What are the causes of photovoltaic bolt failure?

Update time:14 Dec 2019
abstract:

What are the reasons for the failure of photovoltaic bo […]

What are the reasons for the failure of photovoltaic bolt? Bolts: a type of fastener consisting of a head and a screw (a cylinder with external threads), which need to cooperate with a nut to fasten the connection between two Components. This type of connection is called a bolted connection. If the nut is unscrewed from the bolt, the two parts can be separated again, so the bolt connection is a detachable connection.
① The tightening torque is too large during assembly, and the force is uneven. Because there is no strict torque wrench in the assembly, the specific tightening torque is not well understood, it is believed that the tighter the better; the longer the tightening rod is used to tighten the connecting rod bolt, the tightening torque is too large, exceeding the bolt material. Yield limit, which causes yield deformation of the connecting rod bolt, causing it to break due to excessive elongation under the action of impact load. It should be emphasized that the connecting rod bolts must be tightened according to the standard. Do not consider that the tighter the stronger the better.
② The connecting rod of the diesel engine is divided into multiple levels. In the maintenance, it should be noted that the connecting rods of different levels cannot be replaced. If the connecting rod cover is carelessly messed up and incorrectly installed during maintenance, the connecting surface of the connecting rod's large head will not fit tightly, and the connecting rod cover will loose during the engine operation, which will cause the connecting rod bolt to break. The large head of WD615 series diesel engine connecting rod is beveled, the angle of bevel is 45 °, and the connecting surface of connecting rod cover and connecting rod large head adopts 60 ° zigzag positioning structure. This structure has tight fit, accurate positioning, reliability and compact structure. specialty. If the connecting rod cover is messed up or incorrectly installed during maintenance, it will inevitably result in poor positioning of the joint teeth, which will easily cause the connecting rod cover to loosen during the engine operation, which will cause the connecting rod bolt to break.
③During the operation of the diesel engine, there was a running fault or the piston burned out of the cylinder, and the connecting rod bolt was broken. If the engine has experienced flying problems during use, you should conduct a comprehensive inspection of the engine and it is best to replace the connecting rod bolts; if individual cylinders have experienced severe pulling cylinders during operation, the connecting rods should also be replaced when replacing the piston assembly Bolt replacement.
④ Material problems, processing defects and heat treatment process problems will also cause the connecting rod bolts to break during engine operation.

0
Views: 200