U.S. patent application number 17/534641 was filed with the patent office on 2022-03-17 for pcoil and non-contact power supply device.
This patent application is currently assigned to SWCC SHOWA CABLE SYSTEMS CO., LTD.. The applicant listed for this patent is SWCC SHOWA CABLE SYSTEMS CO., LTD.. Invention is credited to Hideki MATSUMOTO, Kiyoshi MURA, Kentaro NOUCHI.
Application Number | 20220084745 17/534641 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-17 |
United States Patent
Application |
20220084745 |
Kind Code |
A1 |
MATSUMOTO; Hideki ; et
al. |
March 17, 2022 |
PCOIL AND NON-CONTACT POWER SUPPLY DEVICE
Abstract
A coil according to one embodiment of the present invention is a
coil in which a first electric wire on an inner peripheral side and
a second electric wire on an outer peripheral side are wound side
by side to connect ends of the electric wires with each other, and
the coil includes a first region where the first electric wire
abuts on the second electric wire of another adjacent turn and
separates from the second electric wire of a same turn.
Inventors: |
MATSUMOTO; Hideki;
(Kawasaki-shi, JP) ; MURA; Kiyoshi; (Kawasaki-shi,
JP) ; NOUCHI; Kentaro; (Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SWCC SHOWA CABLE SYSTEMS CO., LTD. |
Kawasaki-shi |
|
JP |
|
|
Assignee: |
SWCC SHOWA CABLE SYSTEMS CO.,
LTD.
Kawasaki-shi
JP
|
Appl. No.: |
17/534641 |
Filed: |
November 24, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16900228 |
Jun 12, 2020 |
11222745 |
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17534641 |
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PCT/JP2018/046588 |
Dec 18, 2018 |
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16900228 |
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International
Class: |
H01F 38/14 20060101
H01F038/14; H02J 50/10 20060101 H02J050/10; B60L 53/12 20060101
B60L053/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2017 |
JP |
2017-242081 |
Claims
1. A coil in which a first electric wire is disposed on an inner
peripheral side in a winding direction, a second electric wire is
disposed on an outer peripheral side in the winding direction, and
the electric wires are wound side by side to connect ends of the
electric wires with each other, wherein the second electric wire on
the outer peripheral side is disposed in a spiral shape at regular
intervals, and in the interval of the second electric wire, the
first electric wire on the inner peripheral side is disposed to
meander so as to repeatedly abut on and separate from the adjacent
second electric wire.
2. The coil according to claim 1, wherein sections where the first
electric wire and the second electric wire abut on each other are
bonded.
3. A non-contact power supply device comprising: a board made of
metal or made of resin; and the coil according to claim 1 which is
disposed directly on the board or with a magnetic core plate
interposed therebetween.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional application of U.S.
patent application Ser. No. 16/900,228, filed Jun. 12, 2020 (now
U.S. Pat. No. ______, issued ______), which claims priority to
International Application No. PCT/JP2018/046588, filed Dec. 18,
2018, which claims priority to Japanese Patent Application No.
2017-242081, filed Dec. 18, 2017; the entire contents of all of
which are incorporated herein by reference.
FIELD
[0002] The present invention relates to a coil and a non-contact
power supply device.
BACKGROUND
[0003] In recent years, to power supply for an electric vehicle
(EV) and a plug-in hybrid vehicle (PHV), the study of application
of a non-contact type using a wireless power transmission technique
in addition to a contact type using a cable is also in
progress.
[0004] A technique for non-contact power supply is a technique for,
for example, supplying power to the electric vehicle by wirelessly
transmitting power while facing a planar coil (ground-side coil)
for power transmission (primary side) provided so as to be embedded
in a road surface of a power supply station and a planar coil
(vehicle-side coil) for power reception (secondary side) provided
at the bottom of the electric vehicle at an interval of about
several tens of centimeters.
[0005] The non-contact power supply is required for its
transmission efficiency to be high, and a coil used for the
non-contact power supply is also required for a loss to be reduced.
Accordingly, these days, various measures are taken to reduce a
copper loss, namely, to reduce alternating-current resistance for
the coil used for the non-contact power supply.
[0006] As factors that affect the alternating-current resistance of
the coil, the following two factors are considered. A first factor
is direct-current resistance depending on a conductor
cross-sectional area of a winding wire rod, and a second factor is
a loss caused by a proximity effect and a skin effect which vary
depending on a frequency, a twist configuration of a wire rod, a
coil form, and the like.
[0007] Because the non-contact power supply is used at
high-frequency bands of kHz order in particular, the effect of the
second factor becomes large. A coil using a Litz wire for a wire
rod and, as a form of the coil, being wound while providing a gap
between turns of the wire (hereinafter, this is called "gap winding
coil") is considered suitable for reducing the effect of the second
factor.
[0008] In consideration of the above circumstances, a conventional
coil used for the non-contact power supply is required to be formed
by winding the Litz wire (insulated conductor) formed by twisting a
plurality of thin enameled wires in a spiral shape in a planar
manner and winding it while providing a gap between turns of the
wire. As a conventional technique for providing the gap between
turns of the wire of the coil, for example, there is known a
technique for providing a spacer between adjacent turns of the wire
(refer to Patent Document 1, for example).
[0009] For example, because the planar coils for the non-contact
power supply for the electric vehicle called EV or the like are
required to be capable of transmitting power securely and
efficiently against positional displacement between the power
transmission-side coil (installed in a power transmission/power
supply station) and the power reception-side coil (mounted on the
bottom of the electric vehicle), their respective shapes are
standardized to certain sizes.
[0010] When the coils are actually installed in the electric
vehicle and the power supply station, a shape, an outer shape, an
inside diameter, and the number of turns of the coils, and the like
are specified, thus requiring formation of the coils which retain
strength for coil shape retention as well as restrain a loss by
reducing alternating-current resistance of the coils within the
specified ones.
[0011] The conditions of a coil for non-contact power supply for EV
which are being summarized at present are likely to be in ranges
where, for example, an outer shape of the coil is 250 mm to 600 mm
and an inside diameter of the coil is about 100 mm to 200 mm.
Further, there is a desire to also make a thickness of the coil as
small as possible from the viewpoint of space saving. Specifically,
there is a desire to set the thickness of the coil to, for example,
5 mm or less. Moreover, regarding the number of turns of the coil,
because a transmission frequency is defined to be 85 kHz, the
number of turns is about 8 to 22 turns in terms of an inductance to
resonate with respect to this frequency.
[0012] Incidentally, even though a matter of providing a gap
between turns of the wire is simplified, the work to convey a
product as the coil and to move the coil also during manufacturing
is performed, and variations in inductance of the coil are
suppressed, in a manufacturing site, thus requiring the product in
consideration of shape retention and handleability also after
manufacturing the coil.
[0013] Under the constrain of the coil shape as described above, in
order to reduce the previously-mentioned alternating-current
resistance, there is proposed a coil, after dividing one wire rod
into two, wound apart from and in parallel with each other, what is
called, a coil having a form of parallel gap winding.
[0014] However, since the coil having a form of parallel gap
winding is provided with a gap between turns of a wire, it is
difficult for only the coil to retain its shape.
[0015] This requires such measures for the shape retention as to
sandwich the coil with a shape retaining tool such as a spacer or a
bobbin or as to wind the coil therearound, which cause rising cost
in manufacturing and in transporting.
[0016] Further, because a difference occurs in line lengths between
an inside wire rod and an outside wire rod when a pair of two wire
rods is wound in a planar manner, in a case of forming a coil
having, for example, an outside diameter of 500 mm.times.650 mm, a
winding width of 180 mm, and the number of turns of eight turns,
the line length is about 12 meters, and a line length difference of
about 60 cm occurs between the inside wire rod and the outside wire
rod, resulting in that an electrical characteristic such as
alternating-current resistance deteriorates due to a phase
difference caused by the line length difference.
[0017] Thus, the present invention has been made to solve the above
problems, and it is an object to provide a non-contact power supply
device and a coil which conform to predetermined dimensions and
shape and a predetermined electrical characteristic, are low in
cost, and have good handleability.
SUMMARY
[0018] To achieve the above object, a coil according to one
embodiment of the present invention is a coil in which a first
electric wire on an inner peripheral side and a second electric
wire on an outer peripheral side are wound side by side to connect
ends of the electric wires with each other, and the coil includes a
first region where the first electric wire abuts on the second
electric wire of another adjacent turn and separates from the
second electric wire of a same turn.
[0019] A non-contact power supply device according to one
embodiment of the present invention includes: a board made of metal
or made of resin; and the coil disposed directly on the board or
with a magnetic core plate interposed therebetween.
[0020] According to the present invention, it is possible to
provide a coil and a non-contact power supply device which conform
to predetermined dimensions and shape and a predetermined
electrical characteristic, are low in cost, and have good
handleability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a plan view of a spiral-shaped coil (para hybrid
winding) of a first embodiment according to the present
invention.
[0022] FIG. 2 is an enlarged view schematically (linearly)
illustrating a substantial part of the coil in FIG. 1.
[0023] FIG. 3 is a frequency-alternating-current resistance
characteristic chart of the coil in FIG. 1.
[0024] FIG. 4 is a plan view of a spiral-shaped coil (power
reception side) of a second embodiment.
[0025] FIG. 5 is a sectional view of a non-contact power supply
device using the coil of the above first or second embodiment.
[0026] FIG. 6 is an enlarged view illustrating the other embodiment
of a coil.
DETAILED DESCRIPTION
[0027] Hereinafter, embodiments of the present invention will be
explained based on the drawings.
[0028] A non-contact power supply system is configured to dispose a
non-contact power supply device on a primary side (power
transmission side) and a non-contact power supply device on a
secondary side (power reception side) to face each other. In the
non-contact power supply device on the primary side being a side on
which power is supplied and the non-contact power supply device on
the secondary side being a side on which power is received,
elements of parts of coils are composed of almost the same
elements, and here, one side is explained, and it goes without
saying that the other side is also similar.
First Embodiment
[0029] Hereinafter, a coil 20 of a first embodiment according to
the present invention is explained with reference to FIG. 1 and
FIG. 2. FIG. 1 is a plan view of a spiral-shaped coil (para hybrid
winding) of the first embodiment according to the present
invention, and FIG. 2 is an enlarged view of a substantial part (a
zone P1 of zones P1 to P4).
[0030] As illustrated in FIG. 1, the coil 20 of the first
embodiment according to the present invention is a coil which is
formed (manufactured) in a spiral shape by arranging a pair of two
Litz wires 21, 22 as electric wires or insulated conductors in a
planar manner and winding them from an inner peripheral side to an
outer peripheral side, and has a substantially rectangular (corner
portions are rounded) outer shape in which ends of the Litz wires
21, 22 are combined (connected). The coil in this shape is
installed, for example, on the primary side (power transmission
side or power supply side), specifically, for example, in a road
surface of a charging station for EVs. To arrange the Litz wires
21, 22 in a planar manner means a state of arranging them on a
surface crossing (orthogonal to) the winding axis.
[0031] The Litz wires 21, 22 each have a wire diameter of, for
example, about 5 mm, and a crimp terminal 25 is provided at one
ends on the inner peripheral side of the Litz wires 21, 22 to
connect the Litz wires 21, 22 with each other. Further, a crimp
terminal 26 is provided at one ends on the outer peripheral side of
the Litz wires 21, 22 to connect the Litz wires 21, 22 with each
other. That is, both ends of the Litz wires 21, 22 are combined
(connected) by the crimp terminals 25, 26, and a cross-sectional
area equal to one thick electric wire is secured by the two (pair
of) wires, which are wound flat, thereby contributing to reduction
in thickness of the coil 20.
[0032] In the coil 20, the two Litz wires 21, 22 are wound to the
outer peripheral side in order such that a winding start on the
inner peripheral side is a first turn T1, the next round is a
second turn T2 . . . , and the last round is an eighth turn T8, and
for example, when a third turn T3 is set as an Nth turn, the second
turn T2 is an N-1th turn. Note that N is set to an integer of 2 or
more.
[0033] In this example, the example of winding the two Litz wires
21, 22 from the inner peripheral side to the outer peripheral side
has been explained, but they may be wound from the outer peripheral
side to the inner peripheral side. In this case, a winding start on
the outer peripheral side is a first turn T1, the next round is a
second turn T2 . . . , and the last round is an eighth turn T8, and
the order of the round, the order of the turn, and the turn number
are different in expressions. In a case of the winding from the
outer peripheral side to the inner peripheral side, when a
reference sign T3 in FIG. 2 is set as the Nth turn, a reference
sign T2 is an N+1th turn.
[0034] The coil 20 is the one in which the Litz wire 22 on the
outer peripheral side of the two adjacent Litz wires 21, 22 is
wound in a spiral shape at regular intervals and the Litz wire 21
on the inner peripheral side is wound so as to regularly and
repeatedly abut on and separate from the adjacent Litz wire 22 on
the inner peripheral side and/or the outer peripheral side in a
winding direction.
[0035] Note that in this example, the first turn T1 is excluded
from consideration of regularity because end portions (portions
where a form of the winding start is not stable) of the Litz wires
21, 22 are included.
[0036] In other words, in the coil 20, while the pair of Litz wires
21, 22 whose ends are combined is arranged flat to be wound, the
Litz wire 22 on the outer peripheral side is wound at regular
intervals, and in the interval of the Litz wire 22, the Litz wire
21 on the inner peripheral side is disposed to meander so as to
regularly and repeatedly abut on and separate from the adjacent
Litz wire 22. To be regular means to bend and bend back the Litz
wire 21 at regular lengths, intervals, and angles in certain zones
in one round.
[0037] The coil 20 is wound forward while mixing a portion
"close-winding portion" where the pair of two Litz wires 21, 22
(electric wires) abuts on each other and a portion "gap-winding
portion" where the pair of two Litz wires 21, 22 (electric wires)
separates from each other, thus calling this winding manner
"parallel hybrid winding". The winding manner is sometimes called
para hybrid winding, PH winding, or the like as an abbreviated name
of the parallel hybrid winding.
[0038] In short, in the coil 20, the Litz wire 22 on the outer
peripheral side is disposed in a spiral shape at regular intervals,
and in the interval of the Litz wire 22, the Litz wire 21 on the
inner peripheral side is disposed to meander so as to repeatedly
abut "close-winding portion" on and separate "gap-winding portion"
from the adjacent Litz wire 22.
[0039] In formation of the coil 20, the two Litz wires 21, 22 are
fitted, in order from the inner peripheral side, into a winding jig
(a metal mold or a resin mold) having a plate shape and formed with
a spiral-shaped groove, thereby enabling formation of the coil 20
in which the two Litz wires 21, 22 are wound in a spiral shape in a
planar manner.
[0040] Because the coil 20 only wound in a spiral shape in a planar
manner comes apart when taken out of the winding jig or during
transporting, an adhesive is distributed in a state in FIG. 1 where
the Litz wires are fitted into the winding jig, to bond abutting
portions on the wound wires to each other, and the coil is left as
it is for a fixed time until the adhesive solidifies, thereafter
performing handling.
[0041] For the bonding of the abutting portions, other than the
above, for example, the Litz wires 21, 22 around each of which
heat-fusible fiber is wound may be used to perform bonding by
heating, a self-fusing wire provided with a self-fusing layer on
the outermost layer may be used to perform thermal welding or
solvent bonding, and the Litz wires 21, 22 may be wound with
acetate yarn and coated with a solvent, thereby performing
bonding.
[0042] In short, in the coil 20, the two adjacent Litz wires 21, 22
are wound while being arranged flat from the inner peripheral side
to the outer peripheral side, and separating portions and abutting
portions are provided regularly between the wires, to form a spiral
shape as a whole, and for the purpose of shape retention, the
portions where the wires abut on each other are bonded (fixed) with
the adhesive or by welding, and moreover, the respective crimp
terminals 25, 26 are connected with both ends of the Litz wires 21,
22. The crimp terminals 25, 26 may be attached to the both ends
either before bonding or after bonding, and the attachment after
winding is better because the two wire rods are required to match
their lengths.
[0043] The Litz wires 21, 22 are each a wire group formed by
twisting a plurality of enameled wires into a bundle. Note that in
this example, the Litz wires 21, 22 are used, and as an
electrically conductive wire other than the Litz wires 21, 22, for
example, a conductor (wire made of copper or aluminum as a
material) not subjected to insulation coating, a self-fusing wire
provided with a self-fusing layer on an outermost layer, or the
like may be used.
[0044] The crimp terminal 25 is connected with one ends on the
inner peripheral side of the Litz wires 21, 22, and roughly
composed of a crimp portion and a fixing portion provided with a
hole for fixing. The crimp portion is composed by a cylindrical
metal member, and by inserting conductive portions of the Litz
wires 21, 22 therein to be subjected to caulking, the wire rods and
a metal part are crimped to be integrated with each other,
resulting in fixing the crimp terminal 25 to the Litz wires 21, 22.
The crimp terminal 26 is connected with one ends on the outer
peripheral side of the Litz wires 21, 22, and is the same as the
crimp terminal 25, and the caulking is also performed thereon in
the same manner.
[0045] As illustrated in FIG. 2, the coil 20 is wound so as to form
three regions A, B, C in each of the predetermined zones P1 to P4
in one round of winding. In this example, the three regions A, B, C
are provided in each of the four zones P1 to P4 excluding the
corner portions of the substantially rectangular coil 20. The
region A is called a first region, the region B is called a second
region, and the region C is called a third region. Further, in the
same view, a reference sign X indicates a direction of winding the
two Litz wires 21, 22 forward (winding direction) in forming the
coil 20.
[0046] For example, in the zone P1, when attention is paid to the
Nth turn (for example, the third turn T3 counted from the first
turn T1 on the inner peripheral side) and to the (N-1)th turn (the
second turn T2 counted from the first turn T1 on the inner
peripheral side) from the winding start, the region A is a region
having an abutting section Al where the Litz wire 21 on the inner
peripheral side of the third turn T3 abuts on the Litz wire 22 on
the outer peripheral side of the second turn T2 and a separating
section A2 where the Litz wire 21 on the inner peripheral side of
the third turn separates from the Litz wire 22 on the outer
peripheral side of the third turn. Note that N is set to an integer
of 2 or more in this case.
[0047] In short, the region A is the region where the Litz wire 21
abuts on the Litz wire 22 having another adjacent turn number and
separates from the Litz wire 22 having the same turn number. Note
that the turn number corresponds to the order of the turn. In other
words, the region A can be said to be the region where the Litz
wire 21 of the Nth turn excluding the winding start portion of an
innermost periphery abuts on the Litz wire 22 of the adjacent turn
on the inner peripheral side of the Nth turn and separates from the
Litz wire 22 of the Nth turn (N: an integer of 1 or more).
[0048] The region B is a region where the Litz wire 21 on the inner
peripheral side of the Nth turn (the third turn T3) crosses in a
direction of being wound forward from an abutting section B1 on the
Litz wire 22 on the outer peripheral side of the Nth turn (the
third turn T3) to an abutting section B2 on the Litz wire 22 on the
outer peripheral side of the (N-1)th turn (the second turn T2).
[0049] The region C is a region where the Litz wire 21 on the inner
peripheral side of the Nth turn (the third turn T3) crosses in a
direction of being wound forward from an abutting section Cl on the
Litz wire 22 on the outer peripheral side of the (N-1)th turn (the
second turn T2) to an abutting section C2 on the Litz wire 22 on
the outer peripheral side of the Nth turn (the third turn T3). In
being wound forward from the inner peripheral side to the outer
peripheral side, the regions A to C are formed in order of the
region B, the region A, and the region C.
[0050] Subsequently, performance will be explained in the contrast
between the coil 20 of the first embodiment (para hybrid winding in
FIG. 1) and a comparative example (a coil in which the two Litz
wires are wound in a spiral shape in parallel while providing a gap
at regular intervals (hereinafter, this is called "para gap
winding")) with reference to FIG. 3.
[0051] The para gap winding is a coil in which the two Litz wires
are wound in a spiral shape in parallel while providing a gap at
regular intervals. The para gap winding is a standard coil as a
sample in which the two Litz wires are spaced at a predetermined
interval for each one turn, and it is desirable that coil
performance (characteristic) of the para gap winding is regarded as
a prescribed value, to which a value is as close as possible.
[0052] As a test condition, regarding each of the above-described
two samples (the para gap winding and the para hybrid winding),
both ends of each of the coils are connected with an existing LCR
meter, and the frequency is changed from 0 to 200 kHz to measure
alternating-current resistance. A value at the position where the
frequency is "0" (zero) in FIG. 3 (about 15 m.OMEGA.) indicates a
direct-current resistance.
[0053] With reference to the measured result in FIG. 3, it is found
that in an 85 kHz band being a use frequency of non-contact power
supply for EV, the para hybrid winding of the present invention,
whose alternating-current resistance is 30 m.OMEGA. or less, has a
characteristic equal to that of the standard para gap winding, and
predetermined electrical performance can be obtained.
[0054] Hereinafter, a manufacturing method of the coil 20
illustrated in FIG. 1 will be explained.
[0055] In the case of the coil 20, by fitting the two Litz wires
21, 22 in order into the winding jig formed with a spiral-shaped
groove, the two Litz wires 21, 22 are wound in a spiral shape in a
planar manner.
[0056] While the two Litz wires 21, 22 are wound flat in a spiral
shape from the inner peripheral side to the outer peripheral side
by using the winding jig, there are formed the regions A, B, C
where the Litz wire 22 on the outer peripheral side is wound at
regular intervals, and the Litz wire 21 on the inner peripheral
side repeatedly abuts on and separates from the adjacent Litz wire
22.
[0057] In winding the Litz wires 21, 22 forward from the inner
peripheral side, an exception is made in the first turn T1 (first
round) of the winding start to regularity of the winding manner in
order to adjust an interval between the Litz wires 21, 22 so as to
allow the Litz wire 22 on the outer peripheral side to be wound in
substantially parallel at regular intervals subsequently to the
second turn T2.
[0058] When attention is focused on the third turn T3 (third
round), for example, in the region B in FIG. 2, from the abutting
section B1 where the Litz wire 21 and the Litz wire 22 abut on each
other, the Litz wire 22 on the outer peripheral side remains
straight to go forward, and only the Litz wire 21 on the inner
peripheral side is inclined and wound forward in the left direction
in facing the drawing, separates from the Litz wire 22 of the same
turn T3, and abuts on the Litz wire 22 on the outer side of the
second turn T2 at the abutting section B2.
[0059] Then, in a zone of the region A from the abutting section
B2, the Litz wire 21 on the inner side of the third turn and the
Litz wire 22 on the outer side of the second turn remain abutting
on each other to be wound forward. In the zone of the region A, a
state where the Litz wire 21 on the inner side of the third turn
and the Litz wire 22 on the outer side of the third turn which is
twinned with this Litz wire 21 separate from each other is
kept.
[0060] From the abutting section C1 shifting from the region A to
the region C, from the Litz wire 22 on the outer peripheral side of
the second turn T2 which is wound forward in a straight line, the
Litz wire 21 on the inner peripheral side of the third turn T3 is
inclined and wound forward in the right direction in facing the
drawing, and abuts on the Litz wire 22 of the same third turn T3 at
a position of the abutting section C2. The winding is performed in
this manner until the eighth turn T8 (eighth round) subsequently
thereto. Note that the ninth turn (ninth round) of the outermost
periphery is not included in the number of turns due to being a
lead-out wire for terminal connection.
[0061] Thus, there are formed the region A (first region) where the
Litz wire 21 on the inner peripheral side of the Nth turn excluding
the innermost periphery abuts on the Litz wire 22 on the outer
peripheral side of the (N-1)th turn and separates from the Litz
wire 22 of the Nth turn, the region B (second region) where the
Litz wire 21 on the inner peripheral side of the Nth turn crosses
in a direction of being wound forward from the abutting section B1
on the Litz wire 22 on the outer peripheral side of the Nth turn to
the abutting section B2 on the Litz wire 22 on the outer peripheral
side of the (N-1)th turn, and the region C (third region) where the
Litz wire 21 on the inner peripheral side of the Nth turn crosses
in a direction of being wound forward from the abutting section C1
on the Litz wire 22 on the outer peripheral side of the (N-1)th
turn to the abutting section C2 on the Litz wire 22 on the outer
peripheral side of the Nth turn (N: an integer of 2 or more). Note
that in this winding manner, the regions A to C are formed in order
of the region B (second region), the region A (first region), and
the region C (third region).
[0062] After winding, by bringing one ends on the inner peripheral
side of the Litz wires 21, 22 together to put the crimp terminal 25
thereon and subjecting them to caulking, the wire rods and the
metal part are crimped to be integrated with each other, resulting
in connecting end portions (ends) of the Litz wires 21, 22 with
each other. Further, by bring one ends on the outer peripheral side
of the Litz wires 21, 22 together to put the crimp terminal 26
thereon and subjecting them to caulking, the wire rods and the
metal part are crimped to be integrated with each other, resulting
in connecting end portions (ends) of the Litz wires 21, 22 with
each other. Thus, both ends (ends) of the two Litz wires 21, 22 are
combined (connected) with each other to secure a cross-sectional
area equal to one thick electric wire.
[0063] For the purpose of shape retention of the coil 20 formed as
described above, an adhesive is distributed in a state of being
fitted into the winding jig to bond abutting portions of the wound
wires to each other, and the coil is left as it is for a fixed time
until the adhesive solidifies, thereafter performing handling,
namely, removal from the winding jig. Note that either of the
processing of the end portions of the Litz wires 21, 22 and the
bonding of the abutting portions may be performed first.
[0064] According to the first embodiment as described above, in
winding, side by side, the two (pair of) Litz wires 21, 22 whose
both ends are connected, the Litz wire 21 on the inner peripheral
side is wound to meander with respect to the linearly wound Litz
wire 22 on the outer peripheral side, thereby making it possible to
adjust line lengths so as to reduce a line length difference
between the wire rods on the outer peripheral side and the inner
peripheral side.
[0065] Specifically, by adopting such a winding manner as to wind
the Litz wire 22 on the outer peripheral side in substantially
parallel at regular intervals and make the Litz wire 21 on the
inner peripheral side meander in this interval to repeatedly abut
on and separate from the adjacent Litz wire 22 (para hybrid
winding), to make an adjustment so as to reduce the line length
difference between the pair of Litz wires 21, 22, it is possible to
improve an electrical characteristic which deteriorates due to a
phase difference caused by the line length difference.
[0066] In a case of forming a coil having an outside diameter of
500 mm.times.650 mm, a winding width of 180 mm, and the number of
turns of eight turns, the line length is about 12 meters, and it
has been possible to reduce the line length difference between the
Litz wires 21, 22 to about 8 cm at a connection portion of the
crimp terminal 26 in the outermost peripheral portion
(incidentally, a line length difference occurs by about 60 cm in
conventional para gap winding).
[0067] Further, bonding the abutting sections of the Litz wires 21,
22 adjacent to each other enables the shape retention in which a
gap is provided between the wires without providing a shape
retaining tool such as a spacer or a bobbin.
[0068] As a result, it is possible to provide a non-contact power
supply device and a coil which conform to predetermined dimensions
and shape (shape in which the pair of two Litz wires 21, 22 is
wound side by side while providing a gap in a range of
predetermined outer shape and inner shape) and a predetermined
electrical characteristic, are low in cost, and have good
handleability.
[0069] In the first embodiment, in winding the two Litz wires 21,
22 whose both ends are connected, there is adopted such a winding
manner as to make the Litz wire 21 on the inner peripheral side
meander to repeatedly abut on and separate from the Litz wire 22 on
the outer peripheral side (para hybrid winding), and the region A
(refer to FIG. 2) or the regions A, B, C may be disposed for each
certain angular range divided at regular intervals from a winding
center in a radial direction.
[0070] In addition, in the first embodiment, the total number of
turns of the coil 20 is set to eight turns T1 to T8 (eight-round
turns), but even the number of turns and a coil shape other than
the above can be said to be in scope of application of the
invention of the present application. For example, in this example,
a total of the number of turns is set as an even number, but may be
set as an odd number, and the number of turns itself may be
increased or decreased.
Second Embodiment
[0071] Next, a second embodiment will be explained with reference
to FIG. 4. FIG. 4 is a plan view illustrating a coil (vehicle side)
of the second embodiment. Note that in the second embodiment, the
same constituent elements as those of the first embodiment are
denoted by the same reference signs, and explanation thereof will
be omitted.
[0072] As illustrated in FIG. 4, a coil 20 of the second
embodiment, whose outer shape is formed in, for example, a
substantially square shape (corner portions are rounded) of 400
mm.times.400 mm, is installed on a secondary side (power reception
side), specifically, for example, at the bottom of an EV. A
formation manner of regions A to C is similar to that of the first
embodiment.
[0073] In this example, the Litz wires 21, 22 are wound in a spiral
shape so as to form the outer shape in a quadrangle (the four
corner portions are rounded in such a case where the outer shape
has a substantially square shape as described in this example), and
other than the above, the outer shape may be formed in a polygonal
shape such as a substantially triangular shape, a substantially
pentagonal shape, a substantially hexagonal shape, or a
substantially octagonal shape, a substantially D-shaped shape, a
circular shape, or the like.
[0074] According to the second embodiment as described above,
forming the outer shape of the coil 20 in, for example, a
substantially square shape having length and width dimensions of
400 mm.times.400 mm enables application as the vehicle-mounted coil
20 coping with use in the charging station of the first
embodiment.
[0075] A non-contact power supply device using each of the coils 20
(para hybrid winding) illustrated in the above first and second
embodiments includes a board 1 such as an aluminum plate, a
magnetic core plate 2 disposed on an upper surface of the board 1,
and the coil 20 disposed on an upper surface of the magnetic core
plate 2, as illustrated in FIG. 5.
[0076] This allows the non-contact power supply device on the
primary side or the non-contact power supply device on the
secondary side to be formed, for example. Moreover, in order to fix
a position of the coil 20 on the magnetic core plate 2, the upper
surface of the magnetic core plate 2 may be coated with a molding
resin or the like. Further, the magnetic core plate 2 itself may be
provided with a groove for retaining a shape of the coil 20.
[0077] As the board 1, a plate material of an insulating material
such as a resin plate may be used other than a metal plate such as
the above aluminum plate. Note that the magnetic core plate 2 is
disposed on the board 1 and the coil 20 is disposed thereon in the
above-described example, and the coil 20 may be disposed directly
on the board 1, and moreover, the magnetic core plate 2 may be
disposed on the coil 20.
[0078] When the coil 20 is thus moved on the magnetic core plate 2,
bonding the abutting portions of the Litz wires 21, 22 to each
other in advance causes a shape of the coil 20 to be retained and
variations in inductance to be reduced, resulting in obtaining good
handleability (workability of removal work from the winding jig,
conveying work, and the like during coil manufacturing).
[0079] In the above embodiments, the two Litz wires 21, 22 are set
as a pair, and as illustrated in FIG. 6, line lengths may be
adjusted by using three Litz wires 21, 22, 23 and among them,
disposing the Litz wire 22 on the outer peripheral side at regular
intervals and making the Litz wires 21, 23 on the inner peripheral
side which are disposed in the interval of the Litz wire 22
meander.
[0080] While certain embodiments of the present invention have been
described, the above embodiments have been presented by way of
example only, and are not intended to limit the scope of the
inventions. Indeed, the novel embodiments described above may be
embodied in a variety of other forms; furthermore, various
omissions, substitutions, and changes may be made without departing
from the spirit of the inventions. The inventions described in the
accompanying claims and their equivalents are intended to cover the
above forms or modifications as would fall within the scope and
spirit of the inventions.
* * * * *