JP2006210374A - Ignition coil for internal combustion engine and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for internal combustion engines that can be miniaturized and made lightweight. <P>SOLUTION: In the ignition coil for internal combustion engines, at least primary and secondary coils are arranged, a core for magnetically combining the primary and secondary coils is stored in an insulating case in which the upper end is open, and an insulating resin is casted from the above for electrical insulation and fixation. In the ignition coil for internal combustion engines, one portion of the insulating resin is inserted into the opening of the insulating case, when casting the insulating resin, a cover member having a resin inlet is arranged and a recess is formed on the upper surface of a filled insulating resin, after the casting, thus reducing the amount of casting in the insulating resin and miniaturizing and making the ignition coil itself light in weight. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

An example of a conventional ignition coil for an internal combustion engine is shown in FIGS. 3 and 4 (for example, Patent Documents 1 and 2). Here, FIG. 3 is a plan view of a conventional ignition coil for an internal combustion engine, and FIG. 4 is a longitudinal sectional view thereof. The internal combustion engine ignition coil 1 includes at least a primary coil 2 and a secondary coil 3 and a center iron core 4 passing through an inner periphery of the primary coil 2 and an outer periphery of the secondary coil in order to magnetically couple the two coils. The primary current flowing in the passing side iron core 5 and the primary coil 2 is energized and cut off, and a high voltage is generated on the secondary coil side. The whole is housed in an insulating case 6. The primary coil 2 is connected to the primary terminal 7.
JP-A-10-223463 Japanese Patent Laid-Open No. 11-204356

  However, in the conventional ignition coil for an internal combustion engine, as shown in FIG. 4, the primary coil 2, the secondary coil 3, the center iron core 4, the side iron core 5, and the primary terminal housed in the insulating case 6 are thermoset such as epoxy. Is electrically insulated by the conductive resin 8. However, since the casting surface of the insulating resin that electrically insulates the ignition coil for an internal combustion engine is high, there is a problem that the overall weight increases. In general, in an ignition coil for an internal combustion engine, the proportion of the insulating resin itself is large with respect to the total weight, and there is a problem that it is difficult to reduce the weight of the entire ignition coil for the internal combustion engine.

  The present invention has been proposed in view of the above, and when casting an insulating resin, a cover member partially inserted into the opening of the insulating case is disposed on the top surface of the filled insulating resin after casting. An object of the present invention is to provide an ignition coil for an internal combustion engine that has a recess and can be reduced in weight.

  In order to achieve the above object, an ignition coil for an internal combustion engine according to the present invention is provided with at least a primary coil and a secondary coil, and an iron core for magnetically coupling the primary coil and the secondary coil is opened at the upper end. An ignition coil for an internal combustion engine, which is housed in an insulating case and is electrically insulated by casting the insulating resin from above, and is fixed when the insulating resin is cast. And a cover member having a resin inlet is disposed to form a recess on the upper surface of the filled insulating resin after casting.

  In the invention according to claim 2, the cover member is formed of a metal having a resin injection port substantially at the center.

  In the invention according to claim 3, the cover member is formed of a synthetic resin having a resin injection port at substantially the center.

  According to a fourth aspect of the present invention, the shape of the bottom surface of the cover member is formed so as to maintain a substantially equal distance from the upper end of each component housed in the insulating case.

  Further, in the invention according to claim 5, at least a primary coil and a secondary coil are disposed, and an iron core for magnetically coupling the primary coil and the secondary coil is housed in an insulating case having an upper end opened, A method of manufacturing an ignition coil for an internal combustion engine, in which an insulating resin is cast from above to be electrically insulated and fixed, and in a step of injecting the insulating resin into the insulating case, a part of the opening is formed in the insulating case Is inserted, and a cover member having an injection port is disposed, and after the casting is cured, the cover member is removed to form a recess on the upper surface of the filled insulating resin.

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

  In the present invention, at least a primary coil and a secondary coil are disposed, and an iron core for magnetically coupling the primary coil and the secondary coil is accommodated in an insulating case having an upper end opened, and an insulating resin is cast from above. An ignition coil for an internal combustion engine that is electrically insulated and fixed, and when the insulating resin is cast, a part of the ignition coil is inserted into the opening of the insulating case and has a resin injection port. Since the recessed portion is formed on the upper surface of the filled insulating resin after casting and the cover member is disposed, the ignition coil itself can be reduced in size and weight.

  In the present invention, since the cover member is formed of a metal having a resin injection port in the center, it is easy to cast the insulating resin and reduce the amount of the insulating resin to be cast. it can. Therefore, the ignition coil itself can be reduced in size and weight.

  Further, in the present invention, the cover member is molded of a synthetic resin having a resin injection port in the substantially center, so that it becomes easy to cast each component insulating resin housed in the insulating case. The amount of insulating resin to be reduced can be reduced.

  In the present invention, the bottom surface shape of the cover member is formed so as to maintain a substantially equal distance from the upper end of each component housed in the insulating case, so that the injected insulating resin is contained in the insulating case. It is formed with a substantially uniform thickness on each housed part. Therefore, even if the amount of the insulating resin to be cast is reduced, each component is uniformly covered with the insulating resin.

  Further, in the present invention, at least a primary coil and a secondary coil are disposed, and an iron core for magnetically coupling the primary coil and the secondary coil is housed in an insulating case opened at the upper end, and the insulating resin is disposed from above. A method for manufacturing an ignition coil for an internal combustion engine that is cast, electrically insulated, and fixed, and in the step of injecting an insulating resin into the insulating case, a part thereof is inserted into the opening of the insulating case The cover member having the injection port is arranged, and after the casting is cured, the cover member is removed and a recess is formed on the upper surface of the filled insulating resin, so that the ignition coil itself can be reduced in size and weight. it can.

  When casting the insulating resin, the cover member was placed in the opening of the insulating case and the recess was formed on the top surface of the filled insulating resin after casting. The purpose of reducing the size and weight of the coil itself can be achieved.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is an explanatory view showing a manufacturing process of an ignition coil for an internal combustion engine according to the present invention, and FIG. 2 is an explanatory view showing a manufacturing process of the ignition coil for an internal combustion engine of the present invention. Here, the ignition coil 10 for an internal combustion engine includes an insulating case 14 in which at least a primary coil 11 and a secondary coil 12 are disposed, and an iron core 13 that magnetically couples the primary coil and the secondary coil is opened at the upper end. The insulating resin 15 is cast from above to be electrically insulated and fixed, and when the insulating resin 15 is cast, a part of the opening 14a of the insulating case 14 is formed. 16a is inserted, and a cover member 16 having a resin injection port 16b is arranged to form a recess 17 on the upper surface of the filled insulating resin after casting.

  The cover member 16 is molded from a synthetic resin or metal having a resin injection port 16a in the approximate center, and is formed to be detachable from the opening 14a of the insulating case 14. The resin injection port 16b has a funnel shape that expands upward, and is formed so as to facilitate the injection of the insulating resin. Further, the lower surface 16c of the cover member 16 is maintained at an approximately equal distance from the upper end of each component (secondary coil bobbin 18, side iron core 19, primary terminal connection portion 20, etc.) housed in the insulating case 14. Is formed.

  The internal combustion engine ignition coil 10 configured as described above has the cover member 16 inserted into the opening 14 a of the insulating case 14 when the insulating resin 15 is injected into the insulating case 14. Only a part 16a of the cover member 16 is maintained so as to maintain a substantially equal distance from the upper ends of the secondary coil bobbin 18, the side iron core 19, the primary terminal connection portion 20 and the like housed in the insulating case 14. insert.

  Next, the insulating resin 15 is injected from the resin injection port 16a, and the cover member 16 is removed after the insulating resin 15 is cured. Then, the recessed part 17 is formed in the upper surface of the filled insulating resin, and the amount of the resin filled in the insulating case 14 can be reduced. Therefore, the overall weight of the ignition coil can be reduced. In addition, material costs can be reduced, and manufacturing costs can be reduced.

FIG. 1 is an explanatory view showing a manufacturing process of an internal combustion engine ignition coil according to the present invention. FIG. 2 is an explanatory view showing a manufacturing process of the ignition coil for the internal combustion engine. FIG. 3 is a plan view of a conventional ignition coil for an internal combustion engine before resin filling. FIG. 4 is a longitudinal sectional view showing a conventional example of an ignition coil for an internal combustion engine after resin filling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine ignition coil 11 Primary coil 12 Secondary coil 13 Iron core 14 Insulating case 14a Opening part 15 Insulating resin 16 Cover member 16a Part 16b Resin inlet 17 Recessed part 18 Secondary coil bobbin 19 Side iron core 20 Primary terminal connection part

Claims (5)

At least a primary coil and a secondary coil are disposed, and an iron core for magnetically coupling the primary coil and the secondary coil is housed in an insulating case with an upper end opened, and an insulating resin is cast from above to be electrically An ignition coil for an internal combustion engine that is insulated and fixed to
When casting the insulating resin, a part is inserted into the opening of the insulating case, and a cover member having a resin inlet is arranged to form a recess on the upper surface of the filled insulating resin after casting. An ignition coil for an internal combustion engine.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the cover member is formed of a metal having a resin injection port substantially at the center.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the cover member is formed of a synthetic resin having a resin injection port substantially at the center.   The lower surface shape of the cover member is formed so as to maintain a substantially equal distance from the upper end of each component housed in the insulating case. Ignition coil for internal combustion engines. At least a primary coil and a secondary coil are disposed, and an iron core for magnetically coupling the primary coil and the secondary coil is housed in an insulating case with an upper end opened, and an insulating resin is cast from above to be electrically A method of manufacturing an ignition coil for an internal combustion engine that is insulated and fixed to
In the step of injecting an insulating resin into the insulating case,
A part of the insulating case is inserted into the opening, and a cover member having an injection port is disposed. After the casting is cured, the cover member is removed to form a recess on the top surface of the filled insulating resin. A method of manufacturing an ignition coil for an internal combustion engine.

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