JP2000078737A - Molding method of cable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molding method of cable terminal suitable for plug-in connection. SOLUTION: A plug 4 is compression connected with a conductor 3 exposed by removing an insulation layer 2 from the end part of a cable 1, a metal mold 6 is arranged from the plug 4 part to the cable insulation layer 2 part and rubber or plastic is injected into the metal mold 6 thus molding a cable terminal. In such a molding method, a seal 5 is applied onto the cable insulation layer 2 at the forward end part of the metal mold 6 and a rubber or plastic overflow hole 7 is made at a required part of the metal mold 6. Leakage of molding material from the forward end part of the metal mold 6 is suppressed through action of the seal and the overflow hole and shifted flow is prevented. When the seal 5 is applied using a seal ring, the molding material intrudes between the seal 5 and the insulation layer 2 and the seal ring is pressed by the ejected molding material thus enhancing adhesion between the mold and the insulation layer 2. When a tape is applied, the seal ring is pressed by the ejected molding material and adheres firmly to the insulation layer 2. In any case, it is prevented from being peeled off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a cable terminal portion suitable for plug-in connection.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a method of molding a cable terminal portion used for plug-in connection is to remove an insulating layer 2 at a cable 1 terminal portion and to expose an exposed conductor 3 to a cylindrical shape having both ends open. The mold 6 is connected to one end of the plug 4 by compression, and then the mold 6 is placed at the cable end portion composed of the plug 4, the exposed conductor 3, and the cable insulating layer 2 to which the exposed conductor 3 is compression-connected,
Mold material (rubber or plastic) in the mold 6
Is injected and filled by an injection molding machine, and then the mold material 8 is vulcanized, the mold 6 is removed, and burrs at the end of the mold are removed. In FIG. 3, reference numeral 12 denotes a molding material injection port.

[0003]

However, as shown in FIG. 4, a molded article obtained by the conventional molding method has a one-sided flow defect 11 in which the molding material flows out to one side of the cable, or the molding end has a cable end. There is a problem that a peeling defect (not shown) that peels off from the insulating layer easily occurs. The one-sided flow defect is caused by a slight axis deviation between the mold and the cable, and the mold having the one-sided flow defect is liable to peel off. For this reason, the present inventors have conducted intensive research on prevention of defects such as one-sided flow and peeling, and the defects are sealed on the insulating layer of the cable located at the tip of the mold, and They found that this could be prevented by providing an overflow hole in the mold material, and continued further research to complete the present invention. An object of the present invention is to provide a method of molding a cable terminal portion which can prevent the above-mentioned defects such as one-sided flow and peeling without requiring major equipment remodeling.

[0004]

According to the first aspect of the present invention,
A cable end portion in which a plug is compression-connected to an exposed conductor by removing an insulating layer at a cable end portion, a mold is arranged from the plug portion to the cable insulating layer portion, and rubber or plastic is injected and filled in the mold. Wherein a seal is provided on a cable insulating layer located at the tip of the mold, and a rubber or plastic overflow hole is provided at a required portion of the mold. Is the law.

According to a second aspect of the present invention, there is provided the method for molding a cable terminal portion according to the first aspect, wherein the material of the seal is the same as that of a molding material.

According to a third aspect of the present invention, there is provided the method of molding a cable terminal portion according to the second aspect, wherein a tape-shaped sealing material is wound around the cable insulating layer to perform sealing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a method of sealing on a cable insulating layer includes a method of fitting a ring-shaped sealing material (referred to as a sealing ring) to a cable, and a method of applying a tape-shaped sealing material to a cable. A method of winding on an insulating layer or the like is applied. The latter method of winding a tape is advantageous because it can be easily applied to cables of various sizes. Teflon, silicone rubber, nylon, rubber, or the like is used for the sealing material. In the present invention, when a material different from the mold material is used for the seal material, the seal adversely affects the electrical characteristics of the mold as foreign matter after molding. Therefore,
The seal is removed after it has completed its role after molding. On the other hand, when the same material as the molding material is used for the sealing material, the sealing material can be used as it is without removing the seal, thereby saving material costs and reducing man-hours.
The shape, number, and location of the overflow holes are appropriately designed depending on the type of the mold material, the shape of the mold, and the like.
In particular, the installation location is effective at the tip of the mold.

According to the present invention, the mold material is prevented from flowing out of the mold end portion by the seal provided on the cable insulating layer at the mold end portion, and the mold material is formed by the overflow hole provided at a required portion of the mold. The pressure in the mold of the material is properly controlled, and these effects prevent a one-sided flow defect. In the present invention, when sealing is performed using a seal ring, the mold material penetrates between the seal ring and the insulating layer, and then the seal ring is pressed by the injected mold material to improve the adhesion between the mold and the insulating layer. When a seal is applied by wrapping a tape of the same material as the mold, the seal is pressed by the injected mold material and adheres firmly to the insulating layer, preventing the mold from peeling from the cable insulating layer in any case. Is done.

Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 1 is an explanatory longitudinal sectional view showing a first embodiment of the molding method of the present invention. The conductor 3 is exposed by removing the insulating layer 2 of the cable 1, the plug 4 is compression-connected to the exposed end of the conductor 3, and a predetermined position on the insulating layer 2 (corresponding to the end of a mold to be disposed later) Position), a Teflon-made seal ring 5 is fitted, and then a mold 6 is arranged at a cable terminal portion including the plug 4, the exposed conductor 3, and the cable insulating layer 2. The mold 6 is provided with an overflow hole 7 at its tip.

EP rubber (mold material) 8 is placed in the mold 6.
After pressurizing and vulcanizing, the mold 6 was removed, the Teflon-made seal ring 5 was cut and removed, and burrs were further removed to obtain a molded product. The obtained molded body was of good quality without defects such as one-sided flow and peeling. The reason why there is no one-sided flow defect is that the seal ring 5 and the overflow hole 7
This is because the leakage of the EP rubber 8 from the tip of the mold 6 is suppressed by both of the above operations. The reason that there is no peeling defect is that the EP rubber 8 penetrates between the seal ring 5 and the insulating layer 2, and the seal ring 5 is pressed by the injected EP rubber 8, and the EP rubber 8 is firmly attached to the insulating layer 2. This is because they adhered.

FIG. 2 is an explanatory longitudinal sectional view showing a second embodiment of the molding method of the present invention. In this molding method, an EP rubber tape 9 was wrapped around the cable insulating layer 2 to seal it, and otherwise the same as the molding method shown in FIG. No defects such as one-sided flow and peeling were observed in the molded article obtained by this method. The reason why there was no peeling in this case was that the seal 10 wound around the tape 9 was pressed by the injection molding material and was tightly adhered to the cable insulating layer 2.
In addition, the seal material is the same as that of the mold material.
Because of the P rubber, the seal 10 did not need to be removed after molding, and the productivity was excellent. In addition, since the tape 9 is wound and the seal 10 is applied, it is possible to easily cope with various cable sizes.

The same effect as shown in FIG. 2 can be obtained even if sealing is performed using a seal ring made of EP rubber.

In the present invention, if the shape of the seal is made into an arrow blade shape as shown in FIGS. 1 and 2, the movement of the molding material 8 at the end portions of the seals 5 and 10 is suppressed in one direction. It becomes easy to invade between the seal 5 and the cable 1, and the adhesion between the molding material 8 and the cable 1 becomes extremely good.

[0014]

As described above, according to the present invention,
Sealing is performed on the cable insulating layer located at the tip of the mold, and furthermore, an overflow hole of the mold material is provided at a required portion of the mold. Is prevented. When a seal is applied using a seal ring, the mold material enters between the seal and the insulating layer, and the seal ring is pressed against the injected mold material to improve the adhesion between the mold and the insulating layer. When the seal is applied, the seal is pressed against the mold material to be injected and firmly adheres to the insulating layer, and in any case, peeling is prevented. When the seal (seal ring or wrapping tape) is made of the same material as the mold, it is not necessary to remove the seal, so that material costs can be saved and man-hours can be reduced. The method of applying a seal by winding a tape can easily cope with cables of various sizes.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a first embodiment of a molding method of the present invention.

FIG. 2 is an explanatory longitudinal sectional view showing a second embodiment of the molding method of the present invention.

FIG. 3 is an explanatory longitudinal sectional view of a conventional molding method.

FIG. 4 is an explanatory longitudinal sectional view of a conventional molding part.

[Explanation of symbols]

 Reference Signs List 1 Cable 2 Cable insulating layer 3 Exposed conductor 4 Plug 5 Teflon seal ring 6 Mold 7 Overflow hole 8 Mold material 9 EP rubber tape 10 Seal wrapped with tape 11 Single flow defect 12 Mold material injection port.

Claims (3)

[Claims] 1. A plug is compression-connected to a conductor exposed by removing an insulating layer at a cable end, a mold is arranged from the plug portion to the cable insulating layer portion, and rubber or plastic is injected into the mold. In a method of molding a cable end portion to be filled, a cable is provided by providing a seal on a cable insulating layer located at a tip portion of the mold and providing a rubber or plastic overflow hole at a required portion of the mold. Terminal molding method. 2. The method according to claim 1, wherein a material of the seal is the same as a molding material. 3. The method of molding a cable end portion according to claim 2, wherein a tape-shaped sealing material is wound around the cable insulating layer to perform sealing.