# US 5,708,201 A · Fuel delivery measurement system with automatic pump matching > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,201 A - Document ID: US5708201A - Status: Granted - Kind: A - Application number: 08/653,345 - Filed: 1996-05-24 - Granted: 1998-01-13 - Earliest claimed: 1996-05-24 - Assignees: Pierburg Instruments, Inc. - Inventors: Peter Kaub - Web page: https://patentgrep.com/patent/US5708201A ## CPC - F02D 33/003: {Controlling the feeding of liquid fuel from storage containers to carburettors or fuel-injection apparatus (control of electrical fuel pumps F02D41/3082, controlling fuel flow to a common rail F02D41/3845); Failure or leakage prevention; Diagnosis or detection of failure; Arrangement of sensors in the fuel system; Electric wiring; Electrostatic discharge} - F02M 37/0052: {Details on the fuel return circuit; Arrangement of pressure regulators} - G01F 9/001: {with electric, electro-mechanic or electronic means (G01F9/008 and G01F9/02 take precedence)} - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract A vehicular fuel flow measuring system derives a value for the consumption of fuel by an internal combustion engine operated with fuel from a tank containing a source thereof. The engine has a fuel introduction system with a first fuel pump having a suction input and a discharge output. The discharge output is coupled in fuel supply relationship with the engine for carrying out fuel combustion and recirculation functions. The fuel introduction system includes a first return conduit carrying return fuel for the recirculation function. The first return conduit has a first pressure regulating relief valve disposed therein. A second fuel pump is connectible between the first fuel pump and the fuel rail of the engine. The second fuel pump has a suction inlet and a discharge outlet for discharging pressurized fuel to the fuel rail of the engine. At least one flow measuring meter is connectible between the first fuel pump and the fuel rail of the engine. A mechanism is provided for matching the discharge pressure of the first and second fuel pumps. A control mechanism is provided for driving the second fuel pump at a flow rate substantially equal to a fuel flow rate of the first fuel pump. ## Claims ### Claim 1 A fuel delivery measurement apparatus for a fuel injection system having a first fuel pump with a first motive power source, said 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 having a second motive power source separate and independent of said first motive power source, said 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; and means for matching discharge pressure of said first and second fuel pumps. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein said discharge pressure matching means further comprises: a second return conduit connectible in fluid communication between said pressurized discharge of said first fuel pump and said storage tank for returning excess fuel to said tank; a pilot-operated, second pressure regulating relief valve positionable in said second return conduit; and a pilot conduit connectible in fluid communication between said pressurized outlet of said second fuel pump and said pilot-operated, second pressure regulating relief valve. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein said first measuring means further comprises: a first flow measuring meter connectible between said pressurized discharge of said first pump and said fuel rail of said engine for measuring fuel flow from said first fuel pump. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein said first measuring means further comprises: a first flow measuring meter connectible between said pressurized discharge of said second pump and said fuel rail of said engine for measuring fuel flow from said second fuel pump. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein said first measuring means further comprises: a first flow measuring meter connectible 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 testing. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein said first measuring means further comprises: a first flow measuring meter 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; a second flow measuring meter 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; and a third meter 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. ### Claim 7 (depends on 1) The apparatus of claim 1 further comprising: 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. ### Claim 8 (depends on 1) The apparatus of claim 1 further comprising: a central processing unit for controlling said second fuel pump to provide a fuel flow rate substantially equal to said first fuel pump, said central processing unit connected to memory for storage of fuel pump flow rate values based on input criteria defining a vehicle to be tested in a look up table; and said first means for measuring flow generating a signal to said central processing unit corresponding to a measured fuel flow rate for identifying a vehicle to be tested. ### Claim 9 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. ### Claim 10 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. ### Claim 11 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. ### Claim 12 (depends on 11) The method of claim 11 wherein said discharge pressure matching step further comprises the steps of: returning excess fuel to said tank through a second return conduit connectible in fluid communication between said pressurized discharge of said first fuel pump and said storage tank; regulating a second pressure with a pilot-operated relief valve positionable in said second return conduit; and connecting a pilot conduit in fluid communication between said pressurized outlet of said second fuel pump and said pilot-operated, relief valve. ### Claim 13 (depends on 11) The method of claim 11 wherein said measuring step further comprises the step of: measuring fuel flow from said first fuel pump with a first flow measuring meter connectible between said pressurized discharge of said first pump and said fuel rail of said engine. ### Claim 14 (depends on 11) The method of claim 11 wherein said measuring step further comprises the step of: measuring fuel flow from said second fuel pump with a first flow measuring meter connectible between said pressurized discharge of said second pump and said fuel rail of said engine. ### Claim 15 (depends on 11) The method of claim 11 wherein said measuring step further comprises the step of: measuring fuel consumption of the engine during testing with a first flow measuring meter connectible between said pressurized discharge of said first pump and said suction inlet of said second fuel pump. ### Claim 16 (depends on 11) The method of claim 11 wherein said measuring step further comprises the steps of: measuring fuel flow from said first fuel pump with a first flow measuring meter in fluid communication between said pressurized discharge of said first pump and said fuel rail of said engine; measuring fuel flow from said second fuel pump with a second flow measuring meter in fluid communication between said pressurized discharge of said second pump and said fuel rail of said engine; and measuring fuel consumption of the engine with a third meter in fluid communication between said pressurized discharge of said first pump and said suction inlet of said second fuel pump. ### Claim 17 (depends on 11) The method of claim 11 further comprising the step of: controllably driving said second fuel pump at a fuel flow rate substantially equal to a fuel flow rate of said first fuel pump. ### Claim 18 (depends on 11) The method of claim 11 further comprising the step of: controlling said second fuel pump with a central processing unit to provide a fuel flow rate substantially equal to said first fuel pump, said central processing unit connected to memory for storage of fuel pump flow rate values based on input criteria defining a vehicle to be tested in a look up table; and generating a signal to said central processing unit during said measuring step corresponding to a measured fuel flow rate for identifying a vehicle to be tested. ### Claim 19 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. ### Claim 20 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.