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Baotou beiben heavy truck parts share with you that sometimes cracks occur in the body (especially in the cylinder block and cylinder head) during use. The reasons are as follows:

1. Manufacturing defects. Such as sand holes, shrinkage porosity, air holes, etc., as well as body cracks caused by quality defects such as poor aging and stress concentration areas.

2. Improper use. For example, when the engine is under high temperature and water shortage, a large amount of cold water is suddenly added; When starting in the morning of severe winter season, add a large amount of high-temperature water; Start the engine first and add cold water after the temperature rises; In winter, antifreeze was not used, and the cooling water was not drained completely after a long parking time, which caused the cooling water to freeze and burst the cylinder block.

3. Improper maintenance and repair. Main bolts and auxiliary bolts are not tightened as required; The interference of the replaced self-made water plug is too large; Because there is no special maintenance tool, the fuselage is cracked when it is turned over. During use and maintenance, attention should be paid to the above problems to prevent the occurrence of cylinder block cracks.

Crankshaft fracture is a serious mechanical failure of the engine. The fracture usually occurs at the connecting fillet of crank pin, main journal and crank arm, or at the stress concentration parts such as journal oil hole.

Main causes of crankshaft fracture:

1. Due to improper selection of engine oil or failure to pay attention to the cleaning and replacement of "three filters", some users have deteriorated the engine oil after long-term use; Serious overload and over coupling cause long-term overload operation of the engine and burning accident. The crankshaft was severely worn due to the burning of engine pads. The engine crankshaft is repaired by replacement, that is, a new crankshaft is purchased for installation, and the damaged crankshaft is sent to the manufacturer for repair and standby. Some users find some small factories to repair and process seriously worn crankshafts after their vehicles are worn out. For the sake of cost and time, they weld, process and grind the seriously worn crankshafts after overall heat treatment. Due to the repair methods and technological problems, the connecting fillet between the crank pin, the main journal and the crank arm has changed, resulting in local stress concentration; Because the crankshaft is forged with precision 45 steel, the metallographic structure of the crankshaft is changed by surfacing. The above two items are the main causes of crankshaft fracture.

2. After the engine of Baotou beiben heavy truck parts was repaired, the loading did not pass the running in period, that is, the engine was overloaded, and the engine was overloaded for a long time, so that the crankshaft load exceeded the allowable limit.

3. In the repair of the crankshaft, surfacing welding was used, which damaged the dynamic balance of the crankshaft, and balance verification was not carried out. The unbalance exceeded the standard, causing greater vibration of the engine and fracture of the crankshaft.

4. Due to poor road conditions, serious overloading and over coupling of vehicles, the engine often runs within the torsional vibration critical speed, and the failure of the shock absorber will also cause the torsional vibration fatigue damage of the crankshaft of Baotou beiben heavy truck accessories and fracture.

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