JP2000150272A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine, which not only prevents shorting between winding layers by insulating resin which is filled, easily permeating to the central part of a secondary coil, but also effectively prevents expanding of a separating wall caused by the secondary coil which is wound. SOLUTION: Separating walls 24a and 24b are provided on an outer surface of a bobbin cylinder part 23 of a bobbin 22, and a primary coil 15 and a second coil 16 are provided in each space separated by each separating wall 24a and 24b. Rib projecting parts 27 which expand to the outsides of axial directions are formed at four positions, avoiding cross iron core parts 30 and 31 in a separating wall part 24b of the outside of axis core direction of the bobbin 22, which separates the secondary coil part 16, toward the bobbin cylinder 23 from the outer peripheral. The cross iron cores 30 and 31 are so equipped as to attach the bobbin 22 sandwiched between both upper and lower sides, are provided in a case unit 13 under this condition and are solidified by filling thermally cured resin in the case unit 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine used for an internal combustion engine of an automobile or the like, and more particularly, to an ignition device for an internal combustion engine of an independent ignition type provided for each cylinder of the internal combustion engine. It is about.

[0002]

2. Description of the Related Art An ignition device for an internal combustion engine of this type includes a primary coil portion wound with a primary coil winding and a secondary coil portion wound with a secondary coil winding. The core as a core is inscribed or pressed into the bobbin, and is penetrated, set in a predetermined case body in this state, filled with a thermosetting resin as an insulating resin, and heated and cured. There was one.

On the other hand, if the filled thermosetting resin does not penetrate into the wound secondary coil winding, that is, to the center, good insulation performance cannot be exhibited and a high voltage is generated. In the secondary coil, there is a possibility that a rare short may occur between the winding layers, and due to the presence of the partition wall of the bobbin that separates the secondary coil, the thermosetting up to the center of the secondary coil winding. There is also a problem that it takes time to infiltrate the resin.

In order to more surely penetrate into the center, a method of injecting and filling a thermosetting resin by vacuuming,
Various proposals have been made such as a method of forming a narrow groove in the axial direction in a cylindrical portion of a bobbin to secure a filling passage.

[0005] For example, Japanese Patent Application Laid-Open No. 9-120924,
JP-A-9-148171, JP-A-9-50205
It is disclosed in Japanese Patent Publication No. 2 and the like.

[0006]

An object of the present invention is to solve the problem that the insulating resin to be filled easily penetrates into the center of the secondary coil portion, thereby effectively preventing the occurrence of a rare short between the winding layers. It is an object of the present invention to provide an ignition device for an internal combustion engine that not only prevents, but also effectively prevents the partition wall from spreading and deforming due to the wound secondary coil portion.

[0007]

A technical means for solving the above-mentioned problem is that a plurality of partition portions project radially outward on an outer peripheral surface of a cylindrical portion of a bobbin so as to be spaced apart in an axial direction. Formed, in each space portion partitioned by the partition wall portion, a primary coil portion wound with a primary coil winding and a secondary coil portion wound with a secondary coil winding. In an ignition device for an internal combustion engine in which an insulating resin is filled and solidified in a case body in a state in which the bobbin and the iron core are arranged in a case body that is open at the top, a bobbin that partitions the secondary coil portion Is formed on the partition wall portion on the outer side in the axial direction from the outer peripheral edge portion toward the cylindrical portion.

Further, a resin flow hole may be formed in the rib ridge to communicate both sides of the partition.

Further, the iron core is formed in a substantially cross shape and is attached so as to sandwich the bobbin from both sides, and a pair of cross iron cores forming a closed magnetic path passing from the center of the bobbin to the four outer circumferences. In this case, the rib ridges may be formed at four positions avoiding the cross iron core.

[0010] Further, a structure may be employed in which the bulging height of the rib ridge is formed to be smaller than the thickness of the cross iron core.

Further, a structure may be provided in which both end portions in the axial direction of the cylindrical portion are provided with extending wall portions projecting outward in the axial direction from the partition portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 denotes an ignition device for an internal combustion engine, which is formed on a cylinder head 11 of an engine as an internal combustion engine. This is a so-called upper-type configuration that is used by being installed above the opening of the plug hole 12. Then, as shown in FIGS. 2 and 3,
A flat coil body 1 in which a primary side coil part 15 and a secondary side coil part 16 are vertically arranged in a resin case body 13
7 is accommodated and arranged.

As an example of the connection of the ignition device 10, for example, the ignition device 10 has a primary coil 15
One end of the enameled wire wound around is pulled out of the case body 13 and is electrically connected to a positive terminal of an automobile battery, and the negative terminal of the battery is grounded. The other end of the enameled wire wound around the primary coil portion 15 is grounded via a switching element such as a power transistor provided on the case body 13 or outside thereof. This switching element is configured to be 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 is intermittently applied to the primary side coil unit 15. ing. One end of the enamel wire wound around the secondary coil portion 16 is electrically connected to one end portion of the enamel wire wound around the primary coil portion 15 in the case body 13. On the other hand, the other end of the enamel wire wound around the secondary coil portion 16 is electrically connected to the ignition plug 20 via the joint member 19 in the plug hole 12. When the primary voltage is intermittently applied to the primary coil section 15, a high voltage is induced in the secondary coil section 16 by electromagnetic induction, and this high voltage is applied to the spark plug 20, and 20 is configured to be sparked.

As shown in FIGS. 2 to 8, the coil body 17 has a structure in which a primary coil 15 and a secondary coil 16 are mounted on a bobbin 22.

The bobbin 22 has a short rectangular cylindrical bobbin tube portion 2.
3 and a pair of partition walls 24a and 24b formed on the outer peripheral surface of the bobbin cylindrical portion 23 so as to project outward in the axial direction, that is, at the middle and lower portions in the axial direction, that is, in the vertical direction. I have. Further, at both ends in the axial direction of the bobbin cylindrical portion 23, extended wall portions 26a projecting outward in the axial direction from the upper and lower partition portions 24a, 24b, that is, projecting vertically, respectively,
26b is provided.

Each of the partition portions 24a, 24b is
Along with being formed in a substantially rectangular plate shape according to the internal shape of
As shown in FIGS. 7 and 8, each corner is cut out in a chamfered shape, and is formed in a so-called octagonal shape.

The lower partition wall portion 24b has a rib projecting from the outer peripheral edge toward the bobbin cylinder portion 23 toward the outside in the axial center direction of the bobbin 22, that is, the rib protrusion which swells at an appropriate height h. The ridge portion 27 is formed so as to extend, and the bulging portion forms a resin guide groove in the direction from the outer peripheral edge to the bobbin cylinder portion 23. In addition, the rib ridges 27 are formed at four positions at regular intervals in the circumferential direction of the partition wall portion 24b, and in the present embodiment, the rib ridges 27 are located at the corners that are chamfered. Each is formed at a peripheral portion. In addition, each rib ridge 27 may be configured to extend to a position reaching the bobbin cylinder 23. In addition, the height h of the rib protrusion 27 protruding is formed to be shorter than the length S of the extension wall 26b.

Furthermore, a plurality of resin communication holes 27a are formed in each rib projecting portion 27 so as to vertically communicate on both sides of the partition wall portion 24b, that is, a plurality of resin communication holes 27a communicating with the inside of the resin guide grooves are provided. I have.

As shown in FIGS. 2 to 5, the secondary coil section 16 is provided with an enamel wire as a secondary coil winding in a space partitioned by upper and lower partition walls 24a and 24b. By doing so, it is formed in a substantially disk shape.

The enamel wire used for the secondary coil portion 16 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, an enameled wire having a wire diameter of 0.04 to 0.1 mm is 800
It is preferable to form the secondary coil portion 16 by winding 0 to 15000 times.

As shown in FIGS. 2 and 3, the primary side coil portion 15 is fitted in an extended wall portion 26a of a bobbin tube portion 23 projecting upward from an upper partition portion 24a. The primary coil portion 15 is a rectangular coil enamel wire formed by applying an enamel paint to the surface of a substantially rectangular rectangular copper wire having a vertically long cross section as a primary coil winding in the thickness direction. It is formed in a substantially disk shape by being wound so as to be stacked.

The surface of the enameled wire used for the primary coil portion 15 is coated with a heat-welding coating material, and may be wound under heating or heated after winding. As a result, the enameled wire is solidified in a form wound in a substantially disk shape. More specifically,
A rectangular strip-shaped enameled wire rolled 1:15 to 1:30 is wound 90 to 180 times in the radial direction, and the primary coil portion 15 is wound.
Should be formed.

Here, the reason why a rectangular belt-shaped enameled wire is used for the primary coil portion 15 will be described.

For example, when an enamel wire having a substantially circular cross section is used, no matter how densely the enamel wire is wound, a useless space is created between the wound enamel 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, as in the ignition device 10 of the present embodiment, when enameled wires are wound in a rectangular strip shape and wound in such a manner that the enameled wires are stacked in the thickness direction, the enameled wires are separated by a gap. It is possible to wind tightly without any problem, and it is possible to reduce the size of the primary coil portion 15 and thus the thickness and the diameter of the ignition device 10, and to improve the heat transfer of the heat generated there, and to improve the heat dissipation. It will be excellent.

Here, the primary coil section 15 and the secondary coil section 16 are arranged in a stacked manner such that their respective cores are aligned with the axis of the bobbin cylinder section 23, and the flat coil body 1
7 is configured.

In this case, the flat coil body 17 preferably has a height of 10 to 25 mm and a ratio of the height to the width of 1: 2 to 1: 6. The reason why the upper limit of the height dimension is set to 25 mm is that if it is larger than this, it is generally easy to interfere with other intake / exhaust system parts and the like near the cylinder head 11. This is due to restrictions due to the size of accessories such as connectors and switching elements provided on the body 13.

Then, both ends of the enamel wire wound around the primary coil portion 15 and both ends of the enamel wire wound around the secondary coil portion 16 are respectively drawn out of the coil body 17 and With respect to one end of the enameled wire of the side coil portion 15 and one end of the enameled wire of the secondary coil portion 16, they are positioned at the outer peripheral edge of the partition wall portion 24a.
Alternatively, they are electrically connected through a groove 24c formed in the partition 24a (not shown).

As shown in FIGS. 2 to 4 and FIG. 9, on the upper and lower surfaces of the coil body 17 thus constructed,
A pair of cross iron core portions 30 and 31 constituting the iron core are respectively attached.

Each of the cross iron core portions 30 and 31 has a substantially U-shaped iron core portion 30a, 30b, 3 formed by laminating electromagnetic steel plates.
It is formed by combining 1a and 31b in a substantially cross shape such that they intersect at their middle part.

The core 30b disposed on the lower side at the intersection of each of the cores 30a and 30b of the upper cross core 30 has a core 30 on the lower side of the intersection.
A triangular prism-shaped core portion 30c having a tapered surface inclined downward in the longitudinal direction of b is formed. The core portion 30c is configured to be inserted into the bobbin tube portion 23 from above with the cross iron core portion 30 attached to the upper surface side of the coil body 17.

On the other hand, the lower cross core 31 has an upside-down shape with respect to the upper cross core 30, and the upper cross core 31 b is disposed at the intersection of each of the cores 31 a and 31 b. A core part 31c facing the core part 30c is formed on the upper surface side of. This core part 31c also
With the cross iron core 31 attached to the lower surface side of the coil body 17, it is configured to be inserted from below into the bobbin cylinder 23.

When the cross iron cores 30 and 31 are attached to the upper and lower surfaces of the coil body 17, respectively, four upward end faces of the iron cores 31a and 31b located on the lower side and each of the cores 31 and 31 located on the upper side. The four downward end surfaces of the iron core portions 30a and 30b are configured to abut on the outer periphery of the coil body 17.

Then, as shown in FIGS. 3 and 4,
The rib protrusions 27 are formed at positions avoiding the cross iron core portions 30 and 31 respectively.

Further, as shown in FIG.
The opposing tapered surfaces of c and 31c have a structure in which the permanent magnets 33 are arranged parallel to each other in the bobbin cylindrical portion 23 at intervals.

The cross iron core portions 30 and 31 form a structure in which four closed magnetic paths are formed from the central portion of the coil body 17 to the outer peripheral four sides.

Here, the cross iron cores 30, 31 have a thickness of 0.1 mm as the iron cores 30a, 30b, 31a, 31b.
It is good to use what laminated | stacked the silicon plywood of 1-0.5 mm, formed in the substantially U-shape, and formed so that the total cross-sectional area of four closed magnetic paths extended outward from the center might be 100-324 mm < ² >.

In a state where the two cross iron cores 30 and 31 are attached to the coil body 17, as described above, each core 30
A gap having a predetermined interval is formed between the magnets c and 31c, and a permanent magnet 33 that magnetically reversely biases the cross iron cores 30 and 31 is provided in the gap.

As shown in FIGS. 2 and 3, the case body 13 is formed in a flat box shape having a square bottom surface and an open top, and has four substantially L-shaped ridges on its inner bottom surface 13a. The portions 13b are formed so as to face each other with a predetermined space between them, so that the cross-shaped positioning groove 13 for fitting and positioning the cross-shaped core portion 31 is formed.
c is formed.

As shown in FIGS. 1 and 2, a connecting portion 34 having a slightly tapered lower end is provided at the center of the lower surface of the case body 13 so as to protrude downward.

Here, the reason why the connecting portion 38 is formed at the center of the case body 13 is that abnormal vibration of the case body 13 (resonance due to vibration of the internal combustion engine or swing vibration around the connecting portion 38) is caused. This is for preventing and improving the durability of the case body 13 and the like.

Next, a method of assembling the ignition device 10 will be described. The insulating spacers are provided from both upper and lower sides of a coil body 17 provided with a primary coil portion 15 and a secondary coil portion 16 at predetermined positions on a bobbin 22. Attach each of the cross iron core portions 30 and 31 so as to sandwich them so as to sandwich them through 36,
In this state, the cross iron core 31 on the lower surface side is fitted into the positioning groove 13 c in the case body 13, and the coil body 17 is housed in the case body 13 in a positioning manner.

After the coil body 17 and the cross iron cores 30 and 31 are housed in the case body 13, the coil body 1
A thermosetting resin as a liquid insulating resin is injected and filled under vacuum in the case body 13 so that the case 7 is immersed, and is solidified by heat treatment. Thus, the ignition device 10 in which the coil body 17 is integrally fixed to the case body 13 is configured.

The ignition device 10 according to the present embodiment is configured as described above. Of the upper and lower partition portions 24a and 24b that partition the secondary coil portion 16, the lower partition portion 2
4b, a plurality of rib ridges 27 are formed, and the heat injected between the winding layers at the center of each enameled wire of the secondary coil portion 16 through the resin guide groove formed by each of the rib ridges 27. The curable resin is easily guided, and the thermosetting resin sufficiently penetrates into each of the winding layers reaching the center of the secondary coil portion 16, so that the penetration time can be shortened. The occurrence of a rare short between the winding layers in No. 16 can be effectively prevented.

Also, since the resin communication holes 27a are formed in the respective rib protrusions 27, the resin communication holes 27a
Through this, the thermosetting resin infiltrates into the resin guide groove of the rib ridge portion 27, and from this point, there is an advantage that the thermosetting resin permeates into the central portion of the secondary coil portion 16 more easily. .

At this time, since the extending walls 26a and 26b are provided at the upper and lower ends of the bobbin cylinder 23 in a protruding manner, respectively, the space between the upper surface of the partition 24a and the cross iron core 30 is provided.
And between the lower surface of the partition wall portion 24c and the cross iron core portion 31,
In each case, a sufficient gap can be secured, and here, an insulation distance is secured, and the thermosetting resin can easily penetrate into the central portion of the primary coil section 15 or the secondary coil section 16 through the gap. In addition, the permeation time can be further shortened, and from this point, the occurrence of rare short between the winding layers can be more effectively prevented.

Further, each notch 25 has a cross iron core 30,
Since they are formed at four positions avoiding 31, respectively, the guide of the injected thermosetting resin to the center portion of the primary side coil portion 15 or the secondary side coil portion 16 can be more smoothly performed. It can be easily penetrated into the central part of the primary side coil part 15 and the secondary side coil part 16, so that the permeation time can be further reduced, and the occurrence of rare short between the winding layers can be more effectively prevented. .

Further, since the thermosetting resin sufficiently penetrates between the winding layers of the primary coil section 15 and the secondary coil section 16, the primary coil section 15 and the secondary coil section 16 are prevented from being out of shape, and Certainty of positioning and fixing can be achieved.

Further, when an enameled wire having a substantially circular cross section is wound like the secondary coil portion 16, the partition wall portion 24b located on the axially outward side of the bobbin 22 extends outward. However, since the rib portions of the bulging ribs 27 reinforce the partition wall portion 24b, the deformation in the spreading direction can be effectively prevented. Variation of the secondary coil portion 16 can be effectively prevented. Moreover, a pair of cross iron cores 30, 31
In this method, the coil body 17 is attached so as to sandwich the coil body 17 from both upper and lower sides.
Thus, the secondary coil portion 16 can be effectively prevented from becoming uneven.

Also, a substantially disk-shaped primary coil portion 15,
Since the coil body 17 is formed by laminating the substantially coiled secondary side coil portion 16, it is possible to obtain secondary energy large enough to ignite the air-fuel mixture in the cylinder of the internal combustion engine. The shape of the coil body 17 is a flat shape formed by laminating the primary side coil part 15 and the secondary side coil part 16, so that the height dimension is reduced and Interference between the igniters 10 to be provided can also be prevented.

Since the height h of each rib protruding portion 27 is smaller than the length S of the extension wall portion 26b, the height of the coil body 17 itself is increased. It can be made compact without any problems.

The height h at which the rib ridges 27 protrude.
As shown in FIG. 6, if the length of the extension wall portion 26b is smaller than the length S of the extension wall portion 26 + the thickness t of the cross iron core portion 31, the height of the coil body 17 itself can be similarly increased. And compactness can be achieved.

FIG. 10 shows a second embodiment, in which the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

That is, in the present embodiment, similarly to the secondary coil section 16, the primary coil section 15 has a structure in which enameled wire having a substantially circular cross section is wound. Also, a partition wall 24d is provided.

The upper rib portion 24d is also provided with a rib ridge 27 similar to the lower rib portion 24b.
Are formed in a swelling shape on the outer side in the axial center direction.

Therefore, similarly to the first embodiment, since the ribs 24d are reinforced by the rib ridges 27 also on the side of the partition 24d, the direction in which the partition 24d extends outward in the axial center direction. This has the advantage that the deformation of the primary coil 15 can be effectively prevented.

In each of the above embodiments, the structure in which the rib ridges 27 are provided at four positions is shown.
It is sufficient that at least one or more portions are provided, and an appropriate number may be formed as necessary.

[0058]

As described above, according to the ignition device for an internal combustion engine of the present invention, the partition wall on the axially outer side of the bobbin partitioning the secondary coil portion is provided with the cylinder of the bobbin from the outer peripheral edge thereof. A rib ridge that bulges outward in the axial direction toward the part direction, and an insulating resin filled through the rib ridge is provided at the center of the secondary coil part. To prevent the occurrence of rare short-circuits between the winding layers, and the rib function of the rib ridges reinforces the partition wall, effectively deforming outward. And the secondary coil portion can be effectively prevented from becoming uneven.

Further, if the rib ridge has a structure in which a resin flow hole communicating with both sides of the partition is formed, the insulating resin to be filled can flow from the resin flow hole through the rib ridge to the secondary side. This has the advantage that it penetrates more easily into the center of the coil.

Further, the iron core is formed in a substantially cross shape and is attached so as to sandwich the bobbin from both sides, and comprises a pair of cross iron cores forming a closed magnetic path passing from the center of the bobbin to the outer periphery on all sides, If the rib ridges are formed at four positions avoiding the cross iron core, respectively, the infiltration path of the insulating resin can be more effectively secured,
It can be more easily penetrated into the center of the secondary coil part, and the cross iron core can also prevent deformation of the partition wall in the spreading direction, making the occurrence of rare shorts between winding layers even more effective. There is an advantage that it can be prevented.

Further, if the bulging height of the rib ridge portion is formed to be smaller than the thickness of the cross iron core portion, there is an advantage that the size can be effectively prevented and the size can be reduced.

Further, if a structure is provided in which the extended wall portions projecting axially outward from the partition wall are provided at both ends of the cylindrical portion in the axial direction, the infiltration path of the insulating resin is more effective. This also has the advantage that it is possible to more easily penetrate into the central portion of the secondary side coil portion, and it is possible to more effectively prevent the occurrence of rare short between the winding layers.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing the ignition device.

FIG. 3 is an exploded perspective view of the ignition device.

FIG. 4 is an inverted perspective view of the coil body in FIG. 3;

5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a half sectional front view of the bobbin.

FIG. 7 is a plan view of the same.

FIG. 8 is a bottom view of FIG. 6;

FIG. 9 is a perspective view of a cross iron core.

FIG. 10 is a sectional view showing a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ignition device 13 Case 15 Primary coil 16 Secondary coil 17 Coil 22 Bobbin 23 Bobbin cylinder 24a Partition 24b Partition 24d Partition 26a Extended wall 26b Extended wall 27 Rib ridge 27a Resin communication hole 30 Cross core 31 Cross core 33 Permanent magnet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 31/00 501A

Claims (5)

[Claims] A plurality of partition portions are formed on an outer peripheral surface of a cylindrical portion of a bobbin so as to be radially outwardly spaced apart from each other in an axial direction, and a primary space is formed in each space portion partitioned by each partition portion. A primary coil portion wound with a side coil winding and a secondary coil portion wound with a secondary coil winding are provided, and the bobbin and the iron core are arranged in a case body that is open at the top. In the igniter for an internal combustion engine in which the insulating resin is filled and solidified in the case body in the state in which the bobbin partitioning the secondary coil portion is disposed on the partition wall portion on the outer side in the axial direction of the bobbin, An ignition device for an internal combustion engine, wherein a rib ridge bulging outward in the axial direction toward the cylinder is formed. 2. The ignition device for an internal combustion engine according to claim 1, wherein a resin flow hole is formed in the rib ridge to communicate both sides of the partition. 3. A pair of cruciform cores, each of which is formed in a substantially cross shape and is attached so as to sandwich the bobbin from both sides, and forms a closed magnetic path passing from the center of the bobbin to four sides around the bobbin. 3. The ignition device for an internal combustion engine according to claim 1, wherein the rib ridges are formed at four positions except for the cross iron core. 4. 4. The ignition device for an internal combustion engine according to claim 3, wherein the bulging height of the rib ridge portion is formed to be smaller than the thickness of the cruciform core portion. 5. An extended wall portion protruding axially outward from the partition wall portion is provided at both ends in the axial direction of the cylindrical portion. The ignition device for an internal combustion engine according to claim 1.