Toro 03781, Руководство по обслуживанию

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Reelmaster 7000−D Hydraulic System Page 5 − 23
Raise Cutting Units
A four section gear pump is coupled to the piston (trac-
tion) pump. Gear pump section P4 supplies hydraulic
flow to both the lift control manifold and the steering con-
trol valve. Hydraulic flow from this pump section is deliv-
ered to the circuits through a proportional flow divider
located in the fan control manifold. Maximum lift/lower
circuit pressure is limited to 1700 PSI (117 bar) by a relief
valve (RV1) in the lift control manifold. Lift circuit pres-
sure can be monitored at the test fitting in lift control
manifold port G.
A joystick (lower mow/raise control lever) on the console
arm is used to raise and lower the five (5) cutting units
(Fig. 15). The joystick acts as an input to the Toro Elec-
tronic Controller (TEC) which sends electrical outputs to
appropriate lift control manifold solenoid coils in order to
raise or lower the cutting units.
When the cutting units are in a stationary position (not
raising or lowering), lift circuit flow from gear pump sec-
tion P4 bypasses the lift cylinders through the lift control
manifold solenoid valve S1 (de−energized). Return flow
from the manifold is routed to the oil filter and traction
charge circuit.
Raise Cutting Units
NOTE: The operator must be in the operator seat in or-
der to raise the cutting units.
When the joystick is moved to the raise position, sole-
noid valve S1 along with solenoid valves S2, S3, S4 and
S5 are energized by the TEC. To allow the front cutting
units to be raised before the rear cutting units, the con-
troller slightly delays energizing solenoid S5 after the
joystick is moved to the raise position. The energized so-
lenoid valves direct gear pump oil flow to the rod end of
the lift cylinders. The flow to the front lift cylinders passes
through the piloted check valves and bypasses the first
set of control orifices. Hydraulic pressure causes the lift
cylinder shafts to retract, and raise the cutting units.
The return flow from the retracting front lift cylinders
passes through a second set of control orifices in the
junction manifold providing cylinder speed control while
raising the cutting units.
A flow control orifice in the lift control manifold (port C4)
controls the rear cutting unit raising speed by providing
a restriction for the return flow from the lift cylinders.
When the joystick is released, solenoid valves S1, S2,
S3, S4 and S5 are de−energized and the lift cylinders
and cutting units are held in position.
Figure 15
1. Console 2. Joystick
(lower mow/raise
control lever)
1
2
MODEL 03780 SHOWN
Figure 16
CUTTING UNIT LOCATIONS
#4 #1 #5
#3 #2
Hydraulic
System