US5697342A — Hydraulically-actuated fuel injector with direct …

Claim 1

Independent Claim 199 words

A hydraulically actuated fuel injector comprising: an injector body having a needle control chamber, a nozzle chamber and a nozzle outlet that opens to said nozzle chamber; hydraulic means, including said injector body having an actuation fluid cavity that opens to an actuation fluid inlet and an actuation fluid drain and an actuation fluid control valve mounted in said injector body and having a first position in which said actuation fluid cavity is open to said actuation fluid inlet and a second position in which said actuation fluid cavity is open to said actuation fluid drain, for pressurizing fuel in said nozzle chamber; a needle valve positioned to reciprocate in said nozzle chamber between an opened position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed, said needle valve including a closing hydraulic surface exposed to pressure in said needle control chamber; a needle control valve mounted within said injector body, and being movable between an off position in which said needle control chamber is opened to a source of high pressure fluid and an on position in which said needle control chamber is opened to a low pressure passage.

Claim 2

Dependent Claim 199 words

A hydraulically actuated fuel injector comprising: an injector body having a needle control chamber, a nozzle chamber and a nozzle outlet that opens to said nozzle chamber; hydraulic means, including said injector body having an actuation fluid cavity that opens to an actuation fluid inlet and an actuation fluid drain and an actuation fluid control valve mounted in said injector body and having a first position in which said actuation fluid cavity is open to said actuation fluid inlet and a second position in which said actuation fluid cavity is open to said actuation fluid drain, for pressurizing fuel in said nozzle chamber; a needle valve positioned to reciprocate in said nozzle chamber between an opened position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed, said needle valve including a closing hydraulic surface exposed to pressure in said needle control chamber; a needle control valve mounted within said injector body, and being movable between an off position in which said needle control chamber is opened to a source of high pressure fluid and an on position in which said needle control chamber is opened to a low pressure passage.

Claim 3

Dependent Claim 61 words

The fuel injector of claim 1 wherein said needle valve includes an opening hydraulic surface exposed to pressure in said nozzle chamber; said closing hydraulic surface and said opening hydraulic surface are sized and arranged such that said needle valve is hydraulically biased toward said closed position when said needle control chamber is opened to said source of high pressure fluid.

Claim 4

Dependent Claim 85 words

The fuel injector of claim 2 further comprising a spring in contact with said needle valve, for biasing said needle valve toward said closed position when pressure in said nozzle chamber is below a valve opening pressure and said needle control chamber is opened to said low pressure passage; and said needle valve is hydraulically biased toward said opened position when said needle control chamber is connected to said low pressure passage and pressure in said nozzle chamber is greater than said valve opening pressure.

Claim 5

Dependent Claim 82 words

The fuel injector of claim 3 wherein said hydraulic means for pressurizing further includes: said injector body having a plunger bore and a piston bore; an intensifier piston positioned to reciprocate in said piston bore between a forward position and a return position; a plunger positioned to reciprocate in said plunger bore between a retracted position and an advanced position; and a portion of said plunger bore and said plunger define a fuel pressurization chamber that is open to said nozzle chamber.

Claim 6

Dependent Claim 18 words

The fuel injector of claim 3 wherein said source of high pressure fluid is a fuel pressurization chamber.

Claim 7

Dependent Claim 58 words

The fuel injector of claim 5 wherein said needle control valve includes a direct control valve member mounted to reciprocate in said injector body between an off position in which said needle control chamber is open to said fuel pressurization chamber and an on position in which said needle control chamber is open to said low pressure passage.

Claim 8

Dependent Claim 100 words

The fuel injector of claim 6 wherein said direct control valve member includes a hydraulic pressure surface opening to an actuation fluid control passage in said injector body and positioned to produce a hydraulic force on said direct control valve member toward said on position; means, within said injector body, for biasing said direct control valve member toward said off position; said actuation fluid control valve closes said actuation fluid control passage to said actuation fluid inlet when in said second position and said actuation fluid control passage is open to a low pressure drain when in said first position.

Claim 9

Dependent Claim 17 words

The fuel injector of claim 7 wherein said direct control valve member is a spool valve member.

Claim 10

Dependent Claim 18 words

The fuel injector of claim 3 wherein said source of high pressure fluid is said actuation fluid inlet.

Claim 11

Dependent Claim 43 words

The fuel injector of claim 9 wherein said needle valve includes a needle portion with an opening hydraulic surface exposed to pressure in said nozzle chamber and an end portion with a closing hydraulic surface exposed to pressure in said needle control chamber.

Claim 12

Dependent Claim 24 words

The fuel injector of claim 3 further comprising said actuation fluid control valve having a three position solenoid attached to an actuation valve member.

Claim 13

Dependent Claim 115 words

The fuel injector of claim 11 wherein said injector body includes an actuation fluid control passage that communicates actuation fluid pressure to said needle valve; and said actuation fluid control passage and said actuation fluid cavity being closed to said actuation fluid inlet when said actuation valve member is in said first position; said actuation fluid control passage and said actuation fluid cavity being opened to said actuation fluid inlet when said actuation valve member is in said second position; and said actuation fluid control passage is closed to said actuation fluid inlet, and said actuation fluid cavity is opened to said actuation fluid inlet when said actuation valve member is in a third position.

Claim 14

Dependent Claim 16 words

The fuel injector of claim 12 wherein said actuation valve member is a spool valve member.

Claim 15

Dependent Claim 45 words

The fuel injector of claim 13 further comprising a sleeve valve member with a hollow interior and at least one radial flow opening, and being movable between an opened position and a closed position; and said hollow interior being open to said actuation fluid inlet.

Claim 16

Dependent Claim 56 words

The fuel injector of claim 14 wherein said hollow interior opens to an actuation fluid drain passage in said injector body; a ball valve movable by said actuation valve member between a first position in which said actuation fluid drain passage is closed and a second position in which said actuation fluid drain passage is opened.

Claim 17

Dependent Claim 192 words

A fuel injection system comprising: a plurality of hydraulically actuated fuel injectors with direct control needle valves, each injector having a needle valve with a closing hydraulic surface exposed to pressure in a needle control chamber and at least one control valve that alternately opens said needle control chamber to a source of high pressure fluid or a low pressure passage, and each injector also having an actuation fluid cavity, an actuation fluid inlet, an actuation fluid drain and a fuel supply passage and said at least one control valve including an actuation fluid control valve mounted in said injector body and moveable between a first position in which said actuation fluid cavity is open to said actuation fluid inlet and a second position in which said actuation fluid cavity is open to said actuation fluid drain; a source of fuel connected to said fuel supply passage of each said injector; a source of high pressure actuation fluid connected to said actuation fluid inlet; a low pressure reservoir connected to said actuation fluid drain; and a computer in communication with and capable of controlling each of said at least one control valve.

Claim 18

Dependent Claim 192 words

A fuel injection system comprising: a plurality of hydraulically actuated fuel injectors with direct control needle valves, each injector having a needle valve with a closing hydraulic surface exposed to pressure in a needle control chamber and at least one control valve that alternately opens said needle control chamber to a source of high pressure fluid or a low pressure passage, and each injector also having an actuation fluid cavity, an actuation fluid inlet, an actuation fluid drain and a fuel supply passage and said at least one control valve including an actuation fluid control valve mounted in said injector body and moveable between a first position in which said actuation fluid cavity is open to said actuation fluid inlet and a second position in which said actuation fluid cavity is open to said actuation fluid drain; a source of fuel connected to said fuel supply passage of each said injector; a source of high pressure actuation fluid connected to said actuation fluid inlet; a low pressure reservoir connected to said actuation fluid drain; and a computer in communication with and capable of controlling each of said at least one control valve.

Claim 19

Dependent Claim 66 words

The fuel injection system of claim 16 wherein said needle valve includes an opening hydraulic surface exposed to pressure in said nozzle chamber; said closing hydraulic surface and said opening hydraulic surface of each said injector are sized and arranged such that said needle valve is hydraulically biased toward said closed position when said needle control chamber is opened to said source of high pressure fluid.

Claim 20

Dependent Claim 88 words

The fuel injection system of claim 17 further comprising means, including a spring in contact with said needle valve, for biasing said needle valve toward said closed position when pressure in said nozzle chamber is below a valve opening pressure and said needle control chamber is opened to said low pressure passage; and said needle valve is hydraulically biased toward said opened position when said needle control chamber is opened to said low pressure passage and pressure in said nozzle chamber is greater than said valve opening pressure.

Claim 21

Dependent Claim 82 words

The fuel injection system of claim 18 wherein each of said fuel injectors includes: said injector body having a piston bore and a plunger bore; an intensifier piston positioned to reciprocated in said piston bore between a forward position and a return position; a plunger positioned to reciprocate in said plunger bore between a retracted position and an advanced position; and a portion of said plunger bore and said plunger define a fuel pressurization chamber that is open to said nozzle chamber.

Claim 22

Dependent Claim 19 words

The fuel injection system of claim 18 wherein said source of high pressure fluid is said fuel pressurization chamber.

Claim 23

Dependent Claim 14 words

The fuel injection system of claim 18 wherein said actuation fluid is lubricating oil.

Claim 24

Dependent Claim 61 words

The fuel injection system of claim 18 wherein said at least one control valve includes a direct control valve member mounted to reciprocate in said injector body between an off position in which said needle control chamber is open to said fuel pressurization chamber and an on position in which said needle control chamber is open to said low pressure passage.

Claim 25

Dependent Claim 100 words

The fuel injection system of claim 22 wherein said direct control valve member includes a hydraulic pressure surface opening to an actuation fluid control passage in said injector body and positioned to produce a hydraulic force on said direct control valve member toward said on position; means, within said injector body, for biasing said direct control valve member toward said off position; said actuation fluid control valve closes said actuation fluid control passage ton actuation fluid inlet when in said second position and said actuation fluid control passage is open to a low pressure drain when in said first position.

Claim 26

Dependent Claim 18 words

The fuel injection system of claim 23 wherein said direct control valve member is a spool valve member.

Claim 27

Dependent Claim 24 words

The fuel injection system of claim 18 wherein said actuation fluid control valve has a three position solenoid attached to an actuation valve member.

Claim 28

Dependent Claim 116 words

The fuel injection system of claim 25 wherein said injector body includes an actuation fluid control passage that communicates actuation fluid pressure to said needle valve; and said actuation fluid control passage and said actuation fluid cavity being closed to said actuation fluid inlet when said actuation valve member is in said first position; said actuation fluid control passage and said actuation fluid cavity being opened to said actuation fluid inlet when said actuation valve member is in said second position; and said actuation fluid control passage is closed to said actuation fluid inlet and said actuation fluid cavity is opened to said actuation fluid inlet when said actuation valve member is in a third position.

Claim 29

Dependent Claim 17 words

The fuel injection system of claim 26 wherein said actuation valve member is a spool valve member.

Claim 30

Dependent Claim 46 words

The fuel injection system of claim 27 further comprising a sleeve valve member with a hollow interior and at least one radial flow opening, and being movable between an opened position and a closed position; and said hollow interior being open to said actuation fluid inlet.

Claim 31

Dependent Claim 61 words

The fuel injection system of claim 28 wherein said hollow interior opens to an actuation fluid drain passage in said injector body; a ball valve movable by said actuation valve member between a first position in which said actuation fluid drain passage is closed to said hollow interior and a second position in which said actuation fluid drain passage is opened.

Claim 32

Dependent Claim 19 words

The fuel injection system of claim 18 wherein said source of high pressure fluid is said actuation fluid inlet.

Claim 33

Dependent Claim 44 words

The fuel injection system of claim 30 wherein said needle valve includes a needle portion with an opening hydraulic surface exposed to pressure in said nozzle chamber and an end portion with a closing hydraulic surface exposed to pressure in said needle control chamber.

Claim 34

Independent Claim 221 words

A method of fuel injection comprising the steps of: providing a hydraulically actuated fuel injector having a nozzle outlet that pens to a nozzle chamber in which a needle valve reciprocates, and said needle valve having a closing hydraulic surface exposed to pressure in a needle control chamber, and said injector also having at least one control valve that alternately opens said needle control chamber to a source of high pressure fluid or a low pressure passage, and said at least one control valve including an actuation fluid control valve that alternately opens an actuation fluid cavity to an actuation fluid inlet or an actuation fluid drain; hydraulically pressurizing fuel in said nozzle chamber to an injection pressure at least in part by moving said actuation fluid control valve to open said actuation fluid cavity to said actuation fluid inlet; moving said needle valve to an opened position to open said nozzle outlet to said nozzle chamber at least in part by opening said needle control chamber to said low pressure passage with said at least one control valve; and moving said needle valve to a closed position to close said nozzle outlet to said nozzle chamber at least in part by opening said needle control chamber to said source of high pressure fluid with said at least one control valve.

Claim 35

Independent Claim 221 words

A method of fuel injection comprising the steps of: providing a hydraulically actuated fuel injector having a nozzle outlet that pens to a nozzle chamber in which a needle valve reciprocates, and said needle valve having a closing hydraulic surface exposed to pressure in a needle control chamber, and said injector also having at least one control valve that alternately opens said needle control chamber to a source of high pressure fluid or a low pressure passage, and said at least one control valve including an actuation fluid control valve that alternately opens an actuation fluid cavity to an actuation fluid inlet or an actuation fluid drain; hydraulically pressurizing fuel in said nozzle chamber to an injection pressure at least in part by moving said actuation fluid control valve to open said actuation fluid cavity to said actuation fluid inlet; moving said needle valve to an opened position to open said nozzle outlet to said nozzle chamber at least in part by opening said needle control chamber to said low pressure passage with said at least one control valve; and moving said needle valve to a closed position to close said nozzle outlet to said nozzle chamber at least in part by opening said needle control chamber to said source of high pressure fluid with said at least one control valve.

Claim 36

Dependent Claim 71 words

The method of claim 32 wherein said step of moving said needle valve to said opened position includes the steps of: providing said needle valve with an opening hydraulic surface exposed to pressure in said nozzle chamber; biasing said needle valve toward said closed position with a spring; and said step of hydraulically pressurizing raises fuel pressure in said nozzle chamber above a valve opening pressure sufficient to overcome said spring.

Claim 37

Dependent Claim 49 words

The method of claim 33 further comprising the step of opening said needle control chamber to said source of high pressure fluid with said at least one control valve after initiating said step of hydraulically pressurizing but before fuel in said nozzle chamber rises above said valve opening pressure.

Claim 38

Dependent Claim 116 words

The method of claim 34 wherein said injector body has a plunger bore and a piston bore; said actuation fluid control valve mounted in said injector body has a first position in which said actuation fluid cavity is open to said actuation fluid inlet and a second position in which said actuation fluid cavity is open to said actuation fluid drain; an intensifier piston positioned to reciprocated in said piston bore between a forward position and a return position; a plunger positioned to reciprocate in said plunger bore between a retracted position and an advanced position; and said step of hydraulically pressurizing includes a step of moving said actuation fluid control valve to said first position.

Claim 39

Dependent Claim 32 words

The method of claim 35 wherein a portion of said plunger bore and said plunger define a fuel pressurization chamber; and said source of high pressure fluid is said fuel pressurization chamber.

Claim 40

Dependent Claim 12 words

The method of claim 36 wherein said actuation fluid is lubricating oil.

Claim 41

Dependent Claim 112 words

The method of claim 34 wherein said at least one control valve includes a direct control valve member mounted to reciprocate in said injector body between an off position in which said needle control chamber is open to said source of high pressure fluid and an on position in which said needle control chamber is open to said low pressure passage; said step of moving said needle valve to said opened position includes a step of moving said direct control valve member to said on position; and said step of moving said needle valve to said closed position includes a step of moving said direct control valve member to said off position.

Claim 42

Dependent Claim 97 words

The method of claim 38 wherein said direct control valve member includes a hydraulic pressure surface opening to an actuation fluid control passage in said injector body and positioned to produce a hydraulic force on said direct control valve member toward said on position; said step of moving said needle valve to said opened position includes a step of opening said actuation fluid control passage to said actuation fluid inlet; and said step of moving said needle valve to said closed position includes a step of opening said actuation fluid control passage to said actuation fluid drain.

Claim 43

Dependent Claim 37 words

The method of claim 34 wherein said step of moving said needle valve to said opened position and said step of moving said needle valve to said closed position occur during said step of hydraulically pressurizing fuel.

Claim 44

Dependent Claim 114 words

The method of claim 34 wherein said at least one control valve includes a three position actuation fluid control valve; moving said actuation fluid control valve to a second position before said step of hydraulically pressurizing; said step of hydraulically pressurizing is initiated by a step of moving said actuation fluid control valve to a first position; said step of moving said needle valve to an opened position is initiated by a step of moving said actuation fluid control valve to a third position; and said step of moving said needle valve to a closed position is accomplished at least in part by moving said actuation fluid control valve back to said first position.

Claim 45

Dependent Claim 17 words

The method of claim 34 wherein said source of high pressure fluid is a fuel pressurization chamber.

Claim 46

Dependent Claim 17 words

The method of claim 34 wherein said source of high pressure fluid is said actuation fluid inlet.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-12-15	2001-06-16	2001-12-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-12-15	2005-06-16	2005-12-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-12-15	2009-06-16	2009-12-16	$7700.00	Window Closed / Lapsed

Hydraulically-actuated fuel injector with direct control needle valve

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