Method for producing metallic-sodium-filled engine valve

Abstract

In the disclosed method, an engine valve (V) filled with metallic sodium (Na) within is produced by means of hardening metallic sodium (Na)—that has been liquefied through heat-melting—into rods by linearly discharging the metallic sodium (Na) in a liquid hydrocarbon ( 120 ), thus cooling the metallic sodium, then inserting these rods into a hollow section (H) through the opening (M) of a stem section (S) , and then sealing the opening (M).

1 - 4 . (canceled) 
     
     
         5 . A method for producing an engine valve filled inside with metallic sodium, the engine valve produced by: putting metallic sodium into a hollow portion from an opening of a stem portion having the hollow portion in an inner portion and having the opening at an upper end; and thereafter sealing the opening, the method comprising:
 cooling and solidifying metallic sodium heated and melted to a liquid state into a bar-shaped piece; and   thereafter inserting the bar-shaped piece of metallic sodium into the hollow portion from the opening of the stem portion.   
     
     
         6 . The method for producing a metallic-sodium-filled engine valve according to  claim 5 , wherein the metallic sodium heated and melted to a liquid state is discharged linearly into a hydrocarbon-based liquid and is cooled to be solidified into the bar-shaped piece. 
     
     
         7 . The method for producing a metallic-sodium-filled engine valve according to  claim 5 , wherein the metallic sodium heated and melted to a liquid state is injected into a bar-shaped space in an inside of a metal mold having the space in the inside and is then cooled to be solidified into the bar-shaped piece. 
     
     
         8 . The method for producing a metallic-sodium-filled engine valve according to  claim 7 , wherein the bar-shaped space of the metal mold is formed such that at least an end portion on one side is formed in a tapered shape or an elongated ellipse shape.