U.S. patent application number 10/466171 was filed with the patent office on 2004-03-18 for heat exchanger.
Invention is credited to Akaike, Jun, Akiyama, Shoji, Kato, Soichi.
Application Number | 20040050540 10/466171 |
Document ID | / |
Family ID | 27345724 |
Filed Date | 2004-03-18 |
United States Patent
Application |
20040050540 |
Kind Code |
A1 |
Kato, Soichi ; et
al. |
March 18, 2004 |
Heat exchanger
Abstract
A heat exchanger having tubes 21 for flowing a medium and tanks
3 each formed of an end plate 32 having tube insertion holes 5 for
connection of the tubes and a tank plate 31 connected to the end
plate, which are assembled and brazed in a heating furnace, wherein
the tank plate 31 is formed of a plate provided with brazing
materials R1, R2, and at least one of the tank plate 31 and the end
plate 32 is provided with separator portions 311, 321 not provided
with the brazing material for prevention of the brazing material
from outflowing. The tank 3 has partition plates 7 for dividing the
interior, the inner surface of at least one of the tank plate 31
and the end plate 32 is clad with the brazing material, and the
partition plates 7 are formed of a bare material not clad with a
brazing material. And, the end plate 32 has the brazing material
clad on its one surface only, and the ends of the fins 4 and the
surface of the end plate 32 not clad with the brazing material are
opposed to each other at the time of brazing.
Inventors: |
Kato, Soichi; (Saitama,
JP) ; Akiyama, Shoji; (Saitama, JP) ; Akaike,
Jun; (Saitama, JP) |
Correspondence
Address: |
Satoru Takeuchi
Kanesaka & Takeuchi
1423 Powhatan Street
Alexandria
VA
22314
US
|
Family ID: |
27345724 |
Appl. No.: |
10/466171 |
Filed: |
July 14, 2003 |
PCT Filed: |
January 15, 2002 |
PCT NO: |
PCT/JP02/00196 |
Current U.S.
Class: |
165/153 |
Current CPC
Class: |
F28D 1/0391 20130101;
F28F 9/0212 20130101; F28F 9/0224 20130101 |
Class at
Publication: |
165/153 |
International
Class: |
F28D 001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 2001 |
JP |
2001-007442 |
Jan 16, 2001 |
JP |
2001-008162 |
Feb 21, 2001 |
JP |
2001-045071 |
Claims
1. A heat exchanger which has tubes for flowing a medium and a tank
comprising an end plate having tube insertion holes for connecting
the tubes and a tank plate connected to the end plate, and is
formed by assembling the respective members and brazing the members
for connection in a heating furnace; wherein: the tank plate is
formed of a plate provided with a brazing material, and at least
one of the tank plate and the end plate is provided with a
separator portion not having a brazing material for prevention of
the brazing material from outflowing.
2. The heat exchanger according to claim 1, wherein the separator
portion is disposed on a surface of the end plate which is in
contact with the tank plate.
3. The heat exchanger according to claim 2, wherein: the tank plate
has the brazing material disposed on its surface which becomes at
least the inner surface of the tank, and the end plate has the
brazing material disposed on its surface which becomes the inner
surface of the tank.
4. The heat exchanger according to any one of claims 1 to 3,
wherein the tank plate is provided with the separator portion on
its surface which is in contact with the end plate.
5. The heat exchanger according to any one of claims 1 to 4,
wherein: the tank is provided with a partition plate within it, and
the tank is formed by assembling the tank plate and the end plate
while positioning by the partition plate.
6. The heat exchanger according to any one of claims 1 to 5,
wherein the heat exchanger uses tubes which are formed of a
plate.
7. The heat exchanger according to any one of claims 1 to 6,
wherein the tubes have slits on the outer surfaces of the tubes
which are in contact with tube insertion holes of the end
plate.
8. A heat exchanger having tubes for flowing a medium and tanks to
which ends of the tubes are connected, wherein: the tanks are
formed by brazing an end plate which is provided with holes for
connection of the ends of the tubes, a tank plate connected to the
end plate, and a partition plate for dividing the interior, and a
brazing material is clad to the inner surface of at least one of
the tank plate and the end plate, and the partition plate is formed
of a bare material which is not clad with a brazing material.
9. The heat exchanger according to claim 8, wherein the tubes have
slits formed on the surfaces.
10. The heat exchanger according to claim 9, wherein the tubes are
formed of a plate material.
11. A heat exchanger having a core which is formed by stacking
tubes and fins, and tanks to which the ends of the tubes are
connected, and performing heat exchange by a medium flowing through
the tubes by heat conducted to the core, wherein: the tanks have an
end plate which is provided with holes for connection of the tubes
and a tank plate to which the end plate is attached, the heat
exchanger is formed by assembling and brazing the tubes, the fins,
the end plate and the tank plate in a furnace, the end plate has a
brazing material clad on its one surface only, and the ends of the
fins are opposed to a surface of the end plate not clad with the
brazing material at the time of brazing.
12. The heat exchanger according to claim 11, wherein the ends of
the fins have a minimum distance of 2.0 mm or less from the surface
of the end plate which is not clad with the brazing material.
13. The heat exchanger according to claim 11, wherein the ends of
the fins are in contact with the surface of the end plate which is
not clad with the brazing material.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat exchanger used for a
heat-exchange cycle which is mounted on vehicles and the like.
BACKGROUND ART
[0002] It is generally known that a heat exchanger configuring a
heat-exchange cycle mounted on vehicles or the like is, for
example, a radiator, a condenser, an evaporator or the like.
[0003] For example, the condenser has a plurality of flat tubes and
a plurality of fins alternately stacked, the ends of the tubes
inserted in the tube insertion holes of tanks, and integrally
bonded by a brazing material which is clad to the tanks and tubes
in a heating furnace. The condenser performs heat exchange of the
medium flowing through the tanks and tubes with the open air.
Partition plates are disposed within the tanks to change a flowing
direction of the medium. The tanks may be provided with a brazing
material on the outer surfaces of the tanks to connect accessories
such as a connector or the like.
[0004] The heat exchanger used for the heat-exchange cycle for
vehicles is desired to be light-weighted. Therefore, respective
members configuring the heat exchanger are considered to be made of
a material having a thickness as thin as possible with safety taken
into consideration. Generally, the brazing material contains
silicon (Si) and, when the brazing material melts in a heating
furnace, it forms an Al--Si eutectic liquid phase with aluminum
(Al) or an aluminum alloy, which is a material forming the tubes
and the tanks, to braze the respective members.
[0005] The Al--Si eutectic liquid phase has a liquidus temperature
lower than that of the aluminum or aluminum alloy configuring the
tubes and the like. Therefore, when an excessive amount of brazing
material flows to the tubes having a thickness thinner than that of
the tanks in the heating furnace, the Al of the tube surface reacts
with the excessive amount of brazing material to form a large
amount of Al--Si eutectic liquid phase. This may result in a
disadvantage in that a hole is formed in the tubes, erosion is
caused or the like. The erosion is a phenomenon in which the melted
brazing material erodes a base metal.
[0006] Accordingly, the present invention provides a heat exchanger
with high safety which prevents an excessive amount of brazing
material from flowing to the tubes and has an appropriate amount of
brazing material used to braze the respective members.
[0007] The heat exchanger used for a condenser or the like of a car
air conditioner has its core configured by alternately stacking a
plurality of tubes and fins and a pair of tanks connected for
communication with both ends of the stacked tubes. A block member
is attached to the top and bottom ends of both tanks, an inlet
joint for introduction of a medium is attached to an appropriate
portion of one of the tanks, and an outlet joint for discharging
the medium is attached to an appropriate portion of the other
tank.
[0008] Partition plates for dividing the tank interiors are
disposed at required positions in the tanks so that the medium
flows to meander between the inlet joint and the outlet joint.
[0009] The above-described tanks each generally has a substantially
cylindrical shape and is formed to have a single body or a
two-split type body which is formed by assembling members having a
substantially semicircular cross section. Between the members
forming the two-split type tank, one having holes for connection of
the ends of the tubes is called the end plate and the other is
called the tank plate. This two-split type tank has advantages in
that the holes for connection of the ends of the tubes are readily
formed and the partition plates are easily attached.
[0010] It was necessary to accurately fit the dimensions of the
partition plates to the inside surface of the tank so not to have
any gap between the inside wall of the tank and the partition
plates because such a gap allows the medium partly bypass through
the gap and degrades the performance.
[0011] But, the two-split type tank often has a complex sectional
shape at the junction of the end plate and the tank plate, and it
was hard to match the dimensions of the partition plates.
[0012] Under the circumstances described above, an object of the
present invention is to provide a heat exchanger having two-split
type tanks and high airtightness which is free from leakage of a
medium between the inside surface of the tank and the partition
plates without strictly controlling the dimensions of the partition
plates.
[0013] As described above, the heat exchanger such as a radiator or
an evaporator of the refrigeration cycle is configured by
alternately stacking a plurality of tubes and a plurality of fins
to form a core and connecting the ends of the tubes to the
tanks.
[0014] The medium is taken into the inside through the inlet joint
formed on the tank, passed through the tubes while conducting heat
exchange by the heat conducted to the core and discharged to the
outside through the outlet joint formed on the tank. A fan may be
disposed on the outside of the heat exchanger to send air to the
core.
[0015] Besides, this type of heat exchanger is produced by
assembling respective aluminum or aluminum alloy members and
heating the assembly in a furnace to be brazed into one body.
[0016] In view of the heat-exchanging performance of such a heat
exchanger, a gap between the fins and the tank is desired to be as
small as possible. Because, if the gap between the fins and the
tank is large, air leaks through the gap, and the heat-exchanging
performance drops.
[0017] But, there is a problem that, when the fins and the end
plates are approached to one another, the brazing material melted
from the tank at the time of brazing reaches the ends of the fins,
and the ends of the fins are melted by erosion.
[0018] In other words, the fins are thin and their ends have a
disadvantage of easily causing unnecessary erosion because of an
effect of the brazing material.
[0019] The present invention was achieved under the circumstances
as described above, and it is to provide a heat exchanger which
effectively avoids the ends of fins from being eroded by a brazing
material.
DISCLOSURE OF THE INVENTION
[0020] The invention described in claim 1 is a heat exchanger which
has tubes for flowing a medium and a tank comprising an end plate
having tube insertion holes for connecting the tubes and a tank
plate connected to the end plate and formed by assembling the
respective members and brazing the members for connection in a
heating furnace; wherein the tank plate is formed of a plate
provided with a brazing material, and at least one of the tank
plate and the end plate is provided with a separator portion not
having a brazing material for prevention of a brazing material from
outflowing.
[0021] Thus, the heat exchanger is formed of two members of the
tank plate and the end plate, and at least one of the end plate and
the tank plate is provided with the separator portion for
prevention of the brazing material from outflowing, so that the
molten brazing material is prevented from moving by the separator
portion within the heating furnace.
[0022] Generally, the molten brazing material flows along the
brazing material disposed on the members in the heating furnace and
guided into the gaps formed when the members are assembled. An
excessive amount of molten brazing material is especially
accumulated in the gaps between the tubes and the tube insertion
holes to form a large amount of Al--Si eutectic liquid phase, and
erosion tends to occur on the tubes in contact with the tube
insertion holes.
[0023] According to the invention, the separator portion which is
not provided with the brazing material and prevents the brazing
material from outflowing is disposed on at least one of the tank
plate and the end plate, so that the separator portion prevents the
brazing material from flowing, and an excessive amount of brazing
material is prevented from flowing to the tubes. Therefore, erosion
of the tubes configuring the heat exchanger can be prevented, and a
highly safe heat exchanger can be provided.
[0024] For example, even if the molten brazing material flows over
the separator portion in the heating furnace, a flowing amount of
the molten material to the tubes can be reduced by the separator
portion, and the flow of the excessive amount of brazing material
to the tubes can be prevented.
[0025] The invention described in claim 2 relates to the invention
according to claim 1, wherein the separator portion is disposed on
a surface of the end plate which is in contact with the tank
plate.
[0026] For example, when the tank plate is formed to have a
substantially U-shaped cross section and the outer surface of the
end plate is contacted with the inside of the U-shaped opening to
configure the tubular tank, the edges of the end plate is contacted
with the tank plate. The separator portion not having the brazing
material is disposed on one surface of the edges of the end plate
contacted with the tank plate. In the heating furnace, the
separator portion prevents the brazing material disposed on the
tank plate from flowing. Therefore, an excessive amount of brazing
material does not flow to the tubes, and the tubes can be brazed
for connection into the tube insertion holes of the end plate with
an appropriate amount of brazing material.
[0027] The invention described in claim 3 relates to the invention
according to claim 2, wherein the tank plate has the brazing
material disposed on its surface which becomes at least the inner
surface of the tank, and the end plate has the brazing material
disposed on its surface which becomes the inner surface of the
tank.
[0028] Thus, even when the brazing material is disposed on the
surface of the tank plate which becomes the inside of the tank and
the surface of the end plate which becomes the inside of the tank,
the separator portion prevents the brazing material disposed on the
tank plate from flowing and prevents an excessive amount of brazing
material from flowing to the tubes in the heating furnace.
[0029] The invention described in claim 4 relates to the invention
according to any one of claims 1 to 3, wherein the tank plate is
provided with the separator portion on its surface which is in
contact with the end plate.
[0030] For example, even when the brazing material is disposed on
the surface of the tank plate which becomes the outside of the
tank, the separator portion prevents the brazing material disposed
on the tank plate from flowing and prevents an excessive amount of
brazing material from flowing to the tubes.
[0031] The invention described in claim 5 relates to the invention
according to any one of claims 1 to 4, wherein the tank is provided
with a partition plate within it, and the tank is formed by
assembling the tank plate and the end plate while positioning by
the partition plate.
[0032] Thus, the tank formed of two members, the tank plate and the
end plate, has the tank plate and the end plate positioned by the
partition plate disposed within the tank, so that the tank plate
and the end plate can be prevented from displacing.
[0033] The invention described in claim 6 relates to the invention
according to any one of claims 1 to 5, wherein the heat exchanger
uses tubes which are formed of a plate.
[0034] When the tubes are formed of a plate, the tubes which can
secure the required pressure resistance can be formed even if the
plate is thin. Thus, when the tubes formed of a thin plate is used,
the heat exchanger can be light-weighted.
[0035] And, even when the thin tubes are used, the separator
portion prevents the brazing material from flowing, so that an
excessive amount of brazing material does not outflow to the tubes.
Therefore, erosion resulting from the outflowing of an excessive
amount of brazing material to the tubes can be prevented from
occurring, and a highly safe heat exchanger can be provided.
[0036] The invention described in claim 7 relates to the invention
according to any one of claims 1 to 6, wherein the tubes have slits
on the outer surfaces of the tubes which are in contact with tube
insertion holes of the end plate.
[0037] As described above, when the tubes have the slits, the
molten brazing material in the heating furnace is introduced into
the slits. In other words, the brazing material flows through the
gaps between the tube insertion holes and the tubes and is drawn
into the slits. Therefore, the tubes and the end plate are joined
with an appropriate amount of brazing material, and defective
brazing can be avoided.
[0038] The invention described in claim 8 relates to a heat
exchanger having tubes for flowing a medium and tanks to which ends
of the tubes are connected, wherein the tanks are formed by brazing
an end plate which is formed with holes for connection of the ends
of the tubes, a tank plate connected to the end plate, and a
partition plate for dividing the interior, and a brazing material
is clad to the inner surface of at least one of the tank plate and
the end plate, and the partition plate is formed of a bare material
which is not clad with a brazing material.
[0039] Conventionally, when the partition plate clad with the
brazing material was used, the molten brazing material on the inner
surface of the tank became integral with the molten brazing
material of the partition plate at the time of brazing, attracted
by gravitation or capillary phenomenon and outflown to another
portion along the partition plate. Therefore, the brazing material
for brazing the partition plate became short in amount, and the
partition plat was apt to be brazed defectively.
[0040] According to the present invention, since the partition
plate is a bare material which is not clad with the brazing
material, the molten brazing material on the inner surface of the
tank when brazing hardly outflows along the unwet partition plate.
As a result, the brazing material for brazing the partition plate
does not become short, and the partition plates can be brazed
adequately even if there are some gaps between the inner surface of
the tank and the partition plate.
[0041] Therefore, the medium does not leak between the inner
surface of the tank and the partition plate even if the dimensions
of the partition plate are not controlled strictly as before, and a
highly airtight heat exchanger can be provided.
[0042] The invention described in claim 9 relates to the invention
according to claim 8, wherein the tubes have slits formed on the
surfaces.
[0043] The present invention is particularly effective for a heat
exchanger having tubes which have slits in the surface.
[0044] When the tubes have the slits in the surface, the brazing
material melted on the inner surface of the tank at the time of
brazing is drawn into the slits by capillarity phenomenon and
outflown to the tubes. Therefore, the brazing material for brazing
the partition plate became short, and the partition plate was apt
to be brazed defectively.
[0045] According to the invention, even if the brazing material on
the inner surface of the tank outflows to the tubes, the brazing
material does not outflow along the partition plates as before, so
that an outflow amount is substantially reduced, the brazing
material for brazing the partition plate does not become short, and
the partition plate can be brazed adequately.
[0046] The invention described in claim 10 relates to the invention
according to claim 9, wherein the tubes are formed of a plate
material.
[0047] The present invention is particularly effective for a heat
exchanger having the tubes which are formed of a plate
material.
[0048] So-called roll forming tubes which are formed of a plate
material have partitions in their interiors formed by bending a
plate material to have a corrugated shape, and slits are formed in
the surface. Therefore, the brazing material melted on the inner
surface of the tank at the time of brazing is drawn into the slits
by capillary phenomenon and outflows to the tubes. Therefore, the
brazing material for brazing the partition plate became short, and
the partition plate was brazed defectively.
[0049] According to the present invention, even when the brazing
material on the inner surface of the tank outflows to the tubes,
the brazing material does not flow along the partition plate as
before, so that an outflowing amount is substantially reduced.
Thus, the brazing material for brazing the partition plates does
not become short, and the partition plate can be brazed
adequately.
[0050] The invention described in claim 11 is a heat exchanger
having a core which is formed by stacking tubes and fins and tanks
to which the ends of the tubes are connected, and performing heat
exchange by a medium flowing through the tubes by heat conducted to
the core, wherein the tanks have an end plate which is formed with
holes for connection of the tubes and a tank plate to which the end
plate is attached, the heat exchanger is formed by assembling and
brazing the tubes, the fins, the end plate and the tank plate in a
furnace, the end plate has a brazing material clad on its one
surface only, and the ends of the fins are opposed to a surface of
the end plate not clad with the brazing material at the time of
brazing.
[0051] By configuring as described above, erosion of the ends of
the fins by the brazing material can be avoided efficiently.
[0052] In other words, the ends of the fins have a disadvantage
that unnecessary erosion is apt to be caused by an influence of the
brazing material. But, according to the present invention, the
brazing material melted from the tank can be prevented from being
brought to the ends of the fins, and such a disadvantage can be
avoided.
[0053] Besides, it is desirable that the fins and the tanks are
mutually approached as close as possible in view of the
heat-exchange performance of the core. Especially, when air is sent
to the core, air leaks through the gap between the fins and the
tanks if it is large. In this connection, the present invention has
no possibility of causing erosion at the ends of the fins even if
the fins and the tanks are close to each other. And, the heat
exchanger is configured quite rationally.
[0054] The invention described in claim 12 relates to the invention
according to claim 11, wherein the ends of the fins have a minimum
distance of 2.0 mm or less from the surface of the end plate which
is not clad with the brazing material.
[0055] By configuring as described above, the heat-exchange
performance of the core can be secured adequately.
[0056] In other words, if the gap between the fins and the tanks is
large, it causes lowering of the heat-exchange performance, but the
present invention sets the upper limit of the gap to 2.0 mm in
order to prevent the heat-exchange performance from lowering.
[0057] The invention described in claim 13 relates to the invention
according to claim 11, wherein the ends of the fins are in contact
with the surface of the end plate which is not clad with the
brazing material.
[0058] By configuring as described above, the heat-exchange
performance of the core can be secured adequately.
[0059] In other words, if the gap between the fins and the tanks is
large, the heat-exchange performance is lowered, but the present
invention has them mutually contacted to prevent the heat-exchange
performance from lowering.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 is a top view showing a general structure of a heat
exchanger according to an embodiment of the present invention.
[0061] FIG. 2 is an exploded perspective view showing a structure
of a tank according to an embodiment of the invention.
[0062] FIG. 3 is a sectional view of a tank to which a tube is
attached according to an embodiment of the invention.
[0063] FIG. 4 is an end face view of a tube according to an
embodiment of the invention.
[0064] FIG. 5 is a partially enlarged view of the end face of the
tube shown in FIG. 4.
[0065] FIG. 6 is a sectional view showing a tank to which a tube is
attached according to an embodiment of the invention.
[0066] FIG. 7 is a sectional view showing a tank to which a tube is
attached according to an embodiment of the invention.
[0067] FIG. 8 is a front view showing a general structure of a heat
exchanger according to an embodiment of the invention.
[0068] FIG. 9 is an exploded perspective view showing a structure
of a tank according to an embodiment of the invention.
[0069] FIG. 10 is a transverse sectional view showing a tank
according to an embodiment of the invention.
[0070] FIG. 11 is a vertical sectional view showing a tank
according to an embodiment of the invention.
[0071] FIG. 12 is a cross sectional view showing a tank according
to an embodiment of the invention.
[0072] FIG. 13 is a perspective view showing a tube according to an
embodiment of the invention.
[0073] FIG. 14 is a front view showing a heat exchanger according
to an embodiment of the invention.
[0074] FIG. 15 is an exploded perspective view showing the main
portion of a heat exchanger according to an embodiment of the
invention.
[0075] FIG. 16 is an explanatory view showing a tank and a fin
according to an embodiment of the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0076] Embodiments of the invention will be described in detail
with reference to the accompanying drawings.
[0077] FIG. 1 is a top view showing a general structure of a heat
exchanger 1.
[0078] The heat exchanger 1 shown in FIG. 1 shows an example of a
condenser. The heat exchanger 1 has tubes 21 and fins 4 alternately
stacked and both ends of the tubes 21 inserted and connected to
tube insertion holes 5 of a pair of tanks 3. Partition plates 7 for
dividing a medium passage which is formed of the tanks 3 and the
tubes 21 are disposed within the tanks 3. The openings of the tanks
3 are sealed with the partition plates 7. The tanks 3 are provided
with an outflow/inflow ports 31b for feeding or discharge of the
medium to/from the heat exchanger 1. A side plate 8 is disposed on
either side of the stacked tubes 21 and fins 4. The side plate 8 on
the bottom end of the heat exchanger 1 is provided with mounting
members 10 for mounting the heat exchanger 1 on a vehicle body.
[0079] The heat exchanger 1 has the above-described members
assembled and integrally brazed by a brazing material disposed on
the respective members in a heating furnace.
[0080] FIG. 2 is a perspective view showing the tank 3. FIG. 2 is
an exploded perspective view of the tank 3 which is comprised of a
tank plate 31, an end plate 32 and the partition plate 7.
[0081] The tank 3 is formed to have a tubular shape by attaching
the outside face of the end plate 32 to a U-shape open inside face
of the tank plate 31 which is formed to have a U-shaped cross
section. The end plate 32 is formed with the tube insertion holes 5
into which the tubes 21 are inserted.
[0082] The tank plate 31 and the end plate 32 are positioned by the
partition plate 7 which is disposed within the tank 3 to configure
the tubular tank 3. The tank plate 31 of this embodiment is
provided with an attachment hole 31a for attachment of the
partition plate 7 and the outflow/inflow port 31b for the medium.
The partition plate 7 has a projection 7a for insertion into the
attachment hole 31a and notches 7b for engagement of the end plate
32. Specifically, the projection 7a of the partition plate 7 is
inserted into the attachment hole 31a of the tank plate 31 to
attach the partition plate 7 to the tank plate 31. Then, the end
plate 32 is attached to fit the inside surface of the U-shaped
opening of the tank plate 31. Then, the edges of the end plate 32
are connected to the notches 7b of the partition plate 7, and the
tank plate 31 and the end plate 32 are positioned to enable to
assemble the tank 3.
[0083] FIG. 3 is a sectional view of the tank 3 having the tube 21
assembled.
[0084] As shown in FIG. 3, the tank plate 31 is formed with a
brazing material R1 on its surface which becomes the outer surface
of the tank 3 and a brazing material R2 on its surface which
becomes the inner surface of the tank 3. The brazing material R1
disposed on the outer surface of the tank plate 31 is a brazing
material for attaching an accessory such as the connector 4 to the
tank 3, and the brazing material R1 is a brazing material for
attaching the partition plate 7 to be disposed within the tank
3.
[0085] The end plate 32 is formed with a brazing material R3 on its
surface which becomes the inner surface of the tank 3. The brazing
material R3 is a brazing material for attaching the tube 21 and
also the partition plate 7.
[0086] The end plate 32 has its surfaces which are in contact with
the tank plate 31 determined as separator portions 321 which are
not provided with a brazing material and prevents the brazing
material from outflowing. The separator portions 321 prevent
flowing of the brazing material R2 which is disposed on the inside
of tank plates 31 within the heating furnace.
[0087] Generally, the molten brazing material in the heating
furnace flows along the brazing material which is clad to the
plate. The end plate 32 of this embodiment is provided with the
separator portions 321 which are not provided with a brazing
material and prevent the brazing material from outflowing, so that
the flow of the brazing material R2 disposed on the inner surface
of the tank plate 31 in the heating furnace is prevented by the
separator portions 321 and it does not flow to the end plate 32.
Even if the molten brazing material R2 flows over the separator
portions 321, its flowing amount becomes smaller than when the
separator portions 321 are not disposed.
[0088] The tank plate 31 has its surfaces which are in contact with
the end plate 32 determined as separator portions 311 which are not
provided with a brazing material. The brazing material R1 disposed
on the outer surface of the tank plate 31 is prevented its flow by
the separator portions 311 in the heating furnace and does not flow
to reach the end plate 32.
[0089] Therefore, the tube 21 is brazed for connection to the tube
insertion hole 5 of the end plate 32 with an appropriate amount of
brazing material, and the occurrence of erosion which may result
from an excessive amount of brazing material flowing to the tube 21
can be prevented.
[0090] FIG. 4 is a diagram showing an end face of the tube 21. As
shown in FIG. 4, the tube 21 used for the heat exchanger 1 of this
embodiment is formed of a plate by roll forming for forming the
tube 21 by sequentially bending the plate. In the drawing, 21a
indicates medium passages, 21b beads, and 21c a junction.
[0091] When the tube is formed by the roll forming, the tube 21 can
be formed of a thin plate. In the heat exchanger 1 of this
embodiment, an excessive amount of brazing material does not flow
toward the tube in the heating furnace even though the tube 21 is
thin, and the tube 21 can be prevented from having a hole, and the
occurrence of erosion can be prevented. Therefore, the heat
exchanger 1 can be made light in weight, and the safety of the heat
exchanger 1 can be improved.
[0092] FIG. 5 is a partially enlarged view of the end face of the
tube 21. As shown in FIG. 5, the tube 21 is provided with the beads
21b which divides the interior of the tube 21 to provide the medium
passages 21a by bending a plate. When the beads 21b are formed by
bending the plate, slits 21d are formed on the outer surfaces of
the tube 21. In the heating furnace, the brazing material R3
disposed on the end plate 32 melts and drawn into the slits 21d.
Therefore, the molten brazing material flowing through the tube 21
and the tube insertion hole 5 of the end plate 32 does not remain
in the gap between the tube 21 and the tube insertion hole 5 but
flows to the slits 21d, and the tube 21 and the end plate 32 are
connected by an appropriate amount of brazing material.
[0093] FIG. 6 is a sectional view of the tank 3 to show another
embodiment.
[0094] In this embodiment, the tank plate 31 has the brazing
material R1 formed on its surface which forms the outside of the
tank 3 as shown in FIG. 6. The end plate 32 is provided with a
brazing material R4 on its surface which forms the outside of the
tank 3 and the brazing material R3 on its surface which forms the
inside.
[0095] In this embodiment, the tank plate 31 is provided with the
separator portions 311 for prevention of leakage of the brazing
material from outflowing on its surfaces which are in contact with
the end plate 32 and not provided with a brazing material. The
separator portions 311 prevent the flow of the brazing material R1
disposed on the outer surface of the tank plate 31. Therefore, an
excessive amount of brazing material does not flow to reach the
tube insertion hole 7 of the end plate 31.
[0096] It is not limited to this embodiment, but it is possible to
configure the tank by disposing the brazing material on the
partition plate itself and not disposing the brazing material on
the inside surface of the end plate or the tank plate.
[0097] FIG. 7 is a sectional diagram of a tank 30 to show another
embodiment.
[0098] In this embodiment, an end plate 33 is attached from the
outside of a U-shaped opening of the tank plate 31 having a
U-shaped cross section as shown in FIG. 7. The tank plate 31 has
the brazing material R1 disposed on its surface which becomes the
outer surface of the tank 30 and the brazing material R2 disposed
on its surface which becomes the inner surface of the tank 30. And,
the end plate 33 has a brazing material R5 disposed on its surface
which becomes the outer surface of the tank 30.
[0099] The tank plate 31 is provided with the separator portions
311 on its surfaces which are in contact with the end plate 33 and
not provided with the brazing material. The end plate 33 has its
two surfaces which are contacted with the tank plate 31, namely the
surface which becomes the inner surface of the tank 30 and the
edges of the end plate 33, which are designated as separator
portions 331, 332.
[0100] Therefore, the separator portions 311, 331, 332 prevent flow
of the brazing materials R1 and R2 disposed on the tank plate 31.
Therefore, outflow of an excessive amount of brazing material is
prevented by the separator portions 311, 331, 332, and the tube 21
and the end plate 31 are brazed for connection with an appropriate
amount of brazing material.
[0101] Next, another embodiment of the invention will be
described.
[0102] FIG. 8 is a front view showing a general structure of the
heat exchanger 1. This heat exchanger 1 is a condenser for a car
air conditioner. The heat exchanger 1 is configured of a core 2,
which is configured by alternately stacking a plurality of tubes
21, 21 and fins 4, 4, and a pair of tanks 3, 3 into which both ends
of the plurality of tubes 21, 21 are inserted. Within the tanks 3,
3, partition plates 7, 7 are disposed to divide the insides of the
tanks 3, 3. Upper and lower openings of the tanks 3, 3 are sealed
by block members 6, 6, and a pair of side plates 8, 8 are disposed
on top and bottom of the core 2 for reinforcement. Besides, the
tank 3, 3 are provided with an inlet joint 41 and an outlet joint
42 for introduction and discharge of the medium.
[0103] The upper and lower openings of the tanks 3, 3 may be sealed
by partition plates 7, 7 without using the block members 6, 6.
[0104] Those component members of the heat exchanger 1 are made of
an aluminum alloy and assembled, then connected into one body by
brazing in a furnace.
[0105] FIG. 9 is an exploded perspective view showing the tank 3.
The tank 3 is a two-split type tank which is comprised of a tank
plate 31 and an end plate 32.
[0106] The tank 3 has the outer periphery of the end plate 32
contacted with the inner surface of a U-shaped opening of the tank
plate 31 which has a U-shaped cross section to form the tubular
tank 3. The end plate 32 is formed with tube insertion holes 5, 5
into which tubes are inserted.
[0107] The tank plate 31 and the end plate 32 are positioned by the
partition plate 7 disposed within the tank 3, so that the tank
plate 31 and the end plate 32 are attached in position.
[0108] The tank plate 31 of this embodiment is provided with an
attachment hole 31a into which the partition plate 7 is attached
and an outflow/inflow port 31b for connection of an inlet joint 41
or an outlet joint 42. And, the partition plate 7 is provided with
a projection 7a which is inserted into the attachment hole 31a and
notches 7b, 7b for engagement with the end plate 32.
[0109] To assemble the tank 3, the projection 7a of the partition
plate 7 is first inserted into the attachment hole 31a of the tank
plate 31 to attach the partition plate 7 to the tank plate 31.
Then, the end plate 32 is assembled to be attached to the inner
surface of a U-shaped opening of the tank plate 31 so the edges of
the end plate 32 are engaged with the notch 7b of the partition
plate 7, and the tank plate 31 and the end plate 32 can be
positioned to assemble the tank 3.
[0110] FIG. 10 is a cross sectional view of the tank 3 having the
tube 21 assembled.
[0111] As shown in FIG. 10, the tank plate 31 is provided with the
brazing material R1 on its surface which becomes the outer surface
of the tank 3 and the brazing material R2 on its surface which
becomes the inner surface of the tank 3. The brazing material R1
disposed on the surface of the tank plate 31 which becomes the
outer surface is a brazing material for bonding accessories such as
the inlet joint 41 and the outlet joint 42 to the tank 3, and the
brazing material R2 is a brazing material for bonding the partition
plate 7 within the tank 3 and for bonding the tank plate 31 and the
end plate 32.
[0112] And, the end plate 32 is provided with the brazing material
R3 on its surface which becomes the inner surface of the tank 3.
The brazing material R3 is a brazing material for connecting the
tube 21 to the tube insertion hole 5 and for connecting the
partition plate 7.
[0113] FIG. 11 is a partially vertical sectional view showing the
tank.
[0114] As shown in FIG. 11, the outer and inner surfaces of the
tank plate 31 are clad with the brazing materials R1, R2, and the
partition plate 7 is formed of a bare material not clad with the
brazing material.
[0115] According to this embodiment, the partition plate 7 is not
clad with the brazing material, so that the brazing materials R2,
R3 melted during the brazing hardly outflow along the partition
plate 7 which is not wet. As a result, the brazing material for
brazing the partition plate does not become short, and the
partition plate 7 can be brazed adequately even if there is a gap
between the inner surfaces of the tank plate 31 and the end plate
32 and the partition plate 7.
[0116] Therefore, a highly airtight heat exchanger which is free
from a leakage of the medium between the inner surface of the tank
and the partition plate 7 without strictly controlling the
dimensions of the partition plate 7 as before.
[0117] FIG. 12 is a cross sectional view of the tank 3 to show
another embodiment.
[0118] In this embodiment, the tank plate 31 is provided with the
brazing material R1 on its surface which becomes the outer surface
of the tank 3 as shown in FIG. 12. The brazing material R1 is a
brazing material for connecting accessories such as the inlet joint
41 and the outlet joint 42 to the tank 3.
[0119] The end plate 32 has the brazing material R3 disposed on its
surface which becomes the inner surface of the tank 3 and the
brazing material R4 disposed on its surface which becomes the outer
surface. The brazing material R3 disposed on the surface which
becomes the inner surface of the end plate 32 is a brazing material
for attaching the tube 21 to the tube insertion hole 5 and for
attaching the partition plate 7 disposed within the tank 3, and the
brazing material R4 is a brazing material for connecting the tube
21 to the tube insertion hole 5 and for connecting the tank plate
31 and the end plate 32.
[0120] Thus, even when the brazing material R3 is clad to the end
plate 32 and not clad to the tank plate 31 on the inner surface of
the tank 3, the partition plate 7 can be brazed without forming a
gap because the molten brazing material R3 enters the gap between
the inner surface of the tank plate 31 and the side surface of the
partition plate 7 by capillary phenomenon.
[0121] FIG. 13 is a perspective view of the tube 21 to show another
embodiment.
[0122] The tube 21 of this embodiment is a so-called roll forming
tube which is formed by roll forming a plate material, and a
plurality of passages 21a, 21a for flowing a medium are formed
within it.
[0123] The tube 21 is formed with partitions by bending a plate
material into a corrugated shape to form a plurality of beads 21b,
21b, folding in two and bonding to have the beads 21b, 21b inside,
and mutually contacting the beads 21b, 21b. Slits 21d are formed in
the surface of the tube 21 by the beads 21b, 21b and the junction
21c.
[0124] Therefore, the heat exchanger 1 using the tubes 21 tends to
suffer from a shortage of the brazing material for brazing the
partition plate 7 and defective brazing of the partition plate 7
because the molten brazing material on the inner surface of the
tank 3 at the time of brazing is taken into the slits 21d, 21d by
capillary phenomenon and outflows to the tubes 21.
[0125] But, when the partition plate 7 is determined to be a bare
material, the brazing material does not outflow along the partition
plate 7 as before even if the brazing material on the inner surface
of the tank 3 flows to the tube 21, so that an outflow amount is
considerably reduced, the brazing material for brazing the
partition plate 7 does not become short, and the partition plate 7
can be brazed adequately.
[0126] In the above embodiment, the condenser has been described as
an example, but the invention is not limited to it, and the object
of the invention can be achieved for an evaporator or a heater
core.
[0127] Then, another embodiment of the invention will be
described.
[0128] The heat exchanger 1 of this embodiment is a radiator of a
refrigeration cycle for a car air conditioner mounted on an
automobile and provided with the core 2 which is formed by
alternately stacking a plurality of tubes 21 for flowing a medium
(namely, refrigerant) and a plurality of fins 4 and a pair of tanks
3 to which both ends of the tubes 21 are connected as shown in FIG.
14 and FIG. 15 and is configured to perform heat exchange between
the medium and air flowing to the core 2 by heat conducted to the
core 2.
[0129] A side plate 8 as a reinforcing member is disposed on the
upper and lower sides of the core 2. Ends of each side plate 8 are
supported by the tanks 3.
[0130] Besides, the tank 3 is provided with the inlet joint 41 for
introducing the medium and the outlet joint 42 for discharging the
medium, and the medium flows into the tank 3 through the inlet
joint 41, flows through the tubes 21 while performing heat exchange
and is discharged to the outside of the tank 3 through the outlet
joint 42.
[0131] Each tank 3 is substantially cylindrical with its both ends
blocked by the block member 6 and the interior divided by the
partition plates 7 at prescribed intervals, and the medium is
reciprocated for a plurality of times between the tanks 3.
[0132] The tube 21 is formed flat by extrusion forming or roll
forming of a plate. Its interior is divided into a plurality of
sections in order to provide a prescribed pressure resistant
performance. Fins 4 of this embodiment are formed of a clad
material which has its front and rear sides clad with an
appropriate amount of brazing material required for brazing with
the tubes and is roll-formed into a corrugated shape. Its wave
pitch is approximately 1.6 mm to 3.0 mm. And, many louvers which
are not shown are disposed at necessary portions of the fins 4.
[0133] Besides, each tank 3 of this embodiment is configured by
attaching the end plate 32 to the tank plate 31. The tank plate 31
and the end plate 32 are formed by cutting and press-forming a
plate having a required thickness.
[0134] The tank plate 31 is a semicircular cylindrical member, and
the end plate 32 is a member having a plurality of tube insertion
holes 5 into which the ends of the tubes 21 are inserted for
attachment. The tube insertion holes 5 are formed in series at
prescribed intervals in the longitudinal direction of the tank
3.
[0135] The end plate 32 is inserted between both ends of the tank
plate 31 for attachment to the tank plate 31. An inserted amount of
the end plate 32 is restricted by the partition plates 7.
[0136] Bent pieces 31c for holding the end plate 32 and wall
sections 31d which are protruded toward the core 2 are disposed in
parallel at both ends of the tank plate 31. The bent pieces 31c and
the wall sections 31d are alternately disposed at prescribed
intervals along the longitudinal direction of the tank 3.
[0137] The end plate 32 is fixed by positioning on the tank plate
31 and bending the bent pieces 31c. The bent pieces 31c are bent by
a caulking jig or the like.
[0138] And, the tubes 21, fins 4, tank plate 31, end plate 32,
inlet joint 41, outlet joint 42, side plate 8, block member 6 and
partition plate 7 which configure the heat exchanger 1 are members
formed of aluminum or aluminum alloy, assembled by a jig, and
brazed into one body by heating the assembly in a furnace. The
brazing material and flux required for brazing are disposed on
required portions of the respective members before the heating
process.
[0139] As shown in FIG. 16, the tank plate 31 has a brazing
material F clad on both surfaces in this embodiment. The end plate
32 has the brazing material F clad on its one surface only, and the
end of the fin 4 and the surface of the end plate 32 not clad with
the brazing material are opposed to each other when brazing.
[0140] The brazing material F which is clad to the tank plate 31
and the end plate 32 brazes the tank plate 31 and the end plate 32
and also brazes the tube 21, the inlet joint 41, outlet joint 42,
the block member 6 and the partition plate 7.
[0141] And, when the end of the fin 4 and the surface of the end
plate 32 not clad with the brazing material are opposed, even if
the brazing material F clad to the tank plate 31 and the end plate
32 melts, the brazing material F does not reach the end of the fin
4, and unnecessary erosion at the end of the fin 4 can be
avoided.
[0142] Therefore, the above configuration can make the gap between
the fin 4 and the tank 3 as small as possible, and the heat
exchange performance of the core 2 can be improved.
[0143] Especially, it is determined in this embodiment that the fin
4 has a length which is slightly smaller than the gap between the
tanks 3, a minimum distance G between the end of the fin 4 and the
surface of the end plate 32 not clad with the brazing material is
2.0 mm or less at the ends of all the fins 4 of the heat exchanger
1.
[0144] But, some of the ends of the fins 4 may come into contact
with the surface of the end plate 32 not clad with the brazing
material. And, some of the ends of the fins 4 may have a minimum
distance G of 2.0 mm or more depending on some dimensional
error.
[0145] The minimum distance G is a distance of the minimum one of
the gaps. Specifically, the end plate 32 of this embodiment has a
sectional shape which swells toward the core 2, and the minimum
distance G is a distance between the center of the end of the fin 4
and the swelled top of the tank plate 32.
[0146] By configuring as described above, leakage of air from the
gap between the fin 4 and the tank 3 can be remedied, and the heat
exchange performance of the core can be secured satisfactorily.
[0147] The minimum distance G between the end of the fin 4 and the
surface of the end plate 32 not clad with the brazing material is
determined to be 2.0 mm or less in this embodiment, but it is
desirably 1.0 mm or less in order to remedy the air leak.
[0148] It may also be configured that the fin 4 has a length
slightly larger than the gap of the tanks 3, and the fin 4 is
compressed slightly to assemble, so to contact the ends of all fins
4 of the heat exchanger 1 to the surface of the end plate 32 not
clad with the brazing material.
[0149] By configuring as described above, the air leak from the gap
between the fin 4 and the tank 3 can be remedied more securely.
[0150] As described above, the heat exchanger of this embodiment
efficiently avoids the ends of the fins from being eroded by the
brazing material and is preferably used as a radiator of the
refrigeration cycle. And, the configuration of this embodiment can
also be applied to another heat exchanger such as an evaporator, a
car radiator or the like.
INDUSTRIAL APPLICABILITY
[0151] The present invention is a heat exchanger generally used for
a refrigeration cycle of car and home air conditioner and the like,
and particularly suitable for a radiator, a condenser, an
evaporator and the like.
* * * * *