| 摘要 |
PURPOSE: To improve knocking resistance by improving heat conductive effi ciency and decreasing the temperatures of valve seats. CONSTITUTION: The front surfaces of valve seats 1 made of iron-sintered alloy are coated with nickel layers, and on which fluoride flux having the composition of 55mol%, CsF-45mol%, and AlF3 is applied. A chamber core 6 is housed in a lower mold 5, and the valve seats 1 are set in the specified positions of the chamber core 6. After a core of a port core 7 and valve guide hole forming pins 14 are housed, an upper mold 9 is put on it, and a mold 11 is completed. This mold 11 is heated at the temperature of 300 deg.C, and then AC2B (JIS standard) molten aluminum is injected through a molten metal injecting path 12. A cylinder head in which the valve sheet 1 is inserted is obtained by dismantling the mold 11 after cooling. |
