Method and apparatus for fuel metering in internal combustion engines

A method for controlling the fuel supply to an internal combustion engine equipped with an accelerator pedal, comprising the steps of:

• providing a first stored characteristic data field which relates nominal fuel quantity to accelerator pedal position;
• monitoring the position of the accelerator pedal, generating a signal indicative thereof and deriving from the generated accelerator pedal position signal and the first stored characteristic data field a nominal fuel quantity signal;
• providing a second stored characteristic data field which relates nominal fuel quantity to nominal air quantity;
• generating a nominal air quantity signal from the second stored characteristic data field and the nominal fuel quantity signal;
• providing a third stored characteristic data field which relates maximum permissible fuel quantity to actual air flow rate;
• measuring the air flow rate to the engine, generating a signal indicative thereof and deriving from the generated air flow rate signal and the third stored characteristic data field a maximum permissible fuel quantity signal;
• and
• comparing the nominal fuel quantity signal with the maximum permissible fuel quantity signal and selecting the lower of the signals compared.

An apparatus for controlling the fuel supply to an internal combustion engine equipped with an accelerator pedal, comprising:

• a position transducer for generating an accelerator signal related to the position of the accelerator pedal;
• a first stored characteristic data field generator connected to the position transducer, and including a stored characteristic data field which relates nominal fuel quantity to accelerator pedal position, said first stored characteristic data field generator providing a nominal fuel quantity signal from the first stored characteristic data field and the accelerator signal;
• an air flow rate meter for generating a signal indicative of the actual air flow rate to the engine;
• a second stored characteristic data field generator connected to the air flow rate meter, and including a stored characteristic data field which relates maximum permissible fuel quantity to actual air flow rate, said second stored characteristic data field generator providing a maximum permissible fuel quantity signal from the second stored characteristic data field and the actual air flow rate signal;
• a fuel flow control device;
• and
• a fuel controller, connected to both stored characteristic data field generators and to the fuel flow control device for generating a final fuel quantity control signal from the nominal fuel quantity signal and the maximum permissible fuel quantity signal for regulating the fuel flow control device.

An apparatus for controlling the fuel supply to an internal combustion engine equipped with an accelerator pedal, comprising:

• a position transducer for generating an accelerator signal related to the position of the accelerator pedal;
• a first stored characteristic data field generator connected to the position transducer, and including a stored characteristic data field which relates nominal fuel quantity to accelerator pedal position, said first stored characteristic data field generator providing a nominal fuel quantity signal from the first stored characteristic data field and the accelerator signal;
• a second stored characteristic data field generator connected to the first stored characteristic data field generator, and including a stored characteristic data field which relates nominal fuel quantity to nominal air quantity, said second stored characteristic data field generator providing a nominal air quantity signal from the second stored characteristic data field and the nominal fuel quantity signal;
• an air flow rate meter for generating a signal indicative of the actual air flow rate to the engine;
• a third stored characteristic data field generator connected to the air flow rate meter, and including a stored characteristic data field which relates maximum permissible fuel quantity to actual air flow rate, said third stored characteristic data field generator providing a maximum permissible fuel quantity signal from the third stored characteristic data field and the actual air flow rate;
• and
• comparator means connected to the first and third stored characteristics data field generator for comparing the nominal fuel quantity signal with the maximum permissible fuel quantity signal and selecting the lower of the signals compared.