JPS626288B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a multicore electric wire.

For example, as shown in Fig. 1, multi-core electric wires, which are made by twisting two or more insulated wire cores 1 and applying a solid protective sheath 2 on them, have already been used in various types of cab tire cables, etc. Widely used.

However, in this type of multicore wire,
I had the following problem:

In other words, although the thickness of the sheath is originally good in part (a), it is forced to have a circular cross section as a whole, and the other parts (b) and (c) have excessive thickness but cannot be stopped. This is something that was considered impossible to obtain. Furthermore, when covering the sheath 2, the insulator 3 of each insulated wire core 1 sometimes melted and deformed at its contact portion 4 as shown in Fig. 2 due to its thermal history and pressure. In many cases, the thickness of the insulator in the portion 4 is likely to be less than the specified value, and as a result, the product is likely to be branded as a defective product.

The present invention aims to provide a useful manufacturing method for multicore electric wires that can solve the above-mentioned difficulties, and its gist is to assemble a large number of conductive wires without twisting them together. In the method for manufacturing a multicore electric wire, in which a plurality of insulated wire cores made by extruding an insulator on the circumference of a conductor are assembled or twisted together, and then a protective sheath is provided on the circumference of these wires, each of the above-mentioned After forming the insulator, the conductor and insulator are sequentially compression-molded using a specified compression tool while the insulator is still soft, and when the insulated wire cores are assembled or twisted together, each wire The point is that a step is provided for deforming the cross-sectional shape so that the hearts come into surface contact with each other.

The reason why a conductor made of a large number of conductive wires assembled without twisting is used is to facilitate deformation during compression molding.

Next, one embodiment of the present invention will be described with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to this embodiment.
Now, in FIG. 3, first, an insulator 3 is placed on the circumference of a conductor 5, which is made by gathering a large number of conductive wires without twisting them, using a predetermined extruder (not particularly shown).
After forming the insulator, the plurality of insulated wire cores 1, 1 [see figure A] formed by extrusion are passed through a predetermined compression roll 6 while the insulator 3 is still soft, and compressed as shown in the figure. Shape [see figure B]. ]. That is, here, each insulated wire core 1 is compressed together with the conductor 5 and insulator 3 by the compression roll 6, and when each insulated wire core 1 is assembled or twisted as described later, each wire core 1 is It is deformed into a cross-sectional shape such that the comrades are in surface contact with each other.

Next, each insulated wire core 1 is introduced into a drawing die 7, where each insulated wire core 1 is assembled or twisted together so that they are in surface contact with each other, and then again by an extruder (not particularly shown). As shown in FIG. 4, the protective sheath 2 is formed by extrusion on the periphery, and this operation is completed.

Note that FIGS. 5 and 6 show multicore electric wires manufactured according to other embodiments of the present invention.

According to this embodiment carried out as described above, after forming the insulator 3 on each of the insulated wire cores 1 before assembling or twisting the insulated wire cores 1 together, the insulator 3 still remains. The conductor 5 and the insulator 3 are sequentially compression-molded using a predetermined compression roll 6 while still soft, so that when the above-mentioned insulated wire cores 1 are assembled or twisted together, the wire cores 1 are in surface contact with each other. Since the cross-sectional shape is deformed, it is possible to solve the problem that the insulator 3 of each insulated wire core 1 is melted and deformed at its contact portion when the protective sheath 2 is later covered.

In particular, according to this embodiment, since the compression molding of the insulated wire core 1 is carried out at a time when the insulator 3 is still soft after the formation of the insulator 3, the deformation of the insulated wire core 1 can be performed extremely smoothly.

Further, the valley portion between each insulated wire core 1 becomes particularly small, and therefore, in the sheath 2, the excessively thick portion as a whole becomes extremely small.

As described above, the present invention essentially eliminates the difficulties mentioned at the beginning by skillfully adding a relatively simple process called core compression molding to the middle of the conventional manufacturing method. , therefore its practical value is extremely large.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of a conventional multi-conductor electric wire of this type, FIG. 3 is an explanatory diagram of an embodiment of the method for manufacturing a multi-conductor electric wire of the present invention, and FIG. 4 is an explanatory diagram of a multi-conductor electric wire manufactured by the above manufacturing method. FIGS. 5 and 6 are completed views of multi-core electric wires manufactured by manufacturing methods based on other embodiments, respectively. 1: Insulated wire core, 2: Protective sheath, 3: Insulator,
5: Conductor, 6: Compression roll, 7: Drawing die.

Claims (1)

[Claims] 1 A plurality of insulated wire cores made by extruding an insulator on the circumference of a conductor made by gathering a large number of conductive wires without twisting them together or twisting them together, and then a protective sheath is placed on the circumference of these wires. In the method for manufacturing a multicore electric wire, each of the insulated wire cores, after forming the insulator, sequentially compression molds the conductor and the insulator using a predetermined compression tool while the insulator is still soft, and then A method for producing a multicore electric wire, comprising the step of deforming the insulated wire cores into a cross-sectional shape such that the wire cores come into surface contact with each other when assembled or twisted together.