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US 4,903,649 AGranted
Fuel supply system with pneumatic amplifier
AssigneeBrunswick Corporation
InventorRichard E. Staerzl
Life of this patent
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AssigneeBrunswick Corporation
InventorRichard E. Staerzl
Estimating the term…
A fuel control system for an internal combustion engine includes means for pneumatically amplifying sensed air flow pressure differential through an air intake venturi between a first combustion air pressure sensor outside the venturi and a second combustion air pressure sensor in the venturi. Pressure at the inner end of the second pressure sensor is reduced by altering the air flow path to create a vacuum at the inner end of the second pressure sensor relative to the remaining air flow through the venturi. A throttle plate in the venturi has a by-pass hole therethrough directing air flow along a given direction past the inner end of the sensor and through the by-pass hole when the throttle plate is in the idle position. The given direction of air flow past the inner end of the sensor prevents air flow into the inner end of the sensor tube to prevent an increase of sensed pressure thereat, and instead creates a vacuum to pull air out of the inner end of the sensor tube, to reduce pressure thereat. The system maintains a sufficient sensed pressure differential between the sensed pressure outside of the venturi and the sensed pressure in the venturi, including at idle, and also amplifies sensed pressure differential to provide improved tracking of fuel flow requirements between prescribed lean limit and rich limit requirements, including at idle and low speed.
A fuel control system for an internal combustion engine having air intake means supplying combustion air to said engine, and fuel supply means supplying fuel to said engine, a venturi in said air intake means producing a pressure drop, a first pressure sensor sensing pressure outside of said venturi, a second pressure sensor sensing the reduced pressure in said venturi, and means pneumatically amplifying the sensed pressure differential.
A fuel control system for an internal combustion engine having air intake means supplying combustion air to said engine, fuel supply means supplying fuel to said engine, a venturi in said air intake means producing a pressure drop, a first pressure sensor sensing pressure outside of said venturi, a second pressure sensor sensing the reduced pressure in said venturi, a throttle plate in said venturi and pivotable between a high speed position permitting substantial air flow through said venturi, and a low speed idle position permitting minimal air flow through said venturi, wherein said second pressure sensor extends into said venturi and has an inner end spaced upstream of said throttle plate in said idle position, said throttle plate having a by-pass hole therethrough directing air flow along a given direction past said inner end of said second sensor and through said by-pass hole when said throttle plate is in said idle position, said given direction of air flow past said inner end of said second sensor preventing an increase of sensed pressure thereat, whereby to maintain a sufficient sensed pressure differential between the sensed pressure outside of said venturi and the sensed pressure in said venturi, including at idle.
A fuel control system for an internal combustion engine having air intake means supplying combustion air to said engine, fuel supply means supplying fuel to said engine, a venturi in said air intake means producing a pressure drop, a throttle plate in said venturi and pivotable between a high speed position permitting substantial air flow through said venturi, and a low speed idle position permitting minimal air flow through said venturi, a first pressure sensor sensing pressure outside of said venturi, a second pressure sensor sensing the reduced pressure in said venturi and spaced upstream of said throttle plate in said idle position by a distance less than the diameter of said venturi.
A fuel control system for an internal combustion engine having air intake means supplying combustion air to said engine, fuel supply means supplying fuel to said engine, air flow velocity sensing means comprising a venturi in said air intake means producing a pressure drop, a throttle plate in said venturi and pivotable between a high speed position permitting substantial air flow through said venturi, and a low speed idle position permitting minimal air flow through said venturi, means measuring the differential pressure P.sub.D between the absolute pressure outside of said venturi means and the reduced pressure in said venturi means comprising a first pressure sensor sensing pressure outside of said venturi and a second pressure sensor sensing the reduced pressure in said venturi, said second pressure sensor extending into said venturi and having an inner end spaced upstream of said throttle plate in said idle position, a by-pass hole in said throttle plate directing air flow along a given direction past said inner end of said second sensor and through said by-pass hole when said throttle plate is in said idle position, said given direction of air flow past said inner end of said second sensor preventing an increase of sensed pressure thereat, whereby to maintain a sufficient sensed pressure differential between the sensed pressure outside of said venturi and the sensed pressure in said venturi, including at idle, means calculating said air flow velocity as a function of P.sub.D, means sensing the mass of said combustion air comprising said first pressure sensor measuring the absolute air pressure P.sub.A outside of said venturi and temperature sensor means measuring air temperature T and calculating said air mass as a function of P.sub.A and T, means responsive to said air flow velocity sensor means and said air mass sensor means and controlling said fuel supply means, whereby to provide a mass flow fuel control system.
Dependencies are inferred from the claim text.