| 摘要 |
PURPOSE:To reduce thermal loss of exhaust energy and enhance overall thermal efficiency of an internal combustion engine by arranging heat insulation layers around an exhaust port arranged in a cylinder head. CONSTITUTION:In an internal combustion engine with a cylinder head 2 attached over a cylinder block 1 and with an exhaust port 3 formed in the cylinder head 2 of each cylinder 1a within the cylinder block 1, a port liner 5 is embed ded in the exhaust port 3. This port liner 5 serves to fix and protect insulation material 6 arranged around a horizontal part 3a and an upper part of a curved part 3b of the exhaust port 3. The insulation material 6 is made of ZrO2, SiO2, Al2O3 and others. On the other hand, the port liner 5 is made of heat-resistant spheroidal graphite cast iron and others. |
