Two-cycle engine

US6945203B2 · kind B2 · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Helmar Amend · Waiblingen, DE
• Klaus-Martin Uhl · Plochingen, DE
• Werner Geyer · Newton, US
• Claus Fleig · Asperg, DE

Key dates

• Filing date: May 23, 2003
• Grant date: Sep 20, 2005
• Expiry date: Jan 13, 2024

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B2075/025
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A two-cycle engine is provided, especially in a manually-guided implement such as a power chain saw, a brush cutter, a trimmer or the like, and has a cylinder in which is formed a combustion chamber that is delimited by a reciprocating piston that, via a connecting rod, drives a crankshaft that is rotatably mounted in a crankcase. In prescribed positions of the piston, the combustion chamber is connected with the crankcase via at least two transfer channels. At least one air channel is provided that opens out at an air channel window at the cylinder in the region of the piston, and that, in prescribed positions of the piston, is connected with at least two transfer channels via a piston window formed in the piston. To achieve a good scavenging of the combustion chamber, and hence low exhaust gas values of the engine, structural features are provided on the piston window for the defined distribution of air to the transfer channels.