A partition plate is configured to separate an intake passage formed by an intake pipe to be coupled to a combustion chamber into a first intake passage and a second intake passage. The first intake passage is openable and closable by a valve. A shape of a first cross section orthogonal to an extending direction of the intake pipe is set on the basis of a shape of a surface of the intake pipe that faces the partition plate with the second intake passage interposed therebetween.

An intake system of an internal combustion engine includes an intake pipe through which an intake passage extends, a throttle valve, and a baffle arranged at a downstream side of the throttle valve in the intake passage. The throttle valve includes a shaft, a first valve body configured to close a first region located at a first side, and a second valve body configured to close a second region located at a second side. When the throttle valve opens, the first valve body is pivoted toward an upstream side and the second valve body is pivoted toward a downstream side. The baffle includes a ring, a first net located at the first side of the ring, and a second net located at the second side of the ring. The first net occupies a larger region than the second net.

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.

Methods and systems are provided for a noise attenuation device. In one example, a system may include a noise attenuation device located downstream of a throttle body with a height less than or equal to a difference in radiuses between a bore of the throttle body and an intake passage.

An intake noise reduction device that can mitigate deformation of a flow-regulating net portion made of an elastic body. The intake noise reduction device 100 is made of an elastic body that is disposed downstream of a throttle valve and includes an annular gasket portion 110 and a flow-regulating net portion 120 provided inside the gasket portion 110 integrally with the gasket portion 110, constituted by a linear portion having a mesh shape. The linear portion having the mesh shape constituting the flow-regulating net portion 120 includes first linear parts 121 that extend radially and second linear parts 122 that extend circumferentially. One of any given two parts of the first linear part 121 on a radially outer side has a width larger than or equal to that of the other part on a radially inner side, and a radially outermost part of the first linear part has a larger width than a radially innermost part.

An acoustic damper includes a housing with an inlet aperture and an outlet aperture. The housing is configured to receive a gas flow that enters via the inlet aperture and that exits via the outlet aperture. The acoustic damper also includes a barrier member that is disposed within the housing. The barrier member is configured to be disposed within the gas flow and to dampen acoustic energy that propagates in an upstream direction generally from the outlet aperture toward the inlet aperture. The barrier member includes an outer structure that defines an interior volume of the barrier member. The interior volume is oriented toward the outlet aperture.

A partition plate is configured to separate an intake passage formed by an intake pipe to be coupled to a combustion chamber into a first intake passage and a second intake passage. The first intake passage is openable and closable by a valve. A shape of a first cross section orthogonal to an extending direction of the intake pipe is set on the basis of a shape of a surface of the intake pipe that faces the partition plate with the second intake passage interposed therebetween.

A partition plate includes a main body and a plurality of protrusions. The main body is configured to be disposed in an intake passage of an engine partition the intake passage. The protrusions are provided at an end of the main body. The end is located toward a combustion chamber. Each protrusion is inclined relative to a width direction of the main body from an apex toward a base. The apex protrudes so as to be the closest toward the combustion chamber, and the base is the farthest from the combustion chamber.

A plurality of parts that constitute an intake passage connected with an intake port of an engine include a constriction part that has a protrusion formed to protrude on an inner circumferential surface side of the intake passage. The constriction part includes cylindrical connections disposed on both sides of a constriction path in which the protrusion is formed. The constriction path has an outer circumferential surface recessed inwardly in a radial direction so as to follow a shape of the protrusion. A portion recessed most of the recessed outer circumferential surface is disposed inside inner circumferential surfaces of the connections in the radial direction. The constriction path has a uniform wall thickness. The constriction part is connected upstream of the throttle body.

An acoustic component is provided with a flow channel for a fluid. The flow channel has an inlet pipe and an outlet pipe. A flow channel section is arranged between the inlet pipe and the outlet pipe, wherein the flow channel section has a silencer volume connected in the flow channel section via openings to the flow channel. A flow deflection device is arranged at least in the flow channel section with the silencer volume, wherein the flow deflection device deflects a flow of the fluid in the flow channel section with the silencer volume away from the openings. The openings in the flow channel section are arranged in a sheltered zone of the flow deflection device.