Nilfisk-Advance 56110000, Руководство по обслуживанию

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80 - FORM NO. 56043124 - Condor XL
™
HYDRAULIC SYSTEM
SCRUB LIFT CYLINDER OVERVIEW
The scrub lift cylinder is controlled by two proportioning hydraulic valves that work together, on opposite ends of the lift cylinder, to produce the
desired main scrub deck pressure. (Reference Hydraulic Schematic in Appendix).

The lift pressure (scrub pressure up) is controlled by Proportioning Valve S7 which gets its signal from pin J2-24 on the Driver Box.

The down pressure (scrub pressure down) is controlled by Proportioning Valve S5 which gets its signal from pin J2-26 on the Driver Box.
The Driver Box signals are pulse width modulated (PWM) signals (voltages) which open the valves proportionally to produce the appropriate hydrau-
lic pressures on both the piston and rod ends of the scrub lift cylinder. This combination of up and down forces on the lift cylinder applies the correct
amount of downward force to the main scrub deck to produce the desired scrub pressure.
Note that the signals to the valves allow the valves to “dither” (oscillate in a slight back-and-forth motion) (high frequency) to prevent the valves from
sticking.
The table below shows the hydraulic pressures to the Valves and the solenoid coil current draws at the three scrub pressures.
Proportioning
Valve
Pressure
Type
Scrub
Pressure
Setting
Hydraulic Pres-
sure at Test Port
TP4
Valve Solenoid Coil
Current Draw
S7
Scrub
Pressure
Up
1 750 to 774 psi
1.45 to 1.75 amps
(all three scrub pres-
sure settings)
2 750 to 767 psi
3 745 to 779 psi
Proportioning
Valve
Pressure
Type
Scrub
Pressure
Setting
Hydraulic Pres-
sure at Test Port
TP5
Valve Solenoid Coil
Current Draw
S5
Scrub
Pressure
Down
1 333 to 346 psi
1.38 - 1.75 amps
(varies with scrub set-
ting selected)
2 393 to 412 psi
3 458 to 499 psi