Method for producing metallic-sodium-filled engine valve

Abstract

Disclosed is a method—for producing an engine valve (V) filled with metallic sodium (Na) within by means of: forming a stem section (S), which has a hollow section (H), at an intended size by successively drawing the stem section (S) using dies (D1, D2, Dx, Dx+1, Dn) in a manner so as to causing the size of the outer diameter and the inner diameter of the stem section (S) to contact in a stepwise fashion; and inserting metallic sodium (Na) into the hollow section (H) of the stem section (S)—wherein after drawing the stem section (S) until the inner diameter of the hollow section (H) of the stem section (S) has become a prescribed size (steps S11-S15) and then inserting the block-shaped solid metallic sodium (Na) into the hollow section (H) of the stem section (S) (step S16), the stem section (S) is further drawn (steps S17 and S18).

Dependencies are inferred from the claim text.