| 摘要 |
PURPOSE:To avoid corrosion of a valve due to low temperature by adjusting cooling liquid level in a heat exchanger which cools evaporated gas in a siphon, according to an engine load and controlling temperature of an exhaust valve, in a device which cools the exhaust valve by a heat siphon. CONSTITUTION:A cooling material chamber 5 which is filled with a primary cooling material is formed in the umbrella portion 1 of an exhaust valve. The primary cooling material which cools the umbrella portion 1 and is evaporated enters into a heat exchanger 3 through a cooling material evaporation chamber 6, a cooling material guide pipe 8 and a connecting pipe 9, and here, after condensing, it returns to the umbrella portion 1 of the exhaust valve. A secondary cooling material is supplied to the outer circumference on the condensed pipe 15 of the heat exchanger 3, and a secondary cooling material layer 16 and a pressed air layer 17 are formed. Thus, a pressure regulating valve 26, a flow rate controlling valve 23, and a throttle valve 24 are adjusted according to an engine load, and thereby the level of a secondary cooling material layer 16 is adjusted, efficiency of the heat exchanger 3 is controlled, excessive cooling of the exhaust valve is prevented and low temperature corrosion or the like can be prevented. |
