Bayerische Motoren Werke Aktiengesellschaft

Konrad Reif

Ralf Cosfeld

An electromagnetic valve drive of a charge cycle valve for an internal-combustion engine has an electromagnetic actuator and additional electric devices, such as a power system operating the actuator, a controlling and regulating device as well as a power supply. For reducing electromagnetic compatibility problems and connection problems, at least one information signal connection between two of the devices is established using a glass fiber connection.

Electromagnetic valve gear

A process for operating an electromagnetic actuator is provided, in particular to actuate a gas exchange lift valve of an internal combustion engine, with an armature, which is moved oscillatingly between two electromagnetic coils against the force of at least one return spring via an alternating supply of current to the electromagnetic coils. Whereby, during the so-called catch process as the armature approaches the coil that is subjected first to a current flow, the voltage applied to the coil catching the armature is reduced. To avoid unnecessary losses, a voltage curve is chosen with which an eddy current, calculated with a mathematical model, is minimized in the armature.

Process for operating an electromagnetic actuator

A process for setting into oscillation an electromagnetic actuator, which actuates a switching element, in particular an internal combustion engine lift valve, and in which process an armature, which acts on the switching element, is oscillated between two electromagnet coils against the force of at least one reset spring by an alternating flow around the electromagnet coils so that the switching element with the armature and the reset springs represents an oscillatory spring-mass system, and wherein, starting from the quiescent state of the system, where the armature is held by the reset springs essentially in the center between these magnet coils, the electromagnet coils are excited alternatingly by driving with an electric alternating voltage of a specific frequency to set into oscillation this spring-mass system in the form of a constantly sinusoidal voltage curve or in the form of a correspondingly variable pulse width-modulated voltage curve.

Process for setting into oscillation an electromagnetic actuator

The invention relates to a method for controlling the movement of an armature of an electromagnetic actuator, particularly for operating a charge cycle lifting valve of an internal-combustion engine, the armature being moved in an oscillating manner between two solenoid coils in each case against the force of at least one restoring spring by the alternating energizing of the solenoid coils, and, with an approach of the armature to the first-energized coil, during the so-called capturing operation, the electric voltage being reduced which is applied to the coil capturing the armature. The capturing phase of the capturing operation is followed by a braking phase in which, until the armature impacts on the coil, an electric voltage is applied to the latter in a switched manner, the respective switching points in time and the voltage switching ratio being determined by a controller by means of a desired trajectory describing the desired armature movement. Preferably, a positive or negative voltage value, whose amount is constant, or the &ldquo;zero&rdquo; voltage value is applied in a switched manner to the coil capturing the armature.

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Ottobrunn, Germany

Konrad Reif