JPS5826624B2 - How to connect the cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for connecting rubber or plastic cables using a mold.

Recently, among mold connection methods, the development of an injection molding method using extrusion material has been progressing.

Among these methods, the conventional method (Fig. 1) is to connect the cable conductor 12 of the cable 10 and place a mold around it.
4, and a reinforcing insulator 18 was formed by press-fitting heated and melted PE, uncrosslinked PE to which a crosslinking agent was added, etc. using an injection machine 16, and then cooling.

However, in this method, since the press-in port 20 is located in the center of the mold 14, (1) the cable 10 is easily bent and bent toward the opposite side of the press-in port 200 (Fig. 2); (2) the press-fitted plastic There was a problem in that, since these substances flow as shown by the dotted line in FIG. 2, they tend to get caught in the lower side of the cable conductor 12 and cause voids.

This invention provides a solution to these problems, and the mold 1
A press-in port 20 is provided at one end of the cable 10 at the part surrounding the cable 10.
By press-fitting softened plastic or the like in a direction parallel to the cable axis, cable eccentricity and entrainment voids can be prevented.

FIG. 3 schematically shows an example of a molding apparatus used for carrying out the present invention.

10 is a cable, 12 is a cable conductor, 13 is a conductor connection portion, and 14 is a mold.

The press inlet 20 is provided in a concentric cylindrical shape at one end of the mold 14, surrounding the cable 10 (FIG. 4).

For example, a circular die 22 is connected to the side of the mold 14 as an auxiliary means for press-fitting plastic or the like.

FIG. 5 shows this part particularly enlarged.

The circular die 22 includes, for example, a main body 24 and an adapter 26.
Consists of.

The adapter 26 is a thin cylindrical portion 2 surrounding the cable 10.
60 and a flange 262 formed at the end thereof, and the flange 262 is fixed to the main body 24 by bolts 28.

Additionally, the entire circular die 22 is secured to the mold 1 with bolts 30.
It is fixed to the end face of 4.

32 indicates a patch. Injector 16 into circular die 2
2, and heat-melted PE, uncrosslinked PE added with a crosslinking agent, etc. are press-fitted in the same manner as in the conventional method.

The PE changes its flow in the cable axial direction within the circular die 22 and is press-fitted into the mold 14 through the press opening 20.

Although the press-fitted PE and the like are subjected to a slight downward force due to their own weight in the mold 14, they flow in the axial direction of the cable and do not push or bend the cable downward as in the conventional case.

Furthermore, since there is no part that disturbs the flow of PE or the like, the possibility of entrainment voids occurring is reduced.

Test results have proven that the eccentricity ratio (minimum thickness/maximum thickness x 100%) by the method of this invention has been improved to over 90%, compared to the conventional average of about 50. .

Next, another example will be shown.

In the case of FIG. 6, a vacuum hole 34 is provided on the opposite side of the press inlet 20, and PE or the like is press-fitted into the mold 14 in the cable axial direction while vacuum suction is being carried out through the hole.

This reduces the possibility of voids occurring.

In the case of the seventh housing, in order to prevent the generation of voids due to contraction of the reinforcing insulator 18 during cooling, it can be pressurized.

Reference numeral 36 denotes the pressurizing device, which includes a cylinder 360, a piston 362, etc., which communicate with the cavity in the mold 14.

The cylinder 360 is filled with an insulating material of the same quality as the reinforcing insulator 18 .

During cooling, pressurized gas or oil 3 is placed in the upper chamber of the piston 362.
64, which applies a constant and determined pressure to the reinforcing insulator 18.

In this invention, since heat-softened rubber or plastic is press-fitted from one end of the mold in a direction parallel to the cable axis, eccentricity of the cable and occurrence of entrainment voids can be prevented as described above.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the conventional injection molding method, Fig. 2 is an explanatory diagram of eccentricity, Figs. 3 to 5 are for showing an embodiment of the present invention, and Fig. 3 is a schematic explanatory diagram of the device. ,
FIG. 4 is a cross-sectional view taken along the line ■--■ in FIG. 2, FIG. 5 is an enlarged cross-sectional view of the circular die 22, and FIGS. 6 and 7 are explanatory diagrams of different embodiments of the present invention. 10... Cable, 12... Cable conductor, 14... Conductor connection part, 16...
Injection machine, 18...Reinforcement insulator, 20...
- Pressure inlet, 22...Circular die.

Claims (1)

[Claims] 1. The cable conductor 12 of the cable 10 is connected, a mold 14 is placed over the periphery of the cable conductor 12, and rubber or plastic softened by heating is press-fitted into the inside of the mold 14 to form a reinforcing insulator 18. When making the connection, the mold 1
A method for connecting cables, characterized in that a press-in port 20 is provided in a portion surrounding the cable 10 at one end of the cable 10, and the rubber or plastic is press-fitted therethrough in a direction parallel to the axial direction of the cable 10. 2. The cable connection method according to claim 1, wherein the rubber or plastic is press-fitted while vacuum suction is applied from the opposite side of the press-in port 20.