Two-stroke engine

US9353675B2 · kind B2 · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Michael Grether · Waiblingen, DE
• Robert Köhli · Winnenden, DE
• Stefan Kummermehr · Winnenden, DE

Key dates

• Filing date: Dec 15, 2011
• Grant date: May 31, 2016
• Expiry date: May 31, 2032

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B33/04
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A two-stroke engine has a cylinder with a combustion chamber which is bounded by a piston which drives a crankshaft which rotates in a crankcase. The crankcase is connected to the combustion chamber via an overflow passage in the lower dead center region of the piston. The two stroke engine has an intake passage. A carburetor forms a section of the intake passage. The intake passage is partially divided into an air passage, which supplies combustion air into an overflow passage, and a mixture passage which opens into the crankcase. A throttle valve mounted pivotably in the carburetor controls the combustion air quantity supplied to the air and mixture passages. An air-guiding element arranged on the passage wall of the air passage guides the combustion air passing between the throttle valve and passage wall in the idling position of the throttle valve in the direction of the mixture passage.