An intake system of an engine is provided, including a first passage provided to an engine bay, for leading fresh air to the engine, a second passage branched from a branching part at an intermediate location of the first passage, and extending toward a cabin, and an intake noise increasing device provided to the second passage, and configured to increase intake pressure in response to an intake air pressure wave. The intake noise increasing device has a cylindrical bellows part configured to expand and contract in a cylindrical axis direction, and a vibrating membrane formed integrally with the bellows part to close a first opening of the bellows part. The second passage has an introducing passage section connected to a second opening of the bellows part, and extending toward the branching part, and the introducing passage section is disposed so as to be lowered while separating from the bellows part.

An intake system of an engine is provided, which includes a first passage provided to an engine bay, for leading fresh air to the engine, a second passage branched from the first passage and extending toward a cabin, and an intake noise increasing device provided to the second passage. The intake noise increasing device has a cylindrical bellows part, a vibrating membrane formed integrally with the bellows part to close a first opening of the bellows part, and an outer circumferential case provided to cover an outer circumference of the bellows part and configured to allow the expansion and contraction of the bellows part therein. The second passage has a deriving passage section connected to a part of the outer circumferential case on a first opening side and extending toward the cabin. The deriving passage section is disposed to be lowered while separating from the intake noise increasing device.

An apparatus of amplifying sound waves may include a metamaterial structure having a metamaterial inside thereof, an inlet through which air flows into the metamaterial structure, and a penetration portion formed to penetrate a portion of one side of the metamaterial structure, a membrane member coupled to the penetration portion, and a resonance member surrounding the membrane member and coupled to the metamaterial structure and including a space inside thereof and a discharge port fluidically communicating with an outside thereof and the internal space.

An intake system of an engine is provided, including a first passage provided to an engine bay, for leading fresh air to the engine, a second passage branched from a branching part at an intermediate location of the first passage, and extending toward a cabin, and an intake noise increasing device provided to the second passage, and configured to increase intake pressure in response to an intake air pressure wave. The intake noise increasing device has a cylindrical bellows part configured to expand and contract in a cylindrical axis direction, and a vibrating membrane formed integrally with the bellows part to close a first opening of the bellows part. The second passage has an introducing passage section connected to a second opening of the bellows part, and extending toward the branching part, and the introducing passage section is disposed so as to be lowered while separating from the bellows part.

An intake sound amplifier amplifies intake sound that is transmitted from an engine mounted in an engine compartment of a vehicle to a cabin. The intake sound amplifier includes a first passage branched from an intake passage, through which intake air is introduced into an engine; a device body that includes a vibrating body vibrated by pulsation of the intake air and is connected to a downstream end of the first passage; and a second passage that is connected to a downstream end of the device body and extends to the cabin side. The device body is located outward in a vehicle width direction of a side frame that extends in a vehicle front-rear direction and separates inside of the engine compartment from outside in the vehicle width direction.

Suction muffler (1) for a hermetic refrigeration compressor (2), the suction muffler (1) comprising an inlet (3), so that refrigerant can flow into the suction muffler (1), and an outlet (4), so that refrigerant can flow out from the suction muffler (1), the suction muffler (1) further comprising two damping chambers (5, 6) for sound damping, where the two damping chambers (5, 6) each has a floor (8, 9) and where a wall element (11) is provided, in order to separate the two damping chambers (5, 6) from each other for the refrigerant in the region of their floors (8, 9). In order to guarantee that the damping chambers (5, 6) are overall as gas-tight and sound-tight as possible, it is provided according to the invention that in the region of the wall element (11) at least one siphon segment (16) that connects the two floors is disposed, in order to receive oil (14) in an operating position of the suction muffler (1), where the at least one siphon segment (16) connects the two damping chambers (5, 6) in siphon fashion to each other for the oil (14).

An intake sound introducing apparatus has, for example, a branch pipe, a sound creator, a communication pipe, and a resonator. The branch pipe branches from an intake pipe of the engine. The sound creator includes a vibrator that vibrates with the intake pulsation of the intake sound propagating within the branch pipe. The communication pipe provides communication between the inside of a casing of the sound creator and the inside of the cabin. The resonator is provided in the communication pipe.

A variable noise attenuation element is disclosed that comprises a tube, at least one valve seat, at least one valve body and a wire connected to the valve body. The tube has an overall length that defines a first effective length for noise attenuation. The valve seat is disposed in the tube. Retraction of the wire brings the valve body into engagement with the valve seat to selectively define a second effective length of the tube that is less than the overall length.

An apparatus of amplifying sound waves may include a metamaterial structure having a metamaterial inside thereof, an inlet through which air flows into the metamaterial structure, and a penetration portion formed to penetrate a portion of one side of the metamaterial structure, a membrane member coupled to the penetration portion, and a resonance member surrounding the membrane member and coupled to the metamaterial structure and including a space inside thereof and a discharge port fluidically communicating with an outside thereof and the internal space.

An intake system of an engine is provided, which includes a first passage provided to an engine bay, for leading fresh air to the engine, a second passage branched from the first passage and extending toward a cabin, and an intake noise increasing device provided to the second passage. The intake noise increasing device has a cylindrical bellows part, a vibrating membrane formed integrally with the bellows part to close a first opening of the bellows part, and an outer circumferential case provided to cover an outer circumference of the bellows part and configured to allow the expansion and contraction of the bellows part therein. The second passage has a deriving passage section connected to a part of the outer circumferential case on a first opening side and extending toward the cabin. The deriving passage section is disposed to be lowered while separating from the intake noise increasing device.