汽车专业英语读译教程 作者 宋进桂_ 20-U11TC.ppt

UNIT 11 SUSPENSION AND STEERING SYSTEMSTEXT CWheel Alignment TEXT AWheel Alignment? Alignment Measurement Values? Front Wheel Alignment Adjustments? Rear Wheel Alignment Adjustments? Alignment Equipment 本次课学习目标 掌握车轮定位的英文专业词汇 训练快速阅读能力，提高阅读速度 NEW WORDS Steering Axis Inclination 42 The steering knuckle ball joints are closer together at the top than the bottom. The steering axis (view from the front of the car) places the centerline of the steering ball joints closer to the centerline of the wheel. This angle is known as steering axis inclination, or SAI. 43 When the wheel centerline is to the outside of the center line of the steering axis (where they intersect the road), the wheels tend to toe-out. This is caused by the road-tire resistance pushing back on the spindle, causing it to swivel backward on the ball joints or toe-out. When the centerline of the wheel intersects the road at a point inside of the steering axis centerline intersection, the wheels tend to toe-in (tires are closer together in the front than in the back). Toe 45 Toe is the relative positions of the front and rear of a tire in relation to the other tire on the axle. Note that distance at the back of the tires is greater than distance in the front. Rear-wheel drive vehicles are toed in to compensate for the natural tendency of the road-to-tire friction to force the wheels apart. 46 On some front-wheel drive vehicles, the front tires are toed out. This is done to offset the force created by the drive axles, which tend to pull the tires inward during operation. The toe setting compensates for this and allows the front tires to run parallel to one another while rolling straight down the road. 47 Toe compensates for the wheel movement tendencies plus any wear or play in the steering linkage. Proper toe will allow the tires to move forward without a scrubbing, scraping action between the tire and road. Excessive toe conditions will cause a rapid tire wear condition