Fuel delivery measurement system with automatic pump matching

A fuel delivery measurement apparatus for a fuel injection system having a first fuel pump drawing fuel from a storage tank for pressurized discharge to a fuel rail supplying fuel to at least one fuel injector of an internal combustion engine and an excess fuel return system having a first fuel return conduit with a first pressure regulating relief valve disposed between said pressurized discharge of said first fuel pump and said storage tank comprising:

• a second fuel pump connectible between said first fuel pump and said fuel rail, said second fuel pump having a suction inlet and a discharge outlet for discharging pressurized fuel to said fuel rail;
• first means for measuring fuel flow connectible between said first fuel pump and said fuel rail, wherein said first measuring means includes at least one flow measuring meter selectively connectible in first, second and third positions, such that when in said first position, said meter is in fluid communication between said pressurized discharge of said first pump and said fuel rail of said engine for measuring fuel flow from said first fuel pump during a learn-mode of operation, when in said second position, said meter is in fluid communication between said pressurized discharge of said second pump and said fuel rail of said engine for measuring fuel flow from said second fuel pump during a teach-mode of operation, and when in said third position, said meter is in fluid communication between said pressurized discharge of said first pump and said suction inlet of said second fuel pump for measuring fuel consumption of the engine during a test-run mode of operation;
• and
• means for matching discharge pressure of said first and second fuel pumps.

A system for deriving a value for the consumption of fuel by an internal combustion engine operated with fuel from a tank contained source thereof, said engine having a fuel introduction system with a first fuel pump having a suction input and a discharge output, said discharge output being coupled in fuel supply relationship with said engine for carrying out fuel combustion and recirculation functions, said fuel introduction system including a first return conduit carrying return fuel for said recirculation function, said first return conduit having a first pressure regulating relief valve disposed therein, comprising:

• a second fuel pump connectible between said first fuel pump and said engine, said second fuel pump having a suction inlet and a pressurized outlet;
• a second return conduit connectible between said first and second fuel pumps for carrying return fuel for said recirculating function from said discharge output of said first fuel pump to said tank;
• a pilot-operated, second pressure regulating relief valve positionable in said second return conduit;
• a pilot conduit connectible to place said pressurized outlet of said second fuel pump in fluid communication with said pilot-operated, second pressure regulating relief valve;
• a diverting conduit connectible with said first fuel return conduit between said pressure regulating relief valve and said tank for diverting all return fuel flow from said first pressure regulating relief valve to said suction inlet of said second fuel pump;
• and
• control means for driving said second fuel pump at a fuel flow rate substantially equal to a fuel flow rate of said first fuel pump.

A method of measuring fuel flow delivered to an internal combustion engine having a first fuel pump with a first motive power source, a suction input in fluid communication with a fuel storage tank and a pressurized discharge output in fluid communication with a fuel rail supplying fuel to at least one fuel injector of said internal combustion engine, and an excess fuel return conduit in fluid communication with said pressurized discharge output and said fuel storage tank, said return conduit having a pressure regulating relief valve disposed therein, said method comprising the steps of:

• connecting a second fuel pump between said first fuel pump and said fuel rail, said second fuel pump having a second motive power source separate and independent of said first motive power source, a suction inlet and a discharge outlet for discharging pressurized fuel to said fuel rail;
• measuring fuel flow between said first fuel pump and said fuel rail;
• and
• matching discharge pressure of said first and second fuel pumps.

A method of measuring fuel flow delivered to an internal combustion engine having a first fuel pump with a suction input in fluid communication with a fuel storage tank and a pressurized discharge output in fluid communication with a fuel rail supplying fuel to at least one fuel injector of said internal combustion engine, and an excess fuel return conduit in fluid communication with said pressurized discharge output and said fuel storage tank, said return conduit having a pressure regulating relief valve disposed therein, said method comprising the steps of:

• connecting a second fuel pump between said first fuel pump and said fuel rail, said second fuel pump having a suction inlet and a discharge outlet for discharging pressurized fuel to said fuel rail;
• measuring fuel flow between said first fuel pump and said fuel rail, wherein said measuring step further includes the step of selectively connecting at least one flow measuring meter in first, second and third positions, such that when in said first position, said meter is in fluid communication between said pressurized discharge of said first pump and said fuel rail of said engine for measuring fuel flow from said first fuel pump during a learn-mode of operation, when in said second position, said meter is in fluid communication between said pressurized discharge of said second pump and said fuel rail of said engine for measuring fuel flow from said second fuel pump during a teach-mode of operation, and when in said third position, said meter is in fluid communication between said pressurized discharge of said first pump and said suction inlet of said second fuel pump for measuring fuel consumption of the engine during a test-run mode of operation;
• and
• matching discharge pressure of said first and second fuel pumps.

A method for deriving a value for the consumption of fuel by an internal combustion engine operated with fuel from a tank contained source thereof, said engine having a fuel introduction system with a first fuel pump having a suction input and a discharge output, said discharge output being coupled in fuel supply relationship with said engine for carrying out fuel combustion and recirculation functions, said fuel introduction system including a first return conduit carrying return fuel for said recirculation function, said first return conduit having a first pressure regulating relief valve disposed therein, comprising the steps of:

• connecting a second fuel pump between said first fuel pump and said engine, said second fuel pump having a suction inlet and a pressurized outlet;
• connecting a second return conduit between said first and second fuel pumps for carrying return fuel for said recirculating function from said discharge output of said first fuel pump to said tank;
• regulating a second pressure with a pilot-operated, relief valve positionable in said second return conduit;
• connecting a pilot conduit in fluid communication with said pressurized outlet of said second fuel pump and said pilot-operated, relief valve;
• connecting a diverting conduit in fluid communication with said first return conduit between said pressure regulating valve and said tank for diverting all return fuel flow from said first pressure regulating relief valve to said suction inlet of said second fuel pump;
• and
• driving said second fuel pump at a fuel flow rate substantially equal to a fuel flow rate of said first fuel pump.