Abstract: An exhaust emission control device removes particulate matters contained in exhaust gas of an internal combustion engine and deposited in a particulate filter. The device has a catalyst judging block judging the catalytic activity of catalyst held in the particulate filter, an exhaust gas detecting block detecting a flow rate of the exhaust gas, an injection type selecting block selecting a first fuel injection type or a second fuel injection type according to the catalytic activity and the flow rate of the exhaust gas, and a fuel injection control block controlling fuel injected into the engine to heighten the temperature of the exhaust gas according to the first fuel injection type and to supply unburned hydrocarbons to the particulate filter according to the second fuel injection type.

Abstract: An exhaust purification device increases temperature of a particulate filter by at least one of a first temperature increase device and a second temperature increase device to combust and remove particulate matters deposited in a particulate filter. The second temperature increase device increases the temperature of the particulate filter to temperature higher than the temperature achieved by the first temperature increase device. An engine output at the time when the second temperature increase device performs the temperature increase operation is equal to an engine output at the time when the first temperature increase device performs the temperature increase operation. The exhaust purification device sets a ratio between an operation period of the first temperature increase device and an operation period of the second temperature increase device according to estimated temperature of the particulate filter.

Abstract: An exhaust emission control device includes a plurality of devices for removing particulates accumulated in a particulate filter. A temperature increasing device increases a temperature of the particulate filter. A temperature estimator estimates the temperature of the particulate filter. A particulate accumulation quantity estimator estimates a quantity of accumulated particulates. A temperature increase quantity controller controls a temperature increase to an output of the temperature estimator when the quantity of accumulated particulates exceeds a predetermined value. A time ratio processor computes a time ratio between performance and interruption of a temperature increasing operation. A base period processor computes a base period such that the base period varies from time to time. A switching device switches between performance and interruption of the temperature increasing operation based on the time ratio and the period that becomes the base.

Abstract: An exhaust emission control device removes particulate matters contained in exhaust gas of an internal combustion engine and deposited in a particulate filter. The device has a catalyst judging block judging the catalytic activity of catalyst held in the particulate filter, an exhaust gas detecting block detecting a flow rate of the exhaust gas, an injection type selecting block selecting a first fuel injection type or a second fuel injection type according to the catalytic activity and the flow rate of the exhaust gas, and a fuel injection control block controlling fuel injected into the engine to heighten the temperature of the exhaust gas according to the first fuel injection type and to supply unburned hydrocarbons to the particulate filter according to the second fuel injection type.

Abstract: An exhaust purification device increases temperature of a particulate filter by at least one of a first temperature increase device and a second temperature increase device to combust and remove particulate matters deposited in a particulate filter. The second temperature increase device increases the temperature of the particulate filter to temperature higher than the temperature achieved by the first temperature increase device. An engine output at the time when the second temperature increase device performs the temperature increase operation is equal to an engine output at the time when the first temperature increase device performs the temperature increase operation. The exhaust purification device sets a ratio between an operation period of the first temperature increase device and an operation period of the second temperature increase device according to estimated temperature of the particulate filter.

Abstract: In an exhaust gas purifying apparatus for a diesel engine having a diesel particulate filter (DPF) provided in an exhaust pipe, a temperature of the DPF is indirectly detected (presumed) to prevent an over-heat of the DPF during a re-generation operation thereof. For that purpose, the DPF is hypothetically divided into multiple cells, the temperature at the respective cells is presumed based on a heat budget of the cell, and the maximum temperature among those multiple presumed temperatures is controlled to be lower than a predetermined value.

Abstract: An oxidation catalyst is disposed upstream of a diesel particulate filter (DPF) in an exhaust passage of a diesel engine. An electronic control unit (ECU) operates temperature increasing circuit to combust and eliminate particulate matters deposited on the DPF. The ECU determines execution and stoppage of regeneration of the DPF based on a quantity of the particulate matters deposited on the DPF. The ECU increases an exhaust gas recirculation quantity (EGR quantity) during the regeneration to reduce an intake air quantity from the intake air quantity in a non-regeneration period and to achieve a flow rate of the exhaust gas passing through the DPF suitable for the temperature increase. The ECU corrects a valve opening degree of an EGR control valve based on the sensed intake air quantity to reduce a variation in the exhaust gas flow rate.

Abstract: In order to restrict an over-temperature-rising of a diesel particulate filter (DPF), an electronic control unit (ECU) computes a flow rate of the exhaust gas flowing through the DPF so that temperature of the DPF is kept at a temperature in which the DPF can be regenerated. By adjusting a position of a throttle valve, a fresh air flow rate is adjusted so that the flow rate of the exhaust gas flowing through the DPF is equal to a target flow rate of the exhaust gas.

Abstract: In an engine, when it is determined that catalyst, which is held on a filter substrate of a particulate filter, is not in an active state, an ECU executes a fuel injection for mainly obtaining an engine power near a top dead center of a crank. Then, the ECU executes a subsequent fuel injection after lapse of a sufficient injection interval, which does not cause misfiring, to increase the temperature of exhaust gas outputted from the engine. In this way, the temperature of the filter is rapidly increased.

Abstract: A diesel oxidation catalyst is disposed upstream of a diesel particulate filter (a DPF) disposed in an exhaust passage of a diesel engine. An electronic control unit (an ECU) operates a temperature increasing circuit, which performs post-injection, to eliminate particulate matters accumulated in the DPF. The ECU includes a first correcting circuit and a second correcting circuit. The first correcting circuit corrects a manipulated variable of the temperature increasing circuit based on a result of comparison between a target temperature and a temperature of the DPF estimated based on information related to an area upstream of the DPF. The second correcting circuit corrects the manipulated variable of the temperature increasing circuit based on a result of comparison between the target temperature and the temperature of the DPF estimated based on information related to an area downstream of the DPF.

Abstract: An electronic control unit of an internal combustion engine calculates a basic post-injection quantity of temperature increasing means if a deposition quantity of particulate matters deposited on a diesel particulate filter (DPF) exceeds a predetermined value. Then, a final post-injection quantity is calculated by correcting the basic post-injection quantity based on a temperature correction value, which is calculated by multiplying a deviation between DPF upstream exhaust gas temperature and target temperature and past temperature correction values by feedback gains. The feedback gains are switched in accordance with a delay in an exhaust gas temperature change in a present operating state, based on an intake air quantity sensed by an air flow meter. Thus, response can be improved, while maintaining stability.

Abstract: A diesel particulate filter (DPF) having an oxidation catalyst is disposed between exhaust pipes of an internal combustion engine. An exhaust gas temperature sensor senses outlet gas temperature of the DPF. An engine control unit (ECU) calculates estimated central temperature of the DPF from an output of the exhaust gas temperature sensor with the use of an inverse transfer function of a change in the outlet gas temperature with respect to a change in temperature of the DPF. Based on the estimated temperature, the ECU performs excessive temperature increase prevention control or regeneration control of the DPF. The transfer function is simply expressed with first-order lag and dead time. A time constant of the first-order lag and the dead time are set in accordance with an exhaust gas flow rate.

Abstract: An exhaust gas cleaning system for a diesel engine has a diesel particulate filter (DPF) disposed in an exhaust pipe. An electronic control unit of the system controls regeneration of the DPF. The DPF is heated and regenerated only when an operating state of the engine is in an area where temperature-increasing efficiency is high, in the case where a quantity of particulate matters collected by the DPF is equal to or greater than a first threshold and is less than a second threshold. The second threshold is greater than the first threshold. If the quantity of the collected particulate matters becomes equal to or greater than the second threshold, the regeneration is performed even if the operating state is not in the area of the high temperature-increasing efficiency.

Abstract: An exhaust cleaning device of an internal combustion engine includes a particulate filter disposed in an exhaust duct of the internal combustion engine. A regeneration control increases the temperature of the particulate filter to approximately a predetermined target temperature but the amount of the temperature increase controllably corrected by the regeneration control.

Abstract: An exhaust gas cleaning system of a diesel engine includes a diesel particulate filter (a DPF) disposed in an exhaust passage, and a diesel oxidation catalyst (a DOC) disposed upstream of the DPF. When an electronic control unit (an ECU) performs a temperature increasing operation such as post-injection to eliminate particulate matters accumulated in the DPF, a ratio (a duty ratio) between a performing period and an interrupting period of the temperature increasing operation is changed in accordance with temperature of the DPF. Thus, a quantity of hydrocarbon supplied to the DOC is controlled stepwise or continuously. Thus, the temperature of the DPF can be increased to target temperature quickly and can be maintained near the target temperature when the regeneration of the DPF is performed.

Abstract: In order to restrict an over-temperature-rising of a diesel particulate filter (DPF), an electronic control unit (ECU) computes a flow rate of the exhaust gas flowing through the DPF so that temperature of the DPF is kept at a temperature in which the DPF can be regenerated. By adjusting a position of a throttle valve, a fresh air flow rate is adjusted so that the flow rate of the exhaust gas flowing through the DPF is equal to a target flow rate of the exhaust gas.

Abstract: An engine exhaust emission control device determines a differential pressure across a diesel particulate filter (DPF) to enable regeneration of the DPF at optimal timing. An ECU estimates the temperature of a differential pressure sensor provided for the DPF from the output of an intake air temperature sensor when the engine is not running, and determines an offset correction factor for correcting the sensor's offset error. The factor is set using the sensor output at this time as sensor's offset error, and stored in a memory. When detecting the differential pressure across the DPF, the temperature of the sensor at this time is estimated, and an offset correction factor that corresponds to this estimated temperature is selected. The sensor outputs are adjusted with this offset correction factor.

Abstract: In an exhaust gas purifying apparatus for a diesel engine having a diesel particulate filter (DPF) provided in an exhaust pipe, a temperature of the DPF is indirectly detected (presumed) to prevent an over-heat of the DPF during a re-generation operation thereof. For that purpose, the DPF is hypothetically divided into multiple cells, the temperature at the respective cells is presumed based on a heat budget of the cell, and the maximum temperature among those multiple presumed temperatures is controlled to be lower than a predetermined value.

Abstract: A flow rate of gas supplied to a diesel particulate filter is increased when it is determined that rapid combustion of collected particulates, which are collected by the particulate filter, is likely to occur based on an operating state of an internal combustion engine. Alternatively, the flow rate of gas supplied to the filter is increased when it is determined that rapid combustion of the collected particulates is initiated based on a state of the particulate filter.

Abstract: In an engine, when it is determined that catalyst, which is held on a filter substrate of a particulate filter, is not in an active state, an ECU executes a fuel injection for mainly obtaining an engine power near a top dead center of a crank. Then, the ECU executes a subsequent fuel injection after lapse of a sufficient injection interval, which does not cause misfiring, to increase the temperature of exhaust gas outputted from the engine. In this way, the temperature of the filter is rapidly increased.