汽车专业外语052ppt课件.ppt

,The Brake System 制动系统,Unit 6,Passage A,The most important system in your car. If the brakes dont work properly, the result can be disastrous. Good brakes are essential for safety.,Passage A,Brake system (),Passage A,Brake system (),Passage A,Two completely independent braking system,Service brake Main braking system used to slow down or stop the car during normal driving. Foot-operated by the driver depressing and releasing the brake pedal. Parking brake (Hand brake) Hold a car stationary while it is unattended, and to keep the car from rolling on unleveled ground.,Passage A,Brake system (),Passage A,Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes / pads against the rotating drums / disks at wheel. Friction between the shoes / pads and the drums / disks then slows / stops the wheels so that the car is braked.,Passage A,Brake system (),Passage A,Disk brake,Used for years for front wheel applications, are fast replacing drum brakes on the rear wheels of modern cars, due to their simpler design, lighter weight and better braking performance. Provides significantly better resistance to brake fade compared with drum type braking system. Main components: Brake pads, Caliper, Disk / Rotor,Passage A,Brake system (),Passage A,Brake pad,http:/www.diytrade.com/china/4/products/3456706/Brake_Pad.html,http:/news.mycar168.com/2008/03/65076.html,With lining riveted or bonded to it. Mounted in the caliper, one on each side of rotor. Asbestos are primarily used because of its heat absorbing properties and quiet operation.,Passage A,Brake system (),Passage A,Caliper,Floating calipers and fixed calipers,http:/www.jpmagazine.com/techarticles/drivetrain/154_1105_jeep_wrangler_jk_big_brake_bolt_ons/photo_05.html,http:/www.2carpros.com/articles/how-a-brake-caliper-works,Passage A,Brake system (),Passage A,Caliper,How does a floating caliper work? Floats or moves in a track in its support so that it can center itself over the motor. The hydraulic fluid pushes in two direction. Firstly, it forces the piston against the inner pad which in turn pushes against the rotor. Secondly, it also pushes the caliper in the opposite direction against the outer pad which pushes the other side of the rotor.,Passage A,Brake system (),Passage A,Caliper,Single piston calipers are the most popular and also least costly to manufacture and service. Floating calipers are also available on some vehicles with two pistons mounted on the same side.,http:/www.streetperformance.com/part/howe-racing-enterprises/brake-caliper/317513-33701.html,Provides an improved braking feel, found on more expensive cars,Passage A,Brake system (),Passage A,Caliper,Fixed calipers are mounted rigidity to support and are not allowed to move.,http:/www.bmwtuningmag.com/8-piston-high-performance-brake-system-from-ac-schnitzer/,Better brake feel and more efficient, while more expensive to produce and cost more to service.,8-piston High Performance Brake System from AC Schnitzer,Passage A,Brake system (),Passage A,Disk rotor,Be made of iron with highly machined surfaces where the brake pads contact it. Just as the brake pads wear out over time, the rotor also undergoes some wear, usually in the form of ridges and grooves where the brake pad rubs against it.,http:/news.mycar168.com/2008/03/65076.html,Passage A,New words （生词）,Disastrous Foot-operate Unattended Unleveled Significantly Caliper Squeeze Lining Bonded Outlaw,Configuration Groove Service brake Parking brake Brake shoes Brake pads Disk brake Drum brake Wear out Be made of,Passage B,Brake system (),Why do we still have cars with drum brakes? Low cost,Drum brake,http:/www.carbasics.co.uk/what_are_drum_brakes.htm,Consists: Backing plate, brake shoes, brake drum, return spring and an automatic or self adjusting system,Passage B,Brake system (),Typical brake system components: Master cylinder Brake lines and brake hoses Brake fluid Shoes and pads,Brake system,Passage B,Brake system (),Located in engine compartment on the firewall, directly in front of the drivers seat. Two completely separate master cylinder, each handling two wheels.,Master cylinder,http:/www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder,If one side fails, you will still be able to stop the car. The most common problem is an internal leak.,Passage B,Brake system (),The brake fluid travels from the master cylinder to the wheel brake through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as front wheel. Non-corrosive seamless steel tubing with special fitting is used in all rest attachment points. Replace the complete line if needed, and do not use the brass compression fittings or copper tubing.,Brake lines and brake hoses:,Passage B,Brake system (),A special oil that has special properties. Withstand cold Temp. without thickening as well as very high Temp. without boiling. Transparent reservoir is used to easily check the fluid level. Slightly decreasing of the level is a normal condition as the brake pads wear. Never let the level goes down to below the two thirds full. And keep the reservoir covered except for the time you need to fill it.,Brake fluid,Passage B,Brake system (),Amplify the available foot pressure applied to the brake pedal. Power for the booster comes from engine vacuum. Vacuum enters the booster through a check valve, which is connected to the engine with a rubber hose and acts as a one-way valve that allows the vacuum to enter the booster but does not let it escape.,Booster,Passage A,New words （生词）,Compartment Firewall Power-assisted Alert Rarely Malfunction Reinforce Non-corrosive Seamless Fitting,Illegal Spongy Transparent By-product Be composed of Hydraulic pressure Amplify Engine compartment Power brake booster Brake warning light Two thirds full,西华大学,XIHUA UNIVERSITY,交通与汽车工程学院,Faculty of Transportation and Automotive Engineering,Homework,Review the new words and expressions,Exercise 3,5,6,西华大学,XIHUA UNIVERSITY,交通与汽车工程学院,Faculty of Transportation and Automotive Engineering,Thanks,