Two-cycle engine

US6874455B2 · kind B2 · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Werner Geyer · Newton, US
• Claus Fleig · Asperg, DE
• Jorg Schlossarczyk · Winnenden, DE

Key dates

• Filing date: May 15, 2003
• Grant date: Apr 5, 2005
• Expiry date: May 15, 2023

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, especially in a portable, manually-guided implement, is provided, and has a combustion chamber that is formed in a cylinder and is delimited by a reciprocating piston, which via a connecting rod drives a crankshaft mounted in a crankcase. The engine has an inlet and an outlet, as well as at least one transfer channel that, in prescribed positions of the piston, connects the crankcase with the combustion chamber. An air channel that conveys essentially fuel-free air is, in prescribed positions of the piston, fluidically connected via a piston window with an inlet window of a transfer channel into the combustion chamber. For a good scavenging result, the flow resistance through the transfer channel in the direction of flow from the crankcase to the combustion chamber corresponds approximately to the flow resistance in the direction of flow from the combustion chamber to the crankcase.