Note: Descriptions are shown in the official language in which they were submitted.
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H
This is a divisional application of Canadian Patent
Application Serial No. 2,069,783 filed on May 28, 1992.
BACKGROU~1D OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat exchanger
which is suited for use for examp:Le as a condenser or
evaporator employed in the car cooler or .room air
conditioning system, or as an oil cooler.
The subject matter of this divisional application is
directed to a sub-group of heat exchangers disclosed
herein. The subject matter of the parent application was
restricted to another sub-group of heat exchangers.
However, it should be understood that the expression "the
invention°' and the like encompasses the subject matter of
both the parent and the divisional applications.
2. Description of the Prior Art
The heat exchanger of this type may, in a case,
comprise brackets which are attached to its headers for
mounting it on an object such as an automobile body. In a
further case, the heat exchanger raay also comprise pipe
joints which are attached to its headers in order to
connect some external pipings to the headers in fluid
communication therewith.
In the former case wherein tree brackets are
incorporated, they are usually met=al plates formed by the
pressing method and secured to a body of the heat
exchanger. For example, those brackets aye spot-welded to
the headers of the so-called mufti-flow type heat
exchanger, which comprises flat tubes disposed in parallel
with one another and each having ~>oth end; connected to a
left and right hollow headers in fluid communication with
them.
If such plate-like brackets are spot--welded to the
headers, particularly to the headers which are pipes round
in cross section, then the contact between them cannot be
of a sufficiently large area. Thus, it has been observed
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that vibration of an engine or automobile body causes the
junction to be broken before long. 'There are further pro-
blems that stress concentration occurring in the headers
is apt to deform them, and that the positioning or temporary
setting of the headers cannot be done easily when welding.
In the latter case wherein the pipe joints are connected,
a typical example of such pipe joints comprises, as shown
in Fig. 14, a short pipe 251 having an end connected to
the header 203 and a flared joint 252 integral with another
end of the short pipe. Another mating joint attached
to an end of the external piping may he connected to the
flared joint 252 so as to form a cool<~nt circulation path _
together with a compressor or the like.
However, this conventional structure is can not neces-
sarily provide a junction having a sufficient surf ace area
between the flared joint 252 and shori pipe 251, or between
the short pipe 251 and a wall of the header 203, Thus,
there is a possibility that the attached flared joint 252
cannot be regarded as durable and rigid enough under some
conditions. A bracket may, in such a case, be used to.
consolidate the flared joint 252 with the heat exchanger
body, thereby resulting in the undesii_-able increase in the
number of constituent parts of the heat exchanger.
OBJECT AND SUMMARY OF THE INVENTION
Therefore, a first object of the present invention is
to provide a heat,exchanger which comprises headers and
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brackets, which brackets are of a structure such that they
can be attached strong and easily to t:he headers even if
the latter are round in cross section.
A second object of the invention .is to provide a heat
exchanger comprising headers and brackets. attached thereto,
which brackets are easy to manufacture.
A third object is to provide a heat exchanger comprising
headers, brackets and pipe joints, which pipe joints for
connection to external pipings are secured rigid and stable
to the headers without aid of any additional brackets.
In one aspect, the invention provides a heat exchanger
which comprises: a main body having a plurality
of heat exchanging tubes and headers to which both ends
of each tube are connected in fluid communication; header-
75 held members which are held in place on the headers and
each selected from a group consisting of a bracket and an
external pipe-connecting member; and each header-held member
comprising a header-surrounding portion which fits sideways
on the header_and is joined integral. therewith. v
Other objects, features or advantages may become apparent
from the drawings and description given below.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view showing in a disassembled
state essential parts of a heat exchanger provided according
to a first embodiment, wherein the parts include a bracket
to which a coolant inlet pipe is fixedly secured;
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Fig. 2 is a front elevation showing the heat exchanger
in the first embodiment, in its entirety;
Fig. 3 is a plan view also showing the heat exchanger
in its entirety;
Fig. 4 is a horizontal cross section showing the bracket
attached to a header of the heat exchanger;
Fig. 5 is another cross section illustrating the bracket
which is being attached to the header;
Fig. 6 is a perspective view of a connecting member
attached to a header in a second embodiment;
Fig. 7 is is horizontal cross section of the connecting
member shown in Fig. 6;
Fig. 8 is a perspective view illustrating the header
shown in Fig. 6 in its state disassembled from heat ex-
changing tubes and the connecting member;
Fig. 9A is a front elevation showing the heat exchanger
in the second embodiment, in its entirety;
Fig. 9B is a plan view also showing the heat.exchanger
in its entirety;
Fig. 10 shows the heat exchanger in a modification of
the second embodiment, with its essential parts disassembled
from one another;
Fig. 11 is a horizontal cross section of the parts shown
in Fig: 10;
Fig. 12 shows the heat exchanger :in a further modifi-
can on of the second embodiment, also with its essential
parts disassembled from one another;
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Fig. 13 is a horizontal cross section of the parts shown
in Fig. 12; and
Fig. 14 is~a perspective view of a prior art connecting
member attached to a header.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiments of the invention will now be described in
detail referring to the accompanying drawings.
- First Embodiment -
A heat exchanger, which is made of aluminum ( or its
alloy ) for use as a condenser in a first embodiment of
this invention, is shown in Figs. 2 and 3 in its entirety.
A body "A" of the heat exchanger comprises: a plurality
of horizontal tubes 1 stacked one on another; and corrugated
fins 2 each interposed between the adjacent tubes 1.
The tubes 1 are formed flat by extruding an aluminum
material. It is desirable that each tube has one or more
internal partitions each tying an upper wall to a lower
wall of the tube, integral therewith and extending longitudi-
nally thereof. In this desirable structure, those parti-
dons will form longitudinal discrete chambers within the
tube and thus improve its pressure resistance. Such tubes
may be manufactured easily from the so--called "harmonica"
tube made by the extrusion process. Alternatively, the
tubes 1 may be seam--welded pipes which each have a corrugated
internal fin inserted and brazed thereto.
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The external corrugated fins 2 are of substantially
the same width as the tubes, and are fixedly secured to
the adjacent tubes 1 by the brazing method. Further,
the corrugated fins 2 which are also made of aluminum may
desirably comprise louvers opened up from their walls.
The heat exchanger body ''A" further comprises a pair.
of left and right headers 3 and 4. Each of those headers
3 and 4 is a seam-welded and pressure-resistant aluminum
pipe round in cross section, and this pipe is made of a
brazing sheet which has at least one surface covered with
a brazing agent layer. Further, each header 3 and 4 has
tube-insertion apertures which are formed through its peri-
pheral wall and arranged longitudinally of the header at
regular intervals. Bath ends of each tube 1 are inserted
in the apertures, and are brazed rigidly to the headers
by means of the brazing agent layer.
Caps 5 are fitt-ed on an upper and lower ends of the
left and right headers 3 and 4. Ea<~h cap has an upright
peripheral wall which tightly surrounds and is brazed to
an outer surface of the header.
One or more partitions 6 are secured in the headers,
so that the interior of the left header 3 i-s divided into
two chambers disposed one on another, with the interior
of the right header 4 being divided into three chambers
also disposed one on another. Those partitions 6 are
inserted in the headers through their circumferential
openings, and are brazed thereto so as to become integral
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with the headers. Thus, there are provided a few groups
of the tubes, so that a coolant entering the heat exchanger
body °'A°' will flow meandering through all coolant paths
of the tubes in each group. The coolant is subjected
to a heat exchange process while flowing in such a meander
ing manner. The reference numerals 12 and 13 in Fig.
2 indicate an upper and lower side plates.
A coolant inlet pipe ? made of aluminum and extending
downwards has an end connected and brazed to an upper por-
., Lion of the right header 4 in fluid communication therewith,
the upper portion being adjacent to an upper end the right
header.Similarly, a coolant outlet pipe 8 also made
of aluminum but extending upwards has an end connected and
brazed to a lower portion of the right header 4 in fluid
communication therewith, the lower portion being adjacent
to a lower end of the right header.
An upper aluminum bracket 9 is brazed to the right header
at an intermediate portion thereof below the upper portion
mentioned above. This bracket 9 not only reinforces the
inlet pipe 7 but also is used. to mount this heat exchanger
on an automobile body. Similarly, a lower aluminum bracket
10 is brazed to the right header at another intermediate
portion above the lower portion mentioned above. This
bracket 10 also reinforces the outlet pipe 8 and at the
same time is used to mount this heat exchanger on the auto-
mobile body.
Those brackets 9 and 10 are made of an extruded aluminum
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material, as illustrated in Fig. 1 which shows the upper
bracket 9 by way of example.
The bracket 9 comprises, all as integral portions there-
of: a header-surrounding portion 91.. having an opening 91a
and being substantially of a .reverse C-shape in cross section
fittable on an outer periphery of the header 4; an extension
92 extending from an end of the header-surrounding portion
91 so as to bear against side surfaces of the tubes; and
a fastener portion 93 also extending from the surrounding
14 portion 91 in linear alignment with the extension 92 but
in a diction opposite thereto. Thus, the bracket is
attached to the right header, with its opening 91a of the
header-surrounding portion 91 fitting sideways on the header
and being brazed thereto. The surrounding portion 91
may desirably be of a shape such that, once fitted on the
header, it can stand itself in place without aid of any
auxiliary member or tool. A clamp 94 is bolted to the
fastener portion 93, in order to secure the coolant inlet
pipe 7 onto this bracket 9.
The extension 92 of this bracket 9 functions as a posi-
tinning means. In detail, after the surrounding portion
91 is engaged with right header 4, the bracket 9 is turned
around the header until its extension 92 contacts tubes
1. This operation may be done for example by forcing
the fastener portion 93 to rotate anticlockwise in plan
view. The contact of the extension 92 with the tubes
1 prevents a further rotation of the bracket 9, thus setting
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it in place. The bracket 9 must be set on the header's
portion adequate to ensure such a function of the extension
92. A tip end 92a of the extension 92 is arcuate and
thus spaced a slight distance from the tubes 1, in order
that the contact of said~extension with the tubes will not
hurt them.
A recess 96, extending along the height of header-sur-
rounding portion 91, is formed on an inner surface thereof
at its vertical middle region. This recess 9& is advan-
tageous for the following reason, particularly in a case
wherein the header 4 is a cylindrically curled pipe of a
brazing sheet. In a temporary assembly of the heat ex-
changer body, both side edges are abutted against one another
and.are located outwardly of the body, namely opposite to
the tube-insertion apertures of the header. Then, the
abutted edges are brazed one to another concurrently with
the brazing of the tubes t~ the headers, with the surrounding
portion 91 forming a vacant space between a surface of its
recess 96 and the abutted edges, The brazing agent which '
is molten at that time will fill up and be retained in the
space, whereby the abutted side edges are brazed perfect
without causing any unbrazed cavities. A further recess
9? is formed on the extension 92 at its portion facing a
boundary between the header 4 and the tubes 1. This fur-
ther recess will also retain a sufficient amount of molten
brazing agent to thereby ensure a sufficiently rigid brazing
of the tubes 1 to the header 4.
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The structure of the lower bracket 10 is the same as
the upper orie-9 described above. Its header-surround-
ing portion 101 fits on the outer per~.phery of the header
4, with the coolant outlet pipe 8 being similarly secured
to a fastener portion 103 by means of a bolted clamp 104
of the Lower bracket 10. Bores 95 and 105 of the fastener
portions 93 and 103 are used to fix the brackets 9 and 10
on the automobile body or any other object.
The coolant inlet and outlet pipes 7 and 8 are attached
to the heat exchanger body °'A°', in the following manner _
using the brackets 9 and 10, respectively. At first,
the upper bracket 9 will be engaged with the header 4 as
shown in Fig. 5 so that the surrounding portion 91 tightly
fits on the header, with an inner curved surface of the
portion thereby coming into a close contact with an outer
peripheral surface of the header. Next, bracket 9 is
rotated to render its extension 92 to contact the tubes
1, to thereby take a regular position as shown in Fig. 4
f as already described above ). Subsequent to these
operations, an upper end of the coolant inlet pipe 7 is
inserted in a side bore 11 of the right header 4: This
temporary state of the pipe will then be fixed by bolting
the clamp 94 to the bracket 9. Therefore, any other
auxiliary member or tool need not be used for the temporary
setting of the pipe.
Likewise, the coolant outlet pipe 8 will be set in place
also using the lower bracket 10 on the right header 4.
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After the brackets 9 and 10 are set in place in this
manner together with the coolant inlet and outlet pipes
7 and 8, they are subjected to the so-called "one-shot
brazing°° process. In this process, the headers ~ and
4, the tubes 1 and the corrugated fins 2 are brazed one
to another to form the heat exchanger body "A" while the
temporarily set brackets and pipes are brazed to the right
header 4. Such a one-shot brazing may be facilitated
if the headers 3 and 4 and tubes 7 are made of the brazing
sheet. -
It will now be apparent that because the bracket 9
has the header-surrounding portion 91 which is of a shape
closely fitting on the outer periphery of the header 4,
a larger surface area is provided for the bracket 9 to be
held thereon. Thus, with any cross--sectional shape of
the header 4, it will not fail to rigidly secure the bracket
9 in place. Due to this feature, vibration of the auto-
mobile body or other conditions in use will not give rise
to stress concentration at any particular portion of the
header 4, which stress concentration would otherwise cause
deformation of said header.
Since the bracket 9 is a section of an elongate extruded
shape material, it does not incur any difficulty to give
the abovedescribed specific shape to its header-surrounding
portion 91, but any intricate pressing process can be dis-
pensed with to improve not only the productivity.of brackets
themselves but also of the heat exchanger as a whole.
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- Second Embodiment -
Another heat exchanger, which is also made of aluminum
for use as a condenser in the car cooler system, provided
in a second embodiment of this invention, is shown_in Figs.
6 to 13.
A heat exchanger body °'A" illustrated in these figures
is constructed in a manner similar to the first embodiment,
and it comprises: a plurality of horizontal tubes 201 stacked
one on another; corrugated fins 202 each interposed between
the adjacent tubes 201; and a pair of left and right headers
203 to which both ends of each tube 201 are connected in
fluid communication.
A coolant inlet-connecting member~204, as the external
pipe-connecting member in the invention, is attached to
an upper portion of the left header 203. A separable
connector 206 is fixed on an end of the inlet-connecting
member 204. An external pipe 205 for circulation of a.
coolant is held by the connector 206 so that the header
203' is in fluid communication with the pipe 205. The
A coolant outlet-connecting member 207, as the external
pipe-connecting member in the invention, is similarly at-
tacked to a lower portion of the right header 203.
Partitions 209 each secured in the left and right headers
203 divide the interiors thereof so that a coolant entering
the heat exchanger body "A" will flow meandering through
the groups of tubes 201~ The reference numeral 210 denotes
an upper and lower side plates which are disposed outside
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the upper and lower outermost corrugated fins 202, respec-
tively, so asvto protect them.
The flat tubes 201 are sections cut from an elongate
extruded aluminum shape material. They are the so-called
"harmonica" tubes each comprising, as shown in Fig. 6, inter-
nal partitions which define longitudinal discrete chambers
within the tube and thus improve its pressure resistance.
Alternatively, the tubes may be seam-welded pipes.
The external corrugated fins 202 are manufactured by
giving a corrugated shape to a sheet and by opening up
louvers therefrom. The sheet is an aluminum brazing sheet
having its surfaces clad with a brazing agent layer.
The headers 203 are made of another brazing sheet which
has at least one surface, particularly outer surface, covered
with the brazing agent layer. This sheet is bent into
a shape of cylindrical pige 203a round in cross section,
with both side edges of the sheet thereby being abutted
against one another as indicated at the reference numeral
203c. Aluminum header caps 203b, which are fitted on
outer periphery of each header, close its upper and lower
open ends. As shown in Fig. 8, the headers 203 have tube-
insertion apertures 203d which are circua~ferential slits
foamed through peripheral wall portions of the headers and
arranged longitudinally thereof at regular intervals, with
the wall portions being located opposite to the abutted
edges 203c. A round bore 203e for receiving a coolant
from an inlet pipe is formed through a wall portion where
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the side edges 203c abut one another. For convenience
in manufacture of the header pipe 203a, both halves of the '
round bore 203e are formed before the T~razing sheet is bent
to abut the side edges one another. Alternatively, the
header pips 203a may be seam--welded pipe or an extruded
pipe.
On the other hand, the coolant inlet-connecting member
204 is an aluminum piece for receiving a flange-like member
( i.e., the connector 206 as will be described later ),
and comprises a joint body 211 and a header-surrounding
body 212 integral therewith.
The joint body 211,Iooks like a block of parallelepiped
having one flat surface 213 for receiving the flange-like
member, and has a coolant inlet bore 214 which opens on
this surface 213, A female-threaded bore 215 is also
formed near the inlet bore.
The header=surrounding body 212 is composed of integral
portions which are: a header-surrounding portion 217~ an
extension 218 extending therefrom and a towards the tubes
201 constituting a core of this heat exchanger; and an en-
gageable lug 219 protruding from an inner surface of the
extension. The header-surrounding portion 217 has an
inner curved surface which is fittable on an outer peri-
phery of the header, elastically covering or embracing a
little more than semicircle thereof. The extension 218
has a width covering at least two tubes 201, whereas the
lug 219 is of a dimension which permits the lug to be
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inserted, more preferably to be forced, into a gap between
two adjacent tubes 201_ A coolant outlet opening 220
opens round on the inner surface of the header-surrounding
portion 217. This opening 220 leads to a coo3ant inlet
round.openzng 214 on the.flange-connection surface 213,
via an internal passage 221 formed through the pipe con-
necting member 204.
This connecting member 204, which in the second embodi-
ment is an integral section of an extruded piece, can there-
fore be manufactured at a high produci~ivity and a lower
cost.
The outlet pipe-connecting member 207 is of the same
structure as the inlet pipe-connecting member 204.
In manufacture of this heat exchanger, its parts are
combined one with another to for a temporary assembly.
As shown in Figs. 6 and 8, the flat tubes 201 are arranged
at first in parallel with one another in the direction of
their width and at regular intervals. Subsequently, both
ends of each tube 201 are inserted in the tube-insertion
apertures 203d, with each corrugated fin 202 being inter-
posed between the adjacent tubes. '7'he partitions 209,
the side plates 210 and other parts are also incorporated
in the assembly.
The inlet pipe-connecting member 204 will be added to
the assembly, in the following manner_ i~t first, the
surrounding body 222 is fitted sideways on the header 203.
Since the surrounding portion 217 of said body thereby covers
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a little more than the semicircle of the header, the member
204 having this portion 217 is automatically prevented from
disengaging from said header. Then, this connecting member
204 will be rotated around the header 203 at its height
such that the coolant-receiving round bore 203e thereof
coincides with the coolant outlet opening 220 of said member
204. In this way, the lug 219 fits in the gap between
the tubes 201, and an inner surface of the extension 218
contacts core. The extension 218 and the lug 219 in this
state respectively inhibits the further rotation of the
member 204 in one direction and prevents the displacement
thereof longitudinally of the header 203. Due to the
forcible engagement of the lug 219 in addition to the em-
bracing effect of the surrounding portion 217, this con-
necting member 204 remains self-retained in place on the
heat exchanger body. In other worcis,. the round bore 203a
of the header is kept in alignment with the coolant outlet
opening 220 of said member 204, without being assisted by
any tool.
Also, the outlet pipe-connecting member 207 is attached
to the other header in the same manner as the inlet pipe-
connecting member.
Attached to the connecting member 204 of this heat ex
changer is the separable connector 206. This connector,
which is secured to said member 204 in a flange-connection
manner by means of a bolt 223, carries an end of an external
piping 205 as shown in Figs. & and 8. Thus, a portion
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of for example a coolant circulation passage will be formed
between the piping and the header.
A modification of the second embodiment is shown in
Figs. 10 and 11. In this modificat=ion, a short pipe 230
is used which has a~ end,fitted in the outlet opening 220
of the connecting member 204. Another end of the short
pipe protrudes into the header 203 through its coolant-re-
ceiving bore 203e, and this short pipe 230 is brazed in
this state to said member and said header.
The short pipe 230 is a pipe formed by the seam-welding
of an aluminum brazing sheet having at least its outer
surface coated with a brazing agent layer. Due to the
short pipe 230, the opening 220 of the connecting member
204 can be aligned readily with the coolant-receiving bore
203e of the header 203. Inadvertent rotation of said
member 204 around the header is prevented by the short pipe
present in the temporary assembly.
In a further modification shown in Figs. 12 and 13,
an intermediate pipe 232 is interposed between the-pipe-
connecting member 204 and the header 203. The intermediate
pipe 232 is also effective to retain said member in place
free from any unintentional rotation within the temporary
assembly.
The same reference numerals are allotted to the members
or portions in the modifications shown in Figs. 10 and 11
or shown in Figs. 12 and 13, where said members function
similarly to those in the embodiment shown in Figs. 6 to
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9A.
Although the connecting structure provided by the pre-
sent invention is applied to both the coolant inlet and
outlet, the structure may be applied only to the inlet or
only to the outlet.
It will be apparent that the wide contact area between
the connecting member and the header stabilizes and strength-
ens the connection of said member to the heat exchanger
body, thus reliable connection is.realized without relying
upon any additional brackets or the like which would increase
the number of parts.
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