Abstract: An exhaust purification system includes: an NOx reduction type catalyst; an MAF sensor; an SOx purge control unit that uses an air system control having an intake air amount feedback-controlled based on a target intake air amount and an injection system control for a target injection increase amount set based on the target intake air amount, and a fuel injection amount feedback-controlled based on the target injection increase amount; an SOx purge prohibition processing unit that prohibits an SOx purge control; and a warming mode control unit that open-loop controls an air system when the SOx purge control is prohibited, controls the fuel injection amount, and maintains the exhaust gas at a temperature. The SOx purge control unit executes the injection system control by switching the target intake air amount into an actual intake air amount when starting the SOx purge control after a warming mode control is ended.

Abstract: An exhaust purification system includes: an NOx reduction type catalyst, which is provided in an exhaust system; a temperature acquisition unit, which acquires a catalyst temperature of the NOx reduction type catalyst; and a regeneration treatment unit, which executes a catalyst regeneration to recover an NOx purification capacity, wherein the regeneration treatment unit alternately executes a rich control, in which an exhaust air fuel ratio is set to a rich state to raise a temperature of the NOx reduction type catalyst to a predetermined target temperature, and a lean control, in which the exhaust air fuel ratio is set to a lean state to lower the temperature of the NOx reduction type catalyst, and sets an execution period of the lean control based on a deviation between the catalyst temperature acquired by the temperature acquisition unit during the previous rich control and the target temperature.

Abstract: An exhaust purification system includes: an NOx reduction type catalyst; an MAF sensor; an SOx purge control unit that uses an air system control having an intake air amount feedback-controlled based on a target intake air amount and an injection system control for a target injection increase amount set based on the target intake air amount, and a fuel injection amount feedback-controlled based on the target injection increase amount; an SOx purge prohibition processing unit that prohibits an SOx purge control; and a warming mode control unit that open-loop controls an air system when the SOx purge control is prohibited, controls the fuel injection amount, and maintains the exhaust gas at a temperature. The SOx purge control unit executes the injection system control by switching the target intake air amount into an actual intake air amount when starting the SOx purge control after a warming mode control is ended.

Abstract: An exhaust purification system includes: an NOx reduction type catalyst, which is provided in an exhaust system; a temperature acquisition unit, which acquires a catalyst temperature of the NOx reduction type catalyst; and a regeneration treatment unit, which executes a catalyst regeneration to recover an NOx purification capacity, wherein the regeneration treatment unit alternately executes a rich control, in which an exhaust air fuel ratio is set to a rich state to raise a temperature of the NOx reduction type catalyst to a predetermined target temperature, and a lean control, in which the exhaust air fuel ratio is set to a lean state to lower the temperature of the NOx reduction type catalyst, and sets an execution period of the lean control based on a deviation between the catalyst temperature acquired by the temperature acquisition unit during the previous rich control and the target temperature.

Abstract: Exhaust gas of an internal combustion engine is made to pass through an exhaust gas purification device after passing through a pre-oxidation catalyst. When a first temperature of the exhaust gas on an upstream side of the device is lower than a first set temperature, multistage temperature rise injection is performed. When the first temperature becomes the first set temperature or more, post injection is performed in addition to the multistage temperature rise injection, and feedback control of the post injection is executed so that a second temperature of the exhaust gas on a downstream side of the exhaust gas purification device becomes a second set temperature.

Abstract: An exhaust gas purification system which feeds hydrocarbon by a post-injection under preset conditions to an upstream side of an exhaust gas purification device positioned on the exhaust path of an internal combustion engine, restoring the purifying capacity of the device or purifying the exhaust gas of the device. Under hydrocarbon feed conditions, if a combination of the exhaust gas temperature and exhaust gas flowrate or intake flowrate during control is deemed to be in a misfire region in which hydrocarbon which is fed to the exhaust path no longer combusts in the exhaust gas purification unit, the feed of hydrocarbon is stopped. As a result, it is possible to prevent deposit of hydrocarbon on catalysts or other exhaust gas purification units of the device, making it possible to constantly maintain the temperature of the unit in a controllable state.

Abstract: Exhaust gas of an internal combustion engine is made to pass through an exhaust gas purification device after passing through a pre-oxidation catalyst. When a first temperature of the exhaust gas on an upstream side of the device is lower than a first set temperature, multistage temperature rise injection is performed. When the first temperature becomes the first set temperature or more, post injection is performed in addition to the multistage temperature rise injection, and feedback control of the post injection is executed so that a second temperature of the exhaust gas on a downstream side of the exhaust gas purification device becomes a second set temperature.

Abstract: An exhaust-pipe injection system capable of accurately monitoring a lowered injection pressure generated in a fuel line due to exhaust pipe injection and appropriately perform feedback control for the exhaust injection amount. The exhaust-pipe injection system includes: an exhaust pipe injector that injects fuel to an exhaust pipe of an internal combustion engine; a supply pump that sends a fuel to the exhaust pipe injector via a fuel line; a pressure compensating device provided in the vicinity of the exhaust pipe injector of the fuel line; a fuel pressure sensor provided in the fuel line in an upstream side from the pressure compensating device; and an injection control device that adjusts an injection amount of the exhaust pipe injector based on a monitoring value of the fuel pressure sensor.

Abstract: An exhaust gas purification system which feeds hydrocarbon by a post-injection under preset conditions to an upstream side of an exhaust gas purification device positioned on the exhaust path of an internal combustion engine, restoring the purifying capacity of the device or purifying the exhaust gas of the device. Under hydrocarbon feed conditions, if a combination of the exhaust gas temperature and exhaust gas flowrate or intake flowrate during control is deemed to be in a misfire region in which hydrocarbon which is fed to the exhaust path no longer combusts in the exhaust gas purification unit, the feed of hydrocarbon is stopped. As a result, it is possible to prevent deposit of hydrocarbon on catalysts or other exhaust gas purification units of the device, making it possible to constantly maintain the temperature of the unit in a controllable state.

Abstract: An exhaust-pipe injection system capable of accurately monitoring a lowered injection pressure generated in a fuel line due to exhaust pipe injection and appropriately perform feedback control for the exhaust injection amount. The exhaust-pipe injection system includes: an exhaust pipe injector that injects fuel to an exhaust pipe of an internal combustion engine; a supply pump that sends a fuel to the exhaust pipe injector via a fuel line; a pressure compensating device provided in the vicinity of the exhaust pipe injector of the fuel line; a fuel pressure sensor provided in the fuel line in an upstream side from the pressure compensating device; and an injection control device that adjusts an injection amount of the exhaust pipe injector based on a monitoring value of the fuel pressure sensor.