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Description  |
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The present invention relates to automatic transmissions for automobiles
and more particularly to hydraulic control means for such automatic
transmissions.
Conventional automatic transmissions for automobiles generally include a
hydraulic torque converter having an input shaft adapted to be connected
with the engine output shaft and an output shaft adapted to be connected
with a transmission gear mechanism which is associated with one or more
frictional constraining means such as brakes or clutches so as to provide
a plurality of speed ratios. The brakes and clutches are selectively
actuated by hydraulic actuators into engagement to provide the above
plurality of speed ratios. The hydraulic pressure supplied to each of the
actuators is controlled by a so-called hydraulic trimmer valve so that the
pressure is gradually increased from the initial pressure in order to
avoid a shock or rough engagement which may other wise be produced when
the transmission gear mechanism is shifted.
Conventionally, the hydraulic trimmer valve includes a plunger which is
positioned between a pressure line and a return line and biased by means
of a spring toward a position where the pressure line is interrupted from
communication with the return line. The plunger is further subjected to a
pressure which corresponds to the engine throttle valve position and which
acts on the plunger opposite to the biasing spring. Thus, the pressure
line is opened to the return line by an amount corresponding to the engine
throttle valve position to produce a modified pressure which is applied to
the hydraulic actuator to operate the same. The modified pressure is also
applied to the plunger of the trimmer valve to assist the biasing spring
so that the opening from the pressure line to the return line is gradually
decreased resulting in a gradual increase in the modified pressure.
According to the conventional structure, the throttle valve position
pressure is applied to an end of the plunger so as to oppose to the
biasing spring. In this arrangement, however, disadvantages have been
encountered in that any movement of the plunger has an influence on the
throttle valve position pressure and, since the throttle valve position
pressure is usually used for controlling other valves which are employed
for various purposes, fluctuation thus produced in the throttle valve
position pressure often causes improper or erroneous operations of such
valves.
It is therefore an object of the present invention to provide hydraulic
control means for automatic transmissions which does not have the
aforementioned disadvantages.
According to the present invention, the above and other objects can be
accomplished by an automatic transmission for automobiles which comprises
gear means having at least one frictional constraining means adapted for
selective operation to provide a plurality of different speed ratios,
actuator means associated with said constraining means, control circuit
means including at least one hydraulic pressure line for the actuator
means to provide a supply of operating pressure to said actuator means,
said control circuit means further including at least one return line,
trimmer valve means disposed between said hydraulic pressure line and said
return line and including at least one valve member biased toward a first
position wherein the hydraulic pressure line is blocked from communication
with the return line, means for applying hydraulic pressure in the
pressure line to the valve member so that the valve member is urged under
the pressure toward a second position wherein the hydraulic pressure line
is opened to the return line whereby the pressure in the hydraulic
pressure line is allowed to leak into the return line to produce a
modified pressure in the hydraulic pressure line, means for applying the
modified pressure to the valve member so that the valve member is urged by
the modified pressure toward the first position, and means for
establishing in the return line a pressure corresponding to engine load.
According to the present invention, the actuator means is supplied with the
modified pressure which increases gradually from the initial pressure.
Since the return line is at the pressure corresponding to the engine load,
the said initial pressure is determined in accordance with the engine load
which may be represented by the engine throttle valve position. Since the
pressure corresponding to the engine load is not applied directly to the
valve member but maintained at the return line, the pressure is not
affected by any movement of the valve member.
The above and other objects and features of the present invention will
become apparent from the following descriptions of a preferred embodiment
taking reference to the accompanying drawings, in which;
FIG. 1 is a schematic illustration of an automatic transmission to which
the present invention can be applied;
FIG. 2 is a chart showing the operations of brakes and clutches for
providing various speed ratios in the transmission;
FIG. 3 is a diagramatical illustration of general arrangements of several
component which are used in the transmission assembly including the
hydraulic control system in accordance with the present invention and
illustrated in detail in subdivided FIGS. 3A to 3H;
FIGS. 3A, 3B, 3C, 3D, 3E, 3F, 3G and 3H show respective parts of the
hydraulic control circuits in accordance with the present invention;
FIG. 4 is a diagram showing the changes of the governor modulated pressure
and the governor pressure in accordance with the vehicle speed;
FIG. 5 is a diagram showing the operation of the transmission gear
mechanism under D-range;
FIG. 6 is a diagram similar to FIG. 5 but showing the operation under
3-range;
FIG. 7 is a diagram similar to FIGS. 5 and 6 but showing the operation
under 2-range;
FIG. 8 is a diagram similar to FIGS. 5 through 7 but showing the operation
under 1-range;
FIG. 9 is a diagram similar to FIGS. 5 through 8 but showing the operation
under L-range; and,
FIG. 10 is a diagram showing the change in the actuator operating pressure.
Referring now to the drawings, particularly to FIG. 1, there is
schematically shown an automatic transmission to which the present
invention can be applied. The transmission includes a torque converter 10
and a transmission gear device 20. The torque converter 10 is of a
conventional three element, single stage, two phase type and comprises a
pump impeller 12 adapted to be connected with an engine output shaft 11, a
turbine runner 14 and a stator wheel 17 mounted on a casing 15 through a
one-way brake 16. Between the pump impeller 12 and the turbine runner 14,
there is provided a lock-up clutch 18 for connecting them together so that
the rotation of the engine output shaft 11 is mechanically transmitted to
the transmission gear device 20.
The transmission gear device 20 includes an input shaft 13 which is adapted
to be connected with the turbine runner 14 of the torque converter 10 and
an output shaft 19 which is arranged coaxially with the input shaft 13.
Between the input shaft 13 and the output shaft 19, there are disposed a
first planetary gear device 21, a second planetary gear device 22, a third
planetary gear device 23 and a fourth planetrry gear device 24, all of
single pinion types.
The first planetary gear device 21 comprises a first sun gear 25, first
planetary gears 26 meshing with the first sun gear 25, a first ring gear
27 meshing with the first planetary gears 26 and a first planetary carrier
28 rotatably supporting the first planetary gears 26. Similarly, the
second planetary gear device 22 comprises a second sun gear 29, second
planetary gears 30, a second ring gear 31 and a second planetary carrier
32. The third planetary gear device 23 also comprises a third sun gear 33,
third planetary gears 34, a third ring gear 35 and a third planetary
carrier 36. The fourth planetary gear device 24 comprises a fourth sun
gear 37, fourth planetary gears 38, a fourth ring gear 39 and a fourth
planetary carrier 40.
The first ring gear 27, the second planetary carrier 32 and the third ring
gear 35 are connected together so that they rotate as a unit. Further,
they are connected with the input shaft 13 through a first clutch 41. The
first planetary carrier 28 and the second ring gear 31 are connected
together so that they rotate as a unit. The first planetary carrier 28 and
the second ring gear 31 are also connected with the input shaft 13 through
a second clutch 42.
The first sun gear 21 is so arranged that it is driven by the input shaft
13 through a third clutch 43 and adapted to be locked on the case 15
through a first brake 44. The first ring gear 27, the second planetary
carrier 32 and the third ring gear 35 are so arranged that they can be
locked on the case 15 by means of a second brake 45. The second sun gear
22, the third sun gear 33 and the fourth ring gear 39 are connected
together so that they can rotate as a unit and further they are so
arranged that they can be locked on the case 15 through a third brake 46.
The fourth planetary carrier 40 can be locked on the case 15 through a
fourth brake 47. The third planetary carrier 36, the fourth sun gear 37
and the output shaft 19 are connected together so that they rotate as a
unit.
In the gear transmission device 20 described above, the engagements of the
third clutch 43 and the fourth brake 47 provide a LOW drive stage wherein
the slowest forward drive is attained. The simultaneous actuation of the
third clutch 43 and the third brake 46 provides a first forward drive
stage. A second forward drive stage is provided through a simultaneous
actuation of the second clutch 42 and the third brake 46. A third forward
drive stage is provided through a simultaneous actuation of the first
clutch 41 and the third brake 46 and a fourth forward drive stage is
provided through a simultaneous actuation of the first and the second
clutches 41 and 42. In the fourth forward drive stage, the input shaft 13
and the output shaft 19 rotate as a unit at the same speed. An overdrive
stage can be provided through a simultaneous actuation of the first clutch
41 and the first brake 44 and, in this stage, the output shaft 19 is
driven faster than the input shaft 13. A reverse drive stage is provided
when the third clutch 43 and the second brake 45 are simultaneously
engaged. The above functions are shown in FIG. 2 wherein the mark O
designates the engagement of the associated clutch or brake.
The above automatic transmission is controlled by a hydraulic control
device including a hydraulic pump 50, a regulator valve 100, a manually
operated valve 150, a down-shift control valve 200, an engine throttle
position responsive valve 250, a kick-down control valve 300, a LOW-HIGH
shift valve 350, a governor valve 400, a governor modulator valve 450, a
shift valve 500, an engine throttle position modulating valve 550, a
torque converter pressure control valve 600, a L-1 shift valve 650, a 1-2
shift valve 700, a 2-3 shift valve 750, a 3-4 shift valve 800, an OD shift
valve 850, a reverse inhibitor valve 900, a fourth brake trimmer valve
950, a third brake trimmer valve 1000, a second brake trimmer valve 1050,
a first brake trimmer valve 1100, a third clutch trimmer valve 1150, a
second clutch trimmer valve 1200 and a first clutch trimmer valve 1250.
Referring to FIG. 3G, the hydraulic pump 50 in connected through an inlet
conduit 53 having a strainer 52 with an oil reservoir 51 so that hydraulic
oil is introduced through the conduit 53. The pump 50 is also connected
with an outlet conduit 54 to which the hydraulic oil is discharged under
pressure from the pump 50. The pump 50 is connected through the pump
impeller 12 of the torque converter 10 with the engine output shaft 11 to
receive a driving power therefrom.
Referring to FIG. 3E, the pump outlet conduit 54 is connected with a
pressure line 55 which leads to the regulator valve 100. The passage 55
provides a supply of hydraulic pressure for affecting angagement of the
friction devices such as the clutches 41, 42 and 43 and the brakes 44, 45,
46 and 47 to provide the aforementioned functions of the transmission gear
device 20. The regulator valve 100 serves to regulate the pressure in the
passage 55.
The regulator valve 100 includes a valve body 101 having a valve bore in
which a valve member 102 is axially slidably received. The valve member
102 has axially spaced lands 102a, 102b and 102c and is biased by means of
a spring 103 which extends between a spring seat 104 provided on the valve
member 102 and a sleeve 105 fitted in the bore of the valve body 101. The
sleeve 105 has an axially extending bore in which a plug 106 is slidably
but fluid-tightly received.
The valve body 101 is provided at axially spaced portions with ports 101a,
101b, 101c, 101d and 101e and chambers 101g, 101h, 101i, 101j and 101k
respectively communicating with the ports. The port 101a is connected with
the line 54 so as to introduce the line pressure into the chamber 101g
whereby the line pressure is applied to the adjacent end surface of the
valve member 102. The port 101b functions as a return port and connected
through a passage 56 to the pump inlet passage 53. The port 101e is also
connected with the oil reservoir 51.
The port 101c is connected with the passages 54 and 55. The port 101d is
connected through a passage 57 having an orifice 108 with the torque
converter 10 so as to supply hydraulic oil thereto. The valve body 101 is
further provided with a port 101f which communicates with a chamber 101l
defined in the sleeve 105 by means of the plug 106.
The line pressure passage 55 has a branch passage 55a which leads to the
governor valve 400. The governor valve 400 comprises a valve body 401
having axially spaced ports 401a, 401b and 401c and a valve member 402
received in an axial bore of the valve body 401. The port 401a is
connected with the branch passage 55a to receive the line pressure. The
valve member 402 has a smaller land 402a and a larger land 402b. The port
401c is connected with the oil reservoir 51.
The valve body 401 is mounted on the output shaft 19 of the gear device 20
in such a manner that its axis is directed in the radial direction of the
output shaft 19 with the smaller land 402a positioned at the radially
outside. The port 401b is connected with a passage 59 which leads to the
governor modulator valve 450, the OD shift valve 850, the 3-4 shift valve
800 and the 2-3 shift valve 750.
Referring to FIG. 3F, the governor modulator valve 450 comprises a valve
body 451 having an axial bore formed with ports 451a, 451b, 451c, 451d,
451e and 451f, a piston 452 slidably inserted at the right hand portion of
the bore and a plunger 453 slidably inserted into the bore and having
axially spaced lands 453a and 453b which have diameters smaller than that
of the piston 452. The port 451a is connected with the passage 59 and the
ports 451b and 451c are connected with the reservoir 51. The port 451e is
connected with the branch passage 55c so as to receive the line pressure
therefrom. The ports 451d and 451f are connected together and the port
451d is connected with the reverse inhibitor valve 900, the L-1 shift
valve 650 and the 1-2 shift valve 700.
As shown in FIG. 3G, the manually operated valve 150 includes a valve body
151 having an axial bore provided with ports 151a, 151b, 151c, 151d, 151e,
151f, 151g, 151h and 151i and a valve member 152 disposed in the axial
bore of the valve body 151 and having axially spaced lands 152a, 152b and
152c.
The port 151a is connected with the line pressure passage 55 and the port
151b is connected with a passage 61 which leads to the 3-4 shift valve 800
and the shift valve 500, and also with a passage 62 which leads to the
engine throttle position valve 250 and the L-H shift valve 350. The port
151c is connected with a passage 63 leading to the down-shift control
valve 200.
The port 151d communicates with a passage 64 which leads to the down-shift
control valve 200 and the port 151e with a passage 65 leading to the 3-4
shift valve 800 and the OD shift valve 850. The port 151f communicates
with a passage 66 which leads to the 2-3 shift valve 750 and the port 151g
with a passage 67 leading to the 1-2 shift valve 700. The port 151h is
connected with a passage 68 which leads to the L-1 shift valve 650, and
the port 151i with a passage 69 leading to the shift valve 500, the 1-2
shift valve 700 and the reverse inhibitor valve 900.
Referring to FIG. 3G, the down-shift control valve 200 includes a valve
body 201 having an axial bore provided with ports 201a, 201b, 201c and
201d, and a valve member 202 slidably received in the axial bore of the
valve body 201. The valve member 202 has axially spaced lands 202a and
202b and biased toward left by means of a spring 203 which acts between a
pin 204 and the valve member 202.
The port 201d is a return port and connected with the reservoir 51. The
ports 201a and 201b are connected with the passage 63 from the port 151c
in the manually operated valve 150 so as to receive the hydraulic pressure
therefrom. The port 201a is in communication with a chamber 201e to which
the left end of the valve member 202 is exposed so that the hydraulic
pressure is introduced through the port 201a into the chamber 201e. Thus,
the valve member 202 is forced toward right against the action of the
spring 203.
A chamber 201f is defined in the axial bore of the valve body 201 between
the lands 202a and 202b and is always in communication with the port 201c
which is connected through the passage 64 with the port 151d in the manual
valve 150. The port 201b is opened to the chamber 201f when the valve
member 202 is moved toward left under the action of the spring 203 but
blocked from communication with the chamber 201f when the valve member 202
is shifted toward right under the influence of the pressure prevailing in
the chamber 201e.
In this manner, there is produced in the chamber 201f a pressure which is
lower than the line pressure. The pressure thus produced is transmitted
through the passage 64 to the port 151d of the manual valve 150.
Referring to FIG. 3G, the engine throttle position valve 250 includes a
valve body 251 having an axial bore provided with ports 251a, 251b, 251c,
251d, 251e, 251f and 251g. In the axial bore, there are disposed a pair of
valve members 252 and 253, a first spring 254 disposed between the valve
members 252 and 253, and a second spring 255 which forces the valve member
252 in the direction opposite to the biasing force of the first spring
254. The valve member 252 has a smaller diameter land 252a and a pair of
larger diameter lands 252b and 252c. The valve member 253 has a land 253a
which is of a diameter equal to those of the lands 252b and 252c of the
valve 252.
The valve body 251 is further provided with a pin 256 which serves to limit
the leftward movement of the valve member 253. The valve member 253 is
connected with the engine throttle valve actuating member through suitable
means so that it is moved toward right by a distance corresponding to the
engine throttle valve opening. The ports 251d and 251f are connected with
the oil reservoir 51.
The port 251a is connected with the port 151b of the manual valve 150,
while the ports 251b and 251c are connected together and communicates with
a passage 70 which leads to the 1-2 shift valve 700, the 2-3 shift valve
750 and the 3-4 shift valve 800. The passage 70 has a branch passage 70a
which leads to the throttle modulator valve 550. The ports 251e and 251g
are connected together through a passage 71, and the port 251g is
connected with a passage 77 leading to the kick-down control valve 300.
As shown in FIG. 3H, the throttle modulator valve 550 includes a valve body
551 having an axial bore provided with ports 551a, 551b, 551c, 551d and
551e, and a valve member 552 disposed in the axial bore of the valve body
551. The valve member 552 has a pair of axially spaced lands 552a and 552b
and biased toward left by means of a spring 553. The right end of the
axial bore in the valve body 551 is closed by means of a plug 554 and a
pin 555 is provided so as to prevent the plug 554 from being removed from
the bore.
The port 551d is a return port and connected with the oil reservoir 51. The
ports 551c and 551e are connected together by means of a passage 73. The
port 551a is connected through the passage 70a with the port 251b of the
engine throttle position valve 250 so as to receive the throttle position
pressure which corresponds to the engine throttle valve position. The port
551a is connected with a chamber 551f so that the throttle valve position
pressure introduced into the chamber 551f forces the valve member 552
toward right.
Between the lands 552a and 552b, there is defined a chamber 551g which is
always in communication with the port 551c. The chamber 551b is also
connected with the port 551c when the valve member 552 is moved toward
left under the action of the spring 553. The pressure in the chamber 551g
is also applied through the port 551c, the passage 73 and the port 551e to
the left end of the valve member 552 so as to force it toward right. The
port 551b is connected with a passage 55c which is branched from the line
pressure passage 55. Thus, it should be noted that in the chamber 551g
there is produced a pressure which is determined by the pressures in the
chambers 551f and 551g and the spring 553 and which is proportional to but
higher than the throttle position pressure.
The pressure thus produced in the chamber 551g is then transmitted through
the port 551c to a passage 74 which leads to the fourth brake trimmer
valve 950, the third brake trimmer valve 1000, the second brake trimmer
valve 1050, the third clutch trimmer valves 1150, the second clutch
trimmer valve 1200, and the first clutch trimmer as will be explained
later, the port 551b valve 1250, and the passage 55c may be omitted.
As shown in FIG. 3G, the kick-down control valve 300 includes a valve body
301 having an axial bore provided with ports 301a, 301b, 301c and 301d,
and a pair of valve members 302 and 303 are disposed in the bore. The
valve member 302 has a smaller diameter land 302a, while the valve member
303 has a land 303a which has a diameter slightly larger than that of the
land 302a. Between the valve members 302 and 303, there is disposed a
spring 304.
The ports 301b and 301c are return ports and connected with a passage 76a
which leads to the L-H shift valve 350, while the port 301d is connected
with a passage 77 leading to the port 251g of the throttle position valve
250.
Referring further to FIG. 3G, the L-H shift valve 350 includes a valve body
351 having a valve bore provided with ports 351a, 351b and 351c, and a
valve member 352 slidably received in the valve bore. The valve member 352
has a pair of axially spaced lands 352a and 352b which are of the same
diameter.
The port 351a is connected with the passage 62 from the port 151b of the
manual valve 150 to receive a supply of the line pressure through a branch
passage 62a. The port 351b is connected with the passage 76a from the port
301a of the kick-down control valve 300, and further connected with a
passage 76 leading to the OD shift valve 850.
Referring now to FIG. 3D, the reverse inhibitor valve 900 includes a valve
body 901 having a valve bore provided with ports 901a, 901b, 901c, 901d
and 901e, and a valve member 902 which has a pair of axially spaced lands
902a and 902b and is slidably received in the valve bore. In the valve
bore, a spring 903 is disposed so as to bias the valve member 902
upwardly.
The port 901a is connected with the passage 60 which leads from the port
451d of the governor modulator valve 450, while the oprt 901b is connected
with the passage 69 from the port 151i of the manual valve 150. The ports
901c and 901e are connected together and lead to the second brake trimmer
valve 1050 and to the servo chamber 45a of the second brake 45. The port
901d is a return port and connected with the oil reservoir 51. The valve
member 902 is thus moved under the influence of the governor modulated
pressure which is proportional to the governor pressure and of the spring
903.
As shown in FIG. 3D, the L-1 shift valve 650 includes a valve body 651
having a valve bore formed with ports 651a, 651b, 651c, 651d, 651e, 651f,
651g and 651h, and a valve member 652 disposed in the valve bore. The
valve member 652 has a large diameter land 652a and three small diameter
lands 652b, 652c and 652d, and is biased downwardly by means of a spring
653.
The port 651a is connected with the passage 60 which is from the port 451d
of the governor modulator valve 450, while the port 651b is connected with
the passage 68 which comes from the port 151h of the manual valve 150. The
ports 651c and 651f are return ports leading to the oil reservoir 51. The
port 651d is connected with a passage 90 which leads to the third brake
trimmer valve 1000 and to the servo chamber 46a of the third brake 46. The
port 651h is connected with a passage 91 leading to the 3-4 shift valve
800. The ports 651e and 651g are connected together by means of a passage
92 which also leads to the fourth brake trimmer valve 950 and to the servo
chamber 47a of the fourth brake 47.
The 1-2 shift valve 700, which is shown in FIG. 3D, includes a valve body
701 having a valve bore formed with ports 701a, 701b, 701c, 701d, 701e,
701f, 701g, 701h and 701i, and a pair of valve members 702 and 703
disposed in the valve bore. The valve member 702 has a large diameter land
702a, an intermediate diameter land 702b having a diameter slightly
smaller than that of the land 702a, a pair of second intermediate diameter
lands 702c and 702d having diameters smaller than that of the land 702b,
and a smaller diameter land 702e having a diameter smaller than those of
the lands 702c and 702d. The valve member 702 is biased upwardly by means
of a spring 704. The valve member 703 has a diameter which is smaller than
that of the land 702e and is freely received in the valve bore.
The ports 701c and 701g are return ports connected with the oil reservoir
51 and provided with orifices 701j and 701k, respectively. The port 701a
is connected with the passage 60 to receive the governor modulated
pressure therefrom. The port 701b communicates with the passage 67 which
comes from the port 151g of the manual valve 150, while the port 701d is
connected with a passage 93 which leads to the second clutch trimmer valve
1200 and to the servo chamber 42a of the second clutch.
The port 701e is connected with a passage 94 which leads to the 2-3 shift
valve 750. The port 701f is connected with a passage 95 which leads to the
third clutch trimmer valve 1150 and to the servo chamber 43a of the second
clutch, and also with a passage 95a which is branched from the passage 95
and leads to the port 101f of the regulator valve 100. The port 701h is
connected through the passage 70 with the ports 251b and 251c of the
throttle position valve 250 to receive a supply of the throttle position
pressure. The port 701i is in communication through the passage 69 with
the port 151i of the manual valve 150.
As shown in FIG. 3D, the 2-3 shift valve 750 includes a valve body 751
having a valve bore formed with ports 751a, 751b, 751c, 751d, 751e, 751f,
751g, 751h and 751i, and a valve member 752 slidably received in the valve
bore. The valve member 752 has a large diameter land 752a, an intermediate
diameter land 752b having a diameter slightly smaller than that of the
land 752a, two small diameter lands 752c and 752d, a further small
diameter land 752e having a diameter smaller that of the land 752c and a
small diameter land 752f having a diameter smaller than that of the land
752e. The valve member 752 is biased upwardly as seen in the drawing by
means of a spring 753 which acts between the valve member 752 and a spring
retainer 754 provided in the valve body 751.
The ports 751c and 751i are return ports which are connected with the oil
reservoir 51, and the port 751c is provided with an orifice 751k. The port
751a is connected with the governor pressure line 59 which is in turn
connected with the port 401b of the governor valve 400, and the port 751b
with the passage 66 which is from the port 151f of the manual valve 150.
The port 751d is connected with a passage 97 which leads to the first
clutch trimmer valve 1250 and to the servo chamber 41a of the clutch 41 as
well as to the servo chamber 18a of the direct drive clutch 18. The port
751e is connected with a passage 98 leading to the shift valve 500, and
the port 751f with the passage 94 which is from the port 701e of the 1-2
shift valve 700. The port 751g is connected through a passage 98 with the
OD shift valve 850, while the port 751h is connected through the port 701h
of the 1-2 shift valve 700 and the passage 70 with the ports 251b and 251c
of the throttle position valve 250.
Referring now to FIG. 3c, the 3-4 shift valve 800 includes a valve body 801
having a valve bore formed with ports 801a, 801b, 801c, 801d, 801e, 801f,
801g, 801h, 801i, 801j, 801k and 801l. In the valve bore, there are
disposed a first valve member 802 and a second valve member 803. The first
valve member 802 is provided with a large diameter land 802a, a medium
diameter land 802b having a diameter slightly smaller than that of the
land 802a, two second medium diameter lands 802c and 802d having diameters
smaller than the land 802b and a smaller diameter land 802e having a
diameter smaller than those of the lands 802c and 802d. The second valve
member 803 has a land 803a of which diameter is smaller than that of the
small diameter land 802e. Between the first and second valve members 802
and 803, there is disposed a spring 804 which acts between the valve
members. A second spring 805 is provided in the valve bore to force the
first valve member 803 in the upward direction. A spring retainer 806 is
provided on the first valve member 802 so as to receive the springs 804
and 805.
The port 801a is connected with the passage 59 which leads to the port 401b
of the governor valve 400, and the port 801b is connected with the passage
65 which leads to the port 151e of the manual valve 150 and which has a
branch passage 65b leading to the OD shift valve 850. The ports 801d, 801h
and 801j are return ports which are connected with the oil reservoir 51.
The ports 801d and 801h are provided with orifices 801m and 801n,
respectively. The port 801e is connected with a passage 99 which is also
leading to the OD shift valve 850.
The port 801f is connected with a passage 61 which leads to the shift valve
500 as well as with the port 151 of the manual valve 150. The port 801g is
connected with the passage 91 which is in turn connected with the port
651h of the L-1 shift valve 650. The port 801i is connected through a
passage 81 with the port 801k. The port 801l is connected through the port
751h of the 2-3 shift valve 750 and the port 701b of the 1-2 shift valve
700 and through the passage 70 with the ports 251b and 251c of the
throttle position valve 251.
The OD shift valve 850 shown in FIG. 3c includes a valve body 851 having a
valve bore formed with ports 851a, 851b, 851c, 851d, 851e, 851f, 851g and
851h, and a valve member 852 slidably disposed in the valve bore. The
valve member 852 has a large diameter land 852a, two medium diameter lands
852b and 852c having diameters slightly smaller than that of the land
852a, and a small diameter land 852d having a diameter smaller than that
of the lands 852b and 852c. The valve member 852 is biased upwardly as
seen in the drawing by means of a spring 853 which acts between the valve
member 852 and a spring retainer 854 provided on the valve body 851.
The port 851a is connected through the governor pressure passage 59 with
the port 401b of the governor valve 400. The ports 851b and 851f are
return ports which are connected with the oil reservoir 51. These ports
851b and 851f are provided with orifices 851i and 851j, respectively. The
port 851c is connected with a passage 861 which leads to the first brake
trimmer valve 1100 and to the servo chamber 44a of the first brake 44. The
port 851d is connected with the passage 99 which is in turn connected with
the port 801e of the 3-4 shift valve 800, and the port 851e with the
passage 98 which is in turn connected with the port 751g of the 2-3 shift
valve 750. The port 851g is connected through the passage 65b with the
port 801b of the 3-4 shift valve 800 which is in turn connected through
the passage 65 with the port 151e of the manual valve 150. The port 851h
is connected through the passage 76 with the port 351b of the L-H shift
valve 350 and with the port 301a of the kick-down control valve 300.
The shift valve 500 shown in FIG. 3F includes a valve body 501 having a
valve bore formed with valve ports 501a, 501b and 501c, and a valve member
502 slidably received in the valve bore. The valve member 502 is biased by
means of a spring 503 which acts between the valve member 502 and a plug
504 fitted in the valve bore and maintained in position by means of a pin
506. A seal ring 505 is disposed around the plug 504 for the purpose of
maintaining fluid tightness.
The port 501a is connected with the passage 61 with the port 151b of the
manual valve 150 and with the port 801f of the 3-4 shift valve 800. The
port 501b is connected with the port 751e of the 2-3 shift valve 750, and
the port 501c through the passage 69 with the port 151i of the manual
valve 150.
Referring to FIG. 3c, the torque converter pressure control valve 600
includes a valve body 601 having a valve bore formed with valve ports 601a
and 601b, and a valve member 602 slidably received in the valve bore. The
valve member 602 is biased toward left by means of a spring 603 which acts
between the valve member 602 and a pin 604 provided in the valve body 601
for the purpose. The ports 601a receives hydraulic oil from the torque
converter through an oil cooler 1300 and provides a supply of lubricating
oil to various frictional parts in the transmission.
Referring now to FIG. 3B, the fourth brake trimmer valve 950 includes a
valve body 951 having a valve bore formed with valve ports 951a, 951b,
951c, 951d and 951e, and a pair of axially aligned valve members 952 and
953. The valve member 952 is positioned at the lower portion of the valve
bore as seen in the drawing, and the valve member 953 is positioned at the
opper portion thereof. Between the valve members 952 and 953, there is
disposed a spring 954.
The ports 951d and 951e are both connected with a chamber 951f defined in
the valve bore by means of the upper end of the valve member 953, and a
one-way check valve 955 is provided between the port 951e and the chamber
951f in such a manner that fluid flow is permitted from the chamber 951f
to the port 951e but blocked in the opposite direction. The port 951a is
connected through the passage 92 with the ports 651e and 651g of the L-1
shift valve 650 and further with the ports 951d and 951e and the servs
chamber 47a of the fourth brake 47. The port 951b is connected with the
passage 74 which leads to the port 551c of the throttle position modulator
valve 550. The port 951c is a return port connected with the oil reservoir
51.
The trimmer valves 1000, 1050, 1100, 1150, 1200 and 1250 have the same
construction as the trimmer valve 950 does so that their detailed
structures will not be specifically described but only the mutual
connections will hereinafter be described.
As shown in FIG. 3B, the third brake trimmer valve 1000 has a port 1001a
which is connected with the port 651d of the L-1 shift valve 650 and also
with the ports 1001d and 1001e as well as the servo chamber 46a of the
third brake 46. The port 1001b of the valve 1000 is connected through the
passage 74 with the port 551c of the throttle position modulator valve
550. The port 1001c is return line which opens to the oil reservoir 51.
There is also provided a one-way check valve 1005 which functions the same
as the one-way valve 955.
The second brake trimmer valve 1050 shown in FIG. 3B has a port 1051a
connected with the ports 901c and 901e of the reverse inhibitor valve 900
and also with the ports 1051d and 1051e as well as the servo chamber 45a
of the second brake 45. The port 1051b is connected through the passage 74
with the port 551c of the throttle modulator valve 550. The port 1051c is
a return port which opens to the oil reservoir 51. There is also provided
a one-way check valve 1055 which functions as the one-way valve 955 does.
The first brake trimmer 1100 shown in FIG. 3B has a port 1101a which is
connected with the port 801g of the 3-4 shift valve 800 and also with the
ports 1101d and 1101e as well as the servo chamber 44a of the first brake
44. The port 1101b is connected through the passage 74 with the port 551c
of the throttle position modulator valve 550. The port 1101c is a return
port which opens to the oil reservoir 51. There is also provided a one-way
check valve 1105 which functions as the one-way valve 955 does.
Referring now to FIG. 3A, the third clutch trimmer valve 1150 has a port
1151a which is connected with the port 701f of the 1-2 shift valve 700 and
also with the port 101f of the regulator valve 100 as well as the ports
1151d and 1151e and the servo chamber 43a of the third clutch 43. The port
1151b is connected through the passage 74 with the port 551c of the
throttle position modulator valve 550. The port 1151c is a return port
which is connected with the oil reservoir 51. There is also provided a
one-way check valve 1155 which functions as the one-way valve 955 does.
The second clutch trimmer valve 1200 shown in FIG. 3A has a port 1201a
which is connected with the port 701d of the 1-2 shift valve 700 and with
the ports 1201d and 1201e as well as the servo chamber 42a of the second
clutch 42. The port 1201b is connected with the passage 74 which is in
turn connected with the port 551c of the throttle modulator valve 550. The
port 1201c is a return port which opens to the oil reservoir 51. There is
also provided a one-way check valve 1205 which functions as the one-way
valve 955 does.
The first clutch trimmer valve 1250 has a port 1251a which is connected
with the port 751d of the 2-3 shift valve 750 and with the ports 1251d and
1251e as well as the servo chamber 41a of the first clutch 41 and the
servo chamber 18a of the direct drive clutch 18. The port 1251b is
connected with the passage 74 which is in turn connected with the port
551c of the throttle position modulator valve 550. The port 1251c is a
return port connected with the oil reservoir 51. There is also provided a
one-way check valve 1255 which functions as the one-way valve 955 does.
The operation of the transmission will now be described. As soon as the
engine is started, the pump 50 is driven thereby so that the hydraulic oil
is drawn from the reservoir 51 through the strainer 52 and the passage 53
into the pump 50 and discharged into the outlet passage 54. The pressure
thus produced in the passage 54 is supplied to the chambers 101i and 101g
of the regulator valve 100 to act on the land 102a so that the valve
member 102 is shifted upwardly against the influence of the spring 103.
The opward movement of the valve 102 causes a communication between the
chamber 101i with the return port 101b resulting in a decrease in the
pressure in the chamber 101i. Such decrease in pressure in the chamber
101i causes a corresponding decrease in the pressure in the chamber 101g
so that the valve member 102 is moved back under the force of the spring
103 so that the communication between the chamber 101i and the return port
101b is interrupted. In this manner, the regulator valve 100 provides a
substantially constant pressure which is on one hand determined by the
force of the spring 103.
The line pressure thus produced is also introduced through the passage 95a
into the chamber 101l to assist the spring 103 when the transmission is
operated in either of the LOW, ist or REVERSE position so as to provide a
higher line pressure which will be required for resisting higher to torque
reaction forces that may be encountered in either of the operating
conditions.
The port 101d of the regulator valve 100 has the orifice 108 as previously
described and the port 101d is connected with the torque converter 10
through this orifice and the passage 57. By properly determining the
orifice 108, it is possible to determine the hydraulic pressure supplied
to the torque converter 10. The hydraulic oil which has passed through the
torque converter is passed through the oil cooler 1300 to be cooled
therein and further through the torque converter pressure control valve
600 by which the pressure at the outlet side of the torque converter 10 is
appropriately determined.
The hydraulic pressure from the regulator valve 100 is passed into the
passage 55 from which it is further passed through the branch passage 55a
to the inlet port 401a of the governor valve 400. In the governor valve
400, the inlet port 401a is blocked by the land 402a of the valve member
402 when the automobile is not running and therefore the output shaft 19
is stationary. Thus, no outlet pressure is produced under this condition
in the governor valve 400.
As the vehicle is started and the output shaft 19 of the transmission 20
starts to rotate, the centrifugal force on the valve member 402 of the
governor valve 400 shifts the valve member 402 radially outwardly to open
the port 401a to the port 401b so that there is produced in the port 401b
a governor pressure which acts on the lands 402a | | |
