U.S. patent application number 11/570514 was filed with the patent office on 2007-11-15 for heat exchanger with an all-metal construction, in particular an all-aluminium construction.
This patent application is currently assigned to Behr GmbH & Co.. KG. Invention is credited to Franco Ghiani.
Application Number | 20070261836 11/570514 |
Document ID | / |
Family ID | 34971192 |
Filed Date | 2007-11-15 |
United States Patent
Application |
20070261836 |
Kind Code |
A1 |
Ghiani; Franco |
November 15, 2007 |
Heat Exchanger with an All-Metal Construction, in Particular an
All-Aluminium Construction
Abstract
The invention relates to a heat exchanger with an all-metal
construction, preferably an all aluminium construction. Said heat
exchanger comprises a network (2) of ribs and tubes (4), the ends
(4a) of the layer having and enlarged rectangular form,
longitudinal and narrow sides and at least one U-profile (6) with
collection chambers (3) that comprise lateral limbs (6a, 6b). The
longitudinal sides (4b) are connected to one another and the narrow
sides (7a, 7b) to the limbs (6a, 6b) of the U-profile (6) by a
numeral union, preferably by means of soldering. According to the
invention, the U-profile (6) is optimised for tension.
Inventors: |
Ghiani; Franco;
(Bietigheim-Bissingen, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
Behr GmbH & Co.. KG
|
Family ID: |
34971192 |
Appl. No.: |
11/570514 |
Filed: |
June 1, 2005 |
PCT Filed: |
June 1, 2005 |
PCT NO: |
PCT/EP05/05855 |
371 Date: |
June 25, 2007 |
Current U.S.
Class: |
165/173 |
Current CPC
Class: |
F28F 9/0221 20130101;
F28D 1/0535 20130101; F28F 21/084 20130101; F28F 2275/04 20130101;
F28F 1/025 20130101 |
Class at
Publication: |
165/173 |
International
Class: |
F28F 9/02 20060101
F28F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 15, 2004 |
DE |
10 2004 028 652.3 |
Claims
1. A heat exchanger with an all metal, preferably an all aluminium,
construction, comprising a network of ribs and tubes with tube ends
which are widened in rectangular shapes and have longitudinal and
narrow sides, and comprising at least one collecting box which has
a U profile with lateral limbs, the longitudinal sides being
connected to one another, and the narrow sides being connected to
the limbs of the U profile, in a materially joined fashion,
preferably by means of soldering, wherein the U profile is embodied
in an optimized fashion in terms of stress.
2. The heat exchanger as claimed in claim 1, wherein the limbs of
the U profile are of straight design in the region of the narrow
sides and merge continuously into a round arc.
3. The heat exchanger as claimed in claim 2, wherein the limbs
merge, with a continuously increasing curvature, into the round arc
which reaches its maximum curvature at an apex point.
4. The heat exchanger as claimed in claim 3, wherein the U profile
is of symmetrical or asymmetrical design with respect to a center
line M which runs through the longitudinal side of the tube
ends.
5. The heat exchanger as claimed in claim 1, wherein the U profile
has a height H and a width B where H>B, preferably 1.5 B H 2.0
B.
Description
[0001] The invention relates to a heat exchanger with an all metal,
preferably all aluminum, construction, in particular as claimed in
the preamble of patent claim 1.
[0002] All metal heat exchanger, in particular soldered aluminum
heat exchangers, are used as coolant radiators or charger radiators
for motor vehicles. The advantage of these heat exchangers is that
they are of one grade of material and therefore can easily be
recycled. DE-A 195 43 986 by the applicant has also disclosed a
soldered aluminum heat exchanger with flat tubes whose ends are
widened to form a rectangular cross section. The tube ends have
longitudinal sides and narrow sides, with the longitudinal sides
resting one against the other in a sealed fashion and being
soldered to one another, while the narrow sides form external
surfaces which are connected to the internal surfaces of a
collecting box. The collecting box has an approximately U shaped
profile (U profile) with lateral limbs which embrace the narrow
sides of the tubes. This design allows a conventional tube bottom
with the corresponding tube/tube bottom connections to be dispensed
with. As an alternative to the U profile, this document also
discloses a cylindrical collecting vessel which has parallel
collars for abutting against the narrow sides of the tube ends. A
problem with this design is the soldered connections when internal
pressure is applied to the heat exchanger during operation. In
particular in the region of the soldered connections between the
narrow sides of the tube ends and the limbs of the collecting box
it is possible for fractures to form in the soldering seam, in
particular if the collecting box profile is not resilient and
flexural stresses additionally occur in the region of the soldering
seam.
[0003] The object of the present invention is to improve the
durability of the soldered connections, in particular in the region
of the tube ends, in a heat exchanger of the type mentioned at the
beginning.
[0004] This object is achieved by means of the features of patent
claim 1. The invention provides that the U profile of the
collecting box be embodied in a way which is optimized with respect
to stress, the configuration according to the invention providing a
round arc between two straight limbs of the U profile. At the same,
the limbs preferably merge with a continuously increasing curvature
into the round arc which has an upper, symmetrically arranged apex
point. This configuration results in favorable distribution of
stress in the cross sections of the collecting box because the
profile of the collecting box can yield owing to the arcuate
design. As a result, unfavorable flexural stresses can also be kept
away from the soldered connections. Overall, this optimized profile
configuration produces a durable soldered connection with which the
formation of fractures as a result of unfavorable loading is
avoided.
[0005] In one advantageous exemplary embodiment of the invention,
irregularity in the loading, such as force, at the junction from
one material thickness to another material thickness is reduced or
prevented.
[0006] An exemplary embodiment of the invention is illustrated in
the drawing and, will be described in more detail below. In the
drawing:
[0007] FIG. 1 shows a detail of an all aluminum radiator with a
collecting box, and
[0008] FIG. 2 shows a cross section through the collecting box.
[0009] FIG. 1 shows a detail of an all aluminum coolant radiator 1
such as is used in particular for motor vehicles. The coolant
radiator 1 can be embodied as a downdraft radiator or a cross flow
radiator--the exemplary embodiment shows a cross flow radiator with
a network 2 and a laterally arranged collecting or coolant box 3.
The network 2 is composed of horizontally arranged flat tubes 4
between which only partially illustrated corrugated ribs 5 are
arranged. The tubes 4 have tube ends 4a which are widened to form a
rectangular cross section (not illustrated) and bear one against
the other with their longitudinal sides. This design is known from
DE-A 195 43 986 which is mentioned at the beginning and which is
included in its entirety in the disclosure contents of this
application. All the parts of the coolant radiator 1, that is to
say flat tubes 4, corrugated ribs 5 and collecting box 3 are
composed of aluminum or aluminum alloys or metal or metal alloys
and are connected to one another by hard soldering.
[0010] FIG. 2 shows a cross section through the collecting box 3
which has a U shaped cross sectional profile 6 with two limbs 6a,
6b and a round arc 6c which connects the two limbs 6a, 6b. The open
region of the U profile 6 embraces one tube end 4a of the flat tube
4. As mentioned, the flat tube ends 4a are widened to form a
rectangular cross section, the longitudinal side 4b of which can be
seen in FIG. 2, i.e. is in the plane of the drawing. The narrow
sides, which are soldered to the inside of the limbs 6a, 6b, extend
perpendicularly to this longitudinal side 4b, while the
longitudinal sides 4b of adjacent tubes 4 are soldered directly to
one another. The U profile 6 has a width B and a height H, with H
being greater than B, preferably a multiple of 1.75. The limbs 6a,
6b extend from the longitudinal sides 4b, firstly in parallel and
then increasingly assume a convergent direction which merges into
the round arc 6c. The profile 6 is of symmetrical design to the
center line which passes through the round arc 6c at an apex point
6d. To this extent, the two limbs 6a, 6b merge with increasing
curvature into the round arc 6c, it being possible for this round
arc 6c to be made parabolic, ellipsoidal or circular. The increase
in curvature of the U profile 6 in conjunction with the relatively
large height H has the effect that when internal pressure is
applied, represented by arrows P, a favorable, essentially tensile
stress profile is produced in the cross sections of the U profile
6, which is preferably bent out of a piece of sheet metal. As
already mentioned, the U profile 6 is soldered to the tube ends 4a
by means of its limbs 6a, 6b, specifically by means of the solder
faces 7a, 7b. Owing to the previously described configuration of
the U profile 6, the solder faces 7a, 7b are very largely freed of
flexural stresses since the U profile 6 can deform elastically, in
particular in its upper region, i.e. in the region of the round arc
6c. As a result, the soldered connections 7a, 7b are subject to
less critical stressing, as a result of which fracture formation is
also avoided.
[0011] The boxes and side parts form a stable frame so that the
configuration in the manner of a round arc alleviates the
operationally induced thermal stresses by displacing them in the
direction of the tube ends.
* * * * *