Method and system for testing the resilience of an electronic device subjected to cyclic deformation during use and intended to be bonded to at least one component of an elastomer body, preferably a tire

Abstract

Provided are a method and a system for testing the resilience of an electronic device (8) coupled to a component (1) of a tire. 【Solution means】It includes a step of determining a first shape (F1) that the component takes during use, a step of determining a second shape (F2) different from the first shape (F1) that the component takes during use, a step of creating a support (11) including the electronic device (8), a step of subjecting the region of the support (11) where the electronic device (8) is disposed to a series of periodic deformations such that the region can alternately take the first shape (F1) and the second shape (F2), and a step of detecting the operation of the electronic device (8) while the support (11) is being subjected to the periodic deformations.

Description

[Technical Field]

[0001] The present invention relates to a method and system for testing electronic devices that are subjected to cyclic deformation during use.

[0002] The present invention is advantageously applied to testing the resilience of electronic devices intended to be coupled to tire components, to which explicit reference will be made in the following description, without loss of generality. [Background technology]

[0003] In recent years, so-called "smart tires" have appeared, which can provide information about the type of tire fitted, the condition of the tire, as well as information about the surrounding and road conditions, and can form an important part of modern vehicles.

[0004] A "smart tire" is typically equipped with a transponder (i.e., an electronic device suitable for communication at radio frequencies) that allows the tire's identity, characteristics, and history to be communicated remotely (between the vehicle on which the tire is fitted and an operator who inspects or changes the tire using an automated system or nearby the vehicle).

[0005] Recently, it has been proposed to integrate RFID (Radio-Frequency IDentification) technology, which is based on the presence of a transponder, with TPMS (Tire Pressure Monitoring Systems) technology, which measures the effective tire pressure, stores it in a transponder, and then communicates it remotely through the transponder itself.

[0006] Generally, a transponder intended to be coupled to a tire is first inserted into a rubber support (housing), which can fully or partially incorporate the transponder. To then couple the transponder to the tire, the transponder can be attached to the tire's inner or outer surface (usually on the inner liner, which ensures the tire's airtightness), or it can be integrated into the tire's structural components (i.e., placed between the various layers that make up the tire).

[0007] During use (i.e., when the tire is rolling on a road surface), the portion of the tire in contact with the road surface (which constitutes the so-called "ground footprint") undergoes continuous large deformations, and the rolling effect causes the portion of the tire in contact with the road surface to continuously change. As a result, during use, transponders coupled to tire components will be subjected to the same cyclic deformations that those components are subjected to, and may in the long term suffer fatigue failure (which typically manifests as a disruption of the electrical continuity of the chip and / or a disruption of high-frequency transmitting elements such as a relatively large antenna).

[0008] Therefore, to ensure that the transponder (or other electronic device) will continue to function throughout the tire's lifetime, it is necessary to test the effective resilience of the transponder coupled to the tire components. Resilience testing is actually performed when assembling a tire prototype equipped with the transponder (or other electronic device). While this type of testing is very efficient (i.e., highly accurate and reliable) in carrying out durability tests using such prototypes, it is also inefficient in that it is very time-consuming and very expensive (the work is largely manual and the associated costs are extremely high even for manufacturing just a few tire prototypes).

[0009] Patent Document 1 describes a system for testing the resilience of electronic devices coupled to tire components. In this system, the tire component (containing the central electronic device) is engaged at both ends and periodically slides over a series of rollers arranged in a continuous sequence that defines a serpentine path, with readers positioned next to the rollers to periodically inspect the electronic device and determine if and when the electronic device has ceased to function. While this testing system is efficient (i.e., tests can be performed in a short period of time and at low cost), it is inefficient in that it provides results that are not very accurate or reliable (i.e., the resilience measured by the testing system is often significantly different from the actual resilience experienced by a tire mounted on a vehicle). This is because the deformation periodically applied to the component (containing the central electronic device) is different from the deformation the component experiences during actual tire use. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] US8063742B2 Summary of the Invention

[0011] The object of the present invention is to provide a method and system for testing the resilience of an electronic device intended to be subjected to cyclic deformation during use and to be bonded to at least one component of an elastomer, preferably a tire, which is capable of efficiently (i.e. in a short time and at low cost) and effectively (i.e. in a highly accurate and reliable manner) verifying its effective resilience, taking into account the stresses in the actual operating conditions of the electronic device.

[0012] According to the present invention, as set out in the accompanying claims, there is provided a method and system for testing the resilience of an electronic device that is subjected to cyclic deformation during use and that is intended to be coupled to at least one component of an elastomer, preferably a tire component.

[0013] The claims describe preferred embodiments of the invention and form an integral part of this specification.

[0014] The present invention will now be described with reference to the accompanying drawings, which show exemplary and non-limiting embodiments. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view of a tire provided with a transponder; [Figure 2] FIG. 2 shows the tire of FIG. 1 in an undeformed state (unloaded). [Figure 3] FIG. 2 is a diagram showing the tire of FIG. 1 in a deformed state (under load). [Figure 4] FIG. 1 is a schematic diagram illustrating a system for testing the resilience of an electronic device coupled to a tire component. [Figure 5] FIG. 5 is a perspective view showing details of the test system of FIG. 4. [Figure 6] FIG. 6 is a schematic diagram showing the detail of FIG. 5 at a moment in time during operation. [Figure 7] 5 at a different moment in operation than FIG. 6; DETAILED DESCRIPTION OF THE INVENTION

[0016] In FIG. 1 , reference numeral 1 generally denotes a pneumatic tire 1. The pneumatic tire 1 includes a toroidal carcass 2 having two side flaps partially folded over on themselves (i.e., two layers overlapping, collectively referred to as "turnup portions"). Annular beads 3 are provided on both sides of the carcass 2, each surrounded by the carcass 2. The carcass 2 supports an annular tread 4 with a tread belt 5 interposed therebetween. Inside the carcass 2 is disposed an inner liner 6 that is airtight, forms a lining, and has the function of retaining air within the tire 1 and maintaining the air pressure of the tire 1 for an extended period of time. The carcass 2 supports a pair of sidewalls 7, each connecting the bead 3 to the tread 4.

[0017] The tire 1 is equipped with a transponder 8, i.e., an electronic device (usually passive, i.e., without a power supply, although active or semi-passive transponders are not excluded) capable of storing information and / or obtaining signals related to the tire's operating condition or state and capable of communicating by radio frequency. The transponder 8 is thus a small "smart label" or intelligent sensor suitable for responding to remote polling from a specific fixed or mobile device called a reader (or polling device). Alternatively, the transponder 8 can autonomously transmit signals to a receiver. The reader or receiver communicates with the transponder 8 by radio frequency and can read and / or modify the information contained in the transponder 8 itself. The transponder 8 is therefore part of a wireless reading and / or writing system operating according to the so-called RFID technology ("Radio-Frequency IDentification").

[0018] 1, the transponder 8 is coupled to the sidewall 7 of the tire 1. According to other embodiments not shown, the transponder 8 can be coupled to other components of the tire 1 than the sidewall 7, such as, for example, the underside or sides of the tread 4.

[0019] As shown in Figures 2 and 3, during use (i.e., when rolling on a road surface), the tire 1 undergoes continuous large deformations in the part of the tire that is in contact with the road surface (constituting its so-called "ground footprint"), and the rolling effect causes the part of the tire 1 that is in contact with the road surface to continuously change. Thus, during use, the transponder 8 is coupled to components of the tire 7 (in particular the sidewall 7) and is subjected to the same cyclic deformations that the components (in particular the sidewall 7) are subjected to. Figure 2 shows a cross-section of the tire 1 when it is away from the road surface (the so-called "ground footprint"), i.e., undeformed, while Figure 3 shows a cross-section of the tire 1 when it is in contact with the road surface (the so-called "ground footprint"), i.e., when it is deformed.

[0020] As will be explained more clearly below, the tire 1 is first analyzed (usually by using simulations and analyzing actual images) to determine how the tire deforms three-dimensionally during use and under generally unfavorable conditions (i.e., the so-called "worst case"). That is, how the tire deforms under the so-called "worst case" (i.e., "extreme" conditions in which deformations are more pronounced, the vertical load is increased to a load corresponding to a fully loaded vehicle, and the air pressure is reduced) is determined. In this way, a three-dimensional shape F1 that the component (i.e., the sidewall 7) of the tire 1 that includes the transponder 8 when the tire 1 is away from the footprint on the ground (i.e., the sidewall 7) that the tire 1 includes the transponder 8 when the tire 1 is on the footprint on the ground (i.e., the sidewall 7) assumes is determined in advance. The three-dimensional shape F1 has a larger average radius of curvature relative to the centerline of its cross section than the three-dimensional shape F2. In other words, the three-dimensional shape F2 has a more pronounced (larger) curvature than the three-dimensional shape F1.

[0021] In FIG. 4, reference number 9 indicates as a whole a system for testing the resilience of a transponder 8 coupled to a component of the tire 1, in particular to the sidewall 7.

[0022] The test system 9 comprises a closed chamber 10 (with an openable door), preferably thermally insulated for climate control (described in more detail below). The test system 9 uses a support (sample) 11 containing a transponder 8. In the embodiment shown in the accompanying drawings, the support 11 is rectangular, but according to other embodiments not shown, the support 11 can have other shapes (e.g., circular, oval, or polygonal). In particular, the transponder 8 is preferably located in a central area of ​​the support 11. According to a preferred embodiment, the support 11 comprises a rubber housing made of two layers of rubber bonded together to sandwich the transponder 8, the housing being the same rubber housing used in the manufacture of the tire 1 to bond the transponder 8 to the tire 1. That is, to test the resilience of a transponder 8 intended to be bonded to a component (sidewall 7) of the tire 1, the support 11 containing the transponder 8 is implemented, with the transponder 8 preferably being located in the central area of ​​the support 11.

[0023] The test system 9 comprises a deformation unit 12 arranged within the closed chamber 9 and configured to apply a series of periodic deformations to a central region of the support 11 containing the transponder 8 (i.e., the region of the support 11 in which the transponder 8 is arranged).

[0024] The test system 9 comprises a reader 13 configured to detect by radio frequency the functionality of the transponder 8 during the cyclic deformation of the support 11. In use, if the reader 13 is unable to read the transponder 8 due to a fault in the transponder 8, the cyclic deformation of the support 11 is interrupted (i.e. the test is terminated). Typically, the reader 13 comprises an antenna 14 located inside the closed chamber 9 alongside the deformation unit 12 (for proximity to the support 11 housed therein) and a control device 14 located outside the closed chamber 9.

[0025] The deformation unit 12 is configured to periodically deform the central region of the support 11 such that the central region of the support 11 alternates between a three-dimensional shape F1 that the tire 1 component (sidewall 7) assumes when it is away from the footprint on the ground and a three-dimensional shape F2 that the tire 1 component (sidewall 7) assumes when it is in the footprint on the ground. In particular, Figures 6 and 7 show two boundary states that the support 11 assumes. Figure 6 shows the support 11 (schematically) assuming the three-dimensional shape F1, and Figure 7 shows the support 11 assuming the three-dimensional shape F2.

[0026] As shown in Figures 4 and 5, the transformation unit 12 comprises a fixed base 16 (i.e., it does not move during use) with a working surface 17 that reproduces the three-dimensional shape F1. In particular, the fixed base 16 is in the form of a rectangular frame with a central through-opening 18 (rectangular). According to another embodiment not shown, the support 11 has a non-rectangular shape, and as a result, the fixed base 16 also has a non-rectangular shape. The transformation unit 12 comprises a transformation body 19 that has a working surface 20 facing the support 11 and that reproduces the three-dimensional shape F2, and that is arranged inside the through-opening 18 of the fixed base 16, i.e., moves within the through-opening 18 of the fixed base 16.

[0027] The deformation unit 12 includes an actuator 21 that periodically applies an alternating (up and down) movement to the deformable body 19, causing the deformable body 19 to periodically press against the central region of the support 11 (i.e., the region where the transponder 8 is located), thereby deforming the central region of the support 11. Thus, during use, the states shown in Figures 6 and 7 are periodically repeated. That is, when the deformable body 19 is at its lowest point (retracted state), the working surface 20 of the deformable body 19 does not contact (does not push up) the support 11 placed on the working surface 17 of the fixed base 16, and therefore takes the shape F1 (as shown in Figure 6). On the other hand, when the deformable body 19 is at its highest point (raised state), the working surface 20 of the deformable body 19 does not contact (does not push up) the support 11 placed on the working surface 20 of the deformable body 19, and therefore takes the shape F2 (as shown in Figure 7). That is, the alternating movement of the deformable body 19 periodically deforms the central region of the support 11, causing the central region of the support 11 to alternately form the three-dimensional shape F1 and the three-dimensional shape F2.

[0028] According to a possible embodiment, the actuator 21 may be a permanent magnet electromagnetic exciter with a structure similar to that of a loudspeaker. A permanent magnet electromagnetic exciter comprises a coil movably mounted (so that it slides alternately along a linear path) and placed in an electromagnetic field generated by a permanent magnet. When the coil is driven by an alternating current, it moves back and forth at the same frequency as the alternating current.

[0029] Before the alternating movement of the deformable body 19 is initiated, the support 11 is placed on the working surface 17 of the fixed base 16, which reproduces the three-dimensional shape F1. Then, both ends of the support 11 are constrained to the fixed base 16 (i.e., the working surface 17 of the fixed base 16) by two holding elements 22. Each holding element 22 clamps an end of the support 11 against the fixed base 16 (i.e., the working surface 17 of the fixed base 16). According to a preferred embodiment, each holding element 22 is screwed to the fixed base 16 by a pair of screws. Once the support 11 is placed and constrained on the working surface 17 of the fixed base 16, the alternating movement of the deformable body 19 can be activated, whereby the deformable body 19 is periodically pressed against the central region of the support 11, deforming the central region of the support 11.

[0030] According to a preferred embodiment shown in Figure 4, the test system 9 comprises a heating device 23 (climate control device) configured to heat (and, if necessary, cool) the closed chamber 10 to a predetermined test temperature (typically in the range of 50-70°C) in order to reproduce the internal temperature of an in-use tire 1. According to a preferred embodiment, the heating (cooling) is performed by blowing hot (cold) air into the closed chamber 10.

[0031] That is, the test system 9 subjects the area of ​​the support 11 on which the electronic device 8 is located to a series of cyclic deformations, causing that area of ​​the support 11 to alternate between a three-dimensional shape F1 and a three-dimensional shape F2. The two three-dimensional shapes F1 and F2 are not "causal" but are merely two boundary shapes that a component of the tire 7 (the sidewall 7) may assume in use.

[0032] The tire 1 may be any type of tire, such as a tire for an automobile, motorcycle, bus, truck, van, bicycle, work vehicle, agricultural vehicle, airplane, etc.

[0033] In the preferred embodiment described above, the electronic component 8 (for example, but not limited to, a transponder) intended to be coupled to a component of the tire 1 is subjected to a resilience test. However, the invention can also be applied to the testing of any type of electronic component that is subjected to cyclic deformation during use, and also in fields (completely) different from tires.

[0034] The embodiments described herein can be combined without departing from the scope of protection of the present invention.

[0035] The above test method has many advantages.

[0036] First, the above-described test method is very effective (i.e., highly accurate and reliable) in that the results obtained by the test method correspond very closely to those obtained with an actual tire. This significant result is achieved by the fact that the support 11 is subjected to exactly (very accurately) the same deformations that the component (sidewall 7) of the tire 1 incorporating the transponder 8 undergoes during use, and that the support 11 is deformed using working surfaces 17 and 20 that fit the three-dimensional shapes F1 and F2 (which are determined based on the actual deformations of the tire 1).

[0037] Furthermore, the above-described test method is also very efficient in that it allows tests to be performed in a very fast and cost-effective manner. In particular, implementing the support 11 is simple and quick (essentially creating a rectangular piece of rubber measuring approximately 75 x 25 mm with the transponder 8 placed inside). Furthermore, tests can be performed at much higher speeds than "on-road" tests using real tires 1. That is, the actuator 21 can be operated at 50-70 Hz, which corresponds to road speeds of 400-500 km / h (and is therefore much faster than "on-road" tests using real tires 1).

[0038] Finally, the above-described testing system 9 is easy and economical to implement, using components that are readily available on the market and inexpensive. In particular, the fixed base 16 and the deformable body 19 (with working surfaces 17 and 20, respectively, on which the three-dimensional shapes F1 and F2 are to be formed) can be manufactured from plastic materials by additive manufacturing (3D printing), which allows for short lead times and reduced manufacturing costs. (For this purpose, it is important to note that the fixed base 16 and the deformable body 19 are not subjected to high mechanical stresses, and therefore they can also be manufactured using conventional plastic materials.) [Explanation of symbols]

[0039] 1 tire 2. Carcass 3 beads 4 Tread 5 Treadbelt 6 Inner liner 7 Sidewall 8 Transponder 9 Test System 10 Closed Chamber 11 Support 12 Transformation Unit 13 Leader 14 Antenna 15 Control device 16 Fixed base 17 Work Surface 18 Through opening 19 Transformation 20 work surface 21 Actuator 22 Retention element 23 Heating device F1 3D shape F2 3D shape

Claims

1. 1. A method for testing the resilience of an electronic device (8) that undergoes cyclic deformation during use and that is intended to be coupled to at least one component of a tire (1), comprising: creating a support (11) containing said electronic device (8); subjecting the area of ​​the support (11) on which the electronic device (8) is located to a series of cyclic deformations; detecting a movement of the electronic device (8) while the support (11) is subjected to the cyclic deformation, determining a first shape (F1) that the component assumes when in use and away from a ground footprint; determining a second shape (F2) that the component will assume when in use in the footprint on the ground, the second shape (F2) being different from the first shape (F1); and periodically deforming the area of ​​the support (11) on which the electronic device (8) is placed, so that the area of ​​the support (11) adopts the first shape (F1) and the second shape (F2).

2. 2. The method according to claim 1, wherein the support (11) is placed on a first working surface (17) of a base (16) that reproduces the first shape (F1).

3. 3. The method according to claim 2, wherein the base (16) has a through opening (18) in which a deformable body (19) is arranged, the deformable body (19) reproducing the second shape (F2) and having a second working surface (20) facing the support (11).

4. 4. The method according to claim 3, further comprising the step of: imparting an alternating movement to the deformable body (19) such that the deformable body (19) periodically presses against the support (11), thereby deforming the support (11).

5. 3. The method of claim 2, further comprising the step of restraining two opposing ends of the support (11) to the base (16).

6. 6. The method of claim 5, wherein the end of the support (11) is restrained to the base (16) by a corresponding retaining element (22) that fixes the end of the support (11) to the base (16).

7. 7. The method of claim 6, wherein each of the retaining elements (22) is screwed to the base (16).

8. The method of claim 2, wherein the base (16) is frame-like.

9. 2. The method of claim 1, wherein the mean radius of curvature of the first shape (F1) is greater than the mean radius of curvature of the second shape (F2).

10. placing said support (11) in a closed chamber (10); The method of claim 1, further comprising the step of conditioning the closed chamber (10) to a predetermined test temperature.

11. A method as described in claim 10, wherein the step of adjusting the closed chamber (10) to a predetermined test temperature is carried out by introducing hot or cold air into the closed chamber (10).

12. A system (9) for testing the resilience of an electronic device (8) that is subjected to cyclic deformation during use and that is intended to be coupled to at least one component of a tire (1), comprising: a deformation unit (12) configured to subject the support (11) containing said electronic device (8) to a cyclic deformation; a reader (13) for detecting the operation of the electronic device (8) while the support (11) is subjected to the cyclic deformation; The deformation unit (12) is configured to periodically deform an area of ​​the support (11), and the electronic device (8) is arranged so that the area of ​​the support (11) alternates between a first shape (F1) that the component takes when, in use, it is away from its footprint on the ground and a second shape (F2) that is different from the first shape (F1) that the component takes when, in use, it is in its footprint on the ground.

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