Pressure control for the fuel system of an internal combustion engine

An apparatus for maintaining the fuel pressure in an internal combustion engine fuel system within a predetermined pressure range, comprising:

• an electric fuel pump for pumping fuel through the fuel system at a pressure proportional to the electric power applied to said electric fuel pump;
• conversion means for converting said fuel pressure to a corresponding voltage signal;
• comparison means for comparing said voltage signal to a low voltage reference and to a high voltage reference defining a predetermined voltage range corresponding to the predetermined fuel pressure range;
• and
• control means responsive to said comparison means for increasing the electric power supplied to said electric fuel pump when the magnitude of said voltage signal is less than said predetermined voltage range and for decreasing the electric power supplied to said electric fuel pump when the magnitude of said voltage signal is more than said predetermined voltage range and for maintaining the electric power supplied to said electric fuel pump substantially constant when the magnitude of said voltage signal is within said predetermined voltage range.

An apparatus for maintaining the fuel pressure in an internal combustion engine fuel system within a predetermined pressure range, comprising:

• an electric fuel pump for pumping fuel through the fuel system at a pressure proportional to the electric power applied to said electric fuel pump;
• conversion means coupled to the fuel system for converting said fuel pressure into a corresponding voltage signal;
• comparison means coupled to said voltage signal for comparing said voltage signal to a low voltage reference and to a high voltage reference defining a predetermined voltage range corresponding to the predetermined fuel pressure range;
• and
• supply means responsive to said comparison means for supplying electric power to said electric fuel pump, said supply means supplying substantially constant electric power when said voltage signal is within said predetermined voltage range, said supply means supplying increased electric power when said voltage signal is below said predetermined voltage range, and said supply means supplying decreased electric power when said voltage signal is above said predetermined voltage range.

An apparatus for maintaining the fuel pressure in the fuel system of an internal combustion engine within a predetermined range, comprising:

• a carburetor having a fuel inlet;
• an electric fuel pump for pumping fuel into said carburetor inlet at a pressure proportional to the electric power supplied to said electric fuel pump;
• a pressure transducer coupled to said carburetor inlet for converting actual fuel pressure into a corresponding voltage signal;
• reference means for providing a low voltage reference corresonding to the minimum pressure desired in the fuel system and for providing a high voltage reference corresponding to the maximum pressure desired in the fuel system, the difference between said low voltage reference and said high voltage reference defining a predetermined voltage range corresponding to said predetermined pressure range;
• comparison means coupled to both said voltage signal and said reference means for comparing said voltage signal to said predetermined voltage range;
• and
• supply means responsive to said comparison means for supplying electric power to said electric fuel pump, said supply means supplying substantially constant electric power when said voltage signal is within said predetermined voltage range, said supply means gradually increasing the electric power when said voltage signal is below said predetermined voltage range, and said supply means gradually decreasing the electric power when said voltage signal is above said predetermined voltage range.