U.S. patent application number 16/228275 was filed with the patent office on 2019-09-19 for power converter.
The applicant listed for this patent is Keihin Corporation. Invention is credited to Shinichiro Hayakawa, Kazuki Nakamura, Kenichi Sasaki, Morifumi Shigemasa.
Application Number | 20190289753 16/228275 |
Document ID | / |
Family ID | 65037014 |
Filed Date | 2019-09-19 |
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United States Patent
Application |
20190289753 |
Kind Code |
A1 |
Nakamura; Kazuki ; et
al. |
September 19, 2019 |
POWER CONVERTER
Abstract
A power converter includes a sealing member in a loop shape
sealing a space between a sealing surface of a cooler and a sealing
surface of a casing. Either one of the sealing surface of the
cooler and the sealing surface of the casing is provided with a
groove in a loop shape enabling the sealing member to be fitted
therein. A first positioning portion is provided on a bottom
surface of the groove. The sealing member includes an internal
sealing portion with a circular cross-section and located along the
bottom surface of the groove, an external sealing portion with a
circular cross-section and located so as to surround a looped outer
circumference surface of the internal sealing portion, and a
connected portion that connects the internal sealing portion to the
external sealing portion across an entire circumference of the
loop. The connected portion includes a second positioning portion
capable of being fitted in the first positioning portion.
Inventors: |
Nakamura; Kazuki; (Tochigi,
JP) ; Shigemasa; Morifumi; (Tochigi, JP) ;
Hayakawa; Shinichiro; (Tochigi, JP) ; Sasaki;
Kenichi; (Tochigi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Keihin Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
65037014 |
Appl. No.: |
16/228275 |
Filed: |
December 20, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 7/20254 20130101;
H05K 5/061 20130101; H05K 7/20927 20130101; H05K 7/20272 20130101;
H05K 5/0008 20130101 |
International
Class: |
H05K 7/20 20060101
H05K007/20; H05K 5/06 20060101 H05K005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2018 |
JP |
2017-051492 |
Claims
1. A power converter comprising: a cooler that cools down an
electronic component; a casing comprising the cooler; and a sealing
member in a loop shape sealing a space between a sealing surface of
the cooler and a sealing surface of the casing, wherein: either one
of the sealing surface of the cooler and the sealing surface of the
casing is provided with a groove in a loop shape enabling the
sealing member to be fitted therein; a first positioning portion is
provided on a bottom surface of the groove; the sealing member
comprises an internal sealing portion with a circular cross-section
and located along the bottom surface of the groove, an external
sealing portion with a circular cross-section and located so as to
surround a looped outer circumference surface of the internal
sealing portion, and a connected portion that connects the internal
sealing portion to the external sealing portion across an entire
circumference of the loop; and the connected portion comprises a
second positioning portion capable of being fitted in the first
positioning portion.
2. The power converter according to claim 1, wherein: both surfaces
of the connected portion are recessed backwardly relative to the
respective sealing surfaces of the internal sealing portion and the
external sealing portion; and a space surrounded by the internal
sealing portion, the external sealing portion, and the connected
portion forms a drain passage enabling a leaked cooling medium from
the internal sealing portion to pass therethrough.
3. The power converter according to claim 2, wherein: the first
positioning portion comprises a protrusion protruding from the
bottom surface of the groove toward an opening of the groove; the
protrusion has a drain hole capable of discharging the cooling
medium trapped in the drain passage to an exterior of the casing;
and the second positioning portion is a through-hole enabling the
protrusion to be fitted therein.
4. The power converter according to claim 2, wherein: the
electronic component comprises a power module, and other electronic
components that have a little amount of heat generation than the
power module; the cooler comprises a first cooling unit that cools
down the power module and a second cooling unit that cools down the
other electronic components; a drain guide path runs through an
interior of the casing, the drain guide path guiding a leaked
cooling medium from between the first cooling unit and the casing;
the sealing member comprises a second cooling unit sealing member
that seals a space between a sealing surface of the second cooling
unit and a sealing surface of the casing; the groove comprises a
second cooling unit groove enabling the second cooling unit sealing
member to be fitted therein; the first positioning portion
comprises a protrusion protruding from a bottom surface of the
second cooling unit groove toward an opening of the groove; the
protrusion has a drain hole enabling the cooling medium guided from
the drain guide path to flow in the drain passage of the second
cooling unit sealing member; and the second positioning portion is
a through-hole enabling the protrusion to be fitted therein.
5. The power converter according to claim 1, wherein: the sealing
member in the loop shape comprises an extended portion extended
outwardly from an outer circumference surface of the loop or an
inner circumference surface thereof; and either one of the cooler
and the casing has a recess enabling the extended portion to be
fitted therein.
6. The power converter according to claim 1, wherein at least a
part of the cooler is integrally formed with the casing.
Description
FIELD OF THE INVENTION
[0001] The present disclosure relates to an improvement technology
for a power converter.
BACKGROUND
[0002] A power converter is, for example, installed between a
battery and a motor, controls power stored in the battery, and
supplies the controlled power to the motor. A power converter
loaded on a hybrid vehicle or an electric vehicle, i.e., a large
number of sub units (e.g., power modules) which forms a power
control unit (PCU) generates heat, and there is a possibility such
that the performance decreases due to the adverse effect of
generated heat, and thus a cooling mechanism is necessary. Various
cooling technologies have been proposed (see, for example, JP
2016-067096 A).
[0003] A power converter disclosed in JP 2016-067096 A includes a
cooler on a casing. This cooler includes a fluid inlet in which a
cooling fluid is introduced, and a fluid outlet from which the
cooling fluid is discharged. The cooling fluid is circulated via a
plurality of connection paths respectively connected to the fluid
inlet and the fluid outlet. The connection portion between the
fluid inlet and the connection path, and the connection portion
between the fluid outlet and the connection path are sealed by
respective sealers.
[0004] Each sealer includes a first sealing member in a loop shape
which prevents the cooling fluid from being leaked to the exterior
from the connection portion, a second sealing member in a loop
shape that surrounds the first sealing member, and a drain passage
provided between the first sealing member and the second sealing
member. This drain passage is formed in the casing. The cooling
fluid trapped between the first sealing member and the second
sealing member is discharged to the exterior of the casing from a
drain discharging port via the drain passage. Formed in the sealing
surface of the casing are a first groove in a loop shape in which
the first sealing member can be fit, and a second groove in a loop
shape in which the second sealing member can be fit.
[0005] According to the sealing structure disclosed in JP
2016-067096 A, it is necessary to form both the first groove and
the second groove in the sealing surface of the casing. The space
between the first groove and the second groove is partitioned by a
certain width. That is, a partition wall is provided between the
first groove and the second groove. Since the diameter of the
second groove increases by what corresponds to the partition wall,
it is necessary for the sealing surface to have a large sealing
space. Consequently, since the sealing surface becomes large, the
casing and the cooler increase the respective sizes. This is
disadvantageous to attempt downsizing of the power converter. In
particular, when the complicated loop shape and the sealing members
that are large respectively are employed, simply fitting each
sealing member in each groove is disadvantageous in view of the
assemble easiness, and thus there is a leeway for improvement.
[0006] An objective of the present disclosure is to provide a
technology capable of improving the assemble easiness of a sealing
member while achieving downsizing of a power converter.
SUMMARY OF THE INVENTION
[0007] A power converter according to an embodiment of the present
disclosure comprises: [0008] a cooler that cools down an electronic
component; [0009] a casing comprising the cooler; and [0010] a
sealing member in a loop shape sealing a space between a sealing
surface of the cooler and a sealing surface of the casing, wherein:
[0011] either one of the sealing surface of the cooler and the
sealing surface of the casing is provided with a groove in a loop
shape enabling the sealing member to be fitted therein; [0012] a
first positioning portion is provided on a bottom surface of the
groove; [0013] the sealing member comprises an internal sealing
portion with a circular cross-section and located along the bottom
surface of the groove, an external sealing portion with a circular
cross-section and located so as to surround a looped outer
circumference surface of the internal sealing portion, and a
connected portion that connects the internal sealing portion to the
external sealing portion across an entire circumference of the
loop; and [0014] the connected portion comprises a second
positioning portion capable of being fitted in the first
positioning portion.
[0015] According to an embodiment of the present disclosure, both
surfaces of the connected portion are recessed backwardly relative
to the respective sealing surfaces of the internal sealing portion
and the external sealing portion; and a space surrounded by the
internal sealing portion, the external sealing portion, and the
connected portion forms a drain passage enabling a leaked cooling
medium from the internal sealing portion to pass therethrough.
[0016] According to an embodiment of the present disclosure, the
first positioning portion comprises a protrusion protruding from
the bottom surface of the groove toward an opening of the groove;
the protrusion has a drain hole capable of discharging the cooling
medium trapped in the drain passage to an exterior of the casing;
and the second positioning portion is a through-hole enabling the
protrusion to be fitted therein.
[0017] According to an embodiment of the present disclosure, the
electronic component comprises a power module, and other electronic
components that have a little amount of heat generation than the
power module; the cooler comprises a first cooling unit that cools
down the power module and a second cooling unit that cools down the
other electronic components; a drain guide path runs through an
interior of the casing, the drain guide path guiding a leaked
cooling medium from between the first cooling unit and the casing;
the sealing member comprises a second cooling unit sealing member
that seals a space between a sealing surface of the second cooling
unit and a sealing surface of the casing; the groove comprises a
second cooling unit groove enabling the second cooling unit sealing
member to be fitted therein; the first positioning portion
comprises a protrusion protruding from a bottom surface of the
second cooling unit groove toward an opening of the groove; the
protrusion has a drain hole enabling the cooling medium guided from
the drain guide path to flow in the drain passage of the second
cooling unit sealing member; and the second positioning portion is
a through-hole enabling the protrusion to be fitted therein.
[0018] According to an embodiment of the present disclosure, the
sealing member in the loop shape comprises an extended portion
extended outwardly from an outer circumference surface of the loop
or an inner circumference surface thereof; and either one of the
cooler and the casing has a recess enabling the extended portion to
be fitted therein.
[0019] According to an embodiment of the present disclosure, at
least a part of the cooler is integrally formed with the
casing.
[0020] According to an embodiment of the present disclosure, the
sealing member integrally connects the internal sealing portion
that has a circular cross-section to the external sealing portion
that has a circular cross-section across the entire circumference
of a loop by the connected portion. That is, the sealing member is
a single member. This single sealing member can be fitted in the
single groove in a loop shape. Hence, unlike conventional
technologies, it is unnecessary to provide a plurality of grooves
in the sealing surface of the cooler and in the sealing surface of
the casing. This simply requires a relatively small sealing space
for the sealing surface, enabling downsizing of the casing and of
the cooler. Consequently, downsizing of the power converter is
achievable.
[0021] Moreover, the first positioning portion is provided on the
bottom surface of the groove, and the second positioning portion is
provided on the connected portion. Fitting of the second
positioning portion in the first positioning portion facilitates
positioning of the sealing member relative to the groove.
Accordingly, assemble easiness of the sealing member relative to
the groove is improved, reducing the number of steps of assembling.
This is particularly advantageous when a sealing member in a
complex loop shape and a large sealing member are adopted.
[0022] In addition, the internal sealing member and the external
sealing member both have the circular cross-section, an inclination
and a fall-down do not occur when the respective sealing surfaces
are butted with each other and compressed against each other. This
ensures a stable sealing performance by the sealing member.
[0023] According to an embodiment of the present disclosure, the
space surrounded by the internal sealing portion, the external
sealing portion, and the connected portion is utilized as a drain
passage. Hence, it is unnecessary to provide additional drain
passage in the sealing surface of the cooler and in the sealing
surface of the casing. This enables further downsizing of the
casing and of the cooler. Moreover, a component to provide an
additional drain passage is unnecessary, achieving cost
reduction.
[0024] According to an embodiment of the present disclosure, the
first positioning portion that is a protrusion protruding from the
bottom surface of the groove and the second positioning portion
that is a through-hole in which the protrusion can be fitted
facilitate positioning of the sealing member relative to the
groove. Moreover, the protrusion is provided with a drain hole
capable of discharging the trapped cooling medium in the drain
passage to the exterior of the casing. That is, by providing the
drain hole in the protrusion, an additional drain hole is
unnecessary. Consequently, the power converter can be downsized,
while at the same time, costs for the power converter can be
reduced.
[0025] According to an embodiment of the present disclosure, the
first positioning portion that is a protrusion protruding from the
bottom surface of the groove for the second cooling unit and the
second positioning portion that is a through hole in which the
protrusion can be fitted facilitate positioning of the sealing
member for the second cooling unit relative to the groove for the
second cooling unit. Moreover, further provided is a drain hole
that causes a drain guide path which guides the leaked cooling
medium between the first cooling unit and the casing to be in
communication with a drain passage for the second cooling unit.
This drain hole is provided in the protrusion. That is, by
providing the drain hole in the protrusion, an additional drain
hole is unnecessary. Consequently, the power converter can be
downsized, while at the same time, costs for the power converter
can be reduced.
[0026] According to an embodiment of the present disclosure, by
combining the extended portion of the sealing member with the
recess in which this extended portion can be fitted, the fitting
direction of the sealing member relative to the groove is defined.
This prevents a so-called false assembling such that the sealing
member is fitted in the groove with an improper fitting direction.
Accordingly, the assemble easiness of the sealing member relative
to the groove is improved. Moreover, this enables further precise
positioning of the sealing member relative to the groove.
[0027] According to an embodiment of the present disclosure, at
least a part of the cooler is integrally formed with the casing.
That is, by utilizing the space in the casing, the casing serves at
least a part of the cooler. This simplifies the structure of the
power converter, and achieves further downsizing of the power
converter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIGS. 1A to 1D are each an exemplarily diagram illustrating
a cross-section of a power converter according to the present
disclosure and a structure of the major portion thereof;
[0029] FIGS. 2A and 2B are an exploded view of the power converter
illustrated in FIG. 1 and a perspective view around a plurality of
sealers;
[0030] FIGS. 3A to 3H are each a diagram illustrating a sealer
illustrated in FIG. 1A and a component thereof; and
[0031] FIGS. 4A and 4B are a partial cross-sectional view of a
modified example of the power converter illustrated in FIG. 1A, and
a perspective view around the plurality of sealers.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0032] An embodiment to carry out the present disclosure will be
described below with reference to the accompanying drawings.
[0033] FIG. 1A illustrates an exemplarily cross-section of a power
converter 10.
[0034] FIG. 1B illustrates a portion b in FIG. 1A in an enlarged
manner.
[0035] FIG. 1C illustrates a cross-sectional structure along a line
c-c in FIG. 1B.
[0036] FIG. 1D illustrates a structure around a first sealing
member 70 illustrated in FIG. 1B in an exploded manner.
[0037] FIG. 2A illustrates the power converter 10 illustrated in
FIG. 1A in an exploded manner.
[0038] FIG. 2B is a perspective view around a plurality of sealing
members 70, 70, and 80 illustrated in FIG. 1A.
[0039] First, an electronic component 11 and a cooler 12 which are
applied to a power converter 10 illustrated in FIG. 1A will be
defined as follows. The electronic component 11 includes a "power
module 33" and "other electronic components 55 and 56" that have a
smaller amount of heat generation than that of this power module
33. The power module 33 is a kind of high-heat-generating
electronic component which has a large amount of heat generation
through an operation and which needs a passive heat dissipation.
The other electronic components 55 and 56 are, for example, a
smoothing capacitor, a reactor, a DC-DC converter, and a
discharging resistor. In order to facilitate understanding, the one
electronic component 55 in the other electronic components 55 and
56 will be referred to as a "first electronic component 55", and
the other electronic component 56 will be referred to as a "second
electronic component 56". The cooler 12 includes a first cooling
unit 30 that cools down the power module 33, and a second cooling
unit 59 that cools down the other electronic components 55 and
56.
[0040] The power converter 10 will be described below in detail.
The power converter 10 includes a casing 20. This casing 20 is
formed in a substantially rectangular shape in a planar view, and
includes the first cooling unit 30 and the second cooling unit
59.
[0041] As illustrated in FIGS. 1A and 2A, the casing 20 is divided
into a first space 22 and a second space 23 by an integrally formed
dividing plate 21. For example, the first space 22 is located right
above the second space 23.
[0042] The first space 22 has an opened opposite side (upper side)
to the dividing plate 21. Formed in the casing 20 along the edge of
the opened end of the first space 22 is a flat seat 24. This seat
24 will be referred to as a "sealing surface 24 of the casing 20"
as appropriate below. A sealing surface 30a of the first cooling
unit 30 is attached to this sealing surface 24. More specifically,
the first cooling unit 30 is a separate component from the casing
20 and is a substantially flat cooling medium jacket, and is freely
detachably attached to the first space 22 by bolts 31. That is, the
first cooling unit 30 is attached to the casing 20 while blocking
the opened end (opened surface) of the first space 22. This first
cooling unit 30 has a cooling medium passage 32 provided
thereinside. The power module 33 is mounted on the external surface
of the first cooling unit 30.
[0043] The first space 22 holds therein a sub unit 41. This sub
unit 41 includes a board 43 that is freely detachable attached to
the dividing plate 21 by bolts 42, and a third electronic component
44 mounted on this board 43. This third electronic component 44 is
an electronic component which has smaller amount of heat generation
than that of the above-described power module 33, such as a
smoothing capacitor, a reactor, a DC-DC converter, or a discharging
resistor. The first cooling unit 30 and the power module 33 are
covered by a first cover 45. This first cover 45 is freely
detachably attached to the casing 20 by bolts 46.
[0044] The second space 23 is defined by a groove that opens the
opposite side (lower side) to the dividing plate 21. Formed in the
casing 20 along the edge of the opened end of the second space 23
is a flat seat 25. This seat 25 will be referred to as a "sealing
surface 25 of the casing 20" as appropriate below. A lid 51 is
attached to this sealing surface 25. That is, the second space 23
has the opened end at the opposite side to the dividing wall 21
blocked by the lid 51. Thus, the lid 51 is attached to the casing
20 while blocking the opened end (opened surface) of the second
space 23.
[0045] More specifically, the lid 51 is a flat plate which is laid
over on the seat 25 (sealing surface 25) of the second space 23 and
which is freely detachably attached thereto by bolts 53. The
surface of the lid 51 which is laid over on the seat 25 (sealing
surface 25) of the second space 23 will be referred to as a sealing
surface 51a, and the opposite side to this sealing surface 51a will
be referred to as a mount surface 51b. A plurality of cooling fins
51c that extends toward the interior of the second space 23 is
formed on the sealing surface 51a. The other electronic components
55 and 56 are mounted on the mount surface 51b.
[0046] The lid 51 and the other electronic components 55 and 56 are
covered by a second cover 57. The second cover 57 is freely
detachably attached to the casing 20 by bolts 58.
[0047] The second cooling unit 59 is a cooling medium jacket formed
by a wall portion (including the dividing plate 21) which forms the
second space 23, and the lid 51 that blocks the second space 23.
Thus, at least a part of the second cooling unit 59 is integrally
formed with the casing 20.
[0048] The second space 23 will be also referred to as a "cooling
medium passage 23" as appropriate below. The sealing surface 51a of
the lid 51 will be also referred to as a "sealing surface 51a of
the second cooling unit 59".
[0049] Furthermore, the casing 20 includes a plurality of connected
cooling medium paths 61 to 63 provided thereinside. More
specifically, the casing 20 holds therein a first connected cooling
medium path 61 (a cooling medium inlet 61, a first cooling medium
port 61) that introduces a cooling medium from the exterior to the
casing 20, a second connected cooling medium path 62 (a cooling
medium outlet 62, a second cooling medium port 62) that discharges
the cooling medium from the casing 20 to the exterior, and a third
connected cooling medium path 63 that connects the first cooling
unit 30 to the second cooling unit 59. One end of the second
connected cooling medium path 62 and one end of the third connected
cooling medium path 63 are opened to the sealing surface 24 of the
casing 20.
[0050] The first connected cooling medium path 61 and the second
connected cooling medium path 62 are formed on the same surface 26a
of a side wall 26 of the casing 20, and are located at the opposite
side to the third connected cooling medium path 63.
[0051] The first cooling unit 30 includes the cooling medium port
34 (a cooling medium introducing port 34) that introduces the
cooling medium from the third connected cooling medium path 63, and
a cooling medium port 35 (a cooling medium discharging port 35)
that discharges the cooling medium to the second connected cooling
medium path 62. The cooling medium introducing port 34 and the
cooling medium discharging port 35 are in communication with the
cooling medium passage 32 of the first cooling unit 30. A first
connection portion 64 between the cooling medium introducing port
34 of the first cooling unit 30 and the third connected cooling
medium path 63, and a second connection portion 65 between the
cooling medium discharging port 35 of the first cooling unit 30 and
the second connected cooling medium path 62 are both the seat 24 of
the first space 22.
[0052] As illustrated in FIG. 1A, the cooling medium (e.g., cooling
water) supplied from the first connected cooling medium path 61
passes through a route that includes the second cooling unit 59,
the third connected cooling medium path 63, and the first cooling
unit 30, and is discharged from the second connected cooling medium
path 62. The cooling medium that flows through the cooling medium
passage 32 directly cools down the power module 33 via the first
cooling unit 30. The cooling medium that flows through the second
cooling unit 59 directly cools down the other electronic components
55 and 56 via the plurality of cooling fins 51c and the lid 51.
Hence, the power module 33 and the other electronic components 55
and 56 can be directly and efficiently cooled down.
[0053] The first connection portion 64 and the second connection
portion 65 are respectively sealed by first sealing members 70 and
70 each in a loop shape. The description will be given to the first
sealing member 70 that seals the first connection portion 64 as a
representative example with reference to FIGS. 1A to 1D.
[0054] The sealing surface 24 of the casing 20 has a groove 24a in
a loop shape that surrounds the opening of the third connected
cooling medium path 63. The first sealing member 70 can be fitted
in this groove 24a. A first positioning portion 24b is provided on
a bottom surface of this groove 24a.
[0055] The first sealing member 70 is formed of an elastic material
like a rubber, and seals a space between the sealing surface 24 of
the casing 20 and the sealing surfaces 30a of the first cooling
unit 30. More specifically, the first sealing member 70 is an
integral mold component that includes an internal sealing portion
71, an external sealing portion 72, and a connected portion 73.
[0056] The internal sealing portion 71 is in a loop shape along the
bottom surface of the groove 24a and the inner circumference
surface thereof, and has a circular cross-section (e.g., a
true-circle cross-section).
[0057] The external sealing portion 72 is in a loop shape located
along the bottom surface of the groove 24a while surrounding the
looped outer circumference surface of the internal sealing portion
71, and has a circular cross-section (e.g., true-circle
cross-section). That is, this external sealing portion 72 adjoins
to the looped outer circumference surface of the internal sealing
portion 71. The diameter of the circular cross-section of the
external sealing portion 72 is consistent with that of the circular
cross-section of the internal sealing portion 71.
[0058] The connected portion 73 integrally connects the looped
outer circumference surface of the internal sealing portion 71 with
the looped inner circumference surface of the external sealing
portion 72 across the entire circumference of the loop. That is,
the connected portion 73 is an integrated portion between the
looped outer circumference surface of the internal sealing portion
71 that has a circular cross-section and the looped outer
circumference surface of the external sealing portion 72 that has a
circular cross-section.
[0059] Both surfaces of the connected portion 73 are recessed
backwardly relative to the respective sealing surfaces of the
internal sealing portion 71 and external sealing portion 72. That
is, since the looped outer circumference surface of the internal
sealing portion 71 that has a circular cross-section and the looped
outer circumference surface of the external sealing portion 72 that
has a circular cross-section are integrated with each other, a
recess 74 (a space 74) is formed in the boundary portion between
these sealing portions 71 and 72. Thus, the space 74 surrounded by
the internal sealing portion 71, the external sealing portion 72,
and the connected portions 73 forms a drain passage through which
the leaked cooling medium from the internal sealing portion 71 can
pass. This space 74 will be referred to as a "drain passage 74"
below.
[0060] The connected portion 73 includes a second positioning
portion 75 which can be fitted with the first positioning portion
24b.
[0061] The first positioning portion 24b of the groove 24a is
formed by a protrusion that protrudes from the bottom surface of
the groove 24a toward the groove opening. The first positioning
portion 24b will be also referred to as a "protrusion 24b" as
appropriate below. This protrusion 24b has a drain hole 24c capable
of discharging the trapped cooling medium in the drain passage 74
to the exterior of the casing 20.
[0062] This protrusion 24b and the drain hole 24c are located at
the center of the groove 24a in the widthwise direction so as to
correspond to the location of the drain passage 74. The groove
width of the portion of the groove 24a where the protrusion 24b and
the drain passage 74 are located is larger than the groove widths
of other portions.
[0063] Conversely, the clearance between the internal sealing
portion 71 and the external sealing portion 72 is wide at the
portion of the first sealing member 70 corresponding to the
above-described protrusion 24b. Hence, the width of the connected
portion 73 is also wide. The second positioning portion 75 is a
through-hole which is located at the wide portion of the connected
portion 73 and in which the protrusion 24b can be fitted. This
second positioning portion 75 will be also referred to as a
"through-hole 75" as appropriate below.
[0064] As illustrated in FIG. 1A, a space between the sealing
surface 25 of the casing 20 and the sealing surface 51a of the lid
51 (the sealing surface 51a of the second cooling unit 59) is
sealed by a second sealing member 80. This second sealing member 80
will be also referred to as a "second cooling unit sealing member
80" as appropriate below. The second sealing member 80 will be
described with reference to FIGS. 1A, 2A and 2B, and 3A to 3G.
[0065] FIG. 3A illustrates a cross-section taken along a line 3a-3a
in FIG. 1A, i.e., a structure cut along the bottom surface of the
groove 25a of the casing 20, and the second sealing member 80 can
be seen.
[0066] FIG. 3B illustrates a cross-section taken along a line b-b
in FIG. 3A.
[0067] FIG. 3C illustrates a cross section taken along a line c-c
in FIG. 3A.
[0068] FIG. 3D illustrates a structure illustrated in FIG. 3C in an
exploded manner.
[0069] FIG. 3E illustrates the second sealing member 80 along a
line e-e in FIG. 3D.
[0070] FIG. 3F illustrates a cross-section taken along a line f-f
in FIG. 3A.
[0071] FIG. 3G illustrates a structure illustrated in FIG. 3F in an
exploded manner.
[0072] The sealing surface 25 of the casing 20 has a groove 25a in
a loop shape that surrounds the opening of the second space 23. The
second sealing member 80 can be fitted in this groove 25a. A
plurality of (e.g., three) first positioning portions 25b is
provided on the bottom surface of this groove 25a.
[0073] The second sealing member 80 is formed of an elastic
material like a rubber. More specifically, the second sealing
member 80 is an integral mold component that includes an internal
sealing portion 81, an external sealing portion 82, and a connected
portion 83.
[0074] The internal sealing portion 81 is in a loop shape located
along the bottom surface of the loop-shape groove 25a and the inner
circumference surface thereof, and has a circular cross-section
(e.g., true-circle cross-section).
[0075] The external sealing portion 82 employs a looped structure
which surrounds the looped outer circumference of the internal
sealing portion 81 and which is located along the bottom surface of
the groove 25a, and has a circular cross-section (e.g., true-circle
cross-section). That is, as illustrated in FIG. 3B, this external
sealing portion 82 adjoins to the looped outer circumference
surface of the internal sealing portion 81. The diameter of the
circular cross-section of the external sealing portion 82 is
consistent with that of the circular cross-section of the internal
sealing portion 81.
[0076] The connected portion 83 integrally connects the looped
outer circumference surface of the internal sealing portion 81 with
the looped inner circumference surface of the external sealing
portion 82 across the entire circumference of the loop. That is,
the connected portion 83 is an integrated portion between the
looped outer circumference surface of the internal sealing portion
81 that has a circular cross-section and the looped outer
circumference surface of the external sealing portion 82 that has a
circular cross-section.
[0077] Both surfaces of the connected portion 83 are recessed
backwardly relative to the respective sealing surfaces of the
internal sealing portion 81 and the external sealing portion 82.
That is, since the looped outer circumference surface of the
internal sealing portion 81 that has a circular cross-section is
integrated with the looped outer circumference surface of the
external sealing portion 82 that has a circular cross-section, a
recess 84 (a space 84) along the loop is formed in the boundary
portion between these seal portions 81 and 82. Thus, the space 84
surrounded by the internal sealing portion 81, the external sealing
portion 82, and the connected portions 83 form a drain passage
through which the leaked cooling medium from the internal sealing
portion 81 can pass. This space 84 will be referred to as a "drain
passage 84" below.
[0078] The connected portion 83 includes a plurality of second
positioning portions 85 which can be respectively fitted in the
plurality of first positioning portions 25b.
[0079] The plurality of first positioning portions 25b of the
groove 25a is each formed by a protrusion protruding from the
bottom surface of the groove 25a toward the groove opening. The
first positioning portion 25b will be also referred to as a
"protrusion 25b" as appropriate below. The plurality of these
protrusions 25b each has a drain hole 25c capable of discharging
the trapped cooling medium in the drain passage 84 to the exterior
of the casing 20.
[0080] As illustrated in FIGS. 3A to 3E, such protrusion 25b and
drain hole 25c are located at the center of the groove 25a in the
widthwise direction so as to correspond to the location of the
drain passage 84. The groove width of a portion of the groove 25a
where the protrusions 25b and the drain passage 84 are located is
larger than the groove widths of other portions.
[0081] Conversely, the clearance between the internal sealing
portion 81 and the external sealing portion 82 is wide at the
position of the second sealing member 80 corresponding to the
above-described protrusions 25b. Hence, the width of the connected
portion 83 is also wide. The second positioning portions 85 are
each a through-hole which is located at the wide portion of the
connected portion 83 and in which the corresponding protrusion 25b
can be fitted. This second positioning portion 85 will be also
referred to as a "through-hole 85" as appropriate.
[0082] As illustrated in FIGS. 3A, 3F, and 3G, the second sealing
member 80 includes an extended portion 86 that extends outwardly
from the looped inner circumference side (the inner circumference
surface of the internal sealing portion 81) or from the looped
outer circumference surface (the outer circumference surface of the
external sealing portion 82). Either one of the casing 20 and the
second cooling unit 59 (the cooler 12) includes a recess 87 in
which the extended portion 86 can be fitted.
[0083] FIG. 3H illustrates a modified example of the structure
illustrated in FIG. 3C. According to this modified example, the
first positioning portions 25b provided at the bottom surface of
the groove 25a are each formed as a recess, and the second
positioning portions 85 of the connected portion 83 of the sealing
member 80 are each formed as a protrusion. The second positioning
portions 85 can be fitted in the respective first positioning
portions 25b.
[0084] As illustrated in FIG. 1A to FIG. 3H, a space between the
two drain holes 24c and the two drain holes 25c are in
communication with each other by the two drain guide paths 91,
respectively. Such drain guide paths 91 run through the interior of
the casing 20 (e.g., formed inside the casing 20). These drain
guide paths 91 can guide the leaked cooling medium from between the
casing 20 and the first cooling unit 30 to the respective drain
holes 25c. The two drain holes 25c can cause the cooling medium
guided from the respective drain guide paths 91 to flow into the
drain passage 84 of the sealing member 80 for the second cooling
unit.
[0085] As illustrated in FIGS. 1A, 2A and 2B, the remaining drain
hole among the three drain holes 25c is in communication with a
drain discharging port 92. This drain discharging port 92 is
provided in the casing 20, and discharges the leaked cooling medium
to the exterior. That is, the plurality of grooves 24a, 24a, 25a,
and 25a is merged into the single drain discharging port 92.
[0086] The drain discharging port 92 includes a first vertical
passage 92a that extended upwardly from the one drain hole 25c, a
horizontal passage 92b that extends substantially horizontally from
the upper end of this first vertical passage 92a, and a second
vertical passage 92c which extends downwardly from the tip of the
horizontal passage 92b and which is opened to the exterior. The
leaked cooling medium can be discharged from the second vertical
passage 92c to the exterior.
Modified Example
[0087] A power converter 10A according to a modified example will
be described with reference to FIGS. 4A and 4B.
[0088] FIG. 4A is a partial cross-sectional view of the major
portion of the power converter 10A according to the modified
example, and the illustration corresponds to FIG. 1A.
[0089] FIG. 4B is a perspective view around the sealing portion of
the power converter 10A according to the modified example, and the
illustration corresponds to FIG. 2B.
[0090] According to the power converter 10A of the modified
example, the lid 51 has a through-hole 51d that is blocked by a lid
52 (the other lid 52) formed of the different component. The other
components are the same as those of the embodiment illustrated in
FIGS. 1A to 311, and thus the same reference numerals will be given
to those components and the detailed description thereof will be
omitted.
[0091] The second electronic components 56 (the other electronic
components 56) are mounted on the other lid 52. More specifically,
the other lid 52 is a flat plate which is laid over on the mount
surface 51b of the lid 51 so as to block the through-hole 51d of
the lid 51 and which is freely detachably attached thereto by bolts
54. The other lid 52 has a surface facing the mount surface 51b of
the lid 51 as a sealing surface 52a, and has a surface at the
opposite side to sealing surface 52a as the mount surface 52b.
Formed on the sealing surface 52a is a plurality of cooling fins
52c that extends into the second space 23. The second electronic
components 56 are mounted on the mount surface 52b of the other lid
52.
[0092] The space between the mount surface 51b of the lid 51 and
the seal surface 52a of the other lid 52 is sealed by a third
sealing member 100. The mount surface 51b of the lid 51 has a
groove 51e in a loop shape that surrounds the through-hole 51d. The
third sealing member 100 can be fitted in this groove 51e. A drain
hole 51f is formed in the bottom surface of this groove 51e.
[0093] The third sealing member 100 has the substantially same
structure as that of the second sealing member 80, and is an
integral mold component that includes an internal sealing portion
101 with a circular cross-section which is located along the bottom
surface of the groove 51e, an external sealing portion 102 with a
circular cross-section located so as to surround the looped outer
circumference surface of the internal sealing portion 101, and a
connected portion 103 that integrates the internal sealing portion
101 with the external sealing portion 102 across the entire
circumference of the loop.
[0094] Since the fitting structure of the third sealing member 100
to the groove 51e is the same as that of the embodiment illustrated
in FIGS. 3B to 3E, the description will be omitted. The drain hole
51f is in communication with the drain hole 25c of the casing
20.
[0095] The foregoing description will be summarized as follows.
[0096] The sealing members 70, 80 and 100 have respective
structures which integrate the respective internal sealing portions
71, 81 and 101 that have a circular cross-section with the
respective external sealing portions 72, 82 and 102 that have a
circular cross-section across the entire circumference of a loop by
the respective connected portions 73, 83 and 103. That is, the
sealing members 70, 80 and 100 are each formed of a single member.
These single sealing members 70, 80 and 100 can be fitted in the
respective single grooves 24a, 25a, and 51e in a loop shape.
[0097] As illustrated in, for example, FIG. 1A and FIG. 3B, it is
assumed that the pressure of the cooling medium is applied to the
internal sealing portion 81 from the interior (the second space 23)
of the second cooling unit 59. The pressure of this cooling medium
acts on the side surface of the groove 25a via the connected
portion 83 and the external sealing portion 82 from the internal
sealing portion 81. That is, the pressure of the cooling medium can
be caught by entire the second sealing member 80. Therefore, it is
unnecessary to divide the groove 25a into a groove for the internal
sealing portion 81 and a groove for the external sealing portion
82, but the groove 25a can be a single groove.
[0098] The same is true of the groove 24a illustrated in FIG. 1B to
FIG. 1D, and the groove 51e illustrated in FIG. 4B.
[0099] As is clear from the foregoing description, unlike the
conventional technologies, it is necessary to provide a plurality
of grooves in the respective sealing surfaces 30a, 51a, and 52a of
the cooling units 30 and 59 and in the respective sealing surfaces
24 and 25 of the casing 20. What is necessary is to provide a
relatively small sealing space for the sealing surfaces 24, 25,
30a, 51a, and 52a, and thus the casing 20 and the cooling units 30
and 59 can be downsized. Consequently, downsizing the power
converters 10 and 10A can be achieved.
[0100] Moreover, the first positioning portions 24b and 25b are
formed on the bottom surfaces of the grooves 24a and 25a of the
casing 20, and the second positioning portions 75 and 85 are
provided on the connected portions 73 and 83. Accordingly, by
fitting the first positioning portions 24b and 25b in the second
positioning portions 75 and 85, the sealing members 70 and 80 can
be easily positioned relative to the grooves 24a and 25a. Hence,
the assemble easiness of the sealing members 70 and 80 to the
grooves 24a and 25a is improved, decreasing the number of steps of
assembling. This is particularly effective when the respective
sealing member 70 and 80 that have a complex loop shape and are
large are applied.
[0101] Furthermore, since the internal sealing portions 71, 81 and
101 and the external sealing portions 72, 82 and 102 all have a
circular cross-section, when the sealing surfaces 24 and 30a, the
sealing surfaces 25 and 51a, and the sealing surface 51b and 52a
are butted with each other and compressed, an inclination or a
fall-over do not occur. This ensures the stable sealing performance
of the sealing members 70, 80 and 100.
[0102] Still further, the spaces 74, 84 and 104 surrounded by the
respective internal sealing portions 71 81 and 101, the respective
external sealing portions 72, 82 and 102 and the respective
connected portions 73, 83 and 103 can be utilized as the respective
drain passages 74, 84 and 104. Hence, it is unnecessary to provide
individual drain passages in the sealing surfaces 30a, 51a, and 52a
of the cooling units 30 and 59, and the sealing surfaces 24 and 25
of the casing 20. This enables a further downsizing of the casing
20 and the cooling units 30 and 59. Moreover, a component for
providing an individual drain passage is unnecessary, reducing the
costs for the power converters 10 and 10A.
[0103] Yet still further, the first positioning portions 24b and
25b formed by the protrusions 24b and 25b protruding from the
bottom surface of the grooves 24a and 25a, and the second
positioning portions 75 and 85 formed by the through-holes 75 and
85 in which the respective protrusions 24b and 25b can be fitted
facilitate the positioning of the sealing members 70 and 80
relative to the grooves 24a and 25a. Moreover, the protrusions 24b
and 25b are provided with the respective drain holes 24c and 25c
capable of discharging the trapped cooling medium in the drain
passages 74 and 84 to the exterior of the casing 20. That is, an
additional drain hole is unnecessary since the protrusions 24b and
25b have the respective drain holes 24c and 25c. Consequently,
downsizing of the power converters 10 and 10A is achieved, while at
the same time, reduction of the costs for the power converters 10
and 10A is also achieved.
[0104] Moreover, when the extended portion 86 of the sealing member
80 is combined with the recess 87 in which this extended portion 86
can be fitted, the fitting direction of the sealing member 80 in
the groove 25a is defined. This prevents assembling of the sealing
member 80 in the groove 25a in an improper direction, i.e., a false
assembling. Hence, the attachment easiness of the sealing member 80
to the groove 25a improves. Moreover, the sealing member 80 can be
more precisely positioned to the groove 25a.
[0105] Furthermore, the cooling units 30 and 59 are at least
partially formed integrally with the casing 20. That is, by
utilizing the space in the casing 20, the casing 20 serves as at
least a part of the cooling units 30 and 59. This makes it possible
for the power converters 10 and 10A to have a simple structure,
achieving a further downsizing of the power converters 10 and
10A.
[0106] According to the present disclosure, the power converters 10
and 10A are applicable to, in addition to electric vehicles and
so-called hybrid vehicles, ships and general industrial
applications.
[0107] Moreover, the grooves 24a and 25a in a loop shape in which
the respective sealing members 70 and 80 can be fitted may be
provided in either the sealing surfaces 30a and 51a of the cooling
units 30 and 59 or the sealing surfaces 24 and 25 of the casing
20.
[0108] Furthermore, the first cover 45 and the second cover 57
illustrated in FIGS. 1A to 1H are optional.
INDUSTRIAL APPLICABILITY
[0109] The present disclosure is suitable for a power converter
loaded on vehicles.
* * * * *