Method of controlling the demagnetization phase of electromagnetic devices, especially of electromagnetic valves of combustion engines

US4856482A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Ernst Linder · Mühlacker, DE
• Helmut Rembold · Stuttgart, DE
• Walter Teegen · Waiblingen, DE

Key dates

• Filing date: Nov 6, 1987
• Grant date: Aug 15, 1989
• Expiry date: Nov 6, 2007

Classification

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

Abstract

In a method for controlling the demagnetization phase of electromagnetic devices, particularly electromagnetic valves in combustion engines, the exciting current i=i(t), starting from a high holding current value, is decreased not to zero or even to a negative value, but to a value in the positive range below the holding current. Because of the characteristic current and/or voltage values which accordingly occur in the excitation circuit, the start of the opening and the end of the opening of the valve needle of the electromagnetic valve can be determined in a particularly precise manner and can be taken into account for an optimal influencing of the manner of operation of the combustion engine (FIG. 3).