U.S. patent application number 09/731357 was filed with the patent office on 2001-06-07 for electric coupling apparatus for charging device.
Invention is credited to Terazoe, Masahiko.
Application Number | 20010002789 09/731357 |
Document ID | / |
Family ID | 18385238 |
Filed Date | 2001-06-07 |
United States Patent
Application |
20010002789 |
Kind Code |
A1 |
Terazoe, Masahiko |
June 7, 2001 |
Electric coupling apparatus for charging device
Abstract
An electric coupling apparatus for charging a battery. A power
supply coupler is adapted to be inserted to a power receiver
coupler. The power supply coupler has a primary core and a primary
coil located around the primary core. The power receiver coupler
has a secondary core and a secondary coil located in the secondary
core. The secondary core includes first and second core members.
The first core member has a magnetic pole protruding through the
secondary coil and yokes extending from the magnetic pole. The
second core member has a recess that faces the power supply coupler
to conduct air for cooling the power supply coupler.
Inventors: |
Terazoe, Masahiko;
(Kariya-shi, JP) |
Correspondence
Address: |
Kurt E. Richter
Morgan & Finnegan, L.L.P.
345 Park Avenue
New York
NY
10154
US
|
Family ID: |
18385238 |
Appl. No.: |
09/731357 |
Filed: |
December 6, 2000 |
Current U.S.
Class: |
320/108 |
Current CPC
Class: |
H02J 50/10 20160201;
Y02T 90/12 20130101; B60L 53/12 20190201; B60L 53/34 20190201; Y02T
10/70 20130101; H02J 7/025 20130101; Y02T 90/14 20130101; B60L
53/122 20190201; H02J 50/90 20160201; B60L 53/126 20190201; Y02T
10/7072 20130101; H02J 50/80 20160201 |
Class at
Publication: |
320/108 |
International
Class: |
H02J 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 1999 |
JP |
11-346701 |
Claims
What is claimed is:
1. An electric coupling apparatus for a charging device comprising:
a power supply coupler including a first coil and a first core
around which the first coil is located; and a power receiver
coupler including a second core, which is formed with a recess in a
region adjacent to the first coil and which forms a magnetic flux
path with the first core, and a second coil located around the
second core to generate an inductive electromotive force with the
magnetic path in response to electric power applied to the first
coil.
2. An electric coupling apparatus as claimed in claim 1, wherein
the power receiver coupler includes an air passage through which
the recess communicates with external air.
3. An electric coupling apparatus for a charging device,
comprising: a power supply coupler including a hollow casing having
a paddle shape, a first core accommodated in the hollow casing, and
a first coil located around the first core and in the hollow
casing; and a power receiver coupler including a second core
including a first core member, which has having a magnetic pole,
and yokes extending at opposite ends of the magnetic pole, and a
second core member for forming a magnetic flux path with the first
core member, the power receiver coupler further including a second
coil surrounding the magnetic pole to generate an inductive
electromotive force in response to electric power applied to the
first coil and a casing enclosing the second core and the second
coil, the second core having a recess formed in a region facing the
first coil to conduct air to cool the first coil, wherein the
casing of the power receiver coupler receives the casing of the
power supply coupler to couple the power supply coupler with the
power receiver coupler, wherein the first coil is adjacent to the
recess when the power supply coupler is coupled to the power
receiver coupler.
4. An electric coupling apparatus as claimed in claim 3, wherein
the casing of the power receiver coupler has an opening to allow
the insertion of the casing of the power supply coupler and
additional recesses formed between the opening and the second core
to permit the recess of the first core to communicate with outside
air.
5. An electric coupling apparatus as claimed in claim 4, wherein
the power receiver coupler further includes a guide member and an
auxiliary member located in the casing of the power receiver
coupler in spaced relationship, each member having a plurality of
projections protruding inward to form the additional recesses, the
plurality of projections serving to position the casing of the
power supply coupler in the power receiver coupler.
6. An electric coupling apparatus as claimed in claim 4, wherein
the casing of the power receiver coupler has a plurality of
apertures to communicate the additional recesses with the outside
air.
7. An electric coupling apparatus as claimed in claim 6, wherein
the power receiver coupler further includes an electric fan fixed
to the casing for generating an air stream through the recesses of
the second core, the guide member and the auxiliary member.
8. An electric coupling apparatus as claimed in claim 6, wherein
the auxiliary member supports a circuit board.
9. A power receiver coupler for use in an electric coupling
apparatus including a power supply coupler, the power supply
coupler having a first core and a first coil located around the
first core, the coupler comprising: a casing having an opening to
allow insertion of the power supply coupler; a second core located
in the casing, the second core including a first part, which has a
magnetic pole and yokes, a second part, which is magnetically
coupled to the first part, wherein a second coil is wound around
the magnetic pole, the second core having a space between the first
and second parts to accommodate the power supply coupler to cause
the first core to form a closed magnetic flux path with the second
core, which produces an inductive electromotive force in the second
coil, the second core having a recess that faces the first coil to
conduct an air stream to cool the first coil.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to electric charging devices for
batteries and, more particularly, to an electric coupling apparatus
suited for electromagnetic type induction charging devices for use
in self-propelled objects such as electric vehicles powered by
batteries.
[0002] Non-contact type battery charging devices have heretofore
been proposed to charge batteries of electric vehicles by means of
electromagnetic, inductive charging.
[0003] Each of the battery charging devices includes a power supply
charging device, which is located at a charging station and has a
power supply coupler, and a power receiver charging device, which
includes a power receiver coupler that is mounted, for example, in
the vehicle. The power supply charging device and the power
receiver charging device are electrically coupled to each other by
coupling a power supply coupler 50 to a power receiver coupler 51
as shown in FIG. 7.
[0004] The power supply coupler 50 includes a paddle-shaped casing
50a. The casing 50a houses a primary core 52 and a primary coil 53.
The power receiver coupler 51 includes a box-shaped casing 51a
having an opening 56 into which the power supply coupler 50 is
inserted. The casing 51a houses a secondary core 54 and a secondary
coil 55.
[0005] When the power supply coupler 50 is inserted into the power
receiver coupler 51, a closed magnetic flux circuit is formed
between the cores 52 and 54. When an alternating electric current
is supplied to the coil 53 from the power supply charging device,
an electromotive force is induced in the secondary coil 55 of the
power receiver charging device due to electromagnetic induction.
This electric power is converted to direct electric power and is
used to charge the battery of the vehicle.
[0006] In the above-mentioned prior art power receiver coupler, an
extremely small gap is formed between a core member 60 and the
power supply coupler 50, thereby providing a high charging rate.
FIG. 8 shows a typical arrangement of cores of the power supply
coupler and the power receiver coupler.
[0007] The primary core 52 of the power supply coupler 50 is
located in the lower end of the casing 50a. Both ends of the
primary core 52 are exposed. The coil 53 is assembled in the casing
50a, while wound around the primary core 52. The secondary core 54
of the power receiver coupler 51 includes a core member 59 and a
core member 60. The core member 59 has a magnetic pole 57 and a
pair of yokes 58, which extend upright at the ends of the magnetic
pole 57. The core member 60 has a plate like configuration and is
combined with the core member 59 to magnetically connect the yokes
58 to one another. A hollow is formed between the core members 59
and 60. The casing 50a of the power supply coupler 50 fits in the
hollow. A secondary coil 55 is formed in a printed circuit board
and has a bore formed in its center. The magnetic pole 57 fits in
the bore and extends into the hollow between the cores 59 and
60.
[0008] In the prior art electric coupling devices discussed above,
there is a great deal of heat generated by the coils 53 and 55 and
the temperature of the cores 52 and 54 increases. The core 54 and
the coil 55 in the power receiver coupler 51 are cooled by air that
flows through the casing 51a. The core 52 and the coil 53 of the
power supply coupler is cooled by the air surrounding the casing
50a.
[0009] In the structure mentioned above, the gap between the casing
50a and the core member 60 is extremely small and cooling air
scarcely circulates through the gap. For this reason, the casing of
the power receiver coupler 51 tends to overheat. The temperature of
the coil 53, the core 52 and the core member 60 of the power
receiver coupler 51 increase to an extremely high level.
[0010] When the temperature increases, the printed circuit board
and other electric components may be damaged or malfunction.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of the present invention to
provide an electric coupling apparatus for a battery charging
device to enable charging of batteries in a reliable manner at all
times.
[0012] In order to meet the above and other objects, the present
invention provides an electric coupling apparatus for a charging
device.
[0013] The electric coupling apparatus has a power supply coupler
and a power receiver coupler that is coupled to the power receiver
coupler. The power supply coupler includes a first coil and a first
core around which the first coil is located. The power receiver
coupler includes a second core, which forms a magnetic flux path
with the first core. The second coil located around the second core
to generate an inductive electromotive force with the magnetic path
in response to electric power applied to the first coil. The first
coil of the power receiver coupler is formed with a recess in a
region adjacent to the first coil.
[0014] The present invention also provides a coupling apparatus for
a charging device.
[0015] The electric coupling apparatus has a power supply coupler
and a power receiver coupler that is coupled to the power receiver
coupler. The power supply coupler includes a hollow casing having a
paddle shape, the first core accommodated in the hollow casing, and
the first coil located around the first core and in the hollow
casing. The power receiver coupler includes a second core including
a first core member, which has a magnetic pole, and yokes extending
at opposite ends of the magnetic pole, and a second core member for
forming a magnetic flux path with the first core member. The power
receiver coupler further includes a second coil surrounding the
magnetic pole to generate an inductive electromotive force in
response to electric power applied to the first coil and a casing
enclosing the second core and the second coil, the second core
having a recess formed in a region facing the first coil to conduct
air to cool the first coil. The casing of the power receiver
coupler receives the casing of the power supply coupler to couple
the power supply coupler with the power receiver coupler. The first
coil of the power receiver coupler is adjacent to the recess when
the power supply coupler is coupled to the power receiver
coupler.
[0016] The present invention further provides a power receiver
coupler for use in an electric coupling apparatus including a power
supply coupler having a first core and a first coil surrounding the
first core, which includes:
[0017] a casing having an opening to allow insertion of the power
supply coupler;
[0018] a second core located in the casing, the second core
including a first part, which has a magnetic pole and yokes, a
second part, which is magnetically coupled to the first part,
wherein a second coil is wound around the magnetic pole, the second
core having a space between the first and second parts to
accommodate the power supply coupler to cause the first core to
form a closed magnetic flux path with the second core, which
produces an inductive electromotive force in the second coil, the
second core having a recess that faces the first coil to conduct an
air stream to cool the first coil.
[0019] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0021] FIG. 1 is a schematic view of a preferred embodiment of an
electric coupling apparatus according to the present invention as
applied to an electric vehicle and a charging station;
[0022] FIG. 2 is an enlarged cross sectional view of a power supply
coupler and a power receiver coupler taken on line 2-2 of FIG.
1;
[0023] FIG. 3 is an enlarged cross sectional view of the power
supply coupler and the power receiver coupler taken along line 3-3
of FIG. 2;
[0024] FIG. 4 is a front view of the power receiver coupler with a
top cover removed;
[0025] FIG. 5 is a perspective view of a core member constituting
one of a core of the power receiver coupler;
[0026] FIG. 6 is a perspective view of another core member of the
core of the power receiver coupler;
[0027] FIG. 7 is a view illustrating a power supply coupler and a
power receiver coupler of a prior art electric coupling apparatus;
and
[0028] FIG. 8 is a transverse cross sectional view of the electric
coupling apparatus taken along line 8-8 of FIG. 7, the casing of
the power receiver coupler being omitted for illustrative
purposes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] FIGS. 1 to 6 show a preferred embodiment of an electric
coupling apparatus of an electromagnetic induction type according
to the present invention for charging electric vehicle
batteries.
[0030] As shown in FIG. 1, an electric vehicle C includes a power
receiver charging device 1, a power receiver coupler 10, a battery
B and an electric motor (not shown), which is powered by the
battery B. The electric motor forms part of the drive mechanism of
the electric vehicle C. The electric vehicle C is propelled by the
electric motor by electric power delivered from the battery B.
[0031] The power receiver coupler 10 is located at a front part of
the electric vehicle C and is electrically connected to the power
receiver charging device 1 via a cable (not shown). A power supply
charging device 11 is located in a power charging station. A power
supply coupler 12 is electrically connected to the power supply
charging device 11 via a cable. Charging of the battery B is
performed by coupling the power supply coupler 12 to the power
receiver coupler 10.
[0032] As seen in FIG. 2, the power supply coupler 12 has a hollow
casing 15 which is configured in a paddle shape. In the lower ends
of the lower end of the hollow casing 15 is a disk like primary
core 13 having a relatively large thickness and an annular primary
coil 14, which is wound around the primary core 13. The primary
core 13 is located in a through bore formed at the lower end of the
casing 15 and its end surfaces 13a are exposed. The primary coil 14
is located around the primary core 13, is accommodated in the
casing 15, and is electrically connected to the power supply
circuit of the power supply charging device 11.
[0033] The power receiver coupler 10 includes a casing 10a. The
casing 10a includes a housing 16 and a cover 17, which is attached
to the housing 16. The housing 16 is box shaped and has a bottom
end and a rear end, which is open. The housing 16 has an upper wall
25 formed with a coupler opening 26 to allow insertion of the power
supply coupler 12. The cover 17 is attached to the housing 16 to
cover the rear opening of the housing 16 and is fixed by
screws.
[0034] A core 18 and a secondary coil 19 are located in the casing
10a at a lower location as shown in FIG. 2.
[0035] The secondary coil 19 may be formed on a printed circuit
board formed by a plurality of multiplier boards. The winding may
be printed on the circuit board. As best shown in FIG. 3, the core
18 includes a first core member 20 having an E-shaped cross
sectional area and a second core member 21 having an I-shaped cross
section. The first and second core members 20 and 21 are formed of
a sintered ferrite material.
[0036] The first core member 20 is shown in detail in FIG. 5. The
first core member 20 has a cylindrical magnetic pole 22 and a pair
of yokes 23, which are formed at both sides of the magnetic pole
22. More specifically, the yokes 23 have flat portions and upright
portions extending from the flat portions, and upright portions are
extending parallel to the magnetic pole 22. The upright portions
extend further from the flat portions than the magnetic pole 22, as
shown in FIG. 5. Each of the yokes 23 has an internal, cylindrical
surface 23a having the same center point, and the curved surfaces
23a extend in the same direction as the axis of the magnetic pole
22. The yokes 23 have a V-shape cutout 20a to permit the flow of
air, which will be discussed later.
[0037] As shown in FIG. 3, the circuit board, on which is formed
the secondary coil 19, is formed with a bore, through which the
magnetic pole 22 passes. The periphery of the circuit board is
supported by the housing 16, which is part of the power receiver
coupler 10. The coil 19 is then electrically connected to a power
receiving circuit of the power receiver charging device 1.
[0038] In FIG. 3, the second core member 21 is attached to the
yokes 23 of the first core member 20 to bridge and couple the ends
of the yokes 23 for providing a magnetic coupling to the first core
member 20. As clearly shown in FIG. 6, the second core member 21
has a generally plate like configuration and a recess 24 formed on
a surface facing the first core member 20 to provide a cooling air
passage, which will be described below in detail. Part of the
recess 24 matches a circle, the center of which is on the axis of
the magnetic pole 22 of the first core member 21. As seen in FIG.
3, a space 18a is defined between the first and second core members
20 and 21. The space 18a communicates with a lower end opening 16a
of the housing 16 (see FIG. 2) with which the recess 24 also
communicates. The second core members 21 also has V-shape cutout
21a to permit the flow of air.
[0039] As best seen in FIG. 2, the secondary core 18 is attached to
the casing 10a such that the space 18a is aligned with the coupler
opening 26. The distance between the end of the magnetic pole 22 of
the first core member 20 and the internal surface of the second
core member 21 is slightly larger than the thickness of the casing
15 of the power supply coupler 12.
[0040] During charging of the battery B (see FIG. 1), the lower, or
distal, end of the power supply coupler 12 is inserted through the
coupler opening 26 into the casing 10a and into alignment in the
space 18a formed between the magnetic pole 22 and the internal
surface of the second core member 21. When the lower end of the
power supply coupler 12 is inserted into the casing 10a, the
primary core 13 of the power supply coupler 12 is placed between
the magnetic pole 22 of the power receiver coupler 10 and the
second core member 21, which forms a closed magnetic flux path in
the core 18. In this condition, the coil 14 is placed at a location
close to the recess 24.
[0041] As shown in FIG. 2, the housing 16 of the power receiver
coupler 10 includes a guide plate 28. The upper end of the guide
plate 28 is located near the upper wall 25 of the housing 16 and
the lower end of the guide plate 28 located near the lower end
opening 16a. Assembling the guide plate 28 is carried out by
placing the guide plate 28 over the printed circuit board 19 and
fixing the guide plate 28 in the housing 16. The guide plate 28 has
an upper portion extending upward from the core 18 and a lower
portion located in the space 18a. The guide plate 28 has a bore
through which the magnetic pole 22 extends. As best shown in FIG.
4, the upper portion of the guide plate 28 has a plurality of
projections 29a, each being semi circular shape or I-shaped in
cross section and integrally formed on the surface of the guide
plate 28. The projections 29a are formed on the guide plate 28 and
extend parallel to each other. As shown in FIG. 2, the front
surface of the casing 15 of the power supply coupler 12 contacts
the rear ends of the projections 29a, which positions the casing
15. As clearly seen in FIG. 4, the guide plate 28 also has a
plurality of projections 29b, which form a plurality of recesses 33
together with the projections 29a. The projections 29b also have a
semi circular shape or an I-shape in cross section and are formed
integrally with the guide plate 28 such that major portions of the
projections 29b extend along the first core member 20.
[0042] Under a condition that the power supply coupler 12 shown in
FIGS. 2 to 4 is plugged into the power receiver coupler 10, the
plural recesses 33 formed in the vicinity of the center of the
guide plate 28 are opposed to the front surface of the power supply
coupler 12, and the recesses 33 formed in the vicinity of the guide
plate 22 are exposed to the space 18a defined between the core
members 20 and 21 such that, as best shown in FIG. 3, the recesses
33 communicate with the recess 24 through spaces, forming part of
the space 18a, between both the front and rear surfaces of the
power supply coupler 12 and inner surfaces of the yokes 23 of the
core member 20.
[0043] As best seen in FIG. 2, the power receiver coupler 10 has an
auxiliary hollow member 31 which is located close to the rear
surface of the power supply coupler 12 between the upper wall 25 of
the housing 16 and the core 18 of the power receiver coupler 10.
The auxiliary hollow member 31 is formed of a material having a
channel in cross section. The open end is fixed to the cover 17 by
fasteners such as screws. The auxiliary member 31 supports a
printed circuit board 30, which is designed to include a
communication circuit for communicating battery charging
information between the power receiver charging device 1 and the
power supply charging device 11 via the power receiver coupler 10
and the power supply coupler 12.
[0044] As seen in FIG. 2, the inner surface of the auxiliary member
31 is integrally formed with a plurality of projections 32a and
32b. These projections 32a and 32b are paralleled to the
projections 29a, 29b and are parallel to each other. The
projections 32a, 32b form a plurality of recesses 34, one of which
is shown in FIG. 2. The projections 32a and 32b include short and
long projections, which alternate. As seen in FIGS. 2 and 4, for
example, the plurality of projections 32a and 32b are formed in the
auxiliary member 31 directly to oppose the projections 29b and 29a
of the guide plate 28, respectively. Each of the projections 32a
and 32b has a semi circular shape or an I-shape in cross section
like the projections 29a and 29b. The front of the casing 15 is
supported by the projections 29a and 29b and the rear of the casing
15 is supported by the projections 32a and 32b. The casing 15 is
guided by the projections 29a, 24a, 32a, 32b during coupling and
uncoupling of the power supply coupler 12 to and from the power
receiver coupler 10. The recesses 34 communicate with the recesses
24 of the core 18, which communicate further with the space
18a.
[0045] In FIG. 2, the upper end portion 25 of the housing 16 is
formed with a plurality of apertures 27a, 27b and 27c located
around the periphery of the coupler opening 26. The apertures 27a
communicate with the recesses 34 via a passage defined between the
upper wall 25 of the housing 16 and the auxiliary member 31. The
upper wall 25 of the housing 16 includes double walls. The
apertures 27b are formed in the upper wall of the double walls,
whereas the apertures 27c are formed in a side wall located between
the double walls as shown in FIG. 2. The apertures 27b and 27c
communicate with the recess 33 through a passage defined between
the double walls.
[0046] With the structure mentioned above, the power supply coupler
10 is surrounded by the recess 24, the hollow spacing 18a and 21a,
and the recesses 33 and 34. More specifically, the recess 24 faces
the rear surface of the power supply coupler 10 as shown in FIG. 2.
The front surface of the power supply coupler 12 is exposed to the
space 18a, as shown in FIG. 3. The upper rear surface of the power
supply coupler 12 is positioned outside the core 18 of the power
receiver coupler 10 and faces the recess 34. Likewise, the upper
front surface of the power supply coupler 12 faces the recess 33
and is exposed through the lower end opening 16a of the casing
10a.
[0047] As shown in FIG. 2, a cooling fan 35 is fixed to the bottom
of the power receiver coupler 10. The cooling fan 35 includes, for
example, an electric motor to drive the fan, and a casing. The
cooling fan is located outside the opening 16a of the casing
10a.
[0048] When the electric fan 35 is operated, external air is drawn
through the apertures 27a. This air flows through the recess 34 to
the recess 24, and the air further passes to the lower end of the
casing 10a via the opening defined by the cutouts 20a and 21a of
the first and second core members 20 and 21, respectively.
Thereafter, the air is forced through the lower end opening 16a of
the casing 10a to the outside by the electrically driven fan 35. In
addition, the external air drawn through the apertures 27a flows
through the recess 34 into the space 18a. Thereafter, the air
passes through the recess 33 into the opening 16a of the casing 10a
and is forced outside by the fan 35. Also, the external air is
drawn through the apertures 27b and 27c of the casing 10a and flows
through the recess 33. This air flows through the opening defined
by the cutouts 20a and 21a of the first and second core members 20
and 21 into the lower end opening 16a of the casing 10a and is
exhausted to the outside by the action of the fan 35. Furthermore,
the air drawn from the apertures 27b and 27c flows through the
recess 33 into the space 18a between the first and second core
members 20 and 21 and, thereafter, flows through the recess 24 into
the opening 16a, from which the air is exhausted to the outside by
the electric fan 35.
[0049] More specifically, the air passing through the recesses 33
formed in the vicinity of the center of the guide plate 28 flows
into the opening 16a along the front surface of the power supply
coupler 12. The air passing through the recesses 33 formed adjacent
the sides of the guide plate 28 flows through the spaces between
both the side surfaces of the power supply coupler 12 and the inner
surfaces of the core member 20 such that a part of the air flows
into the opening 16a along the side surface of the power supply
coupler 12 while remaining air leaving from the space 18a flows
into the opening 16a through the recess 24 opposite to the rear
surface of the power supply coupler 12.
[0050] At the charging station, the battery charging of the
electric vehicle C is carried out by inserting the power supply
coupler 12 into the power receiver coupler 10 as shown in FIG. 1.
When the power supply coupler 12 is inserted into the power
receiver coupler 10 and an alternating current is supplied to the
coil 14, an electromagnetic, induction current is generated in the
coil 19 of the power receiver coupler 10. This inductive current is
delivered to and converted by the charging device 11. A resulting
DC current changes the battery B mounted in the vehicle C. After
the battery charging is completed, the power supply coupler 12 is
pulled out from the power receiver coupler 10. When the power
supply coupler 12 is inserted into the power receiver coupler 10,
the electric fan 35 of the power receiver coupler 10 also rotates.
In this instance, the electric fan 35 is operated during the time
that electric power is supplied to the power receiver coupler 10
from the power supply coupler 12.
[0051] Due to the action of the electric fan 35, external air is
drawn through the apertures 27a, 27b and 27c into the casing 10a
and is exhausted from the opening 16a of the lower end of the
casing 10a. In this instance, the air drawn through the aperture
27a flows through the recesses 34 and 24 into the lower end opening
16a of the casing 10a. At the same time, the air drawn through the
aperture 27a flows through the recess 34 and the space 18a between
the first and second core members 20 and 21 into the lower end
opening 16a of the casing 10a. The air also flows from the space
18a into the lower end opening 16a via the recess 33. Further, the
air drawn through the apertures 27b and 27c flows through the
recess 33 into the lower end opening 16a of the casing 10a. At the
same time, the air drawn through the apertures 27b and 27c flows
through the recess 33 and the space 18a into the lower end opening
16a. Also, cooling air flows through the recess 24 into the lower
end opening 16a.
[0052] The whole rear surface of the power supply coupler 12 is
thus cooled by an air stream flowing through the recess 34 and the
recesses 24, and another air stream flowing through recess 33, the
hollow spacing 18a and the recesses 34 into the recess 24. The
whole front surface of the power supply coupler 12 is cooled by an
air stream flowing through the recess 33 and another air stream
flowing through the recess 34 and the hollow spacing 18a into the
recess 33. In this fashion, the coil 14 is efficiently cooled by
the casing 15, which is cooled by air flowing through the recesses
33, 34 and 24.
[0053] The primary core 13 of the power supply coupler 12 is
directly cooled by air stream passing through the recess 24 and is
cooled by heat transfer with the casing 15, which is cooled by the
air passing through the recesses 33, 34 and 24.
[0054] The secondary core 18 of the power receiver coupler 10 is
not only cooled by air passing through the casing 10a but is cooled
by the air passing through the recess 24 and the space 18a between
the first and second core members 20 and 21. In addition, the
secondary coil 19 is not only cooled by outside air via the casing
10a but is also cooled by heat transfer with the guide plate 28,
which is cooled by the air stream passing through the recess
33.
[0055] The electric coupler for the battery charging device has
various advantages which will be described below.
[0056] Since the power receiver coupler 10 has a cooling recess 24
in the region surrounding the primary coil 14 of the power supply
coupler 12, the coil 14 of the power supply coupler 12 is cooled
with high efficiency by heat transfer with the casing 15, which is
cooled by air passing through the recess 24. For this reason, even
if the gap between the casing 15 and the second core member 21 is
thin, efficient cooling of the coil 14 is achieved in a highly
reliable manner without loss of high charging rates.
[0057] The coolant air recess 24 communicates with a first cooling
air passage formed by the aperture 27a and the recess 34, a second
cooling air passage formed by the apertures 27b and 27c, the recess
33 and the space 18a between the first and second core members 20
and 21, and a third cooling air passage formed by the cutouts 20a
and 21a and the lower end opening 16a, through which the coolant
air is exhausted to the outside. For these reasons, the casing 10a
of the power supply coupler 12 is efficiently cooled by the air
flowing through the coolant air recess 24 and the plural cooling
air passages.
[0058] The front and rear surfaces of the power supply coupler 12
by the air passing through the recess 33 and the space 18a are the
air passing through the recesses 34 and 24. On the other hand, the
casing 10a of the power receiver coupler 10 and the auxiliary
member 31 are cooled by the air passing through the recess 34. In
addition, the core 18 is cooled by the air passing through the
recesses 24 and 33 and the space 18a. For the above reasons, most
of the component parts of the power supply coupler 12 and the power
receiver coupler 10 are reliably cooled.
[0059] The electric fan 35 serves to drawn external air into and
out of casing of the power receiver coupler 10. Thus, both the
power supply coupler 12 and the core 18 of the power receiver
coupler 10 are reliably cooled.
[0060] Since the recesses 33 and 34 are formed by the projections
29a and 29b, it is easy to arbitrarily modify the distance between
the adjacent projections, that is, the width of the recess, in
accordance with various circumstances.
[0061] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
Particularly, it should be understood that the invention may be
embodied in the following forms.
[0062] While the secondary core 18 of the power receiver coupler 10
includes the first core member 20, including the magnetic pole and
the yokes 23 and the second core member 21, the secondary core may
have other configurations. For example, both of the first and
second core members may have a magnetic pole and a pair of yokes
like the first core member 20, and the secondary core 18 may be
assembled in such a manner that the magnetic poles and the yokes
face each other to provide a space between the magnetic poles to
accommodate the power supply coupler. In this case, the recess 24
may be formed on each surface of the yokes of the first and second
core members to face the surfaces of the power supply coupler such
that the power supply coupler is efficiently cooled by air stream
passing through these recesses.
[0063] In the preferred embodiment discussed above, while the
electric fan is employed to produce an air stream within the power
receiver coupler, the electric fan may be removed depending on the
usage circumstances or the usage objectives.
[0064] In addition, while there are plural recesses 33 and 34 in
the illustrated embodiment, it is possible to modify these recesses
into a single recess having an extended width, if required.
[0065] Further, while the secondary coil 19 of the power receiver
coupler 12 is described as being formed by a printed circuit board,
the coil 14 may have the same constitution as that of the secondary
coil 19.
[0066] Lastly, while the electric coupling apparatus of the present
invention has been described as being applied to the electric
vehicles, the above apparatus may be incorporated into battery
charging devices of other self-propelled apparatus such as
self-propelled robots powered by batteries.
* * * * *