Mazda Motor Corporation

Kaori Sako

Shinya Kamada

Tatsutoshi Mizobe

Tatsuhiko Iwasaki

Tadashi Saito

Tomotaka Ishizaka

Norio Iwashita

Manabu Sasahara

Yutaro Fukuda

Tomohiro Kubo

Koshiro Saji

Masahiro Kaji

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

An automatic transmission is provided with a brake device provided with a rotatable rotation-side friction plate and a non-rotatable fixed-side friction plate; a transmission case which accommodates the brake device; a lubrication oil supply section which supplies lubrication oil introduced into the transmission case to an upper portion of the brake device; and a lubrication oil discharge section disposed below the brake device, and configured to discharge lubrication oil supplied from the lubrication oil supply section to the brake device.

Growing community of inventors

Hiroshima, Japan

Kaori Sako