Automated system for improved cooling of aluminum castings in sand molds

Abstract

An improved and efficient method and apparatus for convective cooling of cast sand molds containing molten metal, utilizing vertically-arrayed cooling stations (preferably arranged on a plurality of shelves inside a housing enclosure for temporarily storing said sand molds during their cooling from a molten temperature level to a lower solidification temperature. A draft of cooling air is circulated through said stations in said housing whereby the time for solidifying the molten metal in said cast sand molds is reduced as compared with passive air cooling of said molds. Robot means are provided for moving hot sand molds from a feeding port in said housing to said shelves and for moving cooled sand molds from said shelves to a delivery port in said housing. The robot means is programmed so that the time period of each mold is maintained within said housing according to the individual time required for the solidification of the metal in such individual mold (based on empirical data for typical solidification required for the given individual cast sand mold package or based on other appropriate discernible physical property attributable to achieved solidification).

1 . An apparatus for convective cooling of cast sand molds containing molten metal, comprising:
 an enclosure housing having a roof and side wall;   a plurality of vertically arrayed stations contained inside said housing for temporarily storing said cast sand molds for their cooling from a molten temperature level to a lower solidification temperature level;   means for actively producing a draft of cooling air circulating through said stations and around said molds therein from at least one inlet cooling air source in said housing to at least one hot air outlet from said housing whereby the cooling of said cast sand molds is accelerated and the solidification time is reduced as compared with passive air cooling of said cast sand molds; and   programmable robot means for moving hot cast sand molds from a feeding port in said housing each to a respective station and for moving cooled cast sand molds containing solidified metal from said respective stations to a delivery port in said housing.   
     
     
         2 . An apparatus according to  claim 1 , wherein said robot means is programmable for introducing and then for withdrawing said molds after a given time interval as required for the solidification of said metal therein. 
     
     
         3 . An apparatus according to  claim 2 , further comprising conveying means for introducing said cast molds containing molten metal into said housing. 
     
     
         4 . An apparatus according to  claim 3 , further comprising conveying means for withdrawing cooled molds containing adequately solidified metal from said housing. 
     
     
         5 . An apparatus according to  claim 4 , wherein there is a single inlet for said cooling air source which is located at a central part in the roof of said housing. 
     
     
         6 . An apparatus according to  claim 5 , wherein said means for actively producing a draft of cooling air is a blowing means in said single inlet located above said stations. 
     
     
         7 . An apparatus according to  claim 6 , wherein there are a plurality of hot air outlets located spaced at the outer periphery of the roof of said housing. 
     
     
         8 . An apparatus according to  claim 7 , wherein there are a plurality of inlets for said cooling air source located at the lower part of said housing. 
     
     
         9 . An apparatus according to  claim 8 , wherein said means for actively producing a draft of cooling air includes extraction means in the form of fans each in a plurality of hot air outlets located spaced at the outer periphery of the roof of said housing and above said stations. 
     
     
         10 . An apparatus according to  claim 9 , wherein said extraction means is structured to withdraw hot air through the roof of said housing. 
     
     
         11 . An apparatus according to  claim 1 , wherein said vertically arrayed stations are shelves disposed in a linear arrangement and said robot means travel alongside said shelves. 
     
     
         12 . An apparatus according to  claim 1 , where said housing has a cylindrical shape; and said robot means is located anchored in the center of said housing, and said vertically arrayed stations are a single set of shelving circularly arranged around said robot means. 
     
     
         13 . An apparatus according to  claim 12 , where said vertically arrayed stations are a single set of shelving arranged in a semi-circle around said robot means. 
     
     
         14 . An apparatus according to  claim 13 , further comprising scrubbing means for cleaning any noxious gases emanating from said cast sand molding within said housing. 
     
     
         15 . A method for convective cooling of cast sand molds containing molten metal, comprising:
 feeding cast sand molds containing molten metal into a housing containing a vertical array of closely spaced cooling stations;   robotically placing individual cast sand molds each into a respective cooling station;   actively circulating cooling air into said housing from at least one cooling air source, through said stations and around said cast sand molds situated therein, and on out of said housing through at least one hot air discharge, whereby the cooling of said cast sand molds is accelerated and the solidification time is reduced as compared with passive air cooling of said cast sand molds;   robotically removing individual cast sand molds upon solidification from its respective cooling station;   said robotic placement and removal being controlled by applied programming to control the time spent by each cast sand mold within said housing to that needed to achieve solidification of the metal sufficient to permit proper handling in subsequent processing steps;   removing the resulting cast sand molds from said housing.   
     
     
         16 . The method of  claim 15 , wherein the cast sand molds containing molten metal are all essentially the same and the robotic programming retains each such mold in its cooling station in the housing for a time determined to be minimally required for adequate solidification of the molten metal and is thereafter promptly removed from the housing. 
     
     
         17 . The method of  claim 15 , further comprising monitoring in each cooling station any cast sand mold present therein to sense the presence of an intrinsic attribute of the metal present only when adequately solidified and promptly removing such mold from the station and the housing upon sensing such an intrinsic attribute, irrespective of when such mold was introduced into the housing relative to when the other molds within the housing. 
     
     
         18 . The method of  claim 17 , wherein the intrinsic attribute is a given surface temperature of the mold, which temperature has been determined to be indicative of adequate solidification of the metal within the cast mold. 
     
     
         19 . The method of  claim 15 , further comprising cleaning any noxious gases emanating from any cast sand moldings within said housing. 
     
     
         20 . The method of  claim 18 , further comprising cleaning any noxious gases emanating from any cast sand moldings within said housing.