JPH0229700Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of Industrial Application The present invention relates to an ignition system for an engine, and more particularly to an ignition system in which an ignition coil for generating high voltage for ignition is attached to a spark plug.

〓Summary of the invention〓 The invention is based on a case where the ignition coil is housed and sealed with resin, at the joint part with the ignition plug.
A high voltage side terminal made of conductive rubber is provided, and the secondary side of the ignition coil and the spark plug are electrically connected via the high voltage side terminal,
This invention relates to an engine ignition device that facilitates connection between the secondary side and the high voltage side terminal during assembly, prevents leakage of injected resin, and prevents transmission of vibrations.

〓Prior art〓 An ignition device used in an engine supplies a high voltage generated by an ignition coil to a spark plug, and generates a spark using the electrode of the plug to perform an ignition operation. . If the ignition coil and spark plug are located far apart, they will be connected by a high-voltage cord, but with this configuration, the voltage cord will emit radio waves that become noise. may cause radio interference. Therefore, as shown in Japanese Utility Model Publication No. 52-54673, an ignition device in which an ignition coil is attached to a spark plug has come into use.

When assembling such an ignition device, before inserting the ignition coil into the case, connect the secondary lead wire electrically to the high voltage side terminal attached to the deepest part of the case using solder. After the connection, the ignition coil is inserted into the case and resin is injected to seal the ignition coil. Therefore, soldering must be performed at the innermost part of the case, resulting in poor assembly workability.

〓Problems to be solved by the invention〓 In order to solve such problems, the applicant of the present invention made the above-mentioned soldering work unnecessary by patent application No. 59-55086. We are proposing an ignition device. In other words, in a state where the secondary coil of the ignition coil and the high voltage side terminal are connected, the inner side is molded with the first synthetic resin, and then the second resin is further molded. The outer resin forming the case is formed later. With such a configuration, the process of soldering at the back of the case is not necessary, but the synthetic resin must be molded twice, which increases the number of man-hours and reduces productivity. This will result in lower disadvantages.

Therefore, as shown in FIG.
and the lead wire on the high voltage side of the secondary coil 2 are connected by soldering. Then, the bobbin 3 holding the high voltage side terminal 4 is housed in the ignition coil case 5, and the high voltage side terminal 4 is fitted into the through hole 7 formed so as to face the lower joint part 6. The through hole 7 is closed.

According to such a method, the terminal 4 on the high voltage side is connected in advance.
Since the secondary coil 2 and the secondary coil 2 are housed in the case 5 in a connected state, there is no need to perform soldering work in the inner part of the case 5. However, if a clearance is created between the high voltage side terminal 4 and the through hole 7, the resin injected later will leak downward through this clearance. In order to prevent such resin leakage, the high voltage side terminal 4
It is necessary to reduce the clearance between the through hole 7 and the through hole 7, but if the clearance is made too small, workability will be impaired.

The present invention was developed in view of these problems, and is particularly designed to facilitate the connection work between the high voltage side of the ignition coil and the high voltage side terminal, and to prevent leakage of the injected resin. It is an object of the present invention to provide an ignition device for an engine which is capable of preventing vibrations from being transmitted.

〓Means for solving the problem〓 The present invention is an ignition device in which an ignition coil that generates high voltage for ignition is attached to a spark plug, in which the ignition coil is housed in a case and sealed with resin. A high-voltage side terminal made of conductive rubber is provided at the joint part of the case with the ignition plug, and the high-voltage output of the ignition coil is supplied to the ignition plug via this high-voltage side terminal. be.

〓Operation〓 Therefore, according to the present invention, by inserting the connecting means such as a pin connected to the lead wire drawn out from the secondary coil of the ignition coil into the high voltage side terminal made of the conductive rubber. A connection between the secondary coil and the high voltage side terminal can be achieved. In addition, the elastic high-voltage terminal prevents resin from leaking from the case, and the conductive rubber high-voltage terminal prevents vibrations from being transmitted from the spark plug to the ignition coil. will be done.

〓Embodiments〓 The present invention will be explained below with reference to illustrated embodiments. First, a first embodiment of the present invention will be described with reference to FIG. The ignition coil 10 according to this embodiment is composed of a primary coil 11 and a secondary coil 12, and is wound around a section bobbin 13 in sections divided in the axial direction. An iron core 15 is inserted into the center hole 14 of this bobbin 13. The ignition coil 10 wound around the bobbin 13 is made of a synthetic resin case 1.
6 and is sealed with injected resin as described below.

A connecting portion 17 is connected to the lower end of the case 16, and the head of a spark plug 19 is connected to the connecting portion 17 via a rubber sleeve 18. A through hole 20 is formed in the bottom of the case 16 so as to face the coupling portion 17 . Note that the inner circumferential surface of this through hole 20 is composed of a stepped portion. And in this through hole 20,
A high voltage side terminal 21 made of conductive rubber is attached. A lead wire 22 drawn out from the high voltage side of the secondary coil 12 of the ignition coil 10 is soldered to a pin 23, and this pin 23 is attached to the bobbin 1.
3, its tip is inserted into the high-voltage terminal 21 made of conductive rubber, thereby establishing a connection between the high-voltage terminal 21 and the secondary coil 12. There is.

A synthetic resin such as epoxy resin is injected into the case 16, and the ignition coil 10 is enclosed in the resin 24. Furthermore, bobbin 13
is positioned within the case 16 by legs 25 formed at its lower end, and from the case 16 sealed with synthetic resin 24, a primary terminal 26 and a ground terminal are located at its upper end. 27 are drawn out.

In the above configuration, when a current is suddenly supplied from a charging/discharging capacitor (not shown) to the primary coil 11 of the ignition coil 10 at the ignition timing, a high voltage is induced in the secondary coil 12. This high voltage is supplied to the spark plug 19 via the lead wire 22, pin 23, and high voltage side terminal 21 made of conductive rubber, and a spark is generated at the electrode, thereby igniting the engine. It is done.

In the ignition device according to this embodiment, since the high voltage side terminal 21 is made of conductive rubber, the high voltage side lead wire 22 of the secondary coil 12 is connected to the pin 23 held at the lower end of the bobbin 13. When the bobbin 13 is inserted into the case 16 in an electrically connected state, the pin 23 is inserted into the terminal 21 made of conductive rubber, thereby establishing a connection between the secondary coil 12 and the terminal 21. will be done. Therefore, there is no need to perform soldering work on the bottom of the case 16 in advance, and the high voltage side terminal 2
1 can be easily connected. After this, the synthetic resin 24 is attached to the case 16.
The ignition coil 10 may be enclosed by injecting the ignition coil 10. This leakage of the resin 24 from the lower part of the case 16 is prevented by the high voltage side terminal 21 mounted in the through hole 20. That is, since the high voltage side terminal 21 has elasticity, the through hole 20 can be completely sealed, thereby making it possible to reliably prevent the resin 24 from leaking.

Further, according to the ignition device according to the present invention, vibrations from the ignition plug 19 attached to the cylinder head of the engine are blocked by the high voltage side terminal 21 made of conductive rubber, and therefore the ignition coil Transmission of vibrations to 10 is prevented. Furthermore, this high voltage side terminal 21 has a much lower thermal conductivity than metal and has a heat insulating effect, so that heat transfer from the plug 19 to the ignition coil 10 is prevented. Furthermore, since the high voltage side terminal 21 made of conductive rubber has an appropriate resistance value, it can also be used as a noise prevention resistor. Further, since the terminal 21 is made of conductive rubber, there is no need to insert and mold a metal terminal into the case 16, and the cost of the case 16 is also reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. In the following embodiments, parts corresponding to those in the first embodiment are given the same reference numerals, and descriptions of parts having the same configuration will be omitted.

The feature of this second embodiment is that the ignition coil 10 is constructed from an air-core coil, and a noise prevention resistor 30 is inserted into the center hole 14 of the bobbin 13. This resistor 30 is connected between the high voltage side lead wire 22 of the secondary coil 12 and the pin 23. Therefore, according to this embodiment, there is no need for the high voltage side terminal 21 to also serve as a noise prevention resistor, making it possible to increase the conductivity of this terminal 21, and using a dedicated resistor 3.
0 makes it possible to prevent noise.
Furthermore, since the ignition coil 10 does not include an iron core, the weight of the ignition coil 10 is reduced, and the load applied to the spark plug 19 can be reduced.

Next, a third embodiment of the present invention will be explained with reference to FIG. The feature of this third embodiment is that the center hole 14 of the bobbin 13 of the air-core coil 10 is also used as a coupling part 17, and the head of the spark plug 19 is received in this coupling part 17. . The upper end side of the section bobbin 13 is closed, and a high voltage side terminal 21 made of conductive rubber is attached.
Connection with 9 has been achieved. The conductive rubber 21 and the lead wire 22 are connected by crimping the lead wire 22 to the outer circumference of the terminal 21 without using a pin.

According to such an ignition device, the inner part of the bobbin 13 is also used as the inner part of the case 16, thereby making it possible to reduce the radial dimension. Furthermore, in this embodiment, the case 16 is designed to be installed upside down, so that the ignition device is covered from above. Therefore, the opening into which the synthetic resin 24 is injected is located on the lower side, making it difficult for water to accumulate on the upper surface of the case 16, and even if a gap occurs at the boundary between the case 16 and the synthetic resin 24, this This will prevent water from entering the gap. Therefore, it becomes possible to provide a highly reliable engine ignition system.

In the ignition device according to the third embodiment, the outer case 16 is made of a magnetic material such as an iron plate or ferrite instead of synthetic resin, so that magnetic flux can pass through the case 16. This makes it possible to prevent leakage of magnetic flux to the outside, making it possible to provide an ignition device that is less likely to cause radio wave interference.

〓Effects of the invention〓 As described above, the present invention houses the ignition coil in a case and seals it with resin, and also provides a high-voltage side terminal made of conductive rubber at the connection part of the case with the ignition plug. The output of the high voltage side of the ignition coil is supplied to the spark plug via the side terminal. According to the invention, therefore, it is possible to achieve the connection between the high-voltage side of the ignition coil and the high-voltage side terminals by means of pins or also directly by means of lead wires, but also by means of soldering at the bottom of the case. It is no longer necessary to make a connection. Therefore, the workability of assembly is improved. In addition, the high-voltage side terminal made of conductive rubber can prevent leakage of the injected resin from the case, and moreover, the transmission of vibration from the spark plug to the ignition coil is transmitted to the high-voltage side terminal made of conductive rubber. It can be prevented by twisting.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an ignition system for an engine according to a first embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of an ignition system according to a second embodiment, and FIG. 3 is a vertical cross-sectional view of an ignition system according to a second embodiment of the present invention. FIG. 4 is a vertical cross-sectional view showing a conventional method of assembling an ignition device. In addition, in the symbols used in the drawings, 10...Ignition coil, 11...Primary coil, 12...Secondary coil, 13...Section bobbin, 16...Case, 19...Spark plug, 20...Through hole , 21
...High voltage side terminal (conductive rubber), 23...pin,
24...Synthetic resin (epoxy resin).

Claims (1)

[Claims for Utility Model Registration] 1. In an ignition device in which an ignition coil that generates high voltage for ignition is attached to a spark plug, the ignition coil is housed in a case and sealed with resin, and the An engine characterized in that a high-voltage side terminal made of conductive rubber is provided at a connecting part with the ignition plug, and the high-voltage output of the ignition coil is supplied to the ignition plug via the high-voltage side terminal. Ignition device. 2. Utility model registration claim 1, characterized in that the ignition coil is composed of an air-core coil, and a resistor for noise prevention is inserted into the center of the bobbin around which this coil is wound.
The ignition system for the engine described in paragraph. 3. The engine according to claim 1, wherein the ignition coil is formed of an air-core coil, and the head of the ignition plug is inserted into the center of the coil. Ignition device.