U.S. patent application number 12/511351 was filed with the patent office on 2011-02-03 for end plate with area of weakness for a heat exchanger.
Invention is credited to Nicolas CORMET, Christian RIONDET.
Application Number | 20110024081 12/511351 |
Document ID | / |
Family ID | 43525883 |
Filed Date | 2011-02-03 |
United States Patent
Application |
20110024081 |
Kind Code |
A1 |
RIONDET; Christian ; et
al. |
February 3, 2011 |
END PLATE WITH AREA OF WEAKNESS FOR A HEAT EXCHANGER
Abstract
The present invention relates to an end plate for a heat
exchanger, running longitudinally, comprising at least one opening
(5, 5', 5''), said opening (5, 5', 5'') forming a cut in the end
plate (1), and at least two areas of weakness (6, 6'),
characterized in that the two areas of weakness (6, 6') are
situated in distinct parallel planes. It also relates to an
exchanger equipped with such an end plate.
Inventors: |
RIONDET; Christian;
(Bourgogne, FR) ; CORMET; Nicolas; (Reims,
FR) |
Correspondence
Address: |
HOWARD & HOWARD ATTORNEYS PLLC
450 West Fourth Street
Royal Oak
MI
48067
US
|
Family ID: |
43525883 |
Appl. No.: |
12/511351 |
Filed: |
July 29, 2009 |
Current U.S.
Class: |
165/81 ; 165/149;
165/67 |
Current CPC
Class: |
F28F 2265/26 20130101;
F28F 9/001 20130101 |
Class at
Publication: |
165/81 ; 165/67;
165/149 |
International
Class: |
F28F 9/013 20060101
F28F009/013 |
Claims
1. An end plate (1) for a heat exchanger, running longitudinally,
said end plate (1) comprising at least one opening (5, 5', 5'', 9,
9', 10, 10', 12, 12', 13, 13'), said opening (5, 5', 5'', 9, 9',
10, 10', 12, 12', 13, 13') forming a cut in said end plate (1), and
at least two areas of weakness (6, 6', 11, 11', 11'', 14, 14',
14''), characterized in that said two areas of weakness (6, 6', 11,
11', 11'', 14, 14', 14'') are situated in distinct parallel
planes.
2. An end plate (1) according to claim 1, characterized in that
said two areas of weakness (6, 6', 11, 11', 11'', 14, 14', 14'')
are the only material elements that form a discontinuity in said
cut such that the said cut is interrupted only by said two areas of
weakness (6, 6', 11, 11', 11'', 14, 14', 14'').
3. An end plate (1) according to claim 1 characterized in that said
end plate (1) comprises a substantially flat web (4) from which at
least one projection (2 or 3) extends.
4. An end plate (1) according to claim 3, characterized in that
said end plate (1) comprises two projections (2, 3) extending from
said flat web (4).
5. An end plate (1) according to claim 3, characterized in that
said at least one projection (2 or 3) has a substantially square,
rectangular, or round cross section.
6. An end plate (1) according to claim 1, characterized in that
said end plate (1) comprises a plurality of openings (5, 5', 5'',
9, 9', 10, 10', 12, 12', 13, 13').
7. An end plate (1) according to claim 1, characterized in that
said opening (5, 5', 5'', 9, 9', 10, 10', 12, 12', 13, 13') extends
linearly, perpendicular to the longitudinal axis of said end plate
(1).
8. An end plate (1) according to claim 1, characterized in that
said areas of weakness (6, 6', 11, 11', 11'', 14, 14', 14'') have a
reduction in thickness of material (15).
9. An end plate (1) according to claim 1, characterized in that at
least one of said areas of weakness (6, 6', 11, 11', 11'', 14, 14',
14'') is situated on a flat portion (4).
10. An end plate (1) according to claim 1, characterized in that at
least one of said areas of weakness (6, 6', 11, 11', 11'', 14, 14',
14'') is situated on a curved, bent, or sinusoidal portion (7,
7').
11. An end plate (1) according to claim 3, characterized in that
said two areas of weakness (6, 6', 11, 11', 11'', 14, 14', 14'')
are situated respectively on an upper face of said at least one
projection (2 or 3) and on said flat web (4).
12. An end plate (1) according to claim 1, characterized in that
said areas of weakness (6, 6', 11, 11', 11'', 14, 14', 14'') are
all situated on one and the same linear axis (AA).
13. An end plate (1) according to claim 1, characterized in that
said areas of weakness (6, 6', 11, 11', 11'', 14, 14', 14'') are
situated on different linear axes.
14. A heat exchanger, particularly for a motor vehicle, comprising
two headers connected by a core of tubes and of inserts,
characterized in that said heat exchanger comprises at least one
end plate (1) according to claim 1.
15. A heat exchanger according to claim 14, characterized in that
said end plate (1) is fixed to at least one of the ends or sides of
said core.
16. An end plate (1) according to claim 2, characterized in that
said end plate (1) comprises a substantially flat web (4) from
which at least one projection (2 or 3) extends.
17. An end plate (1) according to claim 16, characterized in that
said end plate (1) comprises two projections (2, 3) extending from
said flat web (4).
18. An end plate (1) according to claim 4, characterized in that
said at least one projection (2 or 3) has a substantially square,
rectangular, or round cross section.
19. An end plate (1) according to claim 4, characterized in that
said two areas of weakness (6, 6', 11, 11', 11'', 14, 14', 14'')
are situated respectively on an upper face of said at least one
projection (2 or 3) and on said flat web (4).
Description
[0001] The present invention relates to an end plate for a heat
exchanger, particularly a heat exchanger intended to be fitted to a
motor vehicle.
[0002] Conventional heat exchangers comprise a core of tubes
delimited by two end tubes. In addition, there may be inserts
between the tubes of the core in order to improve the exchange of
heat. An insert may be positioned on the external face of each of
the end tubes.
[0003] The exchanger further comprises two header plates through
which the ends of the core of tubes pass. Furthermore, an end plate
is conventionally positioned directly on the end insert of each of
the end tubes.
[0004] The end plates of a heat exchanger thus form a brace between
the header plates in order to maintain a constant separation
between these header plates and make the exchanger easier to
manufacture. Furthermore, they may be used to support and hold
accessories associated with the heat exchanger, such as an engine
fan.
[0005] In general, each end plate comprises a central web flanked
by two longitudinal flanges which run along the end plate. The
central web is generally of rectangular and flat shape. Each
longitudinal flange projects with respect to the plane defined by
the central web. The end plate thus in cross section is
substantially U-shaped. The longitudinal flanges are conventionally
designed to stiffen and strengthen the associated end plate.
[0006] When the exchanger is in operation, variations in the flow
of coolant inside the tubes may give rise to temperature
differences which cause these tubes to undergo thermal expansion.
This results in mechanical stresses in the tubes. Such stresses may
cause the tubes to break.
[0007] Furthermore, conventional heat exchanger tubes have a
tendency to have a relatively small thickness, in order to limit
the cost of manufacture of the exchanger. As a result, the tubes
are increasingly less able to withstand thermal shock and the
aforementioned risks of breakage increase accordingly.
[0008] To limit these risks of breakage, it is appropriate for the
ends of each end plate to be mechanically dissociated from the
central part of the end plate, so as to prevent the transfer of
stresses associated with the thermal expansion of the tubes. To do
that, it is known practice to make a transverse cut in the end
plate in the region of its central part, once the exchanger has
been brazed. For example, a cut such as this can be made with a
saw. This solution improves the ability of the tubes to withstand
thermal shock, but has the disadvantage of generating swarf which
detracts from the cleanness of the exchangers and of the machines,
and of reducing the ability of the exchanger to withstand vibration
and/or reverse-cycle pressures.
[0009] In other existing embodiments, it is known practice to
create weaknesses in the end plate in order to allow it to expand
locally, and thereby limit the transfer of stress to the tubes.
[0010] For example, patent FR 2 183 375 proposes a transverse bend,
in the form of a loop, on the attaching lug that connects the end
plate to the header plate or on the end plate directly.
[0011] Patents EP 1 195 573 and U.S. Pat. No. 6,328,098 propose an
opening in each end plate so that part of the edge of the opening
is situated near an edge of the U-shaped end plate. Furthermore, a
bend (rupture zone) is provided and this runs transversely from the
aforesaid part of the edge of the opening to the edge of the end
plate located near to it. The V-shaped rupture zones locally reduce
the thickness in the central web and/or in the flanges of the U.
Also, each opening between the bends is directed, in its elongate
part, such that it makes an acute angle with the lengthwise
direction of the end plate.
[0012] At the present time, these solutions do not propose end
plates which have both small thicknesses and which are able to
provide all the elements of the exchanger with the required
rigidity, particularly while the components are being handled or
when the temperature of the fluid entering the exchanger is very
high, and this therefore leads to severe thermal shocks
particularly between the end plate and the adjacent inserted
tubes.
[0013] The present invention intends to overcome the disadvantages
of the existing end plates and existing heat exchangers.
[0014] Thus, the invention relates to an end plate for a heat
exchanger, running longitudinally, comprising at least one opening,
said opening forming a cut in the end plate, and at least two areas
of weakness, characterized in that the two areas of weakness are
situated in distinct parallel planes.
[0015] What is meant by the expression "area of weakness" is an
area that has a frangible function and/or a longitudinal expansion
function, that is to say, by virtue of the invention, that the end
plate is able to break at the area of weakness if necessary and is
possibly able to expand longitudinally (in the longitudinal
direction of the end plate).
[0016] Furthermore, by virtue of the fact that at least two areas
of weakness have been positioned in two distinct parallel planes,
the phenomenon of bending of the end plate while it is being
handled, and during its expansion due to thermal differences, is
avoided. Specifically, by positioning its areas of weakness, which
incidentally retain two sides or parts of the end plate, in two
parallel planes, one below the other, the end plate is stiffened a
great deal thereby avoiding the phenomena of bending.
[0017] Other particulars or features are listed below: [0018] the
two areas of weakness are the only material elements that form a
discontinuity in the cut such that the cut is interrupted only by
said two areas of weakness; [0019] the end plate consists in a
substantially flat web from which at least one projection extends;
[0020] the end plate comprises two projections extending from the
flat web; [0021] the projection or projections has(have) a
substantially square, rectangular or round cross section; [0022]
the end plate comprises a plurality of openings; [0023] the opening
or openings extends(extend) linearly, perpendicular to the
longitudinal axis of the end plate; [0024] the areas of weakness
have a reduction/decrease in thickness of material; [0025] at least
one of the areas of weakness is situated on a flat portion; [0026]
at least one of the areas of weakness is situated on a curved, bent
or sinusoidal portion; [0027] the two areas of weakness are
situated respectively on the upper face of the projection and on
the flat web; [0028] the areas of weakness are all situated on one
and the same linear axis; [0029] according to another possibility
offered by the invention, the areas of weakness are situated on
different linear axes (in the case of at least three areas of
weakness, one of these areas of weakness not being on the axis
defined by the other two areas of weakness).
[0030] The present invention also relates to a heat exchanger, not
depicted in the attached figures, particularly for a motor vehicle,
comprising two headers connected by a core of tubes and of inserts,
characterized in that it comprises at least one end plate as
defined hereinabove.
[0031] Advantageously, the end plate is fixed to one of the ends or
sides of the aforesaid core.
[0032] One embodiment of the invention will be described
hereinafter, by way of nonlimiting example, with reference to the
attached drawings in which:
[0033] FIG. 1 depicts a perspective view of a portion of an end
plate in which the areas of weakness according to the invention are
situated;
[0034] FIG. 2 is a view from above of another embodiment of a
portion of an end plate according to the invention;
[0035] FIG. 3 is a view in section on the axis AA of the end plate
depicted in FIG. 2;
[0036] FIG. 4 is a view from above of another embodiment of an end
plate according to the invention;
[0037] FIG. 5 is a view in section on the axis AA of the end plate
depicted in FIG. 4;
[0038] FIG. 6 is a view in section on the axis BB of the end plate
depicted in FIG. 4;
[0039] FIG. 7 is a view from above of another embodiment of an end
plate according to the invention;
[0040] FIG. 8 is a view in section on the axis AA of the end plate
depicted in FIG. 7;
[0041] FIG. 9 is a view in section on the axis BB depicted in FIG.
8;
[0042] FIG. 10 illustrates a view from above of a portion of an end
plate according to the invention;
[0043] FIG. 11 is a view in section on the axis AA of the end plate
depicted in FIG. 10;
[0044] FIG. 12 illustrates a view from above of another embodiment
of an end plate according to the invention;
[0045] FIG. 13 is a view in section on the axis AA depicted in FIG.
12.
[0046] FIG. 1 depicts a portion of an end plate according to one
embodiment of the invention, it being understood that this portion
means both lengthwise and widthwise. In the example chosen to
illustrate the invention, the profile of the cross section of this
end plate 1 has two distant square waves 2, 3 extending from flanks
and a substantially flat web 4. The end plate 1 is made of metal,
for example of aluminum or of steel.
[0047] Viewed from above, there are, in this embodiment, three
openings 5, 5', 5'', two openings 5', 5'' extending from the
opposite lateral edges and a central opening 5 positioned between
the two areas of weakness 6, 6'. The openings 5', 5'' extending
from a lateral edge are directed obliquely, that is to say that
they make an acute angle .beta. (with
0.degree.<.beta.<90.degree.) with the longitudinal axis XX'
of the end plate 1. The central opening 5 is V-shaped with its two
segments also extending at an acute angle with respect to the
longitudinal axis XX'.
[0048] The areas of weakness 6, 6' here are present in each of the
two projections 2, 3 and are respectively incorporated into a
sinusoidal or wave-shaped portion 7, 7' of these projections 2, 3.
The areas of weakness 6, 6' extend from the parts located near the
vertex, including the vertex, of each of these sinusoidal portions
7, 7'. In this example, the areas of weakness 6, 6' consist of the
two elements shown enlarged in FIG. 1 so that while these two areas
6, 6', in the material elements/segments of which they are
respectively formed, do effectively meet the definition of distinct
parallel planes, they can also be lengthened or flattened. Each of
these two areas of weakness 6, 6' is indeed able to extend
horizontally, or linearly, along the axis XX', a flattened one, 6',
of these areas of weakness therefore extending in the plane of the
upper face 3' of the projection 3 while the other area of weakness
6 then extends in the plane defined by the flat flanks, or the web
4, of the end plate. Thus, the areas of weakness 6, 6' in the
embodiment depicted in FIG. 1 will be created by consecutive
bending of the areas of weakness 6, 6', one of them, 6, initially
running along the plane of the flat parts, or of the web 4, of the
end plate 1, while the other area of weakness 6' runs along the
plane of the upper face 2', 3' of the projections 2, 3 of the end
plate, it being understood that these two projections 2, 3 have
substantially equal heights so that their respective upper faces
2', 3' run in the same plane.
[0049] Because one, 7, of these sinusoidal portions is directed
upward while the other portion 7' is directed downward, the
respective vertices of each of these sinusoidal portions 7, 7' are
opposed, one of the vertices being situated in the flat flanks 4
while the other vertex is situated in the upper face of the
projections 2, 3.
[0050] Furthermore, the areas of weakness 6, 6' comprise a
narrowing or decrease in material 8, 8' located at the respective
vertices of each of the areas of weakness 6, 6'; this narrowing or
decrease in material 8, 8' extending over the entire width of the
area of weakness 6 or 6'. Thus, aside from the possibility that the
areas of weakness 6, 6' have of extending, in this instance
longitudinally along the axis XX', particularly under the effects
of thermal expansion phenomena, these areas of weakness 6, 6' are
also capable of breaking; this breakage being facilitated by these
narrowings or decreases in material 8, 8' of the areas of weakness
6, 6'.
[0051] FIGS. 2 and 3 show a second embodiment of an end plate 1
according to the invention. This embodiment of the end plate 1 here
is identical to that of FIG. 1 except for the openings and the
areas of weakness. In this exemplary embodiment, there are four
openings 9, 9', 10, 10', two of them, 9, 9', extending from the
opposite lateral edges whereas the other two openings 10, 10' are
central, that is to say distant from the two lateral edges. All the
openings 9, 9', 10, 10' extend linearly along a common axis AA
perpendicular to the longitudinal axis XX' of the end plate 1. The
openings 9, 9', 10, 10' are more or less in the shape of rectangles
with rounded corners.
[0052] As can be seen in FIG. 3, there are in this embodiment three
areas of weakness 11, 11', 11'', one of these areas, 11, being
situated in the plane of the flat parts, or of the web 4, of the
end plate 1, whereas the other two areas 11, 11' are situated in
the plane comprising the two upper faces or sides 2', 3' of the
projections 2, 3. Once again, in this embodiment, by virtue of the
presence of at least two areas of weakness 11, 11', 11'' in
distinct parallel planes, and, in theory, three areas as in this
second embodiment, the end plate 1 is stiffer and able to resist
flexing as a result of handling and of phenomena of thermal
expansion of the end plate/body of the exchanger (core of tubes
situated under the end plate). It will be noted that, in this
embodiment, there is no narrowing or decrease in material at the
areas of weakness 11, 11', 11'' but, of course, this solution of
decrease in the amount of material may be envisioned on at least
one or for all of these areas of weakness.
[0053] The third embodiment, illustrated in FIGS. 4, 5 and 6, once
again has an end plate 1 identical to those presented in the first
two embodiments, but in which the openings and the areas of
weakness differ.
[0054] In this example, two openings 12, 12' extend from the
respective two opposite lateral edges, while two other central
openings 13, 13', that is to say openings distant from the lateral
edges, have an L-shape or L-shaped cross section. In this
embodiment as in all the embodiments, the areas of weakness 14,
14', 14'' extend between the openings 12, 12', 13, 13'. Once again,
one area of weakness 14 is situated in the bottom plane, that is to
say the plane formed by the flat parts, or the plane of the web 4,
of the end plate 1, while two other areas of weakness 14', 14'',
are situated in the plane formed by, or containing, the upper faces
or sides 2', 3' of the projections 2, 3, these two planes indeed
being parallel planes.
[0055] In this embodiment, the areas of weakness 14, 14', 14'' do
not extend along the same axis, for example along the axis AA of
the second embodiment, but each of the two groups of areas of
weakness 14 and 14', 14'', which run respectively in the aforesaid
two parallel planes, are aligned along distinct axes.
[0056] The fourth embodiment, depicted in FIGS. 7 and 8, reuses the
second embodiment of FIGS. 2 and 3 and adds a narrowing or decrease
in material 15 of the areas of weakness 11, 11', 11''. This
decrease in material 15 may be by at least 1/3 of the thickness of
material of the end plate 1, which is substantially equal in its
other parts, for example a reduction in material 15 by half the
thickness of the sheet of which the end plate 1 is formed.
[0057] As illustrated in FIG. 9, this decrease or removal of
material may have a cross section substantially in the shape of a
triangle, an inverted triangle in FIG. 9, because it is performed
from the upper face of the end plate. Of course, provision could be
made for this decrease or removal of material 15 to be done from
the underside of the end plate 1 and/or for this decrease in
material to have a different shape or cross section other than that
depicted here.
[0058] The fifth embodiment, shown in FIGS. 10 and 11, again reuses
the second embodiment, varying the shape of the openings 9, 9', 10,
10'. Here, the openings 9, 9', 10, 10' still have a substantially
rectangular shape but their corners have an oblique cross section
such that the ends of the openings are triangular or V-shaped.
[0059] Finally, the last embodiment chosen for illustrating the
invention, depicted in FIGS. 12 and 13, differs from the second
embodiment only in that the end plate 1 has just one projection 2.
Thus, there are still here four openings 9, 9', 10, 10' of which
two 9, 9' extend from opposite lateral edges, and two areas of
weakness 11', 11'' are situated in the bottom plane, or plane of
the web 4, of the end plate 1, while one area of weakness 11 is
present on the upper face 2' of the projection 2.
[0060] All the embodiments depicted here have features that can be
combined, while still remaining within the scope defined by the
invention in the attached claims.
[0061] The present invention applies to any kind of exchanger that
requires end plates designed to counter the phenomena of expansion
and torsion due to thermal differences.
* * * * *