Hitachi ZW180 Technical Manual page 70

Manual Speed Shift Control
Purpose: To shift the speed manually
Operation:
1. When manual (M) of the travel mode switch is
selected, MC is provided with voltage of 1V.
2. The manual speed shift program is started in MC.
3. The shift switch is a rotary type and has two
switches inside. When one of a speed among
speed 1 through speed 4 is selected, the signal of
the selected shift position is transmitted to MC
according to the combination of ON of the shift
switches.
Speed
Speed Shift
Internal Switch
1
Internal Switch
2
4. MC transmits the signal to the speed shift solenoid
valve for the selected speed.
5. If forward or reverse of the FNR lever or the FNR
switch is selected, traveling is started when the
accelerator pedal is depressed.
6. When the vehicle speed reaches the set speed for
the selected speed shift, MC transmits the signal
to the speed shift solenoid valve for the selected
speed.
SYSTEM / Control System
Speed Speed
1 2 3
ON
ON
NOTE: MC is programmed in order to dtermine the
NOTE: When the shift switch is turned from speed
NOTE: In case a malfunction occurs in either so-
Speed
4
ON
ON
NOTE: In case the speed shift is raised, the se-
NOTE: The shift switch has two switches, and the
NOTE: The FNR switch does not transmit the neu-
NOTE: Each mode switch of the travel mode switch
NOTE: The speed shift selected by the shift
T2-1-28
vehicle speed ranges to change to the re-
spective speed shifts.
3 to speed 1 while traveling, the vehicle
automatically shifts down to speed 2, and
then shifts down to speed 1 after the vehicle
speed becomes the range of speed 1.
lenoid valve of speed 1, speed 3, or speed
4, the vehicle speed is fixed at speed 2. In
case a malfunction occurs in either the
forward clutch solenoid valve or reverse
clutch solenoid valve, or speed 2 solenoid
valve, only the abnormal one cannot be
used.
lected speed shift is immediately obtained
regardless of the vehicle speed.
combination of their ON varies depending
on each speed shift. The controller judges
which speed shift has been selected by the
combination of the two input signals.
tral signal. In case of no electric current
from the FNR switch, the controller judges
that the switch is neutral (N).
is supplied with respectively different volt-
ages from the monitor unit, and if a switch is
selected, MC judges which mode has been
selected.
switch is the highest speed shift.