摘要 |
A hollow poppet valve (10) having an improved heat transfer capability is provided. The valve has an internal cavity (S), extending from within a valve head (14) into a stem (12) of the valve, is loaded with a coolant (19) together with an inert gas. The coolant in the valve head (14) is stirred by swirl flows of the coolant generated during reciprocal motions of the valve. A multiplicity of swirl-forming protrusions are formed on at least on one of the bottom and the ceiling of the valve head cavity (S1) in such a way that swirl flows (F20, F30) of coolant are generated by the protrusions in the valve head cavity (S1) during reciprocal motions of the valve to thereby stir the coolant in the circumferential direction of the cavity (S1). |