Mazda Motor Corporation

Mazda Motor Corporat Ion

Hidetoshi Nobumoto

Minzi Sakaki

Mitsuo Hitomi

Tetsuro Takaba

Shingo Harada

Yuji Shitani

Seiji Terauchi

Tetsuya Kyakuno

Osamu Sunahara

Kiyotaka Mamiya

Kazuhiko Ueda

Kazuo Sasaki

Tatsuya Uesugi

Osamu Sado

Noboru Hashimoto

Makoto Hotate

Seiji Esaki

Fumio Hinatase

Kazuaki Umezono

Yoshikuni Yada

Hisanori Nakane

Hiromasa Yoshida

Koji Onishi

Takayuki Ueda

Taizou Shoya

Akio Wakasaki

Shinichiro Yamashita

A movement control device for a vehicle comprises a yaw-acceleration calculation portion to calculate a target yaw acceleration of the vehicle, a turn-back steering determination portion to determine whether a turn-back steering of the vehicle is conducted or not, and a drive-force control portion to a drive force of the vehicle. The control of the drive-force control portion is configured such that when the turn-back steering is not conducted, the amount of drive-force decreasing is increased with a specified increasing rate as the target yaw acceleration increases, the specified increasing rate becoming smaller as the target yaw acceleration increases, and when the turn-back steering is conducted, the drive force is increased in a case in which an absolute value of a steering angle of the vehicle decreases.

Movement control device for vehicle

An engine starting system for a power train including an engine and an automatic transmission includes an engine stop/restart controller. The automatic transmission having special mode includes first and second planetary gear sets having respective sun gears, a turbine shaft, an output gear, a forward clutch and a 2-4 brake. The forward clutch sets the automatic transmission in a drive condition when engaged and in a neutral condition when disengaged. If the special mode is selected under conditions where the output gear is locked, the sun gear of the first planetary gear set is locked. During execution of automatic engine stop control operation, the engine stop/restart controller causes the automatic transmission to initiate a transfer to the special mode before fuel supply is interrupted and causes the forward clutch to completely engage at a specific point in time after the automatic transmission has completed the transfer to the special mode.

Engine starting system for power train

In an automatic transmission including a forward clutch and a lockup clutch of a torque converter which are provided on a driving-power transmitting path between an engine and a driving wheel, a vehicle driving condition is classified into a plurality of regions and an associated slip control between the forward clutch and the lockup clutch is executed. Accordingly, both of improvements of gas mileage and drivability can be attained at a high level.

Transmission control device

An automatic transmission control system for controlling a gear ratio of an automatic transmission connected to an engine so as to bring an engine speed of rotation to a target speed of rotation predetermined according to a vehicle speed and a throttle opening of the engine. The control system includes an engine speed sensor for detecting an engine speed of rotation of the engine, a throttle opening sensor for detecting a throttle opening of a throttle of the engine, a vehicle speed sensor for detecting a vehicle speed a control mechanism for interrupting delivery of fuel to the engine while the engine speed of rotation is higher than a specified speed of rotation and the throttle opening is less than a specified opening, increasing the target engine speed of rotation while the throttle opening is less than the specified opening to increase the gear ratio and, when the trottle opening sensor detects a throttle opening increase above the specified opening after having once been decreased below the specified opening, the control mechanism controls the gear ratio according to the increased target engine speed of rotation until a target engine speed of rotation set according to the vehicle speed and a throttle opening becomes greater than the increased target engine speed of rotation.

Automatic transmission control system

A control system for a continuously variable transmission continuously varies a gear ratio according to predetermined control patterns specified according to engine speeds and loadings, each predetermined control pattern including two separate sections, one of which is used only during acceleration of the vehicle and another of which is used only during deceleration of the vehicle, for a specified band of vehicle speeds within which a specific vehicle speed at which power transmission paths are switched over from one to another.

Control system for a continuously variable transmission

A continuously variable transmission control system employs a gear ratio control map which has a step-wise control zone of driving condition where engine speed is controlled to repeat alternate gradual increase and rapid decrease with an increase in vehicle speed so as thereby to vary step-wise a gear ratio and a continuous control zone of driving conditions where engine speed is controlled to increase approximately linearly with an increase in vehicle speed so as thereby to continuously vary a gear ratio, the step-wise control zone of driving condition based on which the gear ratio control is performed being narrowed when a driving condition is judged to be within a specified unstable zone.

Control system for a continuously variable transmission capable of

A toriydal type of automatic transmission is changeable between an automatic shift mode and a manual shift mode in which a shift up switch or a shift down switch is operated. The automatic transmission in the manual shift mode is shifted down by one step when the shift down switch is operated and shifted up by two step when the shift up switch is operated, so that the transmission gear ratio changes at a rate smaller during a manual down shift than during a manual up shift.

An automatic transmission control system causes a downshift to a gear which can provide an effect of engine braking greater than that provided before the downshift when the vehicle falls its speed with a specified rate of speed reduction as a result of footbrake application while the vehicle is traveling on a downgrade having a slope greater than a specified slope.

Control system for automatic transmission

An automatic transmission control system, which applies an ordinary gear shift control map set up for flat road driving and a downgrade gear shift set up for downgrade driving which has broadened range of driving conditions for lower gears, causes gear shifts according to the ordinary gear shift control map even during downward driving when an accelerator pedal is stepped on with intention of accelerating the vehicle.

Gear shift control system for automatic transmission

A power transmission device for a vehicle comprises a first power transmitting path for transmitting engine output to a wheel side via a reduction gear, a second power transmitting path for transmitting engine output to the wheel side via a stepless speed change gear mechanism, a path switching clutch for switching between the paths to transmit by one of the paths, a switch-over control part for controlling switch-over operation of the clutch according to a driving condition of the vehicle, and a rotational condition abrupt change restraining part for restraining an abrupt change of a rotational condition of an engine output shaft at switch-over between the paths. The restraining part adjusts to conform rotating speeds of the input and output sides of the clutch to each other at switch-over of the clutch, or conform output torque to the wheel side between before and after switch-over of the clutch. Thus, an abrupt change of rotation of the engine output shaft is restrained to prevent a shock owing to switch-over, and the durability of a friction element is enhanced.

Power transmission device for vehicle

A fluid coupling has a lockup mechanism, which is unlocked at an increased speed upon a large displacement of an accelerator pedal, and is provided with an activator for applying hydraulic pressure to the lockup mechanism to couple and uncouple the fluid coupling. The activator is controlled by a release controller so as to decrease graudally the hydraulic pressure at a predetermined rate. The fluid coupling is thus uncoupled with a gradual decrease of coupling force when an engine operates in a predetermined engine operating condition. The predetermined rate of pressure change is modified so as to advance uncoupling of the fluid coupling when an engine load is higher than a predetermined engine load, while the release controller controls the activator so as to decrease gradually the hydraulic pressure.

Coupling force control system for fluid coupling

The coupling force of a fluid coupling interposed between the combustion engine and the driving wheels is controlled when the automotive vehicle is decelerated. When the automotive vehicle is brought into a decelerated state, the supply of fuel to the combustion engine is suspended by cutting the fuel off. The control of cutting fuel off is delayed by a given period of time after the control over the coupling force of the fluid coupling has been started. The given delay time is so set as to correspond to the state in which the fluid coupling slips.

System for controlling coupling force of a fluid coupling

A slip control system for a lock-up clutch of an automatic trnasmission includes a torque converter having an input member, connected to an engine output shaft so that engine output torque is transmitted, and an output member, driven by virtue of a rotation of the input member through a hydraulic fliud. A slip control device controls an engaging force of the lock-up clutch to carry out a slip control so that an amount of slippage in the lock-up clutch is controlled to a target value, corresponding to a target speed difference between the input and output members. An acceleration detecting device detects an accelerating condition of a vehicle, and an engine load detecting device detects an engine load. A slip control changing device suppresses a responsiveness in controlling the slippage in accordance with change in the engine load at the end of the accelerating condition of the vehicle.

Slip control system for automatic transmission with lock-up clutch

An exhaust gas recirculating system for a combustion engine has at least one cylinder communicating with a source of combustible air-fuel mixture through at least one intake port adapted to be selectively closed and opened for effecting the interruption and admission of the supply of the combustible mixture into the combustion chamber, the cylinder also communicating with an exhaust system through first and second exhaust ports both adapted to be selectively opened and closed. The exhaust gas recirculating system includes an intake valve for selectively opening and closing the intake port, first and second exhaust valves each for selectively closing and opening the associated first and second exhaust ports, wherein the first exhaust valve is operable to completely close the associated first exhaust port subsequent to the complete closure of the second exhaust port by the associated second exhaust valve, an exhaust shutter valve for selectively opening and closing a passage extending between the first exhaust port and the exhaust system, and a control unit for controlling the shutter valve according to an engine operating condition to adjust the amount of a portion of the exhaust gases allowed to substantially remain within the cylinder.

Automobile exhaust gas recirculating system

In a turbocharged engine, a bypass passage bypassing the impeller of the turbocharger is provided in the intake system to be opened and closed by a bypass valve. A flow control valve is provided in the intake system on the intake side or discharge side of the impeller. During heavy load operation of the engine, the bypass valve is closed and the flow control valve is opened so that all intake air flows through the impeller of the turbocharger. On the other hand, during light load operation of the engine, the bypass valve is opened and the flow control valve is partly closed so that the ratio of the pressure in the intake system downstream of the impeller to the pressure in the intake system upstream of the impeller is set near the surging line but below the same.

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Hiroshima, Japan

Hidetoshi Nobumoto