Strand for wiring harness and wiring harness

#The present invention relates to a strand for a wiring harness and a wiring harness. This application claims priority to Japanese Patent Application No. 2016-222989 filed on Nov. 16, 2016, and the entire contents of the Japanese Patent Application are incorporated herein by reference.

#Wiring harnesses are used to enable electric power supply, transmission, etc. in mechanical equipment such as automobiles. For example, a wiring harness has a structure in which connectors are disposed at terminal portions of a conducting wire portion made of copper, which is an electric conductor.

#A conducting wire portion of a wiring harness requires not only low electrical resistance but also a strength that can ensure durability. Using copper or a copper alloy as a material for a conducting wire portion provides a conducting wire portion with low electrical resistance. However, to provide the conducting wire portion with sufficient strength, the conducting wire portion made of copper or a copper alloy needs to be somewhat thick. This increases the amount of copper used. To address this, strands for wiring harnesses obtained by twisting together a first element wire made of stainless steel and a second element wire made of copper or a copper alloy have been proposed (see, for example, PTLs 1 and 2). These can provide a strand, which reduces the amount of copper used and achieves both strength and conductivity, for a wiring harness.

#FIG. 1 is a schematic sectional view of a section perpendicular to the longitudinal direction of a strand for a wiring harness according to a first embodiment.

#FIG. 2 is a schematic sectional view of the structure of the vicinity of a boundary portion between a core portion and a covering layer.

#FIG. 3 is a schematic sectional view of a section perpendicular to the longitudinal direction of a strand for a wiring harness according to a second embodiment.

#In producing a wiring harness, one conducting wire portion and another conducting wire portion may be joined (splice joint method) to form a branch. The joining of the conducting wire portions can be performed, for example, by ultrasonic welding. However, if the strands for wiring harnesses disclosed in PTLs 1 and 2 are used as conducting wire portions, they are disadvantageously difficult to join by ultrasonic welding.

#Thus, an object of the present invention is to provide a strand, which is able to reduce the amount of copper used, achieve both strength and conductivity, and facilitate joining by ultrasonic welding, for a wiring harness, and a wiring harness.

#The above-described strand for a wiring harness can reduce the amount of copper used, achieve both strength and conductivity, and facilitate joining by ultrasonic welding.