Lagesensor.

摘要

This invention relates to a solenoid device for a flow rate control valve and a displacement sensor. In a conventional solenoid device, it is not possible to obtain the characteristics permitting ease-of-control of the voltage applied to an electromagnetic coil and the stroke of a plunger, or the stroke of the plunger and the oscillation frequency of the coil. Thus, it is difficult to carry out a control operation or accurate measurement, and the stroke of the plunger is short. Therefore, in the present invention, the above problems are solved by forming an end portion of the plunger convergently, whereby the present invention can provide a solenoid device having linear characteristics and used suitably for a long-stroke electromagnetic valve or a highly accurate displacement sensor.