PROFESSIONAL ENGLISH UNIT 11 SUSPENSION AND STEERING SYSTEMS TEXT O Wheel Alignment
UNIT 11 SUSPENSION AND STEERING SYSTEMS TEXT C Wheel Alignment PROFESSIONAL ENGLISH
本次课学习内容 TEXTA Wheel Alignment Alignment Measurement values Front Wheel Alignment Adjustments Rear Wheel Alignment Adjustments ● Alignment Equipment
TEXT A Wheel Alignment • Alignment Measurement Values • Front Wheel Alignment Adjustments • Rear Wheel Alignment Adjustments • Alignment Equipment 本次课学习内容
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
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 wandering[ wonder]n漫游,神志恍惚离题 provision[ pre vigen]n预备,防备,设备,装置 misalign[ mislaid]w不重合,未对准,失准 setting [setin] n调整位置,设定值,安置,安 装 caster Ika:sta] n主销后倾(角) camber[kemb]n车轮外倾 toe [teu] n前束 toe-out [teuaut] n(负)前束 toe-in [touin] n(正)前束 offset Io: fset n.&v偏移,抵销
NEW WORDS wandering ['wɔndəriŋ] n.漫游, 神志恍惚, 离题 provision [prə'viƷən] n.预备, 防备, 设备，装置 misalign ['misəlain] v.不重合, 未对准，失准 setting ['setiŋ] n.调整位置，设定值，安置, 安 装 caster ['kɑ:stə] n.主销后倾（角） camber ['kæmbə] n.车轮外倾 toe [təu] n.前束 toe-out [təuaut] n.(负)前束 toe-in [təuin] n.(正)前束 offset ['ɔ:fset] n. & v.偏移, 抵销
scraping ['skreipin] n刮,擦 scrubbing [skrAbin] n洗擦,擦净 ImagInary[i' maedsinari]a假想的,想象的,虚构的 deviation[di:vi' ei fan]n背离,偏离 chisel [t∫izl n凿子;v凿,雕 eccentric[ ik'sentrik]n,偏心轮;a偏心的 trammel Tramal] n束缚物,量规 elaborate[i" separat]a精心制作的 necessitate[ni' sestet]v成为必要
scraping ['skreipiŋ] n.刮, 擦 scrubbing [skrʌbiŋ] n.洗擦, 擦净 imaginary [i'mæ ʤinəri] a.假想的, 想象的, 虚构的 deviation [ֽ di:vi'ei∫ən] n.背离，偏离 chisel ['t∫izl] n.凿子；v.凿，雕 eccentric [ik'sentrik] n.偏心轮；a.偏心的 trammel ['træməl] n.束缚物，量规 elaborate [i'læbərət] a.精心制作的 necessitate [ni'sesiteit] v.成为必要
PHRASES AND EXPRESSIONS wheel alignment 车轮定位 steering axis 转向轴线内倾角 inclination toe-out on turns 转弯负前束 tipping effect 侧倾效应 thrust angle 推力角,推力线 wheel tracking (前轮与后轮)同辙行驶 dog tracking 蛇形行驶 eccentric cam 偏心凸轮
PHRASES AND EXPRESSIONS wheel alignment 车轮定位 steering axis inclination 转向轴线内倾角 toe-out on turns 转弯负前束 tipping effect 侧倾效应 thrust angle 推力角，推力线 wheel tracking （前轮与后轮）同辙行驶 dog tracking 蛇形行驶 eccentric cam 偏心凸轮
Wheel Alignment 4 Wheel alignment is the process of measuring and correcting the various angles formed by the front and rear wheels spindles and steering arms. Correct alignment is vital. Improper alignment can cause hard steering pulling to one side, wandering noise, and rapid tire wear. Types of Wheel Alignment 11 Rear-wheel drive vehicles require a two-wheel alignment or front-wheel alignment only. The rear wheels are attached to a solid rear axle assembly which cannot be adjusted, and generally stays in alignment throughout the life of the vehicle 12 Today, most front-wheel drive vehicles have provisions for adjusting the rear wheels. In addition many rear-wheel drive vehicles are equipped with independent rear suspensions, which also must be adjusted Also modern solid rear axles and suspension systems are lightweight and can become misaligned Therefore the four-Wheel alignment in which the front and rear wheel alignment angles are checked and adjusted is commonly performed
Wheel Alignment 4 Wheel alignment is the process of measuring and correcting the various angles formed by the front and rear wheels, spindles, and steering arms. Correct alignment is vital. Improper alignment can cause hard steering, pulling to one side, wandering, noise, and rapid tire wear. Types of Wheel Alignment 11 Rear-wheel drive vehicles require a two-wheel alignment or front-wheel alignment only. The rear wheels are attached to a solid rear axle assembly which cannot be adjusted, and generally stays in alignment throughout the life of the vehicle. 12 Today, most front-wheel drive vehicles have provisions for adjusting the rear wheels. In addition, many rear-wheel drive vehicles are equipped with independent rear suspensions, which also must be adjusted. Also, modern solid rear axles and suspension systems are lightweight and can become misaligned. Therefore, the four-wheel alignment, in which the front and rear wheel alignment angles are checked and adjusted, is commonly performed
159 Adjustable front wheel settings on most modern vehicles are caster, camber, and toe. Nonadjustable settings are steering axis inclination and toe-out on turns. Rear wheel settings that can be made on many modern vehicles are camber and toe. Modern practice is to check both front and rear wheel alignment. Note that the various alignment angles are all related a change in one can alter the others Alignment Measurement Values 14 All alignment values except for toe are measured in degrees. Toe is measured in fractions of an inch or millimeters Caster 15 Positive caster tends to force the wheels to travel in a straight ahead position It also assists in recovery( wheels turning back to straight ahead position after making a turn On late model cars, there is often little or no positive caster. Positive caster makes it more difficult to turn the wheels from the straight ahead position than when no caster angle is present [1]
159 Adjustable front wheel settings on most modern vehicles are caster, camber, and toe. Nonadjustable settings are steering axis inclination and toe-out on turns. Rear wheel settings that can be made on many modern vehicles are camber and toe. Modern practice is to check both front and rear wheel alignment. Note that the various alignment angles are all related. A change in one can alter the others. Alignment Measurement Values 14 All alignment values, except for toe, are measured in degrees. Toe is measured in fractions of an inch or millimeters. Caster 15 Positive caster tends to force the wheels to travel in a straight ahead position. It also assists in recovery (wheels turning back to straight ahead position) after making a turn. On late model cars, there is often little or no positive caster. Positive caster makes it more difficult to turn the wheels from the straight ahead position than when no caster angle is present [1]
17 Another aspect of positive caster is a mild tipping effect when cornering When making a right turn the right wheel will cause the steering knuckle to raise slightly, while the left wheel will allow the knuckle to lower, creating the tipping effect. If the left side of the vehicle was allowed to rise during a right turn, it would have an adverse effect on the vehicle's cornering ability 18 To ease turning many cars employ a negative caster angle, which angles the top of the steering knuckle to front of car. This will ease steering while also causing the mild tipping effect needed when cornering Camber 19 Camber is the tilting of the wheel centerline, viewed from the front of the vehicle, away from a true vertical line. Camber angles are usually small, usually no more than 10 positive or negative from zero. an incorrect camber setting will cause pulling and tire wear
17 Another aspect of positive caster is a mild tipping effect when cornering. When making a right turn, the right wheel will cause the steering knuckle to raise slightly, while the left wheel will allow the knuckle to lower, creating the tipping effect. If the left side of the vehicle was allowed to rise during a right turn, it would have an adverse effect on the vehicle's cornering ability. 18 To ease turning, many cars employ a negative caster angle, which angles the top of the steering knuckle to front of car. This will ease steering while also causing the mild tipping effect needed when cornering. Camber 19 Camber is the tilting of the wheel centerline, viewed from the front of the vehicle, away from a true vertical line. Camber angles are usually small, usually no more than 1º positive or negative from zero. An incorrect camber setting will cause pulling and tire wear
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)
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)
