JP2001217131A - Ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the ignition coil of a structure, where the side of the low voltage of such a secondary coil as an S-DLI coil is connected with a primary coil and the connection of the secondary bobbin terminal of the secondary coil with the primary bobbin terminal of the primary coil is facilitated and the reliability of the connection is also satisfactory in the ignition coil. SOLUTION: An ignition coil is formed into a structure, where either a primary bobbin terminal of a primary coil and a secondary bobbin terminal of a secondary coil is made a spring elastic force have, the connection of the primary coil with the secondary coil is made in a contact connection state using the terminal and a soldering is not applied to the connection. A primary copper wire is wound around the primary bobbin terminal, the primary coil is formed, both ends of the primary coil are connected with the primary bobbin terminal, and the primary bobbin terminal which is connected with the secondary coil is made to project from the primary bobbin terminal. Moreover, a secondary copper wire is wound around the secondary bobbin terminal, the secondary coil is formed and in the secondary coil with the secondary bobbin terminal connected to both ends of the secondary copper wire, the secondary bobbin terminal which is connected with the primary coil is made to project to the side of the inner diameter of the secondary bobbin terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil device for an internal combustion engine, and more particularly to a connection structure between a primary coil and a secondary coil.

[0002]

2. Description of the Related Art FIG. 5A is a top view of a conventional ignition coil of an internal combustion engine before filling with an insulating material, and FIG.
FIG. 6 shows a circuit diagram of the present invention and a conventional ignition coil for an internal combustion engine.

In FIG. 5, a primary coil 23 in which a primary copper wire is wound around a primary bobbin 21, and a secondary coil 14 in which a secondary copper wire is wound around a secondary bobbin 11 are arranged around the primary coil 23. These primary coil 23 and secondary coil 14 are
0. The end of the primary copper wire of the primary coil 23 is connected to the primary connector 4 attached to the primary bobbin 21.
The secondary coil 14 is electrically connected to the primary connector terminal 41 provided on the secondary coil 0, and one high-voltage side of the secondary coil 14 is connected to the secondary bobbin terminal B13, and the secondary bobbin terminal B13 is electrically connected to the secondary high-voltage terminal 15. Connected. The other 2
The low voltage side end of the secondary coil 14 is connected to the secondary bobbin terminal A12.
, And is electrically connected to the primary connector terminal 41. In the case 30, the primary coil 23 and the secondary coil 14 having the primary connector 40 are embedded, and are integrally molded by injecting and hardening the epoxy resin 70. An iron core 60 is inserted into the internal space of the primary bobbin 21.

The connection between the secondary bobbin terminal A12 and the terminal 22 of the primary bobbin is connected by soldering.

Further, in the circuit diagram of FIG. 6, the conventional ignition coil is an S-DLI coil which performs a single high-voltage discharge, and the low voltage side of the secondary coil 14 is electrically connected to the primary coil 23. When an ignition signal is input from the ignition signal generation circuit to the base side (B) of the switching element 50, a current flows from the + of the battery power supply 51 into the primary coil 23 to generate a magnetic field. It is held by the core 60. Next, when the ignition signal on the base side (B) of the switching element 50 is cut off, the current flowing through the primary coil 23 is also cut off, and the high current corresponding to the turns ratio of the primary coil 23 and the secondary coil 14 is cut off. Voltage is excited by the secondary coil 14 and the spark plug 80 is electrically connected to the secondary coil 14.
Power is distributed to

[0006]

However, the above-mentioned 2
In the connection between the secondary bobbin terminal A12 and the terminal 22 of the primary bobbin, the above connection method requires a lot of man-hours for soldering,
In addition, there is a possibility that insulation breakdown between the secondary copper wires may occur due to a problem caused by the dripping of the solder during the soldering operation.

[0007] Also, in the case of welding, there is a possibility that the same problem as in the connection by soldering may occur due to welding dust or the like. Then, the present invention solves the above-mentioned problems, and
-For an ignition coil such as DLI in which the low voltage side of the secondary coil is connected to the primary coil, the connection between the secondary bobbin terminal of the secondary coil and the primary bobbin terminal of the primary coil is facilitated, and Provides an ignition coil with good reliability.

[0008]

According to the present invention, a secondary bobbin terminal A12 of the secondary bobbin 11 is provided.
Is partially exposed on the inner diameter side of the secondary bobbin 11 to expose the secondary bobbin 1
When the exposed portion is to be pushed into the secondary bobbin 11 from the inner diameter side, it is arranged to be pushed back by its spring elastic force. Further, the primary bobbin terminal 22 of the primary bobbin 21 is arranged so as to partially protrude from the outer shape of the primary bobbin 21, and is partially exposed to the inner diameter side of the secondary bobbin 11 of the secondary bobbin terminal A12 when assembling the ignition coil. The portion and the portion of the primary bobbin terminal 22 that partially protrude from the outer shape of the primary bobbin 21 come into contact with each other, and the electrical connection is established by the spring elastic force of the terminal of the secondary bobbin, thereby making an electrical connection.

[0009]

The above connection reduces the number of soldering steps as in the connection method described above, and eliminates the possibility of insulation breakdown between the secondary copper wires due to a problem caused by the dripping of the solder during the soldering operation. Furthermore, when assembling the ignition coil, the secondary bobbin 11
While the terminal A12 and the terminal 22 of the primary bobbin are connected, an epoxy resin 70 as an insulating material is injected and hardened and fixed.

[0010]

FIG. 1 is a longitudinal sectional view of an ignition coil for an internal combustion engine according to the present invention, FIG. 2 is a view showing a combination of a secondary bobbin and a secondary bobbin terminal according to the present invention, and FIG. FIG. 4 is a diagram showing a state before assembling the primary coil and the secondary coil of the present invention, and FIG. 4 is an enlarged view of a connection portion after the connection of the primary coil and the secondary coil of the present invention.

1 to 4, the ignition coil according to the present invention has a primary bobbin 21, a coil wound around a secondary bobbin 11, an iron core 60, and a case 3 for housing a switching element 50.
0, a primary connector terminal 41 for inputting a primary voltage such as a battery, and a secondary high voltage terminal 15 for outputting to a spark plug 80. The secondary bobbin 11 and the primary bobbin 21
2 and 3 are shown in FIGS.

In FIGS. 2 and 3, the primary bobbin 21
The primary coil 23 is formed of an assembly integrating the secondary connector 40 and the switching element 50 and is connected to the primary connector terminal 41. The primary coil 23 is wound around the primary bobbin 21. Here, the wound portion of the primary coil 23 has a hollow cylindrical shape, and a primary bobbin terminal 22 is arranged in the axial direction of the hollow portion. It is connected to the secondary coil and is provided so as to protrude from the primary bobbin 21. The secondary bobbin 11 is provided with a large number of grooves, and a secondary coil is wound around the grooves sequentially from the inside of each groove. At both ends of the secondary bobbin, a storage groove for storing the secondary bobbin terminal A12 and the secondary bobbin terminal B13 is provided, and a hole communicating with the inner diameter side of the secondary bobbin 11 is provided at a part of the storage groove. When the terminal is mounted on the secondary bobbin, a part of the secondary bobbin terminal is partially exposed from the inner side of the secondary bobbin, and when the exposed portion is to be pushed into the secondary bobbin 11, the A secondary bobbin terminal A12 formed to have a structure in which a pushing back force is exerted by a spring elastic force is attached,
Further, a secondary bobbin terminal B13 is attached.

In FIG. 4, during assembly, the secondary coil 14 and an assembly for integrating the primary coil 23, the primary connector 40, and the switching element 50 into the inner side of the secondary coil 14 are inserted into a case 30. When the secondary bobbin 11 is disposed, the secondary bobbin terminal A12, part of which is exposed to the inner diameter side of the secondary bobbin 11, and the primary bobbin terminal 22, a part of which protrudes from the outer shape of the primary bobbin 21, come into contact with each other.
The connection is made electrically by the spring elastic force of the terminal, and the connection portion makes an electrical connection.

While the secondary bobbin terminal A12 and the primary bobbin terminal 22 are still connected, an epoxy resin 70 as an insulating material is injected into the case 30, cured and fixed. It has been confirmed that satisfactory performance can be satisfied even when a realistic cooling / heating stress and vibration satisfying the performance and specifications of the ignition coil are continuously reproduced on a test basis. In addition, the connection method as described above reduces the number of steps of the soldering operation, and eliminates the possibility of insulation breakdown between the secondary copper wires due to the drip problem of the solder during the soldering operation.

In the above, the structure in which only the secondary bobbin terminal has a spring elastic force has been described. However, the structure may be such that only the primary bobbin terminal has a spring elastic force.

[0016]

According to the present invention, the terminal of the secondary bobbin of the secondary coil and the primary bobbin of the primary coil are connected to the ignition coil in which the low voltage side of the secondary coil such as S-DLI is connected to the primary coil. It is possible to provide an ignition coil that can be easily connected to the terminals and has good connection reliability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an ignition coil for an internal combustion engine according to the technique of the present invention.

FIG. 2 is a diagram showing a combination of a secondary bobbin and a secondary bobbin terminal according to the technique of the present invention.

FIG. 3 is a diagram showing a state before assembling a primary coil and a secondary coil according to the present invention.

FIG. 4 is an enlarged view of a connection portion after connection of a primary coil and a secondary coil of the present invention.

FIG. 5 (a) is a top view of a conventional internal combustion engine ignition coil before filling with an insulating material, and FIG. 5 (b) is a longitudinal sectional view taken along AA of FIG. 5 (a).

FIG. 6 is a circuit diagram of the present invention and a conventional ignition coil for an internal combustion engine.

[Explanation of symbols]

 In the drawings, the same reference numerals indicate the same or corresponding parts. DESCRIPTION OF SYMBOLS 1 Ignition coil 11 Secondary bobbin 12 Secondary bobbin terminal A 13 Secondary bobbin terminal B 14 Secondary coil 15 Secondary high voltage terminal 21 Primary bobbin 22 Primary bobbin terminal 23 Primary coil 30 Case 40 Primary connector 41 Primary Connector terminal 50 Switching element 51 Battery power supply 60 Iron core 70 Epoxy resin 80 Spark plug

Claims (3)

[Claims] An ignition coil comprising a primary coil wound with a primary copper wire and a secondary coil wound with a secondary copper wire, wherein at least one of a primary bobbin terminal and a secondary bobbin terminal is provided. Characterized in that the terminal has a spring elastic force, and the connection between the primary coil and the secondary coil is a contact connection by the terminal, and the structure is such that soldering is not performed. 2. A primary coil is formed by winding a primary copper wire around a primary bobbin, and both ends of the primary coil are connected to a primary bobbin terminal provided on the primary bobbin and connected to a secondary coil. 2. The ignition coil for an internal combustion engine according to claim 1, wherein the primary bobbin terminal protrudes from the primary bobbin. 3. A secondary coil is wound around a secondary bobbin to form a secondary coil. Both ends of the secondary winding are connected to a secondary bobbin terminal provided on the secondary bobbin. 2. The ignition coil for an internal combustion engine according to claim 1, wherein a secondary bobbin terminal connected to the primary coil protrudes toward the inner side of the secondary bobbin.