HIGH FLOW INLINE AIR/FUEL VORTEX INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES

Abstract

An air-fuel mixer includes a body having an inlet, an outlet, and an air passage therebetween. One or more fuel injectors are mounted to the body and positioned to inject fuel into the air passage with little or no space between the injector nozzles and the air passage. The fuel injectors may be inclined in an air-fuel mixer outlet direction whereby they inject fuel into the air passage with momentum in a direction of the outlet. Swirl guides are provided within the air passage. The air-fuel mixer may be installed between an intake manifold and an intercooler. The air-fuel mixer provides good mixing, low resistance to air flow, reduced fuel slip, and crisp responses to throttle up and throttle down commands.

Claims

1. An air-fuel mixer, comprising: a body having an air inlet, an air outlet, and an air passage extending from the air inlet to the air outlet; a fuel injector attached to the outside of the body, wherein the fuel injector has a nozzle positioned to inject fuel into the air passage through a port in the body; and swirl guides projecting into the air passage, wherein the swirl guides are positioned to impart swirl to air flowing from the air inlet to the air outlet.

2. The air-fuel mixer of claim 1, wherein the fuel injector is one of a plurality of fuel injectors attached to the body and having nozzles positioned to inject fuel into the air passage through corresponding ports in the body.

3. The air-fuel mixer of claim 2, wherein the plurality of fuel injectors comprise six or more.

4. The air-fuel mixer of claim 2, wherein two or more of the fuel injectors are provided by a fuel rail and have nozzles that are parallel.

5. The air-fuel mixer of claim 4, wherein the fuel rail abuts a planar outer surface of the body.

6. The air-fuel mixer of claim 1, wherein the nozzle is angled toward the air outlet.

7. The air-fuel mixer of claim 6, wherein the nozzle is angled away from a centerline of the air passage.

8. The air-fuel mixer of claim 6, wherein the port opens onto an outer surface of the body that has a surface normal parallel to an axis of the nozzle.

9. The air-fuel mixer of claim 1, wherein: the port is a bore; and the nozzle has an outlet within the bore.

10. The air-fuel mixer of claim 1, wherein a centerline of the air passage is unobstructed.

11. The air-fuel mixer of claim 1, wherein the swirl guides are downstream from the port.

12. The air-fuel mixer of claim 1, wherein: the body comprises a first part and a second part that are attached together; the first part and the second part each define a portion of the air passage; and the swirl guides are held between the first part and the second part.

13. The air-fuel mixer of claim 1, wherein the air passage is wider where the port meets the air passage than at the air inlet or the air outlet.

14. The air-fuel mixer of claim 1, wherein an internal wall of the air passage is slanted where it meets the port and the air passage is widening where it meets the port.

15. The air-fuel mixer of claim 1, wherein: the air passage has a centerline extending from the air inlet to the air outlet; the air passage has a cross-sectional area that is an area of the air passage in a plane perpendicular to the centerline; a maximum of the cross-sectional area between the air inlet and the air outlet is four times or less a minimum of the cross-sectional area between the air inlet or the air outlet.

16. The air-fuel mixer of claim 15, wherein the maximum is two times or less the minimum.

17. The air-fuel mixer of claim 1, wherein the air passage comprises a core volume extending from the air inlet to the air outlet, wherein the core volume has a cross-section corresponding to at least one of the air inlet or the air outlet; and 75% or more of the core volume as viewed from the air inlet is unobstructed.

18. The air-fuel mixer of claim 17, wherein 90% or more of the core volume as viewed from the air inlet is unobstructed.

19. The air-fuel mixer of claim 1, wherein the air passage has a core volume extending from the air inlet to the air outlet, wherein the core volume has a cross-section corresponding to at least one of the air inlet or the air outlet; the air passage has a peripheral volume surrounding the core volume; and a majority of a volume of the swirl guides that projects into the air passage is within the peripheral volume.

20. The air-fuel mixer of claim 1, wherein the swirl guides slant toward a center of the air passage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 illustrates a perspective view from the inlet side of an air-fuel mixer according to some other aspects of the present disclosure.

[0028] FIG. 2 illustrates a side cut-away view of the air-fuel mixer of FIG. 1.

[0029] FIG. 3 illustrates another side cut-away view of the air-fuel mixer of FIG. 1 taken from a second angle.

[0030] FIG. 4 illustrates another side cut-away view of the air-fuel mixer of FIG. 1 taken from a third angle.

[0031] FIG. 5 illustrates a view of the air-fuel mixer of FIG. 1 from the inlet side.

[0032] FIG. 6 illustrates a view of the air-fuel mixer of FIG. 1 from the outlet side.

[0033] FIG. 7 illustrates an exploded view of the air-fuel mixer of FIG. 1.

[0034] FIG. 8 illustrates a powertrain according to some other aspects of the present disclosure.

DETAILED DESCRIPTION

[0035] FIGS. 1-7 illustrate an air-fuel mixer 100 according to some aspects of the present disclosure. The air-fuel mixer 100 comprises a body 105 defining an air passage 119 between an air inlet 101 and an air outlet 107. The air passage 119 includes a core volume 201 (see FIGS. 2 and 5). The core volume 201 is cylindrical and has a cross-section corresponding to cross-sections of the air inlet 101 and of the air outlet 107. The core volume 201 is more than 90% unobstructed.

[0036] The air passage 119 also includes a peripheral volume 203 (see FIG. 2). The peripheral volume 203 is 10% or less the core volume 201. Swirl guides 109 (see FIGS. 2 and 5) are project into the air passage 119 and protrude into the core volume 201, but a majority of a the volume of the swirl guides 109 that projects into the air passage 119 is in the peripheral volume 203.

[0037] The swirl guides 109 are fins projecting from a periphery of the air passage 119 and comprise surfaces 231 that are angled in such a way as to impart swirl to air flowing from the air inlet 101 to the air outlet 107. The swirl guides 109 are installed in an area where the air passage 119 in narrowing and slant toward a center of the air passage 119. With reference to FIG. 7, the swirl guides 109 are provided by a ring-shaped part 233 that encircles the air passage 119. The body 105 is composed of three parts, a main part 105A, and outlet part 105B, and an inlet part 105C each of which defines a portion of the air passage 119. The ring-shaped part 233 that includes the swirl guides 109 may be clamped between the main part 105A and the outlet part 105B.

[0038] Fuel rails 103 are attached to the body 105. The fuel rails 103 each comprise three fuel injectors 111 (see FIGS. 3 and 7). The fuel injectors 111 have nozzles 205 that have outlets within bores 207 that are formed in the body 105. The fuel rails 103 may rest against planar surfaces 209 (see FIG. 7) on the outside of the body 105 and may be held to the body 105 by brackets 211. The nozzles 205 of the three fuel injectors 111 of each fuel rail 103 may be parallel to each other and to a normal of the corresponding planar surface 209. The bores 207 may have orientations parallel to those of corresponding nozzles 205.

[0039] With reference to FIG. 3, the bore 207 and the nozzle 205 are at an angle ?.sub.1 with respect to a centerline 221 of the air passage 119. The angle ?.sub.1 is an acute angle and give fuel passing through the fuel injector 111 momentum in an air inlet 101 to air outlet 107 direction. In some embodiments, the angle ?.sub.1 is about 45 degrees or less, e.g., about 30 degrees. The fuel injector 111 and the corresponding bore 207 may be tilted out of the plane of FIG. 3 so that passage through the fuel injector 111 also imparts swirl to the fuel flow.

[0040] With reference to FIGS. 3 and 4, the fuel injectors 111 have valve seats 235 in close proximity to or within the bores 207. A distance D.sub.1 from the nozzle 205 to the air passage 119 is about 1 cm or less. The nozzle 205 may be at a perimeter of the air passage 119 or project slightly into the air passage 119. The nozzles 205 and the bores 207 are positioned so that injected fuel enters the air stream within the peripheral volume 203 (see FIG. 2) of the air passage 119.

[0041] The air passage 119 has a cross-sectional area that has a minimum that occurs in the area of the air inlet 101 and again in the area of the air outlet 107. The cross-sectional area of the air passage 119 has a maximum between the air inlet 101 and the air outlet 107. The bores 207 meet the air passage 119 at a position upstream of where the maximum occurs in an area. Where the bores 207 meet the air passage 119 an inner sidewall 241 of the air passage 119 is sloped so that the air passage 119 is widening.

[0042] With reference to FIG. 7, the inner sidewall 241 may be machined into the main part 105A prior to attaching the main part 105A to the inlet part 105C. The swirl guides 109 or the single ring-shaped part 233 that provides the swirl guides 109 may be clamped between the main part 105A and the outlet part 105B, whereby when the main part 105A is attached to the outlet part 105B is securely held in place. The fuel rails 103 may be attached to the main part 105A via the brackets 211 or otherwise either before or after attaching the main part 105A to the inlet part 105C or to the outlet part 105B. Alternatively, the inlet part 105C, the main part 105A, and the outlet part 105B may be cast or otherwise formed as a single part. Optionally, the swirl guides 109 may be formed into that same part.

[0043] FIG. 8 illustrates a power train 800 that includes the air-fuel mixer 100. The power train 800 further includes an internal combustion engine 803 having an intake manifold 801 and an outlet manifold 819, a turbocharger 811, and an intercooler 807. A pipe 817 channels an exhaust air stream from the outlet manifold 819 to the turbocharger 811. Driven by the exhaust air stream, the turbocharger 811 compresses and heats an intake air stream drawn in through an intake air filter 815. A pipe 809 channels the compressed and heated intake air stream from the turbocharger 811 to the intercooler 807. The air-fuel mixer 100 is positioned so that the intake air stream passes through the air-fuel mixer 100 as it passes from the intercooler 807 to the intake manifold 801.

[0044] A pipe 805 of length D.sub.2 connects the air outlet 107 of the air-fuel mixer 100 to the intake manifold 801. Another pipe 806 connects the air inlet 101 to the intercooler 807. In some embodiments, the length D.sub.2 is in the range from about 15 cm to about 60 cm. In some embodiments, the length D.sub.2 is greater than 30 cm, e.g., about 45 cm. If the length D.sub.2 is too short, the fuel-air mixture may be inadequately blended before it reaches the intake manifold 801 and the fuel may spread unevenly through the intake manifold 801. It the length D.sub.2 is too large the fuel pulses may be attenuated.

[0045] The pipe 809, the pipe 806, and the pipe 805 may all have the same diameter, which may also be a diameter of the air inlet 101 and of the air outlet 107. In some embodiments, the pipe 805 has a diameter in the range from about 2 cm to about 25 cm. In some embodiments, the pipe 805 has a has a diameter in the range from about 5 cm to about 15 cm. The pipe 805 may have any standard pipe size The pipe size may be matched to a size of the internal combustion engine 803. In some embodiments, the internal combustion engine 803 uses port injection. In some embodiments, the internal combustion engine 803 uses direct injection. In some embodiments, the internal combustion engine 803 is a compression ignition engine.

[0046] The power train 800 may be an OEM product to which the air-fuel mixer 100 and a controller (not shown) have been added. Installing the air-fuel mixer 100 in the power train 800 may include removing a pipe between the intercooler 807 and the intake manifold 801 and replacing it with the pipe 805, the pipe 806, and the air-fuel mixer 100. The pipe 805 and the pipe 806 may have the same diameter as the pipe that was replaced.

[0047] The controller may be programmed to control the air-fuel mixer 100 in such a way that a secondary fuel introduced through the air-fuel mixer 100 reduces consumption of a primary fuel that is supplied to the engine 803 through direct injection or port injection within the intake manifold 801. The controller may cause the secondary fuel injection rate to be dependent on such factors as a speed-load operating point of the engine 803 and throttle commands. In some embodiments, the controller limits secondary fuel injection to speed-load conditions above idle.

[0048] In some embodiments, the controller is configured to receive crankshaft position and/or camshaft position information and uses that information to time secondary fuel injection in relation to a cam cycle of the engine 803. The timing may be such that distinct fuel pulses from the air-fuel mixer 100 supply the secondary fuel to distinct cylinders of the engine 803. In some embodiments, a plurality of fuel injectors 111 on the air-fuel mixer 100 are batch fired. Batch firing may facilitate providing secondary fuel doses to distinct cylinders. The short dwell time provided by the structure of the air-fuel mixer 100 and its position within the power train 800 enable these modes of operation.

[0049] The components and features of the present disclosure have been shown and/or described in terms of certain disclosure and examples. While a particular component or feature, or a broad or narrow formulation of that component or feature, may have been described in relation to only some aspects of the present disclosure or some examples, all components and features in either their broad or narrow formulations may be combined with other components or features to the extent such combinations would be recognized as logical by one of ordinary skill in the art.