Intermediate stalk, method of producing the same, and low-pressure die-casting apparatus

Abstract

An intermediate stalk ( 10 ) that is used for a low-pressure die-casting apparatus includes a metal covering material ( 2 ), and a precast refractory material ( 1 ) that is removably fitted into the metal covering material ( 2 ), an air release opening ( 3 ) being formed between the metal covering material ( 2 ) and the precast refractory material ( 1 ) when viewed from above. According to the present invention, an intermediate stalk that allows water to be sufficiently released from the refractory heat insulator during heating, does not explode, does not produce cracks in the refractory heat insulator due to the difference in coefficient of thermal expansion between the refractory heat insulator and the metal covering material, and allows easy replacement of the refractory heat insulator, a method of producing the same, and a low-pressure die-casting apparatus can be provided.

1 . An intermediate stalk that is used for a low-pressure die-casting apparatus, the intermediate stalk comprising a metal covering material, and a precast refractory material that is removably fitted into the metal covering material, an air release opening being formed between the metal covering material and the precast refractory material when viewed from above. 
     
     
         2 . The intermediate stalk according to  claim 1 , wherein an opening having a width of 0.5 or more is formed between the covering material and the precast refractory material over the entire circumference of the intermediate stalk. 
     
     
         3 . The intermediate stalk according to  claim 1 , wherein a heat insulator is formed on an outer circumferential surface of the precast refractory material. 
     
     
         4 . The intermediate stalk according to  claim 1 , wherein a packing material that prevents entrance of molten metal is provided between the precast refractory material and the covering material around a bottom opening of the intermediate stalk. 
     
     
         5 . (canceled) 
     
     
         6 . A method of producing an intermediate stalk that is used for a low-pressure die-casting apparatus, the method comprising fitting a precast refractory material into a metal covering material, the precast refractory material being formed in advance so that an air release opening is formed between the metal covering material and the precast refractory material when viewed from above in a state in which the precast refractory material is fitted into the metal covering material. 
     
     
         7 . The intermediate stalk according to  claim 2 , wherein a heat insulator is formed on an outer circumferential surface of the precast refractory material. 
     
     
         8 . The intermediate stalk according to  claim 2 , wherein a packing material that prevents entrance of molten metal is provided between the precast refractory material and the covering material around a bottom opening of the intermediate stalk. 
     
     
         9 . The intermediate stalk according to  claim 3 , wherein a packing material that prevents entrance of molten metal is provided between the precast refractory material and the covering material around a bottom opening of the intermediate stalk. 
     
     
         10 . A low-pressure die-casting apparatus comprising an intermediate stalk that is used for a low-pressure die-casting apparatus, the intermediate stalk comprising a metal covering material, and a precast refractory material that is removably fitted into the metal covering material, an air release opening being formed between the metal covering material and the precast refractory material when viewed from above. 
     
     
         11 . The intermediate stalk according to  claim 10 , wherein an opening having a width of 0.5 or more is formed between the covering material and the precast refractory material over the entire circumference of the intermediate stalk. 
     
     
         12 . The intermediate stalk according to  claim 10 , wherein a heat insulator is formed on an outer circumferential surface of the precast refractory material. 
     
     
         13 . The intermediate stalk according to  claim 10 , wherein a packing material that prevents entrance of molten metal is provided between the precast refractory material and the covering material around a bottom opening of the intermediate stalk.