HYDRAULIC
Hydraulic Circuits
88
M2.0-1055-008
Tilt Down Circuit
Pressing on the bottom part of the multitask handle
thumb ball closes TDS, (Tilt Down Switch). Refer to
Figure 15982. When Tilt Down is selected, SVTE will
energize and shift fully. SPA will be ramped open to the
point required for tilt speed, and the pump motor will be
ramped up to the rpm required for tilt speed.
The oil flow supplied by P1 will flow across SVTE and
up to CBVR. In order for a double acting circuit such as
Tilt to operate correctly, there needs to be a path to al-
low oil in the other side of the circuit to move.
CBVE and CBVR are "load holding" counter balance
valves which allow oil flow in the Tilt circuit but control
overrunning load conditions and drift. This simply
means the CBVE and CBVR use pressure differentials
to make sure Tilt doesn't move any further or faster
than what is commanded regardless of the load on the
forks.
Each counterbalance valve contains a check portion
and a load holding or blocking portion. The valve will
allow "free flow" when the direction of oil flow is such
that it is able to move the check portion of the valve. If
oil is "free flowing" through the check portion of CBVR,
the load holding portion of CBVE will act as a blocking
valve. This blocking portion of the valve needs to be
opened far enough to allow the tilt function to operate
in response to demand without overrunning that de-
mand.
Figure 15982
1 Tilt Cylinders
Suction
Return
Relief
Pressure
Crown 2007 PF15675-8
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