2-18
Boom up operation
P3
From P3 side bypass passage
To P3 side parallel passage
To P2 side parallel passage
P3
From P3 side bypass passage
To P1 side parallel passage
Oil flows into P2 side parallel passage and then
out of PTO bypass passage to tank passage
From P3 side bypass passage
Boom up
To P1 side parallel passage
To P2 side parallel passage
Connecting piston
P3
P3 side (Connecting side) circuit
T1
T2
P1
Boom
Boom lock
valve comp
P1
Dr1
To cylinder head side
via A9 port
To B8 port
via cylinder rod side
Oil flows into lock valve comp. and
then out of A9 port through lock valve
parallel passage
Spool changeover
direction
Bridge passage
B8
P1 side circuit
To bridge passage
in boom comp.
Pa8
Pa8
R35Z72MCV13