Casting mold making method and casting mold making system

Abstract

In blowing gas-curing casting sand, which is accommodated in a receiver of a blow head, into a cavity in molding dies and thereby packing it into the cavity, prior to the blowing and packing of the casting sand into the cavity, the casting sand in the receiver is stirred by a stirrer until the stirring resistance of the stirrer enters a predetermined range (a range corresponding to an optimum bulk density range of casting sand within which casting sand can efficiently blow out through blow nozzles).

1 . A method for making a casting mold, comprising:
 a blowing and packing step of feeding pressurized gas into a receiver that is provided in a blow head and accommodates gas-curing casting sand, thereby blowing the casting sand in the receiver into a cavity in molding dies through a blow nozzle that is provided in the blow head and communicates with the receiver and packing the casting sand into the cavity;   a curing step of, after the blowing and packing step, introducing curing gas into the cavity to cure the casting sand packed in the cavity; and   a stirring step of, before the blowing and packing step, stirring the casting sand in the receiver with a stirrer until the stirring resistance of the stirrer enters within a predetermined range.   
   
   
       2 . The method of  claim 1 , wherein
 the stirring step, the blowing and packing step and the curing step are sequentially repeated, and   the predetermined range is set in each stirring step.   
   
   
       3 . The method of  claim 2 , wherein the predetermined range is set based on the amount of casting sand in the receiver in each stirring step. 
   
   
       4 . The method of  claim 1 , wherein
 the casting sand contains a binder and a solvent, and   the method further comprises a solvent feed step of, before or during the stirring step, supplementally feeding the solvent into the receiver.   
   
   
       5 . A casting mold making system including a blow head having a receiver for accommodating gas-curing casting sand and a blow nozzle communicating with the receiver and a pressurized gas feed system for feeding pressurized gas into the receiver of the blow head and configured to feed pressurized gas into the receiver through the pressurized gas feed system and thereby blow the casting sand in the receiver through the blow nozzle into a cavity in molding dies and pack the casting sand into the cavity, the casting mold making system further comprising:
 a stirrer for stirring the casting sand in the receiver;   a stirrer drive unit for driving the stirrer;   a stirring resistance detection device for detecting the stirring resistance of the stirrer; and   an operation controller for controlling the operation of the stirrer drive unit, the operation controller being configured to, prior to the feeding of pressurized gas into the receiver through the pressurized gas feed system, operate the stirrer drive unit until the stirring resistance detected by the stirring resistance detection device enters within a predetermined range.   
   
   
       6 . The casting mold making system of  claim 5 , further comprising
 a casting sand amount detection device for detecting the amount of casting sand in the receiver,   wherein the operation controller is configured to set the predetermined range based on the amount of casting sand detected by the casting sand amount detection device.   
   
   
       7 . The casting mold making system of  claim 5 , wherein
 the casting sand contains a binder and a solvent,   the casting mold making system further comprises a solvent spray device for supplementally feeding, under the control of the operation controller, the solvent into the receiver by spraying, and   the operation controller is configured to, before or during the operation of the stirrer drive unit, operate the solvent spray device to supplementally feed the solvent into the receiver.