| 摘要 |
PURPOSE:To prevent oil from leaking from a sliding surface, by forming a given slope at least on one side out of mutually opposing faces of an oil ring and faces touch the opposing faces of the oil ring of a leaf spring pushing the oil ring outward. CONSTITUTION:An oil relief hole 8 is formed on the bottom 7e of an oil ring groove 7 formed on the side of a circumference of a piston 3 and a pair of a top and a bottom oil rings 9a and 9b to be energized outward by a leaf spring 12 whose cross section is in about a U shape is fitted in the groove 7. In this instance, the oil rings 9a and 9b are formed by providing slopes 10a and 10b so that mutually opposing surfaces of the slopes 10a and 10b are expanded mutually toward an inner diametral side. The leaf spring 12 is formed also by providing slopes 14a and 14b touching the above slopes 10a and 10b respectively. In this way, oil is prevented from leaking by converting dragging displacement of the oil rings 9a and 9b into pressing force of the leaf spring 12 and increasing facial pressure against a cylinder wall 2. |
