An under-floor catalyst (33) includes a GPF (41) capable of trapping fine exhaust particles in exhaust gas, and a downstream-side catalyst (42) positioned on the downstream side of GPF (41). GPF (41) can be supplied with secondary air. When an internal combustion engine (10) is stopped during travel, the secondary air is supplied to GPF (41) in which the fine exhaust particles are accumulated. At this time, the temperature of GPF (41) is equal to or higher than a predetermined temperature. Thus, a deterioration in the exhaust gas purification performance of under-floor catalyst (33) at the time of the start of internal combustion engine (10) can be suppressed.

An exhaust muffler is made up of a plurality of layers including an exhaust passage pipe and expansion chambers, and includes a front assembly and a rear assembly sub-assembled separately from the front assembly. The front assembly includes a front exhaust passage pipe, a front muffler body disposed in covering relation to the outside of the front exhaust passage pipe and cooperating with the front exhaust passage pipe in making up double-walled pipes, and an exhaust valve disposed in the front exhaust passage pipe. The rear assembly includes a rear exhaust passage pipe and a rear muffler body disposed in covering relation to the outside of the rear exhaust passage pipe and cooperating with the rear exhaust passage pipe in making up double-walled pipes. There is thus provided an exhaust device for an internal combustion engine in which the accuracy of a position where the exhaust valve is installed is high.

An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC) or a passive NOx adsorber (PNA), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst, which may also include an additional PNA.

A engine device for a work vehicle, in which an engine, a first case, and a second case can be constituted in the same vibration structure, and exhaust gas path structure between the engine and the second case can be constituted in such a manner as to reduce costs. The engine device for a work vehicle according to the present invention of the instant application includes the first case for removing particulate matter in exhaust gas of the engine and the second case for removing nitrogen oxides in the exhaust gas of the engine, and configured to connect the first case to the second case via a urea mixing pipe. The engine, the first case, and the second case are integrally adhered, and the engine, the first case, and the second case are configured to be integrally vibrated in a swingable manner.

An exhaust gas aftertreatment system for an internal combustion engine charged by an exhaust gas turbocharger and spark-ignited by means of spark plugs has a particulate filter and a first three-way catalytic converter downstream from the particulate filter in a position close to the engine in an exhaust gas system connected to an outlet of the internal combustion engine and another three-way catalytic converter arranged in the underbody position of the motor vehicle, downstream from the first three-way catalytic converter. An exhaust gas burner is active from the start of the engine, introducing hot exhaust gas into the exhaust gas system downstream from the particulate filter, in order to heat at least one of the three-way catalytic converts to a light-off temperature, as quickly as possible after the cold start, thereby allowing an efficient exhaust gas aftertreatment. The exhaust gas burner can be switched off when at least one of the two three-way catalytic converters has reached its light-off temperature.

A heating device for an exhaust system of an internal combustion engine and having: a tubular body, where a combustion chamber is obtained on the inside; a fuel injector, which injects fuel into the combustion chamber; at least one inlet opening, which can be connected to a fan so as to receive an air flow, which is directed to the combustion chamber and gets mixed with the fuel; a feeding channel, which receives air from the inlet opening, surrounds an end portion of the fuel injector and ends with a nozzle, which is arranged around an injection point of the fuel injector; and a spark plug, which is mounted through a side wall of the tubular body so as to trigger the combustion of a mixture of air and fuel. The fuel injector is configured to spray at least 80% of the fuel against an inner surface of the feeding channel.

An exhaust pipe has an upstream-side exhaust pipe extending downward from an engine to house a catalyst for exhaust gas purification, and a downstream-side exhaust pipe located downstream of the upstream-side exhaust pipe, and extending upward from the catalyst and then bending downward. Under a configuration in which an exhaust pipe is disposed below an engine, with a simple configuration, a catalyst is hardly exposed to water.

Certain catalytic articles, systems or methods provide for excellent NOx conversion and are especially suitable for low temperature NOx conversion. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles or systems contain an upstream SCR composition and a downstream LNT composition. The substrate(s) may advantageously be electrically heated.

The invention relates to a method for controlling the pressure of the exhaust gas of a machine, in particular an internal combustion engine. The exhaust gas is discharged from the machine via an exhaust gas line, and the exhaust gas line has a regulating device, preferably comprising a throttle valve or a throttle flap, said regulating device delimiting a pressure-regulated section of the exhaust gas line. Gas, preferably air, which is regulated into the pressure-regulated section via a compressed gas line is supplied such that the pressure in the pressure-regulated section is substantially kept at a constant value. The invention additionally relates to a corresponding device.

The present disclosure describes methods for operating an EAS including a close coupled SCR unit, a downstream SCR unit, a diesel oxidation catalyst unit (DOC) and a diesel particulate filter (DPF). The methods utilize the close coupled SCR unit to manage NOx emissions from the EAS during regeneration of a diesel particulate filter (DPF).