Excavator routine maintenance technology

Modern excavators are generally used to control the hydraulic integration mode, common faults of the engine speed drops, work slowdowns, mining weakness and some other daily use fault. This paper briefly describes the excavator in these types of faults in fault diagnosis and repair technology, also describes the daily maintenance of the excavator technology to ensure the normal work of the excavator.

With the advancement of technology, modern excavators are generally used hydraulic integration control mode, we have to exclude some failures, the solution is more matching engine, hydraulic pumps, dispensing valve, external loads. Usually excavator operation, these areas can not match, often expressed as: engine speed drops, the work slows down, unable to dig and frequently asked questions.

An engine speed drop

First to test the output power of the engine itself, if the engine output power is lower than the rated power, the cause of failure may be of poor quality fuel, low fuel pressure, valve clearance does not, a cylinder of the engine does not work, wrong injection timing, fuel the amount of the setting value is wrong, the intake system leak, brake lever and faulty turbocharger and coke. If the engine output power is normal, because they do not need to see whether the match pump flow and engine power output.

Hydraulic excavator in operation speed is inversely proportional to the load, that is, the flow and pump output pressure product is not a variable, pump output power constant or nearly constant. If the pump control system fails, the engine can not be achieved, pumps and valves in different regional conditions optimal load matching state, excavator which will not work. Such failures from the first electrical system to start, and then check the hydraulic system, and finally check the mechanical drive system.

Second, the work slows down

Excavator work slows down mainly due to machine wear and tear caused by decreased engine power ministries and hydraulic system leakage. Excavator hydraulic pumps piston pump, work after a certain time, inevitably produce internal hydraulic pump components (cylinder, piston, valve plate, abalone plate, Turtle, etc.) for excessive wear, can cause internal leakage, According to the parameters of uncoordinated, leading to inadequate oil flow rate is too high, work slowly. Then we need to overhaul the machine, wear overrun parts repair replacement.

However, if the working time is not very long excavator suddenly slows down, you need to check the following aspects. First check the fuse open or short circuit, then check the pilot pressure is normal, and then look at the control valve servo - servo piston is stuck and dead confluence dispenser if the fault, and finally the pump removed for measurement data, confirm digging machine problem .

Third, the inability excavator

Mining is one of the typical inability fault excavators. For mining weakness can be divided into two cases: one for excavation weakness, the engine does not hold the car, I feel very light load; second is mining weakness, or when the boom arm extension in the end, the engine hold serious car, or even turn off .

① Mining weakness but the engine does not hold the car. Digging force is determined by the size of the main pump output pressure, depending on whether the car engine choke pump absorption torque and the relationship between the engine output torque. Description car engine does not hold the pump absorption torque is small, the engine load is light. If the excavator working speed is no obvious abnormality, should focus on checking the maximum output pressure of the main pump, that system relief pressure. If the relief pressure measurement is below a predetermined value, indicating an overload relief valve setting of the institution of the hydraulic circuit is incorrect, resulting in premature overflow of the institution, unable to work. It can turn the adjustment screw to adjust the machine.

② mining weakness, hold the engine car. Engine oil pump absorption torque hold car show is larger than the output torque of the engine, causing the engine overload. This failure should first check the engine speed sensing system is normal, check the method is similar to the earlier engine inspection method. After more careful inspection and troubleshooting, engine speed sensing system to restore normal function, the engine choke car disappears, digging force will return to normal.

Fourth, the excavation work during common fault

Some common faults excavator construction jobs often appear, such as: digging machine walking deviation, the reasons may be assigned to walk seal (also known as the central rotary joint seals) damage; two hydraulic flow sizes; side travel motor has a problem. Hydraulic cylinders may be discharged quickly to safety relief valve closed lax, or serious damage to cylinder seals and so on.

V. Routine maintenance excavator

To prevent the excavator fault occurs in the course of daily use requires careful attention to the maintenance of the excavator. Routine maintenance including inspection, clean or replace the air filter; clean the inside of the cooling system; check and tighten the track shoe bolts; check and adjust the tension of the anti-track; check air intake heater; replacement bucket teeth; adjust bucket gap; check the front window cleaning fluid level; check, adjust the air conditioning; clean cab floor; replace the broken filter element (optional). When cleaning the inside of the cooling system, until the engine is fully cooled, slowly loosen the filling opening lid, releasing the tank internal pressure, and then to turn on the water; do cleaning work when the engine is working, high-speed rotation of the fan can be dangerous; when cleaning or replacing the cooling when the liquid, the machine should be parked on level ground.

At the same time before starting the engine to check the height of the liquid level position coolant (water); check the engine oil level, add oil; check the fuel level (refueling); Check hydraulic oil level (plus hydraulic oil); check the air filter It is blocked; check wiring; check the speaker is normal; check bucket lubrication; check the water separator in the water and sediment.

Fault excavator encountered in their daily work, there are many, here only it describes the more common types of fault repair method, and in order to reduce the occurrence of failure, the daily maintenance of the excavator is very important. Only do maintenance and repair of double protection, in order to better protect the excavator to work.