For automobile maintenance personnel, automobile engine bolts and nuts are even more commonplace. In the process of automobile maintenance, they face the disassembly and assembly of various fasteners on the automobile and the engine. More than 80% of the mechanical failures of the automobile are Caused by problems with bolts.
A complete and normal engine is assembled together through a variety of different standards, models, functions, materials, etc. screw nuts, etc., through the connection of these different fasteners, can make an engine normal operation.
Knowledge of Car Bolts
According to the winding direction of the thread: there are two types: left-hand thread and right-hand thread. Most of the threads are right-handed threads, and a few special parts use left-handed threads.
According to the number of threads, it can be divided into a single thread, double thread, and three thread. Among them, a single thread is mostly used for connection, and the others are mostly used for transmission.
According to the shape of the thread, it is divided into triangular thread, rectangular thread, trapezoidal thread, and sawtooth thread. Among them, the triangular thread has good self-locking property and high thread strength. It is generally used for connection and is the most widely used thread.
According to the pitch, it is divided into two categories: coarse thread and fine thread. Coarse thread is the basic thread. Fine thread screw has high strength, but the strength of thread is lower than that of coarse thread. It is generally used for thin-walled pipe fittings, shaft parts, and precision On the adjustment piece of the mechanism. When the screw diameter is greater than 70mm, only fine thread can be used.
There are countless car breakdowns and accidents caused by bolts and nuts. The reasons for the engine failure caused by the bolt problem are rough as follows:
- The bolts are not pre-tightened according to the technical specifications. Too loose or too tight will cause malfunction.
- The bolts are not installed according to the specified position. In the beginning, there are special requirements for the location of the engine, what function, what space, what torque, and what bolt design technology.
- Special bolts do not use original design materials and processing techniques. Use ordinary material processing to replace special materials, and use general processing technology to replace special processing technology to process special bolts.
- Special bolts are in specific positions, using incorrect disassembly tools
- The requirements of different functional areas ignore the use of different bolts for various washers.
- The anti-loose measures are not correct when the bolts and nuts are installed.