Air induction apparatus for use with karman vortex shedding flow meter
AssigneeNissan Motor Co., Ltd.
InventorToru Kita
Life of this patent
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Abstract
A cylindrical vortex generator of a Karman shedding flow meter is set in an inlet tube of an air cleaner of a combustion engine. An air flow uniforming device such as a wire netting is disposed in the inlet tube at a position upstream of the vortex generator for producing in the inlet tube a turbulent but considerably uniformed air flow directed toward the vortex generator. A bypass means is arranged in the inlet tube to make a bypass flow of air directed toward the vortex generator when the combustion engine is under high speed operation.
Claims12
An air induction apparatus for feeding a combustion engine with air which is metered by using a Karman vortex shedding flow meter to control as a result of this meterage the amount of fuel fed to the engine, comprising:
- an inlet tube of an air cleaner which is arranged upstream of the engine proper;
- a cylindrical vortex generator of said flow meter, said generator being disposed in said inlet tube in a manner to be perpendicular to the longitudinal axis of said inlet tube;
- a first wire netting disposed in said inlet tube at a position upstream of said vortex generator in a manner to be perpendicular to the longitudinal axis of said inlet tube;
- a second wire netting disposed in said inlet tube at a position upstream of said first wire netting in a manner to be perpendicular to the longitudinal axis of said inlet tube, said second wire netting producing a turbulent but uniformed air flow directed toward said vortex generator upon flowing of the air in said inlet tube;
- means for defining an opening in said inlet tube at a position upstream of said first wire netting;
- a damper door swingably connected to said inlet tube to selectively open and close said opening;
- and
- damper door operator for operating said damper door in such a manner that under low speed operation of the engine, the damper door closes said opening, and under high speed operation of the engine, the damper door opens said opening.
An air induction apparatus having a tube through which air to be metered by a Karman vortex shedding flow meter passes, said air induction apparatus comprising:
- a vortex generator of said flowmeter, said generator being disposed in said tube for generating vortexes in the air flow;
- an air flow uniforming device disposed in said tube upstream of said vortex generator for producing in the tube a turbulent but uniformed flow of air directed toward said vortex generator;
- and
- bypass means for making a bypass flow of air directed toward said vortex generator when increase in air flow rate in the tube is required, said bypass means comprising means defining an opening in said tube at a position upstream of said vortex generator, a damper door hingedly mounted to said tube so as to selectively open and close said opening, and damper door operator for operating said damper door in a manner that when an increased flow rate of air in the tube is required, said damper door opens, and when a decreased flow rate of air in tube is required, said damper door closes, said opening being located just below said air flow uniforming device leaving an enlarged section of said tube at a position upstream of said vortex generator.
Dependencies are inferred from the claim text.