Method of controlling a device for varying the valve control times of an internal combustion engine, especially a camshaft adjustment device with a hydraulicaly releasable start locking system

US6491009B1 · kind B1 · utility

Assignee

• INA Wälzlager Schaeffler oHG · DE

Inventors

• Jens Schmaler · Mering, DE
• Rainer Ottersbach · Bonn, DE

Key dates

• Filing date: Jan 9, 2002
• Grant date: Dec 10, 2002
• Expiry date: Jan 9, 2022

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F01L1/3442
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

The invention concerns a method of actuating a device for varying the valve timing of an internal combustion engine, said device comprising an element fixed to the camshaft and an element fixed to the crankshaft, which elements are in power-transmitting relationship with each other through at least one hydraulic working chamber formed within the device. When the internal combustion engine has been switched off, the element fixed to the camshaft can be mechanically coupled by a locking element to the element fixed to the crankshaft in a preferred basic position for starting the internal combustion engine. According to the invention, to avoid a jamming of the locking element during starting of the internal combustion engine, the solenoid of the hydraulic valve is at first subjected to a sudden energization with a current of an intensity lower that that required for the central position of the valve piston of the hydraulic valve. Following this, the energization is gradually increased to a current intensity higher than that required for the central position of the valve piston. If the microprocessor now determines that the element fixed to the camshaft is still in its basic position, …