Document 57.4402.9200 - 1
st
Edition 10/2006
INDEX
TELELIFT 3713 SX
INTRODUCTION
iv
retraction, attachment locking/unlocking, outriggers and
chassis sway function). In the head there is a pressure
relief valve set at 280 bar also serving as a safety valve
of the circuit which directly acts on the main line of the
hydraulic oil. Again in the input head of the main valve
there is a solenoid valve discharging the main flow
("deadman” function) which activates the movements
of the main valve only when its solenoid is energised.
When such solenoid is not energised all the flow from
the pump is discharged. In this specific version of the
machine, this solenoid valve is mainly used to stop
some movements of the machine when the stability
limits are reached, and also to completely deactivate
such functions when the relevant selector in the driving
place is turned to the "road" position. The solenoid valve
is activated by the "deadman" pushbuttons located on
the mechanical levers of the main valve.
By moving the main lever in the driving place to one side,
section 1 of the main valve directly delivers oil to the
oil-dynamic block (
) consisting of a 6-way/2-position
electrical switch block and 2 pressure relief valves (
).
These valves, calibrated at 295 bar, are mounted on the
lines controlling the rotation of the attachment holding
frame. When the coil of the electrical switch block is
energised by the activation of the pushbutton placed
at the top of the main lever in the cab,
the oil coming
from section 1 of the main valve is sent to the extension
cylinders (
6
) and (
8
) of the telescopic boom, connected
in series with each other. Cylinder (
6
), which activates
the second telescope of the boom, is equipped with a
double-acting compensation valve (
5
) serving also as
a safety valve, while cylinder (
8
), which activates the
third telescope of the boom, is equipped with a single-
acting compensation valve (
7
) again serving also as a
safety valve.
When the coil of the electrical switch block is not
energised, oil is sent to the attachment holding frame
cylinder (
4
) of the telescopic boom. This cylinder is
equipped with a double-acting compensation valve (
)
serving also as a safety valve. Parallel to this cylinder,
there is the fork levelling compensation cylinder (
)
(also called balancing cylinder) which is equipped with
a special double-acting compensation valve (
1
).Inside
this valve, the one-way valves are mounted in reversed
manner with respect to the normal position to avoid the
pressurisation of the cylinder when the rotation control
of the attachment holding frame is activated. Again
inside this valve, there are other two one-way valves
(
0
), set at 5 bar, serving as anti-cavitation check valves.
These valves deliver oil, taken from the low-pressure
line of the transmission pump (
), to the fork levelling
compensation circuit when needed. The two pressure
relief valves (
) set at 295 bar and mounted in the oil-
dynamic block (
), protect the automatic fork levelling
Summary of Contents for Telelift 3713 SX
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