As a tool commonly used in fixtures, bolts are widely used, but long-term use will also bring many problems, such as loose connection, insufficient clamping force, and rusted bolts. During the processing and production of parts, the quality and efficiency of processing will be affected due to the loose connection of bolts. So how to prevent the bolt from loosening? Anti-loose purpose: to work more effectively for a long time; to improve the reliability of related workpieces.
There is a 30° wedge-shaped slope at the bottom of the 30° wedge-shaped female thread. When the bolts and nuts are tightened together, the cusps of the bolts are tightly pressed against the wedge-shaped slope of the female thread, resulting in a great locking. force.
Due to the change in the angle of the tooth shape, the normal force applied to the contact between the threads is at an angle of 60° to the bolt axis instead of the 30° angle like ordinary threads. Obviously, the normal pressure of the 30° wedge thread is far greater than the fastening pressure, so the resulting anti-loosening friction must be greatly increased.
From the figure below, it can be seen that the force represented by the two arrows is Pɑ, the normal pressure of the traditional 60° angle thread is P=1.15Pɑ; and the 30° wedge thread has a 30° wedge-shaped slope at the bottom of the tooth. The angle and size of the normal pressure are changed, and the normal pressure P=2Pɑ.
In this way, the ratio of the normal pressure between the 30° wedge thread and the traditional 60° thread is ≈12:7, and the anti-loosening friction force increases accordingly. The wedge-shaped surface of the 30° wedge thread can also eliminate the problems of uneven stress on ordinary threads, tripping and seizure.