Tire pressure drop alarm device

摘要

Disclosed is a tire pressure drop alarm device for judging a pneumatic pressure drop by calculating rotational angular velocities of tires provided for a four-wheel vehicle. When the vehicle is traveling on a road which varies in condition between left and right sides, a front/rear ratio of rotational angular velocities of the tires at the shoulder side of the road changes more markedly than that of rotational angular velocities of the tires at the center side, and a time differential value appears largely. Therefore, it is possible to judge the traveling condition which varies in road condition between left and right sides. When it is judged to be the traveling condition which varies in road condition between left and right sides, the tire rotation of four wheels is likely to become the unbalanced state to give a false alarm even if the tire pressure does not drop. In this case, therefore, to inhibit the judgment by pneumatic pressure drop judging means prevents an issuance of a false alarm. <IMAGE>