JP2002075759A - Ignition coil device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently and easily secure core sectional area required for the high-pressure drive of an ignition coil, and to achieve a high-output ignition coil device for internal combustion engine, in a limited space in an independent- ignition-type ignition coil device. SOLUTION: This ignition coil device for internal combustion engine is an independent ignition type, and is fitted to the cylinder head of an internal combustion engine for each ignition plug of each cylinder. In a cylindrical case 8 of the ignition coil device, a core 5 for composing a magnetic circuit, and primary and secondary coils 2 and 4 concentrically arranged outside the core 5 are arranged so that their concentric axis is at right angle to the center axis of the cylindrical case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil device for an internal combustion engine, and more particularly, to an independent ignition type ignition coil device for an internal combustion engine which is mounted on a cylinder head of an internal combustion engine for each ignition plug of each cylinder.

[0002]

2. Description of the Related Art Conventionally, an elongated cylindrical (pencil-shaped) ignition coil device is disposed in each plug hole of a cylinder head of an internal combustion engine, and a secondary coil of the ignition coil is electrically connected to each ignition plug. A connected independent ignition type ignition coil device is known.

[0003] A conventional ignition coil device for an internal combustion engine of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-230964, in which a coil is concentrically wound around a core via a core (center core) and a bobbin. The secondary coil and the secondary coil are housed in the elongated cylindrical coil case, but the concentric axes of the core, the primary coil, and the secondary coil are made to be in the same direction as the central axis of the coil case. Of the ignition coil members.

[0004]

The above-described independent ignition type ignition coil device has a very small space for accommodating the coil portion. Has been an issue.

[0005]

The present invention is basically configured as follows in order to achieve the above object.

That is, in an ignition coil device for an internal combustion engine of an independent ignition type mounted on a cylinder head of an internal combustion engine for each ignition plug of each cylinder, a magnetic circuit is provided in a cylindrical case (coil case) of the ignition coil device. The core and the primary coil and the secondary coil which are arranged concentrically outside the core are arranged such that their concentric axes are perpendicular to the central axis of the cylindrical case. Here, the right-angled arrangement means a substantially right-angled arrangement including a slight tolerance error, that is, a substantially right angle.

According to the above configuration, the cross-sectional direction of the core (center core), which is the concentric axis of the primary coil and the secondary coil, is oriented in the up-down direction (longitudinal direction) of the case. It is easy to secure a sufficient core cross-sectional area without being restricted by the diameter of the case. Also, the core whose central axis and the concentric axis are perpendicular to the coil case according to the coil characteristic specifications, Two or more primary coil and secondary coil assemblies (coil units) can be arranged in series in the vertical direction in the case.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an entire configuration of an ignition coil device for an internal combustion engine according to one embodiment of the present invention, FIG. 2 is a diagram showing an exploded state of a core portion thereof, and FIG. It is a cross-sectional view showing the shape which cross-sectioned the part by the concentric axis. The ignition coil case 8 is made of a thermoplastic synthetic resin (for example, polyethylene terephthalate (hereinafter, referred to as “PBT”)),
It is formed of polyphenylene sulfide (hereinafter referred to as “PPPS”) or the like.

The coil case 8 is formed in an elongated cylindrical shape so that it can be inserted into a plug hole (not shown), and has an ignition coil assembly (closed magnetic path core 5, primary coils 2, 2) inside. The lower coil has a plug cap 8 'formed integrally with the case 8 at a lower end thereof for introducing a part of a spark plug (not shown).

A terminal pin 10 and a high voltage terminal 11 connected to the high voltage side of the secondary coil are provided inside the coil case 8, and a high voltage terminal 11 is provided inside the plug cap 8 '.
For connecting a spark plug electrically connected to the
Is decorated.

The portion of the plug cap 8 'into which the spark plug is inserted is insulated by a rubber boot such as silicone rubber.

An igniter case 2 for mounting a circuit unit 15 of an ignition coil is provided on an upper portion of the coil case 8.
0 is fixed. The igniter case 20 is molded integrally with the connector 16 having the connector terminal 17.

Inside the coil case 8, the core 5 constituting the magnetic circuit and the primary coil 2 and the secondary coil 4 arranged concentrically outside the core 5 are arranged such that their concentric axes are the center axis of the coil case 8. They are arranged at right angles.

In the present embodiment, the center core 5a, the primary bobbin 1, the primary coils 2, 2
A secondary bobbin 3 and a secondary coil 4 are arranged. The positional relationship between the coils 2 and 4 can be such that the inner side is the secondary coil 4 and the outer side is the primary coil 2.

Here, the primary bobbin 1 is formed of a thermoplastic synthetic resin (for example, PPS), modified polyphenylene oxide (hereinafter, referred to as “modified PPO”), etc., and a primary coil 2 is wound around its outer periphery. ing. The primary coil 2 is
It is an enameled wire having a wire diameter of about 0.3 to 1.0 mm. The enameled wire is laminated several layers, several tens of times per layer, and is laminated and wound about 50 to 300 times in total. Similarly, thermoplastic synthetic resin (for example, PPS, modified PPO, etc.)
A secondary coil 4 is wound on the secondary bobbin 3 formed by the above. The secondary coil 4 has a wire diameter of 0.03 to 0.06 mm.
About 5,000 to 20,000 times in total. The secondary bobbin 3 is located between the primary coil 2 and the secondary coil 4 and also has a role of insulating a high voltage generated in the secondary coil 4.

The core 5 of this embodiment includes primary coils 2 and 2
A center core portion 5a, which is a concentric axis of the next coil 4, is composed of an upper bridge core (upper side core) 5b and a lower bridge core (lower side core) 5c extending upward and downward from both ends of the center core portion 5a. The center core portion 5a and the upper bridge core portion 5b and the center core portion 5a and the lower bridge core portion 5c respectively form closed magnetic paths, and the primary coil 2 and the secondary coil 4 are arranged in these closed magnetic paths. . There is a great feature in that the center core portion 5a is arranged at right angles to the axial direction of the coil case 8. The core 5 is formed by press-stacking a silicon steel plate or a directional silicon steel plate having a thickness of 0.2 to 0.5 mm. As shown in FIG. 2, the shape is composed of a center core portion 5a having an E shape and entering the inside of the primary coil 2, and bridge core portions 5b and 5c located outside the secondary coil 4. The closed magnetic path described above is formed by abutting the E-shaped core on the target shape.

The abutting surface of the center core 5a has
A magnet 7 for generating a magnetic flux in a magnetic path opposite to the magnetic flux formed by the next coil 2 is interposed. In order to prevent electric field concentration and stress concentration between the primary coil 2, the secondary coil 4 and the core 5, the primary bobbin 1 and the core 5
A flexible epoxy 6a is injected under vacuum (for example, 4 Toor or less) and cured, or a silicone rubber 6b is wound around the core 5.
Or heat shrink tube 6c around core 5. The coil portions such as the primary coil 2, the secondary coil 4, and the core 5 are inserted so that their concentric axes are perpendicular to the center axis of the case 8, and the epoxy resin 9 is evacuated in the coil case 8. Inject underneath (eg, 4 Toor or less) and cure to insulate high voltage.

According to this embodiment, the concentric axis of the coil portion is
By arranging at right angles to the center axis of the coil case 8, the cross-sectional area of the core 5 can be increased without being restricted by space, and by forming a closed magnetic circuit, it is possible to increase the sectional area. It is possible to generate a high voltage by reducing the number of windings. FIG. 3 shows a cross section of the primary coil 2, the secondary coil 4, the core 5, and the like, taken along a concentric axis.
At both ends of the primary bobbin 1 and the secondary bobbin 3, a space is provided between the primary bobbin 1 and the secondary bobbin 3 so that the primary coil 2 and the secondary coil 4 are routed. The high voltage generated in the secondary coil 4 is supplied to the ignition plug via the terminal pin 10, the high voltage terminal 11, the spring 12, and the like. A plug hole seal 14 is provided at a portion of the coil case 8 located at the entrance of the plug hole so that water does not enter the plug hole and ventilation is possible. A power supply necessary for the primary coil 2 and an ignition signal to the igniter 15 are supplied from a connector terminal 17 of the connector 16. A cover 18 may be attached to the upper surface of the connector 16 for design purposes. FIG. 4 relates to a second embodiment of the present invention, and basically has the same configuration as the first embodiment (in the figure, the same reference numerals as those in the first embodiment denote the same or common elements. is there),
The difference is that the cores 5, 1 and
An example is shown in which a plurality of coil units (coil assemblies) such as the secondary coil 2 and the secondary coil 4 are arranged in series in the case 8 (here, two are illustrated). This makes it possible to easily output the characteristics according to the required specifications.

[0020]

According to the present invention, even in a system in which the coil portion is housed in an elongated cylindrical case as in an independent ignition type ignition coil device, the core cross-sectional area required for driving the ignition coil at high pressure is sufficient. An ignition coil device for an internal combustion engine that can be easily secured and has a high output in a limited space can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the configuration of an ignition coil device for an internal combustion engine according to one embodiment of the present invention.

FIG. 2 is an exploded explanatory view showing a shape of a core used in the embodiment.

FIG. 3 is an explanatory diagram showing a cross section of a coil portion used in the above-mentioned embodiment, which is perpendicular to a concentric axis.

FIG. 4 is a longitudinal sectional view of an ignition coil device according to another embodiment of the present invention.

[Explanation of symbols]

1. Primary bobbin, 2. Primary coil, 3. Secondary bobbin, 4.
... Secondary coil, 5 ... Core, 5a ... Center core part, 5b,
5c: Bridge core portion, 8: Coil case.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyuki Tanaka 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Yoshiaki Shimadzu 4-6-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. F-term (for reference) 3G019 KC02 KC03 KC04 KC05

Claims (5)

[Claims] 1. An independent ignition type ignition coil device for an internal combustion engine which is mounted on a cylinder head of an internal combustion engine for each ignition plug of each cylinder, wherein a core forming a magnetic circuit is provided in a cylindrical case of the ignition coil device. Primary coil, 2 concentrically arranged outside
An ignition coil device for an internal combustion engine, wherein secondary coils are arranged such that their concentric axes are perpendicular to the central axis of the cylindrical case. 2. The internal combustion engine according to claim 1, wherein the cylindrical case is accommodated in each plug hole of a cylinder head, and a high-pressure side of a secondary coil is electrically connected to a spark plug in the plug hole. Ignition coil device. 3. The core according to claim 1, wherein the core comprises a center core portion which is a concentric axis of the primary coil and the secondary coil, and an upper bridge core portion and a lower bridge core portion which extend from both ends of the center core portion upward and downward. The center core portion and the upper bridge core portion, and the center core portion and the lower bridge core portion each form a closed magnetic path, and the primary coil and the secondary coil are arranged so as to fit in these closed magnetic paths. The ignition coil device for an internal combustion engine according to claim 1 or 2. 4. The apparatus according to claim 1, wherein the core, the primary coil, and the secondary coil are arranged concentrically in order from the inside.
The ignition coil device for an internal combustion engine according to any one of claims 1 to 3. 5. A plurality of assemblies of the core, the primary coil, and the secondary coil are arranged in series in the up-down direction in the cylindrical case.
An ignition coil device for an internal combustion engine according to claim 1.