Pneumatic tire equipped with electronic device

Abstract

The present invention relates to a pneumatic tire (1) comprising: an inner liner (6) constituting an inner coating and having the purpose of holding air within the pneumatic tire (1); a joint (13) of the inner liner (6) that imparts a cylindrical shape to the inner liner (6); and an RFID tag (8) that is applied to the radially inner surface of the inner liner (6) constituting the innermost free surface of the pneumatic tire (1), and that is disposed completely in a region (14) that extends circumferentially from the joining part (13) centered on the joining part (13) and extends no more than 90 DEG on each side.

Description

Technical Field

[0001] The invention is advantageously applied to pneumatic tires equipped with RFID tags, ie pneumatic tires equipped with identification tags based on RFID (“Radio Frequency IDentification”) technology, to which the discussion below will explicitly refer without thereby sacrificing general applicability. Background Art

[0002] In recent years, so-called "smart" pneumatic tires have emerged, which can form active devices of modern vehicles, providing information about the type of pneumatic tire installed, information about the state of the pneumatic tire and information about environmental conditions. The "smart" pneumatic tire is provided with an RFID ("Radio Frequency Identification") tag, which enables remote communication of information about the pneumatic tire, such as identification, characteristics and history.

[0003] It has been proposed (for example, as described in patent applications US2020070597A1, US20210016614A1 and EP4019241A2) to glue the RFID tag to the inner or outer surface of the sidewall of the pneumatic tire; this solution is extremely simple from a design point of view and can also be applied to existing pneumatic tires; however, by contrast, it does not guarantee that the transponder will not be detached from the pneumatic tire after the cyclic deformations experienced by the sidewall of the pneumatic tire (especially when it is glued to the outer surface). It has also been proposed (for example, as described in patent applications US20080289736A1, EP2186658A1 and EP1366931A2) to integrate the transponder into the structure of the pneumatic tire, that is, into the various layers that make up the pneumatic tire.

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

[0005] Patent application EP 3 798 020 A1 describes a pneumatic tire ( 1 ) having an overlap region in which the inner layers of the pneumatic tire overlap.

[0006] Particularly in the case where an RFID tag is glued to the radially inner surface (composed of an inner liner) of a pneumatic tire, it has been observed that, at non-indifferent frequencies, cracks (fissures) may exist in the inner liner near the area to which the RFID tag is glued. Summary of the invention

[0007] The object of the present invention is to provide a pneumatic tire provided with an electronic device which does not have the above-mentioned disadvantages, namely no risk of separation or rupture of the inner liner in the vicinity of the zone to which the electronic device is applied, and which can be produced in an easy and economical manner.

[0008] According to the present invention, there is provided a pneumatic tyre equipped with an electronic device, as set out in the accompanying claims.

[0009] The claims describe preferred embodiments of the invention, which form an integral part of the present description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The invention will now be described with reference to the accompanying drawings, which show exemplary, non-limiting embodiments, in which:

[0011] · Figure 1 is a schematic cross-sectional view of a pneumatic tire provided with an RFID tag;

[0012] · Figure 2 and Figure 3 They are Figure 1 A three-dimensional diagram and a three-dimensional exploded diagram of an RFID tag of a pneumatic tire;

[0013] · Figure 4 yes Figure 1 A schematic diagram of the structure of a pneumatic tire; and

[0014] · Figure 5 and Figure 6 yes Figure 1 Two different schematic side views of a pneumatic tire. DETAILED DESCRIPTION

[0015] exist Figure 1 , reference numeral 1 indicates a pneumatic tire 1 as a whole, which includes an annular carcass 2, which is partially folded onto itself and thus has two side wings (i.e., two layers are superimposed on each other and are collectively referred to as "turnbacks"). Two annular beads 3 are provided on opposite sides of the carcass 2, wherein each of the annular beads is surrounded by the carcass 2. The carcass 2 supports an annular tread 4, in which a tread belt 5 is inserted. An inner liner 6 is arranged inside the carcass 2, which is airtight, constitutes an inner liner, and has the function of retaining air inside the tire 1 so as to maintain the same inflation pressure of the tire 1 over time. The carcass 2 supports a pair of lateral walls 7, each of which couples the beads 3 to the tread 4.

[0016] The pneumatic tire 1 is provided with an RFID ("Radio Frequency Identification") tag 8, also called a "smart tag", which is capable of storing information and / or acquiring signals related to the operating conditions or status of the pneumatic tire 1 and is capable of communicating via radio frequencies. In other words, the RFID tag 8 is configured to respond to remote polling on the part of a suitable fixed or portable device, called a reader (or interrogator), or to autonomously transmit signals to a receiver; the reader or receiver is capable of reading and / or modifying the information contained in the RFID tag 8 communicating in a radio frequency manner.

[0017] according to Figure 1 , the RFID tag 8 is configured on the lateral wall 7 of the pneumatic tire 1; Figure 1 In other embodiments shown by dashed lines in FIG. 1 , the RFID tag 8 may be disposed on a component of the pneumatic tire 1 other than the lateral wall 7 , such as the tread 4 .

[0018] according to Figure 1 , the RFID tag 8 is glued to the inner liner 6, i.e. it is applied to the inner surface of the pneumatic tire 1, which inner surface is constituted by the inner liner 6 (the RFID tag 6 is therefore in direct contact with the inner liner 6). In other words, the RFID tag 8 is located outside the pneumatic tire 1, i.e. it is not integrated into the pneumatic tire 1, but is applied (fixed, attached) to the radially inner surface of the inner liner 6, i.e. it is applied to the following surface of the inner liner 6: this surface is located outside the pneumatic tire 1 and is therefore in direct contact with the air inside the pneumatic tire 1, and is therefore applied to the innermost free surface of the pneumatic tire 1. According to a different embodiment (not shown), the RFID tag 8 is integrated inside the pneumatic tire 1, i.e. it is inserted between the components of the pneumatic tire 1 during the construction of the pneumatic tire 1 itself (for example, the RFID tag 8 can be configured between the carcass 2 and the inner liner 6 or between the carcass 2 and the lateral wall 7).

[0019] according to Figure 2 and Figure 3 , the RFID tag 8 comprises an electronic circuit 9 (i.e., 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, i.e., the RFID tag 8 is essentially a transponder); these components are inserted into a rubber housing consisting of two rubber strips 11 and 12, which overlap and are pressed one on top of the other.

[0020] The raw components of the pneumatic tire 1 (carcass 2, tread belt 5, tread 4, inner liner 6, ...) overlap each other to form a flat strip, which is then wound (wound around, i.e., wound on, a building drum of a building machine) to form a cylinder, which is then deformed to assume the final annular shape. In particular, the strip wound into a ring is connected to itself, forming a plurality of joints (each component of the pneumatic tire 1 is joined at a different location to avoid overlapping of the joints and, therefore, to avoid forming large discontinuities at a single point). In the various joints within the pneumatic tire 1 and according to Figure 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 in which two opposite flaps of the inner liner 6 are joined to each other (with a slight overlap). The green pneumatic tire 1 then undergoes a vulcanization process in a suitable vulcanization mold.

[0021] The engagement portion 13 imparts a cylindrical shape to the inner liner 6 of the pneumatic tyre 1 and is axially oriented, ie it is parallel to the central axis of the pneumatic tyre 1 about which it rotates during use.

[0022] according to Figure 5 , the RFID tag 8 is arranged in a region 14 that is centered on the joint 13 (i.e., the joint 13 is arranged exactly at the center of the region 14) and extends circumferentially from the joint 13, extending no more than 90° on each side (i.e., the maximum extension of the region 14 is 90° on each side). In other words, the region 14 has a maximum circumferential extension of 180° (thus covering at most exactly half of the pneumatic tire 1). According to an alternative embodiment, the region 14 has a maximum circumferential extension of 150°, 120° or 90°; that is, the region 14 extends circumferentially from the joint 13, extending no more than 75°, 60° or 45° on each side.

[0023] according to Figure 5 , the RFID tag 8 preferably does not overlap with the joint 13, that is, (as Figure 6 The RFID tag 8 (better illustrated in FIG. 1 ) is arranged at a non-zero circumferential distance D1 from the joint 13.

[0024] More generally and according to Figure 6 As better illustrated in FIG. 1 , the proximal end of the RFID tag 8 is arranged at a circumferential distance D1 greater than 0° from the joint 13 and the distal end of the RFID tag 8 (circumferentially opposite to the proximal end) is arranged at a circumferential distance D2 (greater than the circumferential distance D1) less than 90° (i.e., less than 75°, 60°, or 45°) from the joint 13. Obviously, the circumferential distance D2 is greater than the circumferential distance D1 because the circumferential extension of the RFID tag 8 is included between the two circumferential distances D1 and D2.

[0025] Before initiating the vulcanization process, a release agent (i.e., lubricating liquid) is applied (sprayed) on the inside of the pneumatic tire 1 and its purpose is to prevent the rubber of the inner liner 6 from adhering (vulcanizing) to the air chamber, which is inflated inside the pneumatic tire 1 to apply the necessary mechanical pressure. After the process of applying (spraying) the release agent, the raw pneumatic tires 1 to be vulcanized (i.e., ready for vulcanization) should usually be arranged in a vertical orientation in a rack, where they can be kept for a certain time (or even different times or days). When the raw pneumatic tires 1 (to be vulcanized) are "stored" in the rack, the joint 13 is carefully arranged high (i.e., at the highest point), that is, each pneumatic tire 1 is oriented (turned) so that the joint 13 is located at the top; the purpose of this orientation is that the release agent dripping due to gravity will not accumulate near the joint 13, but accumulate in the area of ​​the pneumatic tire 1 away from the joint 13 (and usually also away from other joints). In fact, if the release agent accumulates near the joint 13 or in any case flows in large quantities near the joint 13, it may eventually penetrate into some microcracks of the joint 13, causing separation of the inner liner 6 or premature formation of cracks, which will lead to a loss of the indispensable impermeability of the pneumatic tire 1 in a short period of time.

[0026] In the same manner, if the release agent accumulates near the RFID tag 8 or in any case flows in large quantities near the RFID tag 8, it may eventually penetrate into the RFID tag 8 and the inner liner 6, resulting in separation of the inner liner 6 or premature formation of cracks, which in a short period of time will lead to a loss of the indispensable impermeability of the pneumatic tire 1. Therefore, keeping the RFID tag 8 in the area 14 prevents the release agent from accumulating near the RFID tag 8 or in any case flowing in large quantities near the RFID tag 8, thereby preventing the potential formation of cracks (ruptures) in the inner liner 6 (i.e., preventing rupture of the inner liner 6 due to penetration of the release agent).

[0027] In the embodiment shown in the accompanying drawings and described above, the RFID tag 8 is applied 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 tag 8, for example an electronic device constituting a TMS ("Tire Mounted Sensor") or being part of a TMS, is applied to the radially inner surface of the inner liner (6) (which constitutes the innermost free surface of the pneumatic tire 1).

[0028] The embodiments described herein may be combined without departing from the scope of protection of the present invention.

[0029] The pneumatic tire 1 described above has many advantages.

[0030] First, the above-described pneumatic tire 1 has a slight defect of the inner liner 6 at the RFID tag 8; this result is obtained by preventing the release agent from accumulating near the RFID tag 8 before the vulcanization process.

[0031] Furthermore, the above-described pneumatic tire 1 is particularly simple and economical to implement, since it does not require any additional components, and the focus only needs to be on the positioning of the RFID tag 8 (which can be easily automated).

[0032] Description of Reference Numerals

[0033] 1 Tire

[0034] 2 Carcass

[0035] 3 Beads

[0036] 4 tread

[0037] 5. Tread belt

[0038] 6 Lining

[0039] 7 Sidewall

[0040] 8RFID tags

[0041] 9Electronic circuit

[0042] 10 Antenna

[0043] 11 Rubber Strip

[0044] 12 Rubber Strip

[0045] 13 Joint

[0046] 14 Regions

[0047] D1 Circumferential distance

[0048] D2 Circumferential distance

Claims

1. A pneumatic tire (1), comprising: an inner liner (6) constituting an inner covering and having the purpose of retaining air inside the pneumatic tire (1); a joining portion (13) of the liner (6) which imparts a cylindrical shape to the liner (6); and an electronic device, in particular an RFID tag (8), applied to the radially inner surface of the inner liner (6) constituting the innermost free surface of the pneumatic tire (1); The pneumatic tire (1) is characterized in that the electronic device is arranged in the following area (14): the area is centered on the joint (13) and extends circumferentially from the joint (13) and extends no more than 90° on each side.

2. Pneumatic tire (1) according to claim 1, wherein the area (14) in which the electronic device is arranged has a maximum circumferential extension of 180°.

3. Pneumatic tire (1) according to claim 1, wherein the area (14) in which the electronic device is arranged has a maximum circumferential extension of 150°, 120° or 90°.

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

5. A pneumatic tyre (1) according to any one of claims 1 to 4, wherein the electronic device is arranged at a non-zero first circumferential distance (D1) from the joint (13).

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

7. The pneumatic tire (1) according to claim 6, wherein a proximal end of the electronic device, circumferentially opposite to the distal end, is arranged at a non-zero first circumferential distance (D1) from the joint (13).

8. An inflatable tire (1) according to any one of claims 1 to 7, wherein the proximal end of the electronic device is configured at a first circumferential distance (D1) greater than 0° from the joint (13), and the distal end of the electronic device circumferentially opposite to the proximal end is configured at a second circumferential distance (D2) less than 90° from the joint (13).

9. A method for producing a pneumatic tire (1), comprising the following steps: Creating an inner liner (6) which constitutes the inner covering and has the purpose of keeping the air inside the pneumatic tire (1); folding the liner (6) into a ring around a forming drum of a building machine to form a joint (13) which gives the liner (6) a cylindrical shape; as well as applying an electronic device, in particular an RFID tag (8), to the radially inner surface of the inner liner (6) constituting the innermost free surface of the pneumatic tire (1); The production method is characterized in that the production method arranges the electronic device entirely in the following area (14): the area is centered on the joint (13) and extends circumferentially from the joint (13) and extends no more than 90° on each side.

10. The production method according to claim 9, comprising the following steps: Applying a release agent to a green pneumatic tire (1) for subsequent vulcanization; as well as The green pneumatic tire (1) is stored in a vertical orientation after applying the release agent and before the vulcanization process, in which orientation the joint (13) is arranged high and preferably located at the highest point.

11. Production method according to claim 9 or 10, wherein the region (14) in which the electronic device is arranged has a maximum circumferential extension of 150°, 120° or 90°.

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

13. Production method according to any one of claims 9 to 12, wherein the electronic device is arranged at a non-zero first circumferential distance (D1) from the joint (13).

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

15. A production method according to any one of claims 9 to 14, wherein the proximal end of the electronic device is configured at a first circumferential distance (D1) greater than 0° from the joint (13), and the distal end of the electronic device circumferentially opposite to the proximal end is configured at a second circumferential distance (D2) less than 90° from the joint (13).

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