An exhaust-gas purifying device purifies an exhaust gas exhausted from a gasoline engine of a vehicle and flowing in an exhaust pipe, and has a purifying function part disposed in the exhaust pipe and a detector located downstream of the purifying part in the exhaust pipe. The purifying function part has a three-way catalyst that oxidizes and reduces a toxic substance and a filter that collects a particular matter included in the exhaust gas. The detector detects an amount of the particular matter based on electrical conductivity between the electrodes of the detector. The detector is located at a position that is one meter distanced from a downstream end of the purifying function part in a path length of the exhaust pipe or a position at which a temperature of the exhaust gas flowing after a warm-up operation of the gasoline engine is lower than or equal to 450° C.

An exhaust gas aftertreatment system for an internal combustion engine has an exhaust system that can be connected to an outlet of the internal combustion engine. A three-way catalytic converter that is situated close to the engine and, downstream from the three-way catalytic converter that is situated close to the engine, a second catalytic converter and a particle reduction device are arranged in the direction in which an exhaust gas of the internal combustion engine flows through an exhaust gas channel of the exhaust system. A fuel injector is arranged on the exhaust gas channel so as to inject fuel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter, and the exhaust system comprises a secondary air system with which secondary air can be blown into the exhaust gas channel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter.

An automotive exhaust aftertreatment system includes a three-way catalyst (TWC) fluidly coupled to an internal combustion engine and a muffler, a selective catalytic reduction (SCR) unit located downstream from the TWC and upstream from the muffler, the SCR unit configured as a NOx catalytic converter and a hydrocarbon (HC) trap, and an electrically heated catalyst (EHC) located downstream from the SCR and upstream from the muffler, the EHC configured as a catalytic converter for the trapped HCs once the HCs are released from the SCR.

This exhaust structure for a vehicle-mounted engine has an air intake channel 3 disposed on one side of an engine main body and an exhaust channel disposed on the other side thereof, the exhaust structure for the vehicle-mounted engine comprising: a turbine of a turbocharger disposed on the other side of the engine main body and connected to the exhaust channel; a first exhaust gas purification device connected to the exhaust channel downstream of the turbine; and a second exhaust gas purification device connected to the exhaust channel 4 downstream of the first exhaust gas purification device. The first exhaust gas purification device is disposed so as to be near the rear of the turbocharger, and the second exhaust gas purification device is disposed so as to be near a cylinder hock on the other side of the engine main body.

A tractor includes: a vehicle body; an engine disposed in an engine compartment; a radiator that is disposed, in the engine compartment, further toward a vehicle-body front side than the engine and cools the engine; an exhaust-gas cleaning device that purifies exhaust gas exhausted from the engine using a reducing agent; a reducing-agent tank that stores the reducing agent supplied to the exhaust-gas cleaning device; and a battery, the reducing-agent tank being disposed, in the engine compartment, side-by-side with the battery and further toward the vehicle-body front side than the radiator.

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

An exhaust system for an engine has a volume element such as a muffler or a silencer. First and second exhaust pipes are connected as dual exhaust pipes upstream of or downstream of the volume element. The first exhaust pipe has a first length (L1). A valve is positioned in the second exhaust pipe at a distance (D) from the volume element. The distance D is a fraction of L1 such that the second pipe is a resonator for the first pipe with the valve in a closed position. A method of controlling exhaust noise includes positioning a valve in the first exhaust pipe at a distance (D) from a volume element with D being a specified fraction of a length of the second exhaust pipe, and closing the valve such that the first pipe provides a resonator for the second pipe to counteract standing wave in the second pipe.

A method for controlling exhaust gas aftertreatment in an exhaust gas aftertreatment system having at least one nitrogen oxide storage catalyst and at least one catalyst for selective catalytic reduction is provided, wherein, in phases of a high load, a combustion engine is operated with a substoichiometric fuel/air mixture, and nitrogen oxides in the exhaust gas are reduced in the nitrogen oxide storage catalyst to ammonia, which is stored in the catalyst for selective catalytic reduction, and, when the storage capacity of the catalyst for selective catalytic reduction is exceeded, the combustion engine is operated with a superstoichiometric fuel/air mixture, thus allowing nitrogen oxides in the catalyst for selective catalytic reduction to be reduced by the stored ammonia.

A muffler includes an exhaust pipe, a shell, and a cover. The exhaust pipe includes communication holes and is configured to allow an exhaust gas to flow through an interior of the exhaust pipe. The shell is disposed outside the communication holes to cover the communication holes. The cover has a tubular shape. The cover is disposed between the exhaust pipe and the shell. The cover is disposed at a distance, which is specified in advance, from the exhaust pipe.

An engine system for internal combustion and reformation of a fuel includes an engine, and a reforming reactor. The engine comprising an intake manifold for receiving a first fuel and an exhaust manifold for releasing an exhaust gas. The reforming reactor includes a first end portion, a second end, a wall having an outer surface and an inner surface. The inner surface defines an interior cavity for receiving the first fuel, a second fuel, reactants for the first fuel, or combinations thereof. The exhaust manifold of the system is sized and shaped for receiving a portion of the reforming reactor such that the exhaust gas flows along a surface of the reforming reactor within the exhaust manifold.