Patent ID: 9561695
Date: 2017-02-07
CPC Classifications: B60C,G01L

Claim:
1. A tire internal pressure warning system, comprising: an internal pressure data acquisition apparatus for obtaining data of internal pressure of each tire of a vehicle by directly measuring the internal pressure; and an information terminal device for determining whether there is a puncture-based failure or a failure resulting from a natural pressure drop, based on a change in the internal pressure of each tire received from the internal pressure data acquisition apparatus, and displaying a warning in accordance with the failure condition, wherein the information terminal device is adapted to judge, in determining whether there is a puncture-based failure or a failure resulting from a natural pressure drop based on data of differences in internal pressure between the respective tires, that i) a nail stuck has occurred when: difference between an internal pressure value thus measured and an internal pressure reference value is within the range of 15% to 30% of the internal pressure reference value for at least one of the left-hand side two tires or at least one of the right-hand side two tires; and difference between the highest internal pressure value of the tires of all wheels and the internal pressure value in the range of 70% to 85% of the internal pressure reference value of said tire is equal to or larger than a prescribed threshold value, ii) air pressure of the tires need be checked when difference between the internal pressure value and the internal pressure reference value is within the range of 15% to 30% of the internal pressure reference value for at least one tire of all wheels, iii) the tire must be inflated immediately when the internal pressure reference value is within the range of 220 kPa to 330 kPa and difference between the internal pressure value and the internal pressure reference value is 30% or more of the internal pressure reference value for at least one tire of all wheels, iv) puncture has occurred when the internal pressure reference value exceeds 330 kPa and the internal pressure value is smaller than (the internal pressure reference value−100 kPa) for at least one tire of all wheels or when the internal pressure reference value is less than 220 kPa and the internal pressure value is smaller than 150 kPa for at least one tire of all wheels.