Two-stroke engine having a ventilated transfer channel

US6257181A · kind A · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Heiko Rosskamp · Adelberg, DE
• Lars Bergmann · Waiblingen, DE

Key dates

• Filing date: Aug 24, 2000
• Grant date: Jul 10, 2001
• Expiry date: Aug 24, 2020

Classification

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

Abstract

The invention relates to a two-stroke engine having a combustion chamber (3) configured in a cylinder (2). The combustion chamber is delimited by a piston (5) which moves upwardly and downwardly. The crankcase (4) is connected to the combustion chamber (3) via an transfer channel (14). A first end (20) of the transfer channel (14) opens into the combustion chamber (3) via an entry window (12) lying in the cylinder wall (16) and controlled by piston the (5). Between its ends (19, 20), the transfer channel (14) is connected to a gas channel (22) via a valve (21). The gas channel (22) essentially supplies fuel-free gas. The air/fuel mixture, which is necessary for the operation of the two-stroke engine, is supplied to the crankcase (4) via an inlet (11). In order to ensure a full charge of the transfer channel (14) with fuel-free gas, the entry window (12) of the transfer channel (14) is held open to the crankcase (4) in a stroke position of the piston (5) in the region of top dead center. The maximum cross section then corresponds only to a portion of the area of the entry window (12).