Abstract: A contactless charging coil unit includes a base member with an upper surface having a coil housing portion formed therein in a spiral shape in a direction from the central portion to the outer periphery side; a coil formed by winding a litz wire along the coil housing portion, the litz wire having been obtained by twisting together a plurality of round wires each having a circular cross-section and covered with an insulating film; a covering member adapted to cover an upper portion of the base member, the covering member having a lower surface with a projection corresponding to and fittable into the coil housing portion of the base member; and a sealing material for firmly fixing the coil between the base member and the covering member to form a watertight seal.

Abstract: A manufacturing method of a rectangular wire bundle product includes a bending step of bending an assembled wire composed of a plurality of strand wires having an insulating film into a predetermined shape, a rectangular shape formation step of forming the assembled wire bent into the predetermined shape in the bending step into a rectangular shape so that a cross section becomes a rectangular shape, and an integration step of integrating at least a part of the assembled wire formed into the rectangular shape in the rectangular shape formation step by thermal bonding.

Abstract: A method of manufacturing a high-density coil formed by press working a coil to cope with the manufacture of high-density coils having various cross-sectional shapes. The method includes: a step of setting the coil at a predetermined press working position in a press working machine; and a step of sequential press working the coil, which is set at the predetermined press working position, in a plurality of directions sequentially with a time lag.