JPH0144006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing a coil case/iron core assembly for an ignition coil.

Conventionally, the above-mentioned assembly includes a synthetic resin coil case having a cylindrical coil accommodating portion with a bottom and a core holding portion protruding from the inner surface of the bottom of the coil accommodating portion; There is a known type consisting of an iron core with both ends protruding outside the coil case.

Inside the coil case, the primary and secondary coils are wrapped around the outer periphery of the core holding part in double layers, inside and outside, and housed therein. Next, a liquid synthetic resin such as epoxy resin is injected into the coil case and the coil is heated under vacuum. After degassing, the resin is cured to obtain an ignition coil.

In this case, there would be a great advantage in manufacturing the ignition coil if the coil case and the iron core were integrated when molding the coil case, but in the past there was no way to accurately position the iron core, so There was no integration.

In view of the above, the present invention provides accurate positioning of the iron core.
Another object of the present invention is to provide the above-mentioned manufacturing apparatus which is easy to perform and can integrate the coil case and the iron core when molding the coil case.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Figures 5 and 6 show a coil case/iron core assembly C manufactured by the apparatus of the present invention, which will be described later. The coil case 1 is made of synthetic resin. A coil accommodating part 2 which is molded and has a bottomed cylindrical shape with a substantially square cross section, and a bottom part 3 of the coil accommodating part 2.
It consists of an iron core holding part 4 with a substantially square cross section protruding integrally with the inner surface, and a square hole 5 penetrating through the core holding part 4 and the bottom part 3 is made of a layered silicon steel plate with a substantially square cross section. The iron core 6 is fixed,
Both ends of the iron core 6 protrude from both ends of the square hole 5, respectively, in order to attach the ignition coil to the vehicle body.

A secondary coil 7 is wound around the outer periphery of the core holding part 4, and a primary coil 8 is wound around the outer periphery of the secondary coil 7. After the resin R is subjected to a vacuum degassing treatment, it is cured, thereby obtaining an ignition coil.

Next, the manufacturing apparatus will be explained with reference to FIGS. 1 to 4. The movable male mold 9 located at the upper part has a downward convex part 10 with a substantially square cross section, and the fixed female mold 11 located at the lower part has a movable male mold 9 located at the upper part. It has an upwardly directed recess 12 having a substantially rectangular cross section that cooperates with the protrusion 10 to form a coil housing molding cavity 2c (see FIGS. 2 and 3). A guide hole 13 having a substantially rectangular cross section is opened at the bottom of the recess 12 of the female mold 11, and a positioning pedestal 14 for the iron core 6 projects from the bottom of the guide hole 13. The guide hole 13 is recessed to a predetermined depth from the bottom surface of the recess 12 to support the iron core 6 .

A holding cylinder 16 having a substantially rectangular cross section is slidably fitted inside the guide hole 13, that is, between the inner circumferential surface of the hole 13 and the outer circumferential surface of the positioning pedestal 14, and four operating rods protruding from the end surfaces of the holding cylinder 16 are fitted. 17 (see FIG. 4) project out of the female mold 11 through the four insertion holes 18 at the bottom of the guide hole 13, and when the operating rods 17 are pushed, the holding cylinder 16 is advanced and plunged into the recess 12. If the holding tube 16 is pulled back, the holding tube 16 can be moved back and removed from the recess 12.

In its forward position, the holding cylinder 16 plunges deeply into the recess 12 and slides onto the iron core 6, allowing it to hold it over a wide range.On the other hand, in its retracted position, the holding cylinder 16 moves out of the recess 12 and slides into the iron core 6. The iron core 6 can be held over a small area. Further, in the retracted position of the holding cylinder 16, the annular end face 19 thereof matches the bottom face of the recess 12, and the iron core 6 of the coil housing part 2
The outer surface of the surrounding bottom 3 is defined (see Figure 3).

The male die 9 is provided with a concave portion 20 that opens at the end surface of the convex portion 10 and a positioning concave portion 21 that opens at the bottom surface of the concave portion 20. The concave portion 20
When the holding cylinder 16 is in the forward position, it surrounds the outer periphery of the holding cylinder 16, and in the illustrated example, can be fitted to the outer circumferential surface of the holding cylinder 16. On the other hand, when the holding cylinder 16 is in the retracted position, it surrounds the outer periphery of the iron core 6. A cavity 4c for molding the part can be formed. The positioning recess 21 can fit into the end of the iron core 6.

Next, the manufacturing process of the coil case/iron core assembly C using the above-mentioned apparatus will be explained.

First, the male mold 9 is raised as shown in FIG. Further, the holding cylinder 16 is moved forward, that is, raised, and slidably engages the outer peripheral surface of the iron core 6 supported on the positioning pedestal 14 over a wide range, thereby holding the iron core 6 in an upright state. In this case, the holding cylinder 16 is slid onto the iron core 6 so that the end of the iron core 6 on the side of the male die 9 can protrude a predetermined length from the annular end surface 19 of the holding cylinder 16, and the end thereof is fitted into the positioning recess 21 of the male die 9. Make sure that they match.

Next, as shown in FIG. 2, the male mold 9 is lowered to close both molds 9 and 11, and the convex part 10 of the male mold 9 is fitted into the concave part 12 of the female mold 11, so that the two molds 10 and 12 cooperate with each other. A cavity 2c for molding the coil accommodating portion is formed between them. Further, the recess 20 of the male die 9 is fitted into the holding cylinder 16, and the positioning recess 21 is fitted into the end of the iron core 6. In this case, since the iron core 6 is held by the holding cylinder 16 over a wide area,
The iron core 6 and the positioning recess 21 are smoothly fitted.

Next, the holding cylinder 16 is moved backward, that is, lowered, and
When the annular end surface 19 is aligned with the bottom surface of the recess 12 of the female mold 11, both ends of the iron core 6 are supported by the holding cylinder 16 and the positioning recess 21, and the male mold 9
A cavity 4c for forming the core holding portion is formed on the outer periphery of the core 6 by the concave portion 20, and the outer surface of the bottom 3 of the coil housing portion 2 around the core 6 is defined by the annular end surface 19 of the holding cylinder 16. The protrusion length of the iron core 6 from the coil case 1 is the positioning pedestal 1.
4 and the depth of the positioning recess 21.

Thereafter, by filling the cavities 2c, 4c with molten synthetic resin, a coil case/core assembly C is obtained in which the coil case 1 and the iron core 6 are integrated at the same time as the coil case 1 shown in FIGS. 5 and 6 is formed.

As described above, according to the present invention, a male mold having a convex portion and a female mold having a concave portion that cooperates with the convex portion to form a cavity for molding a coil accommodating portion are configured to be freely openable and closable. , a forward position in which a guide hole opening at the bottom of the recess and a positioning cradle for supporting the iron core in the guide hole are provided, and a forward position in which the recess deeply plunges into the recess, slides on the iron core, and holds the iron core over a wide range; A holding cylinder that can be moved back from the inside and a retracted position where it slides against the iron core and holds the iron core over a small area is slid into the guide hole, and is opened in a male shape at the end face of the convex part, and the holding cylinder moves forward. a recessed part that can surround the outer periphery of the core when the holding cylinder is in the retracted position, and that can form a cavity for forming the core holding part around the outer periphery of the core when the holding cylinder is in the retracted position; Since positioning recesses that cooperate with each other to support both ends of the iron core are formed, the iron core can be accurately positioned using the holding cylinder, and it can be smoothly fitted into the positioning recess, and the recess and the holding cylinder can cooperate with each other. It is possible to support both ends of the iron core. Then, by filling both cavities with molten synthetic resin, a coil case/iron core assembly that integrates the coil case and the iron core can be obtained at the same time as the coil case is formed, which saves many man-hours in manufacturing the ignition coil and significantly reduces manufacturing costs. can be reduced.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS. 1 to 3 are explanatory diagrams of the manufacturing process of the apparatus of the present invention and a coil case/core assembly using the same, and FIG.
The figure is a perspective view of the holding cylinder, FIG. 5 is a perspective view of the coil case/iron core assembly, and FIG. 6 is a sectional view taken along the line of FIG. 5. C... Coil case/core assembly, 1... Coil case, 2... Coil housing section, 2c... Cavity, 4... Core holding section, 4c... Cavity,
6...Iron core, 9...Male type, 10...Protrusion, 11...
...female mold, 12... recess, 13... guide hole, 14
...Positioning pedestal, 16...Holding cylinder, 20...Concave portion, 21...Positioning concave portion.

Claims (1)

[Claims] 1 A synthetic resin coil case having a cylindrical coil housing portion with a bottom and a core holding portion protruding from the inner surface of the bottom of the coil housing portion; passing through the core holding portion and holding both ends of the coil case; An apparatus for manufacturing a coil case/core assembly for an ignition coil consisting of an iron core protruding from the case, a male die having a convex portion, and a cavity for forming a coil housing portion in cooperation with the convex portion. A female mold having a recess to be formed is configured to be openable and closable, and the female mold is provided with a guide hole opening at the bottom of the recess and a positioning pedestal for supporting the iron core within the guide hole, A forward position in which the recess deeply penetrates into the recess and slides against the core to hold the core over a wide range, and a retreat position in which the recess exits the recess and slides against the core to hold the core over a small range. A holding cylinder to be obtained is slid into the guide hole, and the male mold has an opening at the end face of the convex portion so as to surround the outer periphery of the holding cylinder when the holding cylinder is in the forward position, while the holding cylinder is in the retracted position. a recessed portion capable of forming a core holding molding cavity on the outer periphery of the iron core when the iron core is located at Manufacturing equipment for coil case/iron core assemblies for ignition coils.