Coiling machine, method for manufacturing coil spring, and coil spring

1 . A coiling machine comprising:

a helix forming unit which feeds a wire and forms the wire into a helical shape while feeding;

a laser heating machine which irradiates the wire formed into the helical shape with laser light;

cutting components which cut the wire; and

a controller which controls the helix forming unit, the laser heating machine, and the cutting components,

wherein:

the cutting components include:

a mandrel which supports thereon an inner circumferential surface of the wire formed into a helical shape; and

a cutter which applies an impact to an outer circumferential surface of a part of the wire protruding from an end part of the mandrel to thereby cut the wire, and

the controller is configured to execute processes comprising:

controlling the helix forming unit to feed the wire and form the wire into the helical shape, and thereafter to stop feeding the wire;

while the feeding of the wire is stopped, controlling the laser heating machine to irradiate a portion of the wire positioned under the cutter with the laser light to thereby heat the portion; and

after the irradiation of the laser light and while the feeding of the wire is stopped, controlling the cutting components to cut the portion of the wire whose temperature has been raised as compared to a temperature thereof before irradiation with the laser light.

2 . The coiling machine of claim 1 , wherein the processes comprise controlling the cutting components to cut the portion of the wire when the temperature of the portion of the wire is higher than or equal to 500° C.

3 . The coiling machine of claim 1 , wherein the processes comprise:

controlling the laser heating machine to irradiate the portion of the wire with the laser light to thereby form a melt pool and a heat affected zone around the melt pool in the wire, and

controlling the cutting components to cut the heat affected zone of the wire.

4 . The coiling machine of claim 1 , wherein:

a clearance is provided between the cutter and the end part of the mandrel in a feed direction of the wire, and

when the cutter applies the impact to the wire, a center of the clearance and a center of an irradiated area irradiated with the laser light on the wire are shifted from each other in the feed direction.

5 . The coiling machine of claim 4 , wherein the center of the irradiated area is positioned on the cutter side of the center of the clearance in the feed direction.

6 . The coiling machine of claim 5 , wherein:

the processes comprise controlling the laser heating machine to irradiate the portion of the wire with the laser light to thereby form a melt pool and a heat affected zone around the melt pool in the wire, and

when the cutter applies the impact to the wire, the end part of the mandrel and a part of the heat affected zone positioned on the upstream side of the melt pool in the feed direction are overlapped with each other when viewed from a moving direction of the cutter.