U.S. patent application number 10/552720 was filed with the patent office on 2006-06-08 for heat exchanger, especially a charge-air cooler for motor vehicles.
This patent application is currently assigned to BEHR GmbH & CO. KG. Invention is credited to Karsten Emrich, Stefan Weise.
Application Number | 20060118285 10/552720 |
Document ID | / |
Family ID | 33039046 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060118285 |
Kind Code |
A1 |
Emrich; Karsten ; et
al. |
June 8, 2006 |
Heat exchanger, especially a charge-air cooler for motor
vehicles
Abstract
The invention relates to a heat exchanger, especially a
charge-air cooler for motor vehicles, comprising flat tubes (9)
with tube ends (9a), and collecting tanks (1) which are connected
to tube plates (4), said tube plates (4) comprising openings (8)
provided with long sides (8a) and short sides (8b) for receiving
the tube ends (9a), in addition to edge strips (5, 6) and
transition regions (12, 13) which are embodied in a groove-type
manner and located between the short sides (8b) and the edge strips
(5, 6), the tube ends (9a) being soldered in the openings (8).
According to the invention, the transition regions (12, 13)
comprise a reinforcing element.
Inventors: |
Emrich; Karsten; (Stuttgart,
DE) ; Weise; Stefan; (Stuttgart, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
BEHR GmbH & CO. KG
|
Family ID: |
33039046 |
Appl. No.: |
10/552720 |
Filed: |
March 22, 2004 |
PCT Filed: |
March 22, 2004 |
PCT NO: |
PCT/EP04/02967 |
371 Date: |
October 11, 2005 |
Current U.S.
Class: |
165/173 |
Current CPC
Class: |
F28F 2225/08 20130101;
F28D 2021/0082 20130101; F28F 9/0224 20130101; F28D 1/0535
20130101 |
Class at
Publication: |
165/173 |
International
Class: |
F28F 9/02 20060101
F28F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 10, 2003 |
DE |
103 16 756.0 |
Claims
1. A heat exchanger, especially a charge-air cooler for motor
vehicles, with flat tubes having tube ends, and with header boxes
which are connected, especially soldered, to tube bottoms, the tube
bottoms having orifices with longitudinal sides and narrow sides
for receiving the tube ends, furthermore edge strips and
transitional regions of channel-like design between the narrow
sides and the edge strips, and the tube ends being soldered in the
orifices, wherein the transitional regions have a
reinforcement.
2. The heat exchanger as claimed in claim 1, wherein the
reinforcement is designed as a material thickening.
3. The heat exchanger as claimed in claim 1, wherein the
reinforcement is designed as a stiffening, especially as a
bead.
4. The heat exchanger as claimed in claim 1, wherein the
reinforcement is designed as a profile strip which at least
partially fills the transitional region and which is soldered to
the tube bottom.
5. The heat exchanger as claimed in claim 4, wherein the profile
strips are produced in one piece with the header box.
6. The heat exchanger as claimed in claim 4, wherein the profile
strips are designed as insert strips.
7. The heat exchanger as claimed in claim 4, wherein the orifices
are designed as inwardly directed rim holes, and in that the
profile strips have recesses which are adapted to the form of the
narrow sides of the rim holes.
8. The heat exchanger as claimed in claim 1, wherein the orifices
are designed as outwardly directed rim holes.
9. The heat exchanger as claimed in claim 5, wherein the orifices
are designed as inwardly directed rim holes, and in that the
profile strips have recesses which are adapted to the form of the
narrow sides of the rim holes.
10. The heat exchanger as claimed in claim 6, wherein the orifices
are designed as inwardly directed rim holes, and in that the
profile strips have recesses which are adapted to the form of the
narrow sides of the rim holes.
11. The heat exchanger as claimed in claim 2, wherein the orifices
are designed as outwardly directed rim holes.
12. The heat exchanger as claimed in claim 3, wherein the orifices
are designed as outwardly directed rim holes.
13. The heat exchanger as claimed in claim 4, wherein the orifices
are designed as outwardly directed rim holes.
14. The heat exchanger as claimed in claim 5, wherein the orifices
are designed as outwardly directed rim holes.
15. The heat exchanger as claimed in claim 6, wherein the orifices
are designed as outwardly directed rim holes.
16. The heat exchanger as claimed in claim 7, wherein the orifices
are designed as outwardly directed rim holes.
Description
[0001] The invention relates to a heat exchanger, especially a
charge-air cooler for motor vehicles, according to the preamble
of-patent claim 1.
[0002] Known heat exchangers for motor vehicles, such as, for
example, charge-air coolers and coolant radiators, are produced
from aluminum (aluminum alloys) and soldered, this applying either
only to the heat exchanger block or the entire heat exchanger,
including header boxes. The heat exchanger block, especially where
charge-air coolers are concerned, is constructed from a series of
flat tubes, between which corrugated ribs are arranged. The tube
ends of the flat tubes are received in orifices, what are known as
rim holes, of the tube bottom and are soldered to the rim holes.
This gives rise to a firm and leaktight tube/bottom connection. The
header boxes are soldered or welded to the tube bottoms. For the
connection between header box and tube bottom, the tube bottom has
a peripheral edge strip which engages over or under the header box
and thus forms a soldering surface. The rim holes in the tube
bottom extend over the entire depth of the latter, that is to say
from longitudinal side to longitudinal side, there being between
the narrow sides of the rim holes and the edge strips a
transitional region which has a channel-like, for example
approximately U-shaped design. The tube bottom thus has an
approximately rectangularly designed, if appropriate continuous
channel which is composed of two parallel longitudinal sides and
two parallel narrow sides. The longitudinal sides of the tube
bottom are located opposite the narrow sides of the rim holes.
During operation, the header boxes are loaded by the internal
pressure of the heat exchange medium, for example compressed charge
air. This gives rise, in the transitional region between the
longitudinal sides of the tube bottom and the narrow sides of the
rim holes, to deformations as a result of bending stresses which
lead to stress peaks in the region of the narrow sides of the rim
holes. The tube/bottom connection, in particular, is subjected to
these stresses and deformations on its narrow side and in the tube
corner regions in such a way that leaks of the heat exchanger may
occur.
[0003] The object of the present invention is, in a heat exchanger
of the type initially mentioned, to improve the tube/bottom
connection and to avoid adverse stresses.
[0004] This object is achieved by means of the features of patent
claim 1. According to the invention, a reinforcement is provided in
the transitional region of the tube bottom. This affords the
advantage that an inadmissible deformation or flexion of the tube
bottom in the transitional region is avoided and the harmful stress
peaks are reduced. The tube bottom, which, by being produced from a
sheet steel billet, has approximately the same wall thickness in
the remaining region, thus becomes deformable to a lesser extent on
the longitudinal sides in the region of the tube narrow sides. The
tube/bottom connection is consequently subjected to less or
virtually no bending stress, but essentially to shearing stress,
which constitutes an appreciably more favorable load.
[0005] The reinforcement of the transitional region may be
implemented by means of various structural solutions which arise as
advantageous refinements from the subclaims. For example, the
reinforcement may be configured as a material thickening, thus
leading to an increased bending resistance for the transitional
region. This could take place, in production terms, by means of the
compression of the material. Another advantageous possibility for
reinforcement is to reinforce the tube bottom in the transitional
region, for example, by one or more beads. Thus, by stability being
increased, with the wall thickness of the tube bottom remaining the
same, an increased deformation resistance would be achieved. The
beads are preferably to be arranged in the region of the narrow
sides of the rim holes, in order to achieve an increased bending
resistance there.
[0006] According to a further advantageous refinement of the
invention, the reinforcement is designed as a profile strip which
fills the channel-like transitional region and is soldered to the
tube bottom. This profile strip likewise achieves a reinforcement,
that is to say by means of an additional part which is connected to
the tube bottom to form a bend-resistant region. Between the outer
edge strip of the tube bottom and the narrow side of the rim hole,
therefore, a connection, that is to say a firm bridge, is produced,
which prevents a flexion or deformation of the transitional region.
The harmful bending stresses are consequently "kept away" from the
tube/bottom connection.
[0007] According to an advantageous development of the invention,
the profile strip is produced or integrated in one piece with the
header box, that is to say it forms a prolongation of the
longitudinal edges of the header box downward, that is to say in
the direction of the tube bottom. This does not entail any
additional outlay in terms of manufacture or assembly, since the
header box is placed onto the bottom and soldered to the latter, as
hitherto.
[0008] According to a further refinement of the invention, the
profile strip is designed as a (separate) insert strip, that is to
say an additional part which is inserted into the channel-like
transitional region and is soldered to the tube bottom. The
advantage of this solution is that modifications do not have to be
made either to the tube bottom or to the header box. For example,
such insert strips may be used for heat exchangers, especially
charge-air coolers, which are to be employed for higher charge-air
pressures. Thus, by means of this simple purposeful measure, the
same cooler can be adapted to the higher operating stresses.
[0009] In a further advantageous refinement of the invention, the
profile or insert strips have toward the inside of the tube bottom,
in the region of the tube narrow sides, recesses which partially
surround the rim holes, that is to say bear against the narrow
sides and corner regions and are supported with respect to these.
Consequently, in particular, the corner regions of the tubes are
also protected from harmful stress peaks.
[0010] Exemplary embodiments of the invention are illustrated in
the drawing and are described in more detail below. In the
drawing:
[0011] FIG. 1 shows a detail of a charge-air cooler,
[0012] FIG. 2 shows a view of the charge-air cooler according to
FIG. 1 with hatched insert strips,
[0013] FIG. 3 shows a sectional illustration of the charge-cooler
according to FIG. 1 and 2,
[0014] FIG. 4 shows a view of the tube bottom with hatched insert
strips,
[0015] FIG. 4a shows a cross section through the tube bottom,
and
[0016] FIG. 5 shows a further embodiment of the invention with an
integrated profile strip.
[0017] FIG. 1 shows a detail, that is to say a "slice", of a
charge-air cooler in the region of the charge-air box and of the
tube/bottom connection. Charge-air coolers of this type are used
for the cooling of compressed charge air in motor vehicles,
especially commercial vehicles. A header box 1 (also called a
charge-air box) has a U-shaped design in cross section and is
preferably produced from aluminum alloy. Overall, the header box 1
has the form of an elongate box which can be produced by deep
drawing or casting. The U-profile of the header box 1 has two legs
2, 3 which form the longitudinal sides of the charge-air box. The
header box 1 is inserted into a tube bottom 4 which has, along the
longitudinal sides, edge strips 5, 6 which are angled approximately
perpendicularly with respect to a bottom plate 7. The bottom plate
7 has a multiplicity of rim holes, of which only one rim hole 8
receiving a tube end 9a of a flat tube 9 is illustrated here. The
entire heat exchanger or charge-air cooler thus has a multiplicity
of flat tubes, between which are arranged corrugated ribs, not
illustrated, which form secondary heat exchange surfaces for
ambient air. The legs 2, 3 of the box profile have, on their lower,
that is to say open side, connecting portions 2a, 3a which overlap
with the edge strips 5, 6 in the tube bottom 4 and are soldered to
one another in this region. What are known as insert strips 10, 11,
illustrated by hatching, are arranged below the lower edges of the
connecting portions 2a, 3a.
[0018] FIG. 2 shows the header box 1 according to FIG. 1 as a front
view, that is to say in a sectional plane in front of the rim hole
8. As is known from the prior art, the tube bottom 4 is produced
from a sheet metal billet and therefore has essentially a constant
wall thickness s; the rim holes 8 are directed inward, that is to
say toward the side of the box 1. The tubes 9 project with their
tube ends 9a inward beyond the rim hole 8. In a further exemplary
embodiment, not shown, the rim holes are directed outward. The
tubes may in this case project beyond a tube bottom surface or
advantageously terminate under such a tube bottom surface.
[0019] The bottom plate 7 is planar on the longitudinal sides of
the tube bottom 4, that is to say outside the rim holes 8, but has
a channel-like design within the edge strips 5, 6, this channel
merging, on the one hand, into the bottom plate 7 and, on the other
hand, into the edge strips 5, 6, that is to say forming the
transitional regions 12, 13. These transitional regions 12, 13 thus
form longitudinal beads for increasing the stability of the tube
bottom 4. By the box 1 being loaded by the internal pressure caused
by the compressed charge air, this gives rise in the longitudinal
sides 2, 3 of the box 1 to compressive and/or tensile forces which
are transmitted to the edge strips 5, 6 of the bottom and bring
about bending stresses and deformations in the transitional regions
12, 13. This is where the invention comes in with the arrangement
of the insert strips 10, 11 which are designed as profile strips
and have a profile which corresponds to that of the transitional
regions 12, 13. The insert strips 10, 11 thus bear on the outside
against the edge strips 5, 6, at the bottom against the
channel-like transitional regions 12, 13 and on the inside against
the narrow sides of the rim holes 8. Air gaps 14, 15 are left above
the edge strips 10, 11. As already mentioned, the insert strips 10,
11, which preferably likewise consist of an aluminum alloy, are
soldered to the bottom 4, that is to say in one operation with the
entire heat exchanger.
[0020] FIG. 3 shows a sectional illustration in a plane parallel to
the drawing plane according to FIG. 2. In this illustration, in
particular, the rim holes 8 can be seen clearly in their profile:
the rim holes 8 form with the outer wall of the tube 9 an acute
angle which is filled with a solder meniscus 16 after soldering.
Above the solder meniscus, the tube bears against the rim hole 8
with a relatively narrow gap. As mentioned, the rim hole 8 forms,
with the two outer edge strips 5, 6 of the bottom, the transitional
regions 12, 13 which here are in the form of an asymmetric U in
cross section and are filled by the insert strips 10, 11. Between
the edge strips 5, 6 and the rim holes 8, more precisely the narrow
sides of the rim holes, the insert strips 10, 11 form a firm bridge
which prevents a deformation of the transitional regions 12, 13.
Consequently, the stress peaks occurring in the prior art are
reduced, and the tube/bottom connection is relieved considerably in
the region of the narrow sides. The air box 1 can thus withstand
higher pressures.
[0021] FIG. 4 shows a sectional illustration along the line IV-IV,
as depicted in FIG. 4a. Correspondingly to the form of the tubes 9,
not illustrated here, the rim holes 8 have an approximately
rectangular inner and outer cross section with longitudinal sides
8a and narrow sides 8b. The insert strips 10, 11 fit snugly onto
the narrow sides 8b of each rim hole, that is to say they have in
the region of the narrow sides 8b recesses 10a, 11a in the form of
the narrow sides 8b. This snug fit of the insert strips 10, 11
results, together with the soldering, in a very good support of the
bottom regions located opposite one another, that is to say a
bend-resistant interconnected structure. The recesses 10a, 11a may
be produced by pressing.
[0022] FIG. 4a shows the tube bottom 4 in cross section, with the
rim holes 8 which have an outer conical region 8c and an inner
cylindrical region 8d (adapted to the cross section of the flat
tubes 9). The conical region 8c also serves as an introduction
slope for the tube ends 9a. The rim holes 8 are produced from the
tube bottom plate 7 by hole-punch pressing (cf. FIG. 2).
[0023] FIG. 5 shows a further embodiment of the invention, in which
the insert strips described above are integrated with the air box,
that is to say are produced in one piece with the latter here. The
tube bottom 4 is unchanged; the header box 17 has connecting
regions 17a, 17b, the lower edges of which are designed as profile
strips 18, 19 which fill the channel-like transitional regions 12,
13 of the bottom 4. In principle, the same effect as that described
above is achieved by means of this solution, that is to say a
reinforcement of the transitional regions 12, 13. Insofar as the
box 17 is produced as a casting or injection molding, the rounded
profile strips 18, 19 may readily be produced by means of the
corresponding configuration of the mold. In this design of the air
box 17 with the profiled lower edges 18, 19, therefore, the
insertion of the insert strips described above is dispensed with,
that is to say one operation is saved. Similarly, the profile
strips may also be fastened to the lower edges of the air box, for
example by adhesive bonding.
[0024] Further solutions, not illustrated here, for reinforcing the
transitional regions are possible, for example reinforcement by
means of beads, that is to say an increase in the bending
resistance by an appropriate shaping for increasing the moment of
resistance. The beads may be formed in the region of the narrow
sides of the rim holes at the same time as the production of the
bottom. Furthermore, there is the possibility of designing the
transitional region with a greater wall thickness, which may be
carried out, for example, by compressing the bottom in the
transitional region. These solutions, too, have the result that the
harmful stress peaks in the region of the tube/bottom connection,
that is to say in the region of the narrow sides and of the tube
corner regions, are reduced.
REFERENCE NUMERALS
1 Charge-air box
[0025] 2 Longitudinal side 2a Connecting region 3 Longitudinal side
3a Connecting region 4 Tube bottom 5 Edge strip 6 Edge strip 7
Bottom plate 8 Rim hole 8a Longitudinal side 8b Narrow side 8c
Conicalfliregion 8d Cylindrical region 9 Flat tube 9a Tube end 10
Insert strip 11 Insert strip 12 Transitional region 13 Transitional
region 14 Gap 15 Gap 16 Solder meniscus 17 Header box 17a
Connecting region 17b Connecting region 18 Integrated profile strip
19 Integrated profile strip
* * * * *