Piston for IC engine

Abstract

An object of the present invention is to effectively achieve the reduction in piston slap sound in both of an expansion stroke and a compression stroke in consideration of a difference between the behaviors of a piston in the expansion stroke and the compression stroke. For this purpose, in a piston P having a skirt 12 formed into an intermediately bulged barrel type, the axis L2 of a piston pin is offset with respect to the cylinder axis L1, and the decrement in radius of a lower skirt portion 20 is set to be large on a thrust side and small in an anti-thrust side. In the expansion stroke, the piston is positively swung, while the skirt 12 is put into abutment against a wall surface of a cylinder bore, thereby reducing the piston slap sound.

Description

technical field [0001] The present invention relates to internal combustion engine pistons having skirts, and more particularly to piston shapes that reduce piston rattle. Background technique [0002] In an internal combustion engine piston, the piston comprises a piston pin having an axis offset relative to the cylinder axis and a skirt forming a centrally convex barrel shape. From the Japanese Utility Model Publication No. 53-40546 can know such a technology: partially cut away the upper part of the skirt portion on the side opposite to the offset side of the piston pin, and the upper part of the cut away is easy to Causes scratches and spots between the wall surface of the cylinder bore and this part, thus preventing seizing. [0003] The barrel shaped skirt tends to reduce the piston rattle produced by the piston hitting the cylinder bore wall, but in the known pistons described above an improvement is made in the upper barrel shape of the skirt from a lubrication poin...

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Problems solved by technology

This doesn't help reduce piston smack

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