Ngk Spark Plug Company, Limited

Yuki Saito

Takaya Yoshikawa

Tetsuya Ito

Takaaki Yamada

An air-fuel ratio control system () including an air-fuel ratio control section () for controlling the air-fuel ratio &#x3bb; of an air-fuel mixture, an exhaust gas purifier (); an air-fuel ratio sensor () whose output changes sharply when &#x3bb; in the exhaust gas changes between rich and lean sides about a stoichiometric air-fuel ratio; a heater (); and a temperature control section (). The air-fuel ratio control section () controls &#x3bb; based on the output of the air-fuel ratio sensor () using, as a target air-fuel ratio, a predetermined air-fuel ratio such that 0.980&#x2264;&#x3bb;&#x3c;1.000 is satisfied, and when a change amount &#x394;&#x3bb; &#x3bb; is 0.008, an output difference &#x394;V is 150 mV or smaller. The temperature control section () controls the temperature of the air-fuel ratio sensor () to a predetermined target temperature of 650&#xb0; C. or higher.

Air-fuel ratio control system and air-fuel ratio control method

A catalyst apparatus is disposed in an exhaust passage for exhaust gas discharged from an internal combustion engine and includes a catalyst section for purifying the exhaust gas, and a heater section disposed upstream of the catalyst section in the exhaust passage and adapted to heat the exhaust gas. The heater section is configured such that a plurality of metal thin plates and insulators are stacked alternatingly are wound. The heater section contains a pair comprising a positive electrode and a negative electrode for energizing and heating the metal thin plates. The positive and negative electrodes are joined to each of the metal thin plates in such a manner that the positive electrode is located away from the negative electrode in a winding direction of the metal thin plates.

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Nagoya, Japan

Yuki Saito