Cause analysis of brake drum cracking

Automobile brake drum is an important functional part of the automobile, is also the main component to measure the safety performance of the automobile, but also is the first to be checked in the daily maintenance of the components, relevant information shows that the brake drum failure is mainly in five forms: crack, crack, bottom, excessive wear, abnormal wear.The main cause of the first two types of fracture is discussed below: thermal fatigue fracture caused by high temperature shock.

Sampling scheme and inspection basis

Source of the brake drum in the sample of the product is the replacement for the garage scrap products, from shijiazhuang, the city of chaff, and positive definite three areas of six repair shop purchase 30 samples, the choice of the garage are relatively large, the vehicles involved sort is more, the product model is more, and the repair shop service object is all over the country, so the purchasing has certain representativeness of sample as shown in figure.

The damage location and damage degree of the sample are different, so that the analyst can have a more comprehensive grasp of the quality of the sample.

Samples from the sample appearance analysis, most of the damage location of friction surface crack, and brake drum causes of crack is, vehicles running down the hill too long can produce high temperature brake drum, if wade, immediately after the downhill brake drum with water and a sharp contraction, so the friction brake drum surface cracks along axis direction, this kind of crack extension with continue to brake, brake drum rupture.Some brake drums are under warranty and their friction surfaces appear to be shiny patches, which are caused by the brake drum encountering water at high temperatures.