Abstract: A filter is arranged in an exhaust passage of an engine. The filter supports a catalyst. An accumulating amount estimating means detects differential pressure of the filter to estimate an amount of soot accumulating on the filter. An oxidizing condition detecting means detects an oxidizing condition of soot accumulating on the filter. A forcible oxidizing means increases temperature of the filter more than oxidizing temperature of soot for forcibly oxidizing soot accumulating in the vicinity of the catalyst of the filter. When the oxidizing condition detecting means detects a condition, in which soot accumulating on the filter is only partially oxidized, the accumulating amount estimating means estimates the amount of soot accumulating on the filter after oxidizing soot accumulating in the vicinity of the catalyst using the forcible oxidizing means.

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 exhaust gas purifying apparatus for an internal combustion engine includes a collector, a differential pressure sensing device, a differential pressure based estimating device, a partition wall exposure sensing device, and a second regenerating device. The collector captures exhaust particles in exhaust gas. The differential pressure sensing device senses a differential pressure across the collector. The differential pressure based estimating device estimates an accumulation amount of the exhaust particles based on the differential pressure. The partition wall exposure sensing device senses a partition wall exposure state. The second regenerating device forcibly completely combusts the exhaust particles captured in the collector when the partition wall exposure sensing device senses the partition wall exposure state.

Abstract: A method is disclosed for estimating an amount of deposited particulates (PM) in a collector of an internal combustion engine. The method includes estimating the amount of inflow of PM into the collector and estimating a basic amount of decreased PM that flows into the collector and is burned and decreased. The method also includes estimating the amount of ash deposited on the collector. The method further includes correcting the basic amount of decreased PM based on the estimated amount of ash. Moreover, the method includes estimating an amount of deposited PM by a history expression based on the estimated amount of inflow of PM and the corrected amount of decreased PM. A related device is also disclosed.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine includes a collector, which collects exhaust particles in exhaust gas. The apparatus computes a pressure-difference-based measured value of a collected amount of the particles based on a pressure difference, and computes a pressure-difference-based estimated value by correcting the measured value. The apparatus computes an operational-state-based estimated value of the collected amount. The apparatus regenerates the collector by burning the exhaust particles when one of the pressure-difference-based estimated value and the operational-state-based estimated value reaches a predetermined value.

Abstract: An exhaust emission control system for an internal combustion engine is located on a vehicle and provided with a particulate filter to accumulate particulate matters in an exhaust gas of the engine. The system has a pressure difference detector, an exhaust flow rate detector, a regeneration controller and a detection accuracy increaser. The pressure difference detector detects a differential pressure in the particulate filter. The exhaust flow rate detector detects an exhaust flow rate of the engine. The regeneration controller determines to regenerate the particulate filter based on the differential pressure and the exhaust flow rate. The detection accuracy increaser increases a detection accuracy of the differential pressure.

Abstract: In an exhaust emission control system for a vehicular internal combustion engine, a particulate filter collects particulate matters in an exhaust gas of the internal combustion engine. A filter regenerator regenerates the particulate filter by burning the particulate matters accumulated in the particulate filter. A filter front clogging detector determines whether a front end portion of the particulate filter is clogged by the particulate matters. A filter regeneration controller that controls the filter regenerator to perform a front regeneration to remove the particulate matters accumulated in the front end portion of the particulate filter when the filter front clogging detector determines that the front end portion of the particulate filter is clogged.

Abstract: An exhaust gas purifying device for an engine includes a particulate filter midway in an exhaust passage for collecting particulate matters. A control means calculates an accumulating amount of particulate matters on the particulate filter. An accumulating amount calculating means calculates the accumulating amount in accordance with an accumulating characteristic and differential pressure of the particulate filter detected using a differential pressure detecting means. When the accumulating amount becomes a predetermined regeneration demand amount, the control means performs a forcible regeneration, in which particulate matters on the particulate filter are burned and removed to regenerate the particulate filter.

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: A diesel particulate filter (DPF) for trapping exhaust particulates is located in an exhaust passage of a diesel engine. Deposit amounts of a soluble organic fraction (SOF) as an organic solvent soluble component and soot as a solid carbon component of exhaust particulate components deposited in the DPF are estimated respectively. When the SOF deposit amount reaches an SOF elimination execution deposit amount, the DPF is heated to or over relatively low SOF combustion temperature to execute SOF elimination treatment. When the soot deposit amount reaches a soot elimination execution deposit amount, the DPF is heated to or over relatively high soot combustion temperature to execute soot elimination treatment. The SOF elimination treatment is executed before the SOF becomes excessive to prevent rapid combustion of the soot due to combustion of the SOF.

Abstract: An exhaust gas purification system has a first accumulation quantity estimation device that estimates an accumulation quantity of exhaust particulate matters collected by a diesel particulate filter (DPF) based on a flowing state of exhaust gas and a second accumulation quantity estimation device that estimates the accumulation quantity based on an operating state of an engine. The first estimation device is employed only when a flow rate of the exhaust gas is equal to or greater than a predetermined value and the engine is in a steady operating state. Otherwise, the second estimation device is employed. The exhaust gas flow rate is increased if the estimation by the second estimation device continues for a long time. Thus, an opportunity to perform the accumulation quantity estimation with the first estimation device is increased, and accumulation accuracy is improved.

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: A compression ignition engine injects fuel through injection holes of an injector at a substantially constant injection rate to atomize the fuel so that the fuel can be easily vaporized and to make the fuel penetrate an atmosphere inside a cylinder. A spatial distribution of the injected fuel in which mixing of the fuel and air is promoted as the fuel recedes from the injection hole and the fuel reaches a premixing space where the fuel is premixed with the air is provided. The engine controls oxygen concentration inside the cylinder and an ignition delay so that a ratio of a quantity of the fuel injected before a start of ignition to a total fuel injection quantity falls within a range from 25% to 50% and so that the premixed gas formed in the premixing space is combusted serially.

Abstract: The amount of accumulated particulate matter, which is accumulated in a particulate filter, is computed based on the amount of exhausted particulate matter, which is exhausted from an engine, and the amount of reduced particulate matter, which is reduced in the filter. The amount of reduced particulate matter includes the amount of reduced particulate matter, which is reduced through oxidizing reaction of the accumulated particulate matter with NO2. At the time of computing this amount, reduction of the particulate matter through oxidizing reaction with adsorbed NO2, which is adsorbed by the accumulated particulate matter, is concerned in addition to reduction of the particulate matter through oxidizing reaction with NO2, which is present in the surrounding atmosphere around the accumulated particulate matter.

Abstract: A heat generation amount qr/r per unit flow amount of combustible substances supplied to a catalyst is estimated based on upstream and downstream temperature information and supplemental engine information. A deteriorated condition of the catalyst is detected based on a judgement whether or not the estimated heat generation amount is smaller than a predetermined judging value D.

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: An exhaust gas purifying device for an engine includes a particulate filter midway in an exhaust passage for collecting particulate matters. A control means calculates an accumulating amount of particulate matters on the particulate filter. An accumulating amount calculating means calculates the accumulating amount in accordance with an accumulating characteristic and differential pressure of the particulate filter detected using a differential pressure detecting means. When the accumulating amount becomes a predetermined regeneration demand amount, the control means performs a forcible regeneration, in which particulate matters on the particulate filter are burned and removed to regenerate the particulate filter.

Abstract: In an exhaust gas purifying apparatus for a diesel engine having a diesel particulate filter provided in an exhaust pipe, a pressure loss at the filter is detected. An accumulated amount of diesel particulates in the filter is calculated based on the pressure loss and a map for a relationship between the pressure loss and the accumulated amount. A compulsory re-generating operation is carried out when the calculated accumulated amount reaches at a predetermined threshold value, which is decreased to a smaller value depending on a combustion amount of the diesel particulates which are combusted and removed from the filter as a natural re-generating operation.

Abstract: A filter is arranged in an exhaust passage of an engine. The filter supports a catalyst. An accumulating amount estimating means detects differential pressure of the filter to estimate an amount of soot accumulating on the filter. An oxidizing condition detecting means detects an oxidizing condition of soot accumulating on the filter. A forcible oxidizing means increases temperature of the filter more than oxidizing temperature of soot for forcibly oxidizing soot accumulating in the vicinity of the catalyst of the filter. When the oxidizing condition detecting means detects a condition, in which soot accumulating on the filter is only partially oxidized, the accumulating amount estimating means estimates the amount of soot accumulating on the filter after oxidizing soot accumulating in the vicinity of the catalyst using the forcible oxidizing means.