Speed-dependent ignition timing system for internal combustion engines

US4237835A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Friedrich Rabus · Schwieberdingen, DE
• Gunter Grather · Pinache, DE
• Richard Schleupen · Großingersheim, DE

Key dates

• Filing date: Nov 28, 1978
• Grant date: Dec 9, 1980
• Expiry date: Nov 28, 1998

Classification

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

Abstract

A speed discriminator circuit furnishes an upper speed range signal if the engine speed is above a preselected speed. When the engine speed is above the preselected speed, the electronic switch controlling the current flow through the primary winding of the ignition coil is switched to the conductive state at a time when a control signal which varies as a function of actual engine speed becomes less than a speed varying reference signal. The switch is opened, thereby creating the first spark, either when the control signal, which is an AC signal, passes through zero or when the current in the primary winding of the coil has reached a predetermined value indicating that sufficient energy for ignition has been stored in the ignition coil. When the speed is less than the preselected speed the electronic switch is closed when the AC control signal passes through zero and is reopened when the current through the primary winding of the ignition coil is indicative of sufficient stored energy for ignition. A circuit for creating a series of additional sparks following the first spark is also disclosed.