Cooling apparatus for casting mold and cooling method for casting mold

Abstract

A cooling apparatus 1 cools a casting mold K with a refrigerant circulating in a refrigerant passage pipe 2 and comprises an expansion tank 3 for pressurizing the refrigerant to a pressure at which the refrigerant has a set boiling temperature T0 at which the refrigerant boils, a mold cooling section 4 inside the casting mold K for cooling the casting mold K through vaporization heat of the refrigerant boiling, an orifice portion 5 that is formed upstream of the mold cooling section 4, a pump 6 that is attached downstream of the expansion tank 3 and upstream of the orifice portion and pumps out the refrigerant pressurized by the pressurizing unit to the orifice portion, and a heating device 7 attached downstream of the pump 6 and upstream of the orifice portion 5 for heating the refrigerant to a temperature T2 close to the set boiling temperature T0.

What is claimed is: 
     
         1 . A cooling apparatus for a casting mold to cool the casting mold with a refrigerant flowing in a refrigerant passage pipe comprising;
 a pressurizing unit for pressurizing the refrigerant to a pressure at which the refrigerant has a set boiling temperature preset at which the refrigerant boils;   a mold cooling section that is formed inside the casting mold and cools the casting mold through vaporization heat of the refrigerant boiling through heat transmitted from the casting mold;   an orifice portion that is formed upstream of the mold cooling section and configured to increase a pipe pressure loss of the refrigerant passage pipe,   a pump that is attached downstream of the pressurizing unit and upstream of the orifice portion and pumps out the refrigerant pressurized by the pressurizing unit to the orifice portion; and   a heating device attached downstream of the pump and upstream of the orifice portion for heating the refrigerant to a temperature close to the set boiling temperature.   
     
     
         2 . The cooling apparatus for the casting mold as described in  claim 1  further comprising;
 a refrigerant temperature meter for measuring a temperature of the refrigerant supplied into the mold cooling section; and 
 a control unit for controlling the pressurizing unit in such a way that the set boiling temperature becomes higher if the temperature of the refrigerant measured by the refrigerant temperature meter becomes higher than the set boiling temperature. 
 
     
     
         3 . A cooling method for a casting mold with a refrigerant circulating through a refrigerant passage pipe inclusive of an orifice portion in which a pipe pressure loss is increased and a mold cooling section formed inside the casting mold, the cooling method comprising;
 a pressurizing process of pressurizing the refrigerant to a pressure at which the refrigerant boils at a set boiling temperature that is set in advance;   a pumping-out process of pumping out the pressurized refrigerant toward the orifice portion;   a heating process of heating the pressurized refrigerant flowing upstream of the orifice portion to a temperature close to the set boiling temperature; and   a mold cooling process of cooling the casting mold through vaporization heat generated from the refrigerant boiling in the mold cooling section after flowing through the orifice portion.   
     
     
         4 . The cooling method for a casting mold as described in  claim 3  further comprising an additional pressurizing process of pressurizing the refrigerant so as to make the set boiling temperature become higher if a measured temperature of the refrigerant in the mold cooling section is higher than the set boiling temperature.