JP2000058350A - Coil and ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy connection to other terminal or the like without using high temperature solder and performing terminal treatment work in advance, by constituting a wire where an insulating coating film is formed on only one surface side of a flat rectangular conducting wire is wound so as to be laminated in the width direction. SOLUTION: An enamel wire 100, where an insulating coating film 102 is formed on one surface side of a flat rectangular copper strand wire 101, is manufactured. A coil in which the enamel wire 10 is used is finished into an almost discoidal shape, by winding the flat rectangular enamel wire 100 so as to be laminated in the widthwise direction. At this time, winding is performed by making a surface on which an insulating coating film 102 of the enamel wire 100 inside. The winding layer section of the coil is made in a state in which the insulating coating film 102 and the copper strand wire 101 are alternately laminated from the winding center to the outer peripheral side. That is, the copper strand wire 101 at every winding turn is insulated by the insulating coating film 102 which is interposed between the copper strand wires 101, and a coil where the enamel wire 100 is wound by a plurality of number of turns is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coil and an ignition coil for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, for example, an ignition coil for an internal combustion engine of an automobile has used an enameled wire in which an insulating coating such as polyimide or urethane is formed on a surface of a copper wire having a circular cross section.

[0003]

However, in the above-described ignition coil, when the end of the enameled wire is electrically connected to a connection member on the other side such as another terminal, the following problem occurs. Had occurred.

[0004] First, when an enameled wire on which a polyimide insulating film is formed is used, before the end portion is soldered, the insulating film on the end portion is removed by cutting with a knife or abrasive paper. This requires an end processing operation, which makes the connection operation cumbersome.

On the other hand, when an enameled wire on which a urethane insulating film is formed is used, if the soldering is performed using, for example, a 350 ° C. high-temperature solder, the work of removing the insulating film at the end is unnecessary. is there. However, in this case, the wear of the solder is severe, and the thermal influence on the surroundings due to the high-temperature heating also becomes a problem.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and the end of the wound electric wire is subjected to an end treatment without using high-temperature solder. It is an object of the present invention to provide a coil and an ignition coil for an internal combustion engine that can be easily connected to other terminals and the like without any problem.

[0007]

According to a first aspect of the present invention, there is provided a coil according to the first aspect of the present invention, wherein a wire in which an insulating coating is formed only on one surface side of a rectangular strip-shaped conductive wire is formed in a thickness direction thereof. It is configured to be wound on a stack.

The ignition coil for an internal combustion engine according to the second aspect of the present invention is a primary coil formed by winding an electric wire in which an insulating coating is formed only on one surface side of a rectangular strip-shaped conductive wire so as to be stacked in the thickness direction thereof. A side coil unit is provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coil according to a first embodiment of the present invention will be described below.

First, an enameled wire 100 as an electric wire used for this coil will be described with reference to FIG. 1. This enameled wire 100 is one type of a rectangular rectangular copper wire 101 having a rectangular cross section as a conductive wire. An insulating coating 102 is formed on the side.

Next, a method of manufacturing the enameled wire 100 will be described with reference to FIG.

FIG. 2 is a view showing an apparatus for manufacturing the enameled wire 100. The apparatus for manufacturing the enameled wire 100 is arranged along the manufacturing line X from the upstream side to the downstream side in this order.
A rolling roller 112, a coating unit 114, a heating furnace 116, and a take-up reel 118 are provided.

A copper wire L having a circular cross section as shown in FIG. 3A is wound and housed in the housing reel 110, and the copper wire L drawn out from the reel 110 is wound on a manufacturing line X. Is fed downstream along the winding reel 11
8 is housed in a winding state.

A pair of rolling rollers 112 are provided at positions that sandwich the copper wire L from above and below.
The drawn copper wire L passes between the rolling rollers 112 and is rolled into a rectangular strip having a rectangular cross section as shown in FIG. 3B.

The application section 114 is a sponge-like member, and is disposed at a position where it is in sliding contact with the upper surface side of the rolled copper wire L. The coating portion 114 is impregnated with an enamel paint that forms the insulating film 102, and the rolled copper wire L slides on the lower surface of the coating portion 114,
As shown in FIG. 3 (c), the enamel paint is applied only to the upper surface of the copper wire L.

Next, the copper wire L coated with the enamel paint is passed through the heating furnace 116 and heated to a predetermined temperature, and the enamel paint is baked on the copper wire L. Thereby, as shown in FIG. 1, the enameled wire 10 in which the insulating coating 102 is formed on one side of the rectangular strip-shaped copper wire 101 is formed.
0 is produced.

[0017] Finally, the manufactured enameled wire 100 is
The take-up reel 118 takes up and is housed.

A coil 120 using the enameled wire 100 is configured as shown in FIGS. 4 and 5 (a cross section of one half of the coil is shown).

That is, the coil 120 is finished in a substantially disc shape by winding the rectangular strip-shaped enameled wire 100 so as to be stacked in the thickness direction. At this time, for example, when the enameled wire 100 is wound with the surface on the side on which the insulating coating 102 is formed facing inward, the winding layer cross section of the coil 120 is, as shown in FIG. (From left to right in FIG. 5), the insulating coating 102 and the copper wires 101 are alternately laminated. Thus, the copper wire 101 for each winding is insulated by the insulating coating 102 interposed therebetween, and thus the enamel wire 100 functions as a coil 120 wound a plurality of times.

According to the coil 120 configured as described above, since the insulating coating 102 is formed only on one side of the rectangular strip-shaped copper wire 101, its end is connected to a connecting member such as a terminal on the other side. At the time of connection, if the other side, on which the insulating coating 102 is not formed, is soldered so as to come into contact with the mating connection member, an electrical connection between the enameled wire 100 and the mating connection member is made. Connection is made.

Therefore, for example, when using a conventional enameled wire having a polyimide insulating film formed thereon, it is necessary to remove the insulating film at the end in advance. In such a case, such an operation of removing the coating film is not required, and the connection with the connection member on the partner side becomes easy.

For example, when a conventional enameled wire on which a urethane insulating film is formed is used, it is necessary to perform soldering using a high-temperature solder. Although the thermal effect on the surroundings due to high-temperature heating has also been a problem, in the case of the enameled wire 100, soldering may be performed using ordinary solder without using high-temperature solder. There is no problem.

Further, the enameled wire 1 having a rectangular band shape
When the coil 120 is manufactured using 00, the following advantages are obtained as compared with the case where the coil is manufactured using enameled wire having a circular cross section.

That is, as shown in FIG. 6 (showing a cross section of one half of the coil), when an enamel wire 130 having a circular cross section is wound to form a coil, how densely the enamel wire 130 is formed Even if it is wound, the wound enameled wire 1
Unnecessary space is created between the coils 30, which is a factor that hinders the size of the coil and dissipates the heat generated there.

However, when the rectangular strip-shaped enameled wires 100 are wound so as to be stacked in the thickness direction, the enameled wires 100 can be densely wound without gaps as shown in FIG. In addition, the size and the heat radiation of the coil 100 are improved.

Further, as described above, the insulating film 1 is formed only on one side.
In the case of using the enamel wire 100 on which 02 is formed,
Even with the same rectangular band-shaped enameled wire, the following effects can be obtained as compared with the case where insulating films are formed on both sides of the enameled wire.

That is, when the insulating coating is formed on both sides of the enameled wire, the thickness in the radial direction per one turn of the enameled wire is obtained by adding twice the thickness of the insulating coating to the thickness of the copper wire. Value. However, when the insulating film 102 is formed only on one surface side like the enamel wire 100, the radial thickness per one turn of the enamel wire 100 is insulated by the thickness of the copper wire 101. This is a value obtained by adding the thickness of the coating 102. Therefore, the size of the coil 120 can be further reduced.

The coil 120 constructed as described above can be used not only as an ignition coil for an internal combustion engine described as a second embodiment but also as a general coil such as a coil for a transformer.

Next, an ignition coil for an internal combustion engine according to a second embodiment of the present invention will be described.

As shown in FIG. 7, 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 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.

The coil portion 20A with the iron core is shown in FIGS.
As shown in FIG. 5, radially core portions are formed on both upper and lower surfaces of a flat coil body 20 in which a substantially disk-shaped primary coil portion 45 and a substantially disk-shaped secondary coil portion 40 are also arranged in the vertical direction. The cross iron core portions 30A and 30B are attached.

FIG. 16 shows an example of connection of the ignition coil 10. As shown in FIG. 16, the ignition coil 10 is formed of an enameled wire wound around a primary coil portion 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. 7 to FIG.
The configuration of each unit of 0 will be described.

First, as shown in FIGS. 8 to 10, the coil body 20 is formed by mounting or winding a primary coil portion 45 and a secondary coil portion 40 on a bobbin 22.

The bobbin 22 is formed by forming a pair of flanges 24 and 25 extending radially at the 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 conforming 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 belt-like shape with its middle 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 attaching the coil terminal 60 to the flange portion 24, for example, the coil terminal 60 may be insert-molded in advance in the flange portion 24, or a hole may be formed in the coil terminal 60. 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 a 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 where the coil terminal 60 is attached is a portion from one corner of the flange portion 24 to the center thereof, that is, a position where the cross iron core portions 30A and 30B described later are not attached, and is originally a dead space. The non-attachment space of a certain cross iron core portion 30A is effectively used so that the secondary coil winding and the high voltage terminal portion 74 are electrically connected.

Further, in one corner of the upper flange 25, FIG.
As shown in FIGS. 9 and 11, the relay connection terminal 80 is attached so as to protrude outward.

The relay connection terminal 80 is a long plate-shaped member formed of a thin metal plate, and its base end is buried in one corner of the flange 25 by insert molding or the like. By connecting one end 45a of the enamel wire of the primary coil portion 45 and one end 40a of the enamel wire of the secondary coil portion 40 to the relay connection terminal 80, one end 45a of the enamel wire is connected. , 40a
Are electrically connected to each other.

As shown in FIGS. 8 to 10, the secondary coil portion 40 is formed in a substantially disc shape by winding an enamel wire as a secondary coil winding between the flange portions 24 and 25. (See FIG. 6 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 side coil portion 45 is used as the primary side coil winding of the enameled wire 10 described in the first embodiment.
0 is a coil using an enameled wire having the same configuration as that of the coil.

That is, a rectangular strip-shaped enameled wire in which an insulating coating is formed only on one side of a rectangular strip of copper wire (see FIG. 1), the thickness of which is set such that the surface on which the insulating coating is formed is on the inside. It is finished in a substantially disk shape by winding so as to be stacked in the direction (see FIG. 5 for the winding form). A substantially rectangular hole through which the upper end of the bobbin main body 23 can be inserted is formed at the center of the primary coil part 45.

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.

At this time, since the rectangular coil-shaped enameled wire is used for the primary coil portion 45, the primary coil portion 45 is formed for the same reason as described in the first embodiment.
In addition to making the ignition coil thinner and smaller in diameter, the conductivity of the heat generated there is improved,
Excellent heat dissipation.

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 the ratio of the height to the width (minimum width; the dimension of the minimum width portion in plan view) is 1: 2. ~
The ratio is preferably in the range of 1: 6, more preferably in the range of 1: 3 to 1: 5. The reason for setting the upper limit of the height dimension to 25 mm is that the coil body 20 having a height dimension higher than this is
This is because the case body 12 generally interferes with other intake / exhaust system components near the cylinder head H. The reason for setting the lower limit to 10 mm is as follows.
This is because the mounting space in the case where accessories such as the connector portion 15, the fixing portion 16 (see FIG. 7, described later), and the switching element are provided in the case body 12 accommodating the coil body 20 is considered.

It is to be noted that a substantially disk-shaped primary side coil portion 45,
Since the flat coil body 20 is formed by laminating the substantially disk-shaped secondary coil portion 40, secondary energy sufficiently large to ignite the air-fuel mixture in the cylinder of the internal combustion engine is obtained. This makes it possible to reduce the height of the ignition coil and prevent interference between adjacent ignition coils.

Then, both ends of the enamel wire wound around the primary coil portion 45 and both ends of the enamel wire wound around the secondary coil portion 40 are drawn out of the coil body 20 respectively. As shown in FIG.
5 is wound around the relay connection terminal 80 with one end 45a of the enameled wire having the side on which the insulating coating is not formed facing inward. Next, after removing one end portion 40a of the enameled wire of the secondary side coil portion 40 from its insulating coating, the relay connection terminal 8
Wrap around 0. In this state, by soldering to the relay connection terminal 80, one end 45
a and 40a are electrically connected.

As shown in FIGS. 8 to 10, cross iron cores 30A and 30B are respectively attached to the upper and lower surfaces of the coil body 20 configured as described above.

The cross iron core portion 30B is formed by combining substantially U-shaped iron core portions 31B and 35B formed by laminating electromagnetic steel sheets 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 in the middle 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 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.

The tapered surfaces of the core portions 34A and 34B are provided inside the bobbin main body 23 so that the permanent magnet 5
0 are arranged in parallel with each other with an interval capable of accommodating 0.

With these cross iron cores 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 cores 30A and 30B have
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 a 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. 9 and 10, 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 3 disposed on the upper surface side of the coil body 20 are formed.
0B and a pair of insulating spacers 42
Is interposed.

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. 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. 7, 8, 14, and 15, the case body 12 is formed in a flat box shape with a square bottom surface and an open top, and the outer side portions of the case body 12 are formed as shown in FIGS. As shown by a two-dot chain line, a fixing portion 16 for attaching the ignition coil 10 to the cylinder head H is provided, and a connector portion 15 for making electrical connection between the ignition coil 10 and the ECU or the like is provided on the front surface thereof. Is provided.

The inner bottom surface 12a has four substantially L
The letter-shaped ridges 13a are formed so as to face each other at predetermined intervals, thereby forming a cross-shaped positioning groove 13 for fitting and positioning the cross core 30A.

Further, as shown in FIGS. 14 and 15,
At the center of the lower surface of the case body 12, a connecting portion 14 whose lower end is slightly tapered is vertically provided.

Here, the reason why the connecting portion 14 is formed at the center of the case body 12 will be described. This is because abnormal vibration of the case body 12 (resonance due to 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.

As shown in FIGS. 14 and 15, an embedded terminal 70 is embedded in the bottom of the case body 12 by insert molding.

The buried terminal 70 is formed in a substantially belt-like shape in which both ends are bent in opposite directions by punching a thin metal material. 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 positions where the notches 73 and 65 are formed intersect with each other as intersections (see FIG. 15). 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 part 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.

As described above, the engagement connecting portion 7 of the embedded terminal 70
Since the secondary coil winding is electrically connected to the high-voltage terminal portion 74 by the connection between the coil terminal 2 and the engaged connection portion 64 of the coil terminal 60, the connection configuration becomes more compact, This contributes to reducing the height of the ignition coil. Further, by housing the cored coil portion 20 </ b> A in the case body 12, the engaging connection portion 72 and the engaged connection portion 64 are electrically connected to each other such that the respective notches 73 and 65 engage with each other. So that the coil unit 20A with the iron core is
2 only, the electrical connection between the secondary coil winding and the high voltage terminal portion 74 is made, and the connection work is also facilitated.

Next, the method of assembling the ignition coil will be described. First, as shown in FIG.
The enameled wire is wound between 4 and 25 and the secondary coil section 40
Is formed, and the primary coil portion 45 is arranged on the upper flange portion 25. Then, as shown in FIG. 11, the one end 45 a of the enamel wire drawn from the primary coil portion 45 is wound around the relay connection terminal 80 with the surface on the side where the insulating coating is not formed inside. Further, the secondary coil unit 4
After removing one end 40a of the enameled wire drawn from 0, the insulating coating is removed, and wound around the relay connection terminal 80,
A soldering process is performed on those connection portions. Next, FIG.
As shown in FIG. 2, the other end 40b of the enameled wire of the secondary coil part 40 is wound around the coil connection part 62 of the coil terminal 60, and soldering, spot welding,
Apply laser welding and the like. Then, the cross core 30A on the lower surface side is attached to the case
The cored coil portion 20 </ b> A is housed in the case body 12 so as to be positioned and housed in the positioning groove 13 in the inside 2. At this time, the notched portions 73, 6 of the engaged connection portion 64 of the coil terminal 60 and the engagement connection portion 72 of the embedded terminal 70, respectively.
5 so that they engage with each other.
And the engagement connection portion 72 are electrically connected to each other. As described above, after the coil unit 20A with the iron core is accommodated in the case body 12, a liquid insulating resin is injected and filled into the case body 12 so that the coil unit 20A with the iron core is immersed, and then heat-treated. And solidify. Thereby, the coil part 2 with the iron core
OA is fixed to case body 12. At this time, since the insulating spacer 42 is interposed between the upper surface of the primary coil portion 45 and the cross core 30B as described above, there is sufficient space between the primary coil 45 and the cross core 30B. Insulating resin is injected between them with a sufficient insulation distance secured. Further, as described above, since the insulating resin is injected between the primary coil portion 45 and the cross core portion 30B,
The insulating resin sufficiently penetrates between the layers of the enameled wire of the primary side coil portion 45. Thereby, the primary side coil part 4
5 and excellent in the insulation between the cross core 30B,
It is possible to prevent the primary coil portion 45 from being deformed 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 constructed as described above, the primary coil portion 45 is formed by stacking enameled wires having an insulating coating formed only on one surface side of a rectangular copper wire in the thickness direction. Because it is wound around and formed
When electrically connecting the end portion 45a of the enameled wire of the primary coil portion 45 to the relay connection terminal 80, the solder is formed so that the surface on which the insulating coating is not formed is brought into contact with the relay connection terminal 80. If they are attached, electrical connection between them will be made.

Therefore, for example, even when an enameled wire on which an insulating film such as urethane is formed is used, the connection operation can be performed without using a high-temperature solder. Further, for example, even when an enameled wire on which a high-melting-point insulating film such as polyimide is formed is used, there is no need to perform an end processing operation such as removal of the insulating film at the end, so that the connection operation is easy. .

Further, since the insulating coating is formed only on one side of the enameled wire, the diameter of the primary side coil portion 45 can be reduced by the absence of the insulating coating on the other side.
As a result, the size of the ignition coil can be reduced.

Although an enameled copper wire is exposed on the outer peripheral surface of the primary coil portion 45, since the primary coil portion 45 is immersed in the insulating resin in the case body 12, Problems such as insulation with other conductive members do not occur.

The relay connection terminal 80 is shown in FIG.
7 may be configured like the relay connection terminal 80B of the first modification shown in FIG.

That is, the relay connection terminal 80B is provided on the base end side of the long plate-shaped mounting portion 82B with a substantially U-shaped mounting portion 84 in side view.
B is provided. Inside the both ends of the mounting portion 84B,
The protruding portion 85B is formed to face each other, and the flange portion 25B is formed.
A hole 26B is formed at one corner of the member (corresponding to the flange 25 in the above embodiment) with which the projection 85B can be engaged.

Then, the protrusion 85B is inserted into the hole 26B so that one corner of the flange 25B is sandwiched in the mounting portion 84B.
, The relay connection terminal 80B is attached.

Mounting portion 84B of relay connection terminal 80B
Protrudes outward from one corner of the flange portion 25B, and similarly to the case where it is attached to the relay connection terminal 80, one end portion 45a of the enameled wire of the primary coil portion 45 and the enamel of the secondary coil portion 40. One end 40a of the wire is attached.

The relay connection terminal 80 may be configured like a relay connection terminal 80C of the second modification shown in FIG.

The relay connection terminal 80C has a press-contact portion 82C formed at one end and a mounting portion 84C formed at the other end, and the press-contact portion 82C has a slit-shaped notch 83C whose opening is expanded outward. It is formed. The outer periphery of the mounting portion 84C is formed in a substantially U-shape, and detent pieces 86C having inclined surfaces 87C that are inclined outward toward the mounting portion 84C are formed on both sides thereof.

On the other hand, a slit-shaped notch 26C is formed at one corner of the flange 25C (a member corresponding to the flange 25 in the above embodiment), and the slit 26C is formed.
A mounting groove 27C into which the mounting portion 84C can be press-fitted is formed along the U-shaped inner peripheral surface.

Then, by pressing the mounting portion 84C into the mounting groove 27C, the detent piece 86C is attached to the mounting groove 2C.
7C is engaged with the groove bottom, and the relay connection terminal 80C is
It is attached to 5C in a retaining shape.

The enameled wire of the primary coil portion 45 is attached to the relay connection terminal 80C attached to the flange portion 25C in such a manner that one end portion 45a thereof is pressed into the cutout portion 83C. At this time, since the insulating coating is not formed on one side of the enameled wire, the enameled wire electrically contacts the relay connection terminal 80C, and thereby, between the enameled wire and the relay connection terminal 80C. Electrical connection is achieved.

The enameled wire of the secondary coil portion 40 is also removed by press-fitting into the notch 83C after removing the insulating coating on one end portion 40a of the enameled wire of the secondary coil portion 40. The portion 40a is electrically connected to one end 45a of the enameled wire of the primary coil portion 45.

[0092]

As described above, according to the coil of the first aspect of the present invention, the electric wire in which the insulating coating is formed only on one surface side of the rectangular strip-shaped conductive wire is wound in such a manner as to be stacked in the thickness direction. When connecting the end of the wire to the connection member on the other side, if the other side is connected to a connection member such as a terminal on the other side and soldered, both ends are connected. The electrical connection between them will be made.

Therefore, for example, even when an electric wire on which an insulating coating such as urethane is formed is used, the connection operation can be performed without using high-temperature solder. Further, for example, even when an electric wire having a high-melting-point insulating film such as polyimide is used, it is not necessary to perform an end processing operation such as removal of the insulating film at the end, so that the connection operation is easy. Since the insulating coating is formed only on one side of the conductive wire, the diameter of the coil can be reduced because the insulating coating is not formed on the other side.

Further, according to the ignition coil for an internal combustion engine according to the second aspect of the present invention, the electric wire in which the insulating coating is formed only on one surface side of the rectangular strip-shaped conductive wire is wound so as to be stacked in the thickness direction thereof. When connecting the end of the electric wire of the primary coil portion to the connection member of the other party, the other side contacts with the connection member such as the terminal of the other party. If soldering is performed in such a manner, electrical connection between them will be made.

Thus, for example, even when using an electric wire on which an insulating film such as urethane is formed, the connection can be performed without using a high-temperature solder. Further, for example, even when an electric wire having a high-melting-point insulating coating such as polyimide is used, it is not necessary to perform an end processing such as removing the insulating coating at the end, so that the connecting operation is easy.

Further, since the insulating coating is formed only on one side of the conductive wire, the diameter of the primary side coil portion can be reduced by the absence of the insulating coating on the other side.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an enamel wire used for a coil according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing an enamel wire manufacturing apparatus according to the first embodiment;

3 (a) is a cross-sectional view of a copper wire, FIG. 3 (b) is a cross-sectional view of a rolled copper wire, and FIG. 3 (c) is a cross-sectional view of a copper wire coated with enamel. .

FIG. 4 is a perspective view showing a coil of the first embodiment.

FIG. 5 is a cross-sectional view showing a winding layer configuration of the same coil.

FIG. 6 is a sectional view showing a comparative example.

FIG. 7 is a view showing a mounted state of an ignition coil for an internal combustion engine according to a second embodiment of the present invention.

FIG. 8 is an exploded perspective view showing the same ignition coil.

FIG. 9 is an exploded perspective view of a coil unit with an iron core.

FIG. 10 is a cross-sectional view of a coil unit with an iron core.

FIG. 11 is an enlarged perspective view of a main part of a coil unit with an iron core.

FIG. 12 is an enlarged bottom view of a main part of a coil unit with an iron core.

FIG. 13 is a development view of a coil terminal.

FIG. 14 is a sectional view of a case body.

FIG. 15 is a plan view of a case body.

FIG. 16 is a connection diagram of the ignition coil.

FIG. 17 is an enlarged view of a main part of an ignition coil according to a first modification.

FIG. 18 is an enlarged view of a main part of an ignition coil according to a second modification.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 enamel wire 101 copper wire 102 insulating film 120 coil

Claims (2)

[Claims] 1. A coil formed by winding an electric wire in which an insulating coating is formed only on one surface side of a rectangular strip-shaped conductive wire so as to be stacked in the thickness direction thereof. 2. An ignition coil for an internal combustion engine having a primary side coil portion formed by winding an electric wire having an insulating coating formed only on one surface side of a rectangular strip-shaped conductive wire so as to be stacked in the thickness direction thereof.