CAP OF TIRE PRESSURE INJECTION VALVE, TIRE PRESSURE INJECTION VALVE, AND TIRE MONITORING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a cap of a tire pressure injection valve having a simple structure having a detecting device requiring no battery, the tire pressure injection valve having the cap, and a tire monitoring system comprising the detecting device requiring no battery and a relay device that supplies power to the detecting device without wire and facilitates battery replacement. SOLUTION: The detecting device 3 driven by power supplied by electromagnetic wave of an information request signal is disposed in a valve cap of a wheel 2 of a vehicle 1, and the relay device 4 is disposed outside a tire air chamber on a tire wheel. The relay device 4 amplifies the information request signal from a monitor device 5 and transmits it to the detecting device 3, and amplifies a response signal from the detecting device 3 and transmits it to the monitor device 5.