JP3518360B2 - Ignition coil for internal combustion engine - Google Patents

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 used in an internal combustion engine of an automobile or the like, and in particular, an ignition coil for an internal combustion engine of an independent ignition type provided for each cylinder of the internal combustion engine. Regarding

[0002]

BACKGROUND ART As an ignition coil for an internal combustion engine of this type, there is one having the following configuration.

That is, the ignition coil has a substantially disk-shaped primary coil portion formed by winding a primary coil winding and a substantially disk-shaped primary coil portion formed by winding a secondary coil winding. The secondary side coil portion and the secondary side coil portion are laminated and arranged so that their respective cores are aligned on the same straight line, and a flat coil body is provided.
Then, a pair of cross iron core portions are attached so as to sandwich the coil body from both sides thereof, whereby a closed magnetic circuit passing from the central portion of the coil body to the four outer circumferences is formed. In this way, the coil body with the cross iron core attached is
It is configured to be housed in a case body and attached to an upper opening of a plug hole formed in a cylinder head of an internal combustion engine.

This ignition coil is desired to have a small height and to prevent interference between adjacent ignition coils and to obtain a sufficiently large secondary energy to ignite the air-fuel mixture in the cylinder of the internal combustion engine. It was in response to the request.

[0005]

By the way, in the ignition coil having the above-mentioned structure, the secondary high voltage generated in the secondary coil portion is transmitted through the high voltage terminal portion provided in the bottom portion of the case body. It is applied to the ignition plug at the bottom of the plug hole.

In this case, it is necessary to electrically connect the secondary coil winding and the high-voltage terminal portion inside the case body. However, this ignition coil is required to have a small height. Therefore, a compact structure that can contribute to the reduction of the height of the ignition coil is required as the structure for connecting the secondary coil winding and the high voltage terminal.

Therefore, the present invention has been made to solve the above problems, and an ignition coil for an internal combustion engine capable of connecting the secondary coil winding and the high-voltage terminal portion with a more compact structure. The purpose is to provide.

[0008]

In order to solve the above problems, an ignition coil for an internal combustion engine according to claim 1 of the present invention has a secondary coil winding between a pair of upper and lower flange portions formed on a bobbin. A substantially disk-shaped secondary side coil part formed by winding a coil, and a substantially disk-shaped primary side coil part formed by winding a primary side coil winding. Is disposed on the upper collar portion and finished to be flat, a case body having an opening formed in the upper portion and accommodating the coil body therein, and a substantially central portion of the bottom portion of the case body. A connecting portion vertically extending downward and one end embedded in the bottom of the case body so as to project into the case body to serve as an engaging connection portion and the other end projectingly disposed in the connection portion. Embedded terminal that is a high-voltage terminal for connection with a spark plug, and Attached to the lower surface of the portion, one end of which serves as a coil connecting portion for connecting the secondary coil winding, and the other end of which is an engaged connected portion for connection with the engaging connecting portion of the embedded terminal. And an engaged connection part of the embedded terminal and an engaged connection part of the coil terminal are opposed to each other in a state where the coil body is housed in the case body. Alternatively, it is bent and bent so as to project downward, and slit-shaped notches are formed at the respective tip portions, and the engagement connection portion and the cover are formed by accommodating the coil body in the case body. The engaging connection portion is configured to be electrically connected to each other so that the respective cutout portions mesh with each other.

According to a second aspect of the present invention, the coil terminal is separated between the coil connecting portion and the engaged connecting portion, and a pair of the separating ends is below the lower flange portion. It may be bent and bent toward and the notch portion for sandwiching the lead of the electronic component may be formed at the tip end portion thereof.

According to a third aspect of the present invention, a pair is formed in a substantially cross shape and is attached so as to sandwich the coil body from both upper and lower surfaces to form a closed magnetic path extending from the central portion of the coil body to the four outer peripheral sides. When the cross iron core portion is provided, the coil terminal may be provided on the lower surface of the lower collar portion and at the non-attachment position of the cross iron core portion.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An ignition coil for an internal combustion engine according to an embodiment of the present invention will be described below.

As shown in FIG. 1, the ignition coil 10 for an internal combustion engine is a so-called upper type which is installed and used above an opening of a plug hole Ha formed in a cylinder head H of an internal combustion engine. As shown in, a coil case 20A with an iron core is housed and arranged in a case body 12 made of resin.

In the coil portion 20A with an iron core, as shown in FIGS. 2 to 4, a substantially disk-shaped primary coil portion 45 and a substantially disk-shaped secondary coil portion 40 are arranged in the longitudinal direction. Cross core parts 30A and 30B are formed on both upper and lower surfaces of the flat coil body 20.
Is installed.

Here, FIG. 11 shows an example of connection of the ignition coil 10. As shown in FIG. 11, the ignition coil 10 has an enamel wire wound around its primary coil portion 45. One end is pulled out from the case body 12 and electrically connected to the positive terminal of the battery B of the automobile.
The negative terminal of the battery B is grounded.
The other end of the enamel wire wound around the primary coil portion 45 is grounded via the case body 12 or a switching element S such as a power transistor provided outside the case body 12. The switching element S is ON / OFF controlled by receiving an ignition signal from an ECU or the like provided in the vehicle, so that the primary voltage from the battery B is intermittently applied to the primary coil portion 45. Composed. Further, one end of the enameled wire wound around the secondary coil portion 40 is electrically connected to one end of the enameled wire wound around the primary coil portion 45 in the case body 12. On the other hand, the other end of the enamel wire wound around the secondary coil portion 40 is
It is electrically connected to the spark plug P through the joint member 8 in the plug hole Ha. Then, when the primary voltage is intermittently applied to the primary coil portion 45, a high voltage is induced in the secondary coil portion 40 by electromagnetic induction, and this high voltage is applied to the ignition plug P, and the ignition plug concerned. P is sparked.

Returning to FIGS. 1 to 4, the ignition coil 10
First, the coil body 20 will be described.
As shown in FIGS. 2 to 4, the bobbin 22 is equipped with a primary coil portion 45 and a secondary coil portion 40.

The bobbin 22 is formed by forming a pair of flange portions 24 and 25 that spread in the radial direction at the lower end portion of a bobbin main body portion 23 having a short rectangular tube shape and at an axially intermediate portion thereof.

Each of the collar portions 24 and 25 is formed in a substantially rectangular plate shape that matches the internal shape of the case body 12, and the lower surface of the lower collar portion 24 of the collar portions 24 and 25 is as shown in FIGS. 7 and 8. The coil terminal 60 is attached.

The coil terminal 60 is formed by punching a thin metal plate into a substantially strip shape with its middle portion bent. The bent piece on the one side is arranged along the line connecting the corners of the central portion of the collar portion 24, and the bent piece on the other side is extended outward from the corner of the collar portion 24. The coil terminal 60 is attached to the lower surface of the collar portion 24.

Of the both ends of the coil terminal 60, the collar portion 2
The end portion on the side extending outward from 4 is a coil connecting portion 62 having a thread winding cross-section, and the other end portion of the enamel wire of the secondary side coil portion 40 described later is wound around this coil connecting portion 62. Configured as possible. In addition, the ends of the coil terminal 60 on both sides of the central portion of the collar portion 24 of the both ends are the collar portion 24.
Is bent and bent substantially vertically in the middle of a central portion of the shaft and a corner thereof to be an engaged connection portion 64 for connection with an engagement connection portion 72 described later. This engaged connection portion 64
A vertical slit-shaped cutout portion 65 is formed at the tip of the cutout portion, and the opening portion of the cutout portion 65 is finished as a guide portion 65a that is slightly inclined outward.

The coil terminal 60 may be attached to the collar portion 24 by, for example, pre-insert molding the coil terminal 60 in the collar portion 24, or forming a hole in the coil terminal 60. A pin-shaped convex portion that can be inserted into the hole is formed on the flange portion 24 side, and the tip end portion of the pin-shaped convex portion is melted and crushed in a state where the pin-shaped convex portion is fitted into the hole of the coil terminal 60, or , A structure of adhering with an adhesive, and the like.

As a metal forming the coil terminal 60, a high copper alloy (for example, a copper alloy containing a small amount of Ni--Si, Be, etc. added) is desirable. This is excellent in strength and stress relaxation because the ignition coil using the coil terminal 60 is installed in a high temperature environment on the cylinder head and is pressure-contacted with an engagement connection portion 72 described later. Is required.

The position where the coil terminal 60 is attached is a portion from one corner of the collar portion 24 to the central portion thereof, that is, a non-attachment position of cross core portions 30A and 30B described later.

As shown in FIGS. 2 to 4, the secondary coil portion 40 is formed in a substantially disc shape by winding an enameled wire as a secondary coil winding between the collar portions 24 and 25. (See FIG. 5 for the winding form). At this time, the ends of the winding and the ending of the enameled wire are pulled out from between the collar portions 24 and 25. The enamel wire used for the secondary coil portion 40 has a general structure in which an enamel paint is applied to the surface of a copper wire having a substantially circular cross section.

More specifically, the wire diameter is 0.04 to 0.1.
It is advisable to wind the enamel wire having a diameter of 8000 times 8000 to 15000 times to form the secondary coil portion 40.

Further, the upper end of the bobbin main body portion 23 projects above the upper collar portion 25, and the primary side coil portion 45 is attached thereto.

The primary coil portion 45 is a rectangular strip-shaped enameled wire formed by applying enamel paint to the surface of a rectangular strip-shaped copper wire having a vertically-elongated substantially rectangular shape as the primary coil winding.
By winding so as to be stacked in the thickness direction, it is finished in a substantially disc shape (see FIG. 6 for winding form). At the center of the primary coil portion 45, the bobbin body 23
Is formed with a substantially rectangular hole that can be inserted through the upper end of the.

The surface of the enamel wire used for the primary side coil portion 45 is coated with a thermosetting paint, which can be wound under heating or by heating after winding. The enamel wire is solidified in the form of being wound into a substantially disc shape.

More specifically, it is preferable to form the primary side coil portion 45 by winding a flat strip enameled wire rolled in the range of 1:15 to 1:35 90 to 180 times in the radial direction.

Here, the reason why the flat coil enameled wire is used for the primary coil portion 45 will be described.

For example, as shown in FIG. 5 (a cross section of one half of the coil is shown), when an enameled wire 90 having a substantially circular cross section is used, how densely the enameled wire 90 is
Even if it is wound, a useless space is created between the wound enamel wires. This invites an increase in the size of the primary side coil portion and is also a factor that hinders the dissipation of heat generated there.

On the other hand, like the present ignition coil, when a flat rectangular strip is used as the enamel wire 92 and the enamel wire is wound so as to be stacked in the thickness direction,
As shown in FIG. 6 (showing the shape of one half of the coil),
The enamel wire 92 can be tightly wound without a gap, the primary side coil portion 45 can be downsized, and the ignition coil can be thinned and the diameter thereof can be reduced, and the heat transfer property of heat generated there can be improved. This is because the heat dissipation is excellent.

The primary side coil portion 45 constructed in this way
Is arranged on the upper surface side of the collar portion 25 such that the upper end portion of the bobbin main body portion 23 is inserted into the hole portion of the central portion thereof, so that the primary side coil portion 45 and the secondary side coil portion 40 respectively have The winding cores are stacked so that they are aligned on the axis of the bobbin main body 23, whereby the flat coil body 20 is formed.

Here, the flat coil body 20 has a height dimension of 10 to 25 mm, and a height dimension and a width dimension (minimum width dimension; in the embodiment, a length dimension of one side of the collar portions 24, 25).
Ratio of 1: 2 to 1: 6, more preferably 1: 3 to 1:
It is desirable to be within the range of 5. Maximum height is 2
The reason why the size is 5 mm is that the coil body 2 having a height higher than this is used.
This is because assuming that 0 is housed in the case body 12, the case body 12 generally interferes with other intake and exhaust system components in the vicinity of the cylinder head H. Also, the lower limit is 10 m
The reason for setting m is that the mounting space is taken into consideration when the case body 12 accommodating the coil body 20 is provided with accessories such as the connector portion 15, the fixing portion 16 and the switching element.

Then, both ends of the enamel wire wound around the primary side coil portion 45 and both ends of the enamel wire wound around the secondary side coil portion 40 are drawn out to the outside of the coil body 20, respectively. One end of the enamel wire of the side coil portion 45 and one end of the enamel wire of the secondary coil portion 40 are electrically connected to each other at the position of the outer peripheral edge of the collar portion 25 (not shown).

As shown in FIGS. 2 to 4, cruciform iron core portions 30A and 30B are attached to the upper and lower surfaces of the coil body 20 thus constructed, respectively.

The cross core portion 30B is formed by combining the substantially U-shaped iron core portions 31B and 35B formed by laminating electromagnetic steel plates in a substantially cross shape so that their intermediate portions intersect each other. At this time, a groove is formed in each of the overlapping portions of the respective iron core portions 31B and 35B, and the two iron core portions 31B and 35B are combined so that the groove portions on the other side are fitted to each other. The thickness dimension is kept small.

The iron core portion 31B arranged on the lower side at the intersection of the iron core portions 31B and 35B has a triangular prism shape having a taper surface inclined downward in the longitudinal direction of the iron core portion 31B on the lower surface side of the intersection. Core portion 34B is formed. The core portion 34B is adapted to be inserted into the bobbin main body portion 23 from above with the cross core portion 30B attached to the upper surface side of the coil body 20.

On the other hand, the lower cross iron core portion 30A has an upside down shape with respect to the upper cross iron core portion 30B, that is, the substantially U-shaped iron core portions 31A and 35A are formed in the middle portion thereof. A core portion 34A is formed on the upper surface side of the iron core portion 35A arranged on the upper side at the intersecting portions by intersecting at the groove portions and combining in a substantially cross shape.

The core portion 34A is also inserted into the bobbin main body portion 23 from below with the cross iron core portion 30A attached to the lower surface side of the coil body 20.

Further, these cross iron core portions 30A, 30B
In a state in which the coil body 20 is attached to both upper and lower surfaces of the coil body 20, the four upward end surfaces of the iron core portions 31A and 35A located on the lower side and the four downward end surfaces of the iron core portions 31B and 35B located on the upper side are The outer circumferences of the coil bodies 20 are configured to come into contact with each other.

Further, the tapered surfaces of the core portions 34A and 34B are provided in the bobbin main body portion 23 with permanent magnets 5 to be described later.
They are arranged in parallel with each other with an interval that can accommodate 0.

With these cross core portions 30A and 30B,
Four closed magnetic paths that pass from the central portion of the coil body 20 to the four outer circumferences are formed.

Here, the cross core portions 30A and 30B are
As the iron core portions 31A, 35A, 31B and 35B, those formed by laminating silicon plywood having a plate thickness of 0.1 to 0.5 mm in a substantially U-shape may be used, and the core portion 34A of the closed magnetic circuit, 34B has an inner magnetic path having a cross-sectional area of 100 to 32.
As a 4 mm ^2, further cross core portions 30A, 3
It is preferable that the total cross-sectional area of the four outer magnetic paths formed around the outer circumference of the coil body 20 by 0B be 100 to 324 mm ² .

It should be noted that, as described above, each core portion 3 with the two cross core portions 30A and 30B attached to the coil body 20.
A gap having a predetermined interval is formed between 4A and 34B, and a permanent magnet 50 that applies a reverse bias to the cross core portions 30A and 30B is arranged in this gap.

As shown in FIGS. 3 and 4, the upper surface of the primary side coil portion 45 exposed on the upper surface side of the coil body 20 and the cross core portion 30 disposed on the upper surface side of the coil body 20.
A pair of insulating spacers 42 are interposed between the B core portion 35B and the iron core portion 35B.

The both insulating spacers 42 are made of an insulating material and are provided at respective positions sandwiching the bobbin main body 23 from both sides thereof. With this insulating spacer, the cross iron core portion 30B is attached to the primary side coil portion 45 with a sufficient insulation distance maintained therebetween.

As shown in FIGS. 2, 9 and 10, the case body 12 is formed in a flat box shape with a square bottom surface and an open top, and four substantially L-shaped inner bottom surfaces 12a. Ridges 13a of the cross core portion 3a are formed in such a manner that their vertices face each other with a predetermined gap therebetween.
A cross-shaped positioning groove 13 for fitting and positioning 0A is formed.

Further, as shown in FIGS. 9 and 10, at the center of the lower surface of the case body 12, a connecting portion 14 having a slightly tapered lower end is vertically provided.

Here, the reason why the connecting portion 14 is formed in the central portion of the case body 12 will be explained. This is due to abnormal vibration of the case body 12 (resonance due to vibration of the internal combustion engine and the connecting portion 14). To prevent case vibration)
This is to prolong the life of the second grade product. For example, when the connecting portion 14 is formed at one corner of the case body 12, the case body 12 is attached to the cylinder head H via the connecting portion 14, and therefore the vibration of the internal combustion engine causes the case body 12 to be attached. 12 will vibrate greatly.
However, when the connecting portion 14 is formed in the central portion of the case body like the ignition coil, the connecting portion 14 can be mounted as a mounting portion in a well-balanced manner, so that the large vibration as described above is prevented. Because it is done.

The embedded terminal 70 is embedded in the bottom of the case body 12 by insert molding.

The embedded terminal 70 is formed into a substantially strip shape by punching a thin metal plate so that both ends thereof are bent in opposite directions. The middle portion is the bottom portion of the case body 12 and is embedded in a portion from the center portion to a point halfway.

Of the both ends of the embedded terminal 70, one end of the case body 12 on one corner side is bent substantially vertically upward at a position corresponding to the engaged connection portion 64, and the case body 12 is bent.
The engaging connection portion 72 is arranged so as to project inside. In addition, a slit-shaped notch 73 is formed in the upper end portion of the engagement connection portion 72 along the vertical direction, and the engagement connection portion 72 and the engaged connection portion 64 are seen in a plan view. The positional relationship is such that the formation positions of the cutouts 73 and 65 intersect each other (see FIG. 10). When the coil portion 20A with the iron core is housed in the case body 12, the engaged connecting portion 64 and the engaging connecting portion 72 are electrically connected to each other such that the cutout portions 73 and 65 mesh with each other. Is configured to be.

Of the both ends of the embedded terminal 70, the end on the side of the central portion of the case body 12 is bent downward substantially vertically and is arranged so as to project from the bottom lower surface of the case body 12 into the connecting portion 14. And is used as a high voltage terminal portion 74. Then, when the upper end portion of the joint member 8 is externally fitted to the connection portion 14, the high voltage connection terminal 7 housed inside the joint member 8 is electrically connected to the high voltage terminal portion 74 via the spring 6. ing.

As a metal forming the embedded terminal 70, a high copper alloy (for example, a copper alloy to which a small amount of Ni--Si, Be or the like is added) is desirable for the same reason as in the case of the coil terminal 60.

Next, the method of assembling the ignition coil will be described. As shown in FIG. 7, the other end 40a of the enamel wire of the secondary coil portion 40 is connected to the coil connecting portion 62 of the coil terminal 60.
It is wound around, and soldering, spot welding, laser welding or the like is applied to the connection portion thereof. Then, in a state where the coil portion 20A with an iron core is assembled, the cross iron core portion 30A on the lower surface side is positioned and housed in the positioning groove portion 13 in the case body 12, and the coil portion 20A with an iron core is housed in the case body 12. At this time, the engaged connection portion 6 of the coil terminal 60
4 and the notch portions 73 and 65 of the engaging connecting portion 72 of the embedded terminal 70 mesh with each other, so that the engaged connecting portion 64 and the engaging connecting portion 72 are electrically connected to each other. In this way, the coil portion 20A with the iron core is attached to the case body 12
After being housed inside, a liquid insulating resin is injected and filled into the case body 12 so that the coil portion 20A with an iron core is immersed, and then heat treatment is performed to solidify. Thereby, the coil portion 20A with the iron core is fixed to the case body 12. At this time, as described above, the upper surface of the primary coil portion 45 and the cross core portion 30B are
Since the insulating spacer 42 is interposed between and, the insulating resin is injected between the primary side coil portion 45 and the cross iron core portion 30B with a sufficient insulating distance secured therebetween. It In addition, as described above, the primary coil portion 45
Since the insulating resin is injected between the cross core portion 30B and the cross core portion 30B, the insulating resin sufficiently penetrates into the layers of the enamel wire of the primary side coil portion 45. Thus, the insulation between the primary coil portion 45 and the cross core portion 30B is excellent, and the primary coil portion 45 can be prevented from losing its shape and can be positioned and fixed reliably. Further, since the primary coil portion 45 is pressed downward via the insulating spacer 42, the reliability of the positioning and fixing of the primary coil portion 45 can be increased in this respect as well.

In the ignition coil for an internal combustion engine configured as described above, the coil body 20 is formed by stacking the substantially disk-shaped primary side coil portion 45 and the substantially disk-shaped secondary side coil portion 40. Since it is formed, it is possible to obtain sufficiently large secondary energy to ignite the air-fuel mixture in the cylinder of the internal combustion engine. Further, since the shape of the coil body 20 is a flat shape formed by stacking the primary side coil portion 45 and the secondary side coil portion 40, the height dimension thereof is reduced and the coil body 20 is provided adjacently. Interference between the ignition coils can also be prevented.

Then, at the bottom of the case body 12, one end is arranged so as to project into the case body 12 to form an engaging connecting portion 72, and the other end is arranged so as to project into the connecting portion 14 to form an ignition plug P. Embedded terminal 7 which is a high voltage terminal portion 74 for connecting
On the other hand, on the lower surface of the lower collar portion 24, one end is a coil connecting portion 62 for winding and connecting a secondary coil winding, and the other end side is an embedded terminal 70. By attaching the coil terminal 60, which is the engaged connection portion 64 for connection with the engagement connection portion 72, by connecting the engagement connection portion 72 of the embedded terminal 70 and the engaged connection portion 64 of the coil terminal 60. Since the secondary coil winding is electrically connected to the high-voltage terminal portion 74, the connection structure is more compact and contributes to reducing the height dimension of the ignition coil.

Further, the engaging connecting portion 72 of the embedded terminal 70 and the engaged connecting portion 64 of the coil terminal 60 are opposed to each other in the state where the coil portion 20A with the iron core is housed in the case body 12. Bending upwards or downwards, forming notches 73 and 65 at the respective tip portions, and accommodating the coil portion 20A with the iron core in the case body 12 allows the engagement connection portion 72 and the engaged connection portion. Since the notch portions 73 and 65 are electrically connected to each other so that the notch portions 73 and 65 mesh with each other, only the coil portion 20A with the iron core is housed in the case body 12, the secondary side The coil winding is electrically connected to the high-voltage terminal portion 74, which facilitates the connection work.

Further, since the coil terminal 60 is provided at one corner side of the lower surface of the collar portion 24, that is, at the non-attachment position of the cross iron core portion 30A, the non-attachment space of the cross iron core portion 30A which is originally a dead space. Is effectively utilized, the secondary side coil winding and the high voltage terminal portion 74 are electrically connected.

Some ignition coils for internal combustion engines have a structure in which a rectifying diode D is interposed between a secondary coil winding and an ignition plug P, as shown in FIG. Of the high voltage induced in the secondary coil section 40, the diode D only allows the voltage in one direction to ignite.
It is for applying to.

In such a case, the ignition coil shown in the modification of FIG. 13 may be used.

That is, in the ignition coil of this modified example, of the two bending pieces of the coil terminal 60B mounted on the lower surface of the collar portion 24, the bending piece on the central side of the coil body 20 is separated at the intermediate portion in the longitudinal direction. At the same time, the two separated ends are the collar portions 24.
Is bent and bent almost vertically downward to form a diode connecting portion 66. A slit-shaped holding notch 67 is formed at the tip of each of the diode connecting portions 66, and a pair of lead portions DL of the diode D can be held in each holding notch 67. Then, the lead portions DL are soldered to the diode connecting portions 66 in a state where the lead portions DL are inserted into the sandwiching cutout portions 67, respectively. As a result, it becomes possible to insert an electronic component such as the diode D between the secondary coil portion 40 and the spark plug P.

[0063]

As described above, according to the ignition coil for an internal combustion engine according to the first aspect of the present invention, one end of the case body is projectingly disposed in the bottom of the case body to form an engaging connection portion, and the other. The embedded terminal, which has a high-voltage terminal for connecting to the spark plug and whose end is projectingly arranged in the connecting portion, is embedded, and one end is connected to the secondary coil winding on the lower surface of the lower collar portion. And a coil terminal whose other end is an engaged connection portion for connection with the engaging connection portion of the embedded terminal, and the engaging connection portion of the embedded terminal and the coil terminal are attached. The secondary side coil winding is electrically connected to the high-voltage terminal by connecting with the engaged connection part of, so the connection structure becomes more compact, and the height dimension of this ignition coil is reduced. Contribute to making it smaller.

Further, the engaging connection portion of the embedded terminal and the engaged connection portion of the coil terminal may be projected upward or downward at positions where they are opposed to each other with the coil body housed in the case body. By bending and raising to form a notch at each tip, and the coil body is housed in the case body, the engaging connection part and the engaged connection part engage each other notch part and electrically connect to each other. Therefore, if the coil body is placed in the case body, the secondary coil winding and the high-voltage terminal portion are electrically connected, which facilitates the connection work.

Further, as described in claim 2, the coil terminal is separated between the coil connecting portion and the engaged connecting portion, and both separated ends thereof are bent and bent downward from the lower flange portion. At the same time, by forming a notch for holding the lead of the electronic component at the tip end thereof, the secondary side coil winding has a compact structure while inserting an electronic component such as a diode between the secondary side coil and the ignition plug. It is possible to electrically connect the high voltage terminal portion and the high voltage terminal portion.

Further, when a pair of cross-shaped iron core portions formed in a substantially cross shape are mounted so as to sandwich the coil body from both upper and lower surfaces as described in claim 3, the coil terminal is attached to the lower side. If it is provided on the lower surface of the collar portion and at the non-attachment position of this cross iron core portion, the non-attachment space of the cross iron core portion, which is originally a dead space, is effectively utilized, and the secondary coil winding and the high voltage terminal portion are Electrical connection is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a mounted state of an internal combustion engine ignition coil according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the above ignition coil.

FIG. 3 is an exploded perspective view of a coil body.

FIG. 4 is a cross-sectional view of a coil body.

FIG. 5 is a cross-sectional view showing a comparative example.

FIG. 6 is an enlarged cross-sectional view of a primary coil portion.

FIG. 7 is an enlarged bottom view of the main parts of the coil body.

FIG. 8 is a development view of coil terminals.

FIG. 9 is a cross-sectional view of a case body.

FIG. 10 is a plan view of a case body.

FIG. 11 is a wiring diagram of the ignition coil.

FIG. 12 is a configuration diagram of an ignition coil according to a modification.

FIG. 13 is an enlarged bottom view of the main parts of the coil body of the ignition coil of the same.

[Explanation of symbols]

12 case body 14 Connection 20 coil body 24,25 collar part 40 Secondary coil 45 Primary coil part 60 coil terminals 62 coil connection 64 Engagement connection part 65 Notch 70 Embedded terminal 72 Engagement connection 73 Notch 74 High voltage terminal P spark plug

Claims (3)

(57) [Claims] 1. A substantially disk-shaped secondary coil formed by winding a secondary coil winding between a pair of upper and lower flanges formed on a bobbin, and a primary coil winding. A coil body having a substantially disk-shaped primary side coil part mounted thereon, the primary side coil part being disposed on the upper flange part, and having a flat finish, and an opening formed in the upper part. A case body that accommodates the coil body therein, a connecting portion that extends downward from a substantially central portion of the bottom portion of the case body, and one end portion that is embedded in the bottom portion of the case body is inside the case body. An embedded terminal that is projectingly arranged to serve as an engaging connection part and has the other end projectingly arranged in the connecting part to serve as a high-voltage terminal part for connection with an ignition plug; and a lower surface of the lower collar part. And one end is a coil connecting portion for connecting the secondary coil winding. Both of them include a coil terminal whose other end side is an engaged connection portion for connection with the engaging connection portion of the embedded terminal, the engaging connection portion of the embedded terminal and the engaged connection of the coil terminal. Are bent and bent so as to project upward or downward at positions facing each other in a state where the coil body is housed in the case body, and a slit-shaped notch is formed at each tip. An internal combustion engine in which the coil body is housed in the case body so that the engagement connection portion and the engaged connection portion are electrically connected to each other so that the respective cutout portions are engaged with each other. Ignition coil. 2. The coil terminal is separated between the coil connection portion and the engaged connection portion, and a pair of separation end portions is bent and raised downward from the lower collar portion, The ignition coil for an internal combustion engine according to claim 1, wherein a cutout portion for holding a lead of an electronic component is formed at a tip portion thereof. 3. A pair of cross iron core portions which are formed in a substantially cross shape and are mounted so as to sandwich the coil body from both upper and lower surfaces and form a closed magnetic circuit passing from the central portion of the coil body to the four outer circumferences. Item 3. The ignition coil for an internal combustion engine according to Item 1 or 2, wherein the coil terminal is provided on a lower surface of the lower collar portion and at a non-attached position of the cross core portion.