Patent ID: 8823505
Filing Date: 2014-09-02
Classification: B60C

Abstract:
1. A tire air pressure detecting device comprising: an air pressure detecting unit configured and arranged to detect a tire air pressure of a tire mounted to a vehicle; a transmitting unit configured and arranged to transmit a detected value of the tire air pressure detected by the air pressure detecting unit; a running state detecting unit configured and arranged to detect a running state of the vehicle; an air pressure change rate detecting section configured to detect an air pressure change rate at which the tire air pressure changes; and a frequency adjustment section configured to adjust a transmitting frequency at which the detected value of the tire air pressure detected by the air pressure detecting unit is externally transmitted by the transmitting unit according to the running state detected by the running state detecting unit and the air pressure change rate detected by the air pressure change rate detecting section, the frequency adjustment section being further configured to variably set an air pressure change rate threshold value for switching the transmitting frequency from low frequency to high frequency according to the running state, such that the frequency adjustment section sets the air pressure change rate threshold value used while the running state indicates a low-speed travel state of the vehicle to a smaller value than the air pressure change rate threshold value used while the running state indicates a high-speed travel state of the vehicle so that the transmitting frequency is changed from the low frequency to the high frequency at a value of the detected air pressure change rate that is lower for the low-speed travel state than a value of the detected air pressure change rate for the high-speed travel state.