Air pressure detection device for tire

Abstract

A vehicle is provided with an air pressure detection device for a tire which includes a temperature sensor for measuring the temperature of a tire and an air pressure sensor for measuring the air pressure of the tire. A reduced air pressure arithmetic portion is provided for calculating a reduced air pressure Pm from the temperature Tx measured by the temperature sensor and the air pressure Px measured by the air pressure sensor by the formula set forth below. An alarm signal generating portion is provided for generating an alarm signal when the reduced air pressure Pm calculated by the reduced air pressure arithmetic portion is decreased to or below a first threshold value Pa. Pm=Px−K(Tx−T0) The condition where the tire air pressure is lowered to or below a threshold value determined based on a recommended air pressure can be accurately detected, and an alarm can be issued, without being affected by tire temperature rise or temperature variations.

Dependencies are inferred from the claim text.