JP2007250642A - Compact and lightweight plug top direct-coupled ignition coil device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plug top direct-coupled ignition coil device with high withstand voltage performance, where a longitudinal dimension is shortened as much as possible. <P>SOLUTION: This ignition coil device is directly coupled to the plug top of an internal combustion engine. The axial direction of the coil is arranged to be orthogonally crossed with the axial direction of an ignition plug. The opening end of a coil case is positioned to be lower. A partitioning board composed of a high insulating material is arranged between a secondary winding wire wound around a secondary bobbin, and the opening end of the coil case. The partitioning board is successively arranged at the opening end of the coil case at the side of a connector, integrally extended to the high voltage side of the secondary bobbin, and includes holes to suppress air storage when an epoxy resin is injected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small ignition coil device that is directly connected to, for example, an ignition plug of an independent ignition type engine among ignition coil devices of an automobile engine. Hereinafter, these coils are referred to as PTC. PTC is an abbreviation for Plug Top Coil.

Conventionally, the PTC used in the internal ignition system of the internal combustion engine is attached to the periphery of the engine head cover. Therefore, it is desired to reduce the size and weight, and the arrangement on the upper part of the engine head cover is limited. When mounted on the ignition coil, the ignition coil tends to be designed so that the length corresponding to the axial direction of the spark plug is as short as possible. In the vertical type in which the axial direction of the coils 3 and 5 coincides with the axial direction of the spark plug 18 as in the patent document 1 shown in FIG. 6, since it is directly inserted into the plug hole, it is exposed on the head cover of the engine. There is an advantage that the number of parts to be reduced is reduced, and the degree of design freedom around the head cover is improved. However, as shown in FIG. 6, since the coil built-in components are arranged up to the edge of the upper opening of the coil case, there is no allowance when injecting the epoxy resin liquid, and management is troublesome and manufacturing efficiency is reduced. was there. In addition, a horizontal type ignition coil device in which the axial direction of the coil is horizontal is provided. Incidentally, what is presented in Patent Document 2 has a horizontal arrangement as shown in FIG. 5, and thus the vertical dimension of this portion is shortened, but the upper portion of the case 1 is secured to ensure withstand voltage performance. Since the opening end is made high so that the distance between the insulating resin 21 surface and the built-in component is sufficient, the total vertical dimension is slightly higher. In order to meet the demand for further miniaturization, it is conceivable to design the axial direction as a closed end and an opening end in a direction perpendicular to the axial direction to shorten the axial length. With this design, the secondary coil part that is at a high voltage can be covered with a casing made of a highly insulating material, so the vertical dimension can be shortened. there were.
JP-A-4-62812 "Ignition Coil for Internal Combustion Engine" Published on February 27, 1992 JP 2002-48046 A "Ignition Coil for Internal Combustion Engine" Published on February 15, 2002

  An object of the present invention is to provide a plug-top directly connected ignition coil device having a vertical dimension as short as possible and having a high withstand voltage performance.

An ignition coil device according to the present invention is an ignition coil device directly connected to a plug top of an engine of an internal combustion engine, in which the axial direction of the coil is arranged in a direction perpendicular to the axial direction of the ignition plug. The opening end position is lowered, and a partition plate made of a highly insulating material is disposed between the secondary winding wound on the secondary bobbin and the opening end of the coil case.
The partition plate is connected to the open end of the coil case on the connector side, and extends integrally to the high-pressure side of the secondary bobbin, and is a hole that suppresses air accumulation during epoxy resin injection. Is provided.
Further, in a preferred embodiment of the ignition coil device according to the present invention, the partition plate is integrated with the connector, or separately attached to the opening end of the coil case on the connector side. The part extending to the high pressure side is raised one step further.
Furthermore, an air vent hole is provided in the lower part of the raised partition plate in a chimney shape.

An ignition coil device according to the present invention is an ignition coil device directly connected to a plug top of an engine of an internal combustion engine, in which the axial direction of the coil is arranged in a direction perpendicular to the axial direction of the ignition plug. Since the opening end position is lowered and a partition plate made of a high insulating material is disposed between the secondary winding wound on the secondary bobbin and the opening end of the coil case, Due to the presence of the partition plate made of an insulating material, high withstand voltage performance can be obtained without being embedded deeply in the insulating resin, and the opening end position of the coil case can be lowered, so that the dimensions of the ignition coil device can be set in the axial direction of the ignition plug. Can be shortened. In addition, since the built-in components can be inserted from above as in the past, there is no problem of assembling.
The partition plate is connected to the open end of the coil case on the connector side, and extends integrally to the high-pressure side of the secondary bobbin, and is a hole that suppresses air accumulation during epoxy resin injection. Therefore, it is possible to exhibit high insulation against the high voltage of the secondary coil, and there is no possibility of forming a cavity that deteriorates insulation in the solidified insulating resin.

In addition, the partition plate is an integral structure with the connector, or is attached separately to the open end of the coil case on the connector side, and the part extending to the high-pressure side of the secondary bobbin is further raised. In the ignition coil device according to the present invention, the partition plate and the connector, which are constituent parts, are firmly fixed to the coil case, and further, the ignition coil device has a considerable distance from the high voltage portion of the secondary coil that generates a high voltage. Since a partition plate made of a highly insulating material is disposed, high withstand voltage performance can be obtained.
Further, since the air vent hole is provided in the chimney shape below the partition plate portion that is raised one step higher, the air can surely escape even if the resin level to be filled varies slightly, and it can come into contact with the resin. The partition plate part which is not raised one step can be firmly fixed with resin.

  A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view of a first embodiment of an ignition coil device according to the present invention, in which the opening end position of the coil case 1 is lowered and the secondary winding 5 wound on the secondary bobbin 4 and the aforementioned FIG. 2 shows a plan view of the partition plate 7 made of a highly insulating material provided with an air vent hole 8 which is disposed between the open ends of the coil case 1 and suppresses air accumulation during epoxy liquid casting. In FIG. 1, a primary winding 3 is wound around a primary bobbin 2 in which an I-shaped center core 6 in which a plurality of silicon steel plates are laminated is insert-molded, and is further coaxial with the primary winding 3 as a center. A secondary bobbin 4 around which a secondary winding 5 is wound is arranged. A connector 9 is connected to the low voltage side of the coil case 1, and an ignition unit 10 for controlling ignition is disposed in the connector 9. A terminal 11 of the ignition unit and a terminal 12 of the connector 9 are connected by resistance welding or the like. Yes. As shown in FIG. 2, the partition plate 7 has a region where the air vent holes 8a and 8b are arranged in two rows, a hole 7a for fitting a predetermined part of the secondary bobbin 4 and the air vent holes 8c and 8d. And three regions of an opening 7b for injecting an insulating resin such as epoxy. The area where the air vent holes 8a, 8b are arranged in two rows is inclined between the hole 7a for fitting a predetermined part of the secondary bobbin 4 and the area where the air vent holes 8c, 8d are arranged. It is one step higher than the part. The air vent holes 8a and 8b arranged in two rows are formed in a chimney shape up to the level of the lower surface of the other region.

  The partition plate 7 is disposed so as to cover the opening of the coil case 1. In this embodiment, the partition plate 7 is formed integrally with the connector 9. The partition plate 7 is arranged to be coupled to the ignition coil in such a manner that a predetermined portion of the secondary bobbin 4 is fitted into the hole 7a. Thus, the positional relationship is such that the secondary winding 5 that generates high voltage is covered. As shown in the connection circuit diagram of FIG. 3, a connection terminal 11 for applying an input signal from the ignition unit 10 is connected to the primary winding 3, which is connected to the secondary bobbin 4 as shown in FIG. Above, it is made with the ignition unit 10 by resistance welding or the like. The secondary bobbin 4 is provided with a secondary terminal 13 connected to the end of the secondary winding 5 (high voltage side) and connected to the spark plug 18 side. (Hereinafter, this state is referred to as “coil comp”.) As an assembling step, as shown in FIG. 1, a high voltage terminal connected to a secondary terminal 13 at a predetermined position of a high voltage tower 14 formed integrally with the coil case 1. 15 is installed in the press fit. Next, the outer peripheral core 16 as a magnetic circuit for not leaking the magnetic flux of the center core 6 is installed in the coil case 1. At this time, since the width of the outer peripheral core 16 and the inner surface width of the coil case 1 have a controlled clearance, the play after the outer peripheral core 16 is installed hardly occurs.

  Next, when the coil comp is inserted from the upper side to the lower side of the axis of the coil case 1, the secondary terminal 13 comes into contact with the high-voltage terminal 15 and electrical connection is maintained. At this time, the connector 9 is formed with a concave groove 17 that engages with a predetermined position on a side surface perpendicular to the axial direction of the coil case 1, and the concave groove 17 and the coil case 1 (not shown). The U-shaped open part on the side surface of is engaged and incorporated. Next, an epoxy resin for casting is poured in the axial direction from the resin injection hole 7b of the partition plate 7 and solidified to obtain an ignition coil device. The epoxy resin is injected to such a height that the tip of a predetermined portion of the secondary bobbin 4 fitted in the fitting hole 7a of the partition plate 7 is filled. At this time, bubbles generated on the lower surface portion of the partition plate 7 are discharged to the outside through the air vent holes 8a, 8b, 8c and 8d so that a void portion is not formed in the solidified epoxy resin. The surface of the epoxy resin is lower than the surface of the partition plate 7 that is raised one step higher, but the air venting holes 8a and 8b are formed in a chimney shape in the lower part in order to ensure air venting in that region and to secure the fixing with the resin. Is formed.

  The spark plug 18 is connected by installing a high tension spring 19 at the high-pressure terminal 15 at the center of the high-pressure tower 14 of the coil case 1 and engaging a high-pressure boot 20 made of heat-resistant rubber so as to match the unevenness of the high-pressure tower 14. To do. In this state, the ignition coil device of the present invention is engaged with the spark plug 18 from the upper part of the engine cover. The coil case 1 is provided with a mounting arm (not shown) so as to be fixed to the engine cover through a screw in a mounting hole formed in the mounting arm.

  The ignition coil device according to the present invention is formed such that the partition plate 7 covering the high voltage portion of the secondary coil 5 on the left side in FIG. 1 is one step higher than the other regions as described above. That is, the high voltage portion of the secondary coil 5 is embedded in an insulating epoxy resin like other regions, and is further covered with a partition plate 7 made of a highly insulating material at a distance from other regions. Therefore, the insulation of this part becomes higher.

  In the above-described embodiment, the partition plate 7 and the connector 9 are integrally formed. However, the present invention is not limited to this and may be formed separately. FIG. 4 shows a second embodiment of the present invention. The upper part is a partial longitudinal sectional view of a second embodiment of the ignition coil device of the present invention. In this example, the lower plate is a plan view of the partition plate 7, and the partition plate 7 is not connected to the connector 9 and covers a high voltage portion of the secondary winding 5 wound around the secondary bobbin 4. Although the point which is extended is the same, it has the structure which notched the coupling member with the connector 9 which formed the resin injection hole 7b in previous embodiment. The partition plate 7 includes two areas: an area where the air vent holes 8a and 8b are arranged in two rows, and an area where the hole 7a which fits a predetermined part of the secondary bobbin 4 and the air vent holes 8c and 8d are arranged. It consists of areas. The area where the air vent holes 8a, 8b are arranged in two rows is inclined between the hole 7a for fitting a predetermined part of the secondary bobbin 4 and the area where the air vent holes 8c, 8d are arranged. It is the same as the previous embodiment in that the air vent holes 8a and 8b arranged in two rows are formed in a chimney shape up to the level of the lower surface of the other region. is there. Although the partition plate 7 and the connector 9 are not integrally formed, the partition plate 7 has a hole 7a for fitting a predetermined portion of the secondary bobbin 4 and air vent holes 8a and 8b formed in a chimney shape below, and is made of resin. By the reliable fixing, the secondary coil is stably fixed so as to cover the high voltage portion of the secondary coil.

It is a longitudinal cross-sectional view of 1st Embodiment of the ignition coil apparatus of this invention. It is a top view of the partition plate used by this invention. It is a connection circuit diagram of the ignition coil device of the present invention. It is a figure which shows 2nd Embodiment of the ignition coil apparatus of this invention. It is a longitudinal cross-sectional view of the conventional ignition coil apparatus. It is a longitudinal cross-sectional view of a different conventional ignition coil device.

Explanation of symbols

1 Coil case 2 Primary bobbin 3 Primary coil 4 Secondary bobbin 5 Secondary coil 6 Center core 7 Partition plate 7a Fitting hole
7b Resin injection hole 8a, 8b, 8c, 8d Air vent hole 9 Connector 10 Ignition unit
11 Ignition unit terminals 12 Connector terminals
13 Secondary terminal 14 High voltage tower
15 High voltage terminal 16 Outer core
17 Groove 18 Spark plug
19 Spring 20 High pressure boot
21 Insulating resin

Claims (4)

  An ignition coil device directly connected to a plug top of an engine of an internal combustion engine, in which the axial direction of the coil is arranged in a direction perpendicular to the axial direction of the ignition plug, the opening end position of the coil case is lowered, An ignition coil device characterized in that a partition plate made of a highly insulating material is disposed between a secondary winding wound on a next bobbin and an open end of the coil case.   The partition plate is connected to the open end of the coil case on the connector side, and extends integrally to the high pressure side of the secondary bobbin, and has a hole for suppressing air accumulation during injection of epoxy resin. The ignition coil device according to claim 1, wherein the ignition coil device is provided.   The partition plate is an integral structure with the connector, or is attached separately to the open end of the coil case on the connector side, and the portion extending to the high pressure side of the secondary bobbin is raised one step higher. The ignition coil device according to claim 1 or 2, characterized in that.   4. The ignition coil device according to claim 3, wherein an air vent hole is provided in a chimney shape downward in the raised partition plate portion.

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