Cooling apparatus and cooling method for steel material

A bending device comprising:

• a feeding apparatus including a gripper 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 that ejects a first cooling medium;
• a plurality of second cooling apparatuses that are disposed on the downstream side from the first cooling apparatus, disposed along the feeding direction, and that ejects a second cooling medium;
• and
• processing circuitry for controlling the cooling medium of each of the second cooling apparatuses,
• wherein each of the second cooling apparatuses having a plurality of cooling mechanisms, each of which including a header that are disposed along a circumferential direction of the steel material in a cross section across the feeding direction of the steel material and that respectively eject the second cooling medium in a manner that flow rates of the second cooling media are controllable independently of each other,
• wherein the respective cooling mechanisms are disposed so that the second cooling media ejected from the respective cooling mechanisms do not cross each other until the second cooling media reach the steel material ejected from the respective cooling mechanisms.

A method for cooling a steel material, comprising:

• gripping one end portion of an elongated steel material;
• moving the 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 elongated steel material is fed in the longitudinal direction;
• a first cooling process of ejecting a first cooling medium to a heated portion;
• and
• a plurality of second cooling processes of ejecting a second cooling medium to the heated portion, on a downstream side from an ejection position of the first cooling process when viewed along a feeding direction of the elongated steel material,
• the second cooling media being ejected to a plurality of locations along the feeding direction of the elongated steel material while flow rates of the second cooling media are controlled independently of each other in the second cooling process,
• wherein the second cooling media are ejected from a plurality of positions along a circumferential direction of the steel material in a manner that flow rates of the second cooling media in a cross section across the feeding direction of the steel material are controllable independently of each other in the second cooling process,
• wherein the moving process is a passive moving process in which the predetermined shape of the steel material which is obtained by contacting an outer shape of the steel material is reflected on each arrangement of a plurality of second cooling apparatuses which ejects the second cooling medium and which is disposed along the feeding direction, and the respective second cooling apparatuses are connected to each other so as to maintain each of the ejection interval to be constant in the feeding direction of the second cooling medium.