Patent ID: 8047246

Claim:
An apparatus for controlling tire inflation pressure in which pressurized air supplied from a pressure generating device is introduced into a tire air chamber of a vehicle wheel assembly through a supplying passageway provided in an axle and an introducing passageway provided in a wheel of the vehicle wheel assembly which is removably mounted onto a flange portion of the axle, comprising: sealing means provided in the inlet side end portion of the introducing passageway, the sealing means opening the introducing passageway to air when the vehicle wheel assembly is mounted onto the axle and closing the introducing passageway air tightly when the vehicle wheel assembly is removed from the axle, wherein a column-shaped boss portion which projects in an outward direction of a vehicle from the flange portion of the axle is provided as a portion of the axle so as to be capable of fitting with an annular hub portion of the wheel, and an outlet side end portion of the supplying passageway has an opening on an outer circumference of the column-shaped boss portion, an inlet side end portion of the introducing passageway has an opening on an inner circumference of the annular hub portion, and by mounting the wheel of the vehicle wheel assembly onto the axle, the inner circumference of the annular hub portion in the wheel of the vehicle wheel assembly is fitted with the outer circumference of the column-shaped boss portion in the axle, and thereby the outlet side end portion of the supplying passageway and the inlet side end portion of the introducing passageway are communicatively connected to each other air tightly; wherein the apparatus for controlling tire inflation pressure comprises a plurality of the outlet side end portions of the supplying passageways and a plurality of the inlet side end portions of the introducing passageways so that the outlet side end portions and the inlet side end portions are arranged at equiangular intervals so as to match with a mounting phase of the vehicle wheel assembly relative to the axle.