Method for detecting valve play in a cylinder valve actuated by an electromagnetic actuator

A method for detecting play between a cylinder valve of a piston engine and an electromagnetic actuator that actuates the cylinder valve, the electromagnet having a closing electromagnet and an opening electromagnet, two restoring springs and an armature which is guided to be movable back and forth between the two electromagnets, in each case counter to a force of a respective one of the restoring springs for acting upon the cylinder valve, the cylinder valve including a cylinder body, the method comprising the steps of:

• with the armature held at one of the electromagnets by a holding current, measuring a time interval t.sub.H after turnoff of the holding current I.sub.H at the holding electromagnet until the arrival of the armature at the other one of the electromagnets;
• and
• calculating the valve play by subtracting from the time interval t.sub.H a motion time t.sub.B predetermined by the spring-mass system comprising the armature, valve body and restoring springs and a sticking time t.sub.K during which the armature remains at the holding electromagnet after cutoff of the holding current.