Toyota Jidosha Kabushiki Kaisha

Shigemitu Iisaka

Takashi Kawai

Toshinari Nagai

Masaaki Tanaka

Kenji Harima

Tadayuki Nagai

Michio Furuhashi

Hiroki Matuoka

Yuuichi Gotou

An exhaust purifier for an internal combustion engine is capable of properly heating a catalyst in consideration of a deterioration with time and manufacturing variation in an electric heater that heats the catalyst. The exhaust purifier has the catalyst 4 disposed in an exhaust pipe, the electric heater for forcibly heating the catalyst 4, a power source for supplying power to the heater, an estimate unit for estimating the temperature that the catalyst 4 will reach, a comparator for providing the difference between the estimated temperature and a target temperature, and an operation controller for controlling the operating conditions of the engine according to the temperature difference. The estimate unit measures the voltage and current of the heater, calculates the resistance or power of the heater according to the voltage and current, and estimates the temperature. The operation controller adjusts the quantity of intake air and ignition timing, or adjusts ignition timing and then the quantity of intake air to maintain an engine speed, or, if a battery 6 is abnormal, adjusts the quantity of intake air and ignition timing to increase the temperature of exhaust gas.

Exhaust purifier for internal combustion engine

An exhaust purifier of an internal combustion engine supplies secondary air into an exhaust pipe without cooling nor inactivating an electrically heated catalyst (EHC) that is active. The exhaust purifier includes the EHC 3 disposed in the exhaust pipe 2, a main catalyst 4 disposed in the exhaust pipe 2 downstream from the EHC 3, and a unit for supplying secondary air into the exhaust pipe 2. The secondary air supply unit has a main path 10 for supplying secondary air into a space defined in the exhaust pipe 2 between the EHC 3 and the main catalyst 4 when it is determined that the main catalyst 4 is active. The secondary air supply unit may additionally have a second path 9 for supplying secondary air into the exhaust pipe 2 on the upstream side of the EHC 3 when it is determined that the EHC 3 is active, so that the secondary air may pass through the EHC 3 and reach the main catalyst 4.

Exhaust purifier of internal combustion engine

Growing community of inventors

Suntou-gun, Japan

Shigemitu Iisaka