1. Field of the Invention
The present invention relates to a method of producing a winding of a dynamo-electric machine such as an on-vehicle alternating current generator or the like mounted on passenger's automobiles or auto trucks.
2. Description of Related Art
Recently, improvement of generating ability of an on-vehicle alternating current generator has been increasingly required with an increase of current consumers such as a safety control device and the like. To respond to this request of the improvement of the generating ability, a method of producing a winding of a dynamo-electric machine is known. In this method, high power is obtained by arranging regularly electric conductors formed in a U-shape to place the electric conductors at high density in slots of a stator (for example, pp. 3 to 5 and FIGS. 1 to 19 in Published Unexamined Japanese Patent Application Publication No. 2001-69731). In this winding producing method, electric conductors arranged along a circumferential direction of a stator core are protruded from an end surface of the stator core to form coil ends, a plurality of pin-shaped jigs adjacent to each other along the circumferential direction are respectively inserted into predetermined areas in a radial direction of the stator core so as to fix the protruded portions of the electric conductors, tops of the electric conductors are twisted in the circumferential direction while using the pin-shaped jigs formed in a circular shape in section along the circumferential direction as a supporting point, and the coil ends are reshaped.
In the dynamo-electric machine's winding producing method disclosed in the Patent Application Publication, because the electric conductors are twisted while using the pin-shaped jigs as the supporting points, damage to insulating coats of the electric conductors at bending portions of the electric conductors can be prevented. However, because the pin-shaped jigs are inserted into the areas apart from the end surface of the stator core, a problem occurs in that the coil ends become taller. Because the coil ends are taller, the winding is lengthened so as to increase the resistance of the winding, and the output power of the dynamo-electric machine is undesirably lowered.