The utility vehicle includes a body; a frame that supports the body; an on-board device that is mounted on the frame and requires outside air; and an air intake conduit that is connected to the on-board device. An air intake port of the air intake conduit that sucks in outside air faces a center side of the utility vehicle.

The utility vehicle includes a body; a frame that supports the body; an on-board device that is mounted on the frame and requires outside air; and an air intake conduit that is connected to the on-board device. An air intake port of the air intake conduit that sucks in outside air faces a center side of the utility vehicle.

An engine includes a cylinder head having a first face defining an entrance to an intake port, and an intake manifold having a second face defining an outlet from a runner. The first and second faces mate to fluidly connect the entrance and the outlet, and an area mismatch or offset exists between the entrance and the outlet. A tongue is positioned into the intake port to extend over a floor of the intake port and has an area substantially equal to a difference between the entrance area and the outlet area. The tongue maintains in-charge motion and mixing of intake gases in-cylinder in the engine.

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 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.

This air intake duct for an internal combustion engine is provided with a duct body having a cylindrical sidewall. At least part of the sidewall is provided with a support section which is formed from an air permeable material which allows air to flow between the inside and outside of the sidewall and which supports the portions of the sidewall, which face each other.

A first downstream part of an intake manifold has a first downstream passage configured to communicate with an intake port of a first cylinder head. A second downstream part of the intake manifold has a second downstream passage configured to communicate with an intake port of a second cylinder head. An upstream part is coupled to the first downstream part and the second downstream part. The upstream part is arranged upstream from the first and second downstream parts in the flow direction of intake air and has a first upstream passage and a second upstream passage. The material of the first downstream part and the material of the second downstream part both have higher rigidity than the material of the upstream part.

An intake port structure has a sleeve disposed along an inner peripheral surface of an intake port of a cylinder head and made of a material having a thermal conductivity lower than a material of the cylinder head. When a cross-sectional area of an intake passage on an upstream side in an vicinity of a mating surface between the cylinder head and the intake passage toward the cylinder head is defined as a mating surface upstream area, and an intake port cross-sectional area of the intake port, which excludes the sleeve, on a downstream side in the vicinity is defined as a mating surface downstream area, the mating surface downstream area is greater than the mating surface upstream area, and the intake port cross-sectional area at a place where the sleeve is disposed in the intake port is gradually reduced from the mating surface toward a combustion chamber side.

A first downstream part of an intake manifold has a first downstream passage configured to communicate with an intake port of a first cylinder head. A second downstream part of the intake manifold has a second downstream passage configured to communicate with an intake port of a second cylinder head. An upstream part is coupled to the first downstream part and the second downstream part. The upstream part is arranged upstream from the first and second downstream parts in the flow direction of intake air and has a first upstream passage and a second upstream passage. The material of the first downstream part and the material of the second downstream part both have higher rigidity than the material of the upstream part.

An intake module of a fresh air system for an internal combustion engine may include a housing having openings through which fresh air is flowable, and a control device for controlling a cross-section of the openings. The control device may include at least one control staff rotationally mounted about an axis rotation on the housing by at least one bearing bracket, and at least one control valve rotationally fixed on the control shaft for at least one of the openings. The housing may have at least one bearing receiving portion having an insertion opening through which the bearing bracket may be inserted in an insertion direction oriented perpendicularly to the axis of rotation. The bearing bracket may have a first bearing part having a first bearing section on which the control shaft rests with a circumferential section, and a second bearing part having a second bearing section opposite the first bearing section on which the control shaft rests with a second circumferential section opposite the first circumferential section. The bearing parts may each have an inner surface facing one another in a transverse direction perpendicular to the axis of rotation and insertion direction, and at least one flat positioning surface extending perpendicularly to the transverse direction and raised from the inner surface. The positioning surfaces of the first and second bearing parts may rest flat against each other, and a gap may be formed in the transverse direction between the inner surfaces outside the positioning surfaces.