JP2000058348A - Ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition coil for internal combustion engines, which can connect secondary coil winding and a high-voltage terminal with more compact constitution. SOLUTION: An embedded terminal is embedded in the bottom part of a case body, wherein one end of the embedded terminal is protrudingly located inside of the case body to form an engaging connector, while the other end is protrudingly located inside of a connecting member to form a high-voltage terminal for connecting to an ignition plug. At the lower surface of a lower collar member 24 of the coil body 20, one end of the coil terminal 60 serves as a coil connector 62 by having a secondary coil winding wound around it, while the other end serves as a connector 64 to be engaged with the engaging connector 72 of the embedded terminal 70. When the coil body 20 is accommodated in the case body 12, the engaging connector of the embedded terminal is connected to the connector 64 to be engaged of the coil terminal 60, and the secondary coil winding is connected electrically to the high-voltage terminal.

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 for an internal combustion engine of an automobile or the like, and more particularly to an ignition coil for an internal combustion engine of an independent ignition type provided for each cylinder of the internal combustion engine. About.

[0002]

2. Description of the Related Art As an ignition coil for an internal combustion engine of this type, there is one having the following configuration.

[0003] That is, this ignition coil has a substantially disk-shaped primary coil portion formed by winding a primary coil winding, and a substantially disk shape formed by winding a secondary coil winding. And a secondary-side coil portion, which is laminated and arranged so that the respective winding cores are aligned on the same straight line, and has a flat finished coil body.
A pair of cruciform iron cores are attached so as to sandwich the coil from both sides thereof, thereby forming a closed magnetic path extending from the center of the coil to the outer periphery on all sides. The coil body to which the cross iron core is attached in this way
It is housed in the case body and attached to the upper opening of a plug hole formed in the cylinder head of the internal combustion engine.

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

[0005]

By the way, in the ignition coil configured as described above, the secondary high voltage generated in the secondary coil portion passes through the high voltage terminal portion provided at the bottom of the case body. The configuration is applied to the ignition plug at the bottom of the plug hole.

[0006] In this case, it is necessary to electrically connect the secondary coil winding and the high voltage terminal in the case body. In this ignition coil, it is required to reduce the height dimension. Therefore, there is a demand for a compact configuration that can contribute to reducing the height of the ignition coil even when the secondary side coil winding is connected to the high voltage terminal.

Accordingly, the present invention has been made to solve the above-described problem, and is an ignition coil for an internal combustion engine capable of connecting a secondary coil winding and a high voltage terminal in a more compact configuration. The purpose is to provide.

[0008]

According to a first aspect of the present invention, there is provided an ignition coil for an internal combustion engine, wherein a secondary coil winding is provided between a pair of upper and lower flanges formed on a bobbin. Has a substantially disk-shaped secondary coil part formed by winding a primary coil winding and a substantially disk-shaped primary coil part wound by a primary coil winding. A coil body arranged on the upper flange portion and finished flat, a case body having an opening formed in the upper part and accommodating the coil body therein, and a substantially central portion of the bottom of the case body. A connection portion vertically extending downward, and one end portion buried in the bottom of the case body and protrudingly arranged in the case body to form an engagement connection portion, and the other end portion protrudingly arranged in the connection portion. Embedded terminal which is a high-voltage terminal for connection with a spark plug, One end portion is attached to the lower surface of the portion and serves as a coil connection portion for connecting the secondary coil winding, and the other end portion is an engaged connection portion for connection with the engagement connection portion of the embedded terminal. And the engagement connecting portion of the embedded terminal and the engaged connection portion of the coil terminal are located at positions facing each other in a state where the coil body is housed in the case body. Or, it is bent and raised so as to protrude downward, and a slit-shaped notch is formed at each end portion, and the engagement connection portion and the cover are formed by housing the coil body in the case body. The engagement connection portions are configured to be electrically connected to each other such that the notches engage with each other.

According to a second aspect of the present invention, the coil terminal is separated between the coil connection portion and the engaged connection portion, and a pair of separated ends thereof is located below the lower flange. And a notch for holding the lead of the electronic component may be formed at the front end thereof.

According to a third aspect of the present invention, there is provided a pair of coils which are formed in a substantially cross shape and are mounted so as to sandwich the coil body from both upper and lower surfaces to form a closed magnetic path extending from a central portion of the coil body to the outer periphery on all sides. When the cross iron core is provided, the coil terminal may be provided on the lower surface of the lower flange portion and at a position where the cross iron core is not attached.

[0011]

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

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

As shown in FIGS. 2 to 4, the coil portion 20A with an iron core has a substantially disk-shaped primary coil portion 45 and a substantially disk-shaped secondary coil portion 40 arranged in the vertical direction. Cross iron cores 30A, 30B on both upper and lower surfaces of the flat coil body 20
Is attached.

FIG. 11 shows an example of connection of the ignition coil 10. As shown in FIG. 11, the ignition coil 10 is formed of an enameled wire wound around a primary coil 45. One end is drawn out of the case body 12 and is electrically connected to a positive terminal of the battery B of the vehicle.
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 a switching element S such as a power transistor provided outside the case body 12 or outside the case body 12. The switching element S is turned on / off in response to an ignition signal from an ECU or the like provided in the automobile, so that the primary voltage from the battery B is intermittently applied to the primary coil unit 45. Be composed. In addition, one end of the enamel wire wound around the secondary coil portion 40 is electrically connected to one end of the enamel wire wound around the primary coil portion 45 in the case body 12. On the other hand, the other end of the enameled wire wound on the secondary coil portion 40 is
It is electrically connected to the ignition plug P via the joint member 8 in the plug hole Ha. 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 spark plug P, P is sparked.

Returning to FIG. 1 to FIG.
The configuration of each part will be described first.
As shown in FIGS. 2 to 4, the primary coil portion 45 and the secondary coil portion 40 are mounted on the bobbin 22.

The bobbin 22 is formed by forming a pair of flanges 24 and 25 extending radially at a lower end of a short rectangular cylindrical bobbin main body 23 and an intermediate portion thereof in the axial direction.

Each of the flanges 24 and 25 is formed in a substantially rectangular plate shape corresponding to the internal shape of the case body 12, and the lower surface of the lower flange 24 is formed on the lower surface as shown in FIGS. , The coil terminal 60 is attached.

The coil terminal 60 is formed in a substantially band shape with an intermediate portion bent by punching a thin sheet metal material. The bent piece on one side is arranged along a line connecting the corner from the center of the flange 24 and the bent piece on the other side extends outward from one corner of the flange 24, The coil terminal 60 is attached to the lower surface of the flange 24.

The flange 2 of the two ends of the coil terminal 60
The end on the side extending outward from 4 is a coil connection portion 62 having a thread-wound cross section, and the other end of an enamel wire of a secondary coil portion 40 described later is wound around the coil connection portion 62. Configured as possible. The end of the coil terminal 60 that is closer to the center of the flange 24 than the center of the flange 24
Is bent and raised substantially vertically downward substantially in the middle of the central portion of the center portion and one corner thereof to form an engaged connection portion 64 for connection with an engagement connection portion 72 described later. This engaged connection portion 64
A notch 65 in the form of a vertical slit is formed at the front end of each of them, and the opening of the notch 65 is finished as a guide portion 65a that is slightly inclined outward.

As a specific configuration for mounting the coil terminal 60 on the flange 24, for example, the coil terminal 60 is insert-molded in the flange 24 in advance, or a hole is formed in the coil terminal 60 and A pin-shaped protrusion that can be inserted into the hole is formed on the flange 24 side, and the tip of the pin-shaped protrusion is melted and crushed in a state where the pin-shaped protrusion is fitted into the hole of the coil terminal 60, or And a configuration of bonding using an adhesive.

As the metal forming the coil terminal 60, 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. This is because the ignition coil using the coil terminal 60 is installed in a high-temperature environment on the cylinder head, and is connected to the engagement connection portion 72 described later by pressure welding, so that the strength and the stress relaxation are excellent. Is required.

The position to which the coil terminal 60 is attached is a portion extending from one corner of the flange 24 to the center thereof, that is, a position where the cross iron cores 30A and 30B described later are not attached.

As shown in FIGS. 2 to 4, the secondary coil portion 40 is formed in a substantially disk shape by winding an enamel wire as a secondary coil winding between the flange portions 24 and 25. (See FIG. 5 for the winding form). At this time, the ends of the winding start and end of the enameled wire are drawn out from between the flanges 24 and 25. Note that the enamel wire used for the secondary coil portion 40 has a general configuration 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.
The secondary coil section 40 may be formed by winding 8000 to 15000 turns of an enameled wire having a diameter of 2 mm.

The upper end of the bobbin main body 23 projects above the upper flange 25, and the primary coil 45 is mounted here.

The primary coil portion 45 is a rectangular coil enamel wire formed by applying an enamel paint to the surface of a rectangular rectangular copper wire having a substantially rectangular cross section as a primary coil winding.
It is finished in a substantially disc shape by being wound so as to be stacked in the thickness direction (see FIG. 6 for the winding form). The bobbin main body 23 is provided at the center of the primary coil portion 45.
A substantially rectangular hole through which the upper end of the hole can be inserted is formed.

The surface of the enamel wire used for the primary coil part 45 is coated with a thermosetting paint, and can be wound under a heated state or heated after winding. The enameled wire is solidified in a form wound in a substantially disk shape.

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

Here, the reason why a rectangular belt-shaped enameled wire is used for the primary coil portion 45 will be described.

For example, as shown in FIG. 5 (showing a cross section of one half of the coil), when an enamel wire 90 having a substantially circular cross section is used, how densely the enamel wire 90 is.
Even if it is wound, a useless space is generated between the wound enameled wires. This leads to an increase in the size of the primary coil portion, and also causes the heat generated there to be dissipated.

On the other hand, in the case where the enameled wire 92 is formed into a rectangular band as in the case of the present ignition coil, and the enameled wire is wound in the thickness direction thereof,
As shown in FIG. 6 (showing the shape of one half of the coil),
The enameled wire 92 can be densely wound without any gaps, and the primary coil 45 can be reduced in size and the ignition coil can be made thinner and smaller in diameter, and the heat conductivity of the heat generated therefrom can be improved. This is because heat dissipation is excellent.

The primary side coil part 45 thus configured
Is disposed on the upper surface of the flange 25 such that the upper end of the bobbin main body 23 is inserted into the hole at the center thereof, so that the primary coil portion 45 and the secondary coil portion 40 The winding cores are stacked and arranged so as to be aligned with 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 of 10 to 25 mm, and a height and a width (minimum width; length of one side of the flanges 24 and 25 in the embodiment).
Is 1: 2 to 1: 6, more preferably 1: 3 to 1:
It is desirably within the range of 5. Maximum height dimension is 2
The reason for setting it to 5 mm is that the coil body 2 having a height
This is because, assuming that the case 0 is accommodated in the case body 12, the case body 12 generally interferes with other intake and exhaust system components near the cylinder head H. Also, the lower limit is 10m
The reason for setting m is to take into account the mounting space when accessories such as the connector 15, the fixing part 16, and the switching element are provided in the case body 12 that houses the coil body 20.

Then, both ends of the enameled wire wound on the primary coil portion 45 and both ends of the enameled wire wound on the secondary coil portion 40 are drawn out 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 at the position of the outer peripheral edge of the flange 25 (not shown).

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

The cross iron core portion 30B is formed by combining substantially U-shaped iron core portions 31B and 35B formed by laminating electromagnetic steel plates so as to intersect at an intermediate portion thereof to form a substantially cross shape. At this time, a groove is formed in the overlapping portion of each of the core portions 31B and 35B, and the two core portions 31B and 35B are combined with each other so that the grooves on the other side are fitted to each other. The thickness dimension is not increased.

The iron core portion 31B disposed below the intersection of the iron core portions 31B and 35B has a triangular prism shape having a tapered surface inclined downward in the longitudinal direction of the iron core portion 31B on the lower surface side of the intersection portion. Is formed. The core portion 34B is inserted from above into the bobbin main body portion 23 with the cross iron 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 at the intermediate portions thereof. The core portion 34A is formed on the upper surface side of the iron core portion 35A arranged on the upper side at the intersection portion by crossing the grooves to form a substantially cross shape.

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

The cross iron cores 30A, 30B
Are attached to the upper and lower surfaces of the coil body 20, respectively, 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. It is constituted so that it may mutually contact on the outer circumference of the coil body 20.

Further, the tapered surfaces of the core portions 34A and 34B are provided within the bobbin main body 23 so that the
0 are arranged in parallel with each other with an interval capable of accommodating 0.

With these cross iron core portions 30A and 30B,
Four closed magnetic paths are formed from the center of the coil body 20 to the outer periphery in four directions.

Here, the cross iron core portions 30A and 30B include:
As the iron core portions 31A, 35A, 31B, and 35B, those formed by laminating silicon plywood having a thickness of 0.1 to 0.5 mm and forming a substantially U-shape may be used, and the core portions 34A, The cross-sectional area of the inner magnetic path composed of 34B is 100 to 32.
As a 4 mm ^2, further cross core portions 30A, 3
It is preferable that the total cross-sectional area of four external magnetic paths formed around the coil body 20 be set to 100 to 324 mm ² by 0B.

In the state where the two cross iron cores 30A and 30B are attached to the coil body 20, each core 3
A gap having a predetermined interval is formed between 4A and 34B, and a permanent magnet 50 for applying a reverse bias to cross iron cores 30A and 30B is provided 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 iron core portion 30 disposed on the upper surface side of the coil body 20 are formed.
A pair of insulating spacers 42 is interposed between B and the iron core 35B.

The two insulating spacers 42 are formed of an insulating material, and are provided at respective positions sandwiching the bobbin body 23 from both sides thereof. With this insulating spacer, the cross iron core 30B is attached to the primary coil 45 while maintaining a sufficient insulation distance between them.

As shown in FIGS. 2, 9 and 10, the case body 12 is formed in a flat box shape with a square bottom and an open top, and has four substantially L-shaped inner bottom surfaces 12a. Are formed so as to face each other apexes at a predetermined interval, thereby forming the cross iron core 3.
A cross-shaped positioning groove 13 for fitting and positioning 0A is formed.

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

Here, the reason why the connecting portion 14 is formed in the central portion of the case body 12 will be described. This is due to abnormal vibration of the case body 12 (resonance caused by vibration of the internal combustion engine or the connection portion 14). The case body 1)
This is for prolonging the product life of the second or the like. 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, so that the case body 12 is vibrated by the internal combustion engine. 12 will vibrate greatly.
However, when the connection portion 14 is formed at the center of the case body as in the case of the ignition coil, the connection portion 14 can be attached in a well-balanced manner as an attachment portion, so that the large vibration as described above is prevented. Because it is done.

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

The embedding terminal 70 is formed in a substantially strip shape by bending a thin sheet metal material so that both ends are bent in opposite directions. The middle part is buried in the bottom part of the case body 12 and in a part of the way from the center to one corner.

One end on one corner side of the case body 12 among the both ends of the embedded terminal 70 is bent substantially vertically upward at a position corresponding to the engaged connection portion 64 so that the case body 12
An engagement connection portion 72 protrudes inside. A slit-shaped notch 73 is formed at the upper end of the engagement connection portion 72 along the up-down direction, and the engagement connection portion 72 and the engaged connection portion 64 are viewed from above. The positions are such that the cutouts 73 and 65 intersect each other at the intersections (see FIG. 10). Then, when the coil portion 20A with the iron core is accommodated in the case body 12, the engaged connection portion 64 and the engagement connection portion 72 are electrically connected to each other such that the respective notches 73 and 65 engage with each other. It is configured to be.

The end of the center of the case body 12 among the two ends of the embedded terminal 70 is bent substantially vertically downward and protrudes into the connection portion 14 from the lower surface of the bottom of the case body 12. The high-voltage terminal 74. When the upper end 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.

The metal forming the embedded terminal 70 is preferably a high copper alloy (for example, a copper alloy to which a small amount of Ni-Si, Be or the like is added) 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 enameled wire of the secondary coil portion 40 is connected to the coil connecting portion 62 of the coil terminal 60.
And soldering, spot welding, laser welding, and the like are applied to their connection parts. Then, the core-attached coil portion 20A is accommodated in the case body 12 in such a manner that the cross iron core portion 30A on the lower surface side is positioned and accommodated in the positioning groove portion 13 in the case body 12 in a state where the core-attached coil portion 20A is assembled. At this time, the engaged connection portion 6 of the coil terminal 60 is
The engaged connection portions 64 and the engagement connection portions 72 are electrically connected to each other such that the cutouts 73 and 65 of the engagement connection portions 72 of the embedded terminal 4 and the embedded terminal 70 engage with each other. As described above, the coil unit 20A with the iron core is
After that, 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 therein, and then solidified by heat treatment. As a result, the cored coil portion 20A 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 iron core portion 30B
Insulating resin is injected between the primary coil portion 45 and the cross iron core portion 30B while a sufficient insulating distance is secured between the primary coil portion 45 and the cross core portion 30B. You. Also, as described above, the primary side coil portion 45
Since the insulating resin is injected between the first coil portion 30B and the cross core portion 30B, the insulating resin sufficiently penetrates between the enameled wires of the primary coil portion 45. Thereby, while being excellent in the insulation between the primary side coil part 45 and the cross iron core part 30B, it is possible to prevent the primary side coil part 45 from being out of shape and to ensure the positioning and fixing. In addition, since the primary coil portion 45 is pressed down via the insulating spacer 42, the reliability of the positioning and fixing of the primary coil portion 45 can be enhanced also in this regard.

In the ignition coil for an internal combustion engine configured as described above, the substantially coiled primary coil portion 45 and the substantially disc shaped secondary coil portion 40 are stacked and arranged to form the coil body 20. Due to this, it is possible to obtain a secondary energy large enough to ignite the 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 part 45 and the secondary side coil part 40, the height dimension is reduced and the coil body 20 is provided adjacent to the coil body 20. Interference between ignition coils can also be prevented.

At the bottom of the case body 12, one end is protruded into the case body 12 to form an engagement connection portion 72, and the other end is protruded into the connection portion 14 so that the ignition plug P Terminal 7 which is a high-voltage terminal 74 for connection of
On the other hand, on the lower surface of the lower flange portion 24, one end is a coil connection portion 62 for winding and connecting a secondary coil winding, and the other end is formed on the lower surface of the embedded terminal 70. The coil terminal 60 serving as the engaged connection portion 64 for connection with the engagement connection portion 72 is attached, and the connection between the engagement connection portion 72 of the embedded terminal 70 and the engaged connection portion 64 of the coil terminal 60 is established. Since the secondary coil winding is electrically connected to the high-voltage terminal portion 74, the connection configuration becomes more compact, which contributes to reducing the height of the ignition coil.

Further, the engaging connection portion 72 of the embedded terminal 70 and the engaged connection portion 64 of the coil terminal 60 are positioned at positions facing each other with the cored coil portion 20A housed in the case body 12. It is bent upward and downward, and cutouts 73 and 65 are formed at the respective distal ends, and the coiled portion 20A with the iron core is accommodated in the case body 12 so that the engagement connection portion 72 and the engagement connection portion are formed. 64 is configured so that the cutouts 73 and 65 are engaged with each other so as to be electrically connected to each other. The electrical connection between the coil winding and the high-voltage terminal portion 74 is made, and the connection work is facilitated.

Since the coil terminal 60 is provided at one corner of the lower surface of the flange portion 24, that is, at the position where the cross iron core 30A is not mounted, the space where the cross iron core 30A is originally dead space is not provided. Is effectively used to electrically connect the secondary coil winding to the high voltage terminal 74.

As shown in FIG. 12, there is an ignition coil for an internal combustion engine in which a rectifying diode D is interposed between a secondary coil winding and an ignition plug P. This diode D outputs only a voltage in one direction from the high voltage induced by the secondary coil unit 40 to the spark plug P.
Is to be applied.

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

That is, in the ignition coil of this modified example, of the two refracting pieces of the coil terminal 60B attached to the lower surface of the flange portion 24, the refracting piece on the central portion side of the coil body 20 is separated at the longitudinally intermediate portion. In addition, the two separated ends of the flange 24
It is bent and raised substantially vertically downward to form a diode connection 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 leads DL of the diode D can be held in each holding notch 67. Then, with the respective lead portions DL being inserted into the respective notch notches 67, the lead portions DL are soldered to the diode connection portions 66. This makes it possible to interpose an electronic component such as the diode D between the secondary coil unit 40 and the ignition 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 portion is disposed at the bottom of the case body so as to protrude into the case body to form an engagement connection portion. An embedded terminal whose end protrudes into the connection part and is a high-voltage terminal for connection with the ignition plug is embedded, and one end connects the secondary coil winding to the lower surface of the lower flange. And a coil terminal having the other end side as an engaged connection portion for connection with the engagement connection portion of the embedded terminal, and the engagement connection portion of the embedded terminal and the coil terminal. Since the secondary coil winding is electrically connected to the high-voltage terminal by the connection with the engaged connection portion, the connection configuration becomes more compact, and the height of the ignition coil is reduced. It contributes to making it smaller.

Further, the engaging connection portion of the embedded terminal and the engaged connection portion of the coil terminal are projected upward or downward at positions facing each other with the coil body housed in the case body. Notches are formed at the respective distal ends, and the coil body is housed in the case body, so that the engaging connection portion and the engaged connection portion engage with each other with the respective notches being electrically connected to each other. When the coil body is placed in the case body, the secondary coil winding and the high-voltage terminal section are electrically connected, and the connection work is facilitated.

Further, as described in claim 2, the coil terminal is separated between the coil connection portion and the engaged connection portion, and both separated ends are bent downward from the lower flange portion. At the same time, when notches are formed at the tips of the leads to hold the leads of the electronic components, the secondary coil windings are compact in a compact configuration while interposing electronic components such as diodes between the secondary coil and the spark plug. And the high-voltage terminal section can be electrically connected.

Further, when a pair of cross cores formed in a substantially cross shape are attached so as to sandwich the coil body from both upper and lower surfaces, the coil terminal is connected to the lower side. When provided on the lower surface of the flange portion at the non-attached position of the cross core portion, the non-attached space of the cross core portion, which is originally a dead space, is effectively utilized to allow the secondary coil winding and the high voltage terminal portion to be connected to each other. Electrical connection becomes possible.

[Brief description of the drawings]

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

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

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

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

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

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

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

FIG. 8 is a development view of a coil terminal.

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

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

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

FIG. 12 is an assembled view of an ignition coil according to a modification.

FIG. 13 is an enlarged bottom view of a main part of a coil body of the ignition coil of the above.

[Explanation of symbols]

 12 Case body 14 Connection part 20 Coil body 24, 25 Flange part 40 Secondary side coil part 45 Primary side coil part 60 Coil terminal 62 Coil connection part 64 Engaged connection part 65 Notch part 70 Embedded terminal 72 Engagement connection part 73 Notch 74 High voltage terminal P Spark plug

Claims (3)

[Claims] 1. A substantially disk-shaped secondary coil formed by winding a secondary coil between a pair of upper and lower flanges formed on a bobbin, and a primary coil wound. A coiled body having a substantially disk-shaped primary coil portion mounted thereon, the primary coil portion being arranged on the upper flange portion to be flattened, and an opening formed in an upper portion. A case body for accommodating the coil body therein; a connecting portion vertically extending downward from a substantially central portion of a bottom of the case body; and one end portion embedded in the bottom of the case body and inside the case body. An embedded terminal protruding to form an engagement connection portion and the other end protruding into the connection portion to serve as a high-voltage terminal portion for connection to a spark plug; and a lower surface of the lower flange portion And one end is a coil connection part for connecting the secondary coil winding. Both the other end side includes a coil terminal having an engaged connection portion for connection with the engagement connection portion of the embedded terminal, and the engagement connection portion of the embedded terminal and the engagement connection of the coil terminal. Parts are bent and raised so as to protrude 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 end. An internal combustion engine, wherein the engagement connection portion and the engaged connection portion are electrically connected to each other by housing the coil body in the case body so that the notches engage 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 separated ends are bent and raised downward from the lower flange portion. 2. The ignition coil for an internal combustion engine according to claim 1, wherein a cutout portion for holding a lead of the electronic component is formed at a tip portion thereof. 3. A pair of cross iron cores formed in a substantially cross shape and attached so as to sandwich the coil body from both upper and lower surfaces to form a closed magnetic path extending from the center of the coil body to four outer peripheral sides. 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 flange portion and at a non-attached position of the cross iron core portion.