JPH0723945Y2 - Ignition coil for internal combustion engine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION This invention is applied to a cylinder of an internal combustion engine.
The present invention relates to an ignition coil used for a low voltage distribution type ignition system that supplies a high voltage directly to an ignition plug of each cylinder by using a built-in switching module.

[0002]

2. Description of the Related Art As such an ignition coil, the applicant of the present invention has a primary coil in which an insulating resin is cast in an insulating case, and a cured insulating resin layer is fitted in the insulating case outside a core. A device in which a secondary coil fitted outside the primary coil and a switching module electrically connected to the both coils are fixed is proposed in Japanese Utility Model Laid-Open No. 4-8419.
As shown in FIG. 6, the switching module 10 solders a switch element chip (power transistor chip) 12 on the bottom inside a shallow dish-shaped metal case 11 and bonds a hybrid integrated circuit (hybrid IC) 13 thereto. The inside is filled with silicon gel and the plastic lid 14 is fixed to the open surface of the case to close the case. This lid may be omitted.

[0003]

The conventional switching module has a collector (output) lead wire 17 in addition to the base lead wire 15 and the emitter lead wire 16 connected to the hybrid integrated circuit 13 for connection with an external device. Soldered to a metal case and connected to one end of the primary coil by soldering, the above-mentioned base lead wire 15 and emitter lead wire 16
Are connected to separate primary terminals provided on the insulating case by soldering. For this reason, the connecting work by soldering the collector lead wire 17 and the electric wire at one end of the primary coil is troublesome, or the connecting portion and the base lead wire or the emitter lead wire contact each other, or the one end portion of the primary coil And the metal case are connected via a collector lead wire, resulting in a decrease in reliability.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, the collector lead wire is prevented from being attached to the metal case of the switching module by soldering, and one end of the primary coil is provided.
Since the metal case of the switching module is directly connected, the insulating resin is cast into the insulating case (4), and the cured insulating resin layer (7) is used to insert the iron core (3) into the insulating case. The primary coil (1) fitted outside and 1
The secondary coil (2) fitted outside the secondary coil, and the switch element chip (12) on the bottom of the dish-shaped metal case (11).
And an ignition coil for an internal combustion engine in which a hybrid integrated circuit (13) is attached and a switching module (10) electrically connected to the both coils is fixed, and a terminal portion (18) is provided in a metal case (11) of the switching module. ) Are integrally projected, and the primary coil (1) is connected to the terminal portion (1
It is characterized in that it is connected to 8).

[0005]

1 shows a switching module 10 used in the present invention, which is different from that shown in FIG. 6 in that it has no collector lead wire 17 and instead has a metal case 11 integrally formed with a terminal portion 18 at the time of molding. Is equipped with.

2 to 5, 1 is a primary coil, 2 is 2
A secondary coil, 3 is an iron core partially penetrating the bobbin of the primary coil, and 4 is an insulating case. As shown in FIG. 5, the insulating case 4 is made of a synthetic resin and integrally includes a housing portion 4a for both the primary and secondary coils and a pocket-type auxiliary housing portion 6 separated from the housing portion 4a by a wall 5. I have it. Both the housing portion 4a and the auxiliary housing portion 6 are open to the open surface of the case, but since the height of the wall 5 is lower than the open surface of the case, insulating resin,
For example, when the epoxy resin is cast into the housing portion 4a, a part of the resin also enters the auxiliary housing portion 6 and is cured together to form the insulating resin layer 7.

The insulating case 4 is a holding portion 4 for the high voltage terminal 8.
b, a holding portion 4c for holding the low-voltage terminal 9, and these holding terminals 4 and 9 are used to hold the holding portions 4b and 4 when the insulating case 4 is molded.
It is integrally fixed to c by insert molding. The low-voltage terminal 9 is composed of a terminal for connecting the primary coil to the battery of the automobile, a terminal for applying a drop signal from the control unit to the switching module, and a ground terminal.
The connection state of the primary coil 1, the secondary coil 2, the switching module 10, the high voltage and low voltage terminals 8 and 9 is shown in the circuit diagram of FIG.

In the illustrated embodiment, since the auxiliary accommodating portion 6 is directed between the accommodating portion 4a and the holding portion 4c of the low voltage terminal,
The insulating case 4 is molded in the state shown in FIG. Two sets of E-shaped iron cores 3 are used facing each other.

Since a hole for passing an iron core is formed in the center of the bottom of the accommodating portion 4a, one end of the bobbin of the primary coil is fitted into this hole to fit the primary coil 1 into the accommodating portion 4a. While standing on the bottom, the secondary coil 2 is concentrically fitted to the outside of the primary coil to accommodate both coils in the accommodation portion 4a.
A switching module 10 is housed in the auxiliary housing portion 6, and one end of the primary coil 1 has a low voltage terminal 9 as shown in FIG.
Is supplied with the battery voltage, the base lead wire 15 of the switching module is soldered to the low voltage terminal 9 to receive an ignition signal from an external control unit, and the emitter lead wire 16 is soldered to the low voltage terminal 9. So that it is connected to the external ground. Then, the other end of the primary coil is connected to the terminal portion 18 integrally provided in the metal case of the switching module and soldered to connect the output of the switching module and the primary coil.

Insulation resin is vacuum-molded in the case where wiring is performed in this way, and the resin is cured to form the primary and secondary insulating resin layers 7.
The secondary coils are fixed in the accommodating portion 4a, the switching module is fixed in the auxiliary accommodating portion 6, and the central legs of the two E-shaped iron cores 3 are fixed to the bobbin of the primary coil from the bottom of the case. Insert from the top of the case, and fix the legs on both sides of each core along the outside of the side of the case.

Although the illustrated embodiment uses two opposing E-shaped cores, the present invention can also be implemented with one U-shaped core as shown in the previous proposal.

[0012]

As is apparent from the above, according to the present invention, since the metal case and the primary coil can be directly connected to each other, the collector lead wire and the soldering portion can be omitted, the number of parts can be reduced, and the collector lead has been heretofore available. Problems related to soldering of wires can be eliminated. Workability is also greatly improved. From the above, according to the present invention, an inexpensive and highly reliable ignition coil can be easily provided.

[Brief description of drawings]

FIG. 1 is a perspective view of a switching module used in the present invention.

FIG. 2 is a perspective view of an ignition coil according to the present invention.

3 is a cross-sectional view of FIG.

FIG. 4 is a plan view showing a wiring state of a coil, a switching module, and a low voltage terminal.

FIG. 5 is a perspective view of an insulating case.

FIG. 6 is a perspective view of a conventional switching module.

FIG. 7 is a circuit diagram of an ignition coil.

[Explanation of symbols]

 1 Primary coil 2 Secondary coil 2 Iron core 4 Insulation case 7 Insulating resin layer 9 Low voltage terminal 10 Switching module 11 Metal case 18 Terminal part

Claims (1)

[Scope of utility model registration request] 1. A primary coil in which an insulating resin is cast into an insulating case, and a cured insulating resin layer is fitted into the insulating case outside the iron core, and a secondary coil which is fitted outside the primary coil. An ignition coil for an internal combustion engine in which a coil, a switch element chip on a bottom of a dish-shaped metal case, and a hybrid integrated circuit are fixed, and a switching module electrically connected to the both coils is fixed. An ignition coil for an internal combustion engine, characterized in that a terminal portion is integrally provided on the terminal and the primary coil is connected to the terminal portion.