JP2008153581A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine that can improve workability and productivity when a permanent magnet flake is included between one end of a central iron core around which a primary coil is wound and the inner periphery of an outer-ring iron core that surrounds the primary coil to enhance the capabilities of the ignition coil. <P>SOLUTION: An ignition coil for an internal combustion engine laminates and threads a central iron core, which makes up a closed magnetic circuit, in the inner periphery of a primary coil fitted into the inner periphery of a secondary coil, and includes a permanent magnet flake into a position brought into contact with the inner periphery of the outer-ring iron core making up the closed magnet circuit surrounding the primary and secondary coils at one end of the central iron core, wherein because a positioning member for positioning the permanent magnet flake is provided at one end of the central iron core, this can assure the positioning when including the flake of the permanent magnet between one end of the central iron core and the inner periphery of the outer-ring iron core, thus improving the workability and productivity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ignition coil for an internal combustion engine for generating a spark discharge in an ignition plug of an engine such as an automobile.

  In general, as shown in FIG. 3, a molded type ignition coil for an internal combustion engine includes a secondary coil 2, a primary coil 1 that penetrates the inner periphery of the secondary coil, and a center iron core that penetrates the inner periphery of the primary coil. The outer ring core portion 3 of the closed magnetic circuit core including the portion 3 ′ is accommodated inside the insulating case 4, and the high-pressure cylinder 5 containing the high-voltage terminal 6, which partially enters the inside of the insulating case. An elastic pin 7 for connecting the winding end side of the secondary winding is attached to the bobbin of the secondary coil, and this elastic pin 7 is brought into elastic contact with the intrusion end portion 6 'in the insulating case of the high-voltage terminal 6; The secondary coil 2, the primary coil 1, the closed magnetic circuit core, the elastic pin 7, and the high-voltage terminal 6 are fixed in the insulating case 4 by an insulating resin layer 8 that is cast and solidified in the insulating case. In order to increase the output of the ignition coil, a square permanent magnet is formed between one end of the center core 3 'of the closed magnetic circuit core and the inner circumference of the outer ring core 3 opposite to the one end as shown in the figure. The thin piece 9 may be interposed. Of the two perpendicular sides of the square permanent magnet thin piece 9, the length of one side L1 is made larger than the laminated thickness t of the straight core portion 3 'of the closed magnetic circuit core (hereinafter, one side is also referred to as the long side), and the other side L2 Is formed to be smaller than the width w of the straight iron core portion 3 '.

The magnetic pole on the surface facing the one end of the center core portion 3 'of the thin piece 9 of the permanent magnet and the magnetic pole on the opposite surface facing the inner periphery of the outer ring core portion 3 are produced when the primary coil is energized. The permanent magnet flakes are placed in series with the closed magnetic circuit in a direction to generate a magnetic flux opposite to the generated magnetic flux, a magnetic bias is applied to the closed magnetic circuit core, and the magnetic flux of the closed magnetic circuit core is reduced when the current to the primary coil 1 is interrupted. This structure increases the amount of change and increases the output.
In this case, the permanent magnet thin piece 9 is positioned at the end of the center iron core only by magnetic force, and the bobbin 11 attached to the end of the center iron core 3 'as shown in FIG. At the center of the end portion of the flange 11 'at one end of the plate, the thickness and depth of the thin piece 9 of the permanent magnet are the same, and the notch portions 12 and 12 for receiving the respective end portions of the long side L1 of the thin piece 9 are arranged to face each other. In some cases, the end portions of the long side L1 of the thin piece 9 of the permanent magnet are engaged with the notches 12 and 12.

  When the closed magnetic circuit core is assembled by assembling the outer ring core portion 3 and the primary coil having the linear core portion 3 'on the inner periphery, the thin piece 9 of the permanent magnet rubs against the inner periphery of the outer ring core portion. Does not move, but adheres to the inner circumference. As described above, the magnetic pole on the side of the permanent magnet thin section facing the linear iron core portion 3 'and the magnetic pole on the side of the outer ring core core facing the inner circumferential direction are as described above when the current to the primary coil is interrupted. It works to increase the amount of change in the magnetic flux of the closed magnetic circuit core and increase the output of the ignition coil.

However, in a conventional ignition coil for an internal combustion engine having such a configuration, if the center magnet core is attracted and positioned only by the magnetic force of the permanent magnet, the performance of the permanent magnet is deteriorated during assembly. Etc. problems existed.
In addition, when positioning at the end of the center core with the bobbin rod, the magnet must be attached after the center core and bobbin are assembled, which may limit assembly work procedures and may not improve productivity. Existed.

  The present invention has been proposed in view of the above, and by providing a positioning member for positioning the permanent magnet piece at one end of the center core, the positioning of the permanent magnet piece can be ensured without depending on the magnetic force or the bobbin, and workability can be improved. It is another object of the present invention to provide an internal combustion engine ignition coil that can achieve an improvement in productivity.

  In order to achieve the above object, the present invention inserts a center core portion constituting a closed magnetic path in a laminated manner on the inner periphery of a primary coil fitted to the inner periphery of a secondary coil, and also inserts one end of the center core portion. In the ignition coil for an internal combustion engine in which a permanent magnet piece is interposed in a portion that contacts the inner periphery of the outer ring core that forms the closed magnetic circuit surrounding both the primary and secondary coils, and one end of the center core Further, a positioning member for positioning the permanent magnet piece is provided.

  Moreover, in this invention, the said positioning member is a recessed part formed in the one end part of the center iron core, It is characterized by the above-mentioned.

  In the present invention, the positioning member is one or more protrusions formed at one end of the center iron core and disposed around the permanent magnet piece.

  Since this invention consists of an above-described structure, there can exist an effect which is demonstrated below.

  In the present invention, a center core portion constituting a closed magnetic path is laminated and inserted into the inner periphery of the primary coil fitted to the inner periphery of the secondary coil, and at the one end of the center core portion, the primary, In an internal combustion engine ignition coil in which a permanent magnet piece is interposed in a portion that contacts the inner periphery of an outer ring core that forms a closed magnetic circuit that surrounds both secondary coils, the permanent magnet piece is positioned at one end of the center core. Since the positioning member is provided, it is possible to improve workability and productivity when a thin piece of permanent magnet is interposed between one end of the center core and the inner periphery of the outer ring core.

  In the present invention, since the positioning member is a recess formed at one end of the center iron core, the positioning can be performed simply by attaching a thin piece of magnet to the recess, thereby improving workability and productivity during assembly. Can do.

  Further, in the present invention, the positioning member is one or more protrusions formed at one end of a center iron core and disposed around the permanent magnet piece. Positioning is possible, and workability and productivity during assembly can be improved.

  In an internal combustion engine ignition coil in which a permanent magnet piece is interposed at a portion in contact with the inner periphery of an outer ring core that forms a closed magnetic circuit surrounding a primary coil and a secondary coil at one end of the center core By providing a positioning member for positioning the permanent magnet piece at one end of the magnet, the object of improving workability and productivity can be achieved.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is a main part enlarged perspective view showing an ignition coil for an internal combustion engine according to the present invention, and FIG. 2 is a main part enlarged perspective view showing a second embodiment of the ignition coil for an internal combustion engine according to the present invention. Here, the ignition coil 10 for an internal combustion engine is inserted through the center core portion that forms a closed magnetic path on the inner periphery of the primary coil 1 fitted to the inner periphery of the secondary coil 2. A permanent magnet piece 14 is interposed at one end of 3 'at a portion in contact with the inner periphery of the outer ring core portion 3 constituting the closed magnetic path surrounding the primary and secondary coils. A positioning member 13 for positioning the permanent magnet piece 14 is provided at one end of the portion 3 '.

  The positioning member 13 is a recess formed at one end of the center iron core 3 ′. The concave portion is provided with a notch 15a capable of storing the long side L1 of the permanent magnet piece 14 at the center at one end of the center core material 15 to be laminated. Further, locking protrusions 15 b are formed at both ends of the one end of the center core material 15 in the width direction. The depth of the notch 15a is formed substantially equal to the thickness t of the permanent magnet piece 14. Further, the uppermost part and the lowermost part of the center iron core material 15 are overlapped without notches to form a concave part which is a positioning member.

  When configured as described above, the permanent magnet piece 14 is housed in a recess formed at one end of the center core 3 'and is attracted by magnetic force, so that it rubs against other parts during assembly. There is no possibility that the permanent magnet piece is displaced. Therefore, the performance of the ignition coil for the internal combustion engine is not deteriorated. Further, as in the case where the permanent magnet piece is positioned by the bobbin rod, the assembly work procedure in which the permanent magnet piece must be attached after assembling the iron core and the bobbin is not limited. Workability and production efficiency can be improved.

  FIG. 2 is an enlarged perspective view of an essential part showing a second embodiment of the ignition coil for an internal combustion engine of the present invention. In this embodiment, the positioning member 20 is formed by a locking piece 22 erected on the end surface of the center core material 21. The locking piece 22 is erected at an appropriate position so as to surround the periphery of the permanent magnet piece 14. In the example shown in FIG. 2, the center core material 21 a located at the uppermost part and the lowermost part of the center core 3 ′ has two locking pieces 22 having a predetermined interval in the width direction of the plate material. . In addition, the other center core material 21b has a space for accommodating the permanent magnet piece 14 in the center at both ends in the width direction, and the locking piece 22 is formed. Furthermore, the other center core material 21c is formed short so that the end surface can accommodate the permanent magnet piece 14. In such a center core material, the center core material 21a is arranged at the uppermost part and the lowermost part, and the center core material 21b and the center core material 21c are arranged in an appropriate combination therebetween.

  When comprised as mentioned above, the locking piece 22 standingly arranged by the end surface of the center iron core raw material 21 can control the circumference | surroundings of the permanent magnet piece 14 by a suitable space | interval, and can prevent the permanent magnet piece 14 from dropping off. . Therefore, the permanent magnet piece 14 can be securely fixed to the end surface of the center iron core 3 ′ by the magnetic force, the attractive force, and the regulating force by the locking piece 22. Further, since the locking pieces 22 are erected at appropriate intervals, it is possible to reduce the number of members and reduce the weight of the product.

  The present invention is not limited to the above-described embodiments, and various design changes can be made based on the description of the scope of claims.

FIG. 1 is an enlarged perspective view of an essential part showing an ignition coil for an internal combustion engine according to the present invention. FIG. 2 is an enlarged perspective view of an essential part showing a second embodiment of the ignition coil for the internal combustion engine. FIG. 3 is a longitudinal sectional view showing a schematic configuration of a mold type internal combustion engine ignition coil. FIG. 4 is an enlarged perspective view of a main part showing an iron core part of a conventional ignition coil for an internal combustion engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Primary coil 2 Secondary coil 3 Outer ring core part 3 'Center core part 4 Insulation case 5 High voltage cylinder 6 High voltage terminal 7 Elastic pin 8 Insulation resin layer 9 Thin piece of permanent magnet 10 Ignition coil 13 for internal combustion engines Positioning member 14 Permanent Magnet piece 15 Center core material 20 Positioning member 21 Center core material 22 Locking piece

Claims (3)

A center iron core portion constituting a closed magnetic path is laminated and inserted on the inner circumference of the primary coil fitted to the inner circumference of the secondary coil, and the primary and secondary coils are inserted at one end of the center iron core portion. In the ignition coil for an internal combustion engine in which a permanent magnet piece is interposed at a portion that contacts the inner periphery of the outer ring core that constitutes the closed magnetic path surrounding
An ignition coil for an internal combustion engine, wherein a positioning member for positioning the permanent magnet piece is provided at one end of the center iron core.   The ignition coil for an internal combustion engine according to claim 1, wherein the positioning member is a recess formed at one end of the center core.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the positioning member is one or more protrusions formed at one end portion of a center iron core and disposed around the permanent magnet piece.

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