JP2009295702A - Ignition coil for internal combustion engine and manufacturing method of insulation case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine capable of reducing assembly man-hours by reducing assembly components. <P>SOLUTION: In the ignition coil 11 for the internal combustion engine comprising a primary coil 16, a secondary coil 18, an iron core 19 composed of a center iron core part 20 and an annular iron core part 21 for magnetically coupling the secondary coil 18 and the primary coil 16, an iron core cover arranged between the primary coil 16 and the secondary coil 18 and the annular iron core part 21, and the insulation case 12A, the iron core cover (iron core cover part 12c) is provided on the inner side of the insulation case 12A by inserting the annular iron core part 21 to the insulation case 12A, and the primary coil 16, the secondary coil 18 and the center iron core part 20 are assembled and housed inside the insulation case 12A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ignition coil for an internal combustion engine that supplies a high voltage for generating spark discharge to an ignition plug of an internal combustion engine such as an automobile engine, and a method of manufacturing an insulating case that constitutes the ignition coil for an internal combustion engine. Is.

  FIG. 7 is an exploded explanatory view of components constituting a conventional ignition coil for an internal combustion engine, and FIG. 8 is an explanatory view of a coil-core assembly in which the primary coil, secondary coil, iron core and iron core cover shown in FIG. FIG. 9 is a cross-sectional view in which a part of an ignition coil for an internal combustion engine in which the components of FIG. 7 are accommodated in an insulating case is broken.

  In FIG. 9, reference numeral 11 denotes an ignition coil for an internal combustion engine, and includes an insulating case 12, a coil-iron assembly 13 accommodated in the insulating case 12, and a socket portion (not shown) located on the side surface of the insulating case 12. A plurality of low voltage terminals (primary terminals, not shown) and a high voltage terminal (secondary terminal) disposed so as to close the upper end portion of the cylindrical high voltage tower portion 12t located at the lower end portion of the insulating case 12 ) 24 and an insulating material which injects (fills) into the insulating case 12 and solidifies by being solidified, thereby performing high voltage insulation between the components housed in the insulating case 12, for example, an insulating resin such as a thermosetting resin 25.

As shown in FIGS. 7 and 8, the coil-iron core assembly 13 includes a primary coil bobbin 15, a primary coil 16 wound around the outer periphery of the primary coil bobbin 15, and a secondary coil bobbin into which the primary coil bobbin 15 is inserted. 17, the secondary coil 18 wound around the outer periphery of the secondary coil bobbin 17, the primary coil 16 and the secondary coil 18 are magnetically coupled to form an iron core 19 that forms a closed magnetic circuit, the primary coil 16 and the secondary coil 18. It is comprised by the iron core cover 22 arrange | positioned between the secondary coil 18 and the cyclic | annular iron core part 21 which comprises the iron core 19. As shown in FIG.
Further, as shown in FIG. 7, the iron core 19 has a center iron core portion 20 penetrating the primary and secondary coil bobbins 15 and 17 and the primary and secondary coils 16 and 18, and the center iron core portion 20 is positioned inside. The primary and secondary coil bobbins 15 and 17 and the annular core portion 21 surrounding the primary and secondary coils 16 and 18 are configured.
As shown in FIG. 7, the iron core cover 22 is connected to the hanging portion 22 d inserted inside the annular core portion 21 and the upper end of the hanging portion 22 d, and is placed on the annular core portion 21. And an upper annular portion 22u.
The iron core cover 22 has a function of holding the primary coil 16 and the secondary coil 18, and a function of suppressing the occurrence of cracks from the iron core 19 (annular iron core portion 21) to the insulating resin 25 due to changes over time (aging) and heat. (For example, refer to Patent Document 1).

Next, an example of assembly of the internal combustion engine ignition coil 11 will be described.
First, after inserting the primary coil bobbin 15 with the primary coil 16 wound on the outer periphery into the secondary coil bobbin 17 with the secondary coil 18 wound on the outer periphery, the primary coil bobbin 15, the primary coil 16, the secondary coil bobbin 17 and The assembly of the secondary coil 18 is inserted and assembled into the iron cover 22 from above.
And after inserting the center iron core part 20 in the primary coil bobbin 15, the hanging part 22d of the iron core cover 22 is inserted along the inner periphery of the annular core part 21, and the upper annular part 22u of the iron core cover 22 is inserted into the annular iron core part. The coil-iron core assembly 13 in the state shown in FIG. 8 is obtained by placing the iron core cover 22 on the annular core portion 21.
Next, the coil-iron assembly 13 shown in FIG. 8 is accommodated in the insulating case 12 in which the high voltage terminal 24 is disposed and the upper end portion of the high voltage tower portion 12t is closed, and the primary coil 16, the secondary coil 18, After connecting a plurality of low-voltage terminals and high-voltage terminals 24 so as to constitute a predetermined circuit, an insulating resin 25 is injected into the insulating case 12 and solidified, as shown in FIG. The assembly of the coil 11 is completed.

JP 2006-269843 A

  The conventional ignition coil 11 for an internal combustion engine has a large number of assembly parts because the primary coil bobbin 15 to the iron core cover 22 are assembled in the coil-iron core assembly 13 in the state shown in FIG. As a result, there were many assembly man-hours.

  The present invention has been made to solve the above-described disadvantages, and provides an ignition coil for an internal combustion engine that can reduce the number of assembly steps by reducing assembly parts, and a method for manufacturing an insulating case. To do.

The present invention is as follows.
(1) A primary coil, a secondary coil, an iron core composed of a center core portion and an annular core portion that magnetically couples the secondary coil and the primary coil, the primary coil, the secondary coil, and the In an ignition coil for an internal combustion engine comprising an iron core cover disposed between an annular core and an insulating case, the iron core cover is provided inside the insulating case by inserting the annular iron core into the insulating case. The primary coil, the secondary coil, and the center core portion are assembled and accommodated in the insulating case.
(2) A method for manufacturing an insulating case constituting an ignition coil for an internal combustion engine, wherein the annular core is lifted and positioned in the insulating case, and the annular core moves in the horizontal direction. In addition to blocking, the annular core portion was positioned with a fixed mold having a horizontal positioning portion for positioning the annular core portion in the insulating case, and the fixed mold and the movable mold were clamped Then, the insulating case is formed by injecting an insulating resin into a space formed by the fixed mold and the movable mold.
(3) In the method for manufacturing an insulating case according to (2), an injection port for injecting the insulating resin into the space above the annular core portion is provided.

According to the present invention, since the core cover is provided inside the insulating case by inserting the annular core portion into the insulating case, assembly parts can be reduced.
Therefore, it is possible to reduce the number of assembly steps for assembling the internal combustion engine ignition coil.
And, since the injection port for injecting the insulating resin into the space above the annular core part formed by the fixed side mold and the moving side mold is provided, the injected insulating resin moves the annular core part downward. By pressing, the movement of the annular core portion in the axial direction can be prevented, and the annular core portion can be insighted into the intended position of the insulating case.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an exploded explanatory view of components constituting an ignition coil for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a coil-iron core assembly in which the primary coil, secondary coil, and center core shown in FIG. FIG. 3 is a cross-sectional view in which a part of the ignition coil for an internal combustion engine in which the components shown in FIG. 1 are housed in an insulating case is broken. The description is omitted.

In FIG. 1, reference numeral 12 </ b> A denotes an insulating case, and an iron core cover portion 12 c that functions as an iron core cover is provided inside so as to cover the annular iron core portion 21 by inserting the annular iron core portion 21 during molding.
The iron core cover portion (iron core cover) 12c is formed from the iron core 19 (annular iron core portion 21) to the insulating resin 25 by the holding function of the primary coil 16 and the secondary coil 18, and the secular change (aging) and the heat change (heat cycle). (See FIG. 3) has a function of suppressing the occurrence of cracks.

  In FIG. 2, reference numeral 14 denotes a coil-iron core assembly. After the primary coil bobbin 15 with the primary coil 16 wound around the outer periphery is inserted into the secondary coil bobbin 17 with the secondary coil 18 wound around the outer periphery, the primary coil bobbin is inserted. 15 is assembled by inserting the center core 20 into the inside.

Next, an example of assembly of the internal combustion engine ignition coil 11 will be described.
First, after inserting the primary coil bobbin 15 with the primary coil 16 wound around the outer periphery into the secondary coil bobbin 17 with the secondary coil 18 wound around the outer periphery, the center iron core portion 20 is inserted into the primary coil bobbin 15. The coil-iron core assembly 14 in the state shown in FIG.
Then, the coil-core assembly 14 shown in FIG. 2 is accommodated in the insulating case 12 in which the high voltage terminal 24 is disposed and the upper end portion of the high voltage tower portion 12 t is closed, and the center core portion 20 is opposed to the annular core portion 21. In addition, after the primary coil 16, the secondary coil 18, a plurality of low voltage terminals, and the high voltage terminals 24 are connected to form a predetermined circuit, an insulating resin 25 is injected into the insulating case 12 and solidified. As shown in FIG. 3, the assembly of the ignition coil 11 for the internal combustion engine is completed.

According to the ignition coil 11 for an internal combustion engine of one embodiment of the present invention, since the iron core cover portion (iron core cover) 12c is provided inside the insulating case 12A by inserting the annular iron core portion 21 into the insulating case 12A, the internal combustion engine The assembly parts of the engine ignition coil 11 can be reduced.
Therefore, the number of assembling steps for assembling the internal combustion engine ignition coil 11 can be reduced.

  4 to 6 are explanatory views showing a manufacturing method of an insulating case constituting an ignition coil for an internal combustion engine according to an embodiment of the present invention. FIG. 4 (a) is a front view of a fixed side mold, and FIG. 4B is a plan view of the fixed mold, FIG. 4C is a front sectional view of the movable mold, and FIG. 5A is a front view of the fixed mold with the annular core and the high-voltage terminal attached. Fig. 5 (b) is a plan view of the fixed side mold with the annular core and high voltage terminal attached, Fig. 5 (c) is a front sectional view of the moving side mold, and Fig. 6 is the moving side mold. It is the front view which made the movement side metal mold | die of the state moved and clamped and shape | molded as the front cross-sectional view, attaches | subjects the same code | symbol to the part which is the same as that of FIGS. 1-3, and FIGS. Description is omitted.

In FIG. 4, reference numeral 31 denotes a fixed-side mold, and a rectangular upper end surface molding portion 32 for molding the upper end surface of the insulating case 12 </ b> A, and the upper end surface molding portion 32 on the upper end surface molding portion 32. An upper portion molding portion 33 that is small and has a quadrangular shape with a cylindrical curved surface in a plan view, is formed concentrically with the upper end surface molding portion 32, and molds an upper portion of the core cover portion 12c in the insulating case 12A. It is smaller than the upper part molding part 33 on the molding part 33, has four corners in plan view and is formed concentrically with the upper part molding part 33, and is lower than the iron core cover part 12c in the insulating case 12A. Thus, a lower partial molding portion 34 that molds the upper side of the bottom of the insulating case 12A, and a lower partial molding portion 34 that is formed concentrically with the lower partial molding portion 34 on the inner side of the high-pressure tower portion 12t. Mold part It is composed of a high voltage tower portion forming portion 35 of the frustum shape.
Then, the annular core portion 21 is lifted in the axial direction so as to be separated from the upper partial molding portion 33 on each of the upper surfaces of the four sides that protrude from the lower partial molding portion 34 and circulate. Pins 36 are provided as lifting portions for positioning 21 in the insulating case 12A.
Further, on the four side surfaces of the lower partial molding portion 34, the annular core portion 21 is separated from the side surface of the lower partial molding portion 34 to prevent the annular core portion 21 from moving in the horizontal direction, and the annular core. Projections 37 are provided as horizontal positioning portions for positioning the portion 21 in the insulating case 12A.
In addition, a high-voltage terminal placement recess 35 d for placing the high-voltage terminal 24 at the center is provided on the upper surface of the high-voltage tower partial molding portion 35.

In FIG. 4, reference numeral 41 denotes a moving-side mold, which is provided with a recess 42 for molding the outer side surface of the insulating case 12A and the inner side surface of the high-pressure tower portion 12t.
Although not shown, the moving side mold 41 is provided with an injection port (gate) for injecting an insulating resin at a portion above the annular core portion 21.

Next, molding of the insulating case 12A will be described.
First, the annular core portion 21 is lowered from the upper side of the fixed mold 31 in the state shown in FIG. 4 and the lower partial molding portion 34 is inserted into the annular core portion 21, as shown in FIG. The iron core 21 is placed horizontally on each pin 36.
When the annular core portion 21 is placed on each pin 36 in this way, a part of the inner peripheral surface of the annular core portion 21 contacts the four protrusions 37, so that the annular core portion 21 moves in the horizontal direction. Positioning is impossible.
And as shown in FIG. 5, the high voltage terminal 24 is mounted in the high voltage terminal mounting recessed part 35d of the high voltage tower partial shaping | molding part 35. As shown in FIG.

Next, the moving-side mold 41 is lowered to accommodate the annular core portion 21 and the upper partial molding portion 33 to the projection 37 in the recess 42, and the mold is clamped as shown in FIG.
Then, the insulating case 12A shown in FIG. 1 can be molded by injecting an insulating resin into the space (cavity) formed by the fixed mold 31 and the moving mold 41 from the injection port.
When the insulating resin is injected from the injection port located above the annular core portion 21 in this manner, the injected insulating resin presses the annular core portion 21 downward, so that the axial direction of the annular core portion 21 is increased. And the annular core portion 21 can be insighted into the expected position of the insulating case 12A.

According to the method of manufacturing the insulating case 12A of the embodiment of the present invention, the core cover portion (iron core cover) 12c is provided inside the insulating case 12A by inserting the annular core portion 21 into the insulating case 12A. The assembly parts of the engine ignition coil 11 can be reduced.
Therefore, the number of assembling steps for assembling the internal combustion engine ignition coil 11 can be reduced.
And since the injection port which inject | pours insulating resin to the space above the cyclic | annular iron core part 21 formed with the fixed side metal mold | die 31 and the movement side metal mold | die 41 was provided, the injected insulation resin is the cyclic | annular iron core part 21. Is pressed downward to prevent the annular core portion 21 from moving in the axial direction, and the annular core portion 21 can be insighted into the expected position of the insulating case 12A.

  In the above-described embodiment, an example in which four pins 36 are provided has been described. However, since the number of pins 36 can be three and the annular core portion 21 can be lifted horizontally, the number of pins 36 may be three or more. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded explanatory view of components constituting an internal combustion engine ignition coil according to an embodiment of the present invention. It is explanatory drawing of the coil-iron core assembly which assembled the primary coil shown in FIG. 1, the secondary coil, and the center iron core part. FIG. 2 is a cross-sectional view of a part of an ignition coil for an internal combustion engine in which each component of FIG. 1 is accommodated in an insulating case. It is explanatory drawing which shows the manufacturing method of the insulation case which comprises the ignition coil for internal combustion engines which is one Example of this invention. It is explanatory drawing which shows the manufacturing method of the insulation case which comprises the ignition coil for internal combustion engines which is one Example of this invention. It is explanatory drawing which shows the manufacturing method of the insulation case which comprises the ignition coil for internal combustion engines which is one Example of this invention. It is decomposition | disassembly explanatory drawing of the components which comprise the conventional ignition coil for internal combustion engines. It is explanatory drawing of the coil-iron core assembly which assembled the primary coil shown in FIG. 7, a secondary coil, an iron core, and an iron core cover. It is sectional drawing which fractured | ruptured some internal combustion engine ignition coils which accommodated each component of FIG. 7 in the insulation case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Ignition coil for internal combustion engines 12 Insulating case 12A Insulating case 12t High pressure tower part 12c Iron core cover part (iron core cover)
DESCRIPTION OF SYMBOLS 13 Coil-core assembly 14 Coil-core assembly 15 Primary coil bobbin 16 Primary coil 17 Secondary coil bobbin 18 Secondary coil 19 Iron core 20 Center iron core part 21 Ring core part 22 Iron core cover 22d Drooping part 22u Upper ring part 24 High voltage terminal (secondary Terminal)
25 Insulating resin (insulating material)
31 Fixed side mold 32 Upper end surface molding part 33 Upper part molding part 34 Lower part molding part 35 High pressure tower part molding part 35d High voltage terminal mounting recess 36 Pin (lifting part)
37 Protrusion (horizontal direction positioning part)
41 Moving side mold 42 Recess

Claims (3)

A primary coil; a secondary coil; an iron core comprising a center core portion and an annular core portion for magnetically coupling the secondary coil and the primary coil; the primary coil, the secondary coil, and the annular core portion; In an internal combustion engine ignition coil consisting of an iron core cover disposed between and an insulating case,
By providing the core cover inside the insulating case by inserting the annular core into the insulating case,
In the insulating case, the primary coil, the secondary coil, and the center iron core are assembled and accommodated.
An ignition coil for an internal combustion engine. A method of manufacturing an insulating case constituting an ignition coil for an internal combustion engine,
A lifting portion that lifts the annular core portion and positions it in the insulating case, and a horizontal positioning portion that prevents the annular core portion from moving in the horizontal direction and positions the annular core portion in the insulating case. Positioning the annular core with a fixed mold having
After clamping the fixed side mold and the moving side mold,
Insulating resin is injected into the space formed by the stationary mold and the movable mold to mold the insulating case,
A method for manufacturing an insulating case. In the manufacturing method of the insulation case of Claim 2,
An injection port was provided for injecting the insulating resin into the space above the annular core.
A method for manufacturing an insulating case.

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