JP2007242763A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine for preventing leak of water into a plug hole in the ignition coil for supplying a high voltage to an ignition plug of the internal combustion engine like an automobile. <P>SOLUTION: An elastic water-proof cover is formed of an annular aperture where an upper part or an internal part and a lower connecting portion are engaged, and an annular flange provided in the periphery of the end of the upper part. The upper part of the elastic water-proof cover is provided between the bottom of an accommodation case and an upper part of an upper socket, and is in contact with the bottom of the accommodation case. The internal side of the elastic water-proof cover is in contact with the upper part of the lower connection. The annular aperture of the elastic water-proof cover is engaged with the lower connection. The annular flange of the elastic water-proof cover can prevent leak of water into the plug hole by placing the lower part in contact with a cylinder head. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is for supplying a high voltage to an ignition plug of an internal combustion engine in an automobile or the like to generate a spark discharge, and water enters between the ignition plug and the plug hole, thereby causing a problem due to leakage. The present invention relates to an ignition coil for an internal combustion engine to be prevented.

  FIG. 4 is a view for explaining an ignition coil for an internal combustion engine in a conventional example. The ignition coil 41 for the internal combustion engine in FIG. 4 includes at least a storage case 42 and a high-voltage terminal portion 424 that extends below the storage case 42. The storage case 42 stores an ignition coil 421, an iron core, a filler, and the like, and is provided with a connector housing 422 and a mounting portion 423. The spark plug is connected via an upper socket 431, a plug joint 432, a conductive spring 433, and a lower socket 434. The spark plug, the upper socket 431, the plug joint 432, the conductive spring 433, and the lower socket 434 are accommodated in the plug hole 441 of the cylinder head 44. The internal combustion engine ignition coil 41 is described in detail in JP-A-8-213258. A spark plug (not shown) is attached to the portion indicated by reference numeral 43.

FIG. 5 is a diagram for explaining another ignition coil for an internal combustion engine in a conventional example. In FIG. 5, the internal combustion engine ignition coil 51 includes a cylindrical housing case 52 in which a connector housing 522 and a mounting portion 523 are provided at an upper portion, and an ignition coil and an iron core are accommodated in a lower portion. The storage case 52 is stored in the plug hole 541 of the cylinder head 54. The internal combustion engine ignition coil 51 is described in detail in JP-A-6-251963. A spark plug (not shown) is attached to a portion indicated by reference numeral 53.
JP-A-8-213258 JP-A-6-251963

  However, the ignition coil for an internal combustion engine in Patent Document 1 is provided with an annular recess 435 in the upper part of the upper connector 431, and the upper part of the annular recess 435 and the bottom of the storage case 42 are in contact with each other. Was demonstrating. However, when the relatively hard storage case and the upper socket are deformed due to aging, the internal combustion engine ignition coil may have a gap between them, and water may enter the gap and cause a leak. . The ignition coil for an internal combustion engine in Patent Document 2 has a problem that the space between the storage case 52 and the plug hole 541 is open, and water enters this portion to cause a leak and cause a malfunction.

  In order to solve the above-described problems, the present invention provides a highly reliable ignition coil for an internal combustion engine in which a gap is not formed due to secular change between a storage case and a cylinder head and water does not enter. For the purpose. It is another object of the present invention to provide an ignition coil for an internal combustion engine that is configured to flow in the direction opposite to the plug hole even when water hits the elastic waterproof cover.

(First invention)
An ignition coil for an internal combustion engine according to a first aspect of the present invention is based on an ignition signal, a primary coil and a secondary coil, an iron core that magnetically couples the primary coil and the secondary coil, and energization and interruption of current in the primary coil. A control circuit to perform, a storage case for storing these, and a high-voltage terminal portion provided at a lower portion of the storage case, and holds a high-voltage terminal portion and a spark plug provided at the lower portion of the storage case An upper socket for connecting a plug joint; an upper surface provided between a lower portion of the storage case and an upper portion of the upper socket; an upper surface contacting the lower portion of the storage case; and an inner surface contacting the upper portion of the upper socket; An opening in which the high-voltage terminal portion fits in the center, and an annular flank provided around the upper surface and the inner surface and in contact with the cylinder head Characterized in that an elastic waterproof cover made of a.

(Second invention)
An ignition coil for an internal combustion engine according to a second aspect is characterized in that an annular recess is provided in the upper part of the upper socket according to the first aspect, and the protrusion of the annular recess is in contact with the inner surface of the elastic waterproof cover.

(Third invention)
An ignition coil for an internal combustion engine according to a third aspect of the present invention is based on an ignition signal based on an ignition signal, a primary coil and a secondary coil, an iron core that magnetically couples the primary coil and the secondary coil, and energization and interruption of current in the primary coil. A control circuit to perform, and at least a cylindrical storage case that stores the coil and the iron core and is inserted into the cylinder head, and an opening that fits into the cylindrical storage case, and extends from the opening And an elastic waterproof cover comprising an annular flange provided around the upper portion and in contact with the cylinder head.

(Fourth invention)
The ignition coil for an internal combustion engine according to a fourth aspect is characterized in that the upper surface and / or the annular flange in the elastic waterproof cover according to the first to third aspects is inclined outward.

  According to the present invention, the elastic waterproof cover is provided between the bottom of the storage case that stores the ignition coil, the iron core, and the like and the top of the upper socket of the spark plug, so that water does not enter the plug hole of the cylinder head. I did it. The elastic waterproof cover is made of a material rich in elasticity as compared with the synthetic resin constituting the storage case or the upper socket, so that it does not deform even with aging and has a high quality ignition coil for internal combustion engines Can be provided.

  According to the present invention, it is possible to provide an ignition coil for an internal combustion engine with higher reliability by flowing the water to the plug hole to the outside by providing an outwardly inclined ring-shaped elastic waterproof cover. it can.

(First invention)
An ignition coil for an internal combustion engine according to a first aspect of the present invention is based on an ignition signal, a primary coil and a secondary coil, an iron core that magnetically couples the primary coil and the secondary coil, and energization and interruption of current in the primary coil. A control circuit to perform, a storage case for storing these and a connector housing and a mounting portion; and a high voltage terminal for a spark plug provided at a lower portion of the storage case and generating a spark by a high voltage generated in a secondary coil At least. The high-voltage terminal portion is connected to the spark plug via, for example, an upper socket, a plug joint, a lower socket, and a conductive spring provided therein.

  The upper socket provided on the upper portion of the high-voltage terminal is connected to a plug joint to which the spark plug is attached. The elastic waterproof cover includes an upper portion or an inside, an opening portion into which the high-voltage terminal portion is fitted, and an annular flange provided around the end portion of the upper portion. The upper part of the elastic waterproof cover is provided between the lower part (bottom part) of the storage case and the upper part of the upper socket, and is in contact with the lower part (bottom part) of the storage case. The inside of the elastic waterproof cover is in contact with the upper portion of the high voltage terminal portion. The opening of the elastic waterproof cover is fitted with the high voltage terminal portion. The annular flange of the elastic waterproof cover prevents the water from entering the plug hole by having the lower part in contact with the cylinder head.

  The storage case is made of, for example, a synthetic resin and needs strength for storing an ignition coil, an iron core, a filler, and the like. Further, since the upper socket fitted to the high voltage terminal portion of the storage case is fitted to the storage case, it needs elasticity and strength corresponding to the strength of the storage case. The synthetic resin having elasticity and strength tends to deteriorate with the passage of time, creating a gap between the plug hole and the waterproof effect. The elastic waterproof cover according to the first aspect of the invention can sufficiently exhibit a waterproof effect even with aging due to the shape and elasticity.

(Second invention)
In the ignition coil for an internal combustion engine of the second invention, an annular recess is provided in the upper part of the upper socket of the first invention. Since the annular recesses are formed with two rows of projections in an annular shape, this portion comes into close contact with the inner surface of the elastic waterproof cover and exhibits a waterproof effect. Since the lower portion of the annular recess is flat and has strong surface contact with the weight of the storage case, it has a waterproof effect.

(Third invention)
The ignition coil for an internal combustion engine of the third invention is the first in that the ignition coil and the iron core are housed in a cylindrical housing case and enter the plug hole of the cylinder head, and there are no upper socket and lower socket. It is different from the invention. The annular elastic waterproof cover is provided with an opening for fitting the storage case, and an annular flange in contact with the cylinder head around an upper portion provided continuously from the opening. The tip of the annular flange contacts the cylinder head to prevent water from entering the plug hole.

(Fourth invention)
An ignition coil for an internal combustion engine according to a fourth aspect of the invention is configured such that the upper surface and / or the annular flange of the elastic waterproof cover according to the first to third aspects of the invention is inclined so as to go outward from the center of the ignition coil for the internal combustion engine. Yes. Even if there is a gap between the elastic waterproof cover and the cylinder head, water acts to flow outward, so that it is difficult to enter the plug hole due to secular change.

  FIG. 1 is a cross-sectional view for explaining an ignition coil for an internal combustion engine in an embodiment of the present invention. FIG. 2 is a plan view of an internal combustion engine ignition coil and an elastic waterproof cover according to an embodiment of the present invention. In FIG. 1 and FIG. 2, the internal combustion engine ignition coil 11 includes at least a storage case 12 and a high-voltage terminal portion 124 extending below the storage case 12. The storage case 12 stores an ignition coil 121, an iron core, a filler, and the like, and is provided with a connector housing 122, a mounting portion 123, and the like. The spark plug is attached via an upper socket 131, a plug joint 132, a conductive spring 133, and a lower socket 134. The upper socket 131, the plug joint 132, the conductive spring 133, and the lower socket 134 are accommodated in the plug hole 141 of the cylinder head 14. A spark plug (not shown) is attached to the portion indicated by reference numeral 13.

  The storage case 12 is provided with a high-voltage terminal portion 124 that fits into the upper socket 131 at a lower portion, and a flat bottom portion is provided between the high-voltage terminal portion 124 and the storage case 12. In addition, a fitting portion that fits with the plug joint 132 is provided at a lower portion of the upper socket 131. Further, an upper portion of the upper socket 131 has a lower portion in contact with the cylinder head 14 and an upper portion provided with an annular recess 135.

  An annular elastic waterproof cover 15 is in intimate contact between the bottom of the storage case 12 and the annular recess 135. The annular elastic waterproof cover 15 includes an annular flange 151 whose periphery extends downward, an annular opening 153 into which a high-voltage terminal portion 124 provided at a lower portion of the storage case 12 enters a central portion, and the annular flange 151. And an annular upper part 152 between the annular opening 153. The elastic waterproof cover 15 is in contact with the annular recess 135 of the upper socket 131 and the upper surface of the annular upper portion 152 is in contact with the bottom of the storage case 12. Further, the end of the annular flange 151 in the elastic waterproof cover 15 is in contact with the upper surface of the cylinder head 14. The elastic waterproof cover 15 has a structure that can be sealed at the annular upper portion 152, the end of the annular recess 135 of the upper socket 131, and the end of the annular flange 151.

  FIG. 3 is a cross-sectional view for explaining an internal combustion engine ignition coil according to another embodiment of the present invention. In FIG. 3, an ignition coil 31 for an internal combustion engine includes a storage case 32 in which a connector housing 322 and a mounting portion 323 are provided at an upper portion, and a cylindrical storage in which an ignition coil 321 and an iron core are stored in a lower portion of the storage case 32. Case 324 is formed. The cylindrical storage case 324 is stored in the plug hole 341 of the cylinder head 34. A spark plug (not shown) is attached to the portion indicated by reference numeral 33.

  The elastic waterproof cover 35 is provided at the center and has an annular opening 353 into which the cylindrical storage case 324 can be fitted, an annular upper part 352 extending from the annular opening 353, and downward toward the periphery of the upper part. And an annular flange 351 that protrudes. The end of the annular flange 351 contacts the upper surface of the cylinder head 34, so that water does not enter the plug hole 341.

  As a modification of the embodiment of FIGS. 1 and 2, the elastic waterproof covers 15 and 35 are inclined so that the upper surfaces thereof are lowered in the direction of the annular flanges 151 and 351. Further, the annular flanges 151 and 351 can be inclined in a direction to open downward. The water transmitted from the storage cases 12 and 32 and the like flows in a direction far from the plug holes 141 and 341 along the inclined surface. Further, the shape of the elastic waterproof covers 15 and 35 is not limited to a circular shape, and may be a non-circular shape or a polygonal shape in consideration of a storage case or the like.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example. The present invention can be modified in various ways without departing from the scope of the claims. For example, the capacitor, the ignition coil for the internal combustion engine, the material for the storage case, and the material for the filler in this embodiment can be known or known. In addition, as the material of the elastic waterproof cover, a known or well-known material can be adopted as long as it is more elastic than the material of the storage case or the like.

It is sectional drawing for demonstrating the ignition coil for internal combustion engines in the Example of this invention. Example 1 It is a top view of the ignition coil for internal combustion engines and the elastic waterproof cover in the Example of this invention. It is sectional drawing for demonstrating the ignition coil for internal combustion engines in the other Example of this invention. (Example 2) It is a figure for demonstrating the ignition coil for internal combustion engines in a prior art example. It is a figure for demonstrating another ignition coil for internal combustion engines in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 31 ... Ignition coil for internal combustion engines 12, 32 ... Storage case 121, 321 ... Ignition coil 122, 322 ... Connector housing 123, 323 ... Attachment part 124 ... High voltage terminal part DESCRIPTION OF SYMBOLS 13, 33 ... Spark plug 131 ... Upper socket 132 ... Plug joint 133 ... Conductive spring 134, 334 ... Lower socket 135 ... Annular recessed part 14, 34 ... Cylinder head 141 , 341 ... plug hole 15, 35 ... elastic waterproof cover 151, 351 ... annular flange 152, 352 ... annular upper part 153, 353 ... annular opening 324 ... cylindrical storage case

Claims (4)

A primary coil and a secondary coil, an iron core that magnetically couples the primary coil and the secondary coil, a control circuit that performs energization and interruption of current in the primary coil based on an ignition signal, and a storage case that stores them And an internal combustion engine ignition coil comprising at least a high-voltage terminal provided at a lower portion of the storage case,
An upper socket for connecting a high voltage terminal portion provided at a lower portion of the storage case and a plug joint for holding a spark plug;
The high voltage terminal portion is provided between the lower portion of the storage case and the upper portion of the upper socket, and the upper surface contacting the lower portion of the storage case, the inner surface contacting the upper portion of the upper socket, and the center. An elastic waterproof cover comprising: an opening to be formed; and an annular flange provided around the upper surface and the inner surface and in contact with the cylinder head;
An ignition coil for an internal combustion engine, comprising:   2. The ignition coil for an internal combustion engine according to claim 1, wherein an annular recess is provided in an upper portion of the upper socket, and the protrusion of the annular recess is in contact with the inner surface of the elastic waterproof cover. A primary coil and a secondary coil, an iron core that magnetically couples the primary coil and the secondary coil, a control circuit that conducts and cuts off current in the primary coil based on an ignition signal, and the coil and the iron core are housed And an ignition coil for an internal combustion engine configured at least from a cylindrical storage case inserted into the cylinder head
An elastic waterproof cover comprising an opening fitted into the cylindrical storage case, an upper portion extending from the opening, and an annular flange provided around the upper portion and in contact with the cylinder head;
An ignition coil for an internal combustion engine, comprising:   The ignition coil for an internal combustion engine according to any one of claims 1 to 3, wherein the elastic waterproof cover has an upper surface and / or an annular flange inclined outward.

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