Device for detecting faults in an apparatus for detecting knocking

US5517969A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Stefan Unland · Schwieberdingen, DE
• Oskar Torno · Schwieberdingen, DE
• Werner Haeming · Neudenau, DE
• Ulrich Rothhaar · Milano, IT
• Iwan Surjadi · Leinfelden, DE
• Wolfgang Hilbert · Heubach, DE
• Robert Sloboda · Yokohama, JP
• Michael Baeuerle · Rutesheim, DE

Key dates

• Filing date: May 11, 1995
• Grant date: May 21, 1996
• Expiry date: May 11, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A device for detecting faults in conjunction with the detection of knocking in an internal combustion engine is disclosed, in which device the sensor output signals are compared with an engine speed-dependent, normalized reference level in order to detect knocking. As a function of the comparison result, knocking is detected and, when knocking is detected, knocking-preventing measures are initiated. So that the internal combustion engine does not erroneously go into unacceptable operating states when a knocking sensor or the associated evaluation circuit is operating incorrectly, continuous detection of faults takes place, during which it is tested whether the normalized reference level lies within a permitted range which is formed as a function of engine speed, this range being either the permitted, normalized reference level band or a range between an engine speed-dependent upper limit value (UGO) and an engine speed-dependent lower limit value (UGU). If the normalized reference signal level leaves this range for a prescribable time, a fault is detected and safety measures are initiated which are effective until the reference level lies within the permitted range again.