JP2008130885A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine capable of stopping the progress of cracks generated from the edge of an igniter. <P>SOLUTION: The ignition coil for the internal combustion engine comprises a primary coil, a secondary coil, a laminated iron core for magnetically coupling the two coils, an igniter for turning a current flowing to the primary coil on and off, an igniter housing with an open upper surface for housing the igniter, and an insulation case for housing them, and is composed by filling an insulating resin in the insulation case. Since the height dimension of the side wall surface of the igniter housing is formed to be higher than the height dimension of the igniter itself, the progress of the cracks generated from the edge of the igniter is stopped, the intrusion of rain water or the like is prevented, and the reliability of the ignition coil is improved. <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 a conventional ignition coil for an internal combustion engine, for example, as shown in FIGS. 3 and 4, an igniter 1 that turns on and off a current flowing in a primary coil and generates a high-voltage current in a secondary coil is built in an insulating case 2. Often done. When it is built in the insulating case 2, it is usually stored after being placed on a dedicated igniter storage portion 3. Further, the side wall 3a of the igniter accommodating portion 3 is formed so as to accommodate the igniter 1 and the whole is accommodated in an insulating resin (epoxy resin) 4 after being accommodated in the insulating case 2. .

  However, in the conventional ignition coil for an internal combustion engine having such a configuration, the internal temperature rises when the ignition coil is operated, and a thermal stress is generated in the insulating resin. At this time, a crack C is likely to occur in the insulating resin 4 starting from the edge portion 1 a of the igniter 1. When the crack C progresses and reaches the surface of the epoxy resin, there is a possibility that rainwater or the like may enter the ignition coil and cause deterioration of internal components.

  The present invention has been proposed in view of the above, and by forming the height dimension of the side wall of the igniter accommodating portion higher than the height dimension of the igniter itself, the progress of cracks generated at the edge portion is stopped, and the insulating resin It is an object of the present invention to provide an ignition coil for an internal combustion engine in which rainwater or the like does not enter from the outside by reaching the surface of the engine.

  To achieve the above object, the present invention provides a primary coil and a secondary coil, a laminated iron core that magnetically couples the two coils, an igniter that turns on and off the current flowing through the primary coil, and the igniter. In an ignition coil for an internal combustion engine, comprising an igniter accommodating portion whose upper surface is opened and an insulating case for accommodating these, and an insulating resin filled in the insulating case, the height of the side wall of the igniter accommodating portion It is characterized in that the dimensions are higher than the height of the igniter itself.

  In the present invention, the igniter accommodating portion is characterized in that a side wall in two directions is formed higher than an upper surface of the igniter.

  In the present invention, the igniter accommodating portion is characterized in that the side walls in three directions are formed higher than the upper surface of the igniter.

  In the present invention, the igniter accommodating portion is characterized in that the side walls in four directions are formed higher than the upper surface of the igniter.

  Further, in the present invention, the igniter accommodating portion has a polygonal planar shape, and a side wall standing on two or more adjacent sides is formed higher than the upper surface of the igniter.

  Further, in the present invention, the igniter accommodating portion has a circular planar shape, and a part or all of the side walls standing upright are formed higher than the upper surface of the igniter.

  Further, in the present invention, the igniter accommodating portion is composed of a horizontal distance A from a side surface of the accommodated igniter to a side wall surface of the igniter accommodating portion, and a vertical distance B from the upper surface of the igniter to the upper end of the side wall of the igniter accommodating portion. The ratio is 0.577 to 5.67.

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

  In the present invention, the primary coil and the secondary coil, the laminated iron core that magnetically couples the two coils, the igniter that turns on and off the current flowing through the primary coil, and the upper surface that houses the igniter are opened. In an ignition coil for an internal combustion engine comprising an igniter housing portion and an insulating case for housing these, and the insulating case filled with an insulating resin, the height of the side wall of the igniter housing portion is set to the height of the igniter itself. Since it is formed higher than the dimension, the progress of cracks generated from the edge portion of the igniter can be stopped by the side wall.

  Further, in the present invention, since the igniter accommodating portion is formed such that the two-side walls are higher than the upper surface of the igniter, the progress of cracks generated from the edge portion of the igniter can be stopped by the two-side walls.

  In the present invention, since the igniter accommodating portion has the three-direction side walls formed higher than the upper surface of the igniter, the progress of cracks generated from the edge portion of the igniter can be stopped by the three-direction side walls.

  In the present invention, since the igniter accommodating portion is formed such that the four side walls are higher than the upper surface of the igniter, the progress of cracks generated from the edge portion of the igniter can be stopped by the four side walls.

  Further, in the present invention, the igniter accommodating portion has a polygonal planar shape, and a side wall standing on two or more adjacent sides is formed higher than the upper surface of the igniter, so cracks generated from the edge portion of the igniter Can be stopped by the side wall.

  Further, in the present invention, the igniter accommodating portion has a circular planar shape, and a part or all of the side walls provided in the periphery are formed higher than the upper surface of the igniter, so that the progress of cracks generated from the edge portion of the igniter Can be stopped by the side wall.

  Further, in the present invention, the igniter accommodating portion is a ratio of a horizontal distance A from the side surface of the accommodated igniter to the side wall surface of the igniter accommodating portion and a vertical distance B from the upper surface of the igniter to the upper end of the side wall of the igniter accommodating portion. Is 0.577 to 5.67, the progress of cracks in the range of 30 to 60 degrees generated from the edge portion of the igniter can be effectively stopped at the side wall.

  In the ignition coil for an internal combustion engine, the height of the side wall of the igniter housing is higher than that of the igniter, the horizontal distance A from the end surface of the igniter to the side wall of the igniter housing, and from the upper surface of the igniter to the upper end of the side wall of the igniter housing By setting the ratio to the vertical distance B to 0.577 to 5.67, it is possible to achieve the purpose of stopping the progress of cracks generated from the edge portion of the igniter and improving the reliability of the ignition coil.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is an enlarged cross-sectional view of a main part showing an ignition coil for an internal combustion engine according to the present invention. Here, the internal combustion engine ignition coil 10 includes a primary coil 11 and a secondary coil 12, a laminated core 13 that magnetically couples the two coils, and an igniter 14 that turns on and off the current flowing through the primary coil 11. An igniter accommodating portion 15 having an open upper surface for accommodating the igniter 14 and an insulating case 16 for accommodating these, and an insulating resin 17 is filled in the insulating case 16, The height dimension of the side wall 15a of the accommodating part 15 is higher than the height dimension of the igniter itself, the horizontal distance A from the side surface of the accommodated igniter 14 to the side wall surface of the igniter accommodating part 15, and the igniter accommodating part from the upper surface of the igniter 14 The ratio to the vertical distance B to the upper end of the side wall is 0.577 to 5.67.

  When configured as described above, as shown in FIG. 1, the crack C generated from the edge portion 18 of the igniter 14 does not proceed as it is, but stops at the side wall 15a and does not proceed any further. Therefore, since the crack C does not reach the surface of the insulating resin, there is no possibility that rainwater or the like enters and deteriorates internal components.

  FIG. 2 is an enlarged cross-sectional view of a main part showing a second embodiment of an ignition coil for an internal combustion engine according to the present invention. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. Here, the igniter accommodating portion 19 has two side walls 19 a and 19 b formed higher than the upper surface of the igniter 14. Further, the ratio of the horizontal distance A from the side surface of the accommodated igniter 14 to the side walls 19a, 19b of the igniter accommodating part 19 and the vertical distance B from the upper surface of the igniter 14 to the upper end of the side wall of the igniter accommodating part is 0.577 to 5.67. In general, the crack generation angle is in the range of 30 to 60 degrees. In order to effectively prevent these cracks, the ratio of the horizontal distance A to the vertical distance B is set to 0.577 to 5.67. It is preferable that

  When configured as described above, the crack C generated from the left and right edge portions 18 of the igniter 14 does not proceed as it is, stops at the side walls 19a and 19b, and does not proceed further. For this reason, since the crack C does not reach the surface of the insulating resin, there is no possibility that rainwater or the like enters and deteriorates internal components.

  Further, the side wall of the igniter accommodating portion may be formed such that the side wall in three or four directions is higher than the upper surface of the igniter 14. Also in this case, the ratio of the horizontal distance A from the side surface of the accommodated igniter 14 to the side wall of the igniter accommodating part and the vertical distance B from the upper surface of the igniter 14 to the upper end of the side wall of the igniter accommodating part is 0.577-5. .67.

  When configured as described above, even if a crack C is generated from an edge portion in three or four directions of the igniter, it stops at the side wall and does not advance further. Therefore, there is no possibility that rainwater or the like enters from the generated crack.

  In addition, when the planar shape of the igniter accommodating portion is a polygon, if the side wall standing on two or more adjacent sides is formed higher than the upper surface of the igniter, the progress of cracks generated from the edge portion of the igniter can be prevented. You can stop at.

  Further, when the planar shape of the igniter accommodating portion is a circle, if a part or all of the side walls standing upright are formed higher than the upper surface of the igniter, the progress of cracks generated from the edge portion of the igniter is stopped by the side walls. be able to.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine ignition coil 11 Primary coil 12 Secondary coil 13 Laminated core 14 Igniter 15 Igniter accommodating part 15a Side wall 16 Insulating case 17 Insulating resin 18 Edge part 19 Igniter accommodating part 19a, 19b Side wall

Claims (7)

A primary coil and a secondary coil, a laminated iron core that magnetically couples the two coils, an igniter that turns on and off the current flowing through the primary coil, and an igniter housing that is open on an upper surface that houses the igniter; In an ignition coil for an internal combustion engine comprising an insulating case for storing these, and an insulating resin filled in the insulating case,
An ignition coil for an internal combustion engine, characterized in that a height dimension of a side wall of the igniter accommodating portion is formed higher than a height dimension of the igniter itself.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the igniter housing part has two side walls formed higher than an upper surface of the igniter.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the igniter housing part has three side walls formed higher than an upper surface of the igniter.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the igniter housing part has four side walls formed higher than an upper surface of the igniter.   2. The ignition for an internal combustion engine according to claim 1, wherein the igniter accommodating portion has a polygonal planar shape, and a side wall standing on two or more adjacent sides is formed higher than an upper surface of the igniter. coil.   2. The ignition coil for an internal combustion engine according to claim 1, wherein the igniter housing portion has a circular planar shape, and a part or all of a side wall provided upright is formed higher than an upper surface of the igniter.   The ratio of the horizontal distance A from the side surface of the accommodated igniter to the highest sidewall surface of the igniter accommodation portion and the vertical distance B from the upper surface of the igniter accommodation portion to the upper end of the highest sidewall of the igniter accommodation portion is 0. It is 577-5.67, The ignition coil for internal combustion engines of any one of Claims 1-6 characterized by the above-mentioned.

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