U.S. patent application number 11/013140 was filed with the patent office on 2005-06-23 for easily assembled cooler.
Invention is credited to Inagaki, Mitsuharu, Shirai, Motohiro.
Application Number | 20050133210 11/013140 |
Document ID | / |
Family ID | 34682262 |
Filed Date | 2005-06-23 |
United States Patent
Application |
20050133210 |
Kind Code |
A1 |
Inagaki, Mitsuharu ; et
al. |
June 23, 2005 |
Easily assembled cooler
Abstract
A cooler capable of reducing the fabrication cost is provided.
In the cooler, in which electronic parts 6 are held between
neighboring tubes 1, each of the tubes 1 is formed by joining the
edges of plates 1a, 1b, each of which is formed into a
predetermined shape by press molding, and fins 5 for accelerating
heat exchange are arranged in the tube 1. As an inner wall
conventionally exists when the tube 1 is manufactured by extrusion,
can be removed, it is no longer necessary to remove the inner wall
by machining, therefore, the fabrication cost can be reduced.
Inventors: |
Inagaki, Mitsuharu;
(Kariya-city, JP) ; Shirai, Motohiro;
(Kariya-city, JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
34682262 |
Appl. No.: |
11/013140 |
Filed: |
December 15, 2004 |
Current U.S.
Class: |
165/152 |
Current CPC
Class: |
H01L 2924/0002 20130101;
F28F 19/06 20130101; F28D 1/0333 20130101; F28F 2275/04 20130101;
F28F 3/025 20130101; F28D 2021/0029 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101 |
Class at
Publication: |
165/152 |
International
Class: |
F28F 013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2003 |
JP |
2003-421340 |
Feb 12, 2004 |
JP |
2004-035226 |
Jun 15, 2004 |
JP |
2004-177351 |
Aug 25, 2004 |
JP |
2004-245140 |
Claims
1. A cooler, comprising: a plurality of tubes internally including
a fluid passage through which a cooling fluid flows and piled at
predetermined intervals in a direction perpendicular to a direction
(X) in which the cooling fluid flows through the fluid passage; and
coupling means arranged between the neighboring tubes and for
coupling the neighboring tubes; wherein connection holes for making
the fluid passage and the inside of the coupling means communicate
with each other are formed in each tube, electronic parts are held
between the neighboring tubes, each of the tubes is formed by
joining edge parts of at least a plate formed into a predetermined
shape by press molding, and at least a fin for accelerating heat
exchange is arranged in each of the tubes.
2. A cooler as set forth in claim 1, wherein plate thickness of the
fins is equal to or less than 0.4 mm.
3. A cooler as set forth in claim 1, wherein at least the fin is
joined to the tube and portions of the fin, which are joined to the
tube, are arc-shaped.
4. A cooler as set forth in claim 1, wherein at least the fin is
arranged at a position at which the fin does not overlap the
connection holes when viewed in a direction of built-up (Y) of the
tubes, and the electronic part is within an area of installation of
the fin when viewed in the direction of built-up (Y) of the
tubes.
5. A cooler as set forth in claim 1, wherein a plurality of the
fins are arranged in the single tube at intervals (.delta.) along
the direction (X) in which the cooling fluid flows through the
fluid passage.
6. A cooler as set forth in claim 4, wherein the intervals
(.delta.) are greater than or equal to 1 mm.
7. A cooler as set forth in claim 1, wherein the connection holes
are formed by press molding.
8. A cooler as set forth in claim 1, wherein each of the tubes is
formed by joining the two plates.
9. A cooler as set forth in claim 1, wherein each of the tubes is
formed by bending and joining the single plate.
10. A cooler as set forth in claim 1, wherein the coupling means
are bellows.
11. A cooler as set forth in claim 1, wherein each of the fins is a
corrugated fin that divides the fluid passage into two or more fine
flow passages, and the height (hf) of the fin is greater than width
(wf) of the fine flow passage of the fin at a central position of
the fine flow passage in a direction of height of the tube.
12. A cooler as set forth in claim 11, wherein the width (wf) of
the fine flow passage is equal to or less than 1.2 mm.
13. A cooler as set forth in claim 11, wherein the height (hf) of
the fin is 1 to 10 mm.
14. A cooler as set forth in claim 1, wherein the plate thickness
(tf) of the fin is less than thickness (tp) of at least the
plate.
15. A cooler as set forth in claim 14, wherein the plate thickness
(tf) of the fins is 0.03 to 1.0 mm.
16. A cooler as set forth in claim 14, wherein the thickness (tp)
of at least the plate is 0.1 to 5.0 mm.
17. A cooler as set forth in claim 1, wherein the tube is formed-by
joining at least the plate by brazing, and at least the plate is
made of a bare material.
18. A cooler as set forth in claim 1, wherein the tube is formed by
joining at least the plate by brazing, at least the plate is made
of a brazing sheet having a core material and a sacrifice anode
material, and the core material is located at an outside of the
tube.
19. A cooler as set forth in claim 1, wherein the tube is formed by
joining at least the plate by brazing, at least the plate is made
of a brazing sheet having a core material and a brazing material,
and the core material is located outside the tube.
20. A cooler as set forth in claim 1, wherein the tube is formed by
joining at least the plate by brazing, at least the plate is made
of a brazing sheet in which a sacrifice anode material is arranged
between a core material and a brazing material, and the core
material is located at an outside of the tube.
21. A cooler as set forth in claim 1, wherein the fins are made of
a material that is potentially baser than that of at least the
plate.
22. A cooler, comprising: a plurality of flat tubes internally
including a fluid passage through which a cooling fluid flows and
piled at predetermined intervals in a direction perpendicular to a
direction (X) in which the cooling fluid flows through the fluid
passage; and header tanks arranged at both ends of the flat tubes
and for distributing and gathering the cooling fluid; wherein
electronic parts arranged between the neighboring flat tubes are
held by applying a pressing force in a direction of built-up (Y) of
the tubes; and wherein narrow parts that become narrower in the
direction of built-up (Y) of the tubes are formed in each of the
flat tubes.
23. A cooler as set forth in claim 22, wherein the narrow parts are
located at portions of the flat tube, at which the electronic parts
are not held.
24. A cooler as set forth in claim 22, further comprises a
reinforcement plate at one end in the direction of built-up (Y) of
the tubes, whose rigidity in the direction of built-up (Y) of the
tubes is greater than that of each flat tube.
25. A cooler as set forth in claim 22, wherein the electronic parts
are arranged in two or more rows when viewed in the direction of
built-up (Y) of the tubes and a pressing force is applied to each
of the rows independently of each other.
26. A cooler as set forth in claim 22, wherein the narrow parts
extend in a direction perpendicular to both the direction of
built-up (Y) of the tubes and the direction (X) in which the
cooling fluid flows through the fluid passage.
27. A cooler as set forth in claim 22, wherein fins that accelerate
heat exchange are arranged at positions in the flat tube, at which
the narrow parts are not formed.
28. A cooler of a built-up type for cooling electronic parts from
both sides thereof, comprising: a plurality of flat cooling tubes
provided with a refrigerant flow passage through which a cooling
medium flows and arranged in layers, so as to sandwich and hold the
electronic parts at both sides thereof; and a supply header section
for supplying the cooling medium to each of the refrigerant flow
passages; and a discharge header section for discharging the
cooling medium from each of the refrigerant flow passages; wherein
each of the cooling tubes has protruding pipe parts opening and
protruding toward the direction of built-up of the cooling tubes,
and neighboring cooling tubes make the refrigerant flow passages
thereof communicate with each other by inserting the protruding
pipe parts into each other and, at the same time, joining the
sidewalls of the protruding pipe parts to each other, and thus
forming the supply header section and the discharge header
section.
29. A cooler of a built-up type as set forth in claim 28, wherein
each of the cooling tubes has a diaphragm part formed around each
of the protruding pipe parts, which deforms in the direction of
built-up.
30. A cooler of a built-up type as set forth in claim 29, wherein
the cooling tube has the diaphragm part formed only around one of a
pair of the protruding pipe parts arranged in opposition to each
other, but not one formed around the other of a pair of the
protruding pipe parts.
31. A cooler of a built-up type as set forth in claim 30, wherein
the cooling tube has the diaphragm part formed around one of a pair
of the protruding pipe parts, which is formed on the downstream
side of the supply header section.
32. A cooler of a built-up type as set forth in claim 28, wherein
the cooling tube has a throttle part at an inlet part of the
refrigerant flow passage, which narrows width of the refrigerant
flow passage.
33. A cooler of a built-up type as set forth in claim 28, wherein
the cooling tube has a pair of outer shell plates, an intermediate
plate arranged between a pair of the outer shell plates, and
corrugated inner fins arranged between the intermediate plate and
the outer shell plates.
34. A cooler of a built-up type as set forth in claim 33, wherein
the outer shell plates are made of a brazing sheet having a core
material and a brazing material arranged on an inner surface of the
core material, the intermediate plate and the inner fins are made
of a metal plate including a metal baser than the core material of
the outer shell plates, and a pair of the outer shell plates are
formed by joining the inner surfaces at the ends thereof to each
other.
35. A cooler of a built-up type as set forth in claim 34, wherein
each of the outer shell plates is made of a brazing sheet having a
core material, a sacrifice anode material arranged on the inner
surface of the core material, and the brazing material arranged on
an inner surface of the sacrifice anode material.
36. A cooler of a built-up type as set forth in claim 33, wherein
each of the outer shell plate is made of a brazing sheet having a
core material and a sacrifice anode material arranged on an inner
surface of the core material, the intermediate plate is made of a
brazing sheet having a core material and brazing materials arranged
on both sides of the core material, the inner fins are made of a
metal plate including a metal baser than the core material of the
outer shell plate, and a pair of the outer shell plates are formed
by joining the inner surfaces at ends thereof to both sides of the
intermediate plate at ends thereof.
37. A cooler of a built-up type as set forth in claim 28, wherein a
first cooling tube arranged at one end in the direction of built-up
of a plurality of the cooling tubes has a refrigerant introduction
inlet for introducing the cooling medium to the supply header
section and a refrigerant discharge outlet for discharging the
cooling medium from the discharge header section, each of the
refrigerant introduction inlet and the refrigerant discharge outlet
has a protruding opening part protruding toward the outside of the
first cooling tube, and a refrigerant introduction pipe and a
refrigerant discharge pipe are inserted into the protruding opening
parts at the refrigerant introduction inlet and the refrigerant
discharge outlet, respectively.
38. A cooler as set forth in claim 1, wherein electronic parts
arranged between the neighboring tubes are held by applying a
pressing force in a direction of built-up (Y) of the tubes; and
wherein narrow paths that become narrower in the direction of
built-up (Y) of the tubes are formed in each of the tubes.
39. A cooler as set forth in claim 1, comprising: a supply header
section for supplying the cooling fluid to each of the fluid
passages; and a discharge header section for discharging the
cooling fluid from each of the fluid passages; wherein the coupling
means is formed by protruding pipe parts provided on each of the
tubes, and opening and protruding toward the direction of built-up
of the tubes, and neighboring tubes make the fluid passages thereof
communicate with each other by inserting the protruding pipe parts
into each other and, at the same time, joining the sidewalls of the
protruding pipe parts to each other, and thus forming the supply
header section and the discharge header section.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a cooler for cooling
electronic parts and can be preferably used, particularly, as a
cooler for cooling electronic parts of a double-sided cooling type
in an inverter for a hybrid electric vehicle. More particularly,
the present invention relates to a cooler of a built-up type for
cooling an electronic part from both sides thereof.
[0003] 2. Description of the Related Art
[0004] Conventionally, a known semiconductor module (an electronic
part) is attached to a cooler of a water-cooling type for cooling.
A semiconductor device of a double-sided cooling type is proposed
in Patent document 1. The device described in Patent document 1 has
a configuration in which tubes having a cooling water passage and
semiconductor modules of a double-sided cooling type are piled
alternately and a pressing force is applied in the direction of
built-up of the tubes to hold the semiconductor modules between the
tubes. Neighboring tubes are coupled to each other by bellows
(coupling means) arranged between the neighboring tubes and by
communication holes for making the cooling water passages and the
insides of the bellows communicate with each other are formed in
respective tubes. In Patent document 1, many examples are described
in which the semiconductor module and the tube are brought into
close contact with each other even if there are variations in the
interval between tubes and in the thickness of the semiconductor
modules.
[0005] In one of the examples (hereinafter, referred to as a first
conventional device), neighboring tubes are coupled to each other
by a bellows-shaped elastic cylinder sections and the elastic
cylinder sections extend and contract in accordance with the
interval between the tubes or the thicknesses of the semiconductor
modules.
[0006] In another example (hereinafter, referred to as a second
conventional device), a flange-shaped cylinder section with low
rigidity is provided in the tube and the flange-shaped cylinder
section is made to deform in accordance with the interval between
the tubes or the thickness of the semiconductor modules.
[0007] In still another example (hereinafter, referred to as a
third conventional device), the tube is made thinner to have lower
rigidity and the tube itself is made to deform in accordance with
the interval between tubes or the thickness of the semiconductor
module.
[0008] Conventionally, a cooler of a built-up type 2009 is known,
in which a plurality of cooling tubes 2092 are arranged in layers
so as to sandwich and hold an electronic part 2004 from both sides
thereof and which cools the electronic part 2004 from both sides
thereof, as shown in FIG. 39 (refer to Patent document 2).
[0009] The cooler of a built-up type 2009 comprises a supply header
2094 for supplying a cooling medium to the cooling tubes 2092 and a
discharge header 2095 for discharging the cooling medium from the
cooling tubes 2092. One end of each of the plurality of the cooling
tubes 2092 arranged in layers is connected to the supply header
2094 and the other end is connected to the discharge header
2095.
[0010] However, in the conventional cooler of a built-up type 2009,
the cooling tubes 2092 are connected to the supply header 2094 and
the discharge header 2095, both being made of a member different
from that of the cooling tubes 2092. Because of this, there is the
possibility that the manufacture of the cooler of a built-up type
2009 requires a large number of parts and, therefore, the
manufacturing cost thereof is high.
[0011] Moreover, in the cooler of a built-up type 2009, the
plurality of the cooling tubes 2092 are fixed to the supply header
2094 and the discharge header 2095 and, therefore, it is difficult
to change the intervals between the plurality of the cooling tubes
2092. Because of this, it becomes difficult to insert the
electronic part 2004 between the cooling tubes 2092 so as to bring
the cooling pipes 2092 into close contact with both main surfaces
of the electronic part 2004 without fail.
[0012] On the other hand, a cooler of a built-up type 2090 is
known, which is configured in such a manner that a plurality of the
cooling tubes 2092 are arranged so as to sandwich and hold an
electronic part 2004 from both sides and, at the same time, a
plurality of the cooling tubes 2092 are made to connect with each
other via connecting pipe 2093 so that a cooling medium can flow to
each cooling tube 2092, as shown in FIG. 40 (refer to Patent
document 1).
[0013] However, in this cooler of a built-up type 2090 also, it is
necessary to join the connecting pipe 2093, which are made of a
member different from that of the cooling tubes 2092, to the
cooling tubes 2092 to assemble the cooler of a built-up type 2090.
Because of this, a problem arises in that the manufacturing cost is
high and, at the same time, the productivity is difficult to
improve.
[0014] [Patent document 1] Japanese Unexamined Patent Publication
(Kokai) No.2002-26215
[0015] [Patent document 2] Japanese Unexamined Patent Publication
(Kokai) No.2001-320005
[0016] However, as in the device described in Patent document 1,
when a tube is manufactured by extrusion, inner walls 2001x are
formed on the inside of the tube 2001 in order to accelerate heat
exchange and to ensure the strength thereof, and the inner walls
2001x exist in the entire area in the direction of extrusion, as
shown in FIG. 38. In addition, after extrusion, it is necessary to
remove the inner wall 2001x of the tube 2001 at the portion where
the tube 2001 and a bellows are joined, that is, at the portion
where a connection hole 2011 is formed. Therefore, this process
raises the cost. Moreover, the extruded tube 1 requires side caps
and this also raises the cost.
[0017] Moreover, the first conventional device and the second
conventional device require the elastic cylinder sections or the
flange-shaped cylinder sections, the number of which corresponding
to the number of piled layers of the tubes and, therefore, a
problem arises in that the number of parts of a product is
increased.
[0018] In the third conventional device, as the tube is deformed in
an arc shape, it is not possible for the tube to completely come
into close contact with the surface of the semiconductor module and
a problem arises in that the contact area between two decreases.
Moreover, the third conventional device brings about a problem in
that, when the tube deforms, stress tend to concentrate on the
joined parts between the tubes and the header tanks.
SUMMARY OF THE INVENTION
[0019] The above-mentioned problems being taken into account, an
object of the present invention is to provide a cooler capable of
reducing the forming process cost and further, the manufacturing
cost. Another object of the present invention is to make it
possible to ensure a sufficient contact area between an electronic
part and a tube without increasing the number of parts.
[0020] In order to attain the above-mentioned objects, a cooler
according to a first aspect of the present invention comprises: a
plurality of tubes (1) internally including a fluid passage (10)
through which a cooling fluid flows and piled at predetermined
intervals in a direction perpendicular to a direction (X) in which
the cooling fluid flows through the fluid passage (10); and
coupling means (2) arranged between the neighboring tubes (1) and
for coupling the neighboring tubes (1); and in the tube (1),
connection holes (11) are formed which make the fluid passage (10)
and the inside of the coupling means (2) communicate with each
other, electronic parts (6) are held between the neighboring tubes
(1), each of the tubes (1) is formed by joining edge parts of
plates (1a, 1b, 1c) formed into a predetermined shape by press
molding, and fins (5) for accelerating heat exchange are arranged
in each of the tube (1).
[0021] According to the first aspect, it is possible to dispense
with the inner wall, which is required and therefore exists when
the tube is manufactured by extrusion and, therefore, a process for
removing the inner wall can also be dispensed with. Moreover, it
becomes possible to seal the tube without the side cap present in
the extruded tube. Still moreover, as the thickness of the plate
can be reduced, a process for drilling the connection holes is made
easier. Therefore, the forming process (fabrication) cost can be
reduced.
[0022] As it is possible to form the fin by press molding, as well
as the tube, the manufacturing process is made easier and the
manufacturing cost can be reduced.
[0023] In a second aspect of the present invention, when a
semiconductor modules are sandwiched and pressed by plate springs,
the fins can deform elastically or buckle without inflicting damage
on the semiconductor modules (without destroying circuits, etc.).
According to the experimental result, the thickness of the fin in
this case was equal to or less than 0.4 mm.
[0024] In a third aspect of the present invention, each of the fins
(5) is joined to the tube (1) and the portions of the fin (5),
which are joined to the tube (1), are arc-shaped.
[0025] According to the third aspect, both the fact that the
portions of the fin, which are joined to the tube, are arc-shaped
and the fact that the tube and the fins can be made thin produce a
synergic effect to make it easier for the tubes to deform when an
electronic part is held between the tubes and, therefore, the
contact surface between the tube and the electronic part is made
easier to fit and the adhesiveness is improved. As a result, the
contact thermal resistance can be reduced.
[0026] In a fourth aspect of the present invention, when viewed in
the direction (Y) of built-up of the tubes (1), the fins (5) are
arranged at positions at which the fins (5) do not overlap the
connection holes (11), and when viewed in a direction (Y) of
built-up of the tubes (1), the electronic parts (6) are within the
areas of installation of the fins (5).
[0027] According to the fourth aspect, the pressure loss can be
reduced compared to the case where the fins are present in the
entire area in the tube because the fins do not occupy excess
area.
[0028] In a fifth aspect of the present invention, a plurality of
the fins (5) are arranged in the single tube (1) and, at the same
time, the fins (5) are arranged at intervals (.delta.) along the
direction (X) in which the cooling fluid flows through the fluid
passage (10).
[0029] According to the fifth aspect, as the plurality of the fins
are arranged in the single tube, it is possible to properly use
fins of different heat exchange performance in accordance with, for
example, the amount of heat produced by the electronic parts.
[0030] By providing the interval, the velocity boundary layer of
the cooling fluid is cleared in the interval and the thermal
boundary layer of the cooling fluid is also removed and, therefore,
the ability to cool the electronic parts on the downstream side of
the interval is improved. It is effective for the interval (6) to
be equal to or greater than 1 mm, as shown in a sixth aspect of the
present invention.
[0031] As shown in a seventh aspect of the present invention, it is
possible to reduce the fabrication cost by forming the connection
holes (11) by press molding.
[0032] As shown in an eighth aspect of the present invention, the
tubes (1) may be formed by joining the two plates (1a, 1b).
Moreover, as shown in a ninth aspect of the present invention, the
tubes (1) may be formed by bending and joining the single plate
(1c).
[0033] In a tenth aspect of the present invention, the coupling
means (2) are bellows. According to the tenth aspect, it is
possible to change the dimension between neighboring tubes in
accordance with the thickness of an electronic part by extending
and contracting the bellows.
[0034] In an eleventh aspect of the present invention, the fins (5)
are corrugated fins that divide the fluid passage (10) into two or
more fine flow passages and the height (hf) of the fins (5) is
greater than the width (wf) of the fine flow passage of the fin (5)
at the central position of the fine flow passage in a direction of
height of the tube.
[0035] According to the eleventh aspect, the heat transfer area of
the fin is increased and the cooling performance of the cooler is
improved. It is preferable that the width (wf) of the fin flow
passage be equal to 1.2 mm or less as in a twelfth aspect of the
present invention or that the height (hf) of the fin (5) be 1 to 10
mm as in a thirteenth aspect of the present invention.
[0036] In a fourteenth aspect of the present invention, the
thickness (tf) of the fins (5) is less that the thickness (tp) of
the plates (1a, 1b, 1c).
[0037] According to the fourteenth aspect, when pressure is applied
to an electronic part in order to bring the electronic part into
closer contact with the plate surfaces (the tube surfaces), as the
fins deform more readily than the plates do, it is made easier for
the electronic part and the plate surfaces to come into closer
contact and, therefore, the contact thermal resistance is reduced
and the cooling efficiency is improved.
[0038] It is preferable that the thickness (tf) of the fins (5) be
0.03 to 1.0 mm as in a fifteenth aspect of the present invention or
that the thickness (tp) of the plates (1a, 1b, 1c) be 0.1 to 5.0 mm
as in a sixteenth aspect of the present invention.
[0039] In a seventeenth aspect of the present invention, the tube
(1) is formed by brazing the plates (1a, 1b, 1c) and the plates are
made of a bare material.
[0040] According to the seventeenth aspect, as the plates are made
of a bare material, it is unlikely that the plate surface (the tube
surface) becomes rough due to brazing. Therefore, the contact
thermal resistance between the electronic part and the plates is
reduced and the cooling efficiency is improved.
[0041] In an eighteenth aspect of the present invention, the tube
(1) is formed by brazing the plates (1a, 1b, 1c), the plates (1a,
1b, 1c) are made of a brazing sheet having a core material and a
sacrifice anode material, and the tube (1) has the core material at
the outside thereof.
[0042] According to the eighteenth aspect, the tube can be
prevented from being pitted by making the sacrifice anode material
first corrode before the core material to prevent the corrosion of
the core material of the plate. Moreover, as the core material is
located at the outside of the tube, it is unlikely that the plate
surface (the tube surface) becomes rough due to brazing and,
therefore, the contact thermal resistance between the electronic
part and the plates is reduced and the cooling efficiency is
improved.
[0043] In a nineteenth aspect of the present invention, the tube
(1) is formed by brazing the plates (1a, 1b, 1c), the plates (1a,
1b, 1c) are made of a brazing sheet having a core material and a
brazing material, and the tube (1) has the core material at the
outside thereof.
[0044] According to the nineteenth aspect, as the plate is provided
with the brazing material, the time (man-hour) for an assembling
process including steps, such as a step of attaching a paste
brazing material, can be reduced. Moreover, as the core material is
located at the outside of the tube, it is unlikely that the plate
surface (the tube surface) becomes rough due to the brazing and,
therefore, the contact thermal resistance between the electronic
part and the plates is reduced and the cooling efficiency is
improved.
[0045] In a twentieth aspect of the present invention, the tube (1)
is formed by brazing the plate (1a, 1b, 1c), the plates (1a, 1b,
1c) are made of a brazing sheet having a sacrifice anode material
arranged between a core material and a brazing material, and the
tube (1) has the core material at the outside thereof.
[0046] According to the twentieth aspect, as the plate is provided
with the brazing material, the time (man-hour) for an assembling
process including steps, such as a step of attaching a paste
brazing material, can be reduced. Moreover, the tube can be
prevented from being pitted by making the sacrifice anode material
first corrode with priority over the core material to prevent the
corrosion of the core material of the plate. Still moreover, as the
tube has the core material located at the outside thereof, it is
unlikely that the plate surface (the tube surface) becomes rough
due to the brazing and, therefore, the contact thermal resistance
between the electronic part and the plates is reduced and the
cooling efficiency is improved.
[0047] In a twenty-first aspect of the present invention, the
material of the fins (5) is potentially baser than that of the
plates (1a, 1b, 1c). According to the twenty-first aspect, as the
fin is made to corrode before the plates, the tube can be prevented
from being pitted.
[0048] A cooler according to a twenty-second aspect of the present
invention comprises: a plurality of flat tubes (501) internally
including a fluid passage (501a) through which a cooling fluid
flows and piled at predetermined intervals in a direction
perpendicular to a direction (X) in which the cooling fluid flows
through the fluid passage (501a); and header tanks (503, 505)
arranged at both ends of the flat tubes (501) and for distributing
and gathering the cooling fluid; and wherein electronic parts (507)
arranged between the neighboring flat tubes (501) are held by
applying a pressing force thereto in a direction of built-up of the
tubes (Y) and the flat tube (501) is provided with narrow parts
(501b) that become narrower in the direction of built-up of the
tubes (Y).
[0049] According to the twenty-second aspect, the flat tube deforms
readily in the direction of built-up of the tubes at the narrow
parts in accordance with the interval between the flat tubes and
the thickness of the electronic part. At this time, the part of the
flat tube between the narrow parts does not deform in an arc-shape
and, therefore, it is possible for the flat tube and the electronic
part to come into close contact with each other at the entire
opposing surfaces of both and a sufficient contact area between the
electronic part and the tube can be ensured.
[0050] As only the narrow parts are formed in the flat tube, the
number of parts is not increased in the present embodiment.
[0051] Moreover, as the flat tubes readily deform in the direction
of built-up of the tubes at the narrow parts, it is unlikely that
stress concentrates on the joined parts between the flat tubes and
the header tanks when the flat tubes deform and, thus, the stress
due to deformation can be reduced.
[0052] When the header tank and the flat tube are brazed, the
brazing material gathers at the narrow parts and, therefore, the
brazing material can be prevented from flowing up to the position
of contact between the flat tube and the electronic part.
[0053] In a twenty-third aspect of the present invention, the
narrow parts (501b) are located at portions at which the electronic
parts (507) are not held in the flat tube (501).
[0054] According to the twenty-third aspect, it is possible to
prevent the contact area between the electronic part and the flat
tube from decreasing.
[0055] In a twenty-fourth aspect of the present invention, a
reinforcement plate (509) having greater rigidity in the direction
of built-up of the tubes (Y) than the flat tube (501) is provided
at one end in the direction of built-up (Y) of the tubes.
[0056] According to the twenty-fourth aspect, it is possible for
the cooler itself to support the pressing force in the direction of
built-up of the tubes. Moreover, as the strength of the cooler can
be increased, it is possible to prevent the cooler itself from
deforming when the cooler is transported in a state in which an
electronic parts are not held in the cooler yet.
[0057] In a twenty-fifth aspect of the present invention, a
plurality of rows of electronic parts (507) are arranged when
viewed in the direction of built-up of the tubes (Y) and a pressing
force is applied to each row independently of each other.
[0058] According to the twenty-fifth aspect, as a pressing force is
applied to each row independently of each other, even if
neighboring electronic parts vary in thickness, the variation can
be absorbed and the contact thermal resistance can be reduced.
[0059] In a twenty-sixth aspect of the present invention, the
narrow parts (501b) extend in a direction perpendicular to the
direction of built-up (Y) of the tubes and, at the same time,
extending in the direction perpendicular to the direction of flow
of the cooling fluid (X) in the fluid passage (501a).
[0060] According to the twenty-sixth aspect, it is possible to
readily deform the flat tube in the direction of built-up of the
tubes at the narrow parts.
[0061] In a twenty-seventh aspect of the present invention, the
fins (2) for accelerating heat exchange are arranged at positions
in the flat tube (1), where the narrow parts (501b) are not
formed.
[0062] According to the twenty-seventh aspect, during the
manufacture process of a cooler, the narrow parts can be used for
determining the positions of the fins.
[0063] The present invention relates to a cooler of a built-up type
for cooling electronic parts from both sides thereof, the cooler of
a built-up type comprises: a plurality of flat cooling tubes, each
having a refrigerant flow passage through which a cooling medium
flows and arranged in layers so as to sandwich and hold the
electronic parts at both sides thereof; a supply header section for
supplying the cooling medium to the refrigerant flow passage; and a
discharge header section for discharging the cooling medium from
each of the refrigerant flow passages; wherein each of the cooling
tubes is provided with protruding pipe parts opening and protruding
toward the direction of built-up of the cooling tubes and
neighboring cooling tubes make the refrigerant flow passages
thereof communicate with each other by inserting the protruding
pipe parts into each other and, at the same time, joining the
sidewalls of the protruding pipe parts to each other, and thus
forming the supply header section and the discharge header section
(the twenty eighth aspect of the present invention).
[0064] Next, the functions and effects of the present invention are
explained below.
[0065] In the cooler of a built-up type, by inserting the
protruding pipe parts formed on each of the cooling tubes into each
other, the refrigerant flow passages in neighboring cooling tubes
are made to connect with each other. Due to this, it is not
necessary, in particular, to connect the plurality of cooling tubes
via members separately provided and, therefore, the number of parts
can be reduced and the manufacture thereof is made easier.
[0066] The protruding pipe parts in neighboring cooling tubes are
connected by joining the sidewalls of the protruding pipe parts to
each other. Therefore, it is possible for the supply header section
and the discharge header section to ensure a diameter of a flow
passage substantially equal to the inner diameter of the protruding
pipe part. Due to this, the flow resistance of the supply header
section and the discharge header section can be reduced and the
pressure loss can also be reduced. Therefore, it is possible to
distribute the cooling medium evenly to each of the plurality of
the cooling tubes and, as a result, the electronic parts can be
cooled evenly.
[0067] As described above, according to the present invention, it
is possible to provide a cooler of a built-up type capable of
reducing the manufacturing cost.
[0068] In a twenty-eighth aspect of the present invention, the
electronic part may be, for example, a semiconductor module that
incorporates semiconductor elements, such as an IGBT, and diodes.
The semiconductor module can be used in an inverter for a vehicle,
a motor drive inverter for industrial equipment, an air-conditioner
inverter for air-conditioning buildings, etc.
[0069] In addition to the semiconductor module described above, a
power transistor, a power FET, an IGBT, etc., can be used as the
electronic parts.
[0070] As the cooling medium described above, for example, water
mixed with an ethylene glycol base antifreeze liquid, a natural
refrigerant such as water and ammonia, a fluorocarbon base
refrigerant such as fluorinate, a chlorofluorocarbon base
refrigerant such as HCFC123 and HFC134a, an alcohol-based
refrigerant such as methanol and alcohol, and a ketone-based
refrigerant such as acetone may be used.
[0071] It is preferable that diaphragm parts that deform in the
direction of built-up are formed around the protruding pipe parts
of the cooling tube (a twenty-ninth aspect of the present
invention).
[0072] In this case, it is possible to easily adjust the interval
between neighboring cooling tubes and to easily and firmly arrange
the electronic parts between neighboring cooling tubes. Moreover,
it is possible to firmly make the electronic part come into close
contact with the cooling tube, or to firmly make the electronic
part and the cooling tube come into close contact with a heat
transfer member, etc., to be interposed between both.
[0073] When arranging electronic parts in the cooler of a built-up
type described above, it is possible to sandwich and hold the
electronic parts between the cooling tubes by, for example,
deforming the diaphragm parts toward the inside of the cooling
tube. Moreover, the electronic parts may be sandwiched and held
between the cooling tubes by temporarily deforming the diaphragm
part toward the outside of the cooling tube to widen the interval
between the neighboring cooling tubes and narrowing the interval
between the cooling tubes after inserting the electronic part
therebetween.
[0074] It is preferable that the diaphragm part be formed around
one of a pair of the protruding pipes arranged in opposition to
each other of the cooling tube and be not formed around the other
protruding pipe part (a thirtieth aspect of the present
invention).
[0075] In this case, it becomes easy to manufacture a cooler of a
built-up type so as to have a constant shape in a state in which an
electronic parts are sandwiched and held therebetween.
[0076] In other words, if the diaphragm parts are provided around
both the protruding pipe parts and are deformed, both the diaphragm
parts may vary in the amount of deformation from each other. Then,
in this case, if an attempt is made to adjust the amount of
deformation of each diaphragm part, it becomes necessary to
accurately control various conditions, such as the throttle
(area-reducing) rate of the cooling tube during press molding and
the plate thickness thereof.
[0077] Therefore, by providing the diaphragm part to only one of
the protruding pipe parts, it becomes easy to perform specific
deformation of the diaphragm parts when the electronic parts are
sandwiched and held by the cooling tubes substantially in
accordance with the design It is preferable that the diaphragm part
be formed around the protruding pipe part formed on the downstream
side of the supply header section, which is one of the pair of the
protruding pipe parts of the cooling tube (a thirty-first aspect of
the present invention).
[0078] In this case, it is possible to prevent the smooth supply of
the cooling medium from the supply header section to the cooling
tubes from being blocked by the diaphragm parts.
[0079] It is preferable that a throttle (area-reduced) part for
narrowing the width of the refrigerant flow passage be provided at
the inlet part of the refrigerant flow passage in the cooling tube
(a thirty-second aspect of the present invention).
[0080] In this case, it becomes easy to make the minimum sectional
areas of the flow passages in a plurality of the refrigerant flow
passages even and it is possible to make the flow rate of the
cooling medium to each of the refrigerant flow passages even.
[0081] It is preferable that the cooling tube has a pair of outer
shell plates, an intermediate plate arranged between a pair of the
outer shell plates, and a corrugated inner fins arranged between
the intermediate plate and the outer shell plates (a thirty-third
aspect of the present invention).
[0082] In this case, it is possible to obtain a cooling tube having
a so-called drawn-cup structure by joining the outer shell plates,
the intermediate plate, and the inner fins all together after the
separate manufacture thereof by means of press molding. Therefore,
it is possible to easily manufacture the cooling tube.
[0083] It becomes easy to form the inner fins at desired areas. Due
to this, for example, it is possible to easily form a supply header
section and a discharge header section by not arranging the inner
fins at the areas at which the supply header section and the
discharge header section are formed.
[0084] In this case, two rows of the refrigerant flow passages are
formed in the direction of built-up of the cooling tubes, as a
result. Therefore, it is possible to prevent the transfer of heat
between the electronic parts arranged at both sides of the cooling
tube. As a result, it is possible, for example, to prevent the
rapid rise in temperature of one of the electronic parts from
affecting the other electron part.
[0085] It is preferable that the outer shell plates are made of a
brazing sheet having a core material and a brazing metal arranged
on an inner surface of the core material, the intermediate plate
and the inner fins are made of a metal plate including a metal
baser than the core material of the outer shell plates, and a pair
of the outer shell plates are joined to each other at the inner
surfaces thereof at the ends (a thirty-fourth aspect of the present
invention).
[0086] In this case, it is possible to prevent the outer shell
plates from corroding by making the inner fins and the intermediate
plate corrode before the outer shell plates. Due to this, it is
possible to prevent the cooling medium from leaking out from the
cooling tubes.
[0087] The brazing material is arranged on the joined surface
between a pair of the outer shell plates and, therefore, it is
possible to easily join a pair of the outer shell plates by brazing
and to easily manufacture the cooling tube.
[0088] The description "a metal baser than the core material" means
a metal, the corrosion potential of which is lower than that of the
metal used as the core material. For example, when aluminum (Al) is
used as the core material and the brazing material, a metal
material, which is aluminum added with zinc (Zn) can be used as a
metal plate used for the intermediate plate and the inner fin.
[0089] It is preferable that the outer shell plates are made of a
brazing sheet having a core material, a sacrifice anode material
arranged on the inner surface of the core material, and the brazing
material arranged on the inner surface of the sacrifice anode
material. (a thirty-fifth aspect of the present invention).
[0090] In this case, it is possible to prevent the core material
from corroding by making the sacrifice anode material corrode first
before the core material in the outer shell plate. Due to this, it
is unlikely that corrosion advances in the direction of thickness
of the outer shell plate and it is possible to prevent the cooling
tube from being pitted.
[0091] For example, when aluminum (Al) is used as the core
material, a meta material, which is aluminum added with zinc (Zn)
can be used as the sacrifice anode material.
[0092] It is preferable that the outer shell plates are made of a
brazing sheet having a core material and a sacrifice anode material
arranged on the inner surface of the core material, the
intermediate plate is made of a brazing sheet having core material
and brazing materials arranged on both surfaces of the core
material, the inner fins are made of a metal plate including a
metal baser than the core material of the outer shell plate, and a
pair of the outer shell plates are formed by joining the inner
surface at ends thereof to both surfaces at the ends of the
intermediate plate (a thirty-sixth aspect of the present
invention).
[0093] In this case, it becomes possible to cover the entire inner
surface of the cooling tube with the sacrifice anode material, and
it is possible to prevent the core material of the outer shell
plates from corroding and also to prevent the cooling tube from
being pitted.
[0094] Moreover, a pair of the outer shell plates are joined to the
end parts of both surfaces of the intermediate plate, both surfaces
of which are provided with the brazing material. Therefore, it is
possible to easily join a pair of the outer shell plates to the
intermediate plate by brazing and, therefore, to easily manufacture
the cooling tube.
[0095] It is preferable that a first cooling tube, which has been
arranged at one end in the direction of built-up of a plurality of
the cooling tubes, has a refrigerant introduction inlet for
introducing the cooling medium to the supply header section and a
refrigerant discharge outlet for discharging the cooling medium
from the discharge header section and, at the same time, the
refrigerant introduction inlet and the refrigerant discharge outlet
have a protruding opening part protruding toward the outside of the
first cooling tube, and a refrigerant introduction pipe and a
refrigerant discharge pipe are inserted into the protruding opening
parts at the refrigerant introduction inlet and the refrigerant
discharge outlet, respectively (a thirty-seventh aspect of the
present invention).
[0096] In this case, it is possible to prevent the flow passage
between the supply header section and the refrigerant flow passage
or between the discharge header section and the refrigerant flow
passage from being blocked by the above-mentioned refrigerant
introduction pipe or the refrigerant discharge pipe. Due to this,
it is possible for the first cooling tube also to ensure the
sectional area of the flow passage similar to that of other cooling
tubes and it becomes possible to evenly cool the electronic
parts.
[0097] The above-mentioned protruding opening part can be formed by
means of, for example, burring process by erecting the protruding
opening part on the main surface of the cooling tube substantially
vertically. Moreover, the protruding opening part can be made to
protrude, for example, 2 mm.
[0098] The symbols in the parenthesis attached to each means
indicate the relationship of correspondence with specific means in
embodiments, which will be described later.
[0099] The present invention may be more fully understood from the
description of the preferred embodiments of the invention set forth
below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0100] FIG. 1 is a front view of a cooler according to a first
embodiment of the present invention.
[0101] FIG. 2 is a sectional view of an important part, along the
I-I line in FIG. 1.
[0102] FIG. 3A is a front view of a tube alone in FIG. 1.
[0103] FIG. 3B is a plan view of the tube in FIG. 3A.
[0104] FIG. 4 is an enlarged view of an important part of an inner
fin in FIG. 2.
[0105] FIG. 5 is a diagram showing a relationship between the fin
flow passage width wf and the tube surface temperature Tw.
[0106] FIG. 6 is a diagram showing a relationship between the fin
height hf and the tube surface temperature Tw.
[0107] FIG. 7 is a diagram showing a relationship between the fin
plate thickness tf and the tube surface temperature Tw.
[0108] FIG. 8 a diagram showing a relationship between the plate
thickness tp of plates 1a and 1b and the tube surface temperature
Tw.
[0109] FIG. 9A is a front view of a cooler according to a second
embodiment of the present invention.
[0110] FIG. 9B is a plan view of the cooler in FIG. 9A.
[0111] FIG. 10 is a sectional view of a tube alone in a cooler
according to a third embodiment of the present invention.
[0112] FIG. 11A is a sectional view of a tube 1 in a free state in
a cooler according to a fourth embodiment of the present
invention.
[0113] FIG. 11B is a sectional view of a fin 5 in a state of being
buckled.
[0114] FIG. 12A is a sectional view of a tube alone in a cooler
according to a fifth embodiment.
[0115] FIG. 12B is an enlarged sectional view of part B in FIG.
12A.
[0116] FIG. 13A is a sectional view of a tube alone in a cooler
according to a sixth embodiment of the present invention.
[0117] FIG. 13B is an enlarged sectional view of part C in FIG.
13A.
[0118] FIG. 14A is a sectional view of a tube alone in a cooler
according to a seventh embodiment of the present invention.
[0119] FIG. 14B is an enlarged sectional view of part D in FIG.
14A.
[0120] FIG. 15A is a sectional view of a tube alone in a cooler
according to an eighth embodiment of the present invention.
[0121] FIG. 15B is an enlarged sectional view of part E in FIG.
15A.
[0122] FIG. 16 is a front view of the cooler according to the first
embodiment of the present invention.
[0123] FIG. 17 is a plan view of the cooler in FIG. 16.
[0124] FIG. 18 is a sectional view along the II-II line in FIG.
16.
[0125] FIG. 19 is a sectional view of a tube along the III-III line
in FIG. 17.
[0126] FIG. 20 is an enlarged view of part C in FIG. 16.
[0127] FIG. 21 is a front view of the cooler according to the
second embodiment of the present invention.
[0128] FIG. 22 is a plan view of a cooler of a built-up type in an
eleventh embodiment.
[0129] FIG. 23 is a sectional view in the vicinity of a supply
header section of the cooler of a built-up type in the eleventh
embodiment.
[0130] FIG. 24 is a sectional view in the vicinity of the supply
header section in the eleventh embodiment before a diaphragm part
is deformed.
[0131] FIG. 25 is a sectional perspective view of a cooling tube in
the eleventh embodiment.
[0132] FIG. 26 is a sectional view of a connection part of a
refrigerant introduction pipe (or a refrigerant discharge pipe) and
a refrigerant introduction inlet (or a refrigerant discharge
outlet) in the eleventh embodiment.
[0133] FIG. 27 is a sectional view in the vicinity of a supply
header section of a cooler of a built-up type in a twelfth
embodiment.
[0134] FIG. 28 is a sectional view in-the vicinity of the supply
header section in the twelfth embodiment when the radius of
curvature at the rise part of a protruding pipe part is
increased.
[0135] FIG. 29 is a sectional view in the vicinity of the supply
header section in the twelfth embodiment when the rise part of the
protruding pipe part is reinforced with a fillet made of a brazing
material.
[0136] FIG. 30 is a sectional view in the vicinity of a supply
header section of a cooler of a built-up type in a comparative
example.
[0137] FIG. 31 is a sectional view in the vicinity of a supply
header section of a cooler of a built-up type in a thirteenth
embodiment.
[0138] FIG. 32 is a sectional view of a cooling tube, which is
perpendicular to a refrigerant flow passage in a fourteenth
embodiment.
[0139] FIG. 33 is a sectional view of a supply header section (a
discharge header section) in the fourteenth embodiment.
[0140] FIG. 34 is a sectional view of a cooling tube, which is
perpendicular to a refrigerant flow passage in a fifteenth
embodiment.
[0141] FIG. 35 is a sectional view of a supply header section (or a
discharge header section) in the fifteenth embodiment.
[0142] FIG. 36 is a sectional view of a cooling tube, which is
perpendicular to a refrigerant flow passage in a sixteenth
embodiment.
[0143] FIG. 37 is a sectional view of a supply header section (or a
discharge header section) in the sixteenth embodiment.
[0144] FIG. 38 is a perspective view of a tube alone in a
conventional cooler.
[0145] FIG. 39 is a plan view of a cooler of a built-up type in a
conventional example.
[0146] FIG. 40 is a sectional view of a cooler of a built-up type
in another conventional example.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0147] A cooler according to a first embodiment of the present
invention is explained below. FIG. 1 is a front view of the cooler
according to the first embodiment, FIG. 2 is a sectional view of an
important part along the I-I line in FIG. 1, FIG. 3A is a front
view of a tube alone in FIG. 1, FIG. 3B is a plan view of the tube
in FIG. 3A, and FIG. 4 is an enlarged view of an important part of
a fin in FIG. 2.
[0148] The cooler of the present invention can be used to cool a
semiconductor module of a double-sided cooling type in an inverter
for a hybrid electric vehicle.
[0149] As shown in FIG. 1 and FIG. 2, the cooler comprises: a
plurality of tubes 1 in which a fluid passage 10 is formed
internally through which a cooling fluid flows and piled at
predetermined intervals in the direction Y (hereinafter, referred
to as the direction of built-up Y) perpendicular to the direction X
(hereinafter, referred to as the direction of flow X) of flow of
the cooling fluid in the fluid passage 10; bellows 2 arranged
between neighboring tubes 1 and coupling the neighboring tubes 1;
an inlet pipe 3 joined by brazing to the tube 1 located at the end
in the direction of built-up Y and into which the cooling fluid
flows; an outlet pipe 4 joined by brazing to the tube 1 located at
the end in the direction of built-up Y and from which the cooling
fluid flows out; and fins 5 arranged within the fluid passage 10
and accelerating heat exchange. The bellows 2 correspond to
coupling means of the present invention. As the cooling fluid,
water mixed with an ethylene glycol base antifreeze liquid is used
in the present embodiment.
[0150] As shown in FIG. 2 to FIG. 4, the tube 1 comprises two
plates 1a and 1b, which are made by forming a thin plate made of
aluminum into a predetermined shape by press molding, and is formed
by joining by brazing the edges of the two plates 1a and 1b in a
state in which the fin 5, which is made by forming a thin plate
made of aluminum into a corrugated plate by press molding, is
sandwiched between the two plates 1a and lb. It is preferable that
the plates 1a and 1b and the fin 5 use a brazing sheet material
with a sacrifice anode material attached to the inside thereof, in
order to prevent pitting corrosion. The joined part is brazed using
a paste brazing material, etc. Moreover, it is also preferable that
the fin uses a brazing sheet material, both surfaces of which are
clad with a brazing material.
[0151] In the tube 1, circular connection holes 11, which allow the
fluid passage 10 and the inside of the bellows 2 to connect with
each other, are formed at both ends in the direction of the cooling
fluid flow within the fluid passage 10 and, at the same time, at
the end faces in the direction of built-up Y. The connection holes
11 are formed by press molding before joining by brazing.
[0152] The bellows 2 is a bellows-shaped pipe and can extend and
contract readily in the direction of built-up Y. In addition, the
bellows 2 is made of aluminum and is joined by brazing to the tubes
1 so as to surround each of the connection holes 11 of the tube 1
adjacent thereto.
[0153] The inlet pipe 3 and the outlet pipe 4 are made of aluminum,
and inserted into the connection holes 11 of the tube 1 located at
the end in the direction of built-up Y and are joined by brazing to
the tube 1. The inlet pipe 3 and outlet pipe 4 are connected to a
pump (not shown) for circulating the cooling fluid and a heat
exchanger (not shown) for cooling the cooling fluid.
[0154] The fin 5 is partly joined by brazing to the tube 1 and the
portions of the fin 5, which are joined to the tube 1, are formed
into an arc shape. The fins 5 are arranged in areas so that the
fins 5 do not overlap the connection holes 11 when viewed in the
direction of built-up Y. In addition, the fin 5 divides the fluid
passage 10 within the tube 1 into a plurality of fine (small) flow
passages.
[0155] A semiconductor module of a double-sided cooling type 6,
which is a heat producing body, incorporates an IGBT element and a
diode, corresponding to an electronic part according to the present
invention. As shown in FIG. 1, the semiconductor module 6 is
arranged between neighboring tubes 1 and the tubes 1 and the
semiconductor module 6 come into contact with each other directly,
or via an insulating material (a ceramic plate, in most cases) or a
thermally conductive grease. The semiconductor module 6 is held
between the tubes 1 by sandwiching and pressing the piled tubes 1
from both ends in the direction of built-up Y using plate springs,
not shown.
[0156] In the above-mentioned configuration, the cooling fluid that
has flowed in from the inlet pipe 3 flows into one end of the fluid
passage 10 of each of the tubes 1 through the bellows 2, flows
through the fluid passage 10 along the direction of flow X, and
reaches the outlet pipe 4 through the bellows 2 from the other end
of the fluid passage 10. Then, heat exchange is effected between
the cooling fluid flowing through the fluid passage 10 and the
semiconductor module 6 and, thus, the semiconductor module 6 is
cooled.
[0157] In order to reduce the temperature of the semiconductor
module 6 below the warranty temperature, the specifications of the
plates 1a and 1b and the fin 5 are designed and optimized so that a
temperature Tw (hereinafter, referred to as a tube surface
temperature) at the portion of the tube 1, with which the
semiconductor module 6 comes into contact, falls below a
predetermined temperature (110.degree. C., in the present
embodiment).
[0158] The result of the discussion on the specifications of the
plates 1a and 1b and the fin 5 is explained below. Here, a fin flow
passage width wf, a fin height hf, a fin plate thickness tf, and a
plate thickness tp are discussed. The fin flow passage width wf is
a dimension in the direction perpendicular to both the direction of
flow X and the direction of built-up Y, at a central position in
the direction of fin height in the fine flow passage.
[0159] The design conditions are as follows: the temperature of the
cooling fluid that flows into the cooler is 65.degree. C.; the
heating value of the semiconductor module 6 is 400 W/unit; and the
flow rate of the cooling fluid in the single tube 1 is a constant
value of 1 L/min. In addition, the relationship between a plate
width wp and a width we of the semiconductor module 6 is determined
so that wp>we holds. The plate width wp is a dimension in the
direction perpendicular to both the direction of flow X and the
direction of built-up Y in a flat surface of the tube 1 in
opposition to the semiconductor module 6. The width we of the
semiconductor module 6 is a dimension thereof in the direction
perpendicular to both the direction of flow X and the direction of
built-up Y.
[0160] FIG. 5 shows the tube surface temperature Tw when the fin
flow passage width wf is varied. Here, the fin height hf is set to
4.0 mm, the fin plate thickness tf is set to 0.2 mm, and the plate
thickness tp is set to 0.4 mm.
[0161] From the result, it is found possible to reduce the tube
surface temperature Tw to 110.degree. C. or lower by setting the
fin flow passage width wf to 1.2 mm or less. It is preferable that
the fin flow passage width wf be about 0.9 mm if clogging with
foreign matter and the cooling performance are taken into
account.
[0162] FIG. 6 shows the tube surface temperature Tw when the fin
height hf is varied. Here, the fin flow passage width wf is set to
0.9 mm, the fin plate thickness is set to 0.2 mm, and the plate
thickness tp is set to 0.4 mm.
[0163] From the result, it is found possible to reduce the tube
surface temperature Tw to 110.degree. C. or lower by setting the
fin height hf to 1 mm to 10 mm. It is preferable that the fin
height hf be about 4 mm if the dimension of the cooler in the
direction of built-up Y and cooling performance are taken into
account.
[0164] FIG. 7 shows the tube surface temperature Tw when the fin
plate thickness tf is varied. Here, the fin flow passage width wf
is set to 0.9 mm, the fin height hf is set to 4.0 mm, and the plate
thickness tp is set to 0.4 mm.
[0165] From the result, it is found possible to reduce the tube
surface temperature Tw to 110.degree. C. or lower by setting the
fin plate thickness tf to 1 mm or less. It is most preferable that
the fin plate thickness tf be 0.2 mm from the standpoint of cooling
performance. Currently, the limit of the plate thickness is about
0.03 mm.
[0166] FIG. 8 shows the tube surface temperature Tw when the plate
thickness tp is varied. Here, the fin flow passage width wf is set
to 0.9 mm, the fin height hf is set to 4.0 mm, and the fin plate
thickness tf is set to 0.2 mm.
[0167] From the result, it was found possible to reduce the tube
surface temperature Tw to 110.degree. C. or lower by setting the
plate thickness tp to 5 mm or less. It is preferable that the plate
thickness tp be 0.1 mm or greater from the standpoint of
moldability in the press working and that the plate thickness tp be
about 0.4 mm if the ease of fitting between the semiconductor
module 6 and the surfaces of the plates 1a and 1b (the tube
surface) and moldability are taken into account.
[0168] In the present embodiment, as the tube 1 is formed by
joining the edges of the two plates 1a and 1b formed by press
molding, the inner wall of the coupling part that exists when the
tube is manufactured by extrusion can be removed and it is no
longer necessary to remove the inner wall by machining. Moreover,
as the plate thickness of the plates 1a and 1b can be reduced,
drilling the connection holes 11 is made easy. Therefore, the
fabrication cost can be reduced.
[0169] As the fin 5, as well as the tube 1, can also be formed by
press molding, the manufacturing process is simplified and the
manufacturing cost can be reduced.
[0170] Both the fact that the portion of the fin 5, which is joined
to the tube 1, is arc-shaped and the fact that the tube 1 and the
fin 5 can be made thin produce a synergic effect to make it easier
for the tube 1 to deform when the semiconductor module 6 is held
between the tubes 1 and, therefore, the opposing contact surfaces
of the tube 1 and the semiconductor module 6 are made easier to fit
with each other and the adhesiveness thereof is improved. As a
result, the contact thermal resistance thereof can be reduced.
[0171] As the plate thickness of the plates 1a and 1b can be
reduced, the sectional area of the flow passage of the fluid
passage 10 can be increased accordingly. As a result, the flow
resistance thereof can be reduced and the power of the pump
required to circulate the cooling fluid can also be reduced.
[0172] As the fins 5 are arranged in areas in which the fins 5 do
not overlap the connection holes 11 when viewed in the direction of
built-up Y of the tubes 1, the fins 5 do not occupy any excess area
and, therefore, the pressure loss can be reduced accordingly
compared to the case where the fin 5 occupies the entire area
within the tube 1.
[0173] As the bellows 2 can extend and contract readily in the
direction of built-up Y, it is possible to easily vary the distance
between neighboring tubes 1 in accordance with the thickness of the
semiconductor module 6 when sandwiching and pressing the laminated
(piled) tubes 1 in the direction of built-up Y using the plate
springs.
[0174] As the fin height hf is set greater than the fin flow
passage width wf, the heat transfer area of the fin 5 increases and
the cooling performance improves.
[0175] As the fin plate thickness tf is set to less than the plate
thickness tp, when the semiconductor module 6 is made to come into
closer contact with the surfaces of the plates 1a and 1b (the
surfaces of the tube 1) by applying pressure to the semiconductor
module 6, the surfaces of the semiconductor module 6 and the plates
la and 1b become easier to fit with each other because the fin 5 is
easier to deform compared to the plates 1a and 1b, and, therefore,
the contact thermal resistance therebetween is reduced and the
cooling efficiency is improved.
Second Embodiment
[0176] A cooler according to a second embodiment of the present
invention is explained below. FIG. 9A is a front view of the cooler
according to the second embodiment and FIG. 9B is a plan view of
the cooler in FIG. 9A. The same numerals or letters are assigned to
the parts the same as or similar to those in the first embodiment
and no explanation thereof will be given here.
[0177] In FIG. 9B, the broken line denotes the position at which
the fin 5 is arranged and the alternate long and short dash line
denotes the position at which the semiconductor module 6 is
arranged. As shown in FIG. 9B, the two fins 5 are arranged in the
single tube 1 and the two fins 5 are arranged apart from each other
at an interval 6, along the direction of flow X of the cooling
fluid within the fluid passage 10. The semiconductor module 6 is
arranged within the area in which the fin 5 is arranged when viewed
in the direction of built-up Y of the tubes 1.
[0178] In the present embodiment, as the two fins 5 are arranged in
the single tube 1, it is possible to properly use the two fins 5
having different heat exchange performance according to the heating
value, etc. of the semiconductor module.
[0179] As the cooling fluid receives the heat generated by the
semiconductor module 6 on the upstream side and rises in
temperature, the semiconductor module 6 on the downstream side
relatively rises in temperature accordingly, but it is possible to
improve the cooling performance of the semiconductor module 6 on
the downstream side by changing the type of the fin 5 on the
downstream side to a type having higher performance (for example,
an offset fin). When the semiconductor module 6 on the upstream
side has a high heating value, the cooling performance can be
improved by arranging the fin 5 having higher performance on the
upstream side.
[0180] By providing the intervals 6, the velocity boundary layer of
the cooling fluid is cleared in the interval and the thermal
boundary layer of the cooling fluid is also removed and, therefore,
the ability to cool the semiconductor module 6 on the downstream
side of the interval 6 is improved. It is effective for the
interval 8 to be equal to or greater than 1 mm.
Third Embodiment
[0181] A cooler according to a third embodiment of the present
invention is explained below. FIG. 10 is a sectional view of a tube
in the cooler according to the third embodiment. In the present
embodiment, the configuration of the tube 1 differs from that in
the first embodiment but the other parts are the same as those in
the first embodiment.
[0182] As shown in FIG. 10, the tube 1 in the present embodiment is
formed by bending a plate 1c, which is a thin plate formed into a
predetermined shape by press molding, and joining by brazing the
edges of the plate 1c in a state in which the fin 5 is sandwiched
between the bent plate 1c.
[0183] According to the present embodiment, it is possible to
reduce the number of parts, the time of the fabricating process
and, therefore, the cost compared to the first embodiment in which
the tube 1 is formed by the two plates 1a and 1b. It is preferable
that the plate 1c uses a brazing sheet material having a sacrifice
anode material attached to the inside thereof in order to prevent
the pitting corrosion and a brazing material attached to the
outside thereof in order to effectively perform the joining,
respectively. It is also preferable that the fin use a brazing
sheet having both surfaces clad with a brazing material.
Fourth Embodiment
[0184] A cooler according to a fourth embodiment of the present
invention is explained below. FIG. 11A is a sectional view of the
tube 1 in the cooler according to the fourth embodiment in a free
state and FIG. 11B is a sectional view in a state in which the fin
5 is deformed by buckling force. In the present embodiment, the
configuration of the fin 5 differs from that in the first
embodiment and other parts are the same as those in the first
embodiment.
[0185] In the first embodiment, the arc-shaped fin 5, the portion
of which to be joined to the tube 1 has been formed into an arc
shape, is used, but in the present embodiment, a rectangular fin 5,
the portion of which to be joined to the tube 1 has been formed
into a flat shape as shown in FIG. 11A, is used.
[0186] An experiment was conducted as follows. An electronic part
(not shown) was sandwiched from both sides thereof by the tubes 1
according to the present embodiment and stress was applied in the
direction of built-up Y. The result was that when the thickness of
the fin 5 was 0.4 mm or less, the fin 5 buckled without inflicting
damage (for example, the destruction of the circuit) on the
electronic part.
[0187] From the comparison between the rectangular fin (according
to the present embodiment) and the arc-shaped fin (according to the
first embodiment) having the same thickness of 0.4 mm and the same
pitch, it was found that the arc-shaped fin deformed under less
stress than the rectangular fin and the arc-shaped fin was more
preferable in shape to reduce the stress applied to the electronic
part.
Fifth Embodiment
[0188] A cooler according to a fifth embodiment of the present
invention is explained below. FIG. 12A is a sectional view of a
tube alone in the cooler according to the fifth embodiment and FIG.
12B is an enlarged sectional view of part B in FIG. 12A. In the
present embodiment, the configurations of the tube 1 and the fin 5
differ from those in the first embodiment and the other parts are
the same as those in the first embodiment.
[0189] The plates 1a and 1b in the present embodiment are each made
of a bare material made of aluminum, and the fin 5 is made of a
brazing sheet, which comprises an aluminum core material 50 and
brazing materials 51 coated on the both sides thereof. Zinc (Zn) is
added to the core material 50. The plates 1a and 1b and the fin 5
are joined by the brazing materials 51 of the fin and the two
plates 1a and 1b are joined by a paste brazing material, a
pre-placed brazing material, or the like. The melting point of the
brazing materials 51 is lower than the melting point of the core
material 50 of the fin 5 and the melting point of the plates 1a and
1b.
[0190] According to the present embodiment, as the plates 1a and 1b
are each made of a bare material, it is unlikely that the surfaces
of the plate 1a and 1b (the surface of the tube 1) become rough due
to brazing and, therefore, the contact thermal resistance between
the semiconductor module 6 and the plates 1a and 1b is reduced and
the cooling efficiency is improved.
[0191] As zinc (Zn) is added to the core material 50 of the fin 5,
the fin 5 becomes potentially baser than the plates 1a and 1b.
Therefore, the fin 5 corrodes before the plates 1a and 1b and it is
possible to prevent the tube 1 from being pitted.
Sixth Embodiment
[0192] A cooler according to a sixth embodiment of the present
invention is explained below. FIG. 13A is a sectional view of a
tube alone in the cooler according to the sixth embodiment and FIG.
13B is an enlarged sectional view of part C in FIG. 13A. In the
present embodiment, the configurations of the tube 1 and the fin 5
differ from those in the first embodiment and the other parts are
the same as those in the first embodiment.
[0193] The plates 1a and 1b in the present embodiment are each made
of a brazing sheet, which is an aluminum core material 100 one side
of which is coated with a sacrifice anode material 101, and both
plates are joined so that the core material 100 is located on the
outside and the sacrifice anode material 101 is located on the
inside. The sacrifice anode material 101 is potentially
(electrically) baser than the core material 100. The fin 5 is
identical to the fin 5 in the fifth embodiment.
[0194] According to the present embodiment, even after the fin 5
has corroded completely, the sacrifice anode material 101 corrodes
before the core material 100 in the plates 1a and 1b and,
therefore, the core material 100 of the plates 1a and 1b can be
prevented from corroding and the tube 1 can be prevented from being
pitted.
[0195] As the plates 1a and 1b are joined so that the core material
100 is located on the outside, it is unlikely that the surfaces of
the plates 1a and 1b (the surface of the tube 1) become rough due
to the brazing and, therefore, the contact thermal resistance
between the semiconductor module 6 and the plates 1a and 1b is
reduced and the cooling efficiency is improved.
[0196] As Zn is added to the core material 50 of the fin 5, the fin
5 becomes potentially baser than the plates la and 1b. Therefore,
the fin 5 corrodes before the plates 1a and 1b and it is possible
to prevent the tube 1 from being pitted.
Seventh Embodiment
[0197] A cooler according to a seventh embodiment of the present
invention is explained below. FIG. 14A is a sectional view of a
tube in the cooler according to the seventh embodiment and FIG. 14B
is an enlarged sectional view of part D in FIG. 14A. In the present
embodiment, the configurations of the tube 1 and the fin 5 differ
from those in the first embodiment and the other parts are the same
as those in the first embodiment.
[0198] The plates 1a and 1b in the present embodiment are each made
of a brazing sheet, which is the aluminum core material 100 one
side of which has been coated with a brazing material 102, and both
plates are joined so that the core material 100 is located on the
outside and the brazing material 102 is located on the inside. The
fin 5 is identical to the fin 5 in the fifth embodiment.
[0199] According to the present embodiment, as the plates 1a and 1b
are coated with the brazing material 102, the time (man-hour) of
assembling processes such as a process in which a paste brazing
material is attached can be reduced.
[0200] As the plates 1a and 1b are joined so that the core material
100 is located on the outside, it is unlikely that the surfaces of
the plates 1a and 1b (the surface of the tube 1) become rough due
to the brazing and, therefore, the contact thermal resistance
between the semiconductor module 6 and the plates 1a and 1b is
reduced and the cooling efficiency is improved.
[0201] As Zn has been added to the core material 50 of the fin 5,
the fin 5 becomes potentially baser than the plates 1a and 1b.
Therefore, the fin 5 corrodes before the plates 1a and 1b and it is
possible to prevent the tube 1 from being pitted.
Eighth Embodiment
[0202] A cooler according to an eighth embodiment of the present
invention is explained below. FIG. 15A is a sectional view of a
tube in the cooler according to the eighth embodiment and FIG. 15B
is an enlarged sectional view of part E in FIG. 15A. In the present
embodiment, the configurations of the tube 1 and the fin 5 differ
from those in the first embodiment but the other parts are the same
as those in the first embodiment.
[0203] The plates 1a and 1b in the present embodiment are each made
of a brazing sheet, in which the sacrifice anode material 101 is
arranged between the aluminum core material 100 and the brazing
material 102, and both plates are joined so that the core material
100 is located on the outside and the brazing material 102 is
located on the inside. The fin 5 is identical to the fin 5 in the
fifth embodiment.
[0204] According to the present embodiment, as the plates 1a and 1b
are coated with the brazing material 102, the time (man-hour) of
assembling processes, such as a process in which a-paste brazing
material is attached, can be reduced.
[0205] Moreover, even after the fin 5 has corroded completely, the
sacrifice anode material 101 corrodes before the core material 100
in the plates 1a and 1b and, therefore, the core material 100 of
the plates 1a and 1b can be prevented from corroding and it is
possible to prevent the tube 1 from being pitted.
[0206] As the plates 1a and 1b are joined so that the core material
100 is located on the outside, it is unlikely that the surfaces of
the plates 1a and 1b (the surface of the tube 1) become rough due
to the brazing and, therefore, the contact thermal resistance
between the semiconductor module 6 and the plates 1a and 1b is
reduced and the cooling efficiency is improved.
[0207] As Zn has been added to the core material 50 of the fin 5,
the fin 5 becomes potentially baser than the plates 1a and 1b.
Therefore, the fin 5 corrodes before the plates 1a and 1b and it is
possible to prevent the tube 1 from being pitted.
Ninth Embodiment
[0208] A cooler according to a ninth embodiment of the present
invention is explained below. FIG. 16 is a front view of the cooler
according to the ninth embodiment, FIG. 17 is a top plan view of
the cooler in FIG. 16, FIG. 18 is a sectional view along the II-II
line in FIG. 16, FIG. 19 is a sectional view of a tube along the
III-III line in FIG. 17, and FIG. 20 is an enlarged view of part C
in FIG. 16.
[0209] As shown in FIG. 16 to FIG. 19, the cooler comprises a
plurality of flat tubes 501 having, internally, a fluid passage
501a through which a cooling fluid flows. The plurality of flat
tubes 501 are arranged in layers at predetermined intervals in the
direction Y (hereinafter, referred to as the direction of built-up
Y) perpendicular to the direction X in which the cooling fluid
flows within the fluid passage 501a (referred to as the direction
of flow X). In the present embodiment, water mixed with an ethylene
glycol base antifreeze liquid is used as the cooling fluid.
[0210] The flat tube-501 comprises two plates, which are an
aluminum thin plate formed into a predetermined shape by press
molding. The flat tube 501 is formed by joining by brazing the
edges of the two plates in a state in which a fin 502, which is an
aluminum thin plate formed into a corrugated shape by press
molding, is sandwiched between the two plates.
[0211] In the flat tube 501, in total, three narrow parts 501b,
which become narrow in the direction of built-up Y, are formed in
the vicinity of both ends in the direction of flow X and at the
central part, respectively. The narrow parts 501b extend in the
direction perpendicular to the direction of built-up Y and the
direction of flow X. The narrow parts 501b are located at portions
of the flat tube 501 at which are semiconductor modules (to be
described in detail later) are not held.
[0212] The fins 502 accelerate heat exchange between the cooling
fluid and the flat tube 501 and are arranged at positions at which
the narrow parts 501b are not formed.
[0213] To one end of each flat tube 501, an inlet header tank 503
made of aluminum for distributing the cooling fluid to the flat
tubes 501 is joined by brazing, and to one end of the inlet header
tank 503, an inlet pipe 504 made of aluminum, through which the
cooling fluid flows in, is joined by brazing.
[0214] To the other end of each flat tube 501, an outlet header
tank 505 made of aluminum for gathering the cooling fluid from the
flat tubes 501 is joined by brazing, and to one end of the outlet
header tank 505, an outlet pipe 506 made of aluminum, through which
the cooling fluid flows out, is joined by brazing.
[0215] The inlet pipe 504 and the outlet pipe 506 are connected to
a pump (not shown) for circulating the cooling fluid and to a heat
exchanger (not shown) for cooling the cooling fluid.
[0216] Two semiconductor modules, of a double-sided cooling type
507, which are heat producing bodies, are arranged between
neighboring flat tubes 501. In other words, the semiconductor
modules 507 are arranged in two or more rows (two rows in the
present embodiment) when viewed in the direction of built-up Y. The
flat tube 501 and the semiconductor module 507 come into contact
with each other directly or via an insulating material (a ceramic
plate, in most cases) or thermally conductive grease. The
semiconductor module 507 in the present embodiment which
incorporates an IGBT element and a diode and corresponds to the
electronic part in the present invention.
[0217] The semiconductor module 507 is held between the flat tubes
501, to which a pressing force is applied in the direction of
built-up Y, by sandwiching and pressing the laminated (piled) flat
tubes 501 from both ends in the direction of built-up Y using plate
springs 508. The plate spring 508 applies a pressing force to each
of a plurality of the rows of the semiconductor modules 507
independently of each other by independently sandwiching and
pressing each of the rows in which a plurality of the semiconductor
modules 507 are arranged.
[0218] As described above, when a pressing force is applied in the
direction of built-up Y by the plate spring 508, the flat tube 501
deforms in the direction of built-up Y at the narrow parts 501, as
shown in FIG. 20, in accordance with the interval between the flat
tubes 501 and the thickness of the semiconductor module 507. Due to
this, both the flat tubes 501 and the semiconductor module 507 come
into close contact with each other over the entire surfaces thereof
in opposition to each other. Moreover, as a pressing force is
applied to each of the rows independently of each other, even if
neighboring semiconductor modules 507 vary in thickness from each
other, the flat tube 501 deforms in the direction of built-up Y at
the portion of the central narrow part 501b, thereby the variation
is absorbed.
[0219] In the above-mentioned configuration, the cooling fluid that
has flowed in through the inlet pipe 504 flows into one end of the
fluid passage 501a of each of the flat tubes 501 through the inlet
header tank 503, flows into the outlet header tank 505 through the
fluid passage 501a, and reaches the outlet pipe 506. Then heat
exchange is effected between the cooling fluid flowing through the
fluid passage 501a and the semiconductor module 507 and the
semiconductor module is thus cooled.
[0220] In the present embodiment described above, the flat tube 501
deforms readily in the direction of built-up Y at the narrow parts
501b in accordance with the interval between the flat tubes 501 and
the thickness of the semiconductor modules 507. At this time, as
the part of the flat tube 501 between the narrow parts 501b does
not deform in an arc-shape, the flat tube 501 and the semiconductor
module 7 come into close contact with each other at the entire
surfaces thereof in opposition to each other and a sufficient
contact area can be ensured between the semiconductor module 507
and the flat tube 501.
[0221] What is required is only to form the narrow parts 501b in
the flat tube 501 and, therefore, the above can be achieved without
increasing the number of parts.
[0222] Moreover, as the flat tube 501 deforms readily in the
direction of built-up Y at the narrow parts 501b, stress can be
prevented from concentrating on the joined parts d between the flat
tube 501 and the header tanks 503 and 505 when the flat tube 501
deforms (refer to FIG. 20) and the stress produced by deformation
can be reduced.
[0223] When the header tanks 503 and 505 and the flat tube 501 are
brazed, the brazing material gathers in the narrow parts 501b and,
therefore, it is possible to prevent the brazing material from
flowing up to the part at which the flat tube 501 and the
semiconductor module 507 come into contact with each other.
[0224] As the narrow parts 501b are located at the portions of the
flat tubes 501 at which the semiconductor modules 507 are not held,
it is possible to prevent the contact area between the
semiconductor module 507 and the flat tube 501 from being
reduced.
[0225] As a pressing force is applied to each of the two rows of
the semiconductor modules 507 independently of each other, when
viewed in the direction of built-up Y, even if neighboring
semiconductor modules 507 vary in thickness from each other, the
flat tube 501 deforms in the direction of built-up Y at the center
narrow part 501b and, thereby the variation can be absorbed and the
contact thermal resistance can be reduced.
[0226] As the narrow parts 501b extend perpendicular to both the
direction of built-up Y and the direction of flow X, it is possible
to easily deform the flat tubes 501 in the direction of built-up Y
at the narrow parts 501b.
[0227] As the fins 502 are arranged at positions in the flat tube
501, at which the narrow parts 501b are not formed, it is possible
to utilize the narrow parts 501b to determine the positions of the
fins 502 in the manufacturing process.
Tenth Embodiment
[0228] A cooler according to a tenth embodiment of the present
invention is explained below. FIG. 21 is a front view of the cooler
according to the tenth embodiment. The same numerals or letters are
assigned to the same or equivalent parts as those in the ninth
embodiment and no explanation will be given to them here.
[0229] In the present embodiment, as shown in FIG. 21, a
reinforcement plate 509, the rigidity of which, in the direction of
built-up Y, is higher than that of the flat tube 501, is provided.
The reinforcement plate 509 is made of aluminum and both ends
thereof are joined by brazing to the header tanks 503 and 505 and
the intermediate part is in contact with the flat tube 501 at one
end in the direction of built-up Y.
[0230] After the cooler is mounted on, for example, a vehicle, coil
springs 511 are provided between the flat tube 501 at the other end
in the direction of built-up Y and a fixed wall 510 of the vehicle.
A pressing force is applied in the direction of built-up Y by the
coil springs 511 and, thereby, the semiconductor modules 507 are
held between the flat tubes 501. At this time, the pressing force
of the coil springs 511 is supported by the reinforcement plate
509. The coil spring 511 presses each of the rows of the
semiconductor modules 507, which are arranged in two or more rows,
independently of each other.
[0231] As described above, due to the application of the pressing
force in the direction of built-up Y by the coil spring 511, the
flat tubes 501 deform in the direction of built-up Y at the narrow
parts 501b in accordance with the interval between the flat tubes
501 and the thickness of the semiconductor modules 507 and, thereby
the flat tubes 501 and the semiconductor module 507 come into close
contact at the entire surfaces thereof in opposition to each other.
Moreover, as a pressing force is applied to each of the rows
independently of each other, even if neighboring semiconductor
modules 507 vary in thickness from each other, the flat tube 501
deforms in the direction of built-up Y at the center narrow part
501b and, thereby the variation is absorbed.
[0232] In the present embodiment, as the strength of the cooler can
be improved by the reinforcement plate 509, it is possible to
prevent the cooler itself from deforming during the transportation
of the cooler that does not hold a semiconductor module 507.
[0233] Although coil springs 511 are used in the present
embodiment, a pressing force may be applied in the direction of
built-up Y by plate springs.
Eleventh Embodiment
[0234] A cooler of built-up type according to an embodiment of the
present invention is explained below with reference to FIG. 22 to
FIG. 26.
[0235] As shown in FIG. 22, a cooler of built-up type 1001
according to the present embodiment cools an electronic parts 1004
from both sides thereof, each of which accommodates an power
element, etc., for controlling large power and is formed into a
plate-like shape. The electronic part 1004 is formed into a flat
rectangular solid, in which an electrode for power extends from the
outer surface including one long side and another electrode for
control extends from the outer surface including the other long
side.
[0236] A cooling tube 1002 is arranged in contact with one of the
main surfaces of the electronic part 1004 and another cooling tube
1002 is arranged in contact with the other main surface of the
electronic part 1004. These cooling tubes 1002 are connected to a
supply header section 1011 and a discharge header section 1012
provided at both ends of the cooling tubes 1002. In the present
embodiment, a plurality of the electronic parts 1004 are cooled
from both sides thereof. Because of this, a plurality of the
electronic parts 1004 and a plurality of the cooling tubes 1002 are
arranged alternately. In an assembled body in which a plurality of
the electronic parts 1004 and a plurality of the cooling tubes 1002
are arranged in layers, the cooling tubes 1002 are arranged at both
ends of the assembled body in the direction of built-up
thereof.
[0237] The cooler of a built-up type 1001 comprises a plurality of
the cooling tubes 1002, which are each flat and are provided with a
refrigerant flow passage 1021 through which a cooling medium 1005
flows, and which are arranged in layers so as to sandwich and hold
the electronic parts 1004 from both sides thereof. The cooler of a
built-up type 1001 comprises the supply header section 1011 for
supplying the cooling medium 1005 to each of the refrigerant flow
passages 1021 and the discharge header section 1012 for discharging
the cooling medium 1005 from each of the refrigerant flow passages
1021.
[0238] As shown in FIG. 22 and FIG. 23, the above-mentioned cooling
tube 1002 is provided with protruding pipe parts 1022 that protrude
as well as opening toward the direction of built-up. As shown in
FIG. 25, the cooling tube 1002 is made up by building plates made
of metal having a high thermal conductivity, such as aluminum or
copper, and by joining the plates by means of joining techniques
such as brazing. The plates have a substantially rectangular shape
as a whole. An outer shell plate 1027 that makes up the outer shell
of the cooling tube 1002 comprises parts making up a flat pipe that
comes into contact with the electronic part 1004 to take heat
therefrom and parts making up the supply header section 1011 and
the discharge header section 1012. The parts making up the supply
header section 1011 and the discharge header section 1012 are
formed at both ends of the outer shell plate 1027.
[0239] The parts making up the supply header section 1011 and the
discharge header section 1012 of the outer shell plate 1027 are
characterized by the protruding pipe parts 1022 protruding in the
vertical direction from the plate-shaped surface of the outer shell
plate 1027 and diaphragm parts 1023 formed into an annular shape on
the periphery of the root parts of the protruding pipe parts 1022
and having a predetermined width in the radial direction. The
respective protruding pipe parts 1022 couple neighboring cooling
tubes 1002 in the direction of built-up, make up the supply header
section 1011 and the discharge header section 1012, and provide a
strength that can prevent buckling in the direction of
built-up.
[0240] The cooling tube 1002 can comprise the flat pipe part, the
diaphragm parts 1023, and the protruding pipe parts 1022 extending
in the direction of built-up. The protruding pipe part 1022 may
comprise a pipe-shaped member separately provided.
[0241] The protruding pipe parts 1022 are connected using
counter-lock joints (like female and male joints). In other words,
the protruding pipe part 1022 has a stepped protruding pipe part
having a large diameter 1223 arranged outside and a protruding pipe
part having a small diameter 1222 inserted into the inside of the
protruding pipe part having a large diameter 1223. Because of this,
the cooler of a built-up type 1001 comprises at least two kinds of
outer shell plates 1027. One of the two kinds of outer shell plates
1027 has the protruding pipe part having a large diameter 1223 and
the other kind of outer shell plates 1027 has the protruding pipe
part having a small diameter 1222. These two kinds of outer shell
plates 1027 are laminated (piled) alternately in such a manner that
the top surface of one (first) kind of the outer shell plates faces
the undersurface of the other kind, the topsurface of which in turn
faces the undersurface of the first kind, and so on.
[0242] The cooler of a built-up type 1001 further comprises the
outer shell plates 1027 for end use at both ends thereof. In other
words, one of the outer shell plates 1027 for end use neither forms
the protruding pipe part 1022 nor opens. The other outer shell
plate 1027 for end use is the outer shell plate 1027 to be used for
a cooling pipe 1020, which will be described later, and forms a
protruding opening parts 1024 for connecting a refrigerant
introduction pipe 1031 and a refrigerant discharge pipe 1032
instead of the protruding pipe parts 1022, as shown in FIG. 26.
[0243] The protruding pipe part having a large diameter 1223
accommodates the protruding pipe part having a small diameter 1222
therein. The stepped part formed in the protruding pipe part having
a large diameter 1223 functions as a control part for controlling
the insertion length of the protruding pipe part having a small
diameter 1222. The front end of the protruding pipe part having a
small diameter 1222 comes into contact with the stepped part and
thus the insertion length in the axial direction is controlled. The
controlled part can be composed of a swelling part or a bulged part
formed on the outer surface of the protruding pipe part with small
diameter 1222 in a protruding manner. There exists an interval
between the inner surface of the protruding pipe part having a
large diameter 1223 and the outer surface of the protruding pipe
part having a small diameter 1222, which may allow an insertion in
the assembling process thereof, but the interval is closed and
sealed by joining both protruding pipe parts by brazing.
[0244] After being joined, the protruding pipe parts 1022 provide
rigidity that can prevent buckling even if a pressure in the axial
direction, namely in the direction of built-up, which can
plastically deform the diaphragm part 1023, is applied thereto.
[0245] On each of the outer edge parts of the outer shell plate
1027, an outer wall surface 1274 that is erected in the direction
of built-up, a flange part 1275 having a narrow width and extending
from the outer wall surface 1274 toward the outside, and an edge
part 1276 further extending obliquely from the front end of the
flange part 1275 are formed, as shown in FIG. 23 and FIG. 24. The
flange part 1275 provides a plane extending in the direction
perpendicular to the direction of built-up.
[0246] A pair of the outer shell plates 1027 is joined by brazing
in a state in which the flange parts 1275 thereof are arranged so
as to be parallel to and in contact with each other. Therefore, the
outer shell plates 1027 are piled and joined at the outer edge part
thereof by the flange part 1275 via a plane perpendicular to the
direction of built-up in between. On the other hand, the outer
shell plates 1027 are piled and joined at the parts making up the
supply header section 1011 and the discharge header section 1012 by
connecting the protruding pipe parts 1022 using counter-lock joints
via a cylindrical plane in parallel to the direction of built-up in
between. It may be possible to adopt a configuration in which
flange parts are provided at the front ends of the protruding pipe
parts 1022 extending in the directions in opposition to each other
and the outer shell plates are piled and joined via a plane
perpendicular to the direction of built-up in between.
[0247] The configuration in which the protruding pipe parts 1022
are connected using counter-lock joints has advantages that the
degree of freedom in adjusting the length in the axial direction is
higher compared to the structure in which built-up is conducted via
a plane perpendicular to the direction of built-up in between, that
the manufacture of the outer shell plate 1027 in the forming
process is easy, and that the cost is low.
[0248] As described above, neighboring cooling tubes 1002 make the
refrigerant flow passages 1021 thereof communicate with each other
by joining the sidewalls of the protruding pipe parts 1022 as well
as inserting the protruding pipe parts 1022 into each other. Due to
this, the supply header section 1011 and the discharge header
section 1012 are formed.
[0249] Moreover, as shown in FIG. 23, the cooling tube 1002
comprises the diaphragm parts 1023 that deform in the direction of
built-up and which are formed around the protruding pipe parts
1022. The diaphragm part 1023 deforms toward the inside of the
cooling tube 1002 when the electronic part 1004 is arranged in the
cooler of a built-up type 1001 and the interval between neighboring
cooling tubes 1002 is narrowed.
[0250] In other words, before sandwiching and holding the
electronic parts 1004, the cooler of a built-up type 1001 laminates
a plurality of the cooling tubes 1002 at intervals somewhat wider
than the thickness of the electronic parts 1004 and connects the
cooling tubes 1002 at the protruding pipe parts 1022 thereof, as
shown in FIG. 24. A plurality of the electronic parts 1004 are
arranged between the cooling tubes 1002 of the cooler of a built-up
type 1001 in such a state. After this, the cooler of a built-up
type 1001 is compressed in the direction of built-up. Due to this,
a pressing force is applied to the diaphragm parts 1023 via the
protruding pipe parts 1022 and the diaphragm parts 1023 deform
toward the inside of the cooling tube 1002, as shown in FIG. 23. As
a result, the interval between neighboring cooling tubes 1002 is
narrowed, the cooling tubes 1002 and the electronic part 1004 come
into close contact with each other, and the electronic part 4001 is
sandwiched and held by the cooling tubes 1002.
[0251] Moreover, the cooling tube 1002 comprises a pair of the
outer shell plates 1027, an intermediate plate 1028 arranged
between the pair of the outer shell plates 1027, and a corrugated
inner fins 1029 arranged between the intermediate plate 1028 and
the outer shell plates 1027, as shown in FIG. 25.
[0252] The refrigerant flow passages 1021 are formed between the
intermediate plate 28 and the outer shell plates 27.
[0253] Moreover, the outer shell plates 1027, the intermediate
plate 1028, and the inner fins 1029 are joined to one another by
brazing to make up the cooling tube 1002.
[0254] The intermediate plate 1028 is a rectangular plate-like
shape. The intermediate plate 1028 has circular opening parts 1284
at both ends thereof corresponding to the supply header section
1011 and the discharge header section 1012. The outer edge part of
the intermediate plate 1028 may be sandwiched and held between the
outer shell plates 1027.
[0255] As shown in FIG. 22, a first cooling tube 1020 among a
plurality of the cooling tubes 1002, which is arranged at one end
in the direction of built-up, comprises a refrigerant introduction
inlet 1013 for introducing the cooling medium 1005 to the supply
header section 1011 and a refrigerant discharge outlet 1014 for
discharging the cooling medium 1005 from the discharge header
section 1012. The refrigerant introduction inlet 1013 and the
refrigerant discharge outlet 1014 comprise the respective
protruding opening parts 1024 protruding toward the outside of the
first cooling tube 1020, as shown in FIG. 26. Then, the respective
refrigerant introduction pipe 1031 and the refrigerant discharge
pipe 1032 are inserted into the respective protruding opening parts
1024 of the refrigerant introduction inlet 1013 and the refrigerant
discharge outlet 1014.
[0256] The protruding opening part 1024 protrudes about 2 mm from
the main surface of the first cooling tube 1020 as well as rising
substantially vertically on the main surface thereof by means of a
burring process.
[0257] Moreover, the refrigerant introduction pipe 1031 and the
refrigerant discharge pipe 1032 are each provided with a flange
part 1034 at a part about 2 mm apart away from the end surface of
each of opening front end parts 1033.
[0258] The respective opening front end parts 1033 of the
refrigerant introduction pipe 1031 and the refrigerant discharge
pipe 1032 are inserted into the insides of the respective
protruding opening parts 1024 and, at the same time, the flange
parts 1034 come into contact with the front ends of the protruding
opening parts 1024. Due to this, each of the opening front end
parts 1033 of the refrigerant introduction pipe 1031 and the
refrigerant discharge pipe 1032 is unlikely to be inserted as far
as the inside of the outer shell plate 1027 in the cooling tube
1002 and, therefore, the refrigerant flow passage 1021 is unlikely
to be cut off.
[0259] The above-mentioned electronic part 1004 is a semiconductor
module that incorporates semiconductor elements such as an IGBT and
diodes. The semiconductor module makes up a part of an inverter for
a vehicle.
[0260] As the cooling medium 1005, water mixed with an ethylene
glycol base antifreeze liquid is used.
[0261] Moreover, the electronic part 1004 can be arranged in a
state in which the electronic part is in direct contact with the
cooling tube 1002. However, it is possible, as the case may be, to
interpose an insulating plate such as ceramic, thermally conductive
grease, etc. between the electronic part 1004 and the cooling tube
1002.
[0262] Next, the functions and effects of the present embodiment
are explained below.
[0263] In the above-mentioned cooler of a built-up type 1, as shown
in FIG. 22 and FIG. 23, the respective refrigerant flow passages
1021 of neighboring cooling tubes are communicated with each other
by inserting the protruding pipe parts 1022 formed on the cooling
tubes 1002, with each other. Because of this, it is not necessary
for a plurality of the cooling tubes 1002 to be connected
specifically via members separately provided and, therefore, the
number of parts can be reduced and the manufacture of the cooler is
easy.
[0264] Moreover, as shown in FIG. 23, the protruding pipe parts
1022 of neighboring cooling tubes 1002 are connected by joining the
sidewalls of the protruding pipe parts 1022 to each other.
Therefore, it is possible for the supply header section 1011 and
the discharge header section 1012 to ensure a flow passage diameter
substantially the same as the inner diameter of the protruding pipe
part 1022. Due to this, it is possible to not only reduce the flow
resistance in the supply header section 1011 and the discharge
header section 1012 but also to prevent pressure loss. Because of
this, the cooling medium 1005 can be supplied evenly into a
plurality of the cooling tubes 1002 and, moreover, a plurality of
the electronic parts 1004 can be cooled evenly.
[0265] As shown in FIG. 23, the cooling tube 1002 comprises the
diaphragm parts 1023 formed around the protruding pipe parts 1022.
Due to this, it is possible to easily adjust the interval between
neighboring cooling tubes 1002 and to easily and firmly arrange the
electronic parts 1004 between neighboring cooling tubes 1002. As a
result, the electronic part 1004 can be made to come into close
contact with the cooling tubes 1002.
[0266] The cooling tube 1002 comprises a pair of the outer shell
plates 1027, the intermediate plate 1028, and the inner fins 1029.
Because of this, it is possible to obtain the cooling tube 1002
having a so-called drawn-cup structure by joining together the
outer shell plates 1027, the intermediate plate 1028, and the inner
fins 29 after separate manufacture thereof by press molding, etc.
Therefore, the cooling tube 1002 can be manufactured easily.
[0267] Moreover, it becomes easy to form the inner fins 1029 at
desired positions (areas). Because of this, the forming of the
supply header section 1011 and the discharge header section 1012
can be made easy by not arranging the inner fins 1029 at areas at
which the supply header section 1011 and the discharge header
section 1012 are formed.
[0268] In this case, as shown in FIG. 25, the refrigerant flow
passages 1021 are formed in two rows in the direction of built-up
of the cooling tubes 1002, as a result. Because of this, it is
possible to prevent the transfer of heat between the electronic
parts 1004 arranged at both ends of the cooling tube 1002.
Therefore, it is possible, for example, to prevent the rapid rise
in temperature of one of the electronic parts 1004 from affecting
another electronic part 1004.
[0269] The refrigerant introduction inlet 1013 and the refrigerant
discharge outlet 1014 of the first cooling tube 1020 are each
provided with the protruding opening part 1024, as shown in FIG.
26. Because of this, it is possible to prevent the refrigerant
introduction pipe 1031 and the refrigerant discharge pipe 1032 from
cutting off the flow passage between the supply header section 1011
or the discharge header section 1012 and the refrigerant flow
passage 1021. Therefore, it is also possible for the first cooling
tube 1020 to ensure a flow passage sectional area similar to that
of the other cooling tubes 1002 and, as a result, the electronic
parts 1004 can be cooled evenly.
[0270] As described above, according to the present embodiment, it
is possible to provide a cooler of a built-up type capable of not
only reducing the manufacturing cost but also making a cooling
medium flow evenly to a plurality of cooling tubes.
Twelfth Embodiment
[0271] A twelfth embodiment is an embodiment, as shown in FIG. 27
to FIG. 29, in which a cooling tube 1002 comprises a diaphragm part
1023 formed around one of a pair of protruding pipe parts 1022
arranged in opposition to each other, and does not comprise a
diaphragm part 1023 around the other protruding pipe part 1022.
[0272] The cooling tube 1002 comprises the diaphragm part 1023
formed around one of a pair of the protruding pipe parts 1022 which
is provided on the downstream side of the supply header section
1011.
[0273] Moreover, a flow rectifying part 1025 is provided at the
inlet part of the cooling tube 1002 which is a part of the
intermediate plate 1028 deformed so as to be involved in the
upstream side of the supply header section 1011. The flow
rectifying part 1025 controls the flow passage sectional area at
the inlet part of one of the two rows of refrigerant flow passages
1021 sandwiching the intermediate plate 1028 to be equal to that of
the other refrigerant flow passage 1021.
[0274] The flow rectifying part 1025 is formed at the edge of the
opening part 1284 of the intermediate plate 1028. The flow
rectifying part 1025 adjusts the flow rate of the refrigerant fluid
to be distributed to the upper and lower flow passages defined by
the intermediate plate 1028. It is possible to adjust the flow rate
of the refrigerant fluid to be distributed evenly or unevenly by
the shape of the flow rectifying part 1025 in accordance with, for
example, the need to cool the electronic parts 1004, which are
objects to be cooled. The flow rectifying part 1025 is formed by
deforming the edge part of the opening part of the intermediate
plate 1028 by a predetermined deformation amount in the same
direction as that in which the diaphragm part 1023, provided to
only one of the cooling tubes 1002, deforms.
[0275] As described above, methods for forming the diaphragm part
1023 around only one of the protruding pipes 1022, namely methods
for deforming only one part includes, for example, a method in
which the other protruding pipe part 1022 is prevented from being
deformed by a pressing force in the direction of built-up by
reinforcing the rising part of the other protruding pipe part 1022,
as shown in FIG. 28 and FIG. 29. In other words, the method shown
in FIG. 28 is a method in which the radius of curvature of the
outer shell plate 1027 is increased at the rising part of the other
protruding pipe part 1022. The method shown in FIG. 29 is a method
in which a fillet 1221 made of a brazing material, which is formed
by joining the protruding pipe parts 1022 of neighboring cooling
tubes 1002 by brazing, is made to overlap the rise part of the
other protruding pipe part 1022.
[0276] Others are the same as those in the eleventh embodiment.
[0277] In the case of the present embodiment, it becomes easy to
manufacture the cooler of a built-up type 1 so as to have a
constant shape in a state in which the electronic part 1004 is
sandwiched and held therebetween.
[0278] In other words, if the diaphragm parts 1023 are provided
around both the protruding pipe parts 1022 and deformed as in the
eleventh embodiment (refer to FIG. 23), the two protruding pipe
parts may vary in the amount of deformation from each other. Then,
in this case, if an attempt is made to adjust the amount of
deformation of the diaphragm parts 1023, it becomes necessary to
accurately control various conditions such as the throttle
(reducing area) rate during press molding and the plate thickness
of the cooling tube 1002.
[0279] Therefore, as described above, by providing the diaphragm
part 1023 to only one of the protruding pipe parts 1022, it becomes
easy to perform a specific deformation, when the electronic part
1004 is sandwiched and held by the cooling tubes 1002,
substantially in accordance with the design.
[0280] Moreover, the cooling tube 1002 comprises the diaphragm part
1023 formed around the protruding pipe part 1022 formed on the
downstream side of the supply header section 1011, which is one of
a pair of the protruding pipe parts 1022. Because of this, it is
possible to prevent the smooth supply of the cooling medium 1005
from the supply header section 1011 to the cooling pipe 1002 from
being blocked by the diaphragm part 1023.
[0281] In other words, if, as shown in FIG. 30, the diaphragm part
1023 is provided around only one of a pair of the protruding pipe
parts 1022 which is formed on the upstream side of the supply
header section 1011, the smooth supply of the cooling medium 1005
from the supply header section 1011 to the cooling tube 1002 may be
blocked. In other words, when the cooling medium 1005 is supplied
from the supply header part 1011 to the cooling tube 1002, the flow
of the cooling medium 1005 may separate in the vicinity of the
diaphragm part 1023.
[0282] Other parts have the same functions and effects as those in
the eleventh embodiment.
Thirteenth Embodiment
[0283] A thirteenth embodiment is an embodiment, as shown in FIG.
31, in which the cooling tube 1002 comprises a throttle (reducing
area) part 1026 for narrowing the width of the refrigerant flow
passage 1021 at the inlet part of the refrigerant flow passage
1021.
[0284] The cooling tube 1002 is provided with the diaphragm part
1023 and the flow rectifying part 1025 as in the twelfth
embodiment.
[0285] The throttle part 1026 is formed simultaneously when the
outer shell plate 1027 is formed by press molding.
[0286] The throttle part 1026 extends continuously across a part of
the outer shell plate 1027 in the direction of width of the
outershell plate, which makes up the flat part of the cooling tube
1002. The throttle part 1026 is formed on the outer shell plate
1027 into a groove-like shape when viewed from the outside thereof.
The throttle part 1026 reduces the height of the refrigerant flow
passage 1021 in the direction of built-up. The throttle part 1026
can be formed as a recess part arranged discretely.
[0287] The throttle part 1026 is arranged on the downstream side of
the diaphragm part 1023. To be more exact, the throttle part 1026
is arranged between a portion of the cooling tube 1002, which comes
into contact with the electronic part 1004, and the diaphragm part
1023. In other words, the throttle part 1026 is arranged on the
upstream side of the portion of the cooling tube 1002, which comes
into contact with the electronic part 1004.
[0288] The throttle part 1026 can also be arranged on the
downstream side of the portion of the cooling tube 1002, which
comes into contact with the electronic part 1004. Further, the
throttle part 1026 can also be arranged on both the upstream side
and the downstream side of the portion of the cooling tube 1002,
which comes into contact with the electronic part 1004.
[0289] The throttle part 1026 has greater rigidity than that of the
diaphragm part 1023. The diaphragm part 1023 can be regarded as a
part having relatively small rigidity, which readily deforms
plastically in the direction of built-up.
[0290] The shape of the throttle part 1026 is specified so that the
flow passage sectional area of the refrigerant flow passage 1021 at
the throttle part 1026 is a minimum. Then, all of the cooling tubes
1002 are made to have the same minimum flow passage sectional
area.
[0291] Other features are the same as those in the eleventh
embodiment.
[0292] In the case of the present embodiment, even if the
communication area between the header section and the refrigerant
flow passage changes because of the deformation of the diaphragm
part 1023, the flow rate in the refrigerant flow passage can be
adjusted to a desired value by means of the throttle part 1026.
This configuration exhibits an advantageous effect when the amount
of deformation varies among a plurality of the diaphragm parts
1023. In other words, even if the amount of deformation varies
among the diaphragm parts 1023, it becomes easy to make the minimum
flow passage sectional area uniform in a plurality of the
refrigerant flow passages 1021 and, therefore, the flow rate of the
cooling medium 1005 to the respective refrigerant flow passages
1021 can be made uniform.
[0293] Other parts have the same functions and effects as those in
the eleventh embodiment.
Fourteenth Embodiment
[0294] A fourteenth embodiment is an embodiment, as shown in FIG.
32 and FIG. 33, in which metal plates are used as an outer shell
plate 1027, an intermediate plate 1028, and an inner fin 1029 all
making up the cooling tube 1002.
[0295] In other words, the outer shell plate 1027 is made of a
brazing sheet having a core material 1271 and a brazing material
1272 arranged on the inner surface of the core material 1271.
[0296] The intermediate plate 1028 and the inner fin 1029 are
composed of metal plates including a metal baser (that is, the
corrosion potential is lower) than the core material 1271 of the
outer shell plate 1027.
[0297] A pair of the outer shell plates 1027 join the inner
surfaces, at end parts thereof, to each other.
[0298] In the case of the present embodiment, as shown in FIG. 33,
the protruding pipe part 1022 is provided with the brazing material
1272 arranged on the inner surface thereof. Then, when the
protruding pipe parts 1022 of neighboring cooling tubes 1002 are
inserted into each other, the brazing material 1272 arranged on the
inner surface of one of the protruding pipe parts 1022 comes into
contact with the outer surface of the core material 1271 of the
other protruding pipe part 1022. Therefore, by heating the contact
part in this state, the protruding pipe parts 1022 are joined to
each other by the brazing material 1272.
[0299] Aluminum (Al) can be used as the core material 1271 and the
brazing material 1272 of the outer shell plate 1027 and a metallic
material, which is aluminum to which zinc (Zn) has been added, can
be used as the intermediate plate 1028, the inner fin 1029,
etc.
[0300] Others are the same as those in the eleventh embodiment.
[0301] FIG. 33 shows a state of the diaphragm part 1023 before
deformed. This is applicable to FIG. 35 to FIG. 37, which will be
described later.
[0302] In the case of the present embodiment, by making the inner
fin 1029 and the intermediate plate 1028 corrode before the outer
shell plate 1027, the outer shell plate 1027 can be prevented from
corroding. Because of this, the cooling medium 1005 can be
prevented from leaking from the cooling tube 1002.
[0303] As the brazing material 1272 is arranged on the surfaces, to
be joined, of a pair of the outer shell plates 1027, it is possible
to easily join a pair of outer shell plates 1027 to each other by
brazing and to easily manufacture the cooling tube 1002.
[0304] As shown in FIG. 33, the brazing material 1272 is arranged
on the inner surface of the protruding pipe part 1022 and,
therefore, when the protruding pipe parts 1022 of neighboring
cooling tubes 1002 are inserted into each other, the brazing
material 1272 arranged on the inner surface of one of the
protruding pipe parts 1022 comes into contact with the outer
surface of the core material 1271 of the other protruding pipe part
1022. Because of this, it is possible to easily join the protruding
pipe parts 1022 to each other using the brazing material 1272.
[0305] Other parts have the same functions and effects as those in
the eleventh embodiment.
Fifteenth Embodiment
[0306] A fifteenth embodiment is an embodiment, as shown in FIG. 34
and FIG. 35, in which as the outer shell plate 1027, a brazing
sheet is used, having a core material 1271, a sacrifice anode
material 1273 arranged on the inner surface of the core material
1271, and a brazing material 1272 arranged on the inner surface of
the sacrifice anode material 1273.
[0307] A metallic material, which is aluminum (Al) to which zinc
(Zn) has been added, can be used as the sacrifice anode material
1273.
[0308] Other parts are the same as those in the fourteenth
embodiment.
[0309] In the case of the present embodiment, by making the
sacrifice anode material 1273 corrode before the core material 1271
also in the outer shell plate 1027, the core material 1271 can be
prevented from corroding. Because of this, corrosion is unlikely to
advance in the direction of thickness of the outer shell plate 1027
and the cooling tube 1002 can be prevented from being pitted.
[0310] Other features have the same functions and effects as those
in the fourteenth embodiment.
Sixteenth Embodiment
[0311] A sixteenth embodiment is an embodiment, as shown in FIG. 36
and FIG. 37, in which, as the outer shell plate 1027, a brazing
sheet having a core material 1271 and a sacrifice anode material
1273 arranged on the inner surface of the core material 1271, is
used.
[0312] An intermediate plate 1028 is made of a brazing sheet having
a core material 1281 and a brazing material 1282 arranged on both
sides of the core material 1281. An inner fin 1029 is composed of a
metallic plate including a metal baser (a metal having a lower
corrosion potential) than the core material 1271 of the outer shell
plate 1027.
[0313] A metallic material, which is aluminum (Al) to which zinc
(Zn) has been added, can be used as a metallic plate making up the
inner fin 1029, and a sacrifice anode material 1273.
[0314] A pair of the outer shell plates 1027 is formed by joining
the inner surfaces at the ends thereof to both sides at the ends of
the intermediate plate 1028.
[0315] Moreover, as shown in FIG. 37, the protruding pipe part 1022
is composed of the outer shell plate 1027 on which the brazing
material is not arranged. Therefore, the protruding pipe parts 1022
of neighboring cooling tubes 1002 are joined by newly arranging a
paste brazing material, a ring brazing material, etc (not
shown).
[0316] Other features are the same as those in the eleventh
embodiment.
[0317] In the case of the present embodiment, it becomes possible
to cover the entire inner surface of the cooling tube 1002 with the
sacrifice anode material 1273, to prevent the core material 1271 of
the outer shell plate 1027 from corroding and to prevent the
cooling tube 1002 from being pitted.
[0318] Moreover, a pair of the outer shell plates 1027 are joined
to the end parts of both sides of the intermediate plate 1028, on
both sides of which the brazing material 1282 has been arranged.
Therefore, it is possible to easily join a pair of the outer shell
plates 1027 to the intermediate plate 1028 by brazing and to easily
manufacture the cooling tube 1002.
[0319] Other features have the same functions and effects as those
in the eleventh embodiment.
Other Embodiments
[0320] In the embodiments described above, aluminum is used as a
material of a tube and a fin, but a metallic material such as
copper and resin can also be used as a material of a tube and a
fin, and in this case, a material having a high thermal
conductivity is preferable.
[0321] In each of the embodiments described above, water mixed with
an ethylene glycol base antifreeze liquid is used as a cooling
fluid, but a natural refrigerant such as water and ammonia, a
fluorocarbon base refrigerant such as fluorinate, a
chlorofluorocarbon base refrigerant such as HCFC123 and HFC134a, an
alcohol-based refrigerant such as methanol and alcohol, and a
ketone-based refrigerant such as acetone can also be used as a
cooling fluid.
[0322] In the embodiments described above, the present invention is
applied to cooling of a semiconductor module of a double-sided
cooling type of an inverter for a hybrid electric vehicle, but the
present invention can also be applied to cooling of, for example, a
semiconductor module of a motor drive inverter for industrial
equipment, an air-conditioning inverter for air-conditioning
buildings, etc.
[0323] The cooler according to the present invention can also cool
an electronic part such as a power transistor, a power FET, and an
IGBT, in addition to the semiconductor module 6.
[0324] While the invention has been described by reference to
specific embodiments chosen for the purposes of illustration, it
should be apparent that numerous modifications could be made
thereto by those skilled in the art without departing from the
basic concept and scope of the invention.
* * * * *