Patent · US Active

Method for switching off a rotational speed limit in an internal combustion engine

US9322329B2 · kind B2 · utility

2Cited by

3References

18Claims

0Family size

Assignee

Andreas Stihl AG & Co. KG · DE

Inventors

Tim Gegg · Waiblingen, DE
Armin Koelmel · Haiterbach, DE
Manuel Dangelmaier · Plochingen, DE

Key dates

Filing date	Jul 31, 2013
Grant date	Apr 26, 2016
Priority date	—
Expiry date	Mar 14, 2034

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF02D31/009
WIPO fieldEngines, pumps, turbines
WIPO sectorMechanical engineering

Abstract

A method controls the rpm of a combustion engine in a hand-held work apparatus such as a brushcutter. The engine drives a work tool via a clutch which engages as a function of the engine rpm (n). A spark plug is arranged in the combustion chamber and is driven by an ignition unit. During start of the engine, an rpm lock circuit is active and defines a control variable as a function of the instantaneous rpm (nact) of the engine. According to the magnitude of this control variable, operating parameters of the engine are adapted to change the instantaneous rpm (nact). A control variable is determined for the adaptation of the operating parameters by the rpm lock circuit. The switch-off of the rpm lock circuit is provided when the control variable of the control lies outside a predetermined bandwidth of the absolute magnitude of the control variables.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.