Toyota Jidosha Kabushiki Kaisha

Kunio Hattori

Atsushi Ayabe

Shinya Toyoda

Taira Iraha

Shinji Oita

Yusuke Ohgata

Takuro Shimazu

Hiroki Kondo

Daisuke Inoue

Kenji Matsuo

Mitsuhiro Fukao

Taichi Washio

Wataru Matsubara

Naonari Satoh

Koji Hattori

Naoto Tanaka

Akihide Ito

Jun Amano

Shotaro Arai

Asami Fujita

A shift control apparatus for a vehicle automatic transmission to be provided in a vehicle that includes a hydraulic transmission device having a lockup clutch, an engine, an input shaft connected to the engine through the hydraulic transmission device, and drive wheels. The shift control apparatus includes a shift-down control portion configured, when a shift-down operation is executed to establish a first gear position by releasing a second engagement device, during running of the vehicle in a driven state with a second gear position being established with engagement of the second engagement device, to increase a torque of the engine so as to increase an input rotational speed as a rotational speed of the input shaft through the lockup clutch that is placed in an engaged state, and to release the lockup clutch before the input rotational speed reaches a synchronous speed of the first gear position.

Shift control apparatus for vehicle automatic transmission

A control apparatus for a vehicle drive-force transmitting apparatus which defines a first drive-force transmitting path provided with a first clutch and a two-way clutch and a second drive-force transmitting path provided with a continuously variable transmission and a second clutch. The control apparatus switches the two-way clutch from its lock mode to its one-way mode, when the second drive-force transmitting path is to be established in place of the first drive-force transmitting path. The drive-force transmitting apparatus includes a hydraulic actuator configured to control switching of the two-way clutch between the lock mode and the one-way mode. When a request for establishing the second drive-force transmitting path in place of the first drive-force transmitting path is made during forward running of the vehicle with the two-way clutch being in the lock mode, the control apparatus executes a dither control for fluctuating a hydraulic pressure applied to the hydraulic actuator.

Control apparatus for vehicle drive-force transmitting apparatus

A control device for a power transmission mechanism, includes: a continuously variable transmission including a primary pulley, a secondary pulley, an oil pump; and a hydraulic control device to control a primary thrust for moving a primary movable sheave of the primary pulley and a secondary thrust for moving a secondary movable sheave of the secondary pulley, so that in a case where a secondary target pressure for generating the secondary thrust is smaller than an oil pump discharge capacity when a maximum gear ratio is requested, a primary target pressure for generating the primary thrust is made smaller than that in a case where the secondary target pressure is larger than an oil pump discharge capacity.

Control device for power transmission mechanism

A control apparatus for a vehicle drive-force transmitting apparatus that defines (i) a first drive-force transmitting path established by engagement of a first engagement device controlled by an on-off solenoid valve and (ii) a second drive-force transmitting path established by engagement of a second engagement device controlled by a linear solenoid valve. A third engagement device, which is, as well as the first engagement device, disposed in the first drive-force transmitting path, is configured to transmit a drive force during a driving state of the vehicle and to cut off transmission of the drive force during a driven state of the vehicle. In a case in which the second drive-force transmitting path is to be established in place of the first drive-force transmitting path, the second engagement device is engaged when the first engagement device is engaged, and the first engagement device is released after an inertia phase is started.

A power transmission device for a vehicle includes a first power transmission path that is provided between an engine and a driving wheel, a second power transmission path that is provided in parallel with the first power transmission path, and an electronic control unit. The electronic control unit changes over a secondary clutch to a one-way mode while releasing a first clutch, when a request is made to change over a power transmission path between the engine and the driving wheel from the first power transmission path to the second power transmission path at a time of a predetermined state. The electronic control unit is configured to engage a second clutch when the secondary clutch is changed over to the one-way mode.

Power transmission device for vehicle, and control method of power transmission device

A control apparatus for a vehicle drive-force transmitting apparatus including a gear mechanism and a continuously-variable transmission mechanism and defining first and second drive-force transmitting paths. When the continuously-variable transmission mechanism is in a failure state in which an actual gear ratio of the continuously-variable transmission mechanism is not the highest gear ratio as a target gear ratio, the control apparatus sets the target gear ratio to a transient target gear ratio that is gradually changed toward the highest gear ratio, for causing the actual gear ratio to be gradually changed toward the highest gear ratio. A rate of change of the transient target gear ratio is higher in a state in which a drive force is transmitted through the first drive-force transmitting path by the gear mechanism, than in a state in which the drive force is transmitted through the second drive-force transmitting path by the continuously-variable transmission mechanism.

A control apparatus for a drive-force transmitting apparatus that includes a transmission having primary and secondary pulleys. The control apparatus calculates a target thrust applied to the secondary pulley such that the target thrust is larger during a vehicle driven state than during a vehicle driving state. The control apparatus sets a first determination threshold of a drive-force related value used to determine whether it is the vehicle driving state or vehicle driven state and a second determination threshold of the drive-force related value used to switch from determination of the driven state to determination of the driving state, such that a difference of the first and second determination thresholds is larger and a range of the drive-force related value in which the driven state is determined is wider, when an automatic running-speed control is executed, than when the automatic running-speed control is not executed.

A control apparatus for a drive-force transmitting apparatus that includes a transmission having primary and secondary pulleys. When a detection accuracy of rotational speed of the primary and secondary pulley is not assured, the control apparatus sets each of (i) a secondary-thrust calculation thrust ratio value used for calculation of a secondary thrust that is to be applied to the secondary pulley and (ii) a primary-thrust calculation thrust ratio value used for calculation of a primary thrust that is to be applied to the primary pulley, such that each of the secondary-thrust calculation thrust ratio value and the primary-thrust calculation thrust ratio value is dependent on a result of a determination as to whether an actual gear ratio of the transmission is the highest gear ratio and a result of a determination as to whether an input torque inputted to the transmission is lower than a given torque value.

A control apparatus for a vehicle drive-force transmitting apparatus including a continuously-variable transmission mechanism whose gear ratio is calculated based on a detected value of an input rotational speed of the transmission mechanism and a processed output-rotational-speed value that is a detected value of an output rotational speed of the transmission mechanism subjected to a filter processing. Updating the gear ratio of the transmission mechanism is inhibited (i) when the processed output-rotational-speed value is in a low rotational speed range with an absolute value of a rate of change of the processed output-rotational-speed value being not smaller than a given value, and also (ii) when the processed output-rotational-speed value is in the low rotational speed range with the absolute value of the rate of change of the processed output-rotational-speed value being smaller than the given value, if a certain operation that increases the absolute value is being executed.

When a power transmission path of a power transmission system is set to a second power transmission path, a continuously variable transmission is controlled at a speed ratio (&#x3b3;) that provides a higher vehicle speed in the case where an input shaft angular acceleration (d&#x3c9;i/dt) is small than in the case where the input shaft angular acceleration (d&#x3c9;i/dt) is large. Therefore, it is possible to control the speed ratio (&#x3b3;) of the continuously variable transmission to a speed ratio (&#x3b3;) that reflects an inertial loss (Tli) of the continuously variable transmission. The inertial loss (Tli) changes with the input shaft angular acceleration (d&#x3c9;i/dt). Thus, in a vehicle in which the continuously variable transmission and a gear mechanism are provided in parallel with each other between an input shaft and an output shaft, it is possible to appropriately reduce a loss of the idling continuously variable transmission.

Control apparatus for vehicle

When a line pressure is dominated (determined) by at least one of a primary pressure and a secondary pressure during idling of a continuously variable transmission, the hydraulic pressure that is applied to at least one of pulleys, to which the hydraulic pressure larger than a clutch pressure is applied, is reduced. On the other hand, when the line pressure is dominated by the clutch pressure during idling of the continuously variable transmission, the speed gear ratio of the continuously variable transmission is controlled to a lowest speed gear ratio.

Control apparatus for vehicle transmission

In correcting a throttle opening degree for speed ratio control in accordance with an auxiliary load torque, when the throttle opening degree for speed ratio control is corrected in an increasing manner such that an engine rotational speed rises, a smoothing process of changes in a throttle opening degree correction amount is executed. When the throttle opening degree for speed ratio control is corrected in a decreasing manner such that the engine rotational speed falls, the aforementioned smoothing process is not executed.

A controller for a continuously variable transmission includes an electronic control unit. The electronic control unit reduces a change in a target speed ratio of the continuously variable transmission when a sensitivity coefficient is large as compared to when the sensitivity coefficient is small. When the sensitivity coefficient is large, a change in speed ratio is suppressed, so the stability of the speed ratio is improved. When the sensitivity coefficient is small, the response of a shift is improved. The controller changes a degree of suppressing a shift of the continuously variable transmission in response to the sensitivity coefficient, so it is possible to suppress a shift where necessary. Thus, it is possible to achieve both improvement in the stability of the speed ratio and improvement in the response of a shift in automatic vehicle speed control. This suppresses a feeling of strangeness experienced by a driver.

Controller for continuously variable transmission

When a rotational speed of a secondary pulley is less than a first reference value, the disclosed electronic control device implements lower limit hydraulic control to adjust the hydraulic pressure of a primary pulley to be at a lower limit hydraulic pressure. When the rotational speed is equal to or exceeds the first reference value, but is less than a second reference value, the electronic control device implements balanced hydraulic control to adjust the hydraulic pressure to be more than the lower limit hydraulic pressure. When the rotational speed is equal to or exceeds the second reference value, the electronic control device implements feedback control to correct the hydraulic pressure on the basis of the size of the difference between a target transmission gear ratio and a transmission gear ratio, calculated on the basis of rotational speeds detected by each rotational speed sensor.

Control device for stepless transmission

A control device of a continuously variable transmission for a vehicle having a pair of variable pulleys with variable effective diameters of an input-side variable pulley and an output-side variable pulley and a transmission belt wound around between the pair of the variable pulleys, the continuously variable transmission respectively controlling an input-side thrust force in the input-side variable pulley and an output-side thrust force in the output-side variable pulley to set an actual gear ratio to a target gear ratio while preventing a slip of the transmission belt, the continuously variable transmission includes: a hydraulic control circuit capable of accurately controlling one of the input-side variable pulley and the output-side variable pulley in terms of thrust force as compared to the other, in the case that a target thrust force on the one side for assuring belt slip prevention of the both pulleys on the one side is set, based on a target thrust force on the one side, a target thrust force on the other side for achieving a target gear ratio on the other side being set, and a larger one being selected as the target thrust force on the one side out of a limit thrust force to a slip on the one side required for belt slip prevention on the one side, and a thrust force on the one side required for achieving a target gear ratio on the one side calculated based on a limit thrust force to a slip on the other side required for belt slip prevention on the other side.

Growing community of inventors

Nagoya, Japan

Kunio Hattori