Honda Civic Service Manual page 1077

t
To STEERING GEARBOX
To STEERING GEAREOx
@ The fluid volume that flows thorough oil passage A
and the pressure djfference applied to the sub-valve
i n c r e a s e i n p r o p o r t i o n t o t h e e n g i n e s p e e d . T h e
sub-valve lowers overcoming the spring force, and
it stans to close the variable orifice to regulate the
discharge volume, When this happens, the fluid vol-
ume flowing to the steering gearbox decreases as
the engine speed increases. At the same time, the
flow control valve continues to control the fluid vol-
ume to the return Port,
@ As the engine speed increases funher, the pressure
difference at the sub-valve increases further as well.
The sub-valve then closes the variable orifice com-
p l e t e l y , r e g u l a t i n g t h e d i s c h a r g e v o l u m e f u r t h e r .
W h e n t h i s h a p p e n s , t h e f l u i d v o l u m e d i s c h a r g e d
from the pump to the steering gearbox is regulated
a n d m a i n t a i n e d a t a g i v e n l e v e l u n t i l t h e e n g i n e
speed reaches the high speed range The flow con-
trol valve functions continues to control the fluid
volume to the return Port.
Pressure Relief
P r e s s u r e a t t h e d i s c h a r g e s i d e o f t h e f i x e d o r i f i c e i s
directed to the bottom of the flow control valve. When
the pressure builds up, the relief valve in the flow con-
trol valve opens to release the pressure at the bottom of
t h e v a l v e . T h i s a l l o w s t h e f l o w c o n t r o l v a l v e t o b e
pushed back by the pressure difference, and the fluid
volume to the pump return port increases.
As explained above. the system keeps the pump dis-
c h a r g e p r e s s u r e ( r e l i e f p r e s s u r e ) f r o m e x c e e d i n g t h e
given level by controlling the volume of the fluid to the
pump relurn pon,
1 . ,
DAMPING ORIFICE
{Docreases excessiv€
vibration in the valv6.)
1 7- 19
)
RELIEF VALVE {Opan)
SUB.VALVE
FLOW CONTROL VALVE
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o'.'to"5lo'#2"n af
1 1 \ D 7
FLOW CONTROL VALVE