JP2009266851A - Ignition coil unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate assembly of a closed magnetic path type ignition coil by using a plug top type ignition coil. <P>SOLUTION: The ignition coil unit is provided with a side core enclosing a coil unit portion comprising a rod-shaped center core, formed by stacking steel plates made of magnetic materials, and a coil portion, has the center core disposed crossing the inside of the side core, has a pair of magnetic paths, passing through the side core with the center core as a common magnetic path, constituted to cross the coil portion, and has the side core constituted by a metal laminated steel plate made of a plurality of radially laminated magnetic materials having axial-direction slits. The ignition coil unit have intervals of slits wider than those in a natural state in a state wherein the side core is in contact with an outer periphery of a cylindrical coil unit case made of a resin material interposed between the coil unit and side core, the side core wraps an outer periphery of the coil unit case with its own elastic force. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ignition coil for an internal combustion engine that supplies a high voltage to generate a spark discharge in an ignition plug of the internal combustion engine, and in particular, a closed magnetic circuit that is linked to the ignition coil by a center core and a side core that surrounds the center core. The present invention relates to an ignition coil device of the type to be formed.

  A conventional ignition coil for an internal combustion engine has a rod-shaped center core formed of a laminated steel plate made of a magnetic material as described in Japanese Patent Application Laid-Open No. 2007-221040, and a side core is provided so as to surround the center core. The center core and the side core form a closed magnetic circuit that is linked to the coil.

  A primary bobbin around which a primary coil connected to the battery is wound is inserted into the outer periphery of the center core, and a secondary coil bobbin around which a secondary coil connected to the plug is wound is inserted into the outer periphery of the primary coil. . The center core, the coil portion, and the side core are housed in a resin-made coil case, and are sealed and insulated with an insulating resin filled in the coil case.

  In this prior art, the side core magnetic steel sheet has a rectangular cross section with an axial slit.

JP 2007-2221040 A

  In such a conventional technique, since the magnetic steel sheet forming the side core has a rectangular cross section having a slit, when a plurality of sheets are processed and stacked in the same shape, a gap is formed between the stacked magnetic steel sheets. In order to make this gap impossible, it is necessary to change the degree of corner bending for each steel plate to be stacked. Or it is necessary to shape | mold so that a cross section may become a rectangle in the state which accumulated several sheets. In any case, the processing work takes time.

  An object of the present invention is to provide an ignition coil device that can easily assemble a coil unit and a side core.

  Other objects are as described in the description of the embodiments.

  A side core is provided so as to surround a coil unit composed of a bar-shaped center core laminated with magnetic steel plates and a coil portion, and the center core is disposed so as to cross the inside of the side core, and a pair passing through the side core with the center core as a common magnetic path The side core is composed of a cylindrical magnetic metal laminated steel plate laminated in the radial direction, and the side core has slits along the axial direction. In the state where it is installed on the outer periphery of a cylindrical resin material coil unit case interposed between the coil unit and the side core, the gap between the slits is wider than the natural state. An ignition coil device configured to hug the outer periphery of a coil unit case.

  According to the present invention, the side core and the center core that form the closed magnetic path of the ignition coil device can be easily assembled.

  Hereinafter, the construction and assembly of an ignition coil device for an internal combustion engine to which the present invention is applied will be described in detail based on an embodiment shown in the drawings. First, the main configuration and main functions and effects of this embodiment will be described. Then, it demonstrates still in detail based on each drawing.

  The ignition coil device for an internal combustion engine according to this embodiment is basically configured as follows.

  As shown in FIG. 1, a bar-shaped center core 6A in which 7 to 10 magnetic steel plates 6A1 to 6An are laminated is provided.

  The primary coil unit 23 includes a primary bobbin 2 and a primary coil 3 wound around the outer periphery thereof.

  The secondary coil unit 45 includes a secondary bobbin 4 in which a plurality of division grooves are formed on the outer periphery, and a secondary coil 5 that is divided and wound in the division grooves.

  An insertion hole 2A for the center core 6A is formed at the center of the primary bobbin 2.

  The primary coil portion 23 is inserted into the insertion hole at the center of the secondary coil portion 45 and combined to constitute the coil portion 24.

  A coil core 246 is configured by inserting the center core 6 </ b> A through the insertion hole (the insertion hole 2 </ b> A at the center of the primary bobbin 2) of the coil portion 24, and the side core 6 </ b> B is provided so as to surround the coil unit 246.

  The center core 6A is arranged so as to cross the inside of the side core 6B, and as shown in FIG. 4, one closed magnetic circuit 6AR is constituted by the center core 6A and a half portion of the side core 6B, and the center core 6A and the side core 6B Another half magnetic path 6AL is formed with the remaining half portion, and as a result, a pair of magnetic paths 6AR, 6AL having the center core 6A as a common magnetic path are linked to the coil portion 24. .

  The side core 6B is composed of magnetic metal laminated steel plates 6B1 to 6Bn that are laminated in the radial direction.

  A coil unit case 11 made of a cylindrical resin material is interposed between the coil unit 246 and the side core 6B. Specifically, the coil unit 246 is fitted into the coil unit case 11 made of a cylindrical resin material, and both are assembled. At this time, the center core 6 </ b> A is fitted into the notch 11 </ b> C of the coil unit case 11 so as to match. As a result, one end of the center core 6A protrudes slightly outward in the radial direction from the outer periphery of the coil unit case 11. One end of the center core 6 </ b> A is formed in an arc shape following the outer periphery of the coil unit case 11.

  The magnetic material laminated metal steel plates 6B1 to 6Bn of the side core 6B are provided with slits 6BA along the axial direction, and are configured such that when the coil unit case 11 is mounted on the outer periphery, the interval between the slits 6BA is wider than the natural state. ing. As a result, the coil unit case 11 is configured to be hugged by its own elastic force.

  The diameter of the coil portion 24 is configured to be smaller at both end portions than the central portion in the axial direction. Specifically, the secondary winding is wound in winding grooves (also referred to as divided grooves) 4B1 to 4Bn provided on the secondary bobbin 4, but the height of the annular partition forming the groove is centered from both ends. The height is high. As a result, the secondary winding is wound many times in the center, and the number of turns decreases toward the both sides.

  One end 6AD of the center core 6A passes through the coil unit case 11 and faces the inner peripheral surface of the side core 6B. Since it is better to reduce the magnetic resistance of this portion, the gap is set small as long as there is no problem in assembly.

  The other end 6AF of the center core 6A has phase portions 6AR and 6AL along the inner diameter of the coil unit case 11, and the phase portions 6AR and 6AL are formed over a range of dimensions in the circumferential direction wider than the width of the center core 6A.

  Concave and convex portions 6AP and 11b are provided between the phase portions 6AR and 6AL of the center core 6A and the inner peripheral surface of the coil unit case 11 to be fitted to each other.

  The slits 6BA of the magnetic material laminated metal steel plates 6B1 to 6Bn of the side core 6B are arranged in a line at one end of the center core 6A.

  The interval between the slits 6BA is larger in the outer magnetic material-made metal laminated steel plates 6Bn when the magnetic material-made metal laminated steel plates 6B1 to 6Bn of the side core 6B are mounted on the outer periphery of the coil unit case 11.

  On the outer periphery of the coil unit case 11, at least one protrusion (two protrusions in the embodiment) 11b that protrudes radially outward and extends in the axial direction is formed at a position matching the slit 6BA.

  A coil case 7 is provided that houses an assembly body 624 in which the coil unit 246 and the side core 6B are combined.

  The coil case 7 is provided with a space 7C in which an igniter chip (ignition circuit unit) 12 is accommodated and a connector portion 7B.

  Insulating resin 10 is filled in the coil case 7 including the storage space 7 </ b> C of the igniter chip (ignition circuit unit) 12 inside the coil unit case 11.

  The insulating resin 10 includes an assembly body 624, an igniter chip (ignition circuit unit) 12, a connecting conductor portion (embedded in the insulating resin) between the coil unit 246 and the igniter chip (ignition circuit unit) 12, and an igniter chip (ignition circuit unit) 12. And a conductor portion (embedded in an insulating resin) that connects the connector 8 and the terminal 8 of the connector 7B, and is insulated from the outside. Thereby, the insulation rating between internal electrical components can be satisfied.

  The housing portion of the assembly body 624 of the coil case 7 has an inner peripheral cylindrical surface facing the outer peripheral surface of the side core 6B, and a concave portion 7D that receives the large diameter portion at the center of the coil unit 246 is formed on the bottom surface portion. Yes. Further, an annular shelf 7E on which the assembly body 624 is placed is formed between the inner peripheral cylindrical surface of the coil case 7 and the recess 7D. Thereby, it is possible to secure a space where the insulating resin 10 can be sufficiently filled around the assembly body 624. In addition, assembly is simplified.

  The assembly body 624 is mounted on the shelf 7B via an annular silicon rubber 13 as a stress relaxation member disposed at least between the side core 6B and the shelf 7E. This prevents the side core 6B from being pressed against the coil case 7 by the thermal strain after molding by the insulating resin 10 to damage the resin parts such as the coil case 7 and the coil unit case 11.

  The plurality of magnetic metal laminated steel plates 6B1 to 6Bn forming the side core 6B are formed as a cylindrical body, have the same diameter before being mounted on the outer periphery of the coil unit case 11, and the spacing between the slits 6BA is substantially the same. It is formed in width. This simplifies the processing of the magnetic material laminated metal steel plates 6B1 to 6Bn of the side core 6B. In addition, since all the metal-made metal laminated steel plates 6B1 to 6Bn can have the same shape, the magnetic characteristics are different for each product, so-called machine differences are small, and stable and uniform magnetic characteristics between products can be realized.

  Examples will be described in more detail below.

  1 and 2 show an embodiment of an ignition coil device for an internal combustion engine according to the present invention. FIG. 1 is an external top view of an ignition coil for an internal combustion engine according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The internal combustion engine ignition coil 1 is an independent ignition type internal combustion engine ignition coil that is attached to a plug hole of each cylinder of the internal combustion engine and directly connected to the ignition plug. The center core 6A and the side core 6B are formed by laminating silicon steel plates as magnetic steel plates made of 0.2 to 0.7 mm to form a closed magnetic circuit.

  On the outer periphery of the primary bobbin 2 formed of a thermoplastic synthetic resin, enameled wires having a wire diameter of about 0.3 to 1.0 mm are laminated several layers, several hundred times per layer, about 100 to 300 times in total. The primary coil 3 is formed by being wound.

  A secondary bobbin 4 is disposed on the outer periphery of the primary bobbin 2 with a gap. The secondary bobbin 4 is formed of a thermoplastic synthetic resin similarly to the primary bobbin 2, and the secondary bobbin 4 has a plurality of winding grooves 4B1 to 4Bn. A secondary coil 5 is formed on the outer periphery of the secondary bobbin 4 by using an enameled wire having a wire diameter of about 0.03 to 0.1 mm and being divided and wound into a total of about 5,000 to 30,000 winding grooves 4B1 to 4Bn. ing.

  As described above, the primary coil portion 23 is inserted inside the secondary bobbin 4, but there is a specific insulation for insulation between the outer periphery of the primary coil portion 23 and the inner periphery of the secondary bobbin 4. A gap 42 is formed to keep the interval, and the insulating resin 10 is also filled there.

  The primary coil 3 wound around the primary bobbin 2, the secondary coil 5 wound around the secondary bobbin 4, and the center core 6 </ b> A fitted into the center of the primary bobbin 2 constitute a coil unit 246. The coil unit 246 is housed in the side core coil case 7. The coil unit 246 and the side core coil case 7 constitute an assembly body 624.

  An end portion of the primary bobbin 2 is integrally formed with a flange portion 2S that matches the surface of the center surface 6A on the side surfaces of the phase portions 6BR and 6BL on the coil portion 23 side.

  The center core 6A is inserted into the insertion hole 2A of the primary bobbin 2 from the flange portion 2S side, and the flange portion 2S and the surfaces on the coil portion 23 side of the surface portions 6BR and 6BL of the center core 6A are combined.

  Thus, the surface portions 6BR and 6BL formed on the other end 6AF of the center core 6A are in contact with the inner peripheral surface of the coil unit case 11, and the one end 6AD of the center core 6A is in contact with the innermost peripheral surface of the side core 6B.

  In this state, when the side core 6B is mounted on the outer periphery of the coil unit case 11, a force for contracting to the inside of the side core 6B acts on the one end 6AD of the center core 6A, and the phase portion 6BR formed on the other end 6AF of the center core 6A, 6BL is pressed against the inner peripheral surface of the coil unit case 11. As a result, the assembly body 624 is held in an integrated state.

  Moreover, the electric power supplied to the primary coil 3 is supplied through the terminal 8, and the terminal 8 is connected to a terminal of an external connector (not shown), which is not shown.

  On the other hand, a high voltage terminal 9 is connected to the secondary coil 5. The secondary coil 5 is cut off by an igniter chip (ignition circuit unit) 12 with respect to the energization of the primary coil 3 and an ignition signal sent from an ECU (not shown) of the automobile, and spark discharge is caused to the spark plug. A high voltage is induced to generate. The high voltage induced in the secondary coil 5 is supplied to the spark plug via the high voltage terminal 9, and the spark plug generates a spark discharge upon receiving the high voltage induced in the secondary coil 5. .

  The coil case 7 in which the primary coil 3 wound around the primary bobbin 2 and the secondary coil 5 wound around the secondary bobbin 4 are accommodated has an insulating resin made of a thermosetting resin ( Specifically, an epoxy resin) 10 is enclosed. This insulating resin (specifically, epoxy resin) 10 is a gap between the inside of the coil case 7 and the primary coil 3 wound around the primary bobbin 2 and the secondary coil 5 wound around the secondary bobbin 4. The insulating resin (specifically, epoxy resin) 10 is cured to insulate the primary coil 3 and the secondary coil 5 from each other. In this way, the primary coil 3, the secondary coil 5, the primary bobbin 2, and the secondary bobbin 4 are insulated in the coil case 7 by the insulating resin (specifically, epoxy resin) 10, and the coil case 7 It is fixed inside and integrated.

  FIG. 4 shows a sectional view of the coil portion of the present invention. The side core 6B is formed by laminating about 2 to 10 pieces of magnetic steel plates of the same size cut in a strip shape and are bent in the shape of a circular tube. By making the shape into a strip shape, it is not necessary to punch out a magnetic steel plate as in the conventional structure, and the strip-shaped roll material can be produced simply by cutting it with the same dimensions, and the remainder of the material can be extremely reduced.

  When the side core 6B is bent and stacked like a U-shape, a gap is generated for each stack at the corner where the magnetic steel plate is bent. In addition, a sudden bending causes distortion in the magnetic steel sheet, resulting in an increase in magnetic resistance and loss of magnetic energy. Furthermore, problems such as peeling off of the insulating film covered on the surface of the magnetic steel sheet occur, and stress concentration occurs in the insulating resin (specifically, epoxy resin) 10 around the corners when a thermal stress is applied. Cracks of the resin (specifically, epoxy resin) 10 are likely to occur.

  On the other hand, when the bent shape of the side core 6B is a circular tube shape, there is no gap for each stack even if a plurality of the same shape is produced, and the post-process such as caulking and welding is performed because it is accommodated by light press-fitting. do not need. FIG. 5 shows a method for assembling the side core 6B. As shown in FIG. 5, the side core 6B is lightly press-inserted into a circular coil unit case 11 formed of a thermoplastic resin. Although only one side core is shown in FIG. 5, a plurality of sheets are also stacked on the outer peripheral side in the same manner. By providing the coil unit case 11, the center core, the primary coil, and the secondary coil can be easily positioned. Further, by providing the coil unit case 11 with the protrusion 11a, the side core 6B is prevented from being rotated and positioned. By assembling in this way, no post-process such as caulking or welding is required for laminating the side cores, so there is no loss of magnetic energy due to a decrease in the amount of magnetic flux at the caulking part or the welding part. Furthermore, since it has a circular tube shape, stress is not concentrated, and even when thermal stress is applied, there is no crack of the epoxy resin due to the stress concentration. Further, the ignition coil unit case has a side core stress relieved so that no stress is generated on the epoxy resin.

  Therefore, the side core shape of the present invention has a structure in which a belt-shaped magnetic steel plate is bent into a circular tube shape and laminated.

  Furthermore, the longitudinal direction of the side core is matched with the rolling direction of the magnetic steel sheet. Since the magnetic flux always flows in the rolling direction with respect to the flow of the magnetic flux generated by the coil, the characteristics of the magnetic steel sheet can be used effectively. When a grain-oriented magnetic steel sheet having remarkable rolling characteristics is used, the magnetic energy is higher and a high-energy coil can be formed.

  Both end portions of the side core are arranged at end portions in the longitudinal direction of the center core. Further, a gap is provided on the side where both end portions of the side core are disposed, and the end portion of the center core spreads out in a fan shape to increase the cross-sectional area. This is because the side cores are made in the same shape, and the distance between the both ends of the side core increases as it goes to the outer periphery when laminated, so that the cross-sectional area of the center core is widened to prevent a decrease in magnetic flux. Since the flow of magnetic flux spreads in the vicinity of the gap, even if both ends of the side core are arranged on the gap side, there is little loss of magnetic flux. Further, a recess is provided in the center of the fan-shaped portion of the center core to perform positioning with the ignition coil unit case. As a result, the magnetic flux is divided into two, and the structure is less likely to cause magnetic saturation.

  The figure shown in FIG. 6 is a figure which shows 2nd Embodiment of this invention. The end of the magnetic steel plate disposed on the outermost peripheral side of the side core 6B is bent outward, and the bent portion and the GND terminal (not shown) of the ignition coil are electrically connected. By grounding the outermost periphery of the side core 6B to GND, potential is not stored in the core 6 during spark discharge of the ignition coil, and noise generation from the core 6 is suppressed. Moreover, since the primary coil and the secondary coil are accommodated in the inner peripheral side of the side core 6, the side core 6 made into GND serves as a noise shield, and noise generated in the primary coil and the secondary coil can be suppressed.

  In this embodiment, a coil unit composed of a center core and a cylindrical coil having a center core inserted through the center portion is axially inserted into the cylindrical side core portion so that the center core crosses the inside of the side core portion. Arrange and surround the outside of the coil unit with a side core.

  Thus, the center core and the half of the side core form a pair of semicircular (or arc-shaped) closed magnetic paths.

  More specifically, a gap is provided between one end of a casing center core formed in a tubular shape with a thermoplastic resin and the inner peripheral surface of the side core. A side core is a cylindrical core formed by curling a magnetic steel plate of the same size cut in a strip shape with the rolling direction of the magnetic steel plate as a longitudinal direction into a circular tube, and is axially between the start and end of the curl. A slit is provided.

  A cylindrical coil unit case made of a resin material is disposed on the inner periphery of the side core. The cylindrical coil unit case made of a resin material is surrounded by a side core, and the side core is a cylindrical coil unit case. The outer periphery is locked (without caulking or welding) with its own clamping force. With this structure, the remaining amount of the magnetic steel sheet is greatly reduced, and an inexpensive side core can be obtained. Further, caulking and welding are not required for lamination. Further, since the magnetic flux flows in the rolling direction of the magnetic steel sheet, magnetic energy loss can be reduced.

  The problems of the prior art to be solved in the embodiment are summarized as follows.

  A conventional ignition coil for an internal combustion engine is provided with a center iron core so as to form a closed magnetic circuit and a side iron core so as to surround the center iron core, and a primary iron connected to a battery on the outer periphery of the center iron core. A coil is wound, and a secondary coil connected to a plug is wound around the outer periphery of the primary coil with a space between the coils and accommodated in the coil case, and an insulating resin is enclosed in the coil case. Further, the side iron cores are laminated with the same number or many magnetic steel plates punched into C-type or E-type as the center, and are fixed by caulking or welding.

  In such iron core processing or assembly, when the magnetic steel sheet is punched into C-type or E-type, the remaining pieces must be discarded due to the uniqueness of the shape, resulting in wasted electrical steel sheets and high-cost coils. End up.

  In addition, when the laminated side cores are fixed by caulking or welding, the flow of magnetic flux deteriorates at the caulking part or the welding part, resulting in a loss of magnetic energy.

  Furthermore, when the magnetic steel sheet is punched into C-type or E-type, both the rolling direction of the magnetic steel sheet and the direction perpendicular to the rolling are present with respect to the direction in which the magnetic flux flows, and the magnetic resistance of the magnetic steel sheet increases in the direction perpendicular to the rolling. It is necessary to make the cross-sectional area of the iron core larger than the cross-sectional area in the rolling direction. Therefore, the ignition coil becomes large.

  Furthermore, in the prior art in which a plurality of magnetic steel plates having a rectangular cross section (square shape) are laminated from the inside to the outside, stress concentrates on the corners, and there is a risk of corrosion or damage from there.

  An object of the present embodiment is to make it possible to easily manufacture a side core. Another object of the present invention is to provide an ignition coil for an internal combustion engine that reduces the waste of magnetic steel sheets in the formation of side cores and is laminated without caulking or welding so that there is no loss of magnetic energy, caulking defects, or welding defects.

  The ignition coil for an internal combustion engine according to the present embodiment is mounted on an upper portion of a high voltage conductor portion that is inserted and arranged in a plug hole of each cylinder of the internal combustion engine, and is used by being directly connected to the ignition plug via the high pressure conductor portion. The present invention is applied to an ignition coil for an independent ignition type internal combustion engine.

  The side core portion and the center core portion constitute a closed magnetic circuit. The center core portion has one end facing the inner peripheral surface of the side core portion and facing the other end, and the other end facing the side core portion via the gap.

  The primary coil is wound around the outer periphery of the primary bobbin in which the center core portion is housed, and the secondary coil is wound around the outer periphery of the secondary bobbin disposed outside the primary bobbin. The primary bobbin and the secondary bobbin are connected to the center core. The coil unit is constituted by the above.

  The coil unit is accommodated in a cylindrical coil unit case, and the insulating resin is enclosed in the coil unit case and integrated.

  The side core curls a magnetic steel plate of the same size cut in a strip shape into a circular tube, and holds it around the outer periphery of the coil unit case with the force of shrinking a plurality of sheets inwardly without using caulking or welding.

  Thus, the side core can be attached to the outer periphery of the coil unit case with one touch.

  Moreover, even if it is the cylindrical magnetic steel plate of the same shape, since the space | interval of a slit will spread automatically and it will hold on the outer periphery of a lower magnetic steel plate as it overlaps outside, mutual adhesiveness is better than the thing of a rectangular cross section.

  One end of the center core is provided with a curved surface that extends in a fan shape over a wider width than the rod-shaped metal laminated steel plate along the inner peripheral surface of the side core, and the center of the curved surface overlaps the slit portion of the side core. Since it is arranged so that the curved surface faces the inner peripheral surface of both ends of the curled cylindrical side core, the magnetic flux saturation of the closed magnetic path is relaxed, the amount of magnetic flux is increased, and the magnetic properties are improved. Become.

  When the magnetic steel plate of the side core is mounted on the outer periphery of the coil unit case, the slit portions of the magnetic steel plate of the side core are split on both sides within the elastic deformation and fitted into the outer periphery from one end of the cylindrical coil unit case. At this time, the side core magnetic steel plate is fixed by being held on the outer periphery of the coil unit case by a force that causes the magnetic steel plate of the side core to shrink inward.

  The cylindrical coil unit case is provided with at least one protrusion (in the embodiment, two formed at a specific interval) protruding radially from the outer periphery of the coil unit case from one end to the other end. The slit of the magnetic steel plate is locked to prevent the magnetic steel plate from rotating.

  The other end of the center core protrudes outward from a notch or hole provided in the coil unit case, and is in contact with or close to the inner peripheral surface of the side core. The curved surface of the other end is in close contact with the inner peripheral surface of the coil unit case, and a gap is formed between the inner peripheral surface of the side core by the thickness of the coil unit case, and this gap suppresses saturation of the magnetic flux. Acts as a magnetic gap.

  By arranging the slit portion of the side core on the gap side, the magnetic flux of the closed magnetic path is efficiently concentrated on the curved surface of the center core, and the magnetic characteristics are improved.

  In addition, according to the present embodiment, the side core of the ignition coil can be manufactured with simple processing without waste of material, and an ignition coil having an inexpensive and highly efficient magnetic structure can be supplied.

  Furthermore, since the side core is circular, there is no portion where stress is concentrated, and there is little risk of damage or corrosion.

  An embodiment of the example is summarized as follows.

Embodiment 1
Side iron core provided on the outer periphery of an iron core primary coil and secondary coil in an internal combustion engine ignition coil having an iron core that forms a closed magnetic circuit with a gap and a primary coil and a secondary coil wound around the outer periphery of the iron core Is an ignition coil characterized in that electromagnetic steel sheets of the same size cut in a strip shape are bent into a tubular shape and a plurality of layers are laminated without caulking or welding.

[Embodiment 2]
The ignition coil described in Embodiment 1 is provided with a structure in which the side iron core is disposed by being lightly press-fitted into a circular iron core cover made of a thermoplastic resin provided on an inner periphery of the side iron core. .

[Embodiment 3]
The ignition coil described in Embodiment 2 is characterized in that in the direction in which the side iron core is cut into a strip shape, the longitudinal direction of the side iron core is the rolling direction of the magnetic steel sheet.

[Embodiment 4]
In the ignition coil described in the third embodiment, both bent ends of the side iron core are arranged at one end of a center iron core disposed on the inner periphery of the primary coil and the secondary coil, and the side of the center iron core An ignition coil provided with a structure in which a side where both ends of the iron core are disposed spreads in a fan shape and a cross-sectional area of the center iron core is enlarged.

[Embodiment 5]
In the ignition coil described in the fourth embodiment, the iron core cover is provided with a protrusion on the side surface of the tubular shape, and both ends of the side iron core are fixed to the protrusion, and the periphery of the side iron core is stopped and positioned. Characteristic ignition coil.

[Embodiment 6]
In the ignition coil described in the fifth embodiment, the outermost magnetic steel plate of the side iron core is bent at one end, and the bent portion and the GND terminal of the coil are electrically connected. Ignition coil.

  The present invention relates to an ignition coil device for an internal combustion engine that supplies a high voltage to generate a spark discharge in an ignition plug of the internal combustion engine.

  It can also be used as a closed magnetic circuit type transformer.

The top view of the ignition coil of this invention. It is a figure which shows the AA cross section of the ignition coil in 1st Embodiment. It is a figure which shows the BB cross section of the ignition coil in 1st Embodiment. It is a figure which shows the coil part cross section of the ignition coil in 1st Embodiment. (A), (b) is a figure which shows the assembly method of the coil unit case and side core of this invention. It is a figure which shows the AA cross section of the ignition coil in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ignition coil 2 for internal combustion engines Primary bobbin 3 Primary coil 4 Secondary bobbin 5 Secondary coil 6A Center core 6B Side core 7 Coil case 8 Terminal 9 High voltage terminal 10 Insulating resin 11 Coil unit case 12 Igniter chip (ignition circuit unit)

Claims (12)

A rod-shaped center core formed by laminating magnetic steel plates;
A coil part composed of a primary coil part and a secondary coil part, and having an insertion hole of the center core in the center;
A side core provided so as to surround the coil unit portion composed of the coil portion and the center core;
The center core is disposed so as to cross the inside of the side core, and one closed magnetic path is formed by the center core and a half portion of the side core, and another portion is formed by the center core and the remaining half portion of the side core. A closed magnetic path is configured, and as a result, a pair of magnetic paths having the center core as a common magnetic path are formed to be linked to the coil portion,
The side core is composed of a metal laminated steel plate made of magnetic material laminated in a radial direction,
A cylindrical resin-made coil unit case is interposed between the coil unit and the side core,
The laminated steel sheet of the side core is provided with a slit along the axial direction,
In the state where it is mounted on the outer periphery of the coil unit case, it is configured such that the gap between the slits is wider than the natural state.
An ignition coil device configured to be hugged on the outer periphery of the coil unit case by its own elastic force. In claim 1,
An ignition coil device in which the diameter of the coil portion is configured to be smaller at both ends than the axially central portion. In the one according to claim 1 or 2,
One end of the center core is an ignition coil device that penetrates the coil unit case and faces the inner peripheral surface of the side core. In claim 3,
The other end of the center core has a phase portion along the inner diameter of the coil unit case, and the phase portion is formed over a circumferential dimension range wider than the width of the center core. The thing of Claim 4 WHEREIN:
An ignition coil device in which a concavo-convex portion is provided between the phase portion of the center core and an inner peripheral surface of the coil unit case. In claim 1,
The slit of each laminated steel plate of the said side core is an ignition coil apparatus arrange | positioned in a part at the one side end of the said center core. What is described in claim 6,
The slit coil interval is an ignition coil device in which the slit interval increases toward the outer laminated steel sheet when the coil unit case is mounted on the outer periphery. In any of claims 6 or 7,
An ignition coil device, wherein at least one protrusion that protrudes radially outward and extends in an axial direction is formed on an outer periphery of the ignition coil case at a position that matches the slit. In claim 1,
A coil case that houses an assembly body in which the coil unit case and the side core are combined;
The coil case is provided with a space for storing the igniter chip and a connector portion.
The coil unit case includes an igniter chip storage space, and the coil case is filled with insulating resin,
The insulating resin is an ignition coil device that is insulated from the outside including the assembly body, the igniter chip, the ignition coil, the control circuit chip, and the conductor portion that connects the additive circuit chip and the connector. The assembly storage portion of the coil case according to claim 9 has an inner peripheral cylindrical surface facing the outer peripheral surface of the side core,
A recess for receiving the large diameter portion of the central portion of the coil is formed on the bottom surface portion thereof,
An ignition coil device in which a shelf portion on which the assembly is placed is formed between the inner peripheral cylindrical surface and the recess. The thing of Claim 10 WHEREIN:
The assembly is an ignition coil device mounted on the shelf through a stress relaxation member disposed at least between the side core and the shelf. In the thing in any one of Claims 1 thru | or 11,
The plurality of the laminated steel plates forming the side core are formed as a cylindrical body, are the same diameter before being mounted on the outer periphery of the coil unit case, and the slits are formed to have substantially the same width. Coil device.

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