JP2018152446A - Ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine, in which falling down of an outer circumferential core can be prevented when a center iron core provided with a primary bobbin is arranged inside an outer circumferential iron core and which therefore takes less time to be assembled.SOLUTION: The ignition coil for an internal combustion engine 1 comprises a rod-shaped center iron core 3, a primary bobbin 5 which is provided around the center iron core 3 and around which a primary coil 4 is wound, a secondary bobbin 7 which is provided around the primary bobbin 5 and around which a secondary coil 6 is wound, an outer circumferential iron core 8 provided around the secondary bobbin 7, and a permanent magnet 9 provided between the center iron core 3 and the outer circumferential iron core 8. A projected portion 18 for supporting the outer circumferential iron core 8 is provided at the end portion of the primary bobbin 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ignition coil for an internal combustion engine for supplying a high voltage to generate a spark discharge in an ignition plug of an automobile engine, for example.

  Conventionally, a central iron core, a primary bobbin provided around the central iron core and wound with a primary coil, a secondary bobbin provided around the primary bobbin and wound with a secondary coil, and a secondary There is known an ignition coil for an internal combustion engine including an outer peripheral iron core provided around a bobbin and a permanent magnet provided between a central iron core and the outer peripheral iron core (for example, Patent Document 1). In this internal combustion engine ignition coil, the entire primary bobbin is disposed inside the outer peripheral iron core together with the central iron core.

JP 2010-212395 A

  In the ignition coil for an internal combustion engine disclosed in Patent Document 1, the entire primary bobbin is disposed between the outer peripheral iron cores, so that the outer peripheral iron core falls when the permanent magnet is not magnetized. Therefore, it is necessary to hold the central core in a predetermined position until the permanent magnet is magnetized and the central core and the outer peripheral core are magnetically coupled, and it takes time to assemble the ignition coil for the internal combustion engine.

  Accordingly, an object of the present invention is to provide an ignition coil for an internal combustion engine that can prevent the outer peripheral iron core from dropping when the central iron core provided with the primary bobbin is disposed inside the outer peripheral iron core, and does not require time for assembly. .

  The ignition coil for an internal combustion engine of the present invention is provided with a rod-shaped first iron core, a primary bobbin around which the primary coil is wound, a primary bobbin, and a secondary coil provided around the primary bobbin. It is provided with a wound secondary bobbin and a second iron core provided around the secondary bobbin, and a convex part for supporting the second iron core is provided at an end of the primary bobbin. .

  The ignition coil for an internal combustion engine according to the present invention is characterized in that a plurality of convex portions are provided along the end portion of the first bobbin.

  In the ignition coil for an internal combustion engine of the present invention, the convex portion is formed from one end and the other end of the primary bobbin toward the axial direction of the primary bobbin, the concave portion is formed at the bottom of the second iron core, and the convex portion is formed into the concave portion. The second iron core is supported by the primary bobbin by being fitted together.

  The ignition coil for an internal combustion engine according to the present invention includes a plurality of second iron cores, and each second iron core has a fitting portion that fits with an adjacent second iron core.

  In the ignition coil for an internal combustion engine of the present invention, the convex portion provided at the end of the primary bobbin supports the second iron core. For this reason, when the central core including the primary bobbin is disposed inside the outer peripheral core, the outer peripheral core can be prevented from falling off.

  In an ignition coil for an internal combustion engine, a permanent magnet is provided between an outer peripheral iron core and a central iron core, and the permanent magnet is magnetized to magnetically couple the outer peripheral iron core and the central iron core. Therefore, it is necessary to maintain the central iron core at a desired position until the permanent magnet is magnetized. In the ignition coil for an internal combustion engine according to the present invention, since the convex portion of the primary bobbin supports the second iron core, it is not necessary to maintain the center iron core at a desired position, and the assembly is not time-consuming.

  Further, the ignition coil for an internal combustion engine of the present invention can be assembled without magnetizing the permanent magnet at the time of assembly, so that it is not necessary to generate a magnetic force of the permanent magnet at the time of assembly. If it does so, the surrounding metallic substance contaminant will not be drawn near to the 1st iron core or the 2nd iron core, and the insulation distance can be secured. Therefore, a high quality ignition coil for an internal combustion engine can be assembled.

  In the ignition coil for an internal combustion engine of the present invention, a plurality of convex portions can be provided along the end portion of the primary bobbin. If it does so, since the location (area) where a primary bobbin will support a 2nd iron core will increase, a 2nd iron core will be stably supported by a primary bobbin.

  Furthermore, a concave portion is formed in the outer peripheral iron core of the ignition coil for an internal combustion engine of the present invention, and the convex portion of the primary bobbin is fitted into the concave portion. Therefore, when placing the central bobbin including the primary bobbin and the outer peripheral iron core, it is only necessary to connect the convex part so as to fit the concave part, the positioning of the primary bobbin can be facilitated, and the assembly is not troublesome. .

It is sectional drawing of the ignition coil for internal combustion engines which concerns on embodiment of this invention. It is a bottom view of the ignition coil for internal combustion engines which concerns on embodiment of this invention. It is an enlarged view of the connection part of the primary bobbin which comprises the ignition coil for internal combustion engines which concerns on embodiment of this invention, and an outer periphery iron core.

An ignition coil for an internal combustion engine according to the present embodiment will be described with reference to FIGS.
As shown in FIG. 1, an ignition coil 1 for an internal combustion engine according to the present embodiment includes an insulating case 2, a central iron core 3 as a first iron core housed in the insulating case 2, and the central iron core 3. A primary bobbin 5 around which a primary coil 4 is wound, a secondary bobbin 7 around which the primary bobbin 5 is wound and a secondary coil 6 is wound, and the periphery of the secondary bobbin 7 And a permanent magnet 9 provided between the central iron core 3 and the outer iron core 8 as a second iron core.
In the internal combustion engine coil 1, a current is passed through the primary coil 4 to generate a magnetic flux in the central core 3, and a high voltage is applied to the secondary coil 6 in order to interrupt the magnetic flux. The permanent magnet 9 magnetizes the central iron core 3 and the outer peripheral iron core 8 in the direction opposite to the magnetic flux generated in the primary coil 4 and the secondary coil 6.

The insulating case 2 can be made of a thermoplastic resin.
The insulating case 2 has an open upper surface, and a connector 12 that accommodates the low-voltage terminal 11 on the side of the insulating case 2 and a high-voltage cylinder portion 14 that accommodates the high-voltage terminal 13 on the lower side are provided so as to protrude. The low voltage terminal 11 is connected to the primary coil 4, and the high voltage terminal 13 is connected to the secondary coil 6. In addition, an igniter 10 connected to the primary coil 4 is provided inside the insulating case 2. The internal combustion engine ignition coil 1 controls the current using the igniter 10 after flowing a predetermined current through the primary coil 4, so that the high voltage current generated in the secondary coil 6 is high from the high voltage terminal 13. The spark plug is supplied to the spark plug via a tension cord, and a spark is generated between the electrodes at the tip.
A ceramic resistor 22 connected to the high voltage terminal 13 is provided inside the high voltage cylinder portion 14 in order to reduce discharge noise.

The central iron core 3 is a rod-shaped member, and a magnetic circuit is formed on the central iron core 3. For example, a silicon steel plate can be press-laminated on the central iron core 3 to form a closed magnetic circuit.
The central iron core 3 is accommodated in a primary bobbin 5, and a primary coil 4 is wound around the primary bobbin 5. For the primary coil 4, for example, an enameled wire can be used.

The primary bobbin 5 can be made of a thermoplastic resin, and the primary bobbin 5 includes a cylindrical body 15 and an upper part formed to project from the upper part of both ends of the cylindrical body 15 in the axial direction of the cylindrical body 15. A support 16 and a lower support 17 formed so as to protrude in the axial direction of the cylinder 15 from the lower part of the cylinder 15 are provided.
The upper support 16 is designed to be longer than the lower support 17 and covers the end of the central core 3 and the upper portion of the outer peripheral core 8.

Convex portions 18 are formed on one end portion and the other end portion of the lower support body 17 in the axial direction of the primary bobbin 5, respectively. As shown in FIG. 2, the convex portion 18 is formed in the middle of the end portion, is designed to have a width that decreases toward the outside, and has a trapezoidal shape. In addition, a step is formed on the lower support 17 by forming the convex portion 18.
In addition, the convex part 18 can also be provided with two or more along an edge part, and the shape of the convex part 18 is not limited to trapezoid shape, It can change suitably.

A secondary bobbin 7 is provided on the outer periphery of the primary bobbin 5 so that a gap is formed between the primary bobbin 5 and the primary bobbin 5 (FIG. 1).
A flange 19 is formed on the outer periphery of the secondary bobbin 7, and a plurality of the flanges 19 are provided at predetermined intervals in the axial direction of the secondary bobbin 7. The secondary coil 6 is wound between the collars 19. An enameled wire can be used for the secondary coil 6 as in the case of the primary coil 4.

The outer peripheral iron core 8 is for returning the magnetic flux generated in the central iron core 3, and has a rectangular tube shape having an upper part 8A and a bottom part 8B. Inside the outer peripheral iron core 8, the central iron core 3 provided with the primary bobbin 5 and the secondary bobbin 7 is disposed.
A recess 20 is formed in the bottom 8 </ b> B of the outer peripheral iron core 8. The recesses 20 are formed one by one at opposing positions. The concave portion 20 has the same shape as the convex portion 18, and the vertical depth of the concave portion 20 and the thickness of the convex portion 18 are formed substantially the same.
A plurality of the recesses 20 can be provided along the end portion, and are provided together with the number of the protrusions 18.

A method for producing the ignition coil 1 for an internal combustion engine will be described.
First, the central core 3 is pushed into the primary bobbin 5, the primary coil 4 is wound around the primary bobbin 5, and the primary bobbin 5 is inserted into the secondary bobbin 7, and between the flanges 19 of the secondary bobbin 7. The secondary coil 6 is wound. At this time, the primary bobbin 5 and the secondary bobbin 7 are disposed concentrically. Moreover, the high voltage | pressure cylinder part 14 and the secondary coil 6 are arrange | positioned so as to cross | intersect substantially right angle (FIG. 1).

Next, a non-magnetized permanent magnet 9 is disposed between the upper support 16 and the lower support 17 on one end side of the primary bobbin 5. Then, as shown in FIG. 3, the convex portion 18 of the lower support 17 is fitted into the concave portion 20 of the outer peripheral iron core 8, and the outer peripheral iron core 8 is disposed around the central iron core 3. At this time, since the thickness of the convex portion 18 and the depth of the concave portion 20 are the same, the lower support 17 and the bottom surface 8B of the outer peripheral iron core 8 are in the same plane, and the convex portion 18 supports the outer peripheral iron core 8 from below. Moreover, the upper support body 16 covers the whole upper part of the outer periphery iron core 8 (FIG. 1).
Then, the permanent magnet 9 is magnetized, and the central iron core 3 and the outer peripheral iron core 8 are magnetically coupled.

Next, the effect of the ignition coil 1 for internal combustion engines is demonstrated.
In the internal combustion engine ignition coil 1 according to the present embodiment, the convex portion 18 formed on the lower support 17 of the primary bobbin 5 is fitted into the concave portion 20 of the outer peripheral iron core 8 (FIG. 3). Then, the outer peripheral iron core 8 is supported by the primary bobbin 5 from below. Since the outer peripheral iron core 8 is supported by the primary bobbin 5, it is possible to prevent the outer peripheral iron core 8 from falling.

In the internal combustion engine ignition coil 1, the outer peripheral iron core 8 and the central iron core 3 are magnetically coupled by magnetizing the permanent magnet 9. Therefore, it is necessary to maintain the central core 3 at a desired position until the permanent magnet 9 is magnetized.
In the internal combustion engine ignition coil 1 of the present embodiment, since the outer peripheral iron core 8 is supported by the primary bobbin 5, it can be assembled without magnetizing the permanent magnet 9 during assembly. By assembling the permanent magnet 9 without magnetizing, the surrounding metallic core contaminants are not attracted to the central iron core 3 and the outer peripheral iron core 8, and an insulation distance is secured. Therefore, a high quality ignition coil 1 for an internal combustion engine can be assembled.

Furthermore, when the central iron core 3 is disposed inside the outer peripheral iron core 8, the positions of the convex portions 18 and the concave portions 20 may be aligned, and the convex portions 18 may be fitted into the concave portions 20. Therefore, the outer peripheral iron core 8 can be easily positioned, and the labor for assembling the ignition coil 1 for an internal combustion engine can be saved.
Furthermore, the convex portion 18 is fitted into the concave portion 20, whereby the operation of the primary bobbin 5 in the planar direction is restricted. For this reason, even when the primary bobbin 5 and the outer peripheral iron core 8 are fitted and then subjected to some impact, the primary bobbin 5 and the outer peripheral iron core 8 can be prevented from being displaced in the plane direction.

  In addition, a plurality of convex portions 18 can be provided along the end portion of the lower support 17. In this case, the outer peripheral iron core 8 is supported by the plurality of convex portions 18. Then, since the location (area) where the primary bobbin 5 supports the outer periphery iron core 8 will increase then, the primary bobbin 5 can support the outer periphery iron core 8 stably.

Although the present embodiment has been described above, the configuration described in the above embodiment can be selected or changed to other configurations as appropriate without departing from the gist of the present invention. .
For example, the outer peripheral iron core 8 may be composed of a plurality of divided outer peripheral iron cores 8. Each outer peripheral iron core 8 is provided with a fitting portion (not shown), and can be fitted to the adjacent outer peripheral iron core 8 via this fitting portion.
Further, in the present embodiment, the example in which the concave portion 20 is formed in the outer peripheral iron core 8 is shown, but the convex portion 18 of the primary bobbin 5 supports the outer peripheral iron core 8 even when the outer peripheral iron core 8 is not formed with the concave portion 20. The configuration can be made.

  Furthermore, in this embodiment, although the convex part 18 of the lower support body 17 showed the example formed toward the axial direction of the primary bobbin 5, the outer periphery iron core 8 should just be set as the structure supported by the convex part 18. FIG. Further, it may be formed in an oblique direction from the end of the lower support 17.

1 Ignition coil for internal combustion engine 2 Insulation case 3 Central iron core
4 Primary coil 5 Primary bobbin 6 Secondary coil 7 Secondary bobbin 8 Outer peripheral iron core (second iron core)
8A Upper part 8B Bottom part 9 Permanent magnet 10 Igniter 11 Low voltage terminal 12 Connector 13 High voltage terminal 14 High voltage cylinder part 15 Cylindrical body 16 Upper support body 17 Lower support body 18 Convex part 19 鍔 20 Concave part 22 Ceramic resistor

Claims (4)

A rod-shaped first iron core, a primary bobbin provided around the first iron core and wound with a primary coil, a secondary bobbin provided around the primary bobbin and wound with a secondary coil, In an ignition coil for an internal combustion engine comprising a second iron core provided around the secondary bobbin,
A convex portion that supports the second iron core is provided at an end of the primary bobbin.
An ignition coil for an internal combustion engine. A plurality of the convex portions are provided along an end portion of the primary bobbin.
The ignition coil for an internal combustion engine according to claim 1. The convex portion is formed from one end and the other end of the primary bobbin toward the axial direction of the primary bobbin,
A recess is formed at the bottom of the second iron core,
The second iron core is supported by the primary bobbin by fitting the convex portion to the concave portion.
The ignition coil for an internal combustion engine according to claim 1 or 2, characterized by the above. It is composed of a plurality of the second iron cores,
Each second iron core has a fitting portion that fits with the adjacent second iron core.
The ignition coil for an internal combustion engine according to any one of claims 1 to 3, wherein the ignition coil is used.

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