JP2009121352A - Ignition coil protector for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve sealing performance between an ignition coil main body and a protector part of an ignition coil protector for internal combustion engine. <P>SOLUTION: This ignition coil protector 11 for internal combustion engine is structured from a flexible insulating cylindrical body 110 and structured of at least a high-voltage terminal insertion hole 111 to which a high-voltage terminal is inserted, an inner periphery axial seal part, an outer periphery axial seal part, an outer periphery radial seal part, and a seal connection part 115 connecting the inner periphery axial seal part with the outer periphery axial seal part. The inner periphery axial seal part abuts on an ignition coil body at a protruded circumferential protrusion surface thereof. The outer periphery axial seal part abuts on the ignition coil body at a protruded ring-like protrusion surface thereof. The inner periphery axial seal part and the outer periphery axial seal part are connected to each other by the seal connection part, on which an axial protrusion part provided in a plug hole abuts from under the seal connection part. The inner periphery axial seal part and the outer periphery axial seal part have respective abutting faces of protruded double-ring shape with respect to the ignition coil body, and thus can maintain high sealing performance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ignition coil for an internal combustion engine that supplies a high voltage for generating spark discharge, for example, in an ignition plug of an automobile engine, and more particularly to a protector for an ignition coil for an internal combustion engine. The protector for an ignition coil for an internal combustion engine of the present invention is for improving the sealing performance between the ignition coil body and the protector portion.

  FIG. 4 is a view for explaining a seal structure with an ignition coil main body in a conventional protector for an ignition coil for an internal combustion engine. In FIG. 4, the ignition coil body 51 is provided with an attachment portion 511 and an attachment hole 512 formed in the attachment portion 511. The protector 52 is formed from a ring shape having an insertion hole 521 for inserting a high voltage terminal portion 514 provided at the lower portion of the ignition coil main body 51, a radial seal portion 523 protruding from the peripheral surface, and a wide surface at the upper portion. And at least an axial seal portion 524. The plug hole 53 has a hole 531 into which the protector 52 is inserted, and an axial protrusion 532 is provided on the inner peripheral surface of the plug hole 53. The protector 52 is connected to the ignition coil main body 51 by the axial seal portion 524 and the seal to the plug hole 53 by the radial seal portion 523, that is, by a total of two places, the ignition coil main body 51 and the plug are plugged. The seal at the hole 53 is solid.

  FIG. 5 is a view for explaining the problem of the seal structure between the ignition coil main body and the protector in the conventional ignition coil protector for an internal combustion engine. In FIG. 5, the ignition coil body 51 is attached to the attachment portion 535 of the plug hole 53 with a bolt 513. In the mounting portion 535, the bolt 513 is unbalanced in the portion indicated by reference numerals 54 and 55 in the axial direction seal portion 524 of the protector 52 sandwiched between the ignition coil body 51 and the plug hole 53 depending on the degree of tightening. It may become. For example, the portion indicated by the reference numeral 55 may be floated, resulting in an incomplete seal, and moisture or the like may enter.

  FIG. 6 is a view for explaining another problem of the seal structure between the ignition coil body and the protector in the conventional ignition coil protector for an internal combustion engine. In FIG. 6, the foreign matter 71 may enter between the attachment portion 511 of the ignition coil body 51 and the attachment portion 535 of the protector 52. In such a case, the foreign matter 71 floats between the protector 52 and the seal portion of the plug hole 53, and the seal becomes incomplete.

Patent documents relating to the protector include, for example, Japanese Patent Application No. 2006-310775, Japanese Patent Application No. 2006-291888, and Japanese Patent Application No. 2005-235969.
Japanese Patent Application No. 2006-310775 Japanese Patent Application No. 2006-291888 Japanese Patent Application No. 2005-235969

  The ignition coil protector for an internal combustion engine has a large reaction force on the axial seal portion when the amount of compression differs due to dimensional variations when the axial seal portion is attached to the protector. The reaction force causes a force to push up the ignition coil body, and there is a concern that the sealing function in the portion may be lost. For example, since the protector for an ignition coil for an internal combustion engine shown in FIG. 5 is screwed at one location, the reaction force at this portion increases, and the other of the ignition coil body rises.

  The internal combustion engine ignition coil protector can assume a situation where the sealing function cannot be satisfied due to some external factor in addition to the above factors. For example, as shown in FIG. 6, when there is a foreign object in the attachment portion of the ignition coil main body, the ignition coil main body is in a lifted state, and the axial seal portion is not pressed against the ignition coil main body. Can not be satisfied.

(First invention)
A protector for an ignition coil for an internal combustion engine according to a first aspect of the present invention protects a high-voltage terminal portion that supplies a high voltage generated from the ignition coil body to the spark plug, from a high-voltage terminal insertion hole into which the high-voltage terminal portion is inserted. A flexible insulating cylinder, an outer peripheral axial seal portion in which a projecting portion protruding from the flexible insulating cylinder toward the ignition coil main body abuts on the ignition coil main body, and the inner peripheral axial seal portion And the outer circumferential axial seal portion, and at least a seal coupling portion in which an axial projection provided in the plug hole abuts from below.

(Second invention)
In the ignition coil protector for an internal combustion engine according to the second aspect of the invention, the flexible insulating cylinder of the first aspect includes an outer peripheral radial seal portion that comes into contact with the inner peripheral surface of the plug hole.

(Third invention)
In the ignition coil protector for an internal combustion engine according to the third invention, the outer peripheral axial seal portion of the first or second invention is larger than the outer diameter of the axial protrusion provided on the inner peripheral surface of the plug hole. And

(Fourth invention)
According to a fourth invention of the ignition coil protector for an internal combustion engine, the outer circumferential axial seal portion of the first to third inventions has a diameter that decreases from the base end portion to the tip end portion and is substantially vertical when attached. It is characterized by.

  According to the present invention, even if there is an imbalance in tightening between the ignition coil main body and the plug hole, the inner peripheral axial direction seal portion and the outer peripheral axial direction seal portion are pressed against the ignition coil main body, and the sealing function Can be satisfied. In particular, since the seal connecting portion that connects the inner peripheral axial seal portion and the outer peripheral axial seal portion is slanted, the reaction force during assembly to the engine is reduced by being pressed against the ignition coil body. In addition, it is easy to secure a seal allowance.

  According to the present invention, the contact between the ignition coil main body and the protector is performed at two locations, so that the sealing function can be satisfied even by imbalance due to tightening or foreign matter mixing.

  According to the present invention, the watertightness between the ignition coil main body and the plug hole is achieved by the contact between the lower portion of the seal connecting portion and the axial protrusion in the plug hole, and the contact between the outer circumferential radial seal portion and the plug hole. Sex can be maintained.

(First invention)
A protector for an ignition coil for an internal combustion engine according to a first aspect of the invention is for protecting a high voltage terminal portion that supplies a high voltage generated from an ignition coil body to a spark plug from moisture and the like. The internal combustion engine ignition coil protector comprises a flexible insulating cylinder, a high-voltage terminal insertion hole into which the high-voltage terminal portion is inserted, an inner circumferential axial seal portion, an outer circumferential axial seal portion, It is comprised at least from the outer periphery radial direction seal part and the seal | sticker connection part which connects the said inner periphery axial direction seal part and an outer periphery axial direction seal part.

  The inner circumferential axial direction seal portion protrudes from the flexible insulating cylinder toward the ignition coil main body, and abuts on the ignition coil main body at the protruding circumferential convex surface. The outer peripheral axial seal portion is provided on the outer periphery of the inner peripheral axial seal portion so as to protrude from the flexible insulating cylinder toward the ignition coil main body, and the protruding ring-shaped convex surface is provided on the ignition coil main body. Abut. The inner peripheral axial seal portion and the outer peripheral axial seal portion are connected to each other by a seal connecting portion where an axial protrusion provided in the plug hole abuts from below. The inner peripheral axial direction seal portion and the outer peripheral axial direction seal portion have a ring shape in which the respective contact surfaces with respect to the ignition coil main body are double-projected, so that high sealing performance can be maintained.

(Second invention)
In the ignition coil protector for an internal combustion engine of the second invention, an outer peripheral radial direction seal portion is provided on the outer peripheral surface of the flexible insulating cylinder of the first invention. The outer peripheral radial seal portion can maintain high sealing performance by abutting with the inner peripheral surface of the plug hole.

(Third invention)
An ignition coil protector for an internal combustion engine according to a third aspect of the invention is characterized in that the outer peripheral axial seal portion of the first or second aspect of the invention is larger than the outer diameter of the axial protrusion provided on the inner peripheral surface of the plug hole. Due to the contact with the seal connecting portion, the adhesiveness between the two can be improved.

(Fourth invention)
The protector for an ignition coil for an internal combustion engine according to a fourth aspect of the present invention has a diameter that decreases from the base end portion to the tip end portion of the outer peripheral axial seal portion according to the first to third aspects of the invention. When the axial projection of the plug hole comes into contact with the seal connecting portion, the distal end of the outer peripheral axial seal portion spreads outward and comes into contact with the ignition coil body almost vertically to make it watertight. it can.

  In the above-described ignition coil protector for an internal combustion engine, the seal connecting portion according to the first to fourth aspects of the present invention is formed to have a thickness that is recessed by a force generated when an axial protrusion provided in the plug hole comes into contact with the lower portion. . Further, the seal connecting portion is recessed in a ring shape when the axial projection of the plug hole is brought into contact, and the tip of the outer peripheral axial seal portion is inclined inward in the vertical direction. It will be bent, abuts at right angles to the ignition coil body, and has a watertight configuration.

  In the ignition coil protector for the internal combustion engine, it is desirable that the flexible insulating cylinder is made of a rubber material. The rubber-based material can improve the sealing performance of each part by skillfully using its own reaction force.

  FIG. 1 is a schematic view for explaining the structure of a protector for an ignition coil for an internal combustion engine according to the present invention. In FIG. 1, the protector 11 is arranged in the outer peripheral radial direction for sealing a cylindrical body 110 having a high voltage terminal insertion hole 111 for inserting a high voltage terminal and the like and a plug hole not shown in the outer periphery of the cylindrical body 110. An outer circumferential radial seal portion 112 having a protruding portion, an inner circumferential axial seal portion 113 provided in a ring shape on the inner circumference of the upper portion of the cylindrical body 110, and an outer circumference of the inner circumferential axial seal portion 113. The outer peripheral axial seal portion 114 and at least the inner peripheral axial seal portion 113 and the seal connecting portion 115 connecting the outer peripheral axial seal portion 114 are configured.

  The outer peripheral axial direction seal portion 114 is provided on the upper portion of the cylindrical body 110 so as to be lower in height and inclined inward than the inner peripheral axial direction seal portion 113. In addition, the seal connecting portion 115 that connects the inner peripheral axial direction seal portion 113 and the outer peripheral axial direction seal portion 114, and the outer peripheral axial direction seal portion 114 are configured to be thin and to be deformable. ing. Further, since the seal connecting portion 115 is inclined obliquely downward toward the periphery, the seal margin can be increased while reducing the reaction force when assembled to the engine.

  FIG. 2 is a schematic view for explaining a seal structure with the ignition coil body in the ignition coil protector for an internal combustion engine of the present invention. In FIG. 2, the ignition coil main body 21 is attached to an attachment portion (not shown) with a bolt or the like. In the protector 11, the front end portion of the inner peripheral axial direction seal portion 113 and the front end portion of the outer peripheral axial direction seal portion 114 are in contact with the lower surface of the ignition coil body 21. That is, the inner circumferential axial seal portion 113 formed of a ring shape having a wide surface at the upper portion and the outer circumferential axial seal portion 114 having a small thickness and a high height are provided at two locations on the bottom surface of the ignition coil body 21. Because of the contact in a ring shape, the seal is ensured.

  FIG. 3 is a schematic view for explaining the details of the seal structure with the ignition coil body in the ignition coil protector for an internal combustion engine of the present invention. In FIG. 3, the seal connecting portion 115 and the outer peripheral axial direction seal portion 114 are configured to be thin and to be highly flexible. For example, the seal connecting portion 115 is formed with a recess when the plug hole 31 is engaged with the axial projection 311 in the plug hole 31, and this portion is contacted in a ring shape. In addition, the ring-shaped contact of the axial projection 311 is caused by bending the outer circumferential axial seal portion 114 inclined inwardly at a substantially right angle, so that the distal end portion of the outer circumferential axial seal portion 114 and the ignition coil The bottom part of the main body 21 comes into contact with the ring-shaped surface to improve water tightness.

  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 block in this embodiment can be achieved by known or well-known technical means. Moreover, the material which comprises the ignition coil main body, protector, and plug hole in a present Example can use a well-known or well-known rubber-type member.

It is the schematic for demonstrating the structure of the protector for ignition coils for internal combustion engines of this invention. Example 1 It is the schematic for demonstrating the seal structure with the ignition coil main body in the protector for ignition coils for internal combustion engines of this invention. It is the schematic for demonstrating the detail of the seal structure with the ignition coil main body in the protector for ignition coils for internal combustion engines of this invention. It is a figure for demonstrating the seal structure with the ignition coil main body in the protector for ignition coils for conventional internal combustion engines. It is a figure for demonstrating the problem of the seal structure of the ignition coil main body and protector in the protector for ignition coils for conventional internal combustion engines. It is a figure for demonstrating the other problem of the seal structure of the ignition coil main body and protector in the conventional protector for ignition coils for internal combustion engines.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Protector 110 ... Cylindrical body 111 ... High voltage terminal insertion hole 112 ... Outer peripheral radial direction seal part 113 ... Inner peripheral axial direction seal part 114 ... Outer peripheral axial direction seal part 115 ... Seal connection part 21 ... Ignition coil body 211 ... Mounting part 212 ... Mounting hole 213 ... Bolt 22 ... High voltage terminal 31 ... Plug hole 311 ... Axial protrusion

Claims (4)

In the protector for an ignition coil for an internal combustion engine that protects the high-voltage terminal portion that supplies a high voltage generated from the ignition coil body to the ignition plug,
A flexible insulating cylinder comprising a high-voltage terminal insertion hole into which the high-voltage terminal portion is inserted;
An outer peripheral axial seal portion that comes into contact with the ignition coil body projecting from the flexible insulating cylinder to the ignition coil body side;
A seal connecting portion for connecting the outer circumferential axial seal portion and an axial projection provided in the plug hole abutting from below;
An ignition coil protector for an internal combustion engine, comprising at least   2. The protector for an ignition coil for an internal combustion engine according to claim 1, wherein the flexible insulating cylinder includes an outer peripheral radial direction seal portion that comes into contact with an inner peripheral surface of the plug hole.   3. The internal combustion engine ignition coil according to claim 1, wherein the outer circumferential axial seal portion is larger in outer diameter than an axial projection provided on an inner circumferential surface of the plug hole. Protector.   The diameter of the outer peripheral axial seal portion decreases from the proximal end portion to the distal end portion, and becomes substantially vertical when attached. 4. An ignition coil protector for an internal combustion engine.

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