Abstract: An intake air sound generation device 40 for an internal combustion engine 2, comprises an introduction tube 41 which is connected to an intake passage 30 of the internal combustion engine 2 to introduce an intake pulse of an intake system, a vibrating body 50 which has a vibration surface 52 that is vibrated by the intake pulse and an accordion portion 53 that promotes vibration of the vibration surface 52, and is provided to cover one end of the introduction tube 41, and a resonance tube 42 which is connected to the introduction tube 41 via the vibrating body 50 and increases a sound pressure in a predetermined frequency band of an intake air sound generated by the vibration of the vibration surface 52. Thus, the sound pressure of the intake air sound at the predetermined frequency can be increased, and the durability of the vibrating body 50 can be improved.

Abstract: A pair of intake collectors (1A, 1B) separated by a partition (4A) aspirates air into each cylinder of a multi-cylinder internal combustion engine via branch pipes (3A-3F). A valve (8A, 8B) which shuts off the air flow between the intake collectors (1A, 1B) is fitted onto the partition (4A) via a valve frame (11) and a bearing boss (16A) provided on the valve frame (11). An edge of the partition (4A) is fitted into a groove (18) formed on the outer circumference of the valve frame (11) so as to prevent air from leaking through an engaging part between the partition (4A) and the valve frame (11) due to a Labyrinth effect. Further, an elastically connecting member (20) disposed on both sides of the bearing boss (16A) elastically connects the valve frame (11) and the groove (18), thereby preventing relative oscillation between the partition (4A) and the valve frame (11).

Abstract: An intake air sound generation device 40 for an internal combustion engine 2, comprises an introduction tube 41 which is connected to an intake passage 30 of the internal combustion engine 2 to introduce an intake pulse of an intake system, a vibrating body 50 which has a vibration surface 52 that is vibrated by the intake pulse and an accordion portion 53 that promotes vibration of the vibration surface 52, and is provided to cover one end of the introduction tube 41, and a resonance tube 42 which is connected to the introduction tube 41 via the vibrating body 50 and increases a sound pressure in a predetermined frequency band of an intake air sound generated by the vibration of the vibration surface 52. Thus, the sound pressure of the intake air sound at the predetermined frequency can be increased, and the durability of the vibrating body 50 can be improved.

Abstract: A variable air intake control system includes first and second variable intake control valves, a vacuum tank, actuators, a one-way valve and a controller. The controller selectively is configured to control the first and second actuators to offset operating timings of the first and second variable intake control valves so as to suppress the noise in the one-way valve, when the first and second variable intake control valves are switched from a first operating state in which the first and second variable intake control valves are both in one of the open and closed states to a second operating state in which the first and second variable intake control valves are both in one of the open and closed states that is opposite to the first operating state.

Abstract: A variable air intake control system includes first and second variable intake control valves, a vacuum tank, actuators, a one-way valve and a controller. The controller selectively is configured to control the first and second actuators to offset operating timings of the first and second variable intake control valves so as to suppress the noise in the one-way valve, when the first and second variable intake control valves are switched from a first operating state in which the first and second variable intake control valves are both in one of the open and closed states to a second operating state in which the first and second variable intake control valves are both in one of the open and closed states that is opposite to the first operating state.

Abstract: An internal combustion engine intake device is configured to suppress the occurrence of freezing in a portion thereof where blow-by gas or another gas is introduced into an intake passage. The intake device basically has a throttle chamber, an intake air collector, an air induction pipe, a partitioning part, a gas introducing pipe and a volume chamber. The air induction pipe is provided between the throttle valve and the intake air collector. The partitioning part divides the space inside the air induction pipe into first and second air induction spaces. The gas introducing pipe introduces the blow-by gas into the first and second air induction spaces directly. The blow-by gas contains moisture and has a higher temperature than the fresh air in the first and second air induction spaces. The volume chamber is arranged between the gas introducing pipe and the first and second air induction spaces.

Abstract: A pair of intake collectors (1A, 1B) separated by a partition (4A) aspirates air into each cylinder of a multi-cylinder internal combustion engine via branch pipes (3A-3F). A valve (8A, 8B) which shuts off the air flow between the intake collectors (1A, 1B) is fitted onto the partition (4A) via a valve frame (11) and a bearing boss (16A) provided on the valve frame (11). An edge of the partition (4A) is fitted into a groove (18) formed on the outer circumference of the valve frame (11) so as to prevent air from leaking through an engaging part between the partition (4A) and the valve frame (11) due to a Labyrinth effect. Further, an elastically connecting member (20) disposed on both sides of the bearing boss (16A) elastically connects the valve frame (11) and the groove (18), thereby preventing relative oscillation between the partition (4A) and the valve frame (11).

Abstract: An internal combustion engine intake device is configured to suppress the occurrence of freezing in a portion thereof where blow-by gas or another gas is introduced into an intake passage. The intake device basically has a throttle chamber, an intake air collector, an air induction pipe, a partitioning part, a gas introducing pipe and a volume chamber. The air induction pipe is provided between the throttle valve and the intake air collector. The partitioning part divides the space inside the air induction pipe into first and second air induction spaces. The gas introducing pipe introduces the blow-by gas into the first and second air induction spaces directly. The blow-by gas contains moisture and has a higher temperature than the fresh air in the first and second air induction spaces. The volume chamber is arranged between the gas introducing pipe and the first and second air induction spaces.

Abstract: In a branch pipe of an intake manifold, portion c in the central part is kept at relatively small constant inner diameter for an interval C, and portion e of which an end is connected to the surge tank is kept at relatively large constant inner diameter for an interval E, whereby the volumetric efficiency at the time of medium speed and high speed of engine is excellent.

Abstract: An air intake structure of an engine has a first intake air passage and a second intake air passage provided independently and having downstream end portions branched into a plurality of intake ducts connected to a plurality of cylinders of the engine. The neighborhood of the downstream end portion of the first intake air passage and the neighborhood of the down stream end portion of the second intake air passage can be brought into communication by a first communication element. The first intake air passage and the second intake air passage are rendered communicable by a second communication element upstream from the first communication element in the flowing direction of intake air. The first communication element and the second communication element are controlled in accordance with the operating state of the engine.

Abstract: An air intake structure of an engine has a first intake air passage and a second intake air passage provided independently and having downstream end portions branched into a plurality of intake ducts connected to a plurality of cylinders of the engine. The neighborhood of the downstream end portion of the first intake air passage and the neighborhood of the downstream end portion of the second intake air passage can be brought into communication by a first communication element. The first intake air passage and the second intake air passage are rendered communicable by a second communication element upstream from the first communication element in the flowing direction of intake air. The first communication element and the second communication element are controlled in accordance with the operating state of the engine.