JP2010278106A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine such that the high voltage-side terminal of a secondary coil can be electrically connected to a conductive coil spring at the lower part of a high-voltage terminal. <P>SOLUTION: In a mold type ignition coil 10 for the internal combustion engine which has a primary coil 2, a secondary coil 3, and an iron core 4 magnetically coupling the secondary coil 3 to primary coil 2, in which the high voltage-side terminal 3b of the secondary coil 3 is connected to the high-voltage terminal 5, and the high-voltage terminal 5 is connected to the ignition plug 9 fitted to an engine through the conductive coil spring 8, the primary coil 2, secondary coil 3, and iron core 4 are stored in an insulating case 1, and which is molded and cured with a thermosetting resin, the high-voltage terminal 5 has a through hole 5a, and the high voltage-side terminal of the secondary coil 3 penetrates the through hole 5a and is connected to the coil spring 8. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

For example, an ignition coil for an internal combustion engine disclosed in Japanese Patent Application Laid-Open No. 2008-270392 includes a primary coil bobbin 111 and a primary coil 112, and a secondary coil bobbin 113 and a secondary coil 114 positioned outside the primary coil 112, as shown in FIG. A center iron core 115 and a side iron core 116 that form a closed magnetic path by magnetically coupling the secondary coil 114 and the primary coil 112, an iron core cover 117 covering the side iron core 116, the iron core cover 117, and a primary coil bobbin. 111 and the primary coil 112, the secondary coil bobbin 113 and the secondary coil 114, the center iron core 115 and the side iron core 116 are accommodated, and the secondary coil 114 is attached to the secondary coil bobbin 113 and the insulating case 118 provided with the high voltage terminal 117. And the high-voltage terminal 117 are electrically connected by their own spring characteristics. A connection conductor 118, is injected into the insulating case 118, the insulating resin 119 is cured, a configuration having a. (See Patent Document 1)
In this type of internal combustion engine ignition coil, for example, as described in Japanese Patent Application Laid-Open No. 2001-193620, generally, a high voltage terminal and an ignition plug are electrically connected by a conductive coil spring. ing. (See Patent Document 2)

JP 2008-270392 A JP 2001-193620 A

  The ignition coil for an internal combustion engine has a variation in the contact area because the position of contact with the high voltage terminal differs depending on the size of the high voltage side terminal of the secondary coil. Further, the visual confirmation of the connection state was impossible, and the position accuracy was uncertain. Therefore, even if there is electrical continuity in the initial stage, there is a difference in the coefficient of linear expansion from the wire, high-voltage terminal, and insulating material, so the connection between the high-voltage terminal of the secondary coil and the high-voltage terminal is disconnected due to temperature stress. As a result, there are cases where electrical continuity is lost, and improvement has been desired.

  In order to solve the above-mentioned problems, the present invention provides a high voltage side terminal of the secondary coil that can be electrically connected to a conductive coil spring at a lower part of the high voltage terminal, It is an object of the present invention to provide an ignition coil for an internal combustion engine that allows visual confirmation of the connection state of a conductive coil spring.

  In order to solve the above-described problem, the invention according to claim 1 includes a primary coil, a secondary coil, and an iron core that magnetically couples the secondary coil and the primary coil, and the secondary coil. The high voltage side terminal of the battery is connected to a high voltage terminal, the high voltage terminal is connected to a spark plug attached to the engine via a conductive coil spring, and the primary coil, the secondary coil, and the iron core are insulated from each other. In a mold-type internal combustion engine ignition coil housed in a case and cast-cured with a thermosetting resin, the high-voltage terminal has a through hole, and the high-voltage end of the secondary coil penetrates the through-hole. And an ignition coil for an internal combustion engine connected to the coil spring.

  The invention according to claim 2 is the ignition coil for an internal combustion engine according to claim 1, wherein the through hole of the high-voltage terminal has a funnel shape.

  In the present invention, the high voltage terminal has a through hole, and the connection position can be visually confirmed by connecting the high voltage side terminal of the secondary coil to the conductive coil spring through the through hole of the high voltage terminal, Since the connection between the high voltage side terminal of the secondary coil and the spark plug can be reliably performed, the reliability of the connection structure is improved.

It is the schematic sectional drawing which looked at the ignition coil for internal combustion engines concerning the example of the present invention from the front. It is a perspective view of a high voltage terminal. It is sectional drawing of the conventional ignition coil for internal combustion engines.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of an ignition coil for an internal combustion engine according to an embodiment of the present invention as seen from the front, and FIG. 2 is a perspective view of a high-voltage terminal.

  In FIG. 1, an ignition coil 10 for an internal combustion engine has at least a primary coil 2 and a secondary coil 3 wound around an insulating case 1, and a cylindrical primary coil bobbin 2 a and a secondary coil bobbin 3 a arranged concentrically are magnetized. And a high-voltage terminal 5 that is connected to the outside, and a high-pressure cylinder portion 6 that protrudes outward from the side wall of the insulating case 1.

  An external socket 7 is detachably fitted to the outside of the high-pressure cylinder portion 6. Further, a conductive coil spring 8 and a spark plug 9 are disposed inside the external socket 7. The high-voltage terminal 5 has a through hole 5a at the center in the axial direction. The through hole 5a has a wide upper opening 5b and gradually decreases in diameter in a tapered shape tapered to a predetermined depth, a downwardly conical hollow portion 5c is formed in the upper portion, and a predetermined depth. A pore 5d having substantially the same diameter is formed in the lower part from the position to the tip, and the whole has a funnel shape.

  The high voltage side terminal of the secondary coil 3 is inserted through the through hole 5 a of the high voltage terminal 5 and protrudes from the bottom of the high voltage terminal 5. The secondary coil 3 has a high voltage side terminal 3b protruding from the bottom of the high voltage terminal 5, and the protruding high voltage side terminal 3b is connected to a conductive coil spring 8, thereby igniting the high voltage generated in the secondary coil 3. It is configured to supply to the plug.

  Thus, the high voltage terminal is provided with a through hole, the high voltage side terminal of the secondary coil is inserted through the through hole of the high voltage terminal and protrudes from the bottom of the high voltage terminal, and the protruded high voltage side terminal is connected to the conductive coil spring. Therefore, the connection position between the high voltage side terminal of the secondary coil and the conductive coil spring can be visually confirmed. Therefore, the high voltage side terminal of the secondary coil is reliably connected to the spark plug, so that the reliability of the connection structure is improved.

DESCRIPTION OF SYMBOLS 1 Insulation case 2 Primary coil 2a Primary coil bobbin 3 Secondary coil 3a Secondary coil bobbin 3b High voltage | pressure side terminal 4 Iron core 5 High voltage terminal 5a Through-hole 5b Opening 5c Downward conical hollow part 5d Pore 6 High voltage | pressure cylinder part 7 External socket 8 Coil spring 9 Spark plug 10 Internal combustion engine ignition coil

Claims (2)

A primary coil, a secondary coil, and an iron core that magnetically couples the secondary coil and the primary coil, the high-voltage side terminal of the secondary coil is connected to a high-voltage terminal, and the high-voltage terminal is electrically conductive A mold that is connected to a spark plug attached to the engine via a coil spring and accommodates the primary coil, the secondary coil, and the iron core in the insulating case and is cast-cured with a thermosetting resin. Type ignition coil for internal combustion engine,
The ignition coil for an internal combustion engine, wherein the high voltage terminal has a through hole, and a high voltage side terminal of the secondary coil is connected to the spring through the through hole.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the through hole of the high voltage terminal has a funnel shape.

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