JPH08339931A - Ignition coil for internal combustion engine - Google Patents

Abstract

PURPOSE: To provide an ignition coil for an internal combustion engine which has a primary and a secondary coil stored in a case filled with synthetic resin and which can be formed in such an outer shape as to correspond to the stored members. CONSTITUTION: This component has an upper case 30 which has openings 30a and 30b in a bottom and a side face, a primary coil 12 and a secondary coil 22 which are stored in the upper case, a secondary terminal 24 which is electrically connected to the secondary coil and which is located at the opening 30a side in the upper case, a lower case 40 which is joined to the opening 30a, and a high-voltage terminal 8 which is supported in the lower case. The upper case and the lower case are joined to each other and the high-voltage terminal 8 and the secondary terminal 24 are electrically connected and synthetic resin is put into the upper case 30 and the lower case 40 to fill the insides of these cases through the opening 30b which is formed in the side face of the upper 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 for an internal combustion engine, and more particularly to an ignition coil which houses a primary coil and a secondary coil in a first case and which is filled with a synthetic resin.

[0002]

2. Description of the Related Art An ignition coil for an internal combustion engine has a core wound with a primary coil and a secondary coil. The primary coil is connected to a control circuit for controlling a primary current through a connector, and the secondary coil is It is connected to a spark plug via a high voltage terminal. For example, in Japanese Unexamined Patent Publication No. 6-77066, a first core accommodated in a first case and a first core that is arranged at a predetermined position to form a magnetic path with the first core are disclosed. An ignition coil for an internal combustion engine, comprising: a second core; and a primary coil and a secondary coil wound around a second core; a primary bobbin that incorporates the second core and winds at least the primary coil; A connecting part, which is connected to the bobbin and has a primary terminal for connecting the winding of the primary coil, and a connector part, which is connected to this connecting part and has at least a connector terminal for connecting to the primary terminal, are integrally formed. To form a primary coil assembly, and dispose the primary coil assembly in the first case such that at least a part of the first core is located in a space defined by the primary bobbin, the connecting portion and the connector portion. To do Ignition coil has been proposed to. According to the ignition coil disclosed in the publication, the number of parts can be reduced, and the first core housed in the first case and the second core contained in the primary bobbin can be easily and appropriately joined. Therefore, it is possible to secure good assemblability as an ignition coil.

[0003]

In the ignition coil described in the above publication, the secondary connector portion for supporting the secondary side high voltage terminal, that is, the high voltage connector portion (also referred to as the high voltage tower portion) is formed integrally with the case. Has been done. Since the case is filled with the synthetic resin, an opening is provided on the upper surface side of the case opposite to the high-voltage connector section on the bottom surface side. The position and size of this opening are restricted by the relationship in the die-cutting direction when integrally molding the case and the high-voltage connector section, so that in the ignition coil described in the above publication, a useless portion is formed at the top of the case. To be done.

There is also known an ignition coil which is die-cut in the left-right direction and is provided with an opening only on the side surface of the case. In such an ignition coil, one side of the top is formed into the outer shape of the housing member. Although it can be formed into a curved surface shape, the other side cannot be formed into a curved surface and a useless portion is formed. Therefore, in these ignition coils, not only the resin material is wasted, but also it is difficult to reduce the size.

Therefore, in the present invention, in an ignition coil for an internal combustion engine in which a primary coil and a secondary coil are housed in a case and which is filled with a synthetic resin, an internal combustion engine which can be formed into an outer shape corresponding to a member housed in the case. An ignition coil is provided.

[0006]

In order to achieve the above-mentioned object, the present invention provides a first case of a housing having an opening on a bottom surface and a side surface as described in claim 1, and the first case. A primary coil and a secondary coil housed in the case, a secondary terminal electrically connected to the secondary coil and disposed on the opening side of the bottom surface in the first case, and the first case A second case joined to the opening on the bottom surface of, and a high-voltage terminal supported in the second case,
The second case is joined to the first case, the high-voltage terminal and the secondary terminal are electrically connected, and the first case is opened through an opening on a side surface of the first case.
And the second case is configured to be filled with the synthetic resin.

Further, in the ignition coil for an internal combustion engine according to claim 1, as described in claim 2, one end is connected to the secondary terminal and the other end is directed toward the opening of the bottom surface of the first case. It shall be equipped with a relay terminal extended to
The other end of the relay terminal may be electrically connected to the high voltage terminal.

[0008]

In the ignition coil for an internal combustion engine according to claim 1 of the present invention, the first case and the second case are joined together. First, the secondary terminal is electrically connected to the secondary coil housed in the first case together with the primary coil, and the secondary terminal is arranged on the opening side of the bottom surface of the first case. On the other hand, the high-voltage terminal is supported in the second case, the first case and the second case are joined together, and then the secondary terminal and the high-voltage terminal are electrically connected. Then, from the opening on the side surface of the first case to the first
And, when the second case is filled with the synthetic resin, the insulation property with respect to the primary coil, the secondary coil, and the electrical connection portion is secured. Thus, when the ignition coil for the internal combustion engine is configured and the primary current supplied to the primary coil is interrupted,
A change in magnetic flux occurs and a high voltage is induced in the secondary coil.

In the ignition coil for an internal combustion engine according to the second aspect, one end of the relay terminal is connected to the secondary terminal, the first case and the second case are joined together, and the other end of the relay terminal is high in voltage. It is electrically connected to the terminal. At this time, for example, a predetermined jig can be inserted from the opening 30b and the other end of the relay terminal can be press-fitted and connected to the high-voltage terminal, so that the connection work is easy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an ignition coil for an internal combustion engine of the present invention will be described below with reference to the drawings. 1 to 4 show an ignition coil for an internal combustion engine of a simultaneous ignition system (also called a double ignition system) according to an embodiment of the present invention.
The upper case 30 and the lower case 40 are joined together.
FIG. 5 shows the configuration of the upper case 30 side, and the secondary coil assembly 20 is assembled to the primary coil assembly 10 and housed in the upper case 30. 6 to 9 show the configuration of the lower case 40 side, and the upper case 3
When bonded to 0, it becomes as shown in FIG.

The upper case 30 constitutes the first case according to the present invention, and has a bottom surface (lower case 40 as shown in FIG. 1).
And the openings 30a, 30 on one side surface.
A housing made of synthetic resin, for example, polybutylene terephthalate (PBT) having b, the core 3 is integrally housed by insert molding. Then, as shown in FIG. 5, the primary coil assembly 10 and the secondary coil assembly 20 are housed in the recess 30 h formed inside the core 3. In FIG. 5, a high voltage connector portion 31 is formed so as to extend on a side surface of the upper case 30 facing the opening portion 30b, and one high voltage terminal 7 is accommodated therein. Further, an opening 30c into which the support portion 15 of the primary coil assembly 10 is fitted is formed on the other side surface of the upper case 30, and a flange portion 33 is formed so as to extend on the opposite side thereof. The collar 3 is formed on the flange portion 33 by insert molding.
4 is buried.

The primary coil assembly 10 is shown in FIGS.
It is configured as shown by cutting off a part of it. That is, the primary bobbin 11 in which the core 2 is integrally housed by insert molding is provided, and the primary coil 1 is attached to the primary bobbin 11.
The two windings are wound in two layers or four layers to form the primary coil assembly 10. Further, the primary bobbin 11 has a support portion 15 in which the primary terminals 6a and 6b are planted.
And the connector 16 are integrally formed.

The secondary coil assembly 20 comprises a secondary bobbin 21 and a secondary coil 22 wound around the secondary bobbin 21. Secondary bobbin 2
Reference numeral 1 denotes a resin cylindrical body having a substantially rectangular cross section in which a plurality of collar portions 21a are formed at predetermined intervals in the axial direction. These collar portions 21a
The windings of the secondary coil 22 are sequentially wound from the upper side to the lower side in FIG. 5 in a plurality of grooves formed therebetween. Since the present embodiment is a simultaneous ignition type ignition coil, the secondary bobbin 21
Both ends of the collar portion 21a are wide collar portions 21d and 21e, and secondary terminals 23 and 24 are planted in these collar portions 21d and 21e as shown in FIG.

Both ends of the winding of the secondary coil 22 are wound around the secondary terminals 23 and 24 planted in the collar portions 21d and 21e at both ends, and the relay terminals 2 are respectively wound around these windings.
5, 26 are connected. One secondary terminal 23
Is connected to one end of a relay terminal 25, and the other end is connected to one high-voltage terminal 7. A relay terminal 26 is joined to the other secondary terminal 24 and extends substantially parallel to the axis of the secondary bobbin 21 as shown in FIG. 1, and the lower case 40 is connected to the upper case 3 as described later.
When assembled to 0, this relay terminal 26
It is connected to the other high-voltage terminal 8 provided on the lower case 40.

An opening 30b is formed on one side surface of the upper case 30 as shown in FIGS. 1 and 3, and is supported by an opening 30c (FIGS. 1 and 5) formed on the other side surface. The part 15 is fitted. The connector 16 has primary terminals 6a and 6b extending into the upper case 30, and is electrically connected to an external connector (not shown) outside the upper case 30. The ends of the primary terminals 6a and 6b are folded back, and both ends of the winding of the primary coil 12 are connected.

A lower case 40 made of synthetic resin, which constitutes the second case of the present invention, is joined to the upper case 30. The lower case 40 includes a lid portion 40a and a tubular portion 40b which extends in a direction perpendicular to the surface of the lid portion 40a and constitutes a high voltage connector portion. As shown in FIGS. 8 and 9, three ribs 41 to 43 are provided at the tip of the tubular portion 40b.
Is formed, and the base end portion 8b of the high-voltage terminal 8 is supported by these three ribs 41 to 43. That is, as shown in FIG. 8, the shaft-shaped high-voltage terminal 8
Is disposed on the axial center of the cylindrical body portion 40b and is insert-molded, and the boss portion 8a formed at one end slightly projects from the lid body portion 40a (joint surface with the upper case 30). The base end portion 8b is supported by the tubular portion 40b.

In assembling each part of the ignition coil having the above-described structure, first, the secondary coil assembly 20 is assembled to the primary coil assembly 10 and one end of the winding of the primary coil 12 is connected to the primary terminal. 6a, and the other end is electrically connected to the primary terminal 6b. Specifically, as shown in FIGS. 1 and 5, both ends of the winding of the primary coil 12 are held by the bent portions of the primary terminals 6a and 6b, respectively, and welded.
These connections are made before the primary coil assembly 10 and the secondary coil assembly 20 are housed in the upper case 30, and thereafter, as shown in FIG.
The support portion 15 is fitted into the opening portion 30c of the, and the core 2, the primary coil assembly 10, and the secondary coil assembly 20 are housed in the recess 30h.

Then, the upper case 30 and the lower case 4
When 0 is joined, it becomes as shown in FIG. As this joining means, any means such as a snap-fit structure, an adhesive, and heat caulking may be used. In this way, the upper case 30
After the lower case 40 is joined to the lower case 40, a predetermined jig is inserted from the opening 30b, whereby the relay terminal 26
The connecting portion 26c at the tip of the boss 8a of the high-voltage terminal 8
Is pressed into. Then, via the relay terminal 26,
The secondary terminal 24 and the high voltage terminal 8 are electrically connected.

Thereafter, the opening 30b of the upper case 30 is formed.
From the above, the spaces in the upper case 30 and the lower case 40 are filled with a thermosetting synthetic resin, for example, an epoxy resin, and cured to form the resin portion 9 as shown by the dotted lines in FIG. Thereby, the upper case 30 and the lower case 40 are firmly joined, the primary coil 12 and the secondary coil 22 are impregnated and fixed, and the secondary terminals 23 and 24, the relay terminals 25 and 26, and the high voltage terminals 7 and 8 are connected. Each electrical connection is properly insulated, and further, the insulation that can withstand the high output voltage of the secondary coil 22 is secured. In particular, since the resin is also filled in the tubular portion 40b of the lower case 40 and the resin portion 9 is formed around the high voltage terminal 8 (not shown in FIG. 1), good insulation is achieved over the entire length of the high voltage terminal 8. Can be secured.

Thus, a simultaneous ignition type ignition coil for an internal combustion engine is formed and mounted on an internal combustion engine (not shown), and the base end 8b of the high-voltage terminal 8 is directly connected to one ignition plug (not shown). At the same time, the high voltage terminal 7 is connected to another ignition plug (not shown) through a high tension cord (not shown). And the primary coil 1
When the primary current of 2 is interrupted, a counter electromotive force is induced in the secondary coil 22 and a high voltage of 30 to 40 kv is generated. This high voltage is output to the spark plug (not shown) via the secondary terminals 23 and 24 and the high voltage terminals 7 and 8, respectively. As a result, a high voltage is individually applied to each spark plug, spark discharge is generated in each electrode portion, and the compressed air-fuel mixture in each combustion chamber (not shown) is ignited.

As described above, according to this embodiment, the opening 30b on the side surface is provided for resin injection, and the upper case 30 is provided.
Since both sides of the top can be formed into a curved outer shape corresponding to the shapes of the primary coil 10 and the secondary coil 20 accommodated in the interior, compared to a conventional ignition coil having an opening only on the side surface, The shaded portion in FIG. 4 can be omitted, resulting in a smaller size. The opening 30b is also provided as a working hole, and a jig can be inserted through the opening 30b when the relay terminal 26 is connected to the high-voltage terminal 8. Therefore, the connection work is easy. Although this embodiment relates to a simultaneous ignition type ignition coil having two high voltage terminals 7 and 8, it can also be applied to a normal internal combustion engine ignition coil. In this case, the high voltage terminal 7 is used. , 8 is used, and either one of the relay terminals 25, 26 is used accordingly.

[0022]

Since the present invention is constructed as described above, it has the following effects. That is, claim 1 of the present invention
In the ignition coil for an internal combustion engine according to the first aspect, the second case is joined to the first case to electrically connect the high-voltage terminal and the secondary terminal, and the first case is provided with an opening from a side surface of the first case. Since the second case is configured to be filled with the synthetic resin, it can be formed into an outer shape corresponding to the shapes of the primary coil, the secondary coil, etc. housed in the first and second cases, Further miniaturization is possible.

In the ignition coil for an internal combustion engine according to a second aspect, one end is connected to the secondary terminal and the other end is provided with a relay terminal extending toward the opening of the bottom surface of the first case, and the other end is provided. Is electrically connected to the high-voltage terminal, the electrical connection can be made easily and surely, and good workability can be secured.

[Brief description of drawings]

FIG. 1 is a partial sectional front view of an internal combustion engine ignition coil according to an embodiment of the present invention.

FIG. 2 is a plan view of an internal combustion engine ignition coil according to an embodiment of the present invention.

3 is a sectional view showing a part of an ignition coil for an internal combustion engine according to an embodiment of the present invention, which is a sectional view taken along the line AA of FIG.

FIG. 4 is a side view of an internal combustion engine ignition coil according to an embodiment of the present invention.

FIG. 5 is a partial cross-sectional bottom view of the upper case portion according to the embodiment of the present invention.

FIG. 6 is a side view of a lower case portion according to the embodiment of the present invention.

FIG. 7 is a bottom view of a lower case portion according to the embodiment of the present invention.

FIG. 8 is a cross-sectional view of a lower case portion in one embodiment of the present invention, which is a cross-sectional view taken along line BB of FIG.

9 is a cross-sectional view of a lower case portion according to the embodiment of the present invention, which is a cross-sectional view taken along line CC of FIG.

[Explanation of symbols]

2,3 Cores 6a, 6b Primary terminal 7,8 High voltage terminal 9 Resin part 10 Primary coil assembly 11 Primary bobbin 12 Primary coil 15 Support part 16 Connector 20 Secondary coil assembly 21 Secondary bobbin 22 Secondary coil 23,24 Secondary Terminal 25, 26 Relay terminal 30 Upper case 30a, 30b, 30c Opening 31 High-voltage connector part 33 Flange part 40 Lower case, 40a Lid part, 40b Cylindrical part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Hitoshi Takeuchi, 1-1-1-1, Kyowa-cho, Obu-shi, Aichi Aisan Industry Co., Ltd.

Claims (2)

[Claims] 1. A first case of a housing having openings on a bottom surface and side surfaces, a primary coil and a secondary coil housed in the first case, and an electrical connection to the secondary coil, A secondary terminal arranged in the first case on the side of the opening of the bottom surface, a second case joined to the opening of the bottom surface of the first case, and a high-voltage terminal supported in the second case. And connecting the second case to the first case to electrically connect the high-voltage terminal and the secondary terminal, and through the opening on the side surface of the first case to the first and the second cases. 2. An ignition coil for an internal combustion engine, characterized in that the case 2 is filled with a synthetic resin. 2. A relay terminal, one end of which is connected to the secondary terminal and the other end of which extends toward the opening of the bottom surface of the first case, the other end of which is electrically connected to the high-voltage terminal. The ignition coil for an internal combustion engine according to claim 1, wherein the ignition coil is configured to be connected to the.