Patent ID: 7562575

Claim:
An acceleration sensor comprising: an acceleration sensor element having a weight located in a center of the acceleration sensor element, a support frame surrounding the weight and being at a predetermined distance from the weight, a plurality of elastic arms bridging an upper portion of the weight and an upper portion of the support frame and hanging the weight, and strain gauges formed on the elastic arms; a first regulation plate mounted on the acceleration sensor element with a first predetermined gap with a top surface of the weight; and a protection case with an inner bottom plate fixed to a bottom surface of the support frame of the acceleration sensor element, wherein said inner bottom plate has a gap between a weight bottom surface and a part of the inner bottom plate of the protection case facing the weight bottom surface; wherein an impact buffer material is fixed to at least one of the weight bottom surface and the part of the inner bottom plate of the protection case facing the weight bottom surface, and the other of the weight bottom surface and the part of the inner bottom plate of the protection case facing the weight bottom surface forms a second predetermined gap with the impact buffer material.