Collision detecting apparatus for vehicle

The invention provides acollision detecting apparatus for a vehicle, including an integrating means for cumulatively integrating an output from the acceleration sensor when the output exceeds a specific calculation start level, and a collision detecting means for outputting a collision signal when a cumulative integral value calculated by the integrating means exceeds a threshold value, wherein the collision detecting apparatus is intended to accurately perform the collision decision with a high responsiveness irrespective of the severeness of collision. The collision detecting means includes a differentiating means(D) for differentiating the output(G) from the acceleration sensor(S), and a correcting means(H) for correcting the threshold value( alpha ) on the basis of a differential value (dG/dt) calculated by the differentiating means(D).