Abstract:
A evaporator provides an evaporator that includes an evaporator core, an evaporator tank attached to the evaporator core, and at least one single-piece and folded baffle having raised surfaces incorporated into the evaporator tank. The baffle has opposed sides having a pair of opposed raised surfaces. The baffle further includes a top edge and a side edge. The pair of opposed raised surfaces is provided adjacent one of the edges and includes two pairs of opposed raised surfaces. The raised surface can be a flat-sided ramp, a curve-sided ramp, or a dimple.

Description:
TECHNICAL FIELD 
       [0001]    The disclosed inventive concept relates to vehicle air conditioning systems and particularly to the evaporator of such systems. More particularly, the disclosed inventive concept relates to a baffle for an evaporator tank wherein the baffle is a cladded and folded plate having elevated areas, the baffle being brazed or otherwise attached to the evaporator tank. 
       BACKGROUND OF THE INVENTION 
       [0002]    Most vehicles today include air conditioning systems to provide for improved occupant comfort. While being first introduced in the automotive world several decades ago, air conditioning systems have changed little. Thus the fundamental parts of the modern vehicle&#39;s air conditioning system are known and understood. These parts include the compressor, the condenser, the evaporator, the thermal expansion valve, and the drier or accumulator. In many ways the compressor is the heart of the vehicle&#39;s air conditioning system. The compressor pressurizes hot gaseous refrigerant and forces it on to the condenser. The condenser, which is like a small radiator, cools the hot gases received from the compressor. As these gases cool, they become liquid in the condenser. 
         [0003]    Liquid refrigerant leaves the condenser under high pressure and enters the drier or accumulator. The drier catches any liquid water that may inadvertently have entered the system. The liquid refrigerant, once cleared of any water, flows to the expansion valve which functions to remove pressure from the liquid refrigerant and literally allows it to expand. This reduction of pressure allows the liquid refrigerant to return to the vapor stage in the evaporator, the refrigerant&#39;s next stop. 
         [0004]    The evaporator is also similar in shape and function to a small radiator. Typically the evaporator is fitted inside of the vehicle&#39;s passenger compartment in or around the instrument panel. The still-liquid refrigerant enters the evaporator under low pressure from the expansion valve. The liquid refrigerant vaporizes while absorbing heat from inside the car. Cold air is circulated within the passenger compartment by a fan that pushes air across the fins of the evaporator. Low pressure refrigerant, now in gaseous form, exits the evaporator and returns to the compressor where the cycle is repeated. 
         [0005]    Evaporators are typically manufactured from aluminum and usually include an upper tank, a lower tank and a series of refrigerant-containing tubes fitted there between. Baffles are located within the tanks to regulate the flow of liquid refrigerant. The baffles are usually brazed to the inner wall of the tank. However, known technology makes positioning the baffles during the brazing process challenging and frequently results in the baffles being out of alignment prior to the brazing process. 
         [0006]    Accordingly, an improvement in evaporator design and assembly is required to overcome the challenges faced by the prior art. 
       SUMMARY OF THE INVENTION 
       [0007]    The disclosed inventive concept overcomes the problems associated with known evaporators by providing an arrangement in which the baffles are fixed in position prior to brazing to provide an accurate and fluid-tight seal without error and with minimum production time. The disclosed inventive concept provides an evaporator that includes an evaporator core, an evaporator tank attached to the evaporator core, and at least one single-piece and folded baffle having raised surfaces incorporated into the evaporator tank. 
         [0008]    The evaporator tank includes an interior wall. The raised surface has a wall-contacting portion that is in contact with the interior wall. More particularly, the baffle has two opposed sides. Each of the opposed side has a raised surface defined by a pair of opposed raised surfaces. The baffle further includes a top edge and a side edge. The pair of opposed raised surfaces is provided adjacent one of the edges and includes two pairs of opposed raised surfaces. One of the two pairs of opposed surfaces is provided adjacent the top edge of the baffle and the other of the two pairs of opposed surfaces is provided adjacent the side edge of the baffle. The raised surface is selected from the group consisting of a flat-sided ramp, a curve-sided ramp, and a dimple. 
         [0009]    The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention wherein: 
           [0011]      FIG. 1  is an isometric view of a evaporator according to the disclosed inventive concept; 
           [0012]      FIG. 2  is an exploded view of the upper portion of the evaporator of  FIG. 1  showing the upper tank in spaced apart relation to the cooling fins and the end plate assemblies and baffles also spaced apart from the upper tank portions; 
           [0013]      FIG. 3  is a perspective view of a baffle according to the disclosed inventive concept illustrating the baffle being folded from a single sheet of material; 
           [0014]      FIG. 4  is a perspective view of a baffle according to a first embodiment of the disclosed inventive concept; 
           [0015]      FIG. 5  is an end view of the baffle of  FIG. 4 ; 
           [0016]      FIG. 6  is a perspective view of a baffle according to a second embodiment of the disclosed inventive concept; 
           [0017]      FIG. 7  is an end view of the baffle of  FIG. 6 ; 
           [0018]      FIG. 8  is a perspective view of a baffle according to a third embodiment of the disclosed inventive concept; 
           [0019]      FIG. 9  is an end view of the baffle of  FIG. 8 ; 
           [0020]      FIG. 10  is a perspective view of a portion of upper tank portions shown in cutaway and illustrating baffles according to the disclosed inventive concept; 
           [0021]      FIG. 11  is a view taken along line  11  of  FIG. 10 ; 
           [0022]      FIG. 12  is a top plan view of a portion of upper tank portions shown in cutaway and illustrating baffles according to the disclosed inventive concept; 
           [0023]      FIG. 13  is a view taken along line  13  of  FIG. 12 ; and 
           [0024]      FIG. 14  is an end view of a single-layer baffle according to an alternative embodiment of the disclosed inventive concept. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    In the following figures, the same reference numerals will be used to refer to the same components. In the following description, various operating parameters and components are described for different constructed embodiments. These specific parameters and components are included as examples and are not meant to be limiting. 
         [0026]    The evaporator for use with an air conditioning system for a vehicle according to the disclosed inventive concept is illustrated in its various embodiments in  FIGS. 1 through 13 . However, it is to be understood that the illustrated embodiments are suggestive and are not intended as being limiting. 
         [0027]    The evaporator of the disclosed inventive concept is illustrated in  FIG. 1  while the baffles and end plates are illustrated in  FIG. 2 . The evaporator of the disclosed inventive concept is a multi-pass evaporator having a thickness range of between about 25 mm and 80 mm. Various embodiments of the baffles are shown in  FIGS. 3 through 9 .  FIGS. 10 through 13  illustrate the baffles in place in the tank portions. Regardless of the embodiment, the evaporator of the disclosed inventive concept overcomes challenges and limitations associated with the construction of current evaporators. 
         [0028]    Referring to  FIG. 1 , an evaporator, generally illustrated as  10 , is shown. The overall configuration of the evaporator  10  as illustrated is intended as being suggestive and not limiting. 
         [0029]    The evaporator  10  includes an upper tank assembly  12  and a lower tank assembly  14 . The upper tank assembly  12  and the lower tank assembly  14  are typically made of a metal, although other materials including polymerized materials may be used alone or in combination. A lower pressure, liquid refrigerant input  16  is provided as is a lower pressure, gas refrigerant output  18 . The liquid refrigerant input  16  is connected to liquid input upper tank portion  20 . The gas refrigerant output  18  is connected to a gas output upper tank portion  24 . A series of refrigerant-containing tubes  26  fluidly connect the upper tank assembly  12  and the lower tank assembly  14 . 
         [0030]    Referring to  FIG. 2 , an exploded view of the upper portion of the evaporator  10  is illustrated in spaced apart relation to the refrigerant-containing tubes  26 , a pair of baffles  27 , and a pair of end plate assemblies  28 . One of the end plate assemblies  28  is shown separated into its two portions, an inner end plate  30  having an inlet refrigerant input passageway  31  and an outlet refrigerant output passageway  32 , and an outer end plate  33  having an inlet refrigerant input port  34  (connected to the liquid refrigerant input  16 ) and an outlet refrigerant output port  36  (connected to the gas refrigerant output  18 ). The illustrated shapes of the baffles  27 , the inner end plate  30  and the outer end plate  33  may be altered from the illustrated shapes without varying the scope of the present invention. 
         [0031]      FIGS. 3 through 9  illustrate various embodiments of the baffle of the disclosed inventive concept. A single type of baffle may be used in a single tank or different embodiments of the baffle may be used. 
         [0032]    In  FIG. 3 , a perspective view of the baffle  27  is illustrated. The baffle  27  is preferably stamped from a single piece of cladded sheet aluminum and is then folded as illustrated to form the two-layer baffle of the disclosed inventive concept. The baffle  27  includes a first baffle half-portion  38  and a second baffle half-portion  40 . 
         [0033]    The folding of the baffle  27  provides spring back that helps to retain the baffle  27  inside the evaporator tank. This feature results in a robust brazing process to prevent any internal refrigerant leaks. 
         [0034]    In addition to folding as a method of retaining the baffle  27  in its pre-brazed position within the tank, the baffle  27  is also provided with raised areas that contact the inner wall of the tank. In this way, the baffle  27  is held in place during the brazing process. In addition to  FIG. 3 , this arrangement according to a first embodiment of the disclosed inventive concept is also illustrated in  FIGS. 4 and 5 . 
         [0035]    A pair of opposed upper ramped raised areas  42  and  42 ′ are provided to contact the inside top wall of the tank while a pair of opposed lower ramped raised areas  44  and  44 ′ are provided to contact the inside side wall of the tank. In combination with the springing action of the folded baffle  27 , the ramped raised areas  42 ,  42 ′,  44  and  44 ′ retain the baffle  27  in its proper aligned position to allow correct brazing of the baffle  27  in place within the tank. 
         [0036]      FIGS. 6 and 7  illustrate raised areas according to an alternate embodiment of the disclosed inventive concept. Particularly, a baffle  50  is showing having a first baffle half-portion  52  and a second baffle half-portion  54 . A pair of opposed, upper semi-circular raised areas  56  and  56 ′ and a pair of opposed, lower semi-circular raised areas  58  and  58 ′ are formed on the baffle  50 . In combination with the springing action of the folded baffle  50 , the semi-circular raised areas  56 ,  56 ′,  58  and  58 ′ retain the baffle  50  in its proper aligned position to allow correct brazing of the baffle  50  in place within the tank. 
         [0037]      FIGS. 8 and 9  illustrate raised areas according to a third embodiment of the disclosed inventive concept. Particularly, a baffle  60  is showing having a first baffle half-portion  62  and a second baffle half-portion  64 . A pair of opposed, upper dimpled raised areas  66  and  66 ′ and a pair of opposed, lower dimpled raised areas  68  and  68 ′are formed on the baffle  60 . In combination with the springing action of the folded baffle  60 , the dimpled raised areas  66 ,  66 ′,  68  and  68 ′ retain the baffle  60  in its proper aligned position to allow correct brazing of the baffle  60  in place within the tank. 
         [0038]    Beyond the configurations of the raised areas illustrated in  FIGS. 3 through 9 , other configurations are possible, provided contact is made between the raised area and the upper or side wall of the interior of the tank. Accordingly, the embodiments shown are intended as being suggestive and not limiting. 
         [0039]      FIGS. 10 through 13  illustrate adjacent baffles  27  in position relative to the upper tank in various views. Particularly, is a perspective view of a portion of an evaporator  10  shown in cutaway and illustrating side-by-side baffles  27  while  FIG. 11  is a view taken along line  11  of  FIG. 10 . The ramped raised areas  42  and  42 ′ are illustrated as being in contact with an inner wall  70  of the gas output upper tank portion  24 . The other raised areas (not shown) are also in similar contact. 
         [0040]      FIG. 12  is a top plan view of a portion of an evaporator  10  shown in cutaway and illustrating more particularly the side-by-side relationship of the baffles  27  according to the disclosed inventive concept.  FIG. 13  is a more detailed view of the side-by-side arrangement of the baffles  27  taken along line  13  of  FIG. 12 . Once the baffles  27  are positioned inside of the tank portions  20  and  24 , the baffles  27  are brazed in position, thus permanently securing the baffles  27  inside the tank portions  20  and  24 . 
         [0041]      FIG. 14  illustrates an alternative approach to a baffle according to the disclosed inventive concept. As shown in this figure, a flat plate baffle  42  is formed from a non-folded, single layer of material. The flat plate baffle  42  includes a first outer side  44  and a second outer side  46 . Formed on the first outer side  44  is a pair of raised areas  48  and  48 ′ and formed on the second outer side  46  is a pair of raised areas  50  and  50 ′. Because the flat plate baffle  42  is formed from a single layer, the positions of the raised areas  48  and  48 ′ are offset with respect to the positions of the raised areas  50  and  50 ′ due to manufacturing constraints. It is to be understood that while the raised areas  48 ,  48 ′,  50  and  50 ′ are dimples, other configurations such as the ramps and semi-circles discussed above could be incorporated as well. 
         [0042]    The disclosed inventive concept shown in the accompanying figures and described above effectively overcomes the problems known to be associated with known evaporators. By providing a system and method for properly aligning the baffles relative to the tank portions, proper brazing can be achieved. 
         [0043]    While the preferred embodiments of the disclosed inventive concept have been discussed are shown in the accompanying drawings and are set forth in the associated description, 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 true spirit and fair scope of the invention as defined by the following claims.