Takeuchi TB175W, Руководство по ремонту

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HYDRAULIC UNITS
CONTROL VALVES
IV-55
TB175W
OPERATION
When the Spool is in the Neutral Position
When the control valve spool is not moving, hydrau-
lic oil flows through the center bypass passage (1) and
then through the tank passage (T) in the arrow direc-
tion, returning to the tank.
When the Spool is Actuated
Explanation is given for the case where the spool is
moved to the right.
When the spool (2) is moved to the right, the center
bypass passage (3) is closed and hydraulic oil entering
from the pump passes through the load check valve
(5) from the parallel passage (4), flowing from the A
port to the actuator. On the other hand, oil returning
from the B port flows through the tank circuit (T) and
returns to the tank.
Load Check Valve
A load check valve (5) is included in each section
except the travel (right, left) sections.
This valve prevents oil from flowing backward due to
the load pressure (C) from the actuator port during
switching of the spool.