Launch X-712, Руководство пользователя

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LAUNCH X-712 Wheel Aligner Introduction
1-2
Fig.1.3
Correct steering axle inclination can equalize the loads
applied on bearings so that the life of bearings can be
prolonged and the controllability of steering is improved.
Without the inclination, the controllability of the steering
may be affected; further more, the vehicle weight and
the ground counterforce may cause significant stress in
the axle and finally damage the axle.
Correct inclination of king pin is also helpful for the
vehicle to restore its straight-ahead position after
steering.
Steering axle inclination is determined when the vehicle
suspension is designed. It is not service adjustable.
Caster
Caster is the tilting of the kingpin either forwards or
backwards from vertical, as viewed from side of the
vehicle. See Fig.1.4
Fig.1.4
When the king pin is tilted backwards from the vertical,
caster is positive. When the king pin is tilted forwards,
caster is negative.
Caster angle influences the directional stability of the
steering. To increase the tendency of the steering to
self-centre, the steering will normally be designed with
positive caster.
Toe-out on Turns
Toe-out on turns is defined as the difference of the
steering angle between the two front wheels when
turning left or right by 20
°
as shown in Figure 1.5. The
inner wheel will turn more degrees than the outer wheel
when the vehicle is steered, the difference is usually
about 2
°
. This angle is designed to reduce steering
resistance.
Fig.1.5
Note: This angle can be tested when a turntable is
equipped for X-712.
Thrust angle
The trust angle is defined according to the driven mode
of vehicle.
z Rear wheel driven: the thrust angle equals half of
the toe-in difference between the two rear wheels.
As shown in Fig.1.6.
z Front wheel driven: the thrust angle equals half of
the toe-in difference between the two front wheels.
z
Four-wheel driven: the thrust angle equals half of
the toe-in difference between the two front wheels
plus half of the toe-in difference between the two
rear wheels.
The trust angle is defined as positive when the trust line
is towards left, and negative when the line is towards
right.
If the thrust angle is not zero, the vehicle will have the
side-moving trend. In this case, adjust the front toe-in of
the drive wheels first, and then adjust the toe-in of driven
wheels.