Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An exhaust purifying device for an internal combustion engine is provided that can regenerate an exhaust purifying filter at high efficiency without deteriorating the fuel economy.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An exhaust purification device for an internal combustion engine can achieve high NOx purifying performance independent of operating conditions of the engine. The exhaust purification device has a NOx purification catalyst (33) mounted in an exhaust pipe (4) of the internal combustion engine, adsorbing or occluding NOx in exhaust gas when the exhaust gas air/fuel ratio is made lean, and reducing the adsorbed or occluded NOx when the exhaust gas air/fuel ratio is made rich; a fuel reformer (50) mounted separately from the exhaust pipe (4), reforming fuel to produce a reducing gas containing hydrogen and carbon monoxide, and supplying the reducing gas into that part of the exhaust pipe (4) which is located upstream of the NOx purification catalyst (33); and enriching means for enriching the exhaust gas air/fuel ratio.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Provided is an exhaust emission control device for an internal combustion engine capable of high-efficiency DPF regeneration processing. The exhaust emission control device comprises a DPF for collecting PMs in exhaust emissions, which is provided in an exhaust pipe of an engine, a fuel reformer for reforming fuel to manufacture a reducing gas containing hydrogen and carbon monoxide and supplying the reducing gas from an introduction port provided on the upstream side of the DPF of the exhaust pipe into the exhaust pipe, which is provided separately from the exhaust pipe, a catalyst converter for continuously oxidizing the reducing gas, which is provided between the introduction port and the DPF of the exhaust pipe, and a regeneration means for performing regeneration processing for burning the PMs collected by the DPF while the reducing gas is supplied into the exhaust pipe by the fuel reformer.