Abstract:
An exhaust pulse control unit and related method comprise an inlet tube communicating with incoming exhaust gas, an outlet tube communicating with exiting exhaust gas, and a housing extending between and connected with the inlet tube and outlet tube at opposite ends thereof. At least one pulse capture and expansion zone is disposed between the inlet tube and an intermediate zone portion of the housing, and is configured to increase exhaust manifold vacuum in an associated internal combustion engine. A first connector flange, having an attachment portion and central aperture, is connected with an inlet end of the housing. A second connector flange, having an attachment portion aligned with the attachment portion of the first flange and a central aperture, is connected with the inlet tube. The central aperture of the second flange has a beveled surface formed integrally therein to define a nozzle which forms the pulse capture and expansion zone. A fastener detachably, yet securely, connects the attachment portions of the first and second flanges to form an airtight seal between the inlet tube and the housing.

Description:
CLAIM OF PRIORITY  
       [0001]     Applicants hereby claim priority benefits under the provisional of 35 U.S.C. § 119, basing said claim of priority to Provisional Patent Application Ser. No. 60/638,550, filed Dec. 22, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to engine exhaust pulse control units for motor vehicles and the like, and in particular to an integrated nozzle/connector and method therefor.  
         [0003]     Exhaust pulse control units, such as that disclosed in U.S. Patent Publication 2003/0159437 to Oberhardt, are known in the art, and are designed to control the expansion of exhaust gases from an internal combustion engine to improve engine power and efficiency. In the referenced Oberhardt patent document, the exhaust pulse control unit has an intermediate zone which extends between inlet and outlet tubes. A first exhaust pulse capture and expansion zone is integrally formed in the trailing end of the inlet tube, and a second exhaust pulse capture and expansion zone is integrally formed in the leading end of the intermediate zone or housing. A merging zone is integrally formed in the leading end of the outlet tube and mates with the interior of the intermediate zone or housing to create negative pressure exhaust pulses upstream of the exhaust pulse control unit for increasing exhaust manifold vacuum in the engine to improve performance and efficiency. The size and shape of the exhaust pulse capture and expansion zones, as well as the merging zone, are important to achieve proper tuning with the engine. Hence, the formation of the associated surfaces, and their interconnection, must be carefully controlled to achieve proper operation of the exhaust pulse control unit.  
       SUMMARY OF THE INVENTION  
       [0004]     One aspect of the present invention is an exhaust pulse control unit for internal combustion engines, comprising an inlet tube configured for communication with incoming exhaust gas, an outlet tube configured for communication with exiting exhaust gas, and a housing extending between and operably connected with the inlet tube and the outlet tube adjacent opposite ends thereof. An intermediate zone is disposed along a medial portion of the housing. At least one pulse capture and expansion zone is disposed between the inlet tube and the intermediate zone of the housing, and is configured to increase exhaust manifold vacuum in an associated internal combustion engine. A first connector flange, having a radially outwardly extending attachment portion, and a central aperture axially aligned with the housing, is operably connected with the housing. A second connector flange, having a radially outwardly extending attachment portion which is axially aligned with the attachment portion of the first connector flange, and a central aperture which is axially aligned with the inlet tube, and includes an inlet portion and an oppositely disposed outlet portion, is operably connected with the inlet tube adjacent the inlet portion thereof. The outlet portion of the central aperture of the second connector flange has a beveled surface formed integrally therein to define a nozzle which forms the pulse capture and expansion zone. A fastener detachably, yet securely, connects the attachment portion of the first connector flange with the attachment portion of the second connector flange to form an airtight seal between the inlet tube and the housing.  
         [0005]     Another aspect of the present invention is a method for making an exhaust pulse control unit for internal combustion engines, comprising forming an inlet tube into a shape configured for communication with incoming exhaust gas, forming an outlet tube into a shape configured for communication with exiting exhaust gas, and forming a housing shaped to extend between the inlet tube and the outlet tube. The method further comprises operably connecting the inlet tube to one end of the housing and the outlet tube to the opposite end of the housing, and forming an intermediate zone along a medial portion of the housing. The method further includes forming a first connector flange having a radially outwardly extending attachment portion and a central aperture therethrough, axially aligning the central aperture of the first connector flange with the housing, and operably connecting the first connector flange with the housing. The method also includes forming a second connector flange having a radially outwardly extending attachment portion and central aperture therethrough which includes an inlet portion and an oppositely disposed outlet portion, axially aligning the central aperture of the second connector flange with the inlet tube, such that the attachment portions of the first and second connector flanges are axially aligned, and operably connecting the second connector flange with the inlet tube, such that the attachment portions of the first and second connector flanges are axially aligned, and operably connecting the second connector flange with the inlet tube adjacent the inlet portion thereof. The method further includes integrally forming at least one beveled surface in the outlet portion of the central aperture of the second connector flange to define a nozzle which forms at least one pulse capture and expansion zone configured to increase exhaust manifold vacuum in an associated internal combustion engine, and detachably, yet securely, fastening the attachment portion of the first connector flange with the attachment portion of the second connector flange to form an airtight seal between the inlet tube and the housing.  
         [0006]     Yet another aspect of the present invention is to provide an exhaust pulse control unit having an uncomplicated design with reduced manufacturing costs. The exhaust pulse control unit can be accurately and repeatedly manufactured with improved nozzle surface quality. By removing welding operations from the nozzle areas, more consistent engine tuning can be achieved. The exhaust pulse control unit is efficient in use, capable of a long operating life and particularly well adapted to for the proposed use. These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a fragmentary, cross-sectional view of an exhaust pulse control unit embodying the present invention.  
         [0008]      FIG. 2  is a fragmentary, cross-sectional view of another embodiment of the present invention.  
         [0009]      FIG. 3  is a fragmentary, cross-sectional view of yet another embodiment of the present invention.  
         [0010]      FIG. 4  is a fragmentary, cross-sectional view of yet another embodiment of the present invention.  
         [0011]      FIG. 5  is a fragmentary, cross-sectional view of yet another embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]     For purposes of description herein, the terms “upper”, “lower”, “right”, “left”, “rear”, “front”, “vertical”, “horizontal” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.  
         [0013]     The reference numeral  1  ( FIG. 1 ) generally designates an exhaust pulse control unit embodying the present invention. Exhaust pulse control unit  1  includes a first connector flange or collar  2  rigidly attached to a housing portion  3  of exhaust pulse control unit  1  adjacent an inlet end  4  thereof. A second connector flange  5  has at least one pulse capture and expansion zone  6 , in the form of a nozzle, integrally formed therein, and is rigidly attached to an inlet tube portion  7  of exhaust pulse control unit  1  adjacent the inlet end  4  of housing  3 . Collar  2  and connector flange  5  have mating surfaces  8  and  9 , which abut to form an airtight seal therebetween. Fasteners  10  securely, yet detachably, interconnect collar  2  and connector flange  5  in the abutting, sealed condition to create negative pressure exhaust pulses in housing  3 , increase exhaust manifold vacuum, and improve engine power and efficiency.  
         [0014]     In the illustrated example, collar  2  is in the form of an annularly-shaped disk, having a circular central aperture axially aligned with housing  3 , and defined by an inside surface, as well as a circular outside surface, and opposing side faces. The side faces are generally flat and parallel to one another. The inside surface of collar  2  is shaped to be closely received over the outside surface of housing  3 . A weld  19  extends about the periphery of the side face adjacent the inside surface of collar  2  to rigidly interconnect collar  2  to housing  3 , and form a substantially airtight seal therebetween. Collar  2  includes a radially outwardly extending attachment portion, with a plurality of axially extending, threaded apertures  20 , which are spaced circumferentially about collar  2  in a predetermined pattern.  
         [0015]     The illustrated connector flange  5  is also generally annular in shape, and includes a circular central aperture axially aligned with housing  3  and defined by an inside surface, as well as a circular outside surface, and opposite side faces. The side faces are generally flat and parallel to one another. The outside surface of connector flange  5  is sized to mate with the outside surface of collar  2 . The inside surface of connector flange  5  includes an inlet portion with stepped portion  29  configured to closely receive the trailing end  30  of inlet tube  7  therein. A weld  31  extends around the circumference of inlet tube  7  adjacent end  30  to rigidly attach connector flange  5  to inlet tube  7  and form a substantially airtight seal therebetween.  
         [0016]     In the illustrated example, the interior or outlet side face of connector flange  5  includes two exhaust pulse capture and expansion zones  35  and  36  formed integrally therein. A circular lip  37  is formed in the side face of connector flange  5  adjacent end  30  of inlet tube  7 . Exhaust pulse capture and expansion zone  35  is defined by an integrally formed beveled or angled surface adjacent lip  37 , and exhaust pulse capture and expansion zone  36  is formed adjacent or adjoining zone  35  by an integrally formed beveled or angled surface, and tapers to the inner face between the side face of connector flange  5  and the side face of collar  2 . Since collar  2  and connector flange  5  are fabricated as separate parts, the sizes and shapes of the exhaust pulse capture and expansion zones  35  and  36 , as well as lip  37 , can be formed precisely by means such as grinding or the like at relatively low cost. In the example shown in  FIG. 1 , beveled surface  36  is disposed at an angle substantially greater than the angle of beveled surface  35 . Connector flange  5  also includes a radially outwardly extending attachment portion, with a plurality of axially extending apertures  38  disposed about the circumference thereof, which are aligned with the apertures  20  in collar  2  to receive threaded fasteners  10  therethrough. Apertures  38  are preferably not threaded.  
         [0017]     The illustrated housing  3  is cylindrical in shape, and includes an intermediate zone disposed along a medial portion thereof, which is configured to cooperate with the pulse capture and expansion zone  6  to increase exhaust manifold vacuum.  
         [0018]     In the illustrated example, collar  2  and connector flange  5  are constructed from hardened steel, and formed using known manufacturing techniques, such as machining, casting, powdered metal forming, and the like. Collar  2  is positioned on housing  3  and connected therewith by welding in the manner described above. Connector flange  5  is positioned on inlet tube  7  and welded thereto in the manner described above. A plurality of bolts  10 , or other similar fasteners, are inserted through apertures  38  in connector flange  5  and threadedly engaged in the threaded apertures  20  on collar  2  to securely, yet detachably, draw the adjacent faces  8  and  9  into close sealing contact to define a substantially airtight seal therebetween.  
         [0019]     It is to be understood that connector flange  5  may be formed using a variety of alternative processes, such as machining wrought steel, molded in powdered metal, spin formed, ram formed, deep drawn, or the like. The specific process selected will depend upon quantity of production, tool cost, geometric precision, and other similar factors.  
         [0020]     The reference numeral  1   a  ( FIG. 2 ) generally designates another embodiment of the present invention, having a step  45  formed in the inside surface of collar  2   a  and a mating land  46  formed in the interior face of connector flange  5   a.  Since exhaust pulse control unit  1   a  is similar to the previously described exhaust pulse control unit  1 , similar parts appearing in  FIGS. 1 and 2  respectively are represented by the same, corresponding reference numerals, except for the suffix “a” in the numerals of the latter. In the illustrated example, step  45  has a generally L-shaped side elevational cross-sectional configuration, and includes a groove  47  in which the end  4   a  of housing  3   a  is closely received, with weld  19   a  extending therebetween.  
         [0021]     The reference numeral  1   b  ( FIG. 3 ) generally designates yet another embodiment of the present invention, having an indented step  50  on the inside surface of collar  2   b.  Since exhaust pulse control unit  1   b  is similar to the previously described exhaust pulse control units  1  and  1   a,  similar parts appearing in  FIGS. 1-2  and  3  respectively are represented by the same, corresponding reference numerals, except for the suffix “b” in the numerals of the latter. In the illustrated example, indented step  50  has a generally L-shaped side elevational cross-sectional configuration, wherein the inlet end of housing  3   b  is closely received against the inside surface of collar  2   b.  The indented step design shown in  FIG. 3  can be used on the band clamp embodiment shown in  FIG. 4 , and discussed below, as well as the embodiments shown in  FIGS. 1 and 2 .  
         [0022]     The reference numeral  1   c  ( FIG. 4 ) generally designates yet another embodiment of the present invention, having a band clamp  55  to detachably interconnect collar  2   c  and connector flange  5   c.  Since exhaust pulse control unit  1   c  is similar to the previously described exhaust pulse control units  1 ,  1   a  and  1   b,  similar parts appearing in  FIGS. 1-3  and  FIG. 4  respectively are represented by the same, corresponding reference numerals, except for the suffix “c” in the numerals of the latter. In the illustrated exhaust pulse control unit  1   c,  the outside surface of collar  2   c  and the outside surface of connector flange  5   c  are both tapered in opposite directions to form a V-shaped or wedge-like exterior. Band clamp  55  has a similar V-shaped or wedged configuration which mates with the outside surfaces of collar  2   c  and connector flange  5   c,  and extends about the circumference thereof. Band clamp  55  may be split, with a threaded connector  56  interconnecting the opposite ends thereof in a manner which permits band clamp  55  to be securely, yet detachably, tightened in place in a constricting manner about collar  2   c  and connector flange  5   c.    
         [0023]     The reference numeral  1   d  ( FIG. 5 ) generally designates yet another embodiment of the present invention, having a merger zone  60  located at the outlet end of the associated exhaust pulse control unit  1   d.  Since exhaust pulse control unit  1   d  is similar to the previously described exhaust pulse control unit  1 , similar parts appearing in  FIGS. 1 and 5  respectively are represented by the same, corresponding reference numerals, except for the suffix “d” in the numerals of the latter. In the illustrated exhaust pulse control unit  1   d,  the inlet side thereof is identical to that disclosed in  FIG. 1 , which includes a first connector flange or collar  2   d  rigidly attached to a housing portion  3   d  of exhaust pulse control unit  1   d  adjacent the inlet end  4   d  thereof. A second connector flange  5   d  has at least one pulse capture and expansion zone  6 , in the form of a nozzle, integrally formed therein, and is rigidly attached to an inlet tube portion  7   d  of exhaust pulse control unit  1   d  adjacent the inlet end  4   d  of housing  3   d.  Collar  2   d  and connector flange  5   d  have mating surfaces  8   d  and  9   d,  which abut to form an airtight seal therebetween. Fasteners  10   d  securely, yet detachably, interconnect collar  2   d  and connector flange  5   d  in the abutting, sealed condition to create negative pressure exhaust pulses in housing  3   d,  increase exhaust manifold vacuum, and improve engine power and efficiency.  
         [0024]     Exhaust pulse control unit  1   d  also includes a third connector flange or collar  65  rigidly attached to the housing portion  3   d  of exhaust pulse control unit  1   d  adjacent an outlet end  66  thereof. A fourth connector flange  67  has merger zone  60 , in the form of a nozzle, integrally formed therein, and is rigidly attached to an outlet tube portion  68  of exhaust pulse control unit  1   d  adjacent the outlet end  66  of housing  3   d.  Collar  65  and connector flange  67  have mating surfaces  69  and  70 , which abut to form an airtight seal therebetween. Fasteners  71  securely, yet detachably, interconnect collar  65  and connector flange  67  in the abutting, sealed condition to create negative pressure exhaust pulse gases in housing  3   d,  increase exhaust manifold vacuum, and improve engine power and efficiency.  
         [0025]     In the illustrated example, collar  65  is substantially identical in construction to collar  2   d,  and connector flange  67  is substantially identical to connector flange  5   d,  except that both are located at the outlet end of housing  3   d.  The inside surface of collar  65  is shaped to be closely received over the outside surface of housing  3   d,  at the end thereof opposite collar  2   d.  A weld  75  extends about the periphery of the side face adjacent the inside surface of collar  65  to rigidly interconnect collar  65  to housing  3   d,  and form a substantially airtight seal therebetween. The outside surface of connector flange  67  is sized to mate with the outside surface of collar  65 . The inside surface of connector flange  67  includes an outlet portion with a stepped portion  76  configured to closely receive the leading end  77  of outlet tube  68  therein. A weld  78  extends around the circumference of outlet tube  68  adjacent the stepped portion  76  of connector flange  67  to rigidly attach connector flange  67  to outlet tube  68  and form a substantially airtight seal therebetween.  
         [0026]     In the illustrated example, the inlet side face of connector flange  67  includes two merger zones  61  and  62  formed integrally therein in a concentric relationship with the central aperture or lip  63 . Merger zone  61  is defined by an integrally formed beveled or angled surface adjacent lip  63 , and merger zone  62  is formed adjacent or adjoining merger zone  61  by an integrally formed beveled or angled surface, and tapers to the interface between the side face  70  of connector flange  67  and the side face  69  of collar  65 . Since collar  65  and connector flange  67  are fabricated as separate parts, as are collar  2   d  and connector flange  5   d,  the sizes and shapes of the merger zones  61  and  62 , as well as lip  63 , can be formed precisely by means such as grinding or the like at relatively low cost. Connector flange  67  also includes a radially outwardly extending attachment portion, with a plurality of axially extending apertures  80  disposed about the circumference thereof, which are aligned with the apertures  81  in collar  65  to receive threaded fasteners  71  therethrough. The tightening of threaded fasteners  71  draws collar  65  and connector flange  67  closely together to create an airtight seal between outlet tube  68  and housing  3   d.    
         [0027]     In each example, the formation of the exhaust pulse capture and expansion zones  35  and  36 , merger zones  61  and  62 , as well as lips  37  and  63 , in the separate connector flanges, which are detachably connected by fasteners to an associated collar, permits forming critical dimensions into hard surfaces with the dimensional tolerances closer than that possible in prior art exhaust pulse control units. The associated method provides accurate and repeatable manufacturing of exhaust pulse control units in an economical manner. Since the surfaces forming exhaust pulse capture and expansion zones  35  and  36  and merger zones  61  and  62 , as well as lips  37  and  63 , are critical to performance, the present design provides a greatly improved design. By forming critical dimensions into a hard connector flange, the tolerances can be held much closer than possible when forming the nozzle from tubing.  
         [0028]     In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein.  
         [0029]     The invention claimed is as follows.