Three-stage fuel injection system

Abstract

Method for injecting fuel into a combustion chamber (30) of an engine (10), comprising: rotating an inner element (222) relative to an injection body (202) by a first rotational amount and aligning an exhaust channel (204) with an exhaust source to enable the exhaust gas to enter a pre-chamber (215) for a first duration; rotating the inner element (222) relative to the injection body (202) by a second rotational amount and aligning a fuel channel with a fuel source to enable the fuel to enter a pre-chamber (215) for a second duration; and rotation of the inner element (222) relative to the injection body (202) by a third amount of rotation and alignment of injector nozzle connecting pieces (228) with injector nozzles (208) for a third duration to enable a mixture of the fuel and the exhaust gas to be injected from the pre-chamber (215) into the combustion chamber (30).

Description

REGIONThe present invention relates to fuel injectors and, more particularly, to a fuel injector having a pre-chamber and three stages.GENERAL ARTDuring the operation of internal combustion engines, the quality of the combustion processes depends on various conditions. One condition is how well the fuel is mixed with air in the combustion chamber. A poor air-fuel mixture may produce undesirable soot and / or hydrocarbon emissions. This may occur in particular during cold starts.Heretofore, fuel injectors have been used to inject fuel into the combustion chamber of engines at a generally high speed in an effort to atomize the fuel. Nevertheless, fuel injectors may still provide a deceptive air-fuel mixture. In addition, long spray penetration, often characteristic of the injectors, may result in the spray encountering the combustion chamber wall, which, especially under cold engine conditions, tends to maintain the fuel in a cooler, liquid state.The document EP 0 844 387 A2 proposes an injection method in which exhaust gas can enter a prechamber via an exhaust gas nozzle, into which fuel can also enter via a fuel nozzle, wherein a mixture of fuel and exhaust gas can be injected from the prechamber into the combustion chamber with the aid of injection nozzles. Similar injection devices are also known from the documents DE 101 26 355 B4, U.S. Pat. No. 5,746,189 A, FR 2 734 869 A1, DE 695 11 506 T2 and KR 10 1998 0 036 643 A.US 7 458 364 B discloses a fuel injection system in which an attempt is made to improve atomization. The disclosure of US 7 458 364 B includes a so-called mixing chamber into which a positive displacement pump injects a measured amount of fuel. An air or exhaust conduit provides a supplemental gaseous volume to the mixing chamber while creating a partial vacuum in the adjacent combustion chamber to draw exhaust gas and fuel into the combustion chamber in a combined flow tending to introduce the fuel into the exhaust stream. The vacuum is created in the combustion chamber by retarding the opening of an intake valve while the piston begins a down stroke. The mixing chamber includes an atomizing nozzle at an outlet side thereof to accelerate the flow.This approach has a number of deficiencies. First, U.S. Pat. No. 7,458,364 B requires a special operation of the charge air inlet valve to create a vacuum in the combustion chamber to cause air or exhaust gas to flow through the mixing chamber for introducing the fuel. U.S. Pat. No. 7,458,364 B design is intended to be used with smaller single cylinder engines that do not include a fuel pump. The positive displacement pump is designed for metered injection, not for increased pressure. In addition, there appears to be a relatively short period of time during which the fuel is exposed to the passing air or exhaust flow. There also seems to be little time for any appreciable heat transfer between the fuel and the exhaust gas. The exhaust gas stream and the fuel stream appear to be poorly mixed. It seems that the fuel is only atomized when it flows from the atomizing nozzle into the combustion chamber within the mixture.The inventors herein disclose an engine, a fuel injector, and a method for injecting fuel into a combustion chamber of the engine that provides an improved air-fuel mixture. The method may include rotating an inner member relative to an injector body by a first amount of rotation and aligning an exhaust passage with an exhaust source to allow the exhaust gas to enter a pre-chamber for a first duration. The method may also include rotating the inner member relative to the injector body by a second amount of rotation and aligning a fuel passage with a fuel source to allow fuel to enter a pre-chamber for a second duration. The method may also include rotating the inner member relative to the injector body by a third amount of rotation and aligning an injector coupler with injectors for a third duration to allow a mixture of the fuel and the exhaust gas to be injected from the pre-chamber into the combustion chamber. Embodiments may provide a three-stage (exactly three-stage in one example) fuel injector configuration that initiates hot exhaust flow within a pre-chamber within the nozzle needle to promote fuel vaporization prior to injection into the combustion cylinder.In this way, a more significant exposure of fuel to warmed exhaust gas may be achieved over a predetermined time exposure and over a sufficient spatial exposure. In this way, fuel in the pre-chamber may be heated. With an exhaust gas supply, sufficient heat transfer exposure can be provided to the fuel to heat the fuel to advantageous temperatures. In this way, the fuel can also be vaporized in the heated exhaust gas.The foregoing advantages, as well as other advantages and features of the present specification, will be readily apparent from the following detailed description when taken alone or in conjunction with the accompanying drawings.It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely in the claims following the detailed description. Further, the claimed subject matter is not limited to implementations that eliminate disadvantages noted above or in any part of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGSIn FIG. I is a schematic system diagram of an engine according to the present disclosure.FIG. 2 is a schematic partial cross-sectional drawing of a fuel injector according to the present disclosure.FIGS. 3A and 3B are schematic partial cross-sectional views of the fuel injector shown in FIG. 2 taken along lines 3A- 3A and 3B- 3B, respectively, illustrating the fuel injector in an off position.FIGS. 4A and 4B are schematic partial cross-sectional views of the fuel injector shown in FIG. 2 taken along lines 3A- 3A and 3B- 3B, respectively, illustrating the fuel injector in the first stage.FIGS. 5A and 5B are schematic partial cross-sectional views of the fuel injector shown in FIG. 2 taken along lines 3A- 3A and 3B- 3B, respectively, illustrating the fuel injector in the second stage.FIGS. 6A and 6B are schematic partial cross-sectional views of the fuel injector shown in FIG. 2 taken along lines 3A- 3A and 3B- 3B, respectively, illustrating the fuel injector in the third stage.FIG. 7 is a schematic flow diagram illustrating a method according to the present disclosure.DETAILED DESCRIPTIONWith reference to Figure. I is an internal combustion engine 10 including a plurality of cylinders, one cylinder of which is shown in FIG. I is shown controlled by an electronic motor controller 12. The engine 10 includes a combustion chamber 30 and the cylinder walls 32 with a piston 36 positioned therein and connected to a crankshaft 40. A flywheel may be connected to the crankshaft 40.Combustion chamber 30 is shown communicating with intake manifold 44 and exhaust manifold 48 via corresponding intake valve 52 and exhaust valve 54. The position of the intake cam 51 may be determined by an intake cam sensor 55. The position of the exhaust cam 53 may be determined by an exhaust cam sensor 57. The intake cam 51 and exhaust cam 53 may be moved relative to the crankshaft 40.Fuel injector 66 is shown positioned to inject fuel directly into cylinder 30, which is known to those skilled in the art as direct injection. Alternatively, fuel may be injected into an intake passage, known to those skilled in the art as port injection. Fuel injector 66 may supply liquid fuel in proportion to the pulse width of the signal from controller 12. Fuel is supplied to fuel injector 66 by a fuel system (not shown) including a fuel tank, a fuel pump, and a fuel rail (not shown).As shown, the intake manifold 44 communicates with an optional electronic throttle 62 that adjusts a position of the throttle 64 to control air flow from the air inlet 42 to the intake manifold 44.In one example, a direct injection system with low pressure may be used, where fuel pressure may be increased to approximately 20-30 bar. Alternatively, a two-stage, high pressure fuel system may be used to generate higher fuel pressures.In some examples, throttle 62 and throttle 64 may be positioned between intake valve 52 and intake manifold 44 such that throttle 62 is an intake manifold throttle.An ignition system 88 may provide spark to combustion chamber 30 via a spark plug 92 in response to controller 12. As shown, a universal exhaust gas oxygen (UEGO) sensor 126 is coupled to the exhaust manifold 48 upstream of the catalyst 70. Alternatively, the UEGO sensor 126 may be replaced with a binary oxygen sensor.In another example, the engine may be coupled to an electric motor / battery system in a hybrid vehicle. Further, in some examples, other engine configurations may be employed, for example, a diesel engine.The catalyst 70 may include multiple catalyst building blocks in one example. In another example, multiple emission control devices, each having multiple devices, may be used. The catalyst 70 may be a three-way catalyst in one example. A temperature of the catalyst 70 may be measured or estimated via engine speed, engine load, engine coolant temperature, and spark timing.In FIG. I, controller 12 is shown as a conventional microcomputer including microprocessor unit 102, input / output ports 104, read only memory 106 (e.g., non-volatile memory), random access memory 108, keep alive memory 110, and a conventional data bus. As shown, controller 12 senses various signals from the sensors coupled to engine 10, in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114; a position sensor 134 coupled to an accelerator pedal 130 for sensing force applied by foot 132; an engine manifold pressure (MAP) measurement from pressure sensor 122 coupled to intake manifold 44; an engine position sensor from Hall effect sensor 1 1 8 sensing position of crankshaft 40; a measurement of mass of air entering the engine from sensor 120; a measure of road grade from inclinometer 35 and a measurement of throttle position from sensor 58; atmospheric pressure may also be detected (sensor not shown) for processing by controller 12.In a preferred aspect of the present description, the engine position sensor 118 generates a predetermined number of equally spaced pulses each revolution of the crankshaft from which the engine speed (U / min) can be determined.In another example, the engine may be coupled to an electric motor / battery system in a hybrid vehicle. Further, in some examples, other engine configurations may be employed, for example, a diesel engine.During operation, each cylinder in engine 10 typically undergoes a four stroke cycle: the cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. During the intake stroke, generally, the exhaust valve 54 closes and the intake valve 52 opens. Air is introduced into the combustion chamber 30 via the intake manifold 44, and the piston 36 moves to the bottom of the cylinder to increase the volume in the combustion chamber 30. The position at which the piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when the combustion chamber 30 has its largest volume) is commonly referred to by those of skill in the art as bottom dead center (BDC). During the compression stroke, the intake valve 52 and the exhaust valve 54 are closed. The piston 36 moves toward the cylinder head to compress the air within the combustion chamber 30. The point at which the piston 36 is closest to the cylinder head (e.g., when the combustion chamber 30 has its smallest volume) at the end of its stroke is commonly referred to by those of skill in the art as top dead center (TDC). In a process referred to below as injection, fuel is introduced into the combustion chamber. In a process referred to as ignition hereinafter, the injected fuel is ignited by known igniting means such as the spark plug 92, resulting in combustion. In example diesel applications, fuel may be burned via auto-ignition through increased compression. During the power stroke, the expanding gases push the piston 36 back to BDC. The crankshaft 40 converts piston movements into a torque of the rotating shaft. Finally, during the exhaust stroke, the exhaust valve 54 opens to deliver the combusted air-fuel mixture to the exhaust manifold 48, and the piston returns to TDC. It should be appreciated that the foregoing is merely exemplary and that intake and exhaust valve opening and / or closing timings may vary, such as to provide positive or negative valve overlap, late intake valve closing, or various other examples.The controller 12 may be configured to receive input from the engine 10, as shown in FIG. I, and to control a torque output of the engine and / or operation of the torque converter, transmission, driveline integrated starter / generator (DISG), clutches, and / or brakes accordingly. As one example, engine torque output may be controlled by adjusting a combination of spark timing, fuel pulse width, fuel pulse timing, and / or air charge by controlling throttle opening and / or valve timing, valve lift, and boost pressure for turbo- or compressor-charged engines. In the case of a diesel engine, controller 12 may control engine torque output by controlling a combination of fuel pulse width, fuel pulse timing, and air charge. Engine control may be performed on a cylinder-by-cylinder basis to control engine torque output.Various embodiments may provide an engine system 150, which may include a combustion chamber 30 for combusting an air-fuel mixture. A fuel line 152 may be included to provide high pressure fuel for combustion in the combustion chamber 30. Engine system 150 may include a fuel pump 154 configured to move fuel from a fuel tank (not shown) via an upstream fuel line 156. The fuel pump 1 54 may also pressurize the fuel to thereby provide the high-pressure fuel.A connection line 158 may also be provided to port a portion of the exhaust gas from the combustion chamber 30. The connecting conduit 158 may be fluidly coupled to an exhaust gas recirculation (EGR) conduit 160. An EGR valve 162 may be provided to at least partially regulate the EGR system. The connection line 158 may also include a regulation mechanism, such as a valve (not shown). In some embodiments, the connecting conduit 158 may be fluidly coupled to the engine exhaust in other ways that may not include an EGR conduit.FIGS. 2-7 illustrate example configurations with relative positioning of the various components. When such elements are shown as directly contacting or directly coupled to each other, they may be referred to as directly contacting or directly coupled, respectively, at least in one example. Similarly, elements shown abutting or adjacent to each other may be abutting or adjacent to each other, at least in one example. As an example, components that are in face sharing contact with each other may be referred to as face sharing contact. As another example, elements positioned apart from each other with only a space therebetween and no other components may be referred to as such in at least one example. As yet another example, elements shown above / below each other, on opposite sides of each other, or left / right of each other may be referred to as such relative to each other. Further, as shown in the figures, a top element or point of an element may be referred to as a "top" of the component and a bottom element or point of the element may be referred to as a "bottom" of the component in at least one example. As used herein, top / bottom, top(r / s) / bottom(r / s), above / below may refer to a vertical axis of the figures and may be used to describe the positioning of elements of the figures relative to each other. Thus, elements depicted above other elements are positioned vertically above the other elements in one example. As yet another example, shapes of the elements depicted in the figures may be referred to as having these shapes (such as circular, straight, planar, curved, rounded, beveled, angled, or the like). Further, elements illustrated as intersecting one another may be referred to as intersecting elements or intersecting one another in at least one example. Still further, an element shown within another element or outside another element may be referred to as such in an example.Referring also to FIGS. 2-6B, engine system 150 may now include a fuel injector 200. Fuel injector 200 may include an injector body 202 and an inner member 222 disposed within and rotatable relative to injector body 202. A pre-chamber 215 may be defined within the inner member 222 between portions of the inner member 222 and the injector body 202. The inner member 222 may be rotatable to selectively align a first passage 224 between the pre-chamber 215 and the connecting conduit 158 to allow the exhaust gas to enter the pre-chamber 215. The inner member 222 may also be rotatable to selectively align a second passage 226 between the pre-chamber 215 and the fuel line 152 to direct fuel into the pre-chamber 215. The first and second channels may include one or more segments that may be aligned to allow fluid to pass therethrough. The inner member 222 may also be rotatable to align one or more injector connectors 228 between the pre-chamber and the one or more injectors 208 for injecting a fuel-exhaust mixture from the pre-chamber into the combustion chamber 30. The selective rotation of the inner member 222 relative to the injector body 202 may be directly or indirectly controlled by the controller 12. The rotation may be effected by an actuator 230 such as a spool or the like.The inner member 222 may include a substantially cylindrical outer wall 213 or a chamber wall 213 that surrounds and defines the mixing chamber 215. The one or more injector fittings 228 may be, for example, eight injector fittings 228 that extend radially through the outer wall 213 circumferentially at eight substantially equal intervals. The injection body 202 may include a substantially cylindrical body wall 233 surrounding the substantially cylindrical outer wall 213 of the inner member 222. Similarly, the one or more injectors 208 may be eight injectors 208 that extend radially outward and longitudinally toward a central region of the combustion chamber 30. They may form an angle with a central axis 235 of the injector body 202, for example.As noted, the injector body 202 may have a central axis 235. The inner member 222 may also have a central axis that may be coincident with the central axis 235 of the injector body 202. Alternatively, the central axis of the inner member 222 may be offset from, parallel, or at an angle to the central axis 235 of the injector body 202. In the illustrated exemplary embodiment, the central axis 235 is central to the cylindrical outer wall 213. The exhaust nozzle 224 and the fuel nozzle 226 may be at a first longitudinal position relative to the central axis 235 and the one or more injector connectors 228 may / may be at a second longitudinal position relative to the central axis 235. The second longitudinal position may be different than the first longitudinal position; i.e., the exhaust nozzle 224 and the fuel nozzle 226 may pass through a first plane and the one or more injector connectors 228 may / may pass through a second plane. The central axis 235 may be perpendicular to both the first and second planes, and the first and second planes may be parallel to each other.FIGS. 3A and 3B illustrate the inner member 222 positioned within the injector body 202 in a starting or closed or zero angle position 248 where neither exhaust gas nor fuel can enter the pre-chamber 215. FIGS. 4A and 4B illustrate the inner member 222 positioned within the injector body 202 in a first step position, with the inner member 222 rotated a first angle 250 to allow the exhaust gas to enter the pre-chamber 215. FIGS. 5A and 5B illustrate the inner member 222 positioned within the injector body 202 in a second step position, with the inner member 222 rotated a second angle 252 to allow fuel to enter the pre-chamber 215. FIGS. 6A and 6B illustrate the inner member 222 positioned within the injector body 202 in a third step position, with the inner member 222 rotated to a third angle 254 to allow the fuel-exhaust mixture to be expelled from the pre-chamber 215 and injected into a combustion chamber 30. These figures also illustrate an exemplary spacing or orientation of the respective channels, connectors, and nozzles.The exhaust nozzle 224 and the fuel nozzle 226 may extend radially through the cylindrical outer wall or chamber wall 213, and may be angularly spaced from each other by, for example, approximately I I degrees. Additionally, one of the at least one injector coupler 228 may be angularly spaced from the fuel passage by, for example, approximately 23 degrees. The one or more injector connectors 228 may be eight injector connectors 228 angularly spaced from each other by approximately 45 degrees.Various embodiments may also include an injector needle 240 that may be configured to enter pre-chamber 215 to urge the fuel-exhaust mixture from pre-chamber 215, through injectors 208, and into combustion chamber 30.As noted, in some cases, the communication passage 158 is configured to receive exhaust gas from an EGR passage 160 downstream of an exhaust manifold 48. A plurality of similar exhaust passages downstream of a plurality of similarly configured combustion chambers 30 may fluidly open into a common flow path. Embodiments may provide a fuel injector 200 that may include an injector body 202 defining passages therethrough. The passages may include one or more exhaust passages 204, one or more fuel passages 206, and one or more injectors 208. Fuel injector 200 may also include an inner member 222 having a chamber wall 213 defining a pre-chamber 215 therein. The chamber wall 213 may have channels extending therethrough. The passages may include one or more exhaust nozzles 224, one or more fuel nozzles 226, and one or more injector connectors 228. The inner member 222 may be substantially disposed within the injector body 202 and may be movable relative to the injector body 202 to selectively align the one or more exhaust nozzles 224 with the one or more exhaust passages 204, the one or more fuel nozzles 226 with the one or more fuel passages 206, and the one or more injector connectors 228 with the one or more injector nozzles 208 to inject a mixture of fuel and exhaust gas into a combustion chamber 30 of an engine 10. After injection of the fuel-exhaust mixture, the inner member 222 may or may not rotate back to the zero angle position.Embodiments may provide a fuel injector 200 in which the inner member 222 is rotatable within the overmold body 202 to align with successive movements: an exhaust nozzle 224 having an exhaust passage 204, a fuel nozzle 226 having a fuel passage 206, and one or more injector connectors 228 having the one or more injectors 208.With particular reference to Figures. I, in some embodiments, the inner member 222 includes a substantially cylindrical outer wall 213 defining the pre-chamber 215 therein. The inner member 222 may be pivotable about a central axis 235 of the injector body 202. The one or more exhaust nozzles 224 may be an exhaust nozzle 204 that may pass radially through the outer wall 213 at a circumferentially first position of the inner member outer wall 213 and at a longitudinally first position. Similarly, the one or more fuel nozzles 226 may be a fuel nozzle 226 that extends radially through the outer wall 213 at a circumferentially second position of the inner member outer wall 213 and at the longitudinally first position. The one or more injector connectors 228 may / may pass through the inner member outer wall 213 at a longitudinally second position.The injector body 202 may define a space 225 therein in which the inner member 222 may be disposed for fitting. A sealing member, for example a first O-ring 242, may be positioned in the space 225 in sealing engagement with the inner member outer wall 213 above the exhaust nozzle 224, the exhaust passage 204, the fuel nozzle 226, and the fuel passage 206 to prevent or reduce the leakage of exhaust gas or fuel. A second O-ring 244 may be positioned in the space 225 in sealing engagement with the inner member outer wall 213 below the exhaust nozzle 224 but above the injector connectors 228 and the injectors 208. In this way, leakage of the fuel-exhaust mixture and / or direct flow from the exhaust passage 204 and the fuel passage 206 may be prevented or reduced.The one or more injector connectors 228 may be eight injector connectors 228 that extend radially through the outer wall 213 at eight substantially equally circumferentially spaced positions. The one of the injector connectors may define a second angle with the fuel nozzle and the fuel nozzle may form a first angle with the exhaust nozzle, and wherein a sum of the first angle 250 and the second angle 252 is substantially equal to the third angle 254, which may be 45 degrees, for example.Embodiments may provide a method 700 for injecting fuel into a combustion chamber of an engine. Method 700 may include, at 702, rotating an inner member relative to an injector body by a first amount of rotation and aligning an exhaust passage with an exhaust source to allow the exhaust gas to enter a pre-chamber for a first duration. Method 700 may include, at 704, rotating the inner member relative to the injector body by a second amount of rotation and aligning a fuel passage with a fuel source to allow fuel to enter a pre-chamber for a second duration. Method 700 may also include, at 706, rotating the inner member relative to the injector body by a third amount of rotation and aligning an injector coupler with injectors to allow a mixture of the fuel and the exhaust gas to be injected from the pre-chamber into the combustion chamber for a third duration. In some embodiments, method 700 may include moving an injector needle 240 into pre-chamber 215 to urge the mixture of fuel and exhaust gas into the combustion chamber.In some embodiments, the alignment of the exhaust passage with the exhaust source may be effected by rotating the inner member relative to the injector body by I I degrees; the alignment of the fuel passage with the fuel source may be effected by rotating the inner member relative to the injector body by an additional 11 degrees; and the alignment of the injector connectors with the injector nozzles may be effected by rotating the inner member relative to the injector body by 23 degrees.The sum of the first amount of rotation plus the second amount of rotation plus the third amount of rotation may be substantially equal to 360 degrees divided by a number of nozzle passages equally spaced radially about a periphery of the nozzle body. For example, the number of nozzle passages may be eight, and the sum of the first rotation amount plus the second rotation amount plus the third rotation amount may be substantially equal to 45 degrees.As noted, the inner member 222 may be rotated into the respective first, second, and third stages for predetermined periods of time and thus aligned relative to the injector body 202. In this way, efficient mixing and / or heat transfer can be achieved. For example, the first predetermined duration may be 10 ms, the second predetermined duration may be 15 ms, and the third predetermined duration may be 60 ms.One skilled in the art will recognize that although the present disclosure has been described by way of example with reference to one or more embodiments, it is not limited to the disclosed embodiments and that one or more modifications of the disclosed embodiments or alternative embodiments could be constructed without departing from the scope of the present disclosure.Accordingly, it should be understood that the configurations and methods disclosed herein are exemplary in nature and these specific embodiments are not to be interpreted in a limiting sense as numerous variations are possible. For example, the above technique may be applied to V-6, I-4, I-6, V-12, 4-cylinder boxer, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and arrangements, and other features, functions, and / or characteristics disclosed herein.The following claims particularly set forth certain combinations and sub-combinations which are considered novel and non-obvious. These claims may refer to "a" element or "a first" element or the equivalent thereof. Such claims are to be understood to include inclusion of one or more such elements and neither require nor exclude two or more such elements. Further combinations and sub-combinations of the disclosed features, functions, elements and / or characteristics may be claimed by altering the present claims or by filing novel claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope than the original claims, are also considered to be included within the subject matter of the present disclosure.

Claims

A method of injecting fuel into a combustion chamber (30) of an engine (10), comprising: rotating an inner member (222) relative to an injector body (202) a first amount of rotation and aligning an exhaust passage (204) with an exhaust source to enable the exhaust gas to enter a pre-chamber (215) for a first duration; rotating the inner member (222) relative to the injector body (202) a second amount of rotation and aligning a fuel passage with a fuel source to enable the fuel to enter a pre-chamber (215) for a second duration; and rotating the inner member (222) relative to the injector body (202) a third amount of rotation and aligning injector connectors (228) with injectors (208) for a third duration to allow a mixture of the fuel and the exhaust gas to be injected from the pre-chamber (215) into the combustion chamber (30).The method of claim 1, further comprising moving an injector needle into the pre-chamber (215) to force the mixture of the fuel and the exhaust gas into the combustion chamber (30).The method of claim 1, wherein: aligning the exhaust passage (204) with the exhaust source is effected by rotating the inner member relative to the injector body (202) by I I degrees; aligning the fuel passage with the fuel source is effected by rotating the inner member relative to the injector body (202) by an additional 11 degrees; and aligning the injector fittings (228) with the injectors is effected by rotating the inner member relative to the injector body (202) by 23 degrees.The method of claim 1, wherein the sum of the first amount of rotation plus the second amount of rotation plus the third amount of rotation is substantially equal to 360 degrees divided by a number of nozzle passages equally spaced radially about a periphery of the nozzle body.The method of claim I wherein the sum of the first amount of rotation plus the second amount of rotation plus the third amount of rotation is substantially equal to 45 degrees.The method of claim 1, wherein the first predetermined duration is 10 ms, the second predetermined duration is 15 ms, and the third predetermined duration is 60 ms.An engine system (150) comprising: a combustion chamber (30) for combusting an air-fuel mixture; a fuel line (152) to provide a high pressure fuel for combustion in the combustion chamber (30); a connection line to port a portion of the exhaust gas from the combustion chamber (30); and a fuel injector (66) including an injector body (202) and an inner member (222) disposed within and rotatable relative to the injector body (202) therein, a pre-chamber (215) defined within the inner member (222) between portions of the inner member (222) and the injector body (202), the inner member rotatable to selectively: align a first passage between the pre-chamber (215) and the connection line to allow the exhaust gas to enter the pre-chamber (215), aligning a second passage between the pre-chamber (215) and the fuel line (152) to direct fuel into the pre-chamber (215) and aligning one or more injector connectors (228) between the pre-chamber (215) and the one or more injectors (208) for injecting a fuel-exhaust mixture from the pre-chamber (215) into the combustion chamber (30).The engine system (150) of claim 7, wherein the fuel is pressurized by a fuel pump (154) prior to entering the fuel injector (66).The engine system (150) of claim 7, wherein: the inner member includes a substantially cylindrical outer wall (213) surrounding and defining the mixing chamber, and wherein the one or more injector connectors (228) are eight injector connectors (228) extending radially through the outer wall (213) circumferentially at eight substantially equal intervals; and the injector body (202) includes a substantially cylindrical body wall surrounding the substantially cylindrical outer wall (213) of the inner member (222), and the one or more injector nozzles (202) are eight injector nozzles (202) extending radially outward and longitudinally toward a central portion of the combustion chamber (30).The engine system (150) of claim 9, wherein: the inner member has a central axis (235) that is central to the cylindrical outer wall; and the exhaust nozzle (224) and the fuel nozzle (226) are at a first longitudinal position relative to the central axis (235), and wherein the one or more injector connectors (228) are / are at a second longitudinal position relative to the central axis (235) different from the first longitudinal position.The engine system of claim 10, wherein: the exhaust nozzle (224) and the fuel nozzle (226) extend radially through the cylindrical outer wall or chamber wall and are angularly spaced apart from each other by I I degrees.The engine system of claim 10, wherein one of the at least one injector coupler (228) is angularly spaced from the fuel passage by approximately 23 degrees.The engine system of claim 7, wherein: the one or more injector connectors (228) are eight injector connectors (228) angularly spaced apart from each other by approximately 45 degrees.The engine system of claim 7, further including an injector needle configured to enter the pre-chamber (215) to urge the fuel-exhaust mixture from the pre-chamber (215) through the injectors (202) and into the combustion chamber (30).The engine system of claim 7, wherein the connecting conduit (158) is configured to receive exhaust gas from an EGR conduit; downstream of an exhaust manifold (48); wherein a plurality of similarly configured exhaust passages fluidly open to a common flow path.

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