Molding method

Abstract

A cycle is repeatedly carried out, the cycle including: a material feeding step of feeding a material whose amount is larger than an amount that is needed to form a single mold; a mixing step; an ejection step; and a measurement step of measuring, once before or after the ejection step, an amount of foamed mixed sand contained in a mixing tank. The material at least partially is not fed in the material feeding step in the cycle in which the amount of the foamed mixed sand is not less than a first threshold.

1 . A molding method comprising:
 repeatedly carrying out a cycle,   the cycle including:
 a material feeding step of feeding, into a mixing tank, a material whose amount is larger than an amount that is needed to form a single mold; 
 a mixing step of mixing the material, contained in the mixing tank, so as to produce foamed mixed sand; 
 an ejection step of pressing, by air, the foamed mixed sand, contained in the mixing tank, so as to eject the foamed mixed sand; and 
 a measurement step of measuring, once before or after the ejection step, an amount of the foamed mixed sand contained in the mixing tank, 
   the material at least partially not being fed in the material feeding step in the cycle in which the amount of the foamed mixed sand is not less than a first threshold.   
     
     
         2 . The molding method as set forth in  claim 1 , wherein
 the ejection step is carried out while the mixing tank and a lid member configured to open and close the mixing tank are connected to each other, and the material feeding step, the mixing step, and the measurement step are carried out while the mixing tank and the lid member are disconnected from each other, and   the measurement step is carried out before or after the ejection step.   
     
     
         3 . The molding method as set forth in  claim 1 , wherein the mixing step is further omitted in the cycle in which the amount of the foamed mixed sand is not less than the first threshold. 
     
     
         4 . The molding method as set forth in  claim 1 , wherein a weight of the material that is fed into the mixing tank in the material feeding step is not less than 105% and not more than 200% of a weight that is needed to form the single mold. 
     
     
         5 . The molding method as set forth in  claim 1 , wherein water included in the material is fed into the mixing tank in the material feeding step in the cycle in which the amount of the foamed mixed sand is not less than the first threshold. 
     
     
         6 . The molding method as set forth in  claim 1 , wherein a warning is given in the cycle in which the amount of the foamed mixed sand is less than a second threshold. 
     
     
         7 . The molding method as set forth in  claim 6 , wherein a molding machine for carrying out the cycle is subjected to maintenance in a case where the warning is given.