| 摘要 |
PROBLEM TO BE SOLVED: To detect a reduction in the air pressure of a tire without using a dedicated tire.SOLUTION: Tire air pressure detection devices 10 are mounted inside tires 6. Each of the tire air pressure detection devices 10 includes a tire sensor unit 3. The tire air pressure detection device 10 includes a power supply 18, electrodes 19, a measurement circuit 17, and a sensor unit controller 14. The electrodes 19 are joined to the inner peripheral surface of the tire 6 while being apart from each other in the circumferential direction of the tire 6 and insulated. The measurement circuit 17 measures an electrostatic capacitance of the electrodes 19. When the electrostatic capacitance measured by the measurement circuit 17 is larger than a threshold, the sensor unit controller 14 determines that the air pressure of the tire 6 is reduced. |
