초록 ▼

The device has an entrance and an exit with two low-restriction venturi sections placed in parallel between the entrance and exit. The entering gas flow is separated into two parts, one to pass through one venturi section and the other to pass through the other venturi section. The two parts reunite

The device has an entrance and an exit with two low-restriction venturi sections placed in parallel between the entrance and exit. The entering gas flow is separated into two parts, one to pass through one venturi section and the other to pass through the other venturi section. The two parts reunite as they leave the exit. The venturi sections are substantially identical and each contains at least one venturi. The two sections are axially offset from each other by a distance that is equal to one-quarter of the wavelength of the frequency of a principal noise component so that that particular noise frequency is phase shifted 180 degrees by one venturi section relative to the other with resulting cancellation and significant noise attenuation. Usage in an air induction system of an internal combustion engine for attenuating noise from the engine is illustrated. The device is capable of functioning irrespective of the direction of noise in relation to the direction of gas flow.

대표청구항 ▼

An in-line noise attenuation device for insertion into a gas-carrying conduit to significantly attenuate noise propagating through the conduit without imposing significant restriction on the gas flow, said device comprising inlet and outlet ends via which gas respectively enters and exits the device

An in-line noise attenuation device for insertion into a gas-carrying conduit to significantly attenuate noise propagating through the conduit without imposing significant restriction on the gas flow, said device comprising inlet and outlet ends via which gas respectively enters and exits the device, noise entering one of said ends and exiting the other of said ends, said device further comprising two venturi sections arranged as parallel flow paths between said inlet and outlet ends, the noise passing through said two venturi sections between said one end and said other end, each of said venturi sections comprising at least one venturi, and wherein one venturi section is offset from the other in the direction of noise propagation to create at said other end a relative phase shift between the noise that has passed through one venturi section and the noise that has passed through the other venturi section such that at least some of the noise that has passed through said one venturi section cancels at least some of the noise that has passed through said other venturi section whereby the noise that exits said other end of the device is significantly attenuated from that which would otherwise exist in the absence of the device.