U.S. patent application number 11/043310 was filed with the patent office on 2005-07-28 for heat exchanger manifold with formed corner joint.
This patent application is currently assigned to Valeo, Inc.. Invention is credited to Dey, Lavoyce, Fitzgerald, Jonathan, Powers, Michael V..
Application Number | 20050161207 11/043310 |
Document ID | / |
Family ID | 34633033 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050161207 |
Kind Code |
A1 |
Powers, Michael V. ; et
al. |
July 28, 2005 |
Heat exchanger manifold with formed corner joint
Abstract
The present invention relates to heat exchangers and heat
exchanger assemblies, and, in particular, leak tight heat exchanger
assemblies with coined or extruded corners. The present invention
further provides for heat exchanger assemblies that improves leak
tight features while maintaining or providing increased heat
exchanger assembly structural integrity and durability. The present
invention also provides for a method for making leak tight heat
exchangers using various bonding processes.
Inventors: |
Powers, Michael V.;
(Lakewood, NY) ; Fitzgerald, Jonathan; (Warren,
PA) ; Dey, Lavoyce; (Youngsville, PA) |
Correspondence
Address: |
Valeo, Inc.
Intellectual Property Dept
4100 North Atlantic Boulevard
Auburn Hills
MI
48326
US
|
Assignee: |
Valeo, Inc.
Auburn Hills
MI
48326
|
Family ID: |
34633033 |
Appl. No.: |
11/043310 |
Filed: |
January 26, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60539368 |
Jan 26, 2004 |
|
|
|
Current U.S.
Class: |
165/173 |
Current CPC
Class: |
F28F 9/0224 20130101;
F28F 2275/04 20130101 |
Class at
Publication: |
165/173 |
International
Class: |
F28F 009/02 |
Claims
What is claimed is:
1. A heat exchanger assembly comprising: a heat exchanger core
composed of at least one tube and fin, and at least one tank or
manifold, the tank or manifold, having a header portion with at
least one opening, for an end of the at least one tube; a first and
second component portion having a planar surface within or near a
corner, each portion having an extended planar bonding surface
being closely aligned to each other; wherein the second component
portion bonding surface is mated with the first component portion
planar bonding surface such that the second portion is locally
deformed to create a transition area with the first component
portion forming a bonding joint, said bonding joint bonded with a
bonding material.
2. A heat exchanger assembly as in claim 1, further having a third
component portion having an extended planar bonding surface
adjoined or affixed to the first component portion bonding surface,
the bonding surfaces intersecting near terminal ends of the first
and second component portions planar bonding surfaces, the terminal
ends of the bonding surfaces being within or near a corner
area.
3. A heat exchanger assembly as in claim 1 wherein the first and
second component portion have terminal ends found within or near a
corner, each portion having an extended planar bonding surface that
closely follows or runs in parallel to each other.
4. A heat exchanger assembly as in claim 1 wherein the first and
second component portion are formed in a "U" channel shape such
that the second portion is more narrow and sets within and between
the first portion.
5. A heat exchanger assembly as in claim 4 wherein the first and
second component portion has symmetrically opposed formed
transition corners.
6. A heat exchanger assembly as in claim 1 wherein the transition
area forms a sharp corner.
7. A heat exchanger assembly as in claim 6 wherein the corner is a
coined corner.
8. A heat exchanger assembly as in claim 1 wherein a part of the
transition area forms a radius and a part of the transition area
forms a sharp or coined corner.
9. A heat exchanger assembly as in claim 3 wherein the first or
second component is made of material that has essentially the same
metallurgical composition as the bonding material.
10. A heat exchanger assembly as in claim 4 wherein the first or
second component is made of material that has essentially the same
metallurgical composition as the bonding material.
11. A heat exchanger assembly as in claim 7 wherein the heat
exchanger has a joint formed into a single assembly and bonded by
an oven baking or brazing process.
12. A heat exchanger assembly as is claim 2 wherein the first,
second and third component portions, meet in a coined corner.
13. A heat exchanger assembly as in claim 1, wherein the first or
the second component portion comprises a terminal end of a
tube.
14. A heat exchanger assembly as in claim 1, wherein the first or
the second component portion comprises a tank.
15. A heat exchanger assembly as in claim 1, wherein the first
component portion comprises a terminal end of a tube and the second
component portion comprises a tank.
16. A heat exchanger assembly as in claim 1, wherein the first or
the second component portion comprises a header.
17. A heat exchanger assembly as in claim 16, wherein the heat
exchanger is essentially leak tight at the area of the corner.
18. A heat exchanger assembly as in claim 13, wherein the heat
exchanger assembly is essentially leak tight at the corner
area.
19. A heat exchanger assembly comprising a manifold assembly having
at least one tube and a header and, a heat exchanger core, wherein
the manifold assembly has at least one coined corner and wherein
the assembly is essentially leak tight at the area of the
corner.
20. A heat exchanger assembly as in claim 18, having at least one
bond joint comprising a tube and header ferrule formed by the
surfaces of the header wherein the assembly is brazed to form a
leak tight joint at the area of the corner.
21. A method of providing for a heat exchanger assembly with
manifold and first and second component portions at the area of at
least one corner by: coining the manifold and portions in the area
of the corner by press fitting or extrusion; forming a bond joint
at the area of the corner between surfaces at their mating areas;
brazing the heat exchanger assembly; so that the heat exchanger
assembly two component portions meet at a sharp angle to one
another in at least one coined corner that is essentially leak
tight after brazing.
22. The method of claim 21, further comprising a third component
portion, the third portion parallel to one of the first or second
component portions, wherein coining occurs at an area that is
naturally reinforced.
Description
[0001] This application claims priority of provisional application
60/539,368 filed Jan. 26, 2004
FIELD OF THE INVENTION
[0002] The present invention relates generally to a heat exchanger
and heat exchanger assembly, and, particularly, leak tight heat
exchanger assemblies with coined or extruded corners.
BACKGROUND OF THE INVENTION
[0003] Heat exchangers are used in the automotive industry as
essential parts of a vehicle cooling system. Modern heat exchangers
usually consist of a fin and tube assembly called a core, with
variations to the basic design including tube attachments to
manifold components on opposite ends of the core. As part of a
normal production process, the heat exchanger can be placed in an
oven along with other attachments and components to `bake` or braze
individual them together, yielding a resultant product that
combines fins, tubes, and manifolds bonded together to form a
single integrated heat exchanger assembly.
[0004] Physical parameters determine the required characteristics
of heat exchanger assemblies. For example, heat exchangers
assemblies are subject to pressure variations and act as pressure
vessels. Such so-called vessels can take many shapes and require
specific contours in order to deal with the constraints of limited
space packaging, etc. of the motor vehicle. They must, however, at
the same time, be able to maintain their structural integrity
(remain `leak tight`) in often extremely high and/or low pressure
environments.
[0005] In the past many designs have compromised more efficient
practices in order to obtain functional units for use in automotive
applications. However, these designs have often been made at the
expense of process consistency and have led to less than reliable
braze joints or junctions between individual or multiple components
in heat exchanger assemblies, due, in large part, to the
variability of the contact surfaces or areas of mating (mating
fits) between parts. In addition to the resultant leaks at the
braze junctions and the like, many prior art solutions have led to
designs where leaks are difficult to locate and expensive to
repair, while at the same time producing heat exchanger assembly
products not capable of reaching their full design potential.
[0006] Assemblies requiring sheet metal formed channels to seal off
multiple brazing planes within the manifold are subjected to the
variability in sheet stock such as gauge and temper, along with
tool wear resulting in poor dimensional control. At corner braze
junctions where a first intersecting set of surfaces must braze to
seal against a second set of braze surfaces it is difficult to
match the radial bends of set surfaces due to tolerances on
materials and variability of processes. To accommodate this design
shortfall a variety of `repair` methods are used including
rebonding, welding, epoxy fill, additional components, and
additional applications of a bonding alloy.
[0007] One of the common problems found in the prior art relates to
bonding joints, and, in particular, compound bonding joints.
Compound bonding joints are joints commonly made up of at least two
flat intersecting planes forming a sharp corner, mated with two
flat intersecting planes connected by a radius. The fit yields a
form of bonding joint, and, particularly, a joint that may be
bonded or brazed in an oven or the like. Compound bonding joints
often have the disadvantage of developing leaks at points where the
greatest gap occurs between the radius and sharp corner in the
bonding joint. The same problem exists in the prior art in similar
designs involving at least three intersecting planes. Also, bonding
joints are often comprised of various bonding materials of somewhat
differing natures, including added bonding materials to increase
material mass, addition of other components parts near or around
the joint area, or otherwise compensate for structural weakness.
These manufacturing variations may comprise good joint fitup, or
joint integrity and the like. Addition of increased mass or volume
of materials near or around the joint area may be a way of
providing thicker gage base material to get better bonding results,
but is not an ideal way to compensate for poor bonding joint
design, as it does not assure the joint will be leak free, and
usually results in resultant higher manufacturing costs.
[0008] In addition to bonding material problems, the need for
durability or increased lifetimes under high pressure environments
means that joints in heat exchanger assemblies must maximize fit
between elements in order to retain both durability and to remain
basically leak tight. The prior art solution of flat planes with a
curve or radius connecting them, though providing some structural
stability, led to joint `mismatches` or related fit problems has
often led to leaks through the mismatched area after brazing or
oven bonding.
[0009] Other solutions to prior art problems have involved the use
of resins, such as epoxy, to seal small leaks from poorly bonded
joints. These solutions, however, also ultimately increase
manufacturing costs and provide a "soft" seal with shorter
longevity that can reduce the ultimate effective life of the heat
exchanger. Testing and then welding or re-bonding in areas of small
leaks after brazing is also found in the prior art. These
solutions, however, have the disadvantages of not only distorting
the physical parameters of the heat exchanger, but also may weaken
adjacent braze joints and/or increase assembly costs.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide an improved
joint, and, in particularly, a "bonded" or bonding joint that would
be used in a `leak tight` heat exchanger assembly. It is further an
object of the present invention to provide for a improved heat
exchanger assembly that retains its leak tight features while
additionally maintaining heat exchanger assembly structural
integrity and durability. The present invention, in its preferred
embodiments, eliminates the radius found in the prior art, while
maintaining structural integrity and providing for leak tight bonds
in the bonding joint area, particularly for heat exchanger
assemblies that have brazed bonding joints.
[0011] In preferred aspects of the present invention, the heat
exchanger assembly is designed to provide for a leak tight seal or
connection between heat exchanger assembly components, without the
need for a radius for increased structural integrity. Preferred
aspects of the present invention provide for a leak tight joint or
joints at areas of contact between elements of the manifold
assembly. Particularly preferred aspects of the present invention
provide for a leak tight joint at the point of contact or
`intersection` of plane surfaces in a manifold assembly. Preferred
aspects of the present invention also provide for a method of
making a heat exchanger assembly providing leak tight features
while maintaining heat exchanger structural integrity and
durability by `coining` or extruding matching component
intersecting surfaces in a local area to preferably create shaped
contour areas that match or mate with each other at the binding
joints. More preferred aspects provide for a method a making and a
heat exchanger assembly wherein the local area comprises a
localized brazing zone at the point or points of contact or mating
fits found at or near the intersection of the manifold assembly
intersecting planes, creating a so-called `mating` or `pairing`
surface or surfaces where consistent bonding may occur. Even more
preferred aspects of the present invention provide for a heat
exchanger assembly, with manifold, having corner bonding joint
between the header or manifold, formed from a channel, a tube, or a
cap, or any combination of the above. Also more preferred aspects
provide for at least one corner bonding joint that is sharp or
angled, and, preferably straight angled corner; in most preferred
aspects, the corner comprising the bonding joint is a coined
corner.
[0012] In preferred embodiments of the present invention, heat
exchanger assemblies are found with localized transition zone bonds
provide for optimized seal formation without compromising
structural or braze seal integrity. The advantage of this
strengthened bond design is components designed for strength also
have a properly designed bond joint which provides superior quality
bond joints for leak free service, improved fitup of components, no
impact to durability of the assembly, and reduced cost to
manufacture.
[0013] A coined corner is a corner formed by at two or more
straight planes at some angle of intersection. In preferred aspects
of the present invention, three or more straight planes meet at
straight (uncurved) angles at a zone of intersection.
[0014] By corner bonding joint is meant a joint capable of being
bonded, formed at a corner, the corner formed with straight angles,
and not utilizing a radius between connecting planes of the bonding
joint area.
[0015] By coined corner is mean a corner formed by extrusion or
press fit, or, preferably, by extrusion and press fitting. In
preferred embodiments, the coined corner is formed at a localized
zone of junction of the tube and header and more preferred, formed
at a localized zone between the tube and header. More preferably,
it is formed at the transition wherein the tube, or tube and
header, all have mating surfaces where a bond joint can be formed.
More preferably, the tube at the area of the bond joint has
approximately the same or similar dimension (is equal to or less
then twice the size of the tube at the corner area), or is
unsplit.
[0016] In another preferred aspect of the invention, a method of
producing an heat exchanger assembly that is designed for strength
and durability, with components that have a strength/bond
transition zone for providing proper joint clearances to oven bond
leak tight heat exchangers, is provided. The heat exchanger
assembly is subsequently tested prior to other procedures or
immediately leak tested and shipped to the customer thereby
shortening the manufacturing process and reducing overall cost.
[0017] Also, the present invention provides for preferred
embodiments whose design promotes the use of a single material or
materials that have approximately the same metallurgical
composition as the bonding material to make the complete heat
exchanger thereby supporting recycling mandates. In summary, this
invention reduces cost, and rework, while shortening manufacturing
time. This invention provides a manifold designed for durability,
where needed, and designing proper bond joints, where needed,
without compromising either durability or bond joint design.
[0018] The present invention, therefore, provides a method of
making a heat exchanger assembly wherein maximum durability of the
heat exchanger co-exists with best practices, i.e. efficient and
leak tight assemblies utilizing bond joint designs. In preferred
embodiments of the present invention, various materials may be used
in the manufacture of the heat exchanger assembly. In more
preferred embodiments, the present invention provides for use of
clad or unclad materials. These materials may be metallic or
non-metallic materials. Preferred is when the materials used in the
heat exchanger are either metallic or non-metallic. Preferred is
when at least one of the materials used in the heat exchanger
assembly is metallic at a point of surface contact or bonding, or
at a joint. Also preferred is when at least one of the materials
used in the heat exchanger assembly is non-metallic. Even more
preferred is a heat exchanger assembly using combination of
metallic and non-metallic materials. Even more preferred is a heat
exchanger assembly wherein the joints and/or surface areas or zones
where bonding occur are comprised of metallic or non-metallic
materials. Most preferred is wherein the joints and/or surface
areas or zones where bonding occur are of essentially the same
material. Also preferred is wherein the joints and/or surface areas
or zones where bonding occur are more than 90% metallic and are
essentially the same material.
[0019] In preferred embodiments of the present invention, the bond
joint uses standard materials (i.e. materials used in normal
quantity and of normal quality during assembly and brazing, and not
including additional material or products such as glues or resins
or other such additional materials) in the construction of heat
exchangers comprising the embodiments of the present invention,
resulting in reduced overall production costs per unit of the heat
exchanger.
[0020] In more preferred embodiments of the present invention, the
adjacent surface area is maximized for bonding. The present
invention uses `simplified` bond joint designs to provide adjacent
surface areas or a zone of a relatively greater nature than those
in the prior art designs described hereinabove.
[0021] In a preferred method of the present invention, a
standardized method of producing a bond joint is provided. The heat
exchangers produced thereby provide a substantially or essentially
leak tight heat exchanger assembly joint or bond. In more preferred
methods of the present invention, the surfaces that form the joint
or bond are `coined` or extruded contiguous with a transition
surface to provide for a long durability bonding between components
of the heat exchanger assembly, and, particularly, brazed
components. Also, in more preferred methods of the present
invention, additional process steps of component manufacturing
found in the prior art are eliminated via the integrality of form
tooling, thereby reducing assembly complexity. In the more
preferred methods of the present invention, additional formed
features such as `fillers` or other `gap closers` that have been
used to close gaps of normal bend radii at the joint area, are
eliminated.
[0022] The present invention provides for a heat exchanger and heat
exchanger assembly, particularly a `one shot` or similar material
brazed heat exchanger assembly wherein braze closure is uniform or
practically achieved over the entire surface of the joint areas or
zone, to form essentially leak proof joints. The present invention
further provides a multiple component interface braze closure
uniform or practically achieved over the entire surfaces of the
joint areas or zone at multiple component interfaces. The present
invention further provides a sealed multiple component assembly
useful in a variety of bonding process. The present invention
preferably provides a braze sealed with a bend radius.
[0023] Preferred embodiments of the present invention provide a
light weight heat exchanger, essentially without additional
material to ensure braze leak tight joints or correct for joint
deficiencies.
[0024] By all metal heat exchanger or manifold assembly it is meant
a heat exchanger or assembly where all or most parts or components
capable of being brazed or joined together in a device such as an
oven, are based on metallic materials. Preferred are so called `one
shot braze` all metal heat exchanger with manifold assemblies
wherein the part or components, as well as any brazing or joining
materials, are of a similar or like substance, so as to be capable
of being brazed or joined together in an oven while providing for
leak tight seals amongst the components at the joints. More
preferred are all metal heat exchanger or manifold assemblies
wherein coining or extrusion features appear at the areas of
contact or zones of the joint. Also, more preferred are heat
exchanger or manifold assemblies where the edges or surfaces of
joints that occur at the junctures of planes in the assembly are
coined or extruded.
[0025] In preferred embodiments of the present invention, the
coining or extrusion feature is only done at the naturally
reinforced juncture of multiple planes so as it does not impact the
durability of the heat exchanger. By naturally reinforced it is
meant that multiple thicknesses of the mating surfaces in the area
of the coined corner are bonded together to form a single zone or
area, a so called `single assembly`. The heat exchanger assembly
and, subsequently the heat exchanger `single assembly` so produced,
maximizes durability and design for the bond joint in the area of
the coined corner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an elevation view of heat exchanger joint section
using forms in the header pan to fill gaps in braze joint in the
prior art;
[0027] FIG. 2 is an elevation view of an heat exchanger using
nothing to fill gaps left by header pan radius, the cap butts
against end header well radius in the prior art;
[0028] FIG. 3 is an elevation view of a heat exchanger header and
tank assembly used for the example of coined edge for square corner
in accordance with an aspect of the present invention.
[0029] FIG. 4 is a perspective view of FIG. 3 Section A (47) from
inside manifold tank in accordance with an aspect of the present
invention.
[0030] FIG. 5 is a perspective view of FIG. 4 sealing cap rotated
90 degrees in accordance with an aspect of the present
invention.
[0031] FIGS. 6a and b show corners, as typically found in the prior
art;
[0032] FIGS. 7a and b show localized bond transition areas at
corners, as they appear in accordance with an aspect of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] As described above, the present invention provides for
structual sections designed for strength and durability with formed
sections having two or more planes unconnected by a radius, that
increase or enhance the leak proof or leak tight nature of the
assembly at the area of the angle and joint formed at the
intersection of the two or more planes.
[0034] In a preferred embodiment of a heat exchanger assembly in
accordance with the present invention, the heat exchanger comprises
a core composed of tubes and fins, with manifolds preferably formed
of flat sheet stock, the manifold having a header portion with at
least one opening or openings connecting to the at least one tube
end or ends; a first and second component portion comprising or
consisting of an header or tubes or tanks or channels within or
near a corner area with each portion having an extended planer
bonding surface that are closely aligned to each other; and, a more
preferably third component portion. Preferrably the third component
portion has an extended planar bonding surface being adjoined or
affixed to the first bonding surface forming intersecting bonding
surfaces located near the terminal end of the first and second
portion surfaces bonding surfaces. Preferable, the second component
portion has matching intersecting surfaces such that the transition
contour of the second portion is locally deformed to create a
shaped contour that matches the transition area of the first
component portion intersecting surface transition area forming
bonding joints. More preferably, the bonding joints are bonded with
a bonding material.
[0035] In more preferred embodiments of the present invention, a
first part of the bonding joint is formed into one section where
two or more planes are at an angle with each other (a structural
part or section), while a second part is formed out of the
structural section and is coined to form a small section where the
planes are at an angle with each other and mate with the first part
of the bonding joint to form an improved complete bonding
joint.
[0036] The preferred bonding joints of the present invention can be
formed with intersection planar surfaces from various components of
the heat exchanger assembly. For example, the bonding joint
preferably occurs at an area where a heat exchanger core tube and
header meet at the header ferrule, where a heat exchanger core tube
and tank meet, where a tank and a header meet, where a tube and a
header meet, or where a bonding joint is itself included as part of
a mounting structure to a tank. Caps, walls, pans, channels and
other such components where flat planes are capable of intersection
in a corner transition area, are intended as unlimiting examples
useful in embodiments of the present invention.
[0037] In more preferred embodiments, the first and second
component portion within or near a corner area are found, with each
portion having an extended planer bonding surface that closely
follows or runs in parallel to each other. In preferred embodiments
having three or more component portions, one of the component
portions forms a single plane in the area of the bonding joint, and
the two other component portions (two structural members) abutt and
are parallel to the bonding joint adjacent to the single plane;
even more preferred are two component portions parallel to one
another and a third forming an angle relative to the two at the
intersection area of the joint.
[0038] Also, preferably, embodiments of the present invention
further have a third component portion having an extended planar
bonding surface adjoined or affixed to the first component portion
bonding surface, the bonding surfaces intersecting near terminal
ends of the first and second component portions planar bonding
surfaces, the terminal ends of the bonding surfaces being within or
near a corner area.
[0039] In other preferred embodiments of the present invention, the
first and second component portion are formed in a "U" channel
shape such that the second portion is more narrow and sits or rests
within and between the first portion. Also preferred are
embodiments wherein the heat exchanger first and second component
portion has symmetrically opposed formed transition corners. Even
more preferred is wherein the transition area approximately forms a
sharp corner.
[0040] Preferably, in one aspect of the present invention, a heat
exchanger assembly comprising a manifold assembly having at least
one tube and a header and, a heat exchanger core, wherein the
manifold assembly has at least one coined corner and wherein the
assembly is essentially leak tight at the area of the corner.
[0041] Referring to FIG. 1, FIG. 1 shows a design wherein tank 12
forms a braze joint between tank 12 and header wall 11 to form the
manifold assembly. Header wall 11 has an additional form 13 to fill
a gap caused by fitting the flat side of tank 12 against a formed
radius on tank end 14.
[0042] FIG. 2 refers to an all-metal heat exchanger assembly, for
example, wherein a plurality of components is assembled together to
create the manifold assembly. In FIG. 2, Sealing Cap 23, Header
Wall 22, Header Pan 21, and Cap Crimp Tab 25 are `baked` of oven
`brazed` to form an integral manifold 26 for an heat exchanger
assembly.
[0043] FIG. 2 is a prior art design where header wall 22 butts
against header pan 21 and against sealing cap 23 forming the
manifold assembly. Header wall 22, sealing cap 23, and header pan
21 form a joint where the radius of the header pan 21 fits against
the square edges of header wall 22 and sealing cap 23 at location
24.
[0044] FIG. 3 is an embodiment of the present invention wherein
combined header and channel 32 is assembled to a cap 32 to form a
manifold assembly with the coined area 33 providing a proper braze
joint between header and channel 32 and cap 31 at the junction
shown at section A (35).
[0045] Referring to FIGS. 3, 4 and 5, FIG. 3 shows a preferred
embodiment of the present invention wherein header and channel 32
are combined and assembled to a cap 31 to form a manifold assembly.
Coined area 33 provides a proper braze joint between header and
channel 32 and cap 31 at the junction shown at section A 35.
[0046] Referring to FIG. 4, in a preferred embodiment of the
present invention a transition or transition zones 42 is created in
a component between the area 43 designed for durability and the
somewhat small area 44 wherein bonding occurs at the intersection
of intersecting planes 47. Typically in a sheet metal manifold one
half of the bond joint will consist of one or more components. FIG.
4 further illustrates intersecting on different planes with a sharp
corner 47 at the intersection of said planes. Planar component
portion P1 and planar component portion P2 has a radius that
connects the plane for strength. Area 47 of intersecting planes is
coined to improve the braze joint by having a sharp or straight
angled corner fit into another sharp or straight angled corner.
[0047] Referring to FIGS. 4 and 5, FIG. 5 shows a preferred
embodiment of the present invention wherein formed components with
intersecting planes 65 are connected with a radius 62, which
provides a transition zone for stresses between planes. FIG. 5
further illustrates an embodiment wherein the design is
particularly suitable for bond joint fitup. Intersecting planes 65
include a sharp corner at intersection localized section or zone
64, to assure appropriate levels of material adjacent to the mating
portion or zone of the bond joint over the maximum surface. FIG. 5
shows FIG. 3 Section A 35 with the details of the header pan 46
with a reverse bend 48 and header wall 41 as an integral component,
cap 45 has bend radius 43 for strength with connecting transition
42 to coined area 44 which enable proper design for durability and
proper design for bonding at the intersection of the intersecting
planes 47. FIG. 5 is FIG. 4 cap 45 rotated 90 degrees, cap 63 is
comprised of features of intersecting planes 65, radius 62 for
durability, coined corner 64 for bonding, and transition 61
connecting radius 62 to coined corner 64. Plane demarcations A1 and
B1 show a structural strengthening joint area. Plane demarcations
A1 and B2 show a joint area that allows for improved brazing while
surprisingly maintaining structural integrity and providing for
reduced possibility for leakage (leak tight joint).
[0048] The mating component FIG. 5 will have matching planes 65
formed into said component with a radius 62 connecting said planes.
This invention utilizes a coining or extrusion process to reform
and remold a localized portion 64 of a component from intersecting
planes connected by a radius 62 to intersection planes with a sharp
corner at the localized portion 64 at the intersection of the
intersecting plane with transition 61 as a key feature. The
reformed section 44 of the component FIG. 4 will then fit adjacent
to the mating portion of the bond joint 46, 41, 48, maximizing the
surface area of the bond joint and minimizing the gaps between
components. This enables the bond joint 47 to be fused in an oven
for leak tight service. The coining or extrusion process would
typically be part of the component form tooling, thereby providing
this feature with minimal cost.
[0049] As shown in FIG. 5, part of the transition area between the
two planar component portions forms a radius 62 and part of the
transition area forms a sharp or coined corner 64. In such
embodiments, the total bonding joint is improved by the structural
strength sections as well as the leak tight coined corner
sections.
[0050] Referring to FIGS. 6a and 6b is shown typical prior art
corner 600, 601 showing un-sharp 603 and non-coined 604 corner in
area 602. First plane component 605 and second plane component 606
meet at intervening radius 607 to form structural feature. Gap 608
partially filled by feature 609. Gap 610 for potential leak path
not filled during bonding.
[0051] Referring to FIGS. 7a and 7b is shown sharp 701 and coined
702 corners, with improved leak tight areas 703, 704, illustrated.
Coined corner 705, has, preferably, all bonding surfaces at a
constant distance apart 707.
[0052] In more preferred embodiments of the present invention,
components of the heat exchanger manifold, after assembly, are
bonded together using a heating means such as a `furnace` or
`oven`. The ability of the manifold assembly to bond together
without detectable leaks, as in the present invention, has been
found to be related directly to the design constraints related to
durability and bond joint fitup. The present invention, therefore,
provides for durability and bond joint fitup in a non-compromising
manner.
[0053] In preferred embodiments of the present invention, it is
especially preferred where the first or second component is made of
material that has essentially the same metallurgical composition as
the bonding material. It is possible, however, that depending on
materials, component material can differ in metallurgical
composition from the bonding material.
[0054] In preferred embodiments of the present invention, a method
of providing for a heat exchanger assembly with manifold and first
and second component portions at the area of at least one corner
by: coining the manifold and portions in the area of the corner by
press filting or extrusion; forming a bond joint at the area of the
corner between surfaces at their mating areas; brazing the heat
exchanger assembly; so that the heat exchanger assembly two
component portions meet at a sharp angle to one another in at least
one coined corner that is essentially leak tight after brazing.
[0055] As described herein, heat exchangers in accordance with the
present invention preferably have a joint or joints bonded by an
oven baking or brazing process. In particularly preferred
embodiments in accordance with the present invention, the joints
are bonded by a flame braze process.
[0056] In addition, while a feature of the present invention may
have been described in the context of only one of the illustrated
embodiments, such feature may be combined with one or more other
features of other embodiments, for any given application. It will
also be appreciated from the above that the fabrication of the
unique structures herein and the operation thereof also constitute
methods in accordance with the present invention.
[0057] The preferred embodiment of the present invention has been
disclosed. A person of ordinary skill in the art would realize
however, that certain modifications would come within the teachings
of this invention. Therefore, the following claims should be
studied to determine the true scope and content of the
invention.
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