GÓC ĐẶT BÁNH XE DẪN HƯỠNG WHEEL ALIGNMENT pot

Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
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WHEEL ALIGNMENT
WHEEL

ALIGNMENT
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Description
Description
Camber
Steering axis
inclination
Caster
Toe
Turning radius
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Camber
Description
Cb
Negative Positive
Camber
0
C
am
b
er
• Uneven wear of tire
Excess on positive side

90°
Outside
Excess on negative side
Outside
Inside
Outside
Inside
Outside
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Camber
Negative Camber
Negative camber Positive camber
Camber thrust
Inside Outside
Inside Outside
Load
Load
Camber thrust
Camber thrust
O O
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Camber
Camber During Cornering
Negative camber
Centrifugal
force
Small positive camber
Positive camber

Straight-ahead
driving
Small

positive

camber
Cornering force
Centrifugal
force
Straight-ahead
driving
Large positive camber
Cornering force
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Camber
Zero Camber and Positive Camber
Zero camber
Positive camber
•Reduction of vertical load •Prevention of wheel slip-off
Spindle
F
F
1
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Caster and Caster Trail
Description
Negative

-0 +
Positive
Caster
Front
Caster angle
90°
Caster trail
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Caster and Caster Trail
Straight-line Stability and Wheel
Recovery
Straight-line stability due to caster angle
without Caster angle with Caster angle Jack-up
t
t
orque
Wheel recovery due to caster trail
P
Ta
P’
T’
a’
Front
Trail
F2
F
F1
F’2
F’

F’1
O’
Caster trail
P, P’ : Driving force
a, a’ : Steering axis
O, O’ : Center of tire-road contact area
F, F’ : Reactive force
F1, F2 : Composite force F
F’1, F’2 : Composite force F’
TT
’
: Recovery force
(1/1)
T
,
T
:

Recovery

force

Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Caster and Caster Trail
Nachlauf and Vorlauf Geometry
Offset
Steering axis
Large change in trail
Nachlauf geometry
Offset

Ordinary geometry
Caster trail
Offset
Small change in trail
Vorlauf geometry
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Steering Axis Inclination
Description
Steering axis
inclination
Steering axis centerline
Wheel centerline
90°
Offset
L
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Steering Axis Inclination
Roles of Steering Axis Inclination
1. Reduction of steering effort
2. Reduction of kickback and pulling to one side
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Steering Axis Inclination
Roles of Steering Axis Inclination
1. Reduction of steering effort
• Camber = zero
• Steering axis inclination = zero
1.Reduction of steering effort

Large offset
Steering axis inclination Positive camber
Small offset
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Steering Axis Inclination
Roles of Steering Axis Inclination
2. Reduction of kickback and pulling to one side
2. Reduction of kick-back and
pulling to one side/
3. Improvement straight-line
stability
Large moment
Driving or
braking force
Large offset
Small moment
Small

moment
Driving or
braking force
Small offset
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Steering Axis Inclination
Roles of Steering Axis Inclination
Small
moment
Large

moment
Large angle
small offset
Small angle
large offset
small

offset
large

offset
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Toe (Toe angle, Toe-in and Toe-out)
Description
Toe angle
Front
Toe angle
Toe angle (toe-in
and toe-out)
A
Toe-in : A < B
Toe-out : A > B
Role of toe angle
B
No toe angle Toe-in
Gravity
(pull)
Gravity
(pull)

(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Turning Radius (Wheel Angle, Turning Angle)
Description
(the knuckle arm is parallel to the vehicle centerline)
When the rotational angle of left and right wheels is the same
Front
Side-slip
Tie rod
Knuckle arm
(the knuckle arm inclined to the vehicle centerline)
When adjusting the rotational angle of left and right wheels
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Wheel Alignment Service
Description
1. General/
2. Where to measure and cautions concerning tester handling/
3. Necessity of inspection before measurement of wheel alignment
(1/2)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Wheel Alignment Service
Description
4. Importance of chassis-to-
ground clearance adjustment
before alignment measurement/
5. Road test/
6. Measurement results and
4.Important of chassis-to-ground clearance
adjustment before alignment adjustment

how to use them
Bounding *1
Toe
Caster
Camber
*1 State in which shock absorbers is shortened
*2 State in which shock absorbers is lengthened
Rebounding *2
(2/2)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Toe-angle
1. Tie rod behind the spindles
AA
B
Short
B
Long
2. Double tie rod type
Tie rod end
Steering rack housing
Steering rack
end
AB
A = B
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Camber and Caster
1. Separate camber adjustment 2. Separate caster adjustment

3. Simultaneous camber and caster adjustment
(1)
(2) (3)
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Camber and Caster
1. Separate camber
adjustment
Shock
absorber
Steering knuckle
movement
absorber
Adjusting bolt
Lower arm
Front view
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Camber and Caster
2. Separate caster
adjustment
Adjusting nut or spacer
Strut bar bracket
Strut bar
L
Lower arm
Movement of lower ball joint center
when strut bar length is changed

Top view
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Camber and Caster
3. Simultaneous
camber and
caster
adjustment
(1) (3)
Movement of
lower ball joint
center when
center of lower
Lower arm
Upper arm
Front shims
arm is shifted by
turning of cam
Top view
Adj ti
Front

shims
Rear shims
Upper arm
Adj
us
ti
ng cam

Upper

arm

shaft
Frame
Adjusting cam
Lower arm
Movement of upper ball joint
center when number or rear
(2)
Lower

arm
Front
center

when

number

or

rear

shims is increased or decreased
Movement of upper ball joint
center when number or front
shims is increased or decreased
Movement of ball

j
oint center
j
when number or front and rear
shims is increased or decreased
simultaneously
(1/1)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Example of Camber and Caster
Adjustment
Camber
Left-ri
g
ht error
Standard values
-0° 20’ ± 45’
(-0.33°±
075
°
)
Measure values
-0° 10’
(+
016
°
)
g
Caster
Left-right error

0
.
75
)
30’ (0.5°) or
less
3° 20’ ± 45’
(3.33°±
0.75°)
30’ (0.5°) or
less
0
.
16
°
)
+4° 20’
(+
4.33°)
Gauge
Alignment
tester
(1/2)
Diagnosis Technician >> Suspension and Steering >> Wheel Alignment
Front Wheel Alignment Service
Example of Camber and Caster
Adjustment
Front cam
graduation
+(Longer)

Camber
Caster
-(Shorter)
Front cam
graduation
(L )
Camber
Rear
cam
2.2 Front cam
-(Shorter)
+
(L
onger
)
Front cam : (Longer) 1.8
Rear cam :
(Shorter) 2.2
Front and rear cams
Front
Front cam Front cam
(Longer)
(Shorter)
(Longer)
Rear cam Rear cam
(2/2)
(Shorter)
(Longer)
(Shorter)