Method for generating an electric current within a tyre

• US 20030000615A1
• Filed: 09/03/2002
• Published: 01/02/2003
• Est. Priority Date: 03/09/1998
• Status: Active Grant

• Current Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Original Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Inventors: Volpi, Alessandro
• Granted Patent: US 6,885,111 B2
• Time in Patent Office: Days
• US Class Current: 152/152.1
• CPC Class Codes: B29D 30/48 Bead-rings or bead-cores from wire B21F37/00; Treatment thereof prior to building the tyre
• CPC Class Codes: B60C 15/04 Bead cores
• CPC Class Codes: B60C 19/00 Tyre parts or constructions not otherwise provided for
• CPC Class Codes: B60C 2019/005 Magnets integrated within the tyre structure
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/041 Means for supplying power to the signal- transmitting means on the wheel
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: Y10T 152/10819 Characterized by the structure of the bead portion of the tire
• CPC Class Codes: Y10T 152/10846 Bead characterized by the chemical composition and or physical properties of elastomers or the like

Abstract

A tire (20) comprises a bead core (22) of ferromagnetic material, for example steel wire, around which one or more windings (30a, 30b, . . . , 30n) of conducting wire are wound to form the secondary of an electricity generator of the induction type. The assembly of windings and bead core (22), together with the circuits using the electricity thus generated, is produced as a single unit to be incorporated, together with the bead filler (26), in a bead (28) of the tire, and of one or more magnets fixed with respect to the hub of the wheel or integral with the chassis of a vehicle comprising a wheel (18) fitted with the tire (20), which induce current in the windings. If the magnets are electromagnets (32) supplied with alternating current, the electricity generator operates both when the wheel (18) is rotating and when the wheel is stationary. On the other hand, if the magnets are permanent magnets (66) or electromagnets supplied with direct current, the electricity generator operates only if the wheel (18) is rotating.

Claims

1. Tire (20) for vehicle wheels, comprising:

a toroidal carcass provided with a pair of axially opposing sidewalls terminating in beads (28) for fixing the said tire (20) to a corresponding mounting rim (16), each of the said beads (28) being provided with a reinforcing annular core (22),

a tread band (27) disposed on the crown of the said carcass and axially extending continuously between the said sidewalls,

characterized in that

at least one of the said annular cores (22) comprises at least one turn (30) of conducting wire wound around the transverse profile of the said annular core (22) to form a secondary inductive element of an electricity generator.

2. Tire according to claim 1, in which the said secondary inductive element can be associated with at least one primary inductive element (36, 66) to form the said electricity generator, the said primary inductive element (36, 66) and the said secondary inductive element being movable with respect to each other.

3. Tire according to claim 1, in which the said annular core (22) comprises at least one layer of material with high magnetic permeability.

4. Tire according to claim 1, in which the said annular core (22) comprises a plurality of blocks of material with high magnetic permeability.

5. Tire according to claim 1, in which the said annular core (22) is made from steel and comprises a matrix of the elastomer or plastomer type, either thermoplastic or thermosetting, containing soft ferromagnetic material in powder form.

6. Tire according to claim 1, comprising electronic circuits supplied from the said secondary inductive element.

7. Tire according to claim 6, in which the said electronic circuits comprise means (46, 48) for sensing certain parameters of the tire.

8. Tire according to claim 6, in which the said electronic circuits are fixed to the said annular core (22).

9. Tire according to claim 7, in which the said sensing means comprise at least one temperature sensor.

10. Tire according to claim 7, in which the said sensing means comprise at least one pressure sensor.

11. Tire according to claim 7, in which the said sensing means comprise a pair of extensometers (46, 48), disposed in two orthogonal directions, which sense the deformations of the said annular core (22).

12. Tire according to claim 11, in which the said electronic circuits comprise data transmission means capable of transmitting the said parameters of the tire.

14. Sensing system according to claim 13, in which the said secondary inductive element can be associated with at least one primary inductive element (36, 66) to form the said electricity generator, the said primary inductive element (36, 66) and the said secondary inductive element being movable with respect to each other.

15. Sensing system according to claim 14, in which the said primary inductive element comprises at least one permanent magnet (66a-66f).

16. Sensing system according to claim 14, in which the said primary inductive element comprises at least one electromagnet (36a, 36b) and at least one second turn (39a, 39b) of electrically conducting wire wound around the transverse profile of the said at least one electromagnet (36a, 36b) to form at least one primary winding of the said electricity generator.

17. Sensing system according to claim 15, in which the said electromagnet (36a, 36b) is supplied with direct current.

18. Sensing system according to claim 15, in which the said electromagnet (36a, 36b) is supplied with alternating current.

19. Sensing system according to claim 15, in which the said electromagnet (36a, 36b) is supplied with direct current and with alternating current.

13. System for sensing and signalling parameters of the physical state of a tire for vehicle wheels, mounted on a corresponding mounting rim (16), comprising:

a tire having a toroidal carcass provided with axially opposing sidewalls terminating in beads (28) for fixing the said tire (20) to the said rim, each of the said beads (28) being provided with a reinforcing annular core (22), and a tread band (27) disposed on the crown of the said carcass and axially extending continuously between the said sidewalls,

a device for sensing the said parameters of the physical state of the said tire, and

an electricity generator for the supply of the said sensing device, characterized in that at least one of the said annular cores (22) comprises at least one turn (30) of conducting wire wound around the transverse profile of the said annular core (22) to form a secondary inductive element of the said electricity generator.

20. Method for producing a tire, comprising the following steps:

producing on the preparation machines the semi-finished products required for building a tire, comprising a pair of ferromagnetic annular elements (22) for fixing the said tire to a corresponding mounting rim (16);

forming a first secondary winding (30) of an electricity generator, by disposing on at least one annular core (22) of the said pair, called the annular coil element, at least one first turn of electrically conducting wire, wound around the transverse profile of the said annular coil core (22), and

assembling the said semi-finished products on tire building machines to form a green carcass for the said tire, comprising at least one annular coil core (22).

21. Method for producing a tire, according to claim 20, comprising the further step of fixing means (46, 48) for sensing certain physical parameters of the tire, supplied from the said power generator, to the said annular coil core (22).

22. Method for producing a tire, according to claim 20, in which the step of disposing a layer of material with high magnetic permeability on the circumference of the said at least one annular core (22) while it is without the said one turn is carried out before the step of forming a first secondary winding.

23. Method for generating an electrical current within a tire for the supply of at least one electronic device, comprising the stage of inducing a variable magnetic field in a winding formed by at least one turn wound around a bead core belonging to the said tire.