U.S. patent application number 10/013145 was filed with the patent office on 2003-06-12 for system and method for winding an ignition coil.
Invention is credited to Hazelwood, John E., Moga, Viorel N..
Application Number | 20030106956 10/013145 |
Document ID | / |
Family ID | 21758534 |
Filed Date | 2003-06-12 |
United States Patent
Application |
20030106956 |
Kind Code |
A1 |
Moga, Viorel N. ; et
al. |
June 12, 2003 |
System and method for winding an ignition coil
Abstract
A coil winding system is provided for making a secondary winding
for an automotive ignition coil. The system includes a roller
configured to apply a holding force to wire being dispensed from a
wire nozzle onto a bobbin. The nozzle and roller are moved by a
drive mechanism under control of a controller from one axial end to
the other axial end of the bobbin for winding the bobbin in a
progressive winding fashion. The roller allows an increase in the
winding angle of the layers, which reduces the voltage difference
between adjacent layers, thereby reducing incidence of dielectric
break down in that region.
Inventors: |
Moga, Viorel N.; (Anderson,
IN) ; Hazelwood, John E.; (Anderson, IN) |
Correspondence
Address: |
MARGARET A. DOBROWITSKY
DELPHI TECHNOLOGIES, INC.
Legal Staff, Mail Code: 480-414-420
P.O.Box 5052
Troy
MI
48007-5052
US
|
Family ID: |
21758534 |
Appl. No.: |
10/013145 |
Filed: |
December 10, 2001 |
Current U.S.
Class: |
242/478.6 |
Current CPC
Class: |
H01F 38/12 20130101;
H01F 41/082 20160101 |
Class at
Publication: |
242/478.6 |
International
Class: |
B65H 054/28 |
Claims
1. A method of winding a bobbin having a main axis to form a coil
comprising the step of holding wire being wound on the bobbin in
place using a roller.
2. The method of claim 1 wherein said bobbin extends along the main
axis and has first and second opposing axial ends, said bobbin
having a winding flange at said first axial end tapered at a
predetermined angle relative to said main axis, said method further
including the step of orienting said roller such that a rotation
axis associated therewith is parallel to said tapered winding
flange.
3. The method of claim 2 wherein said wire is dispensed from a
movable nozzle associated with a winding system, said method
further comprising the step of: moving said nozzle and said roller
relative to said bobbin from said first axial end to said second
axial end.
4. The method of claim 3 further comprising the step of: providing
said roller having an outer surface with a predetermined
hardness.
5. The method of claim 4 wherein said providing step comprises the
substep of: selecting a material for said outer surface having a
pliability within a preselected range.
6. The method of claim 4 wherein said providing step comprises the
substep of: selecting a rubber material for said outer surface.
7. The method of claim 3 wherein said providing step comprises the
substep of: forming said outer surface so as to have a
predetermined texture configured to facilitate holding said wire in
place.
8. The method of claim 1 wherein said wire is progressively wound
according to a winding angle relative to said main axis, said
method further comprising the step of: orienting said roller so
that a rotation axis associated therewith is parallel to said
winding angle.
9. The method of claim 1 wherein said holding step comprises the
substep of: holding said wire using a plurality of rollers.
10. A method of winding a bobbin to form a secondary ignition coil
comprising the steps of: (A) providing a roller with an outer
surface comprising rubber material having a hardness in a
predetermined range; (B) providing a nozzle configured to dispense
wire onto said bobbin according to a progressive winding strategy
with a winding angle relative to a main axis associated with said
bobbin; and (C) dispensing wire from said nozzle onto said bobbin
and holding said wire in place using said roller.
11. The method of claim 10 further comprising the step of:
orienting said roller such that an axis of rotation associated
therewith is parallel to said winding angle.
12. The method of claim 10 wherein said bobbin has first and second
axial ends, and wherein said dispensing and holding step comprises
the substep of: moving said nozzle and roller relative to said
bobbin from said first axial end to said second axial end.
13. A winding system for winding a bobbin to form a coil
comprising: a base including at least one spindle configured to
receive said bobbin; a nozzle proximate said spindle configured to
dispense wire onto said bobbin; a roller proximate said spindle
configured to hold dispensed wire in place on said bobbin; and a
controller configured to rotate said spindle and move said nozzle
and roller axially relative to said spindle.
14. The system of claim 13 wherein said roller is configured to
allow rotation about a rotation axis associated therewith.
15. The system of claim 14 wherein said roller includes an outer
surface comprising material with a hardness in a predetermined
range.
16. The system of claim 15 wherein said material comprises
rubber.
17. The system of claim 14 wherein said roller is oriented such
that said rotation axis is parallel to a winding angle of the wire
being dispensed by said nozzle.
18. The system of claim 14 wherein said system comprises a
plurality of rollers associated with said at least one spindle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to the field of
engine ignition coils, and, more particularly, to a system and
method for winding an ignition coil.
[0003] 2. Description of the Related Art
[0004] It is known to use an automated winding system for the
manufacture of ignition coils wherein the system has a plurality of
spindles for receiving empty coil spools or bobbins, as seen by
reference to U.S. Pat. No. 5,950,956 issued to Yukitake. Yukitake
discloses an ignition coil winding machine capable of
simultaneously forming a plurality of engine ignition coils. The
machine has a driver for rotating a shaft on which a coil bobbin is
disposed, all under the control of a controller. The machine
further includes a tensioning device in between a wire spool
(containing wire destined for being wound on the bobbins) and a
nozzle. The nozzle reciprocates in the coil winding direction,
thereby laying out the wire on the bobbin according to a method
specified in the Yukitake patent.
[0005] It is also known to provide an ignition coil of the type
suitable for mounting directly above the spark plug, sometimes
referred to as a "pencil" coil, that employs a progressive wound
secondary winding, as set forth in U.S. Pat. No. 6,276,348 issued
to Skinner et al. entitled "IGNITION COIL ASSEMBLY WITH SPOOL
HAVING RAMPS AT BOTH ENDS THEREOF." As disclosed in Skinner et al.,
a progressive winding is a one segment winding where a "top" layer
advances under an angle from one end of the spool to the other. The
winding angle is important in such a configuration because it sets
the voltage difference between adjacent layers. In current,
conventional pencil coils, a typical winding angle ranges between
about 8-12 degrees. Increasing the winding angle, however, has been
heretofore limited by the wire collapsing at the bottom of the
winding. Increasing the winding angle would be beneficial inasmuch
as it would be reduce the voltage difference between adjacent wire
layers, thereby decreasing the risk of failure due to voids
produced in the secondary winding area. That is, in a conventional
pencil coil, the secondary winding region is encapsulated with a
dielectric material, such as an epoxy potting material. Increased
voltage differences may break down such dielectric material,
thereby allowing a short circuit between turns.
[0006] There is therefore a need for an improved winding system
that minimizes or eliminates one or more of the problems as set
forth above.
SUMMARY OF THE INVENTION
[0007] One advantage of the present invention is that it solves one
or more of the problems set forth above. Another advantage of the
present invention is that it facilitates manufacture of a
progressive wound coil having an increased winding angle, which
reduces a voltage difference between adjacent layers, thereby
reducing the occurrence of dielectric break down and possible coil
failure. In addition, the invention provides an improved robustness
of the winding due to a reduction or elimination of the occurrence
of wire movement during the winding process.
[0008] In accordance with the present invention, a method is
provided for winding a bobbin having a main axis to form a coil.
The method comprises the step of holding the wire being wound on
the bobbin in place using a roller. Accordingly, increased winding
angles can be employed inasmuch as the wire layers need not rely
solely on the tension in the wire during winding to maintain
placement, but also benefits from the force exerted by the roller
to keep the wire in place.
[0009] In a preferred embodiment, the roller comprises an outer
surface formed of a material having a predetermined hardness (or
pliability, as the case may be), for example, rubber having a
preselected durometer. In a still further preferred embodiment, the
outer surface of the roller is formed so as to have a predetermined
pattern configured to facilitate holding the wire in place.
[0010] In another aspect of the invention, a system for winding a
bobbin is also presented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Additional objects and advantages of the present invention
will be more readily apparent from the following detailed
description of preferred embodiments thereof, when taken together
with the accompanying drawings in which:
[0012] FIG. 1 is a simplified block diagram view of a winding
system according to the present invention;
[0013] FIG. 2 is a partial, perspective view showing the winding
system of FIG. 1 in a multi-spindle configuration;
[0014] FIG. 3 is a simplified cross-sectional view of a bobbin
being wound using a progressive winding strategy; and
[0015] FIG. 4 is a simplified cross-sectional view of the bobbin of
FIG. 3 enlarged, showing use of a roller according to the
invention.
[0016] FIG. 5 is a simplified side view of an alternate preferred
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Referring now to the drawings wherein like reference
numerals are used to identify identical components in the various
views, FIG. 1 shows a winding system 10 in accordance with the
present invention. Winding system 10 includes a main controller 12,
a dereeler assembly 14, and a base with a drive portion 16 that
includes one or more spindles 18 and corresponding number of
nozzles 20. The basic winding system 10 (exclusive of a roller 40
to be described below) is generally of a conventional nature and
may be any one of a number of commercially available systems. For
example, a multi-spindle coil winding machine (exclusive of roller
40 and the accompanying software functionality to be described in
detail hereinafter), may be obtained from Prosys Industries, Inc.,
Plymouth, Mich., USA or Marsilli, for example only. FIG. 1 further
illustrates an ignition coil bobbin 22, a wire feed assembly 24
comprising wire 26 contained on spool 28. In alternate embodiments,
the winding system 10 may comprise a single-spindle winder, a fly
type winder (i.e., post for receiving bobbin does not move but
winding head does), an insertion type winder, an armature type
winder, and a yolk type winder.
[0018] FIG. 2 illustrates the drive portion 16 of machine winding
system 10 in greater detail. As shown in FIG. 2, winding system 10
is of the type that is capable of simultaneously winding at least
one, and for example, a plurality of bobbins 22.sub.1, 22.sub.2, .
. . , 22.sub.i respectively mounted to spindles 18.sub.1, 18.sub.2,
. . . , 18.sub.i. Corresponding parallel structure such as nozzles
20.sub.1, 20.sub.2, . . . , 20.sub.i, and dereeler assemblies
14.sub.1, 14.sub.2, . . . , 14.sub.i are operative to feed
respective runs of wire 26.sub.1, 26.sub.2, . . . 26.sub.i for
winding ignition coils. As also shown, corresponding parallel
structure also includes a plurality of rollers 40.sub.1, 40.sub.2,
. . . 40.sub.i to facilitate holding the wire in place as it is
being dispensed and wound onto the bobbins.
[0019] With continued reference to FIG. 1, generally, wire 26 is
drawn from spool 28 and is fed through dereeler 14, which may
provide a tensioning and/or take-up function relative to the wire
26. Drive portion 16 is configured, generally, to rotate spindle 18
containing bobbin 22, and, further, to reciprocate nozzle 20 over a
preprogrammed axial length over bobbin 22. Drive portion 16
operates in accordance with control signals received from and
generated by controller 12. Nozzle 20 can be moved by drive portion
16 axially with respect to spindle 18, as well as being rotated,
all as known to one of ordinary skill in the art. Roller 40,
generally, is moved in a manner corresponding to the movement of
nozzle 20, preferably, in synchronism therewith. Roller 40 is
operative to hold the wire in place as it is being dispensed onto
the bobbin 22.
[0020] Through the foregoing, a variety of coils having desired
winding patterns may be made. In a preferred embodiment, the coil
may be a primary or secondary coil of an ignition coil for an
engine, such as an automotive engine. It should be understood that
the invention may be used for many other types of winding patterns
and coil types.
[0021] FIG. 3 is a simplified cross-sectional view showing the
winding process for one bobbin 22 in greater detail. In one
embodiment, bobbin 22 comprises a secondary winding bobbin for use
in an ignition coil (i.e., a "pencil" coil) for an internal
combustion engine. The bobbin 22 is substantially cylindrical and
extends along a main axis 34, and has opposing first and second
axial ends 30 and 32. A winding bay is defined between tapered
surfaces of winding flanges located at axial ends 30, and 32. As
further illustrated in FIG. 3, in accordance with one embodiment of
the present invention, a progressive winding approach is taken
wherein wire 26 is set down in layers that move from one axial end
(e.g., end 30) to the other axial end (e.g., end 32). As further
shown, to achieve the progressive wound secondary winding, nozzle
20 moves axially, as described above. As shown in FIG. 3, nozzle 20
is shown in a first intermediate axial position 36, and a second
intermediate axial position 38 between its beginning axial position
and ending axial position near ends 30, 32, respectively. It should
be understood, however, that the tapered ends are not needed for
the present invention.
[0022] FIG. 4 is an enlarged view of a portion of FIG. 3 showing,
in greater detail, the winding process according to the present
invention. Bobbin 22 at axial end 30 includes a winding flange 39
that is tapered at a predetermined angle, designated .theta.
relative to a horizontal axis 41. Horizontal axis 41 is
substantially parallel to main axis 34 of bobbin 22. In one
embodiment, angle .theta. is equal to or greater than about
13.degree., and less than or equal to about 90.degree..
[0023] Roller 40 is oriented, by way of connection to drive 16, so
that its axis of rotation 42 is substantially parallel to the
tapered winding surface of flange 39. Roller 40 is configured to
apply a pressure, designated by vector 43 is FIG. 4, so as to hold
wire 26 in place on spool 22 while nozzle 22 dispenses the same.
Controller 12 is configured to move roller 40 in nozzle 20,
relative to bobbin 22, from one axial end (e.g., end 30) to the
other axial end (e.g., end 32) in a predetermined relationship,
preferably, in synchronism.
[0024] For example, as shown in FIG. 4, roller 40 is moved from a
first axial position 44 to a second, intermediate axial position
46. The roller would be moved by drive 16 under control of
controller 12 all the way to end 32 of bobbin 22. It would then be
programmed to move radially outwardly as the last layers of the
winding are dispensed onto bobbin 22.
[0025] Roller 40, as mentioned above, is configured to rotate about
its own axis of rotation 42. In the embodiment of FIG. 4, the
roller 40 is generally cylindrical in shape, with tapered ends.
However, other shapes may be used. In addition, roller 40 is
provided with an outer surface formed of a material having a
predetermined hardness. In one embodiment, roller 40 has an outer
surface comprising a rubber material having a pliability within a
preselected range. In alternate embodiments, roller 40 would be
formed so that an outer surface thereof has a predetermined texture
configured to facilitate holding wire 26 in place during
winding.
[0026] FIG. 5 shows an alternate preferred embodiment of system 10,
designated 10a in the drawing. In this alternate embodiment, an
alternate shaped roller, designated roller 40a, is provided. Spool
40a is generally frusto-conical in shape, with an outer surface
that tapers radially inwardly, as taken axially along axis 42a
toward spool 22. Winder guide needle 20 and roller 40a move in
direction 48 along the length of spool 22, just as described above
for the first embodiment. In still other embodiments, multiple
rollers may be employed around the circumference of bobbin 22.
[0027] It should be understood that the nozzle 20, while not shown
in FIG. 4, will typically be disposed normal to the paper (either
above the paper, or into or behind the paper) and roller 40.
* * * * *