Tire module with piezo-electric transducer and tire equipped therewith

1. A tire module for attaching to an inside of a pneumatic tire for motor vehicles, the tire module comprising:

a pressure sensor configured for measuring and/or monitoring the air pressure in the tire;

a transmitter for transmitting radio signals, the radio signals containing information regarding the air pressure in the tire, the transmitter connected to the pressure sensor;

a mechanical-electrical transducer with a flexible, circular, disc-shaped piezo-electric element, which converts alternating changes in the shape of the piezo-electric element caused by the rolling tire into electric energy, hereinafter described as a piezo disc, and on which an electrical voltage generated through the piezo effect is tapped off at contact points; and

a storage unit for the electric energy, which is connected to the transducer and powering the pressure sensor and transmitter;

wherein the contact points are located on opposite sides of the piezo disc.

2. The tire module of claim 1 , wherein a contact point is formed through a circular metal disc, which completely covers a first side of the piezo disc and is so thin and flexible that it can transmit deformations of the tire which occur during the passage of the tire module through the contact patch of the tire to the piezo disc.

3. The tire module of claim 2 , wherein the metal disc has a larger diameter than the piezo disc.

4. The tire module of claim 1 , wherein the second side of the piezo disc is only partially provided with at least one contact point or with a plurality of contact points, which are connected to one another in an electrically conductive manner.

5. The tire module of claim 4 , wherein the at least one or the plurality of the contact points are arranged in the middle on the second side of the piezo disc.

6. The tire module of claim 4 , wherein the at least one or the plurality of the contact points on the second side of the piezo disc cover a maximum of 20% of the surface of the second side of the piezo disc.

7. The tire module of claim 4 , wherein the at least one or the plurality of the contact points on the second side of the piezo disc cover a maximum of 10% of the surface of the second side of the piezo disc.

8. The tire module of claim 1 , wherein the piezo disc is arranged between the metal disc on the first side and a flexible conductor path film on the second side of the piezo disc.

9. The tire module of claim 8 , wherein the metal disc adheres to the piezo disc.

10. The tire module of claim 8 , wherein the conductor path film, which covers the first side of the piezo disc, forms a circular area, which is connected to a circuit substrate by a web, which likewise consists of the conductor path film and originates from the edge of the circular area.

11. The tire module of claim 10 , wherein the circuit substrate likewise consists of the conductor path film which forms a circular area, and the two circular areas are unitarily connected to one another by the web, coincide in the diameter and subject to the intermediate inserting of a circular spacer disc are arranged on top of one another and coaxially to one another.

12. The tire module of claim 11 , wherein the spacer disc on its side facing the piezo disc is convexly curved.

13. The tire module of claim 11 , wherein between the spacer disc and the circular area formed by the conductor path film, which faces the piezo disc, a sealing ring is provided.

14. The tire module of claim 12 , wherein the components of the tire module, with the exception of a free space between the convex side of the spacer disc and the circular area facing the convex side of the spacer disc and with the exception of the side of the metal disc facing away from the piezo disc, are embedded in an electrically insulating casting compound forming a cast tire module.

15. The tire module of claim 14 , wherein the solidified casting compound has a substantially cylindrical circumferential surface.

16. The tire module of claim 15 , wherein a cap is provided, which receives the cast tire module and has a flange for connecting the cap to the inside of the tire.

17. The tire module of claim 16 , wherein the height of the cast tire module, the cast tire module including the solidified casting compound in which the tire module is embedded, has an oversize with respect to the clear height of the empty cap.

18. The tire module of claim 1 , wherein the tire module is disposed within a tub, the tub receiving the components of the tire module including a casting compound.

19. The tire module of claim 18 , wherein the tub is molded from a plastic foil.

20. The tire module of claim 18 , wherein the tub has a bottom which is so thin that it follows the deformation of the tire transmitting it to the mechanical-electrical transducer, while the latter with rolling tire moves past the contact patch of the tire.

21. The tire module of claim 18 , wherein the tub is formed through deep-drawing a foil.

22. The tire module of claim 16 , wherein the cap comprises an elastomer material.

23. A pneumatic tire for vehicles, on the inside of which a tire module is fastened, the tire module comprising:

a pressure sensor configured for measuring and/or monitoring the air pressure in the tire;

a transmitter for transmitting radio signals, which contain information regarding the air pressure in the tire, the transmitter connected to the pressure sensor;

a mechanical-electrical transducer with a flexible, circular, disc-like piezo-electric element, which converts alternating changes in shape of the piezo-electric element caused by the rolling tire into electric energy, hereinafter described as a piezo disc, and on which an electrical voltage generated through the piezo effect is tapped off at contact points;

and a storage unit for the electric energy, which is connected to the transducer and powering the pressure sensor and transmitter;

wherein the contact points are located on opposite sides of the piezo disc;

the tire module being fastened to the inside of the pneumatic tire in such a way that a deformation of the inside of the pneumatic tire results in a reversible deformation of the metal disc and of the piezo disc.

24. The pneumatic tire of claim 23 , wherein the metal disc contacts the inside of the pneumatic tire with pressure.

25. The pneumatic tire of claim 23 , wherein the tire module has, as an integral part, a tub, which receives the further components of the tire module including a casting compound, and wherein the tub has a bottom, which contacts the inside of the tire with pressure.