新编汽车专业英语第3版黄汽驰电子课件Unit5PassageB.pptxVIP

Unit Five Automobile Braking System　 Passage BBasic Brake Parts and Safety Brake SystemTypical braking system has the following basic parts: brake pedal, brake booster, master cylinder, brake lines and brake fluidas shown in Fig.5-8．Brake pedalBrake pedal located on the right foot side in the car can amplify the force of your leg and evenly transmit it to the brake fluid when the right foot steps on the pedal (see Fig.5-9). Brake boosterBrake booster mounted on the firewall between the brake pedal and master cylinder increases the force applied to the pistons in the master cylinder so that the car can stop with less effort． The two most common types of power brake boosters are vacuum booster and hydraulic booster, both of which accomplish the same thing．Master cylinderA master cylinder has actually two completely independent working chambers respectively with one piston, each controlling two wheels． If only the two of the wheels lose their brakes, the other two wheels will still be able to stop the car． On the top of the master cylinder is a brake fluid reservoir that is transparent so as to see the fluid level without opening the cover (see Fig.5-10).Brake linesThe brake lines run from the master cylinder along the frame of the car to each wheel (see Fig.5-8). The lines are made of steel and reinforced rubber hoses which are flexible enough to use only at the front wheels and rear axles where the suspension system works and wheels turn when you steer．Brake fluidBrake fluid travels from the master cylinder to the wheels through the brake lines． It is special oil that has specific properties． It must withstand cold temperature in winter without thickening as well as very high temperature in summer without boiling．Safety brake systemOne cannot think of the safety brake system without thinking of ABS, nor of ABS without EBD, EBA and ESC, etc．ABS, short for Anti-lock Brake System, is designed to prevent the car from skidding on a wet and slippery road, and make the car