Active air control

Abstract

An air-balanced engine assembly is configured to operate efficiently while producing a reduced level of harmful emissions. The engine assembly includes a two-stroke internal combustion engine with multiple power cylinders and intake and exhaust manifolds that fluidly communicate with the cylinders. The engine assembly also includes an air balancing assembly with valves that control intake air flow from the intake manifold to the cylinders. The valves cooperate to balance intake air flow among the cylinders and are configured to substantially equalize trapped equivalence ratios among the cylinders.

What is claimed is: 
     
         1 . A reciprocating internal combustion engine comprising:
 a plurality of combustion cylinders spaced along an engine axis, with each of the combustion cylinders having a combustion chamber and an intake port that fluidly communicates with the combustion chamber to permit a flow of intake air into the combustion chamber;   an intake manifold in fluid communication with the intake ports and configured to supply intake air for the intake ports; and   a plurality of independently variable air balancing valves each in fluid communication with the intake manifold and configured to control the flow of intake air from the intake manifold through a respective intake port,   each air balancing valve being configured to divert intake air not passing into the respective intake port to another intake port via the intake manifold.   
     
     
         2 . The reciprocating internal combustion engine as claimed in  claim 1 ; and
 a plurality of intake runners that each fluidly interconnect the intake manifold and a corresponding intake port,   said intake ports each fluidly communicating with a corresponding air balancing valve,   said air balancing valves configured to cooperatively adjust trapped equivalence ratios of the combustion cylinders.   
     
     
         3 . The reciprocating internal combustion engine as claimed in  claim 2 ,
 said intake runners each extending from the respective intake port to the intake manifold,   said intake manifold and each intake runner cooperatively providing an air flow restriction from the inlet end to the intake port, with the air flow restrictions being different from each other.   
     
     
         4 . The reciprocating internal combustion engine as claimed in  claim 3 ,
 said intake manifold extending from an inlet end along the combustion cylinders and substantially parallel to the engine axis,   said intake runners each extending transversely to the engine axis to extend from the respective intake port to the intake manifold,   said intake runners presenting substantially similar runner lengths.   
     
     
         5 . The reciprocating internal combustion engine as claimed in  claim 3 ,
 each of the air balancing valves being operably mounted within a corresponding intake runner and configured to throttle the flow of intake air,   said air balancing valves, intake manifold, and each intake runner cooperatively providing a combined air flow restriction, with the combined air flow restrictions being substantially the same.   
     
     
         6 . The reciprocating internal combustion engine as claimed in  claim 2 ,
 said air balancing valves each comprising a throttle plate pivotally mounted within the corresponding intake runner and pivotal between open and closed positions.   
     
     
         7 . The reciprocating internal combustion engine as claimed in  claim 6 ,
 said intake runner including a wall that surrounds the throttle plate, with the throttle plate being spaced apart from the wall to present an annular gap.   
     
     
         8 . The reciprocating internal combustion engine as claimed in  claim 6 ; and
 a mass flow sensor installed in a corresponding intake runner, said mass flow sensor comprising a hot wire anemometer.   
     
     
         9 . The reciprocating internal combustion engine as claimed in  claim 6 ; and
 a motor attached to a respective throttle plate and operable to shift the throttle plate between open and closed positions.   
     
     
         10 . The reciprocating internal combustion engine as claimed in  claim 1 ; and
 a turbocharger in fluid communication with the intake manifold and configured to provide intake air to the intake manifold.   
     
     
         11 . The reciprocating internal combustion engine as claimed in  claim 1 ,
 said engine comprising a two-stroke engine.