Abstract:
In accordance with the teachings of the present invention, an off gas emission engine intake system is provided which uses engine cooling fluid to deliver warm emission gasses to the engine. The heater provides an outer body which has a channel therethrough. The channel is defined by an annular inner surface. An emission intake tube is disposed through the channel defining a toroidal chamber between the inner surface and air intake tube. The outer body further defines a pair of opposed orifices which accept coolant into the toroidal chamber. The system further has a lower extension tube which journally accepts the emission intake tube. A cylindrical chamber, coupled to the toroidal chamber, to further increase the contact area between the intake fluid.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 09/840,440 filed on Apr. 23, 2001. The disclosure of the above application is incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates generally to internal combustion engines and refers more particularly to the heating system engine gasses traveling through a PCV valve into the air intake of the fuel vaporizing system for such engine.  
         BACKGROUND OF THE INVENTION  
         [0003]    The operation of an automotive vehicle in climates where air temperatures are constantly frigid and in latitudes which are seasonally cold present an arduous problem for the handling of engine emissions. The problem of overcoming inefficient engine performance during cold weather operation imposes several important ramifications consequent the inherent characteristics of internal combustion engines. Numerous attempts have been made in the past to surmount the aforementioned problems by devising methods and apparatus to deliver warmer air at temperatures greater than that of outside air temperatures.  
           [0004]    Current emission requirements require that off gasses from engine casings be returned into the intake of a vehicle to improve vehicle emissions. The coupling allows for the off gasses from the engine to be drawn into the emission intake tube  23  and allow them to be burned within the engine&#39;s combustion chamber.  
           [0005]    Several of these systems include methods whereby exhaust gasses are circulated around an intake manifold to increase the temperature of the incoming air through the intake. These systems, which have the disadvantage of having to transfer heated exhaust gasses into the air intake system, and then back into the exhaust system, cannot handle crank case emissions which travel through the PCV valve of the engine into the engine&#39;s air intake.  
         SUMMARY OF THE INVENTION  
         [0006]    In accordance with the teachings of the present invention, an engine air intake heat exchanger is provided which uses engine cooling fluid to warm the engine block off gasses which are introduced into the engine air intake. The heat exchanger provides an outer body, which has a channel therethrough. The channel is defined by an annular inner surface and a pair of orifices. An emission intake tube is disposed through the channel defining a toroidal chamber between the inner surface and emission intake tube. The outer body further defines a pair of opposed orifices which allows the flow of coolant into and out of the toroidal chamber. The heat exchanger further has a lower extension tube which journally accepts the emission intake tube. A cylindrical chamber, fluidly coupled to the toroidal chamber, is defined therebetween. The PCV valve is incorporated into the channel.  
           [0007]    The heater exchanger further provides a hexagonal outer body which has the channel therethrough. An emission intake tube is disposed through the channel defining a chamber between the inner surface and emission intake tube. The outer body further defines a pair of opposed orifices having input ports, which provide ingress and egress for engine coolant fluid. The heat exchanger&#39;s lower extension tube journally accepts the emission intake tube. All components are brazed or soldered together to fluidly seal the input ports to the first toroidal chamber while keeping the air intake fluidly separated from the first toroidal and cylindrical chambers. Several constructions are disclosed which facilitate the coupling of the various heat exchanger members. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Still other advantages of the present invention will become apparent to those skilled in the art after reading the following specification and by reference to the drawings in which:  
         [0009]    [0009]FIG. 1 depicts emission intake heater coupled to an engine air intake manifold;  
         [0010]    [0010]FIG. 2 is a perspective view of the emission intake heater of the present invention;  
         [0011]    [0011]FIGS. 3 and 4 depict side and front views of one embodiment of the invention;  
         [0012]    [0012]FIG. 5 depicts a side view of one embodiment of the current invention;  
         [0013]    [0013]FIG. 6 depicts an exploded view of the embodiment as shown in FIG. 5;  
         [0014]    [0014]FIG. 7 depicts a lower extension tube coupled to the main body;  
         [0015]    [0015]FIG. 8 depicts an emission intake tube sub-component of the current invention;  
         [0016]    [0016]FIGS. 9 and 10 depict alternate embodiments of the current invention;  
         [0017]    [0017]FIGS. 11 and 12 depict cross-sections of an alternate embodiment of the current invention;  
         [0018]    [0018]FIG. 13 depicts an exploded view of the emission intake heater as shown in FIGS. 11 and 12;  
         [0019]    [0019]FIG. 14 depicts an alternate embodiment of the emission intake heater;  
         [0020]    [0020]FIG. 15 depicts a cross-sectional view of the emission intake heater of FIG. 14 within an engine valve cover;  
         [0021]    [0021]FIG. 16 depicts a side view of the engine intake heater of FIG. 14 within an engine a valve cover; and  
         [0022]    [0022]FIG. 17 shows an interior view of an engine valve cover incorporating the engine intake heater of FIG. 14. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    [0023]FIG. 1 depicts the off gas intake heater  21  coupled to an engine air intake manifold  20 . The off gas intake heater  21  has a PCV or emission intake tube  23  for bringing the engine off gasses into the combustion chambers of the engine. The off gas intake heater  21  functions to bring heated engine coolant into contact with the emission intake tube  23 , thus increasing the temperature of the incoming emissions by increasing the temperature of the emission intake tube  23 .  
         [0024]    As best shown in FIGS. 2 and 3, the off gas intake heater  21  is defined by a generally annular outer body  22 . The outer body  22  defines a cavity therethrough  28 . The cavity  28  accepts the emission intake tube  23  and is defined by an annular inner surface  29 . The emission intake tube  23 , which is disposed through the cavity  28 , defines a toroidal chamber  27  between the inner surface  29  and emission intake tube  23  and functions to hold the integral PCV valve  19 . The outer body  22  further defines a pair of opposed orifices  25  and  26 , which accepts coolant into the toroidal chamber  27 .  
         [0025]    The off gas intake heater  21  has a lower extension tube  24  which journally accepts the emission intake tube  23 . A cylindrical chamber  32 , which is fluidly coupled to the toroidal chamber  27 , is defined by the emission intake tube  23  and the lower extension tube  24 . The lower extension tube  24  is fluidly sealed by brazing on one side to the outer body  22 . At its other end, it is brazed to the emission intake tube  23 . The lower extension tube  24  has an external thread for fastening the off gas intake heater  21  to the intake manifold  20 . It is envisioned that the surface of the emission intake tube  23  can be textured by threads or fins to increase heat exchange with the cooling fluid.  
         [0026]    [0026]FIGS. 3 and 4 depict side and front views of a second embodiment of the invention. The emission intake tube  23  has a flange  33 , which corresponds to seat  35  formed in an upper portion  36  of the outer body  22 . The flange  33  and seat  35  are brazed together to couple and fluidly seal the components. Further depicted are hose coupling regions  34  on intake and output ports  30  and  31 .  
         [0027]    [0027]FIG. 5 depicts a side view of one embodiment of the current invention wherein the lower extension tube  24  is mounted to the outer body  22  by a flange  33  mounted to a seat  35  on a lower portion of the outer body  22 . As shown in FIG. 6, the emission intake tube  23  can be constructed of three tubular members  40 ,  41 , and  42 . The larger diameter outer tube  40  has a hose coupling  34 . An intermediate tube  41  is used to couple tube  42 , which has a smaller diameter to the outer tube  40 . The outer tube  40  is brazed to an orifice  37  in the outer body  22 .  
         [0028]    [0028]FIG. 7 depicts the outer body  22  of one embodiment of the current invention. The outer body  22  has a hexagonal outer surface and chamber defined therein. The hexagonal outer surface functions to assist in the installation of the heater into the air intake manifold. The lower extension tube has a mounting flange  51  which is inserted by a interference fit into bore  52 . The components are then brazed or soldered together to fluidly seal and join the components.  
         [0029]    [0029]FIG. 8 depicts an emission intake tube sub-component of the current invention. Shown is a mounting flange  48  which is used to couple the emission intake tube  23  to the outer body  22 . The emission intake tube  23  further has a restricted orifice  47  to regulate the amount of engine off gasses being drawn into the vehicle engine.  
         [0030]    [0030]FIGS. 9 and 10 depict alternate embodiments of the current invention. Specifically shown, are different methods of coupling the emission intake tube  23  to the outer body  22 . As can be seen, the emission intake tube  23  can have a variety of shapes which allow for varying amount of fluids to be circulated through the toroidal and cylindrical chambers  27  and  32 . Further shown is that the lower extension tube  24  can have a varying number of outer dimensions and threads to readily couple the off gas intake heater  21  to the engine. It is preferable that the outer diameter of the lower extension tube  24  be from  3  to  6  millimeters.  
         [0031]    [0031]FIGS. 11 and 12 depict a cross-sectional view of an alternate embodiment of the current invention. Shown is the use of a PCV valve cartridge  53  which incorporates the PCV valve  19  into a easily deposited housing. The PCV valve cartridge  53  is disposed within a cap portion  54  which functions to couple the PCV valve  19  to the emission intake tube  23 . Disposed about the cap  54  is a O-ring  55  which is used to seal the gas intake heater  21  to the air intake manifold  20 . The retaining member  56  is used to couple the PCV valve cartridge  53  to the cap  54 . It is specifically envisioned that the PCV valve can be incorporated into any of the gas intake heaters  21  depicted in FIGS. 110.  
         [0032]    [0032]FIG. 13 depicts an exploded view of the gas intake heater  21  as depicted in FIGS. 11 and 12. As can be seen, a subassembly is produced which is formed by the emission intake tube  23 , lower extension tube  24 , and main outer body  22 . Disposed on top of this subassembly is the cap portion  54  which functions to seal the toroidal chamber  27  formed by the outer body  22  and the emission intake tube  23 . Disposed within the cap  54  is the PCV cartridge  53 . The PCV cartridge  53  has an outer ledge  57  which functions to couple to a surface  58  within the cap  54 . The PCV cartridge  53  further has a lower body portion  59  which is disposed within the emission intake tube  23 . The entire assembly is closed using the retaining member  56  and brazed together using standard manufacturing techniques.  
         [0033]    [0033]FIG. 14 depicts an alternate embodiment of the emission intake heater  60 . The emission the intake heater  60  is a generally L-shaped cylindrical tube formed by a first leg  62 , a second leg  64 , and a curved transition portion  66 . The first leg  62  of the emission intake heater  60  is coupled to a hose (not shown), which takes the engine off gas and provides them to the air intake manifold. The first leg  62  defines rib  68 , which mates the first leg  62  to a quick coupler (not shown) on the hose. Additionally, the first leg  62  defines a coupling region  69  used to couple the emission intake heater  60  to a bore  70  defined by the valve cover.  
         [0034]    The second leg  64  of the emission intake heater  60  is formed by a first section  72  having a first diameter and a second section  74  having a second diameter. Incorporated within the first section  72  is an internal PCV cartridge  53 . Disposed about the second section  74  is a grommet or sealing mechanism  78 , which will be further described below.  
         [0035]    As best seen in FIG. 15, the first leg  62  is formed by two tubular members  80  and  82 . The first tubular member  80  is an extension of the curved transition portion  66 . The second tubular member  82  is annularly coupled to the first tubular member  80  at a braze joint  84 . The second tubular member  82  defines the coupling region  69  that couples the emission intake heater into the bore  70  valve cover  86  for an engine. The coupling region  69  uses a press fit connection, which allows for a simple mechanism for replacement of the emission intake heater  60  during service. Formed adjacent to the press fit connection is a sealing flange  88 , which assists in the sealing of the press fit joint between the emission intake heater and the valve cover  86 . It is, however, envisioned that any type of coupling mechanism which will couple the emission intake heater  60  to the valve cover  86  can be used.  
         [0036]    [0036]FIG. 15 depicts a cross-sectional view of the emission intake heater  60  of FIG. 14 within the engine valve cover  86 . The emission intake heater  60  is positioned so that heated oil, which is agitated within the valve cover  86 , splashes the exterior surface  90  of the emission intake heater  60  to heat the off gasses from the oil. An opening  92 , defined by the second leg  64 , is disposed in a first region of the valve cover  86  so that it is shielded from the hot oil. Disposed between the valve cover  86  and the opening  92  defined in the first leg  62  is a baffle  94 . The baffle  94  functions to prevent hot oil from being splashed into the opening  92  of the emission intake heater  60 . In order to seal the emission intake heater  60  to the baffle  94 , a grommet  78  is used to isolate the exterior surface  90  of the emission intake heater  60  from the opening  92 . The PCV valve cartridge  53  can be incorporated into either the first leg  62 , second leg  64 , or any location between the valve cover  86  and the engine intake.  
         [0037]    [0037]FIGS. 16 and 17 depict side and interior views of a valve cover  86  incorporating the engine intake heater  60  of FIG. 14. The valve cover  86  defines a first oil containing interior cavity  96  and a second generally oil free cavity  98 . The first and second cavities  96  and  98  are separated by a flange member  100  and the baffle  94 . The engine intake heater  60  fluidly couples the second cavity to the engine air intake manifold. Additionally, the engine intake  60  heater, in passing through the first chamber  96 , functions to provide a heat exchange surface  90  which is in contact with heated engine oil. This functions to heat the off gasses from the second chamber  98  prior to the introduction of the off gasses into the engine intake manifold.  
         [0038]    The emission intake heater  60  functions to provide a mechanism for utilizing oil circulating within an engine valve cover  86  as a heat exchange fluid for transferring heat from the engine to the engine off gasses prior to the off gasses leaving the engine. Essentially, the engine intake heater provides a passage  102  within the valve cover  86  that exposes the engine off gasses from heat from circulating oil. It is preferred that the PCV valve be incorporated into this passage  102 , but it can be located at any point between the valve cover  86  and the engine air intake.  
         [0039]    The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention.