JP7259471B2 - ignition coil - Google Patents

Description

The present invention relates to ignition coils.

Patent Document 1 discloses an ignition coil for an internal combustion engine. The ignition coil described in Patent Document 1 includes a primary coil, a secondary coil, a core, a case, and sealing resin. The primary coil and secondary coil are magnetically coupled to each other. The core forms a magnetic path for magnetic flux generated by energizing and interrupting the primary coil. The core has a central core arranged on the inner peripheral side of the primary coil and the secondary coil, and an annular outer core arranged on the outer peripheral side of the primary coil and the secondary coil. The case houses the ignition coil components such as the primary coil, the secondary coil, and the core. The sealing resin is filled in the case and seals the components of the ignition coil accommodated in the case.

Here, the outer core can be constructed by laminating coated steel plates. A coated steel plate is manufactured, for example, by forming an insulating coating for reducing eddy current loss on the surface of a silicon steel plate, and then punching the silicon steel plate into a specific shape. As a result, the punched surfaces of the steel plate are exposed on the laminated surfaces appearing on the inner and outer circumferences of the outer core, and the sealing resin is bonded to the laminated surfaces of the outer core.

Here, the sealing resin made of epoxy resin, for example, has a larger coefficient of linear expansion than the peripheral core formed by laminating the silicon steel plates as described above. Therefore, when the temperature of the ignition coil changes, stress is generated in the ignition coil due to the difference in coefficient of linear expansion between the outer core and the sealing resin, and cracks may occur in the sealing resin.

Therefore, in the ignition coil disclosed in Patent Document 1, the surface of the outer peripheral core is coated with a release material that is releasable from the sealing resin. As a result, even if the temperature of the ignition coil changes, the sealing resin and the outer core are actively peeled off, so that stress is generated between the outer core and the sealing resin. It prevents cracks from occurring in the

JP 2004-169619 A

However, the ignition coil described in Patent Literature 1 is likely to cause a decrease in productivity. That is, the ignition coil disclosed in Patent Document 1 requires a step of applying a release material to the outer peripheral core, a step of drying the applied release material, and the like, which tends to cause a decrease in productivity.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide an ignition coil that facilitates improvement in productivity.

One aspect of the present invention comprises a primary coil (11) and a secondary coil (12) magnetically coupled to each other;
A steel plate (31) and a plurality of coated steel plates (3) having an insulating coating (32) covering the surface of the steel plate are laminated in a lamination direction (Z) orthogonal to the coil axial direction (X), and the primary an outer core (2) disposed on the outer peripheral side of the coil and the secondary coil;
A facing coated steel plate composed of the coated steel plate facing at least one of an inner laminated surface (2a) formed on the inner circumference of the outer core and an outer laminated surface (2b) formed on the outer circumference of the outer core. Part (4);
A sealing resin (13) that seals the primary coil, the secondary coil, the opposed coated steel plate portion, and the outer core ,
The facing coated steel plate portion is composed of a part of a specific coated steel plate (30) that is at least one of the coated steel plates that constitute the outer peripheral core, and the specific coated steel plate is such that the facing coated steel plate portion is the outer peripheral core. An ignition coil (1) having a bent shape so as to face at least one of the inner laminated surface of the core and the outer laminated surface of the outer core.

The ignition coil of the above aspect is provided with a facing coated steel plate portion that faces at least one of the inner laminated surface and the outer laminated surface of the outer core and is composed of a coated steel plate. Therefore, even when the temperature of the ignition coil changes from high temperature to low temperature, separation between the insulating coating and the steel plate or between the insulating coating and the coating resin of the facing coated steel plate portion may cause the outer core and the seal to peel off. It is possible to suppress the occurrence of thermal stress with the stopping resin. Therefore, it is possible to prevent cracks from occurring in the sealing resin.

In addition, since the facing covered steel plate portion is made of the covered steel plate, productivity of the ignition coil can be easily improved.

As described above, according to the aspect, it is possible to provide an ignition coil that facilitates improvement in productivity.
It should be noted that the symbols in parentheses described in the claims and the means for solving the problems indicate the corresponding relationship with the specific means described in the embodiments described later, and limit the technical scope of the present invention. not a thing

FIG. 2 is a cross-sectional view orthogonal to the Y direction of the ignition coil in Reference Embodiment 1; FIG. 2 is a cross-sectional view orthogonal to the Z direction of the ignition coil in Reference Embodiment 1; FIG. 2 is a perspective view of an outer core, an opposed coated steel plate portion, a central core, and a magnet body in reference form 1; FIG. 2 is a plan view of an outer core, an opposed coated steel plate portion, a central core, and a magnet body in Reference Embodiment 1; A cross-sectional view taken along the line VV of FIG. 4 . 2 is a perspective view of a first split core and a second split core of an outer peripheral core in reference form 1. FIG. FIG. 2 is a perspective view of a pair of split coated steel plates that constitute a facing coated steel plate portion in reference form 1; FIG. 4 is an enlarged cross-sectional view of the vicinity of the opposed coated steel plate portion of the ignition coil, showing a state in which the insulating coating of the opposed coated steel plate portion and the steel plate are peeled off in Reference Embodiment 1; 4 is an enlarged cross-sectional view of the periphery of the facing covered steel plate portion of the ignition coil, showing a state in which the insulation coating and the sealing resin of the facing covered steel plate portion are peeled off in Reference Embodiment 1. FIG . FIG. 11 is a perspective view of an outer core, an opposed coated steel plate portion, a central core, and a magnet body in Reference Embodiment 2; FIG. 11 is a perspective view of a pair of split coated steel plates that constitute the facing coated steel plate portion in Reference Embodiment 2; FIG. 11 is a perspective view of a pair of split coated steel plates that constitute the opposing coated steel plate portion in Reference Embodiment 3; The perspective view of the outer peripheral core in Embodiment 4. FIG. A cross-sectional view taken along line XIV-XIV in FIG. A cross-sectional view taken along line XV-XV in FIG. The perspective view of the outer peripheral core in Embodiment 5. FIG. A cross-sectional view taken along line XVII-XVII in FIG. The perspective view of the outer peripheral core in Embodiment 6. FIG.

( Reference form 1)
A reference embodiment showing the basic structure of the ignition coil will be described with reference to FIGS. 1 to 9. FIG.
As shown in FIGS. 1 and 2, the ignition coil 1 of this reference embodiment includes a primary coil 11, a secondary coil 12, an outer core 2, an opposing coated steel plate portion 4, and a sealing resin 13. As shown in FIGS.

Primary coil 11 and secondary coil 12 are magnetically coupled to each other. As shown in FIGS. 3 and 5, the outer core 2 is formed by stacking a plurality of coated steel plates 3 in a stacking direction Z orthogonal to the coil axial direction X. As shown in FIGS. As shown in FIG. 5 , the coated steel plate 3 includes a steel plate 31 and an insulating coating 32 covering both surfaces of the steel plate 31 . As shown in FIG. 2, the outer core 2 is arranged on the outer peripheral side of the primary coil 11 and the secondary coil 12 . As shown in FIGS. 1 to 5, the facing coated steel plate portion 4 faces the inner laminated surface 2a formed on the inner circumference of the outer core 2 and is composed of the coated steel plate 3. As shown in FIG. As shown in FIGS. 1 and 2 , the sealing resin 13 seals the primary coil 11 , secondary coil 12 , opposing coated steel plate portion 4 , and outer core 2 .
Hereinafter, this reference embodiment will be described in detail.

In this specification, the coil axis direction X is the direction in which the winding axes of the primary coil 11 and the secondary coil 12 extend. Hereinafter, the coil axial direction X will be referred to as the X direction. For the sake of convenience, one side in the X direction, which is the side on which the center core flange 52 of the center core 5 described later is formed, is referred to as the front side X1, and the opposite side is referred to as the rear side X2. Also, the lamination direction Z of the coated steel plates 3 of the outer core 2 is referred to as the Z direction. A direction orthogonal to both the X direction and the Z direction is called the Y direction.

The ignition coil 1 of this reference embodiment can be used, for example, in internal combustion engines such as automobiles and cogeneration systems. The ignition coil 1 is connected to a spark plug (not shown) installed in an internal combustion engine and used as means for applying a high voltage to the spark plug.

As shown in FIGS. 2 to 4, the outer core 2 has a rectangular annular shape. The outer peripheral core 2 includes a front side portion 212 and a rear side portion 222 that face each other in the X direction, and a pair of sides that connect one ends of the front side portion 212 and the rear side portion 222 in the Y direction and the other ends in the Y direction. Square sides 211 and 221 are provided. The pair of lateral sides 211 and 221 face each other in the Y direction. Note that the side edge portion of the first split core 21 described later is denoted by 211, and the side edge portion of the second split core 22 to be described later is denoted by 221. As shown in FIG.

As shown in FIGS. 2 to 4 and 6, the outer core 2 is formed by combining a first split core 21 and a second split core 22 which are L-shaped when viewed in the Z direction. The first split core 21 consists of a front edge 212 and one side edge 211 , and the second split core 22 consists of a rear edge 222 and the other side edge 221 . The first split core 21 and the second split core 22 have the same shape.

As shown in FIGS. 4 and 6 , the first split core 21 has an assembly protrusion projecting in the Y direction from the end of the front side 212 opposite to the side side 211 . It has a part 23 . In addition, the first split core 21 has an assembly recess 24 in which a part of the end face in the Y direction is recessed in the Y direction at the end of the side side portion 211 opposite to the front side portion 212 .

The second split core 22 has, at the end of the rear side portion 222 opposite to the side side portion 221 , an assembly convex portion 23 having a Y-direction end face protruding in the Y direction. In addition, the second split core 22 has an assembly recess 24 in which a part of the Y-direction end surface is recessed in the Y-direction at the end of the lateral side 221 opposite to the rear side 222 .

The first split core 21 and the second split core 22 are configured such that the assembly protrusion 23 of the first split core 21 is attached to the assembly recess 24 of the second split core 22, and the assembly protrusion 23 of the second split core 22 is attached to the attachment recess 24 of the second split core 22. They are assembled by fitting into the assembly recesses 24 of the first split core 21 . Each of the first split core 21 and the second split core 22 is formed by laminating L-shaped coated steel plates 3 in the Z direction.

As shown in FIG. 5 , the coated steel plate 3 includes a planar steel plate 31 perpendicular to the Z direction, and insulating coatings 32 covering both sides of the steel plate 31 . The coated steel plate 3 is formed by, for example, forming a plate-shaped silicon steel of a soft magnetic material, surface-treating the plate-shaped silicon steel to form an insulating coating 32 on both sides of the silicon steel, and then forming it into an L-shape. It is formed by punching into As a result, both surfaces of the steel plate 31 in the coated steel plate 3 are covered with the insulating coating 32 , and the edges of the steel plate 31 are exposed from the insulating coating 32 . Therefore, on each of the inner laminated surface 2a forming the inner peripheral surface of the outer core 2 and the outer laminated surface 2b forming the outer peripheral surface of the outer core 2, the edge portion of the steel plate 31 exposed from the insulating coating 32 is formed. appear. A facing coated steel plate portion 4 is arranged so as to cover the inner laminated surface 2a.

As shown in FIGS. 1 and 2, the facing coated steel plate portion 4 covers substantially the entire surface portion of the inner laminated surface 2a of the outer core 2 exposed from the central core 5 and the magnet body 14, which will be described later. As shown in FIG. 7, the facing coated steel plate portion 4 is formed by combining two separate coated steel plates 41 that are divided in the circumferential direction of the outer core 2 .

As shown in FIGS. 4 and 7, each of the two split coated steel plates 41 has a U-shape opening in the Y direction facing each other when viewed from the Z direction. That is, the split coated steel plate 41 has a bottom portion 411 orthogonal to the Y direction and side portions 412 orthogonal to the X direction that protrude from both ends of the bottom portion 411 in the X direction toward the other split coated steel plate 41 in the Y direction. have. The two split coated steel plates 41 are combined so that the ends of the side surface portion 412 opposite to the bottom surface portion 411 are opposed to each other, and have a tubular shape as a whole.

As shown in FIG. 7 , the pair of side surface portions 412 of each split coated steel plate 41 has recesses 412 a recessed toward the bottom surface portion 411 at the ends opposite to the bottom surface portion 411 . By combining two split coated steel plates 41, a hole portion 413 surrounded by the recess 412a of one split coated steel plate 41 and the recess 412a of the other split coated steel plate 41 is formed. As shown in FIG. 2, the magnet body 14, which will be described later, is inserted into the hole 413 at the front X1, and the rear end of the center core 5 is inserted into the hole 413 at the rear X2.

A slight gap is formed between the ends of the side portions 412 of the two split coated steel plates 41 facing each other. That is, slits 414 are formed in the opposed coated steel plate portion 4 from both ends of the hole portion 413 in the Z direction and divide the opposed coated steel plate portion 4 in the circumferential direction of the hole portion 413 .

The split coated steel plates 41 are made of the same material as the coated steel plates 3 forming the outer core 2 . The split coated steel plates 41 are arranged so that their thickness is in the normal direction of the inner lamination surface 2a. Insulating coatings 32 are arranged on both sides of the split coated steel plate. Then, as shown in FIG. 5, the entire inner peripheral surface of the opposed coated steel plate portion 4 formed by combining the pair of divided coated steel plates 41 is constituted by the insulating coating 32 . 2 and 4, the center core 5 is arranged on the inner peripheral side of the opposing coated steel plate portion 4. As shown in FIGS.

The central core 5 forms a closed magnetic circuit together with the outer core 2 . The central core 5 includes a rectangular parallelepiped central core main body 51 formed in the X direction and central core flanges 52 projecting from the front end of the central core main body 51 to both sides in the Y direction, and is T-shaped as a whole. is presenting.

The center core 5 is formed by stacking the same coated steel plates 3 constituting the outer core 2 in the Z direction with the thickness direction of the steel plates 3 . As shown in FIG. 2 , the rear end portion of the central core main body portion 51 is arranged in the rear X2 hole portion 413 of the opposing coated steel plate portion 4 . A magnet body 14 is arranged between the front surface of the central core 5 and the outer core 2 .

When viewed from the X direction, the size of the magnet body 14 is the same as the size of the front surface of the central core 5 . The magnet body 14 is arranged so as to overlap the entire front surface of the central core 5 . In order to improve the output voltage of the ignition coil 1 , the magnet 14 applies a magnetic bias to the central core 5 to increase the amount of change in the magnetic flux when the primary coil 11 is de-energized, thereby inducing an electric current in the secondary coil 12 . to increase the applied voltage. The magnet body 14 is arranged in the hole portion 413 on the front side X1 of the opposed covered steel plate portion 4 .

A primary coil 11 and a secondary coil 12 are concentrically wound around the outer peripheral side of the central core 5 . As shown in FIGS. 1 and 2, the primary coil 11 is wound on a primary bobbin 15 formed over the central core 5 .

The primary bobbin 15 is made of, for example, polybutylene terephthalate resin (that is, PBT resin). The primary bobbin 15 is formed by insert molding in which the central core 5 is arranged in the mold. Thereby, the primary bobbin 15 is integrally formed with the central core 5 . A primary coil 11 is wound around a portion of the primary bobbin 15 that covers the central core body portion 51 . A secondary coil 12 is arranged on the outer peripheral side of the primary coil 11 .

The secondary coil 12 is arranged on a secondary bobbin 16 arranged on the outer peripheral side of the primary coil 11 . The secondary bobbin 16 is made of PBT resin, for example. The secondary bobbin 16 has a tubular shape, and the central core main body 51 and the primary coil 11 are inserted therein.

An igniter 17 is arranged in front X1 of the outer core 2 . The igniter 17 controls energization and interruption of the primary coil 11 . Components that constitute the ignition coil 1 are housed in a case 6 .

The case 6 includes a case main body 61 that accommodates components of the ignition coil 1 . The case body 61 is open on one side in the Z direction. Further, as shown in FIG. 1 , the case 6 has a cylindrical high-pressure tower portion 62 projecting from the case main body portion 61 to the opposite side of the open side of the case main body portion 61 .

When viewing the case 6 alone, the internal space of the high-pressure tower portion 62 communicates with the internal space of the case main body portion 61 . A high-voltage output terminal 18 made of metal is inserted into the high-voltage tower portion 62 of the ignition coil 1 . As a result, the end portion of the high-pressure tower portion 62 on the side of the case main body portion 61 is closed. The high-voltage output terminal 18 has a role of preventing the sealing resin 13 in the case 6 from leaking from the case main body 61 to the high-voltage tower 62 side, and a role of an output terminal of the ignition coil 1 . The sealing resin 13 is filled in the case body portion 61 .

The sealing resin 13 is made of epoxy resin, for example. The sealing resin 13 seals components of the ignition coil 1, such as the primary coil 11, the secondary coil 12, the primary bobbin 15, the secondary bobbin 16, the central core 5, the outer peripheral core 2, the igniter 17, and the like.

A connector 7 for connecting the ignition coil 1 to an external device is fitted to the front end portion of the case main body portion 61 . The connector 7 is molded integrally with the primary bobbin 15 . In FIG. 2, the illustration of the connecting portion of the connector 7 with the mating connector is omitted. Note that the connector 7 may be formed separately from the primary bobbin 15 .

Next, the effects of this reference embodiment will be described.
The ignition coil 1 of this reference embodiment is provided with a facing covered steel plate portion 4 that faces an inner laminated surface 2 a of an outer core 2 and is composed of a covered steel plate 3 . Therefore, even when the ignition coil 1 changes from a high temperature to a low temperature, separation between the insulating coating 32 and the steel plate 31 of the opposed coated steel plate portion 4 or between the insulating coating 32 and the coating resin can occur. , the occurrence of thermal stress between the outer core 2 and the sealing resin 13 can be suppressed.

That is, when the temperature around the ignition coil 1 changes from a high temperature to a low temperature, the outer core 2, which has a relatively small linear expansion coefficient, undergoes a small amount of thermal contraction, while the sealing resin 13, which has a relatively large linear expansion coefficient, undergoes a large amount of thermal contraction. Shrink. Therefore, stress can occur between the outer core 2 and the sealing resin 13 .

Due to this stress, as shown in FIG. 8, for example, the insulating coating 32 of the facing coated steel plate portion 4 and the steel plate 31 are separated to form a gap c, which makes it difficult for the sealing resin 13 to be restrained by the outer core 2 . Alternatively, due to the stress, as shown in FIG. 9, for example, the insulating coating 32 and the sealing resin 13 are peeled off to generate a gap c, and the sealing resin 13 is less likely to be restrained by the outer core 2 .

Therefore, even when the ignition coil 1 changes from high temperature to low temperature, it is possible to prevent stress from concentrating between the outer core 2 and the sealing resin 13 . As a result, it is possible to prevent cracks from occurring inside the sealing resin 13 from between the outer peripheral core 2 and the sealing resin 13 .

The facing coated steel plate portion 4 is composed of a coated steel plate 3 similar to the coated steel plate 3 forming the outer core 2 . Therefore, it is not necessary to prepare a separate member for forming the outer core 2 and the facing coated steel plate portion 4, and the productivity of the ignition coil 1 can be easily improved. Moreover, the process of applying the release material to the outer core 2 and the process of drying the applied release material, which are required when applying the release material to the outer core 2, are not necessary in the present embodiment . Also by this, the productivity of the ignition coil 1 can be improved.

In addition, the facing covered steel plate portion 4 faces at least the inner laminated surface 2a of the outer core 2 . Therefore, cracks can be prevented from occurring in the region of the sealing resin 13 inside the outer peripheral core 2 . Thereby, it is possible to prevent the electrical insulation between the outer core 2 and the secondary coil 12 from deteriorating.

In addition, the facing covered steel plate portion 4 has holes 413 penetrating in the X direction at all portions facing the central core 5 in the X direction. Therefore, eddy current loss due to eddy currents generated in the opposed coated steel plate portion 4 by the magnetic flux entering and exiting the center core 5 passing through the opposed coated steel plate portion 4 in its thickness direction can be reduced. As a result, it is possible to prevent the output voltage of the ignition coil 1 from dropping.

In addition, a slit 414 is formed in the opposed coated steel plate portion 4 from the hole portion 413 to the outer peripheral side of the hole portion 413 and divides the opposed coated steel plate portion 4 in the circumferential direction of the hole portion 413 . Therefore, it is possible to reduce the eddy current loss caused by the loop-shaped eddy current generated around the hole portion 413 in the facing coated steel plate portion 4 . This also prevents the output voltage of the ignition coil 1 from dropping.

As described above, according to the present embodiment , it is possible to provide an ignition coil that can easily improve productivity.

( Reference form 2)
As shown in FIGS. 10 and 11, the present reference embodiment is a reference embodiment in which the opposing coated steel plate portion 4 is changed from the reference embodiment 1. As shown in FIGS. In this reference embodiment, the overall shape of the facing coated steel plate portion 4 is the same as that of the reference embodiment 1, but the shape of the separate coated steel plates 41 constituting the facing covered steel plate portion 4 differs from that of the reference embodiment 1.

As shown in FIG. 11, each of the two split coated steel plates 41 constituting the opposed coated steel plate portion 4 has a U-shape opening in the X direction facing each other when viewed from the Z direction. That is, the split coated steel plate 41 has a bottom portion 411 orthogonal to the X direction and side portions 412 protruding from both ends of the bottom portion 411 in the Y direction toward the other split coated steel plate 41 in the X direction and orthogonal to the X direction. have. The two split coated steel plates 41 are combined so that the ends of the side surface portion 412 opposite to the bottom surface portion 411 are opposed to each other, and have a tubular shape as a whole. A bottom portion 411 of the split coated steel plate 41 is formed with a hole portion 413 penetrating through the bottom portion 411 in the X direction.

Others are the same as those of the first embodiment .
In addition, among the reference numerals used in Reference Embodiment 2 and later, the same reference numerals as those used in the reference embodiments and embodiments described above are the same components as those in the reference embodiments and embodiments described above unless otherwise indicated. represents
This reference embodiment also has the same effects as those of the first reference embodiment.

( Reference form 3)
As shown in FIG. 12 , this reference embodiment is a reference embodiment in which slits 414 are provided in the split coated steel plate 41 in contrast to the reference embodiment 2. As shown in FIG.

The slit 414 is formed from the hole portion 413 of the split coated steel plate 41 to the outer peripheral side of the hole portion 413 , and divides the split coated steel plate 41 in the circumferential direction of the hole portion 413 , as described in the first embodiment . The slit 414 is formed at one place in the circumferential direction around the hole 413 of the split coated steel plate 41 . That is, the slit 414 is formed only on one side of the hole 413 in the Z direction. A part of the split coated steel plate 41 is formed on the other side of the hole 413 in the Z direction, and the slit 414 is not formed.
Others are the same as those of the second embodiment .

In this reference embodiment, since the split coated steel plate 41 is provided with the slit 414, the eddy current loss caused by the loop-shaped eddy current generated around the hole 413 in the opposing coated steel plate portion 4 is reduced. be able to. As a result, it is possible to prevent the output voltage of the ignition coil 1 from dropping.
In addition, it has the same effects as those of the reference form 2.

(Embodiment 4)
As shown in FIGS. 13 to 15, this embodiment is an embodiment in which the facing coated steel plate portion 4 is constituted by a part of the specific coated steel plate 30 which is at least one coated steel plate 3 constituting the outer core 2. FIG.

In this embodiment, the coated steel plate 3 at one end of the first split core 21 in the Z direction and the coated steel plate 3 at one end of the second split core 22 in the Z direction constitute the specific coated steel plate 30 .

As shown in FIGS. 13 and 15, the specific coated steel plate 30 of the first split core 21 has the opposing coated steel plate portion 4 extending from the portion forming the lateral side portion 211 to the inner side of the outer peripheral core 2 in the Y direction. there is In the specific coated steel plate 30 of the first split core 21 , the facing coated steel plate portion 4 is bent with respect to the portion forming the lateral side portion 211 . The facing coated steel plate portion 4 is arranged at a position facing the inner lamination surface 2 a of the lateral side portion 211 of the first split core 21 . In the first split core 21, the opposed coated steel plate portion 4 faces substantially the entire inner laminated surface 2a of the lateral side portion 211 in the Y direction.

The specific coated steel plate 30 of the second split core 22 has the opposed coated steel plate portion 4 extending from the portion forming the lateral side portion 221 to the inner side of the outer peripheral core 2 in the Y direction. In the specific coated steel plate 30 of the second split core 22 , the facing coated steel plate portion 4 is bent with respect to the portion forming the lateral side portion 221 . The facing coated steel plate portion 4 is arranged at a position facing the inner lamination surface 2 a of the lateral side portion 221 of the second split core 22 . As shown in FIG. 14 , in the second split core 22 , the opposed coated steel plate portion 4 faces substantially the entire inner laminated surface 2 a of the lateral side portion 221 in the Y direction.

In the present embodiment, the first split core 21 and the second split core 22 have the specific coated steel plates 30 formed at the ends on the same side in the Z direction, but the present invention is not limited to this. The inner laminated surfaces 2a of the front side portion 212 and the rear side portion 222 are not formed with the opposing coated steel plate portions 4 facing them.

As shown in FIG. 15, the opposing covered steel plate portion 4 is formed by laminating an insulating coating 32 and a steel plate 31 in the normal direction of the inner laminated surface 2a. The inner surface of the outer core 2 in the opposed covered steel plate portion 4 is formed of an insulating coating 32 .
Others are the same as those of the first embodiment.

In the present embodiment, the facing coated steel plate portion 4 is part of a specific coated steel plate 30 that is at least one coated steel plate 3 that constitutes the outer core 2, and the specific coated steel plate 30 is the facing coated steel plate portion 4 is bent so as to face the inner lamination surface 2 a of the outer core 2 . That is, since the opposed covered steel plate portion 4 is formed of a part of the outer core 2, it is easy to reduce the number of parts. In addition, since the opposed coated steel plate portion 4 can be formed by bending a portion of the specific coated steel plate 30, which is one of the coated steel plates 3 forming the outer core 2, the productivity of the ignition coil 1 can be improved. Cheap.

Further, the specific coated steel plate 30 is the coated steel plate 3 arranged at the end of the outer core 2 in the Z direction. Therefore, by bending a portion of the specific coated steel plate 30 to one side in the Z direction, the opposing coated steel plate portion 4 can be arranged at a position covering substantially the entire inner laminated surface 2a of the outer core 2 in the Z direction. .
Others are the same as those of the first embodiment.

(Embodiment 5)
As shown in FIGS. 16 and 17, this embodiment has the same basic structure as that of the fourth embodiment, but the facing covered steel plate portions 4 are also opposed to the inner laminated surfaces 2a of the front side portion 212 and the rear side portion 222. Embodiment.

As shown in FIG. 16 , in this embodiment, the coated steel plates 3 on both ends of the first split core 21 in the Z direction and the coated steel plates 3 on both ends of the second split core 22 in the Z direction It constitutes a specific coated steel plate 30 with

The first split core 21 has a first inner facing portion 40a, which is the facing coated steel plate portion 4 facing substantially the entire inner laminated surface 2a of the lateral side portion 211, and substantially the entire inner laminated surface 2a of the front side portion 212. and a second inner facing portion 40b that is the facing coated steel plate portion 4 facing the .

The first inner facing portion 40a extends toward the inner side of the outer peripheral core 2 in the Y direction from a portion forming the side edge portion 211 of the specific coated steel plate 30 disposed at one end of the first split core 21 in the Z direction. is set. As shown in FIG. 16, the second inner facing portion 40b extends rearward X2 from a portion constituting the front side portion 212 of the specific covered steel plate 30 disposed at the other end of the first split core 21 in the Z direction. is set. Each of the pair of specific coated steel plates 30 in the first split core 21 has a shape that is bent such that the opposing coated steel plate portion 4 is arranged at a position facing the inner laminated surface 2 a of the first split core 21 .

As shown in FIGS. 16 and 17, the second split core 22 includes a third inner facing portion 40c, which is the facing coated steel plate portion 4 facing substantially the entire inner laminated surface 2a of the lateral side portion 221, and a rear side portion 40c. A fourth inner facing portion 40d, which is the facing covered steel plate portion 4 facing substantially the entire inner laminated surface 2a of 222, is provided.

The third inner facing portion 40c extends toward the inner side of the outer peripheral core 2 in the Y direction from a portion forming the side edge portion 221 of the specific coated steel plate 30 arranged at one end of the second split core 22 in the Z direction. is set. The fourth inner facing portion 40d extends forward X1 from a portion forming the rear side portion 222 of the specific coated steel plate 30 disposed at the other end of the second split core 22 in the Z direction. Each of the pair of specific coated steel plates 30 in the second split core 22 has a shape that is bent such that the opposing coated steel plate portion 4 is arranged at a position facing the inner lamination surface 2 a of the second split core 22 .

As shown in FIG. 17, the opposing covered steel plate portion 4 is formed by laminating an insulating coating 32 and a steel plate 31 in the normal direction of the inner laminated surface 2a. The inner surface of the outer core 2 in the opposed covered steel plate portion 4 is formed of an insulating coating 32 .
Others are the same as those of the fourth embodiment.

In the present embodiment, a first inner facing portion 40a facing the inner laminated surface 2a of the lateral side portion 211 is formed on the specific coated steel plate 30 at one end of the first split core 21 in the Z direction, and the first split core A second inner facing portion 40 b facing the inner lamination surface 2 a of the front side portion 212 is formed on the specific coated steel plate 30 at the other end of the Z direction of 21 . Therefore, in the first split core 21, the lateral The facing portion and the second inner facing portion 40b can be easily formed.

On the other hand, it is difficult in manufacturing to form both the first inner facing portion 40a and the second inner facing portion 40b on one coated steel plate 3 arranged at one end of the first split core 21 in the Z direction. be. In this case, the coated steel plate 3 at one end in the Z direction has a portion extending inside the outer peripheral core 2 in the X direction from the lateral side portion 211 and a portion extending inside the outer peripheral core 2 in the Y direction from the front side portion 212. However, since these parts overlap each other, manufacturing is difficult.

The second split core 22 also has the same configuration as the first split core 21, and the same effect as the first split core 21 can be obtained.
In addition, it has the same effects as those of the fourth embodiment.

(Embodiment 6)
As shown in FIG. 18, this embodiment has the same basic configuration as that of the fourth embodiment, but has a facing covered steel plate portion 4 facing the outer lamination surface 2b of the outer core 2. As shown in FIG.

In this embodiment, the coated steel plate 3 at one end of the first split core 21 in the Z direction and the coated steel plate 3 at one end of the second split core 22 in the Z direction are the specific coated steel plates provided with the facing coated steel plate portion 4. 30.

The specific coated steel plate 30 of the first split core 21 includes a first outer facing portion 400a which is the opposed coated steel plate portion 4 facing substantially the entire outer laminated surface 2b of the lateral side portion 211, and an outer laminated portion of the front side portion 212. A second outer facing portion 400b, which is the facing coated steel plate portion 4 facing substantially the entire surface 2b.

The first outer facing portion 400a extends from a portion forming the lateral side portion 211 of the specific coated steel plate 30 of the first split core 21 toward the outside of the outer peripheral core 2 in the Y direction. The second outer facing portion 400b extends forward X1 from a portion forming the front side portion 212 of the specific coated steel plate 30 of the first split core 21 . The specific coated steel plate 30 of the first split core 21 has a shape in which the first outer facing portion 400a and the second outer facing portion 400b are arranged at positions facing the outer laminated surface 2b of the first split core 21. have.

The second split core 22 has a third outer facing portion 400c, which is the facing coated steel plate portion 4 facing substantially the entire outer laminated surface 2b of the lateral side portion 221, and substantially the entire outer laminated surface 2b of the rear side portion 222. and a fourth outer facing portion 400d that is the facing coated steel plate portion 4 facing the .

The third outer facing portion 400c extends outward from the outer peripheral core 2 in the Y direction from a portion forming the lateral side portion 221 of the specific coated steel plate 30 of the second split core 22 . The fourth outer facing portion 400d extends rearward X2 from a portion forming the rear side portion 222 of the specific coated steel plate 30 of the second split core 22 . The specific coated steel plate 30 of the second split core 22 has a shape in which the third outer facing portion 400c and the fourth outer facing portion 400d are arranged at positions facing the outer laminated surface 2b of the second split core 22. have.

The ignition coil 1 of the present embodiment is configured such that the front edge portion 212, the pair of side edge portions 211 and 221, and the rear edge portion 222 of the outer peripheral core 2 are substantially entirely opposed to the outer lamination surfaces 2b, respectively. A portion 4 (that is, a first outer facing portion 400a, a second outer facing portion 400b, a third outer facing portion 400c, and a fourth outer facing portion 400d) is formed.

In the present embodiment, the first split core 21 and the second split core 22 have the specific coated steel plates 30 formed at the ends on the same side in the Z direction, but the present invention is not limited to this. Further, in the present embodiment, the facing coated steel plate portion 4 is not arranged on the inner peripheral side of the outer core 2 . In addition, the first outer facing portion 400a, the second outer facing portion 400b, the third outer facing portion 400c, and the fourth outer facing portion 400d are arranged in the normal direction of the outer laminated surface 2b of the outer peripheral core 2 facing each other. A steel plate 31 and an insulating coating 32 are laminated, and the insulating coating 32 is arranged on the outer peripheral side of the outer core 2 in each case.
Others are the same as those of the fourth embodiment.

In this embodiment, the facing coated steel plate portion 4 faces at least the outer laminated surface 2b of the outer core 2 . Therefore, it is possible to prevent cracks from occurring in the region of the sealing resin 13 outside the outer peripheral core 2 . Thereby, for example, it is possible to prevent a crack generated on the outer peripheral side of the outer core 2 from extending to the case 6 and cracking the entire case 6 .
In addition, it has the same effects as those of the fourth embodiment.

The present invention is not limited to the embodiments described above, and can be applied to various embodiments without departing from the scope of the invention.

For example, the central core 5 and the peripheral core 2 can be integrally formed. Although the outer core 2 is formed in an annular shape, it is not limited to this, and may be formed in other shapes, such as a U shape, as long as it forms a closed magnetic path through which the magnetic flux generated by the energization and interruption of the primary coil 11 passes. It is also possible to

Further, for example, by appropriately combining Embodiment 4 or Embodiment 5 with Embodiment 6, it is possible to form opposing coated steel plate portions facing both the inner laminated surface and the outer laminated surface of the outer core.

REFERENCE SIGNS LIST 1 ignition coil 11 primary coil 12 secondary coil 13 sealing resin 2 outer core 2a inner laminated surface 3 coated steel plate 31 steel plate 32 insulating coating 4 opposed coated steel plate portion

Claims (5)

a primary coil (11) and a secondary coil (12) magnetically coupled to each other;
A steel plate (31) and a plurality of coated steel plates (3) having an insulating coating (32) covering the surface of the steel plate are laminated in a lamination direction (Z) orthogonal to the coil axial direction (X), and the primary an outer core (2) disposed on the outer peripheral side of the coil and the secondary coil;
A facing coated steel plate composed of the coated steel plate facing at least one of an inner laminated surface (2a) formed on the inner circumference of the outer core and an outer laminated surface (2b) formed on the outer circumference of the outer core. Part (4);
A sealing resin (13) that seals the primary coil, the secondary coil, the opposed coated steel plate portion, and the outer core ,
The facing coated steel plate portion is composed of a part of a specific coated steel plate (30) that is at least one of the coated steel plates that constitute the outer peripheral core, and the specific coated steel plate is such that the facing coated steel plate portion is the outer peripheral core. An ignition coil (1) having a bent shape so as to face at least one of the inner laminated surface of the core and the outer laminated surface of the outer core. 2. The ignition coil according to claim 1, comprising said facing coated steel plate portion facing said inner laminated surface of said outer core. 3. The ignition coil according to claim 1, wherein said specific coated steel plate is said coated steel plate arranged at an end portion of said outer peripheral core in said stacking direction . A center core (5) that forms a closed magnetic circuit together with the outer core is arranged on the inner peripheral side of the primary coil so as to face the inner laminated surface of the outer core, and the facing coated steel plate portion is: A hole (413) is provided between the inner laminated surface of the outer peripheral core and the central core in the coil axial direction, and penetrates in the coil axial direction at a portion facing the central core in the coil axial direction. An ignition coil as claimed in any one of claims 1 to 3, comprising .
A slit (414) is formed in the opposed coated steel plate portion, the slit being formed on the outer peripheral side of the hole portion from the hole portion and dividing the opposed coated steel plate portion in the circumferential direction of the hole portion. 5. The ignition coil according to 4 .

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