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An Experimental Verification of Piston Ring Collapse
Published July 23, 2002 by Society of Automotive Engineers of Japan in Japan
Event: 2002 JSAE Annual Congress
This study has been conducted aiming at an experimental verification of the ring collapse phenomena that occurs in a taper-faced second ring of a direct fuel injection type truck diesel engine. The oil film thickness of the second ring, the ring axial motion and the inter-ring pressure have been measured under various operating conditions of the engine. As a result, it is verified that the back pressure of the second ring becomes lower than the second land pressure, and that the second ring oil film becomes extremely thick temporarily where the second ring contacts with the ring groove upper surface. It is also verified that blow-by passes through the second ring where the oil film of the second ring becomes thick. Hence it is highly probable that the collapse of the second ring has occurred at that time.