JP2002039042A - Ignition coil equipment for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accommodate two or more ignition coils in an insulation case without extending an installation space to excess. SOLUTION: Two or more ignition coils, the first ignition coil 410 having the primary coils 411, 511 and the secondary coil 412, 512 in a mutual induction relation and the second ignition coil 510, are accommodated in the insulation case 300. The ignition coil equipment 30 for engine is designed to feed the high voltage generated by mutual induction of these respective ignition coils 410 and 510 to the ignition plug 20 equipped in the plug hole 11 of engine 10. Accommodation space 302 which is extended inside the above-mentioned plug hole 11 is formed in the above-mentioned insulation case 300, and it makes this space 302 accommodate the second ignition coil 510 therein.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case where a plurality of ignition coil units each having a primary coil and a secondary coil in a mutual induction relationship are accommodated in an insulating case, and a high voltage generated by mutual induction of the ignition coil units is provided. To an ignition coil device for an internal combustion engine, which is supplied to a spark plug mounted in a plug hole of the internal combustion engine.

[0002]

2. Description of the Related Art FIG. 4 shows an ignition coil device for supplying a high voltage to a spark plug B mounted in a plug hole A of an internal combustion engine. This ignition coil device includes an iron core C constituting a closed magnetic circuit, an ignition coil part D, that is, a primary coil E and a secondary coil F, which are mutually induced by the iron core C, and a mutual induction of both coils E and F. A high voltage terminal G for outputting a high voltage generated in the next coil F to the outside is housed in an insulating case H. The insulating case H is formed by integrally molding a wide-mouth main body portion Ha and an insertion portion Hb projecting from the bottom surface of the main body portion into a small-diameter cylindrical shape using an electrical insulating material such as a synthetic resin. In the insulating case H, a core C, a primary coil E and a secondary coil F are housed and held in a main body Ha, and a high-voltage terminal G is housed and held in an insertion portion Hb.

The insulating case H is provided with a plug joint J. The plug joint J is the insertion part H
b, a base socket Ja to be mounted on the outer periphery of the base b, a relay cylinder member Jb extending in a tubular shape from the tip of the base socket Ja,
Plug socket Jc attached to the tip of relay cylinder member Jb
The conductive spring K is built in a portion from the base socket Ja to the plug socket Jc.

In the ignition coil device configured as described above, when the plug joint J is inserted into the plug hole A of the internal combustion engine, the plug socket Jc is mounted on the ignition plug B, and the high voltage terminal G and the ignition plug are connected through the conductive spring K. The terminal B is electrically connected. Accordingly, the high voltage generated in the secondary coil F by the mutual induction of the ignition coil portion D is supplied to the ignition plug B via the high voltage terminal G and the conductive spring K, and a desired spark discharge is generated in the ignition plug B. It is possible to do.

[0005]

Recently, there has been an attempt to accommodate a plurality of ignition coil portions D in the above-mentioned insulating case H. For example, in a lean-burn engine, the air-fuel ratio is set to be extremely low, and the ignition characteristics are inferior to those of a normal engine. It is intended to improve its ignition characteristics by keeping it continuous.

However, in order to accommodate the plurality of ignition coil portions D in the insulating case H, the dimensions of the main body portion Ha must be greatly increased, and this has not yet been realized due to the problem of installation space. That is, when the main body portion Ha of the insulating case H is expanded in the width direction, the insulating cases H of the adjacent cylinders may interfere with each other, and it is difficult to attach the insulating case H to the plug hole A of the engine.
On the other hand, when the main body portion Ha of the insulating case H is enlarged in the height direction, mutual interference between the adjacent insulating cases H can be prevented, but the overall height of the engine increases.
This poses a problem that the mounting location and mounting position of the engine are significantly restricted.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an ignition coil device for an internal combustion engine that can accommodate a plurality of ignition coil portions in an insulating case without greatly increasing the installation space. .

[0008]

According to the present invention, a plurality of ignition coil sections each having a primary coil and a secondary coil, which are in a mutual induction relationship, are accommodated in an insulating case, and the ignition coil section is generated by mutual induction of the ignition coil sections. An ignition coil device for an internal combustion engine adapted to supply a high voltage to an ignition plug mounted in a plug hole of the internal combustion engine, wherein the insulating case is provided with an extension accommodating portion extending inside the plug hole. The extension accommodating portion accommodates at least one ignition coil portion.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments. FIG. 1 shows an embodiment of an ignition coil device for an internal combustion engine according to the present invention. The ignition coil device 30 applied to an automobile engine 10 having a spark plug 20 mounted inside a plug hole 11 is shown.
Is exemplified. The plug hole 11 is used for the engine 10
(More precisely, a cylinder head or a head cover) It is a deep hole-shaped portion extending toward the combustion chamber 13 from the bottom surface of the housing recess 12 provided on the outer surface of the housing. A screw hole 14 is provided in a bottom surface of the plug hole 11 so as to penetrate the combustion chamber 13, and an ignition plug 20 is mounted in the screw hole 14.

The ignition coil device 30 to which the above-described engine 10 is applied has an insulating case 300 and a high-voltage terminal tube 310.

The insulating case 300 is formed by integrally molding a main body portion 301 and an extension accommodating portion 302 with an electric insulating material such as a synthetic resin. Main body 3 of insulating case 300
Reference numeral 01 denotes a wide-open box-like shape, in which a first center core 400 and a first ignition coil portion 410, that is, a primary coil 411 and a secondary coil which are mutually inductive by the first center core 400 are formed. 412 are accommodated. The primary coil 411 is wound around a primary coil bobbin 413 disposed so as to fit around the first center iron core 400, while the secondary coil 412 surrounds the primary coil bobbin 413. Is wound around the bobbin 414 for the secondary coil arranged at the position. The primary coil 411 and the secondary coil 412 are housed inside the opening 301a of the main body 301 together with the respective bobbins 413 and 414, and a first power transistor 415 and a first high-voltage diode 416 described later. The insulating resin 320 is filled and hardened in 301 and fixedly arranged at a predetermined position. In addition.
In the illustrated embodiment, the first center core 400 penetrates the main body 301 of the insulating case 300, and both ends thereof are exposed to the outside of the insulating case 300. Of course, it may be housed in the main body 301 of the 300. Although not explicitly shown in the figure, it is preferable to provide a C-shaped iron core or an annular iron core in the first center core 400 so as to connect between both ends thereof.

The extension housing 302 of the insulating case 300
It is a cylindrical part protruding from the side surface (the lower surface in the figure) of the main body 301. The extension housing portion 302 has an outer diameter that fits into the plug hole 11 described above, and is configured to have a length shorter than the plug hole 11. In addition, the second ignition coil section 510, that is, the primary coil 511 and the secondary coil 512, which are mutually inductively related by the second center core 500, are accommodated. The primary coil 511 is wound around a primary coil bobbin 513 disposed so as to fit around the second center core 500, while the secondary coil 512 surrounds the primary coil bobbin 513. Is wound around the bobbin 514 for the secondary coil arranged in the above. The primary coil 511 and the secondary coil 512 are housed together with the respective bobbins 513 and 514 and a second power transistor 515 and a second high-voltage diode 516 to be described later from the end opening 302a of the extension housing 302, The extension storage part 3
02 is fixedly arranged at a predetermined position by filling and curing the insulating resin 320.

The high-voltage terminal tube 310 is formed into a cylindrical shape by using an electrically insulating material, and the end surface opening 302 a of the extension housing portion 302 is formed.
Is mounted so as to close it, and a conductive spring 330 is housed and held as a high-voltage terminal in the center hole 311. As is clear from the figure, this high-voltage terminal tube 310 has a central portion formed to have the same outer diameter as the extension housing portion 302, while a base end portion having a small diameter is inserted into the extension housing portion 302. In addition, the base end surface is brought into contact with the front end surface of the secondary coil bobbin 514 in the second ignition coil portion 510. The distal end of the high-voltage terminal tube 310 has a smaller diameter and a smaller wall thickness than the central portion, and includes a plug socket 340. The plug socket 340 is formed in a tubular shape from an elastic synthetic resin having electrical insulation properties, such as synthetic rubber. The plug socket 340 has an annular connection hole 341 opened on the base end surface, and is fitted to the distal end of the high-voltage terminal tube 310 by fitting the distal end of the high-voltage terminal tube 310 into the connection hole 341. is there. As for the connection between the extension accommodating portion 302 of the insulating case 300 and the high-voltage terminal tube 310, an adhesive is applied between them, or the high-voltage terminal tube 31 is hardened before the above-mentioned insulating resin 320 is cured.
It is preferable to make it strong by attaching 0 or the like. In connection with the connection between the high-voltage terminal tube 310 and the plug socket 340, snap engagement means 350 including an annular projection and an annular groove is provided between each other for snap-fitting, or an adhesive is applied between them. It is preferable not to drop easily.

Incidentally, reference numeral 360 in the figure denotes a primary terminal 37.
0 (see FIG. 2), a ground terminal 380, and ignition signal input terminals 390, 391 described later.

FIG. 2 is a circuit diagram showing a wiring example of the above-described ignition coil device 30 for an internal combustion engine. As is clear from the drawing, in this wiring example, the primary coil 411 of the first ignition coil unit 410 and the primary coil 511 of the second ignition coil unit 510 are connected in parallel between the primary terminal 370 and the ground terminal 380. The secondary coil 412 of the first ignition coil unit 410 and the secondary coil 512 of the second ignition coil unit 510 are connected to the conductive spring 330 and the ground terminal 38.
0 is connected in parallel.

Power transistors 415 and 515 are interposed between the primary coils 411 and 511 of the ignition coil sections 410 and 510 and the ground terminal 380, respectively. The first power transistor 415 of the first ignition coil unit 410 and the second power transistor 515 of the second ignition coil unit 510 both have a collector connected to the primary coil 41.
1,511 while the emitter is connected to ground terminal 380
, And each base is connected to a separate ignition signal input terminal 390, 391.

On the other hand, the secondary coils 412 and 512 of each of the ignition coil units 410 and 510 have conductive springs 330 respectively.
And high voltage diodes 416 and 516 are interposed therebetween. First high voltage diode 41 of first ignition coil section 410
6 and the second high-voltage diode 516 of the second ignition coil unit 510 are both connected in a direction that allows current from the conductive spring 330.

Reference numeral 60 in the figure denotes a key switch interposed between the battery 61 and the primary terminal 370.

The ignition coil device 30 constructed as described above
First, the insulating case 300 is inserted into the plug hole 11 of the engine 10 to be mounted.
Is inserted, and the spark plug 20 is mounted in the center hole 342 of the plug socket 340. In this state, the conductive spring 330 held in the center hole 311 of the high-voltage terminal tube 310 is connected to the center hole 34 of the plug socket 340.
2 is pressed into contact with the terminal of the ignition plug 20, and both are electrically connected. As described above, since the outer diameter of the extension housing portion 302 of the insulating case 300 is large enough to fit into the plug hole 11 and the length thereof is shorter than the plug hole 11, And is not completely exposed to the outside of the engine 10.

Next, the battery 61 is connected to the primary terminal 370, and the ignition signal generator 70 is connected to the ignition signal input terminals 390 and 391, respectively. The ignition signal generating unit 70 includes, for example, a CPU and a memory, and stores the first ignition coil unit 410 and the second ignition coil unit 510 based on a program stored in the memory in advance, and a detection signal indicating an operation state given each time. Is a control means for switching appropriately.

When the ignition signal Sa is given to the first power transistor 415 of the first ignition coil unit 410 at a predetermined period T as shown in FIG.
As shown in (b), the primary current Ia1 flows intermittently in the primary coil 411 in response to the ignition signal Sa, and a secondary voltage is generated in the secondary coil 412 by the interruption of the primary current Ia1. As shown in FIG. 3C, the discharge current Ia2 flows.

On the other hand, as shown in FIG. 3D, the second power transistor 515 of the second ignition coil unit 510 has the same period T as the ignition signal Sa given to the first power transistor 415. And an ignition signal Sb out of phase with T / 2. Second power transistor 515
Is supplied with the ignition signal Sb, the first ignition coil unit 41
0, the ignition signal Sb as shown in FIG.
Accordingly, the primary current Ib1 flows intermittently through the primary coil 511, and the intermittent primary current Ib1 generates a secondary voltage in the secondary coil 512.
As shown in (f), the discharge current Ib2 flows.

As a result, the discharge current Ia2 of the first ignition coil unit 410 and the discharge current Ib2 of the second ignition coil unit 510 are applied to the ignition plug 20, as shown in FIG.
, That is, a continuous discharge current I flows. Therefore, the lean burn engine 10
Even when the present invention is applied, it becomes possible to maintain the spark discharge without interruption and to improve its ignition characteristics.

Further, according to the ignition coil device 30, when the plug hole 11 is attached to the engine 10,
Storage section 30 of insulating case 300 completely stored in
2 accommodates the second ignition coil unit 510. Therefore, the installation space is the same as that of the conventional ignition coil device having only the ignition coil unit, and there is no possibility that the adjacent insulating cases 300 interfere with each other or increase the overall height of the engine 10 at all. Thus, the mounting location and mounting posture of the engine 10 are not limited, and can be applied to the existing engine 10 as it is.

In the above-described embodiment, the ignition coil device applied to the automobile engine is exemplified.
As long as the spark plug is mounted inside the plug hole, it can be applied to other internal combustion engines. Furthermore, although the ignition coil device provided with two ignition coil units is illustrated, it is needless to say that the ignition coil device may be provided with three or more ignition coil units.

Further, since the primary coil and the secondary coil of the ignition coil unit are connected in parallel,
Although it is possible to improve the ignition characteristics of the internal combustion engine without interrupting the spark discharge of the ignition plug, the present invention is not necessarily limited to this, and the ignition coil units are connected in series, that is, one of the ignition coil units is connected. The ignition coil device may be configured by connecting the secondary coil and the primary coil of the other ignition coil unit. In this case, although the effect of improving the above-described ignition characteristics cannot be expected, the turns ratio of each ignition coil unit can be reduced as compared with the case where a single ignition coil unit is applied. Insulation strength is reduced. As a result, the amount of the insulating resin used can be reduced, so that the cost can be reduced and the weight can be reduced.

Further, the extension housing portion is completely housed in the plug hole when attached to the internal combustion engine, but it is not always necessary to house the entire extension housing portion in the plug hole.

[0028]

As described above, according to the present invention,
The insulating case is provided with an extension accommodating portion extending inside the plug hole, and at least one ignition coil portion is accommodated in the extension accommodating portion. It is possible to suppress the expansion as much as possible, and there is no possibility of causing problems such as mutual interference with an adjacent one or restriction on mounting of the internal combustion engine. As a result, the problem of installation space can be solved, and an ignition coil device in which a plurality of ignition coil units are accommodated inside an insulating case can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view showing an embodiment of an ignition coil device for an internal combustion engine according to the present invention, which is attached to a plug hole of the internal combustion engine.

FIG. 2 is a circuit diagram showing a wiring example of the ignition coil device for an internal combustion engine shown in FIG.

FIG. 3 is a timing chart showing a relationship between a primary current and a discharge current under the control of an ignition signal generator.

FIG. 4 is a sectional side view showing a conventional ignition coil device for an internal combustion engine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 engine 11 plug hole 12 housing recess 13 combustion chamber 14 screw hole 20 ignition plug 30 ignition coil device 60 key switch 61 battery 70 ignition signal generating unit 300 insulating case 301 main body 301a opening 302 extending housing 302a end face opening 310 high voltage terminal Tube 311 Center hole 320 Insulating resin 330 Conductive spring 340 Plug socket 341 Connection hole 342 Center hole 350 Snap engagement means 360 Terminal seat 370 Primary terminal 380 Ground terminal 390,391 Ignition signal input terminal 400 First center iron 410 First ignition Coil section 411 Primary coil 412 Secondary coil 413 Primary coil bobbin 414 Secondary coil bobbin 415 First power transistor 416 First high voltage diode 500 Second center core 510 Second ignition coil section 511 Primary coil 512 Secondary coil 513 Bobbin for primary coil 514 Bobbin for secondary coil 515 Second power transistor 516 Second high voltage diode

Claims (1)

[Claims] A plurality of ignition coil units each having a primary coil and a secondary coil in a mutual induction relationship are housed in an insulating case, and a high voltage generated by mutual induction of the ignition coil units is supplied to a plug of an internal combustion engine. An ignition coil device for an internal combustion engine adapted to be supplied to a spark plug mounted in a hole, wherein the insulating case is provided with an extension housing portion extending inside the plug hole, and at least the extension housing portion is provided in the extension housing portion. An ignition coil device for an internal combustion engine, wherein one ignition coil portion is accommodated.