Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo K.k.

Honda Motor Co., Ltd.

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

Yukio Miyashita

Kunio Noguchi

Yuichi Shimasaki

Hiroaki Kato

Takashi Komatsuda

Takuya Aoki

Akihisa Saito

Hironao Fukuchi

Toshikazu Oketani

Seiji Matsumoto

Hiroshi Mifune

Seiji Hatcho

Masahiko Asakura

Atsushi Matsubara

Hiroshi Hasebe

Hiroshi Ohno

Michio Sakaino

Takashi Isobe

Hideyuki Oki

Kojiro Tsutsumi

Yuzuru Koike

Shinichi Kubota

Koichi Yoshiki

Yoshiaki Akimoto

Tetsuya Ohno

Masaki Kanehiro

Yasunari Seki

Katsuji Wada

Tetsu Teshirogi

Hiroshi Yatani

Daisuke Shiomi

Takaaki Fukusako

Isao Yahata

Seiji Haccho

Tatsuya Ito

In an intake system comprising a first intake passage () having an upstream end communicating with an intake duct () and a downstream end communicating with an intake port of an engine cylinder, a first intake control valve () provided in the first intake passage, a second intake passage () having an upstream end communicating with the intake duct and a downstream end communicating with the intake port of the engine cylinder, a second intake control valve () provided in the second intake passage, an accelerator pedal(ACL) and a control unit () for controlling opening angles of the first and second intake control valves, the second intake control valve is opened when the first intake control valve has opened to an effective opening angle and an intake air flow rate is required to be further increased. The effective opening angle may be defined in a region where a change in the intake air flow rate of the first intake passage for a given change in the opening angle of the first intake control valve falls below a prescribed level. Thereby, as the accelerator pedal is depressed, a continuous increase in the intake air flow rate without involving a saturated region can be achieved.

Intake system for an internal combustion engine

A fault determining apparatus for a variable valve timing mechanism is provided for shortly and accurately determining a fault even at low oil temperatures. The mechanism is driven by an oil pressure to change a cam phase of an intake cam and/or an exhaust cam with respect to a crank shaft of an internal combustion engine, thereby controlling the actual cam phase to reach a target cam phase. The apparatus has a fault determining routine executed by an ECU (electric control unit) for determining that the mechanism is faulty when a cam phase difference between the target cam phase and the actual cam phase is not within a predetermined range, an oil temperature sensor for detecting the temperature of the working oil, and a correcting routine executed by the ECU for correcting the predetermined range in an increasing direction when the detected oil temperature is low.

Fault determining apparatus, fault determining method and engine control unit for variable valve timing mechanism

In a system for controlling opening of a throttle valve installed at an air intake system of an internal combustion engine mounted on a vehicle, a fully-closed value of the opening of a throttle valve is learning-controlled based on a detected opening of the throttle valve to update the learned fully-closed value, when operating state of the vehicle is under a prescribed operating state such as the operator rides the accelerator pedal; and the updating of the learned fully-closed value is inhibited in valve opening direction until the operating state of the vehicle moves outside the prescribed operating state and then again returns to the operating state. In addition, an amount for updating in the opening direction is set smaller than that in the closing direction. With this, it becomes possible to avoid engine speed destabilization and other various problems even if the learned value in effect during pedal riding is used for engine idling speed control.

Throttle opening control system for internal combustion engine

An EGR passage that recirculates exhaust gases in an exhaust pipe of an engine to an intake system by negative intake-gas pressure is provided. An intake cam that opens and closes an intake valve is provided so that a phase angle of the intake cam may be adjusted through a VTC (phase angle adjustment means). The phase angle of the intake cam is adjusted in accordance with increase or decrease of a flow rate of recirculation of exhaust gases, thus restricting occurrence of NO .

Variable valve timing engine

There is provided a failure determination apparatus which is capable of determining the failure of a temperature sensor promptly and correctly regardless of environmental conditions at the start of an internal combustion engine. An ECU calculates an operation progress parameter indicative of a degree of progress of operation of the internal combustion engine from the start thereof. A RAM of the ECU stores a value of the temperature detected by the temperature sensor at a stoppage of the engine. Further, the ECU measures a stop time period from the stoppage to a start of the engine, and determines that the temperature sensor is faulty, when the difference between a value of the temperature detected by the temperature sensor at the start of the present operation of the engine and the value of the temperature stored in the RAM is equal to or smaller than a predetermined reference value on condition that the operation progress parameter calculated during the immediately preceding operation of the engine is larger than a predetermined value, and that the stop time period before the present operation of the engine is longer than a predetermined time period.

Failure determination apparatus and method and engine control unit for determining a failure of a temperature sensor

An exhaust gas-purifying system for an internal combustion engine includes a catalyzer arranged in the exhaust system of the engine. The catalyzer is provided with a heater for heating the same. An ECU controls the operation of the heater. The ECU is responsive to operating conditions of the engine detected by engine operating parameter sensors, for restraining the operation of the heater.

Exhaust gas-purifying system for internal combustion engines

An adsorber temperature-estimating device for an internal combustion engine comprises an adsorber arranged in the exhaust passage, for adsorbing an unburnt gas component present in exhaust gases emitted from the engine. Operating parameter sensors detect operating parameters of the engine, and an ECU estimates the temperature of the adsorber, based on the detected operating parameters. An exhaust gas-purifying system for the engine comprises the adsorber, a catalytic converter arranged in the exhaust passage at a location downstream of the adsorbing means, for purifying exhaust gases, and a secondary air supply pump for supplying secondary air to the exhaust passage at a location upstream of the catalytic converter. The ECU controls an amount of secondary air to be supplied to the exhaust passage, based on the estimated temperature calculated by the adsorber temperature-estimating device.

Adsorber temperature-estimating device for internal combustion engines

An exhaust gas-purifying system for an internal combustion engine has an adsorbing device arranged in an exhaust passage thereof for adsorbing or desorbing unburnt component contained in exhaust gases. An exhaust gas recirculation passage branches off from the exhaust passage at a branch point downstream of the adsorbing device and extending to an intake passage of the engine for returning exhaust gases flowing through the adsorbing device to the intake passage. The path of exhaust gases is changed to selectively introduce the exhaust gases containing the unburnt components into the exhaust gas recirculation passage. The adsorbing capacity of the adsorbing device is checked based on a manner of change in an air-fuel ratio of exhaust gases detected when the exhaust gases are introduced into the exhaust gas recirculation passage.

An internal combustion engine has an adsorber arranged in the exhaust passage for adsorbing unburnt components in exhaust gases, and an exhaust gas-purifying device arranged in the exhaust passage at a location downstream of the adsorber. The exhaust gas-purifying device is equipped with a heater. An ignition timing of an internal combustion engine is retarded when the engine is started at a low engine temperature. The retardation of the ignition timing is restrained over a time period from the start of the engine to a time point the exhaust gas-purifying device is warmed up to a predetermined activated condition.

Ignition timing control system for internal combustion engines

In an engine exhaust emission control system, a ternary catalyst and a hydrocarbon adsorber are provided in an exhaust passageway from an engine. The ternary catalyst includes first passages through which an exhaust gas discharged from the engine flows, and second passages through which the exhaust gas which has flowed through the first passages and the hydrocarbon adsorber flows. The first and second passages are laminated to each other to enable heat exchange therebetween. The hydrocarbon adsorber is capable of being cooled by a cooling medium. Thus, it is possible to reliably prevent hydrocarbons in the exhaust gas from being released to the atmosphere during the cold start of the engine.

Engine exhaust emission control system

An exhaust gas-purifying system for an internal combustion engine is provided with hydrocarbon-adsorbing catalyzer for adsorbing unburnt gas components present in exhaust gases. At least one exhaust gas-purifying catalyzer is arranged in the exhaust passage at a location downstream of the hydrocarbon-adsorbing catalyzer. A bypass passage bypasses the hydrocarbon-purifying catalyzer. A changeover valve is arranged in the exhaust passage at a branchpoint between the bypass passage and the exhaust passage, for selecting a first flow path in which exhaust gases are guided to the unburnt gas component-adsorbing catalyzer, or a second flow path in which exhaust gases are guided through the bypass passage. First and second exhaust gas concentration sensors are arranged in the exhaust passage at locations upstream and downstream of the hydrocarbon-purifying catalyzer. An ECU controls the changeover valve to select the first flow path or the second flow path, based on outputs from the first and second exhaust gas concentration sensors.

Ignition timing control system for internal combustion engines. The system comprises a means for detecting operating parameters of the engine such as engine speed, engine load, the presence of knock, a means for determining a basic ignition timing on the basis of the engine speed and load, a means for determining a first group of retard amounts based on the detected operating parameters to prevent knock from occurring, and a means for determining a second group of retard amounts based on the detected operating parameters to intentionally reduce output torque of the engine. The first retard amount group is compared with the second one the basic ignition timing is corrected by the selected value. With the arrangement, the retard amount is limited to the minimum required even when engine operating conditions producing knock and requiring engine output reduction are present at the same time.

Ignition timing control system for internal combustion engine

A system for determining an oxygen concentration sensor deterioration caused when foreign particles has clogged at a slit for introducing exhaust gas of an internal combustion engine to block the same. Since it is found by the inventors that sensor output fluctuates greatly between its maximum and minimum values in a TDC interval as the clogging increases, the deviation between the maximum and minimum is first calculated. The calculated deviation is then compared with a reference value and if it exceeds the reference value, the sensor is presumed to deteriorate. The reference value is varied on engine speed, engine load, or an air/fuel ratio of the engine.

System for determining deterioration of oxygen concentration sensor

An air-fuel ratio control method for an internal combustion engine. The air-fuel ratio of an air-fuel mixture supplied to the engine is feedback-controlled to a desired air-fuel ratio dependent on operating conditions of the engine. When a transmission is being shifted or before a predetermined time period elapses after the shifting, the desired air-fuel ratio is held at a value assumed immediately before the shifting of the transmission. In another form of the invention, when the transmission is being shifted, or when the operating characteristics of at least one set of a set of intake valves and a set of exhaust valves have been not changed before the predetermined time period elapses after the shifting of the transmission, the desired air-fuel ratio is held at a value assumed before the shifting of the transmission.

Air-fuel ratio control method for internal combustion engines

According to an air-fuel ratio control method, an amount of fuel supplied to an internal combustion engine is calculated by the use of an air-fuel ratio correction coefficient set according to an output from an exhaust gas ingredient concentration sensor. An average value of the air-fuel ratio correction coefficient is calculated. When a difference between an actual value of opening of an exhaust gas recirculation control valve and a desired value of same set in response to operating conditions of the engine is larger than a predetermined value, the calculation of the average value of the air-fuel ratio correction coefficient is inhibited, or alternatively, an averaging rate in the calculation of the average value is decreased.

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Wako, Japan

Yukio Miyashita