| 摘要 |
To provide a hollow poppet valve having an improved heat reduction effect. In a hollow poppet valve (10) having a valve head (14) and a stem (12) integral with the valve head (14), the hollow poppet valve (10) is formed with an internal cavity S that extends in the valve head (14) and the stem (12). The internal cavity S is charged with a coolant (19) and an inert gas. The internal cavity S has a generally disk-shape internal cavity S1 and an internal stem cavity S2 formed in the stem (12) and connected to the internal valve head cavity S1 at a right angle. During a reciprocal motion of the valve (10), a vertical convective flow of coolant (19) along the axis L of the valve (10) is established at least in the internal valve head cavity S1, thereby enhancing its heat reduction effect. |
