Patent ID: 7823683

Claim:
A collision detection apparatus for a vehicle, wherein the collision detection apparatus detects collision of an object with the vehicle, the collision detection apparatus comprising: a bumper reinforcement that is mounted on the vehicle, the bumper reinforcement extending in a transverse direction of the vehicle; a chamber forming member that is provided at a side of the bumper reinforcement, the chamber forming member defining a chamber space that is deformable when the object collides with the vehicle; a pressure sensor that detects pressure in the chamber space; collision object determining means for determining a category of the object by comparing the pressure detected by the pressure sensor with a predetermined determination threshold value; and a collision position sensor that detects a position in the vehicle transverse direction, at which position the object collides, wherein the collision object determining means changes the determination threshold value based on the collision position detected by the collision position sensor, wherein: the chamber forming member has a rigidity in a fore-and-aft direction of the vehicle, which rigidity changes with a position in the chamber forming member in the vehicle transverse direction; the rigidity of the chamber forming member in the vehicle fore-and-aft direction is higher at an end section of the chamber forming member in the vehicle transverse direction than at a center section of the chamber forming member in the vehicle transverse direction; the determination threshold value is set lower when the collision position corresponds to the end section than when the collision position corresponds to the center section; and the chamber forming member has a length in the fore-and-aft direction of the vehicle, which length is largest at the center section, and which length becomes smaller toward the end section.