Jatco Corporation

Nissan Motor Company Limited

Mamiko Inoue

Ryousuke Nonomura

Seiichiro Takahashi

Hiroyasu Tanaka

Takuichiro Inoue

Hideaki Suzuki

Tatsuo Ochiai

Masaaki Uchida

Masato Koga

Tateki Jozaki

Ryoji Kadono

Jouji Seki

Masato Mori

Hideshi Wakayama

Takashi Eguchi

Masahide Ito

Kousuke Waku

Norio Asai

Yoshinobu Kawamoto

Yuzuru Tohta

Hyuk Park

Fumito Shinohara

Satoru Ishii

Tomonari Uchiyama

Incheol Na

Masashi Sato

A transmission includes a sub-transmission mechanism, a variator having lower shift responsiveness than the sub-transmission mechanism, and a controller configured to carry out a coordinated shift for changing a speed ratio of the variator in a direction opposite to a changing direction of a speed ratio of the sub-transmission mechanism as the sub-transmission mechanism is shifted so that a through speed ratio reaches a target through speed ratio. The controller sets a target speed ratio of the sub-transmission mechanism on the basis of the target through speed ratio and an actual speed ratio of the variator in carrying out the coordinated shift.

Transmission and control method for transmission

In gear-shift control apparatus and method for a vehicular transmission, a variator which is interposed between an engine and driving wheels and which is capable of modifying a gear (speed) ratio continuously; a sub transmission which is installed in series with the variator and which is capable of switching a plurality of gear-shift stages through a replacement of engagement elements; and a transmission controller which performs a gear ratio control for the variator and a gear-shift stage control for the sub transmission are installed. During a deceleration through a second speed stage of the sub transmission, when the variator is a state in which the variator is at a lowest gear (speed) ratio, a down-shift in which the sub transmission is forced to perform the gear-shift from a second speed stage to a first speed stage, with the variator maintained at the lowest gear (speed) ratio.

Gear shift control device for vehicle transmission and gear shift control method for vehicle transmission

In a transmission, a controller sets a target line pressure to an offset target value, which is a value obtained by adding a positive offset amount to one of a target PRI pressure and a target SEC pressure, in a speed ratio range in which the offset target value is higher than the other at least during an inertia phase in a sub-transmission mechanism when a coordinated shift is carried out. At that time, the one of the target PRI pressure and the target SEC pressure is the target SEC pressure when a variator is downshifted by the coordinated shift while being the target PRI pressure when the variator is upshifted by the coordinated shift.

A control device for a continuously variable transmission with an auxiliary transmission includes: a cooperative control section being configured to shift the auxiliary transmission mechanism during the first inertia phase time period, and to shift the variator during the second inertia phase time period, when the cooperative control in which an input torque to the continuously variable transmission is equal to or smaller than a predetermined value in the cooperative control is judged, and being configured to shift the auxiliary transmission mechanism during the first inertia phase time period, and to shift the variator during the first inertia phase time period when the cooperative control in which the input torque to the continuously variable transmission is greater than the predetermined value is judged.

Control device for continuously variable transmission equipped with auxiliary transmission

An engine control device for a vehicle including a power train where a continuously variable transmission is coupled to an engine, includes engine torque control means configured to control the engine so as to obtain an basic engine torque corresponding to an operating state of the vehicle, and command means configured to command engine torque control means to increase an engine torque from the basic engine torque during a gear shifting from a first speed stage to a second speed stage. The continuously variable transmission includes a continuously variable transmission mechanism, an auxiliary transmission mechanism that includes at least a first engagement portion and a second engagement portion to achieve the gear shifting from the first speed stage to the second speed stage, and shift control means configured to set a target value of a transmission gear ratio of the entire continuously variable transmission mechanism and the auxiliary transmission mechanism based on the operating state of the vehicle to control the continuously variable transmission mechanism such that the target value is achieved.

Engine control device for vehicle and engine control method for vehicle

A control device for a continuously variable transmission with an auxiliary transmission includes: a cooperative control section; and a depression shift control section, wherein when an actual transmission gear ratio of the variator at the judgment of the depression shift control is higher than a first transmission gear ratio set as a lowest value of a control of the transmission gear ratio, the depression shift control section configured to downshift the variator, and to set a target transmission gear ratio at the shift of the variator to a second transmission gear ratio which is a restriction value that is higher than the first transmission gear ratio.

A control device for a vehicle is provided. The control device includes an automatic transmission constituted of a stepwise variable transmission mechanism configured to switch a plurality of shift stages by engagement and disengagement of a plurality of friction engaging elements, an engine as a driving source, a motor configured to assist a driving force of the engine, a hydraulic controller configured to supply a hydraulic pressure to control the engagement and the disengagement of the friction engaging element, and a control unit configured to control the automatic transmission to a target speed ratio through changing the shift stage of the stepwise variable transmission mechanism. The control unit performs a learning control that learns at least one of hydraulic pressure of the engagement and the disengagement of the friction engaging element, and inhibits the assist of the driving force to the engine by the motor in performing the learning control.

Control device and control method for vehicle

A transmission including a variator capable of continuously changing a speed ratio, a stepped transmission mechanism arranged in series with the variator and in which a gear position is switched and a shilling control unit executing stepped shifting repeatedly performing a shifting suppression phase and an upshift phase when a stepped upshift shifting condition is satisfied is provided, and the shifting control unit completes a change from an n-th gear position of the stepped transmission mechanism to an n+1 gear position if the stepped transmission mechanism is at the n-th gear position before the through speed ratio reaches a Highest speed ratio of the variator when the stepped shifting is performed.

Transmission and control method of transmission

In a control apparatus for an automatic transmission including a continuously variable transmission mechanism continuously modifying speed ratio and a stepped transmission mechanism that is disposed on a downstream side of the continuously variable transmission mechanism and being switched between a plurality of gear positions by engaging and disengaging a plurality of frictional engagement elements, the control apparatus comprises a control unit that performs a coordinated shift by shifting the stepped transmission mechanism and simultaneously shifting the continuously variable transmission mechanism in an opposite direction to a shift direction of the stepped transmission mechanism in order to suppress variation in a through speed ratio, which is an overall speed ratio of the automatic transmission, when the stepped transmission mechanism is upshifted and the control unit predicts, on the basis of an increase in an accelerator opening, that judder will occur in the frictional engagement element during the upshift, the control unit reduces a shift speed of the continuously variable transmission mechanism while shudder is predicted to occur in the frictional engagement element in comparison with a shift speed of the continuously variable transmission mechanism during the coordinated shift, the coordinated shift being executed at an accelerator opening corresponding to the increased accelerator opening.

Control apparatus and control method for automatic transmission

A transmission controller executes synchronization shift of shifting a variator in a direction opposite to a speed ratio change direction of a sub transmission mechanism when shifting a sub transmission mechanism. When a gear position of the sub transmission mechanism is at the second gear position and an output increase request of a power source is made, the transmission controller prohibits the synchronization shift and shifts only the sub transmission mechanism from a second gear position to a first gear position.

Continuously variable transmission and method of controlling the same

A control unit comprises determining unit for determining whether or not a predetermined elapsed time condition is established after a shift has been performed to a specific gear position reached by engaging a specific frictional engagement element of a stepped transmission mechanism, and restricting unit for prohibiting the stepped transmission mechanism from performing a shift back to the specific gear position while allowing a continuously variable transmission mechanism to perform shifts so that an automatic transmission is controlled to a target speed ratio until the determining unit determines that the predetermined elapsed time condition is established.

A transmission controller determines whether or not to downshift a sub-transmission mechanism based on an opening and an opening speed of an accelerator pedal and a torque change rate of an engine, and downshifts the sub-transmission mechanism when a determination is made to downshift the sub-transmission mechanism.

Continuously variable transmission and control method therefor

A continuously variable transmission includes a variator, a sub-transmission mechanism, target value setting means configured to set a speed ratio corresponding to a select gear position as a target value of a through speed ratio which is an overall speed ratio of the variator and the sub-transmission mechanism, shift control means configured to perform a variator shift of downshifting the variator so that the through speed ratio reaches the target value and a coordinated shift of upshifting the variator to maintain the through speed ratio while downshifting the sub-transmission mechanism immediately after the variator is downshifted, and torque increasing means configured to increase a torque input to the continuously variable transmission from the power source more than a torque before the determination of the downshift instruction during the coordinated shift.

A transmission controller determines whether or not an input rotation speed of a sub-transmission mechanism is stagnant and executes a feedback control by adding a rotation speed change rate feedback correction amount caused by a difference between a target input rotation speed change rate and an actual input rotation speed change rate of the sub-transmission mechanism to a rotation speed feedback correction amount if the input rotation speed is determined to be stagnant.

The automatic transmission includes a first friction engagement element which is engaged when a first gear position is realized and disengaged when a second gear position is realized, a second friction engagement element which is engaged when the second gear position is realized and disengaged when the first gear position is realized, and a controller. The controller causes the second friction engagement element to slip by decreasing an instructional pressure for the second friction engagement element while running in the second gear position, and learns an engagement start pressure of the first friction engagement element based on a change in a differential rotation of the second friction engagement element, or in a parameter that changes in accordance with the differential rotation, at a time when an instructional pressure for the first friction engagement element is increased during the slip.

Growing community of inventors

Ebina, Japan

Mamiko Inoue