JP3053285U - Ignition coil for internal combustion engine - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the yield by eliminating unused (waste) material generated by punching, and to reduce the size by reducing the discrepancy between the direction of flowing magnetic flux and the rolling direction of iron core material. So that the weight can be reduced. SOLUTION: The ignition coil for an internal combustion engine according to the present invention has a primary coil 1 and a secondary coil 2 wound, respectively.
It has a cylindrical primary coil bobbin 3 and a secondary coil bobbin 4 arranged concentrically, and an iron core part 5 which forms a closed magnetic path through the inner circumference of the cylinder of the primary coil bobbin 3 and the outer circumference of the secondary coil bobbin 4. A portion 5 is formed by laminating strip-shaped silicon steel plates and has a center iron core 6 passing through the inner circumference of the cylinder of the primary coil bobbin 3.
And a wound iron core 7 formed by winding the outer periphery of the secondary coil bobbin 4 (secondary coil 2) a plurality of times with a relatively thin strip-shaped silicon steel sheet.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a molded ignition coil for an internal combustion engine that supplies a high voltage to generate spark discharge in, for example, a spark plug of an automobile engine, and particularly to an ignition coil for an internal combustion engine that requires a small size. is there.

[0002]

[Prior art]

 A conventional molded ignition coil for an internal combustion engine will be described with reference to FIGS.

FIG. 3 is a longitudinal sectional view of a conventional ignition coil for an internal combustion engine, and FIG. 4 is a sectional view taken along line YY of FIG. In these figures, a conventional ignition coil for an internal combustion engine includes a cylindrical primary coil bobbin 3 and a secondary coil bobbin 4 in which a primary coil 1 and a secondary coil 2 are wound and concentrically arranged, respectively, and the primary coil bobbin. 3 and a laminated iron core 26 and a laminated iron core 27 which form a closed magnetic path through the inner circumference of the cylinder and the outer circumference of the secondary coil bobbin 4.

The laminated iron core 26 and the laminated iron core 27 are formed by laminating silicon steel sheets punched in a substantially E-shape and joining them together with their ends facing each other by means of an adhesive or welding. Is formed.

[0005] The primary coil bobbin 3 is integrally formed of an electrical insulating material such as a synthetic resin, for example, and the primary coil 1 is wound around the outer periphery thereof.

The secondary coil bobbin 4 is disposed concentrically on the outer periphery of the primary coil 1, is made of an electrically insulating material such as a synthetic resin, and is used for winding the secondary coil 2 in a divided manner. A plurality of flanges 8 functioning as partitions are integrally formed. The secondary coil 2 having a turn ratio of 1:70 to 120, for example, with respect to the primary coil 1 is wound around the secondary coil bobbin 4 by divided winding with each flange 8 as a partition.

Further, an insulating case 9 formed of an insulating material such as a synthetic resin is provided on the outer periphery of the secondary coil 2, a primary terminal 10 is provided at one end of the insulating case 9, and the other end is provided at the other end. Is provided with a high voltage terminal 11.

The primary coil 1 and the primary terminal 10 are electrically connected to each other, and the secondary coil 2 and the high-voltage terminal 11 are electrically connected to each other. The high-voltage current generated at this point is supplied from the high-voltage terminal 11 to the spark plug via a high tension cord.

[0009]

[Problems to be solved by the invention]

 However, in the above-mentioned conventional ignition coil for an internal combustion engine (so-called molded coil), since the iron core passing through the outer periphery of the coil is manufactured by stamping, the yield of the material is poor, or the material is cut by the stamping of the iron core. Unused (discarded) parts were generated.

[0010] Further, a discrepancy occurs between the direction in which the magnetic flux flows and the rolling direction of the iron core material (the direction of arrow N in FIG. 4), that is, the direction in which the magnetic flux is easy to pass (the magnetic resistance is small). In Nos. 26a and 27a), the magnetic resistance is increased, so that a larger cross-sectional area must be ensured than in other parts, which is in conflict with the reduction in size and weight of the ignition coil.

This invention has been proposed in view of the above, and improves the yield by eliminating unused (discarded) material generated by punching, and furthermore, the direction of flowing magnetic flux and the direction of rolling of core material. It is an object of the present invention to provide an ignition coil for an internal combustion engine that can be reduced in size and weight by eliminating the inconsistency.

[0012]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a primary coil and a secondary coil are wound respectively, and concentrically arranged cylindrical primary coil bobbins and secondary coil bobbins; In an ignition coil for an internal combustion engine having an iron core forming a closed magnetic path through the outer periphery of a secondary coil bobbin, the iron core is formed by laminating strip-shaped silicon steel plates and passing through a center iron core passing through the inner periphery of the cylinder of the primary coil bobbin. In addition, a closed magnetic circuit is formed by a relatively thin belt-shaped silicon steel sheet and a wound core formed by winding the outer periphery of the secondary coil bobbin a plurality of times.

[0013]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing a longitudinal section of the ignition coil for an internal combustion engine according to the present invention, and FIG. 2 is a sectional view taken along line XX of FIG.

In these figures, an ignition coil for an internal combustion engine has a cylindrical primary coil bobbin 3 and a secondary coil bobbin 4 wound around a primary coil 1 and a secondary coil 2 and arranged concentrically, respectively. It has an iron core part 5 which forms a closed magnetic path through the inner circumference of the cylinder of the coil bobbin 3 and the outer circumference of the secondary coil bobbin 4, and this iron core part 5 is formed by stacking strip-shaped silicon steel sheets. It comprises a center core 6 passing around the periphery and a wound core 7 formed by winding the outer periphery of the secondary coil bobbin 4 (secondary coil 2) a plurality of times with a relatively thin band-shaped silicon steel plate.

The primary coil bobbin 3 is a cylindrical member integrally formed of an electrical insulating material such as a synthetic resin, for example, and the primary coil 1 is wound around the outer periphery thereof.

The secondary coil bobbin 4 is disposed concentrically around the outer periphery of the primary coil 1 and is made of, for example, an electrically insulating material such as a synthetic resin. The secondary coil bobbin 4 is integrally formed with a plurality of flanges 8 functioning as partitions for winding the secondary coil 2 separately. That is, the secondary coil bobbin 4 is divided by a plurality of circumferentially provided flanges 8 at a plurality of locations in the length direction of the secondary coil bobbin 4 so that the divided winding grooves of the secondary coil 2 are formed between the respective flanges 8.

On the secondary coil bobbin 4, for example, the secondary coil 2 having a winding ratio of 1:70 to 120 with respect to the primary coil 1 is wound in divided windings with each flange 8 as a partition. .

The center iron core 6 is formed by laminating strip-shaped silicon steel sheets, and is arranged so as to pass through the inner circumference of the cylinder of the primary coil bobbin 3. Further, the wound iron core 7 is formed by winding the outer periphery of the secondary coil bobbin 4 a plurality of times in a circular or elliptical shape with a band-shaped silicon steel plate having a relatively small thickness. The iron core part 5 is composed of the center iron core 6 and the wound iron core 7, and the inner peripheral surface of the wound iron core 7 is joined to both end surfaces of the center iron core 6 with an adhesive, welding, or the like, so that a closed magnetic circuit is formed as a whole. To form a magnetic circuit.

The primary coil 1 and the primary terminal 10, and the secondary coil 2 and the high voltage terminal 11 are electrically connected to each other, and when a predetermined current is applied to the primary coil 1 and cut off, the secondary coil 2 The generated high-voltage current is supplied from a high-voltage terminal 11 to a spark plug via a high-tension code, and a spark is generated between electrodes at the tip of the plug.

Then, a thermosetting resin 12 having an insulating property such as an epoxy resin is injected from an opening end of the insulating case 9, so that the primary coil 1 and the secondary coil 2 inside the insulating case 9 are concentric. The center core 6 and the wound core 7 are fixed at predetermined positions, respectively.

As described above, in this embodiment, the iron core portion 5 is constituted by the center iron core 6 and the wound iron core 7, and the wound iron core 7 is formed by winding a strip-shaped thin silicon steel plate. In addition, since there is no need to perform punching and no waste such as blanking is generated, there is no loss of material, and the yield can be greatly improved.

In addition, since the rolling direction (the direction of arrow M in FIG. 2) of the strip-shaped silicon steel sheet of the wound core 7 is the circumferential direction of the winding, the rolling direction of the core material and the direction of the magnetic flux are different. All the parts can be matched, and therefore, an output as an ignition coil can be obtained with a minimum iron core cross-sectional area, and the ignition coil can be reduced in size and weight.

[0023]

[Effect of the invention]

 Since the present invention has the above-described configuration, the following effects can be obtained.

The core portion is composed of a center core and a wound core, and the wound core is formed by winding a belt-shaped thin silicon steel plate. Since no part is generated, there is no loss of material, and the yield can be greatly improved. Therefore, the cost can be significantly reduced.

In addition, since the rolling direction of the strip-shaped silicon steel sheet of the wound iron core is the wound circumferential direction, the rolling direction of the iron core material and the direction of the magnetic flux can be made coincident at all portions. Therefore, an output as an ignition coil can be obtained with a minimum iron core cross-sectional area, and the size and weight of the ignition coil can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an internal combustion engine ignition coil according to the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a longitudinal sectional view of a conventional ignition coil for an internal combustion engine.

FIG. 4 is a sectional view taken along line YY of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary coil 2 Secondary coil 3 Primary coil bobbin 4 Secondary coil bobbin 5 Iron core 6 Center iron 7 Winding core 8 Flange 9 Insulation case 10 Primary terminal 11 High voltage terminal 12 Thermosetting resin

Claims (1)

[Utility model registration claims] 1. A magnetic system comprising: a primary coil and a secondary coil wound respectively, and concentrically arranged cylindrical primary coil bobbin and secondary coil bobbin; and an inner circumference of the primary coil bobbin and an outer circumference of a secondary coil bobbin. An ignition coil for an internal combustion engine having an iron core part forming a path, wherein the iron core part is formed by stacking strip-shaped silicon steel sheets, and a center iron core passing through the inner periphery of the cylinder of the primary coil bobbin; And a wound iron core formed by winding the outer periphery of a secondary coil bobbin a plurality of times to form a closed magnetic circuit.