1. Description
the inner surface of the drum brake is the braking position of the brake drum to produce braking torque means. In the case of obtaining the same braking torque, the diameter of the brake drum brake drum brake device may be smaller than the disc brakes of many. So large vehicle truck used to obtain a powerful braking force, the device can only drum brakes in the limited space of the rim.
Briefly, the brake pad drum brake is the use of the stationary drum brakes, friction brake drum to rotate with the wheel, a frictional force to brake the wheel rotational speed reduction.
When the brake pedal, the piston forward to push the brake oil in the brake master cylinder will force the foot and to generate a pressure in the oil passage. Pressure is transmitted via the brake fluid to the wheel brake cylinder of each piston, brake wheel cylinder piston outwardly and then push the brake pads, brake pads and the inner surface of the brake drum friction occurs, and generate sufficient friction to reduce the rotational speed of the wheel, in order to achieve the purpose of the brakes.
2, the advantages of the drum brake
1. tight automatic brake action, so that the system can use a lower brake hydraulic pressure, or using smaller diameter than the brake disc many of the brake drum.
2. easy to install the parking brake mechanism, and some models rear disc brake apparatus, the parking brake mechanism is installed in the drum brake disk rotor central portion.
3 parts of the process and composition of relatively simple, but have relatively low manufacturing costs.
3, drum brake shortcomings
1. The brake drum brake drum diameter increases when heated, causing the brake pedal stroke plus large, the situation is prone to react as expected brakes. Therefore, the use of the vehicle while driving drum brakes, to avoid continuousBrakes cause the brake pads due to high temperature thermal phenomena recession.
2. The brake system response is slow, the depression force of the brake more difficult to control, is not conducive to a high frequency of braking action to do.
3. The multi-part structure is complicated, brake clearance adjustment to be done, so that maintenance is not easy.
As the performance and the traveling speed of the vehicle and the date of the dramatic increase in order to increase the stability of the vehicle brake at high speeds, the disc brake has become the mainstream of the current braking system. Since the disc brake brake disc exposed to air, so that the disc brake has excellent heat dissipation properties, made when the vehicle brakes or multiple brakes at high speed in a short time, the performance of braking is less likely to decline, so that the vehicle can be obtained better braking effect, to enhance the safety of the vehicle. And because of the rapid reaction disc brakes, the braking action has the ability to do high frequency, many car models with disc brake system with ABS and VSC, TCS with other systems, such systems need to meet the demand for rapid action to do.