1990 MITSUBISHI ECLIPSE cruise control

Y 5-FUEL SYSTEM
- Auto-cruise Control System14-71ACTUATOR CONSTRUCTION
The actuator unit consists of a DC motor, a worm
gear, a worm wheel, a planetary pinion gear, a
magnetic clutch, and two limit switches.
The magnetic clutch consists of a magnetic coil
mounted to the actuator case and a clutch plate
connected to the ring gear of the planetary wheel
gear by a spring.The magnetic clutch is energized and deenergized
by the control signal supplied by the control unit.
The clutch transmits the rotation of the DC motor to
the selector drive shaft, and allows the selector
drive shaft to rotate freely with the ring gear
regardless of whether the DC motor is being
energized or not.
Internal construction
Clutch plate
Maanetic clutch coilI ^. ,Planetan/ pinionCircuit diagram
MAIN switch
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Auto-cruise control unit
7S&&or drive shaft
Worm gear03R0077
Cross-section of actuator installation
Actuator bracket

14-72
._FUEL SYSTEM
- Auto-cruise Control System
___ -ACTUATOR OPERATION
IF SET TO A FIXED SPEED
When the SET switch is set to the ON position, the
control unit causes current to flow to the actuator’s
electromagnetic clutch coil; the clutch plate is then
attracted, the ring gear of the planetary gear is
secured, and, at the same time, the path from the
ECU to the DC motor becomes conductive and the
DC motor begins to rotate at high speed.As shown in the illustration, the rotation of the DC
motor is transmitted to the worm gear
--, worm
wheel, sun gear (unified)
+ planetary pinion.
Because the ring gear is fixed at this time, the
planetary pinion revolves while rotating around the
sun gear, and, because the planetary pinions are
installed to the carrier, the carrier and the unifiedselectcr drive shaft and selector rotate.
Clutch plate
<
7 Limit switch
DC motorSelector
Magnetic clutch coil Magnetic clutch coil
Selector diive shaft
MAIN switchTrl
4sTn
aAuto-cruise control
unit07AOO11The selection of the direction (PULL or RELEASE) of the
selector rotation is performed by the reversal of the direction of
conductivity to the motor, and this is controlled by the ECU.
Current Flow in PULL Rotation
.(soiid-line arrows)
The control unit microcomputer output causes transistors
Tr,and Tr, to be turned ON. Then, current flows from transistor
Tr,to DC motor,‘transistor
Tr,, and ground. As a result, the DC
motor rotates in the PULL direction.
Current Flow in RELEASE Rotation (dotted-line arrows)
Microcomputer output causes transistors
Tr2 and Tr3 to be
turned ON. Then, current flows from transistor
Tr3 to DC
motor, transistor
Tr2, and ground, resulting in the DC motor
rotating in the RELEASE direction.
The electromagnetic clutch is controlled by the MAIN and
CANCEL switches. When the MAIN switch is in the
01\L.position, it keeps the clutch plate attracted under norm
conditions (i.e. where there is no cancel condition).

FUEL SYSTEM -Auto-cruise Control System14-73IF MAIN SWITCH
IS SWITCHED OFF
‘*‘hen the driver switches OFF the MAIN switch,
Jconductivity to the electromagnetic clutch is
interrupted, the clutch plate is returned from the
electromagnetic clutch side to the ring gear side by
the spring, thus freeing the spring.
When the ring gear becomes free, the planetary
pinion, carrier, selector drive shaft and selectorbecome free relative to the sun gear (DC motor),
and the selector is returned to the original position
by the return spring installed to the selector.
The planetary pinions
turn on their own axes while
rotating around the sun gear because of the rotation
of the carrier. As a result, the ring gear idles. All this
results in the cruise control being canceled.
DCSelector drive shaft
IF CANCEL SWITCH IS SWITCHED ON
IBattery
IIIIgnition switch 411IInhibitor switch
f’ J
r--
if-Starterz _Auto-cruise
f
AA)\AA
5V
pF p
+ i%zv)
5-VComl
Cancel interface circuit
bs- Tts ec
I
r-
[ON
NC: Normally closed
NO: Normally opened
‘OFF OFF
IMicrocomputer

14-74
_ ,.-..FUEL SYSTEM
- Auto-cruise Control System
When Canceled by the Stop Light Switch (broad
solid-line arrows)
The stop light switch is a four-pole type that
integrates the switch for the stop light (NO) with
that for the auto-cruise control (NC).
When the brake pedal is depressed, the contacts forthe auto-cruise control (NC) open, cutting off the
circuit to energize the electromagnetic clutch coil.
At the same time, the contacts for the stop light
(NO) close to allow a cancel signal to be input from
the
12-V power supply of the control unit to the
cancel circuit and to the microcomputer. As a result,the transistor which energizes the actuator electro-
magnetic clutch coil turns OFF and the electro-
magnetic clutch coil grounding circuit is cut off, thus
canceling the auto-cruise control mode.
When Canceled by the Clutch Switch (thin
solid-line arrows)
When the clutch pedal is depressed, the clutch
switch is turned ON and the battery voltage is
applied to the cancel circuit of the control unit. then,a cancel signal is input to the microcomputer.
causing the transistor that energizes the actuator
electromagnetic clutch coil to turn OFF. This results
in the electromagnetic clutch coil grounding circuit
bma$ndge cut off, which cancels the auto-cruise control
When Canceled by the Selector Lever (position“N”) (dotted-line arrows)
When the transaxle control selector lever is placed
in the “N” (neutral) position, the inhibitor switch is
turned ON and, as a result, current flows from the
control unit to the inhibitor switch, starter, and
ground. Then, a cancel signal is input from the
cancel circuit to the control unit, causing the
transistor which energizes the actuator electro-
magnetic clutch coil to be turned OFF. As a result,
the electromagnetic clutch coil grounding circuit is
cut off and the auto-cruise control mode is canceled.Although a small current (voltage 5 V) flows through
the starter, it is not activated.
MAIN switchLIMIT SWITCH
The function of the limit switch is to shut off the flow of current
to the motor and apply an electric brake to quickly stop the
motor if the throttle valve becomes either fully open or fully
closed, thus preventing problems which might be caused by an
overload of the motor.
The illustration at left shows the condition of the limit switch
when the throttle valve is fully closed, indicating that
.limitswitch
(1) is in the OFF and the RELEASE circuit is being
deenergized.
IAutocruisecontrol unit
07Aool'
.-

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FUEL SYSTEM- Auto-cruise Control System14-75INTERMEDIATE LINKS
Intermediate
iink A(accelerator pedal side)Accelerator cable
A
(accelerator pedal side)
03AO224During Auto-cruise Control Driving
The rotation of the selector causes intermediate link
B to turn
which opens and closes the throttle valve. However, intermedi-
ate link A is not operated and accelerator cable A does not
move, so the accelerator pedal remains stationary in its original
position.During Normal Driving
When the accelerator pedal is operated, the rotation of
intermediate link A, which is connected to accelerator cable A
(accelerator pedal side), causes intermediate link
B to turn, and
accelerator cable
B, which is connected to intermediate link B,then opens and closes the throttle valve.
N
0
s -?s
*=Auto-cruise
control unit
13AOO62Vehicle speed
sensor07Aml
VEHICLE SPEED SENSORThe vehicle speed sensor functions to send pulse signals
[which are proportional to the rotation speed (vehicle speed) of
the transaxle’s output gear] to the control unit. The vehicle
speed sensor is installed within the speedometer.
The vehicle speed sensor is the reed switch type; it generates
four pulse signals for each rotation of the output gear. This
sensor is also used in common for other electronic control
systems.

- -----.--..
14-76FUEL SYSTEM -Auto-cruise Control System
Ignition switch
IGI
9
RESUActuator electro-
Microcomputer
1 T 1
rn’Auto-cruise control unit
Autocruisecontrol switch
IGlMAIN
;FF -+++&Control unit
power supply
terminal voltage
03AO264NC: Normally closed
07*0040
AUTO-CRUISE CONTROL SWITCH
The auto-cruise control switch is built into the steering column
switch.MAIN SWITCH
The MAIN switch is an automatic reset type switch to turn ON
and OFF the power supply of the control unit.
COMMAND INPUT SWITCHES (SET and RESUME)
The SET and RESUME switches function to input the control
signals of the auto-cruise control system; both are the
automatic-reset type.
These switches are ON while pressed and OFF when released.
For the ECU’s input interface, each of the input terminals is
pulled up by the battery voltage; the terminal voltage is LOW
level
(OV) when the switch is ON, and is HIGH level (about 12V)when the switch is OFF. These voltage changes (digital
sig*)are input to the microcomputer as ON and OFF signals
o.:
switches.
.

-- --.-*-.e *._,_-.&” :,.>~‘c,-.y~~ 7, . . --
FUEL SYSTEM- Auto-cruise Control System14-77
(For stop light)
OFF +-ON
0N -+-OFF
(For auto-cruise control)
16RO99r4 3
12
NCNO-w-w
I/0l-COFFOFF*~ON4
321NO: Normally opened
NC: Normally closed
07AOOl:
CANCEL SWITCHESThe cancel switches consist of the stop light switch, the clutch
switch, and the inhibitor switch
(“N” position).
The auto-cruise control operation is canceled if any one ofthese switches functions.
STOP LIGHT SWITCH
The stop light switch is a four-pin type of stop light switch thatcombines the switch for the stop light (NO) and the switch for
the auto-cruise control
(NC).When the brake pedal is depressed, the contacts for the
auto-cruise control (NC) open, the supply of current to the
actuator magnetic clutch is cut off, and the fixed-speed drivingmode is canceled.
At the Same time, the closure of the contacts for the stop lightcauses a cancel signal to be sent to the control unit, and within
the control unit the current supply to the actuator magnetic
clutch is stopped, thus causing the cancellation of the
fixed-speed driving mode.
CLUTCH SWITCH
The contacts of the clutch switch close when the clutch pedal
is depressed, with the result that the cancel signal is sent to
the control unit, thus canceling the fixed-speed driving mode.
INHIBITOR SWITCH
The inhibitor switch is a switch also used in eommon as the
switch for the starter.
If the selector lever is set to the “N” position during
fixed-speed driving, current flows from the control unit to the
inhibitor switch and then to the starter and to ground, with the
result that the cancel signal is input to the microcomputer and
the fixed-speed driving mode is canceled.