| 摘要 |
PURPOSE:To improve the attractive force characteristics to the traveling stroke of a plunger by a method wherein the surface of the plunger and the surface of a fixed core which are facing each other formed into spiral shape. CONSTITUTION:A plunger 3 is composed of magnetic material and inserted into a penetrating hole 2c of a coil frame 2a and can be moved freely. One end 3a of the plunger 3 is facing a fixed core and works as a contact surface of the movable side and is so formed as to be projected from the surface perpendicular to the plunger axis. Another end 3b of the plunger is connected to an outside load. The fixed core is composed of magnetic material and provided in the penetrating hole 2c of an exciting coil 2b. One end 4a of the fixed core is fixed to a yoke 1 and another end 4b works as a contact surface of the fixed side and is facing the spiral contact surface of the plunger 3 and is abutted against the plunger 3 by the excitation of the coil 2b. The shape of the contact surface of the fixed core is concave spiral corresponding to the spiral shape of the plunger 3. |
