JP2010118601A - 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 surely bringing a terminal pin into contact with a high voltage terminal. <P>SOLUTION: The ignition coil for an internal combustion engine is configured with high voltage terminals contained in a cylindrical high voltage tube 62 provided in a linked manner outwardly to a container 61 of an insulating case 6, wherein the high voltage terminals are composed of: a first high voltage terminal 8A directly connected to a terminal pin 7 acting as the terminal of a secondary coil; and a second high voltage terminal 8B connected to the first high voltage terminal 8A while sandwiching the first high voltage terminal 8A. <P>COPYRIGHT: (C)2010,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 in an ignition plug of an engine such as an automobile, for example, and ensures electrical connection between a terminal portion of a secondary coil and a high-voltage terminal. The present invention relates to an ignition coil for an internal combustion engine that meets the expectation of reliability improvement.

  Conventionally, the connection between the terminal portion of the secondary coil and the high voltage terminal in the ignition coil for an internal combustion engine has been established by pressure welding utilizing the elasticity of each component. Specifically, the terminal portion of the secondary coil is a wire-shaped terminal pin, and its tip is extended to the high-pressure cylinder portion provided in the insulating case and pressed against the high-voltage terminal accommodated in this high-pressure cylinder portion. It was.

  In such an ignition coil for an internal combustion engine, when the internal temperature rises during operation and a thermal stress is generated in the insulating resin filled in the insulating case, this thermal stress acts in a direction to cut off the contact between the terminal pin and the high-voltage terminal. In this case, there is a problem that poor conduction occurs.

Therefore, an invention aimed at securing an electrical connection by providing a terminal pin holding portion on a secondary coil bobbin around which a secondary coil is wound and pressing the terminal pin against a high voltage terminal by the terminal pin holding portion is as follows. This is proposed in Patent Document 1.
JP 2008-135494 A

  As shown in FIG. 2, the ignition coil 10 for an internal combustion engine in the invention according to Patent Document 1 includes a primary coil 12 in which an electric wire is wound around a primary coil bobbin 11 and an electric wire wound around a secondary coil bobbin 13. The insulating case 16 provided with the secondary coil 14, the iron core 15 that magnetically couples the secondary coil 14 and the primary coil 12, and the high-voltage cylinder portion 161 that accommodates the high-voltage terminal 18 in the lower part. In particular, as shown in FIG. 3, the secondary coil bobbin 13 has a flange 13 a extending to form a terminal pin holding part 19, and the terminal part of the secondary coil 14 is connected to a wire-like terminal pin. 17, the terminal pin 17 is pressed against the high-voltage terminal 18 by the terminal pin holding part 19, so that the terminal pin 17 is reliably brought into contact with the high-voltage terminal 18 by the terminal pin holding part 19. Bets can be, it becomes such as that it is possible to prevent the causing conduction failure in the thermal stress of the insulating resin generated during operation of the ignition coil.

  However, there is a universal demand for improving the reliability of the ignition coil for an internal combustion engine, and the terminal pin 17 and the high-voltage terminal 18 are connected by pressure contact or pressing as in Patent Document 1 (FIG. 2 or FIG. 3). On the extension line of the conventional technical idea, there is a problem that the possibility that a conduction failure occurs due to some cause cannot be completely avoided.

  The present invention has been proposed in view of the above circumstances, and has created a new technology for connecting the terminal pin, that is, the terminal portion of the secondary coil and the high-voltage terminal, and specifically, the structure of the high-voltage terminal. Provide an ignition coil for an internal combustion engine that can meet the expectation of reliability improvement by ensuring the electrical connection between the terminal portion of the secondary coil and the high voltage terminal by combining two types of high voltage terminals. For the purpose.

  In order to achieve the above object, the present invention includes a primary coil, a secondary coil, a housing part that houses the secondary coil and an iron core that is magnetically coupled to the primary coil, and a housing part that extends outward from the housing part. Each of these components is housed in an insulating case provided with a cylindrical high-voltage cylinder portion that accommodates a high-voltage terminal to which the terminal portion of the secondary coil is connected, and filled with an insulating resin. In the internal combustion engine ignition coil, the high voltage terminal includes a first high voltage terminal directly connected to a terminal portion of the secondary coil, and a second high voltage terminal connected to the first high voltage terminal while sandwiching the first high voltage terminal. It consists of.

  In particular, the first high-voltage terminal has a pinch-like shape with a branch portion, and is clamped by the second high-voltage terminal so that the end portion of the secondary coil is fixed to the branch portion. It is preferable.

  The second high-voltage terminal is preferably a cylindrical metal fitting having a hollow portion having a conductive surface, and the first high-voltage terminal is sandwiched between the hollow portions.

  In the present invention, the high voltage terminal is composed of a first high voltage terminal to which the terminal portion of the secondary coil is directly connected and a second high voltage terminal that is connected to the first high voltage terminal while sandwiching the first high voltage terminal. Therefore, first, the first high voltage terminal is directly connected to the terminal portion of the secondary coil, and the second high voltage terminal is connected to the first high voltage terminal while sandwiching the first high voltage terminal. The secondary coil terminal and the high-voltage terminal do not become poorly conductive due to thermal stress of the insulating resin generated during operation, vibration during engine operation, clumsiness when filling the insulating resin, etc. It is possible to ensure electrical connection between the terminal portion and the high voltage terminal.

  In particular, the first high-voltage terminal has a pinch-like shape with a branch portion, and is clamped by the second high-voltage terminal so that the end portion of the secondary coil is fixed to the branch portion. Therefore, since the terminal part of the secondary coil can be securely connected to the first high-voltage terminal so as to be sandwiched at the branch part, poor conduction between the terminal part of the secondary coil and the high-voltage terminal can be prevented. It becomes possible to prevent reliably.

  Further, since the second high voltage terminal is a cylindrical metal fitting having a hollow portion having a conductive surface and the first high voltage terminal is clamped in the hollow portion, the first high voltage terminal is securely clamped. In addition, since it is possible to ensure the electrical connection with the first high voltage terminal, the conduction between the terminal portion of the secondary coil and the high voltage terminal can be further ensured. .

  That is, in the present invention, the high voltage terminal in the ignition coil for an internal combustion engine has a pinch-like shape having a branch portion, and is clamped by the second high voltage terminal, so that the terminal portion of the secondary coil at the branch portion. Is a cylindrical metal fitting having a first high-voltage terminal that is directly connected to the terminal portion of the secondary coil and a hollow portion having a conductive surface, and the first high-voltage terminal is sandwiched between the hollow portions. However, since the second high voltage terminal is connected to the first high voltage terminal, it can be securely connected (fixed) to the branch portion of the first high voltage terminal so as to sandwich the terminal portion of the secondary coil. Since the first high voltage terminal connected to the terminal portion of the secondary coil can be securely connected so as to be sandwiched by the cavity of the second high voltage terminal, the terminal portion of the secondary coil and the high voltage terminal can be connected. For internal combustion engines that can reliably prevent poor conduction It is possible to provide a fire coil.

Hereinafter, an embodiment of an ignition coil for an internal combustion engine according to the present invention will be described with reference to the drawings.
FIG. 1 is an enlarged cross-sectional view of a main part of an ignition coil for an internal combustion engine according to the present invention, and is a vertical cross-sectional view showing a connection relationship between a terminal portion of a secondary coil and a high-voltage terminal. The principal part expanded sectional view explaining the mode of connection of the terminal part of a secondary coil, and the 1st high voltage terminal, and the mode of inserting this 1st high voltage terminal in the hollow part of the 2nd high voltage terminal, (b) It is a principal part expanded sectional view explaining the mode of a connection of a 1st high voltage terminal and a 2nd high voltage terminal. 2 and 3 are the same as or equivalent to those of the internal combustion engine ignition coil shown as the conventional example, and the description thereof is omitted.

  In the ignition coil for an internal combustion engine according to the present invention, at least a primary coil, a secondary coil, and an iron core that is magnetically coupled to the secondary coil and the primary coil are housed in the housing portion of the insulation case. A high-voltage terminal is accommodated in a cylindrical high-pressure cylinder portion continuously provided outward from the accommodation portion, and then an insulating resin is filled in an insulating case. In particular, as shown in FIG. 1, the ignition coil 1 for an internal combustion engine according to the present invention is a high-voltage terminal accommodated in a cylindrical high-pressure cylinder portion 62 that is connected outwardly from the accommodation portion 61 of the insulating case 6. Is composed of a first high voltage terminal 8A directly connected to a terminal pin 7 as a terminal portion of the secondary coil, and a second high voltage terminal 8B connected to the first high voltage terminal 8A while holding the first high voltage terminal 8A. Has been.

  1, the primary coil wound around the primary coil bobbin, the secondary coil wound around the secondary coil bobbin, and the iron core that magnetically couples these two coils are provided in the insulating case 6. Are housed in the housing portion 61, and are fixed and held by the insulating resin filled in the insulating case 16.

  As shown in FIG. 1A, the first high-voltage terminal 8A is a pinch metal fitting having a substantially Y-shape having a branch portion 8Aa, and is conductive. Further, as shown in FIG. 1B, the first high-voltage terminal 8A expands from the substantially Y-shaped branch portion 8Aa by being sandwiched between the hollow portions 8Ba of the cylindrical second high-voltage terminal 8B. Both end portions 8Ab are particularly pressed down compared to the branching portion 8Aa, and the terminal pin 7 of the end portion of the secondary coil is fixed at the branching portion 8Aa, and securely connected to the terminal pin 7 of the end portion of the secondary coil. It becomes electrically connected.

  As shown in FIG. 1A, the second high-voltage terminal 8B is a cylindrical metal fitting having a hollow portion 8Ba having a conductive surface, and the first high-voltage terminal 8A is sandwiched between the hollow portions 8Ba. Yes. The cavity portion 8Ba has a cavity portion bottom surface 8Bb, and sandwiches the entire first high-voltage terminal 8A having a substantially Y shape while being surrounded by a region other than the entrance of the cavity portion 8Ba. Note that the bottom of the second high voltage terminal 8B functions as a spark plug connecting portion 8Bc that is electrically connected to a spark plug (not shown) via a conductor, like the bottom of the conventional high voltage terminal.

  Here, how to reliably connect the terminal portion of the secondary coil and the high voltage terminal in the ignition coil for an internal combustion engine according to the present invention will be described with reference to FIG.

First, various components are accommodated in predetermined positions in the accommodating portion 61 of the insulating case 6, and then the terminal pin 7 of the terminal portion of the secondary coil is connected to the high-pressure cylinder of the insulating case 6 as shown in FIG. Arranged near the portion 62. Next, the first high-voltage terminal 8A is directed from the lower side of the high-pressure cylinder part 62 of the insulating case 6 to the high-pressure cylinder part 62, with both end parts 8Ab expanding from the substantially Y-shaped branch part 8Aa facing upward. While inserting, the terminal pin 7 of the terminal part of a secondary coil is made to contact the branch part 8Aa.
Further, the second high-voltage terminal 8B is inserted from the lower side of the high-pressure cylinder part 62 of the insulating case 6 into the high-pressure cylinder part 62 with the side having the entrance of the cavity part 8Ba facing upward, and the first part is inserted into the cavity part 8Ba. The high voltage terminal 8A is inserted in a state where the terminal pin 7 of the terminal portion of the secondary coil is in contact with the branch portion 8Aa.

Then, as shown in FIG. 1B, the entire first high-voltage terminal 8A is substantially Y-shaped and is sandwiched between the hollow portions 8Ba of the cylindrical second high-voltage terminal 8B. In particular, both end portions 8Ab of the first high-voltage terminal 8A are pressed by the surface of the cavity portion 8Ba of the second high-voltage terminal 8B as compared to the branch portion 8Aa, and the terminal pin 7 of the terminal portion of the secondary coil is the first high-voltage terminal. The first high voltage terminal 8A is securely connected to the terminal pin 7 of the terminal portion of the secondary coil by being fixed at the branch portion 8Aa of 8A. The second high-voltage terminal 8B is electrically connected to the first high-voltage terminal 8A while surrounding and sandwiching the entire first high-voltage terminal 8A having a substantially Y shape in a region other than the entrance of the cavity 8Ba. Will also be connected.
Thereafter, the internal combustion engine ignition coil 1 is electrically connected to the spark plug in the plug hole of the engine. That is, the ignition coil 1 for an internal combustion engine according to the present invention can reliably prevent poor conduction between the terminal portion of the secondary coil and the high voltage terminal and supply a high voltage to the spark plug. It becomes like this.

  The ignition coil 1 for an internal combustion engine according to the present invention has a pin-like shape having a high voltage terminal provided with a branch portion 8Aa, and is sandwiched between the second high voltage terminal 8B, whereby a secondary coil is provided at the branch portion 8Aa. A terminal fitting 7 is fixed to the terminal pin 7, and the first high-voltage terminal directly connected to the terminal pin 7 and a cylindrical fitting having a hollow portion 8 Ba having a conductive surface, the hollow portion 8 Ba The second high voltage terminal 8B connected to the first high voltage terminal 8A while sandwiching the entire first high voltage terminal 8A. Therefore, the terminal pin 7 of the terminal portion of the secondary coil is sandwiched between the first high voltage terminal 8A and the second high voltage terminal 8B. 1 can be reliably connected (fixed) to the branch portion 8Aa of the high-voltage terminal 8A, and the entire first high-voltage terminal 8A connected to the terminal pin 7 is sandwiched between the hollow portions 8Ba of the second high-voltage terminal 8B. Can be connected securely. It is possible to provide an internal combustion engine ignition coil 1 capable of reliably preventing the conductive failure and the like between the terminal portion of the coil and the high voltage terminal.

  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.

  The present invention can also change the shape of the ignition coil for an internal combustion engine without departing from the matters described in the claims. Needless to say, the material used for the ignition coil for the internal combustion engine of the present invention can be a known or known material.

It is a principal part expanded sectional view of the ignition coil for internal combustion engines which concerns on this invention, Comprising: It is a longitudinal cross-sectional view which shows the relationship between the terminal part of a secondary coil, and a high voltage | pressure terminal, (a) is a terminal part of a secondary coil The main part enlarged sectional view explaining the state of connection between the first high-voltage terminal and the state of inserting the first high-voltage terminal into the cavity of the second high-voltage terminal, FIG. It is a principal part expanded sectional view explaining the mode of a connection with 2 high voltage terminals. It is a longitudinal cross-sectional view which shows the relationship between the high voltage terminal and the terminal pin in the conventional ignition coil for internal combustion engines. It is a principal part expanded sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ignition coil for internal combustion engines 6 Insulating case 61 Accommodating part 62 High pressure cylinder part 7 Terminal pin 8A 1st high voltage terminal 8Aa Branching part 8Ab Both front-end | tip parts 8B 2nd high voltage terminal 8Ba Cavity part 8Bb Cavity part bottom face 8Bc Spark plug connection part 10 Conventional Ignition coil 11 for internal combustion engine 11 primary coil bobbin 12 primary coil 13 secondary coil bobbin 13a collar 14 secondary coil 15 iron core 16 insulating case 161 high pressure cylinder 17 terminal pin 18 high voltage terminal 19 terminal pin holding part

Claims (3)

A primary coil, a secondary coil, a housing part in which an iron core that is magnetically coupled to the secondary coil and the primary coil is housed, and a terminal part of the secondary coil that is connected to the outside from the housing part. In an internal combustion engine ignition coil that is configured by storing these components in an insulating case including a cylindrical high-pressure cylinder portion that accommodates a high-voltage terminal to be connected, and filled with an insulating resin,
The high-voltage terminal includes a first high-voltage terminal to which a terminal portion of the secondary coil is directly connected, and a second high-voltage terminal that is connected to the first high-voltage terminal while sandwiching the first high-voltage terminal.
An ignition coil for an internal combustion engine. The first high-voltage terminal has a pinch-like shape with a branch portion, and is clamped by the second high-voltage terminal, whereby the terminal portion of the secondary coil is fixed to the branch portion.
The ignition coil for an internal combustion engine according to claim 1. The second high-voltage terminal is a cylindrical metal fitting having a hollow portion having a conductive surface, and sandwiches the first high-voltage terminal in the hollow portion.
The ignition coil for an internal combustion engine according to claim 1 or 2, characterized by the above.

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