Information
-
Patent Grant
-
6798328
-
Patent Number
6,798,328
-
Date Filed
Friday, November 15, 200221 years ago
-
Date Issued
Tuesday, September 28, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Hespos; Gerald E.
- Casella; Anthony J.
-
CPC
-
US Classifications
Field of Search
US
- 336 208
- 336 198
- 336 90
- 336 96
- 336 229
- 336 192
-
International Classifications
-
Abstract
A coil apparatus includes a yoke (30) with an open containing chamber (31) that can accommodate a coil (10) formed by binding a wiring (12) around a bobbin (11). The containing chamber (31) is provided on an opening edge with bearings (34) that can receive a lid (40) behind the coil. The lid (40) is secured to the bearings (34) by welding after mounting the lid (40) on the bearings (34). The yoke (30) and lid (40) cover the coil (10.).
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a coil apparatus.
2. Description of the Related Art
Heretofore, a coil apparatus has been produced by binding a wiring around a bobbin to form a coil, transferring the coil to a client and then accommodating the coil in a yoke. A housing is molded around the coil by to prevent the winding from being broken during transport to the client and to enhance a high-impact property of the bobbin. An example of such a coil apparatus is disclosed in Japanese Patent Public Disclosure No. HEI 12-30961 (2000).
The molding method is carried out by setting the coil in a mold die and pouring a molten resin material into the mold die. The mold die, however, increases the cost of production.
In view of the above problem, an object of the present invention is to provide a coil apparatus that can protect a coil at a low cost.
SUMMARY OF THE INVENTION
The invention is directed to a coil apparatus comprising: a coil formed by binding a wiring around a bobbin; and a holding member having a substantially annular containing chamber adapted to accommodate the coil. The holding member includes a closing element for closing the containing chamber to cover the coil.
The closing element preferably includes a lid to be mounted on the containing chamber and secured to the holding member.
An elastic element may be disposed between the lid and the bobbin so that the elastic element is elastically compressed when the lid is mounted on the containing chamber.
A pair of seal rings may be disposed between opposed peripheral surfaces of the lid and containing chamber so that the containing chamber is sealed when the seal rings come into close contact with the opposed peripheral surfaces.
The closing element may include a potting material filled into and solidified in the containing chamber.
Anti-rotation means may be provided between the bobbin and the holding member to maintain the bobbin stationary relative to the holding member when the means are coupled to each other.
The containing chamber is closed by providing the closing element on the holding member to cover the coil after the coil has been accommodated in the containing chamber of the holding member. Thus, the coil is not exposed outwardly and is protected by the holding member and closing element.
The closing element closes the containing chamber. Thus, it is possible to protect the coil at a low cost in comparison with the prior art coil apparatus in which the housing is formed by molding with the mold die.
The lid is mounted on and secured to the holding member after the coil is accommodated in the containing chamber. Thus, the holding member and lid cover the coil.
The elastic member is compressed elastically between the lid body and the bobbin. Therefore, it is possible to hold the coil with no play between the coil and the holding member and between the coil and the lid.
A pair of seal rings seal the containing chamber. As a result, it is possible to prevent external liquid from entering the containing chamber.
The potting material is injected into the containing chamber after the coil has been accommodated in the containing chamber and the coil is fixed in the containing chamber when the potting material is solidified. Accordingly, it is possible to restrict a relative displacement in the peripheral direction between the bobbin and the holding member and to maintain them at an anti-rotation position.
The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the invention with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a rear view of a bobbin in a first embodiment of a coil apparatus in accordance with the present invention.
FIG. 2
is a front elevation view of a yoke.
FIG. 3
is an exploded sectional view of a coil apparatus.
FIG. 4
is an exploded sectional view of a coil apparatus, illustrating a terminal attached to the bobbin.
FIG. 5
is a sectional view of the coil apparatus, illustrating the apparatus containing a coil and a rubber plate in a containing cavity.
FIG. 6
is a sectional view of the coil apparatus, illustrating a lid body secured to the yoke.
FIG. 7
is a sectional view of a second embodiment of the coil apparatus in accordance with the present invention, illustrating the yoke containing the coil.
FIG. 8
is a sectional view of the coil apparatus shown in
FIG. 7
, illustrating the containing chamber in the yoke being filled with a potting material.
FIG. 9
is a sectional view of a bobbin in a third embodiment of the coil apparatus in accordance with the present invention, illustrating the bobbin prior to binding the wiring.
FIG. 10
is a rear view of the bobbin shown in FIG.
9
.
FIG. 11
is an exploded sectional view of the coil apparatus in the third embodiment.
FIG. 12
is an exploded sectional view of the coil apparatus in the third embodiment, illustrating the containing chamber accommodating the coil and a seal ring.
FIG. 13
is a sectional view of the coil apparatus in the third embodiment, illustrating the lid body and a C-ring being secured to the yoke.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of a coil apparatus in accordance with the present invention will be described below by referring to
FIGS. 1
to
6
. A coil apparatus in the first embodiment includes a coil
10
, a yoke
30
for accommodating the coil
10
, and a lid
40
to cover the coil
10
.
As shown in
FIGS. 1 and 3
, the coil
10
comprises a wiring
12
made of a copper wire bound around a synthetic resin bobbin
11
by a number of turns. The bobbin
11
is formed into an annular shape in plan view and includes a pair of flanges that extend outwardly from the opposite ends of a cylindrical portion around which the wiring
12
is bound. A terminal
20
is continuously connected to each of the opposite ends of the wiring
12
. The terminal
20
is supported on a terminal-holding portion
13
on a rear surface (right side surface in
FIG. 3
) of the bobbin
11
. The terminal-holding portion
13
is provided with a press-fitting slot
14
that can receive a press-fitting piece
24
of the terminal
20
by a press-fitting manner. A notch is formed in an outer peripheral edge of the flange opposed to the terminal-holding portion
13
. The notch that permits the distal end of the terminal
20
to enter a space at the wiring side. Two abutments
15
are provided on the rear surface of the bobbin
11
(right side surface in FIG.
3
). The abutments
15
are spaced angularly at about 180 degrees on the inner side from the terminal-holding portion
13
in the radial direction. An anti-rotation boss
16
is provided on the top surface of each abutment
15
at the center. The abutments
15
are adapted to contact an inner surface in the containing chamber
31
of the yoke
30
while the anti-rotation bosses
16
are adapted to fit anti-rotation recesses
33
in the yoke
30
.
The terminal
20
is formed into a shape shown in
FIG. 3
by stamping a metallic sheet into a given shape and bending the stamped metallic sheet. The terminal
20
includes a barrel
21
having a pair of crimping pieces adapted to be crimped onto an end of an electric wire W coupled to an external circuit. The terminal
20
also has a connection portion
22
that extends from the barrel portion
21
in a crank-shaped manner. The distal end of the connection portion
22
has a connecting piece
23
adapted to be connected to the winding
12
by caulking or welding. The connecting portion
22
is provided on the middle part with a press-entering piece
24
. A substantially cylindrical rubber plug
25
is fit on the end of the electric wire W and has a length sufficient to cover the barrel
21
of the terminal
20
. The rubber plug
25
has lips on inner and outer peripheral surfaces. The lips closely contact an outer peripheral surface of the electric wire W and an inner peripheral surface of a wire-drawing hole
32
in a yoke
30
described hereinafter, thereby giving a sealing function between the electric wire W and the wire drawing hole
32
(see FIG.
5
).
The yoke
30
is formed into a substantially annular configuration shown in
FIGS. 2 and 3
by pressing and then machining a metallic material. The yoke
30
is provided with a containing chamber
31
that defines a substantially annular groove with an opening at a front surface (left side surface in FIG.
3
). A pair of wire-drawing holes
32
communicate to the containing chamber
31
and have openings at a rear surface (right side surface in FIG.
3
). The coil
10
is inserted into the containing chamber
31
through a front side opening (left side opening in FIG.
3
). The inner diameter of the containing chamber
31
is substantially the same as that of the coil
10
. An inner wall of the containing chamber
31
is provided with two anti-rotation recesses
33
that are opposed to the anti-rotation bosses
16
of the coil
10
. A bearing
34
is formed in each of inner and outer peripheral edges of the front opening in the containing chamber
31
to support the lid
40
mounted on the opening at the front side of the coil
10
. The inner bearing
34
is formed on the whole open inner peripheral edge of the containing chamber
31
while the outer bearing
34
is formed on the whole open outer peripheral edge of the containing chamber
31
. A raised portion is formed around the outer bearing portion
34
. The electric wires W connected through the terminals
20
to the coil
10
are led out from the wire-drawing holes
32
while the rubber plugs
25
described above closely contact the inner surfaces of the wire-drawing holes
32
.
The lid
40
is formed by cutting a metallic sheet into an annular plate, and is dimensioned to fit on the inner and outer bearings
34
of the containing chamber
31
with no play. Accordingly, when the lid
40
is mounted on the containing chamber
31
, the inner and outer peripheral surfaces of the lid
40
engage the inner and outer bearings
34
, so that the front surface (left side surface in
FIG. 3
) of the lid
40
coincides with the front surface (left side surface in
FIG. 3
) of the yoke
30
(see FIG.
6
). The lid
40
is secured to the yoke
30
by welding. The secured lid
40
can cover the whole front surface (left side surface in
FIG. 3
) of the bobbin
11
, thereby holding the coil
10
in the yoke
30
without exposing the coil
10
outwardly.
An annular rubber plate
41
is disposed between the bobbin
11
and the lid
40
. The rubber plate
41
has a thickness in the natural state greater than a clearance between the bobbin
11
and the lid
40
regularly mounted on the yoke
30
. Consequently, as the lid
40
reaches the bearings
34
, the rubber plate is compressed elastically between the lid
40
and the bobbin
11
to cause an elastic reaction force against them during attachment of the lid to the yoke
30
.
Next, a process for assembling the coil apparatus of the present invention will be explained. As shown in
FIG. 3
, the winding
12
is bound around a cylindrical portion of the bobbin
11
. The terminals
20
are crimped on the ends of the electric wires W after the rubber plugs
25
are mounted on the ends. As shown in
FIG. 4
, the terminals
20
are attached to the terminal-holding portions
13
of the bobbin
11
. Opposite ends of the winding
12
drawn from the bobbin
11
are coupled to the connecting portions
22
of the terminals
20
by crimping or welding.
The coil
10
then is attached to the yoke
30
. More particularly, the coil
10
is accommodated in the containing chamber
31
so that the rubber plugs
25
are inserted into the wire-drawing holes
32
. The inner diameter of the coil
10
is substantially the same as that of the containing chamber
31
, and hence they are fit easily at the coaxial position. The anti-rotation bosses enter the anti-rotation recesses
33
when the coil
10
is accommodated at the regular depth in the containing chamber
31
, thereby preventing the coil
10
from rotating in the yoke
30
(see FIG.
5
). At this time, the abutments
15
contact the inner surface of the containing chamber
31
.
Thereafter, as shown in
FIG. 5
, the rubber plate
41
is put on the left side surface of the bobbin
11
and the lid
40
is mounted on the opening of the containing chamber
31
. The rubber plate
41
is comprised elastically between the lid
40
and the bobbin
11
, while the lid
40
is being attached to the yoke
30
. The lid
40
is urged into contact with the bearings
34
and then is secured to the yoke
30
by welding, as shown in FIG.
6
. Under this condition, the rubber plate
41
is compressed elastically between the bobbin
11
and the lid
40
secured to the yoke
30
to cause an elastic reaction force. This elastic reaction force pushes the bobbin
11
against the inner surface of the containing chamber
31
, thereby eliminating the play between the lid
40
and the yoke
30
.
The yoke
30
and lid
40
cover the coil
10
without exposing the coil
10
outwardly. Thus, the winding
12
and bobbin
11
are not broken by interference with the other parts during transportation to a client. Also, since the coil
10
is held against the yoke
30
and lid
40
with no play by the rubber plate
41
, it is possible to prevent the coil
10
from being broken and generating an abnormal noise due to a relative movement between the yoke
30
and the lid
40
, even if the coil
10
is subject to vibration during transportation.
According to the embodiment described above, the lid
40
closes the containing chamber
31
in the yoke
30
after accommodating the coil
10
in the containing chamber
31
. Thus, it is possible to hold the coil
10
by the yoke
30
and lid
40
without exposing the coil
10
outwardly, and the coil
10
can be protected at a low cost in comparison with the prior art coil apparatus in which the housing is formed around the coil by a molding method using an expensive mold die.
The rubber plate
41
is compressed elastically between the lid
40
and the bobbin
11
. Therefore, the coil
10
can be held against the yoke
30
and lid
40
with no play.
Further, when the coil
10
is accommodated in the containing chamber
31
, the anti-rotation bosses
16
on the coil
10
engage the anti-rotation recesses
33
in the yoke
30
, thereby restricting a relative movement in the peripheral direction between the yoke
30
and the bobbin
11
.
A second embodiment of the coil apparatus in accordance with the present invention will be described by referring to
FIGS. 7 and 8
. In the second embodiment, the lid and rubber plate in the first embodiment are omitted. A potting material
50
made of an epoxy resin or the like closes the containing chamber
31
.
As shown in
FIG. 7
, the coil
10
is accommodated in the containing chamber
31
and the yoke
30
is postured at a horizontal position so that the opening of the containing chamber
31
is directed upward. A nozzle (not shown) connected to a dispenser (not shown) is inserted into the containing chamber
31
to inject the molten potting material
50
into the containing chamber
31
. The potting material
50
fills the containing chamber
31
so that the top surface of the potting material
50
coincides with the top surface of the yoke
30
. The nozzle then is drawn out from the containing chamber
31
and the molten potting material
50
is solidified. The coil
10
, as shown in
FIG. 8
, is surrounded by a unitary matrix of the solidified potting material
50
and hence is secured in the yoke
30
.
Thus, the potting material
50
closes the containing chamber
31
in the yoke
30
and the yoke
30
and potting material
50
protect the coil
10
without exposing the coil
10
outwardly. A potting apparatus is cheaper than the mold die used in the prior art molding method. Therefore, it is possible to lower a cost for equipment. In addition, the potting material
50
can easily seal the coil
10
.
Since the other structure and operational effects in the second embodiment are the same as those of the first embodiment, an overlapping explanation of them will be omitted here.
A third embodiment of the coil apparatus in accordance with the present invention will be described by referring to
FIGS. 9
to
13
. The potting material
50
of the second embodiment gives a simple sealing to the containing chamber
31
. However, the third embodiment is suitable for a requirement of a high sealing function. For example, the third embodiment is suitable for a coil apparatus to be immersed in oil.
As shown in
FIG. 9
, terminals
62
connected to the electric wires W are inserted into a bobbin
61
constituting a coil
60
. In particular, barrels
63
of the terminals
62
are crimped on the ends of the electric wires W and a first rubber plug
66
is mounted on the ends of the electric wires W so that the plug
66
can protect the electric wires W during insert molding of the bobbin
61
. The bobbin
61
is formed from a resin material that covers the outer peripheral surface of the first rubber plug
66
. As shown in
FIG. 10
, the first rubber plug
66
can hold a bundle of two electric wires W passing through it. Connecting portions
64
of the terminals
62
initially extend straight along a radial direction from the insert molded bobbin
61
. However, as shown in
FIG. 11
, a winding
67
is bound around the bobbin
61
, and the connection portions
64
then are bent to the winding
67
and the opposite ends of a winding
67
are coupled to connecting pieces
65
of the connecting portions
64
. A second rubber plug
68
is mounted on the electric wires W at the right side from the first rubber plug
66
in FIG.
13
. The second rubber plug
68
is adapted to come into close contact with a wire-drawing hole
72
in the yoke
70
.
The yoke
70
is provided with a substantially annular containing chamber
71
having an opening at the left side in
FIG. 11. A
wire-drawing portion
73
extends to the right side in FIG.
11
and has a wire-drawing hole
72
communicated to the containing chamber
71
. The containing chamber
71
has a depth sufficient to accommodate the coil
60
, a lid body
80
and a C-ring
83
. The containing chamber
71
has an inner peripheral surface facing the lid body
80
, and a seal ring attachment groove
74
is formed in this inner peripheral surface. An inner seal ring
75
is fit in the groove
74
so that the inner seal ring
75
closely contacts the inner peripheral surface of the lid body
80
accommodated in the containing chamber
71
after accommodating the coil
60
in the chamber
71
. The inner peripheral surface of the containing chamber
71
also has a C-ring attachment groove
76
near the opening from the seal ring attachment groove
74
. A C-ring
83
is fit in the groove
76
after accommodating the lid body
80
in the containing chamber
71
to prevent the coil
60
and lid body
80
from coming out from the yoke
70
.
The lid
80
is formed into an annular shape and is slightly thinner than the bobbin
61
. The inner and outer diameters of the lid
80
are substantially the same as those of the containing chamber
71
. A sealing ring attachment groove
81
is formed in the outer peripheral surface of the lid
80
. An outer seal ring
82
is fit in the seal ring attachment groove
81
to come into close contact with the outer peripheral surface of the containing chamber
71
.
When assembling the coil apparatus, as shown in
FIG. 12
, the coil
60
is accommodated in the containing chamber
71
so that the second rubber plug
68
is inserted into the wire drawing hole
72
to make a seal. After accommodating the coil
60
at the regular position, the inner seal ring
75
is fit in the seal ring attachment groove
74
in the yoke
70
. The outer seal ring
82
then is fit in the seal ring attachment groove
81
of the lid
80
, and the lid
80
is accommodated in the containing chamber
71
. The outer seal ring
82
closely contacts the outer peripheral surface of the containing chamber
71
as the lid
80
is accommodated in the containing chamber
71
, while the inner seal ring
75
closely contacts the inner peripheral surface of the chamber. The lid
80
is inserted into the containing chamber
71
until the right side surface of the lid
80
in the drawing contacts the left side surface of the bobbin
61
in the drawing. Thus, both seal rings
75
and
82
are disposed in substantially the same position in the depth direction of the containing chamber
71
(see FIG.
13
). The C-ring
83
then is fit in the C-ring attachment groove
76
in the yoke
70
, so that the lid
80
and coil
60
are held so as not to come out the yoke
70
, as shown in FIG.
13
.
Under this condition, the second rubber plug
68
seals clearances between the electric wires W and the wire-drawing hole, while the inner seal ring
75
and outer seal ring
82
seal a clearance between the lid
80
and the yoke
70
, thereby positively preventing a liquid, such as oil or the like, from entering the containing chamber
71
from the outside. Consequently, the third embodiment can provide a coil apparatus having a higher sealing performance.
Since the other structure and operational effects in the third embodiment are the same as those of the first embodiment, an overlapping explanation of them will be omitted here.
It should be noted that the present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the present invention includes the following embodiments. Further, the present invention can be embodied within the scope that does not deviate from the gist of the invention except for the following embodiments.
Although the lid is secured to the yoke by welding in the first embodiment, a mechanical fixing means, such as a C-ring, may be used. Similarly, the lid may be secured to the yoke by a means other than the C-ring in the third embodiment.
The number and shape of the anti-rotation boss and recess may be altered in the first and second embodiments. Also, the anti-rotation boss and recess may be applied to the coil apparatus in the third embodiment.
Although the rubber plate is used as an elastic means in the first embodiment, a compression coil spring may be used. Also, the rubber plate may be adhered to the lid or the yoke as an integrated part. The elastic means may be applied to the coil apparatus in the third embodiment.
Although the respective seal ring attachment grooves are provided in the respective lid and yoke in the third embodiment, two seal ring attachment grooves may be provided in either the lid or the yoke.
Although the lid is fit in the containing chamber in the respective embodiments described above, the lid may be secured to the outside of the yoke.
Claims
- 1. A coil apparatus comprising:a coil formed by binding a wiring around a bobbin; and a holding member having a substantially annular containing chamber adapted to accommodate said coil; said holding member including a closing element for closing said containing chamber to cover said coil, said closing element including a lid mounted on said containing chamber and secured to said holding member, an elastic element disposed between said lid and said bobbin so that said elastic element is elastically compressed when said lid is mounted on said containing chamber.
- 2. The coil apparatus of claim 1, wherein said closing element includes a potting material filled into and solidified in said containing chamber.
- 3. A coil apparatus comprising:a coil formed by binding a wiring around a bobbin; a holding member having a substantially annular containing chamber adapted to accommodate said coil, said holding member including a closing element for closing said containing chamber to cover said coil, said closing element including a lid mounted on said containing chamber and secured to said holding member; and a pair of seal rings disposed between opposed peripheral surfaces of said lid and containing said chamber so that said containing chamber is sealed when said seal rings come into close contact with the opposed peripheral surfaces.
- 4. The coil apparatus of claim 3, wherein an elastic element is disposed between said lid and said bobbin so that said elastic element is elastically compressed when said lid is mounted on said containing chamber.
- 5. The coil apparatus of claim 3, wherein anti-rotation means are provided between said bobbin and said holding member to maintain said bobbin at an anti-rotation position relative to said holding member when said means are coupled to each other.
- 6. A coil apparatus comprisinga coil formed by binding a wire around a bobbin; a holding member having a substantially annular containing chamber adapted to accommodate said coil, said holding member including a closing element for closing said containing chamber to cover said coil; and anti-rotation means are provided between said bobbin and said holding member to maintain said bobbin at an anti-rotation position relative to said holding member when said means are coupled to each other.
- 7. The coil apparatus of claim 6, wherein said closing element includes a lid mounted on said containing chamber and secured to said holding member.
- 8. A coil apparatus comprising:a bobbin having a tubular inner wall and first and second substantially parallel end walls extending outwardly from the inner wall to define an open space outwardly from the tubular inner wall and between the first and second end walls; a coil formed by binding a wire in the space around the tubular inner wall of the bobbin and between the first and second end walls; a yoke having a first end wall and inner and outer tubular walls projecting from the first end wall for defining a chamber with an annular opening, the bobbin and the coil thereon being disposed in the chamber of the yoke between the inner and outer tubular walls of the yoke; and a closing lid mounted to the inner and outer tubular walls of the yoke for closing the chamber and covering the bobbin and coil therein.
- 9. The coil apparatus of claim 8, wherein an elastic element is disposed between said lid and said bobbin so that said elastic element is elastically compressed when said lid is mounted over said chamber.
- 10. The coil apparatus of claim 8, wherein a pair of seal rings are disposed between opposed peripheral surfaces of said lid and said chamber so that said containing chamber is sealed when said seal rings come into close contact with the tubular walls of the yoke.
- 11. The coil apparatus of claim 8, wherein said closing element includes a potting material filled into and solidified in said chamber.
- 12. The coil apparatus of claim 8, wherein anti-rotation means are provided between said bobbin and said yoke for to maintaining said bobbin at an anti-rotation position relative to said yoke.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2001-380471 |
Dec 2001 |
JP |
|
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2000-030961 |
Jan 2000 |
JP |