Method for bonding a support for an electronic device to a vulcanized tire

Abstract

A method for bonding a support (8; 36) for an electronic device (7) to a vulcanized tire (1), the support (8; 36) being provided with at least one at least partially unvulcanized rubber compound (9) having a connecting surface (S). The method comprises the steps of applying the support (8; 36) to the wall of the tire (1) so that the connecting surface (S) of the support (8; 36) is placed in direct contact with the wall of the tire (1), and preheating the support (8; 36) so that the connecting surface (S) of the support (8; 36) has a temperature higher than the temperature of the vulcanized tire (1) at the moment of applying the support (8; 36) to the wall of the tire (1).

Description

[Technical Field]

[0001] The present invention relates to a method for joining a support for an electronic device, in particular a transponder, to a vulcanized tire.

[0002] prior art In recent years, so-called "smart" pneumatic tires have appeared, which form an active part of modern vehicles and are capable of providing information about the type of pneumatic tire fitted, about the condition of the pneumatic tire, and even about the state of the environment.

[0003] "Smart" tires are typically equipped with a transponder (i.e., an electronic device with storage suitable for radio frequency communication) that allows the tire's identification, characteristics, and history to be communicated remotely (i.e., both to the vehicle on which the tire is fitted and to an operator who must check or change the tire, or to an external monitoring system such as a gate).

[0004] Recently, the integration of RFID (Radio-Frequency Identification) transponder technology with the presence of transponders or sensors operating using TPMS (Tire Pressure Monitoring System) technology has also been proposed, allowing the sensors to measure air pressure and / or effective internal temperature, then store such measurements in the transponder and subsequently communicate them remotely to a receiver. Even more recently, tires have been equipped with sensors or TPMS (Tire Pressure Monitoring System) transponders internally, which allow reading, processing, receiving, and transmitting characteristics related to the state of the tire, such as acceleration, speed, load, wear, adhesion to the road surface, etc.

[0005] A need has therefore arisen for bonding an electronic device (transponder or sensor) to a tire, and to perform this bonding it is generally necessary to use a rubber support (housing) that houses (or houses or otherwise partially contains) the electronic device inside and is configured to adhere it to the tire in a stable and reliable manner. According to one possible embodiment, the electronic device can be pre-bonded to the support (i.e. the bonding between the electronic device and the support is performed before the support is inserted into the tire), or alternatively the electronic device can be bonded to the support only after it has been inserted into the tire.

[0006] To connect the support for the electronic device to the tire, it is possible to attach the transponder to the inner surface of the tire (typically on the inner liner that ensures the tire is airtight), or alternatively, to integrate the support into the components that make up the tire structure (i.e., to arrange the support in the middle of the various layers that make up the tire). Attaching the support to the inner surface of the tire does not change the structure of the tire in any way with respect to the presence of foreign objects, thus ensuring that the tire can perform as expected. The support for the electronic device can be attached to the inner surface of the tire when it is green (i.e., before it is vulcanized) or alternatively, when it has already been vulcanized.

[0007] During vulcanization, a layer of lubricant is generally applied, the function of which is to facilitate the release of the tire from the vulcanization mold at the end of the vulcanization process. In particular, the lubricant is interposed between the inner surface of the tire and the inner membrane (inflation bladder) of the vulcanization mold. As a result, at the end of the vulcanization process, the inner surface of the vulcanized tire has a layer of lubricant in the area where the support is applied, and this layer must be locally removed (for example, by cleaning with a laser beam, or otherwise by using a special solvent, by partial ablation of the surface, or by other available methods and techniques) (otherwise, the support may not be able to adhere to the tire surface with sufficient strength). As a result, attaching a support to the inner surface of a tire after it has already been vulcanized generally requires additional processing (cleaning the area where the support is applied), which increases production time and costs. Alternatively, the inner membrane (inflation bladder) of the mold can be made of a specific material, preferably silicone, that contributes to the release of the tire without the use of any additional lubricant (mold release material). However, at the current state of the art, such inner membranes are relatively rare.

[0008] Furthermore, to ensure that the support adheres well to the surface of the vulcanized tire, it is necessary to use a sufficiently strong adhesive (glue) that is compatible with the rubber compound that makes up the tire's inner liner and that does not in any way impair the integrity of the tire's inner liner, which adhesive represents an additional cost from an economic and environmental point of view.

[0009] Therefore, in order to reduce production lead time and costs, it is preferable to attach supports for electronic devices to the inner surface of the tire while the tire is still green (i.e., before the tire is vulcanized). However, the high pressure and high temperature reached during the vulcanization process can cause parts of the electronic device (previously bonded to the support) to float outside the support (the so-called "floating" phenomenon), often causing the electronic device to malfunction (if not completely fail). In addition, the high pressure and high temperature reached during the vulcanization process can cause the support or parts of the electronic device (previously bonded to the support) to come into contact with the carcass cord, thereby often causing the electronic device to malfunction (if not completely fail), which, in turn, can adversely affect the operation of the carcass cord. Finally, the high pressure and high temperature reached during the vulcanization process can cause irregularities in the inner liner (especially at the edges of the support), which, in the long term, can cause cracks in the inner liner, impairing the retention of air inside the tire and resulting in pressure loss.

[0010] It has further been observed that if the support is initially empty (i.e. does not initially contain an electronic device that will subsequently be inserted into the support), complex and expensive production processes are required to maintain the necessary shape and elasticity of the support to ensure problem-free subsequent insertion of the electronic device into the support.

[0011] WO 2021126199 A1 describes inserting an electronic sensor, previously bonded to a rubber support, inside a tire during vulcanization of the tire in a vulcanization mold.

[0012] WO 2011040921 A1 describes an electronic patch comprising a vulcanized rubber support on which an electronic device is mounted, which is attached to the wall of a vulcanized tire by means of an intervening adhesive unvulcanized rubber layer that is applied to the inner wall of the electronic patch and is initially covered by a removable protective film.

[0013] EP 3168068 A1 describes applying an electronic patch (comprising a vulcanized rubber support on which an electronic device is mounted) to the inner wall of a vulcanized tire by means of an intervening adhesive layer.

[0014] WO2017105842A1 describes an assembly for mounting an electronic circuit package on a tire, where a mounting patch of the electronic package is permanently attached to the inner liner of the tire by adhesive or by a low temperature polymerization process. Summary of the Invention

[0015] The present invention aims to provide a method for bonding a support for an electronic device to a vulcanized tire, which method makes it possible to avoid damage to the tire, the support and the electronic device, and which is easy and economical to carry out, at the same time aiming to reduce energy consumption and therefore to be more sustainable.

[0016] The claims, which form an integral part of this specification, describe preferred embodiments of the invention. [Brief explanation of the drawings]

[0017] The present invention will now be described with reference to the accompanying drawings which illustrate exemplary and non-limiting embodiments. [Figure 1] 1 is a schematic cross-sectional view of a tire provided with an electronic device; [Figure 2] 2A and 2B are respectively a perspective view and an exploded perspective view of the electronic device of FIG. 1 inserted into a rubber support; [Figure 3] 2A and 2B are respectively a perspective view and an exploded perspective view of the electronic device of FIG. 1 inserted into a rubber support; [Figure 4] 2 shows a schematic representation of some processing stations of a production plant for manufacturing the tire of FIG. 1; [Figure 5] 1 is a schematic diagram of a gripper used in a production plant. [Figure 6]2 shows a schematic representation of some processing stations of a production plant for manufacturing the tire of FIG. 1; [Figure 7] 2 shows a schematic representation of some processing stations of a production plant for manufacturing the tire of FIG. 1; [Figure 8] 1 is a schematic diagram of a tool used in an application station of a production plant. [Figure 9] 1A and 1B are perspective and cross-sectional views, respectively, of different embodiments of a rubber support suitable for containing an electronic device. [Figure 10] 1A and 1B are perspective and cross-sectional views, respectively, of different embodiments of a rubber support suitable for containing an electronic device. [Figure 11] 1 is a graph showing experimentally obtained changes in adhesive force of a support coupled to a transponder to the wall of a vulcanized tire as the surface temperature of the wall changes. DETAILED DESCRIPTION OF THE INVENTION

[0018] In Figure 1, reference number 1 indicates as a whole a tire 1 including a toroidal carcass 2, which is partially folded onto itself and thus has two lateral flaps (i.e., two layers overlapping each other, collectively referred to as "turn-ups"). On either side of the carcass 2, two annular beads 3 are provided, each surrounded by the carcass 2. The carcass 2 supports an annular tread 4 with a tread belt 5 and a pair of sidewalls interposed therebetween that join the beads 3 to the tread 4. An inner liner 6 is arranged within the carcass 2, which is airtight and constitutes an inner lining and has the same function of retaining air within the same tire 1 in order to maintain the tire's inflation pressure over time.

[0019] The tire 1 is provided with a transponder 7 (shown in Figures 2 and 3) inserted into a support 8 and arranged in contact with the wall of the tire 1, i.e., the support 8 is suitable (adapted) to receive and hold the transponder 7. As will be better explained below, the transponder 7 can be coupled to the support 8 before applying the support 8 to the tire 1, or alternatively, can be coupled to the support 8 after applying the support 8 to the tire 1. As shown in Figure 1, the transponder 7 inserted into the support 8 can be arranged either on the inside of the tire 1 (i.e., in contact with the inner liner 6) or alternatively, on the outside of the tire 1 (i.e., opposite the inner liner 6), and also on the sidewall (either on the inside or outside of the tire 1) or alternatively, on the tread 4 (only on the inside of the tire 1).

[0020] A transponder 7 is an electronic device (usually passive or semi-passive, i.e. not including its electrical supply) capable of storing information and communicating by radio frequency. In other words, the transponder 7 is a small "smart label" suitable for responding to remote polling by a specific fixed or portable device, called a reader (or polling device), which is able to read and / or modify the information contained in the transponder 7 being polled while communicating with the transponder 7 itself by radio frequency. The transponder 7 is therefore part of a wireless reading and / or writing system operating according to the so-called RFID technology ("Radio Frequency Identification").

[0021] 2 and 3 , the transponder 7 is inserted into a support 8 consisting of two components 9 and 10 superimposed and pressed against one another: an inner component 9 arranged in direct contact with one wall of the tire 1 (as better explained below), and an outer component 10 arranged on the opposite side relative to the wall of the tire 1 (as better explained below). Generally, the two components 9 and 10 of the support 8 are longer / wider than the transponder 7. Generally, the two components 9 and 10 are both made of rubber and consist of the same type of rubber compound; alternatively, the two components 9 and 10 can both be made of rubber and consist of two different types of rubber compounds. According to different embodiments, only the inner component 9 (i.e., in direct contact with the wall of the tire 1) is made of rubber (at least partially unvulcanized, as better explained below), while the outer component 10 (i.e., arranged on the opposite side relative to the wall of the tire 1) is made of a material other than rubber (plastic).

[0022] According to another embodiment, the support 8 may consist of only the component 9 (ie the outer component 10 may not be present).

[0023] Each component 9 or 10 of the support 8 may have a monolayer structure (i.e., may consist of a single type of material forming a single homogeneous layer) or may have a multilayer structure (i.e., may consist of two or more superimposed materials forming two or more layers).

[0024] The inner component 9 of the support body 8 has a connection surface S, which faces the wall of the tire 1 (i.e. is in direct contact with the wall of the tire 1) and is therefore arranged opposite the transponder 7. In other words, the inner component 9 of the support body 8 has a connection surface S that is in direct contact with the wall of the tire 1 and is arranged opposite the transponder 7, and a surface opposite the connection surface S, on which the transponder 7 is supported.

[0025] According to an alternative embodiment, the transponder 7 is supported on the connection surface S itself, which is in direct contact with one wall of the tire 1. In this embodiment, it can be seen that the transponder 7 is interposed between the connection surface S, and therefore the component 9, and the wall of the tire 1.

[0026] As shown in Figure 4, the support 8 including the transponder 7 is applied to one wall of the vulcanized tire 1 (in particular, in the non-limiting exemplary embodiment shown in Figure 4, to the inner wall of the vulcanized tire 1 consisting of the inner liner 6) to place the connection surface S of the component 9 of the support 8 in direct contact with the wall of the vulcanized tire 1. That is, the support 8 including the transponder 7 is applied to one wall of the tire 1 after the tire 1 has been extracted from the vulcanization mold and thus has finished its construction cycle.

[0027] At least the component 9 of the support 8 coupled to the transponder 7 is preheated before being applied to the wall of the tire 1 so that at the moment of applying the support 8 to the wall of the tire 1 the connection surface S of the component 9 of the support 8 has a temperature higher than the temperature of the wall of the vulcanized tire 1 (which, as will be better explained below, is substantially ambient temperature).

[0028] According to a preferred embodiment, at the moment of applying the support 8 to the wall of the tire 1, the connection surface S of the support 8 has a temperature of approximately 100°C. In particular, at the moment of applying the support 8 to the wall of the tire 1, the connection surface S of the support 8 has a temperature of between 90°C and 110°C, preferably equal to approximately 100°C. More generally, at the moment of applying the support 8 to the wall of the tire 1, the connection surface S of the support 8 has a temperature higher than 80-90°C and lower than 120-110°C.

[0029] According to a preferred embodiment, heating the support 8 coupled to the transponder 7 (obviously before applying the support 8 coupled to the transponder 7 to the wall of the vulcanized tire 1) provides for obtaining (performing) a more or less complete vulcanization of the support 8 or at least of the components 9 of the support 8. For this, just before applying the support 8 coupled to the transponder 7 to the wall of the vulcanized tire 1, the support 8 coupled to the transponder 7 is heated while maintaining the support at a high temperature, for example between 90°C and 110°C, preferably at a temperature equal to about 100°C, for a relatively long time, for example for a period of 15 to 25 minutes, preferably for a period of 20 minutes. During the heating of the support 8 coupled to the transponder 7, the support 8 is subjected only to heat and not to any mechanical pressure.

[0030] Applying the support 8 coupled to the transponder 7 to the wall of the tire 1 provides for pressing the support 8 against the wall of the tire 1 so as to subject the support 8 to a continuous mechanical pressure. In particular, after applying the support 8 coupled to the transponder 7 to the wall of the tire 1, a mechanical pressure is applied to the support 8, pressing the support 8 against the wall of the tire 1, and maintained. According to a preferred embodiment, the mechanical pressure applied to the support 8 is equal to 5 to 15 bar, preferably 10 bar, and is maintained for a period of 10 to 30 minutes, preferably equal to 20 minutes.

[0031] According to the embodiment shown in Figure 5, the mechanical pressure is applied to the support 8 coupled to the transponder 7 by a ratchet gripper 11 provided with a jaw 12 that rests on the support 8 and an outer jaw 13 that rests on the tire 1 from the opposite side of the support 8. According to one possible embodiment, the jaw 12 is heated by a heating device configured to heat the support 8 applied to the tire wall, the heater being able to maintain the support 8 at an initial application temperature (for example 100°C) or alternatively at a temperature lower than the initial application temperature (for example 70-80°C).

[0032] The heat in the support 8 coupled to the transponder 7, when applied to the wall of the vulcanized tire 1, combined with the application of mechanical pressure to the support 8, leads to the complete completion of vulcanization of the rubber present in the support 8, resulting in optimal adhesion of the support 8 coupled to the transponder 7 to the wall of the vulcanized tire 1 without the intervening (use) of any adhesive or glue.

[0033] The support 8 (in particular the inner component 9 of the support 8) comprises unvulcanized rubber that is subjected to vulcanization at least in part due to the effect of preheating the support 8 before it is applied to the wall of the tire 1 and due to the effect of the continuous mechanical pressure applied to the support 8 after it has been applied to the wall of the tire 1. As mentioned above, at least the inner component 9 of the support 8 consists at least in part of unvulcanized rubber, or of rubber in which the vulcanization process has not yet started or in any case not yet completed. In other words, the inner component 9 has at least in part unvulcanized rubber that constitutes the connecting surface S (i.e. the surface in direct contact with the wall of the tire 1). In particular, at least the rubber constituting the connection surface S of the inner component 9 (and therefore in direct contact with the wall of the tire 1) will have a lower degree of vulcanization than the rubber of the (possible) outer component 10, which is not in direct contact with the wall of the tire 1; for example, the rubber of the inner component 9 will be completely unvulcanized and the rubber of the (possible) outer component 10 will be partially vulcanized, or the rubber of both components 9 and 10 will be partially vulcanized, but with different degrees of vulcanization (higher degree of vulcanization of the outer component 10 and lower degree of vulcanization of the inner component 9).

[0034] Preferably, but not necessarily, the inner component 9 consists of completely unvulcanized rubber, i.e., rubber that has not been vulcanized at all, even partially, or partially vulcanized rubber, i.e., rubber in which vulcanization has been initiated but not completed, i.e., rubber that is neither completely unvulcanized nor completely vulcanized. Preferably, but not necessarily, the outer component 10 (if present) consists of only partially vulcanized rubber, i.e., rubber in which vulcanization has been initiated but not completed, i.e., rubber that is neither completely unvulcanized nor completely vulcanized, or fully vulcanized rubber.

[0035] The connection surface S of the inner component 9, which is in direct contact with the inner liner 6, must ensure adhesion to the inner liner 6 and therefore must be less vulcanized (and therefore have a higher adhesive capacity), while the outer component 10 (if present) which covers the transponder 7 must ensure protection of the transponder and therefore must be able to have a higher degree of vulcanization (and therefore become harder and more resistant, but with impaired adhesive capacity).

[0036] According to a preferred embodiment, the support 8 coupled to the transponder 7 is applied to one wall of the vulcanized tire 1 when it is found to be at substantially ambient temperature (the temperature of a tire production plant or of a facility for changing and fitting tires, where operators are constantly working and therefore generally at a temperature of 15-30°C). That is to say, the support 8 coupled to the transponder 7 is applied to one wall of the tire 1 when the surface temperature of the wall of the vulcanized tire 1 is lower than 40°C. In particular, the support 8 coupled to the transponder 7 is applied to one wall of the tire 1 when the surface temperature of the wall of the vulcanized tire 1 is between 0°C and 30°C, preferably between 5°C and 25°C.

[0037] Experimental tests were performed in which a support 8 (already coupled to a transponder 7 or otherwise not coupled to a transponder 7) was preheated to approximately 100°C and applied to one wall of a vulcanized tire 1, the temperature of which varied from a minimum of 5°C to a maximum of 25°C in 5°C intervals. The results of these experimental tests are shown in the graph of FIG. 11, where the x-axis represents the surface temperature T of the wall of the vulcanized tire 1 and the y-axis represents the adhesive force F of the component 9 of the support 8 to the tire 1. That is, FIG. 11 is a graph showing the experimentally obtained change in adhesive force F of the support 8 to the wall of the vulcanized tire 1 as the wall surface temperature changed. During all experimental tests (i.e., while the surface temperature of the wall of the vulcanized tire 1 was between 5°C and 25°C), the adhesive force F of the component 9 of the support 8 to the wall of the vulcanized tire 1 remained fairly constant, yet always remained higher than the optimum value (i.e., a value sufficient to ensure complete and lasting adhesion of the support 8). Therefore, even if the surface temperature of the wall of the vulcanized tire 1 is slightly lower than 5°C (e.g., equal to 0°C) or slightly higher than 25°C (e.g., equal to 30-35°C), it is very likely that the adhesion of the support 8 to the wall of the vulcanized tire 1 will be sufficient.

[0038] In this regard, it has been observed that (all things being equal) the adhesion force between the support 8 (whether or not yet bonded to the transponder 7) and the wall of the vulcanized tire 1 is surprisingly high when the vulcanized tire 1 is "cold" (i.e., at ambient temperature) compared to when the vulcanized tire 1 is "hot" (e.g., immediately after removal from the vulcanization mold). One possible motivation is linked to the fact that when the rubber constituting the vulcanized tire 1 is hot, oils are produced that are interposed between the wall of the vulcanized tire 1 and the support 8 and that hinder adhesion of the support 8; these oils produced when the tire 1 is hot are reabsorbed into the rubber constituting the vulcanized tire 1 as the vulcanized tire 1 cools; therefore, a vulcanized tire 1 at ambient temperature is substantially better suited to promoting adhesion of the support 8.

[0039] As shown in Figure 4, an applicator device 14 applies a support 8 including a transponder 7 to the wall of a vulcanized tire 1. The applicator device 14 is moved by a robotic arm 15 (or by a similar handling device), i.e., the applicator device 14 is mounted on one end of the robotic arm 15. Preferably, the applicator device 14 comprises a frame 16, which is rigidly constrained to the robotic arm 15 and supports both an application head 17 configured to pick up the support 8 and transfer it to the wall of the vulcanized tire 1, and a camera 18, which defines a space in front of the application head 17 and is used to guide the movement of the robotic arm 15.

[0040] According to one preferred embodiment shown in Fig. 4, when the support 8 coupled to the transponder 7 is applied to the wall of the tire 1, a counter element 19 is arranged against one side of the wall of the tire 1 opposite to the side to which the support 8 is applied. In the embodiment shown in Fig. 4, the counter element 19 is provided at the application station S1, and the counter element is moved by the actuator device 20 and arranged on the outside of the tire 1 and located at the applicator device 14. In particular, when the support 8 including the transponder 7 is applied to the wall of the tire 1, the counter element 19 is arranged against the tire 1 on the side opposite to where the support 8 including the transponder 7 was applied. In this way, the applicator device 14 can force the support 8 including the transponder 7 against the wall of the tire 1, since the thrust exerted by the applicator device 14 is sufficiently opposed by the counter element 19 without causing unnecessary deformation of the tire 1. In particular, the actuator device 20 presses (with a certain predetermined force) the counter element 19 against the outside of the vulcanized tire 1 when the applicator device 14 applies the support 8 including the transponder 7 to the wall of the vulcanized tire 1 from the opposite side. Depending on the positioning of the transponder 7, the counter element 19 can press (inwardly or outwardly) against the tread 4 of the tire 1 or against the sidewall (side surface) of the tire 1.

[0041] According to a possible embodiment, one surface of the counter element 19 that is in contact with the outside of the vulcanized tire 1 carries a (small) relief pattern 21 (inscription and / or logo) indicating the presence and position of the transponder 7, preferably the relief pattern 21 being heated to make it possible to better impress the relief pattern 21 on the outside (tread 4 or sidewall) of the vulcanized tire 1. The function of the relief pattern 21 engraved on the outside (tread 4 or sidewall) of the vulcanized tire 1 is to indicate the presence and position of the transponder 7 from the outside.

[0042] According to one possible embodiment shown in Fig. 6, a protective label 22 is applied to the wall of the green tire 1 in the area where the support 8 coupled to the transponder 7 has been applied, and then, after removing the tire 1 from the vulcanization mold and before applying the support 8 coupled to the transponder 7, the protective label 22 is removed from the wall of the vulcanized tire 1. The function of the protective label 22 is to protect (hide) the area of ​​the wall of the tire 1 where the support 8 coupled to the transponder 7 has been applied, so as to keep this area free of the (e.g., silicone-based) lubricant used during vulcanization and to facilitate the release of the vulcanized tire 1 from the vulcanization mold; in fact, the possible presence of residual lubricant between the wall of the vulcanized tire 1 and the support 8 coupled to the transponder 7 would compromise the correct adhesion of the support 8 to the wall of the tire 1. The lubricant can be applied by a lubrication station to the inner membrane (inflation bladder) of the vulcanization mold or, alternatively, to the inner surface of the green tire 1.

[0043] Obviously, the protective label 22 is only used when the support 8 coupled to the transponder 7 is applied to the inner surface of the vulcanized tire 1, if during vulcanization lubricant is only present on the inner surface of the vulcanized tire 1. Conversely, when the support 8 coupled to the transponder 7 is applied to the outer surface (sidewall) of the vulcanized tire 1, the protective label 22 is not necessary.

[0044] Also provided are different embodiments that do not provide for the use of protective label 22, provided that no lubricant is applied before vulcanization, provided that the lubricant formulation does not interfere with proper adhesion of substrate 8 to the wall of tire 1, or provided that the area of ​​the wall of tire 1 where substrate 8 is applied is pre-cleaned to remove residual lubricant before applying substrate 8.

[0045] Preferably, the protective label 22 is made of polyethylene terephthalate (also commercially known as Mylar). Furthermore, the protective label 22 is preferably larger than the support 8 containing the transponder 7 so that positioning tolerances (i.e., errors) (both in the positioning of the protective label 22 and in the positioning of the support 8 containing the transponder 7) can be "compensated" by its larger size.

[0046] 6, in station S2 arranged upstream of the vulcanization station (and obviously upstream of a possible lubrication station where lubricant is sprayed all over the inner surface of the green tire 1), an applicator device 23 (similar to applicator device 14) is moved by a robotic arm 24 (or by a similar handling device) to apply a protective label 22 to one wall of the green tire 1. Preferably, the applicator device 23 comprises a frame 25, which is rigidly constrained to the robotic arm 24 and supports both an application head 26 configured to pick up the protective label 22 and transfer it to the wall of the green tire 1, and a camera 27, which defines a space in front of the application head 26 and is used to guide the movement of the robotic arm 24.

[0047] At the end of the vulcanization process, the vulcanized tire 1 is removed from the vulcanization mold and allowed to cool naturally (over several hours or days) until it finally reaches substantially ambient temperature. As shown in Figure 7, at the application station S1, first the protective label 22 is removed from the wall of the vulcanized tire 1 by a removal device 28 to reveal the underlying part of the wall of the vulcanized tire 1 which does not contain any lubricant (obviously only in cases where the protective label 22 was previously applied).

[0048] The removal device 28 is moved by a robotic arm 29 (or by a similar handling device), i.e. the removal device 28 is mounted on one end of the robotic arm 29. Preferably, the removal device 28 comprises a frame 30, which is rigidly constrained to the robotic arm 29 and supports both a pick-up head 31 configured to remove the protective label 22 from the wall of the vulcanized tire 1, and a camera 32, which defines a space in front of the receiving head 31 and is used to guide the movement of the robotic arm 29.

[0049] According to one possible embodiment, within the application station S1 there are two different moving robotic arms 15 and 29 which respectively move the applicator device 14 and the removal device 28. Alternatively, there can be a single robotic arm 15 or 29 which alternately moves the applicator device 14 and the removal device 28. That is, the single robotic arm 15 or 29 first moves the removal device 28 to remove the protective label 22 from the wall of the vulcanized tire 1, and immediately thereafter replaces the removal device 28 with the applicator device 14 (i.e. releases the removal device 28 and then takes out the applicator device 14) to apply the support 8 to the wall of the vulcanized tire 1.

[0050] According to a further embodiment illustrated in Figure 8, the applicator device 14, which applies the support 8 comprising the transponder 7 to the wall of the vulcanized tire 1, and the removal device 28, which removes the protective label 22 from the wall of the vulcanized tire 1, are supported together (simultaneously) by the same robotic arm 15 or 29, in particular the applicator device 14 and the removal device 28 are mounted on the robotic arm 15 by a rotatable support element 33, which rotates about an axis of rotation 34 to alternately position the applicator device 14 or the removal device 28 towards the wall of the vulcanized tire 1. In this embodiment, a single camera 35 can be provided, which does not rotate (i.e. is not connected to the support element 33) and is common to both devices 14 and 28, thereby replacing the cameras 18 and 32.

[0051] As mentioned above, and according to a different embodiment, before inserting the green tire 1 into the vulcanization mold, it is possible to spray the inner surface of the green tire 1 or the inner membrane (inflation bladder) of the vulcanization mold with a lubricant that does not interfere with the adhesion of the support 8 including the transponder 7 to the inner liner 6, and in this embodiment, the presence of the protective label 22 (and therefore of the applicator device 23 and the removal device 28) is no longer necessary, since the lubricant does not interfere with the adhesion of the support 8 including the transponder 7 to the wall of the vulcanized tire 1.

[0052] As mentioned above, and according to a further embodiment, no lubricant is applied to the inner surface of the green tire 1 or to the inner membrane (inflation bladder) of the vulcanization mold, since the latter has a low-adhesion surface that does not require the presence of a lubricant; obviously, in the absence of a lubricant, the presence of the protective label 22 (and therefore of the applicator device 23 and the removal device 28) is no longer necessary.

[0053] As mentioned above, and according to a further embodiment, the protective label 22 is not applied and the removal device 28 is replaced by a cleaning device, which cleans (e.g. by laser) the area of ​​the wall of the vulcanized tire 1 to which the support 8 including the transponder 7 is applied.

[0054] 1 to 8, the support 8 is pre-bonded to each transponder 7 (i.e., to each electronic device) so that the support 8, already including each transponder 7, is joined to the tire 1 (using the joining method described above); in the embodiment shown in FIGS. 1 to 8, the support 8 surrounds each transponder 7 (i.e., each electronic device) on all sides, providing greater protection for each transponder 7. The embodiment shown in FIGS. 9 and 10 instead provides a support 36, which is provided in the center with a seat 37 that roughly fits into a cup to accommodate and hold each transponder 7 (i.e., each electronic device); in this embodiment, the support 36 is joined to the tire 1 (using the joining method described above) without including each transponder 7 (i.e., each electronic device), which transponder is inserted into the seat 37 of the support 36 only afterwards (i.e., after the support 36 has been joined to the tire 1). The support 36 may comprise a single component (corresponding to component 9 of support 8) or alternatively may consist of several components joined together.

[0055] To summarize the above, the support 8 or 36 is for one electronic device 7 (i.e. suitable / formed for receiving and holding the electronic device 7) and is bonded to the tire 1, allowing the electronic device 7 to be integrated into the tire 1. As mentioned above, the transponder 7 can be coupled to the support 8 or 36 before applying the support 8 or 36 to the tire 1, or alternatively, can be coupled to the support 8 or 36 after applying the support 8 or 36 to the support of the tire 1.

[0056] The method described above has many advantages.

[0057] Firstly, the method described above is particularly simple and cheap to implement, since it offers the execution of a small number of operations that are easily automated and requires only minimal energy consumption (the overall mass of the support 8 including the transponder 7 is very small, and therefore heating the support 8 including the transponder 7 to about 100°C requires almost negligible thermal energy when compared to the thermal energy required, for example, for vulcanization of the tire 1). The method described above is therefore considered sustainable in terms of being environmentally friendly when producing smart tires.

[0058] The method described above makes it possible to prevent damage to the tire 1 and the transponder 7.

[0059] The method described above does not require the use of any adhesive to attach the support 8 including the transponder 7 to the wall of the vulcanized tire 1, since only the adhesive forces established between two rubber layers subjected to pressure at a specific temperature are used to bond the support 8 to the inner liner 6, thus reducing both costs and environmental impact.

[0060] Finally, the method described above ensures a sufficiently strong and resistant adhesion of the transponder 7 to the tire 1, thereby avoiding the risk that the transponder 7 may even partially detach from the tire 1. [Explanation of symbols]

[0061] 1 pneumatic tire 2. Carcass 3 beads 4 Tread 5 Treadbelt 6 Inner liner 7 Transponder 8 Sleeve 9 Strip 10 Strips 11 Gripper 12 Inner jaw 13 Outer jaw 14 Applicator Device 15 Robot Arm 16 frames 17 Application Head 18 Camera 19 Counter Elements 20 Actuator Device 21 Relief Pattern 22 Protective Label 23 Applicator Device 24 Robot Arm 25 frames 26 Application Head 27 Camera 28 Removal Device 29 Robot Arm 30 frames 31 Removal Head 32 Camera 33 Supporting Elements 34 Rotation axis 35 Camera 36 Support 37 seats S Connection surface S1 Application Station S2 Application Station

Claims

1. A method for joining a support (8; 36) for an electronic device (7) to a vulcanized tire (1), said support (8; 36) being provided with at least one partially unvulcanized rubber compound (9) having a connecting surface (S), said method comprising the step of applying said support (8; 36) to one wall of said vulcanized tire (1) so as to place said connecting surface (S) of said support (8; 36) in direct contact with said wall of said tire (1), 1. The method according to claim 1, further comprising the step of preheating said support (8; 36) before applying it to the wall of said tire (1) so that the connecting surface (S) of said support (8; 36) has a temperature higher than the temperature of the vulcanized tire (1) at the moment of applying said support (8; 36) to the wall of said tire (1).

2. 2. The method according to claim 1, wherein at the moment of applying the support (8; 36) to the wall of the tire (1), the connecting surface (S) of the support (8; 36) has a temperature higher than 80°C, preferably higher than 90°C.

3. 3. The method according to claim 1 or 2, wherein, at the moment of applying the support (8; 36) to the wall of the tire (1), the connecting surface (S) of the support (8; 36) has a temperature between 90°C and 110°C, preferably equal to about 100°C.

4. 4. The method according to claim 1, 2 or 3, wherein at the moment of applying the support (8; 36) to the wall of the tire (1), the connecting surface (S) of the support (8; 36) has a temperature of about 100°C.

5. A method according to any one of the preceding claims, wherein the step of preheating the support (8; 36) provides for partially vulcanizing the support (8; 36).

6. 6. The method according to any one of claims 1 to 5, wherein the step of preheating the support (8; 36) provides for subjecting the support (8; 36) to heat and not subjecting the support to any mechanical pressure.

7. 7. Method according to any one of the preceding claims, wherein said step of preheating said support (8; 36) provides for maintaining said support (8; 36) at a temperature between 90°C and 110°C, preferably at a temperature equal to about 100°C, for a period of between 15 and 25 minutes, preferably equal to 20 minutes.

8. 8. The method according to any one of claims 1 to 7, wherein the step of applying the support (8; 36) to the wall of the vulcanized tyre (1) provides for pressing the support (8; 36) against the wall in order to subject the support (8; 36) to continuous mechanical pressure.

9. 9. The method according to any one of claims 1 to 8, comprising the further step of applying and maintaining a mechanical pressure on the support (8; 36) after applying the support (8; 36) to the wall of the tire (1) to press the support (8; 36) against the wall of the tire (1).

10. The method according to claim 9, wherein the mechanical pressure applied to the support (8; 36) is between 5 and 15 bar, preferably equal to 10 bar.

11. Method according to claim 9 or 10, wherein said mechanical pressure applied to said support (8; 36) is maintained for a period of between 10 and 30 minutes, preferably for a period equal to 20 minutes.

12. 12. The method according to claim 9, 10 or 11, wherein the mechanical pressure is applied by a gripper (11), preferably a ratchet, provided with a jaw (12) arranged against the support (8; 36) and a second outer jaw (13) arranged against the tire (1) on the opposite side of the support (8; 36).

13. 13. The method according to claim 12, wherein the first jaw (12) is heated by a heating device configured to heat the support (8; 36) applied to the wall of the tire (1).

14. Method according to any one of the preceding claims, wherein the support (8; 36) is applied to the wall of the tire (1) when the tire (1) is at ambient temperature.

15. Method according to any one of the preceding claims, wherein the support (8; 36) is applied to the wall of the tire (1) when the surface temperature of the tire (1) is below 40°C.

16. Method according to any one of the preceding claims, wherein the support (8; 36) is applied to the wall of the tire (1) when the surface temperature of the tire (1) is between 0°C and 30°C, preferably between 5°C and 25°C.

17. 17. The method according to any one of the preceding claims, comprising the further step that, when the support (8; 36) is applied to the wall of the tyre (1), a counter-element (19) is applied to the wall of the tyre (1) opposite to the side to which the support (8; 36) is applied.

18. 18. The method according to claim 17, wherein the surface of the counter element (19) in contact with the wall of the tire (1) has a relief pattern (21) indicating the presence and position of the electronic device (7).

19. 19. The method of claim 18, wherein the relief pattern (21) of the counter-element (19) is heated.

20. a further step of applying a protective label (22) to the wall of the green tire (1) in the area where the support (8; 36) is applied; The method according to any one of the preceding claims, comprising the further step of removing the protective label (22) from the wall of the vulcanized tyre (1) before applying the support (8; 36).

21. A method according to any one of the preceding claims, comprising the further step of pre-cleaning the wall of the tyre (1) in the area where the support (8; 36) is applied.

22. The method according to any one of the preceding claims, wherein the support (8) consists of an inner component (9) and an outer component (10) enclosing the electronic device (7) between said components.

23. 23. The method according to claim 22, wherein the inner component (9) is arranged in direct contact with the wall of the tire (1) and has the connecting surface (S), and is at least partially made of unvulcanized rubber.

24. 24. The method according to claim 22 or 23, wherein the inner component (9) is arranged in direct contact with the wall of the tire (1) and has the connecting surface (S), and is made of rubber having a lower degree of vulcanization compared to the rubber constituting the outer component (10).

25. A method according to any one of the preceding claims, wherein no adhesive or glue is interposed between the support (8; 36) and the wall of the vulcanized tyre (1).

26. 26. The method according to any one of the preceding claims, comprising the further step of pre-bonding the electronic device (7) to the support (8) before applying the support (8) to the wall of the vulcanized tyre (1).

27. The method according to any one of the preceding claims, comprising the further step of bonding the electronic device (7) to the support (36) only after the support (36) has been applied to the vulcanized tire (1).

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