Reductant dosing unit compact side feed inlet port

Abstract

A side feed inlet port for an injector, which makes use of stamped parts to form a compact, high strength three-piece inlet port at a significantly reduced cost. By using an inner sleeve and an outer sleeve, injector sealing is accomplished using the interior sleeve, creating a sealing point, while allowing for inlet conduit attachment to the outer sleeve at, above, or below the sealing point of the DEF injector. The construction of the inlet port is such that there is proper sealing between the inner sleeve and one or more seals, while allowing for the connection between the inlet conduit and the outer sleeve to reduce the overall height of the inlet port, and therefore, the injector. The position of the inlet conduit may be altered without affecting the sealing connection between the inner sleeve and the seal(s), such that the desirable overall height may be achieved.

Claims

1. An apparatus, comprising: an injector, including: an inlet port for transferring fluid to an inlet tube; an inner sleeve, the inner sleeve being part of the inlet port; an outer sleeve mounted to the inner sleeve, the outer sleeve being part of the inlet port; an inlet conduit partially disposed in the outer sleeve, the inlet conduit being part of the inlet port; a cavity formed at least partly by the outer sleeve; a volume reduction feature that is formed as part of the outer sleeve, wherein the volume reduction feature reduces the volume in the cavity; an upper wall formed as part of the outer sleeve, the volume reduction feature is formed as part of the upper wall of the outer sleeve; wherein fluid flows from the inlet conduit, into the cavity, and then into the inlet tube; wherein the volume reduction feature extends a majority of a distance between the inlet tube and an inner surface of a portion of the upper wall which does not form the volume reduction feature, wherein the volume reduction feature extends at least partly within the inner sleeve at a radial central portion thereof; wherein the inlet port is a side feed inlet port in which a longitudinal axis of the inlet conduit is orthogonal to a longitudinal axis of the injector; wherein fluid flows from the inlet conduit, through the outer sleeve and into the inlet tube; and wherein the volume reduction feature comprises a semi-spherical wall portion of the upper wall, a diameter of the semi-spherical wall portion extending a majority of a distance across an opening of the inlet tube.

2. The apparatus of claim 1, further comprising: an aperture formed as part of the outer sleeve; wherein a portion of the inlet conduit is disposed in the aperture formed as part of the outer sleeve, and the inlet conduit is in fluid communication with the cavity.

3. The apparatus of claim 2, further comprising: a flow path; wherein a portion of the inner sleeve obstructs a majority of the aperture, and the flow path is formed by the portion of the aperture that is unobstructed by the sleeve.

4. The apparatus of claim 1, wherein the outer sleeve, the inner sleeve, and the inlet tube are all separate components that are formed using one selected from the group consisting of a stamping process and a forming process.

5. The apparatus of claim 3, wherein a majority of the aperture is obstructed by the portion of the inner sleeve, the flow path being partly defined by a space between an outer surface of the inner sleeve and at least one of an inner surface of the outer sleeve and an end portion of the inlet conduit.

6. The apparatus of claim 1, further comprising a seal member disposed between an outer surface of the inlet tube and an inner surface of the inner sleeve, wherein a radial axis of the seal member at a center thereof is offset from a longitudinal axis of the inlet conduit.

7. The apparatus of claim 1, wherein the volume reduction feature reduces a volume of the cavity for receiving fluid by 20%.

8. The apparatus of claim 1, wherein an upstream opening of the inlet tube, relative to a direction of fluid flow through the inlet tube, is disposed within an opening of the inner sleeve.

9. The apparatus of claim 1, wherein the volume reduction feature does not directly contact the inner sleeve and does not directly contact the inlet tube.

10. An inlet port for an injector comprising: an inner sleeve mounted to an inlet tube of an injector; an outer sleeve, the inner sleeve partially disposed in the outer sleeve; a cavity formed as part of the outer sleeve, the inner sleeve partially disposed in the cavity; an aperture formed as part of the outer sleeve, the aperture in fluid communication with the cavity; an inlet conduit partially disposed in the aperture such that the inlet conduit is in fluid communication with the cavity; a volume reduction feature, wherein the volume reduction feature reduces the volume in the cavity and is formed as part of the outer sleeve; an upper wall formed as part of the outer sleeve, the volume reduction feature is formed as part of the upper wall of the outer sleeve; and a flow path, the inlet conduit in fluid communication with the cavity through the flow path; wherein the volume reduction feature extends a majority of a distance between the inlet tube and an inner surface of a portion of the upper wall which does not form the volume reduction feature, the volume reduction feature extending at least partly within the inner sleeve at a radial center portion of the inner sleeve; wherein a portion of the inner sleeve obstructs a majority of the aperture, and the flow path is formed by the portion of the aperture that is unobstructed by the inner sleeve; wherein fluid flows through the inlet conduit and into the cavity, and from the cavity into the inlet tube.

11. The inlet port of claim 10, wherein the outer sleeve, the inner sleeve, and the inlet tube are all formed using one selected from the group consisting of a stamping process and a forming process.

12. The inlet port of claim 10, wherein the volume reduction feature comprises a semi-spherical wall portion of the upper wall of the outer sleeve.

13. The inlet port of claim 10, wherein the inlet port is a side feed inlet port.

14. The inlet port of claim 10, wherein a longitudinal axis of the inlet conduit is orthogonal to a longitudinal axis of at least one of the inlet tube and the injector.

15. The inlet port of claim 10, wherein the flow path is defined in part by a space between an outer surface of the inner sleeve and at least one of an inner surface of the outer sleeve and an end portion of the inlet conduit.

16. The inlet port of claim 12, wherein a diameter of the semi-spherical wall portion of the upper wall of the outer sleeve is greater than a radius of an opening of the inner sleeve.

17. The inlet port of claim 12, wherein an upstream opening of the inlet tube, relative to a direction of fluid flow through the inlet tube, is disposed within an opening of the inner sleeve.

18. The inlet port of claim 12, wherein the volume reduction feature does not directly contact the inner sleeve and does not directly contact the inlet tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

(2) FIG. 1 is an exploded view of a portion of an exhaust system having an injector, according to embodiments of the present invention;

(3) FIG. 2 is a side view of an injector having a compact side feed inlet port, according to embodiments of the present invention;

(4) FIG. 3 is an enlarged sectional view of a compact side feed inlet port mounted to an injector, according to embodiments of the present invention;

(5) FIG. 4 is an enlarged sectional view of an alternate embodiment of a compact side feed inlet port mounted to an injector, according to embodiments of the present invention;

(6) FIG. 5 is a perspective view of an alternate embodiment of a compact side feed inlet port mounted to an injector, according to embodiments of the present invention; and

(7) FIG. 6 is an exploded view of an alternate embodiment of a compact side feed inlet port mounted to an injector, according to embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

(9) An injector having a side feed inlet port according to the present invention is shown in FIGS. 1-3 generally at 10. The injector 10 has a multi-piece inlet port, shown generally at 12, which receives diesel exhaust fluid (DEF). The inlet port 12 is connected to a hydraulic connection 62, which is connected to a hose 64 such that DEF is transferred from the hose 64 to the inlet port 12. The injector 10 also includes an inlet tube 14, where the DEF is able to flow from the inlet port 12 and into the inlet tube 14. Furthermore, the injector 10 also includes an actuator, such as a solenoid (not shown), which is used to control a valve assembly (not shown) for controlling the flow of DEF into an exhaust pipe 16. The exhaust pipe 16 includes an external mounting portion 18, that the injector 10 is mounted to.

(10) Surrounding the inlet tube 14 is a first seal, which in this embodiment is an O-ring 20. The injector 10 also includes a housing 22 which surrounds a portion of the inlet tube 14. The housing 22 includes a groove 24, and disposed in the groove 24 is a second seal, which in this embodiment is another O-ring 26.

(11) The inlet port 12 includes several components; one of the components is an inner sleeve 28. The inner sleeve 28 is generally cylindrical in shape, and has a flange portion 30. When the injector 10 is assembled, the inner sleeve 28 surrounds both of the O-Rings 20,26, which provide a sealing function to prevent DEF from migrating around the O-rings 20,26 into certain areas of the injector 10. The inner sleeve 28 also includes an aperture 28a, which DEF passes through prior to entering into the inlet tube 14.

(12) The inlet port 12 also includes an outer sleeve 32, which is also cylindrical in shape, and includes a cavity, shown generally at 34. The outer sleeve 32 surrounds the inner sleeve 28, as shown in FIG. 3. The inner sleeve 28 may be press-fit into the outer sleeve 32, or the inner sleeve 28 may be connected to the outer sleeve 32 using a weld connection, along weld connection points 36,38. The inner sleeve 28 and outer sleeve 32 may also be connected together through a brazing process. The outer sleeve 32 also includes a cylindrical flange portion 40 having an aperture 42. An inlet conduit 44 is partially disposed in the aperture 42, such that the inlet conduit 44 is connected to the outer sleeve 32. The inlet conduit 44 may be disposed in the aperture 42 through a weld connection, press-fit connection, or the like. The inlet conduit 44 is connected to the hydraulic connection 62 to receive DEF from the hose 64.

(13) The inner sleeve 28 includes a circumferential wall 46, and a portion of the circumferential wall 46 obstructs a portion of the aperture 42. The portion of the aperture 42 that is unobstructed provides a flow path, shown generally at 48. The inlet conduit 44 also includes an inlet aperture 50, and the DEF that flows into the inlet aperture 50 and through the inlet conduit 44 flows through the flow path 48 and into the cavity 34 of the outer sleeve 32. The DEF then flows into the inlet tube 14 from the cavity 34.

(14) An area of the first O-ring 20 contacts the circumferential wall 46 of the outer sleeve 32, forming a sealing area, shown generally at 56. The size of the sealing area 56 may vary, depending upon the size of the O-ring 20, and how much the O-ring 20 is compressed, causing a greater or lesser amount of the outer surface of the O-ring 20 to contact the circumferential wall 46. The sealing area 56 has a center 56a, and the inlet conduit 44 has an axis 58 along the center of the inlet conduit 44, as shown in FIG. 3. The axis 58 is located at a distance 60 from the center 56a of the sealing area 56. This distance 60 may be varied, affecting the size of the flow path 48. The size of the flow path 48 may also be affected by changing the diameter of the inlet conduit 44 and correspondingly changing the diameter of the cylindrical flange portion 40, changing the position of the outer sleeve 32 relative to the inner sleeve 28, and changing the position of the cylindrical flange portion 40 relative to the outer sleeve 32. In this embodiment, the center 56a of the sealing area 56 is below the axis 58. However, it is within the scope of the invention that the position and size of any of the above mentioned components may be changed such that the center 56a of the sealing area 56 may be any distance 60 above or below the axis 58.

(15) Each of the inner sleeve 28, the outer sleeve 32, and the inlet conduit 44 are made through a stamping process, and then assembled together during manufacturing.

(16) An alternate embodiment of the invention is shown in FIGS. 4-6. In this embodiment, the outer sleeve 32 also includes a volume reduction feature 52, which in this embodiment is a semi-spherical wall portion. The volume reduction feature 52 is formed as part of an upper wall 54 of the outer sleeve 32. The volume reduction feature 52 reduces the overall volume in the cavity 34 of the outer sleeve 32. In this embodiment, the volume reduction feature 52 has a radius of about six millimeters, and the shape of the volume reduction feature 52 reduces the volume of the cavity 34 by approximately 20%. However, it is within the scope of the invention that other dimensions and shapes may be used to form the volume reduction feature 52, changing the volume of the cavity 34. Reducing the volume in the cavity 34 reduces the amount of DEF in the cavity 34, and therefore the overall amount of DEF in the injector 10. Under certain conditions, the DEF may freeze when exposed to low temperatures. Some systems do not have the capability to purge the DEF when the vehicle is shut off, and the DEF may freeze (and expand) when exposed to low temperature. Reducing the overall volume of DEF in the injector 10 reduces the overall volume expansion of the DEF when the DEF freezes. Less volume expansion by the DEF results in less strain on the components of the injector 10.

(17) There are some injectors which have a purge function. The injector 10 of the present invention may be equipped with this purge function, where the DEF is purged from the injector 10 under certain conditions, such as when the vehicle is shut off. Having the volume reduction feature 52 results in less overall DEF in the injector 10, and therefore less DEF that needs to be purged. Additionally, when the conditions arise that necessitate the use of the injector 10, and the injector 10 must be primed, where the DEF is pumped back into the injector 10, having less volume results in less DEF being necessary to fully prime the injector 10.

(18) The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.