Ignition system for internal combustion engine

US4138977A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunter Grather · Pinache, DE
• Friedrich Rabus · Schwieberdingen, DE

Key dates

• Filing date: May 19, 1977
• Grant date: Feb 13, 1979
• Expiry date: May 19, 1997

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02P15/10
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A signal generator, such as a breaker contact, an electronic ignition control system, or the like, provides signals when an ignition event is to occur, to control the operation of a controlled switch, connected in circuit with a spark coil, to open the circuit and induce a pulse for application to a spark plug. To provide a sequence of pulses to the spark plug for any one ignition event, a pulse generator is enabled when an ignition event is commanded. To ensure generation of at least one pulse, even under abnormal conditions which inhibit proper operation of the pulse generator, a timing circuit is connected to the ignition circuit, controlled by the signal generator commanding the ignition event and opening the circuit to the controlled switch to ensure generation of at least one spark pulse; the timing circuit has a longer time constant than the frequency generator under normal operation and thereby provides its command pulse to the controlled switch only upon failure of operation of the frequency generator under normal conditions.