JP3050442U - Ignition coil for internal combustion engine - Google Patents

Abstract

(57) [Summary] The present invention relates to a molded type internal combustion engine ignition coil.
Provided is an ignition coil which has a small size, a high output, and an increased number of turns of a secondary coil. SOLUTION: A cylindrical primary coil bobbin 2 and a secondary coil bobbin 4 in which a primary coil 3 and a secondary coil 5 are respectively wound and concentrically arranged, an inner circumference of the primary coil bobbin 2 and an outer circumference of the secondary coil bobbin 4 are provided. In the ignition coil 1 of an internal combustion engine having an arcuate core 10 and an insulating case 6 for accommodating the core, the secondary coil bobbin 4 is disposed at a plurality of positions in the longitudinal direction thereof. The flanges 41 are formed so as to be divided at the center of the bobbin and gradually lower toward both ends of the bobbin. Then, the secondary coil 5 was wound around the split winding groove so that the winding outer shape of the secondary coil 5 was substantially parallel to the inner peripheral surface of the iron core 10 and the insulating case 6.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an ignition coil of a molded internal combustion engine that supplies a high voltage to generate a spark discharge in, for example, a spark plug of an automobile engine, and particularly to a small and high output ignition of an internal combustion engine attached to an engine block. It concerns the coil.

[0002]

[Prior art]

 As a small and high-output ignition coil to be attached to an engine block represented by an automobile engine, the present applicant has previously proposed an ignition coil for an internal combustion engine disclosed in Utility Model Registration No. 30404488. The ignition coil 1 has substantially the same configuration as the ignition coil 1 shown in FIGS. 1 to 3, and has a cylindrical primary coil bobbin around which a primary coil 3 and a secondary coil 5 are wound and arranged concentrically. 2 and a secondary coil bobbin 4, and an iron core 10 that forms a closed magnetic path through the inner circumference of the cylinder of the primary coil bobbin 2 and the outer circumference of the secondary coil bobbin 4 (secondary coil 5).

The core portion 10 is formed by laminating substantially E-shaped directional silicon steel sheets, and joining end surfaces 11a and 12a of the laminated iron cores 11 and 12 with an adhesive or welding. The cores 11 and 12 are inserted into the primary coil bobbin 2 around which the secondary coil 5 is provided and the primary coil 3 is wound, and the cores 11 and 12 are disposed in the insulating case 6.

The primary coil 3 and the secondary coil 5 have windings having a turns ratio of 1:80 to 120, and the secondary coil 5 is provided on the secondary coil bobbin 4 in order to ensure a dielectric strength. It is divided and wound in a state of being partitioned by the plurality of flanges 41. That is, the secondary coil bobbin 4 is partitioned by flanges 41 provided circumferentially at a plurality of locations in the length direction thereof, and a space between the respective flanges 41 is formed as a divided winding groove of the secondary coil 5. Has a drum shape that is high in the center of the bobbin and decreases gradually toward both ends of the bobbin.

[0005]

[Problems to be solved by the invention]

 In recent years, there has been a movement toward lean burn, and it has been desired that ignition coils have a longer discharge time. For this purpose, it is necessary to increase the number of turns of the secondary coil 5. However, the secondary coil bobbin 4 in the above-mentioned conventional ignition coil is a drum type in which the center is high and both ends are sequentially reduced. In addition, since the diameter becomes smaller at both ends, the number of turns wound on one winding groove is reduced, and the total number of turns is limited (see FIG. 6). The present invention has been proposed to solve the above-described problems, and has as its object to provide an ignition coil that is small in size and high in output and has an increased number of turns of a secondary coil.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the invention according to claim 1 includes a cylindrical primary coil bobbin and a secondary coil bobbin in which a primary coil and a secondary coil are respectively wound and concentrically arranged, and the primary coil bobbin. In an ignition coil of an internal combustion engine having an arcuate core having an arcuate inner circumference forming a closed magnetic path passing through the inner circumference of the cylinder and the outer circumference of the secondary coil bobbin, and the above-mentioned secondary coil bobbin, It is separated by flanges provided circumferentially at a plurality of locations in the length direction, and each flange is divided into secondary winding grooves for the secondary coil.The flanges are higher at the center of the bobbin and gradually lower toward both ends of the bobbin. Wherein the secondary coil is wound around the split winding groove such that the winding outer shape of the secondary coil is substantially parallel to the iron core portion and the inner peripheral surface of the insulating case. Engine ignition coil.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the cross-sectional shape of the distal end of each flange portion of the secondary bobbin is changed to a curved surface at both ends. An ignition coil for an internal combustion engine, characterized in that the central part has an asymmetric shape in which the central part is angular.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a view showing a longitudinal section of an ignition coil of an internal combustion engine according to the present invention, FIG. 2 is a sectional view taken along line XX of FIG. 1, FIG. 3 is a development view of a main part, and FIG. FIG.

In these figures, an ignition coil 1 of an internal combustion engine includes a cylindrical primary coil bobbin 2 and a secondary coil bobbin 4 in which a primary coil 3 and a secondary coil 5 are wound and concentrically arranged, respectively. It has an iron core 10 that forms a closed magnetic path through the inner circumference of the primary coil bobbin 2 and the outer circumference of the secondary coil bobbin 4 (secondary coil 5).

The primary coil bobbin 2 is a cylindrical body integrally formed of an electrical insulating material such as a synthetic resin, for example, and a primary coil 3 is wound around the outer periphery thereof.

The secondary coil bobbin 4 is provided concentrically around the primary coil 3 and is made of, for example, an electrically insulating material such as a synthetic resin. The secondary coil bobbin 4 is integrally formed with a plurality of flanges 41 functioning as partitions for winding the secondary coil 5 in a divided manner. That is, the secondary coil bobbin 4 is partitioned by flanges 41 provided circumferentially at a plurality of locations in the length direction thereof, and each flange 41 is divided into a divided winding groove of the secondary coil 5. Is higher at the center of the bobbin and gradually lowers toward both sides of the bobbin. That is, as shown in a partially enlarged manner in FIG. 5, the flange portions 41c, 41c opposed at the center are high, the flange portions 41b, 41b located at the middle are slightly lower, and the flange portions 41a, 41a located at the end portions. Is the lowest.

On the secondary coil bobbin 4, for example, a secondary coil 5 having a winding ratio of 1:80 to 120 with respect to the primary coil 3 is wound in divided windings with each flange 41 as a partition. . At this time, in the present invention, the outer diameter of the secondary coil 5 is increased in a tapered manner from one start end 4a to the winding center 4b, and the secondary coil 5 is tapered from the winding center 4b to the end 4c. The secondary coil 5 is wound so that the winding outer shape of the secondary coil 5 is substantially parallel to the inner peripheral surfaces of the iron cores 11 and 12 and the insulating case 6 (the partition 15). In other words, the secondary coil 5 is wound so as to be substantially parallel to the imaginary line P connecting the vertexes of each flange 41.

According to the secondary coil 5 as described above, winding can also be performed on the outer peripheral portion of each divided winding groove, that is, the portion R indicated by hatching in FIG. Can be increased by about 5 to 10% as compared with the conventional coil.

In the illustrated embodiment, as shown in FIG. 5, the cross-sectional shape of the distal end of each flange 41 of the secondary bobbin 4 has a gentle curved surface at both ends and a non-angular shape at the center. It is symmetrical. In the embodiment having such a shape, the secondary coil 5 can be more easily wound around the secondary coil bobbin 4, and no winding deviation occurs.

The iron core portion 10 is formed by joining the ends 11a and 12a of laminated iron cores 11 and 12 formed by laminating substantially E-shaped, for example, oriented silicon steel plates with an adhesive or welding to face each other. The laminated core 11 includes a linear base 110 and side cores 111 extending in an arc shape along the shape of the secondary coil 5 wound around the secondary coil bobbin 4 from both ends of the base 110. , 113 and a central iron core 112 extending from the center of the base 110. Similarly to the laminated core 11, the other laminated core 12 also has a linear base 120, and side cores 121, extending from both ends of the base 120 in an arc shape along the shape of the secondary coil 5, respectively. 123 and a central iron core 122 extending from the center of the root 120.

When joining the two laminated cores 11, 12, the central core 112 of the laminated core 11 is inserted into the primary coil bobbin 2 from one side, and the central core 122 of the laminated core 12 is inserted from the other, respectively. At this time, the end surfaces 11b and 12b facing each other at the center of the bobbin and the end surfaces 11a and 12a facing each other outside the bobbin are joined by an adhesive or welding as described above. By this joining, the iron core portion 10 forms a closed magnetic circuit as a whole through the inner circumference of the primary coil bobbin 2 and the outer circumference of the secondary coil bobbin 4 (secondary coil 5), as described above, and forms a magnetic circuit. I do.

The above-mentioned core 10, primary coil 3 and secondary coil 5 are housed in an insulating case 6 molded of an insulating material such as a synthetic resin. A primary terminal seat 61 having a primary terminal 7 is provided on a peripheral wall on one end side of the insulating case 6, and a cylindrical portion 62 for accommodating the high voltage terminal 8 is formed on the other end. An arc-shaped partition wall 15 is provided inside the insulating case 6 so as to surround the outer periphery of the stored secondary coil 5, and is interposed between the secondary coil 5 and the iron core 10. I have.

The primary coil 3 and the primary terminal 7, and the secondary coil 5 and the high-voltage terminal 8 are electrically connected to each other. The generated high-voltage current is supplied from the high-voltage terminal 8 to the ignition plug via a coil spring 19 provided in the plug socket 18, so that a spark is generated between the electrodes at the tip.

Then, an insulating thermosetting resin 9 such as an epoxy resin is injected from an opening end of the insulating case 6, whereby the primary coil 3 and the secondary coil 5 inside the insulating case 6 are concentric. And the iron core 10 and the like are fixed at predetermined positions, respectively.

In the ignition coil 1 of the internal combustion engine having the above-described configuration, the cylindrical portion 62 of the insulating case 6 having the built-in high-voltage terminal 8 is housed in one end of the plug socket 18. Is mounted and fixed on the engine side. The lower end of the plug socket 18 covers the spark plug, and a coil spring 19 penetrating through the plug socket 18 connects the high voltage terminal 8 to the spark plug.

As described above, in this embodiment, the secondary coil bobbin 4 is partitioned by the flanges 41 provided circumferentially at a plurality of positions in the length direction, and the secondary coil 5 is divided between the flanges 41. The flanges 41 are higher at the center of the bobbin and gradually lower toward both sides of the bobbin, and the outer shape of the winding of the secondary coil 5 is substantially the same as the inner wall surface of the iron core 10 and the insulating case 6.回 It is wound so as to be parallel. Therefore, the length of the secondary coil bobbin 4 becomes short and drum-shaped, and the length of the iron core 10 can be shortened accordingly, so that the entire ignition coil 1 of the internal combustion engine can be significantly reduced in size. In addition, it is possible not only to easily secure a space for mounting the engine, but also to increase the number of windings of the secondary coil 5 to obtain a sufficiently high output even in lean combustion.

In addition, due to the above miniaturization, at least a portion from the upper end surface of the iron core portion 10 to the cylindrical portion 62 of the insulating case 6 as a storage portion for the high-voltage terminal 8 can be mounted inside the engine rocker cover 20 and below it. Since the ignition coil 1 of the engine is configured, even if the ignition coil 1 of the internal combustion engine is mounted on the engine, the amount of protrusion from the engine rocker cover 20 is small, and even in a small engine room, no space is required. Can be installed.

Further, since the inner peripheral shape of the iron core portion 10 passing through the outer periphery of the secondary coil bobbin 4 is formed in an arc shape along the shape of the secondary coil bobbin 4, the magnetic circuit length of the magnetic circuit becomes the shortest distance. Since the magnetic resistance decreases and the amount of change in magnetic flux increases, the output of the ignition coil can be improved.

As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and does not change the configuration described in the claims for utility model registration. As long as it can be implemented in any way.

[0025]

[Effect of the invention]

 Since the present invention has the above-described configuration, the following effects can be obtained. According to the first aspect of the present invention, a cylindrical primary coil bobbin and a secondary coil bobbin in which a primary coil and a secondary coil are respectively wound and concentrically arranged, and the inner circumference of the primary coil bobbin and the outer circumference of the secondary coil bobbin In an ignition coil for an internal combustion engine having an arcuate inner core forming a closed magnetic path and an insulating case for accommodating them, the secondary coil bobbin is circumferentially formed at a plurality of locations in the length direction. The flanges are divided by the provided flanges to form a divided winding groove for the secondary coil between the flanges, and the flange is formed so as to be higher at the center of the bobbin and gradually lower toward both ends of the bobbin. Since the secondary coil is wound so that the winding outer shape of the secondary coil is substantially parallel to the iron core and the inner peripheral surface of the insulating case, the length of the secondary coil bobbin is reduced to a drum shape, According to it Since the core unit can be reduced in length, can be miniaturized greatly the overall ignition coil for an internal combustion engine, can you to be easily secured mounting space of the engine. In addition, since the secondary coil can be wound up to the full capacity of each winding groove, the number of turns of the secondary coil can be sufficiently secured.

According to the invention described in claim 2, based on the configuration described in claim 1, the cross-sectional shape of the front end of each flange of the secondary bobbin is formed such that both end portions have a gentle curved surface and the center portion has a curved surface. Because of the angular and asymmetric shape, the secondary coil can be more easily wound around the secondary coil bobbin, and no winding displacement occurs.

[Brief description of the drawings]

FIG. 1 is a diagram showing a longitudinal section of an ignition coil of an internal combustion engine according to the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a development view of a main part of the ignition coil of the internal combustion engine according to the present invention.

FIG. 4 is an enlarged explanatory view of a main part of an ignition coil of the internal combustion engine.

FIG. 5 is a partially enlarged view of a secondary coil bobbin of the ignition coil.

FIG. 6 is an explanatory view showing a main part of a conventional ignition coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ignition coil of internal combustion engine 2 Primary coil bobbin 3 Primary coil 4 Secondary coil bobbin 5 Secondary coil 6 Insulating case 7 Primary terminal 8 High voltage terminal 9 Thermosetting resin 10 Iron core 11 Laminated core 12 Laminated core 15 Partition wall 18 Socket 19 Spring 20 Engine locker cover 21 Upper end surface of engine locker cover 30 High-voltage cord 31, 32 Permanent magnet 41 Flange 61 Primary terminal seat 62 Tube 110, 120 Root 111, 113 Side core 121, 123 Side core 112, 122 Central core Department

Claims (2)

[Utility model registration claims] 1. A closed magnetic circuit that passes through a cylindrical primary coil bobbin and a secondary coil bobbin in which a primary coil and a secondary coil are wound and disposed concentrically, and an inner circumference of the primary coil bobbin and an outer circumference of the secondary coil bobbin. In an ignition coil of an internal combustion engine having an arcuate inner core portion and an insulating case for accommodating them, the secondary coil bobbin is provided at a plurality of positions in a length direction thereof with a flange portion. A partition is formed between the flanges so as to be a divided winding groove of the secondary coil, and the flange is formed so as to be high at the center of the bobbin and to be gradually lowered toward both ends of the bobbin. An ignition coil for an internal combustion engine, wherein a secondary coil is wound so that a winding outer shape is substantially parallel to an inner peripheral surface of the core and the insulating case. 2. The ignition coil for an internal combustion engine according to claim 1, wherein a cross-sectional shape of a tip of each flange of the secondary bobbin is
An ignition coil for an internal combustion engine, wherein both end portions have a gentle curved surface, and a central portion has an asymmetric shape with a sharp angle.