JPS6482606A - Electromagnet device - Google Patents

Abstract

PURPOSE:To decrease power consumption and to lower manufacturing cost, by determining a position of a recess such that a first opposing section is faced with the recess when an armature is stabilized by a permanent magnet and a return spring and the first opposing section is apart from the recess when the armature is in operation. CONSTITUTION:Position of a recess 9d is determined such that a first opposing section 3a is opposed to the recess 9d when an armature 2 is stabilized by a permanent magnet 5 and a return spring 15 and the first opposing section 3a is away from the recess 9d when the armature 2 is actuated by excitation of a coil 1. Since the first opposing section 3a of the first yoke is opposed to the recess 9d of the second movable section 9b when the armature 2 is in the returned state, magnetic flux of the permanent magnet 5 does not flow through the second yoke 3, and the armature 2 is held with a gap G4 closed. When current is supplied to the coil 1 such that magnetic flux flows in the opposite direction to that of magnetic flux in a path phi1 flowing across the gap G4, the recess 9d is removed from the opposing section 3a as the armature 2 is moved. Thereby, the gap G1 is closed and a closed magnetic loop not pass ing the permanent magnet 5 can be formed.