Fuel pump for an internal combustion engine

US5419686A · kind A · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Michael Wissmann · Markgröningen, DE
• Hans Nickel · Cottenweiler, DE
• Roland Schierling · Marbach am Neckar, DE
• Roland Adam · Besigheim, DE
• Werner Geyer · Newton, US

Key dates

• Filing date: Jul 19, 1993
• Grant date: May 30, 1995
• Expiry date: Jul 19, 2013

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 is directed to a fuel pump for an internal combustion engine such as a two-stroke engine in a portable handheld work apparatus such as a motor-driven chain saw or the like. A pump chamber is connected via a suction valve to a fuel feed and via a pressure valve to a pressure line. A pump membrane delimits the pump chamber and is driven by the fluctuating crankcase pressure of the engine which is present in the work chamber. Pump operation free of disturbances over a wide rpm range is attained with the suction valve to the pump chamber being configured essentially as a valve having the shape of a part circle, The pressure valve is disposed approximately at the center of the suction valve and delimits the pump chamber in the stroke direction of the pump membrane.