Method and apparatus for determining the armature impact time when a solenoid valve is de-energized
AssigneeMTU Motoren-und Turbinen-Union
InventorsJorg Remele, Andreas Schneider
Life of this patent
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Abstract
This invention relates to a method and apparatus for recognizing the impact time of a solenoid valve armature during de-energizing. In order to obtain a detectable impact signal of the armature, a measuring current is provided in the magnet coil during the armature's downward movement to generate a magnetic measuring field. When this magnetic measuring field is changed due to the armature movement, an induction voltage is generated, which is monitored to detect the time of impact of the armature.
Claims11
Method for determining the impact time of a valve armature of a magnetically actuated solenoid valve having a magnet coil for controlling movement of said armature by means of an interruptible control current which flows in said coil, said method comprising the steps of:
- interrupting the control current to initiate a travel phase of said armature;
- causing a measuring current to flow in the magnet coil during the travel phase of the armature, said measuring current having a magnitude sufficient to generate a magnetic field in the magnet coil which causes an induced voltage signal therein in response to movement of the armature, but does not hinder movement of the armature during the travel phase;
- monitoring said induced voltage signal;
- and
- detecting impact of said armature based on a change in said induced voltage signal which occurs in response to said impact.
Device for determining the impact time of a valve armature of a magnetically actuated solenoid valve, comprising:
- a control current circuit for actuating the solenoid valve by means of a selectively interruptible control current;
- a switch for interrupting said control current to thus initiate a travel phase of the armature;
- a control unit which actuates the switch corresponding to the desired injection times;
- a closed clearing circuit with at least one free-running diode;
- and
- means for determining the armature impact time by means of a voltage fed to the magnet coil;
- wherein the clearing circuit comprises an auxiliary voltage source for providing an auxiliary voltage which, when the switch is open, builds up a measuring current in the solenoid valve.
Dependencies are inferred from the claim text.