Abstract:
A heat exchanger for a motor vehicle comprises a fluid reservoir having at least one continuous sidewall. A plurality of first coupling features are formed in a base of the sidewall, wherein the first coupling features are outward extending protrusions. The heat exchanger further comprises a header configured to receive a portion of the fluid reservoir therein. The header includes a mounting tab having a plurality of second coupling features and a plurality of reinforcing features alternately formed therein. Each of the second coupling features are cavities configured to receive a portion of a corresponding one of the first coupling features therein. A receiving surface of each of the second coupling features cooperates with an engaging surface of the corresponding one of the first coupling features.

Description:
CROSS-REFERENCES TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/161,964, filed on May 15, 2015, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a heat exchanger for a motor vehicle, and more particularly, to a recessed header for coupling a fluid reservoir a heat exchanger. 
       BACKGROUND 
       [0003]    Heat exchangers are generally formed of a core configured to facilitate an exchange of thermal energy with a fluid passing therethrough. A header is disposed on at least one end of the core, and provides an interface between the core and a fluid reservoir, such as a tank or manifold. One common type of header is known as a recessed header, wherein a portion of the header is recessed to receive a portion of the fluid reservoir therein. 
         [0004]    In modern heat exchangers, an integrated means for coupling the fluid reservoir to the header is desirable, as it allows the heat exchanger to be assembled without using independent fastening means, such as bolts and clips. By using an integrated means for coupling the headers and fluid reservoirs, manufacturing costs can be substantially reduced by minimizing assembly time and eliminating unnecessary components. 
         [0005]    However, in recent years, increased performance requirements for heat exchangers have caused existing configurations of integrated coupling means to become insufficient. For example, modern heat exchangers operate at increased internal pressures. During operation at the increased internal pressures, the interface between the header and the fluid reservoir may warp or fracture as a result of pressure induced stresses, causing a failure of the heat exchanger. 
         [0006]    In a common heat exchanger configuration, a fluid reservoir is coupled to a header by inserting a portion of the fluid reservoir into the header, and subsequently securing the fluid reservoir by deforming a plurality of tabs of the header over the inserted portion of the fluid reservoir. However, this configuration is prone to failure under the increased pressure conditions of modern heat exchangers. For example, as the pressure within the fluid reservoir increases, the fluid reservoir is biased apart from the header, and the inserted portion of the fluid reservoir applies a bending moment to the tabs of the header. The bending moment forces the tabs of the header outward, allowing the fluid reservoir to separate from the header. Further, deforming the tabs of the header creates residual stress concentrations in the header. Upon application of the increased pressures, the areas of the residual stress concentrations are prone to failure. 
         [0007]    Additionally, modern heat exchangers are commonly integrated into rigid components of the vehicle. By rigidly mounting the heat exchanger within the vehicle, the heat exchanger is more susceptible to harmful vehicle vibrations. Accordingly, increased vibration of the heat exchanger further increases stresses in the interface between the header and the fluid reservoir. 
         [0008]    Accordingly, there exists a need in the art for an improved means of coupling a fluid reservoir to a header of a heat exchanger, wherein the coupling means is integral to the heat exchanger assembly. 
       SUMMARY OF THE INVENTION 
       [0009]    In concordance with the instant disclosure, an improved means of coupling a fluid reservoir to a header of a heat exchanger assembly, wherein the coupling means is integral in the heat exchanger assembly is surprisingly discovered. 
         [0010]    In a first embodiment, a heat exchanger for a motor vehicle comprises a fluid reservoir having at least one continuous sidewall. A plurality of first coupling features are formed in a base of the sidewall, wherein the first coupling features are outward extending protrusions. The heat exchanger further comprises a header configured to receive a portion of the fluid reservoir therein. The header includes a mounting tab having a plurality of second coupling features and a plurality of reinforcing features alternately formed therein. Each of the second coupling features are cavities configured to receive a portion of a corresponding one of the first coupling features therein. A receiving surface of each of the second coupling features cooperates with an engaging surface of the corresponding one of the first coupling features. 
         [0011]    In another embodiment, a heat exchanger for a motor vehicle comprises a core and a fluid reservoir. The core includes an open end and a header coupled adjacent to the open end. The header includes a plurality of enclosed cavities. The fluid reservoir includes a plurality of tapered protrusions extending outwardly therefrom. The protrusions of the fluid reservoir are configured to engage the enclosed cavities of the header to secure the fluid reservoir thereto. 
         [0012]    In yet another embodiment, a method of assembly of a heat exchanger is disclosed. The method includes providing a fluid reservoir having a plurality of first coupling features, and a header configured to receive a portion of the fluid reservoir therein, the header includes a plurality of second coupling features. The method includes bending the mounting tab of the header outward to present a recess of the header to the sidewall of the fluid reservoir. In another step, the sidewall of the fluid reservoir is inserted into the recess, wherein the sidewall compresses a sealing element disposed within the recess. In a third step, the mounting tab is bent inward, wherein each of the second coupling features cooperates with a portion of a corresponding one of the first coupling features to secure the fluid reservoir to the header. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of a heat exchanger of the instant disclosure. 
           [0014]      FIG. 2  is a partially exploded perspective view of the assembly of  FIG. 1 . 
           [0015]      FIG. 3  is an enlarged perspective view of the assembly of  FIG. 1 , taken at area  3  of  FIG. 2 . 
           [0016]      FIG. 4A  is a fragmentary schematic cross-sectional elevation view of a first embodiment of the assembly of  FIG. 1 , wherein the cross-section is taken through a coupling feature of the heat exchanger and the assembly is in a disassembled state. 
           [0017]      FIG. 4B  is a fragmentary schematic cross-sectional elevation view of a second embodiment of the assembly of  FIG. 1 , wherein the cross-section is taken through a coupling feature of the heat exchanger and the assembly is in a disassembled state. 
           [0018]      FIG. 5  is a fragmentary schematic cross-sectional elevation view of the assembly of  FIG. 1 , wherein the cross-section is taken through a coupling feature of the heat exchanger and the assembly is in a partially assembled state. 
           [0019]      FIG. 6  is a fragmentary schematic cross-sectional elevation view of the assembly of  FIG. 1 , wherein the cross-section is taken through a coupling feature of the heat exchanger and the assembly is in an assembled state. 
           [0020]      FIG. 7  is an enlarged fragmentary schematic cross-sectional elevation view of the assembly of  FIG. 1 , taken at area  7  of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical. 
         [0022]      FIGS. 1 and 2  show an intake assembly having an integrated heat exchanger  2  according to the instant disclosure. The heat exchanger  2  is formed of a core  4  having a pair of opposing open ends  6 . Each of the open ends  6  is configured to provide fluid communication into the heat exchanger  2 , wherein fluid enters the heat exchanger  2  through a first one of the open ends  6  and exits the heat exchanger  2  through a second one of the open ends  6 . In an alternate embodiment, the heat exchanger  2  may include a single open end  6 , wherein fluid enters and exits the heat exchanger  2  through the same open end  6 . The heat exchanger  2  further includes a header  8  disposed adjacent each open end  6 . The header  8  may be coupled to the heat exchanger  2  using mechanical means, such as welding, crimping, and brazing, for example. Alternatively, the header  8  may be integrally formed with the heat exchanger  2 . 
         [0023]    As shown in  FIG. 1 , a fluid reservoir  10  is removably coupled to each of the headers  8  of the heat exchanger  2 . In the illustrated embodiment, each of the headers  8  is similarly formed. Accordingly, any description with respect to the configuration of one of the headers  8  and one of the fluid reservoirs  10  will be understood to similarly apply to the other header  8  and fluid reservoir  10 . In alternate embodiments, each of the headers  8  may be configured differently than the other. 
         [0024]    Referring to  FIGS. 1-7 , the fluid reservoir  10  includes at least one continuous sidewall  12 . A base  14  depends from the sidewall  12  and includes a lip  16  formed adjacent an opening of the fluid reservoir  10 , and an intermediate portion  18  connecting the lip  16  and the sidewall  12 . In the illustrated embodiment, the lip  16  of the fluid reservoir  10  is outwardly offset from and substantially parallel to a lower portion of the sidewall  12 . However, in alternate embodiments, it will be appreciated that the lip  16  may be formed at an oblique angle to the sidewall  12 , and that the lip  16  may be aligned with or inwardly offset from the sidewall  12 . 
         [0025]    A plurality of first coupling features  20  is spaced along the base  14  of the fluid reservoir  10 . In the illustrated embodiment, each of the first coupling features  20  is a protrusion extending outward from the base  14  adjacent the lip  16 . A distal end  22  of each of the first coupling features  20  tapers outwardly from the fluid reservoir  10 , wherein a distance from the distal end  22  to the base  14  increases as a distance from a terminal end  24  of the lip  16  increases. In alternate embodiments, the length of the first coupling feature  20  may be substantially constant. 
         [0026]    An engaging surface  26  is formed on each of the first coupling features  20 , opposite the terminal end  24  of the lip  16 . In one embodiment, each of the engaging surfaces  26  of the first coupling features  20  are coplanar. However, the engaging surfaces  26  of the first coupling features  20  may also be offset from one another. 
         [0027]    As shown in  FIGS. 4-7 , the engaging surfaces  26  are inclined with respect to an axis (A), along which a force is applied to assemble the fluid reservoir  10  to the header  8 , wherein a distance from the terminal end  24  to the engaging surface  26  increases as the distance from the base  14  increases. In alternate embodiments, the engaging surface  26  may be formed perpendicular with respect to the axis (A). 
         [0028]    Referring again to  FIGS. 2-7 , the header  8  is configured to cooperate with a portion of the fluid reservoir  10  when the heat exchanger  2  is assembled. Particularly, a recess  28  circumscribes at least a portion of a perimeter of the header  8 , and is configured to receive at least a portion of the base  14  of the fluid reservoir  10  therein. In alternate embodiments, a recess may be formed in the fluid reservoir  10 , wherein a portion of the header  8  is received therein. It will also be appreciated that both or neither of the fluid reservoir  10  and the header  8  may include a recess. In the illustrated embodiment, a plurality of mounting tabs  30  extend from the recess  28 , wherein a single one of the mounting tab  30  spans each of the sides of the header  8 . In alternate embodiments, each of the sides of the header  8  may include a plurality of separately formed mounting tabs  30 . 
         [0029]    Referring again to  FIGS. 2 and 3 , a plurality of second coupling features  32  is spaced along each of the mounting tabs  30 . A position of each of the second coupling features  32  corresponds to a position of a respective one of the first coupling features  20  of the fluid reservoir  10 , wherein the second coupling features  32  are configured to engage the first coupling features  20  to secure the fluid reservoir  10  to the header  8 . In the illustrated embodiment, each of the second coupling features  32  is an enclosed cavity configured to receive at least a portion of the respective of one of the first coupling features  20 . The cavity is defined by a sidewall and an end wall  34 . 
         [0030]    The sidewall of the cavity defines a receiving surface  36  of the second coupling feature  32 , which is configured to cooperate with the engaging surface  26  of the first coupling feature  20 . In the illustrated embodiment, the receiving surface  36  is formed opposite the recess  28 . As shown in  FIGS. 4-7 , the receiving surface  36  may be inclined with respect to the recess  28 , wherein a distance from the recess  28  to the receiving surface  36  increases as a distance from the axis (A) increases. In an alternate embodiment, the receiving surface  36  may be formed substantially parallel to the recess  28 , wherein the receiving surface  36  is perpendicular to the axis (A). 
         [0031]    In the illustrated embodiment, a depth of the second coupling features  32  tapers outwardly from the header with respect to the axis (A), wherein a distance between the end wall  34  and the axis (A) increases as a distance from the recess  28  increases. In alternate embodiments, the depth of the second coupling features  32  remains constant with respect to the distance from the recess  28 . 
         [0032]    As shown in  FIGS. 2 and 3 , a plurality of reinforcement features  38  is formed in each of the mounting tabs  30 , intermediate each of the plurality of the second coupling features  32 . The reinforcement features  38  are configured to militate against a deflection of the receiving surface  36  of the second coupling features  32  when the compressive force is applied along the axis (A). The reinforcement features  38  are formed of a sidewall  40  extending from the recess  28 , and an inwardly formed shoulder  42  extending from the sidewall  40 , wherein an inner profile of the mounting tabs  30  is configured to substantially correspond to an outer profile of the base  14  of the fluid reservoir  10 . 
         [0033]    In an alternate embodiment, a plurality of perforations (not shown) may be formed along a length of each of the mounting tabs  30  to aid in assembly of the fluid reservoir  10  to the header  8 . Particularly, the perforations may be formed in the recess  28  and the sidewall  40  of the header  8  to improve flexibility of the mounting tabs  30 . It will be appreciated that additional structural features may be added to at least one of the first header  12  and the fluid reservoir  10  to aid in assembly. 
         [0034]    A continuously formed sealing element  44  is disposed in the recess  28  of the header  8 . In the illustrated embodiment the sealing element  44  is formed separately formed from each of the fluid reservoir  10  and header  8 . Optionally, the sealing element  44  may be integrally formed with at least one of the fluid reservoir  10  and header  8 . The sealing element  44  is formed of a resilient polymeric material, such as a flouroelastomer (FKM) or an ethylene propylene diene monomer (EPDM). Other suitable materials for the sealing element  44  will be appreciated by those of ordinary skill in the art. 
         [0035]    During assembly, the fluid reservoir  10  is secured to the header  8  of the heat exchanger  2  by inserting the base  14  of the fluid reservoir  10  into the recess  28  of the header  12 , as shown in  FIGS. 4-7 . 
         [0036]    In a first step, shown in  FIGS. 4A and 4B  the fluid reservoir  10  is aligned with the header  8 , wherein the base  14  of the sidewall  12  is aligned with the recess  28  of the header  8  in a direction along the axis (A). 
         [0037]    In a first embodiment of the of the disclosure, shown in  FIG. 4A , the mounting tabs  30  are predisposed in an open position with respect to the axis (A). In the open position, the mounting tabs  30  are spread apart from each other such that the base  14  of the fluid reservoir  10  can be received between the mounting tabs  30  unobstructed. 
         [0038]    In a second embodiment of the disclosure, shown in  FIG. 4B , the mounting tabs  30  are predisposed at an intermediate position with respect to the axis (A). In the intermediate position, the mounting tabs  30  are formed in a partially opened position, wherein the lip  16  of the base  14  can be received inside of the mounting tabs  30 , and wherein the distal ends  22  of the first coupling features  20  are formed at least partially outside of the mounting tabs  30 . 
         [0039]    Although the mounting tabs  30  of the instant disclosure are predisposed in the open position and the intermediate position during stamping or forming of the header  8 , it will be appreciated that the mounting tabs  30  may be actively bent to the open position and the intermediate position immediately prior to or during assembly of the heat exchanger  2 . 
         [0040]    In a second step, shown in  FIG. 5  the fluid reservoir  10  is advanced into the header  8 , wherein the base  14  of the fluid reservoir  10  passes through the mounting tabs  30  of the header  8 . 
         [0041]    As discussed above, in the first embodiment of the disclosure, the mounting tabs  30  are formed in the open position prior to insertion of the base  14 . In the second step of the first embodiment, the fluid reservoir  10  is inserted through the mounting tabs  30  unobstructed. 
         [0042]    In the second step of the second embodiment, the mounting tabs  30  are biased outward by the base  14  as the base  14  is inserted into the recess  28 . As the fluid reservoir  10  is advanced into the header  8 , the lip  16  of the base  14  provides a leading edge and passes inside of the shoulder  42  of the mounting tab  30 . As the first coupling features  20  progress past the shoulder  42 , the outward taper of the distal end  22  of the first coupling feature  20  causes the shoulder  42  and the mounting tab  30  to progressively bend outward, allowing the base  14  of the fluid reservoir  10  to pass. 
         [0043]    As the lip  16  of the fluid reservoir  10  is received in the recess  28 , the sealing element  44  is compressed by the terminal end  24  of the lip  16  to form a fluid seal between the fluid reservoir  10  and the first header  12 , as shown in  FIGS. 6 and 7 . With the sealing element  44  compressed in the recess  28 , the first coupling features  20  are aligned with second coupling features  32 , and the mounting tabs  30  are bent inwards, wherein the first coupling features  20  of the fluid reservoir  10  are received in the second coupling features  32  of the header  8 . In one embodiment, an elastic force of the mounting tab  30  may cause the mounting tab  30  to spring inwardly to a closed position when the base  14  is positioned within the recess  28 . In the second embodiment described hereinabove, the mounting tabs  30  are bent inwards manually after the base  14  is positioned within the recess  28 . It will be understood that a combination of the elastic force and manual bending may be utilized to move the mounting tabs  30  to the closed position. 
         [0044]    In the closed position, shown in  FIGS. 6 and 7 , the engaging surfaces  26  of the first coupling features  20  cooperate with the receiving surfaces  36  of the second coupling features  32  to secure the base  14  of the fluid reservoir  10  from the recess  28  of the header  8 , and to maintain the compressive force on the sealing element  44 . Accordingly, the first coupling feature  20  is compressed against the second coupling feature  32 . As shown in  FIGS. 6 and 7 , when each of the engaging surfaces  26  and each of the receiving surfaces  36  are inclined, the compressive force causes the receiving surfaces  36  of the second coupling features  32  to be biased inward by the engaging surfaces  26  of the first coupling features  20 , further securing the fluid reservoir  10  by preventing the mounting tab  30  from bending outward. 
         [0045]    By forming the coupling features  28 ,  40  of the heat exchanger  2  according to the disclosure, the strength and durability of the heat exchanger  2  are significantly increased over the prior art. Particularly, by forming each of the second coupling features  32  of the enclosed cavity having the receiving surface  36 , stress concentrations imparted on the headers are minimized by distributing the stresses over the entirety of the second coupling features  32 . 
         [0046]    From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.