Table of Contents
Advertisement
14-38
FUEL
SYSTEM
-
Crui~.
COI'II.ol
System
ACTUATOR OPfRATION
The
negative pressure
~noe
ot
the
YOICUUm
pump
,1"1(1
negative
pr1I55Uf'"
chamber
oi
the
actuator ar'"
<:Onne<:1ed
by
the
YM:(JIKl1
ho$ll,
The
DC
moto<.
control
yelve 800
rel8ase
....
lve
in the
motm..driven
vacuum
pUmp
85sembly
~r6
turned ON or
OFF
by
the
control
signa
l
from
th'"
control
unit
and
have
the following
operation
modes.
ACCELERATION
MODE
Current
'Iows
1
0
the
DC
motor.
control
yalve and
release
valve.
The
vacuum pump
1
$
QP&fated
by
Ih$
DC
motor.
the COOlroi
valve
and
release
yalve
are clo$lld
end
the
n&galrYu
hne
..
cut
off from
!he
"
molpher
•.
The
negative
pressure
generated
by
the
v8CtJum
pI.lmp
is
used in the
negative
press",",
chember of
the
Bctuator
8nd
the
diaphregm movfld
in
the
dir8Ctioil to
pull
Ihe
cruise
con
trOl
etlble
to
open
the
throttle
valve
and
lICeeleme
ths v&/1
icle.
HOLD MODE
No c ..
menl flows
10
the DC
mOlor
blll
current
Uows
to the
control valve
and rele3M1
Y81ve.
Since the VllCuum pump
does
not
eperale.
no
negative
preS$ln is
added;
slftce
both
the
CO<ltro!
valve
arid
relene valve are
clond
8M \tie
-
Oper.tior1
"""
negative
pre$sure line
is
cut
0
11
from the
atmO$phere.
negatiwo
pressure
..
not
redoced
.
Con s.eQuen tJv. Itle
diaphr
allm
does not
lunctoo
and the
II\rOt~fI
V8Ml
is
held in
a fixed
position.
DECELERATION MODE
No
current
flows
to
the
DC
mOtOr
end
co ntrol
velve
~
cu
rrent
flows
to
the
relHSf!
v.lve.
Since
the cont.oI
valve is
OFF.
thl
line
hole
in
the
control
valve
core
is
open.
air
flowa
to
the
act
.....
tor
negative
pr6SSlA"ll
chamber
and negatille
pressure
lS
fe<ktce<l.
The
diaphragm
is
returned
by
the
force of
Ihe
rerum
spr;ng
to
loosen
the cruise
control
~ble
to
close
tile
thlCl\lle
v.IWI
and
decelerate
th
B
vehicle
speed.
RELEASE MODE
No currenl flows in
the
DC motor,
CClnl
rol
valve
and rel&il$e
yalve.
The
line
holes
in the
.elease
VlIlve COle
and coollol valve
core
are open
and
ail"
flow$
InlO
the
flIIQiI\ive
pressure chamber
of
tI>e
act
.....
tOl
.
As a
result,
the
dlaphragm is
returned
quickly
by lIle force
of
the relum
$priog to
lhe
initial
condition.
the throttle vel'v$ ml)Vfl in
the
closing dirflction and
t
he cr
uise
control
i!
car.c.led.
t.4oKlr-d
.......
~
SoJllrOd~
puI"IlllOC mota<!
ON
:
0Clsed
OFF:
Open
O~:C
.... rem
flow.
CClntrol
".I~.
A,,"se'ill"'"
OFF:No
cutren!
flow.
Accoleratton
ON
0'
0'
IPUlU
Hold
/HOl
O)
0"
0'
ON
Deceletlllton
0"
""
ON
!RELEASE!
""'"
""
""
0"
(CANCEU
Advertisement
Chapters
Table of Contents
