U.S. patent application number 09/731594 was filed with the patent office on 2001-06-14 for coil of charging paddle.
Invention is credited to Kutsuzawa, Hidechika.
Application Number | 20010003415 09/731594 |
Document ID | / |
Family ID | 18421674 |
Filed Date | 2001-06-14 |
United States Patent
Application |
20010003415 |
Kind Code |
A1 |
Kutsuzawa, Hidechika |
June 14, 2001 |
Coil of charging paddle
Abstract
An inductive charging paddle includes a coil, which is located
about a core. The coil is connected to an electricity supplying
apparatus through a cable. The coil includes a bobbin and a line
wound about the bobbin. The line includes a litz wire and a tubing
for coating the litz wire. The tubing is made of a heat-shrinkable
resin and is heat shrunk for holding strands of the litz wire
together. The strands in the litz wire are prevented from rubbing
against each other by a simple structure.
Inventors: |
Kutsuzawa, Hidechika;
(Kariya-shi, JP) |
Correspondence
Address: |
Kurt E. Richter
Morgan & Finnegan, L.L.P.
345 Park Avenue
New York
NY
10154
US
|
Family ID: |
18421674 |
Appl. No.: |
09/731594 |
Filed: |
December 7, 2000 |
Current U.S.
Class: |
320/108 |
Current CPC
Class: |
B60L 53/12 20190201;
H02J 7/025 20130101; Y02T 10/7072 20130101; Y02T 90/14 20130101;
Y02T 10/70 20130101; H02J 50/10 20160201 |
Class at
Publication: |
320/108 |
International
Class: |
H02J 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 1999 |
JP |
11-352083 |
Claims
What is claimed is:
1. A coil used in an inductive charging paddle, wherein the coil is
located about a core, which is located in the paddle, and wherein
the coil is connected to an electricity supplying apparatus through
a cable, the coil comprising: a wire comprising a bundle of
strands; and a coating for coating the wire, wherein the coating
comprises a heat-shrinkable resin, and wherein the coating is heat
shrunk for holding the strands together.
2. The coil according to claim 1, wherein the coating comprises a
tubing.
3. The coil according to claim 1, wherein the coating comprises
polyurethane.
4. The coil according to claim 1, wherein the wire comprises a litz
wire.
5. The coil according to claim 1, wherein the wire further
comprises a fine fiber layer surrounding the bundle of the
strands.
6. The coil according to claim 1, wherein the wire lies
approximately in a single plane.
7. The coil according to claim 1, wherein the wire is wound a
plurality of times to form windings and the windings are generally
radially arranged.
8. The coil according to claim 7, further comprising a bobbin about
which the wire is wound.
9. The coil according to claim 8, wherein the bobbin includes a
positioner for determining the position of the wire.
10. The coil according to claim 9, wherein the bobbin includes a
cylindrical body and a pair of opposed flanges, which extend
radially from the axial ends of the cylindrical body, wherein the
positioner projects from a side of each flange towards the opposite
flange.
11. A coil used in an inductive charging paddle, wherein the coil
is located about a core, which is located in the paddle, and
wherein the coil is connected to an electricity supplying apparatus
through a cable, the coil comprising: a bobbin; a litz wire wound
about the bobbin, wherein the litz wire comprises a bundle of
twisted, enameled strands; and a tubing that covers the litz wire,
wherein the tubing comprises a heat-shrinkable resin, and wherein
the tubing is heat shrunk for holding the strands of the litz wire
together.
12. The coil according to claim 11, wherein the litz wire lies
approximately in a single plane, and wherein the bobbin includes a
projection for determining the position of the litz wire.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a coil used in a paddle of
an inductive charger coupling for charging a battery of an electric
vehicle.
[0002] A typical inductive charger coupling for charging electrical
vehicle batteries includes a paddle and a receptacle. The paddle is
connected to an electricity supplying apparatus by a cable. When
charging a battery, the paddle is plugged into the receptacle,
which is located in the vehicle. The paddle includes a coil for
transmitting electricity. The coil is wound about a core, which is
located at a part of the paddle that is plugged into the
receptacle. The receptacle includes a coil for receiving
electricity. The receptacle coil is wound about a core, which is
aligned with the paddle core when the paddle is plugged into the
receptacle. Alternating current is supplied to the paddle coil when
the paddle is plugged into the receptacle, which induces
electricity in the receptacle coil. Accordingly, the vehicle
battery is charged.
[0003] The paddle coil is made of a litz wire. The litz wire
includes approximately one thousand twined and enameled strands,
the diameter of each is, for example, 0.1 mm. The enameled strands
are fastened by a coating of fine threads. The litz wire reduces
heat. The paddle coil is formed by winding the litz wire about the
paddle core, for example, four times.
[0004] When the paddle vibrates or receives a shock, adjacent parts
of the litz wire rub one another. Also, since the fastening force
of the thread coating is weak, the enameled strands scrape one
another in the litz wire. Therefore, if the paddle is used for a
long period, the thread coating of the litz wire and insulation
coating of the enameled strands may be partially removed, which may
cause a short circuit. To prevent parts of the litz wire in the
coil and the strands in the wire from rubbing against one another,
the litz wire may be covered by an insulating sheet and then
impregnated with resin. This, however, complicates the manufacture
and cannot sufficiently prevent the enameled strands within the
coating from rubbing against one another.
SUMMARY OF THE INVENTION
[0005] Accordingly, it is an objective of the present invention to
provide a coil used in a charging paddle that protects surface of a
wire in the coil and prevents strands in the wire from rubbing
against one another.
[0006] To achieve the above objective, the present invention
provides a coil used in an inductive charging paddle. The coil is
located about a core, which is located in the paddle. The coil is
connected to an electricity supplying apparatus through a cable.
The coil includes a wire having a bundle of strands and a coating
for coating the wire. The coating includes a heat-shrinkable resin
and is heat shrunk for holding the strands together.
[0007] 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
[0008] 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:
[0009] FIG. 1 is a cross-sectional view illustrating a charging
paddle according to one embodiment of the present invention;
[0010] FIG. 2 is a cross-sectional view taken along line 2-2 in
FIG. 1;
[0011] FIG. 3A is a side view illustrating the transmitting coil in
the paddle of FIG. 1;
[0012] FIG. 3B is the cross-sectional view illustrating the coil of
FIG. 3A; and
[0013] FIG. 4 is a perspective view illustrating the charger
coupling, which uses the paddle FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] One embodiment of the present invention will now be
described with reference to FIGS. 1 to 4.
[0015] As shown in FIG. 4, an inductive charger coupling 1 includes
a charging paddle 2 and a receptacle 3. The paddle 2 is connected
to an electricity supplying apparatus 4 by a cable 5. The
receptacle 3 is located in a predetermined position in a vehicle 6
and is connected to a vehicle battery 8. In this embodiment, the
receptacle 3 is located in front of the hood. When charging the
battery 8, the paddle 2 is plugged into the receptacle 3.
[0016] The electricity supplying apparatus 4 includes a controller
7. The controller 7 controls alternating current supplied to the
paddle 2 based on signals transmitted between the paddle 2 and the
receptacle 3. The signals include an interlock release signal,
which indicates that the paddle 2 is completely plugged into the
receptacle 3, and a voltage level signal, which indicates the
charging level of the battery 8.
[0017] FIG. 1 is a cross-sectional view illustrating the paddle 2.
The paddle 2 includes a case 9, a cylindrical transmitting core 10,
an annular transmitting coil 11 and a communication controller
substrate 12. The coil 11 is located about the core 10. Circuitry
on the substrate 12 exchanges signals with a transmitter-receiver
(not shown) of the receptacle 3.
[0018] The case 9 is made of an infrared-transparent resin and
includes a plug portion 2a and a grip 2b. The plug portion 2a is
plugged into an opening 3a (see FIG. 4) of the receptacle 3. The
case 9 includes two case members 9a, which are welded to each other
by vibration bonding.
[0019] As shown in FIGS. 1 and 2, a circular opening 13 is formed
in the plug portion 2a. The core 10 is fitted in the opening 13
such that an annular projection 10a is fitted in an annular recess
13a formed in the wall of the opening 13.
[0020] As shown in FIGS. 1 and 2, the coil 11 is located in the
case 9 about the core 10. The coil 11 includes a resin bobbin 14
and a single line 15 wound about the bobbin 14. The bobbin 14
includes a cylindrical body and a pair of flanges, which extend
radially from the axial ends of the cylindrical body.
[0021] The substrate 12 is housed in a transparent resin box 12b,
which is located in the case 9. A circuit board 12a is located on
the substrate 12. An infrared transmitter-receiver 17 and a
communication circuit 18 are mounted on the circuit board 12a. The
infrared transmitter-receiver 17 includes a luminous element 19 and
a photodetector 20.
[0022] A prism 21 is located on the substrate 12. An infrared light
signal from the luminous element 19 is refracted in two opposite
directions (both of which are perpendicular to the surface of the
sheet of FIG. 1) by the prism 21. One of the refracted signals is
received by an infrared transmitter-receiver of the receptacle 3.
The photodetector 20 receives an infrared light from the infrared
transmitter-receiver of the receptacle 3 through the prism 21. The
prism 21 permits the paddle 2 and the receptacle 3 to communicate
regardless of which side of the paddle 2 faces the
transmitter-receiver of the receptacle 3. Therefore, the paddle 2
needs only one transmitter-receiver 17. The communication circuit
18 includes a filter circuit for reducing noise in signals form the
controller 7 and an amplifier for amplifying signals from the
controller 7. Instead of infrared, the paddle 2 and the receptacle
3 may exchange radio signals through antennas. Also, the paddle 2
and the receptacle 3 may include both infrared transmitter-receiver
and radio antennas.
[0023] As shown in FIG. 2, the line 15 is guided by projections 14a
formed in the inner surface of the bobbin 14 and is wound four
times. The windings of the line 15 are generally radially arranged
as shown in FIG. 2. In other words, the line 15 lies approximately
in a single plane. A bobbin cap 14c is fitted about the bobbin 14.
Most of the line 15 is accommodated in a chamber 14d, which is
defined by the inner surface of the bobbin 14 and the bobbin cap
14c. The bobbin 14 and the bobbin cap 14c form a guide.
[0024] As shown in FIGS. 3A and 3B, the line 15 includes a litz
wire 22 and a heat-shrinkable polyurethane tubing 25. The litz wire
22 includes about one thousand twisted, enameled strands 23. The
diameter of each enameled strand 23 is about 0.1 mm. The strands 23
are coated by a fine fiber coating layer 24, which is formed by
winding fine threads. Specifically, the litz wire 22 includes
bundles of the enameled strands 23. The number of the bundles is
twenty in this embodiment. Each bundle has tens of enameled strands
23. In this embodiment, each bundle has about fifty strands 23.
[0025] The litz wire 22 is coated with the heat-shrinkable
polyurethane tubing 25. The tubing 25 coats substantially the whole
litz wire 22 except for the ends, which are connected to power
lines 5a (see FIG. 1), which extend from the cable 5. When forming
the line 15, the litz wire 22 is put in the tubing 25 first. Then,
the tubing 25 is heated, which shrinks the tubing 25. The litz wire
22 is held together and protected by the tubing 25.
[0026] As shown in FIG. 2, the size of the chamber 14d and the
locations of the projections 14a are determined based on the
diameter of the line 15, which includes the tubing 25. The position
of the line 15 in the chamber 14d is determined by the inner
surface of the chamber 14d and the projections 14a. Therefore, the
position of the line 15 is stable in the chamber 14d.
[0027] As shown in FIG. 1, the bobbin 14 has a port 14b. The ends
of the line 15 exit from the port 14b and are connected to the
power lines 5a through terminals (not shown) within protective
covers 5b. A signal line 16, which also extends from the cable 5,
is connected to the circuitry on the substrate 12. The line 15 and
the signal line 16 are connected to the electricity supplying
apparatus 4 through the cable 5.
[0028] The illustrated embodiment has the following advantages.
[0029] The litz wire 22 is coated by the heat-shrinkable tubing 25
such that the enameled strands 23 are tightly bundled, which
prevents the strands 23 from rubbing against one another.
Therefore, the insulation layers of the strands 23 are not broken.
Even if the parts of the line 15 rub against one another, the
tubing 25 protects the surface. Thus, if the paddle 2 is used for a
long period, the line 15 and the strands 23 do not short circuit.
Accordingly, the life of the coil 11 is extended, which guarantees
the reliability of the paddle 2 for a long period.
[0030] Since the paddle 2 is flat, the line 15 is wound in the
radial direction about the core 10. The line 15 is held by the
bobbin 14. Also, even if the line 15 is moved in the bobbin 14, the
tubing 25 protects the surface of the line 15.
[0031] The line 15 is placed along the projections 14a in the
bobbin 14 before the bobbin 14 is installed in the case 9. Thus,
the line 15 is easily installed because other members of the paddle
2 do not interfere. When the bobbin 14 is installed in the case 9,
the position of the line 15 is already determined.
[0032] The line 15 is held by the projections 14a in the chamber
14d of the bobbin 14, which prevents the line 15 from moving.
[0033] 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.
[0034] The heat-shrinkable tubing 25 is made of polyurethane in the
illustrated embodiment. However, the tubing 25 may be made of other
heat-shrinkable resin such as polyolefin, polyethylene
terephthalate, or polyvinyl chloride.
[0035] The fine fiber coating layer 24, which coats the twined
enameled strands 23, may be omitted.
[0036] The number of the enameled strands 23 is not limited to
about one thousand as long as the number is sufficient for
charging.
[0037] The bobbin 14 may be omitted and the coil 11 may be directly
housed in the case 9.
[0038] In the illustrated embodiment, the line 15 is wound in the
radial direction. However, the line 15 may be wound in the axial
direction.
[0039] The shape of the paddle 2 may be changed. For example, the
paddle 2 may be shaped like a gun.
[0040] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
* * * * *