Jatco Corporation

Nissan Motor Company Limited

Takahiro Kobayashi

Seiichiro Takahashi

Takashi Eguchi

Tomoaki Honma

Yuta Suzuki

Daisuke Aoki

Shinichiro Watanabe

Tetsuya Izumi

Hisao Nobu

Tomohiro Utagawa

Kenji Sakakibara

Juwan Kim

Yuta Ishinabe

A CVTECU includes a secondary-pressure control section and a line-pressure control section that performs a same-pressure control to equalize a line pressure and a secondary pressure with each other if a predetermined start condition is satisfied. The line-pressure control section realizes a same-pressure state between the line pressure and the secondary pressure by lowering the line pressure below a target secondary pressure, and then controls the line pressure such that an actual secondary pressure is brought to the target secondary pressure by hydraulic feedback control while maintaining the same-pressure state. The secondary-pressure control section includes a restriction section that restricts an accumulation of integral term of an integral action for a duration between a time point at which the actual secondary pressure starts to be pushed down and a time point at which the same-pressure state between the line pressure and the secondary pressure is realized.

Control device for continuously variable transmission

A control apparatus for a continuously variable transmission () that includes a belt-type continuously variable transmission mechanism () and friction engagement elements (), () is disclosed. The control apparatus includes: an operation position detection section () configured to detect an operation position of a selection lever (); a selection control section () configured to execute a selection control for engaging the friction engagement elements (), () from a time point at which a switching from a non-travel range to a travel range is detected; a determination section () configured to determine engagement states of the friction engagement elements (); and a pulley pressure control section () configured to control a pulley pressure supplied to two pulleys (), (). A belt slippage during an engagement of clutches is suppressed while a load on an oil pump is reduced.

A control device for a belt-type continuously variable transmission CVT includes an engine, a belt-type continuously-variable transmitting mechanism; a forward/reverse switching mechanismincluding a forward clutchand a reverse brake; and a hydraulic control circuitconfigured to control a pulley hydraulic pressure and engagement-element pressures for the forward clutchand the reverse brake. The control device includes a selection control means for outputting a pulley hydraulic command to obtain an idle-time clamping pressure which is higher than an idle-time minimum pressure (idle-time MIN-pressure) calculated from an input torque, to the hydraulic control circuit, when the engineis in operation during a selection of N-range. A position of an element clearance generated in the belt can be maintained even if drag torque is inputted.

Control device for belt-type continuously variable transmission

First control unit performing first pseudo stepwise up-shift control that, in first travelling mode, increases vehicle speed while performing hold of transmission ratio and up-shift by first shifting speed and reduces engine torque upon up-shift, second control unit performing second pseudo stepwise up-shift control that, in second travelling mode, increases vehicle speed while performing hold of transmission ratio and up-shift by second shifting speed and reduces engine torque upon up-shift, and third control unit controlling change of travelling mode and switch between two pseudo stepwise up-shift controls according to control states of first and second control units, are provided. When travelling mode is changed to second travelling mode during progress of up-shift in first pseudo stepwise up-shift control, third control unit maintains first pseudo stepwise up-shift control until up-shift is completed. With this, harmonization between pseudo stepwise up-shift control and engine torque control is secured, then shift shock is suppressed.

Transmission control device for continuously variable transmission

A transmission controller determines whether a shift returning to low, changing a speed ratio of a continuously variable transmission to the lowest when a vehicle decelerates, is being performed or not, calculates a primary pressure measured lower limit value at which a belt begins to slip actually, based on a deceleration of the vehicle and the speed ratio of the continuously variable transmission, and sets a lower limit value of a target value of the primary pressure during the shift returning to low as the primary pressure measured lower limit value.

Continuously variable transmission and its hydraulic pressure control method

A transmission controller detects a rotation speed of an input shaft, calculates an inertia torque input to a continuously variable transmission based on a change ratio of the detected rotation speed, obtains a positive inertia torque by extracting a positive portion from the calculated inertia torque, and corrects pulley pressures based on the extracted positive inertia torque.

Growing community of inventors

Higashikurume, Japan

Takahiro Kobayashi