TIGIEFFE AIRO A Series, Use And Maintenance Manual

Page: 76 / 130

Use and Maintenance Manual – A16 J A18 J Series Page 76
7.2.10. Operation check and adjustment of the braking valves
These valves check the minimum operating pressure during
drive (in both running directions) and affect the dynamic
braking and the drive speed. Normally, these valves do not
require any adjustment, since they are calibrated at the factory
before the machine is delivered.
The braking valves stop the machine when the drive controls
are released. Once the machine has stopped, the parking
brakes automatically come on, thus keeping the machine in
position.
Check operation at least once a year.
To check the operation of the braking system:
▪
With platform completely lowered place the machine
on a flat ground, free of obstacles, operate the drive
control and when the max. speed is reached, release
the control immediately.
▪ The correct operation of the braking system allows
the machine to stop within a distance lower than 70
cm.
Fig. 28
▪
In any case the braking system can stop and keep the machine on slopes as indicated in "Technical features " (the
braking distance on descents is longer; drive downwards at the min. drive speed).
Calibration of both braking valves is required:
▪
In case of replacement of the hydraulic unit A .
▪
In case of replacement of one or both braking valves C (in a few cases only one valve is fitted).
To calibrate the braking valves:
▪
Locate the hydraulic unit (or the units) A called "drive plate".
▪
Locate the braking valves B (one for each running direction).
▪ Introduce a pressure gauge with full scale of at least 250 bar in the special quick coupling of hydraulic control unit (1/4”
BSP).
▪
On the platform control panel select the minimum drive speed.
▪ Unscrew the lock-nuts C of the adjusting dowels.
▪ Using the platform control panel drive the machine (in the direction controlled by the valve) on a flat ground in
straightforward direction and adjust the braking valve (relevant to that running direction) by means of adjusting dowel D
so as to achieve the required pressure value (call the nearest Service Centre to ask for the exact value).
▪ Once the required pressure value has been achieved, check that the valve controlling the braking in the opposite
direction has maintained its adjustment (if present – in a few cases only one valve is fitted)
▪ Once adjustments are complete (pressure values in the two directions must not vary by more than ±5 bar), lock the
adjusting dowel by means of the lock-nut.
WARNING!
AS THIS OPERATION IS VERY IMPORTANT IT IS TO BE CARRIED OUT BY SKILLED TECHNICIANS
ONLY.