Jatco Corporation

Nissan Motor Company Limited

Hiroshi Sekiya

Tatsuya Imamura

Koji Dohi

Toshiji Iida

Kouji Saitou

Satoshi Segawa

Tomoaki Honma

Yuta Suzuki

Hiromu Ogino

Itaru Shinohara

Yasuhiro Endo

Aki Hayakawa

Yuzuru Tohta

Akito Suzuki

Takateru Kawaguchi

Morimasa Yamawaki

Nobuo Kurogo

Masaaki Uchida

Kazutaka Adachi

Seiichiro Takahashi

Hideshi Wakayama

Keichi Tatewaki

Tetsuya Izumi

Daisuke Matsumoto

Masayoshi Nakasaki

Takashi Matsuda

Kohei Kamiya

Kenji Nakashima

Kouki Saitou

Koutarou Tagami

Akihiro Tanabe

Masayuki Kobayashi

A control device for a continuously variable transmission includes: a line pressure generating-section configured to generate a line pressure; a pilot valve configured to supply a pilot pressure regulated so as not to exceed a first predetermined pressure when the line pressure exceeds the first predetermined pressure; a control section configured to generate the clamping forces by controlling the pilot pressure; a line pressure increase section configured to increase the line pressure to be greater than the first predetermined pressure when the control to increase the line pressure is performed when the line pressure is lower than the first predetermined pressure.

Control device for continuously variable transmission

A control device for a continuously variable transmission includes a lock-up clutch of a torque converter which is arranged to connect and disconnect a power transmission between a power source and the driving wheel, and a control section configured to output a hydraulic pressure command value. The control section is configured to control a transmission gear ratio of the continuously variable transmission and an engagement state of the lock-up clutch in accordance with a traveling state of a vehicle. The control device includes a learning control section configured to perform a learning control of the engagement state of the lock-up clutch with respect to the hydraulic pressure command value, an oil vibration sensing section configured to sense oil vibration of a line pressure, and a learning control prohibiting section configured to prohibit the learning control when the oil vibration sensing section senses the oil vibration.

A control device for a lock-up-clutch installed in a torque converter arranged between an engine and an automatic transmission mechanism includes an engagement control means that carries out a calculation to increase an engaging capacity of the lock-up-clutch with the passage of time during an engagement control time in which the torque converter is shifted from a converter condition to a lock-up condition in which the prime mover drives an auxiliary device and in which when, during the control to increase the engaging capacity of the lock-up-clutch, an input torque to the torque converter from the engine is increased due to reduction in load of the auxiliary device, the engagement control means promotes the increase of the engaging capacity of the lock-up-clutch based on the amount of increase of the input torque thereby eliminating undesired pressure shortage that would be induced in the period toward the lock-up condition.

Lock-up-clutch control device

A control device for a continuously variable transmission includes: a line pressure generating means configured to generate a line pressure; a pilot valve configured to supply a pilot pressure regulated so as not to exceed a first predetermined pressure when the line pressure exceeds the first predetermined pressure; a control means configured to control solenoid valves by the pilot pressure, and thereby to generate belt clamping forces; an oil vibration sensing means configured to sense an oil vibration; and a line pressure increase means configured to increase the line pressure to be greater than the first predetermined pressure when the oil vibration sensing means senses the oil vibration.

A device for controlling a start of a vehicle includes a rotation speed obtaining unit that obtains an actual engine rotation speed of the engine, a target rotation speed computing unit that computes a target rotation speed of the engine in the slip control, a control target value computing unit that computes a control target value, which is a target value for controlling the engine rotation speed to the target rotation speed based on the actual engine rotation speed and the target rotation speed, and an instruction value computing unit that computes an instruction value for the lock-up clutch necessary to control the engine rotation speed to the control target value based on the control target value.

Vehicle startup control device and startup control method

A start request detection unit detects a start request for a vehicle. A hydraulic pressure control circuit controls torque transmitted by a lock-up clutch by controlling an engagement force of the lock-up clutch. A rotation speed detection unit detects an output rotation speed of a torque converter. An engagement control unit issues an instruction to the hydraulic pressure control circuit such that the lock-up clutch is placed in slip engagement and is able to transmit the torque when the following conditions are both satisfied: a predetermined time period has elapsed since detection of the start request by the start request detection unit; and the output rotation speed has increased to a predetermined rotation speed or higher.

A control device controls a transmission mechanism which includes a first clutch to be engaged at startup and a second clutch, and is interlocked when hydraulic pressure is supplied to the first and second clutches and when the first and second clutches are completely engaged. The control device includes a hydraulic pressure control unit controlling hydraulic pressure supplied to the transmission mechanism so that the first clutch is set in a completely engaged state and the second clutch is set in a slip interlock state where the second clutch is not completely engaged in the case of a return from an idle stop control in which an engine is automatically stopped. The hydraulic pressure control unit starts reducing hydraulic pressure supplied to the second clutch when an increased amount of an engine rotation speed per unit time becomes smaller than a predetermined value.

Control device and method for stepped transmission ensuring smooth transition in engine idle stop and resumption cycle

A control device of a lock-up clutch of a torque converter interposed between a transmission and engine used with a vehicle, is disclosed. The control device has a sensor which detects an input rotation speed to the torque converter, a sensor which detects an output rotation speed from the torque converter, a differential pressure control device which controls the differential pressure applied to the lock-up clutch, and a controller which sets a target slip rotation speed of the torque converter; calculates a real slip rotation speed which is a difference between the detected input rotation speed and the detected output rotation speed; and performs feedback control to determine the differential pressure applied to the lock-up clutch so that the real slip rotation speed coincides with the target slip rotation speed. The controller is programmed to: set the target slip rotation speed to a first target slip rotation speed determined from a vehicle running parameter; perform feedback control so that the real slip rotation speed coincides with the first target slip rotation speed; change over the first target slip rotation speed to a second target slip rotation speed according to an error between the first target slip rotation speed and the real slip rotation speed; after changing over, and perform feedback control so that the real slip rotation speed coincides with the second target slip rotation speed; wherein the first and second target slip rotation speeds are different functions of time.

Control of lock-up clutch

A lock-up clutch control apparatus for controlling a lock-up clutch () provided in a torque converter () installed between an engine () and a transmission (), is disclosed. The lock-up clutch control apparatus has a differential pressure generator () which engages, causes a slip of or disengages the lock-up clutch by adjusting the differential pressure supplied to the lock-up clutch (); a sensor () for detecting a rotational speed of the engine; a sensor () for detecting an input rotational speed to the transmission; and a controller (). The controller () conducts proportional integration control by using a command signal to the differential pressure generator (), so that an actual slip rotational speed, which is the difference between the engine rotational speed (Np) and input rotational speed (Ni) to the transmission, becomes a target slip rotational speed (Nt). The controller is programmed to conduct integration accumulating the difference (&#x394;N) between the target slip rotational speed (Nt) and the actual slip rotational speed (SN); to determine whether the accumulated integrated value (I) is equal to or higher than a predetermined integration value (It); and to stop the integration when the accumulated integration value (I) is equal to or higher than the predetermined integration value (It).

Lock-up clutch control

A lock-up clutch control device which controls a lock-up clutch provided in a torque converter installed between an engine and a transmission, is disclosed. The lock-up clutch control device changes over between a converter state and a lock-up state of the torque converter according to a differential pressure command value (LUprs) relating to a differential pressure supplied to the lock-up clutch. The lock-up clutch control device includes a differential pressure generating device () which generates the differential pressure supplied to the lock-up clutch; input torque detection means () which detects an input torque (Te) to the torque converter; and a controller (). The controller () is programmed to compute a real differential pressure (P_lu) based on the detected input torque (Te) upon completion of the engagement of the lock-up clutch; compute a learning value (P_learn(Tai)) relating to a differential pressure deviation, based on the difference between the computed real differential pressure (P_lu) and differential pressure command value (P_ref) upon completion of the engagement of the lock-up clutch, and store the learning value (P_learn(Tai)); correct a present differential pressure command value (LUprs_slp) based on the learning value (P_learn(Tai)); and send the corrected differential pressure command value (LUprs) to the differential pressure generating device ().

Lock-up control for torque converter

A lock-up clutch control device which controls a lock-up clutch () provided in a torque converter () interposed between an engine () and a transmission () used with a vehicle, is disclosed. The lock-up clutch control device has a differential pressure generating device (), a vehicle speed sensor (), a throttle valve opening sensor (), an transmission input shaft rotation speed sensor (), engine torque detection means (), and a controller (). The controller () determines, based on the detected vehicle speed (VSP) and the detected throttle valve opening (TVO), whether or not a control region of a torque converter is a converter region wherein control is performed to disengage the lock-up clutch. When the control region of the torque converter is not the converter region, the controller () determines whether or not the control region of the torque converter is a slip control region wherein control is performed to make the lock-up clutch slip, based on the detected input shaft rotation speed (Npri) of the transmission and the detected engine torque (Te). When the control region of the torque converter is the slip control region, the controller commands the differential pressure generating device () to cause a slip of the lock-up clutch ().

A lock-up clutch control device controls a lock-up clutch provided in a torque converter in a vehicle. The lock-up clutch control device includes a sensor for detecting a rise of a vehicle speed; a differential pressure generator which generates a differential pressure to lock the lock-up clutch; and a controller. The controller is programmed to command the differential pressure generator to lock the lock-up clutch when the vehicle speed exceeds a predetermined low vehicle speed, after the vehicle is started; subsequently monitor the rise of the vehicle speed; and command the differential pressure generator to unlock the lock-up clutch when the monitored rise of the vehicle speed is lower than a preset value.

A lock-up clutch control device controls a lock-up clutch provided in a torque converter mounted between an engine and a transmission of a vehicle. The lock-up clutch control device switches between a converter state and a lock-up state by controlling a differential pressure supplied to the lock-up clutch. The lock-up clutch control device has a controller and a differential pressure generator for generating the differential pressure in response to a differential pressure command value. The controller calculates a first differential pressure command value which decreases at a predetermined rate, after the vehicle speed becomes a first predetermined speed; sets the differential pressure command value to a second differential pressure command value, before the vehicle speed becomes a second predetermined speed; and sets the differential pressure command value to a value at which the lock-up clutch is immediately released, when the vehicle speed becomes the second predetermined speed.

A lock-up clutch control device, which controls a lock-up clutch () installed in a torque converter () interposed between an engine () and a transmission () used with a vehicle, is disclosed. The lock-up clutch control device has a differential pressure generating device () which engages or disengages the lock-up clutch by adjusting a differential pressure supplied to the lock-up clutch, a sensor () which detects a vehicle speed, and a controller. The controller is programmed to: determine whether or not the vehicle speed is equal to or larger than a first threshold value (V) corresponding to a lock-up ON vehicle speed; command the differential pressure generating device to engage the lock-up clutch, when the vehicle speed is equal to or larger than the first threshold value (V); determine whether or not the vehicle speed has reached a second threshold value (V) larger than the first threshold value (V); set a lock-up OFF threshold value (V/V) which depends on whether the vehicle speed has reached the second threshold value (V); and command the differential pressure generating device to disengage the lock-up clutch, when the vehicle speed is equal to or less than the lock-up OFF threshold value.

In lock-up capacity control apparatus and method for a torque converter, the torque converter is caused to have a converter state in which a relative revolution between input and output elements of the torque converter is free of limitation in a case where a lock-up capacity (L/Uprso) during a no-load state is equal to or larger than a shock determining lock-up capacity (&#x3b1;), during an acceleration slip lock up in which the lock-up capacity of the torque converter is augmented by means of a time series control which accords with a load state of an engine, and the torque converter is caused to be oriented toward a lock-up state in which the relative revolution is zeroed by continuing an augmentation of the lock-up capacity by means of the time series control in a case where the lock-up capacity during the no-load state is smaller than the shock determining lock-up capacity.

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Atsugi, Japan

Hiroshi Sekiya