Cooling device and thermal treatment device

Abstract

A cooling device cools a workpiece using a mist-like coolant and includes a heat transfer coefficient switching device that switches a heat transfer coefficient of the mist-like coolant from a relatively low state to a relatively high state during cooling the workpiece.

What is claimed is: 
     
         1 . A cooling device which cools a workpiece using a mist-like coolant, comprising:
 a heat transfer coefficient switching device that switches a heat transfer coefficient of the mist-like coolant from a relatively low state to a relatively high state during cooling the workpiece.   
     
     
         2 . The cooling device according to  claim 1 ,
 wherein the heat transfer coefficient switching device adjusts a mist particle diameter of the mist-like coolant from a relatively small particle diameter to a relatively large particle diameter to switch the heat transfer coefficient of the mist-like coolant.   
     
     
         3 . The cooling device according to  claim 2 ,
 wherein the heat transfer coefficient switching device includes,   a first injection nozzle that includes an injection hole having a first hole diameter and converts a coolant into the mist-like coolant having a first mist particle diameter of a relatively small mist particle diameter,   a second injection nozzle that includes an injection hole having a second hole diameter larger than the first hole diameter and converts the coolant into the mist-like coolant having a second mist particle diameter larger than the first mist particle diameter, and   a coolant supply device that supplies the coolant to the first injection nozzle and the second injection nozzle, and   wherein a supply destination of the coolant is switched from the first injection nozzle to the second injection nozzle to adjust the mist particle diameter of the mist-like coolant from the first mist particle diameter to the second mist particle diameter.   
     
     
         4 . The cooling device according to  claim 2 ,
 wherein the heat transfer coefficient switching device adjusts the mist particle diameter of the mist-like coolant from a first mist particle diameter to a second mist particle diameter via a state where the mist-like coolant having the first mist particle diameter and the mist-like coolant having the second mist particle diameter are mixed.   
     
     
         5 . The cooling device according to  claim 3 ,
 wherein the heat transfer coefficient switching device adjusts the mist particle diameter of the mist-like coolant from the first mist particle diameter to the second mist particle diameter via a state where the mist-like coolant having the first mist particle diameter and the mist-like coolant having the second mist particle diameter are mixed.   
     
     
         6 . The cooling device according to  claim 1 ,
 wherein the heat transfer coefficient switching device adjusts a density of the mist-like coolant from a relatively low density to a relatively high density to switch the heat transfer coefficient of the mist-like coolant.   
     
     
         7 . A thermal treatment device, comprising:
 a heating device that heats a workpiece; and   the cooling device according to  claim 1  that cools the workpiece heated by the heating device.   
     
     
         8 . A thermal treatment device, comprising:
 a heating device that heats a workpiece; and   the cooling device according to  claim 2  that cools the workpiece heated by the heating device.   
     
     
         9 . A thermal treatment device, comprising:
 a heating device that heats a workpiece; and   the cooling device according to  claim 3  that cools the workpiece heated by the heating device.   
     
     
         10 . A thermal treatment device, comprising:
 a heating device that heats a workpiece; and   the cooling device according to  claim 4  that cools the workpiece heated by the heating device.   
     
     
         11 . A thermal treatment device, comprising:
 a heating device that heats a workpiece; and   the cooling device according to  claim 5  that cools the workpiece heated by the heating device.   
     
     
         12 . A thermal treatment device, comprising:
 a heating device that heats a workpiece; and   the cooling device according to  claim 6  that cools the workpiece heated by the heating device.