1、附录 A 外文翻译 -原文部分 How Car Suspensions Work Table of Contents: Introduction to How Car Suspensions Work Vehicle Dynamics The Chassis Springs Springs: Sprung and Unsprung Mass Dampers: Shock Absorbers Dampers: Struts and Anti-sway Bars Suspension Types: Front Suspension Types: Rear Specialized Suspensio
2、ns: T Specialized Suspensions: Formula One Racers Specialized Suspensions: Hot Rods The Future of Car Suspensions Lots More Information Compare Prices for Car Suspensions When people think of automobile performance, they normally think of horsepower, torque and zero-to-60 acceleration. But all of th
3、e power generated by a piston engine is useless if the driver cant control the car. Thats why automobile engineers turned their attention to the suspension system almost as soon as they had mastered the four-stroke internal combustion engine. Photo courtesy Honda Motor Co., Ltd. Double-wishbone susp
4、ension on Honda Accord 2005 Coupe The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers. In this article, well explore how car suspensions work, how theyve evolved o
5、ver the years and where the design of suspensions is headed in the future. Vehicle Dynamics If a road were perfectly flat, with no irregularities, suspensions wouldnt be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels of
6、 a car. Its these imperfections that apply forces to the wheels. According to Newtons laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface. The magnitude, of course, depends on whether the wheel is str
7、iking a giant bump or a tiny speck. Either way, the car wheel experiences a vertical acceleration as it passes over an imperfection. Without an intervening structure, all of wheels vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can los
8、e contact with the road completely. Then, under the downward force of gravity, the wheels can slam back into the road surface. What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in t
9、he road. The study of the forces at work on a moving car is called vehicle dynamics, and you need to understand some of these concepts in order to appreciate why a suspension is necessary in the first place. Most automobile engineers consider the dynamics of a moving car from two perspectives: Ride
10、- a cars ability to smooth out a bumpy road Handling - a cars ability to safely accelerate, brake and corner These two characteristics can be further described in three important principles - road isolation, road holding and cornering. The table below describes these principles and how engineers att
11、empt to solve the challenges unique to each. Principle Definition Goal Solution Road Isolation The vehicles ability to absorb or isolate road shock from the Allow the vehicle body to ride undisturbed Absorb energy from road bumps and dissipate it passenger compartment while traveling over rough road
12、s. without causing undue oscillation in the vehicle. Road Holding The degree to which a car maintains contact with the road surface in various types of directional changes and in a straight line (Example: The weight of a car will shift from the rear tires to the front tires during braking. Because t
13、he nose of the car dips toward the road, this type of motion is known as dive. The opposite effect - squat - occurs during acceleration, which shifts the weight of the car from the front tires to the back.) Keep the tires in contact with the ground, because it is the friction between the tires and t
14、he road that affects a vehicles ability to steer, brake and accelerate. Minimize the transfer of vehicle weight from side to side and front to back, as this transfer of weight reduces the tires grip on the road. Cornering The ability of a vehicle to travel a curved path Minimize body roll, which occurs as centrifugal force pushes outward on a cars center of gravity while cornering, raising one side of the vehicle and lowering the opposite side. Transfer the weight of the car during cornering from the high side of the vehicle to the low side.
