Abstract: An intake air noise adjuster includes: a communicating conduit including: a first end communicating to an intake air passage to an engine, and a second end communicating to an external air; an elastic body configured to block the communicating conduit; and a flow channel area changer configured to change a flow channel area of the communicating conduit based on a change of an intake air negative pressure caused in the intake air passage.

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 sound increase apparatus includes a partition wall adapted to divide an engine room for defining a first engine room space that is located on a side of a dash panel and a second engine room space in which an engine is installed, and a first pressure fluctuation amplification unit inter-communicating an engine inlet pipe arranged in the second engine room space and the first engine room space. The first pressure fluctuation amplification unit amplifies a pressure fluctuation of a first frequency selected from a plurality of frequencies when pressure of air residing inside the engine inlet pipe fluctuates at the plurality of frequencies.

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: An intake air noise adjuster includes: a communicating conduit including: a first end communicating to an intake air passage to an engine, and a second end communicating to an external air; an elastic body configured to block the communicating conduit; and a flow channel area changer configured to change a flow channel area of the communicating conduit based on a change of an intake air negative pressure caused in the intake air passage.

Abstract: A resonator 13 is provided including a resonating body 13 which is vibrated by intake air pulsation in an intake system 5, a volume chamber 14 connected through the resonating body 13 to the intake system 5, and a neck section 16 through which an interior space 15 of the volume chamber 14 is communicated with outside. The interior space 15 of the volume chamber 14 and interior of the intake system 5 are partitioned by the resonating body 13. The resonator is so set that a sound pressure in a certain frequency range is released from the neck section 16 to the outside under vibration of the resonating body 13. With this, the sound pressure characteristics of air intake sound can follow a rise in engine speed.

Abstract: An intake apparatus for an internal combustion engine, includes a passage section defining an intake passage; and a throttle valve located in the intake passage, the throttle valve including a rotation shaft, and a plate-shaped valve element arranged to rotate about the rotation shaft, and having a first end and a second end, the throttle valve being opened so that the first end is moved in a downstream direction of the intake passage, and that the second end is moved in an upstream direction of the intake passage. The passage section includes a circumferential wall formed with an expansion chamber recessed radially outwards, the expansion chamber extending partially circumferentially, and being located at a longitudinal position that is downstream of the throttle valve, and that intake air flows passing through the first and second ends of the valve element flow into each other.

Abstract: An intake apparatus for an internal combustion engine, includes a passage section defining an intake passage; and a throttle valve located in the intake passage, the throttle valve including a rotation shaft, and a plate-shaped valve element arranged to rotate about the rotation shaft, and having a first end and a second end, the throttle valve being opened so that the first end is moved in a downstream direction of the intake passage, and that the second end is moved in an upstream direction of the intake passage. The passage section includes a circumferential wall formed with an expansion chamber recessed radially outwards, the expansion chamber extending partially circumferentially, and being located at a longitudinal position that is downstream of the throttle valve, and that intake air flows passing through the first and second ends of the valve element flow into each other.

Abstract: A resonator 13 is provided including a resonating body 13 which is vibrated by intake air pulsation in an intake system 5, a volume chamber 14 connected through the resonating body 13 to the intake system 5, and a neck section 16 through which an interior space 15 of the volume chamber 14 is communicated with outside. The interior space 15 of the volume chamber 14 and interior of the intake system 5 are partitioned by the resonating body 13. The resonator is so set that a sound pressure in a certain frequency range is released from the neck section 16 to the outside under vibration of the resonating body 13. With this, the sound pressure characteristics of air intake sound can follow a rise in engine speed.

Abstract: A sound increase apparatus includes a partition wall adapted to divide an engine room for defining a first engine room space that is located on a side of a dash panel and a second engine room space in which an engine is installed, and a first pressure fluctuation amplification unit inter-communicating an engine inlet pipe arranged in the second engine room space and the first engine room space. The first pressure fluctuation amplification unit amplifies a pressure fluctuation of a first frequency selected from a plurality of frequencies when pressure of air residing inside the engine inlet pipe fluctuates at the plurality of frequencies.