| 摘要 |
A seatbelt retractor includes an acceleration sensor. The acceleration sensor includes a sensor case having a supporting surface which is maintained horizontal. A self-standing inertia body whose bottom surface is placed on the supporting surface is installed inside the sensor case in a self-standing condition, and which tilts when a horizontal acceleration is exerted. An actuating member which, in accordance with a tilting movement of the self-standing inertia body, activates a lock mechanism to lock the extraction of the seat belt. An outer contour of a contact area where the supporting surface of the sensor case and the bottom surface of the self-standing inertia body are in surface contact is configured such that a distance from a center axis of the self-standing inertia body to the outer contour differ, in a horizontal plane, in a first direction and in a second direction orthogonal to the first direction. |
