U.S. patent application number 10/573077 was filed with the patent office on 2007-05-31 for heat exchanger tube.
Invention is credited to Soichi Kato.
Application Number | 20070119581 10/573077 |
Document ID | / |
Family ID | 34419189 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070119581 |
Kind Code |
A1 |
Kato; Soichi |
May 31, 2007 |
Heat exchanger tube
Abstract
In a heat exchanger tube, a brazing material, which is required
for brazing tops (310) of inner fins (300) which are a flow passage
dividing body and the inner surface of a tube body portion (200),
not clad to a first material which constitutes the tube body
portion but clad to a second material which constitutes the inner
fins. In the heat exchanger tube, the tube has a thickness
t.sub.tube of 1.2 mm or less and a width W.sub.tube of 16 mm or
less, the first material has a thickness t.sub.1 of 0.25 mm or
less, the second material has a thickness t.sub.2 of 0.10 mm or
less, and the flow passages divided by the inner fins have an
equivalent diameter of 0.559 mm or less. Besides, when brazing in a
furnace, a brazing material disposed within the flow passages melts
earlier than a brazing material which penetrates from outside into
the flow passages, thereby preventing the flow passages from being
clogged.
Inventors: |
Kato; Soichi; (Saitama,
JP) |
Correspondence
Address: |
Kazunao Kubotera;Takeuchi & Kubotera
Suite 202
200 Daingerfield Road
Alexandria
VA
22314
US
|
Family ID: |
34419189 |
Appl. No.: |
10/573077 |
Filed: |
September 16, 2004 |
PCT Filed: |
September 16, 2004 |
PCT NO: |
PCT/JP04/14005 |
371 Date: |
March 23, 2006 |
Current U.S.
Class: |
165/177 ;
165/183 |
Current CPC
Class: |
F28D 1/0391 20130101;
F28F 2275/04 20130101; F28F 3/025 20130101; F28F 1/022
20130101 |
Class at
Publication: |
165/177 ;
165/183 |
International
Class: |
F28F 1/40 20060101
F28F001/40 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2003 |
JP |
2003-340601 |
Claims
1. A heat exchanger tube comprising: a tube body portion
constituting an outer shell of flow passages for flowing a medium,
and corrugated inner fins for dividing the flow passages, the tops
of the inner fins are flat tubes brazed to the inner surface of the
tube body portion and in which the medium performs heat exchange
with heat conducted to the tube, wherein: a brazing material which
is required for brazing the tops of the inner fins and the inner
surface of the tube body portion is not clad to a first material
constituting the tube body portion but clad to a second material
constituting the inner fins.
2. The heat exchanger tube according to claim 1, wherein a
thickness of a clad layer of the brazing material in the second
material is 5 to 10% in ratio with respect to the thickness of the
second material.
3. The heat exchanger tube according to claim 1, wherein the second
material has a thickness of 0.1 mm or less.
4. The heat exchanger tube according to claim 3, wherein the second
material has a thickness of 0.05 to 0.07 mm.
5. The heat exchanger tube according to claim 1, wherein the first
material has a thickness of 0.25 mm or less.
6. The heat exchanger tube according to claim 5, wherein the first
material has a thickness of 0.18 to 0.24 mm.
7. The heat exchanger tube according to claim 1, wherein the tube
has a thickness of 1.2 mm or less.
8. The heat exchanger tube according to claim 7, wherein the tube
has a thickness of 0.8 to 1.2 mm.
9. The heat exchanger tube according to claim 1, wherein the tube
has a width of 16 mm or less.
10. The heat exchanger tube according to claim 9, wherein the tube
has a width of 12 to 16 mm.
11. The heat exchanger tube according to claim 1, wherein the flow
passages divided by the inner fins have an equivalent diameter of
0.559 mm or less.
12. The heat exchanger tube according to claim 11, wherein the flow
passages divided by the inner fins have an equivalent diameter of
0.254 mm to 0.559 mm.
13. The heat exchanger tube according to claim 1, wherein the tops
of the inner fins have a pitch of 1.0 mm or less.
14. The heat exchanger tube according to claim 1, wherein an Al--Zn
alloy layer is formed on the surface of the first material which
becomes an outer shell of the tube.
15. The heat exchanger tube according to claim 1, wherein the tops
of the inner fins are flat.
16. The heat exchanger tube according to claim 1, wherein ends of
the second material in its breadth direction are brazed with the
first material by the brazing material which is clad to the second
material.
17. The heat exchanger tube according to claim 16, wherein both
ends of the first material in its breadth direction are engaged and
brazed with an end of the second material in its breadth direction
sandwiched at one end of the tube in its breadth direction so as
not to separate from each other.
18. The heat exchanger tube according to claim 1, wherein the
portion between the tops of the inner fins is not perpendicular
with respect to the central axis of the tube in its breadth
direction.
19. The heat exchanger tube according to claim 1, wherein: the tube
is a constituting member of the heat exchanger, and the heat
exchanger is produced by assembling the tube and other constituting
members into one body and brazing the assembled body in a furnace,
and the brazing material clad to the second material melts when
brazed in the furnace earlier than the brazing material which melts
from the other constituting members and penetrates into the flow
passages to prevent the flow passages from being clogged.
20. The heat exchanger tube according to claim 19, wherein the
brazing material clad to the second material has a melting point
lower than that of the brazing material which melts from the other
constituting members and penetrates into the flow passages.
21. The heat exchanger tube according to claim 19, wherein the
brazing material clad to the second material melts earlier than the
brazing material which melts from the other constituting members
and penetrates into the flow passages because the tube has a
thermal resistance lower than that of the other constituting
members.
22. The heat exchanger tube according to claim 1, wherein among
plural flow passages divided by the inner fins, an equivalent
diameter of the flow passage, which is positioned at the lowest
position when brazing in the furnace, or individual equivalent
diameters of the flow passages positioned at the lowest position
and flow passages positioned nearby when brazing in the furnace are
larger than a whole average of the equivalent diameters of the
plural flow passages divided by the inner fins.
23. A heat exchanger tube comprising: a tube body portion
constituting an outer shell of flow passages for flowing a medium,
and corrugated inner fins for dividing the flow passages, the tops
of the inner fins are flat tube brazed to the inner surface of the
tube body portion and in which the medium performs heat exchange
with heat conducted to the tube, wherein: the tube has a thickness
of 1.2 mm or less, the tube has a width of 16 mm or less, the first
material constituting the tube body portion has a thickness of 0.25
mm or less, the second material constituting the inner fins has a
thickness of 0.10 mm or less, and the flow passages divided by the
inner fins have an equivalent diameter of 0.559 mm or less.
24. The heat exchanger tube according to claim 23, wherein the
second material has a thickness of 0.05 to 0.07 mm.
25. The heat exchanger tube according to claim 23, wherein the
first material has a thickness of 0.18 to 0.24 mm.
26. The heat exchanger tube according to claim 23, wherein the tube
has a thickness of 0.8 to 1.2 mm.
27. The heat exchanger tube according to claim 23, wherein the tube
has a width of 12 to 16 mm.
28. The heat exchanger tube according to claim 23, wherein the flow
passages divided by the inner fins have an equivalent diameter of
0.254 mm to 0.559 mm.
29. The heat exchanger tube according to claim 23, wherein the tops
of the inner fins have a pitch of 1.0 mm or less.
30. The heat exchanger tube according to claim 23, wherein an
Al--Zn alloy layer is formed on the surface of the first material
which becomes an outer shell of the tube.
31. The heat exchanger tube according to claim 23, wherein the tops
of the inner fins are flat.
32. The heat exchanger tube according to claim 23, wherein ends of
the second material in its breadth direction are brazed to the
first material.
33. The heat exchanger tube according to claim 32, wherein both
ends of the first material in its breadth direction are engaged and
brazed with an end of the second material in its breadth direction
sandwiched at one end of the tube in its breadth direction so as
not to separate from each other.
34. The heat exchanger tube according to claim 23, wherein the
portion between the tops of the inner fins is not perpendicular
with respect to the central axis of the tube in its breadth
direction.
35. The heat exchanger tube according to claim 23, wherein: the
tube is a constituting member of the heat exchanger, and the heat
exchanger is produced by assembling the tube and other constituting
members into one body and brazing the assembled body in a furnace,
the brazing material which is required for brazing the tops of the
inner fins and the inner surface of the tube body portion is
disposed within the flow passages, and the brazing material
disposed within the flow passages melts when brazed in the furnace
earlier than the brazing material which melts from the other
constituting members and penetrates into the flow passages to
prevent the flow passages from being clogged.
36. The heat exchanger tube according to claim 35, wherein the
brazing material disposed within the flow passages has a melting
point lower than that of the brazing material which melts from the
other constituting members and penetrates into the flow
passages.
37. The heat exchanger tube according to claim 35, wherein the
brazing material disposed within the flow passages melts earlier
than the brazing material which melts from the other constituting
members and penetrates into the flow passages because the tube has
a thermal resistance which is lower than that of the other
constituting members.
38. The heat exchanger tube according to claim 35, wherein among
plural flow passages divided by the inner fins, an equivalent
diameter of the flow passage, which is positioned at the lowest
position when brazing in the furnace, or individual equivalent
diameters of the flow passages positioned at the lowest position
and flow passages positioned nearby when brazing in the furnace are
larger than a whole average of the equivalent diameters of the
plural flow passages divided by the inner fins.
39. A heat exchanger tube comprising: a tube body portion
constituting an outer shell of flow passages for flowing a medium,
and a flow passage dividing body for dividing the flow passages,
the flow passage dividing body being a tube brazed to the inner
surface of the tube body portion, and the medium performing heat
exchange with heat conducted to the tube, wherein: the tube is a
constituting member of a heat exchanger, and the heat exchanger is
produced by assembling the tube and other constituting members into
one body and brazing the assembled body in a furnace, a brazing
material which is required for brazing the flow passage dividing
body and the inner surface of the tube body portion is disposed
within the flow passages, and the brazing material disposed within
the flow passages melts when brazed in the furnace earlier than the
brazing material which melts from the other constituting members
and penetrates into the flow passages to prevent the flow passages
from being clogged.
40. The heat exchanger tube according to claim 39, wherein the flow
passage dividing body is corrugated inner fins, and the tops of the
inner fins are brazed to the inner surface of the tube body
portion.
41. The heat exchanger tube according to claim 39, wherein the flow
passage dividing body is beads obtained by shaping a material
constituting the tube body portion, and the tops of the beads are
brazed to the inner surface of the tube body portion.
42. The heat exchanger tube according to claim 39, wherein the
brazing material disposed within the flow passages has a melting
point lower than that of the brazing material which melts from the
other constituting members and penetrates into the flow
passages.
43. The heat exchanger tube according to claim 39, wherein the
brazing material disposed within the flow passages melts earlier
than the brazing material which melts from the other constituting
members and penetrates into the flow passages because the tube has
a thermal resistance which is lower than that of the other
component members.
44. The heat exchanger tube according to claim 39, wherein the flow
passages divided by the flow passage dividing body have an
equivalent diameter of 0.559 mm or less.
45. The heat exchanger tube according to claim 44, wherein the flow
passages divided by the flow passage dividing body have an
equivalent diameter of 0.254 mm to 0.559 mm.
46. The heat exchanger tube according to claim 39, wherein among
plural flow passages divided by the flow passage dividing body, an
equivalent diameter of the flow passages, which are positioned at
the lowest position when brazing in the furnace, or individual
equivalent diameters of the flow passages positioned at the lowest
position and flow passages positioned nearby when brazing in the
furnace are larger than a whole average of the equivalent diameters
of the plural flow passages divided by the inner fins.
Description
TECHNICAL FIELD
[0001] The present invention relates to heat exchanger tubes in
which a medium flowing through their passages conducts heat
exchange with heat conducted to the tubes.
BACKGROUND ART
[0002] A heat exchanger such as a radiator, an evaporator or the
like used for a refrigerating cycle is known that it is configured
by alternately stacking flat heat exchanger tubes and corrugated
radiating fins to form a core and connecting ends of the tubes to
tanks. A refrigerant is taken into the heat exchanger from one of
the tanks, flowed through the heat exchanger tubes while performing
heat exchange with heat conducted to the core, and discharged out
of the other of the tanks. Such a heat exchanger is produced by
assembling the component members such as heat exchanger tubes,
fins, tanks and the like into one body and brazing the assembled
body in a furnace.
[0003] The heat exchanger tubes of the heat exchanger of the above
type are also disclosed in the following Patent Documents 1 through
33. The heat exchanger tubes have the corrugated inner fins
disposed within the tube body portion which configures the outer
shell of the flow passages where the medium flows, so that the heat
exchange efficiency of the medium can be improved. And, it is
possible to improve the compression strength of the tubes by
brazing the inner fins to the inner surface of the tube body
portion. [0004] Patent Document 1: Japanese Patent Laid-Open
Publication No. Sho 60-114698 [0005] Patent Document 2: Japanese
Utility Model Laid-Open Publication No. Sho 61 8783 [0006] Patent
Document 3: Japanese Patent Laid-Open Publication No. Sho 61-66091
[0007] Patent Document 4: Japanese Utility Model Laid-Open
Publication No. Sho 62-8576 [0008] Patent Document 5: Japanese
Utility Model Laid-Open Publication No. Sho 62 142440 [0009] Patent
Document 6: Japanese Utility Model Laid-Open Publication No. Sho 63
134273 [0010] Patent Document 7: Japanese Utility Model Laid-Open
Publication No. Sho 63 150721 [0011] Patent Document 8: Japanese
Utility Model Laid-Open Publication No. Sho 63 159667 [0012] Patent
Document 9: Japanese Utility Model Laid-Open Publication No. Sho
63-179472 [0013] Patent Document 10: Japanese Utility Model
Laid-Open Publication No. Hei 1-8071 [0014] Patent Document 11:
Japanese Patent Laid-Open Publication No. 4-198692 [0015] Patent
Document 12: Japanese Patent Laid-Open Publication No. Hei 5-1893
[0016] Patent Document 13: Japanese Patent Laid-Open Publication
No. Hei 5-113297 [0017] Patent Document 14: Japanese Patent
Laid-Open Publication No. Hei 5 169246 [0018] Patent Document 15:
Japanese Patent Laid-Open Publication No. Hei 6-74607 [0019] Patent
Document i6: Japanese Patent Laid-Open Publication No. Hei 6-129734
[0020] Patent Document 17: Japanese Patent Laid-Open Publication
No. Hei 7-32133 [0021] Patent Document 18: Japanese Patent
Laid-Open Publication No. Hei 7-265985 [0022] Patent Document 19:
Japanese Patent Laid-Open Publication No. Hei 8 170888 [0023]
Patent Document 20: Japanese Patent Laid-Open Publication No. Hei 8
271167 [0024] Patent Document 21: Japanese Patent Laid-Open
Publication No. Hei 9 206980 [0025] Patent Document 22: Japanese
Patent Laid-Open Publication No. Hei 10 197180 [0026] Patent
Document 23: Japanese Patent Laid-Open Publication No. Hei
10-300382 [0027] Patent Document 24: Japanese Patent Laid-Open
Publication No. Hei 11 101586 [0028] Patent Document 25: Japanese
Patent Laid-Open Publication No. Hei 11-248383 [0029] Patent
Document 26: Japanese Patent Laid-Open Publication No. Hei
11-257886 [0030] Patent Document 27: Japanese Patent Laid-Open
Publication No. Hei 11 264675 [0031] Patent Document 28: Japanese
Patent Laid-Open Publication No. 2000-97589 [0032] Patent Document
29: Japanese Patent Laid-Open Publication No. 2000 105089 [0033]
Patent Document 30: Japanese Patent Laid-Open Publication No.
2001-38439 [0034] Patent Document 31: Japanese Patent Laid-Open
Publication No. 2001 107082 [0035] Patent Document 32: Japanese
Patent Laid-Open Publication No. 2001 221588 [0036] Patent Document
33: Japanese Patent Laid-Open Publication No. 2002-350083
[0037] In recent years, the heat exchanger tubes tend to be made
compact and precise in order to improve the performance of the heat
exchanger. To improve the performance and the productivity, setting
of sizes of individual components, arrangement of a brazing
material and the like are becoming more and more significant
conditions.
[0038] The present invention has been made in view of the above
circumstances and an object of the invention is to provide heat
exchanger tubes which are configured more reasonably based on the
current production technology.
DISCLOSURE OF THE INVENTION
[0039] The invention recited in claim 1 of the present application
is a heat exchanger tube comprising: a tube body portion
constituting an outer shell of flow passages for flowing a medium,
and corrugated inner fins for dividing the flow passages, wherein
tops of the inner fins are flat tubes brazed to the inner surface
of the tube body portion and in which the medium performs heat
exchange with heat conducted to the tubes, wherein a brazing
material which is required for brazing the tops of the inner fins
and the inner surface of the tube body portion is not clad to a
first material constituting the tube body portion but clad to a
second material constituting the inner fins.
[0040] The invention recited in claim 2 of the present application
is the heat exchanger tube according to claim 1, wherein a
thickness of a clad layer of the brazing material in the second
material is 5 to 10% in ratio with respect to the thickness of the
second material.
[0041] The invention recited in claim 3 of the present application
is the heat exchanger tube according to claim 1 or 2, wherein the
second material has a thickness of 0.1 mm or less.
[0042] The invention recited in claim 4 of the present application
is the heat exchanger tube according to claim 3, wherein the second
material has a thickness of 0.05 to 0.07 mm.
[0043] The invention recited in claim 5 of the present application
is the heat exchanger tube according to any one of claims 1 through
4, wherein the first material has a thickness of 0.25 mm or
less.
[0044] The invention recited in claim 6 of the present application
is the heat exchanger tube according to claim 5, wherein the first
material has a thickness of 0.18 to 0.24 mm.
[0045] The invention recited in claim 7 of the present application
is the heat exchanger tube according to any one of claims 1 through
6, wherein the tube has a thickness of 1.2 mm or less.
[0046] The invention recited in claim 8 of the present application
is the heat exchanger tube according to claim 7, wherein the tube
has a thickness of 0.8 to 1.2 mm.
[0047] The invention recited in claim 9 of the present application
is the heat exchanger tube according to any one of claims 1 through
8, wherein the tube has a width of 16 mm or less.
[0048] The invention recited in claim 10 of the present application
is the heat exchanger tube according to claim 9, wherein the tube
has a width of 12 to 16 mm.
[0049] The invention recited in claim 11 of the present application
is the heat exchanger tube according to any one of claims 1 through
10, wherein the flow passages divided by the inner fins have an
equivalent diameter of 0.559 mm or less.
[0050] The invention recited in claim 12 of the present application
is the heat exchanger tube according to claim 11, wherein the flow
passages divided by the inner fins have an equivalent diameter of
0.254 mm to 0.559 mm.
[0051] The invention recited in claim 13 of the present application
is the heat exchanger tube according to any one of claims 1 through
12, wherein the tops of the inner fins have a pitch of 1.0 mm or
less.
[0052] The invention recited in claim 14 of the present application
is the heat exchanger tube according to any one of claims 1 through
13, wherein an Al--Zn alloy layer is formed on the surface of the
first material which becomes an outer shell of the tube.
[0053] The invention recited in claim 15 of the present application
is the heat exchanger tube according to any one of claims 1 through
14, wherein the tops of the inner fins are flat.
[0054] The invention recited in claim 16 of the present application
is the heat exchanger tube according to any one of claims 1 through
15, wherein ends of the second material in its breadth direction
are brazed with the first material by the brazing material which is
clad to the second material.
[0055] The invention recited in claim 17 of the present application
is the heat exchanger tube according to claim 16, wherein both ends
of the first material in its breadth direction are engaged and
brazed with an end of the second material in its breadth direction
sandwiched at one end of the tube in its breadth direction so as
not to separate from each other.
[0056] The invention recited in claim 18 of the present application
is the heat exchanger tube according to any one of claims 1 through
17, wherein the portion between the tops of the inner fins is not
perpendicular with respect to the central axis of the tube in its
breadth direction.
[0057] The invention recited in claim 19 of the present application
is the heat exchanger tube according to any one of claims 1 through
18, wherein the tube is a constituting member of the heat
exchanger, and the heat exchanger is produced by assembling the
tubes and other constituting members into one body and brazing the
assembled body in a furnace, and the brazing material clad to the
second material melts when brazed in the furnace earlier than the
brazing material which melts from the other constituting members
and penetrates into the flow passages thereby to prevent the flow
passages from being clogged.
[0058] The invention recited in claim 20 of the present application
is the heat exchanger tube according to claim 19, wherein the
brazing material clad to the second material has a melting point
lower than that of the brazing material which melts from the other
constituting members and penetrates into the flow passages.
[0059] The invention recited in claim 21 of the present application
is the heat exchanger tube according to claim 19, wherein the
brazing material clad to the second material melts earlier than the
brazing material which melts from the other constituting members
and penetrates into the flow passages because the tube has a
thermal resistance lower than that of the other constituting
members.
[0060] The invention recited in claim 22 of the present application
is the heat exchanger tube according to any one of claims 19
through 21, wherein among plural flow passages divided by the inner
fins, an equivalent diameter of the flow passage, which is
positioned at the lowest position when brazing in the furnace, or
individual equivalent diameters of the flow passage positioned at
the lowest position and flow passages positioned nearby when
brazing in the furnace are larger than a whole average of the
equivalent diameters of the plural flow passages divided by the
inner fins.
[0061] The invention recited in claim 23 of the present application
is a heat exchanger tube comprising: a tube body portion
constituting an outer shell of flow passages for flowing a medium,
and corrugated inner fins for dividing the flow passages, wherein
the tops of the inner fins are flat tube brazed to the inner
surface of the tube body portion and in which the medium performs
heat exchange with heat conducted to the tube, wherein the tube has
a thickness of 1.2 mm or less, the tube has a width of 16 mm or
less, a first material constituting the tube body portion has a
thickness of 0.25 mm or less, a second material constituting the
inner fins has a thickness of 0.10 mm or less, and the flow
passages divided by the inner fins have an equivalent diameter of
0.559 mm or less.
[0062] The invention recited in claim 24 of the present application
is the heat exchanger tube according to claim 23, wherein the
second material has a thickness of 0.05 to 0.07 mm.
[0063] The invention recited in claim 25 of the present application
is the heat exchanger tube according to claim 23 or 24, wherein the
first material has a thickness of 0.18 to 0.24 mm.
[0064] The invention recited in claim 26 of the present application
is the heat exchanger tube according to any one of claims 23
through 25, wherein the tube has a thickness of 0.8 to 1.2 mm.
[0065] The invention recited in claim 27 of the present application
is the heat exchanger tube according to any one of claims 23
through 26, wherein the tube has a width of 12 to 16 mm.
[0066] The invention recited in claim 28 of the present application
is the heat exchanger tube according to any one of claims 23
through 27, wherein the flow passages divided by the inner fins
have an equivalent diameter of 0.254 mm to 0.559 mm.
[0067] The invention recited in claim 29 of the present application
is the heat exchanger tube according to any one of claims 23
through 28, wherein the tops of the inner fins have a pitch of 1.0
mm or less.
[0068] The invention recited in claim 30 of the present application
is the heat exchanger tube according to any one of claims 23
through 29, wherein an Al-Zn alloy layer is formed on the surface
of the first material which becomes an outer shell of the tube.
[0069] The invention recited in claim 31 of the present application
is the heat exchanger tube according to any one of claims 23
through 30, wherein the tops of the inner fins are flat.
[0070] The invention recited in claim 32 of the present application
is the heat exchanger tube according to any one of claims 23
through 31, wherein ends of the second material in its breadth
direction are brazed to the first material.
[0071] The invention recited in claim 33 of the present application
is the heat exchanger tube according to claim 32, wherein both ends
of the first material in its breadth direction are engaged and
brazed with an end of the second material in its breadth direction
sandwiched at one end of the tube in its breadth direction so as
not to separate from each other.
[0072] The invention recited in claim 34 of the present application
is the heat exchanger tube according to any one of claims 23
through 33, wherein the portion between the tops of the inner fins
is not perpendicular with respect to the central axis of the tube
in its breadth direction.
[0073] The invention recited in claim 35 of the present application
is the heat exchanger tube according to any one of claims 23
through 34, wherein the tube is a constituting member of the heat
exchanger, and the heat exchanger is produced by assembling the
tubes and other constituting members into one body and brazing the
assembled body in a furnace, the brazing material which is required
for brazing the tops of the inner fins and the inner surface of the
tube body portion is disposed within the flow passages, and the
brazing material disposed within the flow passages melts when
brazed in the furnace earlier than the brazing material which melts
from the other constituting members and penetrates into the flow
passages thereby to prevent the flow passages from being
clogged.
[0074] The invention recited in claim 36 of the present application
is the heat exchanger tube according to claim 35, wherein the
brazing material disposed within the flow passages has a melting
point lower than that of the brazing material which melts from the
other constituting members and penetrates into the flow
passages.
[0075] The invention recited in claim 37 of the present application
is the heat exchanger tube according to claim 35, wherein the
brazing material disposed within the flow passages melts earlier
than the brazing material which melts from the other constituting
members and penetrates into the flow passages because the tube has
a thermal resistance which is lower than that of the other
constituting members.
[0076] The invention recited in claim 38 of the present application
is the heat exchanger tube according to any one of claims 35
through 37, wherein among plural flow passages divided by the inner
fins, an equivalent diameter of the flow passage, which is
positioned at the lowest position when brazing in the furnace, or
individual equivalent diameters of the flow passages positioned at
the lowest position and flow passages positioned nearby when
brazing in the furnace are larger than a whole average of the
equivalent diameters of the plural flow passages divided by the
inner fins.
[0077] The invention recited in claim 39 of the present application
is a heat exchanger tube comprising: a tube body portion
constituting an outer shell of flow passages for flowing a medium,
and a flow passage dividing body for dividing the flow passages the
flow passage dividing body being a tube brazed to the inner surface
of the tube body portion, and the medium performing heat exchange
with heat conducted to the tube, wherein the tube is a constituting
member of a heat exchanger, and the heat exchanger is produced by
assembling the tube and other constituting members into one body
and brazing the assembled body in a furnace, a brazing material
which is required for brazing the flow passage dividing body and
the inner surface of the tube body portion is disposed within the
flow passages, and the brazing material disposed within the flow
passages melts when brazed in the furnace earlier than the brazing
material which melts from the other constituting members and
penetrates into the flow passages thereby to prevent the flow
passages from being clogged.
[0078] The invention recited in claim 40 of the present application
is the heat exchanger tube according to claim 39, wherein the flow
passage dividing body is a corrugated inner fins, and the tops of
the inner fins are brazed to the inner surface of the tube body
portion.
[0079] The invention recited in claim 41 of the present application
is the heat exchanger tube according to claim 39, wherein the flow
passage dividing body is beads obtained by shaping a material
constituting the tube body portion, and the tops of the beads are
brazed to the inner surface of the tube body portion.
[0080] The invention recited in claim 42 of the present application
is the heat exchanger tube according to any one of claims 39
through 41, wherein the brazing material disposed within the flow
passages has a melting point lower than that of the brazing
material which melts from the other constituting members and
penetrates into the flow passages.
[0081] The invention recited in claim 43 of the present application
is the heat exchanger tube according to any one of claims 39
through 41, wherein the brazing material disposed within the flow
passages melts earlier than the brazing material which melts from
the other constituting members and penetrates into the flow
passages because the tube has a thermal resistance which is lower
than that of the other constituting members.
[0082] The invention recited in claim 44 of the present application
is the heat exchanger tube according to any one of claims 39
through 43, wherein the flow passages divided by the flow passage
dividing body have an equivalent diameter of 0.559 mm or less.
[0083] The invention recited in claim 45 of the present application
is the heat exchanger tube according to claim 44, wherein the flow
passages divided by the flow passage dividing body have an
equivalent diameter of 0.254 mm to 0.559 mm.
[0084] The invention recited in claim 46 of the present application
is the heat exchanger tube according to any one of claims 39
through 45, wherein among plural flow passages divided by the flow
passage dividing body, an equivalent diameter of the flow passages,
which is positioned at the lowest position when brazing in the
furnace, or individual equivalent diameters of the flow passage
positioned at the lowest position and flow passages positioned near
by when brazing in the furnace are larger than a whole average of
the equivalent diameters of the plural flow passages divided by the
inner fins.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] FIG. 1 is an explanatory diagram showing a heat exchanger
according to an embodiment of the present invention (First
embodiment).
[0086] FIG. 2 is an explanatory diagram and an enlarged view of an
essential portion showing sections of a heat-exchanger tube, before
brazing thereof, according to the embodiment of the present
invention (First embodiment).
[0087] FIG. 3 is an explanatory diagram showing a section of a
second material according to the embodiment of the present
invention (First embodiment).
[0088] FIG. 4 is an enlarged diagram of an essential portion
showing a section of a heat-exchanger tube, before brazing thereof,
according to an embodiment of the present invention (Second
embodiment).
[0089] FIG. 5 is an enlarged diagram of an essential portion
showing a section of a heat-exchanger tube, before brazing thereof,
according to an embodiment of the present invention (Third
embodiment).
[0090] FIG. 6 is an enlarged diagram of an essential portion
showing a section of a heat-exchanger tube, before brazing thereof,
according to the embodiment of the present invention (Third
embodiment).
[0091] FIG. 7 is an enlarged diagram of an essential portion
showing a section of a heat-exchanger tube, before brazing thereof,
according to the embodiment of the present invention (Third
embodiment).
[0092] FIG. 8 is an explanatory diagram showing a section of a
heat-exchanger tube, before brazing thereof, according to an
embodiment of the present invention (Fourth embodiment).
BEST MODE FOR CARRYING OUT THE INVENTION
[0093] A first embodiment of the invention will be described below
with reference to FIG. 1 through FIG. 3.
[0094] A heat exchanger 1 shown in FIG. 1 is a radiator for a
refrigerating cycle for in-car air conditioning mounted on an
automobile. This heat exchanger 1 comprises a core 10 which is
formed by alternately stacking heat exchanger tubes 100 and
radiating fins 20, and a pair of tanks 30 with which both ends of
the individual heat exchanger tubes 100 in their longitudinal
direction are in communicative connection.
[0095] Reinforcing members 40 each is disposed on upper and lower
sides of the core 10, and both ends of the individual reinforcing
members 40 in their longitudinal direction are supported by the
tanks 30.
[0096] An inlet 31 and an outlet 32 for a medium (namely, a
refrigerant which circulates through the refrigerating cycle) are
disposed at the required portions of the tanks 30, so that the
medium which has entered through the inlet 31 flows through the
heat exchanger tubes 100 while performing heat exchange with heat
conducted to the core 10 and flows out through the outlet 32.
[0097] Constituting members of the heat exchanger 1, such as the
fins 20, the tanks 30, the inlet 31, the outlet 32, the side plates
40 and the heat exchanger tubes 100 are formed of an aluminum or
aluminum alloy member. They are assembled into one body by means of
a jig, and the assembled body undergoes a heat treatment in a
furnace to be brazed into one body. To braze in the furnace, a
brazing material and flux are disposed on the required portions of
the individual members.
[0098] The heat exchanger tube 100 of this embodiment shown in FIG.
2 has a tube body portion 200 which forms the outer shell of flow
passages 101 for flowing the medium and corrugated inner fins 300
for dividing the flow passages 101 and the tops of the inner fins
300 are flat and brazed to the inner surface of the tube body
portion 200.
[0099] This heat exchanger tube 100 has a thickness t.sub.tube of
1.2 mm or less. It is desirable that the heat exchanger tube 100
has a thickness t.sub.tube of 0.8 to 1.2 mm. And, the heat
exchanger tube 100 has a width w.sub.tube of 16 mm or less. It is
desirable that the heat exchanger tube 100 has a width w.sub.tube
of 12 to 16 mm. Besides, the individual flow passages 101 divided
by the inner fins 200 each having an equivalent diameter of 0.559
mm or less. It is desirable that the flow passage 101 has an
equivalent diameter of 0.254 mm to 0.559 mm.
[0100] An equation to obtain the equivalent diameter de is
de=4.times.(flow passage sectional area)/(overall length of wet
edge of flow passage cross section). The medium performs heat
exchange with heat conducted to the heat exchanger tubes 100.
[0101] The tube body portion 200 is formed by roll forming a first
material of an aluminum or aluminum alloy strip. Both ends 201 of
the first material in its breadth direction are mutually engaged
and brazed at one end 102 of the heat exchanger tube 100 in its
breadth direction so that they are not separated from each other.
And, the other end 103 of the heat exchanger tube 100 in its
breadth direction is a portion where substantially a center of the
first material is bent.
[0102] The inner fins 300 are formed by roll forming a second
material of an aluminum or aluminum alloy strip. Pitch P between
the tops of the inner fins is 1.0 mm or less. The inner fins 300
are inserted between the first materials in an appropriate stage of
the roll forming of the tube body portion 200 and disposed within
the tube body portion 200.
[0103] In this embodiment, the brazing material, which is required
for brazing the tops 310 of the inner fins 300, which are a flow
passage dividing body to the inner surface of the tube body portion
200, is not clad to the first material which forms the tube body
portion 200 but to the second material which forms the inner fins
300.
[0104] Specifically, in a case where the tops 310 of the inner fins
300 and the inner surface of the tube body portion 200 are brazed,
at least one of the first material and the second material is clad
with the brazing material, and the structure of cladding only the
second material with the brazing material is adopted in this
embodiment. The reason for this is to suppress the use of brazing
material to a minimum required quantity. Its concept will be
described below.
[0105] First, the brazing material containing silicon is
indispensable for brazing but becomes a cause of eroding the core
material after brazing. Therefore, it is desirable that the brazing
material is suppressed to a quantity as small as possible. And, a
material clad with the brazing material is produced by stacking and
rolling the core material and the brazing material at a prescribed
ratio, so that the thickness of the clad layer of the brazing
material has a lower limit with respect to the thickness of the
material. According to the present technology, the lower limit of
the thickness of the clad layer is about 5% with respect to the
thickness of the material.
[0106] Besides, where thickness t.sub.1 of the first material and
thickness t.sub.2 of the second material are compared, the
thickness t.sub.2 of the second material can be made thinner to
some extent in view of the structure of the heat exchanger tube
100. As a result, only the second material is desirably clad with
the brazing material to determine the brazing material to a small
quantity.
[0107] Meanwhile, the ends 201 of the first material are brazed
with the brazing material, which penetrates from the tanks 30 by
capillary action, by brazing in the furnace described above.
According to this configuration, the quantity of the brazing
material to be used can be reduced, and the depth of a silicon
diffusion layer of the first material can be decreased, so that the
thickness of the first material can be made thinner.
[0108] For improvement of support strength of the inner fins 300 to
the tube body portion 200 and durability of the inner fins 300, the
ends 301 of the second material in its breadth direction are brazed
to the first material with the brazing material which is clad to
the second material. Brazing of the ends 301 of the second material
to the first material prevents the ends 301 of the second material
from being fluctuated by the flowing medium, and the durability of
the heat exchanger tubes 100 and the stability of the medium flow
can be improved surely.
[0109] The thickness t.sub.1 of the first material is 0.25 mm or
less. It is desirable that the thickness t.sub.1 of the first
material is 0.18 to 0.24 mm. And, an Al--Zn alloy layer is disposed
as a sacrifice layer for improving corrosion resistance of the heat
exchanger tubes 100 on the surface of the first material which
becomes the outer shell of the heat exchanger tube 100.
[0110] Meanwhile, the second material is formed by disposing a clad
layer 300b of the brazing material on both surfaces of a core
material 300a as shown in FIG. 3, and its thickness t.sub.2 is 0.1
mm or less. It is desirable that the thickness t.sub.2 of the
second material is 0.05 to 0.07 mm. And, the thickness of the clad
layer 300b of the brazing material in the second material is 5 to
10% in ratio with respect to the thickness t.sub.2 of the second
material.
[0111] In this embodiment, the tops 310 of the inner fins 300 are
flat, so that sufficient brazing areas are secured between the tops
310 of the inner fins 300 and the inner surface of the tube body
portion 200.
[0112] In other words, brazing strength and reliability of brazing
are improved surely by configuring as described above. And,
friction between the tube body portion 200 and the inner fins 300
is increased because the tops 310 of the inner fins 300 are flat.
Thus, there is also an advantage that when the heat exchanger tube
100 is cut to a prescribed length before brazing, displacement of
the inner fins 300 can be prevented. Width W.sub.flat of the flat
portions of the tops 310 is 2.5 to 0.5 when the thickness t.sub.2
of the material is 1.
[0113] Besides, a portion between the tops 310 and 310 of the inner
fins 300 becomes non-perpendicular to a central axis L of the heat
exchanger tube 100 in its breadth direction. Specifically, an
intersection angle .theta. between the portion between the tops 310
and 310 of the inner fins 300 and the central axis L in the breadth
direction is 65 to 85.degree.. In a case where the intersection
angle .theta. is perpendicular and the heat exchanger tubes 100 is
cut to a prescribed length before brazing, the inner fins 300 are
largely deformed when a cutting blade is moved in parallel to the
central axis L in the breadth direction. But, such a disadvantage
is avoided in this embodiment by setting the intersection angle
.theta. to a favorable value.
[0114] In this embodiment, where the brazing is effected in the
furnace, the brazing material which is clad to the second material
melts earlier than the brazing material, which melts from the other
constituting members such as the tanks 30 constituting the heat
exchanger 1 and penetrates into the flow passages 101, thereby to
prevent the flow passages 101 from being clogged. If the interior
of the heat exchanger tube 100 is dry when the brazing material
penetrates into the flow passages 101 from outside, the penetrated
brazing material stays locally within the flow passages 101 because
of an influence of its surface tension and the like, and the flow
passages 101 are clogged. The brazing material which is clad to the
second material has a melting point lower than that of the brazing
material which melts from the surfaces of the tanks 30 and
penetrates into the flow passages 101. Otherwise, the brazing
material which is clad to the second material melts earlier than
the brazing material which melts from the surface of the tanks 30
and penetrates into the flow passages 101 because a thermal
resistance of the heat exchanger tubes 100 is smaller than that of
the tanks 30.
[0115] Besides, to prevent the flow passages 101 from being
clogged, among the plural flow passages 101 divided by the inner
fins 300, the equivalent diameter of the flow passage 101, which is
positioned at the lowest position when brazing in the furnace, or
the individual equivalent diameters of the flow passage 101 which
is positioned at the lowest position and the flow passages 101
which are positioned nearby when brazing in the furnace are
desirably determined to be larger than a whole average of the
equivalent diameters of the plural flow passages 101 which are
divided by the inner fins 300.
[0116] It is because the melted brazing material tends to move in a
direction of gravitational force, so that the flow passage 101
which is positioned at the lowest position when brazing in the
furnace and the flow passages 101 which are positioned nearby tend
to have a large amount of the penetrated brazing material in
comparison with the other flow passages 101.
[0117] In this embodiment, the heat exchanger 1 is brazed in the
furnace with the core 10 laid on its side, so that the equivalent
diameter of the flow passage 101 which is positioned at one end 102
of the heat exchanger tube 100 in its breadth direction is
determined larger, and if necessary, the equivalent diameter of the
flow passage 101 positioned near the pertinent flow passage 101 is
also determined to be large. Otherwise, the equivalent diameter of
the flow passage 101 which is positioned at the other end 103 of
the heat exchanger tube 100 in its breadth direction is determined
to be large, and if necessary, the equivalent diameter of the flow
passage 101 which is positioned near the pertinent flow passage 101
is also determined to be large.
[0118] Where the equivalent diameter of the flow passage 101 which
is positioned near the flow passage 101 which is positioned at one
end 102 or the other end 103 is determined to be large, a pitch P
of the tops at the required portions of the inner fins 300 is
determined to be larger than a pitch P of the tops at the other
portion.
[0119] Besides, when the equivalent diameter of the flow passage
101 at the one end 102 and the equivalent diameter of the flow
passage 101 at the other end 103 are determined to be large, either
end may be positioned on the lower side, so that it is also
possible to secure generality in terms of brazing posture.
[0120] As described above, the heat exchanger tube 100 of this
embodiment is configured very rationally and can be used favorably
as a component part of the heat exchanger 1. Setting of the values
of the individual portions of the heat exchanger tubes 100 was
obtained by studying the performance of the heat exchanger tubes
100 based on the current manufacturing technology.
[0121] It should be noted that the structure of this embodiment can
be changed in its design appropriately without departing from the
technical scope recited in the appended claims and is not limited
to the illustrated one.
[0122] Then, a second embodiment of the invention will be described
with reference to FIG. 4.
[0123] As shown in FIG. 4, the heat exchanger tube 100 of this
embodiment has both ends 201 of the first material in its breadth
direction mutually engaged and brazed at one end 102 of the heat
exchanger tube 100 in its breadth direction so that they are not
separated from each other. And, the other end 301 of the second
material is brazed with the end 201 of the first material. The
other basic structure is same with that of the above-described
embodiment.
[0124] Thus, the end 301 of the second material may be brazed to
the end 201 of the first material.
[0125] A third embodiment of the present invention will be
described with reference to FIG. 5 through FIG. 7.
[0126] As shown in FIG. 5, the heat exchanger tube 100 of this
embodiment has both ends 201 of the first material in its breadth
direction mutually engaged and brazed at one end 102 of the heat
exchanger tube 100 in its breadth direction with the end 301 of the
second material in its breadth direction sandwiched so that they
are not separated from each other.
[0127] The end 201 of the first material and the end 301 of the
second material are brazed with the brazing material which is clad
to the second material and the brazing material which penetrates
from the tanks 30.
[0128] A shape of the end 201 of the first material and a shape of
the end 301 of the second material can be determined appropriately
as shown in, for example, FIG. 6 and FIG. 7, and are not limited to
a particular shape. The other basic structure is same with that of
the above-described embodiment.
[0129] Thus, the end 301 of the second material may be configured
to sandwich the end 201 of the first material. According to this
embodiment, the ends 201 of the first material can be mutually
brazed with the brazing material which is clad to the second
material. In a case where the ends 201 of the first material in its
breadth direction are mutually brazed with only the brazing
material which penetrates from the tanks 30, there is a case that
the brazing material does not spread sufficiently if the heat
exchanger tube 100 is relatively long, and defective brazing may be
caused. In this connection, such a defect can be avoided by this
embodiment, and the brazing of the ends 201 of the first material
in its breadth direction can be improved surely in its
reliability.
[0130] And, the end 301 of the second material in its breadth
direction is sandwiched between both ends 201 of the first material
in its breadth direction, so that the inner fins 300 can be
positioned accurately within the heat exchanger tube 100.
Especially, the size of the flow passage 101 at one end 102 and the
other end 103 of the heat exchanger tube 100 can also be controlled
accurately. And, a decrease in resistance to pressure due to
displacement of the inner fins 300 can also be prevented.
[0131] Then, a fourth embodiment of the present invention will be
described with reference to FIG. 8.
[0132] As shown in FIG. 8, in the heat exchanger tube 100 of this
embodiment, beads 202 which are formed by shaping the required
portions of the first material are disposed as a flow passage
dividing body for dividing the flow passages 101. The tops of the
beads 202 are brazed to the inner surface of tube body portion
200.
[0133] The brazing material which is required for brazing the tube
body portion 200 with the tops of the beads 202, and the brazing
material which is required for brazing the both ends 201 of the
first material, are clad to one surface of the first material which
becomes the inside of the flow passages. When brazing in the
furnace, the brazing material which is clad to the first material
melts earlier than the brazing material which penetrates from
outside into the flow passages 101, so that the flow passages 101
are prevented from being clogged. And the other basic structure is
same with that of the above-described embodiment.
[0134] Thus, the beads can also be disposed as the flow passage
dividing body. In such a case, the brazing material is clad to the
first material, and to braze in the furnace, it is configured so
that the brazing material melts earlier than the brazing material,
which melts from the other constituting members constituting the
heat exchanger, and penetrates into the flow passages 101.
INDUSTRIAL APPLICABILITY
[0135] The heat exchanger tubes of the present invention can be
used as constituting members of, for example, a vehicle-mounted
heat exchanger.
* * * * *