Abstract:
A system for mounting an injector to an exhaust conduit in an exhaust treatment system includes a boss having an externally threaded surface. The boss is adapted to be fixed to the exhaust conduit. A retention member is adapted to be coupled to the injector housing to transfer an axial load to the housing. An internally threaded nut includes a flange engaging the retention member. The nut threadingly engages with the boss to clamp the housing of the injector to the boss as the nut is rotated.

Description:
FIELD 
       [0001]    The present disclosure generally relates to an exhaust treatment system, and more particularly to a simplified injector mounting system including threaded coupling. 
       BACKGROUND 
       [0002]    In the automotive industry, injectors have been included in exhaust treatment systems, particularly in diesel exhaust gas aftertreatment systems for injecting a fluid such as a suitable fuel, oxygenator or reductant to threat the exhaust gas. One known system for mounting such injectors includes a plurality of bolt studs that extend from an exhaust pipe as part of a bolted flange-type connection for the injector. Another existing mounting system includes a V-band clamp arrangement. While such mounting systems may be suitable for their intended purpose, it may be beneficial to provide a simplified and improved mount. 
       SUMMARY 
       [0003]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0004]    A system for mounting an injector to an exhaust conduit in an exhaust treatment system includes a boss having an externally threaded surface. The boss is adapted to be fixed to the exhaust conduit. A retention member is adapted to be coupled to the injector housing to transfer an axial load to the housing. An internally threaded nut includes a flange engaging the retention member. The nut threadingly engages with the boss to clamp the housing of the injector to the boss as the nut is rotated. 
         [0005]    An injector assembly for injecting a fluid into an exhaust conduit of an exhaust treatment system includes an injector housing having an orifice. A valve member is positioned within the housing and is moveable to allow and cease a flow of fluid through the orifice. A boss including an externally threaded surface is adapted to be fixed to the exhaust conduit. A retention member is adapted to be coupled to the injector housing. An internally threaded nut includes a flange engaging the retention member. The nut is threadingly engaged with the externally threaded surface of the boss. The rotation of the nut axially drives the retention member, which in turn, axially drives the injector housing toward the boss to clamp the injector housing between the nut and the boss. 
         [0006]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0007]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0008]      FIG. 1  is a schematic depicting an exemplary exhaust treatment system including an injector mount constructed in accordance with the teachings of the present disclosure; 
           [0009]      FIG. 2  is an exploded perspective view of an injector assembly including a threaded injector mount; and 
           [0010]      FIG. 3  is a fragmentary cross-sectional side view of the injector and injector mount. 
       
    
    
       [0011]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0012]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0013]    An exhaust gas aftertreatment system  10  is depicted in  FIG. 1  for treating the exhaust  12  from an internal combustion engine  16 . The exhaust  12  will typically contain oxides of nitrogen (NO x ) such as nitric oxide (NO) and nitrogen dioxide (NO 2 ) among others, particulate matter (PM), hydrocarbons, carbon monoxide (CO), and other combustion byproducts. Exhaust aftertreatment system  10  may include one or more components  18  and  20  to assist in the treatment of the exhaust  12 , including, for example, any or all of a burner or combustor, a diesel particulate filter (DPF), and a NO x  reducing device, such as a selective catalytic reduction catalyst (SCR) or a lean NO x  trap. Components  18  and  20  are connected by exhaust flow conduits  21  that are of any suitable construction, including housings that are integrated with components  18  and  20  and/or exhaust pipes or tubing. An injector  22  may be positioned either upstream or downstream (both examples shown in  FIG. 1 ) of such components to inject a fluid into the exhaust  12 , such as, for example, a suitable fuel, an oxygenator, or a reductant. In the illustrated embodiment, each injector  22  is connected to a pressurized supply  24  for the corresponding fluid via a supply conduit  26 . 
         [0014]    Several different suitable constructions for injector  22  may be used in connection with the mounting system of the present disclosure. One construction is shown in  FIGS. 2 and 3  in connection with an injector mounting system  30 . Injector  22  includes a housing  32 , a valve  34 , a molded coil assembly  36  for selectively actuating the valve  34 , an orifice/nozzle  38  in the form of an orifice plate  40  for directing an atomized flow of the fluid into exhaust  12 , and a supply fitting  42  for connection with the supply conduit  26 . 
         [0015]    Mounting system  30  includes nut  50 , a retaining ring  52 , a gasket  54 , and a boss  56 . Boss  56  is a substantially cylindrical member including an externally threaded portion  58 , an internal recess  60  and an internally extending flange  62 . A substantially planar surface  64  of boss  56  is fixed to an external surface  68  of exhaust conduit  21 . An aperture  70  extends through flange  62 . Aperture  70  is aligned with an aperture  72  extending through exhaust conduit  21 . At this position, boss  56  is fixed to exhaust conduit  21  using a process such as welding. It should be appreciated that aperture  70  is sized to receive a reduced diameter end portion  80  of housing  32 . Housing  32  of injector  22  also includes an enlarged body portion  82  and a ring groove  84 . Retaining ring  52  is positioned within retaining ring groove  84 . A land  88  is formed on injector housing  32  at the juncture between reduced diameter portion  80  and enlarged diameter portion  82 . Land  88  is in contact with a first surface  92  of gasket  54 . At the same time, a surface  94  of flange  62  engages an opposite surface  96  of gasket  54 . Gasket  54  includes a bore  100  having an inner diameter sized to closely mate and receive reduced diameter portion  80 . 
         [0016]    Nut  50  includes an externally faceted surface  104  having a hexagonal shape adapted to be engaged by a torquing tool. Nut  50  also includes an internally threaded bore  106  and a radially extending flange  108 . An aperture  110  extends through flange  108  having a size slightly larger than an outer diameter of portion  82  of housing  32 . A surface  114  of nut  50  engages retaining ring  52 . Internal thread  106  mates with external thread  58  of boss  56 . 
         [0017]    To mount injector  22  to exhaust conduit  21 , boss  56  is welded to the conduit after apertures  70  and  72  are aligned with one another. Nut  50  is placed over enlarged portion  82  of injector housing  32 . Retaining ring  52  is expanded over enlarged portion  82  and positioned within retaining ring groove  84 . Gasket  54  is positioned over reduced diameter end  80  and placed into engagement with land  88 . The injector, nut, retaining ring and gasket subassembly is translated until reduced diameter end  80  enters aperture  70  of boss  56 . At this time, nut  50  is rotated to threadingly engage internal thread  106  with external thread  58  of boss  56 . Nut  50  is torqued until gasket  54  is sufficiently compressed between land  88  and surface  94 . Gasket  54  serves the dual purpose of sealing exhaust gasses from a cavity  116  defined by boss  56 , nut  50  and injector  22 . Gasket  54  also functions to thermally isolate housing  32  of injector  22  from boss  56  and exhaust conduit  21 . 
         [0018]    In an alternate arrangement, retaining ring  52  may be replaced with a relatively thick stamped clip or washer having a slot to allow the washer to be positioned within retaining ring groove  84  through a transverse movement. Use of mounting system  30  allows simple threaded interconnection between nut  50  and boss  56  without requiring housing  32  of injector  22  to be threaded. It is also contemplated that gasket  54  may be removed to directly engage land  88  with flange surface  94 . 
         [0019]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.