Abstract: An object of the present invention is to increase the accuracy of a deterioration determination in a deterioration determination system of an exhaust emission control device having a selective reduction type NOx catalyst, by suppressing false determinations when the deterioration determination is made. The deterioration determination system includes a catalyst having an oxidative capacity downstream of a NOx catalyst using ammonia as a reducing agent. When an amount of ammonia adsorbed by the NOx catalyst is larger than an equilibrium adsorption amount, out of the amount of ammonia flowing into the catalyst having the oxidative capacity, at least one of the amount of ammonia flowing out from the catalyst having the oxidative capacity and the amount of ammonia converted to NOx in the catalyst having the oxidative capacity or a total value of both is calculated.

Abstract: The invention provides a technique for more accurately executing failure diagnosis for an exhaust gas control apparatus having both a selective reduction function and a filter function. To this end, a failure diagnosis apparatus according to the invention for the exhaust gas control apparatus having both the selective reduction function and the filter function computes a NOx purification rate pertaining to a case where the exhaust gas control apparatus is normal based on an estimated value of the amount of particulate matter (PM) collected or accumulated in the exhaust gas control apparatus and an estimated value of the NO2 ratio of exhaust gas flowing into the exhaust gas control apparatus, and determines that the exhaust gas control apparatus fails when the difference between the result of the calculation and an actual NOx purification rate exceeds a threshold.

Abstract: In a failure determination system that performs failure determination of an exhaust gas purification apparatus having a NOx selective catalytic reduction catalyst (NOx catalyst) that is disposed in an exhaust passage of an internal combustion engine and uses ammonia as a reducing agent, the failure determination of the exhaust gas purification apparatus is performed by a failure determination unit, based on a detected value of a NOx sensor that detects NOx in exhaust gas. Then, based on an adsorption amount difference at assumed failure that is the difference between an ammonia equilibrium adsorption amount in the NOx catalyst in an equilibrium state of ammonia adsorption, assuming that the exhaust gas purification apparatus is in a predefined failure state, and an actual ammonia adsorption amount in the NOx catalyst, the failure determination itself by the failure determination unit is inhibited or the use of the NOx sensor in the failure determination is restricted.

Abstract: A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed. In order to achieve this, provision is made for a filter that is arranged in an exhaust passage of an internal combustion engine for trapping particulate matter contained in an exhaust gas, an NOx selective reduction catalyst that is arranged at the downstream side of the filter and reduces NOx by means of a reducing agent which is supplied thereto, a supply device that supplies the reducing agent to the NOx selective reduction catalyst from the upstream side of the NOx selective reduction catalyst, a PM sensor that detects an amount of the particulate matter in the exhaust gas at the downstream side of the NOx selective reduction catalyst, and a prohibition part that prohibits the use of a detected value of the PM sensor in cases where the reducing agent supplied from said supply device passes through the NOx selective reduction catalyst.

Abstract: An exhaust gas purification apparatus for an internal combustion engine is designed to prevent a decrease in the accuracy of measurement by a PM sensor (17). The apparatus includes an NOx catalyst (7) provided in an exhaust passage (3) of an internal combustion engine (1) to reduce NOx by reducing agent supplied to it, a supplying device (6) that supplies urea to the NOx catalyst (7) from the upstream of the NOx catalyst (7), the PM sensor (17) that detects the amount of particulate matter in the exhaust gas in the downstream of the NOx catalyst (7), and a restriction part (10) that restricts supply of urea by the supplying device (6) when the amount of particulate matter adhering to the NOx catalyst (7) is equal to or larger than a threshold.

Abstract: A warm-up system for an exhaust system of an internal combustion engine includes an electronic control unit that performs warm-up control for warming up an exhaust system component upon start-up of the internal combustion engine and a failure diagnosis performing module of the electronic control unit that performs failure diagnosis for the exhaust system component after the completion of warm-up of the exhaust system component. If the internal combustion engine repeatedly stops before completion of the failure diagnosis for a predetermined period of time, then the electronic control unit changes the warm-up control performed upon start-up of the internal combustion engine to a control that raises the temperature of the exhaust system component more quickly than the warm-up control performed during the predetermined period.

Abstract: An object of the present invention is to detect any breakdown or failure of a particulate filter more appropriately. A failure detecting apparatus for detecting failure of a particulate filter according to the present invention comprises an acquiring section which acquires an amount of PM contained in an exhaust gas allowed to outflow from the particulate filter; a regeneration process executing section which executes a filter regeneration process for oxidizing and removing PM deposited in the particulate filter; and a failure judging section which judges that the particulate filter is in the failure state if a decreased amount of the amount of PM contained in the exhaust gas acquired by the acquiring section, during a predetermined period of time as started from a point in time at which the execution of the filter regeneration process performed by the regeneration process executing section is completed, is not equal to or larger than a predetermined reference amount.

Abstract: The present invention is intended to detect a failure of a PM filter with a higher degree of accuracy. The present invention is provided with: a PM trapping efficiency calculation part to calculate a PM trapping efficiency (which is a proportion of an amount of particulate matter trapped with respect to an amount of inflow particulate matter) based on an amount of inflow particulate matter obtained by an inflow particulate matter obtaining part, and an amount of outflow particulate matter detected by a PM sensor; and a failure detection part to make a determination that a failure has occurred in the PM filter, in cases where there has appeared a tendency for the PM trapping efficiency to decrease during a period of time until the execution of the following filter regeneration processing is started after the completion of execution of the filter regeneration processing.

Abstract: A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed. To this end, provision is made for an NOx selective reduction catalyst arranged in an exhaust passage of the internal combustion engine to reduce NOx by means of a reducing agent supplied thereto, a supply device to supply urea water as the reducing agent from an upstream side of the NOx selective reduction catalyst, a PM sensor to detect an amount of particulate matter in an exhaust gas at the downstream side of the NOx selective reduction catalyst, and a control unit to make an amount of production of intermediate products from the urea water supplied from the supply device to ammonia smaller when an amount of particulate matter is detected by the PM sensor than when not detected.

Abstract: A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed. In order to achieve this, provision is made for a filter that is arranged in an exhaust passage of an internal combustion engine for trapping particulate matter contained in an exhaust gas, an NOx selective reduction catalyst that is arranged at the downstream side of the filter and reduces NOx by means of a reducing agent which is supplied thereto, a supply device that supplies the reducing agent to the NOx selective reduction catalyst from the upstream side of the NOx selective reduction catalyst, a PM sensor that detects an amount of the particulate matter in the exhaust gas at the downstream side of the NOx selective reduction catalyst, and a prohibition part that prohibits the use of a detected value of the PM sensor in cases where the reducing agent supplied from said supply device passes through the NOx selective reduction catalyst.

Abstract: An object of the invention is to prevent a situation in which failure diagnosis for an exhaust system component in an internal combustion engine cannot be completed from continuing for an unduly long period of time. A warm-up system for an exhaust system of an internal combustion engine according to the invention includes a warm-up control performing unit that performs warm-up control for warming up an exhaust system component upon start-up of the internal combustion engine and a failure diagnosis performing unit that performs failure diagnosis for the exhaust system component after the completion of warm-up of the exhaust system component.

Abstract: A reduction in the accuracy of a failure determination of a filter due to a reduction in the detection accuracy of a PM sensor is suppressed.

Abstract: A failure of a filter is detected with a higher degree of accuracy. There are provided a filter that is arranged on an exhaust passage of an internal combustion engine for collecting a substance contained in an exhaust gas, a substance amount detection part that is arranged on the exhaust passage at a downstream side of the filter for detecting an amount of substance in the exhaust gas, a flow speed detection part that detects or estimates a flow speed of the exhaust gas which passes through the filter, and a determination part that makes a determination that the filter is in a failure, when the higher the flow speed of the exhaust gas passing through the filter, the larger a ratio of an amount of change in the amount of substance to an amount of change in the flow speed of the exhaust gas becomes.

Abstract: An object of the present invention is to detect any breakdown or failure of a particulate filter more appropriately. A failure detecting apparatus for detecting failure of a particulate filter according to the present invention comprises an acquiring section which acquires an amount of PM contained in an exhaust gas allowed to outflow from the particulate filter; a regeneration process executing section which executes a filter regeneration process for oxidizing and removing PM deposited in the particulate filter; and a failure judging section which judges that the particulate filter is in the failure state if a decreased amount of the amount of PM contained in the exhaust gas acquired by the acquiring section, during a predetermined period of time as started from a point in time at which the execution of the filter regeneration process performed by the regeneration process executing section is completed, is not equal to or larger than a predetermined reference amount.

Abstract: A failure of a filter is detected with a higher degree of accuracy. There are provided a filter that is arranged on an exhaust passage of an internal combustion engine for collecting a substance contained in an exhaust gas, a substance amount detection part that is arranged on the exhaust passage at a downstream side of the filter for detecting an amount of substance in the exhaust gas, a flow speed detection part that detects or estimates a flow speed of the exhaust gas which passes through the filter, and a determination part that makes a determination that the filter is in a failure, when the higher the flow speed of the exhaust gas passing through the filter, the larger a ratio of an amount of change in the amount of substance to an amount of change in the flow speed of the exhaust gas becomes.

Abstract: The present invention is intended to detect a failure of a PM filter with a higher degree of accuracy. The present invention is provided with: a PM trapping efficiency calculation part to calculate a PM trapping efficiency (which is a proportion of an amount of particulate matter trapped with respect to an amount of inflow particulate matter) based on an amount of inflow particulate matter obtained by an inflow particulate matter obtaining part, and an amount of outflow particulate matter detected by a PM sensor; and a failure detection part to make a determination that a failure has occurred in the PM filter, in cases where there has appeared a tendency for the PM trapping efficiency to decrease during a period of time until the execution of the following filter regeneration processing is started after the completion of execution of the filter regeneration processing.