JP2008274814A

JP2008274814A - Ignition coil

Info

Publication number: JP2008274814A
Application number: JP2007117831A
Authority: JP
Inventors: Takeshi Morimoto; 雄森本; Atsushi Iwami; 篤岩見; Shuichi Matsubayashi; 秀一松林; Ikuo Hirayama; 育男平山
Original assignee: Denso Corp; Toyo Denso Co Ltd
Current assignee: Denso Corp; Toyo Denso Co Ltd
Priority date: 2007-04-27
Filing date: 2007-04-27
Publication date: 2008-11-13
Anticipated expiration: 2027-04-27
Also published as: JP4887206B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil preventing abrupt dropping off of a coil spring disposed to a plug installation part, before or in installation of the spark plug. <P>SOLUTION: The plug installation part 2 comprises a resin tower part 3, a conduction fitting 12, a coil spring 5, and a rubber plug cap 4. An intermediate enlarged diameter part 52 is formed to the coil spring, and a drop-off prevention hole part 44 is formed to the plug cap 4. A step surface 45 between a cap locking hole part 41 and the drop-off prevention hole part 44 is pressed down by a tip surface of a tower cylinder part 31 of the tower part 3, so that enlargement of an inner diameter of the drop-off prevention hole part 44 is suppressed to prevent passage of the intermediate enlarged diameter part 52 of the coil spring 5 through the drop-off prevention hole part 44. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、車両用エンジン等の内燃機関において、スパークプラグにおける一対の電極間にスパークを発生させるために用いる点火コイルに関する。 The present invention relates to an ignition coil used for generating a spark between a pair of electrodes in a spark plug in an internal combustion engine such as a vehicle engine.

車両用エンジン等の内燃機関に使用する点火コイルにおいては、一次コイル及び二次コイルを収容するコイルケースに連結した樹脂製のタワー部に、ゴム製のプラグキャップを装着し、タワー部及びプラグキャップ内に、二次コイルの高電圧側巻線端部と導通金具（高電圧端子）を介して電気接続したコイルスプリングを配置している。そして、スパークプラグの碍子部をプラグキャップ内に圧入すると共に、碍子部よりも先端側に形成された端子部を、コイルスプリングと当接させて、スパークプラグと二次コイルとを導通させている。 In an ignition coil used for an internal combustion engine such as a vehicle engine, a rubber plug cap is attached to a resin tower connected to a coil case that houses a primary coil and a secondary coil. Inside, a coil spring that is electrically connected to the high-voltage side winding end of the secondary coil via a conductive metal fitting (high-voltage terminal) is disposed. And while pressing the insulator part of a spark plug in a plug cap, the terminal part formed in the front end side rather than the insulator part is made to contact | abut with a coil spring, and the spark plug and the secondary coil are electrically connected. .

例えば、特許文献１においては、コイルケースの先端部にプラグキャップを嵌合すると共に、コイルケースの先端部内にコイルスプリングを配置し、かつプラグキャップ内にスパークプラグの碍子部を圧入して、スパークプラグの端子部をコイルスプリングと導通させる構成の内燃機関用点火コイルについて開示されている。
しかしながら、従来の点火コイルにおいて、コイルスプリングの軸方向上端を導通金具に対して固定していない場合には、コイルスプリング、プラグキャップ等に何らかの工夫を行わないと、プラグキャップ内にスパークプラグが圧入されていない状態において、コイルスプリングが不意に脱落してしまうおそれがある。そのため、コイルスプリングの軸方向上端を導通金具に対して固定していない場合において、プラグキャップに何らかの外力が加わったときに（特に、プラグキャップ内にスパークプラグの碍子部が圧入されるときにプラグキャップの下端部から軸方向に圧力が加わったときに）、コイルスプリングの脱落を防止することができる工夫が望まれていた。 For example, in Patent Document 1, a plug cap is fitted to the tip of the coil case, a coil spring is disposed in the tip of the coil case, and a lever portion of the spark plug is press-fitted into the plug cap. An ignition coil for an internal combustion engine having a configuration in which a terminal portion of a plug is electrically connected to a coil spring is disclosed.
However, in the conventional ignition coil, if the upper end of the coil spring in the axial direction is not fixed to the conductive metal fitting, the spark plug will be press-fitted into the plug cap without any modification to the coil spring, plug cap, etc. There is a possibility that the coil spring may fall off unexpectedly in a state where it is not performed. Therefore, when the axial upper end of the coil spring is not fixed to the conductive metal fitting, when some external force is applied to the plug cap (especially when the insulator of the spark plug is press-fitted into the plug cap) There has been a demand for a device that can prevent the coil spring from falling off when pressure is applied in the axial direction from the lower end of the cap.

特開２００４−７１９１５号公報JP 2004-71915 A

本発明は、かかる従来の問題点に鑑みてなされたもので、スパークプラグの装着前及び装着時において、プラグ装着部に配置したコイルスプリングが不意に脱落することを防止することができる点火コイルを提供しようとするものである。 The present invention has been made in view of such a conventional problem, and an ignition coil that can prevent a coil spring disposed in a plug mounting portion from unexpectedly falling off before and during mounting of a spark plug. It is something to be offered.

第１の発明は、一次コイル及び二次コイルをコイルケース内に配置してなるコイル部の高電圧側端部に、スパークプラグの碍子部を装着するプラグ装着部を形成してなる点火コイルにおいて、
上記プラグ装着部は、上記コイル部と連結した樹脂製のタワー部と、上記二次コイルにおける高電圧側巻線端と電気接続した導通金具と、該導通金具と上記スパークプラグの碍子部よりも先端側に形成された端子部とを導通させるコイルスプリングと、上記スパークプラグの碍子部が圧入されるゴム製のプラグキャップとを有しており、
上記タワー部には、内周側に上記コイルスプリングを挿入配置するためのタワー挿入口を有すると共に外周側に上記プラグキャップを係止する係止外周面を有するタワー円筒部が形成してあり、
上記コイルスプリングは、その軸方向の中間部位に、その軸方向両側の一般部における外径よりも拡径してなる中間拡径部を有しており、
上記プラグキャップは、上記タワー円筒部の上記係止外周面に係止されるキャップ係止穴部と、上記スパークプラグの碍子部を圧入するための圧入穴部とを、上記スパークプラグの端子部を挿入する端子挿入穴部を介して連通形成してなり、
上記キャップ係止穴部と上記端子挿入穴部との連通部分には、該キャップ係止穴部及び該端子挿入穴部の内径よりも小さな内径を有すると共に、上記コイルスプリングの上記一般部における外径よりも大きく、かつ上記コイルスプリングの上記中間拡径部における外径よりも小さな内径を有する脱落防止穴部が形成してあり、
上記コイルスプリングは、その上記中間拡径部が上記タワー円筒部の上記タワー挿入口内に配置されており、
上記タワー円筒部における先端面によって、上記キャップ係止穴部と上記脱落防止穴部との間における段差面を押さえ付けることにより、上記脱落防止穴部の内径が大きくなることを抑制して、上記コイルスプリングの上記中間拡径部が上記脱落防止穴部を通過することができないよう構成したことを特徴とする点火コイルにある（請求項１）。 A first invention is an ignition coil in which a plug mounting portion for mounting a lever portion of a spark plug is formed at a high voltage side end portion of a coil portion in which a primary coil and a secondary coil are arranged in a coil case. ,
The plug mounting portion includes a resin tower portion connected to the coil portion, a conductive fitting electrically connected to a high voltage side winding end of the secondary coil, and a lever portion of the conductive fitting and the spark plug. A coil spring that conducts the terminal portion formed on the tip side, and a rubber plug cap into which the insulator portion of the spark plug is press-fitted,
The tower portion has a tower cylindrical portion having an outer peripheral surface for engaging the plug cap on the outer peripheral side and a tower insertion port for inserting and arranging the coil spring on the inner peripheral side,
The coil spring has an intermediate diameter-expanded portion formed by expanding the outer diameter of the general portion on both sides in the axial direction at an intermediate portion in the axial direction,
The plug cap includes a cap locking hole portion that is locked to the locking outer peripheral surface of the tower cylindrical portion, and a press-fitting hole portion that press-fits an insulator portion of the spark plug, and a terminal portion of the spark plug. Is formed through a terminal insertion hole for inserting
The communicating portion between the cap locking hole and the terminal insertion hole has an inner diameter smaller than the inner diameter of the cap locking hole and the terminal insertion hole, and the outside of the coil spring at the general portion. A drop-off preventing hole portion having an inner diameter that is larger than the diameter and smaller than the outer diameter of the intermediate enlarged portion of the coil spring is formed.
The coil spring has the intermediate enlarged portion disposed in the tower insertion port of the tower cylindrical portion,
By suppressing the step surface between the cap locking hole part and the drop-off prevention hole part by the front end surface of the tower cylindrical part, the inner diameter of the drop-off prevention hole part is suppressed, An ignition coil characterized in that the intermediate diameter-enlarged portion of the coil spring cannot pass through the drop-off preventing hole portion (Claim 1).

本発明の点火コイルにおいては、プラグ装着部に配置したコイルスプリングが不意に脱落することを防止する工夫を行っている。
具体的には、本発明のコイルスプリングには、上記中間拡径部が形成してあり、本発明のプラグキャップには、中間拡径部を通過させることができない上記脱落防止穴部が形成してある。そして、タワー円筒部にプラグキャップを装着した状態においては、コイルスプリングは、上側の一般部及び中間拡径部が、上記タワー円筒部のタワー挿入口内に配置され、下側の一般部が、プラグキャップの脱落防止穴部内及び上記端子挿入穴部内に配置される。 In the ignition coil according to the present invention, a contrivance is made to prevent the coil spring disposed in the plug mounting portion from unexpectedly falling off.
Specifically, the coil spring of the present invention has the intermediate enlarged portion formed therein, and the plug cap of the present invention has the drop prevention hole portion through which the intermediate enlarged portion cannot pass. It is. In the state in which the plug cap is attached to the tower cylindrical portion, the coil spring is arranged such that the upper general portion and the intermediate enlarged portion are disposed in the tower insertion port of the tower cylindrical portion, and the lower general portion is the plug. It arrange | positions in the drop-off prevention hole part of a cap, and the said terminal insertion hole part.

このとき、タワー円筒部における先端面によって、キャップ係止穴部と脱落防止穴部との間における段差面が押さえ付けられる。これにより、スパークプラグの装着前又は装着時において、プラグキャップに何らかの外力が加わったときに（特に、プラグキャップの圧入穴部にスパークプラグの碍子部が圧入されるときにプラグキャップの下端部から軸方向に圧力が加わったときに）、脱落防止穴部の内径が大きくなることが抑制される。そのため、スパークプラグの装着前及び装着時において、タワー挿入口内に配置されたコイルスプリングの中間拡径部が、脱落防止穴部を通過することができず、コイルスプリングがプラグキャップの圧入穴部内へ脱落してしまうことを防止することができる。 At this time, the step surface between the cap locking hole portion and the dropout prevention hole portion is pressed by the tip surface of the tower cylindrical portion. As a result, when any external force is applied to the plug cap before or during the installation of the spark plug (especially when the insulator of the spark plug is press-fitted into the press-fitting hole of the plug cap, When the pressure is applied in the axial direction), an increase in the inner diameter of the dropout prevention hole portion is suppressed. Therefore, before and during the installation of the spark plug, the intermediate diameter enlarged portion of the coil spring disposed in the tower insertion port cannot pass through the drop-off prevention hole, and the coil spring enters the press-fitting hole of the plug cap. It can be prevented from falling off.

それ故、本発明の点火コイルによれば、スパークプラグの装着前及び装着時において、プラグ装着部に配置したコイルスプリングが不意に脱落することを防止することができる。 Therefore, according to the ignition coil of the present invention, it is possible to prevent the coil spring disposed in the plug mounting portion from unexpectedly falling off before and during the mounting of the spark plug.

第２の発明は、一次コイル及び二次コイルをコイルケース内に配置してなるコイル部の高電圧側端部に、スパークプラグの碍子部を装着するプラグ装着部を形成してなる点火コイルにおいて、
上記プラグ装着部は、上記コイル部と連結した樹脂製のタワー部と、上記二次コイルにおける高電圧側巻線端と電気接続した導通金具と、該導通金具と上記スパークプラグの碍子部よりも先端側に形成された端子部とを導通させるコイルスプリングと、上記スパークプラグの碍子部が圧入されるゴム製のプラグキャップとを有しており、
上記タワー部には、内周側に上記コイルスプリングを挿入配置するためのタワー挿入口を有すると共に外周側に上記プラグキャップを係止する係止外周面を有するタワー円筒部が形成してあり、
上記コイルスプリングは、その軸方向の中間部位に、その軸方向両側の一般部における外径よりも拡径してなる中間拡径部を有しており、
上記プラグキャップは、上記タワー円筒部の上記係止外周面に係止されるキャップ係止穴部と、上記スパークプラグの碍子部を圧入するための圧入穴部とを、上記スパークプラグの端子部を挿入する端子挿入穴部を介して連通形成してなり、
上記キャップ係止穴部と上記端子挿入穴部との連通部分には、該キャップ係止穴部及び該端子挿入穴部の内径よりも小さな内径を有すると共に、上記コイルスプリングの上記一般部における外径よりも大きく、かつ上記コイルスプリングの上記中間拡径部における外径よりも小さな内径を有する脱落防止穴部が形成してあり、
上記コイルスプリングは、その上記中間拡径部が上記タワー円筒部の上記タワー挿入口内に配置されており、
上記キャップ係止穴部と上記脱落防止穴部との間における段差部分には、該段差部分の軸方向に突出して上記タワー円筒部の上記タワー挿入口における先端部分の内周側に対向する軸方向突起が形成してあり、
該軸方向突起が上記タワー挿入口における先端部分によって受け止められることにより、上記脱落防止穴部の内径が大きくなることを抑制して、上記中間拡径部が上記脱落防止穴部を通過することができないよう構成したことを特徴とする点火コイルにある（請求項３）。 A second invention is an ignition coil in which a plug mounting portion for mounting a lever portion of a spark plug is formed at a high voltage side end portion of a coil portion formed by arranging a primary coil and a secondary coil in a coil case. ,
The plug mounting portion includes a resin tower portion connected to the coil portion, a conductive fitting electrically connected to a high voltage side winding end of the secondary coil, and a lever portion of the conductive fitting and the spark plug. A coil spring that conducts the terminal portion formed on the tip side, and a rubber plug cap into which the insulator portion of the spark plug is press-fitted,
The tower portion has a tower cylindrical portion having an outer peripheral surface for engaging the plug cap on the outer peripheral side and a tower insertion port for inserting and arranging the coil spring on the inner peripheral side,
The coil spring has an intermediate diameter-expanded portion formed by expanding the outer diameter of the general portion on both sides in the axial direction at an intermediate portion in the axial direction,
The plug cap includes a cap locking hole portion that is locked to the locking outer peripheral surface of the tower cylindrical portion, and a press-fitting hole portion that press-fits an insulator portion of the spark plug, and a terminal portion of the spark plug. Is formed through a terminal insertion hole for inserting
The communicating portion between the cap locking hole and the terminal insertion hole has an inner diameter smaller than the inner diameter of the cap locking hole and the terminal insertion hole, and the outside of the coil spring at the general portion. A drop-off preventing hole portion having an inner diameter that is larger than the diameter and smaller than the outer diameter of the intermediate enlarged portion of the coil spring is formed.
The coil spring has the intermediate enlarged portion disposed in the tower insertion port of the tower cylindrical portion,
The step portion between the cap locking hole portion and the drop-off prevention hole portion projects in the axial direction of the step portion and faces the inner peripheral side of the tip portion of the tower insertion port of the tower cylindrical portion. Direction protrusion is formed,
The axial protrusion is received by the tip portion of the tower insertion port, so that the inner diameter of the drop-off prevention hole portion is suppressed from increasing, and the intermediate enlarged diameter portion passes through the drop-off prevention hole portion. An ignition coil characterized in that it cannot be configured (claim 3).

本発明の点火コイルにおいても、プラグ装着部に配置したコイルスプリングが不意に脱落することを防止する工夫を行っている。
具体的には、本発明のコイルスプリングには、上記中間拡径部が形成してあり、本発明のプラグキャップには、中間拡径部を通過させることができない上記脱落防止穴部が形成してある。また、キャップ係止穴部と脱落防止穴部との間における段差部分には、上記軸方向突起が形成してある。そして、タワー円筒部にプラグキャップを装着した状態においては、コイルスプリングは、上側の一般部及び中間拡径部が、上記タワー円筒部のタワー挿入口内に配置され、下側の一般部が、プラグキャップの脱落防止穴部内及び上記端子挿入穴部内に配置される。 Also in the ignition coil of the present invention, a device for preventing the coil spring disposed in the plug mounting portion from dropping unexpectedly is performed.
Specifically, the coil spring of the present invention has the intermediate enlarged portion formed therein, and the plug cap of the present invention has the drop prevention hole portion through which the intermediate enlarged portion cannot pass. It is. Further, the axial protrusion is formed at a step portion between the cap locking hole portion and the dropout prevention hole portion. In the state in which the plug cap is attached to the tower cylindrical portion, the coil spring is arranged such that the upper general portion and the intermediate enlarged portion are disposed in the tower insertion port of the tower cylindrical portion, and the lower general portion is the plug. It arrange | positions in the drop-off prevention hole part of a cap, and the said terminal insertion hole part.

スパークプラグの装着前又は装着時において、プラグキャップに何らかの外力が加わったときには（特に、プラグキャップの圧入穴部にスパークプラグの碍子部が圧入されるときにプラグキャップの下端部から軸方向に圧力が加わったときには）、軸方向突起が上記タワー挿入口における先端部分によって受け止められることにより、脱落防止穴部の内径が大きくなることが抑制される。そのため、スパークプラグの装着前及び装着時において、タワー挿入口内に配置されたコイルスプリングの中間拡径部が、脱落防止穴部を通過することができず、コイルスプリングがプラグキャップの圧入穴部内へ脱落してしまうことを防止することができる。 When any external force is applied to the plug cap before or during installation of the spark plug (especially when the insulator of the spark plug is press-fitted into the press-fitting hole of the plug cap, pressure is applied in the axial direction from the lower end of the plug cap. ), The axial protrusion is received by the tip portion of the tower insertion port, thereby preventing the inner diameter of the dropout prevention hole portion from increasing. Therefore, before and during the installation of the spark plug, the intermediate diameter enlarged portion of the coil spring disposed in the tower insertion port cannot pass through the drop-off prevention hole, and the coil spring enters the press-fitting hole of the plug cap. It can be prevented from falling off.

それ故、本発明の点火コイルによっても、スパークプラグの装着前及び装着時において、プラグ装着部に配置したコイルスプリングが不意に脱落することを防止することができる。 Therefore, even with the ignition coil according to the present invention, it is possible to prevent the coil spring disposed in the plug mounting portion from being unexpectedly dropped before and during the mounting of the spark plug.

上述した第１、第２の発明における好ましい実施の形態につき説明する。
第１の発明において、上記タワー円筒部の上記タワー挿入口における先端部分には、先端側に向かうに連れて拡径するテーパ内周面が形成してあり、該テーパ内周面の形成によって形成された鋭角状先端部を上記段差面へ食い込ませることによって、上記脱落防止穴部の内径が大きくなることを抑制することが好ましい（請求項２）。
この場合には、脱落防止穴部の内径が大きくなることを一層容易に抑制することができる。 A preferred embodiment in the first and second inventions described above will be described.
1st invention WHEREIN: The taper inner peripheral surface which diameter-expands toward the front end side is formed in the front-end | tip part in the said tower insertion port of the said tower cylindrical part, and it forms by formation of this taper inner peripheral surface. It is preferable to suppress an increase in the inner diameter of the dropout prevention hole portion by causing the sharpened tip portion to bite into the stepped surface (claim 2).
In this case, an increase in the inner diameter of the dropout prevention hole can be more easily suppressed.

また、第２の発明において、上記タワー挿入口における先端部分には、先端側に向かうに連れて拡径するテーパ内周面が形成してあり、上記軸方向突起は、上記テーパ内周面と対面するテーパ外周面を有していることが好ましい（請求項４）。
この場合には、脱落防止穴部の内径が大きくなることを一層容易に抑制することができる。 Further, in the second invention, a tapered inner peripheral surface that increases in diameter toward the distal end side is formed at the distal end portion of the tower insertion port, and the axial protrusion is formed on the tapered inner peripheral surface. It is preferable to have the taper outer peripheral surface which faces.
In this case, an increase in the inner diameter of the dropout prevention hole can be more easily suppressed.

また、第１、第２の発明において、上記脱落防止穴部は、上記プラグキャップの軸方向に平行な内周面を形成してなることが好ましい（請求項５）。
この場合には、脱落防止穴部を適切な軸方向長さに形成することができ、その内径が大きくなることを一層容易に抑制することができる。 In the first and second inventions, it is preferable that the drop-off preventing hole portion is formed with an inner peripheral surface parallel to the axial direction of the plug cap.
In this case, the drop-off preventing hole can be formed to have an appropriate axial length, and an increase in the inner diameter can be more easily suppressed.

また、上記脱落防止穴部は、全周に渡って形成することが好ましい（請求項６）。
この場合には、脱落防止穴部の剛性を高めることができ、その内径が大きくなることを一層容易に抑制することができる。 Further, it is preferable that the drop-off preventing hole is formed over the entire circumference (claim 6).
In this case, the rigidity of the drop-off preventing hole can be increased, and an increase in the inner diameter can be more easily suppressed.

以下に、本発明の点火コイルにかかる実施例につき、図面と共に説明する。
（実施例１）
本例の点火コイル１は、図１、図２に示すごとく、一次コイル及び二次コイルをコイルケース内に配置してなるコイル部１１の高電圧側端部に、スパークプラグ６の碍子部６１を装着するプラグ装着部２を形成してなる。
プラグ装着部２は、コイル部１１と連結した樹脂製のタワー部３と、二次コイルにおける高電圧側巻線端と電気接続した導通金具１２と、導通金具１２とスパークプラグ６の碍子部６１よりも先端側に形成された端子部６２とを導通させるコイルスプリング５と、スパークプラグ６の碍子部６１が圧入されるゴム製のプラグキャップ４とを有している。 Hereinafter, embodiments of the ignition coil according to the present invention will be described with reference to the drawings.
Example 1
As shown in FIGS. 1 and 2, the ignition coil 1 of the present example has an insulator portion 61 of the spark plug 6 at the high voltage side end portion of a coil portion 11 in which a primary coil and a secondary coil are arranged in a coil case. The plug mounting part 2 which mounts is formed.
The plug mounting portion 2 includes a resin tower portion 3 connected to the coil portion 11, a conductive fitting 12 electrically connected to a high-voltage side winding end of the secondary coil, and a lever portion 61 of the conductive fitting 12 and the spark plug 6. In addition, the coil spring 5 for conducting the terminal portion 62 formed on the distal end side, and the rubber plug cap 4 into which the lever portion 61 of the spark plug 6 is press-fitted are provided.

タワー部３は、コイル部１１に連結する連結ベース部３０と、連結ベース部３０からコイル部１１の軸方向に向けて突出した断面円環形状のタワー円筒部３１とを有している。タワー円筒部３１は、その内周側にコイルスプリング５を挿入配置するためのタワー挿入口３２を有すると共に、その外周側にプラグキャップ４を係止する係止外周面３３を有している。コイルスプリング５は、その軸方向の中間部位に、その軸方向両側の一般部５１における外径よりも拡径してなる中間拡径部５２を有している。 The tower portion 3 includes a connection base portion 30 that is connected to the coil portion 11, and a tower cylindrical portion 31 having an annular cross section that protrudes from the connection base portion 30 in the axial direction of the coil portion 11. The tower cylindrical portion 31 has a tower insertion port 32 for inserting and arranging the coil spring 5 on the inner peripheral side thereof, and a locking outer peripheral surface 33 for locking the plug cap 4 on the outer peripheral side thereof. The coil spring 5 has an intermediate enlarged portion 52 formed at the intermediate portion in the axial direction that is larger than the outer diameter of the general portion 51 on both sides in the axial direction.

図１、図２に示すごとく、プラグキャップ４は、タワー円筒部３１の係止外周面３３に係止されるキャップ係止穴部４１と、スパークプラグ６の碍子部６１を圧入するための圧入穴部４２とを、スパークプラグ６の端子部６２を挿入する端子挿入穴部４３を介して連通形成してなる。キャップ係止穴部４１と端子挿入穴部４３との連通部分には、キャップ係止穴部４１及び端子挿入穴部４３の内径よりも小さな内径を有すると共に、コイルスプリング５の一般部５１における外径よりも大きく、かつコイルスプリング５の中間拡径部５２における外径よりも小さな内径を有する脱落防止穴部４４が形成してある。 As shown in FIGS. 1 and 2, the plug cap 4 is press-fitted for press-fitting a cap locking hole 41 that is locked to the locking outer peripheral surface 33 of the tower cylindrical portion 31 and an insulator 61 of the spark plug 6. The hole portion 42 is formed in communication with the terminal insertion hole portion 43 into which the terminal portion 62 of the spark plug 6 is inserted. The communicating portion between the cap locking hole portion 41 and the terminal insertion hole portion 43 has an inner diameter smaller than the inner diameters of the cap locking hole portion 41 and the terminal insertion hole portion 43, and the outside of the general portion 51 of the coil spring 5. A drop prevention hole 44 having an inner diameter that is larger than the diameter and smaller than the outer diameter of the intermediate enlarged portion 52 of the coil spring 5 is formed.

コイルスプリング５は、その中間拡径部５２がタワー円筒部３１のタワー挿入口３２内に配置されている。そして、本例の点火コイル１においては、タワー円筒部３１における先端面によって、キャップ係止穴部４１と脱落防止穴部４４との間における段差面４５を押さえ付けることにより、脱落防止穴部４４の内径が大きくなることを抑制して、コイルスプリング５の中間拡径部５２が脱落防止穴部４４を通過することができないよう構成してある。
なお、図１は、プラグ装着部２にスパークプラグ６を装着した状態を示し、図２は、プラグ装着部２にスパークプラグ６を装着する前の状態を示す。 The coil spring 5 has an intermediate diameter enlarged portion 52 disposed in the tower insertion port 32 of the tower cylindrical portion 31. In the ignition coil 1 of this example, the stepped surface 45 between the cap locking hole portion 41 and the dropout prevention hole portion 44 is pressed by the tip surface of the tower cylindrical portion 31, thereby preventing the dropout prevention hole portion 44. The intermediate diameter enlarged portion 52 of the coil spring 5 is configured not to pass through the drop-off preventing hole 44 by suppressing an increase in the inner diameter of the coil spring 5.
FIG. 1 shows a state where the spark plug 6 is attached to the plug attachment portion 2, and FIG. 2 shows a state before the spark plug 6 is attached to the plug attachment portion 2.

以下に、本例の点火コイル１につき、図１、図２と共に詳説する。
本例の点火コイル１は、ＥＣＵからの信号によりスイッチング制御回路によって通電を行う一次コイルと、一次コイルに対する通電を遮断したときに生ずる誘導磁界により、高電圧を発生させる二次コイルとを、同心状に重ねて配置してなる。一次コイルは、円筒形状を有する樹脂製の一次スプールの外周面に一次電線を巻回してなり、二次コイルは、円筒形状を有する樹脂製の二次スプールの外周面に一次電線よりも細径の二次電線を、一次電線よりも多い巻回数で巻回してなる。
本例のタワー部３は、コイルケース及び二次スプールの軸方向端部に対して連結してある。このタワー部３は、一次スプールの軸方向端部に連結することもできる。 Hereinafter, the ignition coil 1 of this example will be described in detail with reference to FIGS.
In the ignition coil 1 of this example, a primary coil that is energized by a switching control circuit according to a signal from the ECU and a secondary coil that generates a high voltage by an induced magnetic field that is generated when the energization of the primary coil is interrupted are concentric. It is arranged by overlapping. The primary coil is formed by winding a primary wire around the outer peripheral surface of a resin-made primary spool having a cylindrical shape, and the secondary coil has a smaller diameter than the primary wire on the outer peripheral surface of a resin-made secondary spool having a cylindrical shape. The secondary electric wire is wound with a larger number of turns than the primary electric wire.
The tower part 3 of this example is connected with respect to the axial direction edge part of a coil case and a secondary spool. This tower part 3 can also be connected with the axial direction edge part of a primary spool.

本例のタワー部３は、熱可塑性樹脂から構成してあり、本例のプラグキャップ４は、タワー部３を構成する熱可塑性樹脂よりも柔らかい合成ゴムから構成してある。
また、図１、図２に示すごとく、タワー円筒部３１の係止外周面３３には、軸方向に並ぶ複数の環状突起３３１が形成してあり、タワー部３をプラグキャップ４のキャップ係止穴部４１内に圧入したときには、複数の環状突起３３１がキャップ係止穴部４１を係止して、タワー円筒部３１からプラグキャップ４が外れないようになっている。 The tower portion 3 of this example is made of a thermoplastic resin, and the plug cap 4 of this example is made of a synthetic rubber that is softer than the thermoplastic resin that makes up the tower portion 3.
As shown in FIGS. 1 and 2, a plurality of annular protrusions 331 arranged in the axial direction are formed on the outer peripheral surface 33 of the tower cylindrical portion 31, and the tower portion 3 is locked with the cap of the plug cap 4. When press-fitted into the hole 41, the plurality of annular protrusions 331 lock the cap locking hole 41 so that the plug cap 4 cannot be removed from the tower cylindrical portion 31.

連結ベース部３０の表面から突出するタワー円筒部３１の軸方向長さは、キャップ係止穴部４１の軸方向長さよりも若干長く形成してある。また、タワー円筒部３１のタワー挿入口３２における先端部分には、先端側に向かうに連れて拡径するテーパ内周面３２１が形成してある。そして、タワー円筒部３１にプラグキャップ４を装着したときには、テーパ内周面３２１の形成によって形成された鋭角状先端部３２２が、段差面４５に食い込むようにしてある。 The axial length of the tower cylindrical portion 31 protruding from the surface of the connection base portion 30 is formed slightly longer than the axial length of the cap locking hole portion 41. In addition, a tapered inner peripheral surface 321 that increases in diameter toward the distal end side is formed at the distal end portion of the tower insertion portion 32 of the tower cylindrical portion 31. When the plug cap 4 is attached to the tower cylindrical portion 31, the acute-angled tip end portion 322 formed by forming the tapered inner peripheral surface 321 bites into the step surface 45.

図２に示すごとく、コイルスプリング５の上側端部と導通させる導通金具１２の導通端部１２１は、タワー部３のタワー挿入口３２の上側開口端部に配置されている。コイルスプリング５の上側端部は、導通金具１２の導通端部１２１に固定されておらず、プラグ装着部２にスパークプラグ６を装着する際に、スパークプラグ６の端子部６２によってコイルスプリング５が上方に圧縮されたときに、導通金具１２の導通端部１２１に当接するようになっている。
また、コイルスプリング５は、鋼線をつる巻き状に巻回してなる。コイルスプリング５の一般部５１は、鋼線同士の間に所定の間隔を空けて軸方向に巻回してあり、コイルスプリング５の中間拡径部５２は、一般部５１よりも上記間隔を小さくして軸方向に巻回してある。本例の中間拡径部５２は、その剛性を高めるために、鋼線同士を密着させて（上記間隔を空けずに）軸方向に巻回してある。 As shown in FIG. 2, the conducting end 121 of the conducting fitting 12 that conducts with the upper end of the coil spring 5 is disposed at the upper opening end of the tower insertion port 32 of the tower 3. The upper end portion of the coil spring 5 is not fixed to the conduction end portion 121 of the conduction fitting 12, and when the spark plug 6 is attached to the plug attachment portion 2, the coil spring 5 is moved by the terminal portion 62 of the spark plug 6. When compressed upward, it contacts the conductive end 121 of the conductive metal fitting 12.
The coil spring 5 is formed by winding a steel wire in a spiral shape. The general portion 51 of the coil spring 5 is wound in the axial direction with a predetermined interval between the steel wires, and the intermediate diameter enlarged portion 52 of the coil spring 5 has a smaller interval than the general portion 51. It is wound in the axial direction. In order to increase the rigidity, the intermediate diameter enlarged portion 52 of this example is wound in the axial direction with the steel wires in close contact with each other (without leaving the gap therebetween).

スパークプラグ６は、その碍子部６１を形成した側とは反対側に、エンジンの燃焼室内に配置される一対の電極を有している。そして、点火コイル１は、二次コイルに発生した高電圧電流を、導通金具１２及びコイルスプリング５を介してスパークプラグ６に流し、一対の電極間にスパークを発生させるよう構成されている。 The spark plug 6 has a pair of electrodes disposed in the combustion chamber of the engine on the side opposite to the side where the insulator 61 is formed. The ignition coil 1 is configured to cause a high voltage current generated in the secondary coil to flow through the spark plug 6 via the conductive fitting 12 and the coil spring 5 to generate a spark between the pair of electrodes.

また、脱落防止穴部４４は、プラグキャップ４の軸方向に平行な所定の長さの内周面を形成してなる。また、脱落防止穴部４４は、全周に渡って形成してある。
また、本例の段差面４５は、若干傾斜して形成したが、この段差面４５は、傾斜させずにプラグキャップ４の軸方向に略垂直に形成することもできる。
図１に示すごとく、プラグ装着部２は、エンジンに形成されたプラグホール８内に挿入配置される。そして、点火コイル１をエンジンに組み付ける際には、プラグ装着部２をエンジンにおけるプラグホール８に配置するときに、プラグホール８の下端部に螺合したスパークプラグ６の碍子部６１が、プラグキャップ４の圧入穴部４２内に圧入される。 Further, the dropout prevention hole portion 44 is formed with an inner peripheral surface having a predetermined length parallel to the axial direction of the plug cap 4. Further, the drop-off preventing hole 44 is formed over the entire circumference.
Further, although the step surface 45 of this example is formed to be slightly inclined, the step surface 45 may be formed substantially perpendicular to the axial direction of the plug cap 4 without being inclined.
As shown in FIG. 1, the plug mounting portion 2 is inserted and disposed in a plug hole 8 formed in the engine. When the ignition coil 1 is assembled to the engine, when the plug mounting portion 2 is disposed in the plug hole 8 in the engine, the insulator portion 61 of the spark plug 6 screwed into the lower end portion of the plug hole 8 is connected to the plug cap. 4 is press-fitted into the press-fitting hole 42.

図２に示すごとく、タワー円筒部３１内にコイルスプリング５を挿入配置し、タワー円筒部３１にプラグキャップ４を装着して、プラグ装着部２を組み付けた状態においては、コイルスプリング５は、上側の一般部５１及び中間拡径部５２が、タワー円筒部３１のタワー挿入口３２内に配置され、下側の一般部５１が、プラグキャップ４の脱落防止穴部４４内及び端子挿入穴部４３内に配置される。そして、この状態において、コイルスプリング５は、その中間拡径部５２がプラグキャップ４の脱落防止穴部４４に掛止され、プラグキャップ４の圧入穴部４２内へ脱落することが防止されている。 As shown in FIG. 2, when the coil spring 5 is inserted and disposed in the tower cylindrical portion 31, the plug cap 4 is mounted on the tower cylindrical portion 31, and the plug mounting portion 2 is assembled, the coil spring 5 is The general portion 51 and the intermediate enlarged portion 52 are disposed in the tower insertion port 32 of the tower cylindrical portion 31, and the lower general portion 51 is disposed in the drop-off prevention hole portion 44 and the terminal insertion hole portion 43 of the plug cap 4. Placed inside. In this state, the coil spring 5 is prevented from dropping into the press-fitting hole portion 42 of the plug cap 4 because the intermediate enlarged diameter portion 52 of the coil spring 5 is hooked in the drop prevention hole portion 44 of the plug cap 4. .

また、プラグ装着部２を組み付けた状態においては、タワー円筒部３１における鋭角状先端部３２２がキャップ係止穴部４１と脱落防止穴部４４との間における段差面４５に食い込み、鋭角状先端部３２２によって段差面４５が押さえ付けられる。これにより、プラグキャップ４の圧入穴部４２内にスパークプラグ６の碍子部６１が圧入されるときに、プラグキャップ４の下端部からその軸方向に圧力が加わったときには、脱落防止穴部４４の内径が大きくなることが抑制される。そのため、スパークプラグ６の装着前及び装着時において、タワー挿入口３２内に配置されたコイルスプリング５の中間拡径部５２が、脱落防止穴部４４を通過することができず、コイルスプリング５がプラグキャップ４の圧入穴部４２内へ脱落してしまうことを防止することができる。 In the state where the plug mounting portion 2 is assembled, the acute-angled tip portion 322 of the tower cylindrical portion 31 bites into the step surface 45 between the cap locking hole portion 41 and the drop-off prevention hole portion 44, and the acute-angled tip portion. The step surface 45 is pressed down by 322. As a result, when the lever portion 61 of the spark plug 6 is press-fitted into the press-fit hole portion 42 of the plug cap 4, when pressure is applied in the axial direction from the lower end portion of the plug cap 4, An increase in the inner diameter is suppressed. Therefore, before and when the spark plug 6 is mounted, the intermediate diameter enlarged portion 52 of the coil spring 5 disposed in the tower insertion port 32 cannot pass through the drop-off preventing hole 44, and the coil spring 5 It is possible to prevent the plug cap 4 from falling into the press-fitting hole portion 42.

それ故、本例の点火コイル１によれば、スパークプラグ６の装着前及び装着時において、プラグ装着部２に配置したコイルスプリング５が不意に脱落することを防止することができる。 Therefore, according to the ignition coil 1 of this example, it is possible to prevent the coil spring 5 disposed in the plug mounting portion 2 from unexpectedly falling off before and when the spark plug 6 is mounted.

（実施例２）
本例は、図３、図４に示すごとく、上記キャップ係止穴部４１と上記脱落防止穴部４４との間における段差部分に、この段差部分の軸方向に突出して、タワー円筒部３１のタワー挿入口３２における先端部分の内周側に対向する軸方向突起４６を形成した例である。この軸方向突起４６は、キャップ係止穴部４１の方向に円環状に突出して形成されている。本例のタワー挿入口３２における先端部分には、先端側に向かうに連れて拡径するテーパ内周面３２１が形成してあり、軸方向突起４６は、テーパ内周面３２１と対面するテーパ外周面４６１を有している。 (Example 2)
In this example, as shown in FIG. 3 and FIG. 4, the step portion between the cap locking hole portion 41 and the drop-off prevention hole portion 44 protrudes in the axial direction of the step portion, This is an example in which an axial projection 46 facing the inner peripheral side of the tip portion of the tower insertion port 32 is formed. The axial projection 46 is formed to project in an annular shape in the direction of the cap locking hole 41. A tapered inner peripheral surface 321 that increases in diameter toward the distal end side is formed at the distal end portion of the tower insertion port 32 of this example, and the axial projection 46 is a tapered outer periphery that faces the tapered inner peripheral surface 321. A surface 461 is provided.

そして、本例の点火コイル１においては、軸方向突起４６のテーパ外周面４６１がタワー挿入口３２のテーパ内周面３２１によって受け止められることにより、脱落防止穴部４４の内径が大きくなることを抑制して、コイルスプリング５の中間拡径部５２が脱落防止穴部４４を通過することができないよう構成してある。
なお、図３は、プラグ装着部２にスパークプラグ６を装着した状態を示し、図４は、プラグ装着部２にスパークプラグ６を装着する前の状態を示す。 In the ignition coil 1 of this example, the taper outer peripheral surface 461 of the axial projection 46 is received by the taper inner peripheral surface 321 of the tower insertion port 32, thereby preventing the inner diameter of the dropout prevention hole portion 44 from increasing. Thus, the intermediate diameter enlarged portion 52 of the coil spring 5 is configured not to pass through the drop-off preventing hole portion 44.
3 shows a state in which the spark plug 6 is mounted on the plug mounting portion 2, and FIG. 4 shows a state before the spark plug 6 is mounted on the plug mounting portion 2.

本例の点火コイル１において、スパークプラグ６の装着時に、プラグキャップ４の圧入穴部４２にスパークプラグ６の碍子部６１が圧入されるときに、プラグキャップ４の下端部からその軸方向に圧力が加わったときには、軸方向突起４６のテーパ外周面４６１がタワー挿入口３２のテーパ内周面３２１によって受け止められることにより、脱落防止穴部４４の内径が大きくなることが抑制される。そのため、スパークプラグ６の装着前及び装着時において、タワー挿入口３２内に配置されたコイルスプリング５の中間拡径部５２が、脱落防止穴部４４を通過することができず、コイルスプリング５がプラグキャップ４の圧入穴部４２内へ脱落してしまうことを防止することができる。 In the ignition coil 1 of this example, when the insulator 61 of the spark plug 6 is press-fitted into the press-fitting hole 42 of the plug cap 4 when the spark plug 6 is mounted, pressure is applied in the axial direction from the lower end of the plug cap 4. Is added, the taper outer peripheral surface 461 of the axial projection 46 is received by the taper inner peripheral surface 321 of the tower insertion port 32, so that the inner diameter of the drop-off preventing hole 44 is suppressed. Therefore, before and when the spark plug 6 is attached, the intermediate diameter enlarged portion 52 of the coil spring 5 disposed in the tower insertion port 32 cannot pass through the drop-off preventing hole portion 44, and the coil spring 5 It is possible to prevent the plug cap 4 from falling into the press-fitting hole portion 42.

それ故、本例の点火コイル１によっても、スパークプラグ６の装着前及び装着時において、プラグ装着部２に配置したコイルスプリング５が不意に脱落することを防止することができる。本例においても、その他の構成は上記実施例１と同様であり、上記実施例１と同様の作用効果を得ることができる。 Therefore, even with the ignition coil 1 of this example, it is possible to prevent the coil spring 5 disposed in the plug mounting portion 2 from being accidentally dropped before and after the spark plug 6 is mounted. Also in this example, other configurations are the same as those of the first embodiment, and the same effects as those of the first embodiment can be obtained.

実施例１における、プラグ装着部にスパークプラグを装着した状態を示す断面説明図。Sectional explanatory drawing which shows the state which mounted | wore the plug mounting part in Example 1 with the spark plug. 実施例１における、プラグ装着部にスパークプラグを装着する前の状態を示す断面説明図。Sectional explanatory drawing which shows the state before mounting | wearing with a spark plug in the plug mounting part in Example 1. FIG. 実施例２における、プラグ装着部にスパークプラグを装着した状態を示す断面説明図。Cross-sectional explanatory drawing which shows the state which mounted | wore the plug mounting part in Example 2 with the spark plug mounted | worn. 実施例２における、プラグ装着部にスパークプラグを装着する前の状態を示す断面説明図。Sectional explanatory drawing which shows the state before mounting | wearing with a spark plug in the plug mounting part in Example 2. FIG.

Explanation of symbols

１点火コイル
１１コイル部
１２導通金具
２プラグ装着部
３タワー部
３１タワー円筒部
３２タワー挿入口
３２１テーパ内周面
３２２鋭角状先端部
３３係止外周面
４プラグキャップ
４１キャップ係止穴部
４２圧入穴部
４３端子挿入穴部
４４脱落防止穴部
４５段差面
４６軸方向突起
４６１テーパ外周面
５コイルスプリング
５１一般部
５２中間拡径部
６スパークプラグ
６１碍子部
６２端子部 DESCRIPTION OF SYMBOLS 1 Ignition coil 11 Coil part 12 Conductive metal fitting 2 Plug installation part 3 Tower part 31 Tower cylindrical part 32 Tower insertion port 321 Tapered inner peripheral surface 322 Sharp-angled tip part 33 Locking outer peripheral surface 4 Plug cap 41 Cap locking hole part 42 Press fit Hole 43 Terminal insertion hole 44 Drop-off prevention hole 45 Stepped surface 46 Axial protrusion 461 Tapered outer peripheral surface 5 Coil spring 51 General part 52 Intermediate diameter enlarged part 6 Spark plug 61 Insulator part 62 Terminal part

Claims

In an ignition coil formed by forming a plug mounting portion for mounting a lever portion of a spark plug on a high voltage side end portion of a coil portion formed by arranging a primary coil and a secondary coil in a coil case,
The plug mounting portion includes a resin tower portion connected to the coil portion, a conductive fitting electrically connected to a high voltage side winding end of the secondary coil, and a lever portion of the conductive fitting and the spark plug. A coil spring that conducts the terminal portion formed on the tip side, and a rubber plug cap into which the insulator portion of the spark plug is press-fitted,
The tower portion has a tower cylindrical portion having an outer peripheral surface for engaging the plug cap on the outer peripheral side and a tower insertion port for inserting and arranging the coil spring on the inner peripheral side,
The coil spring has an intermediate diameter-expanded portion formed by expanding the outer diameter of the general portion on both sides in the axial direction at an intermediate portion in the axial direction,
The plug cap includes a cap locking hole portion that is locked to the locking outer peripheral surface of the tower cylindrical portion, and a press-fitting hole portion that press-fits an insulator portion of the spark plug, and a terminal portion of the spark plug. Is formed through a terminal insertion hole for inserting
The communicating portion between the cap locking hole and the terminal insertion hole has an inner diameter smaller than the inner diameter of the cap locking hole and the terminal insertion hole, and the outside of the coil spring at the general portion. A drop-off preventing hole portion having an inner diameter that is larger than the diameter and smaller than the outer diameter of the intermediate enlarged portion of the coil spring is formed.
The coil spring has the intermediate enlarged portion disposed in the tower insertion port of the tower cylindrical portion,
By suppressing the step surface between the cap locking hole part and the drop-off prevention hole part by the front end surface of the tower cylindrical part, the inner diameter of the drop-off prevention hole part is suppressed, An ignition coil characterized in that the intermediate diameter-enlarged portion of the coil spring cannot pass through the drop-off preventing hole portion.

In Claim 1, the taper inner peripheral surface which is diameter-expanded toward the tip side is formed in the tip part in the tower insertion slot of the tower cylindrical part,
An ignition coil characterized by suppressing an increase in the inner diameter of the drop-off prevention hole by causing an acute-angled tip portion formed by forming the tapered inner peripheral surface to bite into the stepped surface.

In an ignition coil formed by forming a plug mounting portion for mounting a lever portion of a spark plug on a high voltage side end portion of a coil portion formed by arranging a primary coil and a secondary coil in a coil case,
The plug mounting portion includes a resin tower portion connected to the coil portion, a conductive fitting electrically connected to a high voltage side winding end of the secondary coil, and a lever portion of the conductive fitting and the spark plug. A coil spring that conducts the terminal portion formed on the tip side, and a rubber plug cap into which the insulator portion of the spark plug is press-fitted,
The tower portion has a tower cylindrical portion having an outer peripheral surface for engaging the plug cap on the outer peripheral side and a tower insertion port for inserting and arranging the coil spring on the inner peripheral side,
The coil spring has an intermediate diameter-expanded portion formed by expanding the outer diameter of the general portion on both sides in the axial direction at an intermediate portion in the axial direction,
The plug cap includes a cap locking hole portion that is locked to the locking outer peripheral surface of the tower cylindrical portion, and a press-fitting hole portion that press-fits an insulator portion of the spark plug, and a terminal portion of the spark plug. Is formed through a terminal insertion hole for inserting
The communicating portion between the cap locking hole and the terminal insertion hole has an inner diameter smaller than the inner diameter of the cap locking hole and the terminal insertion hole, and the outside of the coil spring at the general portion. A drop-off preventing hole portion having an inner diameter that is larger than the diameter and smaller than the outer diameter of the intermediate enlarged portion of the coil spring is formed.
The coil spring has the intermediate enlarged portion disposed in the tower insertion port of the tower cylindrical portion,
The step portion between the cap locking hole portion and the drop-off prevention hole portion projects in the axial direction of the step portion and faces the inner peripheral side of the tip portion of the tower insertion port of the tower cylindrical portion. Direction protrusion is formed,
The axial protrusion is received by the tip portion of the tower insertion port, so that the inner diameter of the drop-off prevention hole portion is suppressed from increasing, and the intermediate enlarged diameter portion passes through the drop-off prevention hole portion. An ignition coil characterized in that it cannot be configured.

In Claim 3, the tip end portion of the tower insertion port is formed with a taper inner peripheral surface that increases in diameter toward the tip end side.
The ignition coil characterized in that the axial protrusion has a tapered outer peripheral surface facing the tapered inner peripheral surface.

5. The ignition coil according to claim 1, wherein the drop-off prevention hole portion forms an inner peripheral surface parallel to an axial direction of the plug cap.

6. The ignition coil according to claim 1, wherein the drop-off preventing hole is formed over the entire circumference of the press-fitting hole. 7.