Nissan Motor Company Limited

Jatco Corporation

Hitachi, Ltd.

Satoshi Takizawa

Masato Koga

Mitsuru Watanabe

Hiroyasu Tanaka

Shigeki Shimanaka

Masatoshi Akanuma

Junya Takayama

Yuusuke Minagawa

Yasushi Narita

Takayuki Suzuki

Hiroshi Yamaguchi

Tatsuo Morita

Nobuo Kurihara

Katsunori Oshiage

Shusaku Katakura

Yusuke Minagawa

Yasunori Mouri

Tateki Jozaki

Nobusuke Toukura

Hirofumi Shimizu

Yasutaka Kawamura

Kunifumi Sawamoto

Yoshihide Shinso

Katsuhiro Matsuo

Hiroshi Sanbuichi

Hisaaki Toujima

Takashi Hara

Kiminobu Takebe

Shigeo Kariya

An control apparatus for an automatic transmission includes: a failure shift stage setting section configured to set, to the target shift stage, a shift stage which can be attained in a state in which the one of the solenoids judged that the failure is generated is not energized; and a failure neutral state through section configured to control the solenoids at a predetermined vehicle speed or over so that the automatic transmission is brought to a neutral state, when the target shift stage is a shift stage at which the vehicle speed is suddenly decreased when the solenoids are controlled so that the automatic transmission attains the target shift stage, and to control the solenoids below the predetermined vehicle speed so that the automatic transmission attains the target shift stage.

Control apparatus for automatic transmission

A shift control device comprises: a thermal load prediction unit which predicts a thermal load state of a friction element upon completion of a shift from a current thermal load state of the friction element; and a shift control unit which, when the thermal load state upon shift completion predicted by the thermal load prediction unit corresponds to a predetermined state, either performs the shift in a modified shift mode in which a heat generation amount of the friction element is smaller than the heat generation amount of the friction element when the predetermined state is not established, or prohibits the shift. The predetermined state is set at a different state in a case where the shift is an upshift and in a case where the shift is a downshift, and is set on the basis of a gradient of a traveling road.

Shift control device for automatic transmission and shift control method thereof

A shift control system for a vehicle automatic transmission includes a vehicle speed sensor for detecting a vehicle speed, and a first control means normally performs a shift control of the transmission so that a target speed ratio of the transmission is achieved, which is determined based at least on a vehicle speed detected by the vehicle speed sensor. The shift control system further includes a second control means that properly performs shift control of the transmission when the vehicle speed sensor is in trouble, by generating a command for holding or changing a current speed ratio based on an input rotation speed of the transmission and/or driver's accelerating or decelerating operation of the vehicle.

Shift control system for automatic transmission

In a vehicular control unit, a main power supply voltage detecting section to detect a voltage value of a main power supply is provided and, an abnormality determining section determines an abnormality occurs in the main power supply voltage detecting section when the main power supply voltage detecting section negatively detects the voltage value of the main power supply and a power supply stop command output section outputs a command to stop the supply of the continuous power supply to the power supply control circuit without an execution of a shut-off process when the abnormality determining section determines that the abnormality occurs in the main power supply voltage detecting section.

Vehicular control unit with self shut-off function and abnormality detection function

A starting shift control system for a continuously variable transmission is provided which includes a control unit having a high start judgment device for judging whether or not a high start in a high speed side gear ratio is caused on the basis of a comparison between the generated number of the input rotation pulses and the generated number of the output rotation pulses from the time a first vehicle starting operation is performed after start of a prime mover, and a high start control device for restricting downshifting from the high speed side gear ratio to a target gear ratio when a start of the vehicle is judged to be the high start. A starting shift control method is also provided.

Starting shift control system and method for continuously variable transmission

After an engine ( ) has started, a controller ( ) starts determining whether lockup should be prohibited or permitted based on the cooling water temperature of an engine ( ) or the oil temperature of a transmission ( ). Once it has been determined that lockup should be permitted, the controller ( ) stops determining whether lockup should be prohibited or permitted until the next time the engine ( ) is started. In this way, once the conditions for determining that lockup should be permitted hold, lockup prohibition or permission based on the engine cooling water temperature or transmission oil temperature is no longer determined, so repeat engaging and disengaging of the lockup clutch ( ) due to fluctuations of engine cooling water temperature or transmission oil temperature, is prevented.

Lockup control device for transmission

The vehicle comprises a continuously variable transmission and traction control system (TCS) which controls a driving force. When the TCS is not operating, a controller computes a final target ratio based on a sensor detected vehicle speed. When the TCS is operating, the final target ratio is computed based on an estimated vehicle speed, and the final target ratio is limited by a speed ratio upper limiting value computed based on the sensor detected vehicle speed. The controller controls a speed change actuator so that a real speed ratio approaches the final target ratio.

Speed ratio control device for vehicle

An alarm is emitted when a vehicle attempts to start when the speed ratio of a toroidal continuously variable transmission is small. A sensor ( ) detects that the speed ratio is smaller than a predetermined range. A microprocessor ( ) controls an alarm ( ) to operate when an ignition switch ( ) is in a position for starting an engine, while the speed ratio is smaller than the predetermined range.

Small speed ratio detection and control devices for vehicle start

A first switch ( ) which can select a manual mode, and a second switch ( ) which can select one of an upshift and a downshift, are provided. A microprocessor ( ) varies a speed ratio of an automatic transmission ( ) according to the specification of the second switch ( ) when the first switch ( ) has previously selected the manual mode, and the second switch ( ) subsequently specifies one of the upshift and the downshift (S , S , S , S , S , S , S , S , S , S , S ). On the other hand, variation of the speed ratio of the automatic transmission ( ) according to the specification of the second switch ( ) is prohibited when the second switch ( ) specifies one of the upshift and the downshift at a timing not later than a timing at which the manual mode is selected by the first switch ( ) (S , S , S , S , S , S , S , S , S , S , S ). Due to this processing, an unexpected speed ratio variation is prevented from occurring simultaneously when the first switch ( ) selects the manual mode in the state where the second switch ( ) has been fixed in the ON state due to malfunction or misoperation of the second switch ( ).

Manual operation control of automatic transmission

A speed change control device for an automatic transmission wherein the speed ratio is automatically varied according to a running state when an automatic shift mode is selected, and the speed ratio is varied based on a manual operation when the manual shift mode is selected. When there is a change-over from the automatic shift mode to the manual shift mode, a speed ratio immediately after the change-over is set to a speed ratio such that a transmission input rotation speed after the change-over increases by at least a predetermined rotation speed compared to the transmission input rotation speed before the change-over. In this way, the effectiveness of engine braking is enhanced immediately after a change-over to the manual shift mode, or a downshift for acceleration can be definitively performed.

Speed ratio control device

When a slip control system starts operating, a vehicle speed VSP used for speed change control is simultaneously changed over from a sensor detected vehicle speed VSPSEN to an estimated vehicle speed VSPFL. On the other hand, when the slip control system has stopped, it is first determined whether a speed ratio variation amount, due to the change-over of the vehicle speed used for speed change control from the estimated vehicle speed VSPFL to the sensor detected vehicle speed VSPSEN, is less than a permissible amount. When it is determined that the speed ratio variation amount is smaller than the permissible amount, the vehicle speed used for speed change control is changed over from the estimated vehicle speed VSPFL to the sensor detected vehicle speed VSPSEN. By performing this change-over, a sharp variation of the vehicle speed used for speed change control is suppressed, and a sharp variation of the speed ratio leading to shocks or slipping is suppressed.

A controller determines whether or not the vehicle dynamics controller is operating, and when it is determined that it is operating, a speed change operation by an actuator which changes over a gear position of the automatic transmission is prohibited. This speed change prohibition is continued for a predetermined time even when the vehicle dynamics controller has stopped. In this way, control performance of the vehicle dynamics controller is prevented from becoming unstable due to a speed change of the automatic transmission.

A lock-up torque converter is equipped with a lock-up clutch. The lockup clutch may engage even when the vehicle is coasting (lock-up coasting). When an accelerator pedal is depressed in a stepwise manner during lock-up coasting, the lock-up clutch is temporarily disengaged. By setting the threshold value used for determination so that it is easier to determine that the accelerator pedal was depressed in a stepwise manner the lower the vehicle speed, the dual objectives of vibration suppression of the drive system and improvement of fuel cost-performance are realized.

Lock-up control device for vehicle

When a slip control system is not operating, a speed ratio control device uses a sensor detected vehicle speed for speed ratio control, and when the slip control system is operating, it uses an estimated vehicle speed for speed ratio control. It is determined whether a variation amount of the estimated vehicle speed is greater than a threshold set to a variation amount which could not be obtained when there is no error. When the variation amount of the estimated vehicle speed is greater than the threshold, it is determined that the estimated vehicle speed is abnormal, and use of the estimated vehicle speed for speed ratio control is prohibited.

In a vehicle continuously variable transmission, an engine rotation speed, input rotation speed of the transmission and an output rotation speed of the transmission are respectively detected by sensors (,). Based on the output signals from these rotation speed sensors (,), a controller (,) controls a speed ratio of the transmission within a predetermined speed ratio range. The controller (,) also determines if any of the rotation speed sensors (,) has an abnormality based on the output signals from these sensors (,) and narrows the predetermined speed ratio range (S,) when any of the sensors has been determined to have an abnormality, so as to prevent an extraordinary speed ratio control from being performed.

Growing community of inventors

Yokohama, Japan

Satoshi Takizawa