| 摘要 |
Provided is a poppet valve capable of realizing maximum. combustion efficiency all of three heat transfer forms. In a poppet valve including a head portion (14) formed integrally with one end side of a stem portion (12), in the head portion (14), a hollow portion (19) extending along a head surface (24) is formed, a metal layer (17) that insulates. radiation heat is formed on a upper end surface (25) of the hollow portion (19), and a heat insulating portion is formed between the metal layer (17) and a bottom surface of the hollow portion (19). Among the heat. transfer forms, conduction and convection are insulated by the heat insulating portion, and radiation is insulated by the metal layer (17). |
