Toyota Jidosha Kabushiki Kaisha

Yukio Hamano

Yutaka Taga

Yuji Kashihara

Fumiaki Izumi

Keita Sakurai

Kunihiro Iwatsuki

Seitoku Kubo

Kagenori Fukumura

Hideki Yasue

Hideo Tomomatsu

Yoshio Shindo

Kazuhiko Hayashi

Hiroshi Sasaoka

In a system for integrally controlling an automatic transmission and an engine, an apparatus for controlling the automatic transmission and an apparatus for controlling the engine are formed separately from each other to reduce size and cost, and to facilitate the mounting of control means onto a vehicle. Further, if trouble occurs in this communication system between the engine control apparatus and the automatic transmission control apparatus countermeasures are properly performed, and a trouble is reduced as much as possible.

System for integrally controlling automatic transmission and engine

In a system for shift control in an automatic transmission, wherein a hydraulic control device is operated to selectively switch the engagements of frictionally engaging devices and any one of plurality of gear stages can be achieved in accordance with a preset shift map, a system is provided to judge whether shifting is abnormal or not. When it is judged that the shifting is abnormal, oil pressure for engaging the frictionally engaging devices is raised. With this arrangement, the durability of the frictionally engaging devices can be secured.

System for shift control in automatic transmission

In a system for integrally controlling an automatic transmission and an engine wherein engine torque is changed during shifting, it is detected whether or not various communication means provided for carrying out the engine torque change is in a failed state. If so, a shift parameter or parameters in the automatic transmission, such as a shift point and engagement oil pressure, are changed in a direction for securing the durability of frictionally engaging devices. When the shift point is changed, a measured value of factors for determining the shift point is corrected to substantially lower the shift point. With this arrangement, computer capacity can be decreased.

In a system for shift control in an automatic transmission, wherein gear stages are automatically switched in accordance with a preset shift pattern, judgment is made as to whether or not a shifting was abnormal, and, if it is judged as abnormal, the shift pattern in the subsequent shifting is changed to a fail shift pattern, in which shift points are set slightly low. With this arrangement, the durability of frictionally engaging devices is secured.

A vehicle automatic transmission includes a torque converter which has a rotational power output member, and also includes a gear transmission mechanism. This gear transmission mechanism includes; a friction engaging mechanism; first and second rotational power input members; a first clutch which selectively engages the torque converter rotational power output member to the first rotational power input member; and a second clutch which selectively engages the torque converter rotational power output member to the second rotational power input member. When the torque converter rotational power output member is rotating the first rotational power input member via the first clutch, the gear transmission mechanism is enabled to provide its first speed stage, while, when the torque converter rotational power output member is rotating the second rotational power input member via the second clutch, the gear transmission mechanism is enabled to provide a speed stage other than its the first speed stage in cooperation with the engagement operation of the friction engaging mechanism. The rotational speed of the rotational power output member of the torque converter is detected, when the first clutch is disengaged and the second clutch is engaged, by taking it as being the rotational speed of the second rotational power input member of the gear transmission mechanism. A system is also disclosed for performing the method.

Method and system for detecting the rotation rate of the output shaft of

In the control of a vehicle automatic transmission having a series connection of an overdrive gear mechanism and an underdrive gear mechanism, the overdrive gear being switched over between direct connection and overdrive both when the underdrive gear mechanism is switched to direct connection and to speed reduction, a maximum limit is set for the period over which the overdrive gear mechanism is switched to overdrive while the underdrive gear mechanism is switched to speed reduction, such a maximum period being determined according to a vehicle operational parameter such as vehicle speed, throttle opening or transmission fluid temperature.

Method and system for control of two part type transmission providing

A vehicle automatic transmission includes a torque converter, and also includes a gear transmission mechanism. This gear transmission mechanism includes a manual range setting valve and a plurality of friction engaging mechanisms. Selective engagement of combinations of these friction engaging mechanisms, when the manual range setting valve is set to a forward range, causes the gear transmission mechanism to provide various forward speed stages. In this anti creep control method, a test is performed as to whether anti creep provision conditions hold, the anti creep provision conditions including whether or not the manual range setting valve is set to a forward range, and whether or not the vehicle is substantially stationary. If the anti creep provision conditions hold, after a determinate time interval after the establishment of these conditions, a retest is performed as to whether the anti creep provision conditions hold, and this time if the anti creep provision conditions hold anti creep control is performed from this time point. Thereby hunting of the transmission during anti creep action is prevented. A system is also disclosed for implementing this method.

Anti creep control method and system providing delay before anti creep

An automatic transmission for an automotive vehicle is selectively operable either in a first mode of providing a first, a second next to the first and a third next to the second speed stages, or in a second mode of providing the first and the third speed stages while skipping the second stage. The upshifting from the first speed stage to the second speed stage according to the first mode is effected at a lower vehicle road speed than the upshifting from the first speed stage to the third speed stage according to the second mode for the same load on the engine of the vehicle.

Method and device for controlling automatic transmission between two

A vehicle includes an engine and an automatic transmission which has a fluid torque converter, a forward clutch, and a manual range setting valve. Idling control for providing anti creep control is performed by, during engine idling time while the manual range setting valve is set to a forward driving range and the vehicle is substantially stationary, reducing the engagement pressure of the forward clutch by reducing the actuating pressure provided to it. A rotational speed associated with the fluid torque converter is detected, and the actuating pressure provided to the forward clutch is controlled so that the rotational speed associated with the fluid torque converter does not drop below a certain rotational speed value. Thereby good anti creep control is provided. A system is also disclosed for performing the method.

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Toyota, Japan

Yukio Hamano