During the construction of a tunnel, the water broke down the pond near the tunnel because of the rain, and the water quickly ran from the shaft to the tunnel. At that time, there was a PC200 type excavator in the tunnel slag cleaning operation, because the water potential is fierce, the excavator can not be out of the hole in time, forced to choose a good position to stop, and then flooded. After 7 days, the water was drained away, and the construction task was urgent. First, the appearance of the machine was cleaned, the external damage was checked, and then the items were repaired one by one.
1. Engine
When the engine oil is discharged, it is found that there is water and sediment in the oil. The best treatment is to disassemble the engine and hang it down to repair it, but because the excavator is not able to do this in the hole, it has to be cleaned and checked after disintegration. (Note: it is not possible to remove the water from the nozzle by rotating the crankshaft to remove the water from the cylinder liner. In case the cylinder sleeve is damaged.
The parts of the engine were cleaned and checked, and the result was that the wear of the connecting rod bearing and the main shaft was small and available; the cylinder sleeve piston assembly of the 6 cylinders was worn evenly and not beyond the use range, without replacement, but the opening clearance of the piston ring had exceeded 0.80mm, and the new piston ring should be replaced; the turbocharger was needed. The oil pump works normally; the pump works well after cleaning; the pump and the thermostat work normally; the high pressure oil pump has no water and sediment, it is normal; the 6 cylinder injector is checked by the test bench to show that the work is normal, and the oil spray and atomization are not found bad, the injection holes are even and can be used; the oil radiator has not entered the sediment in the oil radiator. Pressure water is used to clean the waterways and intake and exhaust passages and then dry with pressure air. Meanwhile, the lubricating oil passage of the engine is cleaned with pressure air.
After cleaning the valve and valve seat, valve sand is used for grinding valve to eliminate wear marks and rust generated when water is flooded.
After checking the diesel tank, water was found and there was a small amount of sediment. Then, the water in the bottom of the tank is removed, the diesel oil in the tank is released and then installed, then used for cleaning. The tank is washed with certain pressure water, then the water stains and dirt in the box are tested with cloth, and the compartment and every corner are paid attention to, and the oil tank is washed with diesel oil at the end, and the oil tank is low to the oil pump. Remove the pressure pipe and return pipe and clean it with pressure air.
2. Hydraulic system and transmission parts
The hydraulic tank itself is sealed, but because of the long soaking time, there is also mud intrusion. Remove the oil and water from the oil tank, remove the oil tank to the low pressure line of the hydraulic pump, and remove the oil filter, the filter core component and the by-pass filter core component. After the cleaning of the gasoline, the filter core is dry, the filter core is replaced by the new piece (the filter net is not replaced, the hose is not used for gasoline cleaning) and the water in the tank is repeatedly applied. Stains and dirt, ensure clean, use a small amount of gasoline to clean the tank, then wipe clean with cloth, stop for a period of time after the gasoline volatilization, load the various accessories. Unscrewing the oil screw on the main hydraulic pump, if there is no water in the liquid out of the oil, check the control valve and the components (including the hydraulic oil radiator), if no water is found, it can be determined that the main pump, the high pressure oil road and the working equipment are normal.
3. Electrical components and electrical circuits
Remove the starter and generator from the machine, wash out the exterior with diesel oil, clean up the parts with gasoline, dry the parts, do not find any damage to the coil and components in the inspection, unload the assembly, disintegrate the electronic monitoring disc, clean it with gasoline, dry it, and assemble the standby. After the relay is cleaned, the relay is cleaned after cleaning. After the relay is cleaned, the relay is cleaned after cleaning. After the relay is cleaned, the relay is cleaned after cleaning. After the relay is cleaned, the relay is cleaned after cleaning. After the relay is cleaned, the relay is cleaned after cleaning. After the relay is cleaned, the relay is cleaned after cleaning Dry, check the results of no trouble. All inductors and inductive plugs are checked after cleaning without fault. Check the electrical circuit and electrical connector of the whole machine. Damaged or broken skin is disposed or replaced. After checking the battery and finding no sediment, the liquid in the battery was poured out, and the electrolyte was recharged and recharged. Install the repaired electrical components and wires.
According to the 2000H maintenance regulations of excavator, other parts should be maintained. Enough oil and water for the whole machine will be successfully started. The engine works smoothly, and the cylinders work well when the cylinder is checked, and the hydraulic system moves smoothly and normally. The whole machine is filled with lubricating oil and put into operation after running in.
4. Ponder after the excavator's water is not flooded and repaired
The excavator was flooded and fortunately it did not cause serious damage. Through this accident, we summed up our experience and thought. The phenomenon that the engine is forced to stop when the engine is sucked into the water is stopped before the fan blade is flooded, so as to avoid damage to the fan blades and water tanks; the position of the shutdown is as strong as possible in the foundation, and the unstable place is prone to collapse under the impact of water and cause the equipment to turn over, which will cause greater loss; the machine will cause greater loss. Do not stop on the side of a mountain slope with rock rolling or collapsing; choose the direction of the machine to stop according to the direction of the flood: the bulldozer should take a knife in the direction of the flood, the excavator is heading in the direction of the water with the weight block, and the other machines should choose the position which is not easily smashed by the earth; Power switch;
For computer controlled machines, it is necessary to take time to dismantle the positive pole of the power line to prevent the large damage caused by short circuit when the water is flooded, and the place where the inlet and exhaust pipe of the engine can be directly influent, should be blocked in order to prevent the mud or sediment from entering the engine. The piston rod of each hydraulic cylinder is retracted as far as possible to prevent the damage of the piston rod of the hydraulic cylinder. After the flood, the water is drained and repaired as soon as possible in order to shorten the water time and reduce the difficulty of maintenance.
