Apparatus for controlling the current through an electromagnetically actuatable injection valve in an internal combustion engine valve in an internal combustion engine

US4328526A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Peter Dilger · Schwanau, DE
• Gunter Honig · Ditzingen, DE
• Helmut Kauff · Schwieberdingen, DE

Key dates

• Filing date: Jan 7, 1980
• Grant date: May 4, 1982
• Expiry date: Jan 7, 2000

Classification

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

Abstract

An apparatus for controlling the current through an electromagnetic injection valve of an internal combustion engine during its pickup and holding phases by opening and closing a first switch connecting the valve to a voltage source. The first switch is initially closed by a valve timing circuit to initiate pickup of the valve. A first current-sensing resistor connected in series with the first switch produces a signal to open the first switch when the valve current attains an upper threshold value which assures valve pickup, and to close a second switch connected in series with a second current-sensing resistor across the valve. When the valve current drops to a lower threshold value greater than the valve drop-out current, the second current-sensing resistor produces a signal to reclose the first switch and open the second switch for a predetermined time, after which the first switch is again opened and the second switch closed. The cyclic opening and closing of these switches by the second current-sensing resistor continues until both switches are opened by the valve timing circuit. In another embodiment, the pickup time of the valve is determined by measuring the time for the v…