Abstract: A chain-driven engine balancer has an elastomeric or compliant isolator ring in a balancer drive sprocket to decouple chain whine vibration from an associated balance shaft. The isolator substantially reduces the transmission of chain whine noise to the engine structure. A splined isolator ring is placed between internal and external splines formed on a toothed outer ring and hub respectively of the associated sprocket. The splines are configured to be in loose engagement so that, upon failure of the elastomeric isolator ring, direct engagement of the hub and ring splines with one another will maintain the timing of the balance shafts with respect to the engine crankshaft. In a specific embodiment, application of an isolator ring in only the most heavily loaded sprocket of dual balance shaft sprockets driven in series by the chain eliminates most of the vibration transmission. However, isolation of multiple chain sprockets could be desirable.

Abstract: Methods and apparatus are provided for controlling a shutdown of an internal combustion engine. The apparatus comprises an intake manifold configured to conduct an intake charge of air to an intake port of the internal combustion engine and a throttle configured to alter the intake charge of air to the intake port of the internal combustion engine. The apparatus further comprises a controller configured to control the throttle such that a substantial termination of the intake charge of air is provided during the shutdown of the internal combustion engine.

Abstract: A chain-driven engine balancer has an elastomeric or compliant isolator ring in a balancer drive sprocket to decouple chain whine vibration from an associated balance shaft. The isolator substantially reduces the transmission of chain whine noise to the engine structure. A splined isolator ring is placed between internal and external splines formed on a toothed outer ring and hub respectively of the associated sprocket. The splines are configured to be in loose engagement so that, upon failure of the elastomeric isolator ring, direct engagement of the hub and ring splines with one another will maintain the timing of the balance shafts with respect to the engine crankshaft. In a specific embodiment, application of an isolator ring in only the most heavily loaded sprocket of dual balance shaft sprockets driven in series by the chain eliminates most of the vibration transmission. However, isolation of multiple chain sprockets could be desirable.

Abstract: A side-branch resonator which has a resonator chamber connected to an air intake pipe with two necks. The necks extend into the resonator chamber and provide a conduit for sound to travel to and from the air intake pipe. The presence of two necks increases the magnitude of attenuation at the resonant frequency and the bandwidth of attenuation of other lower frequency engine noises. The two necks also effectively attenuate higher frequencies by utilizing standing waves found within the resonator chamber.

Abstract: Methods and apparatus are provided for controlling a shutdown of an internal combustion engine. The apparatus comprises an intake manifold configured to conduct an intake charge of air to an intake port of the internal combustion engine and a throttle configured to alter the intake charge of air to the intake port of the internal combustion engine. The apparatus further comprises a controller configured to control the throttle such that a substantial termination of the intake charge of air is provided during the shutdown of the internal combustion engine.

Abstract: An air induction system for an internal combustion engine is disclosed. The system includes a housing having a closed end, walls extending from the housing end, and an open end. The open end has a flanged perimeter with a hollow cross section in a portion thereof. The system also may include integral stiffening ribs extending along portions of the walls and the closed end. The stiffening ribs having hollow base portions which operate to minimize depressions caused by the ribs on the sides of the walls opposite the ribs. The hollow base portions allow an increase in rib height and, as such, rib stiffness over typical solid ribs. The hollow cross section perimeter and enlarged stiffener ribs operate to define the area moment of inertia of the housing member.