JP2011243737A - Ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine which can stabilize electric connectability between a terminal pin and a high-voltage terminal without increasing the number of components or complicating the structure.SOLUTION: An ignition coil for an internal combustion engine houses an iron-core/coil assembly to unite a primary coil and a secondary coil magnetically by the iron-core within an insulation case, and connects a high-voltage terminal provided inside a cylindrical high-voltage tower extending to the lower edge of this insulation case and a terminal pin connected to the terminal of the secondary coil. An engaging piece is configured by extending one bottom wall of the site facing the high-voltage tower in the lower edge region of the insulation case in the direction of the central axis line of the high-voltage tower, the lower edge of the engaging piece and the high-voltage terminal pressed in from the lower side of the high-voltage tower press and fix the tip of the terminal pin so that electric connectability between the terminal pin and the high-voltage terminal can be stabilized without increasing the number of components or complicating the structure.

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 an internal combustion engine such as an automobile, and more particularly to a connection structure between a secondary coil and a terminal pin (connection pin). Is.

  FIG. 3 is a longitudinal sectional view showing an example of a conventional ignition coil for an internal combustion engine. In FIG. 3, an ignition coil 11 for an internal combustion engine includes an iron core / coil assembly 12, an insulating case 13 made of synthetic resin that accommodates the iron core / coil assembly 12, a secondary terminal (high voltage terminal) 14, and an insulation. The case 13 is composed of a thermosetting resin 15 or the like having an insulating property that fixes each component while insulating.

  The iron core / coil assembly 12 is wound around the iron core 16, the primary coil bobbin 17, the primary terminal pins 18A and 18B disposed on the primary coil bobbin 17 and connected to the primary terminals, and the primary coil bobbin 17. A primary coil 19 whose winding start is connected to the primary terminal pin 18A and whose winding end is connected to the primary terminal pin 18B, and a secondary coil bobbin 20 in which the primary coil 19 and the secondary coil 21 are wound concentrically. And a secondary terminal pin 22 disposed at one end of the secondary coil bobbin 20 and connected to the secondary coil 21. A cylindrical intermediary terminal 23 that can be fitted to the conical portion of the secondary terminal 14 with which the secondary terminal pin 22 is in pressure contact is disposed. And what provided the V-shaped bending part 22V in the part corresponding to the mediation terminal 23 of the secondary terminal pin 22 is proposed (patent document 1). In this conventional example, the elastic force of the secondary terminal pin 22 is used to stabilize the contact with the high-voltage terminal 14.

  FIG. 4 is an enlarged sectional view of a main part showing another conventional example. In this embodiment, the connection terminal 41 has an annular portion 41a whose diameter is increased by being press-fitted into the upper end of the high-voltage terminal 42, and an interval between the annular portion 41a and the annular portion 41a. The first and second clamping pieces 41b and 41c sandwich the terminal pin 43 connected to the secondary coil from both sides, and the terminal pin 43 is press-fitted between the first and second clamping pieces 41b and 41c. Connected. In addition, in order to make it easy to hold | maintain the terminal pin 43, the upper end of the upper end of the 1st, 2nd clamping pieces 41b and 41c is expanded (patent document 2).

Japanese Patent No. 3655870 Japanese Patent No. 3595285

However, in the conventional ignition coil for an internal combustion engine having such a configuration, in the structure in which the elastic force of the secondary terminal pin is used to make contact with the high-voltage terminal as in Patent Document 1, contact caused by a decrease in elastic force or the like. There was an unstable element called bad.
Further, as shown in the cited document 2, the structure in which the terminal pin is press-fitted between the holding pieces has a drawback that the structure of the holding piece is complicated and that high dimensional accuracy is required.

  The present invention has been proposed in view of the above. A bottom wall of a portion facing the high-pressure tower in the lower end region of the insulating case extends in the direction of the central axis of the high-pressure tower to form a locking piece. Ignition for internal combustion engines that can improve the connection reliability between the terminal pin and the high-pressure tower without increasing the number of parts because the tip of the terminal pin is pressed and fixed with the lower end of the piece and the high-pressure terminal press-fitted from below the high-pressure tower The object is to provide a coil.

  In order to achieve the above object, an iron core / coil assembly for magnetically coupling the primary coil and the secondary coil with an iron core is housed in an insulating case, and a cylindrical high-voltage extending to the lower end of the insulating case An internal combustion engine ignition coil for connecting a high-voltage terminal disposed in a tower and a terminal pin connected to a terminal of the secondary coil, wherein a bottom wall of a portion facing the high-voltage tower in a lower end region of the insulating case A locking piece is formed by extending in the central axis direction of the high-voltage tower, and the tip end portion of the terminal pin is pressed and fixed by a lower end of the locking piece and a high-pressure terminal press-fitted from below the high-pressure tower. It is said.

  In the present invention, the tip of the terminal pin is formed by being bent substantially in parallel with the protruding direction of the locking piece.

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

  In the present invention, an iron core / coil assembly that magnetically couples a primary coil and a secondary coil with an iron core is housed in an insulating case, and is placed in a cylindrical high-voltage tower that extends to the lower end of the insulating case. An ignition coil for an internal combustion engine that connects an installed high voltage terminal and a terminal pin connected to a terminal of the secondary coil, and a bottom wall of a portion facing the high voltage tower in a lower end region of the insulating case is a center of the high voltage tower A locking piece is formed by extending in the axial direction, and the tip of the terminal pin is pressed and fixed by a lower end of the locking piece and a high-pressure terminal press-fitted from below the high-pressure tower, so that a complicated shape or a high The electrical connectivity between the terminal pin and the high voltage terminal can be stabilized without requiring dimensional accuracy. Further, the number of parts is not increased.

  Further, in the present invention, since the tip end portion of the terminal pin is formed by being bent substantially parallel to the protruding direction of the locking piece, the contact range between the tip end of the terminal pin and the high voltage terminal can be widened. Therefore, connection reliability can be improved.

FIG. 1 is a longitudinal sectional view showing an example of an ignition coil for an internal combustion engine according to the present invention. FIG. 2 is an enlarged sectional view of a main part of the ignition coil for the internal combustion engine. FIG. 3 is a longitudinal sectional view showing an example of a conventional ignition coil for an internal combustion engine. FIG. 4 is an enlarged cross-sectional view of a main part showing another example of a conventional ignition coil for an internal combustion engine.

  In the ignition coil for an internal combustion engine, a bottom wall of a portion facing the high pressure tower in the lower end region of the insulating case is extended in the central axis direction of the high pressure tower to form a locking piece, and the lower end of the locking piece and the high pressure tower Since the tip of the terminal pin is pressed and fixed with the high-voltage terminal press-fitted from below, the electrical connection between the terminal pin and the high-voltage terminal is stabilized without requiring a complicated shape or high dimensional accuracy. be able to.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is a longitudinal sectional view showing an example of an ignition coil for an internal combustion engine according to the present invention, and FIG. 2 is an enlarged sectional view of a main part of the ignition coil for an internal combustion engine of the present invention. Here, the ignition coil 100 for an internal combustion engine houses an iron core / coil assembly 104 that magnetically couples a primary coil 101 and a secondary coil 102 with an iron core 103 in an insulating case 105, and a lower end of the insulating case 105. A high-voltage terminal 107 disposed in a cylindrical high-voltage tower 106 extended to a terminal pin 108 electrically connected to a terminal of the secondary coil 102, A bottom wall of the portion 105a facing the high-pressure tower 106 in the lower end region extends in the direction of the central axis L of the high-pressure tower 106 to form a locking piece 109. The lower end of the locking piece 109 and the lower side of the high-pressure tower 106 The distal end portion 108a of the terminal pin 108 is pressed and fixed with the high-voltage terminal 107 that is press-fitted from the terminal. Further, a primary socket 112 in which a primary terminal 111 is accommodated is formed at one end of the insulating case 105, and the primary terminal 111 is connected to the primary coil 101.

  The high-pressure tower 106 is continuously formed at the lower end of the insulating case 105, and a locking piece 109 is horizontally provided at the continuous portion. The locking piece 109 is formed by extending one bottom wall of the insulating case in the direction of the central axis L of the cylindrical high-pressure tower 106. Therefore, the high-voltage terminal 107 press-fitted from below the high-voltage tower 106 is restrained from being lifted by the locking piece 109 and is fitted into the narrow upper end 106a and stopped. Further, since the locking piece 109 is closed only at a part of the bottom surface of the insulating case 105, the terminal pin 108 can be inserted through the opened portion. Furthermore, a non-slip unevenness may be formed on the lower end surface of the locking piece 109.

The terminal pin 108 is made of a conductive material, and one end is inserted and fixed to a part of the coil bobbin 113 around which the secondary coil 102 is wound, and is extended obliquely downward in the direction of the central axis L of the high-voltage tower 106. The tip end portion 108 a (free end) is formed to be bent substantially parallel to the protruding direction of the locking piece 109.
Moreover, you may comprise the front-end | tip part 108a of the terminal pin 108 in a satin finish or uneven | corrugated shape.

The internal combustion engine ignition coil having the above structure is manufactured in the following procedure.
First, a terminal pin 108 is attached to the lower end of an iron core / coil assembly 104 in which a primary coil 101 and a secondary coil 102 are wound around a coil bobbin from an upper end opening of an insulating case 105. Insert so that
Further, the tip end portion 108 a of the terminal pin 108 is inserted so as to be positioned at the lower end of the locking piece 109. Next, the high voltage terminal 107 is press-fitted from below the high voltage tower 106. Further, the rear end of the primary terminal 111 and the primary coil 101 are electrically connected by welding or the like.
In this way, after the iron core / coil assembly 104, the terminal pin 108, etc. are accommodated in the insulating case 105, the whole is placed in a vacuum chamber, and the molten thermosetting resin is vacuum cast after the surroundings are evacuated, Fix by thermosetting. At this time, the lower end of the insulating case 105 is sealed off by the press-fitted high voltage terminal 107.

  Next, the internal combustion engine ignition coil 100 configured as described above presses and fixes the tip end portion 108a of the terminal pin 108 with the lower end of the locking piece 109 and the high-voltage terminal 107 press-fitted from below the high-pressure tower 106. Therefore, the electrical connectivity between the terminal pin and the high-voltage terminal can be stabilized without increasing the number of parts or complicating the structure.

DESCRIPTION OF SYMBOLS 100 Ignition coil 101 for internal combustion engines Primary coil 102 Secondary coil 103 Iron core 104 Iron core / coil assembly 105 Insulation case 105a Lower end area 106 High voltage tower 107 High voltage terminal 108 Terminal pin 108a Tip 109 Locking piece 111 Primary terminal 112 Primary socket 113 Coil bobbin

Claims (2)

A high-voltage terminal that is housed in a cylindrical high-voltage tower that houses an iron core / coil assembly that magnetically couples a primary coil and a secondary coil with an iron core, and extends to the lower end of the insulation case And an ignition coil for an internal combustion engine that connects a terminal pin connected to a terminal of the secondary coil,
A bottom wall of the part facing the high-pressure tower in the lower end region of the insulating case extends in the direction of the central axis of the high-pressure tower to constitute a locking piece,
An ignition coil for an internal combustion engine, wherein a distal end portion of the terminal pin is pressed and fixed by a lower end of the locking piece and a high-pressure terminal press-fitted from below the high-pressure tower.   2. The ignition coil for an internal combustion engine according to claim 1, wherein a distal end portion of the terminal pin is formed to be bent substantially parallel to a protruding direction of the locking piece.

Images