Patent ID: 8413526

Claim:
An impact detection structure comprising: an acceleration detection portion for detecting acceleration; and a two-stage load transmitting portion that transmits load caused by an impact at a predetermined speed to the acceleration detection portion in two stages having a predetermined time lag in such a manner that the load transmitted or a rate of change in the load differs between a first-stage load transmission and a second-stage load transmission, wherein the two-stage load transmitting portion is constructed so that, in the second-stage load transmission to the acceleration detection portion, the load transmitted or the rate of change in the load increases relative to the load transmitted or the rate of change in the load in the first-stage load transmission to the acceleration detection portion, and wherein the two-stage load transmitting portion is constructed so that when the impact at the predetermined speed occurs, a first local maximum peak of a time variation curve of acceleration caused by the load transmitted by the second-stage load transmission substantially coincides with a second local maximum peak of a time variation curve of acceleration caused by the load transmitted by the first-stage load transmission.