| 摘要 |
PURPOSE:To reduce the thermal load by arranging the radiating ribs, in a duct for the cooling water for cylinder head, approx. in parallel with the cooling water's flow direction in said duct and thereby increasing the amount of heat radiation. CONSTITUTION:In the duct 24 provided in a cylinder head 16, a number of radiating ribs 29 are arranged approx. in parallel with the cooling water's flow direction, i.e. in the vertical longitudinal direction of the cylinder head 16. Increase of the height of these ribs 29 does not cause substantially any decrease of the flow area of the duct 24, so that it is possible to increase the area of heat radiation. The radiating ribs 29 do not constitute a larger resistance to the flowing cooling water, and even though the quantity of the cooling water becomes great at the time of attainment of high speed operation range, the flow speed is not sunk to ensure that effective increase of the heat radiation amount is maintained. Moreover, because they are arranged parallelly in engine's longitudinal direction, the bending strength of the cylinder head is enhanced. |
