| 摘要 |
PURPOSE:To improve an exhaust valve in durability, by forming a coolant chamber filled with a primary coolant in the head portion of exhaust valve body and connecting the coolant chamber with an external heat exchanging section via a carburetting chamber so as to cool down the steam of primary coolant with a secondary coolant. CONSTITUTION:The interior of exhaust valve body 1 opening and closing an exhaust port 3 is formed hollow following the outer shape, and a coolant chamber 8 filled with the cooling water of primary coolant is formed in a value head portion 5 of valve integrated with a valve stem 4. A coolant chamber 9 is formed in the valve stem 4, having its upper end opened to an outside and its lower end communicated with the coolant chamber 8. A carburetting coolant guide tube 16 is inserted into the upper end opening 9a of coolant chamber 9. The upper end of guide tube 16 is connected for communication with a header tube 17 which is in turn communicated with a heat exchanging section 23 where the steam of primary coolant has its heat exchanged with the cooling water of secondary coolant for condensation. The secondary coolant is supplied from a water feed port 26 into the heat exchanging section 23 and drained out through a drain port 27. |
