新编汽车专业英语第3版黄汽驰电子课件Unit7PassageA.pptxVIP

Unit Seven Car Body and Electrical System　 Passage ACar Body and Car StyleCar body is one of four key automotive assemblies． It refers to the outer shell of a car． Car body includes engine compartment, passenger compartment and cargo compartment and so on． Car styles refers to the shape of car body． Different cars use different carbodies and car styles befitting their varied uses.Car BodyThere are two types of car body: one is body-on-frame that means the car body and frame are separated． The body is mounted on this rigid frame as shown in Fig.7-1．The main functions of the frame in a car are to support the car’s mechanical components such as the drive train and the car body; to bear the weight of passengers and cargo loads; and to withstand the sudden impact from collisions． This type of body-on-frame is often found in trucks and buses．The other is unitized body that means the car’s frame and body are integrated into a single strong structure (see Fig.7-2). Nowadays, almost all modern passenger cars use unitized body． In this fully integrated body structure approach, the entire car is a load-carrying unit that can withstand the forces from driving and cargo loads．The unitized body is typically manufactured by welding various metal elements such as cross and side members, pillars, rails and other components together as one piece, forming a car’s skeleton or framework (for details to see Fig 7-3). The framework is a base for installing engine hood, truck lid, roof, fenders, doors, and windscreens etc.(for details to see Fig.7-4). Vehicle StyleThere are many different car styles with various streamlines such as sedan, hatchback, SUV, crossover, convertible, van, and pick up． Among these car styles mentioned above, the most common family car styles are sedan and hatchback because they are economical and practical．Sedan is four-door car, also called three-box car． We can see in Fig.7-5, there are three separate compartments: engine compartment , passenger compartment and