JP7226009B2

JP7226009B2 - ignition coil

Info

Publication number: JP7226009B2
Application number: JP2019059210A
Authority: JP
Inventors: 昌冬佐野; 敦之小西
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2019-03-26
Filing date: 2019-03-26
Publication date: 2023-02-21
Anticipated expiration: 2039-03-26
Also published as: JP2020161632A

Description

本発明は、点火コイルに関する。 The present invention relates to ignition coils.

特許文献１には、内燃機関用の点火コイルが開示されている。特許文献１に記載の点火コイルは、互いに磁気結合された一次コイル及び二次コイルを有する。一次コイルは、一次ボビンに巻回されており、二次コイルは、一次コイル及び一次ボビンの外周側に配された二次ボビンに巻回されている。一次ボビンの内側には、中心コアが配されている。そして、これらの点火コイルの構成部品は、点火コイルのケース内に収容されているとともに、ケース内に充填された封止樹脂によって封止されている。 Patent Document 1 discloses an ignition coil for an internal combustion engine. The ignition coil described in Patent Document 1 has a primary coil and a secondary coil that are magnetically coupled to each other. The primary coil is wound around a primary bobbin, and the secondary coil is wound around a secondary bobbin arranged on the outer peripheral side of the primary coil and the primary bobbin. A central core is placed inside the primary bobbin. These components of the ignition coil are accommodated in the case of the ignition coil and sealed with sealing resin filled in the case.

特許文献１に記載された点火コイルにおいて、中心コアは、一次コイルの内側に配されるコア本体部と、前記コア本体部の一端からコイル軸方向に直交する突出方向の両側に突出したコア鍔部とを有し、全体として略Ｔ字状を呈している。なお、コイル軸方向は、一次コイル及び二次コイルの巻回軸が延在する方向である。 In the ignition coil disclosed in Patent Document 1, the center core includes a core main body portion arranged inside the primary coil and a core flange projecting from one end of the core main body portion on both sides in a projecting direction orthogonal to the coil axial direction. , and has a substantially T-shape as a whole. The coil axis direction is the direction in which the winding axes of the primary coil and the secondary coil extend.

一次ボビンは、その成形型の内側に中心コアを配したインサート成形により形成されている。これにより、一次ボビンと中心コアとが一体化されている。 The primary bobbin is formed by insert molding with a central core placed inside the mold. Thereby, the primary bobbin and the central core are integrated.

二次ボビンは、コア鍔部とコイル軸方向に重なる位置に配されている。そして、コイル軸方向におけるコア鍔部と二次ボビンとの間には、一次ボビンの一部が配されている。 The secondary bobbin is arranged at a position overlapping the core collar portion in the coil axial direction. A part of the primary bobbin is arranged between the core collar portion and the secondary bobbin in the coil axial direction.

特開平０６－０７７０６６号公報JP-A-06-077066

しかしながら、前記内燃機関用の点火コイルは、コア鍔部、一次ボビン、及び二次ボビンがコイル軸方向に重なっている箇所において、一次ボビンと二次ボビンとの間に応力が集中することが懸念される。このことにつき、以後説明する。 However, in the ignition coil for the internal combustion engine, there is a concern that stress may concentrate between the primary bobbin and the secondary bobbin at a location where the core collar portion, the primary bobbin, and the secondary bobbin overlap in the coil axial direction. be done. This will be explained later.

特許文献１に記載の点火コイルにおいて、中心コアは、被覆鋼板を積層することで構成することが可能である。被覆鋼板は、例えば、鋼板の表面に、中心コアの渦電流損を低減するための絶縁被膜を形成し、その後、この鋼板を特定形状に打ち抜くことにより製造される。それゆえ、中心コアに表れる積層面は、鋼板の打ち抜き面が露出している。これに伴い、前述のようにインサート成形された一次ボビンは、コア鍔部の前記積層面に接着されるよう形成される。 In the ignition coil disclosed in Patent Document 1, the central core can be constructed by laminating coated steel plates. A coated steel plate is manufactured, for example, by forming an insulating coating on the surface of a steel plate to reduce the eddy current loss of the central core, and then punching this steel plate into a specific shape. Therefore, the punched surface of the steel plate is exposed in the lamination surface appearing in the central core. Along with this, the primary bobbin insert-molded as described above is formed so as to be adhered to the lamination surface of the core collar portion.

また、中心コアは金属（すなわち前述の鋼板）からなり、一次ボビン、二次ボビン、封止樹脂は樹脂からなるため、中心コアの線膨張係数は、一次ボビン、二次ボビン、封止樹脂のそれぞれの線膨張係数よりも小さい。それゆえ、点火コイルが高温から低温に変化した際、中心コアの熱収縮量は、一次ボビン、二次ボビン、封止樹脂のそれぞれの熱収縮量よりも小さくなる。 Also, since the center core is made of metal (that is, the steel plate described above), and the primary bobbin, secondary bobbin, and sealing resin are made of resin, the linear expansion coefficient of the center core is smaller than their respective coefficients of linear expansion. Therefore, when the ignition coil changes from high temperature to low temperature, the amount of thermal contraction of the central core becomes smaller than the amount of thermal contraction of each of the primary bobbin, the secondary bobbin, and the sealing resin.

そのため、点火コイルが高温から低温に変化した際、比較的熱収縮し難い中心コアのコア鍔部の積層面に接着した一次ボビンの部位は、前記積層面に拘束されることによって熱収縮に伴う変位が制限される一方、二次ボビン及び封止樹脂は、比較的大きく熱収縮する。そのため、コア鍔部、一次ボビン、及び二次ボビンがコイル軸方向に重なっている箇所において、一次ボビンと二次ボビンとの間に応力が集中することが懸念される。さらに、この応力に起因して一次ボビンと二次ボビンとの間にクラックが生じた場合、一次コイルと二次コイル間の電気的絶縁性が低下するおそれも考えられる。 Therefore, when the ignition coil temperature changes from high temperature to low temperature, the portion of the primary bobbin adhered to the lamination surface of the core collar portion of the central core, which is relatively difficult to thermally contract, is restrained by the lamination surface and is accompanied by thermal contraction. While displacement is limited, the secondary bobbin and sealing resin undergo relatively large heat shrinkage. Therefore, there is a concern that stress will concentrate between the primary bobbin and the secondary bobbin at the location where the core collar portion, the primary bobbin, and the secondary bobbin overlap in the coil axial direction. Furthermore, if cracks occur between the primary bobbin and the secondary bobbin due to this stress, the electrical insulation between the primary coil and the secondary coil may deteriorate.

本発明は、かかる課題に鑑みてなされたものであり、電気的信頼性を確保しやすい点火コイルを提供しようとするものである。 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 ensuring electrical reliability.

本発明の一態様は、互いに磁気的に結合した一次コイル（１１）及び二次コイル（１２）と、
前記一次コイルが巻回された一次ボビン（２）と、
前記二次コイルが巻回された二次ボビン（３）と、
鋼板（４０１）及び前記鋼板の表面を被覆する絶縁被膜（４０２）を備えた複数の被覆鋼板（４０）をコイル軸方向（Ｘ）に直交する積層方向（Ｚ）に積層してなり、前記一次ボビンの内側に配された中心コア（４）と、
前記一次コイル、前記二次コイル、前記一次ボビン、前記二次ボビン、及び前記中心コアを封止する封止樹脂（５）と、を備え、
前記中心コアは、前記一次コイルの内側に配されるコア本体部（４１）と、前記コア本体部からコイル軸方向と前記積層方向との双方に直交する突出方向（Ｙ）に突出したコア鍔部（４２）とを有し、
前記一次ボビンは、コイル軸方向の一部に、前記一次コイルを巻回するボビン本体部（２１）を有し、かつ、コイル軸方向の他の一部に、コイル軸方向の前記コア鍔部と前記二次ボビンとの間に少なくとも一部が挟まれるボビン狭間部（２２）を有し、
前記ボビン狭間部は、前記コア鍔部にコイル軸方向に重なるボビン重なり部（２２１）を有し、
前記ボビン重なり部と前記コア鍔部との間、又は前記ボビン重なり部の内部には、前記コア鍔部におけるコイル軸方向の前記ボビン重なり部側の面である鍔後積層面（４２１）と対向するとともに、前記被覆鋼板によって構成される対向被覆鋼板部（６）が設けられている、点火コイル（１）にある。 One aspect of the present invention comprises a primary coil (11) and a secondary coil (12) magnetically coupled to each other;
a primary bobbin (2) around which the primary coil is wound;
a secondary bobbin (3) around which the secondary coil is wound;
A steel plate (401) and a plurality of coated steel plates (40) having an insulating coating (402) covering the surface of the steel plate are laminated in a lamination direction (Z) orthogonal to the coil axial direction (X), and the primary a central core (4) arranged inside the bobbin;
A sealing resin (5) that seals the primary coil, the secondary coil, the primary bobbin, the secondary bobbin, and the central core,
The central core includes a core body portion (41) arranged inside the primary coil, and a core flange projecting from the core body portion in a projecting direction (Y) orthogonal to both the coil axial direction and the stacking direction. a portion (42);
The primary bobbin has a bobbin main body (21) on which the primary coil is wound in a part in the coil axial direction, and the core collar part in the coil axial direction in another part in the coil axial direction. and a bobbin gap (22) at least partially sandwiched between the secondary bobbin,
The bobbin narrow portion has a bobbin overlapping portion (221) that overlaps the core collar portion in the coil axial direction,
Between the bobbin overlapping portion and the core flange portion, or inside the bobbin overlapping portion, a post-flange lamination surface (421), which is a surface of the core flange portion on the bobbin overlapping portion side in the coil axial direction, is opposed. In addition, the ignition coil (1) is provided with a facing coated steel plate portion (6) composed of the coated steel plate.

前記態様の点火コイルにおいて、中心コアは、絶縁被膜により表面が被覆された複数の被覆鋼板を積層してなる。そして、ボビン重なり部とコア鍔部との間、又はボビン重なり部の内部には、コア鍔部におけるコイル軸方向のボビン重なり部側の面である鍔後積層面と対向するとともに、被覆鋼板によって構成される対向被覆鋼板部が設けられている。それゆえ、点火コイルが高温から低温に変化したときであっても、対向被覆鋼板部の絶縁被膜と鋼板との間、或いは絶縁被膜と一次ボビンとの間が剥離することで、ボビン狭間部がコア鍔部に拘束されにくくなる。そのため、点火コイルが高温から低温に変化したときであっても、コイル軸方向のボビン狭間部と二次ボビンとの間において応力が集中することを防止することができる。その結果、一次コイルと二次コイルとの間にクラックが生じ、一次コイルと二次コイルとの間の電気的絶縁性が低下することを防止することができる。 In the ignition coil of the aspect described above, the center core is formed by laminating a plurality of coated steel plates whose surfaces are coated with an insulating coating. Between the bobbin overlapping portion and the core flange portion, or inside the bobbin overlapping portion, the post-flange lamination surface, which is the surface of the core flange portion on the side of the bobbin overlapping portion in the coil axial direction, is opposed to the coated steel plate. An opposing clad steel plate section is provided. 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 of the facing covered steel plate portion or between the insulating coating and the primary bobbin may cause the gap between the bobbins to crack. It becomes difficult to be restrained by the core flange. Therefore, even when the temperature of the ignition coil changes from high to low, it is possible to prevent stress from concentrating between the inter-bobbin gap in the coil axial direction and the secondary bobbin. As a result, it is possible to prevent cracks from occurring between the primary coil and the secondary coil, thereby preventing deterioration in electrical insulation between the primary coil and the secondary coil.

以上のごとく、前記態様によれば、電気的信頼性を確保しやすい点火コイルを提供することができる。
なお、特許請求の範囲及び課題を解決する手段に記載した括弧内の符号は、後述する実施形態に記載の具体的手段との対応関係を示すものであり、本発明の技術的範囲を限定するものではない。 As described above, according to the aspect, it is possible to provide an ignition coil that can easily ensure electrical reliability.
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

実施形態１における、内燃機関用の点火コイルのＺ方向に直交する断面図。Sectional drawing orthogonal to the Z direction of the ignition coil for internal combustion engines in Embodiment 1. FIG. 図１の、対向被覆鋼板部周辺の拡大図。FIG. 2 is an enlarged view of the periphery of the opposing covered steel plate portion in FIG. 1 ; 実施形態１における、対向被覆鋼板部を通る、内燃機関用の点火コイルのＹ方向に直交する断面図。FIG. 2 is a cross-sectional view orthogonal to the Y direction of the ignition coil for an internal combustion engine that passes through the opposing coated steel plate portion in the first embodiment; 図３の、対向被覆鋼板部周辺の拡大図。FIG. 4 is an enlarged view of the periphery of the opposing covered steel plate portion in FIG. 3 ; 図４の、対向被覆鋼板部周辺をさらに拡大した拡大図。FIG. 5 is an enlarged view further enlarging the periphery of the opposing coated steel plate portion in FIG. 4 ; 実施形態１における、互いに一体に成形された一次ボビン及びコネクタの側面図。FIG. 2 is a side view of the primary bobbin and connector integrally molded with each other in Embodiment 1; 実施形態１における、中心コアの平面図。2 is a plan view of the central core in Embodiment 1. FIG. 図７の、VIII－VIII線矢視断面図。A cross-sectional view taken along line VIII-VIII in FIG. 実施形態１における、中心コアの斜視図。4 is a perspective view of the central core in Embodiment 1. FIG. 実施形態１における、中心コアの側面図。2 is a side view of the central core in Embodiment 1. FIG. 実施形態１における、中心コアの背面図。2 is a rear view of the central core in Embodiment 1. FIG. 実施形態１における、対向被覆鋼板部を折り曲げる前の状態の中心コアの平面図。FIG. 4 is a plan view of the central core in the state before bending the facing coated steel plate portion according to the first embodiment; 実施形態１における、対向被覆鋼板部の絶縁被膜と鋼板との間が剥離した様子を示す、点火コイルの対向被覆鋼板部付近の拡大断面図であり、図５に対応する図。FIG. 6 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 separated in the first embodiment, and corresponding to FIG. 5 ; 実施形態１における、対向被覆鋼板部の絶縁被膜とボビン重なり部との間が剥離した様子を示す、点火コイルの対向被覆鋼板部付近の拡大断面図であり、図５に対応する図。FIG. 6 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 insulation coating of the opposed coated steel plate portion and the bobbin overlapping portion are peeled off, and corresponding to FIG. 5 ; 実施形態１のバリエーション（その１）を示す図であり、図２に対応する図。FIG. 3 is a diagram showing a variation (part 1) of the first embodiment and corresponding to FIG. 2; 実施形態１のバリエーション（その２）を示す図であり、図２に対応する図。FIG. 3 is a diagram showing a variation (part 2) of the first embodiment and corresponding to FIG. 2; 実施形態１のバリエーション（その３）を示す図であり、図２に対応する図。FIG. 3 is a diagram showing a variation (part 3) of the first embodiment and corresponding to FIG. 2; 実施形態１のバリエーション（その４）を示す図であり、図２に対応する図。FIG. 3 is a diagram showing a variation (part 4) of the first embodiment and corresponding to FIG. 2; 実施形態１のバリエーション（その５）を示す図であり、図２に対応する図。FIG. 3 is a diagram showing a variation (5) of the first embodiment and corresponding to FIG. 2; 実施形態２における、中心コア及び対向被覆鋼板部の斜視図。FIG. 4 is a perspective view of a central core and opposing covered steel plate portions in Embodiment 2; 実施形態２における、点火コイルにおける対向被覆鋼板部周辺の、Ｙ方向に直交する断面図。FIG. 10 is a cross-sectional view orthogonal to the Y direction around the facing covered steel plate portion of the ignition coil in Embodiment 2;

（実施形態１）
点火コイルの実施形態につき、図１～図１４を用いて説明する。
本実施形態の点火コイル１は、図１に示すごとく、一次コイル１１及び二次コイル１２と、一次ボビン２と、二次ボビン３と、中心コア４と、封止樹脂５とを備える。 (Embodiment 1)
Embodiments of the ignition coil will be described with reference to FIGS. 1 to 14. FIG.
The ignition coil 1 of this embodiment includes a primary coil 11, a secondary coil 12, a primary bobbin 2, a secondary bobbin 3, a center core 4, and a sealing resin 5, as shown in FIG.

一次コイル１１及び二次コイル１２は、互いに磁気的に結合している。一次ボビン２には、一次コイル１１が巻回されている。二次ボビン３には、二次コイル１２が巻回されている。 The primary coil 11 and secondary coil 12 are magnetically coupled to each other. A primary coil 11 is wound around the primary bobbin 2 . A secondary coil 12 is wound around the secondary bobbin 3 .

図９、図１０に示すごとく、中心コア４は、複数の被覆鋼板４０をコイル軸方向Ｘに直交する積層方向Ｚに積層してなる。図８に示すごとく、被覆鋼板４０は、鋼板４０１及び鋼板４０１の表面を被覆する絶縁被膜４０２を備える。なお、図１～図４、図９、図１０、図１１等においては、便宜上、絶縁被膜の図示を省略している。図１に示すごとく、中心コア４は、一次ボビン２の内側に配されている。封止樹脂５は、一次コイル１１、二次コイル１２、一次ボビン２、二次ボビン３、及び中心コア４を封止している。 As shown in FIGS. 9 and 10, the central core 4 is formed by stacking a plurality of coated steel plates 40 in the stacking direction Z orthogonal to the coil axial direction X. As shown in FIGS. As shown in FIG. 8 , the coated steel plate 40 includes a steel plate 401 and an insulating coating 402 covering the surface of the steel plate 401 . 1 to 4, 9, 10, 11, etc., illustration of the insulating coating is omitted for the sake of convenience. As shown in FIG. 1, the central core 4 is arranged inside the primary bobbin 2 . A sealing resin 5 seals the primary coil 11 , secondary coil 12 , primary bobbin 2 , secondary bobbin 3 , and center core 4 .

中心コア４は、一次コイル１１の内側に配されるコア本体部４１と、コア本体部４１からコイル軸方向Ｘと積層方向Ｚとの双方に直交する突出方向Ｙに突出したコア鍔部４２とを有する。一次ボビン２は、コイル軸方向Ｘの一部に、一次コイル１１を巻回するボビン本体部２１を有する。また、図１、図２に示すごとく、一次ボビン２は、コイル軸方向Ｘの他の一部に、コイル軸方向Ｘのコア鍔部４２と二次ボビン３との間に少なくとも一部が挟まれるボビン狭間部２２を有する。ボビン狭間部２２は、コア鍔部４２にコイル軸方向Ｘに重なるボビン重なり部２２１を有する。 The central core 4 includes a core body portion 41 disposed inside the primary coil 11, and a core collar portion 42 projecting from the core body portion 41 in a projecting direction Y orthogonal to both the coil axial direction X and the stacking direction Z. have The primary bobbin 2 has a bobbin main body 21 around which the primary coil 11 is wound in a part in the coil axial direction X. As shown in FIG. 1 and 2, at least part of the primary bobbin 2 is sandwiched between the core flange 42 in the coil axial direction X and the secondary bobbin 3 in another part in the coil axial direction X. It has a bobbin gap portion 22 that is connected to the bobbin gap. The bobbin narrow portion 22 has a bobbin overlapping portion 221 that overlaps the core collar portion 42 in the coil axial direction X. As shown in FIG.

図２に示すごとく、ボビン重なり部２２１の内部には、コア鍔部４２におけるコイル軸方向Ｘのボビン重なり部２２１側の面である鍔後積層面４２１と対向するとともに、被覆鋼板４０によって構成される対向被覆鋼板部６が設けられている。
以後、本実施形態につき詳説する。 As shown in FIG. 2 , inside the bobbin overlapping portion 221 , the coated steel plate 40 faces the post-flange lamination surface 421 , which is the surface of the core flange portion 42 on the side of the bobbin overlapping portion 221 in the coil axial direction X. A facing covered steel plate portion 6 is provided.
Hereinafter, this embodiment will be described in detail.

本明細書において、コイル軸方向Ｘは、一次コイル１１及び二次コイル１２の巻回軸が延在する方向である。以後、コイル軸方向ＸをＸ方向という。また、中心コア４の被覆鋼板４０の積層方向ＺをＺ方向という。また、コア本体部４１からのコア鍔部４２の突出方向Ｙを、Ｙ方向という。Ｘ方向とＹ方向とＺ方向とは、互いに直交する方向である。 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. Also, the lamination direction Z of the coated steel plates 40 of the central core 4 is referred to as the Z direction. A direction Y in which the core flange portion 42 protrudes from the core main body portion 41 is referred to as a Y direction. The X direction, Y direction, and Z direction are directions orthogonal to each other.

本実施形態の点火コイル１は、例えば、自動車、コージェネレーション等の内燃機関に用いるものとすることができる。点火コイル１は、内燃機関に設置されるスパークプラグ（図示略）に接続され、スパークプラグに高電圧を印加する手段として用いられる。 The ignition coil 1 of the present 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.

図９、図１０に示すごとく、中心コア４は、被覆鋼板４０をその厚み方向に複数積層してなる。図５、図８に示すごとく、被覆鋼板４０は、軟磁性材料からなる平板状の鋼板４０１と、鋼板４０１の両面を被覆する絶縁被膜４０２とを備える。 As shown in FIGS. 9 and 10, the central core 4 is formed by laminating a plurality of coated steel plates 40 in the thickness direction. As shown in FIGS. 5 and 8, the coated steel plate 40 includes a flat steel plate 401 made of a soft magnetic material and insulating coatings 402 covering both sides of the steel plate 401 .

被覆鋼板４０は、例えば、珪素鋼を板状に形成し、該板状の珪素鋼の表面処理をして珪素鋼の表面に絶縁被膜４０２を形成し、その後、これをＴ字状に打ち抜くことで形成される。これにより、被覆鋼板４０における鋼板４０１の両面は絶縁被膜４０２で覆われており、鋼板４０１の端縁は、絶縁被膜４０２から露出している。図７、図９に示すごとく、中心コア４は、Ｔ字状のコア本体部４１及びコア鍔部４２に加え、前述の対向被覆鋼板部６を備える。 The coated steel plate 40 is produced, for example, by forming a silicon steel into a plate shape, surface-treating the plate-shaped silicon steel to form an insulating coating 402 on the surface of the silicon steel, and then punching it into a T shape. formed by As a result, both sides of the steel plate 401 in the coated steel plate 40 are covered with the insulating coating 402 , and the edges of the steel plate 401 are exposed from the insulating coating 402 . As shown in FIGS. 7 and 9, the central core 4 includes the T-shaped core main body 41 and the core flange 42, as well as the opposed coated steel plate portion 6 described above.

コア本体部４１は、Ｘ方向に長尺な直方体形状を有する。図１に示すごとく、コア本体部４１の一部は、一次コイル１１の内周側に配される。 The core main body 41 has a rectangular parallelepiped shape elongated in the X direction. As shown in FIG. 1 , part of the core main body 41 is arranged on the inner peripheral side of the primary coil 11 .

図７、図９に示すごとく、コア鍔部４２は、Ｘ方向におけるコア本体部４１の一端部からＹ方向の両側に突出しており、一対形成されている。以後、Ｘ方向における中心コア４のコア鍔部４２が形成された側をＸ１側、その反対側をＸ２側という。 As shown in FIGS. 7 and 9, the core flanges 42 are formed in pairs and protrude from one end of the core main body 41 in the X direction to both sides in the Y direction. Hereinafter, the side of the central core 4 on which the core flange 42 is formed in the X direction is called the X1 side, and the opposite side is called the X2 side.

図７～図９に示すごとく、コア鍔部４２のＸ１側の面である鍔前積層面４２２は、Ｘ方向に直交する面状に形成されている。一方、図７、図９に示すごとく、コア鍔部４２のＸ２側の面である鍔後積層面４２１は、Ｙ方向においてコア本体部４１から遠ざかるほどＸ１側へ向かうよう傾斜している。図８に示すごとく、鍔前積層面４２２及び鍔後積層面４２１には、絶縁被膜４０２から露出した鋼板４０１の端縁部が表れる。 As shown in FIGS. 7 to 9, the front-flange laminated surface 422, which is the X1-side surface of the core flange portion 42, is formed in a plane perpendicular to the X direction. On the other hand, as shown in FIGS. 7 and 9, the post-flange lamination surface 421, which is the X2 side surface of the core flange portion 42, is inclined toward the X1 side as the distance from the core body portion 41 increases in the Y direction. As shown in FIG. 8 , edge portions of the steel plate 401 exposed from the insulating coating 402 appear on the front-flange lamination surface 422 and the post-flange lamination surface 421 .

図９に示すごとく、対向被覆鋼板部６は、中心コア４を構成する被覆鋼板４０の一部である。対向被覆鋼板部６を構成する被覆鋼板４０を特定被覆鋼板４００という。特定被覆鋼板４００は、中心コア４のＺ方向の端部に配された被覆鋼板４０である。特定被覆鋼板４００には、一対のコア鍔部４２のそれぞれからＸ２側に延設するよう対向被覆鋼板部６が形成されている。 As shown in FIG. 9 , the facing coated steel plate portion 6 is part of a coated steel plate 40 that constitutes the central core 4 . The coated steel plate 40 constituting the opposed coated steel plate portion 6 is called a specific coated steel plate 400 . The specific coated steel plate 400 is the coated steel plate 40 arranged at the end of the central core 4 in the Z direction. The specific coated steel plate 400 is formed with opposing coated steel plate portions 6 extending from each of the pair of core flange portions 42 toward the X2 side.

特定被覆鋼板４００は、対向被覆鋼板部６が鍔後積層面４２１とＸ方向に対向する位置に配されるよう、コア鍔部４２を構成する部位と対向被覆鋼板部６との境界部４０３が折り曲げられた形状を有する。特定被覆鋼板４００は、図１２に示すように、コア鍔部４２からＸ２側に延設された、対向被覆鋼板部６を構成する部位を有し、当該部位をＺ方向の一方側に折り曲げることにより、図７のように形成される。 The specific coated steel plate 400 has a boundary portion 403 between the portion forming the core collar portion 42 and the opposed coated steel plate portion 6 so that the opposed coated steel plate portion 6 is disposed at a position facing the post-flange laminated surface 421 in the X direction. It has a folded shape. As shown in FIG. 12, the specific coated steel plate 400 has a portion that constitutes the opposed coated steel plate portion 6 extending from the core collar portion 42 to the X2 side, and the portion is bent to one side in the Z direction. is formed as shown in FIG.

図７～図１１に示すごとく、対向被覆鋼板部６は、鍔後積層面４２１をＸ２側から覆うよう配されている。対向被覆鋼板部６は、特定被覆鋼板４００における、鍔後積層面４２１とＸ方向に重なる部位である。 As shown in FIGS. 7 to 11, the opposing coated steel plate portion 6 is arranged to cover the post-flange laminated surface 421 from the X2 side. The facing coated steel plate portion 6 is a portion of the specific coated steel plate 400 that overlaps the post-flange lamination surface 421 in the X direction.

図２に示すごとく、対向被覆鋼板部６は、鍔後積層面４２１と平行に形成されており、鍔後積層面４２１の垂直方向（法線方向）に厚みを有する矩形板状に形成されている。対向被覆鋼板部６の厚みは、特定被覆鋼板４００における対向被覆鋼板部６以外の部位の厚みと同等である。図５、図８に示すごとく、対向被覆鋼板部６は、その両面が絶縁被膜４０２で被覆されている。 As shown in FIG. 2, the opposed coated steel plate portion 6 is formed parallel to the post-flange lamination surface 421, and is formed in a rectangular plate shape having a thickness in the vertical direction (normal direction) of the post-flange lamination surface 421. there is The thickness of the facing covered steel plate portion 6 is the same as the thickness of the portion of the specific covered steel plate 400 other than the facing covered steel plate portion 6 . As shown in FIGS. 5 and 8 , both surfaces of the opposing coated steel plate portion 6 are coated with insulating coatings 402 .

図２に示すごとく、Ｚ方向から見たとき、対向被覆鋼板部６の長さＬ１は、Ｙ方向におけるコア鍔部４２の長さＬａの１／３の長さＬｂ以上である。本実施形態において、Ｚ方向から見たとき、対向被覆鋼板部６は、コア鍔部４２におけるコア本体部４１側の端部の付近から、コア鍔部４２の突出側端部の付近まで形成されている。これにより、対向被覆鋼板部６は、Ｙ方向における鍔後積層面４２１の少なくとも中央の領域において、鍔後積層面４２１と対向している。 As shown in FIG. 2, when viewed from the Z direction, the length L1 of the opposing coated steel plate portion 6 is 1/3 or more of the length La of the core collar portion 42 in the Y direction. In the present embodiment, when viewed from the Z direction, the facing coated steel plate portion 6 is formed from the vicinity of the core body portion 41 side end of the core collar portion 42 to the vicinity of the projecting side end of the core collar portion 42. ing. Thus, the facing covered steel plate portion 6 faces the post-flange laminated surface 421 at least in the central region of the post-flange laminated surface 421 in the Y direction.

なお、Ｚ方向から見たとき、対向被覆鋼板部６の長さＬ１が、Ｙ方向におけるコア鍔部４２の長さＬａの１／３の長さＬｂ以上であれば、対向被覆鋼板部６の形成位置に関しては特に限定されない。例えば、図１５～図１７に示すような構成を採用することができる。 When viewed from the Z direction, if the length L1 of the opposed coated steel plate portion 6 is equal to or greater than 1/3 the length Lb of the length La of the core flange portion 42 in the Y direction, the length of the opposed coated steel plate portion 6 The formation position is not particularly limited. For example, configurations as shown in FIGS. 15 to 17 can be adopted.

また、１つの鍔後積層面４２１に複数の対向被覆鋼板部６が対向しているような場合は、Ｚ方向から見たときの各対向被覆鋼板部６の長さの合計が、Ｙ方向におけるコア鍔部４２の長さＬａの１／３の長さＬｂ以上であればよい。例えば、図１８、図１９に示すような構成を採用することができる。 In addition, in the case where a plurality of opposed coated steel plate portions 6 face one post-flange lamination surface 421, the total length of each opposed coated steel plate portion 6 when viewed from the Z direction is The length Lb of the length La of the core collar portion 42 may be longer than 1/3. For example, configurations as shown in FIGS. 18 and 19 can be adopted.

また、図４に示すごとく、Ｚ方向において、対向被覆鋼板部６の長さＬ２は、コア鍔部４２の長さＬｃの１／２の長さＬｄ以上である。本実施形態において、Ｚ方向の対向被覆鋼板部６の長さＬ２は、Ｚ方向のコア鍔部４２の鍔後積層面４２１の長さと同等である。対向被覆鋼板部６におけるＺ方向の境界部４０３と反対側の端縁は、中心コア４のＺ方向の一端部と同等の位置まで形成されている。そして、Ｚ方向において、対向被覆鋼板部６は、鍔後積層面４２１の略全体とＸ方向に対向している。 Further, as shown in FIG. 4, in the Z direction, the length L2 of the opposing coated steel plate portion 6 is equal to or longer than half the length Ld of the length Lc of the core collar portion 42 . In the present embodiment, the Z-direction length L2 of the opposing covered steel plate portion 6 is equal to the Z-direction length of the post-flange laminated surface 421 of the core flange portion 42 . The end edge of the opposing coated steel plate portion 6 on the side opposite to the boundary portion 403 in the Z direction is formed up to a position equivalent to one end portion of the center core 4 in the Z direction. In the Z direction, the opposing coated steel plate portion 6 faces substantially the entire post-flange lamination surface 421 in the X direction.

図１に示すごとく、中心コア４は、Ｘ方向の両端面を露出した状態で、一次ボビン２の内側に埋設されている。一次ボビン２は、その成形型の内側に中心コア４を配したインサート成形により形成されている。 As shown in FIG. 1, the central core 4 is embedded inside the primary bobbin 2 with both end faces in the X direction exposed. The primary bobbin 2 is formed by insert molding with a central core 4 placed inside the mold.

一次ボビン２は、ポリブチレンテレフタレート樹脂（すなわちＰＢＴ樹脂）等の熱可塑性樹脂からなる。一次ボビン２は、前述のごとく、Ｘ方向の一部にボビン本体部２１を有し、Ｘ方向の他の一部にボビン狭間部２２を有する。ボビン本体部２１は、コア本体部４１を外周側から覆うよう筒状に形成されている。ボビン本体部２１の外周部に、一次コイル１１が巻回されている。 The primary bobbin 2 is made of thermoplastic resin such as polybutylene terephthalate resin (that is, PBT resin). As described above, the primary bobbin 2 has the bobbin main body 21 in part in the X direction and the bobbin gap part 22 in the other part in the X direction. The bobbin body portion 21 is formed in a tubular shape so as to cover the core body portion 41 from the outer peripheral side. A primary coil 11 is wound around the outer circumference of the bobbin main body 21 .

ボビン狭間部２２は、ボビン本体部２１のＸ１側に形成されている。ボビン狭間部２２は、ボビン本体部２１よりも外周側に突出するよう形成されている。ボビン狭間部２２に、中心コア４のコア鍔部４２が埋設されている。 The bobbin narrow portion 22 is formed on the X1 side of the bobbin body portion 21 . The bobbin narrow portion 22 is formed to protrude further to the outer peripheral side than the bobbin main body portion 21 . A core collar portion 42 of the central core 4 is embedded in the bobbin narrow portion 22 .

ボビン狭間部２２におけるコア鍔部４２とＸ方向に重なる位置に形成された部位が、ボビン重なり部２２１である。図２に示すごとく、ボビン重なり部２２１のコア鍔部４２と対向する重なり前面２２１ａは、コア鍔部４２の鍔後積層面４２１と平行であり、鍔後積層面４２１に接着している。また、ボビン重なり部２２１のＸ２側の面である重なり後面２２１ｂは、Ｘ方向に直交する面状に形成されている。 A bobbin overlapping portion 221 is formed at a position overlapping the core collar portion 42 in the bobbin narrow portion 22 in the X direction. As shown in FIG. 2 , the overlapping front surface 221 a of the bobbin overlapping portion 221 facing the core collar portion 42 is parallel to the post-flange lamination surface 421 of the core collar portion 42 and is adhered to the post-flange lamination surface 421 . Moreover, the overlapping rear surface 221b, which is the surface on the X2 side of the bobbin overlapping portion 221, is formed in a planar shape perpendicular to the X direction.

図２、図４、図５に示すごとく、ボビン重なり部２２１の内部に、対向被覆鋼板部６が埋設されている。図５に示すごとく、対向被覆鋼板部６と鍔後積層面４２１との間には、微小間隔があり、この微小間隔にもボビン重なり部２２１が配されている。なお、図２、図４等において、当該微小間隔の図示は、省略している。 As shown in FIGS. 2, 4, and 5, the opposing covered steel plate portion 6 is embedded inside the bobbin overlapping portion 221. As shown in FIGS. As shown in FIG. 5, there is a minute gap between the opposing covered steel plate portion 6 and the post-flange lamination surface 421, and the bobbin overlapping portion 221 is also arranged in this minute gap. In addition, in FIG. 2, FIG. 4, etc., illustration of the said minute space|interval is abbreviate|omitted.

図２に示すごとく、対向被覆鋼板部６と重なり前面２２１ａとの間の最短距離は、対向被覆鋼板部６と重なり後面２２１ｂとの間の最短距離よりも小さい。対向被覆鋼板部６は、ボビン重なり部２２１の重なり後面２２１ｂよりもＸ１側の位置に形成されている。 As shown in FIG. 2, the shortest distance between the opposing coated steel plate portion 6 and the overlapping front surface 221a is smaller than the shortest distance between the opposing coated steel plate portion 6 and the overlapping rear surface 221b. The facing coated steel plate portion 6 is formed at a position closer to the X1 side than the overlapping rear surface 221 b of the bobbin overlapping portion 221 .

二次ボビン３は、ポリフェニレンエーテル樹脂（すなわちＰＰＥ樹脂）等の熱可塑性樹脂を筒状に形成してなる。図１に示すごとく、二次ボビン３は、その内側に一次ボビン２のボビン本体部２１及び一次コイル１１を挿入するよう配されている。 The secondary bobbin 3 is formed by forming a thermoplastic resin such as polyphenylene ether resin (ie, PPE resin) into a cylindrical shape. As shown in FIG. 1, the secondary bobbin 3 is arranged such that the bobbin body 21 and the primary coil 11 of the primary bobbin 2 are inserted therein.

図２、図４、図５に示すごとく、二次ボビン３のＸ１側の面である二次ボビン前面３１は、Ｘ方向において、コア鍔部４２との間にボビン重なり部２２１を挟んでいる。すなわち、コア鍔部４２とボビン重なり部２２１と二次ボビン前面３１とは、互いにＸ方向に重なる位置に形成されている。なお、二次ボビン３とボビン重なり部２２１とは、当接していても、していなくてもよい。対向被覆鋼板部６の一部は、二次ボビン前面３１とコア鍔部４２との双方にＸ方向に重なる位置に形成されている。 As shown in FIGS. 2, 4, and 5, the secondary bobbin front surface 31, which is the X1 side surface of the secondary bobbin 3, sandwiches the bobbin overlapping portion 221 between itself and the core collar portion 42 in the X direction. . That is, the core collar portion 42, the bobbin overlapping portion 221, and the secondary bobbin front surface 31 are formed at positions overlapping each other in the X direction. Note that the secondary bobbin 3 and the bobbin overlapping portion 221 may or may not be in contact with each other. A part of the opposed coated steel plate portion 6 is formed at a position overlapping both the secondary bobbin front surface 31 and the core collar portion 42 in the X direction.

図１、図３に示すごとく、点火コイル１は、中心コア４とともに閉磁路を形成する外周コア１３を有する。外周コア１３は、一次コイル１１、二次コイル１２、及び中心コア４の外周側に形成されている。図１に示すごとく、外周コア１３は、Ｚ方向から見たとき、一次コイル１１、二次コイル１２、及び中心コア４を囲むよう環状に形成されている。外周コア１３は、中心コア４と同様の被覆鋼板を、その厚み方向に複数積層してなる。外周コア１３の被覆鋼板の積層方向は、Ｚ方向である。 As shown in FIGS. 1 and 3, the ignition coil 1 has an outer core 13 that forms a closed magnetic circuit together with the central core 4 . The outer core 13 is formed on the outer peripheral sides of the primary coil 11 , the secondary coil 12 , and the central core 4 . As shown in FIG. 1, the outer core 13 is annularly formed so as to surround the primary coil 11, the secondary coil 12, and the central core 4 when viewed in the Z direction. The outer core 13 is formed by laminating a plurality of coated steel plates similar to the central core 4 in the thickness direction. The lamination direction of the coated steel plates of the outer core 13 is the Z direction.

図１、図３に示すごとく、点火コイル１は、ケース７を有する。ケース７は、一次コイル１１、二次コイル１２、一次ボビン２、中心コア４、その他の点火コイル１の構成部品を内部に収容するケース本体部７１を有する。ケース本体部７１はＺ方向の一方であって、中心コア４における特定被覆鋼板４００が積層された側に開放されている。なお、中心コア４は、本実施形態における中心コア４の姿勢に対してＺ方向に反転したような姿勢でケース７内に配されていてもよい。 As shown in FIGS. 1 and 3, the ignition coil 1 has a case 7. As shown in FIGS. The case 7 has a case body portion 71 that accommodates the primary coil 11, the secondary coil 12, the primary bobbin 2, the central core 4, and other components of the ignition coil 1 therein. The case main body portion 71 is one side in the Z direction, and is open to the side of the center core 4 on which the specific coated steel plate 400 is laminated. Note that the center core 4 may be arranged in the case 7 in a posture that is reversed in the Z direction with respect to the posture of the center core 4 in this embodiment.

図１に示すごとく、ケース本体部７１内に配される点火コイル１の構成部品としては、イグナイタ１４、磁石１５等がある。イグナイタ１４は、一次コイル１１への通電及び通電の遮断を行う。磁石１５は、点火コイル１の出力電圧の向上のため、中心コア４に磁気バイアスをかけ、一次コイル１１への通電の遮断時の磁束の変化量を大きくして二次コイル１２に誘起される電圧を高めるためのものである。 As shown in FIG. 1, the igniter 14, the magnet 15, and the like are components of the ignition coil 1 arranged in the case main body 71. As shown in FIG. The igniter 14 energizes and cuts off the energization of the primary coil 11 . In order to improve the output voltage of the ignition coil 1, the magnet 15 applies a magnetic bias to the central core 4 to increase the amount of change in magnetic flux when the energization to the primary coil 11 is interrupted, thereby induced in the secondary coil 12. It is for increasing the voltage.

図３に示すごとく、ケース７は、ケース本体部７１における開放された側と反対側において、ケース本体部７１からＺ方向に突出するように形成された筒状の高圧タワー部７２を有する。ケース７単体を見たとき、高圧タワー部７２の内部空間は、ケース本体部７１の内部空間と連通している。点火コイル１において、高圧タワー部７２内には、金属製の高圧出力端子（図示略）が嵌入されている。これにより、点火コイル１において、高圧タワー部７２におけるケース本体部７１側の端部は閉塞されている。高圧出力端子は、ケース本体部７１から高圧タワー部７２側に封止樹脂５が漏れ出ないようにするための栓としての役割も有する。 As shown in FIG. 3, the case 7 has a tubular high-pressure tower 72 formed so as to protrude from the case body 71 in the Z direction on the opposite side of the case body 71 to the open side. When looking at the case 7 alone, the internal space of the high pressure tower portion 72 communicates with the internal space of the case main body portion 71 . In the ignition coil 1 , a metal high-voltage output terminal (not shown) is inserted into the high-voltage tower portion 72 . As a result, in the ignition coil 1, the end of the high pressure tower portion 72 on the side of the case main body portion 71 is closed. The high-voltage output terminal also serves as a plug for preventing leakage of the sealing resin 5 from the case body 71 to the high-voltage tower 72 side.

ケース本体部７１内に、封止樹脂５が充填されている。封止樹脂５は、例えばエポキシ樹脂である。封止樹脂５内に、一次コイル１１、二次コイル１２、一次ボビン２、中心コア４、その他の点火コイル１の構成部品が埋設されている。封止樹脂５は、例えば一次ボビン２と中心コア４との間の微小隙間にも含浸され得る。 A sealing resin 5 is filled in the case body portion 71 . The sealing resin 5 is, for example, epoxy resin. A primary coil 11 , a secondary coil 12 , a primary bobbin 2 , a center core 4 and other components of the ignition coil 1 are embedded in the sealing resin 5 . The sealing resin 5 can also impregnate, for example, a minute gap between the primary bobbin 2 and the central core 4 .

図３に示すごとく、ケース本体部７１のＸ１側の部位には、点火コイル１を外部に接続するためのコネクタ１６が嵌合されている。図６に示すごとく、コネクタ１６は、一次ボビン２とともに一体成形されている。なお、図１においては、コネクタ１６における相手方コネクタとの接続部の図示を省略している。コネクタ１６は、一次ボビン２と別体に形成されていてもよい。 As shown in FIG. 3, a connector 16 for connecting the ignition coil 1 to the outside is fitted to the portion of the case main body 71 on the X1 side. As shown in FIG. 6, the connector 16 is integrally molded with the primary bobbin 2. As shown in FIG. In addition, in FIG. 1, the illustration of the connecting portion of the connector 16 with the mating connector is omitted. The connector 16 may be formed separately from the primary bobbin 2 .

次に、本実施形態の作用効果につき説明する。
本実施形態の点火コイル１において、中心コア４は、絶縁被膜４０２により表面が被覆された複数の被覆鋼板４０を積層してなる。そして、ボビン重なり部２２１とコア鍔部４２との間、又はボビン重なり部２２１の内部には、コア鍔部４２におけるＸ方向のボビン重なり部２２１側の面である鍔後積層面４２１と対向するとともに、被覆鋼板４０によって構成される対向被覆鋼板部６が設けられている。それゆえ、点火コイル１が高温から低温に変化したとき、対向被覆鋼板部６の絶縁被膜４０２と鋼板４０１との間、或いは絶縁被膜４０２と一次ボビン２との間が剥離することで、ボビン狭間部２２がコア鍔部４２に拘束されにくくなる。 Next, the effects of this embodiment will be described.
In the ignition coil 1 of this embodiment, the central core 4 is formed by laminating a plurality of coated steel plates 40 whose surfaces are coated with an insulating coating 402 . Between the bobbin overlapping portion 221 and the core collar portion 42 or inside the bobbin overlapping portion 221, a post-flange lamination surface 421, which is a surface of the core collar portion 42 on the side of the bobbin overlapping portion 221 in the X direction, faces. In addition, an opposing covered steel plate portion 6 composed of a covered steel plate 40 is provided. Therefore, when the ignition coil 1 changes from a high temperature to a low temperature, separation between the insulating coating 402 and the steel plate 401 of the facing coated steel plate portion 6 or between the insulating coating 402 and the primary bobbin 2 causes separation of the bobbin gap. The portion 22 is less likely to be restrained by the core collar portion 42 .

すなわち、点火コイル１周辺の温度が高温から低温に変化したとき、線膨張係数の比較的小さいコア鍔部４２に密着するボビン重なり部２２１は、コア鍔部４２に拘束されることにより熱収縮による変位が比較的小さい。一方で、二次ボビン３及びその周囲の封止樹脂５は、比較的大きく熱収縮する。そのため、点火コイル１の温度が高温から低温に変化したとき、ボビン重なり部２２１は、コア鍔部４２に拘束される一方、二次ボビン３及び封止樹脂５によってＸ２側に引っ張られるため、ボビン重なり部２２１内には応力が生じる。 That is, when the temperature around the ignition coil 1 changes from a high temperature to a low temperature, the bobbin overlapping portion 221, which is in close contact with the core collar portion 42 having a relatively small coefficient of linear expansion, is restrained by the core collar portion 42, resulting in thermal contraction. Displacement is relatively small. On the other hand, the secondary bobbin 3 and the surrounding sealing resin 5 undergo relatively large heat shrinkage. Therefore, when the temperature of the ignition coil 1 changes from a high temperature to a low temperature, the bobbin overlapping portion 221 is restrained by the core flange portion 42 and is pulled toward the X2 side by the secondary bobbin 3 and the sealing resin 5. A stress is generated in the overlapping portion 221 .

当該応力により、例えば図１３に示すごとく、対向被覆鋼板部６の絶縁被膜４０２と鋼板４０１との間が剥離し、ボビン狭間部２２がコア鍔部４２に拘束され難くなる。あるいは、当該応力により、例えば図１４に示すごとく、絶縁被膜４０２とボビン重なり部２２１との間が剥離し、ボビン狭間部２２がコア鍔部４２に拘束され難くなる。なお、対向被覆鋼板部６と一次ボビン２との微小隙間に封止樹脂５が浸入することがあるが、この場合、例えば当該微小隙間に配された封止樹脂５と絶縁被膜４０２との間に剥離が生じることで、ボビン狭間部２２がコア鍔部４２に拘束され難くなる。 Due to this stress, as shown in FIG. 13, for example, the insulation coating 402 of the facing coated steel plate portion 6 and the steel plate 401 are separated, and the bobbin narrow portion 22 is less likely to be restrained by the core collar portion 42 . Alternatively, the stress causes separation between the insulating coating 402 and the bobbin overlapping portion 221 as shown in FIG. It should be noted that the sealing resin 5 may enter into the minute gap between the opposed coated steel plate portion 6 and the primary bobbin 2. As a result, the bobbin narrow portion 22 is less likely to be restrained by the core collar portion 42 .

そのため、点火コイル１が高温から低温に変化したときであっても、Ｘ方向のボビン狭間部２２と二次ボビン３との間において応力が集中することを防止することができる。その結果、一次コイル１１と二次コイル１２との間にクラックが生じ、一次コイル１１と二次コイル１２との間の電気的絶縁性が低下することを防止することができる。 Therefore, even when the ignition coil 1 changes from high temperature to low temperature, it is possible to prevent stress from concentrating between the bobbin narrow portion 22 in the X direction and the secondary bobbin 3 . As a result, it is possible to prevent cracks from occurring between the primary coil 11 and the secondary coil 12 and the electrical insulation between the primary coil 11 and the secondary coil 12 from deteriorating.

また、対向被覆鋼板部６は、中心コア４を構成する少なくとも一つの被覆鋼板４０である特定被覆鋼板４００の一部によって構成されており、特定被覆鋼板４００は、対向被覆鋼板部６が鍔後積層面４２１と対向する位置に配されるよう折り曲げられた形状を有する。すなわち、対向被覆鋼板部６は、中心コア４の一部によって構成されている。そのため、部品点数の削減を図りやすい。また、中心コア４を構成する被覆鋼板４０の一つである特定被覆鋼板４００の一部を折り曲げることで対向被覆鋼板部６を形成することができるため、点火コイル１の生産性を向上させやすい。 In addition, the facing coated steel plate portion 6 is configured by a part of a specific coated steel plate 400 that is at least one coated steel plate 40 that constitutes the central core 4, and the specific coated steel plate 400 is configured so that the facing coated steel plate portion 6 is located behind the collar. It has a bent shape so as to be arranged at a position facing the lamination surface 421 . That is, the opposing covered steel plate portion 6 is configured by part of the central core 4 . Therefore, it is easy to reduce the number of parts. In addition, since the opposed coated steel plate portion 6 can be formed by bending a portion of the specific coated steel plate 400, which is one of the coated steel plates 40 forming the central core 4, productivity of the ignition coil 1 can be easily improved. .

また、特定被覆鋼板４００は、中心コア４のＺ方向の端部に配された被覆鋼板４０である。それゆえ、特定被覆鋼板４００の一部をＺ方向の一方側に折り曲げることで、対向被覆鋼板部６を鍔後積層面４２１のＺ方向の略全体を覆う位置に配することができる。 Further, the specific coated steel plate 400 is the coated steel plate 40 arranged at the end of the central core 4 in the Z direction. Therefore, by bending a portion of the specific coated steel plate 400 to one side in the Z direction, the opposed coated steel plate portion 6 can be disposed at a position covering substantially the entire Z-direction laminated surface 421 after the flange.

また、Ｚ方向から見たとき、対向被覆鋼板部６の長さＬ１は、Ｙ方向におけるコア鍔部４２の長さＬａの１／３の長さＬｂ以上である。このように、Ｚ方向から見たときの対向被覆鋼板部６を長く形成することにより、ボビン重なり部２２１とコア鍔部４２との剥離を促しやすい。これにより、Ｘ方向のボビン狭間部２２と二次ボビン３の間における応力を一層低減できることを確認している。 In addition, when viewed from the Z direction, the length L1 of the opposing coated steel plate portion 6 is equal to or longer than 1/3 the length La of the core collar portion 42 in the Y direction. Thus, by forming the facing covered steel plate portion 6 long when viewed in the Z direction, separation between the bobbin overlapping portion 221 and the core collar portion 42 is facilitated. It has been confirmed that this can further reduce the stress between the bobbin narrow portion 22 and the secondary bobbin 3 in the X direction.

また、Ｚ方向において、対向被覆鋼板部６の長さＬ２は、コア鍔部４２の長さＬｃの１／２の長さＬｄ以上である。このように、Ｚ方向の対向被覆鋼板部６の長さを長くすることにより、ボビン重なり部２２１とコア鍔部４２とのＸ方向の剥離を促しやすい。これによっても、Ｘ方向のボビン狭間部２２と二次ボビン３の間における応力を一層低減できることを確認している。 In addition, in the Z direction, the length L2 of the opposed covered steel plate portion 6 is equal to or longer than half the length Ld of the length Lc of the core collar portion 42 . In this way, by increasing the length of the opposing coated steel plate portion 6 in the Z direction, it is easy to promote separation in the X direction between the bobbin overlapping portion 221 and the core collar portion 42 . It has been confirmed that the stress between the bobbin narrow portion 22 and the secondary bobbin 3 in the X direction can be further reduced by this also.

また、対向被覆鋼板部６の少なくとも一部は、一次ボビン２にＸ方向に対向する二次ボビン３の二次ボビン前面３１と、コア鍔部４２との双方にＸ方向に重なる位置に形成されている。それゆえ、点火コイル１が高温から低温に変化したときであっても、ボビン重なり部２２１における二次ボビン前面３１とＸ方向に重なる部位は、対向被覆鋼板部６から剥離しやすい。そのため、点火コイル１が高温から低温に変化したときであっても、Ｘ方向のボビン狭間部２２と二次ボビン３との間において応力が集中することを一層防止しやすい。 At least a part of the opposed covered steel plate portion 6 is formed at a position overlapping both the secondary bobbin front surface 31 of the secondary bobbin 3 facing the primary bobbin 2 in the X direction and the core collar portion 42 in the X direction. ing. Therefore, even when the ignition coil 1 changes from high temperature to low temperature, the portion of the bobbin overlapping portion 221 that overlaps the secondary bobbin front surface 31 in the X direction is likely to separate from the opposed covered steel plate portion 6 . Therefore, even when the ignition coil 1 changes from high temperature to low temperature, it is easier to prevent stress from being concentrated between the bobbin narrow portion 22 in the X direction and the secondary bobbin 3 .

以上のごとく、本実施形態によれば、電気的信頼性を確保しやすい点火コイルを提供することができる。 As described above, according to the present embodiment, it is possible to provide an ignition coil that easily ensures electrical reliability.

（実施形態２）
本実施形態は、図２０、図２１に示すごとく、実施形態１に対して、対向被覆鋼板部６を、中心コア４を構成する被覆鋼板４０と別体で構成した実施形態である。 (Embodiment 2)
As shown in FIGS. 20 and 21, the present embodiment is an embodiment in which the opposing coated steel plate portion 6 is configured separately from the coated steel plate 40 forming the central core 4 in contrast to the first embodiment.

図２０に示すごとく、対向被覆鋼板部６は、鍔後積層面４２１に対向する矩形板状に形成されている。図２１に示すごとく、対向被覆鋼板部６には、鍔後積層面４２１の垂直方向（法線方向）の両面に絶縁被膜４０２が形成されている。対向被覆鋼板部６は、鍔後積層面４２１に当接している。すなわち、対向被覆鋼板部６は、ボビン重なり部２２１とコア鍔部４２との間に配されており、Ｘ１側の面がボビン重なり部２２１から露出して鍔後積層面４２１に当接している。なお、対向被覆鋼板部６は、例えば、ボビン重なり部２２１とコア鍔部４２との間に配されていれば、鍔後積層面４２１に当接していなくてもよい。 As shown in FIG. 20 , the facing covered steel plate portion 6 is formed in a rectangular plate shape facing the post-flange lamination surface 421 . As shown in FIG. 21 , an insulating coating 402 is formed on both sides in the vertical direction (normal direction) of the post-flange lamination surface 421 of the opposing coated steel plate portion 6 . The facing covered steel plate portion 6 is in contact with the post-flange lamination surface 421 . That is, the opposed coated steel plate portion 6 is disposed between the bobbin overlapping portion 221 and the core collar portion 42, and the surface on the X1 side is exposed from the bobbin overlapping portion 221 and abuts on the post-collar lamination surface 421. . Note that the opposed coated steel plate portion 6 does not need to be in contact with the post-flange lamination surface 421 as long as it is arranged between the bobbin overlapping portion 221 and the core flange portion 42 , for example.

その他は、実施形態１と同様である。
なお、実施形態２以降において用いた符号のうち、既出の実施形態において用いた符号と同一のものは、特に示さない限り、既出の実施形態におけるものと同様の構成要素等を表す。 Others are the same as those of the first embodiment.
Note that, of the reference numerals used in the second and subsequent embodiments, the same reference numerals as those used in the previous embodiments represent the same components as those in the previous embodiments, unless otherwise specified.

本実施形態において、対向被覆鋼板部６は、中心コア４を構成する被覆鋼板４０と別体である。それゆえ、例えば従来の中心コア４の鍔後積層面４２１に、これとは別体の対向被覆鋼板部６を対向することで、対向被覆鋼板部６とボビン重なり部２２１との剥離を促すことができる。それゆえ、従来の中心コア４を用いた点火コイル１においても、点火コイル１の電気的信頼性を確保することができる。
その他、実施形態１と同様の作用効果を有する。 In the present embodiment, the facing coated steel plate portion 6 is separate from the coated steel plate 40 forming the central core 4 . Therefore, for example, by facing the post-flange lamination surface 421 of the conventional central core 4 to the facing covered steel plate portion 6 which is separate from this, separation between the facing covered steel plate portion 6 and the bobbin overlapping portion 221 can be promoted. can be done. Therefore, even in the ignition coil 1 using the conventional central core 4, the electrical reliability of the ignition coil 1 can be ensured.
In addition, it has the same effects as those of the first embodiment.

本発明は、前記各実施形態に限定されるものではなく、その要旨を逸脱しない範囲において種々の実施形態に適用することが可能である。 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.

１点火コイル
２一次ボビン
２２ボビン狭間部
２２１ボビン重なり部
３二次ボビン
４中心コア
４０被覆鋼板
４２コア鍔部
４２１鍔後積層面
６対向被覆鋼板部 REFERENCE SIGNS LIST 1 ignition coil 2 primary bobbin 22 bobbin narrow portion 221 bobbin overlapping portion 3 secondary bobbin 4 center core 40 coated steel plate 42 core flange portion 421 rear-flange lamination surface 6 opposing coated steel plate portion

Claims

a primary coil (11) and a secondary coil (12) magnetically coupled to each other;
a primary bobbin (2) around which the primary coil is wound;
a secondary bobbin (3) around which the secondary coil is wound;
A steel plate (401) and a plurality of coated steel plates (40) having an insulating coating (402) covering the surface of the steel plate are laminated in a lamination direction (Z) orthogonal to the coil axial direction (X), and the primary a central core (4) arranged inside the bobbin;
A sealing resin (5) that seals the primary coil, the secondary coil, the primary bobbin, the secondary bobbin, and the central core,
The central core includes a core body portion (41) arranged inside the primary coil, and a core flange projecting from the core body portion in a projecting direction (Y) orthogonal to both the coil axial direction and the stacking direction. a portion (42);
The primary bobbin has a bobbin main body (21) on which the primary coil is wound in a part in the coil axial direction, and the core collar part in the coil axial direction in another part in the coil axial direction. and a bobbin gap (22) at least partially sandwiched between the secondary bobbin,
The bobbin narrow portion has a bobbin overlapping portion (221) that overlaps the core collar portion in the coil axial direction,
Between the bobbin overlapping portion and the core flange portion, or inside the bobbin overlapping portion, a post-flange lamination surface (421), which is a surface of the core flange portion on the bobbin overlapping portion side in the coil axial direction, is opposed. and an ignition coil (1) provided with a facing coated steel plate portion (6) composed of the coated steel plate.

The facing coated steel plate part is composed of a part of a specific coated steel plate (400) that is at least one of the coated steel plates that constitute the central core, and the specific coated steel plate is configured such that the facing coated steel plate part is the collar 2. The ignition coil according to claim 1, wherein the ignition coil has a bent shape so as to face the rear lamination surface.

3. The ignition coil according to claim 2, wherein said specific coated steel plate is said coated steel plate arranged at an end portion of said center core in said stacking direction.

2. The ignition coil according to claim 1, wherein said facing coated steel plate portion is separate from said coated steel plate forming said central core.

When viewed from the stacking direction, the length (L1) of the opposed coated steel plate portion is 1/3 or more (Lb) of the length (La) of the core flange portion in the protruding direction. Item 5. The ignition coil according to any one of Items 1 to 4.

6. Any one of claims 1 to 5, wherein, in the stacking direction, the length (L2) of the opposed coated steel plate portion is equal to or greater than half the length (Ld) of the length (Lc) of the core flange portion. 1. The ignition coil according to claim 1.

At least a part of the facing coated steel plate portion overlaps both the secondary bobbin front surface (31) of the secondary bobbin facing the primary bobbin in the coil axial direction and the core collar portion in the coil axial direction. An ignition coil as claimed in any one of claims 1 to 6, wherein the ignition coil is formed.