JP4079240B2 - Watertight stranded wire and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a watertight stranded electric wire suitable for a signal electric wire to be wired to a body for outdoor use such as an automobile and the like, and a manufacturing method thereof.
[0002]
[Prior art]
As a method of manufacturing a waterproof watertight stranded wire that fills a watertight material between conductor strands in which a plurality of strands are twisted and prevents the intrusion of water components between the strands, for example, Japanese Patent Publication No. 61-173414 There are techniques described. In this case, the twisted conductor wire is once loosened in the next step to fill the gap formed between the wires with a watertight material. After filling with a watertight material, the wire conductor is manufactured by twisting again with a special jig for retwisting.
[0003]
Moreover, in the watertight electric wire manufacturing method described in Japanese Patent Application Laid-Open No. 2-12712, an inner layer is formed by twisting while filling a watertight material between conductor wires, and the conductor element is further filled with a watertight material on the inner layer. The outer layer is formed by twisting the wires. Next, the watertight material is heated and melted with a heater, and the excess watertight material that protrudes from the outer periphery of the conductor wire is scraped off with a special die.
[0004]
In addition, in the method for manufacturing a watertight stranded conductor described in Japanese Patent Laid-Open No. 3-62422, the surface of the conductor wire is covered in advance with a watertight material, and the watertight material on the surface is softened by heating the plurality of conductor wires. Twist together. The twisted product is immediately passed through a special die to make the outer shape circular.
[0005]
Furthermore, in the case of the method for producing a waterproof electric wire described in JP-A-6-84416, air is sucked from one end of the covered electric wire to make the inside of the electric wire negative pressure, and a waterproof insulating shielding agent is sucked between the conductor wires. To be filled.
[0006]
[Problems to be solved by the invention]
By the way, in the prior art disclosed in the above Japanese Patent Publication No. 61-173414, it is inconvenient from the viewpoint of the process to unwind and loosen the conductor wires once twisted in order to fill the watertight material. In addition, since a special tool for retwisting is required, the number of processes and equipment is increased, which is disadvantageous in terms of manufacturing cost.
[0007]
In the case of the prior art disclosed in Japanese Patent Application Laid-Open No. 2-12712, a die dedicated to scraping off the excess water-tight material is required. Considering that multiple types of scraping-only dies are prepared in accordance with the specifications of the outer diameter of the electric wire, the management cost including process and equipment costs will rise.
[0008]
In the prior art disclosed in Japanese Patent Laid-Open No. 3-62422, a complicated facility and process for covering the surface of the conductor wire with a watertight material in advance is required in the previous process. This is disadvantageous.
[0009]
Further, in the prior art found in the above-mentioned JP-A-6-84416, in the case of the law, air for sucking a waterproof insulating shielding agent between conductor wires by making the inside of the electric wire negative pressure Large equipment and processes such as a suction device are required.
[0010]
Accordingly, an object of the present invention is to provide a watertight stranded wire suitable for, for example, an automotive circuit wire that can be manufactured using current facilities and processes and that requires a required waterproof property, and a method for manufacturing the same. is there.
[0011]
[Means for Solving the Problems]
The watertight stranded wire according to claim 1 of the present invention is formed by twisting together a plurality of conductor wires and a watertight material wire having a wire diameter smaller than the wire diameter of the conductor wire made of thermoplastic resin. A twisting step for forming one conductor twisted wire together;
When the conductor stranded wire is sent to an extrusion device and the surface is coated with the insulator, the watertight wire is melted and softened by the heat of fusion of the insulator, and the gap between the conductor strands is formed by the molten watertight material. Including an electric wire extrusion step of filling and sealing the strands with each other,
In the twisting step, a plurality of the conductor strands and the watertight material wires are alternately drawn out from the respective winding bobbins set alternately in the current apparatus and twisted into the conductor twisted wire having an arbitrary wire diameter. It is characterized by matching .
[0015]
The watertight stranded wire according to claim 1 is characterized in that the watertight wire has a wire diameter that can be interposed in a gap generated between the bundled conductor wires.
[0016]
In this case, the wire diameter of the watertight material wire is set to a suitable diameter that is sufficiently smaller than the wire diameter of the conductor wire and that can effectively seal the gap between the conductor wires.
[0017]
Method for manufacturing a watertight stranded wire according to claim 1 according to the present invention, rather than the wire diameter of the conductor wire by the conductor wires and the thermoplastic resin composed of a plurality of respective watertight material wire made small line diameter Are twisted together to form a single conductor stranded wire, and when the conductor stranded wire is sent to an extrusion device to coat the surface with an insulator, the watertight material wire is heated by the heat of fusion of the insulator. A wire extruding step of filling the gap between the conductor strands with this molten watertight material and sealing the strands with each other, and the stranded wire step is a current apparatus. A plurality of the conductor strands and the watertight material wires are alternately drawn out from the respective winding bobbins set alternately to each other and twisted on the conductor stranded wire having an arbitrary wire diameter.
[0018]
Through the above steps, the conductor wire and the watertight material wire are twisted together, and the watertight material wire is softened using the heat of fusion at the time of covering the insulator, so the conventional sealing material filling step, after twisting The excessive sealing material scraping process that protrudes outside the conductor stranded wire, a dedicated jig for scraping, and a special heater device are unnecessary, and can be manufactured using the current apparatus and process.
[0020]
That is, using a current conductor stranding device or the like, a watertight material wire is alternately set with the conductor strand and fed out to obtain one conductor twisted wire with a watertight material wire interposed in advance. It is done.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a watertight stranded wire and a method for manufacturing the same according to the present invention will be described in detail with reference to the drawings.
[0024]
FIG. 1 is a side view schematically showing a process line for manufacturing the watertight stranded wire of the present embodiment. As shown in FIGS. 2 (a) and 2 (b), a twisted wire process line (A) is provided with a twisted wire device and the like, and the conductor wire 1 having the number and the wire diameter corresponding to the wire diameter specification of the manufactured wire is shown in FIGS. Each of them is wound up on a bobbin 2 and prepared. Further, here, watertight material wires 3 made of a plurality of thermoplastic resins having a wire diameter sufficiently smaller than the wire diameter of the conductor wire 1 are simultaneously wound around a dedicated bobbin 4 and prepared. The bobbin 2 of the conductor wire 1 and the bobbin 4 of the watertight material wire 3 are arranged at equal intervals alternately on a circle.
[0025]
That is, in FIG. 2 (a), the conductor wire 1 and the watertight wire 3 are radially drawn out from the bobbins 2 and 4 by such a twisted wire device, twisted into one conductor twisted wire 5, and wound up once. The drum 6 is wound up.
[0026]
As the twisted wire device, the existing device can be used almost as it is without installing a special mechanism, and the bobbin 2 of the conductor wire 1 and the bobbin 4 of the watertight material wire 3 are alternately arranged around the circumference of the existing feeding drum. It is only necessary to arrange them so that they can be twisted out from each bobbin.
[0027]
On the other hand, in the wire extruding process line indicated by the symbol (B) in FIG. 1, the wire extruding device 10 shown in FIGS. 3 (a) and 3 (b) is disposed. The electric wire extrusion device 10 includes an extrusion screw mechanism 11 and an extrusion head mechanism 15.
[0028]
The extrusion screw mechanism 11 is provided with a material port 13 for supplying a compound molten material made of, for example, PVC (polyvinyl chloride), which serves as a covering insulator of an electric wire, at the rear end portion of the main body 12. (Not shown) can be operated to propel the compound molten material forward and feed it into the extrusion head mechanism 15.
[0029]
The extrusion head mechanism 15 is a single nozzle that feeds the compound molten material supplied from the extrusion screw mechanism 11 from the take-up drum 6 shown in FIG. 2 by an ejection nozzle (not shown) built in the main body 16. It is an apparatus for coating the outer peripheral surface of the conductor stranded wire 5. That is, the conductor stranded wire 5 once wound on the winding drum 6 of the stranded wire device is introduced into the head body 16 from the upstream side, and the compound molten material is fused to the outer peripheral surface of the conductor stranded wire 5. As shown to (b), it extrudes as the watertight stranded wire 20 which coat | covered the PVC insulator 7. As shown in FIG.
[0030]
From the above, by the operation of the twisted wire device, the conductor strands 1 and the watertight material wires 3 are drawn out from the alternately arranged winding bobbins 2 and 4 and twisted into one conductor twisted wire 5 to be wound once. It is wound up on the take-up drum 6.
[0031]
FIG. 2 (b) shows a cross section of the conductor wire 1 and the watertight material wire 3 that are twisted and bundled with such a single conductor strand 5. That is, the watertight material wire 3 is uniformly interposed between the plurality of conductor wires 1.
[0032]
Here, an important point is that when the conductor strands 5 are twisted together, a plurality of watertight wires 3 interposed between the plurality of conductor strands 1 are located outside the group bundle of the conductor strands 1. It is to prevent it from protruding (see FIG. 2B). The reason for this is that when the watertight wire 3 is melted and softened in the next process, if it protrudes excessively outside the group bundle of the conductor strands 1, it takes extra work and equipment steps to scrape it off. is there.
[0033]
Subsequently, the conductor stranded wire 5 flows from the winding drum 6 through a drawing line and is sent to the extrusion head mechanism 15 of the wire extrusion device 10 in the wire extrusion process line (B). Here, the PVC insulator 7 in a molten state supplied from the extrusion screw mechanism 11 is coated on the outer peripheral surface of the conductor stranded wire 5.
[0034]
During the coating of the PVC insulator 7, the watertight material wire 3 interposed between the conductor wires 1 is softened at the melting heat temperature, and melted and adhered between the conductor wires 1 to completely block the gap between the wires. The watertight stranded electric wire 20 ensuring the required waterproofness is manufactured. At that time, as shown in FIG. 3B, the softened watertight wire 3 does not protrude into the outer region of the conductor stranded wire 5, and the gap between the plurality of conductor strands 1 and all of the conductor strands 1. Is sealed with the molten watertight material 3a.
[0035]
Further, as is apparent from the manufacturing method shown as the present embodiment, even when the wire diameter specification of the watertight stranded wire 20 is changed, the wire diameter and the number of the conductor wire 1 and the watertight material wire 3 are changed. There is a convenience that can be changed freely. That is, unlike the prior art shown in each of the above-mentioned publications, there is no need to newly add a dedicated tool or equipment, and by using an existing current device, the watertight stranded wire 20 having a different wire diameter specification can be used. Applicable universally.
[0037]
In addition, the method for producing a watertight stranded wire according to the present invention can produce a wire having an arbitrary wire diameter using almost the current apparatus and means, and a single conductor stranded wire by twisting conventional conductor wires. The step of scraping off the sealing agent, that is, the melt-softened watertight material that protrudes outside the conductor stranded wire, is eliminated, and no special die for scraping is required.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically showing a production line for a watertight stranded wire according to the present invention.
FIGS. 2A and 2B are a perspective view showing a twisted wire device according to the present embodiment and a cross-sectional view showing a conductor twisted wire manufactured thereby. FIG.
FIGS. 3A and 3B are a perspective view showing a wire extrusion device according to the present embodiment and a cross-sectional view showing a watertight stranded wire manufactured thereby.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conductor strand 3 Watertight material wire 3a Molten watertight material 2,4 Winding bobbin 5 Conductor twisted wire 6 Winding drum 7 Covering insulator 10 Electric wire extrusion apparatus 15 Extrusion head mechanism 20 Watertight twisted wire (A) Twisted wire process line (B) Electric wire extrusion process line

Claims (1)

A twisting step of twisting together a plurality of conductor wires and a watertight material wire having a wire diameter smaller than the wire diameter of the conductor wire made of thermoplastic resin to form one conductor twisted wire; ,
When the conductor stranded wire is sent to an extrusion device and the surface is coated with the insulator, the watertight wire is melted and softened by the heat of fusion of the insulator, and the gap between the conductor strands is formed by the molten watertight material. Including an electric wire extrusion step of filling and sealing the strands with each other,
In the twisting step, a plurality of the conductor strands and the watertight material wires are alternately drawn out from the respective winding bobbins set alternately in the current apparatus and twisted into the conductor twisted wire having an arbitrary wire diameter. A method for producing a watertight stranded wire, characterized by combining them.

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