摘要:
An adding time a of a fuel addition to an exhaust system is limited to a guard value G or less during an adding period A of a concentrated intermittent fuel of a catalyst recovery control. Accordingly, a one-time fuel adding amount from an adding valve 46 is limited to be equal to or less than a predetermined value, and it is possible to prevent such a great amount of unburned fuel component that cannot be fully purified by a NOx catalyst from being supplied to the NOx catalyst during the adding period A. Further, if a total amount (GF+Q1)·t of the unburned fuel component supplied to the NOx catalyst during the adding period A reaches an allowable upper limit value UL, the concentrated intermittent fuel addition is canceled and a suspend period B is forcibly started. Accordingly, it is possible to prevent a total amount of such a great amount of unburned fuel component that cannot be fully purified by the NOx catalyst from being supplied to the NOx catalyst during the adding period A. Therefore, generation of white smoke in exhaust gas of the internal combustion engine by an excessive supply of the unburned fuel component to the NOx catalyst at a time of executing catalyst recovery control can be prevented.
摘要:
The exhaust gas purifier includes a fuel addition valve, an NOx catalytic converter, and a catalyst loaded PM filter. The catalyst temperature of catalyst loaded PM filter is increased to a target temperature by adding fuel to the exhaust gas from fuel addition valve, whereby PM trapped on the filter is purified. When the NOx catalytic converter is deteriorated, the target catalyst temperature of catalyst loaded PM filter is changed to a value larger than the target catalyst temperature when the NOx catalytic converter is in a normal state.
摘要:
A PM catalyst regeneration control for the purpose of “soot removal” is performed prior to a sulfur poisoning recovery control. In the PM catalyst regeneration control, PM deposits in a catalyst are burned. A target throttle opening degree for the sulfur poisoning recovery control is preset smaller than a target throttle opening for the PM catalyst regeneration control in order to reduce the intake air volume during deceleration. A catalyst bed temperature is thus prevented from dropping, and therefore maintained at a level appropriate to sulfur poisoning recovery. Controlling the intake air volume during deceleration in such a manner results in more efficient catalyst recovery from sulfur poisoning, so that the fuel economy is maintained during the sulfur poisoning recovery control.
摘要:
An ECU corrects a fuel addition interval, based on an amount of change between a present backpressure and a basic backpressure obtained when a basic addition interval is set, to reduce the fuel addition interval with an increase in the amount of change in the backpressure (steps ST1-ST4). Thereby, a required fuel addition amount can be secured even if a pressure in an exhaust path provided with a fuel addition valve is increased and thus the backpressure at an ejection hole portion of the fuel addition valve is increased. Consequently, an increase in a catalyst bed temperature required for an exhaust gas purifying function of a catalyst can be ensured. Further, a temperature at a tip of the fuel addition valve can be maintained at not more than a predetermined value (i.e., a temperature at which production of deposits can be suppressed), and thus clogging of the ejection hole of the fuel addition valve with the deposits can be avoided.
摘要:
An exhaust gas purification apparatus for an internal combustion engine having a movable component that is operated during operation of the internal combustion engine includes: a switching portion that switches the exhaust gas temperature increasing control between a first control in which the temperature of exhaust gas is increased without operating the movable component and a second control in which the temperature of exhaust gas is increased operating the movable component; a detecting portion that detects a temporarily sticking state of the movable component; and a controlling portion that, when a temporarily sticking state of the movable component is detected, extends an execution region for the first control toward an execution region for the second control in the entire operation region of the internal combustion engine, whereby the execution region for the second control is reduced.
摘要:
An output restriction device for restricting engine output when a drive power output system for an internal combustion engine has an abnormality is provided. The output restriction device includes an abnormality detection unit, and initial restriction unit, and a secondary restriction unit. The abnormality restriction unit detects an abnormality in the drive power output system. The initial restriction unit restricts a tolerable range of the engine output to a first restriction region when the abnormality detection unit detects an abnormality in the drive power output system. A secondary restriction unit shifts the tolerable range of the engine output to a second restriction region, which has an upper limit lower than that of the first restriction region, in accordance with an operation history of the engine after the initial restriction unit restricts the tolerable range of the engine output to the first restriction region.
摘要:
A PM catalyst regeneration control for the purpose of “soot removal” is performed prior to a sulfur poisoning recovery control. In the PM catalyst regeneration control, PM deposits in a catalyst are burned. A target throttle opening degree for the sulfur poisoning recovery control is preset smaller than a target throttle opening for the PM catalyst regeneration control in order to reduce the intake air volume during deceleration. A catalyst bed temperature is thus prevented from dropping, and therefore maintained at a level appropriate to sulfur poisoning recovery. Controlling the intake air volume during deceleration in such a manner results in more efficient catalyst recovery from sulfur poisoning, so that the fuel economy is maintained during the sulfur poisoning recovery control.
摘要:
An apparatus for preventing a filter for purifying exhaust gas emitted by a vehicle diesel engine from overheating is provided. The filter filters particulate matter in exhaust gas. Particulate matter that is accumulated in the filter through filtering is burned and purified by executing a temperature increase process in which the filter is heated. The apparatus includes an electronic control unit as overheat prevention means. During the temperature increase process, the overheat prevention means executes an increase process for increasing the flow rate of exhaust gas when the filter is likely to overheat. As a result, the filter is effectively prevented from overheating.
摘要:
An ECU corrects a fuel addition interval, based on an amount of change between an exhaust gas temperature at present and a basic exhaust gas temperature obtained when a basic addition interval is set, to reduce the fuel addition interval with an increase in the amount of change in the exhaust gas temperature. With such correction of the addition interval, when the exhaust gas temperature is increased in a highland region or the like, the fuel addition interval is corrected to be reduced and an fuel addition amount is corrected to be increased according to the increase in the exhaust gas temperature. Thereby, an increase in a temperature at a tip portion of a fuel addition valve can be suppressed, and thus clogging of an ejection hole of the fuel addition valve with deposits can be avoided.
摘要:
An exhaust gas purification apparatus for an internal combustion engine having a movable component that is operated during operation of the internal combustion engine includes: a switching portion that switches the exhaust gas temperature increasing control between a first control in which the temperature of exhaust gas is increased without operating the movable component and a second control in which the temperature of exhaust gas is increased operating the movable component; a detecting portion that detects a temporarily sticking state of the movable component; and a controlling portion that, when a temporarily sticking state of the movable component is detected, extends an execution region for the first control toward an execution region for the second control in the entire operation region of the internal combustion engine, whereby the execution region for the second control is reduced.