Mazda Motor Corporation

Mitsuo Yasuno

Mitsuru Nagaoka

Shinya Kamada

Kenji Sawa

Yasunari Nakayama

Shin Nakano

Mitsukazu Tasaka

An automatic transmission control system, which includes a 2-4 brake having a servo apply fluid chamber and a servo release fluid chamber and a 3-4 clutch having a fluid chamber and causes a 3-2 shift by engaging the 2-4 brake and disengaging the 3-4 clutch, controls engaging pressure for the 3-4 clutch by way of controlling servo apply pressure for the 2-4 brake to disengage the 3-4 brake so as thereby to increase turbine speed during the 3-2 gear shift and, at near the end of the 3-2 gear shift, brings the 2-4 brake into engagement. During control of disengagement of the 3-4 clutch, the pressure difference between servo apply pressure and servo release pressure is changed to become greater at the beginning of the gear shift.

Automatic transmission control system for automobiles

A torque distribution control system for a four-wheel drive vehicle has an engine output controller which controls the output of the engine of the vehicle, a braking controller which separately controls the braking forces applied to the left wheels and the right wheels and/or the braking forces applied to the front wheels and the rear wheels. A torque distribution changing system determines the torque distribution to the wheels according to the running condition of the vehicle and controls the braking controller and the engine output controller to apply a braking force to one of the front wheels and the rear wheels or one of the left wheels and the right wheels and to increase the output of the engine by an amount substantially corresponding to the braking force applied to the one of the front wheels and the rear wheels or the one of the left wheels and the right wheels so that the torque distribution determined according to the running condition of the vehicle can be obtained.

Torque distribution control system for four-wheel drive vehicle

First and second clutch devices releasably and alternately connect respective transmission input shafts with an engine output shaft. The input shafts are connected through respective sets of transmission gears with a transmission output element. In a gear shift up operation, one of the clutch devices, which has not been in driving engagement, is brought into partial engagement with a first engaging speed for a first period of time, while the second clutch device remains in driving engagement, so that there is a certain period of time overlap wherein both clutch devices are in engagement simultaneously. After the second clutch device has been disengaged, the engagement speed of the first clutch device is decreased to a lower speed and then again increased to a higher speed.

Shift up clutch control in a multiple clutch type gear transmission for

A multiple clutch type transmission including a plurality of input shafts, a plurality of clutch devices for releasably and alternately connecting respective ones of the input shafts with an engine output shaft, each of said input shafts being associated with at least one set of transmission gears for connecting the input shaft associate therewith to an output element of the transmission, means for controlling the clutch devices so that selected one of the input shaft is connected through selected one of the clutch devices with the engine output shaft and through selected set of the transmission gears with the output element. There is disclosed a method of controlling the clutch devices in gear shift down operation, which comprises steps of disengaging the clutch device which has been in engagement for connecting the engine output shaft with one of the input shaft so that all of the clutch devices are maintained in disengaged conditions to allow engine speed to increase, and then engaging other clutch device to connect the other input shaft having the transmission gear set of lower gear stage.

Growing community of inventors

Hiroshima, Japan

Mitsuo Yasuno