To miniaturize an automobile body and to reduce occupant deceleration at the time of a collision by continuously breaking a small diameter part of a reaction generating member so as to continuously generate reaction lower than initial reaction with large strokes.
In the initial stage of a collision, an opening 1a is pushed open by an enlarging part 4a, elastic area stress is generated to a large diameter part 1b, and deceleration rises sharp until reaching plastic deformation starting load (a-area). Deformation and breaking are then generated while generating constant reaction load to maintain certain deceleration (b-area). In the middle stage of the collision, deformation and breaking of a taper part 1c are started (c-area). While this small diameter part 1c continues deformation, almost constant low reaction load is continuously generated, and deceleration is constant (d-area). In the final stage of the collision, inertia force of an occupant is already almost nullified, and the deceleration difference between a body and the occupant is small, so that influence on occupant deceleration can be very small (e-area). Reaction is thus changed to reduce occupant deceleration.
ARIMURA YUTAKA
MURAYAMA KEIICHI
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