| 摘要 |
PURPOSE:To heighten the wear and scuff resistance of a cylinder having a flame-sprayed layer on the inside surface, by making the void ratio of the flame- sprayed layer different between its part near the top dead center and its other part. CONSTITUTION:A flame-sprayed layer 2 is provided on the inside surface 11 of a cylinder. To improve the lubrication on the part of the flame-sprayed layer 2 near the top dead center during the operation of the engine which is server on said part at the top dead center, the void ratio of the part of the flame-sprayed layer 2 is set at 20-30% and that of its other part is at set at 10-15%. If the void ratio of the part of the flame-sprayed layer 2 near the top dead center were set at less than 20%, the layer would not function as an effective oil reservoir and the resistance of the cylinder to the wear and scuff not would not be improved. If the void ratio of the part of the layer 2 were set at more than 30%, the roughness of the surface of the layer would be so high as to promote the wear of the piston ring which slides on the layer. |
