SANY LATIN AMERICA
4-61
SY195/205/215/225C9 Crawler Hydraulic Excavator
Structure and Function
Shop Manual - June 2013
4.5.2.7 Option
Option spool is used to control optional work equipment attachment.
[Pilot circuit]
●
When the option spool (309) is switched,
the side path is closed and pressure at port
Px (work equipment signal port) rises.
[Main circuit]
●
When option is operated, pilot pressure
oil is supplied into port XAo (or XBo) and
option spool (309) is switched. Working
oil from port P2 is introduced into neutral
bypass (2) via main passage (3). Neutral
bypass is cut off by switching option spool
(309). Therefore, working oil in the parallel
passage pushes open the cone valve (511)
of the check valve, and
fl
ows into the op-
tion spool (309) via the U passage. Then,
it flows into the periphery of option spool
(309) and is supplied into the optional
equipment via port Ao (or Bo).
●
On the other hand, return oil from the op-
tional equipment flows in via port Bo (or
port Ao). Then, it
fl
ows into tank port (R1)
via the spool periphery and returns to the
working oil tank.
(2) Option confl uence
●
To achieve option confluence, pilot pres-
sure oil is supplied into port XBp1 and the
bypass cutoff valve spool (310) is switched.
Working oil from port P1 is introduced into
neutral bypass (2) via main passage (1).
Neutral bypass is cut off by switching by-
pass valve spool (310). Therefore, work-
ing oil pushes open the cone valve (514)
of check valve, and converges with option
spool (309) via the inside path and the U
passage.
(1) Operation
XAo
XBo
Ao
Bo
ZX225-1102022
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