Toyota Jidosha Kabushiki Kaisha

Sumitomo Rubber Industries Limited

Kota Hayashi

Kenji Ueda

Tokiji Ito

Yoshiyuki Shogenji

Takuya Osawa

Masahiro Nagase

Tomohisa Kuriyama

Takashi Yui

Fumito Takimoto

Hiroto Takenaka

Atsushi Kamigori

Makoto Sonoda

An internal combustion engine includes a variable mechanism that changes a working angle of an intake valve. A controller diagnoses whether there is an abnormality that an intake air amount reduces during idle operation. The controller changes an abnormality determination threshold for diagnosing an abnormality on the basis of a mode in which the working angle is changed by the variable mechanism.

Diagnostic system and diagnostic method for internal combustion engine

A detecting apparatus that detects an abnormality of imbalance of air-fuel ratios among cylinders of a multi-cylinder internal combustion engine, which is equipped with a variable working angle mechanism of an intake valve, the detecting apparatus includes an abnormality detection portion that detects a parameter regarding rotational fluctuations of each of the cylinders and detects whether or not there is an abnormality of imbalance of air-fuel ratios among the cylinders. The abnormality detection portion refrains from determining that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined large working angle range, and determines that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined small working angle range that is on a small working angle side with respect to the large working angle range.

Apparatus and method for detecting abnormality of imbalance of air-fuel ratios among cylinders

A control apparatus of a variable valve system includes a variable valve timing mechanism that performs variable control of the valve timing of an intake valve of an internal combustion engine, a variable operation angle mechanism that performs variable control of the operation angle of the intake valve, and a control unit that performs drive control of the variable valve timing mechanism and the variable operation angle mechanism. The control unit sets an upper guard for the operation angle according to an actual value of the valve timing, and when a target value of the valve timing is a value on the retard side of a specified determining value, the control unit reinforces the upper guard compared with when the target value of the valve timing is not a value on the retard side of the specified determining value.

Variable valve system control apparatus

Growing community of inventors

Nagoya, Japan

Kota Hayashi