Nuts that never loosen—Analysis of the principle of hard lock nuts

As the saying goes, "every country has its own advantages and disadvantages in various fields." Speaking of neighboring Japan, your first impression may think of the powerful automobile manufacturing industry and beautiful natural scenery. But what you may not know is that Japan also has a pivotal position in the world in terms of scientific and technological strength! With convenient transportation today, China has established the world's largest high-speed rail network and technology platform, which to a certain extent also represents a direction for future high-speed rail development. However, China's seemingly powerful high-speed rail used to import a nut from a small Japanese company. Why?

In principle, the loosening of fasteners is caused by the moving gap between bolts and nuts. If the gap is filled, an ideal stable state is achieved. For this reason, Japan started the research of nut loosening, and then developed a part called "the hardest lock nut in the world" in 1974, which became famous in one fell swoop. In terms of composition, the hard lock nut consists of a female nut and a male nut. First, the female nut and the male nut are combined to minimize the gap between the two nuts. Secondly, using the principle of wedging, the nut is locked by the powerful force generated on the bolt shaft. Finally, the bolt and the nut perfectly combine the powerful force generated by the wedge shape of the nut, so as to achieve the purpose of permanently stabilizing the part. From the subsequent use effect, the use effect of the hard lock nut is better than any nut in the world. Therefore, after the birth of this kind of hard lock nut, it has been greatly welcomed by European and American countries. So far, hard lock nuts have been widely used in the manufacture of telephones and radars. The use of the nut greatly improves the safety and firmness of the equipment circuit, and further reduces the maintenance cost. It is worth noting that for some infrastructures with high maintenance cost and difficulty, such as bridges, towers, railways, etc., hard lock nuts are also very adaptable and practical, even on high-speed trains and other transportation vehicles. widely used. It has been used safely for more than 30 years and has won wide acclaim and trust from customers all over the world.

When it comes to the principle of a hard lock nut, it is actually very simple. The nut is locked by the wedge principle. Insert a wedge between the nut and bolt to ensure its stability. But it seems easy in theory, but because it needs to drive a wedge between each nut and bolt, it is almost difficult to reach by manpower. So far, hard lock nuts can be found in many aspects such as railways, bridges, and machinery in Japan. This small nut also greatly promoted the development of basic industries in Japan.