ELECTROMAGNET, MOVABLE IRON CORE THEREOF, AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a movable iron core for an electromagnet which can make its hysteresis small and also can reduce its cost. SOLUTION: The movable iron core 10 of an electromagnet comprises an iron core part 12 and a pin part 14. The iron core part 12 is made in its axial center part with a through hole 11, into which the pin part 14 is disposed as loosely fitted and fixed by spring pins 16. The iron core part 12 and pin part 14 are assembled together by an assembling jig having upper and lower jig parts so that their concentricity is within a predetermined range. For this reason, an increase in cost caused by machining can be prevented. When the movable iron core 10 is disposed within a proportional solenoid, the pin part 14 is slidably supported in a bearing and the through hole 11 of the iron core part 12 can be used also as an oil hole, whereby stable magnetic flux can flow through the iron core part 12 and its hysteresis can be made small.