초록 ▼

A method is provided for reducing an impact speed of an armature on a pole face of an electromagnet in an electro-magnetic actuator, in which the armature moves toward the pole face against a restoring spring force when the coil of the electromagnet is charged with current. The method includes limit

A method is provided for reducing an impact speed of an armature on a pole face of an electromagnet in an electro-magnetic actuator, in which the armature moves toward the pole face against a restoring spring force when the coil of the electromagnet is charged with current. The method includes limiting a voltage applied to the coil to a predeterminable maximum value as the armature approaches the pole face so that a current flowing through the coil drops for a portion of the time of the voltage limitation.

대표청구항 ▼

[ What is claimed is:] [13.] An electromagnetic actuator comprising:an armature having a face;an electromagnet having a coil and a pole face opposite the face of said armature;a restoring spring coupled to said armature for applying a force against said armature when the face of said armature moves

[ What is claimed is:] [13.] An electromagnetic actuator comprising:an armature having a face;an electromagnet having a coil and a pole face opposite the face of said armature;a restoring spring coupled to said armature for applying a force against said armature when the face of said armature moves towards the pole face of said electromagnet;a circuit for applying a voltage and a current to the coil of said electromagnet to move the face of said armature toward the pole face of said electromagnet; anda limiting circuit for limiting the voltage applied to said coil to a maximum value when the face of said armature approaches the pole face of said electromagnet, such that due to a voltage additionally induced across said coil during a final approach of the face of said armature towards the pole face of said electromagnet, the current flowing through said coil decreases for a portion of time just prior to armature impact, thereby reducing an impact speed of the face of said armature on the pole face of said electromagnet.