Toyota Jidosha Kabushiki Kaisha

Kouichi Hoshi

Yukihiro Sonoda

Kouichi Osawa

Hiroshi Sawada

Hiroki Matsuoka

Hiroshi Kanai

Michihiro Ohashi

Takahide Izutani

Mamoru Yoshioka

Hidehiro Oba

Makoto Suzuki

Shinichi Matsumoto

Nobuaki Kayanuma

Hidemi Ohnaka

Michio Furuhashi

Hironori Bessho

Kenichi Nomura

Katsushi Anzai

Akira Hashizume

Ritsuo Masaki

Masaru Goudo

Mitsuhiro Suzuki

Sinji Kato

Kiyoshi Asada

Hiroyuki Sawamoto

Ryouichi Harada

An apparatus for controlling a heater for heating an oxygen sensor provided in an exhaust gas flow passage of an internal combustion engine disposed in an automotive vehicle, includes an operating condition detecting unit for detecting a predetermined operating condition of the internal combustion engine, and a resistance/power detection unit for detecting a heater resistance value of the heater and an amount of power supplied to the heater when the internal combustion engine is in the predetermined operating condition. The apparatus also includes a power control unit for comparing the heater resistance value detected by the resistance/power detection unit with a target resistance value and for supplying the heater with power supplied from a battery in a definite-resistance control mode in which the heater resistance value is controlled to become equal to the target resistance value, a resistance value correction unit for correcting the target resistance value so that a difference between the amount of power detected by the resistance/power detection unit and a standard amount of power becomes equal to zero, and a storage unit for storing the target resistance value corrected by the resistance value correction unit as a learning value. Further, the apparatus includes a storage state judgment unit for judging whether or not the the learning value is correctly stored in the storage unit, and a stop unit for stopping the power control unit to supply the heater with power in the definite-resistance control mode.

Apparatus for controlling heater for heating oxygen sensor

In a double air-fuel ratio sensor system having three-way catalysts, a full O.sub.2 storage amount of the three-way catalysts is estimated and compared with a predetermined amount. When the estimated full O.sub.2 storage amount is smaller than the predetermined amount, the three-way catalysts are determined to have deteriorated.

Method and apparatus for determining deterioration of three-way

An idling speed control device normally controlling the idling speed of the engine so that it becomes equal to a desired idling speed. At the time of acceleration, the lean time and the rich time of the air-fuel mixture are calculated during the lean-rich discriminating time, which is basically equal to a time of an occurrence of the lean time and the rich time when the air-fuel ratio is maintained at the stoichiometric air-fuel ratio at the time of acceleration. If the lean time becomes considerably longer than the rich time when the engine is started, the idling speed is increased.

Idling speed control device of an engine

A fuel injection control device in which the amount of fuel injected by the fuel injector is increased at the time of acceleration. Namely, at the time of acceleration, the lean time and the rich time of the air-fuel mixture are calculated during the lean-rich discriminating time, which is basically equal to a time of an occurence of the lean time and the rich time when the air-fuel ratio is maintained at the stoichiometric air-fuel ratio at the time of acceleration. When the lean time becomes considerably longer than the rich time, the amount of fuel injected by the fuel injector is further increased.

Fuel injection control device of an engine

A fuel injection control device in which the supply of fuel into the engine cylinder is stopped at the time of deceleration, and a rich time of the air-fuel mixture is calculated when the supply of fuel is stopped. If the rich time becomes relatively long, the accelerating increasing rate of the amount of fuel is increased, and if the rich time becomes relatively short, the accelerating increasing rate of the amount of fuel is reduced.

A fuel injection control device in which it is determined whether the air-fuel mixture is lean or rich at a predetermined crankangle during a lean-rich discriminating time at the time of acceleration. The lean-rich discriminating time is shortened as the degree of the acceleration becomes larger, and the times of being lean and the times of being rich within the lean-rich discriminating time are calculated. When the times of being lean are larger than the times of being rich, and the difference therebetween is larger than a predetermined value, the accelerating increasing rate of the amount of fuel fed into the engine cylinder is increased.

For controlling supply of electric power to a heater for an oxygen sensor for detecting oxygen in an exhaust system of an internal combustion engine so as to maintain the electric resistance of the heater to a target value therefor, the target value is corrected based upon detection of the amount of electric power supplied to the heater so that difference between the detected amount of electric power supplied to the heater and a standard value therefor is cancelled.

Control device for heater for oxygen sensor operative to correct target

In an internal combustion engine, a heater for heating an air-fuel ratio sensor provided in the exhaust gas flow passage is controlled in accordance with a parameter of a load of the engine. That is, the heater is turned ON when the load parameter is not larger than a predetermined value, and the heater is turned OFF when the load parameter is larger than the predetermined value. The turning OFF of the heater is delayed with a predetermined delay time when the engine rotational speed is lower than a predetermined value, and the turning ON of the heater is delayed with the predetermined delay time when the engine rotational speed is higher than the predetermined value. Thus, the number of times that the heater is turned ON and OFF is decreased, thereby prolonging the life of the heater.

Method and apparatus for controlling heater for heatng air-fuel ratio

Growing community of inventors

Susono, Japan

Kouichi Hoshi