Diesel engine connecting rod bolts are disposable and are not allowed to be reused. If the use of connecting rod bolts, due to the larger force, the bolt is elongated, it is easy to cause the bearing pad due to the lack of fastening force and the occurrence of rolling tile burning tile accident; at the same time due to lack of tightening force, bearing and crankshaft journal with the gap Increased, resulting in low oil pressure, resulting in excessive wear and tear of the bearing pad burning accident. Diesel engine system of high-strength diesel engine, connecting rod by the impact load is larger, much larger than ordinary diesel engine, connecting rod bolts can easily lead to the use of broken, damage the engine cylinder block, causing the engine scrapped. Some units, although the replacement of the connecting rod bolts, there have been broken faults, there are individual engines in the running rod bolts suddenly broken.
Reason for failure:
① tightening the torque when the assembly is too large, uneven force. As the assembly is not strictly equipped with torque wrench, the specific tightening torque and do not understand, that the more tight the better; tighten the connecting rod bolts with a longer afterburner, tightening torque is too large, more than the bolt material Yield limit, so that the rod bolts appear yield deformation, so that under the action of the impact load due to excessive elongation and fracture. Should be emphasized that must be tightened by standard rod bolts, do not think that the more tight, the greater the better strength.
② diesel engine connecting rod points a variety of levels, in the maintenance should be noted that can not use different levels of connecting rod. If the maintenance of the tiger because the tiger does not carefully confuse the bar, wrong, will cause the joint head with the surface of the tie is not close, in the engine operation will cause the connecting rod loose and lead to break the bolt.
③ diesel engine running in the flight failure or piston piston failure in the cylinder, the connecting rod bolts off. If the engine in the use of the flight failure occurred, the engine should do a comprehensive inspection, it is best to replace the connecting rod bolts; if the operation of the individual cylinder appeared more serious cylinder, in the replacement of the cylinder piston components should also link Bolt replacement.
④ material problems, processing defects and heat treatment process problems can also lead to connecting rod bolts in the engine running in the fracture.