Launch X-631 Plus - Introduction; Definition; When Is Wheel Alignment Required; Main Vehicle Alignment Parameter

LAUNCH X-631/ X-631+ Wheel Aligner Introduction
1-1
Introduction
Thank you for using X-631/X-631+ wheel aligner
manufactured by Launch Tech Co., Ltd.
Definition
X-631/X-631+ CCD wheel aligner adopts the charge
coupled device (CCD) with high resolution, the
clinometer with high precision and the accurate optics
imaging system.
X-631/X-631+ is a device designed to measure the
wheel alignment parameters and compare them with
the specifications provided by vehicle manufacturer. It
also gives instructions to the user for performing
corresponding adjustments so as to get the best
steering performance and reduce tire wear.
The wheel aligner compares the measured results
with the original data of vehicle manufacturer and
gives instruction to the user for adjustment, so its
databank should contain enough information.
X-631/X-631+ Wheel Aligner contains wheel
alignment databank of over 10,000 vehicle types all
over the world. User can also add new vehicle wheel
alignment data in the databank when necessary.
When Is Wheel Alignment
Required
z The driver has to firmly hold the steering wheel
to maintain a straight-ahead driving.
z Abnormal wear of tires occurs, such as single
side wear, concave-convexity wear and
featheriness wear.
z Too heavy or too light steering, or shaking at
high-speed driving.
z When the tire(s), steering knuckle or shock
absorber are replaced.
z When the vehicle is impacted.
z When the vehicle has covered the first 3000km
or 10000km.
Main Vehicle Alignment
Parameter
The wheel alignment mainly consists of camber,
toe-in, kingpin inclination, caster, etc. They are
designed mainly to improve the steering performance
and driving stability of the vehicle, and reduce tire
wear.
Camber
Camber is the leaning of the wheel inwards or
outwards from the vertical.
If the road wheel leans outwards from the vertical, it
has positive camber and when leaning inwards from
the vertical - negative camber, looking from the front
or rear of the vehicle. See Fig.1.1.
Fig.1.1
Camber is measured in degrees.
Toe-in and Toe-out
The toe setting is the amount by which the front or
rear wheels point inwards or outwards at the front of
the wheel in relation to each other (see Fig.1.2).
When the wheels point inwards they are said to toe-in.
Toe-in figures are given a positive value. Conversely
when the wheels point outwards they are toe-out and
the figures are shown as a negative value.
Fig.1.2
The purpose of correct toe is to ensure that the
wheels run parallel when the vehicle is driving. An
incorrect toe setting may affect the stability and
controllability of the vehicle.
Kingpin Inclination (Steering Axle
Inclination SAI)
Kingpin Inclination (KPI or SAI) is the angle of
inclination of the king pin towards the centre-line of
the vehicle from the vertical (see Fig.1.3).