Aisin Seiki Kabushiki Kaisha

Yoshinori Nishi

Kazuo Ishikawa

A lock-up clutch of an automatic transmission is controlled by an electronic control unit using a gear shift diagram and a lock-up clutch changeover diagram each having vehicle velocity plotted along identical abscissa and throttle opening plotted along identical ordinate. Changeover of the lock-up clutch is controlled upon setting a changeover line in the changeover diagram in accordance with which the lock-up clutch is changed over from OFF to ON state, and changeover of transmission gear ranges is controlled upon setting a transmission gear range changeover point in the gear shift diagram. The changeover line is set in such a manner that it will not intersect a region in the gear shift diagram where the shift position is 2nd gear range or less and the throttle opening is less than a predetermined value. Thus, the lock-up clutch is not engaged in a case where the transmission is in 2nd gear range or less and, moreover, the throttle opening is less than a predetermined value.

Growing community of inventors

Aichi, Japan

Yoshinori Nishi