Variable spray angle injector arrangement

Abstract

An injector, comprising, an injector body comprising, an inner wall that defines an injector cavity for fluid, at least one inlet channel into the injector cavity, and at least one outlet channel from the injector cavity, a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the plunger being movable longitudinally in the injector cavity between at least: a first open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a first position, and a second open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a second position different from the first position.

Claims

1. An injector, comprising: an injector body comprising: an inner wall that defines an injector cavity for fluid; at least one inlet channel into the injector cavity; and at least one outlet channel from the injector cavity having a first portion and a second portion in fluid communication with the first portion; and a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the at least one passageway having an outlet end, and the plunger being movable longitudinally in the injector cavity between at least: a first open arrangement in which the outlet end of the at least one passageway is positioned at a first longitudinal position of the at least one outlet channel to direct fluid into the first portion of the at least one outlet channel for a first spray trajectory; and a second open arrangement in which the outlet end of the at least one passageway is positioned at a second longitudinal position of the at least one outlet channel to direct fluid into the second portion of the at least one outlet channel for a second spray trajectory, and the second longitudinal position is different from the first longitudinal position.

2. The injector of claim 1, wherein the first position is spaced longitudinally from the second position.

3. The injector of claim 1, wherein the at least one outlet channel has an inlet end, an outlet end, and a channel axis between the inlet end and the outlet end, and wherein the first position is located on a first side of the channel axis and the second position is located on a second side of the channel axis.

4. The injector of claim 1, wherein the plunger is further movable to a closed arrangement in which the at least one passageway is prevented from directing fluid into the at least one outlet channel.

5. The injector of claim 4, wherein the inner wall of the injector body blocks the at least one passageway when the plunger is moved to the closed arrangement.

6. The injector of claim 1, wherein the plunger is further movable to a third open arrangement in which the outlet end of the at least one passageway is positioned at a third longitudinal position of the at least one outlet channel to direct fluid into the at least one outlet channel for a third spray trajectory, and the third longitudinal position is located longitudinally between the first and second longitudinal positions.

7. The injector of claim 1, wherein the at least one passageway is narrower than the at least one outlet channel.

8. The injector of claim 1, wherein, when the plunger is in the first open arrangement, fluid at the first portion of the at least one outlet channel has a first velocity and fluid at the second portion of the at least one outlet channel has a second velocity less than the first velocity.

9. The injector of claim 1, wherein, when the plunger is in the second open arrangement, fluid at the first portion of the at least one outlet channel has a first velocity and fluid at the second portion of the at least one outlet channel has a second velocity greater than the first velocity.

10. The injector of claim 1, wherein the outlet end of the at least one passageway is adjacent the first portion and spaced apart from the second portion of the at least one outlet channel when the plunger is in the first open arrangement.

11. The injector of claim 1, wherein the outlet end of the at least one passageway is adjacent the second portion and spaced apart from the first portion of the at least one outlet channel when the plunger is in the second open arrangement.

12. A combustion system, comprising: a combustion chamber; a piston disposed in the combustion chamber; and an injector having an injector body, the injector body comprising an inner wall that defines an injector cavity, at least one inlet channel into the injector cavity, and at least one outlet channel from the injector cavity having a first portion and a second portion in fluid communication with the first portion, and a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the plunger having an outlet end, and the plunger being movable in the injector cavity between at least: a first open arrangement in which the outlet end of the at least one passageway is positioned at a first longitudinal position of the at least one outlet channel to direct fluid into the first portion of the at least one outlet channel for a first spray trajectory, and a second open arrangement in which the outlet end of the at least one passageway is positioned at a second longitudinal position of the at least one outlet channel to direct fluid into the second portion of the at least one outlet channel for a second spray trajectory, and the second longitudinal position is different from the first longitudinal position.

13. The combustion system of claim 12, wherein the first position is spaced longitudinally relative to a direction of movement of the plunger from the second position.

14. The combustion system of claim 12, wherein the at least one outlet channel has an inlet end, an outlet end, and a channel axis between the inlet end and the outlet end, and wherein the first position is located on a first side of the channel axis and the second position is located on a second side of the channel axis.

15. The combustion system of claim 12, wherein the at least one passageway is narrower than the at least one outlet channel.

16. An exhaust system, comprising: a particulate filter; a decomposition reactor downstream of the particulate filter; a selective catalytic reduction system downstream of the decomposition reactor; and an injector having an injector body, the injector body comprising, an inner wall that defines an injector cavity, at least one inlet channel into the injector cavity and at least one outlet channel from the injector cavity having a first portion and a second portion in fluid communication with the first portion, and a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the plunger having an outlet end, and the plunger being movable in the injector cavity between at least: a first open arrangement in which the outlet end of the at least one passageway is positioned at a first longitudinal position of the at least one outlet channel to direct fluid into the first portion of the at least one outlet channel for a first spray trajectory, and a second open arrangement in which the outlet end of the at least one passageway is positioned at a second longitudinal position of the at least one outlet channel to direct fluid into the second portion of the at least one outlet channel for a second spray trajectory, and the second longitudinal position is different from the first longitudinal position; wherein the injector is disposed in the decomposition reactor.

17. The exhaust system of claim 16, wherein the first position is spaced longitudinally relative to a direction of movement of the plunger from the second position.

18. The exhaust system of claim 16, wherein the at least one outlet channel has an inlet end, an outlet end, and a channel axis between the inlet end and the outlet end, and wherein the first position is located on a first side of the channel axis and the second position is located on a second side of the channel axis.

19. The exhaust system of claim 16, wherein the at least one passageway is narrower than the at least one outlet channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 is a schematic cross-sectional view of an exemplary injector of the present disclosure having an injector body with a plurality of outlet channels and a plunger with a plurality of passageways, the plunger shown in a closed arrangement;

(3) FIG. 2 is another schematic cross-sectional view of the injector of FIG. 1 shown with the plunger in a first open arrangement;

(4) FIG. 3 is yet another schematic cross-sectional view of the injector of FIG. 1 shown with the plunger in a second open arrangement;

(5) FIG. 4 is yet another schematic cross-sectional view of the injector of FIG. 1 shown with the plunger in a third open arrangement;

(6) FIG. 5 is a detailed view of the circled portion of the injector of FIG. 4;

(7) FIGS. 6A-6C are cross-sectional views of various outlet channels;

(8) FIG. 7 shows a first schematic fluid trajectory corresponding to the first open arrangement of FIG. 2;

(9) FIG. 8 shows a first schematic velocity distribution for the fluid of FIG. 7;

(10) FIG. 9 shows a second schematic fluid trajectory corresponding to the second open arrangement of FIG. 3;

(11) FIG. 10 shows a second schematic velocity distribution for the fluid of FIG. 9;

(12) FIG. 11 shows a third schematic fluid trajectory corresponding to the third open arrangement of FIG. 4;

(13) FIG. 12 shows a third schematic velocity distribution for the fluid of FIG. 11; and

(14) FIG. 13 is a schematic view of the injector spraying the first, second, and third fuel trajectories of FIGS. 7, 9, and 11 into a combustion chamber;

(15) FIG. 14 is a schematic view showing an exhaust system with the injector of FIG. 1.

(16) Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

(17) Referring initially to FIG. 1, an injector 10 is illustrated schematically. The injector is configured to inject fuel into a combustion chamber 1308 (FIG. 13) of an internal combustion engine (not shown) or diesel exhaust fluid into decomposition reactor of an exhaust system of an internal combustion system (not shown). Injector 10 has first end 12, a second end 14, and a longitudinal axis A. First end 12 of injector 10 may be an upper end that is spaced outwardly relative to the combustion chamber 1308, and second end 14 of injector 10 may be a lower end that is spaced inwardly relative to combustion chamber 1308.

(18) The illustrative injector 10 includes an elongate injector body 20. Although injector body 20 is shown as a unitary construct in FIG. 1, injector body 20 may be constructed of a plurality of individual pieces assembled together. Injector body 20 includes an inner wall 21 that defines an injector cavity 22 to receive fluid. Near the first or upper end 12, injector 10 includes at least one inlet channel 24 for receiving fluid from a fluid supply circuit or rail (not shown) and directing the fluid into injector cavity 22. Near the second or lower end 14, injector 10 includes a sac 26 with at least one outlet channel 28, illustratively a plurality of radially-spaced outlet channels 28, for delivering fluid from injector cavity 22 to combustion chamber 1308 (FIG. 13).

(19) The illustrative injector 10 also includes a plunger 30 in injector cavity 22. Plunger 30 may also be referred to herein as a needle or nozzle valve, for example. The illustrative plunger 30 includes a head 32 arranged toward first end 12 of injector 10, a tip 34 arranged toward second end 14 of injector 10, and a shaft 36 extending therebetween. Tip 34 of plunger 30 defines at least one passageway 38, illustratively a plurality of radially-spaced passageways 38, arranged in fluid communication with injector cavity 22.

(20) Plunger 30 may be configured for reciprocal and longitudinal movement in injector cavity 22 between at least one closed arrangement and a plurality of open arrangements. Plunger 30 is shown in a closed arrangement in FIG. 1. In this closed arrangement, passageways 38 do not communicate with outlet channels 28. Instead, passageways 38 interface with inner wall 21 of injector body 20, which prevents fluid in injector cavity 22 from reaching outlet channels 28 via passageways 38. Plunger 30 may be biased in this closed arrangement, such as using a spring (not shown). Plunger 30 is shown in three different open arrangements in FIGS. 2-4. In each open arrangement, tip 34 of plunger 30 is moved longitudinally relative to the closed arrangement to place passageways 38 in fluid communication with outlet channels 28, which allows fluid in injector cavity 22 to reach outlet channels 28 via passageways 38. These open arrangements are described further below.

(21) The illustrative injector 10 further includes an actuating system 40 operably coupled to plunger 30 to control movement of plunger 30 in injector cavity 22 between the open and closed arrangements. Actuating system 40 may control movement of plunger 30 based on one or more engine operating conditions (e.g., engine load, engine speed). Actuating system 40 may include a solenoid actuator, a piezoelectric actuator, a magnetostrictive actuator, or another suitable actuator for controlling movement of plunger 30. Such actuators may interact with head 32 of plunger 30 via a suitable link 42, which may be a mechanical link and/or a hydraulic link, for example. Suitable actuating systems 40 are disclosed in U.S. Patent Application Publication Nos. 2011/0232606 and 2013/0270369, for example, the disclosures of which are expressly incorporated herein by reference in their entirety.

(22) The second or lower end 14 of injector 10, which includes outlet channels 28 in injector body 20 and passageways 38 in plunger 30, is shown in more detail in FIG. 5. FIG. 5 corresponds to the open arrangement of FIG. 4, with passageways 38 being shown in fluid communication with outlet channels 28.

(23) Each outlet channel 28 has an inlet end 50 and an outlet end 52, and each passageway 38 has an inlet end 60 and an outlet end 62. When plunger 30 is in an open arrangement, as shown in FIG. 5, outlet end 62 of passageway 38 is positioned in fluid communication with inlet end 50 of the corresponding outlet channel 28. By contrast, when plunger 30 is in a closed arrangement, as shown in FIG. 1, plunger 30 interacts with inner wall 21 of injector body 20 to interrupt fluid communication between outlet end 62 of passageway 38 and inlet end 50 of the corresponding outlet channel 28.

(24) The size, shape, and orientation of each outlet channel 28 and passageway 38 may vary. With respect to outlet channel 28 of FIG. 5, for example, the diameter D.sub.1, the length L, and the channel angle between channel axis C and reference plane R may vary. The cross-sectional shape of each outlet channel 28 may also vary. For example, outlet channel 28 may be circular in cross-section, as shown in FIG. 6A, oval in cross-section, as shown in FIG. 6B, and/or may include one or more radial extensions 29, as shown in FIG. 6C. With respect to passageway 38 of FIG. 5, for example, the diameter D.sub.2 and the generally L-shaped pathway may vary. The number of outlet channels 28 and passageways 38 may also vary. Outlet channels 28 and passageways 38 may be formed by abrasive flow machining (AFM), electric discharge machining (EDM), laser machining, or other suitable manufacturing methods.

(25) In the direction of longitudinal axis A of injector 10, each outlet channel 28 may have at least a first side 54 and a second side 56. In the illustrated embodiment of FIG. 5, first side 54 of outlet channel 28 is the upper half or high side of outlet channel 28 that is located above channel axis C, and second side 56 of outlet channel 28 is the lower half or low side of outlet channel 28 that is located below channel axis C. First side 54 and second side 56 of the illustrative outlet channel 28 are arranged in fluid communication with one another, such that fluid in first side 54 of outlet channel 28 may travel to second side 56 of outlet channel 28, and vice versa.

(26) Outlet end 62 of each passageway 38 may be smaller in size (i.e., narrower) than inlet end 50 of the corresponding outlet channel 28. For example, as shown in FIG. 5, diameter D.sub.2 at outlet end 62 of passageway 38 may be smaller than diameter D.sub.1 at inlet end 50 of the corresponding outlet channel 28. In this manner, outlet end 62 of passageway 38 may be moved to a plurality of different open arrangements between first side 54 and second side 56 of the corresponding outlet channel 28, as shown in FIGS. 2-4.

(27) By moving plunger 30 between the plurality of different open arrangements shown in FIGS. 2-4, actuating system 40 may control the position of each passageway 38 relative to each outlet channel 28. As a result, actuating system 40 may also control the introduction of fluid into inlet end 50 of each outlet channel 28 from outlet end 62 of each passageway 38, the velocity distribution of the fluid within each individual outlet channel 28, and the trajectory of the resulting fluid spray from outlet end 52 of each outlet channel 28. This trajectory control method is described further below with reference to FIGS. 7-12.

(28) A first spray trajectory or axis S.sub.1 from outlet channel 28 is described with reference to FIG. 7 (which corresponds to the first open arrangement of FIG. 2). In this arrangement, fluid is introduced to inlet end 50 of outlet channel 28 at a first position P.sub.1 corresponding to first side 54 (i.e., the high side) of outlet channel 28. Some of the fluid may travel to second side 56 (i.e., the low side) of outlet channel 28 before reaching outlet end 52. Upon reaching outlet end 52, the fluid in first side 54 of outlet channel 28 may be traveling faster than the fluid in second side 56 of outlet channel 28. In other words, the velocity distribution at outlet end 52 may be biased toward first side 54 of outlet channel 28, which may be referred to herein as a biased high velocity distribution. A biased high velocity distribution is shown schematically in FIG. 8. Upon exiting outlet end 52, the biased high velocity distribution may cause the resulting fluid spray to travel downwardly relative to channel axis C along a first spray axis S.sub.1, as shown in FIG. 7. The first spray angle of the first spray axis S.sub.1 may be deeper than the channel angle of the channel axis C relative to the reference plane R.

(29) A second spray trajectory or axis S.sub.2 from outlet channel 28 is described with reference to FIG. 9 (which corresponds to the second open arrangement of FIG. 3). In this arrangement, fluid is introduced to inlet end 50 of outlet channel 28 at a second position P.sub.2 corresponding to second side 56 (i.e., the low side) of outlet channel 28. Some of the fluid may travel to first side 54 (i.e., the high side) of outlet channel 28 before reaching outlet end 52. Upon reaching outlet end 52, the fluid in second side 56 of outlet channel 28 may be traveling faster than the fluid in first side 54 of outlet channel 28. In other words, the velocity distribution at outlet end 52 may be biased toward second side 56 of outlet channel 28, which may be referred to herein as a biased low velocity distribution. A biased low velocity distribution is shown schematically in FIG. 10. Upon exiting outlet end 52, the biased low velocity distribution may cause the resulting fluid spray to travel upwardly relative to channel axis C along a second spray axis S.sub.2, as shown in FIG. 9. The second spray angle of the second spray axis S.sub.2 may be shallower than the channel angle of the channel axis C relative to the reference plane R.

(30) A third spray trajectory or axis S.sub.3 from outlet channel 28 is described with reference to FIG. 11 (which corresponds to the third open arrangement of FIG. 4). In this arrangement, fluid is introduced to inlet end 50 of outlet channel 28 at a third position P.sub.3 corresponding to channel axis C between first side 54 and second side 56. The velocity distribution at outlet end 52 may be substantially balanced between first side 54 and second side 56, which may be referred to herein as a balanced velocity distribution. A balanced velocity distribution is shown schematically in FIG. 12. Upon exiting outlet end 52, the balanced velocity distribution may cause the third spray axis S.sub.3 to generally follow channel axis C, as shown in FIG. 11. The third spray angle of the third spray axis S.sub.3 may be equal to the channel angle of the channel axis C relative to the reference plane R.

(31) In summary, by introducing fluid to each outlet channel 28 at a desired position P.sub.1, P.sub.2, P.sub.3, the resulting fluid spray from each outlet channel 28 may be delivered along a desired spray trajectory or axis S.sub.1, S.sub.2, S.sub.3. It is also within the scope of the present disclosure to introduce fluid to each outlet channel 28 at a plurality of positions other than (e.g., between) the above-described positions P.sub.1, P.sub.2, P.sub.3 to produce additional fluid spray trajectories. Although the illustrated fluid spray trajectories S.sub.1, S.sub.2, S.sub.3 are linear, the fluid spray trajectories S.sub.1, S.sub.2, S.sub.3 may bend or curve in a non-linear manner.

(32) Referring next to FIG. 13, a combustion system 1300 according to one embodiment of the present disclosure is depicted as including the injector 10 (not fully shown), a cylinder 1302, and a piston 1304. Cylinder 1302 generally includes a cylinder cavity 1306 and piston 1304. Cylinder 1302 is generally formed in an engine block (not shown). A cylinder head (not shown) is positioned on a top surface 1314 of cylinder 1302. The bottom surface of the cylinder head attaches to engine block closing cylinder 1302 from its top surface 1314 and forming a combustion chamber 1308. Piston 1304 is slidably disposed within the cylinder 1302. It should be understood that while piston 1304 is shown in FIG. 13, in certain embodiments, piston 1304 may have different shape without affecting implementation of the present disclosure. The cylinder head includes an exhaust passage (not shown), an intake passage (not shown) and an injector bore (not shown). Injector 10 is securely mounted into the injector bore formed within the cylinder head for injecting fuel in combustion chamber 1308. The exhaust passage formed in the cylinder head directs exhaust gases from combustion chamber 1308 and an intake passage directs intake air into combustion chamber 1308.

(33) The piston 1304 generally includes a depending cylindrical wall 1310, a top surface 1314, a piston crown 1312, and lower surface 1316. Top surface of piston 1304 cooperates with the cylinder head and a portion of cylinder 1302 that extends between the cylinder head and piston 1304 to define combustion chamber 1308. Although not specifically shown in FIG. 13, piston 1304 is connected to a crankshaft by way of a connecting rod which translates reciprocal movement of piston 1304 along a rectilinear path within cylinder 1302 into rotational movement of the crankshaft in a manner that is well known in the art.

(34) Still referring to FIG. 13, an upper portion of piston 1304 is referred to as piston crown 1312. Injector 10 is slidably disposed within the cylinder 1302. Piston crown 1312 is configured to receive fuel from injector 10. The desired spray trajectory S.sub.1, S.sub.2, S.sub.3 (as shown) may be chosen to control the interaction between the fuel spray and the air in piston crown 1312 of combustion chamber 1308. In operation, actuating system 40 may be configured to move plunger 30 (FIG. 1) based on one or more engine operating conditions (e.g., engine load, engine speed) to target a certain feature or location of piston crown 1312 with the desired spray trajectory S.sub.1, S.sub.2, S.sub.3. Such targeting between the fuel spray and the air in combustion chamber 1308 may minimize emissions and improve fuel economy.

(35) Referring now to FIG. 14, an exhaust system 1400 according to one embodiment of the present disclosure is depicted as including the injector 10 (not fully shown), a particulate filter 1402, a decomposition reactor 1404, and a selective catalytic reduction (SCR) catalyst 1406. Decomposition reactor 1404 is connected downstream to particulate filter 1402 and upstream to the SCR catalyst 1406. The decomposition reactor 1404 includes a diesel exhaust fluid (DEF) dosing valve 1408 which is connected to a tank (not shown) containing DEF. Injector 10 is disposed into the DEF dosing valve 1408. Particulate filter 1402 is connected to exhaust passage (not shown) via an exhaust line 1410.

(36) Operationally, exhaust from the combustion chamber 1308 (FIG. 13) enters into particulate filter 1402 over a diesel oxidation catalyst into a wall-flow filter. Carbon particles are contained in the wall-flow filter. Nitric oxide in exhaust is converted into nitrogen dioxide (NO.sub.2) in the diesel oxidation catalyst. As nitrogen dioxide (NO.sub.2) flows through the wall-flow filter, it reacts with carbon (in wall-flow filter) to produce carbon dioxide (CO.sub.2) and nitrogen oxide (NO). As the exhaust passes into the decomposition reactor, injector 10 sprays a small amount of DEF into hot exhaust stream 1404 forming ammonia (NH.sub.3), through a series of reactions. Together nitrogen oxide (NO) and ammonia (NH.sub.3) passes through SCR catalyst 1406 forming water vapor and nitrogen. As explained above with reference to FIG. 13, actuating system 40 may be configured to move plunger 30 (FIG. 1) based on one or more engine operating conditions (e.g., engine load, engine speed) to target a certain feature or location in decomposition reactor 1404 with the desired spray trajectory S.sub.1, S.sub.2, S.sub.3. It should be understood that while combustion system 1300 and exhaust system 1400 are described hereinabove as having the injector 10, in certain embodiments, injector 10 may be positioned in other systems, for example, liquid hydrocarbon dosing systems, without affecting implementation of the present disclosure.

(37) While this invention has been described as having exemplary designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.