TYRE COMPRISING A MONITORING DEVICE

Abstract

The present disclosure is directed to a tyre with a monitoring device equipped with an electronic unit, an electric power supplier and an electrical connection between the electronic unit and the electric power supplier, wherein the electronic unit comprises a rigid printed circuits board on which a sensor is fixed to detect temperature, pressure and/or acceleration, a processing unit and a transceiver and wherein the electronic unit and the electric power supplier are both fixed on an inner surface of the tyre at the crown.

Claims

1-21. (canceled)

22. A tyre comprising a monitoring device, wherein the monitoring device comprises: an electronic unit, an electric power supplier, a first support and a second support, wherein the electronic unit and the electric power supplier are both fixed on an inner surface of the tyre at a crown portion of the tyre through respectively the first and second support, wherein the electronic unit comprises a rigid printed circuit board; at least one sensor for detecting one or more of the following physical quantities: temperature, pressure, and acceleration; a processing unit; and a transceiver, and the at least one sensor, the processing unit, and the transceiver are fixed on the rigid board, and wherein the monitoring device further comprises an electrical connection for electrically connecting the electronic unit to the electric power supplier.

23. The tyre according to claim 22, wherein the rigid board is inscribed in a circle with a diameter less than or equal to 50 mm; the rigid board comprises a laminated layer comprising one or more layers of a core material impregnated with a resin and electrically conductive metal tracks; and the at least one sensor, the processing unit, and the transceiver are fixed by welding on the metal tracks.

24. The tyre according to claim 22, wherein a distance (D) between the electronic unit and the electric power supplier is greater than or equal to 30 mm and less than or equal to 250 mm.

25. The tyre according to claim 22, wherein an equatorial plane of the tyre intersects the first support.

26. The tyre according to claim 22, wherein a straight line passing through the centres of mass of the electronic unit and of the electric power supplier intersects a direction parallel to an equatorial plane of the tyre with an angle less than, or equal to, 10°.

27. The tyre according to claim 22, wherein a straight line passing through the centres of mass of the electronic unit and of the electric power supplier intersects a direction parallel to an equatorial plane of the tyre with an angle greater than or equal to 5°.

28. The tyre according to claim 22, wherein the at least one sensor detects all three of the following physical quantities: temperature, pressure, and acceleration; and the at least one sensor detects at least a radial component or a tangential component of the acceleration.

29. The tyre according to claim 22, wherein the electric power supplier is an electric energy accumulator, and the electrical connection comprises at least two separate electric paths.

30. The tyre according to claim 22, wherein the monitoring device further comprises a third support through which the electrical connection is fixed on the inner surface of the tyre at the crown portion; the third support comprises a flexible substrate; and an overall development of the third support or of the electrical connection, from the electronic unit to the electric power supplier, is greater than a mutual distance (D) between the electronic unit and the electric power supplier.

31. The tyre according to claim 30, wherein the electrical connection is made by a conductive ink deposited on a surface of the flexible substrate facing the inner surface of the tyre.

32. The tyre according to claim 30, wherein the third support comprises an adhesive layer interposed between the inner surface of the tyre and the substrate, and the electrical connection is interposed between the adhesive layer and the substrate.

33. The tyre according to claim 22, wherein the first support or the second support comprise an adhesive layer.

34. The tyre according to claim 22, wherein the first support and the second support comprise a respective attachment portion, flexible and substantially inextensible, and a respective adhesive layer which keeps each attachment portion glued to the inner surface of the tyre; and the attachment portion is chosen from a piece of elastomeric material reinforced with textile or metallic filaments, a film of plastic material, and a polyurethane layer.

35. The tyre according to claim 22, wherein the electronic unit comprises a containment body partially housing the board, the at least one sensor, the processing unit, and the transceiver.

36. The tyre according to claim 22, wherein the electronic unit is encapsulated by an encapsulating material.

37. The tyre according to claim 36, wherein the at least one sensor, the processing unit, and the transceiver are all fixed on a first side of the board; the first side of the board faces a bottom wall of the containment body; and the encapsulating material is only localized on a second side of the board, opposite to the first side.

38. The tyre according to claim 22, wherein the electric power supplier is encapsulated by an encapsulating material with continuity.

39. The tyre according to claim 36, wherein the encapsulating material is a polyurethane or a polyurea material.

40. The tyre according to claim 36, wherein the encapsulating material realizes the first and second support in continuity with the material encapsulating the electronic unit.

41. The tyre according to claim 40, wherein the encapsulating material also realizes the substrate of the third support in a single body.

42. The tyre according to claim 22, wherein the monitoring device comprises at least one further electric power supplier and a fourth support; the further electric power supplier is fixed on the inner surface of the tyre at the crown portion through the fourth support; the fourth support is placed at a respective distance from the first and second support, having development on the inner surface of the tyre; and the monitoring device comprises a further electrical connection for electrically connecting the electronic unit with the further electric power supplier.

43. The tyre according to claim 38, wherein the encapsulating material realizes the first and second support in continuity with the material encapsulating the electric power supplier.

44. The tyre according to claim 22, wherein the electronic unit and the electric power supplier are encapsulated by an encapsulating material that realizes the first and second support with continuity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The features and the advantages of the present invention will be further clarified by the following detailed description of some embodiments, presented as non-limiting example of the present invention, with reference to the attached figures, in which:

[0057] FIG. 1 shows a schematic, perspective and partial view of a tyre section comprising a first embodiment of the monitoring device according to the present invention;

[0058] FIG. 2 shows a schematic perspective view of the monitoring device of FIG. 1 with some parts removed;

[0059] FIG. 3 shows a schematic, perspective and partial view of a tyre section comprising a second embodiment of the monitoring device according to the present invention;

[0060] FIGS. 4a and 4b schematically and respectively show a top view of the monitoring device of FIG. 3 and a section along the line 4b-b of FIG. 4a;

[0061] FIG. 5 shows a schematic, perspective and partial view of a tyre section comprising a third embodiment of the monitoring device according to the present invention;

[0062] FIGS. 6a and 6b schematically and respectively show a top view of the monitoring device of FIG. 5 and a section along the line 6b-6b of FIG. 6a;

[0063] FIG. 7 shows a schematic top view of a fourth embodiment of the monitoring device according to the present invention;

[0064] FIG. 8 shows a schematic sectional view of a comparative monitoring device.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

[0065] In the figures with the reference number 1 it is shown a tyre (in partial perspective section) comprising a monitoring device 10 according to the present invention. In the present description and figures the same reference number is used for the same elements, also in their embodiments.

[0066] The monitoring device 10 comprises an electronic unit 11 and an electric power supplier 12.

[0067] The monitoring device 10 further comprises a first support 13 and a second support 14, by means of which the electronic unit 11 and the power supplier 12, respectively, are fixed on an inner surface 15 of the tyre 1 at a crown portion 16 of the tyre 1 (i.e. the portion of tyre at the tread band 17).

[0068] According to the present invention, the electronic unit 11 and the power supplier 12 are fixed to a mutual distance D having development on the inner surface 15 of the tyre 1.

[0069] The electronic unit 11 comprises a rigid printed circuits board 20 (Printed Circuit Board or PCB), on which are fixed (preferably on the same side of the board): at least one sensor 21 for detecting at least one of the following physical quantities:

[0070] temperature, pressure, acceleration; a processing unit 22; a transceiver 23. The monitoring device 10 comprises an electrical connection 30 for electrically connecting said electronic unit 11 (typically the sensor 21, the processing unit 22 and the transceiver 23) to said electric power supplier 12.

[0071] Exemplarily the rigid board 20 comprises (not shown) a laminated layer comprising one or more layers of woven fiberglass, impregnated with an epoxy resin, and electrically conductive metal tracks, wherein the sensor 21, the processing unit 22 and the transceiver 23 are fixed by welding on the metal tracks.

[0072] Exemplarily the rigid board has circular plan with diameter equal to about 20 mm. The distance D is exemplarily equal to 40 mm in the embodiment of FIG. 1, equal to 3 mm in the embodiment of FIG. 3-4a-4b and equal to 100 mm in the embodiment of FIG. 5-6a-6b.

[0073] In the embodiment of FIG. 1 the two separate elements 11 and 12 are distributed along the circumferential direction and they are substantially centred on the equatorial plane of the tyre 1. In other words, a straight line (not shown) passing through the centres of mass of the electronic unit 11 and of the power supplier 12 (considering the tyre undeformed) lies on the equatorial plane of the tyre (i.e. it forms a substantially null angle with said plane).

[0074] In the embodiment of FIG. 3 the two separate elements 11 and 12 are substantially distributed along the axial direction, substantially symmetrically with respect to the equatorial plane of the tyre 1. In other words, a segment (not shown, substantially coinciding with the segment D shown in broken lines) passing through the centres of mass of the electronic unit 11 and of the electric power supplier 12 (considering the tyre undeformed) is substantially parallel to the axis of the tyre 1 and intersects the equatorial plane of the tyre 1 substantially at its median point.

[0075] In the embodiment of FIG. 5, the electronic unit 11 lies on the equatorial plane, while the electric power supplier 12 lies completely outside of the equatorial plane. Exemplarily a straight line (not shown) passing through the centres of mass of the electronic unit and of the electric power supplier (on undeformed tyre) forms an angle equal to about 10° with the equatorial plane.

[0076] As an example, the sensor 21 can be a model sensor FXTH870911DT1 marketed by NXP Semiconductors®, suitable for detecting all of the three physical quantities of temperature, pressure and acceleration, in particular at least the radial component and the tangential component of the acceleration. For this purpose, it is appropriate that the sensor 21 (and therefore the electronic unit 11 and/or the entire monitoring device 10) is fixed to the tyre with a precise spatial orientation with respect to the axis of the tyre.

[0077] The electric power supplier 12 can comprise a coin cell battery 18, for example of the type CR2032, with diameter of 20 mm and with thickness of 3.2 mm, with a mass equal to 3 g and an electric charge equal to 200 mAh. Typically, the electrical connection 30 comprises two separate electric paths 31 and 32 (one for connection to the positive pole and one for connection to the negative pole of the battery 18), as shown in the figures.

[0078] In the embodiment shown in FIG. 2, the first and second support 13 and 14 exemplarily comprise two distinct and separate attachment portions, flexible and substantially inextensible, for example in the form of pieces of elastomeric material possibly reinforced with textile and/or metallic filaments. Typically, an adhesive layer (e.g. acrylic PSA) keeps the attachment portions glued to the inner surface of the tyre. In this embodiment the electric paths 31 and 32 are insulated conductive wires. In the embodiments of the FIGS. 3, 4a, 4b, 5, 6a, 6b and 7, the electronic unit 11 comprises a rigid containment body 40 which completely houses the rigid board 20, the sensor 21, the processing unit 22 and the transceiver 23. Preferably a first side of the board on which all the active components 21, 22 and 23 are mounted, faces a bottom wall (in the figure the top wall) of the containment body and extends parallel to the bottom wall and for substantially the entire extension of the bottom wall. Preferably an encapsulating material 41 (e.g. polyurethane) encapsulates, fixing it, the rigid board 20 inside the containment body. Preferably the encapsulating material 41 is located only on a second side of the board, opposite to the first side. Advantageously in this way a gap between the board with its components and the bottom wall is left free to facilitate the receiving/transmitting of the signal and/or the monitoring of the pressure and/or of the temperature in the inner cavity of the tyre.

[0079] Preferably the first and second support 13 and 14 comprise respective attachment portions respectively of the containment body 40 (with the board 20 and the components) and of the electric power supplier 12 to the inner surface of the tyre. Preferably the same encapsulating material 41 realizes in a single body and with continuity also the respective attachment portions of the first 13 and second support 14. Preferably the same encapsulating material 41 encapsulates with continuity also the battery 18 of the electric power supplier 12.

[0080] Preferably the same encapsulating material 41 realizes in a single body also a third support 50 for the electrical connection 30, in the form of a flexible substrate, on 2 0 which lower surface (facing the inner surface of the tyre) the two electric paths 31 and 32 made with a conductive ink (for example with screen printing technologies typical of the printed electronics) are molded.

[0081] Preferably an adhesive layer (not shown), e.g. pressure sensitive (e.g., adhesive 468MP7c marketed by 3M®), is arranged to glue the lower face of the encapsulating material to the inner surface of the tyre.

[0082] Exemplarily, the electronic unit 11 has an overall weight equal to about 5 g and the electric power supplier 12 has an overall weight equal to about 3 g. In the embodiment of FIG. 7, the monitoring device 10 comprises a further electric power supplier 60 and moreover a fourth support 61. The further electric power supplier 60 is fixed on the inner surface of the tyre at the crown portion through said fourth support 61 at a respective distance from the electronic unit 11 and from the electric power supplier 12. The monitoring device 10 therefore comprises a further electrical connection (not shown) for electrically connecting the electronic unit 11 with the further electric power supplier 60.

[0083] The further electric power supplier 60 can be the same or of the same type as the aforesaid electric power supplier 12. Preferably the encapsulating material 41 realizes with continuity also the fourth support 61 (in the form of a respective attachment portion of the further electric power supplier) and encapsulates with continuity the respective battery of the further electric power supplier.

[0084] The Applicant has determined the following relationship which binds the masses of the devices to the speeds:

[00001]$v_1=v_0*\sqrt{\frac{m_0}{m_1}}$

[0085] wherein mo and mi are the masses of two devices to be compared, applied to the inner surface of a tyre and v.sub.0 and v.sub.1 are the respective rotational speeds of the tyre to which the two devices to be compared develop the same maximum stresses in radial direction and in tangential direction (or of shear).

[0086] As an example, in the case wherein the overall mass of the monitoring device is divided according to the present invention so that half insists on the electronic unit and half insists on the electric power supplier, the ‘critical’ speed at which the radial and/or the tangential stresses can induce a break of at least one of the two parts (electronic unit or electric power supplier) of the monitoring device is increased by about 1.4 times.

[0087] It is observed that while the shear stress can also be reduced by its distribution by means of an inextensible and sufficiently large attachment portion, the stress in the radial direction is not affected by such a solution. The present invention is instead able to reduce both the stresses (as a first approximation in equal measure, due to the proportionality that links them, as empirically determined by the Applicant).

[0088] Therefore, the present invention allows to preserve the structural and functional integrity of the monitoring device and of the tyre up to extreme speeds.