JP2940160B2 - How to fix the noise prevention core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a noise prevention method in which a cylindrical ferrite core for noise prevention is externally fitted to a cable and fixed to the cable by resin molding. The method of fixing the core for use

[Conventional technology]

In recent years, as a countermeasure against noise, for example, as shown in FIG. 3, a cylindrical ferrite core 15 is externally fitted to one end of a cable 12 connected to a connector (mini-din connector) 10 and is connected with a cable. It is considered to fix it by winding.

However, simply fixing the ferrite core 15 to the cable 12 in this way does not
There is a possibility that the root portion of the connector 10 may be damaged due to twisting or bending of the 12 ferrite core 15 fixing portion.

Thus, the ferrite core 15 and the connector 10 fixed to the cable 12 as described above are connected and fixed by resin molding (primary molding) using a mold, that is, an upper mold and a lower mold are used. A part near the base of the connector 10 and the ferrite core 15 are housed in a mold, and the connector 10, the cable 12, and the ferrite core 15 are integrally joined by filling and curing a molten resin such as polypropylene. It has been considered that the relative behavior is regulated.

The appearance and feel of the primary molded product including the ferrite core fixed to the cable in this manner are not so good, and then, as shown in FIG. It is conceivable that the primary molded product 17 covered with the above resin is arranged in the mold 24, a second resin such as PVC is injected from the gate 26 and cured, and the outer periphery of the primary molded product is secondarily molded and finished. Have been.

[Problems to be solved by the invention]

However, the primary molded article 17 is not
In the case where the secondary molding is performed by disposing the primary molding 17 in the mold 24, the primary molded product 17 is pushed and shaken by the resin pressure as shown by a dashed line in FIG. Can be Then, when the resin for secondary molding is cured in such a state, the thickness of the resin around the primary molded product 17 becomes uneven, and the appearance thereof may be significantly impaired.

In view of the above, the present invention provides a method of fixing a noise prevention core that is prevented from being biased by resin pressure when secondary molding is performed on the outer periphery of a primary molded product with a resin. The purpose is to provide.

[Means for solving the problem]

In order to achieve the above-mentioned object, a method for fixing a noise preventing core according to the present invention is to form a primary ferrite core with a first resin in a state where a cylindrical ferrite core for noise prevention is externally fitted to a cable. A pin guide hole is provided at a predetermined position of the primary molded product when the outer periphery of the ferrite core fixed and covered with the first resin is secondarily molded and finished with the second resin. The secondary molding die is provided with an anti-sway locking pin inserted into the pin guide hole of the primary product, and the primary molding is fixed by the anti-sway locking pin to perform secondary molding. To be.

(Operation)

According to the method for fixing the noise prevention core according to the present invention having the above-described configuration, the primary molded product is locked in the mold by the anti-sway locking pin, and the secondary molded product is fixed in the mold. Since the resin is injected and the resin molding is performed, the primary molded product is prevented from being displaced by the resin pressure, and the periphery of the primary molded product is evenly covered with the resin for the secondary molding to finish.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In carrying out an example of the method for fixing the noise prevention core according to the present invention, the connector (mini-din connector) 10 is used as in the case shown in FIGS. 3 and 4 described above.
A cylindrical ferrite core 15 is externally fitted to one end of a cable 12 connected to the cable, and the inner and outer circumferences of the ferrite core 15 are further wound by the cable 12.

Then, the ferrite core 15 and the connector 10 fixed to the cable 12 in this manner are arranged in a mold 20 as shown in FIG. 1, and a resin for primary molding (polypropylene or the like) is discharged from the gate 22. Fill and do primary molding (injection molding)
The connector 10, the cable 12, and the ferrite core 15 are integrally connected and fixed to obtain a primary molded product 17 as shown in FIG.

In this case, the primary molded article 17 is provided with pin guide holes 19 at upper and lower two places on the outer periphery by an appropriate method at or after the primary molding (see FIG. 2).

Next, the primary molded article 17 is placed in a mold 24 shown in FIG. 2 to perform secondary molding. In this case, the mold 24 is composed of an upper mold and a lower mold, has a cavity for accommodating the primary molded product 17, and has a locking pin for steadying which is inserted into a pin guide hole 19 provided in the primary molded product 17. 21 are provided.

In this manner, the primary molded product 17 is placed in the mold 24, and the locking pin 21 for steadying is inserted into the pin guide hole 19 and fixed. Fill and cure the resin. Thereby, the outer periphery of the primary molded product 17 is uniformly covered with the resin for secondary molding and finished.

As described above, in the present embodiment, the resin is injected into the mold 24 and the secondary molding is performed in a state in which the primary molded product 17 is locked by the locking pin 21 for steadying. Is prevented from being displaced by the resin pressure, and the appearance and feel of the secondary molded product can be satisfactorily finished.

In the above example, the ferrite core 15 and the connector 10
The case where the ferrite core 15 is fixed to the cable 12 only by resin molding is similarly applicable to the method for fixing the noise prevention core according to the present invention.

〔The invention's effect〕

As is apparent from the above description, according to the method for fixing the noise prevention core according to the present invention, the primary molded product is locked in the mold by the anti-sway locking pin, and the secondary molded product is fixed in the mold. Since the resin is injected and the resin molding is performed, the primary molded product is prevented from being displaced by the resin pressure, and the resin for the secondary molding is uniformly coated around the primary molded product, and as a result, the appearance and the like are improved. Good texture is achieved.

[Brief description of the drawings]

1 and 2 are views for explaining an example of a method for fixing a noise prevention core according to the present invention, and FIGS. 3 and 4 are views for explaining a conventional method for fixing a noise prevention core. FIG. 10… Connector, 12… Cable, 15… Ferrite core, 17 …… Primary molded product, 19 …… Pin guide hole, 20,24 …… Die, 21 …… Stabilizing locking pin, 22, 26 ... The gate.

Claims (1)

(57) [Claims] In a state in which a cylindrical ferrite core for preventing noise is externally fitted to a cable, it is primarily molded with a first resin and fixed to the table, and then covered and fixed with the first resin. When the outer periphery of the ferrite core is secondarily molded and finished with the second resin, a pin guide hole is provided at a predetermined position of the primary molded product, and the pin guide hole of the primary molded product is provided in a mold for secondary molding. A method for fixing a noise preventing core, comprising: providing a steady-state locking pin to be inserted into the core;