The brake drum is cast a shape similar to the tambourine, and fixed at the same speed and tire rotation. Brake using hydraulic drive brake shoe, brake shoes) into contact with the brake drum rim and the friction force generated by means of a contact to suppress the tire rotation brake to achieve the purpose. Drum brake by brake plate, brake pump, brake shoe, the connecting rod spring, shoot nail, brake drum. Currently only used in the rear wheel. Lower the cost of the brake drum, the absolute power was higher, the use of more small cars in the rear. However, the wear rate is higher, so the overall cost is higher.
Spiral groove brake drum
Brief introduction
If the brake drum body does not produce hot crack, casting no quality defects, then the general quality of the brake drum can called "brake not broken" only because of brake drum is a brittle gray cast iron material and work under the environment of high temperature and high pressure [1], on the surface of formation of fatigue crack is the physical properties of the cast iron material is irresistible objective law. With the crack in the drum body of the extension and penetration, the drum body of the mechanical strength of a sharp recession, will eventually lead to brake.
The process of spiral groove can change the friction between the drum and shoe, so that it can be changed from "face" to "contact". Follow the horizontal movement of the spiral, and by the "continuous" type of friction with the "intermittent" type of friction, groove brake drum in practice to bring the following benefits:
Characteristic
The 1 groove can block the free extension of the surface crack,
The 2 groove can resist the heat distortion of the drum, and maintain the natural shape of the high temperature state.
The 3 groove is the central part of the drum body and the heat channel is established.
The 4 groove can overcome the oil, water soaked by skid, brake failure prevention.
5 spiral groove brake drum can extend the service life of the brake.
Broadband friction and intermittent friction can real control of the drum body temperature rises, and its low temperature of braking is very favorable, is further evidence that opening the safe and scientific nature of the spiral groove on the inner wall of the brake drum.
Drum brake
Advantage
Self brake: drum brake has a good self braking effect, due to brake to order a, wheel rotating joint with a brake drum twist angle
(of course not to let you it is easy to see) brake to make the tension (braking force) more, the situation is more obvious, therefore, large vehicles or the use of drum brake, except for low cost, large cars and small cars of the drum brake, the difference may be only a large mining pneumatic auxiliary, and small car production vacuum assisted to help stop the car.
Low cost: drum brake manufacturing technology level is low, is the first to brake system, and thus the manufacturing cost to than disc type brake low.
Shortcomings
Due to the drum brake order sheet seal on the brake drum, resulting in brake to make the abrasion of the chip can not be dispersed, the effect of brake drum and to make the contact surface and affect braking performance.
Disc brake
Advantage
Brake drum
As a result of the brake system does not seal, so brake wear fines continuous deposition on the brake, brake disc of centrifugal force can will all water, dust and other pollution thrown outwards, to maintain a clean. In addition, because the disc brake parts in independent, easier to repair than drum brake.
Shortcomings
Disc type brake in addition to the high cost, all basically is better than that of drum brake, but light it, became the its fatal injury, people love money well, unless you are very rich, or buy things basically is to money first consideration, you say yes or no? Disc brake is also known as the disc brake, as the name suggests is the shape of its name. It consists of hydraulic control, the main parts of the brake disc, sub pump, brake clamp, tubing, etc.. The brake disc is made of alloy steel and is fixed on the wheel. Fixed on the base plate of the brake. The two friction plates on the brake clamp are respectively arranged on both sides of the brake disc. The piston of the pump by the tubing conveyed to the hydraulic pressure that pushes the friction plate pressure to the brake disc friction braking, act like a vise pliers rotating plate, forcing it to stop. This brake cooling fast, light weight, simple structure, easy adjustment. Especially when the high temperature performance and high load, braking effect is stable and not afraid of mud invasion, driving in winter and bad road conditions, disc brake drum brake more easily within a short period of time so that the car stopped. Some of the brake disc brake disc also opened a lot of small holes, to speed up the ventilation cooling to improve braking efficiency. The drum brake, due to the poor thermal performance, will gather a large amount of heat during the braking process. Under the influence of high temperature, the brake shoe and wheel drum are more prone to deformation, which is prone to produce the brake recession and the phenomenon of vibration, and the brake efficiency is reduced. Of course, disc brake also has its own defects. For example to the brake and the brake pipe manufacturing requirements higher, wastage of friction plate is big and the cost is expensive and due to the small area of the friction plate, the relative friction working face is also smaller, high brake hydraulic must have vehicle power assisting device can use, so can only be suitable for light vehicles. The drum brake is relatively low cost, economic comparison.