A method of controlling an oxygen purge of a three-way catalyst (TWC) may include: rapidly adjusting, by a controller, an air-fuel ratio (AFR) at an upstream of the TWC to a target AFR when the oxygen purge of the TWC after a fuel cut-off is performed; and maintaining the target AFR until an oxygen purge finish time has passed. According to the method, concentration of NOx slipped from the TWC after the oxygen purge may be reduced.

The deterioration of an exhaust gas purification catalyst is suppressed as much as possible. An exhaust gas purification system for an internal combustion engine comprising: a throttle valve; a turbocharger; an exhaust gas purification catalyst; a bypass passage; a turbo bypass valve (TBV); and a controller. The controller is configured to carry out fuel cut processing and deterioration suppression control. In the deterioration suppression control, when a temperature of the exhaust gas purification catalyst is equal to or higher than a predetermined temperature in the course of the execution of the fuel cut processing, the degree of opening of the TBV becomes smaller, and the degree of opening of the throttle valve becomes larger, than when the temperature of the exhaust gas purification catalyst is lower than the predetermined temperature in the course of the execution of the fuel cut processing.

A system of controlling an engine includes: an engine including a combustion chamber, an intake valve, an ignition switch, and an exhaust valve; a dual continuously variable valve duration device to adjust an intake duration of the intake valve and an exhaust duration of the exhaust valve; and a controller for adjusting an ignition timing of the ignition switch, the intake duration, and the exhaust duration based on a driving condition of the vehicle. In particular, until the temperature of the exhaust gas reaches a predetermined temperature after the engine starts, the controller sets the ignition timing to an ignition timing within a predetermined ignition timing range, sets the intake duration of the intake valve to an intake duration within a predetermined intake duration range, and increases the exhaust duration of the exhaust valve to a limit exhaust duration according to the set intake duration.

A vehicle is provided and includes a GPF (gasoline particulate filter) that is configured to store a soot generated in an engine and burn the soot and a sensor that is configured to detect a first soot mass included in the GPF. A controller is configured to calculate a second soot mass estimated at the ignition off based on the detected first soot mass and determine an inlet temperature of the GPF based on the second soot mass and a predetermined reference value. The engine is then operated based on the determined inlet temperature of the GPF.

A method for catalyst purge control may include the steps of: performing, by a catalyst purge electronic control unit (ECU), catalyst purge control based on engine temperature; calculating an estimated engine temperature the catalyst purge ECU when fuel-cut is completed, and controlling, by the catalyst purge ECU, an amount of purge fuel injected by an injector based on the estimated engine temperature for the catalyst purge control.

Start-up method for heating a selective catalytic reduction (SCR) module in a hybrid propulsion system of a vehicle, comprising an electric motor operatively connected to an internal combustion engine producing exhaust gas, both electric motor and internal combustion engine being operable to power said vehicle, and said internal combustion engine being in fluid communication with an exhaust aftertreatment system having an exhaust passage and comprising the SCR module, said SCR module being disposed in said exhaust passage downstream of said engine and said electric motor, the method comprising the steps of: operating the engine in a start-up mode with a torque restriction on the engine, allowing the SCR module to convert NOx emission; supplying a surplus amount of a reducing agent to the exhaust gas at a position between the engine and the SCR module, the surplus amount of the reducing agent being larger than a required amount of reducing agent for converting NOx emission from the engine; heating said SCR module to a working temperature; and terminating the start-up mode, thereby terminating the torque restriction on the engine and the supply of the surplus amount of the reducing agent.

To facilitate the vaporization of additives added upstream of a selective catalytic reduction device and to suppress their precipitation.

A mixing device includes: a case surrounding a blowing section, through which an exhaust gas is blown out, of a filter or a catalyst; an upper pipe segment having an opening formed therein, the opening facing a direction facing the blowing section, the upper pipe segment being tilted relative to the vertical direction so that the more the upper pipe segment goes vertically downward, the closer it gets to the blowing section in a region facing the blowing section within the case; a lower pipe segment bent from a lower end of the upper pipe segment, the lower pipe segment being tilted relative to the vertical direction so that the more the lower pipe segment goes vertically downward, the further away it gets from the blowing section, the lower pipe segment extending out from the case and being connected to a selective catalytic reduction device; and an injector attached to the case, the injector injecting a liquid additive toward an area faced by the opening, the area being located outside the upper pipe segment in the case.

Methods and systems are provided for HP-EGR and LP-EGR. In one example, a method includes selecting a HP-EGR mode or a LP-EGR mode in response to a first difference calculated between ammonia desired during the two modes, and a second difference calculated between NO.sub.x emitted during the two modes.

Systems and apparatuses include an apparatus including an aftertreatment system control circuit structured to receive a signal indicative of an exhaust gas characteristic from a sensor, determine an aftertreatment system characteristic based on the exhaust gas characteristic, determine an acceptable input value responsive to the aftertreatment system characteristic, and control at least one of a fuel system actuator and an air handling actuator to achieve or substantially achieve the acceptable input value.

In a work machine including an engine; a hydraulic pump; an actuator; an operating member that operates an actuator; an exhaust gas purifying device; a load application device that applies a load to an engine to raise the temperature of exhaust gas; and a control device, the load application device includes a load application valve that is provided in series between the hydraulic pump and the actuator and performs switching as to whether a hydraulic oil flow channel between the hydraulic pump and the actuator is brought into a communication state or a non-communication state in accordance with a control pressure, and if a load application request is input, the control device changes the control pressure exerted on the load application valve on the basis of the presence or absence of input of an operation signal of the operating member.