Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Katsuji Wada

Norio Suzuki

Tomoko Morita

Jun Iwamoto

Hisao Haga

Takashi Konomoto

Shinya Ishimaru

Junichi Hatano

Hiroshi Ohno

Nobuhiro Komatsu

Masaki Ueno

Yukio Miyashita

Satoshi Yamaguchi

Yuzuru Koike

Yosuke Kosaka

Naohiro Sato

Daisuke Shimizu

Mitsuhiro Iwadare

Go Motohashi

Tadao Nakatsuji

Hitoshi Mikami

Tomoko Tsuyama

Kensuke Takahashi

Kazuya Yamamoto

A fuel supply system with a fuel pressure sensor includes a failure detection part which sets a first threshold value and a second threshold value which are deviated by first (smaller) and second (larger) predetermined values with respect to a target fuel pressure respectively; immediately detects a possibility of failure in the case where an absolute value of a difference between an output value of the fuel pressure sensor and the target fuel pressure exceeds an absolute value of a difference between the second threshold value and the target fuel pressure; and determines a failure of the fuel pressure sensor in the case where the absolute value of the difference between the output value of the fuel pressure sensor and the target fuel pressure has been exceeding an absolute value of a difference between the first threshold value and the target fuel pressure for a specified time or longer.

Fuel supply system

An exhaust emission control device for an internal combustion engine is provided that can suppress the adherence of HC to an EGR path and the like accompanying enrichment of the exhaust air/fuel ratio. The exhaust emission control device includes: a high-pressure EGR paththat recirculates a portion of the exhaust gas upstream of a turbineinto an intake manifold; a high-pressure EGR control portion; a low-pressure EGR paththat recirculates a portion of the exhaust gas downstream of the turbineinto intake plumbing; a low-pressure EGR control portion; a NOx purification catalystthat is provided inside exhaust plumbingdownstream of an exhaust inlet of the low-pressure EGR path, traps NOx under an oxidizing atmosphere, and purifies the trapped NOx under a reducing atmosphere; a NOx purification catalyst reduction control unitthat performs reduction control of the exhaust air/fuel ratio; and an EGR switching portionthat selects recirculation control of exhaust gas by the low-pressure EGR control portionin a case of the exhaust air/fuel ratio being at least a predetermined threshold value, and selects recirculation control of exhaust gas by the high-pressure EGR control portionin a case of being lower than the threshold value.

Internal combustion engine exhaust emission control device and exhaust emission control method

An exhaust purification device for an internal combustion engine is provided that can promote the reduction of NOx in a NOx purification catalyst from immediately after startup of the internal combustion engine. The exhaust purification device includes: a fuel reformer that is provided separately from exhaust plumbing, reforms fuel and produces a reducing gas that contains carbon monoxide, hydrogen and hydrocarbons, and supplies the reducing gas upstream of the NOx purification catalyst into the exhaust path; an exhaust gas temperature sensorthat detects a temperature Tof the exhaust flowing in the exhaust plumbing; and a reformer control partthat starts supply of the reducing gas to the exhaust plumbingby starting control of the fuel reformerin a case where the temperature Tthus detected by this exhaust gas temperature sensoris no higher than a predetermined first determination temperature T, and stops the supply of reducing gas to the exhaust plumbingby stopping control of the fuel reformerin a case where the temperature detected by the exhaust gas temperature sensoris at least a second determination temperature T, which is higher than the first determination temperature.

Exhaust purification device for internal combustion engine

An exhaust gas purification device for an internal combustion engine, in which a catalyst installed in an exhaust passage is quickly heated to the activation temperature of the catalyst. The exhaust gas purification device has a NOx purification catalyst () for adsorbing or occluding NOx in exhaust gas and reducing the NOx, a catalytic converter () installed at that position of an exhaust pipe () which is upstream of the NOx purification catalyst (), a fuel reformer () installed separately from the exhaust pipe (), producing a reformed gas, and supplying the reformed gas, as a reducing gas, into the exhaust pipe () from an introduction opening () formed in that portion of the exhaust pipe () which is upstream of the NOx purification catalyst () and the catalytic converter (), and an ECU () which, while the exhaust gas air-fuel ratio is being set to be lean, supplies the reducing gas into the exhaust pipe () and controls at least one of a throttle valve (), an EGR valve (), and a turbocharger () to regulate the flow rate of the exhaust gas flowing in the exhaust pipe ().

Exhaust gas purification device for internal combustion engine

Provided is an exhaust emission control device for an internal combustion engine capable of preventing NOx purification performance from degrading according to the operating condition. The exhaust emission control device comprises a NOx purification catalyst, a catalytic converter for continuously reducing the NOx in the exhaust emissions, a fuel reformer for reforming fuel to manufacture a reformed gas and supplying the reformed gas as the reducing gas from the upstream side of the NOx purification catalyst and the catalytic converter of the exhaust pipe, an operating condition detecting means for detecting the operating condition of an engine, and an enriching means for enriching the exhaust air-fuel ratio. The enriching means enriches the exhaust air-fuel ratio by supplying the reducing gas into the exhaust pipe by using the fuel reformer when the operating condition detected by the operating condition detecting means is a high-load operating condition.

Exhaust emission control device for internal combustion engine

An exhaust emission control device for an internal combustion engine, which is capable of properly regenerating a NOx catalyst, while properly controlling NOx catalyst temperature and ensuring excellent drivability. As a regeneration operation, the exhaust emission control device feedback-controls a detected reducing condition of exhaust gases to a predetermined reducing condition, by controlling the amount of main fuel injected by main injection or feedback-controls the same to the predetermined reducing condition by controlling the amount of auxiliary fuel injected by auxiliary injection. The device determines whether the regeneration operation should be executed in a catalyst temperature control mode for controlling the NOx catalyst temperature. If, as a result of the determination, the regeneration operation should be executed in the catalyst temperature control mode, the device selects the feedback control of the main fuel amount, and otherwise selects the feedback control of the auxiliary fuel amount.

Exhaust emission control device and method for internal combustion engine, and engine control unit

An exhaust emission control device for an internal combustion engine, which is capable of supplying a just enough amount of reducing agent to the NOx catalyst even when a catalyst is provided on an upstream side of the NOx catalyst. A catalyst and a NOx catalyst are disposed at respective upstream and downstream locations in an exhaust system, for purifying NOx and for trapping NOx under an oxidizing atmosphere and reducing the NOx under a reducing atmosphere, respectively. An air-fuel sensor is disposed between the catalyst and the NOx catalyst. A reducing agent is supplied to an upstream side of the catalyst, to control exhaust gases such that the gases form the reducing atmosphere. To determine time of termination of NOx reduction control, an amount of reducing agent supplied to the NOx catalyst is calculated, and calculation of the amount of reducing agent is started when the air-fuel ratio has converged within a vicinity of a target air-fuel ratio.

An exhaust control device for an internal combustion engine, comprises: a NOx purifying catalyst disposed in an exhaust system; and a rich control means for calculating a fuel injection amount based on a difference between a target exhaust air fuel ratio and an actual exhaust air fuel ratio to feedback-control the actual exhaust air fuel ratio so that a reducing atmosphere is created in the exhaust system to thereby reduce NOx trapped by the NOx purifying catalyst, wherein the rich control means includes a learning means for calculating and updating a control correction value of the fuel injection amount based on an actual control value of the fuel injection amount during the feedback control, and wherein the fuel injection amount is calculated during the feedback control by using the control correction value.

Exhaust control device for an internal combustion engine

In a control device for an internal combustion engine provided with a NOX catalytic converter in an exhaust passage thereof, the progress of sulfur purging is computed from the consumption of reducing agent contained in the exhaust gas in the NOX catalytic converter. This computation may be based on the air fuel ratio of exhaust gas upstream of the NOX catalytic converter and the estimated consumption of the reducing agent contained in the exhaust gas or on the difference between the air fuel ratios of exhaust gas upstream and downstream of the NOX catalytic converter. In either case, the accuracy can be improved by taking into account the space velocity of the exhaust gas.

Sulfur purge control device for an internal combustion engine

An exhaust emission control device for an internal combustion engine, which is capable of accurately estimating the amount of NOx trapped by a NOx catalyst even when a catalyst is provided on an upstream side of the NOx catalyst. A catalyst having the function of purifying NOx and a NOx catalyst for trapping NOx under an oxidizing atmosphere are disposed in an exhaust system. The amount of NOx contained in exhaust gases is estimated. A NOx purification performance of the catalyst is calculated. The NOx emission amount is corrected based on the purification performance. An amount of NOx trapped in the NOx catalyst is calculated based on the corrected NOx emission amount. A reducing agent is supplied to an upstream side of the catalyst based on the trapped NOx amount, thereby causing the NOx catalyst to carry out a NOx reducing operation.

Provided is a control device for an internal combustion engine that can execute a sulfur purge in a favorable manner under all conditions without complicating the control action or the engine structure. The process comprises detecting a temperature of the NOx catalytic converter, detecting an exhaust air fuel ratio in the catalytic converter, computing a target exhaust air fuel ratio according to a detected temperature of the NOx catalytic converter, and controlling a fuel injection valve so as to make an actual exhaust fuel ratio agree with the target exhaust air fuel ratio. If the temperature of the NOx catalytic converter is not high enough to enable a sulfur purge, a temperature increase control is executed to increase the temperature of the NOx catalytic converter by suitably changing various engine parameters.

The present invention provides a fuel control for an internal-combustion engine having an exhaust gas purifying device that is disposed in an exhaust system of the engine. A reducing agent is supplied to the exhaust gas purifying device by injecting fuel in an expansion stroke or an exhaust stroke of the engine. An intake air amount supplied to the engine is controllable. The fuel control includes decreasing the intake air amount supplied to the engine during the fuel injection for the supply of the reducing agent. The fuel control also includes advancing an injection timing of the fuel injection for the supply of the reducing agent when an actual intake air amount is less than a desired intake air amount or when an actual boost pressure is higher than a desired boost pressure. The advancement of the injection timing improves the combustibility of engine while decreasing the HC exhaust amount.

Fuel control of an internal-combustion engine

An exhaust gas purifying apparatus for an internal combustion engine having a NOx removing device provided in an exhaust system of the engine and at least one fuel injector for injecting fuel into a combustion chamber of the engine. A temperature of the NOx removing device is detected and a regeneration process, which removes sulfur oxide accumulated in the NOx removing device, is performed. The regeneration process is performed by performing at least one post injection after performing a main injection by the at least one fuel injector to raise a temperature of the NOx removing device or by increasing a main injection amount of fuel to raise the temperature of the NOx removing device without performing the post injection. The exhaust gases are then controlled to flow into the NOx removing device in the reducing state.

Exhaust gas purifying apparatus for internal combustion engine

A control system for an internal combustion engine, which is capable of properly setting fuel injection timing according to the actual degree of delay of the amount of fresh air to be supplied to cylinders of the engine, thereby making it possible to positively suppress torque variation, when the control system has switched an air-fuel ratio mode between a lean mode and a rich mode. The control system controls the air-fuel ratio of a mixture by switching the air-fuel ratio mode. In the lean mode, the control system sets a target fresh air amount for the lean mode, and in the rich mode, it sets a target fresh air amount for the rich mode. Upon switching the air-fuel ratio mode, the control system corrects the fuel injection timing according to the difference between the target fresh air amount for the lean mode or the rich mode and the detected fresh air amount.

Control system and method for internal combustion engine and engine control unit

A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine. A compression end temperature in the combustion chamber is estimated. A target compression end temperature is calculated according to an operating condition of the engine. A main injection and a plurality of pilot injections before the main injection are performed by at least one fuel injection valve. A fuel injection amount in a first-performed pilot injection of the plurality of pilot injections is controlled so that the estimated compression end temperature coincides with the target compression end temperature.

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Wako, Japan

Katsuji Wada