Patent ID: 6135079
Filing Date: 2000-10-24
Classification: F02M

Abstract:
An air intake system for an internal combustion engine, comprising an air filter, an air intake tube leading from said air filter to a throttle valve which in turn communicates with an intake manifold of the engine, and a noise damping chamber through which said air intake tube extends, said noise damping chamber having a volume sized to act as a Helmholtz resonator and attenuate undesired sound frequencies, wherein the air intake tube passes through the noise damping chamber and said noise damping chamber is in communication with said air intake tube such that the air drawn in through the air intake tube passes through at least part of the noise damping chamber volume, said system further comprising means for varying the volume of the sound damping chamber through which the air drawn in through the intake tube passes comprising an openable and reclosable tubular switch which communicates the air intake tube with the noise damping chamber, and an open branching tube of a given length arranged inside the damping chamber extending parallel to the intake tube in a direction opposite the flow of air through the damping chamber and communicating with the intake tube.