A prechamber assembly includes a cylinder head including a coolant cavity, a prechamber body located within the cylinder head, the prechamber body including a nozzle, and an annular sleeve radially surrounding a portion of the prechamber body. The sleeve includes a plurality of coolant inlet holes. A portion of the prechamber body is radially spaced from the sleeve to form a coolant sleeve annulus extending along a length of the prechamber body above the coolant inlet holes. The coolant cavity and the coolant sleeve annulus are in fluid communication through the plurality of coolant inlet holes.

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 system includes a diesel oxidation catalyst (DOC) device mounted to an exhaust pipe for exhausting an exhaust gas of an engine and purifying hydrocarbon (HC) and carbon monoxide (CO) among the exhaust gas, an urea injector positioned at a rear of the diesel oxidation catalyst device for injecting an urea aqueous solution to an inside of the exhaust pipe, a mixer positioned at the rear of the urea injector, a diesel particulate matter filter (DPF) positioned at the rear of the mixer and coated with a catalyst devoid of a noble metal or a hydrolysis catalyst that does not oxidize ammonia and hydrolyzes the injected urea to reduce a particulate material of the exhaust gas, and a selective catalytic reduction (SCR) device positioned at the rear of the diesel particulate matter filter.

An exhaust structure of an internal combustion engine having an exhaust passage communicating between an exhaust port and an exhaust pipe. The exhaust structure includes a heat insulating component covering an inner wall of the exhaust port, the heat insulating component includes a first abutting portion disposed at a first side of the heat insulating component at a combustion chamber side and abutting an inner wall of the exhaust port, a second abutting portion disposed at a second side of the heat insulating component at an exhaust pipe side and abutting the inner wall, and a middle section disposed between the first side and the second side. A gap is formed between the middle section and the inner wall, and a bent portion connecting the middle section and the first abutting portion is bending toward the inner wall of the exhaust port from the middle section.

An exhaust gas purification device having such a structure that exhaust gas can uniformly flow into without depending on a shape of an exhaust gas inlet pipe. A gas purification body which purifies the exhaust gas, a purification casing which accommodates the gas purification body, an exhaust gas inlet pipe which communicates with an exhaust gas inflow port of the purification casing, and an exhaust gas outlet pipe which communicates with an exhaust gas outflow port of the purification casing. The exhaust gas inlet pipe is attached to the purification casing in such a manner as to cover the exhaust gas inflow port and extend in a longitudinal direction of the purification casing. An introduction passage of the exhaust gas is formed by an outside surface of the purification casing and an inside surface of a pipe wall of the exhaust gas inlet pipe. A portion extending along the purification casing in the pipe wall is inclined so as to come close to the outside surface of the purification casing in proportion to heading for an exhaust gas outlet side from an exhaust gas inlet side.

An exhaust manifold for a vehicle configured for improving fuel efficiency of the vehicle by improving fluidity of exhaust gas may include a manifold body having a plurality of inlet portions which are outwardly extended and an outlet portion which is outwardly extended, wherein the manifold body may have a flat surface formed on at least a portion of a top surface thereof.

An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst.

In inline four cylinder internal combustion engine (1), exhaust ports for a #2 cylinder and a #3 cylinder merge inside cylinder head (3) and form an opening serving as a single collective exhaust port. Exhaust manifold (5) has individual exhaust pipes (6, 7) for #1 and #4 cylinders and collective exhaust pipe (8), and the leading ends of these three exhaust pipes (6, 7, 8) are connected to catalytic converter (11). Exhaust gas introduction angle (θ2) of each of individual exhaust pipes (6, 7) is larger by 30-60 degrees than exhaust gas introduction angle (θ1) of collective exhaust pipe (8). Consequently, flow velocity distribution and temperature distribution in a catalyst carrier become uniform.

The device includes an exhaust passage having an upstream end connected to an exhaust port of the engine and a downstream end provided with a catalytic converter, a secondary air passage having a downstream end connected to an intermediate point of the exhaust passage and an upstream end communicating with the atmosphere, and a reed valve provided in an upstream end of the secondary air passage to permit air flow from the atmosphere to the exhaust passage but not in the opposite direction. The reed valve has a resonance frequency which is z times the prescribed exhaust frequency of the engine, where z is an integer. The length of the secondary air passage is selected that the pulsation effect of air in the secondary air passage may be advantageously utilized.

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.