Abstract:
A venturi is provided for aspirating air in a HVAC module assembly having a first HVAC module housing section including a first venturi portion. A second HVAC module housing section includes a second venturi portion. The first and second HVAC module housing sections form a HVAC mixing chamber and venturi chamber. The first venturi portion mates with the second venturi portion to cooperatively form the venturi chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not Applicable 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of Invention 
         [0005]    This invention relates in general to vehicle air conditioning systems, and in particular to an in-molded venturi of a vehicle air conditioning system. 
         [0006]    2. Background of Related Art 
         [0007]    In vehicle heating, ventilation and air conditioning (HVAC) systems, a temperature sensor may be disposed within the interior of the vehicle, sensing the temperature of the interior of the vehicle. The sensor is in pneumatic communication with a HVAC module assembly via a tubular member. The tubular member has one end coupled to the sensor and the other end coupled to a valve for creating a vacuum for drawing air through the sensor from the passenger compartment. 
         [0008]    The valve and tubular member are separate components from the HVAC module assembly and the valve is mechanically coupled to the HVAC module assembly. The mechanical coupling is accomplished by snapping the valve into an opening or by other mechanical means such as fasteners, which generally requires the valve be attached to the HVAC module assembly at a substantially planar surface. That is, it is desirable to attach the valve on a surface that is substantially planar so that the valve seats and seals properly at its point of connection. However, this limits the optimal positioning of the valve since the profile of the HVAC module assembly changes shape regularly so that it can be configured to the underside of the instrument panel and to avoid interference with other surrounding components. Furthermore, having to position the valve at a substantially planar region of the HVAC module assembly may position the valve in an area of turbulence which will lessen the vacuum drawing air past the valve. 
         [0009]    Moreover, damage or loosening of the valve may arise during assembly as a result of the mechanical connection (e.g., snap fit connection) as the valve may become unseated or unsecured during the assembly and handling of the HVAC module assembly. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    The present invention has the advantage of providing a venturi valve that is integrally formed as part of the molded sections of the HVAC module assembly which allows the venturi valve to be formed at a location that is optimum for creating a vacuum in the venture whether the location is a planar or non-planar surface. 
         [0011]    In one aspect of the present invention, a venturi is provided for aspirating air in a HVAC module assembly having a first HVAC module housing section including a first venturi portion. A second HVAC module housing section includes a second venturi portion. The first and second HVAC module housing sections form a HVAC mixing chamber and venturi chamber. The first venturi portion mates with the second venturi portion to cooperatively form the venturi chamber. 
         [0012]    In one aspect of the present invention, a HVAC system is provided for a vehicle. The HVAC system includes a HVAC module assembly comprising a first HVAC module housing section having a first venturi portion. A second HVAC module housing section includes a second venturi portion. The first and second HVAC module housing sections form a HVAC mixing chamber and venturi chamber. The first venturi portion mates with the second venturi portion to cooperatively form the venturi chamber. The first venturi portion and the second venturi portion cooperatively form an air flow opening between the HVAC mixing chamber and the venturi chamber for allowing air flow from the HVAC mixing chamber to the venturi chamber. A sensor disposed within an interior compartment of the vehicle measures a temperature of the interior compartment. The sensor is in fluid communication with the venturi chamber. Forced air from the HVAC mixing chamber to the venturi chamber generates a vacuum within the venturi chamber from the sensor. The vacuum generates air flow from the interior compartment through the sensor for measuring the temperature of the interior compartment of the vehicle. 
         [0013]    Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a partially schematic, front view of a HVAC module assembly of the present invention. 
           [0015]      FIG. 2  is an upper housing section of the HVAC module assembly of the present invention. 
           [0016]      FIG. 3  is a lower housing section of the HVAC module assembly of the present invention. 
           [0017]      FIG. 4  is a cross section of the venturi of the HVAC module assembly of the present invention. 
           [0018]      FIG. 5  is a cross section of a first venturi section of the HVAC module assembly of the present invention. 
           [0019]      FIG. 6  is a cross section of a second venturi section of the HVAC module assembly of the present invention. 
           [0020]      FIG. 7  is a schematic illustration of the air flow paths of the HVAC module assembly of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    Referring now to the drawings, there is illustrated in  FIG. 1  a HVAC system  10  for a vehicle. The HVAC system  10  includes a HVAC module assembly  12  coupled to a temperature sensor  14  for measuring the interior temperature of a vehicle&#39;s passenger compartment  15 . The sensor  14  may be positioned remote from the HVAC module assembly  12  and be pneumatically coupled to the HVAC module assembly  12  by a tubular member  16 . 
         [0022]    Referring to  FIGS. 1-3 , the HVAC module assembly  12  includes first HVAC module housing section  18  and a second HVAC module housing section  20 . The first housing section  18  and second housing section  20  are each formed by a molding operation (e.g., injection molding). The first housing section  18  includes a coupling surface  19 . The second housing section  20  includes a coupling surface  21 . The first housing section  18  and the second housing section  20  are coupled together to form the housing for the HVAC module assembly  12 . The coupling surfaces  19  and  21  form a lip and slot-type of coupling to seat the first housing section  18  against the second housing section  20 . Alternatively, the first and second housing sections  18  and  20  may be coupled together by fasteners, stakes, or a welding process. 
         [0023]    The interior of the HVAC module assembly  12  includes a HVAC mixing chamber  22  and a venturi chamber  24  as shown in  FIG. 4 . An opening  26  is formed between the HVAC mixing chamber  22  and the venturi chamber  24  for allowing air flow between the HVAC mixing chamber  22  and the venturi chamber  24 . The HVAC mixing chamber  22 , in addition to supplying forced air to the venture chamber  24 , combines forced air with conditioned air which is output to various ducts and register vents of the vehicle. 
         [0024]    The venturi chamber  24  is formed by a first venturi portion  28 , shown in  FIG. 5 , and a second venturi portion  30 , shown in  FIG. 6 . The first venturi portion  28  is molded as part of the first housing section  18 . The second venturi portion  30  is molded as part of the second housing section  20 . 
         [0025]    The first venturi portion  28  includes a first passageway  32  having a cross-section area normal to the longitudinal air flow of the first passageway  32 . An end of the first passageway  32  is formed by an edge section  34  of the coupling surface  19  of the first housing section  18 . The first passageway  32  extends a predetermined distance in a longitudinal direction away from the coupling surface  19  and away from the second housing section  20 , and is in fluid communication with the vehicle interior for allowing the discharge of air flow from the venturi chamber  24 . 
         [0026]    The second venturi portion  30  includes an edge section  36  that couples to the edge section  34  of the coupling surface  19  for forming the venturi chamber  24 . A second passageway  38  is formed in the second venturi portion  30 . The second passageway  38  is integrally formed through a wall section  40  of the second housing section  20  and is disposed radially inward from the coupling surface  36 . The second passageway  38  extends a first distance below wall section  40  away from the first housing section  18  for coupling to the conduit  16 . In addition, the second passageway  38  extends in an opposing longitudinal direction above an imaginary plane of the coupling surface  36 . The second passageway  38  extending above the imaginary plane of the coupling surface  36  has a cross section area normal to the longitudinal air flow of the second passageway  38 . 
         [0027]    The cross-section area of the second passageway  38  is smaller than the cross-section area of first passageway  32  such that the second passageway  38  telescopically extends a predetermined distance into the first passageway  32  when the first housing section  18  is coupled to the second housing section  20 . The positioning of the second passageway  38  within the first passageway  32  forms a respective flow path between an inner wall of the first passageway  32  and an outer wall of the second passageway  38 . Preferably, the second passageway  38  is substantially concentric to the first passageway  32 . Alternatively, the second passageway  38  may be axially offset from the first passageway  32 . 
         [0028]      FIG. 7  illustrates the flow paths of first and second passageways  32  and  38  for generating a venturi effect. Forced air generated within the HVAC mixing chamber  22  is directed through the opening  26  and into the venturi chamber  24 . That is, the forced air flows from the opening  26  and into the first passageway  32  and past the opening of the second passageway  38 . The air flow past the opening of the second passageway  38  generates a vacuum over the opening of the second passageway  38 . The vacuum draws air from the interior of a passenger compartment, through the sensor  14  and conduit  16  (as shown in  FIG. 1 ), through the second passageway  38  and the first passageway  32 , and exiting the venturi chamber  24 . The temperature of the air flowing through the sensor  14  is measured. 
         [0029]    The integrally molded venturi chamber allows the venturi to be positioned at substantially any parting line location on the of the HVAC module assembly which provides the optimum results for creating a vacuum or for packaging locations. For example, a valve snapped on to the HVAC module assembly would require it be coupled to a flat portion of the housing so that the valve seats securely against the housing. In the present invention, by molding the venturi as part of the housing, the venturi may be integrally molded in areas that are either planar or non-planar. The valve would avoid any disadvantages of not being securely fastened to the housing as discussed above. Moreover, the valve could be molded at those areas that provide the optimum results for generating a vacuum. 
         [0030]    In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.