Induction heating coil manufacturing apparatus and induction heating coil manufacturing method

1. An induction heating coil manufacturing apparatus comprising:

a winding shaft comprising a quadrangular cross section and a corner, the winding shaft winds a wire around the winding shaft, the wire including stranded wires;

a bending device that bends the wire at a predetermined position at which the wire is to be wound around the corner of the winding shaft so that the bent portion of the wire is predetermined to mate with the corner of the winding shaft before the winding shaft winds the wire at the position around the winding shaft;

a wire supply unit that supplies the wire; and

a feed unit that feeds the wire supplied from the wire supply unit to the bending device,

wherein a controller controls the winding shaft so that the winding shaft rotates in accordance with a feed amount of the wire fed by the feed unit and winds the wire in so that the wire is not under tension between the winding shaft and the bending device.

2. The induction heating coil manufacturing apparatus according to claim 1 ,

wherein the winding device includes

a groove formed in the winding shaft and holding the wire wound around the winding shaft therein, and

a pushing member that pushes the wire into the groove in a direction perpendicular to an axial direction of the winding shaft.

3. The induction heating coil manufacturing apparatus according to claim 1 ,

wherein the winding device includes a compressing member that compresses the wire in the axial direction of the winding shaft.

4. The induction heating coil manufacturing apparatus according to claim 3 ,

wherein a shaft width of at least one end portion of the winding shaft tapers in the axial direction of the winding shaft.

5. The induction heating coil manufacturing apparatus according to claim 3 , further comprising:

a compressing device including

a supporter that supports the wire, which has been compressed by the compressing member, in a state in which the wire is convexly curved in a direction in which the wire has been compressed, and

a compressing body that compresses the wire supported by the supporter.

6. The induction heating coil manufacturing apparatus according to claim 1 ,

wherein the feed unit feeds the wire while the winding device winding the wire.

7. An induction heating coil manufacturing method of winding a wire around a winding shaft having a quadrangular cross section, the method comprising:

providing the induction heating coil manufacturing apparatus according to claim 1 ;

bending the wire, which is to be wound around the winding shaft, at a position at which the wire is to be wound around a corner of the winding shaft; and

winding the wire, that has been bent at the position, around the winding shaft.

8. The induction heating coil manufacturing method according to claim 7 ,

wherein the winding winds the wire in a state that the wire is not under tension.

9. The induction heating coil manufacturing method according to claim 7 , further comprising:

forming the wire by compressing the wire in the axial direction of the winding shaft after the wire has been wound around the winding shaft.

10. The induction heating coil manufacturing method according to claim 9 ,

wherein the wire is wound by using a winding shaft having a width that tapers in an axial direction at least in one end portion thereof, and

wherein the wire is formed by compressing the wire in an axial direction of the winding shaft after the wire has been wound around the winding shaft.

11. The induction heating coil manufacturing method according to claim 9 ,

wherein the forming of the wire by compressing the wire in the axial direction of the winding shaft includes first compression that compresses the wire, which has been linearly wound around the winding shaft, in the axial direction of the winding shaft and second compression that compresses the wire while supporting the wire in a curved state.

12. The induction heating coil manufacturing method according to claim 7 , further comprising:

forming the wire into a shape having a quadrangular cross section by compressing the wire.

13. The induction heating coil manufacturing method according to claim 7 , further comprising:

supplying the wire, which is to be bent, to the bending device by rotating a winder such that a rotation speed of the winder increases as a remaining amount of the wire wound around the winder decreases.

14. The induction heating coil manufacturing apparatus according to claim 1 , wherein the wire supply unit includes:

a winder around which the wire wound, the winder rotating and feeding the wire, and

a driver that supplies the wire to the bending device by rotating the winder such that a rotation speed of the winder increases as a remaining amount of the wire wound around the winder decreases.

15. The induction heating coil manufacturing apparatus according to claim 1 , further comprising:

a driven roller around which the wire is wound, the driven roller being disposed downstream of the wire supply unit and upstream of the feed unit and rotated by the wire that is fed by the feed unit;

a measuring unit that measures a feed amount of the feed unit on the basis of rotation of the driven roller; and

a tension applying mechanism that applies a tension to the wire in a direction such that an amount of the wire wound around the driven roller increases.