U.S. patent application number 10/580408 was filed with the patent office on 2007-04-05 for heat exchanger and process for fabricating same.
This patent application is currently assigned to SHOWA DENKO K.K.. Invention is credited to Keiichi Nakada.
Application Number | 20070074859 10/580408 |
Document ID | / |
Family ID | 37598254 |
Filed Date | 2007-04-05 |
United States Patent
Application |
20070074859 |
Kind Code |
A1 |
Nakada; Keiichi |
April 5, 2007 |
Heat exchanger and process for fabricating same
Abstract
An oil cooler 1 to which a heat exchanger of the invention is
applied comprises a plurality of flat hollow bodies 2 arranged one
above another in parallel at a spacing and extending in a
left-right direction, a communication member 3 disposed between
left end portions of each adjacent pair of flat hollow bodies 2,
and a spacer 4 disposed between right end portions of each adjacent
pair of flat hollow bodies 2. The spacer 4 has bores 36 extending
therethrough in the front-rear direction. The spacer 4 is disposed
at a position corresponding to the cutoff portion of the partition
wall 15 in the hollow body 2. A fluid of high pressure can be
passed through the flat hollow bodies 2 of the oil cooler 1.
Inventors: |
Nakada; Keiichi; (Oyama-Shi,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
SHOWA DENKO K.K.
TOKYO
JP
|
Family ID: |
37598254 |
Appl. No.: |
10/580408 |
Filed: |
December 22, 2004 |
PCT Filed: |
December 22, 2004 |
PCT NO: |
PCT/JP04/19706 |
371 Date: |
May 24, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60532905 |
Dec 30, 2003 |
|
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Current U.S.
Class: |
165/153 ;
165/167 |
Current CPC
Class: |
F28D 1/0383 20130101;
F28D 1/0375 20130101 |
Class at
Publication: |
165/153 ;
165/167 |
International
Class: |
F28D 1/02 20060101
F28D001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2003 |
JP |
2003-423983 |
Claims
1. A heat exchanger comprising a plurality of flat hollow bodies
arranged one above another in parallel at a spacing and extending
in a left-right direction, a communication member disposed between
left end portions of each adjacent pair of flat hollow bodies for
holding the adjacent pair of flat hollow bodies in communication
with each other therethrough, a spacer in the form of a block and
disposed between right end portions of each adjacent pair of flat
hollow bodies, each of the flat hollow bodies comprises an upper
and a lower flat wall elongated in the left-right direction, a
peripheral wall interconnecting the upper and lower walls at
peripheral edges thereof, and a partition wall dividing interior of
the hollow body into two straight channels extending in the
left-right direction, a left end portion of each of the upper and
lower walls being provided respectively at front and rear areas
thereof on opposite sides of the partition wall with two through
holes spaced apart in a front-rear direction for causing the
respective channels to communicate with the communication member
therethrough, the partition wall having a right end portion cut off
to hold the two channels in communication with each other
therethrough, the spacer being provided with a bore extending
therethrough in the front-rear direction, the spacer being
positioned in corresponding relation with the cutoff portion of the
partition wall of the flat hollow body.
2. A heat exchanger according to claim 1 wherein the spacer has a
left-to-right width larger than the length of the cutoff portion of
the partition wall in the left-right direction.
3. A heat exchanger according to claim 1 wherein the spacer has a
plurality of bores extending therethrough in the front-rear
direction and arranged side by side in the left-right
direction.
4. A heat exchanger according to claim 1 wherein the spacer has an
inner peripheral surface defining the bore and provided with a
plurality of ridges and/or furrows extending longitudinally of the
bore.
5. A heat exchanger according to claim 1 wherein each of the flat
hollow bodies comprises upper and lower two flat plates elongated
in the left-right direction and arranged one above the other at a
spacing, and a channel forming body disposed between and brazed to
the two flat plates, the channel forming body comprising two
straight side bars arranged between the upper and lower flat plates
respectively at front and rear side edges thereof and extending in
the left-right direction, an intermediate bar positioned between
and spaced from the two side bars and extending in the left-right
direction, two heat transfer area increasing portions formed
between the intermediate bar and the respective side bars
integrally therewith and provided at an intermediate portion of the
height of the bars, and two end bars extending forwardly or
rearwardly inward respectively from left ends of the side bars
integral therewith and having inner ends bearing on and brazed to a
left end of the intermediate bar respectively at front and rear
side faces thereof, the intermediate bar having a cutoff right end
portion, the two heat transfer area increasing portions each having
a cutoff left end portion, a left end portion of each of the upper
and lower flat plates having two through holes formed respectively
in front and rear areas thereof on opposite sides of the
intermediate bar, the upper and lower flat plates providing the
upper and lower walls respectively, the upper and lower flat plates
having respective right end portions each bent toward the other,
the bent end portions being lapped over and brazed to each other to
provide a right wall portion of the peripheral wall, the two side
bars of the channel forming body providing front and rear side wall
portions of the peripheral wall, the end bars of the channel
forming body providing a left wall portion of the peripheral
wall.
6. A heat exchanger according to claim 5 wherein the upper and
lower flat plates are each made of an aluminum brazing sheet, and a
channel forming body comprises an aluminum extrudate.
7. An industrial machine comprising a heat exchanger according to
claim 1 and serving as an oil cooler.
8. An industrial machine comprising a heat exchanger according to
claim 1 and serving as an aftercooler.
9. A process for fabricating a heat exchanger according to claim 1
comprising: preparing channel forming blanks each comprising two
straight side bars arranged as spaced apart in the front-rear
direction and extending in the left-right direction, an
intermediate bar positioned between and spaced from the two side
bars and extending in the left-right direction, and two flat plate
portions formed between the intermediate bar and the respective
side bars integrally therewith and provided at an intermediate
portion of the height of the bars, pairs of upper and lower flat
plates elongated in the left-right direction, communication members
each having two through bores spaced apart in the front-rear
direction and extending vertically, and spacers each having a bore
extending therethrough in the front-rear direction, making channel
forming bodies from the respective blanks each by cutting off left
and right opposite end portions of the intermediate bar of the
blank, cutting off a left end portion of each of the flat plate
portions of the blank over a length larger than the cutoff length
of the left end portion of the intermediate bar, subjecting the two
flat plate portions of the blank to press work to make heat
transfer area increasing portions, and bending left end portions of
the side bars of the blank leftwardly or rightwardly inward to
cause inner ends of the side bars to bear respectively on front and
rear side faces of the intermediate bar to form end bars, bending
right end portions of each pair of upper and lower flat plates
toward each other to form bent portions and forming two through
holes in a left end portion of each flat plate in areas thereof to
be positioned on front and rear opposite sides of the intermediate
bar, making a plurality of combinations each comprising the
resulting pair of upper and lower flat plates and the channel
forming body disposed therebetween, arranging the combinations one
above another in parallel at a spacing, providing each of the
communication members between left end portions of each adjacent
pair of combinations so as to permit the two through bores to
communicate with the respective through holes of each flat plate,
providing each of the spacers between right end portions of each
adjacent pair of combinations, and further positioning a fin
between each adjacent pair of combinations between the
communication member and the spacer, and brazing each pair of upper
and lower flat plates to the side bars, the intermediate bar and
the end bars of the channel forming body between the pair of
plates, the inner ends of the end bars to the intermediate bar, and
the bent portions of each pair of flat plates to each other, and
further brazing each flat plate to the communication member, the
spacer and the fin which are adjacent thereto.
10. A process for fabricating a heat exchanger according to claim 9
wherein each of the flat plates is made of an aluminum brazing
sheet, and each of the communication members, the spacers and the
channel forming blanks is made of an aluminum extrudate, the fin
being made from a thin aluminum plate, the brazing being performed
with a brazing material released from the flat plates on
melting.
11. A process for fabricating a heat exchanger according to claim 9
wherein the spacers have a left-to-right width larger than the
cutoff length of the right end portion of the intermediate bar of
the channel forming blank in the left-right direction.
12. A process for fabricating a heat exchanger according to claim 9
wherein each of the spacers has a plurality of bores extending
therethrough in the front-rear direction.
13. A process for fabricating a heat exchanger according to claim 9
wherein each of the spacers has an inner peripheral surface
defining the bore and provided with a plurality of ridges and/or
furrows extending longitudinally of the bore.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is an application filed under 35 U.S.C.
.sctn.111(a) claiming the benefit pursuant to 35 U.S.C.
.sctn.119(e) (1) of the filing date of Provisional Application No.
60/532,905 filed Dec. 30, 2003 pursuant to 35 U.S.C.
.sctn.111(b).
TECHNICAL FIELD
[0002] The present invention relates to heat exchangers for use as
oil coolers, aftercoolers, radiators or the like for industrial
machines such as compressors, tool machines and hydraulic machines,
and also to a process for fabricating the same.
[0003] The upper and lower sides and the left- and right-hand sides
of FIG. 1 will herein and in the appended claims be referred to as
"upper," "lower," "left" and "right," respectively. The downstream
side with respect to the direction in which a fluid flows through
each adjacent pair of flat hollow bodies so to be subjected to heat
exchange with a fluid flowing through the hollow bodies, i.e., the
direction indicated by the arrow X in FIGS. 1 and 8, will be
referred to as "front," and the opposite side as "rear." These
terms "upper," "lower," "left," "right," "front" and "rear" are
thus defined for the sake of convenience, and the terms in each
pair may be used as interchanged by each other. Further in the
following description, the term "aluminum" includes aluminum alloys
in addition to pure aluminum.
BACKGROUND ART
[0004] The heat exchangers for use in industrial machines as oil
coolers, aftercoolers, radiators, etc. include those which comprise
a plurality of flat hollow aluminum bodies arranged one above
another in parallel at a spacing and extending in a left-right
direction for passing a fluid of high temperature therethrough, two
aluminum communication members arranged respectively between the
left and right end portions of each adjacent pair of flat hollow
bodies and brazed to the adjacent hollow bodies, the adjacent
hollow bodies being held in communication with each other through
the communication members, and a corrugated aluminum fin disposed
between and brazed to each adjacent pair of flat hollow bodies and
positioned between the left and right communication members. Each
of the flat hollow bodies comprises an upper and a lower flat wall
and a peripheral wall interconnecting the peripheral edges of the
upper and lower walls, each of the upper and lower walls of each
flat hollow body having one through hole formed in each of left and
right end portions thereof, each of the left and right
communication members having one through hole communicating with
the corresponding through holes of the upper and lower walls of the
hollow body, the left and right end portions of the flat hollow
bodies and the left and right communication members respectively
providing a pair of left and right headers extending vertically
(see, for example, the publication of JP-A No. 2001-82891 and the
publication of No. 8-233476).
[0005] The flat hollow body comprises two flat plates arranged one
above the other at a spacing and each made of an aluminum brazing
sheet having a brazing material layer over each of opposite
surfaces thereof, and an aluminum channel forming body interposed
between and brazed to the two flat plates, each of the flat plates
having a through hole formed in each of left and right end portions
thereof, the channel forming body comprising a peripheral wall
interconnecting the peripheral edges of the two flat plates, and a
heat transfer area increasing portion interconnecting longitudinal
intermediate parts of two straight portions of the peripheral wall
which are positioned respectively at the front and rear opposite
side edges of the flat plates.
[0006] However, the conventional heat exchanger has the following
problems. The two communication members arranged respectively
between the left and right end portions of each adjacent pair of
flat hollow bodies give relatively great weight to the heat
exchanger in its entirety. Since the communication member must have
a communication hole for passing a fluid of high temperature and
high pressure therethrough, the portion of the communication member
surrounding the through hole needs to have an increased wall
thickness, consequently increasing the weight of the communication
member and therefore giving increased weight to the entire heat
exchanger. The pair of headers, which are provided respectively at
the left and right sides of the exchanger, give a relatively small
area to the portion of heat exchange between the fluid of high
temperature and a fluid of low temperature, i.e., to the so-called
heat exchange core, relative to the required overall size of the
heat exchanger to be installed, posing a limitation on the
improvement of heat exchange efficiency. The fluid of high
temperature flows into one of the headers, then flows through the
flat hollow bodies into the other header. During this time, the
fluid is subjected to heat exchange with the fluid of low
temperature flowing forward from the rear through the clearances
between the respective adjacent pairs of hollow bodies. The
high-temperature fluid portion flowing through the rear side
portions of the hollow bodies is efficiently cooled in this case,
but the low-temperature fluid portion reaching the front side
portions of the clearances between the hollow bodies has its
temperature raised to a relatively high level, so that the
high-temperature fluid portion flowing through the front side
portions of the interior of the hollow bodies is cooled less
effectively. Thus, the overall heat exchange performance still
remains to be improved.
[0007] Accordingly, the present applicant has previously proposed a
heat exchanger which has overcome these problems. The proposed heat
exchanger comprises a plurality of flat hollow bodies arranged one
above another in parallel at a spacing and extending in a
left-right direction, a communication member disposed between left
end portions of each adjacent pair of flat hollow bodies for
holding the adjacent pair of flat hollow bodies in communication
with each other therethrough, a spacer bar disposed between the
right end portions of each adjacent pair of flat hollow bodies,
each of the flat hollow bodies comprises an upper and a lower flat
wall elongated in the left-right direction, a peripheral wall
interconnecting the upper and lower walls at the peripheral edges
thereof, and a partition wall dividing the interior of the hollow
body into two straight channels extending in the left-right
direction, a left end portion of each of the upper and lower walls
being provided respectively at front and rear areas thereof on
opposite sides of the partition wall with two through holes spaced
apart in a front-rear direction for causing the respective channels
to communicate with the communication member therethrough, the
partition wall having a right end portion cut off to hold the two
channels in communication with each other therethrough, the spacer
bar having a left-to-right width considerably smaller than the
left-to-right length of a cutoff left end portion of the partition
wall of the flat hollow body (see the publication of JP-A No.
2004-184057).
[0008] In the heat exchanger disclosed in the publication of JP-A
No. 2004-184057, each of the flat hollow bodies comprises upper and
lower two flat plates elongated in the left-right direction and
arranged one above the other at a spacing, and a channel forming
body disposed between and brazed to the two flat plates, the
channel forming body comprising two straight side bars arranged
between the upper and lower flat plates respectively at the front
and rear side edges thereof and extending in the left-right
direction, an intermediate bar positioned between and spaced from
the two side bars and extending in the left-right direction, two
heat transfer area increasing portions formed between the
intermediate bar and the respective side bars integrally therewith
and provided at an intermediate portion of the height of the bars,
and two end bars extending forwardly or rearwardly inward
respectively from the left ends of the side bars integral therewith
and having inner ends bearing on and brazed to the left end of the
intermediate bar respectively at the front and rear side faces
thereof, the intermediate bar having a cutoff right end portion,
the two heat transfer area increasing portions each having a cutoff
left end portion, the left end portion of each of the upper and
lower flat plates having two through holes formed respectively in
front and rear areas thereof on opposite sides of the intermediate
bar, the upper and lower flat plates providing the upper and lower
walls respectively, the upper and lower flat plates having
respective right end portions each bent toward the other, the bent
end portions being lapped over and brazed to each other to provide
a right wall portion of the peripheral wall, the two side bars of
the channel forming body providing front and rear side wall
portions of the peripheral wall, the end bars of the channel
forming body providing a left wall portion of the peripheral wall,
the intermediate bar of the channel forming body providing the
partition wall.
[0009] The present inventor has conducted extensive research and
found that the proposed heat exchanger is likely to have the
following problem. At the portion of the channel forming body where
the intermediate bar is cut off, the upper and lower flat plates
are brazed only to the side bars, so that the flat plates have a
reduced strength this portion. When the fluid flowing inside the
flat hollow body has a high pressure, the plates are likely to
bulge or develop other trouble although the fluid gives rise to no
problem when having a low pressure.
[0010] An object of the present invention is to overcome the above
problems and to provide a heat exchanger wherein a fluid of high
pressure can be passed through flat hollow bodies.
DISCLOSURE OF THE INVENTION
[0011] To fulfill the above object, the present invention comprises
the following modes.
[0012] 1) A heat exchanger comprising a plurality of flat hollow
bodies arranged one above another in parallel at a spacing and
extending in a left-right direction, a communication member
disposed between left end portions of each adjacent pair of flat
hollow bodies for holding the adjacent pair of flat hollow bodies
in communication with each other therethrough, a spacer in the form
of a block and disposed between right end portions of each adjacent
pair of flat hollow bodies, each of the flat hollow bodies
comprises an upper and a lower flat wall elongated in the
left-right direction, a peripheral wall interconnecting the upper
and lower walls at peripheral edges thereof, and a partition wall
dividing interior of the hollow body into two straight channels
extending in the left-right direction, a left end portion of each
of the upper and lower walls being provided respectively at front
and rear areas thereof on opposite sides of the partition wall with
two through holes spaced apart in a front-rear direction for
causing the respective channels to communicate with the
communication member therethrough, the partition wall having a
right end portion cut off to hold the two channels in communication
with each other therethrough, the spacer being provided with a bore
extending therethrough in the front-rear direction, the spacer
being positioned in corresponding relation with the cutoff portion
of the partition wall of the flat hollow body.
[0013] 2) A heat exchanger according to par. 1) wherein the spacer
has a left-to-right width larger than the length of the cutoff
portion of the partition wall in the left-right direction.
[0014] 3) A heat exchanger according to par. 1) wherein the spacer
has a plurality of bores extending therethrough in the front-rear
direction and arranged side by side in the left-right
direction.
[0015] 4) A heat exchanger according to par. 1) wherein the spacer
has an inner peripheral surface defining the bore and provided with
a plurality of ridges and/or furrows extending longitudinally of
the bore.
[0016] 5) A heat exchanger according to par. 1) wherein each of the
flat hollow bodies comprises upper and lower two flat plates
elongated in the left-right direction and arranged one above the
other at a spacing, and a channel forming body disposed between and
brazed to the two flat plates, the channel forming body comprising
two straight side bars arranged between the upper and lower flat
plates respectively at front and rear side edges thereof and
extending in the left-right direction, an intermediate bar
positioned between and spaced from the two side bars and extending
in the left-right direction, two heat transfer area increasing
portions formed between the intermediate bar and the respective
side bars integrally therewith and provided at an intermediate
portion of the height of the bars, and two end bars extending
forwardly or rearwardly inward respectively from left ends of the
side bars integral therewith and having inner ends bearing on and
brazed to a left end of the intermediate bar respectively at front
and rear side faces thereof, the intermediate bar having a cutoff
right end portion, the two heat transfer area increasing portions
each having a cutoff left end portion, a left end portion of each
of the upper and lower flat plates having two through holes formed
respectively in front and rear areas thereof on opposite sides of
the intermediate bar, the upper and lower flat plates providing the
upper and lower walls respectively, the upper and lower flat plates
having respective right end portions each bent toward the other,
the bent end portions being lapped over and brazed to each other to
provide a right wall portion of the peripheral wall, the two side
bars of the channel forming body providing front and rear side wall
portions of the peripheral wall, the end bars of the channel
forming body providing a left wall portion of the peripheral
wall.
[0017] 6) A heat exchanger according to par. 5) wherein the upper
and lower flat plates are each made of an aluminum brazing sheet,
and a channel forming body comprises an aluminum extrudate.
[0018] 7) An industrial machine comprising a heat exchanger
according to any one of par. 1) to 6) and serving as an oil
cooler.
[0019] 8) An industrial machine comprising a heat exchanger
according to any one of par. 1) to 6) and serving as an
aftercooler.
[0020] 9) A process for fabricating a heat exchanger according to
par. 1) which is characterized by: preparing channel forming blanks
each comprising two straight side bars arranged as spaced apart in
the front-rear direction and extending in the left-right direction,
an intermediate bar positioned between and spaced from the two side
bars and extending in the left-right direction, and two flat plate
portions formed between the intermediate bar and the respective
side bars integrally therewith and provided at an intermediate
portion of the height of the bars, pairs of upper and lower flat
plates elongated in the left-right direction, communication members
each having two through bores spaced apart in the front-rear
direction and extending vertically, and spacers each having a bore
extending therethrough in the front-rear direction; making channel
forming bodies from the respective blanks each by cutting off left
and right opposite end portions of the intermediate bar of the
blank, cutting off a left end portion of each of the flat plate
portions of the blank over a length larger than the cutoff length
of the left end portion of the intermediate bar, subjecting the two
flat plate portions of the blank to press work to make heat
transfer area increasing portions, and bending left end portions of
the side bars of the blank leftwardly or rightwardly inward to
cause inner ends of the side bars to bear respectively on front and
rear side faces of the intermediate bar to form end bars; bending
right end portions of each pair of upper and lower flat plates
toward each other to form bent portions and forming two through
holes in a left end portion of each flat plate in areas thereof to
be positioned on front and rear opposite sides of the intermediate
bar; making a plurality of combinations each comprising the
resulting pair of upper and lower flat plates and the channel
forming body disposed therebetween, arranging the combinations one
above another in parallel at a spacing, providing each of the
communication members between left end portions of each adjacent
pair of combinations so as to permit the two through bores to
communicate with the respective through holes of each flat plate,
providing each of the spacers between right end portions of each
adjacent pair of combinations, and further positioning a fin
between each adjacent pair of combinations between the
communication member and the spacer; and brazing each pair of upper
and lower flat plates to the side bars, the intermediate bar and
the end bars of the channel forming body between the pair of
plates, the inner ends of the end bars to the intermediate bar, and
the bent portions of each pair of flat plates to each other, and
further brazing each flat plate to the communication member, the
spacer and the fin which are adjacent thereto.
[0021] 10) A process for fabricating a heat exchanger according to
par. 9) wherein each of the flat plates is made of an aluminum
brazing sheet, and each of the communication members, the spacers
and the channel forming blanks is made of an aluminum extrudate,
the fin being made from a thin aluminum plate, the brazing being
performed with a brazing material released from the flat plates on
melting.
[0022] 11) A process for fabricating a heat exchanger according to
par. 9) wherein the spacers have a left-to-right width larger than
the cutoff length of the right end portion of the intermediate bar
of the channel forming blank in the left-right direction.
[0023] 12) A process for fabricating a heat exchanger according to
par. 9) wherein each of the spacers has a plurality of bores
extending therethrough in the front-rear direction.
[0024] 13) A process for fabricating a heat exchanger according to
par. 9) wherein each of the spacers has an inner peripheral surface
defining the bore and provided with a plurality of ridges and/or
furrows extending longitudinally of the bore.
[0025] With the heat exchanger described in par. 1), the spacer is
positioned in corresponding relation with the cutoff portion of the
partition wall of the flat hollow body, so that the upper and lower
walls are prevented from becoming lower in strength even at the
portion of the flat hollow body where no partition wall portion
exits for interconnecting the upper and lower walls. Consequently,
the upper and lower walls are prevented from bulging even when a
fluid of high pressure is passed inside the hollow body, and the
fluid of high pressure can be passed through the hollow body.
Additionally, the spacer can be smaller in weight than when the
spacer has no bore extending therethrough, preventing the heat
exchanger from increasing in weight in its entirety. A fluid for
cooling the fluid of high temperature flowing inside the flat
hollow bodies of the heat exchange unit, for example, cold air,
flows through the through bores of the spacers, with the result
that the spacers also contribute to heat exchange, consequently
achieving a higher efficiency in refrigerating the fluid of high
temperature flowing inside the hollow bodies than when spacers
having no through bores are used.
[0026] With the heat exchanger according to par. 2), the width of
the spacer is larger than the length of the partition wall cutoff
portion of the hollow body with respect to the left-right
direction. This reliably prevents the upper and lower walls from
becoming impaired in strength at the portion of the flat hollow
body where no partition wall portion exits for interconnecting the
upper and lower walls, with the result that the upper and lower
walls are reliably precluded from bulging or developing other
trouble when a fluid of high pressure is passed inside the hollow
body. The fluid of high pressure can therefore passed through the
hollow body.
[0027] With the heat exchanger according to par. 3), the portion of
the spacer between adjacent pair of bores serves to reinforce the
upper and lower walls of the flat hollow body. The upper and lower
walls can therefore be prevented from becoming impaired in strength
more reliably.
[0028] With the heat exchanger according to par. 4), the inner
peripheral surface of the spacer defining the bore is provided with
ridges and/or furrows extending longitudinally of the bore. This
gives an increased area of heat transfer between the fluid of high
temperature flowing inside the hollow body and a fluid of low
temperature flowing through the bore, further improving the
high-temperature fluid refrigeration efficiency mentioned above
with reference to par. 1).
[0029] With the heat exchanger according to par. 5), the spacer is
positioned in corresponding relation with the cutoff portion of the
intermediate bar of the channel forming body which bar provides the
partition wall of the hollow body, so that the upper and lower flat
plates are prevented from becoming lower in strength even at the
hollow body portion where there exists no intermediate bar brazed
to these flat plates, and are consequently precluded, for example,
from bulging even when a fluid of high pressure if passed inside
the hollow body. The fluid of high pressure can therefore passed
through the hollow bodies. With the inner ends of the end bars of
the channel forming body brazed to the intermediate bar, the flat
hollow body has an enhanced strength. Stated more specifically, the
left end portion of the intermediate bar of the channel forming
body is brazed to the upper and lower flat plates each at the
portion thereof between the two through holes, and the inner ends
of the end bars are brazed to this intermediate bar. Accordingly,
the end bars are prevented from breaking even if subjected to a
leftward force as exerted thereon by the fluid flowing inside the
hollow body.
[0030] The heat exchanger according to par. 6) is reduced in weight
in its entirety and is easy to fabricate.
[0031] Heat exchangers having the advantages described with
reference to par. 1) can be fabricated easily by the process
according to par. 9).
[0032] Heat exchangers can be fabricated with greater ease and can
be further reduced in weight when fabricated by the process
described in par. 10).
[0033] Heat exchangers having the advantage described with
reference to par. 2) can be fabricated easily by the process
according to par. 11).
[0034] Heat exchangers having the advantage described with
reference to par. 3) can be fabricated easily by the process
according to par. 12).
[0035] Heat exchangers having the advantage described with
reference to par. 4) can be fabricated easily by the process
according to par. 13).
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a perspective view showing the overall
construction of an oil cooler to which a heat exchanger of the
invention is applied.
[0037] FIG. 2 is an exploded perspective view showing a portion of
the oil cooler.
[0038] FIG. 3 is a perspective view partly broken away and showing
a flat hollow body of the oil cooler, with a heat transfer area
increasing portion omitted.
[0039] FIG. 4 is a view in vertical section showing the right end
portion of the flat hollow body of the oil cooler on an enlarged
scale.
[0040] FIG. 5 is a fragmentary perspective view of the left end
portion of channel forming body of the hollow body to show a
process for making the channel forming portion.
[0041] FIG. 6 is a fragmentary perspective view of the right end
portion of the channel forming body of the hollow body to show the
process.
[0042] FIG. 7 is an exploded perspective view showing the lower end
portion of the oil cooler.
[0043] FIG. 8 is a diagram showing how an oil flows through the oil
cooler.
[0044] FIG. 9 is a perspective view of a modification of a
spacer.
BEST MODE OF CARRYING OUT THE INVENTION
[0045] An embodiment of the present invention will be described
below with reference to the drawings.
[0046] FIG. 1 show the overall construction of a heat exchanger of
the invention, and FIGS. 2 to 4 and 7 show the constructions of
main portions thereof. FIGS. 5 and 6 shows a process for making a
channel forming body of a flat hollow body, and FIG. 8 shows the
flow of a fluid of high temperature through the heat exchanger.
Throughout the drawings, like parts will be designated by like
reference numerals.
[0047] The present embodiment is an oil cooler for compressors to
which a heat exchanger of the invention is applied. Examples of
such compressors are load compressors, compressors for use in gas
turbines, compressors useful for brakes of railroad vehicles,
etc.
[0048] FIG. 1 shows an oil cooler 1 which comprises flat hollow
aluminum bodies 2 arranged one above another in parallel at a
spacing and extending in a left-right direction, i.e., laterally of
the cooler 1, for passing an oil of high temperature therethrough,
a communication member 3 made of an aluminum extrudate, disposed
between the left end portions of each vertically adjacent pair of
flat hollow bodies 2 and brazed to the adjacent pair of flat hollow
bodies 2 for holding the hollow bodies in communication with each
other therethrough, a spacer 4 made of an aluminum extrudate,
disposed between the right end portions of each adjacent pair of
flat hollow bodies 2 and brazed to the adjacent pair of flat hollow
bodies 2, and a corrugated aluminum fin 6 disposed between the
communication member 3 and the spacer 4 in an air passing clearance
5 between each adjacent pair of flat hollow bodies 2 and brazed to
the pair adjacent pair of flat hollow bodies 2.
[0049] An inlet-outlet member 7 made of an aluminum extrudate and
having the same thickness and size as the communication member 3 is
disposed under the left end portion of the flat hollow body 2 at
the lower end of the oil cooler and brazed to the end hollow body
2. A spacer 4 the same as the spacer 4 between the flat hollow
bodies 2 is similarly disposed under the right end portion of the
end hollow body 2 and brazed to the body 2. A lower side plate 8
elongated laterally of the cooler 1 has a left end portion brazed
to the right end portion of the lower surface of the inlet-outlet
member 7 and a right end portion brazed to the entire lower surface
of the spacer 4. The space between the lower side plate 8 and the
end hollow body 2 also serves as an air passing clearance 5, which
is provided with a corrugated fin 6, the fin being brazed to the
lower side plate 8 and the end hollow body 2. The lower side plate
8 comprises an aluminum brazing sheet having a brazing material
layer over the upper surface thereof.
[0050] A communication member 3 the same as the communication
member 3 between the flat hollow bodies 2 is provided on the upper
side of the left end portion of the flat hollow body 2 at the upper
end of the oil cooler 1 and brazed to the upper end hollow body 2.
A spacer 4 the same as the spacer 4 between the flat hollow bodies
2 is similarly disposed on the upper side of the right end portion
of the upper end hollow body 2 and brazed to the body 2. An upper
side plate 9 elongated laterally of the cooler 1 has a left end
portion brazed to the entire upper surface of the communication
member 3 and a right end portion brazed to the entire upper surface
of the spacer 4. The space between the upper side plate 9 and the
upper end hollow body 2 also serves as an air passing clearance 5,
which is provided with a corrugated fin 6. The fin 6 is brazed to
the upper side plate 9 and the upper end hollow body 2. The upper
side plate 9 comprises an aluminum brazing sheet having a brazing
material layer over the upper surface thereof.
[0051] With reference to FIGS. 2 and 3, the flat hollow body 2
comprises an upper and a lower wall 11 elongated laterally of the
cooler 1, a peripheral wall 12 interconnecting the upper and lower
walls 11 at their peripheral edges, and a partition wall 15
dividing the interior of the hollow body 2 into front and rear two
channels 13, 14 extending laterally of the cooler. The left end
portion of each of the upper and lower walls 11 is provided,
respectively at the front and rear areas thereof on opposite sides
of the partition wall 15, with two through holes 16, 17 spaced
apart in the front-rear direction for causing the respective
channels 13, 14 to communicate with the outside therethrough. The
partition wall 15 has a right end portion cut off to hold the two
channels 13, 14 in communication with each other therethrough. The
communication portion is indicated at 18. The flat hollow body 2
comprises two rectangular flat plates 19, 21 made of an aluminum
brazing sheet having a brazing material layer over opposite
surfaces thereof, elongated laterally of the cooler and vertically
spaced apart, and a channel forming body 22 made of an aluminum
extrudate and disposed between and brazed to the upper and lower
flat plates 19, 21.
[0052] The through holes 16, 17 are formed respectively in the
front and rear areas of left end portion of each of the flat plates
19, 21. The two flat plates 19, 20 have respective right end
portions which are bent toward each other. Stated more
specifically, the upper flat plate 19 has its right end portion
bent downward, while the lower flat plate 21 has its right end
portion bent upward to provide bent portions 19a, 21a which are
lapped over and brazed to each other (see FIG. 4). The two flat
plates 19, 21 provide the upper and lower walls 11, and the bent
portions 19a, 21a of the two flat plates 19, 21 provide a right
wall portion 12a of the peripheral wall 12.
[0053] The channel forming body 22 comprises two straight side bars
23 arranged between the upper and lower flat plates 19, 21
respectively at their front and rear side edges and extending
laterally of the cooler 1, an intermediate bar 24 positioned
between and spaced from the two side bars 23 and extending
laterally of the cooler 1, two heat transfer area increasing
portions 25 formed between the intermediate bar 24 and the
respective side bars 23 integrally therewith and provided at an
intermediate portion of the height of the bars, and two end bars 26
extending forwardly or rearwardly inward from the left ends of the
respective side bars 23 integral therewith and having inner ends
bearing on and brazed to the left end of the intermediate bar 24
respectively at the front and rear side faces thereof. The two side
bars 23, intermediate bar 24 and two end bars 26 are brazed to the
upper and lower flat plates 19, 21. The intermediate bar 24 has a
left end portion brazed to the two flat plates 19, 21 at the
portions thereof between the two through holes 16, 17. The
intermediate bar 24 has a right end portion cut out over a
predetermined length to provide the communication portion 18. The
two heat transfer area increasing portions 25 have left end
portions which are cut out over a specified length so as to provide
through holes in register with the respective through holes 16, 17
in the flat plates 19, 21. The side bars 23 of the channel forming
body 22 provide front and rear side wall portions 12b of the
peripheral wall 12, and the two end bars 26 of the body 22 provide
a left wall portion 12c of the peripheral wall 12.
[0054] With reference to FIG. 4, the heat transfer area increasing
portion 25 comprises a plurality of wavy strips 27 each comprising
upward bent portions 27a and downward bent portions 27b which are
arranged alternately laterally of the portion 25 and interconnected
by horizontal portions 27c, the wavy strips 27 being arranged in
the front-rear direction and interconnected by the horizontal
portions 27c into an integral piece. In each adjacent pair of wavy
strips 27 of the portion 25, the upward bent portions 27a of one of
the wavy strips are displaced from those 27a of the other strip
laterally of the portion 25, and the downward bent portions 27b of
one of the wavy strips are displaced from those 27b of the other
strip with respect to the lateral direction. With each wavy strip
27 of the heat transfer area increasing portion 25, there is the
horizontal portion 27c between each laterally adjacent pair of
upward bent portion 27a and downward bent portion 27b, and each
forwardly or rearwardly adjacent pair of wavy strips 27 are joined
to each other at horizontal portions 27c, whereas the horizontal
portions 27c need not always be provided. In each adjacent pair of
wavy strips 27, at the part where the upward bent portion 27a
extends into the downward bent portion 27b in one of the strip
extends across like part of the other strip, so that the two strips
are joined together at such parts.
[0055] The channel forming body 22 is made in the manner shown in
FIGS. 5 and 6. Channel forming blanks 29 each in the form of an
aluminum extrudate are made, each of the blanks 29 comprising two
straight side bars 23 arranged as spaced apart in the front-rear
direction and extending in the left-right direction, an
intermediate bar 24 positioned between and spaced from the two side
bars 23 and extending in the left-right direction, and two flat
plate portions 28 formed between the intermediate bar 24 and the
respective side bars 23 integrally therewith and provided at an
intermediate portion of the height of the bars [see FIG. 5(a) and
FIG. 6(a)]. Left and right opposite end portions of the
intermediate bar 24 of each blank 29 are then cut off over a
specified length, and a left end portion of each of the two flat
plate portions 28 of the blank is cut out over a length larger than
the cutoff length of the left end portion of the intermediate bar
24 [see FIG. 5(b) and FIG. 6(b)]. The two flat plate portions 28 of
the blank are subsequently subjected to press work to make heat
transfer area increasing portions 25 [see FIG. 5(c) and FIG. 6(c)].
The left end portions of the side bars 23 of the blank are
thereafter bent leftwardly or rightwardly inward to cause the inner
ends of the side bars 23 to bear respectively on the front and rear
side faces of the intermediate bar 24 [See FIG. 5(d)] and braze the
inner ends to the intermediate bar 24, whereby two end bars 26 are
formed. In this way, the channel forming body 22 is made. The inner
ends of the end bars 26 are brazed to the intermediate bar 24 with
the molten brazing material released from the flat plates 19, 21 on
melting when a unit-type heat exchanger 1 is fabricated in the
manner to be described later.
[0056] As shown in FIG. 2, each communication member 3 has front
and rear two vertical through bores 31, 32 to be positioned in
register with the respective two through holes 16, 17 of the upper
and lower walls 11 of the flat hollow body 2 when seen from above
so as to communicate with these holes 16, 17. The front side
portions of the front end portions of all flat hollow bodies 2 and
the front side portions of all communication members 3 provide an
inlet header 33A (see FIG. 8). In the inlet header 33A, the left
end portions of the front channels 13 of all flat hollow bodies 2
are caused to communicate with the front vertical through bores 31
of all communication members 3 through the front through holes 16
of the upper and lower walls 11. The rear side portions of the rear
end portions of all flat hollow bodies 2 and the rear side portions
of all communication members 3 provide an outlet header 33B (see
FIG. 8). In the outlet header 33B, the left end portions of the
rear channels 14 of all flat hollow bodies 2 are caused to
communicate with the rear vertical through bores 32 of all
communication members 3 through the rear through holes 17 of the
upper and lower walls 11.
[0057] The two vertical through bores 31, 32 of the communication
member 3 disposed on the upper side of the left end portion of the
flat hollow body 2 at the upper end of the oil cooler 1 have their
upper-end openings closed by the upper side plate 9.
[0058] With reference to FIG. 7, the portion of the inlet-outlet
member 7 leftwardly of the left end of the lower side plate 8 has
front and rear two vertical through bores 34, 35 communicating with
the respective through holes 16, 17 of the lower wall 11 of the
flat hollow body at the lower end of the cooler 1. These through
bores 34, 35 have internally threaded inner peripheries 34a,
35a.
[0059] As shown in FIG. 2, the spacer 4 has a lateral width larger
than the length of the cutoff portion of the intermediate bar 24 of
the channel forming body 22, i.e., the lateral length of the
communication portion 18. The spacer 4 further has a plurality of
bores 36 extending therethrough in the front-rear direction and
arranged side by side in the lateral direction.
[0060] The oil cooler 1 is fabricated by making combinations each
comprising a pair of flat plates 19, 21 of aluminum brazing sheet
and a channel forming body 22 positioned therebetween, arranging
the combinations one above another in parallel at a spacing,
providing a communication member 3 between left end portions of
each adjacent pair of combinations so as to permit the two through
bores 31, 32 to communicate with the respective through holes 16,
17 of the flat plates 19, 21, providing a spacer 4 between right
end portions of each adjacent pair of combinations, and further
positioning a corrugated fin 6 between each adjacent pair of
combinations between the communication member 3 and the spacer 4,
arranging an inlet-outlet member 7, spacer 4, corrugated fin 6 and
lower side plate 8 under the combination at the lower end of the
resulting assembly, arranging a communication member 3, spacer 4,
corrugated fin 6 and upper side plate 9 on the upper side of the
combination at the upper end of the assembly, tacking the resulting
assembly by suitable means, and collectively brazing the assembly.
At this time, the end bars 26 of each channel forming body 22 are
brazed to the intermediate bar 24 thereof with the molten brazing
material released from the flat plates 19, 21 on melting.
[0061] With the oil cooler 1 described above, oil of high
temperature flows into the inlet header 33A through the front
vertical through bore 34 of the inlet-outlet member 7 as indicated
by the arrow Y in FIG. 8, then dividedly flows into all the flat
hollow bodies 2 to flow rightward through the front channels 13
thereof, further flows into the rear channels 14 via the
communication portions 18, then flows leftward through the rear
channels 14 into the outlet header 33B and flows out through the
rear vertical through bore 35 of the inlet-outlet member 7. While
flowing through the front channels 13 and the rear channels 14 of
all the flat hollow bodies 2, the oil is subjected to heat exchange
with the cold air having a low temperature and flowing forward (see
the arrow X) through the air passing clearances 5. At this time,
the oil is cooled also by the spacers 4, whereby an improved
refrigeration efficiency is achieved.
[0062] In the case where the oil flowing inside the flat hollow
bodies 2 has a high pressure, the upper and lower walls 11 of the
hollow bodies 2, i.e., the portions of the upper and lower flat
plates 19, 21 which are not brazed to the intermediate bar 24
adjacent thereto, namely, the portions of the plates 19, 21 which
correspond to the communication portions 18, will be subjected to a
great outward force, whereas such a force is received by the
spacers 4, which prevent the upper and lower walls 11, i.e., the
upper and lower flat plates 19, 21, from bulging outward.
[0063] In the foregoing embodiment, the inner peripheral surfaces
of the spacer 4 defining the bores 36 extending therethrough may
have a plurality of ridges 40 extending in the front-rear direction
as shown in FIG. 9. These ridges 40 give an increased area of heat
transfer from the spacer 4 to the cold air stream to achieve a
further improved refrigeration efficiency. In place of the ridges
40 or in addition to the ridges 40, a plurality of furrows
extending in the front-rear direction may be formed in the inner
peripheral surfaces defining the bores 36.
[0064] In the above embodiment, the lateral width of the spacer 4
is greater than the lateral length of the cutoff portion of the
intermediate bar 24 of the channel forming body 22, i.e., the
lateral length of the communication portion 18, whereas this is not
limitative; the lateral width of the spacer 4 may be smaller than
the lateral length of the communication portion 18. For example,
even if the lateral width of the spacer 4 is smaller than the
lateral length of the communication portion 18 by an amount
corresponding to the lateral width of the upward or downward bent
portion 27a or 27b of the wavy strip 27 of the channel forming body
22, the upper and lower walls 11, i.e., the upper and lower flat
plates 19, 21, are prevented from bulging outward.
[0065] Although the heat exchanger of the present invention is
embodied as an oil cooler for compressors according to the
embodiment described above, this application is not limitative; the
heat exchanger may be used as an aftercooler or a radiator for load
compressors, gas turbine compressors, railroad vehicle compressors,
etc. Furthermore, an aftercooler or radiator of suitable
construction may be assembled into a unit along with the oil cooler
which comprises a heat exchanger of the invention.
[0066] The heat exchanger of the present invention may be used as
an oil cooler for cooling oils for use in tool machines or in
hydraulic devices for cranes as used singly, or for deck cranes,
truck cranes, power shovels or the like.
INDUSTRIAL APPLICABILITY
[0067] The present invention provides a heat exchanger, for
example, for use as an oil cooler, aftercooler, radiator or the
like for industrial machines such as compressors, tool machines and
hydraulic devices
* * * * *