Shift control apparatus and method of transmission for vehicle

(19)
&
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EP 1 312 837 B1
EUROPEAN PATENT SPECIFICATION
(12)
(45) Date of publication and mention
(51) Int Cl.:
F16H 61/02 (2006.01)
of the grant of the patent:
10.09.2008 Bulletin 2008/37
(21) Application number: 02025243.3
(22) Date of filing: 12.11.2002
(54) Shift control apparatus and method of transmission for vehicle
Vorrichtung und Verfahren zum Schalten eines Wechselgetriebes eines Fahrzeuges
Dispositif et procédé de changement de vitesse pour transmission de véhicule
(84) Designated Contracting States:
• Naito, Koji
Toyota-shi,
Aichi-ken, 471-8571 (JP)
• Amano, Takaya
Toyota-shi,
Aichi-ken, 471-8571 (JP)
DE FR GB IT
(30) Priority: 15.11.2001 JP 2001350552
(43) Date of publication of application:
21.05.2003 Bulletin 2003/21
(74) Representative: TBK-Patent
(73) Proprietor: Toyota Jidosha Kabushiki Kaisha
Toyota-shi, Aichi-ken, 471-8571 (JP)
(72) Inventors:
EP 1 312 837 B1
• Yamamoto, Kazuhiro
Toyota-shi,
Aichi-ken, 471-8571 (JP)
• Ogawa, Shinji
Toyota-shi,
Aichi-ken, 471-8571 (JP)
Bavariaring 4-6
80336 München (DE)
(56) References cited:
EP-A1- 0 595 518
DE-A1- 4 446 058
JP-A- 3 089 069
WO-A-97/48923
DE-A1- 19 839 837
US-A- 4 845 621
Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent
Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the
Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been
paid. (Art. 99(1) European Patent Convention).
Printed by Jouve, 75001 PARIS (FR)
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EP 1 312 837 B1
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
[0001] The invention relates to a shift control apparatus
and a shift control method of a transmission capable of
automatic shifting. More particularly, the invention relates
to a technology that allows downshifting to an emergency
low speed gear stage for obtaining the gear ratio greater
than that of the lowest speed gear stage among a plurality
of gear stages normally used for the automatic shifting.
This makes it possible to prevent insufficiency in the driving force of the vehicle.
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2. Description of Related Art
[0002] There is a known transmission capable of automatic shifting. For example, there is a parallel bi-axial
type constant-mesh manual transmission which is capable of automatic shifting using a shift actuator such as a
hydraulic cylinder. There is an automatic transmission
which is capable of automatic shifting using a shift actuator for selectively engaging elements of multiple sets of
planetary gear devices. There is a belt-type continuously
variable transmission having a manual shift mode in
which gear stages with multiple gear ratios are selectively
established in accordance with a command from a manual shift operation switch.
[0003] The gear ratios of multiple gear stages normally
used in the automatic shifting of a vehicle with a transmission capable of automatic shifting may be set so as
to satisfy two contradicting requirements, that is, the driving force and the fuel efficiency. More specifically, the
gear ratio is set to obtain a driving force sufficient for the
vehicle to run on an uphill or sufficient for the vehicle to
achieve acceleration upon taking off while keeping high
fuel efficiency. In order to satisfy one of the above contradicting requirements, the other requirement is likely to
be sacrificed. If the gear ratio of the lowest gear stage is
decreased, the driving force of the vehicle running on the
flat road becomes sufficient while the fuel efficiency is
improved. At the aforementioned gear ratio, it is difficult
for the vehicle to run on the uphill and to achieve acceleration sufficient to take off. Meanwhile, if the gear ratio
of the lowest gear stage is increased so as to obtain the
driving force sufficient for the vehicle to run on the uphill
or to achieve acceleration sufficient to take off, the fuel
efficiency of the vehicle running on the flat road may be
deteriorated.
[0004] There is disclosed a shift control apparatus of
a vehicular automatic transmission provided with an extra
low range. In the above shift control apparatus, if the
extra low range is selected, shifting is performed within
a transmission range including the extra low speed gear
stage, which is different from that of the range normally
used. For example, Japanese Patent Application Laid-
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Open No. 3-89069, considered as closest prior art, discloses the shift control apparatus as aforementioned.
When the vehicle is running on the uphill or takes off in
the acceleration state, the extra low range is selected so
as to obtain the required driving force. Meanwhile, when
the vehicle is running in a normal condition, the D range
is selected so as to improve the fuel efficiency.
[0005] In the aforementioned shift control apparatus,
however, a driver needs to select the D range or the extra
low range using a shift lever depending on the running
state of the vehicle. Since it cannot be expected that an
unskilled driver performs the shift operation appropriately
using the shift lever depending on the running state of
the vehicle, the fuel efficiency of the vehicle may be deteriorated.
SUMMARY OF THE INVENTION
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[0006] It is an object of the invention to provide an improved shift control apparatus of a transmission for a vehicle.
[0007] This object is solved for example by the features
of claim 1. Further developments are subject matter of
the further claims.
[0008] According to an embodiment of the invention,
a shift control apparatus of transmission for a vehicle
including a plurality of gear stages for automatic transmission and an emergency low gear stage set adjacent
to a lowest gear stage of the plurality of gear stages, the
emergency low gear stage having a gear ratio greater
than that of the lowest gear stage. The shift control apparatus is provided with power insufficiency determination means that determines whether the vehicle is in a
power insufficiency state requiring a driving force more
than a predetermined driving force obtained upon establishment of the lowest gear stage on the basis of a predetermined parameter that indicates a state of the vehicle
during running, and shift control means that controls the
transmission to automatically downshift to the emergency low gear stage when the power insufficiency determination means determines that the vehicle is in the power
insufficiency state. When it is determined that the driving
force larger than that obtained upon establishment of the
lowest speed gear stage is required, downshifting is automatically performed from the lowest speed gear stage
to the emergency low speed gear stage. In the case
where the driving force larger than that obtained by the
lowest speed gear stage within the automatic transmission range for the normal running state is required, downshifting is automatically performed from the lowest speed
gear stage to the emergency low speed gear stage, providing the gear ratio greater than that of the lowest speed
gear stage without requiring skilled technique.
[0009] The power insufficiency determination means
determines that the vehicle is in the power insufficiency
state when an actual ascending slope of a road on which
the vehicle is running becomes greater than a predetermined ascending slope of the road on which the vehicle
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is capable of running at the lowest gear stage. This makes
it possible to provide substantially high driving force required for the vehicle to run on the road with a sharp slope.
[0010] The vehicle includes at least one automatic
clutch disposed on a power transmission path between
an engine and the transmission. The power insufficiency
determination means determines that the vehicle is in
the power insufficiency state when the vehicle is in one
of a stopped state and substantially stopped state, and
a slip amount of the automatic clutch becomes equal to
or greater than a predetermined value. This makes it possible to increase the gear ratio of the transmission when
a slip amount of the automatic clutch is equal to or higher
than the predetermined value while the vehicle is in a
stopped or substantially stopped state. The required driving force, thus, can be automatically obtained.
[0011] The shift control apparatus has an automatic
shift mode in which one of the plurality of gear stages is
automatically selected on the basis of an actual state of
the vehicle in accordance with a previously stored shift
map, and a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of
an operator of the vehicle. The shift control means controls the transmission to automatically downshift to the
emergency low speed gear stage in the automatic shift
mode. This allows the transmission to automatically perform downshifting from the lowest speed gear stage to
the emergency low speed gear stage when it is determined that the driving force of the vehicle in the automatic
shift mode becomes insufficient.
[0012] The shift control apparatus has an automatic
shift mode in which one of the plurality of gear stages is
automatically selected on the basis of an actual state of
the vehicle in accordance with a previously stored shift
map, and a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of
an operator of the vehicle. The shift control means controls the transmission to downshift to the emergency low
speed gear stage in the manual shift mode in response
to an operation of a manual shift command switch. This
allows the transmission to automatically perform downshifting from the lowest speed gear stage to the emergency low speed gear stage upon operation of a manual
transmission command switch even in the manual transmission mode. The required high driving force, thus, can
be obtained.
[0013] The shift control apparatus has an automatic
shift mode in which one of the plurality of gear stages is
automatically selected on the basis of an actual state of
the vehicle in accordance with a previously stored shift
map, and a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of
an operator of the vehicle. The shift control means controls the transmission to downshift automatically to the
emergency low speed gear stage in the manual shift
mode. This allows the transmission to automatically perform downshifting from the lowest speed gear stage to
the emergency low speed gear stage when it is deter-
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mined that the driving force of the vehicle is insufficient
even in the manual transmission mode.
[0014] The shift control apparatus employs the transmission formed as a manually shifted transmission of parallel bi-axial constant-mesh type. This makes it possible
to increase the fuel efficiency because of reduced loss
resulting from low friction.
[0015] Preferably a pair of gears disengaged from the
emergency low speed gear in a normal state, and the
emergency low speed gear stage is established by bringing the pair of gears into engagement with the emergency
low speed gears. This makes it possible to improve the
fuel efficiency owing to reduced loss as the gears are
disengaged from the emergency low speed gears in a
normal state, and brought into engagement therewith so
as to establish the emergency low speed gear stage.
BRIEF DESCRIPTION OF THE DRAWINGS
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[0016]
FIG. 1 is a schematic diagram illustrating the construction of a vehicular drive apparatus including a
shift control apparatus of a vehicular transmission
according to an embodiment of the invention;
FIG. 2 is a schematic diagram illustrating the construction of an automatic clutch and a stepped transmission shown in FIG. 1;
FIG. 3 is a functional block diagram illustrating the
main portion of a control function of an electronic
control unit for shifting shown in FIG. 1;
FIG. 4 is a normally-used shift map, which is used
for normal shift control in shift control means shown
in FIG. 3;
FIG. 5 is an emergency shift map, which is used for
shift control when a driving force is insufficient in the
shift control means shown in FIG. 3;
FIG. 6 is a flowchart illustrating the main portion of
the control operation of the electronic control unit for
shifting shown in FIG. 1; and
FIG. 7 is a schematic diagram illustrating the construction of a stepped transmission according to another embodiment of the invention, which corresponds to FIG. 2.
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DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
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[0017] Hereinafter, an embodiment of the invention will
be described with reference to the accompanying drawings.
[0018] FIG. 1 is a schematic diagram illustrating the
construction of a driving apparatus 10 for a vehicle and
a control apparatus. An engine 12 serving as a power
source or a driving power source generates power so as
to be input to a transmission 16 via an automatic clutch
14. Then power output from the transmission 16 is transmitted to driving wheels via a differential gear device (not
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shown) and an axle (not shown). FIG. 2 is a schematic
diagram illustrating the construction of the automatic
clutch 14 and the transmission 16.
[0019] Referring to FIG. 2, the automatic clutch 14 is
provided in a clutch case 20 attached to a crankshaft 18
of the engine 12. The automatic clutch 14 includes a pair
of a first friction clutch 24a and a second friction clutch
24b both of which are dry type single disc clutches. The
first friction clutch 24a and the second friction clutch 24b
are automatically engaged or released by a first clutch
release motor 22a and a second clutch release motor
22b, both of which function as clutch actuators. The
above-mentioned clutch case 20 also functions as a flywheel. The first friction clutch 24a and the second friction
clutch 24b are configured to have a first clutch disc 28a,
a second clutch disc 28b, a first fixed pressing plate 30a,
a first movable pressing plate 30b, a second fixed pressing plate 32a, a second movable pressing plate 32b, a
first diaphragm spring 34a, and a second diaphragm
spring 34b. The first clutch disc 28a and the second clutch
disk 28b are provided on a first clutch output shaft 26a
(a first input shaft of the transmission 16) and a second
clutch output shaft 26b (a second input shaft of the transmission 16) concentric therewith, respectively. The first
clutch output shaft 26a and the second clutch output shaft
26b are concentric with each other. The first fixed pressing plate 30a and the first movable pressing plate 30b,
and the second fixed pressing plate 32a and the second
movable pressing plate 32b are provided in the clutch
case 20 so as to press and interpose the first clutch disc
28a and the second clutch disc 28b, respectively. The
first diaphragm spring 34a and the second diaphragm
spring 34b urge the first movable pressing plate 30b and
the second movable pressing plate 32b against the first
fixed pressing plate 30a and the second fixed pressing
plate 32b, respectively so as to press the first clutch disc
28a and the second clutch disc 28b for transmitting power. Referring to FIG. 1, the above-mentioned first clutch
release motor 22a and the second clutch release motor
22b are respectively engaged with the first diaphragm
spring 34a and the second diaphragm spring 34b directly
or indirectly . The first clutch release motor 22a and the
second clutch release motor 22b disengage the first friction clutch 24a and the second friction clutch 24b, respectively so as to reduce the urging force applied to the
first movable pressing plate 30b and the second movable
pressing plate 32b.
[0020] The transmission 16 is of a parallel bi-axial type
constant-mesh type. This type of transmission is well
known as a manual transmission. However, the transmission 16 also may function as an automatic transmission, in which a gear stage Gi (i = 1 to 5), i.e., a gear ratio
γ (a rotating speed NIN of the first input shaft 26a or the
second input shaft 26b / a rotating speed NOUT of an
output shaft 48) can be automatically selected using an
electric or hydraulic select actuator 50 and a shift actuator
52. The transmission 16 includes (a) the first input shaft
26a and the second input shaft 26b which are concentric
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with each other; (b) a counter shaft 42 which is provided
in parallel with the first input shaft 26a and the second
input shaft 26b; (c) pairs of shift gears 44a to 44e with
different gear ratios which are provided between the first
and second input shafts 26a, 26b and the counter shaft
42 such that they are engaged in a normal state, a pair
of reverse gear 44r, and a pair of emergency low speed
gear 44u; (d) multiple synchro mesh type positive clutches 46a to 46e, 46r, and 46u corresponding to the pairs
of shift gear 44a to 44e, the reverse gear 44r, and the
emergency low speed gear 44u, respectively; and (e) the
output shaft 48 which is provided in parallel with the counter shaft 42, and which is connected to an end thereof.
When the shift actuator 52 drives one shift fork selected
by the select actuator 50 from among four shift forks operatively coupled to the positive clutches 46a to 46e, 46r,
and 46u, a desired gear stage among forward five gear
stages Gi (i = 1 to 5) is established. Note that a pinion
(not shown) is provided between the reverse gears 44r
such that the pinion is mutually engaged with the gears
44r to make the rotating direction of the output shaft 48
opposite to the rotating direction during forward movement.
[0021] Referring to FIG. 2, when power is transmitted
via the pair of shift gears 44a due to engagement of the
positive clutch 46a, a first speed gear stage G1 is established. The first speed gear stage G1 has a gear ratio γ1,
for example, approximately 3.56, as the greatest gear
ratio in the normally-used automatic shift range. When
power is transmitted via the pair of shift gear 44b due to
engagement of the positive clutch 46b, a second speed
gear stage G2 is established. The second speed gear
stage G2 has a gear ratio γ2 which is smaller than the
gear ratio γ1. When power is transmitted via the pair of
shift gear 44c due to engagement of the positive clutch
46c, a third speed gear stage G3 is established. The third
speed gear stage G3 has a gear ratio γ3 which is smaller
than the gear ratio γ2. When power is transmitted via the
pair of shift gear 44d due to engagement of the positive
clutch 46d, a fourth speed gear stage G4 is established.
The fourth speed gear stage G4 has a gear ratio γ4 (= 1)
which is smaller than the gear ratio γ3. When power is
transmitted via the pair of shift gear 44e due to engagement of the positive clutch 46e, a fifth speed gear stage
G5 is established. The fifth speed gear stage G5 has a
gear ratio γ5 (<1) which is smaller than the gear ratio γ4.
When power is transmitted via the pair of shift gear 44r
due to engagement of the positive clutch 46r, a reverse
gear stage Gr is established. In addition, when power is
transmitted via the pair of shift gear 44u due to engagement of the positive clutch 46u, an emergency low speed
gear stage Gu is established. The emergency low speed
gear stage Gu has a gear ratio γu, for example, approximately 4.50 which is greater than the gear ratio γ1.
[0022] In the above-mentioned transmission 16, the
pair of shift gears 44a for establishing the first gear stage
G1, the pair of shift gears 44c for establishing the third
gear stage G3, and the pair of shift gears 44e for estab-
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lishing the fifth gear stage G5 are provided between the
second input shaft 26b and the counter shaft 42. In addition, the pair of shift gears 44b for establishing the second gear stage G2 and the pairs of shift gears 44d for
establishing the fourth gear stage G4 are provided between the first input shaft 26a and the counter shaft 42.
When shifting to an adjacent gear stage is sequentially
performed, the first friction clutch 24a and the second
friction clutch 24b are alternately controlled to be opened
or closed. Accordingly, it is possible to suitably prevent
torque loss during shifting by sliding and disengaging one
of the first friction clutch 24a and the second friction clutch
24b, while engaging the other.
[0023] Referring to FIG. 1, a shift operation device 54
is disposed, for example, next to a driver’s seat. A shift
lever 56 is provided in the shift operation device 54. The
shift lever 56 can be operated to move to a reverse position R for backing up; a neutral position N for bringing
the vehicle into a neutral state in which a power transmitting path in the transmission 16 is interrupted to prevent engagement of all the positive clutches 46a to 46e,
46r, and 46u; a forward running position D in the automatic shift mode; an upshift command position "+" in the
manual shift mode; and a downshift command position
"-" in the manual shift mode. The shift operation device
54 is provided with a switch (not shown) for detecting the
operation position of the shift lever 56. Note that a parking
position P for locking the output shaft 48 of the transmission 16 may be provided next to the above-mentioned
reverse position R.
[0024] The above-mentioned shift operation device 54
supplies an electronic control unit 60 with a signal indicative of the operation position of the shift lever 56 operated by the driver. A throttle opening sensor 62 detects
a throttle opening θTH (%) of the engine 12, and supplies
the electronic control unit 60 with a signal indicative of
the throttle opening θTH. An accelerator opening sensor
64 detects an accelerator opening θACC (%) of an accelerator (not shown), and supplies the electronic control
unit 60 with a signal indicative of the accelerator opening
θACC. An engine rotating speed sensor 66 detects a rotating speed NE of the crank shaft 18 of the engine 12,
i.e., an input rotating speed of the friction clutches 24a,
24b, and supplies the electronic control unit 60 with a
signal indicative of the engine speed NE. A first input shaft
rotating speed sensor 68a and a second input shaft rotating speed sensor 68b detect a first input shaft rotating
speed NINa and a second input shaft rotating speed NINb,
and supply the electronic control unit 60 with signals indicative of the first input shaft rotating speed NINa and
the second input shaft rotating speed NINb, respectively.
In addition, a vehicle speed sensor 70 detects a rotating
speed NOUT of the output shaft 48 of the transmission
16, calculates a vehicle speed V (km/h) based on the
output shaft rotating speed NOUT, and supplies the electronic control unit 60 with signals indicative of the output
shaft rotating speed NOUT and the vehicle speed V.
[0025] The above-mentioned electronic control unit 60
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is a so-called microcomputer including a CPU, a ROM,
a RAM, input and output interfaces, and the like. The
electronic control unit 60 processes the input signals according to a program previously stored in the ROM using
a temporary memory function, and controls the first clutch
release motor 22a, the second clutch release motor 22b,
the select actuator 50, and the shift actuator 52 in order
to perform the engagement control of the automatic
clutch 14 and the shift control of the transmission 16.
[0026] FIG. 3 is a functional block diagram illustrating
a main portion of the control function of the above-mentioned electronic control unit 60. When the shift lever 56
is selected at the position D in the automatic shift mode,
shift control means 80 determines if gear-shifting is required based on the actual vehicle state (the vehicle
speed V and the throttle opening θTH) obtained in accordance with, for example, a map for normal running, i.e., a
normally-used shift map shown in FIG. 4. Then, the shift
control means 80 controls the first clutch release motor
22a, the second clutch release motor 22b, the select actuator 50, and the shift actuator 52 so as to perform the
required gear-shifting, that is, to establish the required
gear stage. As is apparent from FIG. 4, the shifting in the
automatic shift mode ranges between the first gear stage
G1 and the fifth gear stage G5.
[0027] Power insufficiency determination means 82
determines whether the driving force required for driving
the vehicle becomes greater than the driving force generated at the lowest gear stage of the transmission 16,
i.e., the first gear stage G1 based on a map including a
predetermined relationship. The power insufficiency determination means 82 includes slope determination
means 84 and slip amount determination means 86. The
slope determination means 84 determines whether the
required driving force of the vehicle has become larger
than that obtained upon establishment of the first gear
stage G1. When the actual vehicle acceleration (change
rate of the vehicle speed V) is greater than the vehicle
acceleration corresponding to the present throttle opening θTH during running on the flat road by a predetermined
amount or more, it is determined that the actual slope of
the ascending road has become greater than the predetermined slope of the ascending road on which the vehicle is able to run at the first gear stage G1. The slip amount
determination means 86 determines whether the vehicle
speed V is lower than a vehicle speed value V0 (appropriately 5 km/h, for example) which is predetermined to
determine if the vehicle speed V indicate the substantially
stopped state of the vehicle as well as determines whether the slip amount (= NE - NINb)of the automatic clutch
14 has become a predetermined value or greater. The
slip amount of the automatic clutch 14 represents the slip
amount (= NE - NINa or NINb) of one of the first friction
clutch 24a and the second friction clutch 24b, which has
been engaged.
[0028] When the power insufficiency determination
means 82 determines that, either in the automatic mode
or the manual mode, the driving force which is greater
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the driving force to be generated at the lowest gear stage,
that is, the first gear stage G1 of the transmission 16 is
required for driving the vehicle, the shift control means
80 determines the gear stage to be selected on the basis
of the actual state of the vehicle (vehicle speed V and
the throttle opening θTH) referring to a map indicating the
relationship between the throttle opening and the vehicle
speed. Then the first clutch release motor 22a, the second clutch release motor 22b, the select actuator 50, and
the shift actuator 52 are controlled so as to perform shifting to the selected gear stage. As is apparent from FIG.
5, the shifting with insufficient driving force is performed
in the range from the emergency low gear stage Gu to
the fifth gear stage G5. When the vehicle is in the stopped
state or running at a relatively lower speeds during running at the first gear stage G1, it is determined that the
driving force of the vehicle is insufficient, requiring the
driving force further greater than the driving force generated upon establishment of the first gear stage G1. In the
aforementioned case, the emergency low gear stage Gu
may be selected from the first gear stage automatically.
[0029] Power sufficiency determination means 88 determines that the power insufficiency state has been corrected when the vehicle speed V exceeds a reference
vehicle speed value V1 predetermined to, for example,
approximately 20 km/h. The shift control means 80
switches the normal map as shown in FIG. 4 from the
emergency map as shown in FIG. 5 when the power sufficiency determination means 88 determines that the
power insufficiency state has been corrected. Subsequently the shift control means 80 executes the automatic
shifting control on the basis of the switched map.
[0030] When the manual shift mode is selected by operating the shift lever 56, the shift control means 80 upshifts or downshifts the transmission 16 to the adjacent
gear stage in accordance with the operating position "+"
or "-" of the shift lever 56. The shifting in the manual shift
mode is performed in the range from the emergency low
gear stage Gu to the fifth gear stage G5. When it is determined that the driving force for the vehicle is insufficient, the shift lever 56 is operated so as to downshift to
the emergency low gear stage Gu.
[0031] Hereinafter, the main portion of the control operation of the ECU 60, that is, control for switching the
shift map in case of insufficient driving force for the vehicle will be described referring to a flowchart of FIG. 6.
The routine shown in FIG. 6 is repeatedly performed at
a predetermined cycle time, for example, at the cycle
time ranging between several milliseconds and several
ten milliseconds either in the automatic shift mode or the
manual shift mode.
[0032] Referring to FIG. 6, in step S1, it is determined
whether a flag Fu indicating the state of insufficient driving
force has been cleared, that is, the flag Fu has been set
to 0. The flag Fu can be used for indicating if the slope
of the ascending road on which the vehicle is running
exceeds the predetermined value. As YES is expected
to be obtained in step S1 in the initial stage of the routine,
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the process proceeds to step S2. In step S2, the power
insufficiency determination means 82 determines whether the driving power is insufficient for the vehicle to run
on the ascending road with slope greater than the predetermined value. When the actual vehicle acceleration
is equal to or lower than the vehicle acceleration corresponding to the throttle opening θTH obtained during running on the flat road, or the slip amount of the automatic
clutch 14 exceeds the predetermined value at the vehicle
speed V that is substantially zero, it is determined that
the slope of the ascending road has been greater than
the predetermined slope value. If YES is obtained in step
S2, the process proceeds to step S3 where it is determined that the vehicle has been in a predetermined
stopped state when the vehicle speed V is 0, the brake
pedal is at ON state, and the side brake is at ON state,
respectively.
[0033] If YES is obtained in step S3, the process proceeds to step S4 where the flag Fu is set to 1. The process
then proceeds to step S5 corresponding to the shift control means 80. In step S5, the shift map shown in FIG. 4
is switched to the shift map shown in FIG. 5. Accordingly
downshifting from the first gear stage G1 to the emergency low gear stage Gu is automatically performed, and
the vehicle runs at the emergency low gear stage Gu.
The process proceeds to step S6 corresponding to the
power sufficiency determination means 88, where it is
determined whether the vehicle state has been in the
predetermined state, for example, whether the vehicle
speed V is equal to or greater than 20 km. As NO is
obtained in step S6 in the initial step, the routine returns
to step S 1 and subsequent steps.
[0034] In the aforementioned control cycle, as the flag
Fu is set at "1", NO is obtained in step S1 in the next
control cycle, shift control according to the shift map
shown in FIG. 5 is continued, that is, the vehicle continues
running at the emergency low speed gear stage Gu. If
the vehicle speed V increases as the vehicle is operated
by the high driving force, YES is obtained in step S6. The
process then proceeds to step S7 where the flag Fu is
cleared to 0. Then in step S8 corresponding to the shift
control means 80, the shift map shown in FIG. 5 is
switched to the shift map used for the normal operation
of the vehicle such that the normal automatic transmission control is executed subsequently.
[0035] According to the embodiment, if it is determined
that the driving force that is greater than that obtained
upon establishment of the first gear stage (the lowest
speed gear stage) G1 is required in step S2 (corresponding to the power insufficiency determination means 82),
the transmission 16 is downshifted to the emergency low
gear stage Gu from the first gear stage G1 automatically
in step S5 (corresponding to the shift control means 80).
That is, in the state requiring the driving force greater
than the one obtained at the lowest speed gear stage
within the automatic shifting range for normal vehicle operation, the emergency low speed gear stage with greater
gear ratio than that of the first gear stage G1. Such control
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is automatically executed irrespective of driving skill of
the vehicle operator. This makes it possible to automatically control such that greater driving force is provided
to correct insufficient state without deteriorating the fuel
efficiency of the vehicle running in the normal state.
[0036] Also, according to the embodiment, the power
insufficiency determination means 82 determines that
the driving force of the vehicle is insufficient when the
actual ascending slope becomes greater than the predetermined ascending slope of the road on which the
vehicle is able to run at the first gear stage of the vehicle
(the lowest speed gear stage) G1. Therefore, it is possible
to automatically obtain sufficient driving force required
for the vehicle to run on the road with a sharp slope.
[0037] According to the embodiment, the power insufficiency determination means 82 determines that the driving force of the vehicle is insufficient when the vehicle is
in the stopped state or in the substantially stopped state,
and at the same time, the slip amount of the automatic
clutch 14 is equal to or larger than the predetermined
value. Therefore, the gear ratio of the stepped transmission is increased when the slip amount of the automatic
clutch is equal to or larger than the predetermined value
while the vehicle is in the stopped state or in the substantially stopped state. Accordingly, the required driving
force can be automatically obtained.
[0038] According to the embodiment, the shift control
means 80 switches the shift mode between the automatic
shift mode and the manual shift mode. In the automatic
shift mode, the gear stage of the transmission 16 is automatically selected based on the actual vehicle state
according to, for example, the previously-stored shift map
shown in FIG. 4. In the manual shift mode, the gear stage
of the transmission 16 is selected by manual shift operation of the driver. When it is determined that the driving
force is insufficient either in the automatic shift mode or
the manual shift mode, the shift control means 80 automatically downshifts the transmission 16 from the first
gear stage (the lowest speed gear stage) G1 to the emergency low gear stage Gu. Therefore, when the driving
force of the vehicle becomes insufficient, it is possible to
automatically downshift the transmission 16 to the emergency low gear stage Gu without requiring skilled technique. Accordingly, both the high driving force and good
fuel efficiency can be obtained. In the manual shift mode,
the shift control means 80 downshifts the transmission
16 to the emergency low speed gear stage Gu in response to the operation of the manual shift command
switch by the shift lever 56 in the shift operation device
54. Therefore, even in the manual shift, it is possible to
downshift the transmission 16 to the emergency low
speed gear stage Gu in response to the operation of the
manual shift command switch. Accordingly, a high driving
force of the vehicle can be obtained as required.
[0039] According to the embodiment, since the
stepped transmission 16 is a parallel two-axes type constant-mesh transmission, the friction is reduced, resulting
in reduced loss. Therefore, the fuel efficiency is further
5
12
improved.
[0040] FIG. 7 is a schematic diagram illustrating the
construction of a transmission 16 according to another
embodiment of the invention. In this embodiment, the
same components as in the above-mentioned embodiment are identified with the same reference numerals,
and the descriptions thereof are omitted.
[0041] The transmission 16 shown in FIG. 7 is different
from the transmission 16 shown in FIG. 2 in that:
10
15
20
25
30
35
40
45
50
55
7
(a) the pair of emergency low speed gears 44u are
normally in a disengaged state;
(b) a pair of gears 90, 92 constantly in an engaged
state are normally disengaged from the emergency
low speed gears 44u, and the gears 90, 92 are
brought into engaged with the emergency low speed
gears 44u for establishing the emergency low speed
gear stage Gu; and
(c) the positive clutch 46u for the emergency low
gears is not provided.
[0042] The pair of gears 90, 92 are rotatively supported
so as to be moveable in the direction of rotating axis by
the engagement operation lever 94 operated by the actuator or the manual lever. According to the embodiment,
since the emergency low speed gears 44u for establishing the emergency low gear stage Gu are normally in a
disengaged state, the rotation loss of the transmission
16 is further reduced, improving the fuel efficiency.
[0043] Although the embodiments of the invention
have been described in detail with reference to the accompanying drawings, it is to be understood that the invention is not limited to these embodiments, and that the
invention may be realized in other embodiments in which
various changes and modifications are made based on
the knowledge of persons skilled in the art.
[0044] For example, although the transmission 16 according to the above-mentioned embodiments is a parallel two-axes type constant-mesh manual transmission,
it is possible to employ an automatic transmission using
a shift actuator for selectively engaging elements of multiple sets of planetary gear devices. It is also possible to
employ a belt-type continuously variable transmission in
which a transmission belt is wound around a pair of variable pulleys each having variable effective diameter, in
which a manual shift mode is set such that gear stages
with multiple gear ratios are selectively established according to a command from a shift lever or a manual shift
operation switch. Further, a continuously variable transmission with a sub-transmission and the like may be employed.
[0045] The automatic clutch 14 according to the embodiments is operated to be engaged or released by the
first clutch release motor 22a and the second clutch release motor 22b both of which are electrically driven.
However, the automatic clutch 14 may be operated by
another actuator such as a hydraulic cylinder. Although
the automatic clutch 14 according to the embodiments
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EP 1 312 837 B1
includes a pair of the first friction clutch 24a and the second friction clutch 24b, a single friction clutch may be
employed. Further the automatic clutch 14 may be a wet
type multiple disc clutch, an electromagnetic type clutch
in which a friction disc is pressed due to an attraction
force of a magnet, an electromagnetic type magnetic particle clutch in which magnetic particles are adsorbed into
a gap, and power is transmitted through the magnetic
particles, or another type of clutch.
[0046] In the embodiments, the shifting state of the vehicle is determined by the shift control means 80 based
on the vehicle state defined by the throttle opening θTH
and the vehicle speed V. However, instead of the throttle
opening θTH, it is possible to use a parameter representing an engine load, such as an accelerator opening θACC,
an intake air amount, an intake pipe negative pressure,
or a fuel injection amount.
[0047] In the embodiments, the shift control means 80
switches the shift map for an emergency state shown in
FIG. 5 from the shift map for a normal state shown in
FIG. 4 so as to automatically establish the emergency
low speed gear stage Gu when the power insufficiency
determination means 82 determines the power insufficiency state. However, instead of switching between the
shift maps, the shift control means 80 may be structured
to simply downshift the transmission to the emergency
low speed gear stage Gu from the first gear stage G1
[0048] In the embodiments, the power insufficiency determination means 82 determines insufficiency state
when the ascending slope derived from the throttle opening θTH is equal to or greater than the predetermined
value and the slip amount of the automatic clutch 14 is
equal to or greater than the predetermined value. However, the power insufficiency state may be determined
based on the other conditions such as the inclination of
the road detected by the inclination angle detector.
[0049] When power insufficiency determination
means 82 determines that a vehicle is in a power insufficiency state requiring a driving force higher than that
obtained at the lowest gear stage G1 of multiple gears
for normal running of the vehicle, the shift control means
80 controls the transmission 16 to automatically perform
downshifting from the lowest gear stage G1 to the emergency low speed gear stage Gu. This makes it possible
to establish the emergency low speed gear stage with
the gear ratio greater than that obtained at the lowest
gear stage G1 for normal running of the vehicle without
requiring skilled technique.
[0050] When power insufficiency determination
means (82) determines that a vehicle is in a power insufficiency state requiring a driving force higher than that
obtained at the lowest gear stage (G1) of multiple gears
for normal running of the vehicle, the shift control means
80 controls the transmission (16) to automatically perform downshifting from the lowest gear stage (G1) to the
emergency low speed gear stage (Gu). This makes it
possible to establish the emergency low speed gear
stage with the gear ratio greater than that obtained at the
14
lowest gear stage (G1) for normal running of the vehicle
without requiring skilled technique.
Selected figure: Fig. 3
5
Claims
1.
10
15
A shift control apparatus of a transmission (16) for a
vehicle including a plurality of gear stages for automatic transmission and an emergency low gear
stage (Gu) set adjacent to a lowest gear stage (G1)
of the plurality of gear stages, the emergency low
gear stage having a gear ratio greater than that of
the lowest gear stage; the shift control apparatus
comprising:
power insufficiency determination means (82)
that determines whether the vehicle is in a power
insufficiency state requiring a driving force more
than a predetermined driving force obtained upon establishment of the lowest gear stage on
the basis of a predetermined parameter that indicates a state of the vehicle during running; and
shift control means (80) that controls the transmission (16) to automatically downshift to the
emergency low gear stage when the power insufficiency determination means (82) determines that the vehicle is in the power insufficiency state.
20
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30
2.
The shift control apparatus according to claim 1,
wherein the parameter comprises a relationship of
a vehicle speed with respect to one of a throttle opening, accelerator opening, an intake air amount, a
negative pressure of an intake pipe, and a fuel injection amount.
3.
The shift control apparatus according to claim 1 or
2, wherein the power insufficiency determination
means determines that the vehicle is in the power
insufficiency state when an actual ascending slope
of a road on which the vehicle is running becomes
greater than a predetermined ascending slope of the
road on which the vehicle is capable of running at
the lowest gear stage.
4.
The shift control apparatus according to claim 1,
wherein
35
40
45
50
55
8
the vehicle includes at least one automatic
clutch (14) disposed on a power transmission
path between an engine and the transmission
(16); and
the power insufficiency determination means
(82) determines that the vehicle is in the power
insufficiency state when the vehicle is in one of
a stopped state and substantially stopped state,
and a slip amount of the automatic clutch (14)
15
EP 1 312 837 B1
becomes equal to or greater than a predetermined value.
5.
6.
The shift control apparatus according to claim 4,
wherein the at least one automatic clutch (14) comprises one of a dry type clutch, a wet type multiple
disc clutch, an electromagnetic type clutch, and an
electromagnetic type magnetic particle clutch.
The shift control apparatus according to any one of
claims 1 to 5, wherein
an automatic shift mode in which one of the plurality of gear stages is automatically selected on
the basis of an actual state of the vehicle in accordance with a previously stored shift map, and
a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of an operator of the vehicle are set, and
the shift control means (80) controls the transmission (16) to automatically downshift to the
emergency low speed gear stage in the automatic shift mode.
7.
The shift control apparatus according to any one of
claims 1 to 5, wherein
an automatic shift mode in which one of the plurality of gear stages is automatically selected on
the basis of an actual state of the vehicle in accordance with a previously stored shift map, and
a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of an operator of the vehicle are set, and
the shift control means (80) controls the transmission (16) to downshift to the emergency low
speed gear stage in the manual shift mode in
response to an operation of a manual shift command switch.
axial constant-mesh type.
5
10
15
20
30
35
The shift control apparatus according to any one of
claims 1 to 5, wherein
an automatic shift mode in which one of the plurality of gear stages is automatically selected on
the basis of an actual state of the vehicle in accordance with a previously stored shift map, and
a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of an operator of the vehicle are set, and
the shift control means (80) controls the transmission (16) to downshift automatically to the
emergency low speed gear stage in the manual
shift mode.
45
50
11. The shift control apparatus according to any one of
claims 1 to 10, wherein the transmission comprises
one of an automatic transmission with a plurality of
planetary gear sets, a continuously variable transmission with a manual shift mode, and a continuously
variable transmission with a sub-transmission.
12. A shift control method of a transmission (16) for a
vehicle including a plurality of gear stages for automatic transmission and an emergency low gear
stage (Gu) set adjacent to a lowest gear stage (G1)
of the plurality of gear stages, the emergency low
gear stage having a gear ratio greater than that of
the lowest gear stage, the shift control method comprising the steps of:
determining whether the vehicle is in a power
insufficiency state requiring a driving force more
than a predetermined driving force obtained upon establishment of the lowest gear stage on
the basis of a predetermined parameter that indicates a state of the vehicle during running; and
controlling the transmission (16) to automatically downshift to the emergency low gear stage
when it is determined that the vehicle is in the
power insufficiency state.
13. A shift control method according to claim 12, wherein
the parameter comprises a relationship of a vehicle
speed with respect to one of a throttle opening, accelerator opening, an intake air amount, a negative
pressure of an intake pipe, and a fuel injection
amount.
14. A shift control method according to claim 12 or 13,
wherein the power insufficiency determination
means determines that the vehicle is in the power
insufficiency state when an actual ascending slope
of a road on which the vehicle is running becomes
greater than a predetermined ascending slope of the
road on which the vehicle is capable of running at
the lowest gear stage.
15. A shift control method according to claim 12, wherein
55
9.
10. The shift control apparatus according to claim 9, further comprising a pair of gears (90, 92) disengaged
from the emergency low speed gears in a normal
state, wherein the emergency low speed gear stage
(Gu) is established by bringing the pair of gears into
engagement with the emergency low speed gear.
25
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8.
16
The shift control apparatus according to any one of
claims 1 to 8, wherein the transmission (16) comprises a manually shifted transmission of parallel bi-
9
the vehicle includes at least one automatic
clutch (14) disposed on a power transmission
path between an engine and the transmission
(16); and
17
EP 1 312 837 B1
it is determined that the vehicle is in the power
insufficiency state when the vehicle is in one of
a stopped state and substantially stopped state,
and a slip amount of the automatic clutch (14)
becomes equal to or greater than a predetermined value.
16. A shift control method according to claim 15, wherein
the at least one automatic clutch (14) comprises one
of a dry type clutch, a wet type multiple disc clutch,
an electromagnetic type clutch, and an electromagnetic type magnetic particle clutch.
17. A shift control method according to any one of claims
12 to 16, wherein
an automatic shift mode in which one of the plurality of gear stages is automatically selected on
the basis of an actual state of the vehicle in accordance with a previously stored shift map, and
a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of an operator of the vehicle are set, and
the transmission (16) is controlled to automatically downshift to the emergency low speed gear
stage in the automatic shift mode.
manually shifted transmission of parallel bi-axial
constant-mesh type.
5
21. A shift control method according to claim 20, wherein
a pair of gears (90, 92) are disengaged from the
emergency low speed gears in a normal state, and
the emergency low speed gear stage (Gu) is established by bringing the pair of gears into engagement
with the emergency low speed gear.
10
15
22. A shift control method according to any one of claims
12 to 21, wherein the transmission includes one of
an automatic transmission with a plurality of planetary gear sets, a continuously variable transmission
with a manual shift mode, and a continuously variable transmission with a sub-transmission.
Patentansprüche
20
1.
25
18. A shift control method according to any one of claims
12 to 16, wherein
30
an automatic shift mode in which one of the plurality of gear stages is automatically selected on
the basis of an actual state of the vehicle in accordance with a previously stored shift map, and
a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of an operator of the vehicle are set, and
the transmission (16) is controlled to downshift
to the emergency low speed gear stage in the
manual shift mode in response to an operation
of a manual shift command switch.
35
40
45
50
2.
Schaltsteuergerät gemäß Anspruch 1, wobei der Parameter eine Beziehung einer Fahrzeuggeschwindigkeit in Bezug auf entweder eine Drosselöffnung,
eine Gaspedalbetätigung, eine Einlassluftmenge,
einen Unterdruck eines Einlassrohrs oder eine Kraftstoffeinspritzmenge aufweist.
3.
Schaltsteuergerät gemäß Anspruch 1 oder 2, wobei
die Einrichtung zur Bestimmung einer unzureichen-
55
20. A shift control method according to any one of claims
12 to 19, wherein the transmission (16) comprises a
10
Schaltsteuergerät eines Getriebes (16) für ein Kraftfahrzeug mit einer Vielzahl an Gangschaltstufen für
ein automatisches Getriebe und einer Notfallniedriggangstufe (Gu), die benachbart zu einer niedrigsten
Gangschaltstufe (G1) der Vielzahl an Gangschaltstufen eingestellt ist, wobei die Notfallniedriggangschaltstufe ein Übersetzungsverhältnis aufweist,
das größer als dasjenige der niedrigsten Gangschaltstufe ist; wobei das Schaltsteuergerät folgendes aufweist:
eine Einrichtung (82) zur Bestimmung einer unzureichenden Leistung, die bestimmt, ob das
Fahrzeug sich in einem Zustand einer unzureichenden Leistung befindet, bei dem eine Antriebsleistung erforderlich ist, die größer als eine
vorbestimmte Antriebsleistung ist, die bei Verwirklichen der niedrigsten Gangschaltstufe erhalten wird, auf der Basis eines vorbestimmten
Parameters, der einen Zustand des Fahrzeuges
während der Fahrt anzeigt; und
eine Schaltsteuereinrichtung (80), die das Getriebe (16) so steuert, dass es automatisch zu
der Notfallniedriggangschaltstufe herunterschaltet, wenn die Einrichtung (82) zur Bestimmung einer unzureichenden Leistung bestimmt,
dass sich das Fahrzeug in einem Zustand einer
unzureichenden Leistung befindet.
19. A shift control method according to any one of claims
12 to 16, wherein
an automatic shift mode in which one of the plurality of gear stages is automatically selected on
the basis of an actual state of the vehicle in accordance with a previously stored shift map, and
a manual shift mode in which one of the plurality
of gear stages is selected by a manual shift operation of an operator of the vehicle are set, and
the transmission (16) is controlled to downshift
automatically to the emergency low speed gear
stage in the manual shift mode.
18
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EP 1 312 837 B1
den Leistung bestimmt, dass das Fahrzeug sich in
einem Zustand einer unzureichenden Leistung befindet, wenn die momentane ansteigende Neigung
einer Straße, auf der das Fahrzeug fährt, größer als
eine vorbestimmte ansteigende Neigung der Straße
wird, auf der das Fahrzeug dazu in der Lage ist, in
der niedrigsten Gangschaltstufe zu fahren.
4.
manueller Schaltmodus, bei dem eine aus der
Vielzahl an Gangschaltstufen durch einen manuellen Schaltvorgang eines Bedieners des
Fahrzeuges gewählt wird, eingestellt werden,
und
die Schaltsteuereinrichtung (80) das Getriebe
(16) so steuert, dass es im Ansprechen auf eine
Betätigung eines Schalters zum Befehlen eines
manuellen Schaltens in dem manuellen Schaltmodus zu der Notfallniedriggangschaltstufe
herabschaltet.
5
Schaltsteuergerät gemäß Anspruch 1, wobei
10
das Fahrzeug zumindest eine automatische
Kupplung (14) aufweist, die an einer Kraftübertragungsbahn zwischen einem Verbrennungsmotor und dem Getriebe (16) angeordnet ist;
und
die Einrichtung (82) zur Bestimmung einer unzureichenden Leistung bestimmt, dass sich das
Fahrzeug in dem Zustand einer unzureichenden
Leistung befindet, wenn das Fahrzeug sich in
entweder einem angehaltenen Zustand oder einem im Wesentlichen angehaltenen Zustand
befindet, und ein Rutschbetrag der automatischen Kupplung (14) gleich wie oder größer als
ein vorbestimmter Wert wird.
8.
6.
Schaltsteuergerät gemäß Anspruch 4, wobei die zumindest eine automatische Kupplung (14) eine
Kupplung der Trockenart, eine Mehrscheibenkupplung der nasslaufenden Art, eine Kupplung der elektromagnetischen Art oder eine Magnetpartikelkupplung der elektromagnetischen Art aufweist.
ein automatischer Schaltmodus, bei dem gemäß einer zuvor gespeicherten Schaltzuordnung eine aus der Vielzahl an Gangschaltstufen
automatisch auf der Grundlage eines momentanen Zustandes des Fahrzeugs gewählt wird,
und ein manueller Schaltmodus, bei dem eine
aus der Vielzahl an Gangschaltstufen durch einen manuellen Schaltvorgang eines Bedieners
des Fahrzeugs gewählt wird, eingestellt werden,
und
die Schaltsteuereinrichtung (80) das Getriebe
(16) so steuert, dass es automatisch zu der Notfallniedriggangschaltstufe in dem manuellen
Schaltmodus herabschaltet.
20
30
9.
Schaltsteuergerät gemäß einem der Ansprüche 1
bis 5, wobei
35
ein automatischer Schaltmodus, bei dem eine
aus der Vielzahl an Gangsschaltstufen automatisch auf der Grundlage eines momentanen Zustandes des Fahrzeugs gemäß einer zuvor gespeicherten Schaltzuordnung gewählt wird, und
ein manueller Schaltmodus, bei dem eine aus
der Vielzahl an Gangschaltstufen durch einen
manuellen Schaltvorgang eines Bedieners des
Fahrzeugs gewählt wird, eingestellt werden,
und
die Schaltsteuereinrichtung (80) das Getriebe
(16) so steuert, dass es automatisch zu der Notfallniedriggangschaltstufe in dem automatischen Schaltmodus herabschaltet.
40
Schaltsteuergerät gemäß einem der Ansprüche 1
bis 5, wobei
ein automatischer Schaltmodus, bei dem eine
aus der Vielzahl an Gangschaltstufen automatisch auf der Grundlage eines momentanen
Fahrzeugzustandes gemäß einer zuvor gespeicherten Schaltzuordnung gewählt wird, und ein
Schaltsteuergerät gemäß einem der Ansprüche 1
bis 8, wobei
das Getriebe (16) ein manuell geschaltetes Getriebe
der parallelen biaxialen ständig im Zahneingriff stehenden Art aufweist.
10. Schaltsteuergerät gemäß Anspruch 9, das des Weiteren ein Paar an Zahnrädern (90, 92) aufweist, die
von den Notfallniedriggangschaltzahnrädern in einem normalen Zustand außer Eingriff stehen, wobei
die Notfallniedriggangschaltstufe (Gu) verwirklicht
wird, indem das Paar an Zahnrädern mit dem Notfallniedriggangschaltzahnrad in Eingriff gebracht
wird.
45
50
7.
Schaltsteuergerät gemäß einem der Ansprüche 1
bis 5, wobei
15
25
5.
20
55
11
11. Schaltsteuergerät gemäß einem der Ansprüche 1
bis 10, wobei das Getriebe entweder ein automatisches Getriebe mit einer Vielzahl an Planetengetriebesätzen, ein kontinuierlich variables Getriebe mit
einem manuellen Schaltmodus oder ein kontinuierlich variables Getriebe mit einem Nebengetriebe aufweist.
12. Schaltsteuerverfahren eines Getriebes (16) für ein
Kraftfahrzeug mit einer Vielzahl an Gangschaltstufen für ein automatisches Getriebe und einer Notfallniedriggangschaltstufe (Gu), die benachbart zu der
niedrigsten Gangschaltstufe (G1) der Vielzahl an
21
EP 1 312 837 B1
Gangschaltstufen eingestellt ist, wobei die Notfallniedriggangschaltstufe ein Übersetzungsverhältnis
aufweist, das größer als dasjenige der niedrigsten
Gangschaltstufe ist, wobei das Schaltsteuerverfahren die folgenden Schritte aufweist:
Bestimmen, ob das Fahrzeug in einem Zustand
unzureichender Leistung ist, der eine Antriebsleistung erforderlich macht, die größer als eine
vorbestimmte Antriebsleistung ist, die während
des Verwirklichens der niedrigsten Gangschaltstufe erhalten wird, auf der Grundlage eines vorbestimmten Parameters, der einen Zustand des
Fahrzeugs während der Fahrt anzeigt; und
Steuern des Getriebes (16) derart, dass es automatisch zu der Notfallniedriggangschaltstufe
herabschaltet, wenn bestimmt worden ist, dass
sich das Fahrzeug in dem Zustand unzureichender Leistung befindet.
Kupplung der elektromagnetischen Art oder eine
Magnetpartikelkupplung der elektromagnetischen
Art aufweist.
5
10
15
20
13. Schaltsteuerverfahren gemäß Anspruch 12, wobei
der Parameter eine Beziehung einer Fahrzeuggeschwindigkeit in Bezug auf entweder eine Drosselöffnung, eine Gaspedalbetätigung, eine Lufteinlassmenge, einen Unterdruck eines Einlassrohrs
oder eine Kraftstoffeinspritzmenge aufweist.
14. Schaltsteuerverfahren gemäß Anspruch 12 oder 13,
wobei
die Einrichtung zur Bestimmung einer unzureichenden Leistung bestimmt, dass sich das Fahrzeug in
einem Zustand unzureichender Leistung befindet,
wenn eine momentane ansteigende Neigung der
Straße, auf der das Fahrzeug fährt, größer als eine
vorbestimmte ansteigende Neigung der Straße wird,
auf der das Fahrzeug dazu in der Lage ist, in der
niedrigsten Gangschaltstufe zu fahren.
ein automatischer Schaltmodus, bei dem eine
aus der Vielzahl an Gangschaltstufen automatisch auf der Grundlage eines momentanen Zustandes des Fahrzeugs gemäß einer zuvor gespeicherten Schaltzuordnung gewählt wird, und
ein manueller Schaltmodus, bei dem eine aus
der Vielzahl an Gangschaltstufen durch einen
manuellen Schaltvorgang eines Bedieners des
Fahrzeugs gewählt wird, eingestellt werden,
und
das Getriebe (16) so gesteuert wird, dass es automatisch zu der Notfallniedriggangschaltstufe
in dem automatischen Schaltmodus herabschaltet.
25
30
35
40
16. Schaltsteuerverfahren gemäß Anspruch 15, wobei
die zumindest eine automatische Kupplung (14) entweder eine Kupplung der Trockenart, eine Mehrscheibenkupplung der nasslaufenden Art, eine
17. Schaltsteuerverfahren gemäß einem der Ansprüche
12 bis 16, wobei
18. Schaltsteuerverfahren gemäß einem der Ansprüche
12 bis 16, wobei
15. Schaltsteuerverfahren gemäß Anspruch 12, wobei
das Fahrzeug zumindest eine automatische
Kupplung (14) aufweist, die an einer Kraftübertragungsbahn zwischen einem Verbrennungsmotor und dem Getriebe (16) angeordnet ist;
und
bestimmt wird, dass sich das Fahrzeug in dem
Zustand unzureichender Leistung befindet,
wenn sich das Fahrzeug entweder in einem angehaltenen Zustand oder in einem Wesentlichen angehaltenen Zustand befindet, und ein
Rutschbetrag der automatischen Kupplung (14)
gleich wie oder größer als ein vorbestimmter
Wert wird.
22
ein automatischer Schaltmodus, in dem eine
aus der Vielzahl an Gangschaltstufen automatisch auf der Grundlage eines momentanen Zustandes des Fahrzeuges gemäß einer zuvor gespeicherten Schaltzuordnung gewählt wird, und
ein manueller Schaltmodus, bei dem eine aus
der Vielzahl der Gangschaltstufen durch einen
manuellen Schaltvorgang eines Bedieners des
Fahrzeuges gewählt wird, eingestellt werden,
und
das Getriebe (16) so gesteuert wird, dass es zu
der Notfallniedriggangschaltstufe in dem manuellen Schaltmodus im Ansprechen auf eine Betätigung eines Schalters zum Befehlen eines
manuellen Schaltens herabgeschaltet wird.
19. Schaltsteuerverfahren gemäß einem der Ansprüche
12 bis 16, wobei
45
50
55
ein automatischer Schaltmodus, bei dem eine
aus der Vielzahl an Gangschaltstufen automatisch auf der Grundlage eines momentanen Zustandes des Fahrzeugs gemäß einer zuvor gespeicherten Schaltzuordnung gewählt wird, und
ein manueller Schaltmodus, bei dem eine aus
der Vielzahl an Gangschaltstufen durch einen
manuellen Schaltvorgang Bedieners des Fahrzeuges gewählt wird, eingestellt werden, und
das Getriebe (16) so gesteuert wird, dass es automatisch zu der Notfallniedriggangschaltstufe
in dem manuellen Schaltmodus herabschaltet.
20. Schaltsteuerverfahren gemäß einem der Ansprüche
12
23
EP 1 312 837 B1
12 bis 19, wobei das Getriebe (16) ein manuell geschaltetes Getriebe der parallelen biaxialen ständig
im Zahneingriff stehenden Art aufweist.
21. Schaltsteuerverfahren gemäß Anspruch 20, wobei
ein Paar an Zahnrädern (90, 92) von Notfallniedriggangschaltzahnrädern in einem normalen Zustand
außer Eingriff stehen, und die Notfallniedriggangschaltstufe (Gu) verwirklicht wird, indem das Paar
an Zahnrädern in einen Eingriff mit dem Notfallniedriggangschaltzahnrad gebracht wird.
22. Schaltsteuerverfahren gemäß einem der Ansprüche
12 bis 21, wobei
das Getriebe ein Automatikgetriebe mit einer Vielzahl an Planetengetriebesätzen, ein kontinuierlich
variables Getriebe mit einem manuellen Schaltmodus oder ein kontinuierlich variables Getriebe mit einem Nebengetriebe aufweist.
tuyau d’admission, et d’une quantité d’injection de
carburant.
3.
Appareil de commande de changement de vitesse
selon la revendication 1 ou 2, dans lequel le moyen
de détermination d’insuffisance de puissance détermine que le véhicule est dans l’état d’insuffisance
de puissance lorsqu’une pente ascendante effective
d’une route sur laquelle le véhicule roule devient plus
grande qu’une pente ascendante prédéterminée de
la route sur laquelle le véhicule est capable de rouler
à l’étage d’engrenages le plus bas.
4.
Appareil de commande de changement de vitesse
selon la revendication 1, dans lequel
5
10
15
le véhicule inclut au moins un embrayage automatique (14) disposé sur un chemin de transmission de puissance entre un moteur et la
transmission (16); et
le moyen de détermination d’insuffisance de
puissance (82) détermine que le véhicule est
dans l’état d’insuffisance de puissance lorsque
le véhicule est dans l’un d’un état à l’arrêt et d’un
état sensiblement arrêté, et une quantité de glissement de l’embrayage automatique (14) devient supérieure ou égale à une valeur prédéterminée.
20
Revendications
1.
Appareil de commande de changement de vitesse
d’une transmission (16) pour un véhicule incluant
une pluralité d’étages d’engrenages pour une transmission automatique et un étage d’engrenages bas
d’urgence (Gu) établi de manière adjacente à un étage d’engrenages le plus bas (G1) de la pluralité d’étages d’engrenages, l’étage d’engrenages bas d’urgence ayant un rapport d’engrenage plus grand que
celui de l’étage d’engrenages le plus bas; l’appareil
de commande de changement de vitesse
comprenant :
25
30
5.
Appareil de commande de changement de vitesse
selon la revendication 4, dans lequel le au moins un
embrayage automatique (14) comprend l’un d’un
embrayage de type à sec, d’un embrayage multidisque de type humide, d’un embrayage de type électromagnétique, et d’un embrayage à particules magnétiques de type électromagnétique.
6.
Appareil de commande de changement de vitesse
selon l’une quelconque des revendications 1 à 5,
dans lequel
35
un moyen de détermination d’insuffisance de
puissance (82) qui détermine si le véhicule est
dans un état d’insuffisance de puissance nécessitant une force d’entraînement supérieure à
une force d’entraînement prédéterminée obtenue à l’établissement de l’étage d’engrenages
le plus bas sur la base d’un paramètre prédéterminé qui indique un état du véhicule en
marche ; et
un moyen de commande de changement de vitesse (80) qui commande la transmission (16)
pour une rétrogradation automatique à l’étage
d’engrenages bas d’urgence lorsque le moyen
de détermination d’insuffisance de puissance
(82) détermine que le véhicule est dans l’état
d’insuffisance de puissance.
2.
Appareil de commande de changement de vitesse
selon la revendication 1, dans lequel le paramètre
comprend une relation d’une vitesse du véhicule par
rapport à l’une d’une ouverture du papillon des gaz,
d’une ouverture de l’accélérateur, d’une quantité
d’air d’admission, d’une pression négative d’un
24
40
45
50
55
13
un mode de changement de vitesse automatique dans lequel l’un de la pluralité d’étages d’engrenages est automatiquement sélectionné sur
la base d’un état effectif du véhicule conformément à une carte de changement de vitesse précédemment stockée, et un mode de changement de vitesse manuel dans lequel l’un de la
pluralité d’étages d’engrenages est sélectionné
par une opération de changement de vitesse
manuelle d’un opérateur du véhicule sont établis, et
le moyen de commande de changement de vitesse (80) commande la transmission (16) pour
une rétrogradation automatique à l’étage d’engrenages de basse vitesse d’urgence dans le
mode de changement de vitesse automatique.
25
7.
EP 1 312 837 B1
Appareil de commande de changement de vitesse
selon l’une quelconque des revendications 1 à 5,
dans lequel
un mode de changement de vitesse automatique dans lequel l’un de la pluralité d’étages d’engrenages est automatiquement sélectionné sur
la base d’un état effectif du véhicule conformément à une carte de changement de vitesse précédemment stockée, et un mode de changement de vitesse manuel dans lequel l’un de la
pluralité d’étages d’engrenages est sélectionné
par une opération de changement de vitesse
manuelle d’un opérateur du véhicule sont établis, et
le moyen de commande de changement de vitesse (80) commande la transmission (16) pour
une rétrogradation à l’étage d’engrenages de
basse vitesse d’urgence dans le mode de changement de vitesse manuel en réponse à une
opération d’un commutateur de commande de
changement de vitesse manuel.
8.
Appareil de commande de changement de vitesse
selon l’une quelconque des revendications 1 à 5,
dans lequel
un mode de changement de vitesse automatique dans lequel l’un de la pluralité d’étages d’engrenages est automatiquement sélectionné sur
la base d’un état effectif du véhicule conformément à une carte de changement de vitesse précédemment stockée, et un mode de changement de vitesse manuel dans lequel l’un de la
pluralité d’étages d’engrenages est sélectionné
par une opération de changement de vitesse
manuelle d’un opérateur du véhicule sont établis, et
le moyen de commande de changement de vitesse (80) commande la transmission (16) pour
une rétrogradation automatique à l’étage d’engrenage de basse vitesse d’urgence dans le mode de changement de vitesse manuel.
9.
Appareil de commande de changement de vitesse
selon l’une quelconque des revendications 1 à 8,
dans lequel la transmission (16) comprend une
transmission changée manuellement du type à prise
constante bi axiale parallèle.
5
11. Appareil de commande de changement de vitesse
selon l’une quelconque des revendications 1 à 10,
dans lequel la transmission comprend l’une d’une
transmission automatique avec une pluralité d’ensembles d’engrenages planétaires, d’une transmission continuellement variable avec un mode de
changement de vitesse manuel, et d’une transmission continuellement variable avec une sous-transmission.
10
15
20
25
30
12. Procédé de commande de changement de vitesse
d’une transmission (16) pour un véhicule incluant
une pluralité d’étages d’engrenages pour une transmission automatique et un étage d’engrenages bas
d’urgence (Gu) établi de manière adjacente à un étage d’engrenages le plus bas (G1) de la pluralité d’étages d’engrenages, l’étage d’engrenages bas d’urgence ayant un rapport d’engrenage plus grand que
celui de l’étage d’engrenages le plus bas; le procédé
de commande de changement de vitesse comprenant les étapes de:
déterminer si le véhicule est dans un état d’insuffisance de puissance nécessitant une force
d’entraînement supérieure à une force d’entraînement prédéterminée obtenue à l’établissement de l’étage d’engrenages le plus bas sur la
base d’un paramètre prédéterminé qui indique
un état du véhicule en marche; et
commander la transmission (16) pour une rétrogradation automatique à l’étage d’engrenages
bas d’urgence lorsqu’il est déterminé que le véhicule est dans l’état d’insuffisance de puissance.
35
40
45
50
10. Appareil de commande de changement de vitesse
selon la revendication 9, comprenant en plus une
paire d’engrenages (90, 92) désengagés des étages
d’engrenages de basse vitesse d’urgence dans un
état normal, dans lequel l’étage d’engrenages de
basse vitesse d’urgence (Gu) est établi en amenant
la paire d’engrenages dans un engagement avec
l’étage d’engrenages de basse vitesse d’urgence.
26
55
13. Procédé de commande de changement de vitesse
selon la revendication 12, dans lequel le paramètre
comprend une relation d’une vitesse du véhicule par
rapport à l’une d’une ouverture du papillon des gaz,
d’une ouverture de l’accélérateur, d’une quantité
d’air d’admission, d’une pression négative d’un
tuyau d’admission, et d’une quantité d’injection de
carburant.
14. Procédé de commande de changement de vitesse
selon la revendication 12 ou 13, dans lequel le
moyen de détermination d’insuffisance de puissance
détermine que le véhicule est dans l’état d’insuffisance de puissance lorsqu’une pente ascendante
effective d’une route sur laquelle le véhicule roule
devient plus grande qu’une pente ascendante prédéterminée de la route sur laquelle le véhicule est
capable de rouler à l’étage d’engrenages le plus bas.
15. Procédé de commande de changement de vitesse
selon la revendication 12, dans lequel
le véhicule inclut au moins un embrayage auto-
14
27
EP 1 312 837 B1
matique (14) disposé sur un chemin de transmission de puissance entre un moteur et la
transmission (16); et
il est déterminé que le véhicule est dans l’état
d’insuffisance de puissance lorsque le véhicule
est dans l’un d’un état à l’arrêt et d’un état sensiblement arrêté, et une quantité de glissement
de l’embrayage automatique (14) devient supérieure ou égale à une valeur prédéterminée.
ment de vitesse manuel.
5
10
16. Procédé de commande de changement de vitesse
selon la revendication 15, dans lequel le au moins
un embrayage automatique (14) comprend l’un d’un
embrayage de type à sec, d’un embrayage multidisque de type humide, d’un embrayage de type électromagnétique, et d’un embrayage à particules magnétiques de type électromagnétique.
17. Procédé de commande de changement de vitesse
selon l’une quelconque des revendications 12 à 16,
dans lequel
un mode de changement de vitesse automatique dans lequel l’un de la pluralité d’étages d’engrenages est automatiquement sélectionné sur
la base d’un état effectif du véhicule conformément à une carte de changement de vitesse précédemment stockée, et un mode de changement de vitesse manuel dans lequel l’un de la
pluralité d’étages d’engrenages est sélectionné
par une opération de changement de vitesse
manuelle d’un opérateur du véhicule sont établis, et
la transmission (16) est commandée pour une
rétrogradation automatique à l’étage d’engrenages de basse vitesse d’urgence dans le mode
de changement de vitesse automatique.
18. Procédé de commande de changement de vitesse
selon l’une quelconque des revendications 12 à 16,
dans lequel
un mode de changement de vitesse automatique dans lequel l’un de la pluralité d’étages d’engrenages est automatiquement sélectionné sur
la base d’un état effectif du véhicule conformément à une carte de changement de vitesse précédemment stockée, et un mode de changement de vitesse manuel dans lequel l’un de la
pluralité d’étages d’engrenages est sélectionné
par une opération de changement de vitesse
manuelle d’un opérateur du véhicule sont établis, et
la transmission (16) est commandée pour une
rétrogradation à l’étage d’engrenage de basse
vitesse d’urgence dans le mode de changement
de vitesse manuel en réponse à une opération
d’un commutateur de commande de change-
28
15
20
25
30
35
40
45
50
55
15
19. Procédé de commande de changement de vitesse
selon l’une quelconque des revendications 12 à 16,
dans lequel
un mode de changement de vitesse automatique dans lequel l’un de la pluralité d’étages d’engrenages est automatiquement sélectionné sur
la base d’un état effectif du véhicule conformément à une carte de changement de vitesse précédemment stockée, et un mode de changement de vitesse manuel dans lequel l’un de la
pluralité d’étages d’engrenages est sélectionné
par une opération de changement de vitesse
manuelle d’un opérateur du véhicule sont établis, et
la transmission (16) est commandée pour une
rétrogradation automatique à l’étage d’engrenage de basse vitesse d’urgence dans le mode de
changement de vitesse manuel.
20. Procédé de commande de changement de vitesse
selon l’une quelconque des revendications 12 à 19,
dans lequel la transmission (16) comprend une
transmission changée manuellement du type à prise
constante bi axiale parallèle.
21. Procédé de commande de changement de vitesse
selon la revendication 20, dans lequel une paire
d’engrenages (90, 92) sont désengagés des étages
d’engrenages de basse vitesse d’urgence dans un
état normal, et l’étage d’engrenages de basse vitesse d’urgence (Gu) est établit en amenant la paire
d’engrenages en engagement avec l’étage d’engrenages de basse vitesse d’urgence.
22. Procédé de commande de changement de vitesse
selon l’une quelconque des revendications 12 à 21,
dans lequel la transmission inclut l’une d’une transmission automatique avec une pluralité d’ensembles
d’engrenages planétaires, d’une transmission continuellement variable avec un mode de changement
de vitesse manuel et s’une transmission continuellement variable avec une sous-transmission.
EP 1 312 837 B1
16
EP 1 312 837 B1
17
EP 1 312 837 B1
18
EP 1 312 837 B1
19
EP 1 312 837 B1
20
EP 1 312 837 B1
21
EP 1 312 837 B1
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EP 1 312 837 B1
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European
patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be
excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description
•
JP 3089069 A [0004]
23
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