Jatco Corporation

Nissan Motor Company Limited

Fumitaka Nagashima

Takateru Kawaguchi

Hideharu Yamamoto

Hajime Tasaka

Shinya Mochiyama

Yoshihide Shinso

Hirofumi Michioka

Masahiro Hamano

Yoshiaki Ueda

Kakuzou Kaneko

Takeo Aizawa

Hideki Ishii

Kenichi Kaizu

Tomoyuki Suwabe

Yutaka Tohyama

Ryusuke Oshiro

Satoshi Ozawa

Jun Kagawa

Yutaka Tooyama

Toshiomi Nebashi

Ryusuke Ooshiro

A malfunction part sensing device for an automatic transmission for a vehicle which is arranged to attain a plurality of shift stages by selectively engaging a plurality of frictional engagement elements, the malfunction part sensing device includes: a shift stage monitoring section configured to monitor the shift stages before and after the shift of the automatic transmission; a malfunction sensing section configured to sense the malfunction mode from a behavior of the vehicle which is generated in accordance with the malfunction; and a malfunction part limiting section configured to limit the one of the frictional engagement elements in which the malfunction is generated, based on the malfunction mode and a shift manner by a combination of the shift stages before and after the shift.

Malfunction location detection device for automatic transmission, and automatic transmission provided with same

A control device for automatic transmission of the present invention includes a transmission mechanism and a park lock device. The park lock device has a rod member and a lock mechanism. The lock mechanism restricts movement of the rod member when being in a locked state. If a CPU reset (reset of a CPU constituting an ATCU) occurs, the control device maintains the locked state of the lock mechanism after a return from the CPU reset.

Control device and control method for automatic transmission

A Controller constitutes a control device for a vehicle having an automatic transmission on which a shift-by-wire system is mounted. The controller changes display of an range indicator to N-range display after disengagement determination of an power transmission clutch is made when a shifting operation from a D range to a N range is performed.

Control device for vehicle and control method for vehicle

A control device is provided for a vehicle including a drive source and an automatic transmission having a park lock mechanism for locking an output shaft and an engaging element to be engaged at the start of running. Output rotation of the drive source is input to the automatic transmission. The control device includes a control unit to limit a torque of the drive source until the release of locking by the park lock mechanism is completed in response to an instruction being given to change from a parking range to a travel range. The control unit is configured to limit the torque of the drive source from after the instruction is given to change from the parking range to the travel range until the release of locking by the park lock mechanism is completed.

A first hydraulic pressure control unit forms an oil path to supply oil to a frictional engagement element when a select lever is located in a travel range or between the travel range and a non-travel range and forms an oil path to discharge the oil from the frictional engagement element when the select lever is located in the non-travel range. An abnormality determination unit cancels an abnormality determination when only a travel range signal is output from a range signal output unit after a signal of the range signal output unit is determined to be abnormal, and maintains the abnormality determination when only a non-travel range signal is output from the range signal output unit. A second hydraulic pressure control unit forms an oil path to supply the oil to the frictional engagement element during the abnormality determination or when only the travel range signal is output, and forms an oil path to discharge the oil from the frictional engagement element before the abnormality determination or when only the non-travel range signal is output.

Control device for automatic transmission

An automatic transmission has a transmission control section performing a control so that a transmission ratio defined as input rpm/output rpm of the automatic transmission becomes a target transmission ratio, a slip control section slip-controlling a frictional engagement element in the automatic transmission so that the input rpm becomes a value obtained by multiplying the output rpm by the target transmission ratio also adding a predetermined slip revolution speed; and an abnormality judgment section judging abnormality in the automatic transmission. When the slip-control is not in progress, if an actual transmission ratio is out of a predetermined range of the target transmission ratio, the abnormality judgment section judges that abnormality occurs. When the slip-control is in progress, if a value obtained by correcting the actual transmission ratio on the basis of the slip revolution speed is out of the predetermined range, the abnormality judgment section judges that abnormality occurs.

Automatic transmission

An automatic transmission system includes a transmission having transmission elements with lubrication-requiring portions and hydraulic actuators therefor, a switching valve that supplies hydraulic fluid to the hydraulic actuators, a valve actuator that actuates the switching valve, a shift range detection unit that detects a selected shift range of the transmission, and a control unit that controls the valve actuator to actuate the switching valve in accordance with the selected transmission shift range. The switching valve has a bypass position to provide a supply of the hydraulic fluid to the lubrication-requiring portions by bypassing a transmission oil cooler. The control unit judges whether the transmission is in a low lubrication state based on a given operating parameter of the transmission and controls the valve actuator to switch the switching valve to the bypass position at the time the transmission is judged as being in the low lubrication state.

Automatic transmission system and hydraulic control device and method thereof

In vehicular control method and apparatus for a shift-by-wire device, a selected shift position is modified to at least one of a vehicular parking position, a neutral position, and a traveling position, the selected shift position is modified to the vehicular parking position when a power switch is switched to an OFF position, and the modification of the shift position to the vehicular parking position is inhibited when an operation pattern of an operation input section while the power switch is in the ON position is made coincident with the operation pattern prescribed as a cipher code which inhibits the shift position modification to the vehicular parking position, the operation patterns being constituted by a combination of operation patterns which would not be carried out in the operation section during an ordinary traveling.

Vehicular control apparatus and method for shift-by-wire device

In an automatic transmission of this invention, a determination as to whether or not a failure has occurred in a friction element is made repeatedly while a vehicle is traveling, and control to specify the failed friction element is begun when a vehicle speed falls to or below a predetermined value for the first time following detection of the failure in the friction element (S, S). When the failed friction element has been specified (S, S, S, S, S, S, S), usable gear positions are determined on the basis of the specified friction element, whereupon shift control is performed using only the usable gear positions (S, S, S, S, S, S, S, S).

Automatic transmission and control method thereof

An automatic transmission control unit determines whether or not a constantly open failure, in which a switch valve cannot switch a pressure regulating valve and a second hydraulic chamber to a non-communicative state, has occurred on the basis of a parameter (an inertia phase time, for example) representing a dynamic characteristic during a shift from a first gear position to a second gear position. The determination of the constantly open failure is begun after initial variation in the parameter representing the dynamic characteristic during the shift has been eliminated through learning control in which the dynamic characteristic during the shift is caused to approach a target dynamic characteristic.

An automatic transmission includes a planetary gear mechanism, an engagement element group including a particular engagement element having first and second pressure chambers, a pressure control valve to regulate the fluid pressure for the particular engagement element, and a selector valve arranged to connect the second pressure chamber with the pressure control valve at a first valve position, and to disconnect the second pressure chamber from the pressure control valve at a second valve position. A shift control section is configured to command a shift operation from a first gear position, to a second gear position, by controlling the selector valve to the second valve position and to supply the fluid pressure to the first pressure chamber, and to judge the selector valve to be in an abnormal state, in accordance with a parameter in the shift operation.

An automatic transmission includes a plurality of planetary gears disposed between an input shaft and an output shaft and having a plurality of rotational elements. A plurality of frictional elements are selectively engaged and released for controlling rotations and connections of the plurality of rotational elements in accordance with instructions so as to realize a plurality of gear positions. A rotational speed detecting section detects a rotational speed of a predetermined one of the plurality of rotational elements other than the input shaft and the output shaft. A frictional element release section releases all of the plurality of frictional elements when it is judged that the rotational speed of the predetermined one of the plurality of rotational elements is higher than a predetermined rotational speed.

Automatic transmission and method of preventing over-revolution of the same

In a planetary gear type stepped automatic transmission, a gear shift control to shift a gear shift stage between a first gear shift stage and a second gear shift stage is performed by a first shift control section by referring to a first gear shift control data used when the gear shift stage is switched between the first gear shift stage and the second gear shift stage, an abnormality state due to a failure of at least one of a first frictional engaging element and a second frictional engaging element is detected, and an abnormality state gear shift control is performed to shift the gear shift stage between a third gear shift stage (for example, first speed) and a fourth gear shift stage (for example, 2.5 speed) by the first shift control section, while forcefully releasing the first frictional engaging element, when detecting the abnormality state.

A control apparatus for an automatic transmission including a plurality of frictional elements each arranged to be engaged by receiving supply of an engagement pressure regulated by a solenoid, and being arranged to attain a plurality of gear stages by combination of engagements of the frictional elements, the control apparatus includes a failure occurrence sensing section configured to sense an occurrence of a failure-induced disengagement in one of the frictional elements based on a failure of one of the solenoids, based on an engine racing by a depression of an accelerator pedal in a state in which ranges other than a parking range and a neutral range are selected during a stop of a vehicle; and a command output section configured to output a limp home mode command to attain one of the gear stages to enable the vehicle to start.

Control apparatus for automatic transmission having fail-safe function during vehicle stop

An automatic transmission control system is provided with a disengagement malfunction determining section and a disengagement malfunction preventing section in an automatic transmission in which the frictional engaging elements are selectively engaged and disengaged to change a rotational speed of a main power source. The disengagement malfunction determining section determines a disengagement malfunction with a first frictional engaging element from among a plurality of frictional engaging elements of the automatic transmission. The disengagement malfunction preventing section prevents disengagement malfunction of a second frictional engaging element from among the frictional engaging elements of the automatic transmission by lowering the rotational speed of the main power source to a level which will prevent the disengagement malfunction in the second frictional engaging element, when the disengagement malfunction determining section determines that the disengagement malfunction of the first frictional engaging element exist while the automatic transmission is in non-running range.

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Fuji, Japan

Fumitaka Nagashima