JPH08162345A - Internal combustion engine ignition coil - Google Patents

Abstract

PURPOSE: To provide a small type internal combustion engine ignition coil which can be manufactured easily by a method wherein a simultaneous ignition system ignition coil and an igniter are integrally formed. CONSTITUTION: Two sets of ignition coils 1A and 1B are provided side by side, a magnetic path is formed by an inner core and an outer core on which the primary coils 12 and secondary coils 22 are wound around, and a high voltage terminal 7 is connected to both ends of each of the secondary coils 22. An igniter 8, with which the primary current for the primary coil 12 is intermittently controlled, is arranged on the prescribed position in the vicinity of the place located between the two ignition coils 1A and 1B, and the electric connection part of the primary coil 12 and the igniter 8 is provided between the two sets of ignition coils 1A and 1B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil for an internal combustion engine, and more particularly to a simultaneous ignition system ignition coil for an internal combustion engine that ignites two cylinders with one ignition coil.

[0002]

2. Description of the Related Art There are various known ignition systems for internal combustion engines. Among them, in a simultaneous ignition system (also called a double ignition system) ignition coil, one cylinder is in a compression process. The two cylinders are selected so that the other cylinder is in the exhaust process, and the output high voltage is simultaneously applied to these cylinders. For example, regarding a four-cylinder internal combustion engine, the first cylinder and the fourth cylinder
In the case where the cylinders are ignited at the same time and the second cylinder and the third cylinder are ignited at the same time, for example, when the first cylinder is in the compression process, the pressure inside the cylinder is large, so that it does not easily discharge even at high voltage. Since the fourth cylinder is in the exhaust process and the pressure inside the cylinder is close to the atmospheric pressure, it easily discharges at a low voltage, and the resistance of the spark plug becomes a negligible value. Therefore, when the ignition plugs of the first cylinder and the fourth cylinder are connected in series,
The ignition plug of the fourth cylinder in the exhaust process has almost no resistance, and almost all output high voltage is applied to the first cylinder in the compression process. Therefore, it is similar to the case where a high voltage is individually applied to each spark plug by the ignition coil.

An ignition coil that realizes the simultaneous ignition method as described above is disclosed, for example, in Japanese Patent Laid-Open No. 4-226007. According to the invention proposed in the publication, plural sets of second laminated cores, primary coils, and secondary coils are housed in a single container-shaped resin housing in which plural sets of first laminated cores are embedded. Therefore, the number of man-hours and space for assembling the ignition coil to the engine and the vehicle body can be reduced. Specifically, two sets of ignition coils, each having a C-shaped laminated core and an I-shaped laminated core and having a coil wound around the latter, are arranged in parallel, and are clearly shown in FIG. 4 of the publication. As described above, the pair of I-shaped laminated cores located at the axial center of each coil are arranged in parallel.

On the other hand, Japanese Unexamined Patent Publication No. 4-43620 discloses that
An ignition coil device is disclosed in which an igniter for controlling a primary current of a primary coil is housed in a molded case together with a primary coil and a secondary coil wound around an iron core. Also, in the ignition coil device described in Japanese Patent Application Laid-Open No. 4-42909, a pocket portion for accommodating the power transistor unit (corresponding to the above igniter) is provided in the mold case and is integrally formed with the coil. ing.

[0005]

An ignition coil in which the above-mentioned igniter (also called an ignition module) is integrated in a case is provided for each cylinder of an internal combustion engine. In the case of four cylinders, four ignition coils are provided. You need an igniter. However, the igniter has a high cost for the sealing process and the like, and thus disposing the igniter in this manner causes a cost increase. Further, in the simultaneous ignition type ignition coil described above, the igniter is a separate body and is arranged at a position separated from the ignition coil. For this reason, the wiring cost is high and it easily becomes an electrical noise source.

Therefore, an object of the present invention is to provide an ignition coil for an internal combustion engine, which is integrally formed with a simultaneous ignition type ignition coil and an igniter, and which is small and easy to manufacture.

[0007]

To achieve the above object, the present invention is an ignition system including an inner core around which a primary coil and a secondary coil are wound, and an outer core forming a magnetic path with the inner core. In an ignition coil for an internal combustion engine, which has two sets of coils and has high-voltage terminals connected to both ends of each of the secondary coils, an igniter for intermittently controlling a primary current to the primary coil is provided between the two sets of ignition coils. It is arranged at a predetermined position close to the first coil and the electrical connection between the primary coil and the igniter is provided between the two sets of ignition coils.

In the ignition coil for an internal combustion engine, the two sets of ignition coils are housed in one case, and
The igniter may be attached to the case, and high voltage terminals connected to both ends of each of the secondary coils may be arranged parallel to each other on the same plane and integrally juxtaposed to the case. .

The outer cores which form the two sets of ignition coils are formed in a letter V shape, and the two inner spaces of the two pairs of ignition coils are respectively provided in two space portions of the letter-shaped outer cores. It may be configured to house the core.

[0010]

In the ignition coil for an internal combustion engine of the present invention, two sets of ignition coils are arranged in parallel, and in each ignition coil, a magnetic path is formed by an inner core and an outer core wound with a primary coil and a secondary coil. A high voltage terminal is connected to both ends of each of the secondary coils. An igniter for intermittently controlling the primary current to the primary coil is arranged at a predetermined position close to the two sets of ignition coils, and an electrical connection between the primary coil and the igniter is provided between the two sets of ignition coils. Has been. Thus, a single ignition coil for an internal combustion engine having two sets of ignition coils and an igniter is configured, and when the primary current supplied to the primary coil of each ignition coil is interrupted, the magnetic flux changes to the outer core and the inner core. Occurs and a high voltage is induced in the secondary coil of each ignition coil. Therefore,
If both ends of each secondary coil are connected to the spark plug respectively,
A simultaneous ignition type ignition coil is configured, and two spark plugs are ignited at the same time.

In the ignition coil for an internal combustion engine according to the second aspect, the two sets of ignition coils are housed in one case, and the igniter is attached to the case. Further, a total of four high-voltage terminals connected to both ends of each secondary coil are arranged in parallel to each other on the same plane and integrally juxtaposed to the case.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an ignition coil for an internal combustion engine of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of an ignition coil 1 for an internal combustion engine according to the present invention, in which two sets of ignition coils 1A and 1B are integrally arranged side by side. Since both have the same structure, the same reference numerals are given to the same parts and portions, and in the following description, only one of them will be mainly described. The internal combustion engine ignition coil 1 of this embodiment has a letter-shaped core 3 as shown in FIG. 2, and a pair of pillar-shaped cores 2 and 2 are coaxially arranged in two space portions thereof. It has the shape of. That is, the core 3 corresponds to the outer core according to the present invention, and the core 2 corresponds to the inner core according to the present invention. Each core 2 is built in the primary coil assembly 10, and the secondary coil assembly 20
When two sets are assembled, and these are housed in the two space portions of the core 3 in the case 30, the structure shown in FIGS. 1 and 2 is obtained.

The case 30 is a housing made of synthetic resin, and the core 3 is built into the case 30 by insert resin molding at a substantially central portion thereof. Therefore, Case 3 corresponds to the letter-shaped core 3.
Two space parts are formed in 0, and the primary coil assembly 10 and the secondary coil assembly 20 are accommodated therein, respectively. On one side of the side wall of the case 30, four high-voltage connector portions 31a to 31d are arranged in parallel on the same plane, and the high-voltage terminal 7 is housed in each of them.
An igniter 8 is mounted on the side wall of the case 30 opposite to the high voltage connector portions 31a to 31d, and flange portions 33 are formed to extend on the other side walls.

As described above, the core 3 constituting the outer core is a V-shaped iron core and is formed by laminating a plurality of non-oriented silicon steel sheets, but a grain-oriented silicon steel sheet may be used. It is also possible to form a square V-shaped outer core for each ignition coil 1A, 1B and join them together. As shown in the enlarged view of FIG. 5, all the portions of the core 3 facing the core 2 project inward, and the projecting portion 3a is formed to have a wide width.
b is formed to be narrow. The portion including the protruding portion 3a and the protruding portion 3b and contacting the core 2 is exposed without being covered with the resin material of the case 30. on the other hand,
As shown in FIG. 5, the core 2 is a columnar iron core in which both ends of the main body portion 2a are widened and extension portions 2b and 2c are formed.
The extension 2c is formed with a recess into which the protrusion 3a of the core 3 is fitted. The core 2 of this embodiment is formed by laminating a plurality of grain-oriented silicon steel plates whose rolling direction is the axial direction of the main body 2a.

FIG. 5 is an enlarged view showing one ignition coil 1A side. The primary coil assembly 10 includes a primary bobbin 11 and a holding portion 13 in which the core 2 is integrally housed by insert resin molding. ing. Primary bobbin 1
1 is formed around the main body portion 2a of the core 2, and flange portions 11a and 11b are formed at a predetermined distance from each other. The holding portion 13 formed at one end of the primary bobbin 11 in the axial direction is
As shown in FIG. 5, an air gap 5 having a predetermined gap is secured between the extending portion 2b of the core 2 and the protruding portion 3a of the core 3, and the end face in the longitudinal direction of the extending portion 2b is exposed. It is formed so as to face the end surface (exposed surface) of the protruding portion 3 a of the core 3. And, the collar portions 11a and 11b of the primary bobbin 11
The primary coil 12 is wound in two or four layers to form the primary coil assembly 10.

On the other hand, the secondary coil assembly 20 is formed by winding a secondary coil 22 around a secondary bobbin 21. As shown in FIG. 5, the secondary bobbin 21 is a resin tubular body having a substantially rectangular cross section in which a plurality of collar portions 21a are formed at predetermined intervals in the axial direction, and a plurality of grooves 21b are provided between the collar portions 21a. The windings of the secondary coil 22 are sequentially wound in these grooves 21b from the upper side to the lower side in FIG. The both ends of the secondary bobbin 21 are wide brim portions 21c and 21d, and the terminals 23 shown in FIG. 1 are fitted in the grooves (not shown) formed in the brim portions 21c and 21d, respectively. The winding start or winding end of the secondary coil 22 is wound around each terminal 23 and electrically connected thereto. That is,
Both ends of the secondary coil 22 are connected to the terminals 23, respectively. In addition, each terminal 23 extends in a direction orthogonal to the axis of the secondary bobbin 21, and when the terminal 23 is later assembled in the case 30, the terminal 23 is inserted into the high-voltage terminal 7, and the two are electrically connected. Connected.

The high voltage terminals 31a to 3 of the case 30
An igniter 8 is mounted on the side wall opposite to 1d at a position close to between the two sets of ignition coils 1A and 1B.
The igniter 8 may be mounted by bonding or screwing, or by forming a housing portion in the case 30 and housing the igniter 8 in the housing portion 30.
The igniter 8 may be integrally provided at the time of molding. A part of the igniter 8 accommodates, for example, a circuit element indicated by a chain line in FIG. 6 (which will be described later).
terminals 6a, 6b connected to the collector side of r2,
The terminal 6e, which is a common power supply terminal, is formed so as to extend into the case 30 as shown in FIG.

The primary coil assembly 10 and the secondary coil assembly 20 are housed in a case 30 as shown in FIG. 1, and the core 2, inside the core 3 as shown in FIG.
2 are fitted and each terminal 23 is connected to each high voltage terminal 7.
Is inserted into. On the side of the ignition coil 1A, one end 12a of the winding of the primary coil 12 is connected to the leads 6c and 6d.
Is electrically connected to the terminal 6e through the other end 12b, and the other end 12b is guided by a notch (not shown) in the flange 11a and led out, and electrically connected to the terminal 6a (terminal 6b on the ignition coil 1B side). Connected. In this way, the electrical connection between the primary coil 12 and the igniter 8 is provided between the two sets of ignition coils 1A and 1B, so wiring is easy. After this wiring, the space inside the case 30 is filled with a thermosetting synthetic resin, for example, an epoxy resin, and cured to form a resin portion 9 as shown by a dotted line in FIG. As a result, the primary coil 12 and the secondary coil 22 are impregnated and fixed, and the electrical connection between the primary coil 12 and the igniter 8 is appropriately insulated, and further, the insulation that can withstand the high output voltage of the secondary coil 22. Sex is secured.

Thus, as shown in FIG. 3, a single internal combustion engine ignition coil 1 having two sets of ignition coils 1A and 1B is formed in the case 30. The ignition coil 1 for an internal combustion engine is mounted on an internal combustion engine (not shown), and as shown in FIG. 4, the high voltage connector portions 31a to 31d are connected to the ignition plugs 81 to 84 via the high tension cords 71 to 74.
Connected to. That is, the ignition plug 81 attached to the first cylinder and the ignition plug 84 attached to the fourth cylinder are connected to the high voltage connector portions 31a and 31b of the ignition coil 1A,
The ignition plug 82 attached to the second cylinder and the ignition plug 83 attached to the third cylinder are connected to the high voltage connector portions 31c and 31d of the ignition coil 1B.

FIG. 6 shows an essential part of an ignition circuit for a four-cylinder internal combustion engine according to this embodiment. When the primary current of each primary coil 12 is interrupted by the switching transistors Tr1 and Tr2, each secondary coil 22 is connected. A back electromotive force is induced in the and a high voltage of 30 to 40 kv is generated. This high voltage is output to the spark plugs 81 to 84 via the terminal 23 and the high voltage terminal 7 of FIG. As shown in FIG. 3, the igniter 8 is provided with a connector portion 16, in which the power supply terminal 16e, the drive signal terminals 16a and 16b, the ground terminal 16c, and the monitor terminal (see FIG. 6) shown in FIG. Are omitted) are arranged in a line.

In the ignition coil for the internal combustion engine of the present embodiment having the above-mentioned structure, the ignition coil 81 of the first cylinder and the fourth coil
The ignition coil 84 of the cylinder is ignited at the same time, and the ignition coil 82 of the second cylinder and the ignition coil 83 of the third cylinder are ignited at the same time. For example, when the first cylinder is in the compression process, the pressure inside the cylinder is large, so the ignition coil 81 does not easily discharge even at a high voltage, but the fourth cylinder is in the exhaust process and the pressure inside the cylinder becomes atmospheric pressure. Since they are close to each other, they are easily discharged at a low voltage, the resistance of the ignition plug 84 becomes a negligible value, and almost all the output high voltage is applied to the ignition coil 81 of the first cylinder in the compression process. Thus, a high voltage is individually applied to the ignition plugs 81 to 84 by the ignition coils 1A and 1B, a spark discharge is generated in each electrode portion, and a compressed air-fuel mixture in each combustion chamber (not shown) is generated. Is ignited.

[0022]

Since the present invention is constructed as described above, it has the following effects. That is, according to the present invention,
Since the igniter is arranged in a predetermined position close to the two ignition coils, and the electrical connection between the primary coil and the igniter is provided between the two ignition coils, the internal combustion engine including the igniter is included. The engine ignition coil can be configured as a single unit, and the wiring between each ignition coil and the igniter is easy, so that the engine can be miniaturized, easily manufactured, and inexpensive.

Furthermore, in the ignition coil for an internal combustion engine according to a second aspect, two sets of ignition coils are housed in one case, and an igniter is attached to the case so that both ends of each of the secondary coils. Since the high-voltage terminals connected to each other are arranged parallel to each other on the same plane and integrally with the case, it is possible to maintain insulation for high-voltage and large-current wiring. The wiring distance can be minimized, the wiring cost can be reduced, and the generation of noise can be suppressed.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view of an internal combustion engine ignition coil according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an internal combustion engine ignition coil according to an embodiment of the present invention.

FIG. 3 is a perspective view of an ignition coil for an internal combustion engine according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a state in which an internal combustion engine ignition coil according to an embodiment of the present invention is connected to an ignition plug.

FIG. 5 is an enlarged sectional view of a part of an ignition coil for an internal combustion engine according to an embodiment of the present invention.

FIG. 6 is an electric circuit diagram showing a main part of an ignition coil for an internal combustion engine according to an embodiment of the present invention.

[Explanation of symbols]

2 core, 2a body part, 2b, 2c extension part 3
Core, 3a, 3b Projection part 5 Air gap 6a, 6
b, 6e Terminal 7 High voltage terminal 9 Resin part 1
0 primary coil assembly 11 primary bobbin, 11
a, 11b Collar part 12 Primary coil 13 Holding part 20
Secondary coil assembly 21 Secondary bobbin, 21a Collar part, 21b Groove 22 Secondary coil 23 Terminal 3
0 Cases 31a to 31d High-voltage connector section 33 Flange section

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[Procedure amendment]

[Submission date] January 27, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

High-voltage connector portions 31a to 3 of the case 30
An igniter 8 is mounted on the side wall opposite to 1d at a position close to between the two sets of ignition coils 1A and 1B.
The igniter 8 may be mounted by bonding or screwing, or by forming a housing portion in the case 30 and housing the igniter 8 in the housing portion 30.
The igniter 8 may be integrally provided at the time of molding. A part of the igniter 8 accommodates, for example, a circuit element indicated by a chain line in FIG. 6 (which will be described later).
terminals 6a, 6b connected to the collector side of r2,
The terminal 6e, which is a common power supply terminal, is formed so as to extend into the case 30 as shown in FIG.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

In the ignition coil for the internal combustion engine of the present embodiment having the above-mentioned structure, the ignition plug 81 and the fourth cylinder of the first cylinder are used.
The ignition plugs 84 of the cylinders are ignited at the same time, and the ignition plugs 82 of the second cylinder and the ignition plugs 83 of the third cylinder are ignited at the same time. For example, when the first cylinder is in the compression process, the internal pressure of the cylinder is large, so the spark plug 81 does not easily discharge even at a high voltage, but the fourth cylinder is in the exhaust process and the internal pressure of the cylinder becomes atmospheric pressure. Since they are close to each other, they are easily discharged at a low voltage, the resistance of the spark plug 84 becomes a negligible value, and almost all output high voltage is applied to the spark plug 81 of the first cylinder in the compression process. Thus, a high voltage is individually applied to the ignition plugs 81 to 84 by the ignition coils 1A and 1B, a spark discharge is generated in each electrode portion, and a compressed air-fuel mixture in each combustion chamber (not shown) is generated. Is ignited.

Claims (2)

[Claims] 1. Two sets of ignition coils each having an inner core around which a primary coil and a secondary coil are wound, and an outer core forming a magnetic path together with the inner core are provided, and both ends of each of the secondary coils are provided. In an internal combustion engine ignition coil having a connected high-voltage terminal, an igniter for intermittently controlling a primary current to the primary coil is arranged at a predetermined position in the vicinity of the two sets of ignition coils, and the primary coil and the An ignition coil for an internal combustion engine, characterized in that an electrical connection with an igniter is provided between the two sets of ignition coils. 2. The two sets of ignition coils are housed in one case, the igniter is attached to the case, and high-voltage terminals connected to both ends of each of the secondary coils are mutually connected on the same plane. The ignition coil for an internal combustion engine according to claim 1, wherein the ignition coil is arranged in parallel with the case and integrally with the case.