JP5948839B2 - Ignition coil for internal combustion engine - Google Patents

Description

  The present invention relates to an ignition coil for an internal combustion engine used for generating a spark from a spark plug disposed in a combustion chamber of the internal combustion engine.

An ignition coil used in an internal combustion engine such as an engine has a primary coil and a secondary coil that generates an induced electromotive force when power to the primary coil is interrupted, concentrically arranged on the inner and outer circumferences in a case. Configured. An igniter is formed in the case. The igniter is formed by housing a control circuit board for energizing and shutting off the primary coil in the mold resin.
The igniter is formed by pulling out a plurality of igniter terminals from the control circuit board to the outside of the mold resin. The plurality of igniter terminals are connected to the plurality of connector terminals provided in the connector portion of the case by welding, soldering, or the like.
For example, in the ignition coil for an internal combustion engine disclosed in Patent Document 1, the input terminal of the primary coil, the igniter terminal, and the connector terminal are overlapped, and the three overlapped terminals are sandwiched by U-shaped joining terminals. And connecting them. As a result, the connector portions are connected with less variation in the joining state without performing welding, soldering, or the like.

JP 2011-151181 A

  However, in Patent Document 1, the three terminals are connected using joint terminals that are separate components. For this reason, the number of parts for connection increases, and the igniter terminal and the connector terminal cannot be connected with a simple structure.

  The present invention has been made in view of such a background, and can be used for an internal combustion engine in which each igniter terminal and each connector terminal can be connected by a very simple structure by crimping without performing welding, soldering, or the like. It was obtained in an attempt to provide an ignition coil.

The present invention comprises a primary coil and a secondary coil that are concentrically arranged on the inner and outer peripheries,
A control circuit board for energizing and shutting off the primary coil, a mold resin for covering the control circuit board, and an igniter having a plurality of igniter terminals drawn out of the mold resin from the control circuit board;
A case in which the primary and secondary coils and the igniter are disposed;
A connector case portion attached to the case, and a connector having a plurality of connector terminals disposed on the connector case portion and engaged with the plurality of igniter terminals,
One of the plurality of igniter terminals and the plurality of connector terminals has a folded portion folded back in a U shape by a base end side conductor portion and a distal end side conductor portion, and the other is the above folded portion. Has an insertion part to be inserted into an insertion recess formed in the inner part of
The aforementioned front end side conductor of the folded portion, in an internal combustion engine ignition coil, characterized in that protrudes toward the base end side conductor, the protrusion that contacts the side surface of the fitting portion is formed (Claim 1).

The ignition coil for an internal combustion engine can easily connect a plurality of igniter terminals in an igniter and a plurality of connector terminals in a connector without performing welding, soldering, or the like.
Specifically, either one of the plurality of igniter terminals and the plurality of connector terminals has a folded portion that is folded back in a U shape, and the other is a fitting recess formed in an inner portion of the folded portion. It has an insertion part to be inserted. Moreover, the folding | turning part has the projection part which protrudes in the direction which mutually faces in at least one of the base end side conductor part and front end side conductor part which form U shape.

When connecting the plurality of igniter terminals and the plurality of connector terminals, the igniter and the connector are relatively moved so that the insertion portion is inserted into the insertion recess of the folded portion. At this time, the insertion portion is guided into the insertion recess, and the projection formed on the folded portion strongly contacts the plate surface of the insertion portion. And each igniter terminal and each connector terminal are crimped | bonded.
Thereby, each igniter terminal and each connector terminal can be connected with an extremely simple structure by pressure bonding without performing welding, soldering, or the like.

Sectional drawing which shows the ignition coil for internal combustion engines before filling a case with the thermosetting resin concerning the Example in the state seen from the side. The top view which shows the state which looked at the ignition coil for internal combustion engines before filling a case with the thermosetting resin concerning an Example from upper direction. The top view shown in the state which looked at the periphery of the connector attached to the case concerning an Example from upper direction. The perspective view which shows the periphery of the connector before attaching to a case concerning an Example. Sectional drawing which shows the state which the igniter terminal and connector terminal concerning the Example engaged. Sectional drawing which shows the state which engages an igniter terminal and a connector terminal concerning an Example. Sectional drawing which shows the state which the igniter terminal concerning another Example and the other connector terminal engaged. Sectional drawing which shows the state which the igniter terminal concerning another Example and the other connector terminal engaged. The perspective view which shows the other igniter concerning an Example.

A preferred embodiment of the above-described ignition coil for an internal combustion engine will be described.
In the ignition coil for the internal combustion engine, the plurality of fitting portions are fitted into the plurality of fitting recesses, the plurality of igniter terminals and said plurality of connector terminals may be engaged (claim 3) .
In this case, a sufficient crimping force can be applied between each igniter terminal and each connector terminal, and these connections can be made more reliable.

Further, the entire folded portion is formed in one direction in the plurality of connector terminals, and the entire fitting portion is formed in the other direction in the plurality of igniter terminals, When the igniter is attached to the connector, the fitting portions of the plurality of igniter terminals may be configured to be fitted into the fitting recesses of the plurality of connector terminals (claim 4 ).
In this case, using the operation of attaching the igniter to the connector, the fitting portion of each igniter terminal can be simultaneously fitted into the fitting recess of each connector terminal. Therefore, connection between each igniter terminal and each connector terminal can be performed more easily.

Hereinafter, embodiments of the ignition coil for an internal combustion engine will be described with reference to the drawings.
FIG. 1 shows a cross-sectional view of an internal combustion engine ignition coil 1 (hereinafter simply referred to as an ignition coil 1) before the case 5 is filled with a thermosetting resin as viewed from the side.
As shown in the figure, the ignition coil 1 of this example includes a primary coil 21 and a secondary coil 22, an igniter 3, a case 5, and a connector 4.
The primary coil 21 and the secondary coil 22 are concentrically arranged on the inner and outer circumferences. The igniter 3 includes a control circuit board 32 that energizes and interrupts the primary coil 21, a mold resin 33 that covers the control circuit board 32, and a plurality of igniter terminals drawn from the control circuit board 32 to the outside of the mold resin 33. 31.

The case 5 is configured to accommodate the primary coil 21 and the secondary coil 22 and the igniter 3. The connector 4 includes a resin connector case portion 45 attached to the case 5, and a plurality of connector terminals 41 that are disposed in the connector case portion 45 and engaged with the plurality of igniter terminals 31.
The plurality of connector terminals 41 have folded portions 411 that are folded back in a U shape, and the plurality of igniter terminals 31 have fitting portions 311 that are fitted into fitting recesses 412 formed in the inner portion of the folded portion 411. Have. The folded portion 411 has a protruding portion 431 protruding toward the proximal end side conductor portion 42 forming the other side on the distal end side conductor portion 43 forming one side of the U shape.

Hereinafter, the ignition coil 1 of this example will be described in detail with reference to FIGS.
As shown in FIG. 1, the ignition coil 1 of the present example is formed by arranging components such as a primary coil 21, a secondary coil 22, a center core 23, an outer core 24, and an igniter 3 in a case 5. .
In the case 5, the primary coil 21 and the secondary coil 22 are arranged concentrically on the inner and outer circumferences, and the central core 23 is arranged on the inner circumference side of the primary coil 21 and the secondary coil 22. The outer peripheral core 24 is disposed on the outer peripheral side of the primary coil 21 and the secondary coil 22.

The primary coil 21 is formed by a primary electric wire (magnet wire). The secondary coil 22 is formed of a secondary electric wire (magnet wire) that is wound around the outer periphery of a secondary spool 25 made of resin and is thinner than the primary electric wire. The secondary coil 22 is disposed on the outer peripheral side of the primary coil 21.
The primary coil 21 in this example is disposed on the outer periphery of the central core 23. The primary coil 21 can be formed by winding around the outer periphery of the central core 23. Moreover, the primary coil 21 can also be formed by winding around the outer periphery of the primary spool which consists of resin.
The central core 23 is formed by compression-molding soft magnetic powder. The central core 23 can also be formed by laminating a number of electromagnetic steel plates made of a soft magnetic material. The outer peripheral core 24 is formed by compression-molding soft magnetic powder.

In FIG. 2, the ignition coil 1 before filling the case 5 with the thermosetting resin is shown in a plan view as viewed from above.
As shown in the figure, the outer peripheral core 24 includes a pair of outer peripheral side portions 241 positioned on the outer peripheral side of the primary coil 21, the secondary coil 22 and the central core 23, and the primary coil 21, the secondary coil 22 and the central core 23. A pair of axial portions 242 located on both sides in the axial direction are connected to each other to form a square ring shape.
The case 5 is formed in a substantially square shape in accordance with the shape of the outer core 24, and an opening 37 for injecting a thermosetting resin (epoxy resin or the like) to be filled in the case 5 is provided on the upper end side. Have. The thermosetting resin (epoxy resin or the like) fixes the primary coil 21, the secondary coil 22, the center core 23, the outer core 24, and the like that have been positioned, and fixes the case within the case 5.

As shown in FIG. 1, a flange portion 54 for attaching the ignition coil 1 to an internal combustion engine (engine) is formed in the case 5 so as to protrude outward. A seal rubber 6 for sealing the opening of the plug hole is externally provided at the lower end of the case 5. The seal rubber 6 is attached to the opening of the plug hole in the engine, and seals the gap formed between the opening and the case 5.
In the case 5, an igniter 3 having a control circuit board 32 provided with a switching control circuit for energizing and interrupting the primary coil 21 is disposed. The secondary spool 25 of this example is configured to position the igniter 3, the central core 23, the primary coil 21 and the secondary coil 22 in the case 5 by positioning them.

In FIG. 3, the periphery of the connector 4 attached to the case 5 is shown by a plane viewed from above with the connector terminal 41 as a solid line and the other part as a two-dot chain line. In FIG. 4, the periphery of the connector 4 before being attached to the case 5 is shown in a perspective view.
As shown in each drawing, the connector 4 is a part for wiring the igniter 3 to the outside of the ignition coil 1. The plurality of connector terminals 41 have folded portions 411 at positions arranged inside the case 5, and have connection pin portions 44 for external connection at positions arranged outside the case 5. Each connector terminal 41 is insert-molded in the connector case portion 45, the folded portion 411 protrudes in the inner direction of the case 5, and the connection pin portion 44 protrudes in the outer direction of the case 5.
A hole 251 for placing the igniter 3 is formed between the secondary spool 25 and the connector case 45 (see FIG. 1).

As shown in FIGS. 1 and 2, a cutout 51 is formed on the side wall of the case 5 at a portion where the connector case 45 is disposed. The connector case portion 45 is formed with an engaging portion 451 that is engaged with an edge portion of the notch portion 51.
The case 5 is provided with an arrangement recess 52 for positioning the igniter 3 by positioning. The case 5 is formed with a receiving rib 53 for receiving the igniter 3.

As shown in FIG. 1, the insertion portion 311 of this example is formed in each igniter terminal 31 in the igniter 3, and the folded-back portion 411 and the insertion recess 412 are formed in each connector terminal 41 in the connector 4.
The igniter 3 has a plate shape, and each igniter terminal 31 and the fitting portion 311 are formed so as to project upward from the upper end surface (surface on the opening side of the case 5) of the igniter 3 in one direction in the ignition coil 1. Has been.
The entire folded portion 411 is formed in one direction in the plurality of connector terminals 41 arranged in the horizontal direction, and the entire fitting portion 311 is directed in the other direction in the plurality of igniter terminals 31 arranged in the horizontal direction. Is formed.

FIG. 5 is a cross-sectional view showing a state where the igniter terminal 31 and the connector terminal 41 are engaged. FIG. 6 is a cross-sectional view showing a state where the igniter terminal 31 and the connector terminal 41 are engaged.
The folded portion 411 of each connector terminal 41 in the connector 4 protrudes in the lateral direction from the inner side surface of the connector case portion 45, and then the base end side conductor portion 42 is formed upward in one direction in the ignition coil 1, At the upper end portion, it is folded back into a U shape, and a front end side conductor portion 43 is formed downward. And between the base end side conductor part 42 and the front end side conductor part 43, the insertion recessed part 412 is formed toward the downward direction.

The protruding portion 431 in this example is formed by bending a part of the distal end side conductor portion 43 into a V shape in the vicinity of the lower end side portion of the distal end side conductor portion 43 of the folded portion 411. The protrusion 431 is configured to bring the V-shaped tip 432 into contact with the side surface of the insertion portion 311.
The tip portion 432 of the protrusion 431 in a state before contacting the side surface of the fitting portion 311 is formed in a sharp shape (see FIG. 6). The pointed tip portion 432 having a sharp shape is set so as to be scraped off when coming into contact with the side surface of the fitting portion 311.
By pressing the fitting portion 311 with the projection 431, the surface roughness of the contact surface between the base end side conductor portion 42 and the fitting portion 311 is reduced, and the igniter terminal 31 and the connector terminal 41 are reliably connected. Can do. The contact resistance value between the igniter terminal 31 and the connector terminal 41 can be 10 mΩ or less.

The distal end side conductor portion 43 may have a shape in which the distal end side protruding portion 431 and the bent proximal end portion 433 are in contact with the fitting portion 311 of the igniter terminal 31. Further, as shown in FIG. 7, the tip-side conductor portion 43 can be formed such that only the tip-side protrusion 431 contacts the fitting portion 311 of the igniter terminal 31.
The shapes of the proximal end side conductor portion 42 and the distal end side conductor portion 43 can be various structures in which the protruding portion 431 presses the fitting portion 311.
The protrusions 431 can be provided not only on the distal end side conductor portion 43 but also on both the proximal end side conductor portion 42 and the distal end side conductor portion 43 as shown in FIG. A protruding portion provided on the base end side conductor portion 42 is denoted by reference numeral 421.

Further, the shape of the protruding portion 431 can be various shapes other than the V shape as long as the tip portion 432 is formed in a sharp shape. The shape of the protrusion 431 may be an embossed shape, for example.
The thickness of the igniter terminal 31 and the connector terminal 41 can be set within a range of 0.2 to 0.5 mm. Further, the length from the inner base end position of the folded portion 411 to the distal end portion 432 of the protrusion 431 of the distal end side conductor portion 43 can be set to 4 to 7 mm.

  Further, as shown in FIG. 9, folded portions 312 that are folded back in a U shape are formed on the plurality of igniter terminals 31, and fitting portions that are fitted into the fitting recesses 313 in the folded portions 312 are formed on the plurality of connector terminals 41. You can also. Also in this case, the protruding portion 314 can be formed on the folded portion 312. In this case, each connector terminal 41 and each igniter terminal 31 can be engaged by moving the igniter 3 from above the connector 4 in the connector 4.

As shown in FIG. 3, in this example, the conductor member 40 in a state where the plurality of connector terminals 41 are connected to each other is insert-molded into the connector case portion 45. And after performing insert molding, the connection part 401 in the conductor member 40 is parted, and the several connector terminal 41 is mutually cut | disconnected. In the figure, the connector terminal 41 is indicated by a solid line, and the connecting portion 401 of the conductor member 40 is indicated by grating.
By using the conductor member 40, it is easy to set the plurality of connector terminals 41 in a mold when performing insert molding.

  The plurality of connector terminals 41 are formed as a power supply terminal 41A, a ground terminal 41B, and an ignition signal terminal 41C. A connecting conductor portion 413 for connecting one winding end 211 of the primary coil 21 is formed on the power supply terminal 41A. The conductor member 40 is formed with a connection conductor portion 414 for connecting the other winding end 211 of the primary coil 21. The connecting conductor portion 414 is separated from the conductor member 40 by dividing the connecting portion 401 after the connector case portion 45 is formed. A structure similar to the folded portion 411 of the connector terminal 41 is formed at the end of the connection conductor portion 414.

In the connector case portion 45, a capacitor 26 is disposed, and the capacitor 26 is connected between the power supply terminal 41A and the ground terminal 41B. Thereby, the influence of the noise superimposed on the power supply terminal 41A can be reduced.
In the connector case 45, a diode 27 is disposed, and this diode 27 is connected between the low-voltage side winding end of the secondary coil 22 and the power supply terminal 41A.

In manufacturing the ignition coil 1, the igniter 3 is assembled to the connector 4. At this time, the fitting portions 311 of the plurality of igniter terminals 31 in the igniter 3 in the case 5 are fitted into the fitting recesses 412 of the plurality of connector terminals 41 in the connector 4. Moreover, the connector 4, the primary coil 21, the secondary coil 22, the center core 23, and the outer periphery core 24 are assembled | attached, and a temporary assembly is formed. When the temporary assembly is disposed in the case 5, the engagement portion 451 in the connector 4 of the temporary assembly is engaged with the notch 51 in the case 5. Further, when the igniter 3 attached to the connector 4 is assembled in the case 5, the igniter 3 is prevented from being displaced by the receiving rib 53.
When forming the temporary assembly, the primary coil 21 is wound around the outer periphery of the central core 23 in advance, and the secondary coil 22 is wound around the outer periphery of the secondary spool 25 in advance.

As shown in FIG. 6, when the plurality of insertion portions 311 are inserted into the plurality of insertion recesses 412, the tip portions 432 of the protruding portions 431 formed in a sharp shape are scraped off, and the plurality of igniter terminals 31 and the plurality of The connector terminal 41 is engaged.
In this way, the crimping connection between the fitting portion 311 of each igniter terminal 31 and the folded portion 411 of each connector terminal 41 is performed.
Thereafter, the gap in the case 5 is filled and cured with a thermosetting resin (epoxy resin or the like), and the primary coil 21, secondary coil 22, center core 23, outer core 24, secondary spool 25, igniter 3. Are fixed in the case 5 in an insulated state.

  As described above, in the ignition coil 1 of this example, when the plurality of igniter terminals 31 and the plurality of connector terminals 41 are connected, the insertion portion 311 is inserted into the insertion recess 412 of the folded portion 411. Thus, the igniter 3 and the connector 4 are moved relatively. At this time, the insertion portion 311 is guided into the insertion recess 412, and the protrusion 431 formed in the folded portion 411 strongly contacts the plate surface of the insertion portion 311. Then, the distal end portion 432 of the protrusion 431 of the connector terminal 41 is scraped off, and the fitting portion 311 of the igniter terminal 31 is strongly pressed against the proximal end side conductor portion 42 of the connector terminal 41.

Thus, each igniter terminal 31 and each connector terminal 41 are crimped. Accordingly, the igniter terminals 31 and the connector terminals 41 can be connected with an extremely simple structure by pressure bonding without performing welding, soldering, or the like.
Further, in this example, by using the operation of attaching the igniter 3 to the connector 4, the insertion portion 311 of each igniter terminal 31 can be inserted into the insertion recess 412 of each connector terminal 41. Therefore, each igniter terminal 31 and each connector terminal 41 can be more easily connected.

DESCRIPTION OF SYMBOLS 1 Ignition coil for internal combustion engines 21 Primary coil 22 Secondary coil 3 Igniter 31 Igniter terminal 311 Insertion part 32 Control circuit board 33 Mold resin 4 Connector 41 Connector terminal 411 Folding part 412 Insertion recessed part 42 Base end side conductor part 43 Front end side conductor part 431 Projection 432 Tip 45 Connector case 5 Case

Claims (4)

A primary coil and a secondary coil arranged concentrically on the inner and outer circumferences;
A control circuit board for energizing and shutting off the primary coil, a mold resin for covering the control circuit board, and an igniter having a plurality of igniter terminals drawn out of the mold resin from the control circuit board;
A case in which the primary and secondary coils and the igniter are disposed;
A connector case portion attached to the case, and a connector having a plurality of connector terminals disposed on the connector case portion and engaged with the plurality of igniter terminals,
One of the plurality of igniter terminals and the plurality of connector terminals has a folded portion folded back in a U shape by a base end side conductor portion and a distal end side conductor portion, and the other is the above folded portion. Has an insertion part to be inserted into an insertion recess formed in the inner part of
Above the distal side conductor of the folded portion, the ignition coil for an internal combustion engine, characterized in that protrudes toward the base end side conductor, the protrusion that contacts the side surface of the fitting portion is formed. The ignition coil for an internal combustion engine according to claim 1, wherein the protrusion is formed on a tip side portion of the tip side conductor portion.
  An ignition coil for an internal combustion engine, wherein a portion in contact with a side surface of the fitting portion is formed in a proximal end portion of the distal end side conductor portion. The ignition coil for an internal combustion engine according to claim 1 or 2, wherein the plurality of fitting portions are fitted into the plurality of fitting recesses, and the plurality of igniter terminals and the plurality of connector terminals are engaged. An ignition coil for an internal combustion engine. The ignition coil for an internal combustion engine according to any one of claims 1 to 3, wherein the entire folded portion is formed in one direction at the plurality of connector terminals,
  The entire fitting portion is formed in the other direction in the plurality of igniter terminals,
  An ignition coil for an internal combustion engine, wherein when the igniter is attached to the connector, the fitting portions of the plurality of igniter terminals are fitted into the fitting recesses of the plurality of connector terminals.

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