Today's excavators account for the vast majority of all-hydraulic full-turn excavators. Hydraulic excavators are mainly composed of engines, hydraulic systems, working devices, walking devices and electrical controls. The hydraulic system consists of hydraulic pumps, control valves and hydraulic cylinders , Hydraulic motor, pipeline, fuel tank, etc., the electrical control system includes monitoring panel, engine control system, pump control system, various sensors, solenoid valves, etc.
Hydraulic excavator is generally composed of three parts: working device, slewing device and walking device. According to its structure and use, it can be divided into: crawler type, tire type, walking type, full hydraulic, semi hydraulic, full swing, non-full swing, general Type, special type, articulated type, telescopic arm type and other types.
The working device is a device that directly completes the excavation task. It is composed of three parts, such as boom, stick, and bucket. The boom is raised and lowered, the boom extension and bucket rotation are controlled by a reciprocating double-acting hydraulic cylinder. For various construction needs, hydraulic excavators can be equipped with a variety of working devices, such as excavation, lifting, loading, leveling, clamps, bulldozing, impact hammers, etc. as excavator maintenance industry tools.
Rotating and walking device is the body of hydraulic excavator. The upper part of the turntable is equipped with power unit and transmission system. The engine is the power source of hydraulic excavator.
The hydraulic transmission system transmits the power of the engine to the hydraulic motor, hydraulic cylinder and other actuators through the hydraulic pump to push the working device to complete various operations.
First, the engine power is enough, but the phenomenon of boring (suffocating) occurs.
The hydraulic pump itself also has a certain power. If the power of the hydraulic pump is greater than the power of the engine, the phenomenon of boring (suffocating) will occur. This requires the hydraulic pump to be tested and debugged on the experimental platform to reduce the power of the hydraulic pump to 95% of the engine power. can.
Second, walking and running, at the same time, the movement of a handle is not ideal.
The hydraulic pump is divided into front and rear pumps or left and right pumps. Walking deviation shows that one pump is faulty. The simplest way to judge is to remove the two high-pressure oil pipes of the hydraulic pump and swap them. If the original slow walking becomes faster, the faster The walking slows down, which means that there is a faulty pump. The excavator repairs such problems. Just remove the hydraulic pump, process or replace the accessories in one pump, and then go to the test bench for debugging. Solved the problem that one handle is not ideal.
Third, the engine power is sufficient, the operation is normal, and the machine is slow, and the digging is weak.
1. The hydraulic pump of the excavator is a plunger variable pump. After working for a certain period of time, the original parts in the hydraulic pump such as (cylinder, plunger, valve plate, swing, etc.) will inevitably produce excessive wear, resulting in a large number of internal leakage, various parameters The data is not coordinated, resulting in insufficient flow. The oil temperature is too high, the speed is slow, and the high pressure cannot be established. Therefore, the action is slow to excavate. For such problems, the hydraulic pump must be removed and sent to the company's commissioning department to carry the hydraulic pump. Data inspection to confirm the problem of the excavator, replace the accessories that can no longer be used, repair the accessories that can be used, reassemble the hydraulic pump, and then go to the commissioning test bench to match each series of soft parameters (such as: pressure, flow, torque, power, etc. ).
2. The excavator also has an important hydraulic original multi-way distribution valve, which has the main safety valve, secondary valve, jet valve, charge valve and other excavator repair plants. If the pressure set by these safety valves is not up to now To the standard pressure (the standard pressure of the EX200-5 main safety valve is 320kg, and the current pressure is only 230kg), resulting in weak excavation, and if the gap between the valve stem and the valve hole is too large due to wear, the valve stem returns If the position is incomplete, the flow rate will be insufficient and the speed will be slow. For such problems, the multi-way distribution valve must be removed and sent to the company to go to the commissioning station for commissioning, reset the pressure of all safety valves, and eliminate the valve. The gap between the stem and the valve hole is sufficient.
3. The hydraulic pump on the excavator is equipped with a pilot gear pump. This pump is mainly involved in the variable of the hydraulic pump and as the pilot oil to open the valve stem of the multi-way distribution valve to change its direction. A certain pressure or the pressure set by the safety valve on the gear pump is not enough, it will cause the hydraulic pump to always be in a low flow state, and the valve stem cannot be completely commutated. This will cause insufficient flow, slow movement, insufficient pressure, and weak digging In such cases, it is only necessary to replace the pilot gear pump or reset the pilot safety valve.
