POLAR ELECTROMAGNET

摘要

Provided is a polar electromagnet wherein a flux leakage is suppressed at a position in which the flux leakage does not act on an attractive force between an inner yoke and an outer yoke so that the attractive force of a permanent magnet can be improved. The polar electromagnet is comprised of a spool (11) around which an electromagnetic coil is wound, a movable plunger (15) which penetrates through the spool, an inner yoke (22) secured to the outside of the spool, an outer yoke (21) which is spaced from the inner yoke at a predetermined distance and which is disposed on the outside of the inner yoke, and a permanent magnet (24) which is disposed between the inner yoke and the outer yoke. The outer yoke (21) is comprised of a pair of end plate portions (21a, 21b) which are opposite to both ends of the spool, and a connecting plate portion (21c) which connects the end plate portions. The inner yoke (22) is comprised of a first opposite plate portion (22a) which is opposite to the connecting plate portion (21c) of the outer yoke, and second opposite plate portions (22d, 22e) which are opposite to the end plate portion (21b) of the outer yoke. The first opposite plate portion and the second opposite plate portions are connected without being adjacent to the outer yoke.