Hollow poppet valve
AssigneeNittan Valve Co., Ltd.
InventorsOsamu Tsuneishi, Masaaki Inoue
Life of this patent
Estimating the term…
Abstract
With a poppet valve using a coolant, maximum combustion efficiency is realized by adjusting relative values of a heat insulation effect and a heat dissipation effect. From the inside of a head portion (14) to a stem portion (12) of a hollow poppet valve (10) a heat insulating space (S1) and a cooling portion (S2) loaded with a coolant (19), separated from each other by a partition (15), are formed. By properly setting an installation position and a vertical length of the partition (15) according to a type of vehicle for which the valve is used, appropriate heat insulation effect and heat dissipation effect are obtained. Further, by the partition (15), mechanical or thermal strength of the poppet valve in which the heat insulating space (S1) and the cooling portion (S2) are formed is increased.
Claims2
A hollow poppet valve in which a head portion is formed integrally with one end side of a stem portion, a head-side hollow portion and a stem-side hollow portion separated from each other by a partition provided at a position corresponding to a fillet portion between a valve head portion and a valve stem portion are formed, the head-side hollow portion is formed by the partition, a spherical recess of a head portion shell, and a cap member defining a bottom surface of the head-side hollow portion on a combustion chamber side of the head portion, in the head-side hollow portion, a heat insulating portion containing a gas or a material having lower heat conductivity than a valve forming metal is configured, and in the stem-side hollow portion, a cooling portion loaded with a coolant is configured, wherein
- a heat insulation effect is obtained at the heat insulating portion, a heat dissipation effect is obtained at the cooling portion, and by setting at least one of a position in the up-down direction and a length in the up-down direction of the partition, relative values of the heat insulation effect and the heat dissipation effect can be adjusted.
A method for adjusting relative values of a heat insulation effect and a heat dissipation effect of a hollow poppet valve in which a head portion is formed integrally with one end side of a stem portion, a head-side hollow portion and a stem-side hollow portion separated from each other by a partition provided at a position corresponding to a fillet portion between a valve head portion and a valve stem portion are formed, the head-side hollow portion is formed by the partition, a spherical recess of a head portion shell, and a cap member defining a bottom surface of the head-side hollow portion on a combustion chamber side of the head portion, in the head-side hollow portion, a heat insulating portion that exerts the heat insulation effect by containing a gas or a material having lower heat conductivity than a valve forming metal is configured, and in the stem-side hollow portion, a cooling portion that exerts the heat dissipation effect by being loaded with a coolant is configured, wherein relative values of the heat insulation effect and the heat dissipation effect are adjusted by setting at least one of a position in the up-down direction and a length in the up-down direction of the partition.
Dependencies are inferred from the claim text.