Denso Corporation

Nippondenso Co., Ltd.

Kouichi Shimizu

Hisashi Iida

Noriaki Ikemoto

Yukihiro Yamashita

Jun Hasegawa

Masaaki Nakayama

Yasuhito Takasu

Syujiro Morinaga

Yasutoshi Baba

Eiji Takakuwa

Masahiro Kondo

Minoru Hotta

Hideki Morishima

Isamu Nomura

Keiji Wakahara

An electronic control unit of an internal combustion engine performs preheat energization control before activation energization control. In the activation energization control, a gas sensor is energized with electric power capable of heating the gas sensor to activation temperature. In the preheat energization control, the gas sensor is energized with low electric power, which is not enough to heat the gas sensor to the activation temperature. Thus, while there is a possibility that water adheres to a sensor main body of the gas sensor, the sensor main body is prevented from being heated to high temperature. Meanwhile, even if water droplets exist in the sensor main body of the gas sensor, the water is vaporized gradually, while preventing the bumping of the water.

Heating control system for gas sensor of engine

An emission control apparatus for an engine has a plurality of catalysts disposed in series in an exhaust passage. An HC absorbent catalyst is utilized for at least one of the catalysts. An ECU controls an A/F ratio in an upstream side of the HC absorbent catalyst at a target value. The target value is corrected to a leaner value when the HC absorbent catalyst is in a desorbing condition. The leaner value is leaner than the target value during the HC absorbent catalyst is in an absorbing condition or an activated condition. The leaner atmosphere provides sufficient of oxygen to purify desorbed HC from the HC absorbent catalyst itself.

Emission control apparatus for engine and method for reducing emissions of engine

An upstream catalyst and a downstream catalyst are disposed in series in an exhaust pipe, and first through third sensors for detecting the air-fuel ratio or an adsorption amount of hazardous components on the rich/lean side of exhaust gases are disposed on the upstream and downstream sides of the upstream catalyst and the downstream side of the downstream catalyst, respectively. An ECU for controlling an engine controls the air-fuel ratio so that when the adsorption amount of the hazardous components on the rich side of the downstream catalyst is large, that of the hazardous components on the lean side of the upstream catalyst is large. Similarly, the ECU controls the air-fuel ratio so that when the adsorption amount of the hazardous components on the lean side of the downstream catalyst is large, that of the hazardous components on the rich side of the upstream catalyst is large.

Exhaust emission control system for internal combustion engine

Exhaust gas sensors are provided at the upstream side and the downstream side of a catalyst, respectively. An intermediate target value is set on the basis of the output of the downstream-side exhaust gas sensor of preceding computation time and a final target value that is a final downstream-side target air-fuel ratio. The compensation amount of the upstream-side target air-fuel ratio is calculated on the basis of the deviation between the present output of the downstream-side exhaust gas sensor and the intermediate target value. At least one of an update amount and an update rate of the intermediate value, a control gain, a control period and a control range of a sub-feedback control is varied.

Air-fuel ratio control apparatus having sub-feedback control

In a misfire detecting apparatus for a multicylinder internal combustion engine, a rotational signal outputting unit outputs a rotary signal at every predetermined rotary angle, and a tentative misfire decision unit tentatively decides, on the basis of the rotary signal, whether or not misfire has occurred in each cylinders of the engine. A tentative misfire number counting unit counts the number of tentative misfires decided for respective cylinders, and a counting result storage unit stores the counting results. After a given number of tentative misfire decisions have been made, it is decided that misfire has actually occurred, only if the counting result, for a part of the cylinders, among the counting results for respective cylinders stored in the counting result storage unit is larger than a predetermined number.

Misfire detecting apparatus for multicylinder internal combustion engines

An apparatus for detecting a misfire in an internal combustion engine for a vehicle includes a rotational speed change quantity computing unit which detects a rotational speed of the engine and computes a change quantity of the rotational speed of the engine, a misfire determination value correction coefficient setting unit which detects a load on the engine and sets a correction coefficient of a misfire determination value based on a result of detection of the engine load, a misfire determination value setting unit for setting a misfire determination value based on the set misfire determination value correction coefficient, and a misfire determining unit for determining whether a misfire has occurred in the engine by comparing the change quantity of the rotational speed of the engine from the rotational speed change quantity computing unit with the misfire determination value from the misfire determination value setting unit. The misfire detecting apparatus further includes a misfire detection result invalidating unit for invalidating a result of misfire determination by the misfire determining unit.

Apparatus for detecting misfire in internal combustion engines for

A method and an apparatus in which an engine is controlled by a microcomputer on the basis of a basic ignition advanced angle, an ignition advanced angle unit-correction value and a supplied air quantity unit-correction value stored in maps for providing a best fuel consumption corresponding to each of various running conditions such as an intake air quantity, engine revolution number, and the like, as well as on the basis of correction factors corresponding to running conditions such as stable running and unstable running. In order to obtain a best fuel consumption in a stable running state, the ignition advanced angle and the supplied air quantity are parallelly corrected by the ignition advanced angle unit-correction value and the supplied air quantity unit-correction value respectively while discriminating increment of torque so that this correction is successively repeated until a best fuel consumption is reached. The ignition advanced angle correction factors and the air quantity correction factors are stored, updating the previously stored data, on the basis of the respective total correction values searched by the successively repeated corrections.

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Handa, Japan

Kouichi Shimizu