As we all know, it is used to connect mechanical parts. Its effect on the machine is also very important. If the connection is not good, it will directly affect the normal operation of the machine. However, many people are troubled by the fact that bolts often break. Many users don't know what causes them. Here, China Standard Parts Network shares three common reasons for fastener bolt breaks.

1. The tightening torque is too large during assembly and the force is not uniform. Since there is no strict torque wrench in the assembly, the specific tightening torque is not well understood, and the tighter the better; the tightening of the connecting rod bolts is longer, the tightening torque is too large, exceeding the bolt material. The yield limit causes the connecting rod bolt to yield deformation so that it breaks due to excessive elongation under the impact load. It should be emphasized that the connecting rod bolts must be tightened according to the standard. Do not think that the tighter the strength, the better.

2. The connecting rods of diesel engines are divided into various levels. During maintenance, care should be taken not to switch to different levels of connecting rods. If the sloppy handle is messed up or misplaced during the overhaul, the joint of the big joint of the connecting rod will not be tightly fitted, and the connecting rod cover will loosen during the engine running, which will cause the connecting rod bolt to break. The wd615 series diesel engine connecting rod has a large-cut oblique cutting type with a chamfer angle of 45°. The connecting rod cover and the connecting rod large-head joint surface adopt a 60° zigzag positioning structure, which has close fitting, accurate positioning, reliability and compact structure. specialty. If the connecting rod cover is messed up and misplaced during maintenance, it will inevitably result in poor positioning of the joint surface serration, which may easily cause the loosening of the connecting rod cover during the operation of the engine, resulting in the breakage of the connecting rod bolt.

3. If the diesel engine has a flying fault or the piston burns in the cylinder during operation, the connecting rod bolt is broken. If the engine has a fault in the running, the engine should be fully inspected. It is best to replace the connecting rod bolts. If there are serious cylinders in the individual cylinders during operation, the connecting rods should also be replaced when replacing the cylinder piston assembly. Replace the bolts.