Inter-wire connection structure and method for manufacturing the same

A method for manufacturing an inter-wire connection structure for connecting a first wire and a second wire, the first wire including a first core formed by a plurality of first wire elements and a first insulating sheath surrounding the first core, and the second wire including a second core formed by a plurality of second wire elements and a second insulating sheath surrounding the second core, the method comprising:

• exposing a portion of the first core and the second core from the first insulating sheath and the second insulating sheath, respectively;
• performing a single-wire process on the plurality of first wire elements of the first core exposed to form a single-wire structure section in which the first wire elements are joined together;
• joining the single-wire structure section of the first core exposed and the second core exposed to form a core joint section having an outer peripheral surface formed in a continuously circular shape such that at least a portion of the single-wire structure section as formed extends outside of the core joint section wherein the portion of the single-wire structure section is left at the outside of the core joint section;
• and
• covering the first core exposed and the second core exposed with an insulating tube including the single-wire structure section of the first core as formed and the core joint section of the first core and the second core as formed, and further covering portions of the insulating sheath located at both outsides of the first core exposed and the second core exposed with the insulating tube, and shrinking the insulating tube after covering,
• wherein the insulating tube directly contacts at least the first core and the second core of the core joint section with no spacing therebetween;
• wherein forming the single-wire structure section comprises forming an outer peripheral surface of the single-wire structure section in a continuously circular shape;
• and
• wherein at least an outer portion of the first wire and at least an outer portion of the second wire are formed from different materials.