| 摘要 |
PURPOSE:To absorb the crashing sound of the solenoid due to the viscosity of a magnetic fluid by a method wherein the magnetic fluid is adhered to magnetic substances, and said magnetic fluid is pressed directly immediately before the final attracting position of a plunger. CONSTITUTION:When a coil 2 is turned on electricity, the plunger 3 is attracted to a core 1, transfers rapidly up to the neighborhood of the finally attracting position, and the press board 6 is engaged with the inside of the concave notch part 7a of a pressure regulation chamber 7. Then during the time that the plunger 3 to reach the final attracting position moreover, the magnetic fluid 11 adhered to the insides of the press board 6 and the pressure receiving board 10 facing mutually is pressed strongly, and the magnetic fluid 11 flows into escape paths 7b, 7c, 7d. At this time, air escapes from pressure extract valves 7b', 7c', 7d' at the upper edges of the escape paths, the magnetic fluid flows into the escape paths smoothly, and the colliding impact of the plunger 3 to the core 1 is absorbed completely by the viscosity of the magnetic fluid 11. |
