Pneumatic tire equipped with an electronic device

Abstract

The present invention relates to a pneumatic tire (1), comprising an inner liner (6) that forms an inner cover and has a purpose of retaining air inside the pneumatic tire (1), a joint portion (13) of the inner liner (6) that gives a cylindrical shape to the inner liner (6), and an RFID label (8) that is adhered to the radially inner surface of the inner liner (6) that forms the innermost free surface of the pneumatic tire (1), and is entirely arranged within a region (14) that is centered on the joint portion (13) and extends within 90° on one side in the circumferential direction starting from the joint portion (13).

Description

Technical Field

[0001] The present invention is advantageously applicable to pneumatic tires provided with RFID labels, i.e., identification labels based on RFID ("Radio Frequency IDentification") technology. The following detailed description will specifically refer to this RFID label without sacrificing general applicability.

Background Art

[0002] In recent years, so-called "smart" pneumatic tires have emerged, providing information regarding the type of mounted pneumatic tire, the state of the pneumatic tire, and the surrounding environment, and have come to be actively installed in modern vehicles. "Smart" pneumatic tires are provided with RFID ("Radio Frequency Identification") labels, which can remotely communicate information such as the identification, characteristics, and history of the pneumatic tire.

[0003] It has been proposed to adhere an RFID label to the inner or outer surface of the sidewall of a pneumatic tire (as described, for example, in Patent Document 1 (US2020070597A1), Patent Document 2 (US20210016614A1), and Patent Document 3 (EP4019241A2)). This solution is extremely simple from a design perspective and is also applicable to existing pneumatic tires. However, in contrast, it is not guaranteed that the transponder will not peel off from the pneumatic tire due to the periodic deformation received by the sidewall of the pneumatic tire (especially when adhered to the outer surface). It has also been proposed to incorporate the transponder into the structure of the pneumatic tire, i.e., into the various layers that make up the pneumatic tire (as described, for example, in Patent Document 4 (US20080289736A1), Patent Document 5 (EP2186658A1), and Patent Document 6 (EP1366931A2)).

[0004] Patent Document 7 (US7556074B2) describes a pneumatic tire having a cavity formed therein for receiving a removable electronic monitoring module.

[0005] Patent Document 8 (EP3798020A1) describes a pneumatic tire (1) having an overlap region where the inner layers of the pneumatic tire overlap.

[0006] In particular, when an RFID label is adhered to the radially inner surface (constituted by the inner liner) of a pneumatic tire, it has been observed that cracks occur at a specific frequency in the inner liner in the vicinity of the region where the RFID label is adhered.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Summary of the Invention

Problems to be Solved by the Invention

[0008] The object of the present invention is to provide a pneumatic tire provided with an electronic device, which has no above-mentioned drawbacks, that is, there is no risk of peeling or breaking of the inner liner in the vicinity of the area where the electronic device is applied, and at the same time, the pneumatic tire is easy to manufacture and economical.

Means for Solving the Problems

[0009] According to the present invention, as described in the appended claims, there is provided a pneumatic tire equipped with an electronic device.

[0010] The claims describe preferred embodiments of the present invention that form an essential part of this specification.

Brief Description of the Drawings

[0011] Next, the present invention will be described with reference to the accompanying drawings showing exemplary and non-limiting embodiments.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0012] In FIG. 1, reference numeral 1 indicates a pneumatic tire 1 including a carcass 2 of toroidal shape as a whole. Since the carcass 2 is partially folded upon itself, it has two side flaps (i.e., two layers overlapping each other, collectively called "turn up"). Two annular beads 3 are provided on opposite side surfaces of the carcass 2, each of which is surrounded by the carcass 2. The carcass 2 supports an annular tread 4 with a tread belt 5 interposed therebetween. An inner liner 6 disposed within the carcass 2 has airtightness and constitutes an inner lining, and has a function of holding the air within the tire 1 and maintaining the air pressure of the tire 1 over a long period. The carcass 2 supports several sidewalls 7 connecting the bead 3 and the tread 4 respectively.

[0013] The pneumatic tire 1 is attached with an RFID ("Radio-Frequency Identification") label 8, also called a "smart label", which can store information related to the operating conditions or states of the pneumatic tire 1 and / or acquire signals, and can communicate via radio frequency. In other words, the RFID label 8 is configured to respond to remote polling from the side of a suitable fixed or portable device called a reader (or interrogator), or to autonomously transmit signals to a receiver, and the reader or receiver can read and / or modify the information contained in the RFID label 8 while communicating at radio frequency.

[0014] According to the illustration of FIG. 1, the RFID label 8 is disposed on the sidewall 7 of the pneumatic tire 1. However, according to other embodiments illustrated by dashed lines in FIG. 1, the RFID label 8 can also be disposed on components of the pneumatic tire 1 other than the sidewall 7, such as the tread 4.

[0015] According to the illustration of FIG. 1, the RFID label 8 is adhered to the inner liner 6, that is, it is attached to the inner surface of the pneumatic tire 1 constituted by the inner liner 6 (therefore, the RFID label 6 is in direct contact with the inner liner 6). In other words, the RFID label 8 is on the outer side of the pneumatic tire 1, that is, it is not incorporated into the pneumatic tire 1, and is on the radially inner surface of the inner liner 6, that is, on the outer side of the pneumatic tire 1, and therefore is adhered (fixed, attached) to the innermost free surface of the pneumatic tire 1 which is in direct contact with the air inside the pneumatic tire 1. According to another embodiment (not shown), the RFID label 8 is incorporated inside the pneumatic tire 1, that is, it is inserted between the components of the pneumatic tire 1 during the manufacture of the pneumatic tire 1 itself (for example, the RFID label 8 is arranged between the carcass 2 and the inner liner 6, or between the carcass 2 and the sidewall 7).

[0016] According to the illustrations of FIGS. 2 and 3, the RFID label 8 includes an electronic circuit 9 (that is, a microchip) provided with a non-volatile memory, and an antenna 10 connected to the electronic circuit 9 (preferably, the electronic circuit 9 and the antenna 10 constitute a transponder, that is, the RFID label 8 is substantially a transponder), and these components are stacked and inserted into a rubber housing formed by two rubber strips 11 and 12, one of which is pressed against the other.

[0017] The green components of the pneumatic tire 1 (carcass 2, tread belt 5, tread 4, inner liner 6, etc.) overlap each other to form a flat strip, which is wound (around the assembly drum of the production machine) to form a cylinder, which is deformed into the final toroidal shape. In particular, the annularly wound strip is connected to itself to form a plurality of joints (each component of the pneumatic tire 1 is joined at different positions to avoid overlap of the joints and thus avoid the formation of a large discontinuity at one point). Among the various joints within the pneumatic tire 1, according to the illustration of FIG. 4, there is a joint 13 of the inner liner 6. That is, the inner liner 6 of the green pneumatic tire 1 has a joint 13 where two opposing flaps of the inner liner 6 are joined to each other (by a slight overlap). Next, the green pneumatic tire 1 is subjected to a vulcanization process in a suitable vulcanization mold.

[0018] The joint 13 gives a cylindrical shape to the inner liner 6 of the pneumatic tire 1 and is parallel to the axial direction, i.e., the central axis of the pneumatic tire 1 that rotates during use of the pneumatic tire 1.

[0019] According to the illustration of FIG. 5, the RFID label 8 is internally disposed in a region 14 that is centered on the joint 13 (i.e., the joint 13 is disposed exactly at the center of the region 14) and extends circumferentially by 90° or less on one side (i.e., the maximum extension range of the region 14 is 90° on one side) starting from the joint 13. In other words, the region 14 has a maximum circumferential extension range of 180° (thus covering at most exactly half of the pneumatic tire 1). According to another embodiment, the region 14 has a maximum circumferential extension range of 150°, 120°, or 90°. That is, the region 14 extends from the joint 13 by 75°, 60°, or 45° or less on each side circumferentially.

[0020] According to the illustration of FIG. 5, the RFID label 8 is preferably arranged so as not to overlap the joint 13, i.e., (as better shown in FIG. 6) the RFID label 8 is arranged at a non-zero circumferential distance D1 from the joint 13.

[0021] More generally, according to what is better shown in FIG. 6, the proximal end of the RFID label 8 is arranged at a circumferential distance D1 from the joint 13 greater than 0°, and the distal end of the RFID label 8 (on the circumferential opposite side of the proximal end) is arranged at a circumferential distance D2 (greater than the circumferential distance D1) from the joint 13 less than 90° (i.e., less than 75°, 60° or 45°). Clearly, since the circumferential extension range of the RFID label 8 is included between the two circumferential distances D1 and D2, the circumferential distance D2 is greater than the circumferential distance D1.

[0022] Before starting the vulcanization process, a release agent (i.e., a lubricating fluid) is applied (sprayed) inside the pneumatic tire 1 to prevent the rubber of the inner liner 6 from adhering (vulcanizing) to the air chamber filled with air inside the pneumatic tire 1 in order to apply the necessary mechanical pressure. After the application (spraying) process of the release agent, the green pneumatic tire 1, which is to be vulcanized in principle (i.e., ready for vulcanization), is placed on a vertical rack for storage for a certain time (or different times or several days). When "parking" the green pneumatic tire 1 (to be vulcanized) on the rack, the joint 13 is carefully placed at a high position (i.e., the highest position), i.e., each pneumatic tire 1 is oriented (rotated) so that the joint 13 is at the top. The purpose of this orientation is that the release agent dripping by gravity does not accumulate near the joint 13, but instead accumulates in the area of the pneumatic tire 1 far from the joint 13 (generally also from other joints). In fact, if the release agent accumulates near or flows in large quantities at the joint 13, it will penetrate into some minute cracks at the joint 13, and the peeling or cracking of the inner liner 6 will be formed prematurely, and in the short term, the essential impermeability of the pneumatic tire 1 may be lost.

[0023] Similarly, if the release agent accumulates near or flows in large amounts near the RFID label 8, it may penetrate into the RFID label 8 and the inner liner 6, causing early peeling or cracking of the inner liner 6, and in the short term, the essential impermeability of the pneumatic tire 1 may be lost. Therefore, by holding the RFID label 8 within the region 14, accumulation of the release agent near the RFID label 8 or any large-scale flow thereof is prevented, and as a result, the possibility of cracks (ruptures) forming in the inner liner 6 is prevented (i.e., rupture of the inner liner 6 due to intrusion of the release agent is prevented).

[0024] As shown in the attached drawings and in the above-described embodiment, the RFID label 8 is attached to the radially inner surface of the inner liner 6 (which constitutes the innermost free surface of the pneumatic tire 1). According to other embodiments (not shown), an electronic device different from the RFID label 8, for example, an electronic device that constitutes a TMS ("Tire Mounted Sensor") or an electronic device that is part of a TMS, is attached to the radially inner surface of the inner liner (6) (which constitutes the innermost free surface of the pneumatic tire 1).

[0025] The embodiments described herein can be combined without departing from the scope of protection of the present invention.

[0026] The above-described pneumatic tire 1 has many advantages.

[0027] Originally, in the above-described pneumatic tire 1, the defect of the inner liner 6 in the RFID label 8 is minor. This result is obtained by avoiding the accumulation of the release agent near the RFID label 8 before the vulcanization process.

[0028] Furthermore, the above-described pneumatic tire 1 is particularly simple and economical to implement because it only requires focusing on the positioning of the RFID label 8 (which can be easily automated) and does not require additional components.

Explanation of Reference Numerals

[0029] 1 Tire 2 Carcass 3 Bead 4 Tread 5 Tread Belt 6 Inner Liner 7 Sidewall 8 RFID Label 9 Electronic Circuit 10 Antenna 11 Rubber Strip 12 Rubber Strip 13 Joint 14 Region D1 Circumferential Distance D2 Circumferential Distance

Claims

1. A pneumatic tire (1), comprising: an inner liner (6) that forms an inner cover and holds air inside the pneumatic tire (1); a joint portion (13) of the inner liner (6) that gives a cylindrical shape to the inner liner (6); and an electronic device, particularly an RFID label (8), adhered to the radially inner surface of the inner liner (6) that forms the innermost free surface of the pneumatic tire (1); wherein in the pneumatic tire (1), the electronic device is arranged within a region (14) that extends circumferentially by 90° or less on one side from the joint portion (13) around the joint portion (13).

2. The pneumatic tire (1) according to Claim 1, wherein the region (14) where the electronic device is arranged has a maximum circumferential extension range of 180°.

3. The pneumatic tire (1) according to Claim 1, wherein the region (14) where the electronic device is arranged has a maximum circumferential extension range of 150°, 120°, or 90°.

4. The pneumatic tire (1) according to Claim 1, 2, or 3, wherein the electronic device does not overlap the joint portion (13).

5. In the pneumatic tire (1) according to any one of Claims 1 to 4, the electronic device is arranged at a non-zero first circumferential distance (D1) from the joint portion (13).

6. In the pneumatic tire (1) according to any one of Claims 1 to 5, the distal end of the electronic device is arranged at a second circumferential distance (D2) less than 90° from the joint portion (13).

7. In the pneumatic tire (1) according to Claim 6, the proximal end of the electronic device facing the distal end in the circumferential direction is arranged at a non-zero first circumferential distance (D1) from the joint portion (13).

8. In the pneumatic tire (1) according to any one of Claims 1 to 7, the proximal end of the electronic device is arranged at a first circumferential distance (D1) greater than 0° from the joint portion (13), and the distal end of the electronic device facing the proximal end in the circumferential direction is arranged at a second circumferential distance (D2) less than 90° from the joint portion (13).

9. A method for manufacturing a pneumatic tire (1), a step of forming an inner liner (6) that constitutes an inner cover and holds air inside the pneumatic tire (1); a step of bending the inner liner (6) annularly around an assembly drum of a production machine to form a joint (13) that gives the inner liner (6) a cylindrical shape; and a step of attaching an electronic device, particularly an RFID label (8), to a radially inner surface of the inner liner (6) that constitutes the innermost free surface of the pneumatic tire (1); comprising: The manufacturing method is characterized in that the electronic device is entirely arranged in a region (14) that extends circumferentially by 90° or less on one side with the joint (13) as the center and starting from the joint (13).

10. In the manufacturing method according to claim 9, a step of applying a release agent to the green pneumatic tire (1) for a subsequent vulcanization process; and after the step of applying the release agent and before the vulcanization process, a step of storing the green pneumatic tire (1) in a vertical direction in which the joint (13) is at a high position, preferably the highest position.

11. In the manufacturing method according to claim 9 or 10, the region (14) where the electronic device is arranged has a maximum circumferential extension range of 150°, 120°, or 90°.

12. In the manufacturing method according to claim 9, 10, or 11, the electronic device does not overlap at the joint (13).

13. In the manufacturing method according to any one of claims 9 to 12, the electronic device is arranged at a first circumferential distance (D1) other than zero from the joint (13).

14. In the manufacturing method according to any one of claims 9 to 13, the distal end of the electronic device is arranged at a second circumferential distance (D2) smaller than 90° from the joint (13).

15. In the manufacturing method according to any one of claims 9 to 14, the proximal end of the electronic device is arranged at a first circumferential distance (D1) greater than 0° from the joint (13), and the distal end of the electronic device that faces the proximal end circumferentially is arranged at a second circumferential distance (D2) smaller than 90° from the joint (13).

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