JP2007299919A - Ignition coil device with two face openings - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plug top direct connection type ignition coil device excelling in assemblability as well as possessing high withstand voltage and water resistance, while shortening a longitudinal direction size as much as possible. <P>SOLUTION: The ignition coil device is directly connected with the plug top of an internal-combustion engine. A case having two face opening ends in two adjacent directions is arranged so that the axial direction of the coil may be set orthogonal to the axial direction of the ignition plug. The ignition coil device is blockaded by using the coil case and a lid-shaped object consisting of high insulating material after attaching components such as a coil, while making low the opening end position of the axial direction of the ignition plug of the coil case. <P>COPYRIGHT: (C)2008,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. 8, 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. 8, since the coil built-in components are arranged to the edge of the upper opening of the coil case, there is no allowance when injecting the epoxy resin liquid, and it takes time and effort to manage, resulting in reduced manufacturing efficiency. There was a problem. 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. 7, so that the vertical dimension of this portion is shortened, but the upper portion of 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 high. In order to meet this demand for further miniaturization, a design in which the axial direction is a closed end, an open end is provided in a direction perpendicular to the axial direction, and the axial length is shortened can be considered. 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.

As shown in FIG. 6, in the high voltage transformer used in the communication field instead of PTC, an opening is provided in two adjacent surfaces in the coil case, and a part such as a coil is assembled from this part to the opening on one side. Is also shown in which a single-sided opening is formed and a thermosetting resin is injected and solidified from the surface (see Patent Document 3). Since two adjacent surfaces of the coil case are open, workability is high in that internal parts such as coils are incorporated. However, since this transformer does not consider the requirement of the PTC to make the axial (longitudinal) dimension of the coil as short as possible, the technology of this communication transformer cannot be applied to the PTC as it is.
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 Japanese Patent Laid-Open No. 62-49608 “Transformer Casing” Published March 4, 1987

  SUMMARY OF THE INVENTION An object of the present invention is to provide a plug-top directly connected ignition coil device that is as short as possible in the longitudinal direction, has high voltage resistance and water resistance, and is excellent in assembly.

An ignition coil device according to the present invention is an ignition coil device that is directly connected to a plug top of an engine of an internal combustion engine, wherein the axial direction of the coil is disposed in a direction perpendicular to the axial direction of the ignition plug, and the two adjacent openings are opened. The opening end position in the axial direction of the coil case having the end and the ignition plug of the coil case was lowered, and the opening was closed by a lid-like body made of a highly insulating material after assembling components such as a coil.
Further, the lid-like body of the ignition coil device according to the present invention is closed between the coil case and the coil case by a labyrinth structure, and internal components of the coil case such as a coil are fixed with a filling resin from the axial opening of the coil. I did it.
In the ignition coil device according to the present invention, the connector is disposed at the coil case opening end in the direction orthogonal to the plug axis direction.

  Since the ignition coil device of the present invention employs a structure in which the axial direction of the coil is arranged in a direction perpendicular to the axial direction of the ignition plug, the axial dimension of the ignition plug of the device can be kept small. Further, by adopting a coil case having open ends in two adjacent directions, an assembling operation for loading internal components such as a coil and a core into the case can be easily performed. Furthermore, after assembling the parts such as the coil, the one opening is closed with a lid-like body made of a high-insulation material, so that the insulation effect of the high-voltage coil portion is increased and the axial direction of the ignition plug of the coil case is increased. The opening end position can be lowered.

In addition, since the lid body of the ignition coil device according to the present invention is closed between the coil case and the coil case by a labyrinth structure, the structure as the coil case is solid and liquid leakage or the like occurs in the process of filling and solidifying the resin. There is no worry.
In addition, the ignition coil device according to the present invention has a connector disposed at the coil case opening end in a direction orthogonal to the plug axial direction, and internal components of the coil case such as a coil are fixed with a filling resin from the axial opening of the coil. As a result, water does not accumulate on the surface of the filled resin that comes into contact with the outside air, and waterproofness is improved.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a longitudinal sectional view of an embodiment of an ignition coil device according to the present invention, in which a primary winding 3 is formed on 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. A secondary bobbin 4 is disposed in which the secondary winding 5 is wound around the primary winding 3 in a coaxial manner. 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 the connection circuit diagram of FIG. 4, a connection terminal 11 for supplying 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. (Hereafter, this state is referred to as “coil comp”.)

  A high voltage terminal 15 connected to the secondary terminal 13 is installed in a predetermined position at a predetermined position of the high voltage tower 14 formed integrally with the coil case 1. The outer core 16 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 of the axis of the coil case 1 downward, 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 that engages with a predetermined position of the opening surface in a direction perpendicular to the axial direction of the coil case 1, and the U-shaped portion of the concave groove and the opening portion. Are engaged and coupled.

The coil case 1 has an upper opening and two openings in a direction perpendicular to the axial direction of the spark plug adjacent thereto. This is a configuration that can be easily loaded when incorporating the coil or core internal member. Further, the position of the upper opening end of the coil case 1 is lowered, and a lid-like body 7 made of a high insulating material covers the opening surface. The coil case 1 and the lid-like body 7 are respectively provided with groove portions 1a and 7a at their peripheral portions, and are combined in a labyrinth structure that meshes with each other. As shown in FIG. 2 (a plan view of the ignition coil device of the present invention in a state where the upper opening is not yet covered with the lid 7), an inner member such as a coil is loaded. The case 1 is provided in a U shape in three directions excluding the upper peripheral edge opening. The groove 7a of the other lid-like body 7 is also provided in a U shape so as to be fitted with the groove 1a of the coil case. As shown in FIG. 3, the lid 7 that closes the upper opening of the coil case 1 is engaged with the lid 7 by press fitting. At this time, the lid 7 and the opening of the coil case 1 are engaged in a labyrinth structure.
In an engaged state, the other opening surface is directed upward, and an epoxy agent, which is a resin for casting, is poured in a direction perpendicular to the plug axis, that is, from the connector 9 side, and solidified to obtain an ignition coil device. At this time, since the lid and the coil case are engaged in the labyrinth structure as described above, the insulating resin does not leak during casting. The filling of the resin 21 becomes a portion painted with diagonal lines as shown in (1) of FIG. 5 (2) is a cross-sectional view taken along the line AA of FIG. 5 (1), but the resin 21 is poured from the inlet that is open in the state where the coil case 1 lid 7 and the connector 9 are joined. And solidified.

  Further, in the present invention, since the lid-like body 7 is formed of a highly insulating resin, the withstand voltage can be maintained even if the gap with the secondary coil 5 is set as small as possible. Therefore, the opening end position in the axial direction of the ignition plug of the coil case 1 can be lowered. The spark plug 18 is connected to the high tension spring 19 engaged with the high pressure terminal 15 at the center of the high voltage tower 14 of the coil case 1 and the high pressure boot 20 made of heat-resistant rubber so as to match the unevenness of the high pressure tower 14. Fit together. In this state, the ignition coil device 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) and is fixed to the engine cover through a screw in a mounting hole formed in the mounting arm.

When the height of the plug axial direction of the ignition coil device is lowered, the opening end in the axial direction becomes shorter, so that it becomes difficult to manage the epoxy liquid level as it is. In this invention, the lid of the insulating resin having a labyrinth structure is used to close the opening end in the axial direction, and the epoxy casting agent is injected from the direction perpendicular to the axial line, thereby making it easy to manage the epoxy liquid level. become. Moreover, since the high voltage | pressure side is obstruct | occluded with the cover body shape | molded with insulating resin, withstand voltage property is maintained. On the other hand, the liquid level injection part remains at the open end, but since it is on the low voltage side, there is no problem withstand voltage.
Furthermore, since the upper direction (top direction) of the axis line is covered with a labyrinth-structure lid-like body, water and dust do not collect on the epoxy surface, and the water resistance performance and the like are improved.

It is a longitudinal section of one embodiment of an ignition coil device of the present invention. It is a top view of the ignition coil device of the present invention in a state where the upper opening is not covered with a lid-like body. It is a longitudinal cross-sectional view which shows the form which a cover body covers a coil case in 1 embodiment. It is a connection circuit diagram of the ignition coil device of the present invention. It is a figure explaining the form with which resin is filled in the coil case of this invention. It is an exploded perspective view of a transformer casing and a cover to be slid into the transformer casing. 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 Winding 4 Secondary Bobbin 5 Secondary Winding 6 Center Core 7 Lid 1a, 7a Groove 9 Connector 10 Ignition Unit 11 Ignition Unit Terminal 12 Connector Terminal 13 Secondary Terminal 14 High Voltage Tower 15 High pressure 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, the coil case having an axial end arranged in a direction orthogonal to the axial direction of the ignition plug and having open ends in two adjacent directions, The ignition coil device is characterized in that the opening in one direction is closed by a lid-like body made of a highly insulating material.   The ignition coil device according to claim 1, wherein the lid-like body is closed with a labyrinth structure between the lid case and the coil case.   The ignition coil device according to claim 2, wherein a coil case internal component such as a coil is fixed with a filling resin from an axial opening of the coil.   The ignition coil device according to any one of claims 1 to 3, wherein a connector is disposed at an end of the coil case opening in a direction orthogonal to the plug axis direction.

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