Types And Characteristics of Automobile Brake Shoes
As a consumable in the automobile, the brake shoe is not consumed as quickly and obviously as gasoline, but it also needs to pay attention to its wear degree and replace it frequently. This involves the problem of selecting and purchasing brake shoes.
How to choose and buy brake shoes requires understanding the types of brake shoes and the characteristics of different types of brake shoes, so as to find the brake shoes that are suitable for your car's working conditions.
brake shoes are now mainly divided into the following categories: asbestos brake shoes (basically eliminated), semi metal brake shoes, less metal brake shoes, Nao formula brake shoes, ceramic brake shoes, Nao ceramic brake shoes!
Asbestos brake shoe
Now it has been basically eliminated. Asbestos brake shoes are one of the brake shoes. Due to their low cost and light weight, many vehicle enterprises still use asbestos brake shoes when producing commercial vehicles such as trucks and engineering vehicles.
Because asbestos is insulated, its thermal conductivity is particularly poor. Usually, repeated use of the brake will cause heat to accumulate in the brake shoe. After the brake shoe becomes hot, its braking performance will change. To produce the same friction and braking force, it will require more times to step on the brake. This phenomenon is called "brake shrinkage". If the brake shoe reaches a certain heat, it will lead to brake failure.
Semi metal brake shoe
Basically, the brake skin of the upper car is made of this formula when it leaves the factory. Of course, this kind of brake shoe is also relatively cheap. Its friction coefficient is low. Generally, the friction coefficient is 0.38 and its service life is short. Some manufacturers also make this kind of brake shoe with a high friction coefficient. Of course, this is also a disadvantage, which is prone to noise. It is easy to generate noise when using this kind of brake shoe on Japanese cars. Of course, this is closely related to the brake disc.
Less metal brake shoe
The braking effect of the third generation of small metal brake shoes is better than that of semi metal brake shoes, which are not easy to make noise and do not damage the disc. The disadvantage is that it is not wear-resistant. Less metal is the material containing a small amount of iron, usually steel wool, so its production cost is slightly higher than that of semi metal brake shoes.
Nao formula brake shoe
In most cases, the base material of Nao friction materials is a mixture of two or more fibers (inorganic fibers and a small amount of organic fibers), which is asbestos free and metal free.
Its characteristics are: stable friction coefficient (friction times FF), good wear resistance, good mechanical strength and physical properties, low braking noise, less wear on the dual surface, especially superior to other materials, and completely realize the integration of environmental protection in the industrial chain.
Ceramic brake shoe
Ceramic brake shoes appeared in the early 1990s and are relatively new products in the automotive industry. Of course, ceramic fibers are indispensable in the raw materials of ceramic brake shoes. This ceramic is not fired ceramics. The raw materials used by ceramic brake shoes of different manufacturers are different, which also leads to the price difference of ceramic brake shoes themselves (the price of ceramic fibers varies from 20000 to 90000). The difference in price also leads to the advantages and disadvantages of ceramic fibers. The real ceramic brake shoes also contain aramid fibers, which are far superior to the brake shoes with the above formula in terms of service life and brake skin performance. Of course, the price is more expensive!
Nao ceramic brake shoe
The ceramic formula gives customers a smooth impression of stepping. Whether the lining is at room temperature or high temperature, the friction coefficient of the lining of the ceramic formula decreases more slowly than that of the semi metal. At the same time, the noise and vibration of the ceramic formula are relatively small, so the braking is quiet and the damage to the brake disc is small.
It is estimated that 40% of the new cars sold in North America are made of ceramic linings.
When selecting brake shoes for volvo vnl 670, we need to pay attention to several points:
1.Look at the friction coefficient. The friction coefficient determines the basic braking torque of the volvo vnl 670 brake shoes. If it is too high, the wheel will lock, the direction will be out of control and the brake shoe will burn. If it is too low, the braking distance will be too long;
2.it depends on the safety. The volvo vnl 670 brake shoes will produce instantaneous high temperature during braking, especially when driving at high speed or emergency braking, and the friction coefficient of the friction pad will decrease under high temperature;
3.check whether it is comfortable, including braking feeling, noise, dust, smoke, odor, etc., which is the direct embodiment of friction performance;
Fourth, the service life. Usually, the volvo vnl 670 brake shoes can guarantee a service life of 30000 km.
4.look at the maintenance. Don't think that the brake shoes don't need maintenance. The volvo vnl 670 brake shoes also need to be maintained and replaced at intervals.
In a word, Automobile volvo vnl 670 brake shoes produced by regular manufacturers with license number, specified friction coefficient, executive standard, etc. shall be selected, and the packaging box shall be provided with certificate of conformity, production batch number, production date, etc; Secondly, choose to go to a professional maintenance point and ask a professional to install it.