Mazda Motor Corporation

Mitsutoshi Abe

Toshiyuki Kikuchi

Hiroshi Yoshimura

Kazuo Sasaki

Toshihisa Marusue

Masahito Kitada

Yuji Matsuno

Masaki Fujii

Kanji Okamoto

Shinya Kamada

Takuji Fujiwara

Kenji Sawa

Kenji Okamoto

Koichi Yamamoto

Seiji Yashiki

Shigeru Nagayama

Hiroaki Yokota

Takahiro Kyohzuka

Shin Nakano

Hiroyuki Matsumoto

Hiroyuki Takebayashi

Yoshinori Fukumoto

Satoru Kawasoe

Kenji Kurisu

Maski Fujii

Yuji Nakahara

There is provided temporary high-speed gear setting means which causes an automatic transmission to accomplish first-speed gear after it has once been set to second speed gear, for instance, which is selected as a specific high-speed gear upon switching from a non-drive range to the drive range. While it is made possible to manually switch between gear-shifting control operation in automatic mode performed according to preset shifting characteristics and manual mode in which gear-shifting operation is manually performed by a driver, priority is given to accomplishment of the first-speed gear the temporary high-speed gear setting means when the automatic transmission is switched to the manual mode while it is set to the aforementioned specific high-speed gear by the aforementioned temporary high-speed gear setting means.

Controller for automatic transmission

A malfunction judgment system of an oil temperature sensor for detecting a hydraulic oil temperature in an automatic transmission of a vehicle. The system receives an output from the oil temperature sensor to judge a malfunction of the oil temperature sensor when an increase rate of the oil temperature is smaller than a predetermined value in a predetermined time period after the vehicle starts running. A running condition detecting element detects a vehicle running condition. The system further has a plurality of conditions for judging the malfunction of the oil temperature sensor based on the detected running condition of the vehicle and the output of the oil temperature sensor.

Malfunction judgment system of oil temperature sensor for automatic

A shift control system of an automatic transmission includes a first element which is to be released in a shift operation, a second element which is to be engaged in the shift operation, and a target shift time set section for setting a target time period of the shift operation needed for releasing the first frictional element and engaging the second frictional element. A shift time calculation section is provided for obtaining an actual time period of the shift operation needed for releasing the first frictional element and engaging the second frictional element, and a releasing pressure control section is provided for receiving output of the target shift time set section and the shift time calculation section for controlling a releasing pressure of the first frictional element in the shift operation based on the difference between the target and actual time periods of the shift operation. An engaging pressure control section is used for controlling an engaging pressure of the second frictional element in the shift operation. A shift shock is effectively suppressed by the shift control system.

Adaptive pressure control based on difference between target and actual

An automatic transmission shift control system calibrates a locking speed, which is regulated by a regulating valve and at which locking of a specific frictional element is performed so as to shift an transmission gear mechanism to a specific gear, in accordance with a deviation of an input speed of rotation to the transmission from a specified input speed of rotation while shifting the transmission to the specific gear. The system further varies the calibration according to a transitional period of time which is defined from a completion of shifting to a preceding gear from which the transmission is shifted directly to the specific gear to a commencement of shifting to the specific gear subsequently to the shifting to the preceding gear.

Gear shift control system for automatic transmission

A control apparatus for an engine and an automatic transmission controls a starting timing, a terminating timing, or methods of torque reduction of the engine during gear shifts. Using stored information such as a turbine speed signal, a gear shift signal, a degree to which a throttle valve is opened, a vehicle speed, an engine speed and so on, the control apparatus calculates an appropriate torque reduction which is performed by either retarding ignition timing or cutting fuel supplied to fuel injection valves. According to one embodiment of the invention, by detecting a variation ratio or differential value of turbine speed, a period of the torque reduction is started, ended, and kept within a proper timing. According to another embodiment of the invention, based on a 'chasing' state of an input torque of the transmission against the variation of engine load, the timing of torque reduction is changed. Finally, according to yet another embodiment of the invention, a light preceding torque reduction is performed prior to a more significant torque reduction, but only when shocks due to the gear shift tend to occur.

Torque control apparatus for engine and automatic transmission

An automatic transmission includes a multi-speed transmission gear mechanism having an input shaft, an output shaft and a plurality of friction coupling elements. A hydraulic control system selectively supplies a hydraulic pressure to the friction coupling elements, thereby selectively applying the friction coupling elements to cause the transmission gear mechanism to shift to a speed which is determined according to a predetermined shift pattern. The control system sets a target hydraulic pressure to be applied to the friction coupling elements according to the kind of the shift to be effected and the engine load, and, when it is detected that the transmission gear mechanism is to make a backout upshift due to reduction in the engine load, increases the target hydraulic pressure by an amount which is determined according to the throttle opening and the turbine speed.

Hydraulic control system for controlling line pressure based on

An engine speed control system causes an engine, equipped with an automatic transmission which shifts up according to predetermined shift schedules, to reduce its output at a predetermined engine speed so as to protect the engine by preventing the engine from being subjected to 'over-revolution.' The predetermined engine speed is changed according to engine operating conditions such as a decrease in engine temperature. Simultaneously, a shift-up vehicle speed, at which the automatic transmission shifts itself up, is decreased according to engine operating conditions and, more particularly, engine temperatures and throttle openings. As a result, an up-shift of the automatic transmission properly takes place, even when the vehicle travels at lower speeds.

Engine speed control system with changing shift-up speed

A control system for an automatic transmission includes a torque converter having input and output members through which driving power is transmitted. A lock-up clutch is provided in the torque converter for connecting the input and output members without intervention of hydraulic fluid. A multiple stage transmission gear mechanism is connected with the output member of the torque converter and has a plurality of shift gear stages. A shift control device shifts the shift gear stage in accordance with a vehicle operating condition. An engaging force control device controls an engaging force of the lock-up clutch in a manner such that a slip rate of the lock-up clutch is changed. Finally, an acceleration judging device judges a required acceleration, and the engaging force control device reduces the engaging force as the required acceleration is increasd. The control is made in a manner such that the driving power transmitted through the automatic transmission is continuously changed in accordance with the required acceleration. Both acceleration performance and fuel consumption performance can be improved.

Control system for continuously operating transmission according to

A control system for a vehicle, including an automatic transmission provided with a multiple transmission gear mechanism, automatically establishes a specific gear stage of a speed ratio from among a plurality of gear stages in accordance with an vehicle operatiing condition. A shift control signal producing device produces a shift control signal in order to produce a shift operation between different gear stages in accordance with the vehicle operating condition. An engine output control device reduces an engine output in synchronism with the shift operation so as to suppress a torque shock due to the shift operation. A detecting device detects a specific vehicle operating condition in which a change in a time lag between a generation of the shift control signal and an actual initiation of the shift operation in the transmission is greater than a predetermined level and produces a signal denoting the specific vehicle operating condition. Finally, a restricting device restricts the engine output control device from reducing the engine output when the specific vehicle operating condition is detected. The torque shock due to the shift operation, therefore, can be effectively suppressed.

Control system for vehicle with automatic transmission with engine

An engine control system for a vehicle having an automatic transmission in which the gear-shifting is automatically done on the basis of a predetermined shift pattern comprises an engine output control system for controlling the output power of the engine, a detecting system which detects actual shifting action of the gear train mechanism of the automatic transmission, and an engine control unit which receives a signal from the detecting system and delivers to the engine output control system a control signal for temporarily lowering the engine output power while the actual shifting action of the gear mechanism is in progress.

Engine control system for vehicle with automatic transmission

A gear-shifting shock suppressing system for a vehicle provided with an automatic transmission which shifted to a desired gear-speed on the basis of a gear-shifting signal controls the output of the engine of the vehicle in order to suppress gear-shifting shock which occurs when the automatic transmission shifts. The gear-shifting shock suppressing system detects the interval between successive two gear-shifting signals and controls the output of the engine when the interval between successive two gear-shifting signals is longer than the predetermined time in a manner different from the manner in which the gear-shifting shock suppressing system controls the output of the engine when the interval between successive two gear-shifting signals is shorter than the predetermined time.

Gear-shifting shock suppressing system for automatic transmission vehicle

An engine control system for a vehicle provided with an automatic transmission including an engine output control device for reducing an engine output in response to a shift operation of the automatic transmission, brake switch for detecting a braking operation of the vehicle, a restricting element for restricting the engine output control device from reducing the engine output when the braking operation is detected during the shift operation. The engine output is not reduced when the braking operation occurs even under the shift operation so that an undue drop of engine speed can be avoided. The engine speed can be smoothly increased after the braking operation responsive to acceleration operation to thereby improve the controllability.

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Hiroshima, Japan

Mitsutoshi Abe