Method and apparatus for operating an electromagnetic load, especially an injection valve in internal combustion engines

US4266261A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Klaus Streit
• Klaus Harsch · Ditzingen, DE
• Peter Schulzke · Oberriexingen, DE

Key dates

• Filing date: Jun 25, 1979
• Grant date: May 5, 1981
• Expiry date: Jun 25, 1999

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D2041/2058
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A method is proposed for operating an electromagnetic load device with a movable armature, especially an injection valve of an internal combustion engine. The load device is supplied, at the beginning of trigger pulse, with a high amperage current and, at least toward the end of the pulse, with a reduced current. This method is characterized in that, starting with a certain amperage, at which preferably the armature is set into motion but has not as yet reached its final position, the current rise is at least reduced. The apparatus aspect comprises a measuring element and switching element connected in series with the load device. A threshold switch is associated with the measuring element to control the switching element. The switching thresholds of the threshold switch can be controlled in dependence on current and/or on time. The first current threshold is at a value at which the armature of the load is preferably being moved, but has not yet reached its final position. The method and the apparatus achieve a low power operation of the load device with a coincidence factor between the trigger pulse signal and, for example, the switching characteristic of an injection valve. It is…