US5076239A — Fuel injection system

Claim 1

Independent Claim 163 words

A method of controlling the injection of fuel from a pressurized fuel supply via an injector valve of a fuel injector into a combustion chamber of an internal combustion engine, said method comprising: connecting a closed chamber via a permanently open flow restriction to the pressurized fuel supply, and selecting a volume of the closed chamber to be sufficiently large and a cross-sectional flow area of the restriction to be sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed, whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 2

Independent Claim 163 words

A method of controlling the injection of fuel from a pressurized fuel supply via an injector valve of a fuel injector into a combustion chamber of an internal combustion engine, said method comprising: connecting a closed chamber via a permanently open flow restriction to the pressurized fuel supply, and selecting a volume of the closed chamber to be sufficiently large and a cross-sectional flow area of the restriction to be sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed, whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 3

Dependent Claim 162 words

Fuel injection equipment for an internal combustion engine comprising: a fuel injector having an injector valve through which it delivers fuel from a pressurized fuel supply passage, and a closed chamber located on or in the injector and connected to the pressurized fuel supply passage via a permanently open flow restriction, a volume of the closed chamber being sufficiently large and a cross-sectional flow area of the restriction being sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed, whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 4

Dependent Claim 162 words

Fuel injection equipment for an internal combustion engine comprising: a fuel injector having an injector valve through which it delivers fuel from a pressurized fuel supply passage, and a closed chamber located on or in the injector and connected to the pressurized fuel supply passage via a permanently open flow restriction, a volume of the closed chamber being sufficiently large and a cross-sectional flow area of the restriction being sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed, whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 5

Dependent Claim 204 words

Fuel injection equipment for an internal combustion engine comprising: a fuel injection pump adapted to be driven by the engine and having a working chamber with an output to be connected via a fuel supply connection to a fuel injector so that pressure pulses produced periodically in the working chamber at a frequency related to engine speed cause a valve in the injector to open and produce a spray of fuel into a combustion chamber of the engine, and a closed chamber connected via a permanently open flow restriction to the working chamber, a volume of the closed chamber being sufficiently large and a cross-sectional flow area of the restriction being sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed, whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 6

Dependent Claim 204 words

Fuel injection equipment for an internal combustion engine comprising: a fuel injection pump adapted to be driven by the engine and having a working chamber with an output to be connected via a fuel supply connection to a fuel injector so that pressure pulses produced periodically in the working chamber at a frequency related to engine speed cause a valve in the injector to open and produce a spray of fuel into a combustion chamber of the engine, and a closed chamber connected via a permanently open flow restriction to the working chamber, a volume of the closed chamber being sufficiently large and a cross-sectional flow area of the restriction being sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed, whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 7

Dependent Claim 179 words

Fuel injection equipment for an internal combustion engine comprising: a high pressure fuel supply connection adapted to be connected between an output of a fuel injection pump and a fuel injector, said high pressure fuel supply connection having a passage for fluidwise communicating the injection pump and the fuel injector with each other, and a closed chamber connected directly via a permanently open flow restriction to said passage, a volume of the closed chamber being sufficiently large and a cross-sectional flow area of the restriction being sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 8

Dependent Claim 179 words

Fuel injection equipment for an internal combustion engine comprising: a high pressure fuel supply connection adapted to be connected between an output of a fuel injection pump and a fuel injector, said high pressure fuel supply connection having a passage for fluidwise communicating the injection pump and the fuel injector with each other, and a closed chamber connected directly via a permanently open flow restriction to said passage, a volume of the closed chamber being sufficiently large and a cross-sectional flow area of the restriction being sufficiently small that, for a given engine fuel delivery volume, a maximum pressure reached in the closed chamber during each engine cycle varies with engine speed whereby the ratio of fuel flowing into the closed chamber during an entire injection period compared to the total fuel volume delivered to the engine decreases as engine speed increases, thus substantially reducing the flow of fuel into the combustion chamber during an initial period of the injection period at low engine speeds compared to the flow of fuel during said initial period at high engine speeds.

Claim 9

Dependent Claim 47 words

A method as claimed in claim 1 in which the closed chamber is connected via the flow restriction (29) to a working chamber in a fuel injection pump driven by the engine and having a high pressure output connection from the working chamber to the fuel injector.

Claim 10

Dependent Claim 50 words

A method as claimed in claim 5 in which the fuel injection pump is a rotary type pump with a single working chamber with distribution means to connect said working chamber with each of a plurality of high pressure connections in turn, each being connected to a respective fuel injector.

Claim 11

Dependent Claim 53 words

A method as claimed in claim 5 in which the fuel injection pump is an in-line type pump with a plurality of working chambers each connected via a high pressure output connection to a respective fuel injector of the engine, each having a respective closed chamber connected to it via a flow restriction.

Claim 12

Dependent Claim 32 words

A method as claimed in claim 1 in which the closed chamber is connected via the flow restriction to a high pressure output connection between a fuel pump and the fuel injector.

Claim 13

Dependent Claim 49 words

A method as claimed in claim 8 in which the fuel pump is connected via a plurality of high pressure output connections to each of a plurality of respective fuel injectors of the engine, and a respective closed chamber is connected to each output connection via a flow restriction.

Claim 14

Dependent Claim 30 words

A method as claimed in claim 1 in which the fuel injector incorporates a fuel pump element that delivers fuel via the pressurised fuel supply passage to the injector valve.

Claim 15

Dependent Claim 45 words

A method as claimed in claim 1 in which the engine is provided with a plurality of injectors each provided with a respective closed chamber and a flow restriction connecting it to a pressurized fuel supply passage within the injector upstream of the injector valve.

Claim 16

Dependent Claim 42 words

Fuel injection equipment as claimed in claim 2 in which the fuel injector comprises an elongate body in which the injector valve is located as a longitudinal slide fit and in which the closed chamber is formed as a longitudinally extending chamber.

Claim 17

Dependent Claim 31 words

Fuel injection equipment as claimed in claim 2 in which the pressurised fuel supply passage includes a second permanently open flow restriction located downstream of the connection to the closed chamber.

Claim 18

Dependent Claim 35 words

Fuel injection equipment as claimed in claim 13 in which the second flow restriction has a cross-sectional flow area no greater than the minimum cross-sectional flow area downstream of the connection to the closed chamber.

Claim 19

Dependent Claim 27 words

Fuel injection equipment as claimed in claim 13 or 14 in which the second flow restriction is located adjacent to the flow restriction to the closed chamber.

Claim 20

Dependent Claim 31 words

Fuel injection equipment as claimed in claim 2 in which the fuel injector incorporates a fuel pumping element that delivers fuel via said pressurized fuel supply passage to the injector valve.

Claim 21

Dependent Claim 35 words

Fuel injection equipment as claimed in claim 3 in which the closed chamber and flow restriction are formed in a component that is removably secured in a wall of the pump surrounding the working chamber.

Claim 22

Dependent Claim 50 words

Fuel injection equipment as claimed in claim 3 or 26 in which the pump is a rotary type pump with a single working chamber with distribution means to connect said working chamber with each of a plurality of outputs in turn, each output being connected to a respective fuel injector.

Claim 23

Dependent Claim 51 words

Fuel injector equipment claimed in claim 3 or 17 in which the pump is an in-line type pump with a plurality of working chambers each connected via an output to a respective fuel injector of the engine and each having a respective closed chamber connected to it via a flow restriction.

Claim 24

Dependent Claim 36 words

Fuel injection equipment as claimed in claim 4 in which the closed chamber and flow restriction are connected to the high pressure fuel supply connection near that end adapted to be connected to the fuel injector.

Claim 25

Dependent Claim 36 words

Fuel injection equipment as claimed in claim 3 or 20 in which the high pressure fuel supply connection includes a second permanently open flow restriction which is located downstream of the connection from the closed chamber.

Claim 26

Dependent Claim 36 words

Fuel injection equipment as claimed in claim 21 in which the cross-sectional flow area of the second flow restriction is no greater than the minimum cross-sectional flow area downstream of it in the connection or injector.

Claim 27

Dependent Claim 33 words

Fuel injection equipment as claimed in claim 3 or 20 in which the closed chamber and flow restriction are formed in a component that is connected to the high pressure fuel supply connection.

Claim 28

Dependent Claim 33 words

Fuel injection equipment as claimed in claim 21 in which the closed chamber and both flow restrictions are formed in a component (38) that is connected to the high pressure fuel supply connection.

Claim 29

Dependent Claim 27 words

Fuel injection equipment as claimed in claim 3 in which said predetermined engine speed is selected for the reduction of engine combustion noise up to this speed.

Claim 30

Dependent Claim 14 words

An internal combustion engine fitted with fuel injection equipment as claimed in claim 2.

Claim 31

Dependent Claim 28 words

A method as claimed in claim 1 comprising connecting a second permanently open flow restriction in the pressurised fuel supply downstream of the connection to the closed chamber.

Claim 32

Dependent Claim 39 words

A method as claimed in claim 1 comprising locating the closed chamber on or within the fuel injector and connecting the closed chamber to a pressurised fuel supply passage via the flow restriction located upstream of the injector valve.

Claim 33

Dependent Claim 55 words

A method as claimed in claim 1, further comprising: selecting the volume of the closed chamber and the cross-sectional flow area of the restriction so that at engine speeds up to a predetermined engine speed, the maximum pressure reached in the closed chamber corresponds to the maximum compressibility of the fuel in the closed chamber.

Claim 34

Dependent Claim 27 words

A method as claimed in claim 29, further comprising: selecting the predetermined engine speed for the reduction of engine combustion noise up to said predetermined engine speed.

Claim 35

Dependent Claim 56 words

Fuel injection equipment as claimed in claim 2, wherein the volume of the closed chamber and the cross-sectional flow area of the restriction are selected so that at engine speeds up to a predetermined engine speed, the maximum pressure reached in the closed chamber corresponds to the maximum compressibility of the fuel in the closed chamber.

Claim 36

Dependent Claim 27 words

Fuel injection equipment as claimed in claim 31, wherein the predetermined engine speed is selected so that engine combustion noise is reduces up to said predetermined speed.

Claim 37

Dependent Claim 35 words

Fuel injection equipment as claimed in claim 12, wherein the elongate body comprises a main body component, a nozzle component, and an intermediate component located therebetween, the closed chamber being formed in the intermediate component.

Claim 38

Dependent Claim 29 words

Fuel injection equipment as claimed in claim 33, wherein the closed chamber is formed by aligned bores in the intermediate component and the nozzle component of the elongate body.

Claim 39

Dependent Claim 43 words

Fuel injection equipment as claimed in claim 12, wherein the elongate body comprises a main body component, a nozzle component, and an intermediate component located therebetween, the flow restriction being formed in the intermediate component in alignment with the longitudinally extending closed chamber.

Claim 40

Dependent Claim 81 words

Fuel injection equipment as claimed in claim 13, wherein the elongate body comprises a main body component, a nozzle component, and an intermediate component located therebetween, both flow restrictions being formed in the intermediate component so that one flow restriction communicates with the closed chamber on one side of the intermediate component and the pressurized fuel supply passage on the other side of the intermediate component, and the second flow restriction is connected in line with the pressurized fuel supply passage.

Claim 41

Dependent Claim 56 words

Fuel injection equipment as claimed in claim 3, wherein the volume of the closed chamber and the cross-sectional flow area of the restriction are selected so that at engine speeds up to a predetermined engine speed, the maximum pressure reached in the closed chamber corresponds to the maximum compressibility of the fuel in the closed chamber.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-12-30	1995-07-01	1995-12-31	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-12-30	1999-07-01	1999-12-31	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-12-30	2003-07-01	2003-12-31	$7700.00	Window Closed / Lapsed

Fuel injection system

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