U.S. patent application number 09/798901 was filed with the patent office on 2001-09-06 for heat exchanger.
Invention is credited to Inoue, Masashi, Nakado, Koji, Okamura, Toru, Yoshitomi, Kei.
Application Number | 20010018970 09/798901 |
Document ID | / |
Family ID | 18581151 |
Filed Date | 2001-09-06 |
United States Patent
Application |
20010018970 |
Kind Code |
A1 |
Nakado, Koji ; et
al. |
September 6, 2001 |
Heat exchanger
Abstract
A heat exchanger comprises: a pair of headers (10, 10) which are
provided in parallel facing each other through a predetermined
distance and a pathway of the fluid is respectively provided
therein; and a plurality of flat heat-exchange tubes (20, 20 . . .
) which are provided between the headers in parallel, both ends
thereof are fastened to the headers, and a pathway of the
refrigerant for connecting the pathways of both headers is
respectively provided therein. In this heat exchanger, the
heat-exchange tubes and the headers are air-tightly and
liquid-tightly fastened by inserting end portions (21, 21 . . . )
of the heat-exchange tubes into insertion holes (11, 11 . . . )
which are bored on the headers. Furthermore, in the vicinity of
opening ends (29) of both end portions of the flat heat-exchange
tubes, shape-holding portions (41) for preventing deformation of
the opening ends are provided.
Inventors: |
Nakado, Koji;
(Nishi-kasugai-gun, JP) ; Okamura, Toru;
(Nishi-kasugai-gun, JP) ; Inoue, Masashi;
(Nishi-kasugai-gun, JP) ; Yoshitomi, Kei; (Nagoya,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
18581151 |
Appl. No.: |
09/798901 |
Filed: |
March 6, 2001 |
Current U.S.
Class: |
165/174 ;
165/153; 165/173; 165/175 |
Current CPC
Class: |
F28F 3/044 20130101;
F28D 1/0316 20130101; F28F 9/182 20130101; F28D 1/0391
20130101 |
Class at
Publication: |
165/174 ;
165/175; 165/173; 165/153 |
International
Class: |
F28D 001/02; F28F
009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2000 |
JP |
2000-060914 |
Claims
What is claimed is:
1. A heat exchanger comprising: a pair of headers which are
provided in parallel to face through a predetermined distance and a
pathway of the fluid is respectively provided therein; a plurality
of flat heat-exchange tubes which are provided between said headers
in parallel, both ends thereof are fastened to said headers and a
pathway of the refrigerant for connecting the pathways of both
headers is respectively provided therein, wherein connecting
structures between said headers and heat-exchange tubes are
provided by inserting end portions of said heat-exchange tubes into
insertion holes which are bored on said headers, and air-tightly
and liquid-tightly fastening said headers and heat-exchange tubes;
and shape-holding portions for preventing the deformation of
opening ends of said heat-exchange tubes are provided in the
vicinity of the opening ends of each heat-exchange tube.
2. A heat exchanger according to claim 1, wherein said
shape-holding portions are provided by reinforcement members which
project from at least one of opposing wall portion of said
heat-exchange tube toward the opposing wall portion, and the
connecting ends of opposing reinforcement members are in contact
with each other.
3. A heat exchanger comprising: a pair of headers which are
provided in parallel facing each other through a predetermined
distance and a pathway of the fluid is respectively provided
therein; a plurality of flat heat-exchange tubes which are provided
between said headers in parallel, both ends thereof are fastened to
said headers, and a pathway of the refrigerant for connecting the
pathways of both headers is respectively provided therein, wherein
connecting structures between said headers and heat-exchange tubes
are provided by inserting end portions of said heat-exchange tubes
into insertion holes which are bored on said headers, and
air-tightly and liquid-tightly fastening said headers and
heat-exchange tubes; and an insertion end portion, in which the
width thereof between opposing side walls of said heat-exchange
tubes becomes narrower as it approaches an opening end of said
heat-exchange tubes, which is provided on each end portion of said
heat-exchange tubes.
4. A heat exchanger according to claim 3, wherein each of said
insertion holes has a shape corresponding to the shape of said
insertion end portion.
5. A heat exchanger according to claim 4, wherein said insertion
end portion has a contacting portion which inwardly or outwardly
projects from the outer surface thereof, and each insertion hole
has a shape corresponding to the shape of said insertion end
portion in which said contacting portion is provided.
6. A heat exchanger comprising: a pair of headers which are
provided in parallel facing each other through a predetermined
distance and a pathway of the fluid is respectively provided
therein; a plurality of flat heat-exchange tubes which are provided
between said headers in parallel, both ends thereof are fastened to
said headers, and a pathway of the refrigerant for connecting the
pathways of both headers is respectively provided therein, wherein
connecting structures between said headers and heat-exchange tubes
are provided by inserting end portions of said heat-exchange tubes
into insertion holes which are bored on the header, and air-tightly
and liquid-tightly fastening said header and heat-exchange tubes;
and a corner of an opening end of each heat-exchange tube is partly
cut off.
7. A heat exchanger comprising: a pair of headers which are
provided in parallel facing each other through a predetermined
distance and a pathway of the fluid is respectively provided
therein; a plurality of flat heat-exchange tubes which are provided
between said headers in parallel, both ends thereof are fastened to
said headers, and a pathway of the refrigerant for connecting the
pathways of both headers is respectively provided therein, wherein
connecting structures between said headers and heat-exchange tubes
are provided by inserting end portions of said heat-exchange tubes
into insertion holes which are bored on the header, and air-tightly
and liquid-tightly fastening said header and heat-exchange tubes;
and a removal prevention member which is fastened to opposing wall
portions of each heat-exchange tube for preventing the deformation
of said heat-exchange tube caused by the removal of said wall
portions, an which is provided on at least one of said wall
portions.
8. A heat exchanger according to claim 7, wherein said removal
prevention member is provided by bulging members which project from
respective wall portions toward the opposing wall portions, and the
connecting ends of said opposing bulging members contact each other
and are welded by laser.
9. A heat exchanger according to claim 7, wherein said removal
prevention member is provided by projections which project from
respective wall portions toward the opposing wall portions, a hole
which is provided on one of the projections, a pipe member which is
provided on the other projection and passes through the hole, and a
caulked portion which is provided on the ends of said projections
for fastening said projections by turned downward and caulking the
end of said pipe member.
10. A heat exchanger according to claim 7, wherein said removal
prevention member is provided by extending a part of one of the
opposing wall portions from each opening end of said heat-exchange
tubes and bending toward the other wall portion so as to be
fastened to the other wall portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat exchanger which is
suitable for used as a heat exchanger of a refrigerant and
constitutes a condenser and an evaporator of an air
conditioner.
[0003] 2. Description of the Related Art
[0004] In a cooling apparatus such as an air conditioner, a
refrigerant (fluid) which has been transformed into a compressed
gas having high temperature and pressure, is liquefied in a
condenser, and the liquefied refrigerant is vaporized by removing
heat of evaporation in an evaporator. A heat exchanger which equips
a plurality of heat-exchange tubes for flowing the refrigerant in
the inside thereof is used in the condenser and evaporator. In this
heat exchanger, the refrigerant which flows through the
heat-exchange tubes radiates or absorbs heat through the walls of
the heat-exchange tubes.
[0005] Conventionally, the heat exchanger as shown in FIGS. 23 to
26 is known as this type of heat exchanger. The heat exchanger
comprises: a pair of headers 10, 10 which are provided in parallel
facing each other through a predetermined distance, and a pathway
of the refrigerant (fluid) is respectively provided therein; a
plurality of flat heat-exchange tubes 20, 20 . . . which are
provided in parallel between the headers 10, 10, and both ends
thereof are fastened to the headers 10, 10 and a pathway of the
refrigerant for connecting the pathways of both headers 10, 10 is
respectively provided therein; and a plurality of fins 30, 30 . . .
which are provided between the adjacent heat-exchange tubes 20, 20
. . . to contact the outer surfaces of the heat-exchange tubes 20,
20 . . . which face each other. Furthermore, an inlet 13 of the
refrigerant is provided on one end of one of the headers 10, and an
outlet 14 of the refrigerant which is approximately located at the
farthest position from the inlet 13 on a diagonal line toward the
inlet 13, is provided on the other header 10.
[0006] In addition, connecting structures between the headers 10,
10 and the heat-exchange tubes 20, 20 . . . are provided by
inserting end portions 21, 21 . . . of the heat-exchange tubes 20,
20 . . . into insertion holes 11, 11 . . . which are bored on the
headers 10, 10, and air-tightly and liquid-tightly fastening the
headers 10, 10 and the heat-exchange tubes 20, 20 . . . .
[0007] Each heat-exchange tube 20 is constructed by bending a belt
shaped metal plate 22 in which solder is clad on both surfaces
thereof at a folding portion 23 provided along the longitudinal
direction of the metal plate 22, and by forming a passage for the
refrigerant between wall portions 24, 25 which are located on one
and the other sides of the bent metal plate 22 by attaching
connecting end portions 26, 26 which are formed at the ends of the
wall portions 24, 25 along the longitudinal direction of the bent
metal plate 22. Here, in the heat-exchange tube 20, to reduce the
length of the time of heat transmission, the radius of curvature of
the folding portion 23 is smaller than the widths of the wall
portions 24, 25, and therefore, the heat-exchange tube 20 forms a
flat shape in which the distance between the wall portions 24, 25
is shortened to the widths thereof.
[0008] Furthermore, to stir the refrigerant which flows in the
heat-exchange tubes 20, 20 . . . in order to unify the temperature
of the refrigerant, a plurality of bulging members 28, 28 . . .
project from the wall portions 24, 25 toward the opposing wall
portions. Each of these bulging members 28, 28 . . . has a
truncated-cone shape, and a flat connecting portion 28a is provided
on the connecting end thereof. The connecting portions 28a, 28a . .
. of the opposing bulging members 28, 28 . . . contact each
other.
[0009] In addition, a notch 16 is provided on the connecting end
portions 26, 26 of each end portion 21 so as to unify the inserted
length of the end portion 21 by attaching the notch 16 to the edge
of the insertion hole 11 when the end portion 21 is inserted into
the insertion hole 11.
[0010] The heat exchanger is assembled by the following steps:
producing the heat-exchange tubes 20, 20 . . . by forming a metal
tube by press molding or roll molding and cutting both ends of the
metal tube; inserting the end portions 21, 21 . . . of the
heat-exchange tubes 20, 20 . . . into the insertion holes 11, 11 .
. . of the headers 10, 10 . . . ; providing fins 30, 30 . . .
between the adjacent heat-exchange tubes 20, 20 . . . by contacting
the fins 30, 30 . . . to both of the opposing outer surfaces of the
adjacent heat-exchange tubes 20, 20 . . . in order to prevent the
separation of the connecting end portions 26, 26 of each
heat-exchange tube 20 by a spring-back force, and retaining these
heat-exchange tubes 20, 20 . . . and the fins 30, 30 . . . which
form multi-layers, by sandwiching them between a pair of holding
plates 15, 15 from the outside.
[0011] The heat exchanger is temporarily assembled by using jigs,
and braze-welded by heating in a furnace. That is, joints between
the insertion holes 11, 11 . . . and the heat-exchange tubes 20, 20
. . . , and a joint between the opposing connecting end portions
26, 26 are each air-tightly and liquid-tightly fastened by
braze-welding. Furthermore, the connecting portions 28a, 28a . . .
of the opposing bulging members 28, 28 . . . are also fastened by
braze-welding.
[0012] In the above-mentioned conventional heat exchanger, the
refrigerant flows into a header 10 from the inlet 13, branches off
and passes through each heat-exchange tube 20, flows into the
opposite header 10, and flows out from the outlet 14. The
refrigerant exchanges heat toward an outer part through the wall
surfaces of the heat-exchange tubes 20, 20 . . . .
[0013] Furthermore, the heat-exchange tubes 20, 20 . . . in which
the high pressure refrigerant flows, have a structure for improving
the resistance against the pressure force which is exerted on the
wall portions 24, 25 of the flat heat-exchange tubes 20, 20 . . . .
That is, the wall portions 24, 25 which are positioned on the top
and bottom facing each other, are connected by welding the
connecting portions 28a, 28a . . . of the opposing bulging members
28, 28 . . . which are used to stir the refrigerant.
[0014] However, the above-mentioned conventional heat exchanger has
the following problems.
[0015] No bulging members are provided around the opening ends
which provide the inlet/outlet portion for the refrigerant at both
ends of the heat-exchange tubes 20, 20 . . . , in order to prevent
problems such as pressure losses of the refrigerant caused by
sudden expansion/contraction of the refrigerant. However, when
forming the opening ends by cutting both ends of the roll-molded
heat-exchange tube, the formed opening ends tend to be easily
deformed along the cutting direction of the tube because the
bulging members which support the opposing wall portions are not
provided. The opening ends, which have deformations such as bending
or twisting, are difficult to insert into the insertion holes of
the header. Moreover, even if corrections of the deformations are
performed, the deformations still remain in the end portions of the
tube which is easily deformed since the bulging members are not
provided. Therefore, there are problems in that spaces arise
between the end portions and the insertion holes, and sufficient
braze-welding cannot be performed.
[0016] In addition, in the heat-exchange tube formed by bending a
metal plate, a force, which deforms the tube along the opening
direction of the tube and which separates the upper and lower wall
portions which face each other, is produced by a spring back force.
The deformation is hindered by the fins which are provided between
the adjacent tubes and which hold the tubes from the outside along
almost the entire portion of the heat exchanger. However, in the
vicinity of the end portions of the heat-exchange tube, since the
fins cannot be provided by constructive restriction, there are
problems that spaces arise between the opposing connecting portions
or bulging members due to separation of the opposing wall portions
because the end portions are not supported by the fins, and
sufficient braze-welding cannot be performed.
[0017] As described above, in the conventional heat exchanger,
there are problems in that the sealing performance and resistance
against the pressure of the heat exchanger are degraded due to
insufficient braze-welding. The present invention is achieved in
consideration of the above circumstances, and an object thereof is
to provide a heat exchanger in which braze-welding can be performed
more properly and which possesses superior sealing performance and
resistance against the pressure.
SUMMARY OF THE INVENTION
[0018] A first aspect of the heat exchanger of the present
invention comprises: a pair of headers which are provided in
parallel facing each other through a predetermined distance and a
pathway of the fluid is respectively provided therein; a plurality
of flat heat-exchange tubes which are provided between the headers
in parallel, both ends thereof are fastened to the headers and a
pathway of the refrigerant for connecting the pathways of both
headers is respectively provided therein; wherein connecting
structures between the headers and the heat-exchange tubes are
provided by inserting the end portions of the heat-exchange tubes
into insertion holes which are bored on the header, and air-tightly
and liquid-tightly fastening the header and the heat-exchange
tubes; and shape-holding portions for preventing the deformation of
the opening ends of the heat-exchange tube which are provided in
the vicinity of the opening ends of each heat-exchange tube.
[0019] In the heat exchanger, it is preferable that the
shape-holding portions are provided by reinforcement members which
project from at least one of the opposing wall portions of the
heat-exchange tube toward the other opposing wall portion, and the
connecting ends of the opposing reinforcement members contact each
other.
[0020] A second aspect of the heat exchanger of the present
invention comprises: a pair of headers which are provided in
parallel facing each other through a predetermined distance and a
pathway of the fluid is respectively provided therein; a plurality
of flat heat-exchange tubes which are provided between the headers
in parallel, both ends thereof are fastened to the headers, and a
pathway of the refrigerant for connecting the pathways of both
headers is respectively provided therein, wherein connecting
structures between the headers and the heat-exchange tubes are
provided by inserting end portions of the heat-exchange tubes into
insertion holes which are bored on the header, and air-tightly and
liquid-tightly fastening the header and the heat-exchange tubes;
and an insertion end portion, in which the width thereof between
opposing side walls of the heat-exchange tube becomes narrower as
it approaches an opening end of the heat-exchange tube, which is
provided on each end portion of the heat-exchange tubes.
[0021] In the heat exchanger, it is preferable that each insertion
hole has a shape corresponding to the shape of the insertion end
portion.
[0022] It is further preferable that the insertion end portion has
a contacting portion which is inwardly or outwardly projecting from
the outer surface thereof, and each insertion hole has a shape
corresponding to the shape of the insertion end portion in which
the contacting portion is provided.
[0023] A third aspect of the heat exchanger of the present
invention comprises: a pair of headers which are provided in
parallel facing each other through a predetermined distance, and a
pathway of the fluid is respectively provided therein; a plurality
of flat heat-exchange tubes which are provided between the headers
in parallel, both ends thereof are fastened to the headers, and a
pathway of the refrigerant for connecting the pathways of both
headers is respectively provided therein, wherein connecting
structures between the headers and the heat-exchange tubes are
provided by inserting end portions of the heat-exchange tubes into
insertion holes which are bored on the header, and air-tightly and
liquid-tightly fastening the header and the heat-exchange tubes;
and a corner of an opening end of each heat-exchange tube which is
partly cut off.
[0024] A fourth aspect of the heat exchanger of the present
invention comprises: a pair of headers which are provided in
parallel to facing each other through a predetermined distance, and
a pathway of the fluid is respectively provided therein; a
plurality of flat heat-exchange tubes which are provided between
the headers in parallel, both ends thereof are fastened to the
headers and a pathway of the refrigerant for connecting the
pathways of both headers is respectively provided therein, wherein
connecting structures between the headers and the heat-exchange
tubes are provided by inserting end portions of the heat-exchange
tubes into insertion holes which are bored on the header, and
air-tightly and liquid-tightly fastening the header and the
heat-exchange tubes; and a removal prevention member which is
fastened to opposing wall portions of each heat-exchange tube for
preventing the deformation of the heat-exchange tube caused by
removal of the wall portions, and which is provided on at least one
of the wall portions.
[0025] In the heat exchanger, it is preferable that the removal
prevention member is provided by bulging members which project from
respective wall portions toward the opposing wall portions, and the
connecting ends of the opposing bulging members contact each other
and are welded by laser.
[0026] In the heat exchanger, it is also preferable that the
removal prevention member is provided with projections which
project from respective wall portions toward the opposing wall
portions, a hole which is provided on one of the projections, a
pipe member which is provided on the other projection and passes
through the hole, and a caulked portion which is provided on the
ends of the projections for fastening the projections by being
turning downward and caulking the end of the pipe member.
[0027] In the heat exchanger, it is also preferable that the
removal prevention member is provided by extending a part of one of
the opposing wall portions from each opening end of the
heat-exchange tubes and bending toward the other wall portion so as
to be fastened to the other wall portion.
BRIEF EXPLANATION OF THE DRAWINGS
[0028] FIG. 1 is an enlarged cross-sectional view of the main part
of the heat exchanger according to the first embodiment of the
present invention.
[0029] FIG. 2 is an enlarged perspective view of the main part of
the heat-exchange tube according to the first embodiment of the
present invention.
[0030] FIG. 3 is an enlarged perspective view of the main part of
the heat-exchange tube according to the second embodiment of the
present invention.
[0031] FIG. 4 is an enlarged front view of the main part of the
header which has an insertion hole according to the second
embodiment of the present invention.
[0032] FIG. 5 is an enlarged perspective view of the main part of a
variation of the heat-exchange tube according to the second
embodiment of the present invention.
[0033] FIG. 6 is an enlarged front view of the main part of a
variation of the header which has an insertion hole according to
the second embodiment of the present invention.
[0034] FIG. 7 is an enlarged perspective view of the main part of
another variation of the heat-exchange tube according to the second
embodiment of the present invention.
[0035] FIG. 8 is an enlarged front view of the main part of another
variation of the header which has an insertion hole according to
the second embodiment of the present invention.
[0036] FIG. 9 is an enlarged perspective view of the main part of
another variation of the heat-exchange tube according to the second
embodiment of the present invention.
[0037] FIG. 10 is an enlarged front view of the main part of
another variation of the header which has an insertion hole
according to the second embodiment of the present invention.
[0038] FIG. 11 is an enlarged cross-sectional view of the main part
of another variation of the heat exchanger according to the second
embodiment of the present invention.
[0039] FIG. 12 is an enlarged perspective view of the main part of
another variation of the heat-exchange tube according to the second
embodiment of the present invention.
[0040] FIG. 13 is an enlarged front view of the main part of
another variation of the header which has an insertion hole
according to the second embodiment of the present invention.
[0041] FIG. 14 is an enlarged cross-sectional view of the main part
of another variation of the heat exchanger according to the second
embodiment of the present invention.
[0042] FIG. 15 is an enlarged perspective view of the main part of
the heat-exchange tube according to the third embodiment of the
present invention.
[0043] FIG. 16 is an enlarged plan view of the main part of the
heat exchanger according to the third embodiment of the present
invention.
[0044] FIG. 17 is an enlarged perspective view of the main part of
the heat-exchange tube according to the fourth embodiment of the
present invention.
[0045] FIG. 18 is an enlarged cross-sectional view of the main part
of the heat exchanger according to the fourth embodiment of the
present invention.
[0046] FIG. 19 is an enlarged perspective view of the main part of
the heat-exchange tube according to the fifth embodiment of the
present invention.
[0047] FIG. 20 is an enlarged cross-sectional view of the main part
of the heat exchanger according to the fifth embodiment of the
present invention.
[0048] FIG. 21 is an enlarged perspective view of the main part of
the heat-exchange tube according to the sixth embodiment of the
present invention.
[0049] FIG. 22 is an enlarged cross-sectional view of the main part
of the heat exchanger according to the sixth embodiment of the
present invention.
[0050] FIG. 23 is a front view of a conventional heat
exchanger.
[0051] FIG. 24 is an enlarged perspective view of the main part of
the heat exchanger shown in FIG. 23.
[0052] FIG. 25 is an enlarged plan view of the main part of the
heat exchanger shown in FIG. 23.
[0053] FIG. 26 is a cross-sectional view along the line A-A shown
in FIG. 25.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] The preferred embodiments of the present invention will be
explained in the following with reference to the figures.
[0055] [First Embodiment]
[0056] FIGS. 1 and 2 show a first embodiment of the heat exchanger
of the present invention. A heat exchanger denoted by the symbol
"A" has a similar structure to the conventional heat exchanger,
which is disclosed in FIG. 23, and comprises: a pair of headers 10,
10 which are provided in parallel facing each other through a
predetermined distance, and a pathway of the refrigerant (fluid) is
respectively provided therein; a plurality of flat heat-exchange
tubes 20, 20 . . . which are provided in parallel between the
headers 10, 10, both ends thereof are fastened to the headers 10,
10 and a pathway of the refrigerant for connecting the pathways of
both headers is respectively provided therein; and a plurality of
fins 30, 30 . . . which are provided between the adjacent
heat-exchange tubes 20, 20 . . . to contact the outer surfaces of
the heat-exchange tubes 20, 20 . . . which face each other.
[0057] In the connecting structure between the headers 10, 10 and
the heat-exchange tubes 20, 20 . . . , end portions 21, 21 . . . of
the heat-exchange tubes 20, 20 . . . are inserted into insertion
holes 11, 11 . . . which are bored on the header 10, 10, and
air-tightly and liquid-tightly fastened to the header 10, 10.
[0058] Each heat-exchange tube 20 is constructed by bending a
belt-shaped metal plate 22 on which solder is clad on both surfaces
thereof at a folding portion 23 provided along the longitudinal
direction of the metal plate 22, and by forming a passage 27 for
the refrigerant by attaching connecting end portions 26, 26 to the
ends of the wall portions 24, 25 which are formed by bending and
which extend along the longitudinal direction of the metal plate
22.
[0059] Furthermore, to stir the refrigerant which flows in the
heat-exchange tubes 20, 20 . . . in order to unify the temperature
of the refrigerant, a plurality of bulging members 28, 28 . . .
project from the wall portions 24, 25 toward the opposing wall
portions. Each of these bulging members 28, 28 . . . has a
truncated-cone shape, and a flat connecting portion 28a is provided
on the connecting end thereof. The connecting portions 28a, 28a . .
. of the opposing bulging members 28, 28 . . . contact each
other.
[0060] In addition, a notch 16 is provided on the connecting end
portions 26, 26 of each end portion 21 so as to unify the inserted
length of the end portion 21 by attaching the notch 16 to the edge
of the insertion hole 11 when the end portion 21 is inserted into
the insertion hole 11.
[0061] Furthermore, in the vicinity of opening ends 29 of both end
portions 21 of the flat heat-exchange tube 20, reinforcement
members 40, 40 . . . , which project from the wall portions 24, 25
toward the opposing wall portions, are formed. The connecting ends
of opposed reinforcement members 40, 40 . . . contact each other
and shape-holding portions 41 for preventing the deformation of the
opening ends 29 are provided by these contacted reinforcement
members 40, 40 . . . .
[0062] In the heat exchanger A which has the above-described
structure, when the end portions 21 of the flat heat-exchange tubes
20 are cut along the surface which is perpendicular to the wall
portions 24, 25 to form the opening ends 29, the reinforcement
members 40, 40 . . . , which project from the wall portions 24, 25
and which contact each other, support the wall portions 24, 25
along the cutting direction, and therefore, deformation of the wall
portions 24, 25 is prevented by the shape-holding portions 41.
Furthermore, the shapes of the opening ends 29 are maintained by
preventing the deformation of the wall portions 24, 25, since the
opening ends 29 are formed at the cutting surface of the end
portions 21, and therefore, the end portions 21 are smoothly
inserted and closely connected with the insertion holes 11.
[0063] Furthermore, the reinforcement members 40, 40 . . . are
composed of projections which are smaller than the bulging members
28, 28 . . . because they are not designed for stirring the
refrigerant which flows in the heat-exchange tube 20, and
therefore, problems caused by sudden expansion/contraction of the
refrigerant can be prevented if the reinforcement members 40, 40 .
. . are provided adjacent to the opening ends 29.
[0064] In the heat exchanger A shown in FIGS. I and 2, deformation
of the opening ends 29 can be prevented, and therefore, the end
portions 21 can be connected with the insertion holes 11,
braze-welding between the end portions 21 and the insertion holes
11 can be performed more properly, and the sealing performance of
the heat exchanger can be improved.
[0065] [Second Embodiment]
[0066] FIGS. 3 and 4 show a second embodiment of the heat exchanger
of the present invention. A heat-exchange tube 20 constitutes a
main part of the heat exchanger denoted by the symbol "B" (refer to
FIG. 11, for example) and comprises a pair of belt-shaped plates
22a, 22b which extend along the longitudinal direction of the
heat-exchange tube 20. A passage 27 for the refrigerant is provided
between the plates 22a, 22b, by attaching connecting end portions
26a, 26b which project from both ends of plates 22a, 22b and extend
along the longitudinal direction of the plates 22a, 22b.
Furthermore, an insertion end portion 50, in which the width
thereof between the opposing connecting end portions 26a, 26b (the
width between the opposing side walls of the heat-exchange tube 20)
becomes narrower as it approaches the opening end 29, is provided
on each end portion 21 of the heat-exchange tube 20.
[0067] In addition, a contacting portion 60 is provided on wall
portions 24, 25 of the insertion end portion 50. The contacting
portion 60 is constructed of a pair of grooves 61, 62 which extends
along the longitudinal direction of the heat-exchange tube 20.
These grooves 61, 62 bulge toward the opposing wall portions 24, 25
at reference positions 24a, 25a on the wall portions 24, 25, and
return to the reference positions 24a, 25a in roughly V-shaped
sections. Here, the heights of the grooves 61, 62 are set to about
one-fourth of the distance between the opposing wall portions 24,
25, and the width of the grooves 61, 62 are set to about one-tenth
of the width between the opposing connecting end portions 26a, 26b.
Furthermore, the increased amount of the length along the perimeter
of each end portion 21 resulting from the formation of the
contacting portion 60 is about one-tenth of the original length
along the perimeter of the end portion 21.
[0068] In addition, an insertion hole 11 in which the heat-exchange
tube 20 is connected has a shape corresponding to the shape of the
insertion end portion 50 in which the contacting portion 60 is
provided. That is, the insertion hole 11 has the same shape as the
sectional shape of the insertion end portion 50 when the insertion
end portion 50 is cut along a surface which is parallel to the
opening end 29 at a predetermined position. A pair of notches 11a,
11b, in which the connecting end portions 26a, 26b are connected,
is formed at both ends of the flat insertion hole 11, and a pair of
chevron-shaped projections 111, 112, in which the grooves 61, 62
are connected, is formed on the top and bottom of the flat
insertion hole 11.
[0069] In FIGS. 3 and 4, other parts which correspond to the parts
in FIGS. 1 and 2 are given the same reference numbers, and an
explanation is omitted.
[0070] In the heat exchanger B which has the above-described
structure, the opening ends 29 are smaller than the insertion holes
11. Therefore, when the end portions 21 of the flat heat-exchange
tubes 20 are cut along the surface which is perpendicular to the
wall portions 24, 25 to form the opening ends 29, the end portions
21 are smoothly inserted into the insertion holes 11 even if the
opening ends 29 are deformed along the cutting direction thereof.
These deformations not only arise in the opening ends 29, but also
in the end portions 21 in the vicinity of the opening ends 29;
however, the deformed end portions 21 can be entirely inserted into
the insertion holes 11 by including the entire deformed end
portions 21 in the insertion end portions 50, and therefore, the
end portions 21 are closely connected with the insertion holes 11
at the predetermined position.
[0071] The insertion holes 11 are larger than the opening ends 29
and smaller than the cross-sectional shape of the heat-exchange
tubes 20, since the insertion holes 11 are formed in compliance
with the insertion end portions 50. Therefore, the heat-exchange
tubes 20 make contact with the insertion holes 11 at the insertion
end portions 50, and the insertion end portions 50 are closely
connected with the insertion holes 11. Furthermore, since the width
between the opposing walls of each insertion end portion 50
enlarges as the distance from the opening end 29 increases, when a
force is applied on each heat-exchange tube 20 in order to insert
the heat-exchange tube 20 into the insertion hole more deeply, the
insertion end portion 50 and the insertion hole 11 are elastically
deformed, and the contact area between the insertion end portion 50
and the insertion hole 11 is increased. In addition, the insertion
end portion 50, which presses against the insertion hole 11 in the
enlarging direction, receives a reaction force which tightens the
insertion end portion 50 in the insertion hole 11.
[0072] Furthermore, even when each insertion end portion 50 is not
completely connected with the insertion hole 11 by reasons
concerning their processing accuracy, for example, when complicated
deformations such as a warp or distortion of the insertion end
portion 50 which is not restricted a regular deformation in a
certain direction or a defect of the insertion hole 11 which is
caused by uneven cutting, exist, a point(s) at which the insertion
end portion 50 and the insertion hole 11 is definitely contacted
can be ensured on the contacting portion 60. For example, even when
the insertion end portion 50 contacts adjacent to the corner of the
insertion hole 11 on a roughly diagonal line thereof, since the
grooves 61, 62 of the contacting portion 60 which bulge to form
V-shaped sections have inclined surfaces, the grooves 61, 62
definitely contact the chevron-shaped projections 111, 112 of the
insertion hole 11 at the inclined surface. On the other hand, the
increased amount of the length along the perimeter of the insertion
end portion 50 by the formation of the contacting portion 60 is
about one-tenth of the original length along the perimeter of the
insertion end portion 50. Therefore, the amount of contact between
the insertion end portion 50 and the insertion hole 11 is
definitely increased due to the formation of the contacting portion
60.
[0073] In the heat exchanger B shown in FIGS. 3 and 4, the opening
end 29 and end portion 21 adjacent to the opening end 29 which are
deformed as a result of cutting, are smaller than the insertion
hole 11, and therefore, the deformed end portion can be entirely
inserted into the insertion hole 11. As a result, the end portion
21 can be connected with the insertion hole 11 at the insertion end
portion 50, and therefore, braze-welding between the insertion end
portion 50 and the insertion hole 11 can be performed more
properly, and the sealing performance of the heat exchanger B can
be improved.
[0074] Furthermore, the numbers of contact points and the amount of
contact between the insertion end portion 50 and the insertion hole
11 can be increased through the formation of the contacting portion
60. Therefore, braze-welding between the insertion end portion 50
and the insertion hole 11 can be performed more properly, and the
sealing performance of the heat exchanger B can be improved.
[0075] Furthermore, since the width between the opposing walls of
each insertion end portion 50 is enlarged as the distance from the
opening end 29 increases, the insertion end portion 50, which
presses against the insertion hole 11 in the enlarging direction,
receives a reaction force which tightens the insertion end portion
50 in the insertion hole 11, and therefore, the deformation caused
by the spring back force which acts to separate the wall portions
24, 25 which are positioned on the top and bottom facing each
other, can be prevented. Consequently, braze-welding between each
of the connecting portions 26a, 26a, 26b, 26b, and the opposing
bulging members 28, 28 . . . projecting from the end portion 21 of
the heat-exchange tube 20 in which the fins 30 cannot be provided,
can be performed more properly, and the sealing performance and
resistance against the pressure of the heat exchanger B can be
improved.
[0076] In addition, in the above-described embodiment, the grooves
61, 62 which bulge inwardly from the wall portions 24, 25 of each
insertion end portion 50 are provided as the contacting portion 60;
however, as shown in FIGS. 5 and 6, bulging portions 63, 64 which
bulge outwardly from the wall portions 24, 25 may be provided on
the outer surface of each insertion end portion 50 as the
contacting portion 60. The bulging portions 63, 64 have roughly
semicircular-shaped sections and sizes roughly the same as that of
the grooves 61, 62 in their lengths, heights, and widths. In this
case, a pair of semicircular-shaped grooves 113, 114 in which the
bulging portions 63, 64 are connected, is formed at the top and
bottom of each insertion hole 11.
[0077] Furthermore, as shown in FIGS. 7 and 8, in the heat
exchanger B, bulging portions 65, 66 which bulge outwardly from the
wall portions 24, 25, may also be provided on the outer surface of
each insertion end portion 50 as the contacting portion 60. The
bulging portions 65, 66 have wide top or bottom end surface and
heights roughly the same as that of the bulging portions 63, 64. In
this case, a pair of notches 115, 116, which have shapes so as to
connect with the bulging portions 65, 66, is formed at the top and
bottom of each insertion hole 11.
[0078] Furthermore, as shown in FIGS. 9, 10 and 11, in the heat
exchanger B, curved portions 67, 68 which have curved surfaces
curved inwardly toward the center portions of wall portions 24, 25
and which have heights roughly the same as that of the grooves 61,
62 may also be provided on the tip portion of each insertion end
portion 50 as the contacting portion 60. In this case, a pair of
curved edges 117, 118, which have shapes so as to connect with the
curved portions 67, 68, are formed at the top and bottom of each
insertion hole 11.
[0079] Furthermore, as shown in FIGS. 12, 13 and 14, in the heat
exchanger B, an oval portion 69 which has a curved surface bulging
outwardly from the outer surface of the wall portions 24, 25 along
the perimeter thereof, may also be provided on the base portion of
the insertion end portion 50, that is, the position at which the
width of the insertion end portion 50 becomes equal to that of the
heat-exchange tube 20, of each insertion end portion 50 as the
contacting portion 60. In this case, each insertion hole 11 forms
an oval hole 119 in order to connect with the heat-exchange tube 20
closely at the point at which the oval portions 69 are formed.
[0080] In these example, since the contacting portion 60 as
described above is provided at the outer surface of each insertion
end portion 50, even when complicated deformations such as a warp
or distortion of the insertion end portion 50 which is not
restricted a regular deformation in a certain direction or a defect
of the insertion hole 11 which is caused by uneven cutting exist, a
connection between the insertion end portion 50 and the insertion
hole 11 can be performed more certainly. Furthermore, the increased
amounts of the lengths along the perimeter of the insertion end
portions 50 by the formation of the contacting portions 60 are
about one tenth of the original lengths along the perimeter of the
insertion end portions 50. Therefore, the amount of contact between
each insertion end portion 50 and the insertion hole 11 is
definitely increased through the formation of the contacting
portion 60, braze-welding can be performed more properly, and the
sealing performance of the heat exchanger B can be improved.
[0081] Furthermore, when the oval portion 69 is employed as the
contacting portion 60, since each insertion end portion 50 makes
contact with the oval hole 119 on the oval portion 69 of the curved
surface which faces the opening end 29, when the oval portion 69 is
inserted into the oval hole 119, contact points between the oval
portion 69 and the oval hole 1 19 are increased by the elastic
deformation thereof as the insertion force of the oval portion 69
is increased as well as the reaction force from the oval hole 119
which tighten the oval portion 69, and therefore, the deformation
due to a spring back force which separates the wall portions 24, 25
which are positioned on the top and bottom facing each other, can
be prevented.
[0082] [Third Embodiment]
[0083] FIGS. 15 and 16 show a third embodiment of the heat
exchanger of the present invention. In a heat-exchange tube 20
constituting a main part of the heat exchanger denoted by the
symbol "C" shown in FIGS. 15 and 16, a corner 29a of the opening
end 29 is partly cut off. Furthermore, one of the connecting
portions 26, 26 is outwardly extended and bent to form a U-shaped
fastening plate 26c which fastens the connecting portions 26,
26.
[0084] In FIGS. 15 and 16, other parts which correspond to the
parts in FIGS. 1 to 14 are given the same reference numbers, and an
explanation is omitted.
[0085] When cutting the end portion 21 along the surface which is
perpendicular to the opposing wall portions 24, 25 of the flat
heat-exchange tube 20 in order to produce the opening ends 29, even
if the opening end 29 is deformed along the cutting direction
thereof and the width of the opening end 29 is extended, the width
of an end of the opening end 29 becomes narrower than the insertion
hole 11 because the corner 29a of the opening end 29 is cut off,
and therefore, the end portion 21 is smoothly inserted into the
insertion hole 11. Here, the cut-off of the corner 29a beginning
from the opening end 29 in order to prevent additional deformation
of the wall portions 24, 25. In actuality, deformations not only
arise in the opening end 29, but also in the end portion 21 in the
vicinity of the opening end 29, and the width of the end portion is
also extended in the vicinity of the opening end 29, however, since
the deformation of the end portion 21 decreases with the distance
from the opening end 29, the deformed end portion 21 is entirely
inserted into the insertion hole 11 by including the entire
deformed end portion 21 in the insertion hole 11, and therefore,
the end portion 21 is closely connected with the insertion hole 11
at the predetermined position in which the deformation does not
arise.
[0086] In the heat exchanger C shown in FIGS. 15 and 16, the end of
the opening end 29 which is deformed by cutting can be smoothly
inserted into the insertion hole 11 because the width of the
opening end 29 becomes narrower than the insertion bole 11 by
cut-off of the corner 29a of the opening end 29. Then, the end
portion 21 can be closely connected with the insertion holes 11,
and therefore, braze-welding between the end portion 21 and the
insertion hole 11 can be performed more properly, and the sealing
performance of the heat exchanger C can be improved.
[0087] Furthermore, as the result of clipping the corner 29a, the
area of the end portion 21 which is inserted into the header 10
through the insertion hole 11 and the amount of the inserted area
in the pathway of the refrigerant when the header 10 along the
longitudinal direction are decreased, and the loss of the
refrigerant can be reduced in comparison with that of when the the
corner 29a is not cut off.
[0088] In addition, the corner 29a of the opening end 29 is cut off
in a straight line in this embodiment; however, a larger area can
be cut off as long as the corner 29a is included. Furthermore, it
is not necessary to cut off the opening end 29 in a straight line.
As a result of these improvements, the opening end 29 which is
deformed can be more smoothly inserted into the insertion hole 11
because the width of an end of the opening end 29 becomes more
narrow, and the loss of the refrigerant can be reduced more.
[0089] [Fourth Embodiment]
[0090] FIGS. 17 and 18 show a fourth embodiment of the heat
exchanger of the present invention. In heat exchange tubes 20
constituting the main parts of the heat exchanger denoted by the
symbol "D" shown in FIGS. 17 and 18, the contact ends of the
opposing bulging members 28, 28 . . . projecting from the end
portions 21 of the heat-exchange tubes 20 in which the fins 30, 30
. . . cannot be provided, are welded by laser, and these
laser-welded bulging members 28, 28 . . . . provide a removal
prevention member 70.
[0091] In FIGS. 17 and 18, other parts which correspond to the
parts in FIGS. 1 to 16 are given the same reference numbers, and an
explanation is omitted.
[0092] In the heat-exchange tubes 20 formed by bending a metal
plate, forces which deform the tubes along the opening direction of
the tubes and which separate the upper and lower wall portions 24,
25 which face each other, is produced by a spring back force.
However, the deformations caused by the spring back force are
prevented as a result of the connection of the wall portions 24, 25
by the laser-welding of the contact ends of the opposing bulging
members 28, 28 . . . .
[0093] In the heat exchanger D shown in FIGS. 17 and 18, the
deformations of the wall portions 24, 25 of the flat heat-exchanges
tubes 20 caused by the spring back force can be prevented by the
connection of the wall portions 24, 25 by the laser-welding of the
contact ends of the opposing bulging members 28, 28. Therefore,
braze-welding between the connecting portions 28a, 28a . . . ,
which contact each other, and the opposing bulging members 28, 28 .
. . , can be performed more properly, and resistance against the
pressure of the heat exchanger D can be improved; as braze-welding
between the connecting end portions 26, 26 can be performed more
properly as well, and the sealing performance and resistance
against the pressure of the heat exchanger D can be improved.
[0094] [Fifth Embodiment]
[0095] FIGS. 19 and 20 show a fifth embodiment of the heat
exchanger of the present invention. In heat-exchange tubes 20
constituting the main parts of the heat exchanger denoted by the
symbol "E" shown in FIGS. 19 and 20, a pair of projections which
face each other are provided on the wall portions 24, 25 at the end
portions 21 nearby. Each upper projection has a hole 71 and each
lower projection has a pipe member 72. The end of the pipe member
72 which passes through the hole 71 is turned downward and caulked,
and therefore, a caulked portion 73 is provided on the ends of the
projections and the projections are fastened by this caulked
portion 73. Namely, in this embodiment, the projections which are
fastened by the caulked portion 73 provide a removal prevention
member 70.
[0096] In FIGS. 19 and 20, other parts which correspond to the
parts in FIGS. 1 to 18 are given the same reference numbers, and an
explanation is omitted.
[0097] In the heat-exchange tubes 20 formed by bending a metal
plate, forces which deform the tubes along the opening direction of
the tubes and which separate the upper and lower wall portions 24,
25 which face each other, are produced by a spring back force.
However, the deformations by the spring back force are prevented as
a result of the connection of the wall portions 24, 25 by the
caulked portion 73.
[0098] In the heat exchanger E shown in FIGS. 19 and 20, the
deformations of the wall portions 24, 25 of the flat heat-exchange
tubes 20 by the spring back force can be prevented by the
connection of the wall portions 24, 25 by the caulked portion 73.
Therefore, braze-welding between the connecting portions 28a, 28a .
. . which contact each other, of the opposing bulging members 28,
28 . . . , can be performed more properly, and resistance against
the pressure of the beat exchanger E can be improved; as
braze-welding between the connecting end portions 26, 26 can be
performed more properly as well, and the sealing performance and
resistance against the pressure of the heat exchanger E can be
improved.
[0099] In addition, in this embodiment, the projections of the wall
portions 24, 25 are fastened by caulking the ends thereof; however,
the projections may be also fastened by welding or by using a
rivet, a stapler, or the like.
[0100] [Sixth Embodiment]
[0101] FIGS. 21 and 22 show a sixth embodiment of the heat
exchanger of the present invention. In heat-exchange tubes 20
constituting the main parts of the heat exchanger denoted by the
symbol "F" shown in FIGS. 21 and 22, a part of each lower wall
portion 25 is extended from the opening end 29. This extended part
bends upward and toward the upper wall portion 24, and forms a
fastening clip 74 which is fastened to the wall portion 24. Namely,
in this embodiment, the fastening clip 74, which is formed at the
opening end 29, provides a removal prevention member 70.
Furthermore, an opening which has a shape corresponding to the
fastening clip 74 is provided at the upper end of each insertion
hole 11 so as to engage with the fastening clip 74.
[0102] In FIGS. 21 and 22, other parts which correspond to the
parts in FIGS. 1 to 20 are given the same reference numbers, and an
explanation is omitted.
[0103] In the heat-exchange tubes 20 formed by bending a metal
plate, forces which deform the tubes along the opening direction of
the tubes and which separate the upper and lower wall portions 24,
25 which face each other, are produced by a spring back force.
However, the deformations by the spring back force are prevented as
a result of the connection of the wall portions 24, 25 by the
fastening clip 74.
[0104] In the heat exchanger F shown in FIGS. 21 and 22, the
deformations of the wall portions 24, 25 of the flat heat-exchange
tubes 20 by the spring back force can be prevented by the
connection of the wall portions 24, 25 by the fastening clip 74.
Therefore, braze-welding between the connecting portions 28a, 28a .
. . which contact each other, of the opposing bulging members 28,
28 . . . , can be performed more properly, and resistance against
the pressure of the heat exchanger F can be improved; as
braze-welding between the connecting end portions 26, 26 can be
performed more properly as well, and the sealing performance and
resistance against the pressure of the heat exchanger F can be
improved.
[0105] In addition, in the above-described embodiments, in order to
achieve a high braze-welding property of the heat exchanger for
improving its sealing performance and resistance against the
pressure, one of the shape-holding portions 41, the insertion end
portions 50 having contacting portions 60, the opening ends 29 in
which the corners 29a are partly cut off, or the removal prevention
members 70, is provided, however, these means can be simultaneously
provided within the same heat exchanger.
* * * * *