An intake manifold including a surge tank having an inlet and a plurality of outlets extended along a first direction, and configured to form a space having a cross section larger than the inlet between the inlet and the plurality of outlets and a plurality of branch pipes. The space is formed by a bottom surface, an upper surface, a first surface extended from a first end of the bottom surface to a first end of the upper surface, and a second surface extended from a second end of the bottom surface to a second end of the upper surface. The inlet is provided at a substantially central portion in a first direction on the first surface, and the bottom surface includes a swelling portion swelled upwardly at a substantially central portion in the first direction.

A pre-cleaner for an internal combustion engine is arranged in an intake passage of the internal combustion engine at an upstream side of a filter of an air cleaner. The pre-cleaner includes a casing that includes a cylindrical side wall and swirl generation vanes that swirl intake air about an axis of the casing. The side wall has a portion located next to an upstream side of the swirl generation vanes that is formed from an air-permeable fibrous molded body.

A centrifugal compressor includes an impeller, a compressor inlet pipe for guiding air to the impeller, a scroll passage disposed on an outer peripheral side of the impeller, and a bypass passage connecting the compressor inlet pipe and the scroll passage and bypassing the impeller. In a cross-section perpendicular to an axis of the compressor inlet pipe, when A1 is a connection portion on a downstream side in a rotational direction of the impeller of connection portions between an inner wall surface of the compressor inlet pipe and an inner wall surface of the bypass passage, C is a virtual circle constituting the inner wall surface of the compressor inlet pipe, and L1 is a tangent line of the virtual circle C at the connection portion A1, the inner wall surface of the bypass passage is formed from the connection portion A1 along the tangent line L1.

An intake system of an engine supplies gas at least containing fresh air to each cylinder. The system includes an EGR passage that communicates with an internal space of a downstream intake passage and introduces some EGR gas into the downstream intake passage. The EGR passage includes a projected section in a substantially polygonal or cylindrical shape that is projected to the internal space of the downstream intake passage. The projected section is formed in such a shape that a projection length H1 in an outer circumferential surface on an upstream side is longer than a projection length H2 in an outer circumferential surface on a downstream side.

An engine intake air duct 1 has an intake portion 10 that extends along a first center line A, and a main duct portion 20 that extends along a second center line B. The main duct portion 20 has a merging portion 50, a discharge opening 21, and an extending portion 40 that extends from the merging portion 50 towards an opposite end to the discharge opening 20. A reflecting wall 41 is provided at an end face of the extending portion 40. The intake portion 10 merges with the main duct portion 20 in such a way that the first center line A is directed towards a downstream end of the main duct portion 20.

An engine intake duct includes an upstream side linear portion, a bend portion, a downstream side linear portion, and a fin that rises from an inner surface of the bend portion on an inner side in a bend direction. A fin tip portion is located in the bend portion, and a fin rear end portion is located in the bend portion or the downstream side linear portion, and the fin includes a tip side inclined surface, a rear end side inclined surface, and a rear end surface that is a steep wall extending from a rear end of the rear end side inclined surface to the fin rear end portion. At least a part of a top of the tip side inclined surface of the fin is formed along an extension line of an inner surface of the upstream side linear portion toward the bend portion.

An air intake apparatus of an internal combustion engine includes an intake passage, an intake air flow control valve, a housing portion configured to house the intake air flow control valve, a swirl opening arranged at a first side of the intake air flow control valve to generate swirl, and a tumble opening arranged at a second side of the intake air flow control valve to generate tumble. The swirl opening is provided at one of the intake air flow control valve and a portion between the intake passage and the intake air flow control valve, the tumble opening being provided at the other of the intake air flow control valve and the portion between the inner surface of the intake passage and the intake air flow control valve. The intake air flow control valve rotates to achieve a switching between a swirl state and a tumble state.

In an internal combustion engine which performs a homogeneous lean combustion mode and a stratified lean combustion mode, there is provided a new internal combustion engine control device capable of obtaining a stable combustion state by decreasing influences of delay of an air flow and a degree of change of a transient state and smoothly performing switching between the homogeneous lean combustion mode and the stratified lean combustion mode. Accordingly, in the present invention, when switching between the stratified lean mode in which a compression stroke injection is performed by a direct injection injector 7 and the homogeneous lean combustion mode in which an intake stroke injection is performed by the direct injection injector 7 is performed, a predetermined delay time t is provided from at least a switching operation of a tumble control valve 6, a switching operation between the compression stroke injection and the intake stroke injection is performed, and the delay time t is set so as to correspond to a magnitude of the degree of change L of the transient state. A switching timing between the compression stroke injection and the intake stroke injection is controlled according to the flow delay of an air control system such as the tumble control valve 6 and the degree of change L of the transient state, and thus, it is possible to improve combustion stability in a combustion chamber.

The invention relates to a water separating arrangement in a vehicle air intake intended for mounting between a source of ambient air and an air filter unit. The water separating arrangement (101; 201; 301) comprises a first water separator (110; 210; 310) having a horizontal air intake section (212; 312) and a first water separating section (211; 311), which first water separating section is arranged at least partially surrounding an outer portion of the air intake section (212; 312). The water separating arrangement (101; 201; 301) further comprises a second water separator (120; 220; 320) comprising a housing (221; 321) with an air inlet (223; 323) connected to the air intake section (212; 312); an air outlet (224; 324) connected to an air outlet section (229; 329); wherein the second water separator is arranged to redirect the flow of ambient air over an angle of at least 80.

Multiple convergent nozzles define multiple flow passages in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzles each converge toward the outlet of the mixer. An exhaust gas housing includes an exhaust gas inlet leading into an interior of the exhaust gas housing. Multiple convergent-divergent nozzles each correspond to one of the plurality of convergent nozzles. The convergent-divergent nozzles each include an air-exhaust gas inlet in fluid communication to receive fluid flow from a corresponding convergent nozzle and the interior of the exhaust gas housing.