Importance of fasteners
Time：2022/5/31 Browse：5570
When selecting fasteners, first select them from the varieties and specifications of national standards, then select them in the industry, and then design them according to the special needs of mechanical equipment when necessary. Among the requirements, anti loosening and anti fracture are the two main conditions to be considered.
In the 1980s, a local newspaper in Michigan, the United States, published an article saying:; There are about 3~4 casualties caused by out of control driving in the state every week. People speculate that such drivers are asleep or drunk. Later, after they had driven the car, they checked the mechanical part of the car and found that 80% of the fasteners were loose, including the bolts and nuts on the front suspension, rear suspension and shock absorber. Such devices are crucial to the control of the car. The report also pointed out that bolts and nuts were also loose on mechanical parts such as transmission device, differential system, engine rocker arm cover, catalytic converter and body metal components. In 1986, the rear section of an airliner fell in flight, resulting in 532 deaths. After that, an investigation was conducted on the tail of the same aircraft in various countries, and it was found that there were nut looseness and bolt fracture. First, the response of the tail of the aircraft exceeded the fastening force that the fasteners could bear. Second, it was also found that there was internal displacement between the sides of the meshing thread.
Loosening of fasteners is a common problem. A pair of scissors has only one fastener. If it is loosened, it can only be used again if it is tightened. However, a large aircraft may have 300000 fasteners, and if there is a problem, it will be impossible.
People in the industrial field in the industrial developed areas have realized that; There is no problem that bothers the industrial field more than fasteners, and no problem is more critical than solving the fastener problem, which is their personal experience. Therefore, there is a "how to choose" that is, safe, applicable and economical fasteners.
