Poppet valve

Abstract

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).

Description

TECHNICAL FIELD[0001]The present invention relates to a poppet valve that suppresses dissipation of heat caused by heat transfer, specifically, radiation from a combustion chamber.BACKGROUND ART[0002]Patent Literatures 1 describes poppet valves each including a head portion formed integrally with a stem end portion. A poppet valve to be used in an internal combustion drives an engine by opening and closing an intake passage or an exhaust port by being seated on a valve seat of a cylinder head to which the intake passage or the exhaust port is connected.[0003]Normally, in an internal combustion, the smaller the energy loss in a combustion chamber, the higher the combustion efficiency. Energy loss includes cooling loss caused by scattering of heat to the outside, etc. Heat in the combustion chamber dissipates to the outside via the poppet valve and a combustion chamber inner wall in many cases. Therefore, in or near a head surface of the poppet valve which comes into contact with the ...

AI Technical Summary

Benefits of technology

The present invention is a poppet valve that prevents heat from escaping from a combustion chamber. This is achieved by effectively insulating heat transfer in all forms of heat conduction, convection, and radiation of heat from the combustion flame and gas inside the combustion chamber. This reduces combustion efficiency loss due to cooling and prevents metal deterioration caused by heat.

Problems solved by technology

Energy loss includes cooling loss caused by scattering of heat to the outside, etc.

However, although a normal heat insulating material can insulate heat transfer caused by heat conduction and convection among the three forms of heat transfer, the normal heat insulating material transmits radiation heat, and a temperature decrease accordingly caused inside the combustion chamber cannot be avoided.

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