JP2004169639A - Ignition coil for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive ignition coil for an internal combustion engine by reducing using amount of resin molding an insulating case while securing rigidity of a bracket. <P>SOLUTION: The upper and lower surfaces of the bracket 20 are provided with recessed parts 22 having a thin bottom 23 and contacting with a case body 16, and ribs 24 that cross and partition the recessed parts 22, have a V shape expanding to the case body 16 side, and are integrally connected to the bottoms 23 and the peripheral walls of the recessed parts 22. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil for an internal combustion engine that supplies a high voltage for generating a spark discharge to a spark plug fixed to a bottom of a plug hole of the internal combustion engine.
[0002]
[Prior art]
As the ignition coil for the internal combustion engine described above, a primary body and a secondary coil, a case body which incorporates an iron core for magnetically coupling the two coils, and is fixed in an insulating resin filled and solidified, A high-pressure cylinder which is provided downward and has a high-voltage terminal on the inner periphery to which a high voltage induced in the secondary coil is transmitted, and which is inserted from above into a plug hole of an internal combustion engine having an ignition plug fixed to the bottom. It is known to provide an insulating case integrally provided with a bracket fixed to the outside of the internal combustion engine, provided on the side of the case body so as to protrude outward, and the bracket is located near the plug hole. It is fixed to the upper end of the upright support column with a screw (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP 2000-294434 A
[Problems to be solved by the invention]
Since the ignition coil for the internal combustion engine fixed to the internal combustion engine via the bracket is affected by the three-dimensional vibration due to the explosion and rotation in the internal combustion engine, the width and the thickness of the bracket are reduced to prevent the bracket from being damaged. This was addressed by increasing the size and increasing the rigidity.
Therefore, the weight of the bracket portion is increased, the amount of resin used to form the insulating case is increased, and the cost is increased.
[0005]
[Means for Solving the Problems]
The present invention has been made in order to solve the above-mentioned problem, and has a case in which a primary coil and a secondary coil, and an iron core that magnetically couples the two coils are built in, and are fixed in an insulating resin filled and solidified. A high-pressure cylinder having a main body, a high-voltage terminal provided on an inner periphery of the case main body, and having a high-voltage terminal to which a high voltage induced in the secondary coil is transmitted, and an internal-combustion engine having the high-pressure cylinder fixed to the bottom of a spark plug An ignition coil for an internal combustion engine provided with an insulating case integrally provided with a bracket fixed to the outside of the internal combustion engine and provided so as to protrude outward from a side portion of the case main body so as to protrude into the plug hole from above. A concave portion having a thin bottom and a rib which is partitioned across the concave portion and which is integrally connected to the bottom and the peripheral wall of the concave portion are provided on one or both of the upper surface and the lower surface of the bracket. .
It is desirable that the rib be formed in a V-shape that expands toward the case body, and that the recess be provided so as to be in contact with the case body.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
In the illustrated embodiment, reference numeral 12 denotes a secondary coil, and the primary coil 11 is fitted concentrically around the inner periphery of the bobbin. Reference numerals 13 and 14 denote a center iron core and side iron cores constituting a closed magnetic circuit. As is well known, the center iron core 13 penetrates through the bobbin of the primary coil 11 to support the primary and secondary coils 11, 12, The iron core 14 is arranged so as to surround the secondary coil 12, and both ends of the center iron core 13 are in contact with the inner periphery of the side iron core 14. Thus, the iron cores 13 and 14 and the primary and secondary coils 11 and 12 constitute an iron core coil assembly of a closed magnetic circuit, which is housed in the case body 16 of the funnel-shaped insulating case 15, and The insulating resin 17 filled and solidified is insulated and fixed. The case main body 16 is integrally provided with a downward high-pressure cylinder 18, and a high-voltage terminal 19 to which a high voltage induced in the secondary coil 12 is transmitted is attached to the inner periphery thereof.
[0007]
Reference numeral 31 denotes a plug hole of the internal combustion engine 30 which is fixed to the bottom through a spark plug. Near the upper end of the plug hole 31 is provided a column 32 for fixing an ignition coil for the internal combustion engine.
[0008]
Reference numeral 20 denotes a bracket which is integrally provided so as to protrude outward on the side of the case body 16, and is screwed into a support 32 through a screw 33 in a through hole 21 at the tip of the bracket 20, and the bracket is mounted on the support 32. By fixing 20, the lower portion of case main body 16 and high-pressure cylinder 18 shallowly enter plug hole 31 from above.
[0009]
The upper fitting part 35 of the plug socket 34 is fitted into the lower part of the case body 16 and the high-pressure cylinder 18, and the upper end of a coil spring 36 provided to penetrate the plug socket 34 abuts on the high-voltage terminal 19. Although not shown in the figure, as shown in FIG. 2 of JP-A-2000-294434, the insulator portion of the ignition plug in which the lower fitting portion provided at the lower end of the plug socket 34 stands from the bottom of the plug hole 31 And the lower end of the coil spring 36 comes into contact with the upper electrode of the insulator portion from above, and the high voltage transmitted to the high voltage terminal 19 is supplied to the ignition plug.
[0010]
The bracket 20 is thick, and its plan shape is such that the bottom is continuous with the side of the case body 16 and the top 20 ′ having the through hole 21 is a rounded triangle. In the illustrated embodiment, the triangular bracket 20 has a thin bottom 23 on both the upper surface and the lower surface, and a concave portion 22 in contact with the case body 16 and a partition across the concave portion 22. And a rib 24 integrally connected to the peripheral wall of the main body.
[0011]
The concave portion 22 and the rib 24 are not limited to being provided on both the upper surface and the lower surface of the bracket 20 as in the illustrated embodiment, and may be either the upper surface or the lower surface.
[0012]
In the illustrated embodiment, the concave portion 22 is formed by a first triangular concave portion 22a having a low height and having a side portion of the case main body 16 as a base, and first ribs 24a, 24a provided on each oblique side of the first concave portion 22a. The rib 24 is formed by partitioning second and third recesses 22b and 22b. The rib 24 is formed by the second and third ribs 24b and 24b that partition the second and third recesses 22b and 22b and the through hole 21. (As viewed from the relationship between the case body 16, the recesses 22, and the ribs 24, the recesses 22 are in contact with the case body 16, and the ribs 24 have a U-shaped shape that expands toward the case body 16.) The bracket 20 having the concave portions 22a, 22b, 22b is reinforced.
[0013]
【The invention's effect】
As is apparent from the above, according to the present invention, the bracket of the insulating case has a concave portion having a thin bottom on one or both of the upper surface and the lower surface, a partition across the concave portion, and a bottom and a peripheral wall of the concave portion. Since the ribs are provided integrally with each other, the rigidity of the brackets can be secured by the ribs against any three-dimensional vibration received from the internal combustion engine, greatly improving the reliability of the ignition coil for the internal combustion engine. Can be improved.
Further, the use of the resin for molding the insulating case can be reduced by the presence of the concave portion, and an ignition coil for an internal combustion engine can be provided at low cost.
Since the ribs are formed in the shape of a letter that expands toward the case body, the case body can absorb the stress caused by the heat received from the insulating resin, and the case body and the insulating resin can be prevented from peeling off.
Further, since the concave portion is provided so as to be in contact with the case main body, the case main body can further absorb the stress due to the heat received from the insulating resin, and the case main body and the insulating resin can be reliably prevented from peeling off.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a use state of an embodiment of an ignition coil for an internal combustion engine of the present invention.
FIG. 2 is a top view of the ignition coil for an internal combustion engine shown in FIG.
FIG. 3 is a bottom view of a bracket portion of the ignition coil for an internal combustion engine shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Primary coil 12 Secondary coil 13 Center iron core 14 Side iron core 15 Insulating case 16 Case main body 17 Insulating resin 18 High voltage cylinder 19 High voltage terminal 20 Bracket 22 Bracket recess 24 Bracket rib

Claims (3)

A primary coil, a secondary coil, and a case body in which an iron core for magnetically coupling the two coils is built in and fixed in an insulating resin filled and solidified, and a secondary coil provided downward on the case body. A high-pressure cylinder having a high-voltage terminal on the inner periphery through which a high voltage induced by the high-voltage terminal is transmitted, and a side portion of the case main body for projecting the high-pressure cylinder from above into a plug hole of an internal combustion engine having a spark plug fixed to the bottom. An ignition coil for an internal combustion engine provided with an insulating case integrally provided with a bracket fixed to the outside of the internal combustion engine and provided so as to protrude outwardly,
On one or both of the upper surface and the lower surface of the bracket, a concave portion having a thin bottom, and a rib which is partitioned across the concave portion and which is integrally coupled to the bottom and a peripheral wall of the concave portion, are provided.
An ignition coil for an internal combustion engine. The ignition coil for an internal combustion engine according to claim 1,
The rib is formed in a rectangular shape that expands toward the case body side,
An ignition coil for an internal combustion engine. The ignition coil for an internal combustion engine according to claim 2,
The recess is in contact with the case body,
An ignition coil for an internal combustion engine.

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