has a shape similar to cast iron tambourine, called brake drum, which is fixed and the tire is rotated at the same speed. When the brake oil pressure to promote the use of brake shoes (Brake Shoes) in contact with the inner edge of the brake drum, the contact frictional force generated by the rotation of the tire is suppressed in order to achieve the object of the brakes.
1. The drum brake Glossary
has a shape similar to cast iron tambourine, called brake drum, which is fixed and the tire is rotated at the same speed. When the brake oil pressure to promote the use of brake shoes (Brake Shoes) in contact with the inner edge of the brake drum, the contact frictional force generated by the rotation of the tire is suppressed in order to achieve the object of the brakes.
2. BrakeVehicle drum composition
For a drum brake plate brake rod, brake cylinder, brake shoes, etc., a spring, nail tip, brake drum formed. Currently only the ordinary use of the rear wheels. Lower-cost drum brakes, the higher the absolute braking force is greater use of the rear wheel of a small car. But its high attrition rate, thus simultaneously a higher overall cost.
3. The drum brake principle
drum brakes in the automotive above has been nearly a century of history, but because of its reliability, and a powerful braking force, so that the drum brake nowadays many cars are still arranged on the (multi-use on the rear wheel)
by a hydraulic drum brake is the brake pad means to push it inside the brake drum, so that the brake as the inner surface of the sheet with the rotation of the wheel of the brake drum friction occurs, the braking effect is generated.
The inner surface of the drum brake is the brake drum brake device generating position of the braking torque. In the case of obtaining the same braking torque, the brake drum diameter drum brake device may be a brake disc brakes smaller than 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, is the use of a stationary drum brakes the brake drum brakeSheet, with the rotation of the wheel to a friction brake drum to generate 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.
4. Advantages drum brake
● tight automatic brake action, so that the system can use a lower brake hydraulic pressure, or using diameter much smaller than the brake drum brake discs.
● handbrake mechanism easy to install. Some models rear disc brake device, installed hand brake drum brake mechanism in the center of the brake disc.
● parts of the processing composition and relatively simple, but have relatively low manufacturing costs.
5. The drum brake disadvantages
● brake drum brake drum diameter increases when heated, causing increased stroke of the brake pedal, the brake case of the reaction likely to occur as expected. Therefore, the use of the vehicle while driving drum brakes, to avoid causing continuous brake brake pads due to high temperature thermal phenomena recession.
● 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.
● multi-part structure is complicated, brake clearance adjustment to be done, so that maintenance is not easy.