JPH0128656Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an ignition coil structure that is easy to mold, has a uniform mold coating, can be impregnated with varnish completely and economically, and does not cause dielectric breakdown. .

Molded products have recently become the mainstream of this type of ignition coil structure.

However, there are drawbacks in that it requires time and effort to uniformly form a mold coating during the molding operation, and furthermore, it is impossible to completely impregnate the varnish.

First, regarding the uniformity of the mold coating, the coil and core are stably supported at an intermediate position within the mold frame, and then the molding material is injected onto the entire circumferential surface of the coil and core. It takes a lot of work to stably support the core, and if the stable support is incomplete, and the coil has irregularities, thin parts occur in the mold coating, resulting in dielectric breakdown.

In order to eliminate the above-mentioned drawbacks, the present invention uses a coil cup with a closed bottom and an attachment piece at a suitable position.

Next, regarding varnish impregnation, even if the coil and core are immersed in varnish, it will not penetrate inside and most of it will drip down, and the same thing will happen when drying with varnish. However, the disadvantage was that the varnish was wasted.

In the present invention, the coil cup can be completely impregnated with varnish, and there is no unevenness caused by the varnish, so that the mold coating formed on the outer circumferential surface of the coil cup can be made uniform.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In the figure, a denotes a coil body, which is composed of a primary coil 2 wound around a coil bobbin 1, a secondary coil 3, and a core 4 provided as necessary.

In the case of the embodiment shown in the drawings, a flange 1a is formed on one side of the coil bobbin 1, and a primary coil 2 is further attached to the flange 1a.
A pull-out groove 1b for the lead wire 2a is provided.

Further, in the figure, 3a is a lead wire of the secondary coil 3, which is connected to a lead terminal 3b protruding from a cut portion of an insulating tape 5 wound around the outer periphery.

In the present invention, a coil cup 6 is prepared which is attached from one side of the coil body a and has a closed bottom 6a and a mounting piece 6b at a proper position.

In addition, the above lead terminal 3b is connected to the coil body a.
In this case, a notch 6c is formed in the coil cup 6.

In the present invention, as shown in FIG. 2, a coil cup 6 is attached to the coil body a, and an adhesive tape 6d is attached to cover the cut 6c in order to prevent varnish from leaking from the cut 6c of the coil cup 6. In this state, varnish impregnation is performed.

As a result, the varnish penetrates into the coil cup 6,
Furthermore, the coil cup 6 and the adhesive tape 6d prevent the varnish from dripping, and the coil body a can be completely impregnated with varnish.

Next, the varnish-impregnated coil body a and the coil cup 6 are stably supported at an intermediate position within the mold frame 7, as shown in FIG.

Although the stable support is not shown in detail, the mounting piece 6b of the coil cup 6 is used within the mold frame 7 which is divided into two, and the mounting piece 6b is attached to the mold frame 7 or to the fixing pin 8. Therefore, it is fixed to the mold frame 7 side, and the molding material 9 is injected with the mold coating component, that is, the coil cup 6 portion suspended in the mold frame 7.

Furthermore, in the present invention, another mounting piece 9a is formed integrally with the molded material 9.

The other mounting piece 9a can be easily constructed by processing the mold frame 7 in advance so that it is integrated with the mold coating.

The mounting piece 6b and the other mounting piece 9a are arranged at appropriate positions on the coil cup 6 and the molded material 9, respectively, depending on the structure of the internal combustion engine to which the present invention is attached.

FIG. 4 shows the completed drawing. That is, the coil cup 6 can be easily attached to an internal combustion engine by using the attachment piece 6b of the coil cup 6 protruding from the molding material 9 and another attachment piece 9a integrally formed with the molding material 9.

In the present invention having the above structure, even if there are irregularities around the coil body a, it is covered by the installation of the coil cup 6, and the mold coating formed on the entire circumferential surface can be made to have a uniform thickness. The molding operation can be carried out completely without causing dielectric breakdown, and the mounting piece 6b formed on the coil cup 6 can facilitate the molding operation.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a perspective view showing an assembled state, Fig. 2 is a perspective view showing a completed assembly state, and Fig. 3 is a vertical sectional view of the main part during molding. FIG. 4 is a perspective view of the finished product. 1...Coil bobbin, 2...Primary coil, 3...
...Secondary coil, 6...Coil cup, 6a...
Bottom part (of the coil cup), 6b...Mounting piece (of the coil cup), 7...Mold frame, 9...Mold material, a...Coil body.

Claims (1)

[Scope of utility model registration request] a coil body, a coil cup whose bottom is closed and is attached to the coil body and further has a mounting piece at an appropriate position; the mounting piece protrudes to cover the entire circumference of the coil body and the coil cup; and the mounting piece An ignition coil structure characterized by comprising a molded material integrally formed with a mounting piece and a separate mounting piece.