Mazda Motor Corporation

Japan Automatic Transmission Co., Ltd.

Keizo Yanagisawa

Kouichirou Waki

Keiji Boda

Hiroaki Yokota

Kazuo Niide

Hokuto Takeuchi

An automatic transmission including a torque converter and a multiple stage transmission gear mechanism. A hydraulically actuated brake and a hydraulically actuated clutch is provided for alternate engagement to select alternately one of two adjacent gear stages. In order to prevent gear shift shock, the engaging of the clutch or the brake is controlled so that the engaging rate is faster for a predetermined time period in an initial period of a gear shifting operation than in a remainder period. A control circuit is provided to monitor the gear shifting operation and modifying the predetermined time period in accordance with the results of the latest gear shifting operation and store the modified value for the use in a next gear shifting operation.

Control of vehicle automatic transmission

A vehicle automatic transmission having a torque converter and a multiple stage transmission gear mechanism connected with the torque converter. The gear stage of the gear mechanism is selected in accordance with the vehicle operating condition. The transmission includes friction members. One of the friction members is engaged for a higher gear stage and disengaged for a lower gear stage whereas the other is disengaged for the higher gear stage and engaged for the lower gear stage. In shifting down from the higher gear stage to the lower gear stage, the other friction member is engaged after a predetermined time from the disengagement of the one friction member.

Control of a vehicle automatic transmission

Growing community of inventors

Fuji, Japan

Keizo Yanagisawa