck transmission of solenoid valves and damage to the pilot pump. If the valve core is stuck, the valve core can be removed and forcefully pushed open with a straight screwdriver. Repeat this process multiple times and clean impurities with oil; If the pilot pump is faulty, remove the pilot pump and check for damage to the intermediate spline shaft.
2. If several actions controlled by a certain group of control valves are abnormal at the same time, the transposition comparison method can be used to swap the main relief valve in the faulty subsystem with the main relief valve in the normal subsystem and test the machine. If the fault is moved to another subsystem, the original faulty system’s main relief valve is faulty. Otherwise, the hydraulic pump and regulating mechanism should be checked.
3. Single action fault: When the action is slow, weak, or completely inactive, first check the pilot oil circuit and shunt overload valve; If normal, check if the control valve core is stuck; If it is still normal, check the execution components and related parts again. When the action is disturbed, block the corresponding pilot oil pipe to the control valve and test the machine. If the fault disappears, it indicates that the fault is in the control rod and pilot valve parts; Otherwise, check the valve core, valve body, and other components.

3、 Electrical system malfunction

1. Circuit failure in high temperature environment: When the temperature is high, aging circuits are prone to surface cracking due to metal thermal expansion and contraction, resulting in short circuit faults. The circuit should be checked and repaired in a timely manner to avoid the expansion of the fault.
2. Electrical treatment of hydraulic excavators used by Haoyun Heavy Industry in coal mines that are submerged in water: Once the hydraulic excavator used in coal mines is submerged in water, the fuse should be immediately removed, the battery cable should be removed, and the computer board should be removed and handed over to professional personnel for handling.

4、 Other faults

1. Hydraulic cylinder rod damage: If the hydraulic cylinder rod has surface damage such as collision, smashing, or being clicked, work should be stopped immediately. It is strictly prohibited to put the cylinder rod into the cylinder, otherwise it will strain the oil seal and guide sleeve. When the damage is not too serious, the protruding part can be polished off with gauze, oilstone, etc. The concave part can be polished off with water chestnuts and burrs. After confirming that it is not higher than the plane and feels smooth, it can be temporarily used. It is normal to have a trace of oil leakage, and it will be sent to a repair shop for repair when conditions permit.
2. Transmission device “gear jumping”: If the transmission device “gear jumping” occurs during driving, the machine should be stopped (or continue to run) in a timely manner, and then the cause should be identified and the fault eliminated.