Light alloy piston

US4691622A · kind A · utility

Assignee

• Metallgesellschaft AG · DE

Inventors

• Wilfried Sander · Neckarsulm, DE
• Gunder Essig · Heilbronn, DE
• Erich Wacker · Heilbronn, DE

Key dates

• Filing date: Oct 7, 1985
• Grant date: Sep 8, 1987
• Expiry date: Oct 7, 2005

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F05C2201/0448
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In a light alloy piston each of the load-carrying skirt surfaces is divided by a depression into two load-carrying partial shaft surfaces. In order to reduce the friction losses and the consumption of lubricant the depth of the depression (8, 9) between the tapered portions of the curved generatrix (7) at the top and bottom ends of the skirt is approximately twice the peak-to-valley height of the machined surface of the skirt (1). The load-carrying partial skirt surfaces (10, 11, 12, 13) and the depression (8, 9) are at least as wide as the wear pattern area, and the axial extent of the depression (8, 9) is so selected that the depression will not protrude from the cylinder when the piston is at its lower dead center and in the cold engine the load-carrying partial skirt surfaces (10, 11, 12, 13) have between the upper limit of the depression and the lower limit of the tapered portion of the curved generatrix (7) at top end of the skirt an axially parallel portion in a height of 1.5 to 4.5 mm, preferably 1.5 to 2.5 mm.