Pressure sensor mounting method, tire and wheel having pressure sensor, and tire pressure detection device
The accuracy of a measurement value obtained by a tire pressure detection device is lowered by a centrifugal force and an inertial force during travel. A pressure sensor ( 30 ) displaces a diaphragm ( 20 ) in its vertical direction ( 32 ) according to the pressure. The pressure sensor ( 30 ) is arranged in a tire ( 2 ) with the vertical direction ( 32 ) directed to a direction parallel to a rotation axis ( 34 ) instead of the tire circumferential direction or radial direction. The pressure sensor ( 30 ) is mounted onto a substrate with the vertical direction ( 32 ) of its diaphragm ( 20 ) directed in parallel to the substrate surface and the substrate is bonded to a tread portion of the tire ( 2 ) and a wheel rim portion while adjusting the vertical direction ( 32 ) of the diaphragm ( 20 ) with the direction of the rotation axis ( 34 ).
1. A tire pressure detection system comprising:
a tire pressure detection device, mounted inside a tire of a vehicle, for detecting air pressure inside the tire; and
a reader having a coil antenna having an opening surface directed to the tire, and mounted in a highest portion of a wheel housing of the vehicle,
wherein the tire pressure detection device comprises:
a pressure sensor for measuring the air pressure, using a displacement portion to be displaced according to the air pressure; and
a circuit board having a response circuit mounted on a board surface thereof, the response circuit for sending, through interaction with a supply electromagnetic field applied from the reader, data measured by the pressure sensor to the reader,
wherein:
the pressure sensor is mounted on the circuit board such that a displacement direction of the displacement portion is set parallel to the board surface,
the circuit board is attached on a tread portion of the tire or a rim portion of a wheel on which the tire is mounted, such that a displacement direction of the displacement portion is set parallel to a rotational axis of the tire, and
the response circuit has a coil all of which is formed as a wiring pattern on the board surface, and is electromagnetically coupled with the coil antenna to transmit the measured data.