公开(公告)号：US11982212B2

公开(公告)日：2024-05-14

申请号：US18028436

申请日：2021-03-16

Applicant: FUJI OOZX Inc.

Inventor： Takaaki Kumagai ,  Koji Kushima

IPC: F01L3/12 ,  B21K1/24 ,  F01L3/02 ,  F16K49/00

CPC classification number: F01L3/12 ,  B21K1/24 ,  F01L3/02 ,  F16K49/00 ,  F01L2301/00 ,  F01L2303/00

Abstract: A hollow engine valve includes a shaft portion and an umbrella portion of which diameter is enlarged to form an umbrella shape to be provided on a base end of the shaft portion, a cooling material being enclosed in a hollow portion that is at least formed inside the shaft portion. The shaft portion comprises a first shaft portion in a tip end side, a second shaft portion that is provided in a base end side to have an outer diameter larger than that of the first shaft portion, and a stepped portion formed by a difference in the outer diameters between the first and second shaft portions. A wall thickness of the stepped portion is larger than that of the second shaft portion.