ELECTRIC FUEL PUMP CONTROL CIRCUIT FOR INTERMITTENT INJECTION ELECTRONIC FUEL CONTROL SYSTEMS

• US 3,822,677 A
• Filed: 06/30/1971
• Issued: 07/09/1974
• Est. Priority Date: 06/30/1971
• Status: Expired due to Term

• Current Assignee: Siemens-Bendix Automotive Electronics LP
• Original Assignee: Junuthula N. Reddy
• Inventors: Reddy, Junuthula N.
• Primary Examiner(s): Goodridge, Laurence M.
• Assistant Examiner(s): Flint, Cort
• Application Number:
  US05/158,351
• Time in Patent Office: 1,105 Days
• Field of Search: 123/32AE,32EA,119,136,139E,139AW,14MP
• US Class Current: 123/497
• CPC Class Codes: F02D 41/32 of the low pressure type F02D41/3082 takes precedence
• CPC Class Codes: F02D 41/38 of the high pressure type

Abstract

A fuel pump control circuit is disclosed herein to provide optimum fuel delivery at constant operating pressure to the fuel injector valve means of an electronically controlled fuel supply system. By energizing the pump in response to the engine operating parameters which determine the engine fuel requirement, a minimum of fuel in excess of the fuel requirement is recirculated from the area of the engine back to the fuel reservoir. In order to suitably energize the fuel pump, the pump is provided with a maximum voltage during the time period of the injection pulse with the energizing voltage decreasing thereafter so that a minimum of fuel is circulated through the fuel supply system during the noninjection phase. This provides a variable level of average fuel pump energization.

Claims

1. A fuel pump control circuit for an internal combustion engine fuel control system having pulse generating means for producing pulses having durations indicative of the fuel requirement, injector valve means responsive to said pulses for supplying fuel to the engine, and energizable fuel pump means having an average flow capacity proportional to average energization, said fuel pump control circuit comprising:

output means for providing a variable level fuel pump energizing signal; and

control means responsive to the pulse generating means operative to energize the output means to a maximum value during receipt of a pulse and to gradually reduce the energization during the entire interval between successive pulses whereby the average energization is proportional to the output pulse duration and inversely proportional to the interval between successive output pulses.

2. A fuel pump control circuit for an internal combustion engine fuel control system having pulse generating means for producing pulses having durations indicative of the fuel requirement, injector valvE means responsive to said pulses for supplying fuel to the engine, and energizable fuel pump means having an average flow capacity proportional to average energization, said fuel pump control circuit comprising:

output means for providing a variable level fuel pump energizing signal; and

control means responsive to the pulse generating means operative to energize the output means to a maximum value during receipt of a pulse and to gradually reduce the energization during the interval between successive pulses whereby the average energization is proportional to the output pulse duration and inversely proportional to the interval between successive output pulses, wherein said control means comprise;

pulse receiving input means;

first switching control means for providing a maximum energizing signal to said output means during receipt of a pulse;

electrical energy storage means for accumulating energy during receipt of a pulse;

means electrically connecting said storage means to energize said output means; and

energy draining means connected to said energy storage means operative to dissipate the energy stored therein and thereby gradually reduce energization of said output means during intervals between successive pulses.

3. The system as claimed in claim 2 wherein said storage means comprise a capacitor and said draining means comprise a current sink.

4. A fuel supply system for internal combustion engines comprising:

a fuel supply means;

computing means operative to generate an output pulse signal having a duration representative of the engine fuel requirement;

injector valve means responsive to said computing means signal to be actuated for a period of time determined by said signal pulse duration;

energizable fuel pumping means associated with said fuel supply means operative to provide fuel under pressure to said injector valve means whereby said pressurized fuel will be provided to the engine during the period of actuation of said injector valve means;

said fuel pumping means having a flow capacity substantially proportional to the energization thereof; and

fuel pump control means responsive to the computing means output signal duration and further responsive to the interval between successive output pulses operative to energize said fuel pump to a maximum value during a pulse and to gradually reduce fuel pump energization during the entire interval between successive pulses.

5. A fuel supply system for internal combustion engines comprising:

a fuel supply means;

computing means operative to generate an output pulse signal having a duration representative of the engine fuel requirements;

injector valve means responsive to said computing means signal to be actuated for a period of time determined by said signal pulse duration;

energizable fuel pumping means associated with said fuel supply means operative to provide fuel under pressure to said injector valve means whereby said pressurized fuel will be provided to the engine during the period of actuation of said injector valve means;

said fuel pumping means having a flow capacity substantially proportional to the energization thereof; and

fuel pump control means responsive to the computing means output signal duration and further responsive to the interval between successive output pulses operative to energize said fuel pump to a maximum value during a pulse and to gradually reduce fuel pump energization during an interval between succesisve pulses, wherein said fuel pump control means comprises;

input means;

electrical energy storage means responsive to said input means to store electrical energy;

said input means adapted to receive the computing means output pulses and operative to cause said storage means to accumulate a maximum stored value during receipt of the computing means output pulses;

energy draining means connected to said energy storage means operative to dissipate the energy stored therein;

And pump output means connected to said energy storage means and said energy draining means operative to communicate the instantaneous energy level appearing at said storage means to the pump.

6. The fuel supply system as claimed in claim 5 wherein said storage means comprise a capacitor and said draining means comprise a current sink.

7. The fuel pump control circuit as claimed in claim 1 wherein said fuel pump control comprises:

input means;

electrical energy storage means responsive to said input means to store electrical energy;

said input means adapted to receive the computing means output pulses and operative to cause said storage means to accumulate a maximum stored value during the receipt of the computing means output pulses;

energy draining means connected to said energy storage means operative to dissipate the energy stored therein; and

pump output means connected to said energy storage means and said energy draining means operative to communicate the instantaneous energy level appearing at said storage means to the pump.

8. The fuel supply means as claimed in claim 4 wherein said fuel pump control means comprises:

electrical energy storage means responsive to said input means to store electrical energy;

said input means adapted to receive the computing means output pulses and operative to cause said storage means to accumulate a maximum stored value during receipt of the computing means output pulses;

energy draining means connected to said energy storage means operative to dissipate the energy stored therein; and

pump output means connected to said energy storage means and said energy draining means operative to communicate the instantaneous energy level appearing at said storage means to the pump.