Air/fuel ratio controller
AssigneeFord Motor Company
InventorsAladar O. Simko, Michale M. Schechter
Life of this patent
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Abstract
An internal combustion engine has a fuel injection pump and an air/fuel ratio controller. The controller has a lever that is connected to the pump lever. An aneroid moves the controller lever as a function of changes in intake manifold vacuum to maintain a constant air/fuel ratio to the mixture charge. A fuel enrichment linkage is provided that modifies the movement of the fuel flow control lever by the aneroid in response to changes in manifold gas temperature levels and exhaust gas recirculation to maintain the constant air/fuel ratio. A manual override is provided to obtain a richer air/fuel ratio for maximum acceleration.
Claims23
An air/fuel ratio controller for use with the fuel injection system of an internal combustion engine of the spark ignition type having an air-gas induction passage open at one end to air at ambient pressure level and connected at its other end to the engine intake manifold to be subject to manifold vacuum changes therein, a throttle valve rotatably mounted for movement across the passage to control the air-gas flow therethrough, an exhaust gas recirculation (EGR) passage means connecting engine exhaust gases to the induction passage above the closed position of the throttle valve, an EGR flow control valve mounted in the EGR passage means for movement between open and closed positions to control the volume of EGR gas flow, and an engine speed responsive positive displacement type fuel injection pump having a fuel flow output to the engine that varies in direct proportion to changes in engine speed to match fuel flow and mass air flow through the induction system of the engine over the entire speed and load range of the engine to maintain the ratio of air to fuel constant, the fuel pump having a fuel flow control lever selectively movable in opposite directions to vary the fuel flow output per cycle, the controller characterized by,
- a mechanical linkage mechanism including a primary lever fixed to the pump lever for concurrent movement, an engine manifold vacuum responsive servo means, a link connecting the servo means to the primary lever for moving the primary lever and fuel lever to vary the fuel flow output as a function of changes in intake manifold vacuum indicative of changes in air flow through the induction passage to maintain the ratio of air to fuel constant, and a fuel enrichment control lever operably interconnected to the EGR valve and primary lever for modifying the movement of the primary and fuel flow levers to vary fuel flow as a function of the addition or deletion of EGR gases to the induction passage to compensate for the resulting change in percentage of air flow with respect to the total gas flow inducted to maintain a constant air/fuel ratio.
An air/fuel ratio controller for use with the fuel injection control system of an internal combustion engine of the spark ignition type having a gas induction passage open at one end to air at ambient pressure level and connected at its other end to the engine combustion chamber to be subject to manifold vacuum changes therein, a throttle valve rotatably mounted for movement across the passage to control the gas flow therethrough, exhaust gas recirculation (EGR) passage means connecting the engine exhaust gases to the induction passage above the closed position of the throttle valve, and EGR flow control valve mounted in the EGR passage means for movement between open and closed positions to control the volume of EGR gas flow, an engine speed responsive positive displacement type fuel injection pump having a fuel flow output to the engine that varies in direct proportion to changes in engine speed to match fuel flow and mass air flow through the induction system of the engine over the entire speed and load range of the engine to maintain the intake mixture ratio of air to fuel constant, the controller being characterized by regulator means including servo operated means responsive to changes in manifold vacuum for changing the pump output fuel flow, the regulator means also being independently responsive both to changes in density of the intake gas and to the flow level of EGR gases to modify the manifold vacuum force acting to adjust the fuel pump output to compensate for the resultant change in the percentage of air flow with respect to the total gas flow through the induction passages per cycle to maintain the ratio of air to fuel constant.
Dependencies are inferred from the claim text.