Jatco Corporation

Nissan Motor Company Limited

Yoshio Yasui

Hideaki Suzuki

Seiichiro Takahashi

Fumito Shinohara

Yuuji Nagase

Hiroki Iwasa

Tomoaki Honma

Hironori Miyaishi

Takashi Eguchi

Yuta Suzuki

Tomoyuki Mizuochi

Masayuki Mannen

Takaaki Matsui

Sunghoon Woo

Susumu Saitou

Yohei Shimokawa

Control device for continuously variable transmission has continuously variable transmission mechanism (CVT) transmitting power with belt () wound around primary and secondary pulley (); torque convertor () having pump impeller (), turbine runner () and lock-up clutch (); and control unit () controlling lock-up clutch () to predetermined engagement state and controlling the CVT to predetermined transmission ratio, according to travelling condition. Control unit () is configured to, when shifting lock-up clutch () from disengagement to engagement state, control transmission ratio of CVT so that when rotation speed difference (&#x394;N) between engine speed (Ne) and turbine speed (Nt) that is rotation speed of turbine runner is predetermined rotation speed difference (&#x394;N) or less, turbine speed (Nt) approaches engine speed (Ne) more than turbine speed (Nt) of case where control of transmission ratio of CVT, which is set according to travelling condition during shift of lock-up clutch (), is continued.

Control device for continuously variable transmission

A transmission controller searches a mechanical High, which is a minimum value of a possible speed ratio of the continuously variable transmission (CVT), based on an actual speed ratio, sets a control High lower than the mechanical High by a predetermined amount, and controls a speed ratio of the CVT by setting a minimum value of a speed ratio range of the CVT at the control High.

Continuously variable transmission and control method therefor

A first determining unit configured to determine whether the indicated pressure of a primary pulley pressure has become a line pressure during an up shift, an indicated pressure control unit configured to make the indicated pressure of the primary pulley pressure alone higher than the line pressure when the target shift rate is determined to be equal to or lower than a predetermined shift rate and the speed ratio is determined not to have become the target speed ratio, and an estimated time detecting unit configured to detect a predetermined time it takes until the primary pulley pressure can be regarded as being equal to the line pressure after the target shift rate is determined to be equal to or lower than the predetermined shift rate, and the indicated pressure of the primary pulley pressure is made higher than the line pressure, are provided, and the indicated pressure control unit is configured to calculate the deviation between the indicated pressure of the primary pulley pressure and indicated pressure of the line pressure after the estimated predetermined time is over, and control transmission of a continuously-variable transmission while maintaining the deviation after the predetermined time is over.

Continuously-variable transmission and continuously-variable transmission control method

A continuously-variable transmission, which has a first pulley, which has a first fixed pulley and a first mobile pulley, a second pulley, which has a second fixed pulley and a second mobile pulley, and a drive force transmitting member, which is stretched between the first pulley and the second pulley, is provided, and this continuously-variable transmission has an indicated pressure calculation section, which calculates the indicated pressure of the first pulley, a stroke speed calculation section, which calculates the stroke speed of the first mobile pulley, and an oil pressure calculation section, which, when oil is discharged from an oil chamber, calculates the amount of increase of oil pressure in a first pulley oil chamber that increases compared to the indicated pressure due to the channel resistance of the discharge path, based on the channel resistance and the stroke speed, and a correction section, which, when oil is discharged from the first pulley oil chamber, subtracts the amount of increase of oil pressure from the first pulley pressure based on a target speed ratio and input torque, and corrects the indicated pressure of the first pulley.

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Machida, Japan

Yoshio Yasui