Mazda Motor Corporation

Yutaro Fukuda

Tadashi Saito

Manabu Sasahara

Tomohiro Kubo

Shinya Kamada

Tatsuhiko Iwasaki

Tatsutoshi Mizobe

Tomotaka Ishizaka

Norio Iwashita

Kaori Sako

Koshiro Saji

Masahiro Kaji

Takahiro Kashimoto

Masakazu Ohsako

A hybrid vehicle controlling method is provided. In response to an engine startup demand, when a vehicle target driving force is below a given value, an instruction hydraulic pressure for a hydraulic control circuit is set to a first pressure at which an increase rate in an engagement pressure at a start of engaging of a friction engagement element becomes below a given rate and maintained for a given time period, then set to a second pressure at which an engine-startup engagement pressure is applied to the friction engagement element and maintained until the engine startup is completed, and then set to a third pressure for setting the friction engagement element to an engaged state. When the target driving force is above the given value, the instruction hydraulic pressure is set to the second pressure and maintained until the engine startup is completed, and then set to the third pressure.

Control method and control system of hybrid vehicle

A controller as a control apparatus for a hybrid vehicle determines whether or not to perform switching from a first traveling mode in which a hybrid vehicle is caused to travel using torque of a motor without using torque of an engine to a second traveling mode in which the hybrid vehicle is caused to travel using at least the torque of the engine. The controller, when determining that switching is to be performed from the first traveling mode to the second traveling mode, performs control to reduce output torque of the motor by a predetermined amount. After this control, the controller shifts a first clutch from a released state to an engaged state so that the torque of the motor is transmitted to the engine via the first clutch, and cranks the engine using the motor to start the engine.

Control apparatus for hybrid vehicle

In a hybrid vehicle control system, when a first traveling mode using torque of an electric motor is switched to a second traveling mode using torque of an engine, a controller performs an engine start control by applying an engagement pressure to a first clutch and by cranking the engine by the electric motor, so as to start the engine. Specifically, the controller obtains a predicted start time and an actual start time by the engine start control, and corrects the engagement pressure so as to decrease the engagement pressure applied to the first clutch at a subsequent time of starting the engine, when the actual start time is shorter than the predicted start time.

Hybrid vehicle control system

A frictional engagement element includes: a first piston, a second piston, a first urging member for urging the first piston in a direction of releasing a friction plate, and a second urging member for urging the second piston in the direction of releasing the friction plate with an urging force larger than the urging force of the first urging member. One of the first and second pistons has a communicating hole for connecting an engaging hydraulic chamber with an opposite hydraulic chamber and the other of the first and second pistons has a valve part for closing the communicating hole. The difference in travel distance between the first and second pistons in motion due to the different urging forces of the first and second urging members causes the valve part to open the communicating hole.

Automatic transmission and frictional engagement element

An automatic transmission includes a piston movable in an axial direction, a plurality of friction plates disposed on a side of a first surface of the piston, a fastening hydraulic chamber applying a hydraulic pressure to a second surface of the piston to move the piston to a fastening position where the friction plates are pressed to be fastened to each other, a release hydraulic chamber applying a hydraulic pressure to the first surface of the piston to move the piston to a release position where the friction plates are released, and a hydraulic pressure control valve that supplies and discharges the hydraulic pressure to and from each of the fastening hydraulic chamber and the release hydraulic chamber. An area of the second surface of the piston for receiving the hydraulic pressure is set to be larger than an area of the first surface for receiving the hydraulic pressure.

Automatic transmission

A method of controlling an automatic transmission is provided. The automatic transmission includes a piston having first and second surfaces opposite from each other, friction plates, engaging and disengaging hydraulic pressure chambers for supplying hydraulic pressure and directing the piston to push the friction plates to be engaged and disengaged, a hydraulic pressure control valve for supplying and discharging hydraulic pressure to and from the chambers, and first and second oil paths communicating the valve with the chambers. The second surface has a larger area for receiving hydraulic pressure than that of the first surface. The method includes controlling the friction plates to change from the disengaged state to the engaged state. Controlling the friction plates includes adjusting the hydraulic pressure to a first instruction pressure in a first period in response to a gear shift command, and to a second instruction pressure in a second period.

Method and device for controlling automatic transmission

A method of controlling an automatic transmission is provided. The automatic transmission includes a piston having first and second surfaces opposite from each other, friction plates, engaging and disengaging hydraulic pressure chambers for supplying and discharging hydraulic pressure and directing the piston to push the friction plates to be engaged and disengaged, a hydraulic pressure control valve for supplying and discharging hydraulic pressure to and from the chambers, first and second oil paths communicating the valve with the chambers, and a pressure reducing valve disposed in the second oil path and for preventing hydraulic pressure of the disengaging hydraulic pressure chamber from exceeding a given set pressure. The second surface has a larger area for receiving hydraulic pressure than an area of the first surface for receiving hydraulic pressure. The method includes changing the given set pressure according to information regarding a state of the automatic transmission.

A method of controlling an automatic transmission is provided. The automatic transmission includes first and second frictional engageable elements and a hydraulic mechanism. The method includes controlling a first hydraulic pressure control valve of the first element to adjust hydraulic pressure to a given value in a first period in response to the gear shift command and increase the hydraulic pressure until first friction plates engaged in a second period, and a second hydraulic pressure control valve of the second element to pre-charge in response to the gear shift command, maintain the hydraulic pressure at a lower value than a highest target value immediately after the pre-charging, and increase the hydraulic pressure until second friction plates engaged immediately after the maintaining the pressure, a time length of the first period being shorter than a time length between a start of the pre-charging and a start of the increasing the pressure.

A method of controlling an automatic transmission is provided. The automatic transmission includes a piston having first and second surfaces opposite from each other, friction plates, engaging and disengaging hydraulic pressure chambers for supplying/discharging hydraulic pressure and directing the piston to push the friction plates to be engaged and disengaged, a hydraulic pressure control valve for supplying/discharging hydraulic pressure to/from the chambers, and first and second oil paths communicating the valve with the chambers. The second surface has a larger area for receiving hydraulic pressure than the first surface. The method includes controlling the disengaged friction plates to be engaged by adjusting the hydraulic pressure to a first pressure in a first period in response to a gear shift command and adjusting the hydraulic pressure to a second pressure in a second period. The first pressure is changed depending on a state of the automatic transmission.

A method of controlling an automatic transmission mounted on a vehicle having an automatic engine stop mechanism for automatically stopping and restarting an engine, is provided. The transmission includes a piston having first and second surfaces, friction plates, engaging and disengaging hydraulic pressure chambers, a hydraulic pressure control valve for supplying/discharging hydraulic pressure to/from the chambers, first and second oil paths communicating the control valve with the chambers, a pressure reducing valve for preventing pressure of the disengaging chamber from exceeding a given set pressure, a hydraulic pressure supply device for supplying pressure to the control valve in the automatic stop state, and a mechanical oil pump for supplying pressure to the control valve while the engine is driving, the second surface having a larger pressure receiving area than the first surface. The method includes adjusting the set pressure to be lower in the automatic stop state than while driving.

Growing community of inventors

Hiroshima, Japan

Yutaro Fukuda