| 摘要 |
PROBLEM TO BE SOLVED: To provide a small electromagnetic drive device where a housing part supports a movable core, and the hysteresis of a reciprocating movement of the movable core is small to a current applied to a coil and a flow control device using the same. SOLUTION: A non-magnetic layer is formed on the inner circumferential wall of a housing part 13 and the outer circumferential wall of a plunger 17. Provided that the thickness of the non-magnetic layer of the housing part 13, the thickness of the non-magnetic layer of the plunger 17, a magnetic gap formed between the magnetic materials of the housing part 13 and the plunge 17 except their non-magnetic layers, and an air gap between their non-magnetic layer in a radial direction when the plunger 17 is not positioned eccentrically but coaxially with the housing part 13 are represented by t0, t1, d0, and d1, respectively; t0, t1, d0, and d1 are so set as to satisfy formulas, 40μm<=t0+t1<=80μm, d0≈100μm. When a current supplied to a coil 20 is increased to reach a prescribed value ranging from 40 to 60% of the maximum current, an attraction part 14 is so set as to get magnetically saturated.
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