JPH09246074A - Ignition coil for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition coil inside a case of which connector terminals can be connected to a primary coil easily and securely. SOLUTION: The primary and a secondary coils are accommodated in a case 60. A V shape cutout 61a is formed to a base edge part of, for example, a connector terminal 61 out of connector terminals 61 to 64 that are connected to these coils, the base edge part of connector terminals 61 is press fit into the case 60 and fixed so that an edge part 12a of the primary coil touches the inside surface of the cutout 61a. An igniter 8 is accommodated in the case and of which terminals 81 are arranged to touch the inside surface of connector terminal 61.

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 an ignition coil for an internal combustion engine in which a primary coil and a secondary coil are housed in a case and a connector terminal connected to these is mounted in the case. Pertain.

[0002]

2. Description of the Related Art Recently, there has been a demand for the development of an ignition coil for an internal combustion engine which is small in size and easy to wire and assemble. For example, Japanese Patent Laid-Open No. 6-77066 discloses a small number of parts, which can be easily installed in a case. In addition, for the purpose of properly accommodating the core and the coil, a primary bobbin that incorporates the core and winds at least the primary coil, and a primary terminal that connects the primary bobbin and connects the winding of the primary coil To form a primary coil assembly by integrally forming a connecting portion provided with and a connector portion provided with a connector terminal which is connected to the connecting portion and is connected to at least a primary terminal. Discloses an ignition coil for an internal combustion engine.

Further, an ignition coil is known in which a circuit element for controlling energization of the primary coil is housed in a case.
For example, Japanese Utility Model Publication No. 6-27939 proposes an ignition coil of an internal combustion engine in which a primary coil and a secondary coil are fixed in a coil housing part by an insulating resin layer and a switching module is fixed in an auxiliary housing part. Has been done. Further, in Japanese Patent Laid-Open No. 6-66239, a power switch and an ignition coil are assembled, then the power switch and the ignition coil are wire-connected to form an assembly, and then the entire assembly is made of insulating resin. There has been proposed a method of manufacturing an ignition device for an internal combustion engine, which is transfer molded by using the ignition device.

[0004]

In any of the ignition coils described in the above publications, accurate assembly precision is required for electrical connection between the connector terminal and the primary coil, so wiring and assembly work are required. It is desired to improve the performance and secure a stable electrical connection state after assembly. For example, the above Japanese Utility Model Publication No. 6-27939 discloses an ignition coil incorporating a switching module, and as an example thereof, a switching element chip is directly soldered to a metal case to reduce thermal resistance. Although the technology is disclosed, it does not mean that the wiring work becomes easy. Japanese Unexamined Patent Publication No. 6-66239 also relates to a wiring technique for one power switch and an ignition coil, but connection between the connector terminal and the IC package is not always easy.

Therefore, according to the present invention, in an ignition coil for an internal combustion engine in which a primary coil and a secondary coil are housed in a case and a connector terminal connected to these is mounted in the case, the connector terminal is used as a primary coil or the like in the case. An object of the present invention is to provide an ignition coil for an internal combustion engine that can be easily and reliably connected.

[0006]

In order to solve the above-mentioned problems, the present invention provides a case in which a primary coil and a secondary coil are housed in a case, and a plurality of connector terminals for connecting to the primary coil and the secondary coil are provided. In the ignition coil for an internal combustion engine mounted on the case, a substantially V-shaped notch is formed at a base end portion of at least one of the plurality of connector terminals, and at least one end portion of the primary coil is formed. The base end of the connector terminal is press-fitted and fixed in the case so as to abut the inner surface of the notch.

In the ignition coil for an internal combustion engine, an igniter for controlling energization of at least the primary coil in accordance with an ignition signal is housed in the case, and at least one end of the primary coil and at least the igniter are housed. The base end portion of the connector terminal may be press-fitted and fixed in the case so that both members of one terminal abut the inner surface of the notch of the connector terminal. Here, the igniter is an integrated circuit body that controls energization of the primary coil according to an ignition signal to control the primary current.

Further, in the ignition coil for an internal combustion engine, the secondary coil is provided with a secondary terminal connected to one end of the secondary coil and accommodated in the case, and at least one terminal of the igniter is L-shaped. Bent into a shape,
When the bent tip portion of the at least one terminal, the tip portion of the secondary terminal, and the one end portion of the primary coil are arranged so as to be substantially orthogonal to a plane including the notch of the at least one connector terminal. Good.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of an ignition coil for an internal combustion engine of the present invention will be described below with reference to the drawings. FIG. 14 shows the overall outer shape of an ignition coil for an internal combustion engine according to an embodiment of the present invention. FIG. 1 shows a plane and FIG. 2 shows a cross section. The case 60 is a container-like casing made of synthetic resin, which has an igniter portion 60d of a casing having an opening at the top, a cylindrical coil portion 60a extending downward from the bottom surface thereof, and a high-voltage terminal portion 60b. Further, a connector portion 60c is integrally formed on the side surface of the igniter portion 60d.

As shown in FIGS. 2 and 3, the coil portion 60
In a, an inner core 10, a primary bobbin 11 integrally formed with the inner core 10, a primary coil 12 wound around the primary bobbin 11, and a secondary coil assembly 20 surrounding them.
Further, an outer core 30 for accommodating them, a pair of auxiliary cores (representatively represented by 40) and a pair of permanent magnets (representatively represented by 50) are accommodated. As shown in FIGS. 1 and 2, an igniter 8 is housed in the igniter portion 60d. The igniter 8 controls the primary current of the primary coil 12 and is also called an ignition module. As shown in FIG. 2, the high-voltage terminal portion 60b has the high-voltage terminal 7 built therein, and a rubber plug cap 70 is attached to the outer surface thereof.

As shown in FIGS. 2, 3, 5 and 6, the inner core 10 is formed by laminating a plurality of magnetic flat plates, for example, silicon steel plates of various shapes, and both ends thereof are shown in FIG. It is formed on the end face, and the central portion is formed in a circular cross section. The plurality of silicon steel plates can be joined by stacking described later. In FIG. 2, hatching of the cross section of the inner core 10 is omitted because it is difficult to determine the drawing. The structure of the inner core 10 is not limited to the above. For example, a plurality of wire rods may be bundled in a cylindrical shape, or a flat plate of a magnetic material may be spirally wound to form a cylindrical shape.

A primary bobbin 11 is integrally formed on the outer surface of the inner core 10 by a synthetic resin (eg, epoxy resin) as shown in FIGS. 5 and 6, and a main body portion 11c is formed to have a circular cross section. The winding of the primary coil 12 is wound in two or four layers on the outer peripheral surface of the primary bobbin 11. At both ends of the primary bobbin 11, a pair of extension portions (representatively represented by 11 a) and a pair of extension portions (representatively 1 a) are provided.
1b) are formed so as to extend in parallel so as to face each other, and locking pieces (represented by 11s as a representative) are formed so as to extend on the mutually facing surfaces of the respective extending portions. ing.
Further, a protrusion 11p is formed near these locking pieces 11s. Although the protrusion on the extending portion 11b side is not shown in the figure, it is formed similarly to FIG. Further, the extension portion 11
As shown in FIG. 2, a through hole 11h for inserting the end of the winding of the primary coil 12 is formed in a.

Then, as shown in FIGS. 2 and 3, a secondary coil assembly 20 surrounding the inner core 10 and the primary bobbin 11 is provided. The secondary coil assembly 20 includes a secondary bobbin 21 and a secondary coil 22 (a cross-section is shown with an outline in the drawing) wound around the secondary bobbin 21. As shown in FIGS. 7 and 8, the secondary bobbin 21 has a collar portion 21a at both ends in the axial direction,
21b is a cylindrical body made of synthetic resin (for example, modified polyphenylene oxide) in which 21b and 21b are formed.
The winding of the secondary coil 22 is sequentially wound between b, as will be described later. The flange 21a has an annular groove 2 along its outer circumference.
1k is formed. Further, a locking portion 21s is formed on one end side of the hollow portion of the secondary bobbin 21, and when the primary bobbin 11 is accommodated, one end portion thereof abuts and positioning is performed.

Further, a pair of extending portions 21c are formed in parallel with each other in the axial direction from the collar portion 21b. As shown schematically in FIG. 9, the inner surface of the collar portion 21 b has a secondary bobbin 21.
Predetermined angle θ (eg 5 degrees) with respect to the plane orthogonal to the axis of
It is an inclined surface that is inclined outward. Further, as shown in FIG. 3, the winding layer of the winding of the secondary coil 22 on the side of the flange portion 21b, which is the high voltage side, is formed thinnest, and the distance to the primary coil 12 and the distance to the outer core 30 are substantially equal. The secondary coil 22 is located at the center of both, and a predetermined withstand voltage is secured on both sides of the secondary coil 22.

FIG. 10 shows a winding procedure of the winding of the secondary coil 22 on the secondary bobbin 21, which is wound by an automatic winding machine (not shown) in the order indicated by numerals within the circular cross section of the winding. To be turned. That is, the winding of the secondary coil 22 is
The secondary bobbin 21 that is in contact with the inclined surface of b is wound twice in the axial direction from the outer circumference of the main body of the secondary bobbin 21 (Fig. 10), and is wound up on the inclined surface side of the collar portion 21b to be radially oriented After being wound twice (,) on the outer peripheral surface side (), it is wound twice on the axial direction (,) and further wound up on the inclined surface side of the collar portion 21b (,). It is wound twice in the radial direction. In this way, for example, after winding up to 25 layers, a predetermined cross-section layer having an approximately isosceles right triangle (hence, the inclination angle is about 45 degrees) is formed, and then unwinding and winding are repeated in sequence. About 45 in the axial direction
The cross-section layer (not shown) having a substantially inverted triangular shape is formed in the vicinity of the inner surface of the collar portion 21a on the other end side.

Then, as shown in FIG. 11, the secondary bobbin 2
The secondary terminal 17 is attached to the extension part 21c of 1,
One end of the winding of the secondary coil 22 on the winding start side is connected to this. Further, a secondary terminal 18 is provided on the winding end side, and the base end portion 18a of the secondary terminal 18 is provided in the groove 2 of the collar portion 21a.
It is formed so that it is fitted in 1k and the tip portion 18b thereof is bent in a crank shape and extends in the axial direction. Thus, the other end of the winding of the secondary coil 22 is led out through the groove 21j formed on the outer periphery of the collar 21a and wound around the base end 18a of the secondary terminal 18.

On the other hand, the outer core 30 forming a magnetic circuit together with the inner core 10 is housed in close contact with the inside of the coil portion 60a of the case 60 as shown in FIGS. The outer core 30 is formed by bending a silicon steel plate into a cylindrical shape, for example. Alternatively, a cylindrical outer core 3
The case 60 may be integrally formed so as to house 0.

Further, as shown in FIGS. 2 and 3, rectangular permanent magnets 50 are arranged at both axial ends of the inner core 10, and auxiliary magnets 40 (see FIGS. 2 and 3) are arranged outside the rectangular permanent magnets 50, respectively. In FIG. 3, hatching is omitted). The auxiliary core 40 is made of two silicon steel plates each having a substantially rectangular shape (an oval shape) and two slits 40c formed in parallel with each other as shown in FIG. Is formed. Here, stacking means forming a concave portion on one surface and a convex portion on the other surface at the time of press molding for each of a plurality of flat plates, and forming a plurality of flat plates on the convex portions of the surfaces facing each other. Means to form a laminate by press-fitting into the recesses and sequentially polymerizing.

Each of the permanent magnets 50 arranged at both ends is formed in a substantially rectangular shape, and concave portions (not shown) for engaging with the protrusions 11p of the primary bobbin 11 are formed on both long side surfaces. There is. These permanent magnets 50 are arranged such that the directions of the generated magnetic fluxes are the same and are opposite to the directions of the magnetic fluxes formed in the inner core 10 when the primary coil 12 is energized. Thus, the inner core 1 described above
0, permanent magnet 50, auxiliary core 40, and outer core 30
The magnetic circuit is configured by.

Then, as shown in FIGS. 1 and 2, first to fourth connector terminals 61 to 64 are arranged in parallel in a connector portion 60c integrally formed with the case 60. . Igniter terminals 81 to 84 are connected to the base end sides of the first to fourth connector terminals 61 to 64, respectively. Further, one end 12a of the primary coil 12 is connected to the igniter terminal 85, and the energization of the primary coil 12 is controlled to be intermittent.
The first connector terminal 61 is connected to a power source (not shown), and the other end 12b of the primary coil 12 and the secondary terminal 18 are connected to the base end of the first connector terminal 61 together with the igniter terminal 81. Incidentally, these connection structures will be described later together with the assembling procedure.

In manufacturing and assembling the ignition coil having the above-described structure, FIG. 12 shows the assembling conditions of the main parts (igniter 8 and connector terminals 61 to 64 are plan views, and other parts are front views). As shown in the figure, first, the cylindrical outer core 30 is inserted into the coil portion 60a and is brought into close contact with the inner wall surface. On the other hand, the primary bobbin 11 is integrally formed on the outer surface of the inner core 10 made of a plurality of silicon steel plates, and the winding of the primary coil 12 (FIG. 2) is wound around the primary bobbin 11. In addition, the winding of the secondary coil 22 (FIG. 2) is wound around the secondary bobbin 21 as described above to form the secondary coil assembly 20.

Next, as shown in FIG. 2, between the pair of extending portions 11a at both ends of the primary bobbin 11 and between the pair of extending portions 11b, between the axial end surface of the inner core 10 and the locking piece 11s. The permanent magnets 50 are respectively inserted in the
The protrusion 11p of b is engaged with the recess (not shown) to fix the permanent magnet 50 at a predetermined position. And the secondary bobbin 21
The primary bobbin 11 and the inner core 10 around which the primary coil 12 is wound are housed in the hollow portion of the secondary bobbin 2 and the outermost surfaces of the extending portions 11a and 11b at both ends of the primary bobbin 11 are the secondary bobbin 2.
It is arranged so as to be fitted to the inner surface of the hollow portion 1.

As described above, the permanent magnets 50 are attached to both axial ends of the inner core 10 to form the assembly shown in FIG. 11, and then the auxiliary cores 40 are attached to both ends as shown in FIGS. 2 to 4. It That is, the auxiliary core 40 is inserted between the permanent magnets 50 and the locking pieces 11s at both ends, and the protrusion 11p engages with the opening of the slit 40c to fix the auxiliary core 40 at a predetermined position. Then, this assembly is housed in the outer core 30 of the coil portion 60a.
The permanent magnet 50 may be mounted together with the auxiliary core 40. Thus, during assembly, the auxiliary core 40 and the permanent magnet 50 are held in a predetermined position without deviating from the axis of the primary bobbin 11 and easily accommodated in the outer core 30. Then, the high-voltage terminal 7 is press-fitted into the high-voltage terminal portion 60b and electrically connected to the secondary terminal 17.

Further, the igniter 8 is housed in the igniter portion 60d of the case 60, the igniter terminals 81 to 85 are bent in an L-shape as shown in FIG. 2, and each tip end thereof is parallel to the axis of the coil portion 60a. It is arranged in the case 60 so as to extend in the direction. Note that FIG. 12 shows a state before bending the igniter terminals 81 to 85. On the other hand, the respective connector terminals 61 to 64 are formed in the same shape as shown in FIG. 13, and the notches 61a to 6 having a substantially V shape (for example, opening angle γ) are formed at the respective base ends.
4a are formed.

Then, the base end portions of the connector terminals 61 to 64 are press-fitted into the plurality of communication holes (represented by 60h in FIG. 2 as a representative) of the connector portion 60c. As a result, the igniter terminals 81 to 84 come into contact with the inner side surfaces of the cutouts 61a to 64a of the connector terminals 61 to 64, and are gradually guided and joined in the respective bottom direction along them. The planar shapes of the cutouts 61a to 64a are V-shaped and the connector terminals 61 to 64a.
Although it is desirable to form an inclined surface with respect to the press-fitting direction, the shape of the bottom portion may be a curved surface as shown in FIG.

The notch 61a of the connector terminal 61 is also connected to the other end 12b of the primary coil 12 and the tip 18b of the secondary terminal 18 at the same time. And
Soldering is performed around the notches 61a to 64a. At this time, the soldering work can be performed while visually checking the joint portion. Thus, the igniter terminals 81 to 84 and the like are securely joined to the notches 61a to 64a. It should be noted that one end 12a of the winding of the primary coil 12 is led out through the extending portion 11a of the primary bobbin 11, wound around the tip of the igniter terminal 85, and then soldered.

Thereafter, the coil portion 60a and the igniter portion 60d are filled and cured with a thermosetting synthetic resin, for example, an epoxy resin, and the resin portion 9 is replaced with the coil portion 60a as shown by the dotted lines in FIGS. And formed in the igniter portion 60d. As a result, the primary coil 12 and the secondary coil 22 are impregnated and fixed, and the electrical connection portion is appropriately insulated, and further, the insulating property capable of withstanding the high output voltage of the secondary coil 22 is secured. The coil portion 60a and the high-voltage terminal portion 60b, the igniter portion 60d, and the connector portion 60c shown in FIG.
And the igniter portion 60d may be joined.

The internal combustion engine ignition coil 1 is shown in FIG.
The plug cap 70 is attached to the high-voltage terminal portion 60b having the outer shape shown in FIG. Then, it is mounted on an internal combustion engine (not shown) and connected to a spark plug (not shown). In this state, when the primary current of the primary coil 12 is interrupted, a counter electromotive force is induced in the secondary coil 22 and 30 to 40
A high voltage of kv is generated and this high voltage is output to the spark plug. As a result, spark discharge occurs in the electrode portion of each ignition plug, and the compressed air-fuel mixture in each combustion chamber (not shown) is ignited.

[0029]

Since the present invention is configured as described above, the following effects can be obtained. That is, in the ignition coil for an internal combustion engine of the present invention, a substantially V-shaped notch is formed at the base end of at least one connector terminal so that at least one end of the primary coil abuts the inner surface of the notch. The base end of the connector terminal is press-fitted and fixed in the case.When press-fitting the connector terminal in the case, one end of the primary coil is gradually guided along the inner surface of the notch toward the bottom. Therefore, the electrical connection between the connector terminal and the primary coil can be made easily and reliably.

Further, in the ignition coil for an internal combustion engine according to claim 2, the igniter is housed in the case, and at least one end of the primary coil and at least one terminal of the igniter are the inner surface of the notch of the connector terminal. Since the base end portion of the connector terminal is press-fitted and fixed in the case so as to come into contact with, in addition to electrical connection between the connector terminal and one end portion of the primary coil,
Electrical connection between the connector terminal and the igniter terminal can be made easily and reliably, and good workability can be obtained.

Further, in the ignition coil for an internal combustion engine according to the third aspect, the secondary terminal is housed in the case, and at least one terminal of the igniter is bent into an L-shape, and its bent tip end portion, Since the tip portion of the secondary terminal and the one end portion of the primary coil are arranged so as to be substantially orthogonal to the plane including the cutout of at least one connector terminal, the primary coil, the secondary coil and the igniter are arranged. At the same time, it can be easily and surely connected to the connector terminal, and better workability can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of an ignition coil according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of an ignition coil according to an embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a coil portion of the ignition coil according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of a coil portion of the ignition coil according to the embodiment of the present invention.

FIG. 5 is a plan view of the primary bobbin according to the embodiment of the present invention.

FIG. 6 is a front view of the primary bobbin according to the embodiment of the present invention.

FIG. 7 is a plan view of the secondary bobbin according to the embodiment of the present invention.

FIG. 8 is a front view of the secondary bobbin according to the embodiment of the present invention.

FIG. 9 is an enlarged cross-sectional view schematically showing the winding state of the winding of the secondary coil according to the embodiment of the present invention.

FIG. 10 is a cross-sectional view schematically showing the winding sequence of the windings of the secondary coil according to the embodiment of the present invention.

FIG. 11 is a front view showing the coil assembly according to the embodiment of the present invention.

FIG. 12 is an assembly diagram showing an assembly situation of main parts of the ignition coil according to the embodiment of the present invention.

FIG. 13 is a plan view showing a press-fitted state of the connector terminal according to the embodiment of the present invention.

FIG. 14 is a perspective view of an internal combustion engine ignition coil according to an embodiment of the present invention.

[Explanation of symbols]

 1 Ignition coil for internal combustion engine 7 High-voltage terminal 8 Igniter 9 Resin part 10 Inner core 11 Primary bobbin 12 Primary coil 17,18 Secondary terminal 20 Secondary coil assembly 21 Secondary bobbin 22 Secondary coil 30 Outer core 40 Auxiliary core 50 Permanent magnet 60 Case 61 to 64 Connector terminal

Claims (3)

[Claims] 1. An ignition coil for an internal combustion engine in which a primary coil and a secondary coil are housed in a case, and a plurality of connector terminals connected to the primary coil and the secondary coil are mounted in the case. A proximal V-shaped notch is formed at the base end of at least one of the terminals, and the base end of the connector terminal is arranged so that at least one end of the primary coil abuts the inner surface of the notch. An ignition coil for an internal combustion engine, wherein the part is press-fitted and fixed in the case. 2. An igniter for controlling energization of at least the primary coil in response to an ignition signal is housed in the case, and at least one end of the primary coil and at least one terminal of the igniter are connected to the connector. 2. The ignition coil for an internal combustion engine according to claim 1, wherein the base end portion of the connector terminal is press-fitted and fixed in the case so as to come into contact with the inner surface of the notch of the terminal. 3. A secondary terminal for connecting a base end portion to one end of the secondary coil and accommodating in the case is provided, and at least one terminal of the igniter is bent into an L shape, and the at least one terminal is bent. The bent tip portion of one terminal, the tip portion of the secondary terminal, and the one end portion of the primary coil are arranged so as to be substantially orthogonal to a plane including the cutout of the at least one connector terminal. The ignition coil for an internal combustion engine according to claim 2.