Electromagnetic contactor

Patent metadata

Field	Value
Publication number	US-9514896-B2
Application number	US-201414505009-A
Country	US
Kind code	B2
Filing date	Oct 2, 2014
Priority date	Jun 8, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

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.

First claim

What is claimed is:

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.

Assignees

• Fuji Electric Fa Components & Systems Co Ltd
• Fuji Electric Co Ltd

Inventors

• Naka Yasuhiro
• Takaya Kouetsu
• Suzuki Kenji

Classifications

• H01H50/163

  Details concerning air-gaps, e.g. anti-remanence, damping, anti-corrosion · CPC title

• H01H2001/545

  having permanent magnets directly associated with the contacts · CPC title

• H01H50/36

  Stationary parts of magnetic circuit, e.g. yoke · CPC title

• H01H50/42

  Auxiliary magnetic circuits, e.g. for maintaining armature in, or returning armature to, position of rest, for damping or accelerating movement · CPC title

• H01H1/54 Primary

  by magnetic force {(combined with electrodynamic opening H01H77/101)} · CPC title