Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo K.k.

Honda Giken Kogyo K.k. (honda Motor Co., Ltd. in English)

Yoichi Iwata

Toshihiko Sato

Takayoshi Nakayama

Tsuyoshi Takizawa

Shigetaka Kuroda

Yasunari Seki

Hiroshi Ito

Naoki Iida

Kazutomo Sawamura

Hiroshi Maruyama

Tetsu Teshirogi

Yoshiharu Ave

Makoto Kobayashi

Kenichi Maeda

Takuya Aoki

Yasuo Nakamoto

Masataka Chikamatsu

Toshikazu Oketani

Masayoshi Yamanaka

Yoshihisa Hara

Shukoh Terata

Akira Katoh

Tetsuya Kaneko

Seiji Hatcho

Hajime Uto

Hidekazu Kano

Keisuke Uchida

Kentaro Yokoo

Katuhiro Kumagai

Takizawa Tsuyoshi

The engine control system for a hybrid vehicle, according to the present invention, having an internal combustion engine and an electric motor as driving force sources, comprises: a clutch, provided between the engine and a transmission system, for disabling and enabling driving force transmission between the engine and the transmission system; clutch disengagement detector for detecting engagement/disengagement of the clutch; engine speed detector for detecting an engine speed; and fuel cutter for permitting stopping and restarting of the engine in accordance with at least a result of detection by the clutch disengagement detector among predetermined drive conditions, and cutting fuel supply to the engine when the vehicle decelerates, a fuel-supply restart engine speed at which fuel supply is resumed being set in the fuel cutter. Stopping the engine is accomplished by cutting fuel supply by the fuel cutter, and once the engine stop is initiated, even when the engine speed reaches the fuel-supply restart engine speed, fuel supply cut by the fuel cutter is maintained, and when the engine speed detected by the engine speed detector at a time of disengagement of the clutch is detected by the clutch disengagement detector is equal to or lower than a predetermined engine speed, fuel supply cut by the fuel cutter is maintained whereas when the detected engine speed is higher than the predetermined engine speed, fuel supply is restarted.

Engine control system for hybrid vehicle

A control system for an internal combustion engine has a catalyst arranged in the exhaust system, for purifying exhaust gases emitted from the engine. An ECU controls operation of the engine, based on at least one predetermined control parameter, and detects a temperature state of the catalyst at the start of the engine. The at least one predetermined control parameter is changed, based on the detected temperature state of the catalyst, after the start of the engine.

Control system for internal combustion engines and control system for

An air-fuel ratio control system for an internal combustion engine having a catalyst arranged in the exhaust system, for purifying exhaust gases emitted from the engine. Upstream and downstream air-fuel ratio sensors arranged in the exhaust system at respective locations upstream and downstream of the catalyst detect the concentration of a specific component present in the exhaust gases. An ECU controls the air-fuel ratio of an air-fuel mixture supplied to the engine, in response to the outputs from the upstream and downstream air-fuel ratio sensors. The ECU detects deterioration of the catalyst caused by sulfur poisoning, based on at least the output from the downstream air-fuel ratio sensor.

Air-fuel ratio control system for internal combustion engines

An air-fuel ratio control system for an internal combustion engine comprises upstream and downstream O2 sensors arranged in the exhaust system of the engine at respective locations upstream and downstream of a catalytic converter, for detecting concentration of oxygen in exhaust gases from the engine. An ECU sets a control variable having a value proportional to the difference between an output from the downstream O2 sensor and a first predetermined reference value, and compares between an output from the upstream O2 sensor and a second predetermined reference value, to thereby calculate an air-fuel ratio correction coefficient, based on results of comparison and the set control variable. The air-fuel ratio of an air-fuel mixture supplied to the engine is controlled based on the calculated air-fuel ratio correction coefficient.

There is provided an air-fuel ratio control system for controlling the air-fuel ratio of a mixture supplied to an internal combustion engine having an exhaust passage. The system includes upstream and downstream exhaust gas component concentration sensors arranged in the exhaust passage at respective locations upstream and downstream of a catalytic converter, for detecting concentration of a component contained in exhaust gases. Feedback control of the air-fuel ratio of the mixture is carried out based on a value of a control parameter set based on an output from the downstream exhaust gas component concentration sensor and an output from the upstream exhaust gas component concentration sensor. An inversion period is detected with which the output from the upstream exhaust gas component concentration sensor is inverted from one side to another side with respect to a predetermined level during the feedback control of the air-fuel ratio. It is determined whether or not one of the output from the downstream exhaust gas component concentration sensor and the value of the control parameter falls within a predetermined range. It is determined whether or not the inversion period is within a predetermined time period. Then, deterioration of the upstream exhaust gas component concentration sensor is determined based on results of these determinations.

An oxygen sensor deterioration-detecting system for an internal combustion engine having a plurality of groups of cylinders groups, an exhaust system having a plurality of exhaust passages extending, respectively, from the cylinder groups, and catalytic converters arranged in the exhaust system, and a plurality of upstream oxygen sensors arranged, respectively, in the exhaust passages at locations upstream of the catalytic converters, includes a single downstream oxygen sensor arranged in a confluent portion of the exhaust passages at a location downstream of the catalytic converters, for detecting the mixed air-fuel ratio of exhaust gases emitted from the cylinder groups. An ECU is responsive to outputs from the upstream oxygen sensors and an output from the downstream oxygen sensor, for determining air-fuel ratio control amounts for respective ones of the cylinder groups, and for controlling the air-fuel ratios of air-fuel mixtures supplied into the respective cylinder groups by the use of the air-fuel ratio control amounts determined. The ECU detects deterioration of each upstream oxygen sensor, based on an output from the upstream oxygen sensor obtained by the air-fuel ratio control based on a corresponding one of the air-fuel ratio control amounts.

Oxygen sensor deterioration-detecting system for internal combustion

A misfire-detecting system for an internal combustion engine has an ECU which detects a value of a parameter representative of a misfiring state of the engine, and also detects the deterioration degree of a catalytic converter arranged in the engine exhaust system. The ECU sets a misfire-determining reference value, based on the detected deterioration degree of the catalytic converter, compares between the detected value of the above parameter and the misfire-determining reference value, and determines whether the engine is in a misfiring state, based on the result of the comparison.

Misfire-detecting system for internal combustion engines

A method of detecting deterioration of a three-way catalyst of an internal combustion engine comprises the steps of (1) obtaining a first signal and a second signal based on respective signals outputted from a pre-catalyst O.sub.2 sensor and a post-catalyst O.sub.2 sensor at least one of when the fuel supply to the engine is increased and when the fuel supply to the engine is interrupted, (2) comparing a waveform of a signal outputted from the pre-catalyst O.sub.2 sensor with a waveform of a signal outputted from the post-catalyst O.sub.2 sensor, based on the first and second signals while the engine is in a predetermined stable operating condition, and (3) determining from results of the comparison whether or not the three-way catalyst is deteriorated.

Method of detecting deterioration of a three-way catalyst of an internal

An air-fuel ratio control system for an internal combustion engine having a catalytic converter arranged in the exhaust system, and an air-fuel ratio sensor arranged upstream of the catalytic converter calculates an air-fuel ratio correction amount by means of proportional control and integral control based on an output from the air-fuel ratio sensor, and controls an air-fuel ratio of a mixture supplied to the engine, based on the air-fuel ratio correction amount. A control frequency at which the air-fuel ratio control is carried out is increased when deterioration of the catalytic converter is detected.

An air-fuel ratio control system for an internal combustion engine having a catalytic converter arranged in the exhaust system, a first air-fuel ratio sensor arranged upstream of the catalytic converter, and a second air-fuel ratio sensor arranged downstream of the catalytic converter, calculates an air-fuel ratio control variable, based on an output from the second air-fuel ratio sensor. An air-fuel ratio correction amount is calculated based on an output from the first air-fuel ratio sensor and the air-fuel ratio control variable. The air-fuel ratio of a mixture supplied to the engine is controlled based on the air-fuel ratio correction amount. The air-fuel ratio control variable is corrected in the rich direction such that the air-fuel ratio of the mixture supplied to the engine becomes richer, when deterioration of the catalytic converter is detected.

An abnormality-detecting device is provided for an internal combustion engine having first and second oxygen sensors arranged in the exhaust system at locations upstream and downstream of a catalytic converter. An ECU detects the degree of deterioration of the catalytic converter, based on an output from the second oxygen sensor, and sets a reference value for determining an abnormality in the engine, based on the detected degree of deterioration of the catalytic converter. The ECU compares between the set reference value and a value based on an output from the first oxygen sensor, and determines the abnormality in the engine, based on the result of the comparison. Upon detection of the abnormality, an LED is actuated to issue an alarm.

Abnormality-detecting device for internal combustion engines

A device for detecting deterioration of a catalyst temperature sensor which detects the temperature of a three-way catalyst arranged in the exhaust pipe of an internal combustion engine, judges that the sensor has deteriorated when the difference between the actual output value from the catalyst temperature sensor and a reference value based on predetermined engine operating parameters exceeds a predetermined value while the engine is in a predetermined operating condition.

Device for detecting deterioration of a catalyst temperature sensor

An air-fuel ratio control system for an internal combustion engine having a catalytic converter arranged in the exhaust system, and first and second air-fuel ratio sensors arranged upstream and downstream of the catalytic converter respectively has an ECU which calculates an air-fuel ratio correction amount, based at least on an output from the first air-fuel ratio sensor, and detects deterioration of the catalytic converter, based on an output from the second air-fuel ratio sensor when the engine is in a predetermined operating condition. The ECU inhibits detection of deterioration of the catalytic converter when the air-fuel ratio correction amount falls outside a predetermined range.

Air-fuel ratio control system for internal combustion engines, having

A catalyst deterioration-detecting system is provided for an internal combustion engine having an oxygen concentration sensor arranged in an exhaust system downstream of a catalyst provided therein. An electronic control unit (ECU) controls the air-fuel ratio of a mixture supplied to the engine in response to an output from the oxygen concentration sensor. The ECU detects a value of an inversion period with which the output from the oxygen concentration sensor is inverted with respect to a predetermined reference value. Operating parameter sensors detect a value of at least one operating parameter of the engine related to a flow rate of the exhaust gases in the exhaust system. The ECU determines whether the catalyst is deteriorated, based on the detected value of the inversion period and the detected value of the at least one operating parameter. The ECU corrects the value of the inversion period in dependence on the detected value of the at least one operating parameter.

Catalyst deterioration-detecting system for internal combustion engines

An air-fuel ratio control system for an internal combustion engine calculates an air-fuel ratio feedback control parameter by proportional-integral control using a proportional factor and an integral factor, based an output signal from a second air-fuel ratio sensor arranged in an exhaust passage at a location upstream of a catalytic converter. An air-fuel ratio correction amount is calculated based on the air-fuel ratio feedback control parameter and an output signal from a first air-fuel ratio sensor arranged in the exhaust passage at a location upstream of the catalytic converter. An inversion period of the output signal from the second air-fuel ratio sensor is measured, and the proportional factor is changed according to the inversion period measured.

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Wako, Japan

Yoichi Iwata