TIRE AIR PRESSURE DETECTING DEVICE

摘要

A tire air pressure detecting device has a tire air pressure detecting means 71 at a wheel, a main transmitting means 77 at the wheel for transmitting an air pressure signal SP to a vehicle body, a main receiving means 81 at the vehicle body for receiving the air pressure signal SP, a main switch turn-on detecting means 82 at the vehicle body for detecting the turn-on of a main switch 23, a second control means 84 at the vehicle body for receiving the air pressure signal SP and a main switch ON signal Son, an auxiliary transmitting means 85 at the vehicle body for transmitting a transmission instruction signal SR to the wheel when the second control means 84 receives the main switch ON signal Son, an auxiliary receiving means 78 at the wheel for receiving the transmission instruction signal SR, and a first control means 76 for reading a new air pressure signal SP. When the main switch is turned on, the state of the tire air pressure can immediately be recognized. The main transmitting means is not required to transmit the air pressure signal at all times or increase the frequency with which to transmit the air pressure signal, and the consumption of the battery at the wheel can be reduced.