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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
As shown in
Referring to
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.
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.
As shown in
Referring again to
Referring again to
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
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.
As shown in
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.
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.
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
In a first step, shown in
In a first embodiment of the of the disclosure, shown in
In a second embodiment of the disclosure, shown in
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.
In a second step, shown in
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.
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.
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
In the closed position, shown in
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.
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.
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.
Number | Date | Country | |
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62161964 | May 2015 | US |