The hydraulic oil installed in a hydraulic hydraulic tank of a excavator is the 1/2 of all the oil used in the whole hydraulic system. The remaining 1/2 hydraulic oil is stored in the hydraulic pump, motor, multichannel valve, hydraulic cylinder and all parts of the pipeline. In the exchange of oil, if only the hydraulic oil in the tank is replaced, not all the hydraulic oil in the hydraulic system is replaced, this method only It is old oil blending new oil. If two brands of hydraulic oil are blended together, it will cause oil deterioration.
For example, a Sumitomo type 220 type excavator, the hydraulic oil used in the whole car hydraulic system is 420L, and the hydraulic oil of the hydraulic tank is 225L, the remaining oil is stored in the system. The proportions of the oil and fuel tanks of all kinds of excavators and hydraulic systems are identical.
1 prepare for replacement of hydraulic oil
(1) when an excavator changes hydraulic oil, it should be prepared as follows: to purchase the oil used for vehicle hydraulic system. (2 of the volume of the hydraulic tank. 5 times), filter core, oil, 3 kilograms of flour, rope, closed hydraulic oil pipe oil plugging, (according to the oil pipe on the oil transfer of the oil pipe) a steam pump and the size of the oil bucket. Prepare a normal excavator. The moving arm of the excavator is raised to the highest point, the bucket and the bucket are extinguished after the inner point is received. (the cylinder of the arm, the cylinder of the bucket and the bucket of the bucket all out to the vertex).
(2) the cleaning of hydraulic oil tank: all the hydraulic oil in the box is released, the hydraulic filter is withdrawn and the pipeline between the pump and the tank is dismantled from the interface of the pump, and the oil in the pipeline is released. Wash the hydraulic oil tank and pipeline with oil wash. Use medical sand cloth to clean the inside of the hydraulic tank. Divide the flour into the tensile surface and divide it into three parts. The dough is divided into three times to clean the inside of the hydraulic tank, especially the corner of the fuel tank and the cartridge case. The hydraulic oil tank and filter cartridge must be thoroughly cleaned up. Replace the new hydraulic filter core, good cover board.
(3) washing of hydraulic plunger pump: every type of hydraulic plunger pump on excavator has flushing oil outlet (oil outlet). Unscrew the upper and lower oil opening, release the hydraulic oil in the pump shell, screw the oil plug below the pump, fill the oil pump from the top of the pump to the pump shell, then unscrew the oil plugging under the pump, release the oil in the pump shell, rinse the oil from the pump shell for several times, and then blow the remaining oil inside the pump shell with the gas pump, and fill the clean hydraulic oil and tighten the oil. Plugging can be.
(4) replace the pump inlet seal ring, (O shaped ring), connect the hydraulic tank to the oil supply line of the pump, and fill the hydraulic oil tank with the clean hydraulic oil from the hydraulic filter core (the replacement filter core).
2 method of replacing old oil with new oil
(1) the replacement of hydraulic oil in the cylinder of the movable arm: use the spare excavator to pull the moving arm of the excavator which is ready for oil change. (at this time the excavator's moving arm has been raised to the highest point), the tubing of the non rod cavity on the 2 movable arms is dismantled, the hydraulic oil is caught with the spare oil barrel, and the environmental protection should be paid attention to prevent the ring from the ring. Environmental pollution. Then the tubing, which has been disassembled, is placed in the spare oil barrel, and the engine is started. The hydraulic oil from the multiple valves to the tubing is the old hydraulic oil in the multi-channel valve. The oil exchange personnel pay attention to the change of the oil color. When the new hydraulic oil flows out, the engine will be extinguished immediately. Connect the broken pipeline, untie the rope, start the engine, repeatedly do the lifting and falling action of the boom until the boom cylinder is filled with oil. Only do this single action. Pay attention to the liquid level changes in the hydraulic tank, and add the missing hydraulic oil in time.
(2) the replacement of hydraulic oil in the bucket cylinder: after lifting the arm to the highest point, (only the single action is permitted to do this) the engine is extinguished. (the rod cylinder rod is extended all out at this time), the tubing is removed from the multi-channel valve and the pipe with the rod cylinder with the rod cavity. After the oil is put in the pipe, the pipe is reconnected. Then unplug the oil pipe of the rod rod cylinder without the rod, and seal up the already opened multi way valve and the rod cylinder without rod cavity oil pipe by oil plugging. Use the spare oil bucket to get the hydraulic oil released from the cylinder oil cylinder, start the engine and take back the piston rod of the bucket cylinder. (as shown in Figure 2, the bucket rod is indented in the cylinder) and the engine is flameout. After connecting the disassembled tubing, the engine is restarted and the piston rod of the bucket cylinder is telescopic several times. After placing the bucket on the angle of the vertical ground, the engine is extinguished and the oil is finished.
(3) the replacement of hydraulic oil in the bucket cylinder: remove the tubing from the back of the bucket cylinder without the rod cavity in the back of the movable arm, and plug in the tube oil port of the broken multiple valve and the bucket cylinder with the oil plugging. Use the empty oil barrel to catch the broken oil port on the small arm oil cylinder, start the engine, do the action of the bucket, (all the cylinder piston rod back to the cylinder), can only do this kind of single action. The new hydraulic oil enters the cavity of the bucket cylinder, and the piston rod shrinks, so that the hydraulic oil in the rod free cylinder cavity is discharged into the empty oil barrel. The engine is extinguished to connect the broken tubing. Pay attention to the location of the oil level on the hydraulic tank.
(4) oil change of the rotary motor system: any one of the 2 tubing broken off from the multi valve to the rotary motor. The oil outlet of the multi-channel valve and the rotary motor is blocked by oil plugging. The spare barrel is connected to the oil outlet which has been disassembled by the rotary motor, and the engine is started, and the excavator is slowly turned. If turning to a certain direction, the tubing on the motor does not produce oil, then it must be turned to another direction until the oil is discharged correctly. At the same time, we should pay attention to see the color change of the outgoing oil. When the new hydraulic oil flows out, the engine should be shut down immediately. Connect the oil pipe of the broken rotary motor and replace the oil.
(5) the replacement of hydraulic oil of the hydraulic system of the walking motor: the excavator's arm is used to lift the crawler on one side of the excavator and the side cover of the walking motor is disassembled on the inside. To dismantle any oil pipe in the 2 inlet and exit oil pipe of the walking motor, seal the broken oil pipe with oil plugging and use the spare oil bucket on the oil outlet of the walking motor, start the engine, and control the walking control valve which has been supported on this side. The track begins to turn, straight to the oil outlet of the walking motor, until the new oil is out from the oil outlet of the walking motor. At this point, the engine is shut down immediately, and the disconnected oil pipe is connected. The same way is used to replace the running motor and the hydraulic oil in the system. When using this method to change the hydraulic oil in the hydraulic system of the walking motor, be careful not to make a mistake. If you mistake the track that is not supported on the side of the track, the old hydraulic oil in the motor system will return to the hydraulic tank.
3 points for attention to oil exchange
(1) the steps of changing oil for fuel tank, hydraulic plunger pump, boom cylinder, bucket cylinder, bucket cylinder, rotary motor and left and right walking motors can not be changed. Different projects can only manipulate corresponding parts to make them move, so as to avoid operation errors.
(2) requirements for the quality of hydraulic oil: the life of the excavator is directly related to the quality of the hydraulic oil. It is necessary to choose the hydraulic oil which is certified by the quality standard of the American Engineer Association. The viscosity index of this hydraulic oil is stable at 40 ~100 degree C. The same brand of hydraulic oil must be used when changing.
(3) viscosity requirements for hydraulic oil: hydraulic oil has 3 types of antiwear hydraulic oil, such as N32HL, N46HL and N68HL. The excavator with its service life of 1000h hours should use N46HL+N68HL antiwear hydraulic oil (50% of each). N68HL anti wear hydraulic oil is applied to excavators for more than 15000h hours.
(4) the life of hydraulic oil: the service life of hydraulic oil is 4000~6000h hours, which is about two years. In the spring and autumn day and night, the temperature difference between day and night is big. After the working day of the excavator stops working at night, the fluid inside the hydraulic tank is high temperature. The outer air of the tank is low temperature. The hot air in the tank meets the cold air outside the tank and condenses into the hydraulic oil at the top of the tank and falls in the hydraulic oil for a long time. For a long time, water will be mixed in hydraulic oil. Then it evolves into acid to corrode the metal surface. Under the double action of the mechanical operation and the pressure impact of the pipe pressure, the metal particles falling off from the metal surface will be mixed in the hydraulic oil, the large metal particles are filtered out, and the particle hydraulic filter with less than 10 m can not be filtered out, and the non filtered grinding grains in the hydraulic oil will also aggravate the re wear of the metal surface.
(5) the selection of hydraulic oil filter core: the filter precision is 10 m50%, the pressure range is 1, 4~3, 5MPa, the rated flow rate is 40 ~ 400L/min, and the replacement time is 500h.
(6) any tubing that is dismantled must be sealed. (O ring) should be coated with thread sealant on the thread surface to prevent leakage.
