U.S. patent application number 10/138419 was filed with the patent office on 2002-09-12 for heat exchanger tube.
This patent application is currently assigned to Mitsubishi Heavy Industries, Ltd.. Invention is credited to Inoue, Masashi, Nakado, Koji.
Application Number | 20020125002 10/138419 |
Document ID | / |
Family ID | 18540993 |
Filed Date | 2002-09-12 |
United States Patent
Application |
20020125002 |
Kind Code |
A1 |
Nakado, Koji ; et
al. |
September 12, 2002 |
Heat exchanger tube
Abstract
The present invention provides a heat exchanger tube having a
high pressure resistance. A heat exchanger tube A having a tube
body whose interior is defined as a passage of a fluid and whose
inner and outer surfaces are defined as heat entrance and exit
surfaces of the fluid, is characterized in that a bowl-shaped
bulging wall portion bulging toward the direction of the opposite
wall portions is formed on one or both of the opposite wall
portions of said tube body, the bulging leading ends of said
bowl-shaped bulging wall portions are defined as connecting
portions linearly protruding, and said connecting portions are
linearly brought into contact with the opposite wall portions and
are fixed thereto.
Inventors: |
Nakado, Koji;
(Nishi-kasugai-gun, JP) ; Inoue, Masashi;
(Nishi-kasugai-gun, JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
Mitsubishi Heavy Industries,
Ltd.
Tokyo
JP
|
Family ID: |
18540993 |
Appl. No.: |
10/138419 |
Filed: |
May 6, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10138419 |
May 6, 2002 |
|
|
|
09668342 |
Sep 25, 2000 |
|
|
|
Current U.S.
Class: |
165/172 |
Current CPC
Class: |
F28F 3/048 20130101;
F28F 2001/027 20130101; F28D 1/0391 20130101; F28F 3/042 20130101;
F28F 3/044 20130101; F28F 3/04 20130101 |
Class at
Publication: |
165/172 |
International
Class: |
F28F 001/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 21, 2000 |
JP |
2000-013400 |
Claims
What is claimed is:
1. A heat exchanger tube having a tube body whose interior is
defined as a passage for a fluid and whose inner and outer surfaces
are defined as heat entrance and exit surfaces of the fluid,
wherein a bulging wall portion bulging toward the direction of the
opposite wall portions is formed on one or both of the opposite
wall portions of said tube body, the bulging leading ends of said
bulging wall portions are defined as connecting portions linearly
protruding and said connecting portions are linearly brought into
contact with the opposite wall portions and are fixed thereto.
2. A heat exchanger tube according to claim 1, characterized in
providing a first bulging wall portion bulging in a bowl shape in
the direction of the opposite wall portions to serve as said
bulging wall portion, said first bulging wall portion being formed
on said tube body in plurality.
3. A heat exchanger tube according to claim 2, wherein a plurality
of protrusion members protruding linearly in the direction of the
extension of the tube body having a triangular cross-sections are
formed on the inner surface of said tube body in such a manner that
they are adjacent to each other, and said protrusion members being
defined as said connecting portions.
4. A heat exchanger tube according to claim 1 or 2, characterized
in providing a second bulging wall portion including a first
extending portion extending toward the direction of the opposite
wall portions from one reference position of the wall portion to
serve as said bulging wall portion, a return portion which is
folded back from said first extending portion towards said
reference position, and a second extending portion which is folded
from the return portion to said one reference position of the wall
portion.
5. A heat exchanger tube according to claim 1 or 2, wherein said
tube body is formed by a band-shaped plate member extending in one
direction, said plate member is defined as said one wall portion in
the intermediate portion of the plate member in the width direction
and is folded with two folds in the direction of the extension of
the tube body in both end portions as said one wall portion, said
folded portions are extended in closing directions to each other to
form said other wall portion, said folded portion is further folded
in a direction of said one wall portion at a contact position and
is extended toward the same direction of said one wall portion to
form a third extending portion, the end portion of said third
extending portion being brought into contact with said one wall
portion and being fixed thereto.
6. A heat exchanger tube according to claim 5, wherein an opening
portion for allowing the passages for a fluid partitioned by said
third extending portion to communicate with each other is formed in
said third extending portion.
7. A heat exchanger tube according to claim 1, wherein said tube
body comprises a pair of plate members extending in the direction
of the extension of said tube body, said plate members are formed
so that the passage for said fluid is formed between the plate
members, and said plate members have connecting end portions
extending to each side on both respective end portions, the
respective connecting end portions of these plate members being
brought into contact with each other and being fixed thereto.
8. A heat exchanger tube according to claim 7, wherein said
connecting end portions are fastened with a U-shaped folded
fastening plate.
9. A heat exchanger tube having the tube body whose interior is
defined as a passage for a fluid and whose inner and outer surfaces
are defined as heat entrance and exit surfaces for the fluid,
wherein in said tube body a band-shaped plate member is folded with
a fold in the direction of the extension of the plate member, a
passage for said fluid is formed between one wall portion and the
other wall portion extending in the same direction by the folding,
a plurality of spring back prevention portions where said one and
the other wall portions are brought into contact with each other
and are fixed in said folded portion is formed, connecting end
portions brought into contact with each other are formed on the end
portions of said one and the other wall portions, and said
connecting end portions are fixed.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat exchanger tube
preferably used for a heat exchanger tube for a cooling medium or
the like which constitutes a condenser of an air conditioner or a
refrigerator.
[0003] This application is based on Japanese Patent Application No.
2000-13400, the contents of which are incorporated herein by
reference.
[0004] 2. Description of the Related Art
[0005] In a cooling device such as an air conditioner or a
refrigerator or the like, a cooling medium (fluid) of Freon or the
like is first compressed to form a high temperature and high
pressure gas and is then liquefied by cooling the gas with a
condenser. In the condenser is incorporated a heat exchanger tube
through which a cooling medium flows, and a high temperature and
high pressure gaseous cooling medium is gradually cooled by heat
dissipation while passing through the tube so that it is condensed
into a liquid. As this kind of heat exchanger tubes, a heat
exchanger tube shown in FIG. 10 or the like has been known. A tube
body 7 is constituted by a solder material-cladded band-shaped
metallic plate member 1 being folded or bent with a fold 2 in a
direction of its extension, connecting end portions 5, 5, which are
mutually brought into contact with end portions of one wall portion
3 and the other wall portion 4 folded and extended in the same
direction, are formed and are welded thereto, and a cooling medium
passage 6 is formed between these wall portions.
[0006] Further, the curvature radius of the fold 2 is smaller than
the width of the wall portion 3 or 4, and the distance between the
wall portions 3 and 4 is smaller than the width of the wall portion
3 or 4. This shape is defined to reduce the time required for heat
dissipation by decreasing the distance from the center of the tube
body 7 to the wall portion.
[0007] The thus formed interior defines a cooling medium passage 6.
A plurality of bulging wall portions 8, 8 . . . bulging in a bowl
shape toward a direction of the opposite wall portions are formed
on both opposite wall portions 3 and 4 of the tube body 7 in which
the inner surface and the outer surface are defined as the heat
entrance and exit surfaces for the cooling medium, and bulging
leading ends of the bulging wall portions 8, 8 . . . are defined as
connecting portions 9, 9 . . . . The connecting portions 9, 9 . . .
are brought into contact with opposite bulging wall portions in a
plane and are welded by soldering. A cooling medium that flows in
the interior of the tube is caused to generate a turbulent flow by
these bulging wall portions 8, 8 . . . and is uniformly agitated
within the tube body so that the temperature distribution of a
fluid in a plane vertical to the flow is made uniform. Further, the
opposite wall portions 3 and 4 are connected to each other by the
plurality of welded bulging wall portions 8, 8 . . . and are
supported against a pressure applied to the wall portions 3 and 4
of the flat tube body 7 when a high pressure cooling medium flows
in the tube, thereby enhancing the pressure resistance of the tube
body 7.
[0008] However, the above-mentioned conventional heat exchanger
tube has the following problems.
[0009] Since the tube body is formed by folding a band-shaped
metallic plate member with a fold, it tends to be deformed by an
effect of the spring back at the fold, that is, the restoration of
the bent portions, in such a manner that the opposite wall portions
are separated from each other.
[0010] On the other hand, the opposite cooling medium agitating
bulging portions bulging in bowl shapes are soldered in a plane at
the connecting portions brought into contact with each other.
However, when an oxide film formed on the surface of a solder
material has been separated for soldering with flux, the bulging
portion has a structure making discharge of the separated oxide
film from the outer periphery of the surface-shaped connecting
portion difficult. Thus, it is actually difficult to solder at the
center of the connecting portion.
[0011] Therefore, in addition to the circumstances of difficult
soldering, when a force which separates the opposite wall portions
by the spring back is applied to the tube body, firm welding is not
performed at the connecting portion between the bulging wall
portion leading ends. As a result, the tube body has no support
against the pressure of the cooling medium, whereby the pressure
resistance of the tube body deteriorates.
SUMMARY OF THE INVENTION
[0012] The present invention was made in consideration of the
above-mentioned circumstances. The object of the present invention
is to provide a heat exchanger tube having an improved soldering
process and high pressure resistance by forming a structure which
easily discharges an oxide film separated with flux, and prevents
the deformation of the tube body due to the spring back effect.
[0013] A first aspect of the invention relates to a heat exchanger
tube having the tube body whose interior is defined as a passage of
a fluid and whose inner and outer surfaces are defined as heat
entrance and exit surfaces of the fluid and is characterized in
that a bulging wall portion bulging toward a direction of opposite
wall portions is formed on one or both of the opposite wall
portions of said tube body, the bulging leading ends of said
bulging wall portions are defined as connecting portions linearly
protruding and said connecting portions are linearly brought into
contact with the opposite wall portions and are fixed thereto.
[0014] By providing such a configuration, a soldering material
oxide separated with flux at the connecting portion of the leading
end of the bulging wall portion flows out of a linear connecting
portion whereby soldering is improved and the opposite wall
portions are firmly soldered without occurrence of a weld
failure.
[0015] A second aspect of the invention relates to a heat exchanger
tube, and is characterized in that it provides a first bulging wall
portion bulging in a bowl shape in a direction of wall portions
opposite to said bulging wall portion, with a plurality of said
first bulging wall portions being formed on said tube body.
[0016] By providing such a configuration, the opposite wall
portions are connected to each other at a plurality of positions by
a plurality of first bulging wall portions. Further, a fluid
flowing in the interior of the tube generates a turbulence flow
with the plurality of first bulging wall portions and is uniformly
agitated in the tube body.
[0017] A third aspect of the invention relates to a heat exchanger
tube, and is characterized in that a plurality of protrusions with
triangular sections protruding linearly in the direction of the
extension of the tube body are formed on the inner surface of said
tube body in such a manner that they are adjacent to each other,
said protrusions being defined as said connecting portions.
[0018] By providing such a configuration, positions which are
linearly soldered are increased at the connecting portions of the
leading ends of the first bulging wall portions where opposite wall
portions are connected to each other. Thus, the opposite wall
portions are firmly connected to each other.
[0019] Further, since the surface area of the inner surface of the
tube body defined as the heat entrance or exit surface is
increased, a contact area with the fluid is increased.
[0020] A fourth aspect of the invention relates to a heat exchanger
tube, and is characterized in that it provides a second bulging
wall portion including a first extending portion extending toward
the direction of wall portions opposite from one reference position
of the wall portion to serve as said bulging wall portion, a return
portion which is folded back from said first extending portion to
the direction of said reference position and a second extending
portion which is folded back from the return portion to said one
reference position of the wall portion.
[0021] By providing such a configuration the folded portion of the
second bulging wall portion and the opposite wall portions are
linearly brought into contact with each other in a direction of the
extension of the tube body, a soldering length is increased and the
soldering material oxide separated from flux speedily flows out of
the linear connecting portion whereby soldering can be improved.
Thus, the opposite wall portions are firmly connected to each
other.
[0022] A fifth aspect of the invention relates to a heat exchanger
tube, and is characterized in that said tube body is formed by a
band-shaped plate member extending in one direction, said plate
member is defined as said one wall portion in the intermediate
portion of the plate member in the width direction and is folded
with two folds in a direction of the extension of the tube body in
both end portions of said one wall portion, said folded portions
are extended to each other in an adjacent direction to form the
other wall portion, said folded portion is further folded in a
direction of said one wall portion at a contact position and is
extended toward the same direction of said one wall portion to form
a third extending portion, the end portion of said third extending
portion being brought into contact with said other wall portion and
being fixed thereto.
[0023] By providing such a configuration the end portion of the
third bulging wall portion and the other wall portion are linearly
brought into contact with each other in a direction of the
extension of the tube body, the soldering length is increased, and
the soldering material oxide separated from flux speedily flows out
of the linear connecting portion whereby soldering can be improved.
Thus, the opposite wall portions are firmly connected to each
other.
[0024] Further, since the weld surface in the third extending
portion composed of a mutual contact portion is pressed from both
sides by the pressure of a fluid flowing in the passage to be press
bonded, the pressure resistance is enhanced.
[0025] A sixth aspect of the invention relates to a heat exchanger
tube, and is characterized in that an opening portion for allowing
the fluid passages partitioned with said third extending portion to
communicate with each other is formed in said third extending
portion.
[0026] By providing such a configuration a fluid flowing through
the tube body is passed between the passages of a fluid divided
with the third extending portion, whereby it flows through the
entire interior of the tube body.
[0027] A seventh aspect of the invention relates to a heat
exchanger tube, and is characterized in that said tube body
comprises a pair of plate members extending in the direction of the
extension of said tube body, the plate members are formed so that
the passage for said fluid is formed between the plate members, and
the plate members have connected end portions overhanging on each
side, on both respective end portions, the respective connected end
portions of these plate members being brought into contact with
each other and being fixed thereto.
[0028] By providing such a configuration, both the wall portions of
the tube body are formed with a pair of band-shaped plate members.
Thus, to form both wall portions it is not necessary to fold a
band-shaped plate member by 180 degrees with a fold in a direction
of the extension of the plate member. The spring back is increased
with the magnitude of the bending angle. Accordingly, a bending
angle required for forming the tube body is decreased and a force
which acts on the wall portion by the spring back is decreased.
[0029] A eighth aspect of the invention relates to a heat exchanger
tube, and is characterized in that said connecting end portion is
fastened with a U-shaped folded fastening plate member.
[0030] By providing such a configuration the connecting portions
which are brought into contact with each other in a plane and are
soldered therewith are externally reinforced with a fastening plate
member, and a force due to the spring back applied to the weld
surface or a force due to the fluid pressure is reduced.
[0031] A ninth aspect of the invention relates to a heat exchanger
tube having the tube body whose interior is defined as a passage
for a fluid and whose inner and outer surfaces are defined as heat
entrance and exit surfaces for the fluid and is characterized in
that in said tube body a band-shaped plate member is folded with a
fold in the direction of the extension of the plate member, a
passage of said fluid is formed between one wall portion and the
other wall portion extending in the same direction by the folding,
a plurality of spring back preventing portions where said one and
the other wall portions are brought into contact with each other
and are fixed in said folded portion is formed, connecting end
portions brought into contact with each other are formed on the end
portions of said one and the other wall portions, and said
connecting end portions are fixed.
[0032] By providing such a configuration a force which causes the
tube body to deform by the spring back is locally acted on the
spring back preventing portion and the magnitude of the force of
separating opposite wall portions is reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0033] FIG. 1 is a view showing a first embodiment of the present
invention that is a perspective view showing one example of a heat
exchanger tube;
[0034] FIG. 2 is a view showing a first embodiment of the present
invention that is a perspective view showing another example (first
example) of a heat exchanger tube;
[0035] FIG. 3 is a view showing a second embodiment of the present
invention that is a perspective view showing one example of a heat
exchanger tube;
[0036] FIG. 4 is a view showing a second embodiment of the present
invention that is a perspective view showing another example (first
example) of a heat exchanger tube;
[0037] FIG. 5 is a view showing a second embodiment of the present
invention that is a perspective view showing another example
(second example) of a heat exchanger tube;
[0038] FIG. 6 is a view showing a second embodiment of the present
invention that is a perspective view showing another example (third
example) of a heat exchanger tube;
[0039] FIG. 7 is a view showing a third embodiment of the present
invention that is a perspective view showing one example of a heat
exchanger tube;
[0040] FIG. 8 is a view showing a third embodiment of the present
invention that is a perspective view showing another example (first
example) of a heat exchanger tube;
[0041] FIG. 9 is a view showing a fourth embodiment of the present
invention that is a perspective view showing another example of a
heat exchanger tube; and
[0042] FIG. 10 is a perspective view showing one example of a
conventional heat exchanger tube.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] First to fourth embodiments of a heat exchanger tube
according to the present invention will now be described with
reference to drawings.
[0044] [First Embodiment]
[0045] A first embodiment of a heat exchanger tube according to the
present invention is shown in FIG. 1. In a heat exchanger tube A
shown in FIG. 1, a tube body 70 is configured in such a manner that
a soldering material-cladded band-shaped metallic plate member 10
is folded with a fold 20 in a direction of the extension of the
plate member, connecting portions 50, 50, which are brought into
contact with each other, are formed at end portions of one wall
portion 30 and the other wall portion 40 extending in the same
direction by the folding and then are welded (fixed) by soldering
to form a cooling medium passage 60 between these wall portions.
Further, the connecting portions 50, 50 welded by soldering are
fastened and fixed with a U-shaped folded fastening plate member 51
formed by the extension of the one connecting end portion 50.
[0046] Such an interior of the tube body 70 defines the cooling
medium passage 60. A plurality of bowl-shaped bulging wall portions
(first bulging wall portions) 80, 80 . . . bulging toward the
direction of the opposite wall portions in bowl-shapes are formed
on both opposite wall portions 30 and 40 of the tube body 70, the
inner surface and the outer surface of the wall portion being
defined as the heat entrance and exit surfaces for the fluid.
[0047] On the inner surface of the tube body 70 are formed
adjacently to each other with triangle-shaped cross-sections with a
sharp vertical angle a plurality of protrusion members 100, 100 . .
. linearly extending in a direction of the extension of the tube
body 70, which is smaller than the bowl-shaped bulging wall
portions 80, 80 . . . , and the protrusion members 100, 100 . . .
are defined as connecting portions 90, 90 . . . at the bulging
leading ends of the bowl-shaped bulging wall portions 80, 80 . . .
. Opposite bowl-shaped bulging portions 80, 80 are linearly brought
into contact with each other by the protrusion members 100, 100 at
these connecting portions 90, 90 to be soldered to each other.
[0048] In the heat exchanger tube A having this configuration,
oxides of the soldering material separated by flux speedily flow
out of the linear contact portions of the plurality of protrusion
members 100, 100 . . . at the leading end connecting portions 90,
90 of the bowl-shaped bulging wall portions 80, 80 so as to allow
improved soldering. Accordingly, the opposite wall portions 30 and
40 can be connected to each other without occurrence of weld
failures. Further, the opposite wall portions 30 and 40 are further
firmly connected to each other at positions by the plurality of the
bowl-shaped bulging wall portions 80, 80 . . . .
[0049] Furthermore, a fluid flowing in the passage 60 generates
turbulence flows at the plurality of the bowl-shaped bulging wall
portions 80, 80 . . . . Thus, the fluid is uniformly agitated in
the tube body 70.
[0050] According to the heat exchanger tube A shown in FIG. 1,
superior soldering is carried out at the leading end connecting
portions 90 and 90 of the bowl-shaped bulging wall portions 80, 80
. . . , which connects opposite wall portions 30 and 40 to each
other, so that strong weld is obtained. Further, by providing these
bowl-shaped bulging wall portions 80, 80 . . . at a plurality of
positions, the opposite wall portions 30 and 40 are further firmly
connected to each other by a high pressure resistance that is
imparted to the tube body.
[0051] Further, the connecting end portion is externally fixed with
the fastening plate member 51, and a deformation of the tube body
due to the spring back is prevented so that the welding is easily
carried out, and after the formation of the tube body, a force due
to the flow pressure applied to the connecting end portion is
decreased so that a high pressure resistance is imparted to the
tube body.
[0052] Further, since the fluid is agitated, a temperature of the
fluid in a plane vertical to the flow can be made uniform.
Additionally, since the surface area of the inner surface is
increased by the plurality of protrusion members 100, 100 . . . ,
the contact surface area between the fluid and the tube body is
increased and the thermal conductivity from the fluid to the tube
body can be improved.
[0053] Alternatively, as shown in FIG. 2, the heat exchanger tube A
may be configured so that it is composed of a pair of band-shaped
plate members 11 and 12 extending in the direction of the extension
of the tube body 70, a passage 60 of the fluid is formed between
these plate members 11 and 12, the heat exchanger tube A is formed
so as to have connecting portions 50, 50 and 52, 52 extending to
the sides at the respective both end portions, the respective
connecting portions of these plate members are welded and fastened
to each other by U-shaped folded fastening plate members 51 and 53
respectively.
[0054] In the heat exchanger tube A having said configuration, one
wall portion 30 and the other wall portion 40 of the tube body are
formed by a pair of band-shaped plate members 11 and 12. Therefore,
to form the both wall portions 30 and 40 it is not necessary to
fold one band-shaped plate member by 180 degrees with a fold in a
direction of the extension of the plate member. The spring back is
increased with the increase of the bending angle. Thus, by reducing
the bending angle required for the formation of the tube body the
force which acts on the wall portion by the spring back is also
reduced.
[0055] Further, connections at the connecting end portions are
reinforced with the fastening plate members 51 and 53 and the force
applied to the soldered or welded surface of the connecting end
portion due to the fluid pressure is reduced.
[0056] As described above, according to the heat exchanger tube A
shown in FIG. 2, effects due to the spring back are reduced.
Accordingly, reliable soldering can be performed while maintaining
the shape of the tube body, and a higher pressure resistance can be
imparted to the tube body.
[0057] [Second Embodiment]
[0058] FIG. 3 shows a second embodiment of a heat exchanger tube
according to the present invention. A heat exchanger tube B shown
in FIG. 3 includes a wedge-shaped bulging wall portion 200 (second
bulging wall portion) composed of an extending portion 201 (first
extending portion) extending from the wall portion reference
position 30a (one wall portion reference position) of the wall
portion 30 to the direction of the opposite wall portion 40, a
folded portion 202 folded from the extending portion 201 to the
reference position and an extending portion 203 (second extending
portion) which is folded back from the folded portion 202 to the
wall portion reference position 30a.
[0059] Further, the folded portion 202 of the wedge-shaped bulging
wall portion 200 and the opposite wall portion 40 are linearly
brought into contact with each other in the direction of the
extension of the tube body 70, and the leading end (bulging end) of
the folded portion 202 of the wedge-shaped bulging wall portion 200
defines a connecting portion 90 and is welded to each other by
soldering.
[0060] In the heat exchanger tube B shown in FIG. 3 portions
corresponding to the portions shown in FIGS. 1 and 2 respectively
are denoted by the same reference numerals and the details thereof
are omitted.
[0061] Thus, in the heat exchanger tube B having the
above-mentioned configuration, the length of the soldered portion
in a direction of the extension of the tube body 70 is increased
and soldering material oxides separated by flux speedily flow out
of the linear connecting portion to obtain better soldering.
Accordingly, the weld is strengthened so that the opposite wall
portions are firmly connected to each other.
[0062] According to the heat exchanger tube B shown in FIG. 3, the
opposite wall portions 30 and 40 are firmly connected to each other
and a high pressure resistance can be imparted to the tube
body.
[0063] Alternatively, as shown in FIG. 4, the heat exchanger tube B
may be configured so that it is composed of a pair of band-shaped
plate members 11 and 12 extending in the direction of the extension
of the tube body 70, a passage 60 for the fluid is formed between
these plate members 11 and 12, the exchanger tube B is formed so as
to have connecting portions 50, 50 and 52, 52 extending to the
sides at the both respective end portions, the both respective
connecting portions of these plate members are welded to each other
and fastened to each other with U-shaped folded fastening plate
members 51 and 53 respectively.
[0064] In the heat exchanger tube B having said configuration, one
wall portion 30 of the tube body and the other wall portion 40
thereof are formed by a pair of band-shaped plate members 11 and
12. Therefore, to form both wall portions 30 and 40, it is not
necessary to fold one band-shaped plate member by 180 degrees with
a fold in a direction of the extension of the plate member. The
spring back is increased with the increase of the bending angle.
Thus, by reducing the bending angle required for the formation of
the tube body, the force which acts on the wall portion by the
spring back is also reduced.
[0065] Further, the fastening plate members 51 and 53 strengthen
the connection at the connecting end portions, thereby reducing a
force applied by the fluid pressure onto the welded surface of the
connecting end portions.
[0066] According to the heat exchanger tube B shown in FIG. 4, the
effects due to the spring back are reduced. Accordingly, reliable
soldering can be performed while maintaining the shape of the tube
body, and a higher pressure resistance can be imparted to the tube
body.
[0067] Alternatively, as shown in FIGS. 5 and 6, a heat exchanger
tube B may be formed by a band-shaped plate member 10 or a pair of
band-shaped plate members 11 and 12, wedge-shaped bulging wall
portions 200, 200 are provided on both sides of opposite wall
portions 30 and 40, and the leading ends (bulging leading ends) of
these wedge-shaped bulging wall portions 200, 200 are linearly
brought into contact with each other in a direction of the
extension of the tube body 70 at the respective folded portions
202, 202 to form a connecting portion 90 and are welded by
soldering.
[0068] Alternatively, although each of the heat exchanger tubes
shown in FIGS. 3 to 6 has a configurations provided with a single
wedge-shaped bulging wall portion, they may have a plurality of
bulging wall portions.
[0069] [Third Embodiment]
[0070] FIG. 7 shows a third embodiment of a heat exchanger tube
according to the present invention. A heat exchanger tube C shown
in FIG. 7 is formed with a band-shaped plate member 10 extending in
one direction. The plate member 10 is defined as a wall portion 40
in the intermediate portion in the width direction of the plate
member 10 and is folded with two folds 21 and 22 in the direction
of the extension of the tube body 70 at both the ends of the wall
portion 40. The folded portions 31 and 32 are extended in their
closing directions to form the other wall portion 30. Further, the
portions 31 and 32 are bent in the direction of the wall portion 40
at the contact position 30b and are extended in the direction of
the wall portion 40 to form extending portions 300, 300 (third
extending portions). The end portions 301, 301 of the extending
portions 300, 300 are brought into linear contact with the wall
portion 40 in a direction of the extension of the body tube 70 to
be welded to each other by soldering, and serves as a connecting
portion 90.
[0071] In the heat exchanger tube C shown in FIG. 7, portions
corresponding to the portions shown in FIGS. 1 to 6 respectively
are denoted by the same reference numerals and the details thereof
are omitted.
[0072] Thus, in the heat exchanger tube C having the
above-mentioned configuration, the length of the soldered portion
in a direction of the extension of the tube body 70 is increased
and soldering material oxides separated by flux speedily flow out
of the linear connecting portion to obtain better soldering.
Accordingly, the weld is strengthened so that the opposite wall
portions are firmly connected to each other.
[0073] Further, the weld surfaces in the extending portions 300,
300 brought into contact with each other are pressed from both
sides by the pressure of fluid flowing in the passage 60, 60, and a
pressure resistance is enhanced.
[0074] According to the heat exchanger tube C shown in FIG. 7, both
end portions of the band-shaped plate member are directly used as
bulging wall portions. Therefore, a simple configuration can be
obtained without the need to provide a new bulging wall portion,
and since the seam of the plate member at the connecting portion is
welded to the tube body, the pressure resistance can be
enhanced.
[0075] Thus, by the welding of the extending portions 300, 300 at
the connecting portion 90 separation of the opposite wall portions
30 and 40 is prevented and a high pressure resistance can be
imparted to the tube body.
[0076] Alternatively, in the heat exchanger tube C, openings 400,
400 . . . which are allowed to lead to fluid passages 60, 60
divided with the extending portions 300, 300 may be formed in the
extending portions 300, 300, as shown in FIG. 8.
[0077] According to the heat exchanger tube C shown in FIG. 8, a
fluid flows through the entire interior of the tube body 70. Thus,
the difference between temperatures of the fluid do not occur
between the passages 60, 60 divided with the extending portions
300, 300.
[0078] [Fourth Embodiment]
[0079] FIG. 9 shows a fourth embodiment of a heat exchanger tube
according to the present invention. In a heat exchanger tube D
shown in FIG. 9, a band-shaped plate member 10 is folded with a
fold 20 in a direction of its extension, and the folded portions
500, 500 of the wall portions 30 and 40 include a plurality of
spring back prevention portions 503, 503 . . . welded to each other
in contact surfaces 501 and 502.
[0080] In the heat exchanger tube D shown in FIG. 9, portions
corresponding to the portions shown in FIGS. 1 to 8 respectively
are denoted by the same reference numerals and the details thereof
are omitted here.
[0081] In the heat exchanger tube D having the above-mentioned
configuration, the spring back force that deforms the tube body 70
is locally added to the spring back prevention portions 503, 503
and the magnitude of the force due to the spring back which
separates the opposite portions 30 and 40 are decreased.
[0082] According to the heat exchanger tube D shown in FIG. 9, the
spring back effect is reduced by a simple reinforcement to deform
the shape of a fold. Thus, reliable soldering can be performed
while keeping the shape of the tube body and a higher pressure
resistance can be imparted to the tube body.
[0083] Alternatively, the heat exchanger tubes A, B, and C shown in
FIGS. 1, 3, 5, 7 and 8 may have a configuration in which the spring
back prevention portions as shown in FIG. 9 can be provided on the
folded portions of the band-shaped plate members.
[0084] By providing such spring back prevention portions, reliable
soldering can be performed while maintaining the shape of the tube
body and a higher pressure resistance can be imparted to the tube
body.
[0085] The present invention exhibits the following effects.
[0086] As described above, according to the heat exchanger tube
according to a first aspect, opposite wall portions are firmly
connected to each other and a high pressure resistance can be
imparted to the tube body.
[0087] According to the heat exchanger tube according to a second
aspect, opposite wall portions are firmly connected to each other
at a plurality of positions by the first bulging wall portions and
a higher pressure resistance can be imparted to the tube body.
[0088] Further, since the plurality of first bulging wall portions
agitate a fluid flowing through the interior of the tube body, a
distribution of a fluid temperature in the plane vertical to the
direction of the flow can be made uniform.
[0089] According to the heat exchanger tube according to a third
aspect, the connection between the leading ends of the first
bulging wall portions which connects opposite wall portions can be
reinforced by a plurality of protrusion members and a high pressure
resistance can be imparted to the tube body. Further, since the
surface area of the inner surface of the tube body is increased,
the thermal conductivities from a fluid to the tube body can be
enhanced.
[0090] According to the heat exchanger tube according to a fourth
aspect, the opposite wall portions can be linearly connected to
each other by better soldering with the second extending portions
and a high pressure resistance can be imparted to the tube
body.
[0091] According to the heat exchanger tube according to a fifth
aspect, the opposite wall portions can be linearly connected to
each other by better soldering with the third extending portions
and a high pressure resistance can be imparted to the tube
body.
[0092] Further, since the both end portions of band-shaped plate
members can be used as bulging wall portions as they are, the
configuration of the tube body can be simplified without the need
to provide bulging wall portions by bending and a seam of the plate
member can be welded to the tube body and the pressure resistance
can be further enhanced.
[0093] According to the heat exchanger tube according to a sixth
aspect, a fluid flowing in the interior of the tube body can freely
flow through the interior of the tube body. Therefore, a difference
between fluid temperatures between passages divided by extending
portions is prevented.
[0094] According to the heat exchanger tube according to a seventh
aspect, since the spring back force for deforming the tube body is
reduced, reliable soldering can be performed while keeping the
shape of the tube body, and a higher pressure resistance can be
imparted to the tube body.
[0095] According to the heat exchanger tube according to an eighth
aspect, the connections at the connecting end portions are
reinforced with a fastening plate member, and a higher pressure
resistance can be imparted to the tube body.
[0096] According to the heat exchanger tube according to a ninth
aspect, by a simple reinforcement to deform the shape of a fold,
reliable soldering can be performed while maintaining the shape of
the tube body, and a higher pressure resistance can be imparted to
the tube body.
* * * * *