| 摘要 |
PROBLEM TO BE SOLVED: To inhibit a suppression of a displacement of a supermagnetostrictive rod even by extending the rod in a state in which a prestress is actuated and to simultaneously enable a simple regulation of a prestress to an optimum set pressure. SOLUTION: A spring (8) having a smaller spring constant of a preset actuating deflecting range than that when its deflection is smaller than the preset range and having substantially predetermined nonlinear characteristics in which a spring force is equal to the set pressure of the prestress within the deflecting range and a pressurizing member (3T) for actuating the rod (2) in its axial direction with the spring force as the prestress are arranged at a free end side of the rod (2). |
