Piston ring of reciprocating engine

Abstract

The invention provides a piston ring for a reciprocating motion internal combustion engine which can increase gas sealing performance, prevent increase of blow-by gas quantity due to deficiency gas sealing capability between outer circumferential surface of the piston ring and sliding surface of a cylinder sleeve, prevent pollution increase of a inner surface portion of the piston ring due to blow-by gas quantity increase and prevent increase of circumference of a sliding surface 3a of the cylinder sleeve 3 corroded by sulfuric acid due to sulfurous acid gas contained in the blow-by gas by maximatily increasing a first curved surface radius R of outer circumferential surface of the piston ring, and can reduce contact pressure. The outer circumferential surface of the piston ring contacted with the sliding surface of the cylinder sleeve is formed to a curved surface with radius of curvature R along axial direction, which is characterized in that the radius of curvature R of the outer circumferential surface is set from 1.18D to 1.35D relative to cylinder inner diameter D of engine.

Description

field of invention [0001] The invention relates to a piston ring of a reciprocating internal combustion engine, which forms a curved surface with a curvature radius R along the sliding surface slidingly contacting the inner peripheral surface of the cylinder liner of the engine in the axial direction, in particular to a piston ring of a reciprocating internal combustion engine such as a diesel engine. Background technique [0002] FIG. 2(A) is a schematic cross-sectional view around a combustion chamber of a large diesel internal combustion engine, and FIG. 2(B) is a partial cross-sectional view near a piston ring mounting portion. In FIG. 2, a plurality of piston rings 2 are respectively inserted into ring grooves 1a formed along the height direction of the piston 1. In this piston 1, the outer peripheral surfaces 2a of the piston rings 2 slide in contact with the sliding surface 3a of the cylinder liner 3, One side reciprocates. A ring side gap 7 opening to the engine com...

AI Technical Summary

Problems solved by technology

[0015] Therefore, if the radius R0 of the first curved surface is set to be small as R0=about 0.9D to 1D of the inner diameter D as in the above-mentioned prior art, the leakage flow rate Q expressed by the above-mentioned formula (1) will increase, The gas sealing ability of the outer peripheral surface 2a of the above-mentioned piston ring 2 will be reduced, resulting in an increase in the amount of blow-by gas due to insufficient gas sealing ability between the outer peripheral surface 2a of the piston ring 2 and the sliding surface 3a of the cylinder liner 3, and the amount of blow-by gas will Increased contamination of the inner surface of the piston ring (piston ring back portion) due to the increase, increased corrosion of the periphery of the sliding surface 3a of the cylinder liner 3 by sulfuric acid due to the sulfurous acid gas contained in the blow-by gas, etc.

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