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Excavator repair knowledge

We  all know that the second-hand digging machine often has many faults  during work for some troubles that are easy to occur. Here, we will give  you a simple and convenient solution:
In  the construction work, according to the load request of the operation,  the speed is inversely proportional to the load (flow and pressure),  that is, the product of the output pressure and the flow of the pump is a  constant, and the output power of the pump is constant or approximately  constant; If  the pump control system presents a fault, the mobilization  machine-pump-valve-load can not be well optimized in different working  conditions, so that the excavator can not work normally, so we must  control the excavator control produced by various manufacturers. system. Komatsu CLSS system, when dealing with faults, is also a simple and complicated analysis. The  excavator is a machine-electric-liquid integrated product with high  skill content. Therefore, when disposing the fault, generally start with  the electrical system, check the hydraulic system, and finally check  the mechanical transmission system. When  checking the hydraulic system, the component is gradually reviewed from  the help oil circuit - the control oil circuit - the main oil circuit.
First, the work speed is slow:
If  it is a used Komatsu excavator that has been used for many years, the  speed is gradually slower, which is caused by normal wear and tear. Important  factors The wear of the whole machine causes the engine power to  decrease and the hydraulic system to leak. This shows that a series of  faults are manifested. Due to the internal energy consumption caused by  the leakage, a large amount of heat energy is generated, so that all the  systems are heated up agilely, and the viscosity of the hydraulic oil  and engine oil is lowered. In  order to make the whole system high temperature, the performance of the  cool car is slightly faster and slower. This requires overhaul of the  whole machine and repair and replacement of the parts with excessive  wear. If  the new excavator suddenly slows down, this must be simplified first  and then, check from the following aspects: first check whether the  circuit fuse is open or short; whether the pilot pressure is normal;  servo control valve - servo piston is dead; the distributor confluence Trouble, etc.; eliminate other possibilities, and finally disassemble the hydraulic pump.
Second, the excavator is weak:
The  machine is incapable of being divided into several aspects. First, the  engine is rapidly decelerating when the external load is large, which  means the following two aspects:
1. It is necessary to review the launching flexibility as described above.
2. It is to review whether the hydraulic displacement complies with the constant power output. That is, the swash plate angle is reduced to reduce the displacement without affecting the speed. Second,  when the load is heavy, the engine does not slow down, and the system  speed is normal; this requires debugging the system pressure. Because  the pressures of the hydraulic cylinders specified by the hydraulic  components and hydraulic systems of different manufacturers are  different, as long as the manufacturer It is ok to stipulate the scale. In  addition, if the pressure of the regulator relief valve is not  adjusted, and when the relief valve is in good condition, it is  necessary to check the adjustment system of the hydraulic pump, and even  the cylinder block, the distribution plate, the plunger and the like of  the hydraulic pump.
Summary: Common faults in general excavators are indicated in these aspects. With  the increase in the application of excavators, some of the extensive  faults often appear in construction operations, users who generally use  the excavator for more than one or two years can understand some; for  example, the excavator walks away, the user can immediately realize:  walking The  oil seal of the distribution (also known as the center rotary joint oil  seal) is destroyed; the flow rates of the two hydraulic pumps are  different; there is a problem with the travel motor. The  hydraulic cylinder is quickly vented: immediately realize that the  safety relief valve is not tightly closed, or the cylinder oil seal is  seriously damaged, etc.