JPH0945554A - Ignition coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize reduction in diameter of an ignition coil and improvement in energy transfer efficiency between primary and secondary coils, by providing primary and secondary coils in each of regions having magnetic cores different in axial center direction, dividing the primary coil in the axial center direction and arranging the primary coil on both ends of the secondary coil in a manner that the secondary coil is sandwiched between the primary coils. SOLUTION: A plurality of overhang flange portions 11a are formed on the outer peripheral side of a coil bobbin 11. Divided primary coil regions 15 are formed to vertically sandwich a central secondary coil region 16, with the flange portions 11a between the primary coil region 15 and the secondary coil region 16. A single continuous enamel wire is wound on each of the primary and second coil regions 15, 16, thus forming primary and second coils 12, 14. In an inner space of a coil case 18, an epoxy resin, silicone oil or the like are filled. With such a structure, the energy transfer efficiency from the primary coil 12 to the secondary coil 14 is improved and the diameter of an ignition coil is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil for an independent ignition system used in an internal combustion engine of an automobile or the like.

[0002]

2. Description of the Related Art As an ignition coil of this type, there are those shown in FIGS.

The ignition coil shown in FIG. 5 has a long columnar magnetic core 50 formed by stacking electromagnetic steel sheets, a resin-made primary coil bobbin 51 fitted in the magnetic core 50, and an enameled wire wound around the primary coil bobbin 51. The primary coil 52 formed by turning, the primary coil bobbin 51, and the primary coil 5
2 is a resin-made secondary coil bobbin 53 fitted onto the outer peripheral side of
And a secondary coil 54 formed by winding an enamel wire around the secondary coil bobbin 53.

The ignition coil shown in FIG. 6 has a columnar magnetic core 60 formed by laminating electromagnetic steel sheets in the same manner as the ignition coil described above.
A coil bobbin 61 is fitted over the coil bobbin 61, and an enamel wire is wound on the upper part of the coil bobbin 61 to form a primary coil 62, and an enamel wire is wound on the lower part to form a secondary coil 64.

Intermittent current is supplied from the battery to the primary coils 52 and 62 of the ignition coil shown in FIGS. 5 and 6 through a cable, whereby the secondary coils 54 and 6 are supplied.
The high-voltage current generated in 4 is supplied to the spark plug.

[0006]

However, in the ignition coil shown in FIG. 5, the secondary coil bobbin 53 in which the secondary coil 54 is further wound is fitted on the outer peripheral side of the primary coil bobbin 51 in which the primary coil 52 is wound. Because of the structure,
There is a problem that the diameter of the ignition coil becomes large.

Further, in the ignition coil shown in FIG. 6, since the primary coil 62 and the secondary coil 64 are arranged in parallel along the axial direction of the magnetic core 60, the diameter of the ignition coil is reduced, but the primary coil is reduced. 62 and the secondary coil 64 are the magnetic core 6
Since the dimension of 0 in the axial direction is large, there is a problem that the magnetic force from the primary coil 62 to the secondary coil 64 is greatly attenuated and the energy transmission efficiency is deteriorated.

Therefore, the present invention has been made to solve the above-mentioned problems, and an ignition coil in which the efficiency of energy transfer from the primary coil to the secondary coil is improved while reducing the diameter of the ignition coil. The purpose is to provide.

[0009]

In order to solve the above-mentioned problems, an ignition coil according to claim 1 of the present invention comprises a magnetic core,
A primary coil and a secondary coil each of which is formed by winding an electric wire in different regions along the axial direction of the magnetic core, and the primary coil is divided in the axial direction of the magnetic core; Are arranged at both ends of the secondary coil so as to sandwich the secondary coil.

An ignition coil according to a second aspect of the present invention includes a magnetic core and a primary coil and a secondary coil formed by winding electric wires in different regions along the axial direction of the magnetic core. Is divided in the axial direction of the magnetic core,
The divided secondary coil is arranged on both sides of the primary coil so as to sandwich the primary coil.

An ignition coil according to a third aspect of the present invention includes a magnetic core and a primary coil and a secondary coil each having an electric wire wound in different regions along the axial direction of the magnetic core. Both the secondary coil and the secondary coil are divided in the axial direction of the magnetic core, and the divided primary coils and the divided secondary coils are alternately arranged.

As described in claim 4, the magnetic core may be formed in a flexible cable shape.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

As shown in FIG. 1, the ignition coil according to the first embodiment has a long columnar magnetic core 10 formed by laminating electromagnetic steel sheets,
A cylindrical coil bobbin 11 fitted on the magnetic core 10;
Primary coils 12, 12 formed by winding an enameled wire around the primary coil regions 15, 15 of the coil bobbin 11.
And a secondary coil 14 formed by winding an enameled wire around the secondary coil region 16, and the resin coil case 1
It is accommodated and arranged in 8.

On the outer peripheral side of the coil bobbin 11, a plurality of projecting flange portions 11a which are divided along the axial direction of the coil bobbin 11 are formed, and a secondary coil region 16 formed in the central portion of the flange portion 11a is formed. Separated primary coil regions 15 and 15 are formed so as to be sandwiched in the vertical direction. Further, the secondary coil region 16 is further divided into a plurality of flange portions 11b.

A continuous enameled wire is wound around the primary coil regions 15 and 15 to form the primary coil 12,
12 are formed. In addition, one continuous enameled wire is also wound around the secondary coil region 16 so that the secondary coil 14
Are formed.

The space inside the coil case 18 for accommodating and arranging the ignition coil is filled with thermosetting resin such as epoxy resin, silicone oil, edge oil, etc., whereby the primary coil 12 and the secondary coil The secondary coil 14 is impregnated and fixed, and at the same time, the insulation that can withstand the high output voltage of the secondary coil 14 is secured.

The coil case 18 accommodating and arranging the ignition coil is inserted into a plug hole (not shown) of the internal combustion engine, and the primary coils 12, 12 of the ignition coil are connected to a battery (both not shown) via a cable. ), And the secondary coil 14 is connected to a plug (not shown) at the bottom of the plug hole via a connecting portion 19 provided at the lower end of the coil case 18.

According to the ignition coil constructed as described above, the primary coils 12 and 12 and the secondary coil 14 are connected to the magnetic core 1.
Since they are respectively arranged in different regions along the axis direction of 0, the diameter of the ignition coil can be reduced. By reducing the diameter of the ignition coil in this way, it is not necessary to increase the inner diameter of the plug hole in accordance with the diameter of the ignition coil or to arrange the ignition coil outside the upper side of the plug hole. The degree of freedom in designing an internal combustion engine is increased. Further, since the primary coils 12, 12 divided in the axial direction of the magnetic core 10 are arranged on both ends of the secondary coil 14 so as to sandwich the secondary coil 14, the primary coils 12, 1
The attenuation of the magnetic field from the secondary coil 14 to the secondary coil 14 is reduced, and the energy transfer efficiency is also excellent.

Next, an ignition coil according to a second embodiment of the present invention will be described with reference to FIG.

The magnetic core 20 of the ignition coil, the coil case 28, and the manner in which they are attached to the internal combustion engine are the same as in the first embodiment. Therefore, the differences will be mainly described.
On the outer circumference of the coil bobbin 21 fitted on the magnetic core 20, a plurality of flange portions 21a are formed which are divided in the axial direction thereof, and a primary coil region 26 is formed in the central portion thereof and is divided into upper and lower end sides thereof. Secondary coil regions 25, 25 are formed. Each secondary coil area 25, 25
Is further divided by the collar portion 21b.

Then, a continuous enameled wire is wound around the primary coil area 26 to form the primary coil 22, and a continuous enameled wire is also formed in the divided secondary coil areas 25, 25. Is wound around the primary coil 24
Secondary coils 24, 24 divided into both sides are formed.

According to the ignition coil of the second embodiment having the above-described structure, the primary coils 22 are sandwiched between the divided secondary coils 24, 24 so that the primary coil 22 is sandwiched between them. Similar to the embodiment, the diameter of the ignition coil can be reduced, the attenuation of the magnetic field from the primary coil 22 to the secondary coil 24 is reduced, and the energy transfer efficiency is improved.

FIG. 3 is a diagram showing an ignition coil according to a third embodiment of the present invention. With respect to this ignition coil as well, the manner in which the ignition coil is inserted into the magnetic core 30, the coil case 38, and the internal combustion engine are the same as in the first embodiment, and therefore differences will be mainly described.

That is, on the outer peripheral side of the coil bobbin 31 fitted on the magnetic core 30, a plurality of collar portions 31a are formed along the axial direction of the magnetic core 30, and the collar portions 31a are separated from each other.
The primary coil regions 35, 35 and the secondary coil regions 36, 36 divided along the axial direction of the magnetic core 30 are arranged alternately. Further, each of the secondary coil regions 36, 36 is divided by the collar portion 31b.

In the primary coil regions 35, 35, primary coils 32, 32 are formed by winding a single continuous enameled wire, and the secondary coil region 3 is formed.
The secondary coils 34 and 34 are also formed by winding one continuous enameled wire on each of the coils 6 and 36 and dividing the same.

According to the ignition coil of the third embodiment configured as described above, the primary coil 3 is divided into each.
2, 32 and the secondary coils 34, 34 are alternately arranged along the axial direction of the magnetic core 30, so that the primary coil 32 to the secondary coil 34 are arranged in the same manner as the ignition coil of the first embodiment.
Attenuation of the magnetic field is reduced, energy transfer efficiency is improved, and the diameter of the ignition coil can be reduced.

The primary coil area and the secondary coil area of the ignition coil of the third embodiment may be divided into a larger number and arranged alternately.

In the ignition coils of the first to third embodiments described above, the magnetic core may be formed of an amorphous alloy foil. In this case, the relative magnetic permeability of the amorphous alloy is higher than that of the magnetic steel sheet. Is about 50-100
%, The magnetic core 10, which is made of electromagnetic steel,
The size of the magnetic core required to obtain the same inductance as in the cases of 20 and 30 can be reduced, and the outer diameter of the entire ignition coil can be reduced.

Further, instead of filling the coil case with a thermosetting resin, silicone oil or the like, a ceramic or laminated mica cylinder having excellent corona resistance is provided between the outer circumference of the ignition coil and the inner circumference of the coil case. May be interposed to prevent deterioration of insulation due to corona deterioration.

In the first to third embodiments described above, the magnetic cores 10, 20, 30 are not limited to those formed by stacking electromagnetic steel plates, but bundles of wires made of a ferromagnetic material, or those obtained by compressing the wires. But it is okay.

Next, regarding the fourth embodiment of the present invention,
This will be described with reference to FIG.

This ignition coil has a cable-shaped magnetic core 40.
And a plurality of coil bobbins 41 fitted on the magnetic core 40.
And a primary coil 42 and a secondary coil 44 formed on the outer circumference of each coil bobbin 41.

The magnetic core 40 is, for example, an electromagnetic soft iron rod φ.
A wire rod drawn to a size of 0.3 to 2.5 mm is bundled from several to several tens, twisted, and then compressed in the radial direction.
It is flexible and bendable.

Each coil bobbin 41 is formed of a flexible insulating resin, and a collar portion 41a is formed on the outer periphery of the coil bobbin 41 to divide along the axial direction of the magnetic core 40, and the primary coil is provided on one side thereof. A region 45 is formed and a secondary coil region 46 is formed on the other side. Further, each secondary coil region 46 is divided by the collar portion 41b along the axial direction of the magnetic core 40.

The enameled wire is wound around the primary coil area 45 of each coil bobbin 41, and the enameled wire is wound around the secondary coil area 46.

The plurality of coil bobbins 41 formed in this way are fitted onto the cable-shaped magnetic core 40 in a daisy chain so that the primary coil areas 45 and the secondary coil areas 46 are alternately arranged. There is.

Then, the enameled wires wound around the respective primary coil regions 45 of the respective coil bobbins 41 are electrically connected to each other to form the primary coil 42, and also around the respective secondary coil regions 46. The enameled wires are electrically connected to each other to form the secondary coil 44.

An insulating layer 48 is further formed by extrusion on the outer peripheral side of each coil bobbin 41 in which the primary coil region 42 and the secondary coil region 44 are formed in this way, and the sheath layer is further formed on the outer peripheral side. 49 is formed. The insulating layer 48 does not have to be formed by extrusion molding, and insulating oil or the like may be enclosed in the sheath layer 49.

According to the ignition coil of the fourth embodiment having the above-mentioned structure, since it is formed in a cable shape,
This cable-shaped ignition coil can be arranged so as to be inserted in the middle of the cable from the ignition plug of the internal combustion engine to the battery, and space can be saved. Further, since the primary coil regions 45 and the secondary coil regions 46 are alternately arranged, the diameter of the cable-shaped ignition coil is reduced and the efficiency of energy transfer from the primary coil 42 to the secondary coil 44 is improved. .

Further, the primary coil 42 and the secondary coil 44
Since the enamel wire forming the coil bobbin 41 is wound around a plurality of coil bobbins 41 and then the coil bobbins 41 are fitted onto the magnetic core, the ignition coil can be more easily wound than the case where the enamel wire is wound around the long magnetic core 40. Can be assembled, and can be easily bent at the connecting position of each coil bobbin 41.

[0042]

As described above, according to the ignition coil of the first aspect of the present invention, the primary coil is divided in the axial direction of the magnetic core, and the divided primary coil sandwiches the secondary coil. Since they are arranged on both ends, the efficiency of energy transfer from the primary coil to the secondary coil is improved, and the diameter of the ignition coil is reduced.

According to the ignition coil of the second aspect, the secondary coil is divided in the axial direction of the magnetic core, and the divided secondary coils are arranged at both ends of the primary coil so as to sandwich the primary coil. Therefore, the efficiency of energy transfer from the primary coil to the secondary coil is improved, and the diameter of the ignition coil is reduced.

Further, according to the ignition coil of the third aspect, both the primary coil and the secondary coil are divided in the axial direction of the magnetic core, and the divided primary coil and the divided secondary coil are alternated. Since the first coil is arranged in the above position, the efficiency of energy transfer from the primary coil to the secondary coil is improved, and the diameter of the ignition coil is reduced.

According to the ignition coil of the fourth aspect, it is possible to obtain a cable-shaped ignition coil having a small diameter and flexibility, which is excellent in the degree of freedom of the arrangement place.

[Brief description of drawings]

FIG. 1 is a diagram showing an ignition coil according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an ignition coil according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an ignition coil according to a third embodiment of the present invention.

FIG. 4 is a diagram showing an ignition coil according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a conventional ignition coil.

FIG. 6 is a view showing still another conventional ignition coil.

[Explanation of symbols]

 10 magnetic core 11 coil bobbin 12 primary coil 14 secondary coil 15 primary coil region 16 secondary coil region 18 coil case 19 connection part 20 magnetic core 21 coil bobbin 22 primary coil 24 secondary coil 25 primary coil region 26 secondary coil region 28 coil case 30 Magnetic core 31 Coil bobbin 32 Primary coil 34 Secondary coil 35 Primary coil region 36 Secondary coil region 38 Coil case 40 Magnetic core 41 Coil bobbin 42 Primary coil 44 Secondary coil 45 Primary coil region 46 Secondary coil region 48 Insulating layer 49 Sheath layer

Claims (4)

[Claims] 1. A magnetic core, and a primary coil and a secondary coil formed by winding electric wires in different regions along the axial direction of the magnetic core, and the primary coil is divided in the axial direction of the magnetic core. The divided primary coil is arranged at both ends of the secondary coil so as to sandwich the secondary coil. 2. A magnetic core, and a primary coil and a secondary coil formed by winding electric wires in different regions along the axial direction of the magnetic core, and the secondary coil is divided in the axial direction of the magnetic core. And the divided secondary coils are arranged on both sides of the primary coil so as to sandwich the primary coil. 3. A magnetic core, and a primary coil and a secondary coil formed by winding electric wires in different regions along an axial direction of the magnetic core, respectively, the primary coil and the secondary coil being both the magnetic core. The ignition coil is characterized in that it is divided into a plurality of parts in the axial direction, and the divided primary coils and the divided secondary coils are arranged alternately. 4. The ignition coil according to claim 3, wherein the magnetic core is formed in a flexible cable shape.