Abstract:
An HVAC assembly including an HVAC case disposed in a passenger compartment of the vehicle includes a heater core having an upstream side and a downstream side. The heater core accepts air from the upstream side and exhausts air to the downstream side. The exhausted air defines a temperature gradient along a plane of the heater core. An air diverting member is positioned on the downstream side proximate the heater core. The air diverting member includes a first portion aligned for accepting air from a first region of the temperature gradient and a second portion for delivering the accepted air toward a second region of the temperature gradient. The first region has a higher air temperature than the second region.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to HVAC systems in vehicles and more particularly to an HVAC case arrangement having a center plate downstream of a heater core for redirecting air in a more uniform temperature distribution.  
       BACKGROUND OF THE INVENTION  
       [0002]     In automotive vehicles, it is common to have a climate control system located within an instrument panel which provides heated or cooled air to occupants through dash panel defrost air outlets, instrument panel venting air outlets and floor directed air outlets. These traditional climate control systems often include a heater core that performs heat exchange between the engine coolant, which is heated by the engine, and the cool air in the cabin/outside environment, in order to provide warm air to the passenger compartment. Some vehicles include an air conditioning system that cooperates with an evaporator for absorbing heat from the air in the vehicle. The heater core and evaporator are typically provided in an HVAC case located in the passenger compartment of the vehicle.  
         [0003]     In some vehicles, the climate control system is adapted to control three zones of the cabin space. Generally, the three zones include the driver&#39;s side, the passenger&#39;s side and the rear occupant zone. The HVAC case typically includes ducting to accommodate air distribution to these appropriate zones as desired. The heater core is generally disposed downstream of a fan for communicating warmed air into the passenger compartment.  
         [0004]     A heater core typically does not produce uniform temperature distribution across its plane due, in part, to placement of the water inlet. As a result, a temperature gradient is observed along the heater core. With a three zone HVAC configuration, sometimes an undesirable temperature imbalance is observed between the driver and the passenger sides of the case. Conventional methods to compensate for the temperature imbalance are to increase tank depth of the heater core, increase thickness of the heater core, or shift the entire heater core to one side of the case. All of these options involve costly tooling changes and can have a negative impact in terms of airflow volume and noise.  
       SUMMARY OF THE INVENTION  
       [0005]     An HVAC assembly including an HVAC case disposed in a passenger compartment of the vehicle includes a heater core having an upstream side and a downstream side. The heater core accepts air from the upstream side and exhausts air to the downstream side. The exhausted air defines a temperature gradient along a plane of the heater core. An air diverting member is positioned on the downstream side proximate the heater core. The air diverting member includes a first portion aligned for accepting air from a first region of the temperature gradient and a second portion for delivering the accepted air toward a second region of the temperature gradient. The first region has a higher air temperature than the second region  
         [0006]     According to other features, the air diverting member is disposed on a center plate. The center plate defines a longitudinal axis substantially transverse to the plane of the heater core. The heater plate is coupled to the heater core. The first portion of the air diverting member defines an intake plane substantially parallel to the heater core plane. The second portion of the air diverting member defines an exhaust plane substantially transverse to the heater core plane. The air diverting member defines an annular wall extending between the intake plane and the exhaust plane. The center plate is arranged substantially at a midpoint of the heater core plane.  
         [0007]     An HVAC assembly for delivering air to a passenger compartment of an automobile includes an HVAC case and a heater core disposed in the HVAC case. The heater core is adapted to pass air through a plane of the heater core and influence downstream air having a temperature gradient along the plane. An air redirecting member is disposed in the HVAC case downstream of the heater core. The air redirecting member includes an air accepting portion aligned to accept air from a first region of the temperature gradient and an air release portion aligned to release air into a second region of the temperature gradient. The first region defines air having a higher temperature than the second region.  
         [0008]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0010]      FIG. 1  is a functional block diagram of an HVAC system of a vehicle;  
         [0011]      FIG. 2  is a partial cutaway view of the HVAC case according to the present teachings;  
         [0012]      FIG. 3  is a perspective view of the HVAC case center plate according to the present teachings;  
         [0013]      FIG. 4  is a perspective view of the center plate shown attached to the heater core in an assembled position; and  
         [0014]      FIG. 5  is a diagrammatic representation of a temperature gradient of the heater core. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0016]     With initial reference to  FIG. 1 , a block diagram of a conventional vehicle HVAC system is shown and generally identified at reference  10 . An HVAC case  20  forms a ventilation duct through which air conditioned and/or heated air is sent into the passenger compartment. The HVAC case  20  contains a fan  22  which is arranged on the upstream side of an evaporator  26 . Low pressure refrigerant flowing into the evaporator  26  absorbs heat from the air inside the HVAC case  20  for evaporation. An inside/outside air switch box (not shown) is arranged on the suction side of the fan  22  (the left side in  FIG. 1 ). The air inside the passenger compartment (inside air) or the air outside the passenger compartment (outside air) switched and introduced through the inside/outside air switch box is sent into the HVAC case  20  by the fan  22 .  
         [0017]     The HVAC case  20  accommodates, on the downstream side of the evaporator  26 , a hot water heater core (heat exchanger)  30 . The heater core  30  includes an inlet pipe  32  and an outlet pipe  34 . Hot water (coolant) of the vehicle engine (not shown) is directed to the heater core  30  through the inlet pipe  32  by a water pump (not shown). A water valve  36  may be incorporated to control the flow volume of engine coolant supplied to the heater core  30 .  
         [0018]     A bypass channel  40  is formed beside the hot water heater core  30 . An air mix door  42  is provided to adjust the volume ratio between warm air and cool air that passes through the hot water heater core  30  and the bypass channel  40 , respectively. The air mix door  42  adjusts the temperature of the air blown into the passenger compartment by adjusting the volume ratio between the warm air and the cool air.  
         [0019]     Additionally, a face outlet  46 , a defroster outlet  48 , a foot outlet  50  and a rear cabin outlet  52  are formed at the downstream end of the HVAC case  20 . The face outlet  46  directs air toward the upper body portions of passengers, the defroster outlet  48  directs air toward the internal surface of a windshield, the foot outlet  50  directs air toward the feet of the front seat passengers and the rear cabin outlet  52  directs air toward the rear seat passengers of the vehicle. The outlets  46 - 52  are opened and closed by outlet mode doors (not shown). The air mix door  42  and the outlet mode doors mentioned above are driven by such electric driving devices such as servo motors via linkages or the like.  
         [0020]     With reference now to  FIGS. 2-4 , the HVAC case  20  according to the present teachings is shown. The HVAC case  20  includes a center plate  54  extending substantially transverse to the heater core  30 . The center plate  54  is arranged substantially at a midpoint of a longitudinal axis of the heater core  30 . The center plate  54  generally defines an upstream portion  56  extending upstream of the heater core  30  and a downstream portion  58  extending downstream of the heater core  30 . An intermediate portion  60  includes an attachment portion  62  for coupling with an upper surface  64  of the heater core  30  in a saddle relationship. The attachment portion  62  generally includes an arcuate wall member  66  having locating tangs  68  for locating a ledge  70  formed on the heater core  30 .  
         [0021]     The center plate  54  is operable to divide the HVAC case  20  into a driver side region  72  and a passenger side region  74  ( FIG. 4 ). An air diverting member  80  extends from the center plate  54  on the downstream portion  58  and is operable to redirect air on the downstream side of the heater core  30  from a first region to a second region to compensate for a temperature imbalance as will be described in further detail.  
         [0022]     In order to appreciate the advantages realized by the center plate configuration according to the present teachings, a discussion of the operation of the heater core  30  is warranted. With additional reference now to  FIG. 5 , a diagrammatic representation of the heater core  30  is shown. At the outset dashed line V represents the vertical orientation of the center plate  54  with respect to the heater core  30 . In this regard, line V represents a division in the downstream air from the heater core  30  between the driver side region  72  and the passenger side region  74 . A horizontal dashed line H represents a lower zone  84  aligned for directing air to the rear passenger occupants.  
         [0023]     The inlet and outlet pipes  32  and  34 , respectively, are shown connected with the heater core  30  on a first end  88 . It has been shown that the temperature experienced downstream of the heater core  30  across the plane of the heater core  30  is not uniform. In the example shown, a temperature gradient T is experienced that produces downstream airflow having reduced temperature from the first end  88  leftward as viewed from  FIG. 5 .  
         [0024]     As explained above, the center plate  54  is arranged substantially at a midpoint along a longitudinal axis of the heater core  30 . As a result of the positioning of the center plate  54  and the temperature gradient T experienced downstream of the heater core  30 , the air diverting member  54  is adapted to divert air from the passenger side region  74  (warmer air) and deliver it to the driver side region  72  (less warm air). In this regard, the temperature imbalance that would otherwise influence warmer air being introduced into the passenger side region  74  than that of the driver side region  72  is compensated. As a result, the air temperature experienced between the driver&#39;s side and the passenger&#39;s side of the vehicle is modified to a more proportional level.  
         [0025]     With specific reference now to  FIGS. 3 and 4 , the air diverting member  80  will be described in greater detail. The air diverting member  80  generally includes a first portion  90  aligned for accepting air at the passenger side region  74 , an intermediate portion  92  and a second portion  94  for delivering the accepted air to the drivers side region  72 . The first portion  90  of the air diverting member  80  defines an intake plane substantially parallel to the heater core plane. The second portion  94  of the air diverting member  80  defines an exhaust plane substantially transverse to the heater core plane. The intermediate portion  92  defines an annular wall  96  extending between the intake plane and the exhaust plane. The air diverting member  80  may comprise an integrally molded portion of the center plate  54  or may be a separate component adapted to be attached to the center plate  54 . It is appreciated, that other shapes and configurations may be employed for the air diverting member  80  for directing downstream air from the passenger side region  74  to the driver side region  72 .  
         [0026]     Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. For example, while the discussion of the temperature gradient associated with the heater core  30  has been described as having decreasing temperature leftward across a plane of the heater core, other temperature gradients may be experienced. For example, the temperature gradient may be shown to increase leftward across a plane of the heater core. In such an environment, a center plate may be provided having an air diverting member extending into the driver side zone for redirecting air from the drivers side zone in to the passenger side zone. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.