TRANSMISSION DEVICE FOR TRANSMITTING INFORMATION ABOUT TIRE CONDITION AND TIRE CONDITION MONITORING SYSTEM

摘要

A tire condition monitoring system includes a transmission device, a receiving device, and a monitoring section. The transmission device includes a sensor which detects a condition of gas in a tire cavity area surrounded with a tire and a rim as tire information, a transmitter which wirelessly transmits the tire information, and a housing which houses the sensor and the transmitter. An opening portion of an air vent connecting a housing inner space and the cavity area is formed on top of a protruding portion protruding from the surface of the housing. An area of the opening portion is 0.4 mm2 or smaller. An area of contact between the top portion and a contact plane in contact with the top portion and perpendicular to a protruding direction of the protruding portion is not larger than 30% of the opening portion area.