Jatco Corporation

Nissan Motor Company Limited

Jun Yoshino

Hiroyuki Takenaka

Katsunori Satou

Kan Yagi

Masaya Kubota

Yuzuru Tohta

Kenichiro Murakami

Hitoshi Yokose

Tsuyoshi Mori

Makoto Hashimoto

A control apparatus for an automatic transmission includes a shift control section configured to perform a shift of the automatic transmission; and a judder judging section. The shift control section is configured to judge whether or not a progress of the shift is during an inertia phase. The judder judging section calculates a characteristic-gradient index value which is a value obtained by quantifying a phenomenon that appears as a relative rotational speed between input and output of the first friction-engagement element becomes reduced with a progress of the inertia phase. The phenomenon appears in a different way in dependence upon whether a relational characteristic of a friction coefficient of the first friction-engagement element with respect to the relative rotational speed is a positive-gradient characteristic or a negative-gradient characteristic. The judder judging section determines that the judder has occurred based on the characteristic-gradient index value.

Control apparatus and method for automatic transmission

An automatic transmission control apparatus includes an engine rotational speed limit verifying section and a shift control characteristic changing section. The engine rotational speed limit verifying section is configured to receive an engine rotational speed limit value for limiting an engine rotational speed and determine if the engine rotational speed limit value is lower than a prescribed normal upper limit value. The shift control characteristic changing section is configured to change a shift schedule of an automatic transmission based on the engine rotational speed being limited by the engine rotational speed limit value and the automatic transmission having a stronger tendency to select a higher gear stage than if the engine rotational speed limit value was not being limited to a lower value than the prescribed normal limit value, when the engine rotational speed limit value is determined to lower than the prescribed normal upper limit value.

Automatic transmission control apparatus

A shift shock reducing apparatus for a power train having an engine and an automatic transmission having a frictional element that is to be engaged at upshift, comprising a control section that executes, during upshift, a torque down of the engine that starts before the start of an inertia phase in which a gear ratio of the transmission is changing from a before-shift gear ratio to an after-shift gear ratio, and a control section that makes larger a rising gradient of working oil pressure that is supplied to the frictional element to be engaged at upshift when the torque down that starts before the start of the inertia phase is executed than that when the torque down is not executed.

Shift shock reducing apparatus for power train

Growing community of inventors

Fuji, Japan

Jun Yoshino