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 exhaust system for a vehicle having an internal combustion engine includes an exhaust pipe having a central axis and configured to receive an exhaust gas flow from the engine, a catalytic converter disposed within the exhaust pipe, and an exhaust gas burner assembly having a burner unit configured to generate and supply a heated burner flow to a supply pipe. An outlet end of the supply pipe is disposed within the exhaust pipe and extends substantially parallel to the exhaust pipe central axis such that the exhaust gas flows around the supply pipe outlet end. A plurality of mixing apertures are formed in the supply pipe outlet end and configured to promote mixing of the heated burner flow and the exhaust gas flow to disperse heat over the catalytic converter for rapid heating thereof.

First to fourth exhaust passages are provided in a raw blank of a cylinder block, which can be used for both a first exhaust route and a second exhaust route, one of which is selected for use as an exhaust passage. In the first exhaust route, a fifth exhaust passage couples between opening ends of the first and second exhaust passages and is formed in a separate member from the cylinder block, exhaust gas is allowed to flow via the fourth, first, fifth, second, and third exhaust passages, and a catalyst is placed in the exhaust passages. In the second exhaust route, a communication hole is provided in a partition wall between the fourth exhaust passage and the second exhaust passage while the opening ends of the first and second exhaust passages are closed, and the exhaust gas is allowed to flow via the fourth, second, and third exhaust passages.

An exhaust gas purification device is disposed in an exhaust passage of an engine disposed in an engine room defined in a hull, and is configured to remove at least a nitrogen oxide from an exhaust gas discharged from the engine. The exhaust gas purification device includes: a catalytic part including a selective reducing catalyst for selectively reducing the nitrogen oxide; a reducing agent addition device configured to add a reducing agent to the exhaust gas on an upstream side of the catalytic part in a flow direction of the exhaust gas; and a casing configured to contain the catalytic part. At least a part of the casing is disposed inside the engine room.

An arrangement of at least two engine-compartment exhaust system components is provided for an internal combustion engine of a motor vehicle. The at least two engine-compartment exhaust system components are arranged one behind the other downstream from the internal combustion engine of the motor vehicle and are connected to one another by means of a first connecting body, so that exhaust gas from the internal combustion engine can be directed in succession through the at least two exhaust system components in the direction of an exhaust system. In addition, the two exhaust system components are also arranged behind a manifold device of the internal combustion engine by means of a second connecting body. A motor vehicle is also provided which comprises at least one such arrangement.

Methods and systems are provided for a resonator of an exhaust system. In one example, the resonator is a quarter wave resonator with a diaphragm configured to provide pulsations during low-end engine torque conditions.

A system for the treatment of exhaust gases from an internal combustion engine with a combustion chamber includes an upstream DEF injector disposed to introduce DEF to the combustion chamber and a close-coupled SCR catalyst downstream of and in close-coupled relation to the internal combustion engine. Downstream of the close-coupled SCR catalyst may be a primary SCR catalyst and a primary DEF injector. The system may operate to reduce NO.sub.2 in the close-coupled SCR catalyst during low-load conditions of the internal combustion engine and reduce NO.sub.2 in the primary SCR catalyst during loaded conditions.

A hollow first accommodating case (28) is provided on a front part of a revolving frame (5) at a position on a front side of a fuel tank (23), and a fuel supply pump (34) for supplying a fuel stored in an external fuel storage source to the fuel tank (23) is provided on the fuel tank (23) by being connected. A fuel suction port (35) for sucking the fuel toward the fuel supply pump (34) is provided in the first accommodating case (28) by being opened to an outside, and a urea water tank (25) is provided by being accommodated in the first accommodating case (28). A water supply port (25G) of a urea water is provided in the urea water tank (25) by being opened to the outside, and the fuel suction port (35) and the water supply port (25G) of the urea water are juxtaposed and arranged in the first accommodating case (28).

A vehicle engine 2 comprises an exhaust system having an exhaust manifold 12 and an exhaust purification device 18. The exhaust manifold 12 is disposed at a predetermined distance from a dash panel 106 constituting a body of the vehicle 100, the exhaust purification device 18 is disposed in a position overlapping a floor tunnel region 114, formed by a floor tunnel of the body, and is disposed below the exhaust manifold 12 and to one side of the center of the engine 2 in the cylinder-array direction, as viewed from the longitudinal direction of the vehicle 100. An exhaust purification device introduction passage 17 connecting the exhaust manifold 12 and the exhaust purification device 18 is disposed on the other side of the center of the exhaust manifold 12 in the cylinder-array direction, and extends below the exhaust manifold 12 to be connected to the exhaust purification device 18.

An aftertreatment system for treating exhaust gases from an internal combustion engine includes, in series, a diesel oxidation catalyst (DOC), a diesel particular filter (DPF) downstream the DOC, and a primary selective catalyst reduction (SCR) catalyst downstream the DPF. A supplemental SCR catalyst is disposed upstream the DOC, DPF, and primary SCR catalyst to receive raw exhaust gases from the internal combustion engine. The supplemental SCR catalyst may conduct an SCR reaction on the raw exhaust gases until the supplemental SCR catalyst reaches a reaction temperature, at which time the supplemental SCR catalyst may conduct the SCR reaction.