| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication unit for vehicle mounting capable of realizing stable transmitter output even when it is mounted on a wide variety of wheels. SOLUTION: In the communication unit 20A for wheel mounting having one bolt part 28 and fixed to an outer side of an outer peripheral surface of a wheel rim 14 by fastening a nut 24 to the bolt part 28, a casing 22 supports an antenna and is fixed to the wheel rim 14 in the state that a clearance is provided between the outer peripheral surface 14a of the wheel rim and it. A spring urges a lower surface 22a of the casing in a direction leaving from the outer peripheral surface 14a of the wheel rim near an end in a wheel circumferential direction of the casing 22. When the casing 22 is rotated in a rotation direction of the nut 24 at fastening, the spring urges the casing 22 by larger force by force given to the spring by torque at nut fastening such that a surface of the casing 22 in which the clearance with the wheel rim 14 is narrowed is sepatrated from the wheel rim 14. COPYRIGHT: (C)2007,JPO&INPIT |
