Electromagnetic contactor
View Patent ↗The electromagnetic contactor has a pair of fixed contacts disposed to maintain a predetermined interval and a movable contact disposed so as to be attachable to and detachable from the pair of fixed contacts, and an electromagnet unit that drives the movable contact. The electromagnet unit has a magnetic yoke enclosing a plunger drive portion, a movable plunger having a leading end protruding through an aperture formed in the magnetic yoke and biased by a return spring, an annular permanent magnet fixedly disposed so as to enclose a peripheral flange portion formed on a protruding end side of the movable plunger and magnetized in a direction in which the movable plunger can move, and an auxiliary yoke disposed on the annular permanent magnet at a side opposite to that of the magnetic yoke and regulating a movement of the peripheral flange portion of the movable plunger.
1. An electromagnetic contactor, comprising:
a pair of fixed contacts disposed to maintain a predetermined interval and a movable contact disposed so as to be attachable to and detachable from the pair of fixed contacts; and
an electromagnet unit that drives the movable contact, including:
a magnetic yoke enclosing a plunger drive portion,
a movable plunger having a leading end protruding through an aperture formed in the magnetic yoke, the movable plunger supporting the movable contact via a connecting shaft and being urged by a return spring,
an annular permanent magnet fixedly disposed so as to enclose a peripheral flange portion formed on a protruding end side of the movable plunger and magnetized in a direction in which the movable plunger can move, and
an auxiliary yoke disposed on the annular permanent magnet at a side opposite to that of the magnetic yoke and regulating a movement of the peripheral flange portion of the movable plunger,
wherein the auxiliary yoke includes a stepped plate portion formed in a central portion of a flat plate portion to protrude and having an aperture through which the connecting shaft is inserted.
2. The electromagnetic contactor according to claim 1 , wherein the auxiliary yoke is formed such that the flat plate portion and stepped plate portion are integrally formed by pressing.
3. The electromagnetic contactor according to claim 1 , wherein a height of the stepped plate portion is determined in accordance with a stroke necessary for the movable plunger.