Kubota B2910, Workshop Manual

Page: 403 / 426

1-M2
B7800HSD (SUPPLEMENT), WSM HYDRAULIC SYSTEM
Q
Down
When the control lever is moved to “ DOWN ” position,
the spool (2) is moved to the right.
Oil in the hydraulic cylinder is forced out to the
transmission case through the T2 port by the weight of
the implement, causing the implement to lower.
Oil forced into the control valve (1) through the P port
and returns to the transmission case through the T1 port.
W1012863
Q
Slow Down (Quarter Inching Control)
When the hydraulic control lever (3) is set to “ SLOW
DOWN ” position ( B ), the spool (2) is slightly moved to the
right.
The oil forced into the control valve (1) from C port
flows to T2 port in response to the movement of the
hydraulic control lever (3).
Since the spool (2) is two stepped land spool, the oil
forced in the oil passage ( IC ) between the spool (2) and
the control valve body is throttled, and less quantity of
hydraulic oil flows from
C port, through this oil passage
( IC ), to T2 port.
At this time, the hydraulic control lever (3) enables to
control the valve easily in increments of approximately 1/
4 inches “
SLOW DOWN ” at the lower link end.
W1019937
(1) Control Valve
(2) Spool P: Pump Port
C: Cylinder Port
T
1
: Tank Port 1
T
2
: Tank Port 2
(1) Control Valve
(2) Spool
(3) Hydraulic Control Lever
P: Pump Port
C: Cylinder Port
T
1
: Tank Port 1
T
2
: Tank Port 2
A: Down
B: SLOW DOWN
C: SLOW UP
D: UP
N: NEUTRAL
IC: Oil Passage (Cylinder Side)
KiSC issued 09, 2007 A