JP2010010163A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil which is easily assembled and does not cause a problem of a contact failure. <P>SOLUTION: The ignition coil Cl is constituted by storing a coil assembly including a primary coil L1 and a second coil L2 into a coil case 30, and supplies a high voltage to an ignition plug PG through a high-voltage terminal OUT disposed in the coil case 30. The coil case 30 is configured to connect the coil assembly to the high-voltage terminal OUT when vertically receiving from above, the coil assembly generating a magnetic field on a horizontal plane; and the high-voltage terminal OUT is formed integrally of a cylinder portion 31A disposed in the center of a bottom of the coil case, a connection portion 31B which extends radially outward from the cylinder portion 31A, and a base end 31D constituted in such a manner that the folding-back angle of a plate material edge termination is elastically deformed, and an output terminal TR of the secondary coil is in repulsive contact with the plate material edge termination. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ignition coil in which a coil assembly having a primary coil and a secondary coil forms a magnetic field on a horizontal plane, while an output voltage of the secondary coil is supplied to a spark plug positioned vertically below the coil assembly. About.

As an ignition coil in which the coil assembly forms a magnetic field on a horizontal plane and the output voltage of the secondary coil is supplied to a spark plug positioned vertically below the coil assembly, the invention described in Patent Document 1 is known. It has been.
JP 2008-21794 A

  In this invention, when the coil assembly is lowered from above the coil case, the electrical connection between the output terminal of the secondary coil and the high voltage terminal leading to the spark plug is completed, thereby facilitating the assembly work. ing. In the assembled state, the cylindrical high-voltage terminal and the output terminal of the secondary coil are connected via a relay member obtained by bending a wire.

  However, in the above invention, it is necessary to solder the high-voltage terminal and the relay member prior to the assembling work, and this preliminary work is not only complicated, but also the problem that the conductivity is impaired when the soldering is poor. there were.

  Further, since the output terminal of the secondary coil is merely in contact with the relay member, there is a risk of poor contact if the assembled state is incomplete. In particular, in the invention of Patent Document 1, since not only the output terminal of the secondary coil but also the relay member is composed of a wire, if the bending state of any member is inaccurate, even if the assembled state is complete, There was a risk that the contact area would be insufficient.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ignition coil that is easy to assemble and that does not cause a problem of poor contact.

  In order to achieve the above object, the present invention includes a coil assembly including a primary coil that receives an ignition signal and a secondary coil that generates a high voltage by electromagnetic coupling with the primary coil. An ignition coil for an internal combustion engine that supplies a high voltage from the secondary coil to an ignition plug via a high-voltage terminal disposed in the coil case, wherein the coil case generates a magnetic field on a horizontal plane When the assembly is received from vertically above, the coil assembly and the high-voltage terminal are connected to each other, and the high-voltage terminal includes a tip portion disposed at the bottom center of the coil case, and the tip portion. A continuous portion extending radially outward and a base end portion configured to be elastically deformable at a folding end angle of the plate material, and the output terminal of the secondary coil is the base end We are in contact with the elastic to the plate end.

  In the present invention, the terms “horizontal plane” and “vertically upward” are used for the sake of convenience, but only mean a rough direction at the time of assembly work, and are limited to an accurate direction or a direction in use. is not.

  In the present invention, since the high-voltage terminal is integrally formed, soldering work with other members is not required, and there is no problem of conductivity due to poor connection. In addition, since the plate material end of the high voltage terminal and the output terminal of the secondary coil are in elastic contact, not only the contact area is wide, but the problem of poor contact does not occur.

  In the present invention, the tip of the high-voltage terminal is not particularly limited, but is preferably configured in a substantially cylindrical shape. Further, the continuous portion of the high-voltage terminal is preferably configured in a plate shape instead of a linear shape.

  The high-voltage terminal of the present invention should preferably be further provided with a fixing part on which a positioning part is formed. This fixing portion is preferably provided between the connecting portion and the base end portion. The positioning part is realized by a notch groove, for example.

  The coil case of the present invention is preferably provided with a central opening for receiving the tip of the high voltage terminal. In the case where the tip portion is formed in a substantially cylindrical shape, the central opening is correspondingly realized by a cylindrical hole. Note that the central opening is not necessarily formed at the exact center position of the coil case.

  The coil case of the present invention is preferably formed with a guide portion that receives the continuous portion. The guide portion is preferably configured to include a vertical wall on the base end side and a pair of guide walls extending from the vertical wall toward the central opening, and the connecting portion of the high-voltage terminal is the pair of guide walls. Contained between walls. Here, it is optimal that the two positioning portions formed on the fixing portion of the high-voltage terminal are engaged with the positioning portions respectively provided on the pair of guide walls.

  The output terminal of the secondary coil of the present invention is preferably configured by bending one bar, and in the gap between the flanges formed on the secondary bobbin around which the secondary coil winding is wound, The main body is fitted. The output terminal of the secondary coil has a horizontal engagement portion bent in a U-shape extending in the axial direction of the secondary bobbin with the main body portion fitted in the gap between the flanges, It is preferable that the folded plate end of the high voltage terminal is accommodated in the bent horizontal engaging portion.

  According to the present invention described above, it is possible to realize an ignition coil that is easy to assemble and that does not cause a problem of poor contact.

  Hereinafter, the present invention will be described in detail based on examples. FIG. 1A is a circuit diagram showing an ignition coil CL according to an embodiment, which outputs a high voltage to a DC input terminal Vcc that receives a battery voltage, a pulse input terminal SG that receives an ignition pulse, and an ignition plug PG. A high voltage output terminal OUT and a ground terminal GND are shown.

  The ignition coil CL includes a switching element Q that receives an ignition pulse from the control circuit and performs an ON / OFF operation, a primary coil L1 that is charged / discharged in response to the ON / OFF operation of the switching element Q, and a primary coil L1. The secondary coil L2 is electromagnetically coupled, and the diode D is connected in series to the secondary coil L2. Here, the diode D is disposed for the purpose of preventing reverse discharge, and the cathode terminal is connected to receive the battery voltage.

  The secondary coil L2 is configured by winding a secondary winding around a secondary bobbin 20 whose plan view is shown in FIG. 1D is a front view of the secondary bobbin 20, and FIG. 1E is a right side view with respect to the front of the secondary bobbin. Moreover, FIG.1 (c) has shown the output terminal TR of the secondary coil fitted by the secondary bobbin 20 from two orthogonal directions.

  The secondary bobbin 20 has a hollow square cylindrical bobbin body, and a plurality of winding sections SC... SC are formed by mutually parallel flanges FR1 to FR7 that are substantially upright on the bobbin body. The secondary winding starts to be wound from the lower side of FIG. 1B, and the upper winding end end point is connected to the output terminal TR of the secondary coil. The starting point of the secondary winding is connected to the anode terminal of the diode D.

  As shown in FIG. 1 (c), the output terminal TR is formed by bending a conductive wire (round bar), and its main body is closely fitted in the gap between the flanges FR7 and FR8 facing each other. Are combined. Specifically, the output terminal TR is connected to the lower horizontal portion 1 and the lower horizontal portion 7 that are in contact with the bobbin main body, the vertical portions 2 and 6 standing upright from the lower horizontal portions 1 and 7, and the vertical portions 2 and 6. Upper horizontal portions 3 and 5 that are orthogonal to each other, a horizontal engagement portion 4 that is bent in a U-shape perpendicular to the upper horizontal portions 3 and 5, and an inclined portion 8 that rises obliquely from the lower horizontal portion 7. Is done. The end of the secondary winding is connected to the tip of the inclined portion 8.

  As shown in the figure, the whole (main body part) excluding the horizontal engagement part 4 forms the same plane, and these main body parts are fitted between the flanges FR7 and FR8. On the other hand, the horizontal engagement portion 4 extends in the horizontal direction through a notch formed in the upper portion of the flange FR8. As described above, the horizontal engaging portion 4 is formed in a U shape by bending the upper side 4a and the left and right pieces 4b and 4c, but the inside of the left and right pieces 4b and 4c is set to the inner separation distance T1. Has been. Further, the inner bending distance D1 is set from the flange to the inner side of the upper side 4a (see FIG. 1C).

  Although the secondary coil L2 is generally configured as described above, the primary coil L1 in which the primary winding is wound around the primary bobbin is inserted into the hollow portion HO of the secondary bobbin 20. The primary bobbin of the primary coil L1 is also formed in a hollow square cylindrical shape, and a part of the annular iron core is inserted into the primary bobbin. The annular iron core is configured, for example, by contacting a pair of iron cores 21A and 21B configured in an E shape inside and outside the secondary bobbin 20 (see FIG. 1 (f)). In such a case, the central portions Ca and Cb of the iron cores 21A and 21B are inserted into the hollow portions of the primary bobbins and are brought into contact with each other.

  Fig.2 (a) is a top view which shows the coil case 30 which receives the coil assembly which assembled | attached the primary coil L1 and the secondary coil L2 from the perpendicular | vertical upper direction. 2B is a cross-sectional view taken along line AA in FIG. 2A, and FIG. 2C is a perspective view showing a part of the coil case 30. FIG.

  The coil case 30 includes a first housing portion 30A that receives the coil assembly and the switching element Q, a second housing portion 30B that receives the connection terminal, a projecting portion 30C that projects toward the spark plug of the plug hole, and an ignition coil CL. Is roughly divided into a mounting portion 30D for attaching to the engine box. Here, the connection terminal is a member that connects the DC input terminal Vcc, the pulse input terminal SG, and the ground terminal GND of the ignition coil CL to an external circuit.

  An insulating rubber material that houses the coil spring SP is attached to the protrusion 30C of the coil case 30 from below. As a result, the coil spring SP is strongly brought into contact with the high-voltage terminal OUT arranged at the bottom of the first housing portion 30A, thereby realizing a reliable electrical connection between the ignition coil CL and the ignition plug PG. The high voltage terminal OUT constitutes a part of the high voltage output terminal OUT (FIG. 1A) of the ignition coil CL together with the coil spring SP.

  The bottom surface of the first accommodating portion 30A is formed in a mortar shape, and a cylindrical hole 32 into which the tip of the high voltage terminal OUT is fitted is formed at the bottom. And the guide part 33 is integrally molded by the coil case inner surface toward the cylindrical hole 32 from the uppermost part of a mortar surface. The guide part 33 is a part for positioning and receiving a ladle-shaped high-voltage terminal OUT. Specifically, the guide part 33 includes a vertical wall 34 and a pair of guide walls 35, 35 extending in parallel to the vertical wall 34. It consists of The guide wall 35 is divided into a first part 35A extending horizontally and a second part 35B descending along the mortar surface, and a notch groove 36 is formed in the first part 35A.

  FIG. 3 illustrates a handle-shaped high-voltage terminal OUT. The high-voltage terminal OUT is formed by pressing a single conductor plate into an arbitrary shape and does not require soldering or the like during assembly. The high-voltage terminal OUT includes a bottomed cylindrical cylindrical portion 31A located on the distal end side, a continuous portion 31B provided continuously with the cylindrical portion 31A, and a wide fixed portion 31C continuous perpendicular to the continuous portion 31B. The base end portion 31D is folded back and bent.

  The cylindrical portion 31 </ b> A is configured to correspond to the columnar hole 32 of the coil case, and has a cylindrical shape that fits into the columnar hole 32. In addition, a protruding portion 40 that protrudes toward the inner surface is formed at the center of the bottom surface of the cylindrical portion 31A, and cutout portions 41 that are notched in an arc shape are provided at 120 ° intervals on the upper peripheral edge of the cylindrical portion 31A. The raised portion 40 is formed for the purpose of suppressing the amount of resin in the case as much as possible, and the notched portion 41 exists because of the necessity for molding the high-voltage terminal OUT.

  The connecting portion 31 </ b> B is configured to correspond to a pair of guide walls 35 formed in the coil case 30, and is formed slightly narrower than a gap formed by the two guide walls 35, 35. In addition, two notch grooves 42 and 42 corresponding to the notch grooves 36 and 36 formed in the coil case 30 are formed in the fixing portion 31C. When the coil assembly is lowered when the ignition coil CL is assembled, the notch groove 36 of the coil case and the notch groove 42 of the high-voltage terminal OUT are fitted to complete the positioning and attachment work.

  The base end portion 31D is formed in an inverted substantially V shape in cross-sectional view by folding the end of the plate material, and is configured such that the turn-back angle θ of the plate material end is elastically deformable. That is, the base end portion 31D is configured to be able to expand and contract in the plate thickness direction, and is configured so that the inverted substantially V-shaped opening angle θ can be appropriately changed (FIG. 3C). Here, the separation distance between the outer end surface of the starting end portion of the base end portion 31D and the outer end surface of the terminal end portion of the base end portion 31D is set to a horizontal distance D2 in a free state (see FIG. 3B). ). Here, the horizontal distance D2 is set to be larger than the inner bending distance D1 of the horizontal engagement portion 4 of the secondary coil output terminal TR (D2> D1).

  Further, the base end portion 31D has a substantially trapezoidal shape with a plate width narrowing from the bottom portion of the maximum plate width T2 toward the folded top portion (see FIG. 3B). Here, since the maximum plate width T2 of the base end portion 31D is set narrower than the left and right width T1 of the horizontal engagement portion 4 of the secondary coil output terminal TR (T1> T2), when the ignition coil CL is assembled, The base end portion 31 </ b> D can be accommodated inside the horizontal engagement portion 4. In the state where the base end portion 31D is accommodated in the horizontal engagement portion 4, the base end portion 31D contracts in the plate thickness direction, so that reliable electrical connection is realized.

  Then, the manufacturing method of the ignition coil CL which consists of the above structure is demonstrated. First, the primary coil L1 is assembled inside the secondary bobbin 20 of the secondary coil L2, thereby completing the coil assembly. In this completed state, the assembly of the diode D and the output terminal TR has been completed. Further, the arrangement of the annular iron core forming the magnetic flux path of the primary coil L1 and the secondary coil L2 is also completed.

  Next, a handle-like high voltage terminal OUT is assembled to the bottom of the coil case 30. Specifically, the cylindrical portion 31 </ b> A of the high voltage terminal OUT is fitted into the cylindrical hole 32 of the coil case 30, and the connecting portion 31 </ b> B of the high voltage terminal OUT is seated between the guide walls 35 and 35 of the coil case 30. . Further, the notch groove 42 of the high-voltage terminal OUT and the notch groove 36 of the coil case guide wall 35 are fitted to each other. In this assembled state, the base end portion 31D of the high-voltage terminal OUT is positioned on the front surface of the vertical wall 34 and takes a folded posture.

  As described above, since the high-voltage terminal OUT is positioned on the guide portion 33 and attached to the coil case 30, the assembling operation is completed easily and accurately. Further, the high-voltage terminal OUT is simply disposed, and an extra work such as soldering is unnecessary.

  Next, the coil assembly is dropped into the first housing portion 30A of the coil case on which the high-voltage terminal OUT is seated. In this case, since the horizontal engagement portion 4 of the secondary coil L2 is positioned to be horizontal at the bottom of the coil assembly, the right direction in FIGS. 1B and 1D is the lowering direction of the coil assembly. Become.

  When the coil assembly is lowered, the horizontal engagement portion 4 of the secondary coil L2 is lowered toward the base end portion 31D of the high-voltage terminal OUT. Here, the maximum plate width T2 of the base end portion 31D of the high-voltage terminal OUT is set to be narrower than the left and right width T1 of the horizontal engagement portion 4 of the secondary coil output terminal TR. The base end portion 31 </ b> D receives the horizontal engagement portion 4 in a state of being surrounded by the engagement portion 4.

  As described above, since the base end portion 31D is formed in a trapezoidal shape with a narrow width toward the turning vertex, the trapezoidal side piece functions as a slide piece, and the coil assembly is lowered. To guide you accurately. Then, when the horizontal engagement portion 4 is lowered to the lowermost portion of the base end portion 31D, the assembly of the coil assembly to the coil case 30 is completed. In this embodiment, since the horizontal distance D2 of the base end portion 31D is set to be larger than the inner bending distance D1 of the horizontal engagement portion 4, the base end portion 31D contracts in the plate thickness direction, and the secondary coil The output terminal TR and the high-voltage terminal OUT are elastically contacted, and a reliable electrical connection is realized.

  As described above, according to the present embodiment, the secondary coil output terminal TR and the high-voltage terminal OUT can be obtained simply by lowering the coil assembly that generates a magnetic field on a horizontal plane from the vertically upper side and receiving it in the coil case 30. Connected securely.

  Subsequently, the connection terminal and the switching element are arranged in the coil case, and necessary electrical connection is performed by soldering work or the like. Finally, an insulating resin such as an epoxy resin fills the gap in the coil case 30 to complete the ignition coil CL. In use, an insulating rubber material containing the coil spring SP is fitted into the protrusion 30C of the coil case.

  As mentioned above, although the Example of this invention was described concretely, the concrete description content does not specifically limit this invention. In particular, the specific shape and arrangement position of the output terminal TR of the secondary coil and the high voltage terminal OUT connected thereto are not limited to the specific description of the embodiment. For example, the horizontal engagement portion 4 of the secondary coil output terminal TR may be protruded outward in the horizontal direction from the secondary bobbin 20.

The circuit structure of an ignition coil and the structural member of a secondary coil are illustrated. It is drawing explaining a coil case. It is drawing explaining a high voltage terminal.

Explanation of symbols

L1 Primary coil L2 Secondary coil 30 Coil case OUT High voltage terminal PG Ignition plug CL Ignition coil 31A Tip part 31B Connection part 31D Base end part TR Output terminal

Claims (8)

A coil assembly including a primary coil that receives an ignition signal and a secondary coil that generates a high voltage by electromagnetic coupling with the primary coil is housed in a coil case,
An ignition coil for an internal combustion engine that supplies a high voltage from the secondary coil to a spark plug via a high-voltage terminal disposed in a coil case,
The coil case is configured to connect the coil assembly and the high-voltage terminal when the coil assembly that generates a magnetic field on a horizontal plane is received from above.
The high-voltage terminal includes a distal end portion disposed in the center of the bottom portion of the coil case, a continuous portion extending radially outward from the distal end portion, and a base end portion configured to be elastically deformable at the folding end of the plate material. And are integrally formed,
An ignition coil for an internal combustion engine, characterized in that an output terminal of the secondary coil is elastically contacted with a plate end of the base end portion.   The ignition coil according to claim 1, wherein the high-voltage terminal is provided with a fixing portion in which a positioning portion is formed.   The ignition coil according to claim 1 or 2, wherein the coil case is provided with a central opening for receiving the tip portion.   The ignition coil according to any one of claims 1 to 3, wherein a guide portion that receives the connecting portion is formed in the coil case. The guide part includes a vertical wall on the base end side and a pair of guide walls extending from the vertical wall toward the central opening,
The ignition coil according to claim 4, wherein the continuous portion of the high-voltage terminal is accommodated between the pair of guide walls.   The ignition coil according to claim 5, wherein two positioning portions formed on a fixing portion of the high-voltage terminal are engaged with positioning portions respectively provided on the pair of guide walls.   The output terminal of the secondary coil is formed by bending a single bar, and the main body of the output terminal is placed in the gap between the flanges formed on the secondary bobbin around which the secondary coil winding is wound. The ignition coil according to any one of claims 1 to 6, which is fitted. The output terminal of the secondary coil has a horizontal engagement portion bent in a U-shape extending in the axial direction of the secondary bobbin with its main body portion fitted in the gap between the flanges,
The ignition coil according to claim 7, wherein the folded plate member end of the high voltage terminal is accommodated in the bent horizontal engaging portion.

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