Cooling apparatus and cooling method for steel material

A bending device for a steel material in which one portion in a longitudinal direction of an elongated steel material is heated in a state where one end portion of the steel material is gripped, and the one end portion is moved in a two-dimensional or three-dimensional direction so as to form the steel material into a predetermined shape including a bent portion and to cool a heated portion including the bent portion while the steel material is fed in the longitudinal direction, the apparatus comprising:

• a first cooling apparatus that ejects a first cooling medium to the heated portion;
• and
• a second cooling apparatus that is disposed on a downstream side than the first cooling apparatus when viewed along a feeding direction of the steel material, and that ejects a second cooling medium to the heated portion,
• a plurality of the second cooling apparatuses being disposed along the feeding direction, and flow rates of the second cooling media being controllable independently of each other.

A bending device comprising:

• a feeding apparatus for feeding a steel material in a longitudinal direction of the steel material;
• a heating apparatus having a high frequency induction heating coil;
• a bending apparatus having a clamp for gripping one end portion of the steel material and a drive arm for moving the clamp;
• a first cooling apparatus disposed on a downstream side than the heating apparatus when viewed along a feeding direction of the steel material;
• a plurality of second cooling apparatuses disposed on the downstream side than the first cooling apparatus, disposed along the feeding direction;
• and
• a control unit for controlling a cooling medium of each of the second cooling apparatuses.

A method for a steel material, comprising:

• gripping one end portion of an elongated steel material;
• moving one end portion in a two dimensional or three-dimensional direction so as to form the elongated steel material into a predetermined shape including a bent portion;
• heating one portion in a longitudinal direction of the elongated steel material while the steel material is fed in the longitudinal direction;
• a first cooling process of ejecting a first cooling medium to the heated portion;
• and
• a second cooling process of ejecting a second cooling medium to the heated portion, on a downstream side than an ejection position of the first cooling apparatus when viewed along a feeding direction of the steel material,
• the second cooling media being ejected to a plurality of locations along the feeding direction of the steel material while flow rates of the second cooling media are controlled independently of each other in the second cooling process.