| 摘要 |
PURPOSE:To outstandingly improve durability of a ring so as to use the ring for a Diesel engine operated under the severe condition of use, by applying Cr plating on the internal periphery and the periphery of side rails and especially on the internal periphery of the side rail in a thickness above a specific value. CONSTITUTION:A combined oil ring comprising an expander 4 and side rails 5 is mounted to an oil ring groove 3 of a piston 1. Every one sheet of the side rail 5 is mounted to the upper and the bottom of the expander 4, and pressed toward a cylinder bore 2 by expander hooks 6. Cr platings 7, 8 are applied to the internal periphery and the periphery of the side rail 5, and this Cr plating on the internal periphery of the side rail 5 is formed in a thickness of 0.1mm. or more. The 0.1mm. value is a thickness of the internal periphery Cr plating in a minimum limit required for warranting the durable time of 2,000hrs. |
