| 摘要 |
PURPOSE:To suppress the resonance of a mass body caused by the vibration of a vehicle in the captioned sensor in which the mass body is varied by a horizontal acceleration to operate a working body by providing a plurality of mass bodies and providing a means for limiting the displacement to at least one horizontal direction of each mass body. CONSTITUTION:The captioned acceleration sensor which is suitable for a webbing wind-up device has a pole (working body) 38 which can be engaged with the rock ring of the wind-up device. The pole 38 is swingably supported by bearing portions 36, 36 on the base portion 28 of a bracket 18. A partition wall 24 which is bent in a stairway form as a displacement limiting means is erected on the base portion 28, a recessed portion having a conical inclined face 30 is formed on the bottom portion of each portion between the wall faces 24A, 24B and between 24C, 24D thereof, and each sensor ball (mass body) 32A, 32B is housed in each recessed portion. These sensor balls 32A, 32B rise up on the inclined faces 30 when a horizontal acceleration above a certain value is applied, causing the pole 38 to swing to be engaged with the rock ring. |
