Patent ID: 8230834

Claim:
A hollow poppet valve for use with an internal-combustion engine, the hollow poppet valve including: a stem portion provided at one end thereof with a closed tip portion; a cap portion for receiving combustion pressure, the cap portion consisting of a generally disk-shaped member; and a flared fillet portion integrated with the stem portion to form a thin hollow cylindrical member and welded to the cap member to serve as a transitional region between the stem portion and the cap portion, the thin hollow poppet valve characterized in that: the thin hollow cylindrical member, drawn from a metal plate, has a thickness not more than the initial thickness of the metal plate; the cap member has a thickness substantially equal to the maximum thickness of the fillet portion, a generally arcuate axial cross section, and a tapered outer peripheral face; the fillet portion is provided near the open end thereof with a seat-abutment portion having a tapered inner peripheral face to be mated with, and laser-beam-welded or electron-beam-welded to, the tapered outer peripheral face of the cap member; and an extruded weld bead is formed along the inner periphery of the mated faces of the cap member and the fillet portion.