Production method for insulated electric wire and insulated electric wire

Patent metadata

Field	Value
Publication number	US-11657928-B2
Application number	US-202217729432-A
Country	US
Kind code	B2
Filing date	Apr 26, 2022
Priority date	Jul 26, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

An insulated electric wire includes a conductor comprising twisted elemental wires and an insulation covering. The insulated electric wire includes an exposed portion in which the insulation covering is removed from the outer surface of the conductor, and a covered portion in which the insulation covering covers the outer surface of the conductor. The exposed portion and the covered portion are adjacent with each other along a longitudinal axis of the insulated electric wire. A density of the conductive material per unit length is higher in the exposed portion than in the covered portion. The elemental wires are twisted in both the exposed portion and the covered portion including an area that is positioned away from the exposed portion by at least a distance corresponding to a length of the exposed portion. Gaps between the elemental wires of the exposed portion are filled with a sealant.

First claim

The invention claimed is:

1. An insulated electric wire comprising:
a conductor comprising a plurality of twisted elemental wires made of a conductive material, and
an insulation covering covering an outer surface of the conductor, the insulated electric wire comprising:
an exposed portion in which the insulation covering is removed from the outer surface of the conductor, and
a covered portion in which the insulation covering covers the outer surface of the conductor, wherein:

the exposed portion and the covered portion are adjacent with each other along a longitudinal axis of the insulated electric wire,
a density of the conductive material per unit length is higher in the exposed portion than in the covered portion,
the elemental wires are twisted in both the exposed portion and the covered portion including an area that is positioned away from the exposed portion by at least a distance corresponding to a length of the exposed portion, and
gaps between the elemental wires of the exposed portion are filled with a sealant made of an insulated material.

2. The insulated electric wire according to claim 1 , wherein
a twist pitch of the elemental wires is smaller in the exposed portion than in the covered portion.

3. The insulated electric wire according to claim 1 , wherein
in the exposed portion, the sealant further covers the outer surface of the conductor, and
a portion of the sealant covering the outer surface of the conductor and a portion of the sealant filling the gaps between the elemental wires in the exposed portion are continuous.

4. The insulated electric wire according to claim 3 , wherein
the sealant further covers an outer surface of the insulation covering at an end portion of the covered portion adjacent with the exposed portion, and
a portion of the sealant covering the outer surface of the insulation covering and the portion of the sealant covering the outer surface of the conductor in the exposed portion are continuous.

5. The insulated electric wire according to claim 1 , wherein
a density of the conductive material per unit length in the exposed portion is 1.01 times of a density of the conductive material per unit length in the area of the covered portion or higher.

6. The insulated electric wire according to claim 1 , wherein
a density of the conductive material per unit length in the exposed portion is 1.50 times of a density of the conductive material per unit length in the area of the covered portion or lower.

7. The insulated electric wire according to claim 1 , wherein
the exposed portion is placed at a middle portion along the longitudinal axis of the insulated electric wire.

8. The insulated electric wire according to claim 1 , wherein
the sealant comprises a curable resin composition.

9. The insulated electric wire according to claim 1 , wherein
the elemental wires are twisted in entirety of the exposed portion and the covered portion.

10. A production method for producing the insulated electric wire of claim 1 , the method comprising:
a partial exposure step of forming an exposed portion in which the insulation covering is removed from the outer surface of the conductor, and a covered portion in which the insulation covering covers the outer surface of the conductor, with the exposed portion and the covered portion adjacent with each other along a longitudinal axis of the insulated electric wire;
a density modification step of increasing spacing between the elemental wires in the exposed portion, while increasing a density of the conductive material per unit length in the exposed portion; and
a filling step of filling gaps between the elemental wires in the exposed portion with a sealant comprising an insulated material.

11. The production method according to claim 10 , wherein
in the density modification step, a tightening step of tightening a twist of the elemental wires in the exposed portion is performed, and then a loosening step of loosening the twist of the elemental wires in the exposed portion is performed, whereby the spacing between the elemental wires in the exposed portion is increased while the density of the conductive material per unit length in the exposed portion is increased.

12. The production method according to claim 10 , wherein
the exposed portion is provided at a middle portion along the longitudinal axis of the insulated electric wire.

13. The production method according to claim 10 , wherein
a retightening step of reducing the spacing between the elemental wires of the exposed portion is further performed after the filling step.

14. The production method according to claim 13 , wherein
by the retightening step, a twist pitch of the elemental wires in the exposed portion is made smaller than in the covered portion.

15. The production method according to claim 13 , wherein
the sealant comprises a curable resin composition, and
after the filling step is performed with use of the sealant, the retightening step is performed before or during curing of the sealant.

16. The production method according to claim 10 , wherein
in the filling step, the sealant further covers the outer surface of the conductor, and a portion of the sealant covering the outer surface of the conductor and a portion of the sealant filling the gaps between the elemental wires are continuous in the exposed portion.

17. The production method according to claim 16 , wherein
after the filling step, a covering movement step is performed in which the insulation covering in the covered portion is moved toward the exposed portion to contact an end portion of the insulation covering with the sealant disposed in the exposed portion, whereby an outer surface of the exposed portion becomes covered with the sealant continuously together with an outer surface of the insulation covering of the end portion in the covered portion continuously.

18. The production method according to claim 10 , wherein
the filling step is performed with the sealant having a viscosity of 4000 mPa·s or higher.

Assignees

• Autonetworks Technologies Ltd
• Sumitomo Wiring Systems
• Sumitomo Electric Industries

Inventors

• Furukawa Toyoki

Classifications

• H01B13/02

  Stranding-up · CPC title

• H01B7/02

  Disposition of insulation · CPC title

• H01B13/00 Primary

  Apparatus or processes specially adapted for manufacturing conductors or cables · CPC title

• H01B13/0036

  Details · CPC title

• H01B7/285 Primary

  by completely or partially filling interstices in the cable · CPC title