To provide a technology of splitting the data transmission from a spare tire and the data transmission of a traveling tire by a simple structure.
A tire information detection device 10 for detecting the state of a tire of a vehicle comprises a battery 36 for supplying the power, a circuit device 40 having a sensor for detecting the state quantity of the tire and a transmitter for transmitting the detected value by the sensor, and a switch 35 capable of opening/closing the electronic connection between the battery 36 and the circuit device 40. In a valve cap 20 for the spare tire to be attached to a valve 30 of the tire, a pressing unit 26 presses a movable shaft 28 of a valve core 29 in the valve 30 inward of the radial direction. The movable shaft 28 pressed in the pressing unit 26 opens the electric connection of the switch 35 of the tire information detection device 10.
Yusuke Murata
Tomoyuki Miki