Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabishuki Kaisha

Masahiko Nakagawa

Masato Shimei

Shigeki Goto

Takahiro Sakai

Atsuo Okumura

A shift control apparatus for controlling a speed ratio of an automatic transmission of a motor vehicle having an engine during running of the vehicle on a downhill road, on the basis of an actual acceleration value of the vehicle as compared with a reference acceleration value of the vehicle, the apparatus including a device for determining reduction of an actual output of the engine with respect to a desired output of the engine as represented by an operating amount of an accelerator pedal, and a device for reducing the reference acceleration value by a compensating amount which decreases with an increase in the running speed of the vehicle, upon determination of the reduction of the actual output of the engine.

Apparatus for controlling automatic trasmission during downhill running

A control apparatus for an automatic transmission having a set of frictional engagement elements arranged to be selectively engaged or disengaged in shift-up operation of the transmission, and a shift timing valve arranged to be switched over by hydraulic pilot pressure applied there-to under control of a solenoid valve for switching over discharge of fluid under pressure from one of the frictional engagement elements to be disengaged in the shift-up operation from a slow-drain condition to a quick-drain condition. The control apparatus is designed to detect a drive torque of a vehicle engine, to determine a timing period for energization of the solenoid valve in the shift-up operation in accordance with the drive torque of the vehicle engine, to maintain the solenoid valve in its deenergized condition during the timing period, and to energize the solenoid valve upon lapse of the timing period.

Growing community of inventors

Nagoya, Japan

Masahiko Nakagawa