9
LF45/55 series
General
SHOCK ABSORBERS
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1. GENERAL
1.1 OPERATION OF SHOCK ABSORBER
The function of the shock absorber is twofold:
-
to control the movements of chassis and
superstructure in relation to the axle.
Optimum comfort is achieved when the
chassis and superstructure remain truly
horizontal and are not subjected to any
vertical accelerations when moving;
-
to control the movements of the wheels on
the road. Optimum handling is achieved
when all wheels remain in constant contact
with the road surface.
The rate of the above-mentioned movements
depends on the available spring travel. The
available spring travel is the difference in height
between an unloaded spring and a fully loaded
spring.
A well-functioning shock absorber with
characteristics appropriate to the operating
conditions will be the best possible compromise
to fulfil the above-mentioned functions.
DAF only uses double acting type shock
absorbers.
On vehicles with air suspension, hydraulic stroke
limitation is used.
The shock absorber consists of:
-
an operating cylinder, in which the actual
damping is done by a piston with piston rod
of which the valve unit damps the rebound
stroke;
-
a bottom valve which, in combination with
the piston valve unit, damps the bump
stroke.
-
a reservoir tube which draws in oil surplus
(result of the volume taken up by the piston
rod) via the bottom valve;
-
a dust cover, attached to the piston rod.
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