Jatco Corporation

Nissan Motor Company Limited

Koji Dohi

Tatsuya Imamura

Hiroshi Sekiya

Toshiji Iida

Kouji Saitou

Satoshi Segawa

Morimasa Yamawaki

Nobuo Kurogo

Minari Ishii

Hiroyasu Tanaka

Kazutaka Adachi

Hideshi Wakayama

Masayoshi Nakasaki

Katsumi Doihara

Aki Hayakawa

Azusa Shimoda

Tatsuya Ozone

Naohiro Hoshi

Daisuke Aoki

Shoichi Sekiguchi

Masayuki Kobayashi

Hideaki Sasaki

Toshio Saitou

An automatic transmission control apparatus includes: a frictional engagement element; a hydraulic pressure supplying section configured to supply a hydraulic pressure to the frictional engagement element; a progression state judging section configured to judge a progression state of the engagement of the frictional engagement element; a rotational speed change rate control section configured to control the hydraulic pressure so that a change rate of a rotational speed of an input shaft of the automatic transmission becomes equal to a target change rate, from when the engagement of the frictional engagement element is started; and a rotational speed feedback control section configured to perform a feedback control of the hydraulic pressure so that the rotational speed of the input shaft of the automatic transmission becomes equal to a target rotational speed, from when the progression state judging section judges a predetermined progression state.

Automatic transmission control apparatus

A control apparatus for an automatic transmission including a hydraulic pressure control means for controlling supply of hydraulic pressure to a first friction engagement element and a second friction engagement element and discharge of hydraulic pressure from the first friction engagement element and the second friction engagement, and a discharge rate changeover control means for increasing a discharge rate value of the hydraulic pressure which is discharged from the first friction engagement element in a case where when shifting from one of operating ranges to the other thereof is selected, changeover to the other operating range is carried out before completing release of the first friction engagement element, so as to become larger than a discharge rate value of the hydraulic pressure which is discharged from the first friction engagement element before the changeover to the other operating range is carried out.

Control apparatus for automatic transmission

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 hydraulic pressure control device is provided that that controls hydraulic pressure of a clutch supplying torque to a continuously variable transmission while the vehicle is stopped and in a running range. The hydraulic pressure control device has an control section that estimates a clutch engagement hydraulic pressure for changing the clutch from an engaged state to a disengaged state based the hydraulic fluid pressure acting on the clutch during the stopping of the rotational movement of a primary pulley of the continuously variable transmission, and then controls regulation of the hydraulic pressure to the clutch from an engaged state to a disengaged state, when the vehicle is stopped and in the running range, so that the torque from the engine does not rotate a secondary pulley of the continuously variable transmission.

Hydraulic pressure control device for continuously variable transmission

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.

Lock-up capacity control apparatus and method for torque converter

A controller () performs open loop control of the engaging state of a lockup clutch () through a switching mechanism () when a torque converter () transitions from a first state in which the lockup clutch () is disengaged to a second state in which the lockup clutch () is at least partially engaged. At this time, the controller () estimates the engine torque at the time when open loop control ends, estimates a necessary lockup capacity required for the converter () at the time when open loop control ends, based on the estimated engine torque, and controls the engaging state of the lockup clutch () through the switching mechanism () to make the lockup capacity at the time when open loop control ends become the necessary lockup capacity.

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Fuji, Japan

Koji Dohi