Abstract:
An injector mount clamp for coupling an injector of an exhaust gas treatment system to an exhaust conduit of an engine while the conduit is in an installed position includes a resilient monolithic clamp body having an aperture extending therethrough and being shaped as a split collar having a first end spaced apart from a second end a distance allowing the clamp body to be transversely moved relative to an exhaust flow direction to a position circumferentially surrounding the exhaust conduit. An injector mounting boss is disposed on the clamp body and defines a passage that fluidly communicates with the aperture of the clamp body. The mounting boss has a mounting face configured to oppose the injector.

Description:
FIELD 
     The present disclosure relates to injector systems and, more particularly, relates to a retrofit injector mount clamp and related method for coupling an injector of an injector system to an exhaust conduit of an engine. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Lean burn engines provide improved fuel efficiency by operating with an excess of oxygen over the amount necessary for complete combustion of the fuel. Such engines are said to run “lean” or a “lean mixture”. However, this increase in fuel economy is offset by undesired pollution emissions, specifically in the form of oxides of nitrogen (NOx). 
     One method used to reduce NOx emissions from lean burn internal combustion engines is known as selective catalytic reduction (SCR). SCR, when used, for example, to reduce NOx emissions from a diesel engine, involves injecting an atomized reagent into the exhaust stream of the engine in relation to one or more selected engine operational parameters, such as exhaust gas temperature, engine rpm or engine load as measured by engine fuel flow, turbo boost pressure or exhaust NOx mass flow. The reagent/exhaust gas mixture is passed through a reactor containing a catalyst, such as for example, activated carbon or metals, such as platinum, vanadium or tungsten, which are capable of reducing the NOx concentration in the presence of the reagent. 
     An aqueous urea solution is known to be an effective reagent in SCR systems for diesel engines. Several current injector systems include mounting arrangements that position the injector a predetermined distance away from the exhaust pipe. Some injector mounting arrangements may be referred to as a “dog house” or “stand-off” style. Other current injector systems include mounting blocks that have cannulated projections that extend into the exhaust pipe. Such mounting blocks have injectors arranged thereon for communicating a solution through the mounting block and cannulated projection into the exhaust pipe. In many examples, such mounting arrangements may be difficult to quickly and accurately connect to an existing exhaust pipe, such as on a vehicle in the field. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     An injector mount clamp for coupling an injector of an exhaust gas treatment system to an exhaust conduit of an engine while the conduit is in an installed position includes a resilient monolithic clamp body having an aperture extending therethrough and being shaped as a split collar having a first end spaced apart from a second end a distance allowing the clamp body to be transversely moved relative to an exhaust flow direction to a position circumferentially surrounding the exhaust conduit. An injector mounting boss is disposed on the clamp body and defines a passage that fluidly communicates with the aperture of the clamp body. The mounting boss has a mounting face configured to oppose the injector. 
     According to other features, the first and second ends each have a mounting ear extending therefrom. The mounting ears have complementary engaging surfaces that are configured to engage each other in the installed position. The passage of the cylindrical body portion is threaded and configured to threadably mate with complementary threads on the injector. 
     According to yet other features, the injector mount clamp further comprises insulating material that is configured to be located intermediate the clamp body and the exhaust conduit in the install position. The injector mounting boss is welded to the clamp body and formed of stainless steel. The clamp body is configured to allow the clamp body to deflect radially outwardly to accommodate the exhaust conduit during an installation step and subsequently deflect radially inwardly to a position where the clamp body becomes fixed to the conduit. 
     A method for retrofitting an injector of an exhaust gas treatment system to an exhaust conduit of an engine includes forming an opening in the exhaust conduit. A clamp body of an injector mount clamp is advanced around the exhaust conduit in a direction transverse to the flow of exhaust through the conduit. The clamp body has a first end and a second end as well as an injector mounting boss disposed thereon. The mounting boss defines a passage in fluid communication with the opening in the exhaust conduit. A fastener is advanced through apertures in complementary ears extending from the first and second ends of the clamp body. The fastener is tightened relative to the clamp body to move the first and second ends of the clamp body closer to each other and inhibit slidable movement of the clamp body along the exhaust conduit. An insertion end of the injector is advanced into the injector mounting boss until the injector engages the exhaust conduit. 
     According to other features, advancing the clamp body comprises radially expanding the clamp body until the ears extend beyond an outer diameter of the exhaust conduit. Tightening the fastener causes the clamp body to radially contract to a profile that conforms to the exhaust conduit. Insulating material is placed intermediate the clamp body and the exhaust conduit. Advancing the insertion end of the injector comprises threadably advancing the insertion end of the injector along complementary threads formed in the cylindrical body portion. The insertion end of the injector is advanced until the terminal end of the injector engages the exhaust conduit, without extending beyond an inner circumference of the exhaust conduit. 
     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 
       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. 
         FIG. 1  shows a schematic diagram of an exemplary internal combustion engine with an emissions control system using an injector mount clamp according to the present teachings; 
         FIG. 2  is a perspective view of the injector mount clamp and injector secured to an exhaust conduit in an installed position; 
         FIG. 3  is an exploded perspective view of the injector mount clamp, injector and exhaust conduit of  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the injector mount clamp, injector and exhaust conduit taken along lines  4 - 4  of  FIG. 2 ; 
         FIG. 5  is an exemplary installation sequence for retrofitting an existing exhaust conduit with an injector; 
         FIG. 6  is an exemplary installation sequence where the injector mount clamp is initially radially expanded to accommodate an outer diameter of the exhaust conduit and subsequently radially contracted to conform to the exhaust conduit by way of a fastener; and 
         FIG. 7  is an injector mount clamp constructed in accordance to additional features of the present teachings and shown with an injector mount coupled thereto. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     With initial reference to  FIGS. 1 and 2 , an injector mount clamp constructed in accordance to the present teachings is shown and generally identified at reference numeral  10 . The injector mount clamp  10  is shown operatively coupled to an exhaust conduit  12  of an engine  14 . The injector mount clamp  10  of the present teachings can be configured to couple an injector  18  of an exhaust gas treatment assembly  20  to the exhaust conduit  12 . As will become appreciated by the following description, the injector mount clamp  10  can be particularly suited for being retrofit onto an existing exhaust conduit  12 . Prior to describing the injector mount clamp  10 , an exemplary pollution control system  22  incorporating the exhaust gas treatment assembly  20  will initially be described. 
     The pollution control system  22  is configured to reduce NOx emissions from the exhaust conduit  12  of the engine  14 . In the exemplary configuration, the engine  14  is a diesel engine. As denoted in  FIG. 1 , solid lines between the elements of the pollution control system  22  denote fluid lines for reagent and dashed lines denote electrical connections. The pollution control system  22  of the present teachings may include a reagent tank  26  for holding the reagent and a delivery module  28  for delivering the reagent from the tank  26 . The reagent may be a urea solution, a hydrocarbon, an alkyl-ester, alcohol, an organic compound, water, or the like and can be a blend or combination thereof. It should also be appreciated that one or more reagents can be available in the system and can be used singly or in combination. The tank  26  and delivery module  28  may form an integrated reagent tank/delivery module. Also provided as part of the pollution control system  22  is an electronic injection controller  30 , the reagent injector  18 , and an exhaust system  32 . The exhaust system  32  includes the exhaust conduit  12  that provides an exhaust stream to at least one catalyst bed  36 . 
     The delivery module  28  may comprise a pump that supplies reagent from the tank  26  via a supply line  38 . The reagent tank  26  may be polypropylene, epoxy coated carbon steel, PVC, or stainless steel and sized according to the application (e.g., vehicle size, intended use of the vehicle, and the like). A pressure regulator (not shown) may be provided to maintain the system at predetermined pressure set points (e.g., relatively low pressures of approximately 60-80 psi, or in some embodiments a pressure of approximately 60-150 psi) and may be located in a return line  40  from the injector  18 . A pressure sensor may be provided in the supply line  38  leading to the reagent injector  18 . The pollution control system  22  may also incorporate various freeze protection strategies to thaw frozen reagent or to prevent the reagent from freezing. During system operation, regardless of whether or not the injector is releasing reagent into the exhaust gases, reagent may be circulated continuously between the tank  26  and the reagent injector  18  to cool the reagent injector  18  and to minimize the dwell time of the reagent in the injector, so that the reagent remains cool. Continuous reagent circulation may be necessary for temperature-sensitive reagents, such as aqueous urea, which tend to solidify upon exposure to elevated temperatures of 300° C. to 650° C. as would be experienced in an engine exhaust system. Furthermore, in some examples, it may be desirable to keep the reagent mixture below 140° C. and preferably in a lower operating range between 5° C. and 95° C. to insure that solidification of the reagent is prevented. Solidified reagent, if allowed to form, may foul the moving parts and openings of the injector  18 . 
     The amount of reagent required may vary with load, engine rpm, exhaust speed, exhaust gas temperature, exhaust gas flow, engine fuel, injection timing, desired NOx reduction, barometric pressure, relative humidity, EGR rate and engine coolant temperature. A NOx sensor or meter  46  is positioned downstream from the catalyst bed  36 . The NOx sensor  46  is operable to output a signal indicative of the exhaust NOx content to a controller  30 . All or some of the engine operating parameters may be supplied from an engine control unit  48  via the engine/vehicle databus to the reagent electronic injection controller  30 . The reagent electronic injection controller  30  could also be included as part of the engine control unit  48 . Exhaust gas temperature, exhaust gas flow and exhaust back pressure and other vehicle operating parameters may be measured by respective sensors, not specifically shown. 
     With particular reference now to  FIGS. 1-4 , the exhaust conduit  12  includes a substantially cylindrical tube  50  that defines an exhaust passageway  52 . The cylindrical tube  50  further includes an inner surface  54  and an outer surface  55 . 
     With specific reference now to  FIG. 4 , additional features of the injector  18  will be described in greater detail. The injector  18  includes an injector body  56 . The injector body  56  defines a cylindrical chamber  60  that receives an axially translatable valve member  62 . The injector body  56  includes an exit orifice  66  at a discharge location for the injected reagent. A valve seat  70  is formed proximate the exit orifice  66 . The valve seat  70  is selectively engaged by the valve member  62  to control reagent injection into the exhaust gas flow path. The valve member  62  is translatable along an axis of reagent injection  76 . 
     An adapter  80  is fixed to the injector body  56  and includes a radially outwardly extending flange  82  and a cylindrical male extension portion  86 . The cylindrical male extension portion  86  can define an outer diameter  87  having outer threads  88  and can extend to a terminal end  90 . The injector flange  82  can define an outer diameter  91  and includes an injector flange face  92  ( FIG. 3 ). The outer diameter  91  of the injector flange  82  is larger than the outer diameter  87  of the cylindrical male extension portion  86 . 
     With reference now to  FIGS. 2-4 , the injector mount clamp  10  will be described in greater detail. The injector mount clamp  10  generally includes a clamp body  100  and an injector mounting boss  102 . The clamp body  100  generally includes a thin-walled cylindrically shaped band of material that extends from a first end  104  to a second end  106 . The injector mount clamp  10  is formed of metallic material, such as but not limited to, stainless steel. First and second mounting ears  108  and  110  are formed at the ends  104  and  106 , respectively. The mounting ears  108  and  110  collectively define complementary passages  112 ,  114  therein. The passages  112  and  114  can be configured to align and receive fasteners  116  and  118 , respectively therein. The fasteners  116  and  118  can be threaded for receiving nuts  120  and  122  in an assembled position ( FIG. 2 ). Other configurations are contemplated. For example, one or more than two fasteners may be incorporated. Additionally or alternatively, other securing members may be employed, such as clips, rivets, screw-clamps and the like. 
     The injector mounting boss  102  generally includes a cylindrical body portion  130  and an injector mounting boss flange  132  extending therefrom. The injector mounting boss flange  132  includes an outer mounting face  134  ( FIG. 3 ). In one example, the injector mounting boss  102  is welded to the clamp body  100 . The injector mounting boss  102  is pre-welded to clamp body  100  such that a retro-fit installer need not couple the injector mounting boss  102  to the clamp body. 
     The injector mounting boss  102  can define a female receiving portion or passage  136  that is configured to receive the cylindrical male extension portion  86  of the injector  18 . In this regard, the female receiving portion  136  can include inner threads  140  that are complementary to the outer threads  88  of the injector  18 . According to one configuration, the cylindrical body portion can define an outer diameter  150 . The injector mounting boss flange  132  can define an outer diameter  152 . The outer diameter  152  of the injector mounting boss flange  132  is greater than the outer diameter of the cylindrical body portion  130 . The cylindrical body portion  130  can define an inner diameter  154  that is sized to receive the cylindrical male extension portion  86  in an assembled position ( FIG. 4 ). Moreover, and as will be described herein, the outer mounting face  134  of the injector mounting boss flange  132  is configured to oppose the injector flange face  92  of the injector flange  82  in the assembled position. A gasket  156  can be disposed between the injector flange  82  and the injector mounting boss flange  132 . The gasket  156  may be formed of elastomeric material. According to one example, the terminal end  90  of the cylindrical male extension portion  86  of the injector  18  can engage the outer surface  55  of the cylindrical tube  50 . In addition, the injector mount clamp  10  can be arranged at a location on the cylindrical tube  50 , such that the passage  136  of the cylindrical body portion  130  substantially aligns with an opening  160  formed through the cylindrical tube  50 . 
     In one example, the opening  160  can define an inner diameter  162 . The inner diameter  162  of the opening  160  may be less than the outer diameter  87  of the cylindrical male extension portion  86 . Because the opening  160  is less than the outer diameter  87  of the male extension portion  86 , the terminal end  90  can be configured to engage the outer surface  55 . Such engagement may also coincide with engagement of the outer mounting face  134 , gasket  156  and the injector flange face  92 . It can be appreciated that in other configurations, the outer diameter  87  of the male extension portion  86  may be less than the inner diameter  162  of the opening  160 , such that the terminal end  90  extends to a position between the inner surface  54  and outer surface  55  of the cylindrical tube  50 . It can be appreciated, however, that the terminal end  90  does not extend inboard (beyond) the inner surface  54  in the installed position. 
     With specific reference now to  FIG. 5 , an exemplary sequence for retrofitting the injector mount clamp  10  onto an existing exhaust conduit  12  according to one example of the present teachings will be described. At the outset, it can be appreciated that the injector mount clamp  10  may be particularly suited for retrofitting an injector  18 , such as associated with the exhaust gas treatment assembly  20  described above. In this regard, an installer can observe the existing exhaust conduit  12  and identify a preferred location therealong. 
     According to one example, the injector mount clamp  10  can be located at a desired location on the exhaust conduit  12  while a cutting tool  200  is guided through the passage  136  to prepare the opening  160  through the cylindrical tube  50  of the exhaust conduit  12 . It can be appreciated that other methods may be carried out. For example, an installer may wish to alternatively mark a desired position of the injector mount clamp  10 , such as with a marking instrument (not particularly shown) and move the injector mount clamp  10  away from the identified location. The cutting tool  200  can then subsequently be used to prepare the opening  160  through the cylindrical tube  50  of the exhaust conduit  12 . While the cutting tool  200  is shown as a drill bit, other tools may be used, such as a punch for example. 
     With the opening  160  prepared through the cylindrical tube  50  of the exhaust conduit  12 , the injector mount clamp  10  can be coupled to the cylindrical tube  50  at a location, such that the female receiving portion  136  of the injector mounting boss  102  fluidly aligns with the opening  160 . One specific example of coupling the injector mount clamp  10  to the cylindrical tube  50  of the exhaust conduit  12  is shown in  FIG. 6  and described in detail below. Once the injector mount clamp  10  has been secured to the cylindrical tube  50  of the exhaust conduit  12 , the injector  18  can be coupled to the injector mounting boss  102 . More particularly, the male extension portion  86  can be advanced into the receiving portion  136  of the cylindrical body portion  130  of the injector mounting boss  102 . In the specific example provided, the outer threads  88  of the injector  18  are advanced along the inner threads  140  of the cylindrical body portion  130  of the injector mounting boss  102 . In one example, the male extension portion  86  is advanced until it engages the cylindrical tube  50  of the exhaust conduit  12 . At this time, the gasket  156  can be engaged and/or compressed between the injector flange face  92  and the outer mounting face  134  of the injector mounting boss  102 . 
     With reference now to  FIG. 6 , one exemplary sequence of advancing the injector mount clamp  10  onto the cylindrical tube  50  of the exhaust conduit  12  will be described. Initially, the clamp body  100  of the injector mount clamp  10  can be radially expanded by advancing the ears  108  and  110  away from each other until the clamp body  100  has been radially opened sufficiently to advance around the cylindrical tube  50 . The clamp body  100  can then be transversely moved relative to the exhaust flow direction to circumscribe the conduit. The clamp body is then radially contracted around the cylindrical tube  50  of the exhaust conduit  12  and the fasteners  116  and  118  advanced through the respective passages  112  and  114 . The nuts  120  and  122  can then be threadably advanced onto the fasteners  116  and  118  to secure the injector mount clamp  10  onto the cylindrical tube  50 . In the installed position, an insulting material  202  is located intermediate the clamp body  100  of the injector mount clamp  10  and the cylindrical tube  50  of the exhaust conduit  12 . The insulating material  202  can thermally insulate the clamp body  100  from the cylindrical tube  50  of the exhaust conduit  12 . It will be appreciated that while the ears  108  and  110  are illustrated as touching in the installed position, they may also be spaced away from each other. Furthermore, it is contemplated that a plurality of injector mount clamps may be provided for retrofitting with exhaust conduits of various diameters. For example, injector mount clamps may be sized for mounting to exhaust conduits of 2, 2.5, 3, 3.5, 4, 5 and 6 inches. Other sizes are contemplated. 
       FIG. 7  illustrates an injector mount clamp  300  constructed in accordance to additional features of the present teachings. The injector mount clamp  300  includes a generally cylindrical clamp body  302  and an injector mounting boss  304 . Unless described otherwise herein, the injector mount clamp  300  is constructed similarly to the injector mount clamp  10  however the cylindrical clamp body  302  includes mounting ears  312  and  314  that are generally arranged at a different location as compared to the embodiment shown in  FIG. 3 . In this regard, the mounting ears  312  and  314  are shown at a location on the cylindrical clamp body  302  generally closer to the injector mounting boss  304  as compared to the embodiment shown in  FIG. 2 . In this regard, it may be desirable to provide mounting ears  312  and  314  that are positioned differently on the injector mount clamp  10  in applications where access to the fasteners  116  and  118 , as well as the injector mounting boss  304  is more favorable. 
     It should be understood that although the present teachings may be described for retrofitting an exhaust in connection with diesel engines and the reduction of NOx emissions, the retrofit injector mount clamp  10  of the present teachings can be used in connection with any one of a number of exhaust stream, such as by way of non-limiting example, those from diesel, gasoline, turbine, fuel cell, jet, or any other power source outputting a discharge stream. Moreover, the present teachings may be used in connection with the reduction of any one of a number of undesired emissions. For example, injection of hydrocarbons for the regeneration of diesel particulate filters is also within the scope of the present disclosure. 
     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.