1990 MITSUBISHI ECLIPSE clutch

/gi--__ .--.-9
Reducingvalve
To kickdown
servo via 1 - 2
shift valveLine pressureAUTOMATIC TRANSAXLE
- Transaxle Control21-69
PRESSURE CONTROL VALVE, SOLENOID
-_ VALVE AND N-R CONTROL VALVE
: Pressure Control Valve
: This valve regulates the pressure supplied to each
clutch under the control of the pressure control
j.. solenoid<,A ,valve to eliminate shock at the time ofPressure Control Solenoid Valve
This valve has its duty controlled by the transaxlecontrol unit command. It changes an electric com-
mand to corresponding hydraulic pressure.
N-R Control Valve
This valve prevents shock from occurring when the
select lever is shifted from “N” to
“R” (or from “P”
to
“R”) by controlling the oil pressure applied to the
low-reverse brake..Stopping (Selector lever in
“D” or “2”)
‘r) obtain adequate creep force when stopping, the
is kept in
2nd gear by directing the
to the rear clutch and the kickdown brake.
purpose, the pressure acting on the
=nnm is adjusted by the following method
- .--v.._ _ _ __ --Tan that it would be when driving in
..d gear.
he nrennurecontrol solenoid valve is duty control-
..s,. ..Jtransaxle control unit so that the No.231..a
pressure will be lower than the No.23
fine
bressure (reducing pressure). As a result, the
level lower ttlpressure control valve moves to the left under the
line pressure which acts on the difference in area
between the pressure control valve
# 1 and #2lands and the reducing pressure which acts on the
difference in area between the
#2 and #3 lands,
thus closing the No. 5 port by its
#2 land. This
reduces the No. 10 port pressure and the pressure
control valve is moved to the right by the spring
force. Through the No.5 port thus opened, the line
pressure is directed to the kickdown servo. The
pressure applied to the kickdown servo is adjusted
by the above-mentioned sequence.
-

AUTOMATIC TRANSAXLE - Transaxle Control21-71
‘ift (Selector Lever in “D” or “2”)
ReducingLine
ipressureTo kickdown servo
or from clutch
via3H
l-r
I
1 - 2 shift valve
Line pressure
Ext 1II ”i1
Reducingpressure
N-R control,,
II& Pressure control
solenoid valve
b-l
To ensure a smooth gear change when upshifting
:from 1st to 2nd, 2nd to 3rd. etc., the transaxle
lcontrol unit controls the duty of the pressure control
z$olenoid valve in order to regulate the control‘pressure established in the
#23b line which gov-
‘ems the operationof the pressure control valve. The
Jlne pressure that flows from the No.5 port to the
No. 10 port is regulated in this way.
-
i& all upshifts are controlied in a similar manner. the
icontrol for the upshift from 1st to 2nd gear will be
explained as an example.
The state of the hydraulic line in the
1st gear
condition is as mentioned on the previous page.
Ifthe transaxle control unit gives order that an upshift
from the
1st to the 2nd gear be initiated and the
duty of the pressure control solenoid valve
is‘usted accordingly, the No.23b line Pressure
is
-.dught higher than it is. in 1st gear. Then. the
pressure control valve moves to the right, opening
the No.5 port. Through the
No.5 port thus opened.
the line pressure from the No. 10 port is directed to
the kickdown servo via the l-2 shift valve. When
the line pressure is applied between the
# 1 and # 2
lands. of the rxessure control valve, the pressureDuty control
+OFF
1750097
effectively acts on an area equivalent to the differ-
ence in area between these two lands, and pushes
the valve to the left; the No. 5 port is closed by the
#2 land.
When the No. 5 port is closed, the No. 10 port
pressure decreases and, as a result, the valve
moves to the right. opening the No.5 port. Through
the No.5 port thus opened, line pressure is intro-
duced. By this sequence, the pressure directed to
the kickdown servo through the No. 10 port is
controlled. The No. 10 pressure is controlled by the
duty of the pressure control solenoid valve. That is.
if the duty is increased, the No.23b line pressure
which pushes the pressure control valve to the right
decreases and this causes a reduced No. 10 port
pressure.When the
1st to 2nd upshift is completed. the
pressure control solenoid valve is deactivated. In
this state, the No.23b line pressure level is equiva-
lent to that of the No.23 line and, therefore, the
pressure control valve is held pushed all the way to
the right. allowing the No.5 port line pressure to be
applied directly to the kickdown servo through the
No. 10 port and thus the kickdown brake is applied.

?
I
21-76AUTOMATIC TRANSAXLE - Transaxle Control
2-314-3 SHIFT VALVE
Rear clutchexhaust valve
Front clutchRear clutchKlckdown servo
release stdeKickdown servo
apply side
?I
l-2 shift
valve
control valve
_ To end- ciutch
valvet
Line pressure
1750238
II
i Line pressure1750105
To front clutch andI 1 kickdown servo 1 112 release side19n fln
IIT3rd
pressure
t- Line pressureThe
2-WI-3 shift valve operates in response to tine pressure
(3rd or 4th pressure) from the shift control valve, and controls
the pressure acting on the front and rear clutches, and also thekickdown servo release pressure.
Upshift from
2nd to 3rd Gear
When the 2-3/4-3 shift valve is free from hydraulic pressure.the valve is held pushed to the left by the spring force. In
thissituation. the No. 11 pan is closed, cutting off the line pressure
from the
1-2 shift valve. If the 3rd pressure is directed to the
2-3/4-3 shift valve through the No.7 line, the pressure forcesthe valve to the right, clearing the No.
11 port. This allows the
fine pressure from the l-2 shift valve to be directed via the
2-3/4-3 shift valve to the front clutch, kickdown sem(release
side), end clutch valve and rear clutch exhaust valve.

ir yAUTOMATIC TRANSAXLE
- Trahsaxle Control21-774th Gear
3rd GearRear clutchKickdown
1servo
release sideFront clutch
-
Rear clutch3rd1-2 shiftKickdown
Front clutch
q]b Ture,‘r z&eside
7
1750107
1Fromk-D3rd 14th pressure
control valve1 ;l;hiftpressure1750108
Upshift from
3rd to 4th Gear
.When the 4th pressure (line pressure) from the shift
control valve is directed to the rear clutch exhaust
valve through the No.8 line. the valve is pushed to
the right, closing the No.5c port. This cuts off the
pressure to the rear clutch and also releases the
pressure acting on the rear clutch through NO.
15port, No.20a port and No. 20
port.On the other hand, the rear clutch exhaust
valvewhich is pushed to the right opens the NO. 19
POnand directs the 4th pressure (line pressure) to the
right end of the
2-3/4-3 shift valve. The 3rdpressure (or the No.7 line pressure) is acting on theleft
end of the 2-3/4-3 shift valve. As this Pressure
..is equal to the No. 19 line pressure and acts on the
Mme area, the spring at the right end of the valveWhen the 4th pressure is released by the move-
ment of the shift control valve, the rear clutchDownshift from 4th to
3rd Gear
exhaust valve moves to the left, creating a
3rd gearstate, and the pressure is directed to the rear clutch.
At the same time as this happens, the 4th pressure
in No. 19 line which has been acting on the 2-3/4-3shift valve is released. This causes the
3rd pressure
established in the
No.7 line to push the 2-3/4-3shift valve to the right, and creates a 3rd gear state
where the line pressure from the
l-2 shift valve is
directed to the front clutch and the release side
chamber of kickdown servo cylinder through the
No. 12 line.shes the valve toward the
left. closing the No. 11me pressure port. This
btocks the pressure to the
front clutch and the release side chamber ofkickdown servo cylinder, and the pressure is re-
leased through the No. 12. and then the
No.9~ Pofi.

21-78AUTOMATIC TRANSAXLE - Transaxle Control
N-D CONTROL VALVE
.-.‘r
To rear clutch viarear clutch exhaust valve
N-Dcontrol
valve
EXpressure
Pressurecontrol
valve
t
Reducingpressure
t
Red”&pressure
175oz39
The purpose of this valve is to prevent shock from
occurring when shifting the select lever from “N” to
“D”. The valve supplies the rear clutch with the oilpressure regulated by the pressure control valve
only when the N-D shifting is being performed. After
the shifting is completed, the valve is switched over
to allow the line pressure to be supplied to the rear
clutch.
Selector Lever in ‘N”
When the manual valve is shifted to the “N” rangeposition, the line pressure from the oil pump is
directed to the N-D control valve through the No.4line. As the
#2 land has a slightly larger area to
which pressure is applied than that of the #3 land of
the N-D control valve, the movement of the valve
caused by the line pressure is toward the left, whichcloses the
No.5 port.

AUTOMATIC TRANSAXLE - Transaxle Control21-79
70 rear clutch via
rear clutch exhaustvalve
Frommanual valveOrifice
Line pressure From pressure
from manual
control valve
valve
175024
valveFrom manual
From pressure
valvecontrol valve175024Shift from “N” to
“D” .
When the manual valve is shifted from the “N” to the
“D”range position, the following sequence of events occur.
(1) The line pressure from the manual valve is distributed
through the No. 5 line to the NO. 5, NO. 5d and No. 5e lines ofthe N-D control
VdVe.
(2) The No.5 port is closed at this stage by the N-D control
valve.(3) There is a chamber with a check ball on the No.
5d line. Asthe check ball is held pressed against the downstream
opening of the chamber by the line pressure, the line
pressure passes through the
No.Se line, which has an
orifice provided.
(4 The line pressure, after being attenuated by the orifice, is
directed to the No.5c line.
(5) Meanwhile, the pressure from the pressure control valve
which has been regulated by the pressure control solenoid
valve is supplied through the No. 10 line.
(6) There is an orifice in the No. 10 line and the pressure which
is attenuated by passing through this orifice flows into the
No.
5c line.
(7) The No. 5c line pressure is directed to the rear clutch via therear clutch exhaust valve.
(8) If the rear clutch completes engagement, the duty setting
of the pressure control solenoid valve becomes zero
percent, increasing the pressure to the line pressure level.
(9) The line pressure thus established in the No.5c line works
on the N-D control valve to move it towards the right. This
rightward movement is’ caused by the difference in area to
which pressure is applied between the two lands.
(lO)The above movement of the N-D control valve opens theNo.5 port, and through the port, the line pressure estab-
lished in the No. 5 line flows into the No.
5c line and then is
directed to the rear clutch via the rear clutch exhaust valve.

21-80AUTOMATIC TRANSAXLE - Transaxle Control
VALVE WITH ORIFICE
When
oressureis releasedWhen pressure
-is applredTo rear clutch
via rear clutch
exhaust valveTo low-reverse brake
i
Ltne pressure1
- 2 shiftvalve
Ex
1750242If the accelerator pedal is depressed ‘immediately
after shifting the select lever from
“N” to “D”, the
rear clutch engages directly and the vehicle moves
in
1st gear. Due to the arrangement of the hydraulic
circuit, in thjs case, the hydraulic pressure is actuallydirected to both the rear clutch and the low-reverse
brake, thus dividing the quantity of the distributed
fluid. This in turn can cause a delay in clutchengagement when the fluid temperature is high. To
prevent this, a special valve is provided in the
low-reverse brake circuit. This valve has an orifice
which restricts flow of fluid when the pressure is
directed to the low-reverse brake but has no flow
restriction effect when the low-reverse brake press-
ure is released, thus preventing sluggish release of
the brake.

AUTOMATIC TRANSAXLE - Transaxle Control21-81
3 CLUTCH VALVE
To front clutch
.To end clutch
To kickdown
servo release
Shift
control
solenoid
valve
- BShift control
solenoid valve
-A
II
J
ExIPlug
End clutch valve
‘11 E”
Line pressure
1750243End clutch valve controls the timing for supplying hydraulic
pressure to the end clutch.In 2nd Gear
(1) When hydraulic pressure is not being directed to the end
clutch valve, it is held pushed to the left by the spring force
(see above figure).
(2) If the
2nd pressure from the shift control valve is directed
to the end clutch valve via the No.6 line, the end clutch
valve is forced toward the right.
,nd Gear
Lrom manualvalveTo end,&tch.
2ndpressurepressure
I17501i