Tire monitor system having tire valve antenna
A tire monitor system includes a tire monitor sensor unit that has a tire pressure detector, a coupler and a tire valve. The tire valve operates as an antenna to transmit tire data from the tire pressure detector. The coupler provides a capacitive coupling that removably couples the tire pressure detector and the tire valve. The coupler includes two metal layers separated by a dielectric layer. The two metal layers may be formed by the tire valve and a connection tube.
1. A tire monitor sensor unit, comprising:
a tire pressure detector that detects tire pressure and generates tire data including pressure in the tire;
a tire valve operable to receive the tire data form the tire pressure detector and transmit the tire data as an antenna; and
a coupler removably coupling the tire pressure detector and the tire valve, the coupler comprising two metal layers disposed adjacent to one another, the coupler providing direct connection between the two metal layers that becomes a capacitive coupling over time; the two metal layers are provided respectively by the tire valve and a conductive connection tube between the tire valve and the tire pressure detector.
2. The tire monitor sensor unit of claim 1 wherein the coupler provides capacitive coupling between said tire pressure detector and the tire valve.
3. The tire monitor sensor unit of claim 2 wherein the two metal layers are separated by a dielectric layer.
4. The tire monitor sensor unit of claim 1 , wherein the connection tube and the tire valve are inserted into an opening integrally formed with an enclosure of the tire pressure detector.
5. The tire monitor sensor unit of claim 3 , wherein the dielectric layer comprises air.
6. The tire monitor sensor unit of claim 1 , wherein the dielectric layer comprises a plastic coating disposed on at least one of the tire valve and the connection tube.
7. The tire monitor sensor unit of claim 1 wherein the coupler provides inductive coupling.
8. The tire monitor sensor unit of claim 1 wherein the coupler comprises a tab extending from the tire pressure detector, providing a first metal layer and the tire valve provides a second metal layer.
9. The tire monitor of claim 8 wherein the tab and the tire valve are, at least initially, separably directly coupled.
10. The tire monitor sensor unit of claim 1 wherein a first metal layer is secured to a second metal layer using a conductive fastener.
11. A method comprising:
providing a conductive connection tube;
inserting the connection tube into an opening defined by a housing of a tire pressure detector;
electrically connecting the conductive tube to circuitry of the tire pressure detector,
inserting a stem of a tire valve into the opening so that the connection tube surrounds the tire valve stem, thereby coupling the tire pressure detector circuitry and the stem of the tire valve; and
transmitting the tire data using the tire valve stem as an antenna.
12. The method of claim 11 , wherein the coupling is at least one of capacitive coupling, inductive coupling, and a direct connection between the connection tube and the tire valve stem.
13. The method of claim 11 , further comprising forming a dielectric layer between the stem of the tire valve and the connection tube.
14. The method of claim 13 , wherein the dielectric layer comprises air.
15. The method of claim 11 , further comprising applying a plastic coating on at least one of the connection tube or the stem of the tire valve.
16. The method of claim 11 , wherein the inserting the connection tube into the opening defined by the housing of the tire pressure detector comprises molding the housing about the connection tube.
17. The method of claim 11 , wherein the coupling is direct connection between the connection tube and the stem and the direct connection becomes a capacitive coupling over time.