Elimination of 3 cases of engineering machinery engine
Pvc Compounding Line,Four Flights Co-Kneader,Pvc Co-Kneader Line,Compounding Extruder JIANGSU XINDA TECH LIMITED , https://www.xindaextruder.com
When the cylinder liner, piston, piston pin and piston ring of the engine were replaced and the machine was re-tested, black smoke and bulldozing were still weak. The measured fuel injector showed that the injection pressure was within the standard range and the atomization was good; no problem was found in the calibration PT pump. The engine was dismantled again and the timing and piston ring were found to be fine, but when measuring the height of the camshaft cam, it was found to be only 2/3 of the standard height. According to the analysis, the height of the cam is reduced due to wear, which causes the piston to fail to burn when it moves to the top dead center position, resulting in a delay in ignition, causing the engine to emit black smoke and work weak. After replacing the camshaft, the fault is eliminated.
When the 6135AZKa diesel engine used in the X200 T-type bulldozer was working with abnormal sound, the connecting rod bolt of the IV cylinder was found to have been stretched a lot. It was preliminarily concluded that the cause of the failure may be loosening of the connecting rod bolt, resulting in repeated impact. The force is increased and deformed; it may also be a quality problem with the connecting rod screw. For this purpose, other connecting rod bolts were inspected, and the results were all satisfactory, and the tightening torque also met the requirements. After replacing this connecting rod bolt, the installation operation indicates that everything is normal and the fault is eliminated. Later, I learned that the connecting rod of the IV cylinder was slightly deformed during the overhaul of the machine, and the repairman assembled it after correcting it.
Therefore, the real cause of this failure is that since the deformation of the connecting rod is not expected to cause the connecting rod bolt to be plastically deformed, the tensile strength of the connecting rod is lowered, and it is the replacement of the new connecting rod bolt that is not required, but the old rod is still used. The assembly is assembled, thus causing the bolt to elongate due to the reduced tensile strength.
The TATRA3-SIX-type diesel engine used in the TATRA815S1 dump truck has a holding phenomenon. After the machine was overhauled for 1000 hours, the tiling phenomenon occurred. After disassembling the engine, first check the oil. The machine uses the Great Wall 15W/40CD engine oil. Although the oil viscosity is lower at high temperature, it is within the normal value, and the pollution degree, suspension, pH value, etc. are all qualified; The oil road is also unobstructed and has no oil leakage.
When the oil pump was dismantled, it was found that the gap between the gear end face and the front and rear covers was too large, resulting in internal leakage. Since the aluminum pump casing cannot be repaired by a grinding machine, it is machined by a face milling machine so that the gap between the gear end face and the front and rear covers reaches a standard value, and then polished with metallographic sandpaper. There was no leakage during the test after reinstallation, and the work in the subsequent operation was always normal, indicating that the fault has been eliminated.
The analysis believes that the cause of this failure is that the engine is in the spring when the temperature is lower during the overhaul. At that time, the oil viscosity is large, so the internal leakage of the oil pump is small, and the oil pressure can reach the normal value, so the repairman ignores the oil pump. In the summer construction, when the machine is continuously operated at high temperature, the viscosity of the oil is reduced, the internal leakage of the oil is increased, and an effective oil film is not formed, resulting in a holding accident.