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: A diagnostic device of an internal combustion engine diagnoses a condition of a differential pressure sensor. The sensor in a normal condition detects a differential pressure of an exhaust gas between upstream and downstream sides of a diesel particulate filter disposed in an exhaust system of the engine. The sensor in a fault condition detects no differential pressure of the exhaust gas. The device has a block obtaining a first signal from the sensor when the engine is operated in a low flow rate region of the exhaust gas and obtaining a second signal from the sensor when the engine is operated in a high flow rate region of the exhaust gas. A diagnostic block of the device judges from a difference between levels of the first and second signals whether the sensor is in the normal or fault condition.

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: A first intake air control mode of setting an intake throttle valve to (or close to) a fully-opened state and setting an EGR valve to (or close to) a fully-closed state is performed when DPF temperature and a particulate matter deposition quantity are greater than corresponding predetermined values respectively, a no-injection operation state exists, and engine rotation speed is higher than a corresponding predetermined value. A second intake air control mode of setting the intake throttle valve to (or close to) a fully-closed state and setting the EGR valve to (or close to) a fully-opened state is performed when the DPF temperature and the particulate matter deposition quantity are greater than the corresponding predetermined values respectively, the no-injection operation state exists, and the engine rotation speed is lower than the corresponding predetermined value.

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 gas cleaning apparatus (e.g., for a diesel engine) uses a collector for collecting particulates contained in the exhaust gas and is disposed in an exhaust pipe of the engine. Damages in the collector are detected based on a pressure difference between an inlet and an outlet of the collector. In order to correctly detect the damages based on the pressure difference, an exhaust gas volume flowing through the collector is increased to a target volume by raising exhaust gas temperature. The exhaust gas temperature is raised by injecting fuel into the engine at a time when an engine output is not increased by such fuel injection. The pressure difference, based on which damages in the collector are detected, is measured after the exhaust gas volume has reached the target volume. It is determined that damages in the collector have occurred if the pressure difference is lower than a predetermined value.

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: A first intake air control mode of setting an intake throttle valve to (or close to) a fully-opened state and setting an EGR valve to (or close to) a fully-closed state is performed when DPF temperature and a particulate matter deposition quantity are greater than corresponding predetermined values respectively, a no-injection operation state exists, and engine rotation speed is higher than a corresponding predetermined value. A second intake air control mode of setting the intake throttle valve to (or close to) a fully-closed state and setting the EGR valve to (or close to) a fully-opened state is performed when the DPF temperature and the particulate matter deposition quantity are greater than the corresponding predetermined values respectively, the no-injection operation state exists, and the engine rotation speed is lower than the corresponding predetermined value.

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 gas purification device of a diesel engine having a DPF (diesel particulate filter) for collecting particulate matters such as soot and unburned components from exhaust gas of the diesel engine calculates an oil dilution quantity as a quantity of fuel diluting engine oil from a regeneration time of the DPF and an operation state. The exhaust gas purification device alleviates an increase in the oil dilution quantity by using a regeneration device that causes the oil dilution quantity less than the oil dilution quantity caused by another regeneration device when the oil dilution quantity exceeds a predetermined value. Thus, both of suppression of the oil dilution quantity and inhibition of deterioration of fuel consumption due to post-injection can be achieved.

Abstract: A diagnostic device of an internal combustion engine diagnoses a condition of a differential pressure sensor. The sensor in a normal condition detects a differential pressure of an exhaust gas between upstream and downstream sides of a diesel particulate filter disposed in an exhaust system of the engine. The sensor in a fault condition detects no differential pressure of the exhaust gas. The device has a block obtaining a first signal from the sensor when the engine is operated in a low flow rate region of the exhaust gas and obtaining a second signal from the sensor when the engine is operated in a high flow rate region of the exhaust gas. A diagnostic block of the device judges from a difference between levels of the first and second signals whether the sensor is in the normal or fault condition.

Abstract: In an exhaust cleaning system including a DPF in exhaust passages, a pair of temperature sensors is disposed upstream and downstream the filter to detect upstream and downstream exhaust temperatures. An electronic control unit estimates a downstream exhaust temperature from the actual upstream exhaust temperature when an engine is in a predetermined condition such as a cold-start condition or a high speed and high load condition, in which no catalytic reaction heat is generated in the DPF. The control unit then compares the estimated downstream temperature with the actually detected downstream temperature, and determines an exhaust temperature senor malfunction if the difference between the compared temperatures are large.

Abstract: Unless an abnormality exists in piping introducing a pressure from front and rear of DPF 22 into a differential pressure sensor 45, pulsations of pressure propagation through an exhaust passage 21 is offset in a detection value of a pressure difference of the differential pressure sensor 45, and an amplitude of the detection value of the DPF pressure difference resulting from pulsation of the pressure becomes small. If a crack exists in one of the piping 3a and 3b, the influence of a pulsation of the pressure appears in the DPF pressure difference and the amplitude of the detection value of the DPF pressure difference becomes large. The amplitude of the detection value of the DPF pressure difference is compared with the reference value and is detected as being abnormal when it is large, utilizing the phenomenon described above.

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: 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: 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 apparatus of the present invention is advantageously used in a diesel engine. A collector for collecting particulates contained in the exhaust gas is disposed in an exhaust pipe of the engine. Damages in the collector are detected based on a pressure difference between an inlet and an outlet of the collector. In order to correctly detect the damages based on the pressure difference, an exhaust gas volume flowing through the collector is increased to a target volume by raising exhaust gas temperature. The exhaust gas temperature is raised by injecting fuel into the engine at a timing when an engine output is not increased by such fuel injection. The pressure difference, based on which the damages in the collector are detected, is measured after the exhaust gas volume reached the target volume. It is determined that the damages in the collector have occurred if the pressure difference is lower than a predetermined value.