Method and system for testing resilience of electronic device subject to periodic deformation in use and intended to be coupled to at least one component of elastomer, preferably tire

Abstract

A method and system for testing resilience of an electronic device (8) coupled to a component of a tire (1). The following steps are provided: determining a first shape (F1) that the component assumes in use; determining a second shape (F2) that the component presents in use and is different from the first shape F1; manufacturing a support (11) comprising the electronic device (8); subjecting a region of the support (11) in which the electronic device (8) is arranged to a series of periodic deformations in such a way that the region can alternately assume a first shape (F1) and a second shape (F2); and detecting the operation of the electronic device (8) during the periodic deformation of the support (11).

Description

Technical Field

[0001] The present invention relates to a method and system for testing electronic devices which are subject to regular deformation during use.

[0002] The invention is advantageously applied to testing the resilience of electronic devices intended to be coupled to components of a tyre, to which the following description will explicitly refer without loss of generality. Background Art

[0003] In recent years, so-called "intelligent" tyres have emerged which can form an active part of modern vehicles, providing information about the type of tyre installed, information about the condition of the tyre and information about the surrounding environment and road conditions.

[0004] "Smart" tires are typically equipped with a transponder (that is, an electronic device suitable for communicating by radio frequency) that enables remote communication of the tire's identity, characteristics and history (i.e., both to the vehicle on which the tire is mounted and to the operator who must perform the inspection or replacement of the tire, either using an automated system or in the vicinity of the vehicle itself).

[0005] Recently, the integration of RFID (“Radio Frequency Identification”) technology and TPMS (“Tire Pressure Monitoring System”) technology based on the presence of a transponder has been proposed, the TPMS technology measuring the effective inflation pressure so as to store the effective inflation pressure in the transponder and then remotely communicating the effective inflation pressure via the transponder itself.

[0006] Typically, the transponder intended to be coupled to the tire is first inserted into a rubber support (housing). This rubber support may fully incorporate the transponder on all sides or only partially. Subsequently, in order to couple the transponder to the tire, the transponder may be attached to the inner or outer surface of the tire (usually above the inner liner which has the task of ensuring the airtightness of the tire itself), or the transponder may be integrated into those components that constitute the tire structure (i.e. the transponder is arranged in the middle of the various layers that constitute the tire).

[0007] During use (that is to say, when rolling on the road surface), the tire is subjected to continuous deformations of significant magnitude at the portion of the tire found in contact with the road surface (constituting the so-called "ground footprint") and which varies continuously due to the rolling effect. Therefore, during use, the transponder coupled to the tire component is subjected to the same cyclic deformations as the component is subjected to and, therefore, in the long term, it may be subjected to fatigue fracture (which is generally reflected in the interruption of the electrical continuity of the chip and / or of the radio frequency transmitting element, such as, for example, a relatively large antenna).

[0008] It is therefore necessary to test the effective resilience of a transponder (or other electronic device) coupled to a tire component, in order to be able to ensure that the transponder continues to function throughout the life of the tire. Resilience tests are in fact performed when building prototypes of tires including transponders (or other electronic devices) and performing duration tests using such prototypes; these types of tests, although they are very effective (that is to say they exhibit high precision and high reliability), are not very efficient because of their very long duration and very expensive (manufacturing only a few tire prototypes is a substantially manual operation, which has extremely high associated costs).

[0009] Patent US8063742B2 describes a system for testing the resilience of an electronic device coupled to a tire component, wherein the tire component (containing the electronic device at the center) is joined at the ends and periodically slides around a series of rollers, which are arranged in sequence and define a serpentine path; a reader is arranged next to the rollers to periodically interrogate the electronic device and thus determine if and when the electronic device has ceased to function. This testing system is efficient (that is, it enables testing to be carried out in a short time and at reduced cost), but it is not particularly effective (that is, the resilience measured by the testing system often differs significantly from the actual resilience encountered in a tire fitted to a vehicle) because the deformations periodically applied to the component (containing the electronic device at the center) are different from those to which the same component is subjected during actual use of the tire. Summary of the invention

[0010] The object of the present invention is to provide a method and a system for testing the resilience of an electronic device which is subjected to periodic deformation during use and is intended to be connected to at least one part of an elastomer, which is preferably a tire, the method and the system making it possible to test the effective resilience of the electronic device efficiently (that is, in a short time and at reduced cost) and effectively (that is, with high accuracy and high reliability) taking into account the stresses of actual operating conditions.

[0011] According to the present invention, there is provided a method and a system for testing the resilience of an electronic device which, in use, is subjected to periodic deformations and which is intended to be coupled to at least one component of an elastomeric body, preferably a tire component according to the appended claims.

[0012] The claims describe preferred embodiments of the invention, which form an integral part of the present description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will now be described with reference to the accompanying drawings, which show exemplary, non-limiting embodiments, in which:

[0014] · Figure 1 is a schematic diagram and a cross-sectional view of a tire provided with a transponder;

[0015] · Figure 2 and Figure 3 They are Figure 1 Undeformed (unloaded) and deformed (loaded) views of a tire;

[0016] · Figure 4 is a schematic diagram of a system for testing the resilience of an electronic device configured to be coupled to a tire component;

[0017] · Figure 5 yes Figure 4 A perspective view of details of the test system; and

[0018] · Figure 6 and Figure 7 yes Figure 5 Two schematic diagrams of the details at two different moments of operation. DETAILED DESCRIPTION

[0019] 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 flaps (i.e., two layers are superimposed on each other and are collectively referred to as a "turnback"). Two annular beads 3 are provided on opposite sides of the carcass 2, wherein each of the two annular beads 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 is arranged inside the carcass 2, which is airtight, constitutes an inner liner, and has the function of keeping 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 sidewalls 7, each of which connects the beads 3 to the tread 4.

[0020] The tyre 1 is provided with a transponder 8, that is to say an electronic device (generally passive, that is to say it has no power supply, but not excluding active or semi-passive transponders) capable of storing information and / or acquiring signals relating to the operating condition or state of the tyre, and which is capable of communicating by means of radio frequencies. In other words, the transponder 8 is a "smart tag" or intelligent sensor of small size, adapted to respond to remote polling on part of a specific fixed or portable device, called a reader (or polling device); or autonomously to transmit signals to a receiver; the reader or receiver is capable of reading and / or modifying the information contained in the transponder 8, communicating with the transponder 8 itself by radio frequencies. 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").

[0021] according to Figure 1 As shown, the transponder 8 is coupled to the sidewall 7 of the tire 1 ; according to other embodiments not shown, the transponder 8 may be coupled to other components of the tire 1 than the sidewall 7 , such as, for example, the tread 4 or a portion thereof underneath the sides.

[0022] according to Figure 2 and Figure 3 As shown, during use (that is to say, when rolling on a road surface), the tyre 1 is subjected to continuous deformations of significant magnitude at the portion of the tyre 1 found in contact with the road surface (constituting the so-called "ground footprint") and which, due to the rolling effect, varies continuously. Therefore, during use, the transponder 8 coupled to a component of the tyre 7 (in particular the sidewall 7) is subjected to the same periodic deformations to which the component (in particular the sidewall 7) is subjected. Figure 2 In FIG. 1 , a segment of the tire 1 is shown which is away from the road surface (that is to say, away from the so-called “ground footprint”) and is therefore not deformed; on the other hand, in FIG. Figure 3 , a section of the tyre 1 which is in contact with the road surface (that is to say at the so-called "ground footprint") and which is deformed as a result is shown.

[0023] As will be better explained below, the tire 1 is first analyzed in order to determine (generally using simulations that may be confirmed in the analysis of actual images) how the tire deforms three-dimensionally in use and generally under less favorable conditions, that is to say how the tire deforms three-dimensionally in the so-called "worst case" (that is to say, in "extreme" conditions, in which the deformations are more aggravated and therefore have an increased vertical load corresponding to the vehicle under full load and with a reduced inflation pressure). In this way, the three-dimensional shape F1 that the part containing the transponder 8 (that is to say the sidewall 7) assumes in the tire 1 when it is away from the ground footprint is predetermined, and also the three-dimensional shape F2 that the part containing the transponder 8 (that is to say the sidewall 7) assumes in the tire 1 when it is at the ground footprint. The three-dimensional shape F1 has a mean radius of curvature (relative to the center line of the cross section) that is greater than the mean radius of curvature of the three-dimensional shape F2; that is to say, the three-dimensional shape F2 has a more pronounced (larger) curvature than the three-dimensional shape F1.

[0024] exist Figure 4 In the drawing, reference numeral 9 indicates in its entirety a system for testing the resilience of a transponder 8 coupled to a component of a tyre 1 , in particular the sidewall 7 .

[0025] The test system 9 comprises a closed chamber 10 (provided with an openable door) which is preferably thermally insulated for climate control (as will be better described below). The test system 9 uses a support (sample) 11 containing a transponder 8. In the embodiment shown in the figures, the support 11 has a rectangular shape, but according to other embodiments not shown, the support 11 may also adopt other shapes (for example a circular shape, an elliptical shape or a polygonal shape). In particular, the transponder 8 is preferably arranged in the central area of ​​the support 11. According to a preferred embodiment, the support 11 comprises a rubber shell consisting of two layers of rubber that are bonded together to enclose the transponder 8 between them and which is the same as the rubber shell used in the production of the tire 1 for connecting the transponder 8 to the tire 1. In other words, in order to test the resilience of the transponder 8 intended to be connected to a component (sidewall 7) of the tire 1, a support 11 containing the transponder 8 is realized, which is preferably arranged in the central area of ​​the support 11 itself.

[0026] The testing system 9 comprises a deformation unit 12 arranged inside the closed chamber 9 and configured to subject a central region of the support 11 containing the transponder 8 (that is to say the region of the support 11 where the transponder 8 is arranged) to a series of periodic deformations.

[0027] The test system 9 comprises a reader 13 configured to detect radiofrequency operation of the transponder 8 during the periodic deformation of the support 11. In use, the periodic deformation of the support 11 is interrupted (that is to say, the test is terminated) when the reader 13 is no longer able to read the transponder 8 after a failure of the transponder 8. Typically, the reader 13 comprises an antenna 14 and a control device 15, the antenna being arranged inside the closed chamber 9, next to the deformation unit 12 (so as to be in close proximity to the support 11 housed in the deformation unit 12), and the control device 15 being arranged outside the closed chamber 9.

[0028] The deformation unit 12 is configured to periodically deform the central region of the support 11 so that the central region of the support 11 alternately presents a three-dimensional shape F1 present in the tire 1 when the component (sidewall 7) is away from the ground footprint and a three-dimensional shape F2 present in the tire 1 when the component (sidewall 7) is at the ground footprint. In particular, in the central region of the support 11, Figure 6 and Figure 7 The two boundary conditions presented by the support 11 are shown in FIG. 1 ; the support 11 (in a schematic shape) presenting a three-dimensional shape F1 is Figure 6 As shown in FIG. 1 , the support member 11 presenting a three-dimensional shape F2 is Figure 7 Shown in.

[0029] according to Figure 4 and Figure 5 As shown, the deformation unit 12 comprises a fixed base 16 (that is to say, it does not perform any kind of movement when in use) characterized by a working face 17 that reproduces the three-dimensional shape F1. In particular, the fixed base 16 has the shape of a rectangular frame, which has a through opening 18 (of rectangular shape) in the center. According to other embodiments that are 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 deformation unit 12 comprises a deformation body 19, which has a working face 20 that reproduces the three-dimensional shape F2 and faces the support 11; the deformation body 19 is arranged inside the through opening 18 of the fixed base 16, that is to say, it moves into the through opening 18 of the fixed base 16.

[0030] The deformation unit 12 comprises an actuator 21 which imparts an alternating movement (in the vertical direction) to the deformation body 19 which periodically presses the deformation body 19 against a central region of the support 11 (that is to say, the region in which the transponder 8 is arranged) in order to deform the central region of the support 11. Thus, in use, the periodic repetition of the alternating movement Figure 6 and Figure 7 As shown in FIG: when the deformation body 19 is at the lowest point (retracted), the working surface 20 of the deformation body 19 does not contact the support 11 resting on the working surface 17 of the fixed base 16, and thus presents a shape F1 (as shown in FIG. Figure 6 ), and when the deformable body 19 is at the highest point (raised), the working surface 20 of the deformable body 19 does not contact (push) the support 11 resting on the working surface 20 of the deformable body 19, and thus presents a shape F2 (as shown in FIG. Figure 7 In other words, the alternating movement of the deformation body 19 causes the central area of ​​the support member 11 to deform periodically, so that the central area of ​​the support member 11 alternately presents the three-dimensional shape F1 and the three-dimensional shape F2.

[0031] According to a possible embodiment, the actuator 21 can be a permanent magnet electromagnetic vibrator, which has a structure similar to that of a speaker and which includes a coil mounted to be movable (so as to slide alternately along a linear path) and immersed in an electromagnetic field generated by a permanent magnet; when the coil is moved by an alternating current, it moves back and forth at the same frequency as the alternating current.

[0032] Initially, before activating the alternating movement of the deformation bodies 19, the support 11 rests on the work surface 17 of the fixed base 16 that replicates the three-dimensional shape F1; subsequently, the two ends of the support 11 are constrained to the fixed base 16 (that is to say, the work surface 17 of the fixed base 16) by means of two corresponding retaining elements 22, each of which clamps an end of the support 11 against the fixed base 16 (that is to say, against the work surface 17 of the fixed base 16). According to a preferred embodiment, each retaining element 22 is screwed to the fixed base 16 by means of a pair of screw connections. Once the support 11 has been rested on the work surface 17 of the fixed base 16 and constrained there, the alternating movement of the deformation bodies 19 can be activated, which periodically causes the deformation bodies 19 to press against the central area of ​​the support 11 so as to deform the central area of ​​the support 11.

[0033] according to Figure 4 In the preferred embodiment shown, the test system 9 comprises a heating device 23 (climate controller) which is configured to heat (or, if necessary, cool) the closed chamber 10 to a predetermined test temperature (typically of the order of 50 to 70° C.) in order to replicate the internal temperature of the tire 1 during use. According to the preferred embodiment, the heating (cooling) is performed by introducing warm (cold) air into the closed chamber 10.

[0034] In other words, the test system 9 subjects the region of the support 11 in which the electronic device 8 is arranged to a series of periodic deformations, so that the region of the support 11 alternately presents a three-dimensional shape F1 and a three-dimensional shape F2. The two three-dimensional shapes F1 and F2 are not "causal relationships", but are just two boundary shapes that a component (sidewall 7) of the tire 7 presents when in use.

[0035] The tyre 1 may be of any type, that is to say intended for cars, motorcycles, buses, trucks, vans, bicycles, work vehicles, agricultural vehicles, aircraft . . .

[0036] In the preferred embodiment described above, an electronic component 8 (e.g. a transponder, but not only a transponder) intended to be coupled to a component of the tyre 1 is subjected to a resilience test; however, the invention can be applied to testing any type of electronic component that is subjected to regular deformations in use, also in fields of application (completely) different from tyres.

[0037] The embodiments described herein may be combined without departing from the scope of protection of the present invention.

[0038] The above-described testing method has many advantages.

[0039] Firstly, the test method described above is very effective (that is to say it exhibits high precision and reliability) since it provides results that correspond very faithfully to those that a real tire may encounter. This remarkable result is obtained by virtue of the fact that the support 11 is subjected (very precisely) to exactly the same deformations that the part of the tire 1 on which the transponder 8 is integrated (the sidewall 7) is subjected to in use, this being achieved by virtue of the fact that it is deformed by using working surfaces 17 and 20 that conform to the three-dimensional shapes F1 and F2 (determined on the basis of the actual deformations of the tire 1).

[0040] Moreover, the above-described test method is also very efficient, since it allows the test to be carried out in a very rapid and cost-effective manner. In particular, the implementation of the support 11 is simple and rapid (essentially a matter of manufacturing a rectangular rubber strip with dimensions of the order of 75 x 25 mm, inside which the transponder 8 is arranged). Moreover, the test can be performed in a much faster manner than an "on-road" test using a real tire 1: the actuator 21 can be operated at 50 to 70 Hz, which corresponds to a road speed of 400 to 500 km / h (thus many times faster than an "on-road" test using a real tire 1).

[0041] Finally, the test system 9 described above is simple and economical to implement, since it requires the use of components that are easily available on the market and do not require high costs; in particular, the fixing base 16 and the deformation body 19 (with the corresponding working surfaces 17 and 20 that must have three-dimensional shapes F1 and F2) can be manufactured from plastic materials by means of additive manufacturing (3D printing), which has short delivery times and reduced manufacturing costs (in this regard, it is important to note that the fixing base 16 and the deformation body 19 are not subject to increased mechanical stresses and they can therefore also be manufactured using conventional plastic materials.

[0042] Description of Reference Numerals

[0043] 1 Tire

[0044] 2 Carcass

[0045] 3 Bead

[0046] 4 Tread

[0047] 5 Tread belt

[0048] 6 Lining

[0049] 7 Sidewall

[0050] 8 Transponder

[0051] 9 Test system

[0052] 10 Closed Chamber

[0053] 11 Support

[0054] 12 Deformation Unit

[0055] 13 Reader

[0056] 14 Antenna

[0057] 15 Control Device

[0058] 16 Fixed base

[0059] 17 Working surface

[0060] 18 Through opening

[0061] 19 Morph

[0062] 20 Working surface

[0063] 21 Actuator

[0064] 22 Retaining element

[0065] 23 Heating device

[0066] F1 3D Shape

[0067] F2 3D Shape

Claims

1. A method for testing the resilience of an electronic device (8) which, in use, is subjected to periodic deformation and which is intended to be coupled to at least one part of an elastomeric body, preferably a tyre (1); said testing method comprising the following steps: Manufacturing a support (11) comprising the electronic device (8); subjecting the region of the support (11) in which the electronic device (8) is disposed to a series of periodic deformations; and detecting the operation of the electronic device (8) during the periodic deformation of the support (11); The test method is characterized in that the test method further comprises the following steps: determining a first shape (F1) that the component assumes in use; determining a second shape (F2) different from the first shape (F1) that the component assumes in use; The region of the support (11) in which the electronic device (8) is disposed is periodically deformed so that the region of the support (11) exhibits the shape (F1) and the second shape (F2).

2. Testing method according to claim 1, wherein said support (11) rests on a first working surface (17) of a base (16) replicating said first shape (F1).

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

4. The testing method according to claim 3, comprising a further step of imparting an alternating motion to the deformable body (19), causing the deformable body (19) to periodically press against the support (11) to deform the support (11).

5. Testing method according to claim 2, 3 or 4, comprising the further step of constraining the two opposite ends of the support (11) to the base (16).

6. Testing method according to claim 5, wherein the ends of the support (11) are constrained to the base (16) by means of corresponding retaining elements (22) which clamp the ends of the support (11) to the base (16).

7. Testing method according to claim 6, wherein each retaining element (22) is screwed to the base (16).

8. The testing method according to any one of claims 2 to 7, wherein the base (16) has the shape of a frame.

9. The test method according to any one of claims 1 to 8, wherein the first shape (F1) has an average radius of curvature greater than an average radius of curvature of the second shape (F2).

10. The testing method according to any one of claims 1 to 9, further comprising the following steps: The support member (11) is arranged in a closed chamber (10); The closed chamber (10) is preferably conditioned to a predetermined test temperature by introducing warm air or cool air into the closed chamber (10).

11. Testing method according to any one of claims 1 to 10, wherein the elastomer is a tire (1).

12. The testing method according to claim 11, wherein: When the tire component (1) is away from the ground footprint, the tire component assumes the first shape (F1); and When the tire component (1) is located at the ground footprint, the tire component assumes the second shape (F1).

13. A system (9) for testing the resilience of an electronic device (8) which, in use, is subjected to periodic deformations and which is intended to be coupled to at least one component of an elastomeric body, preferably a tyre (1); the testing system comprising: a deformation unit (12) configured to subject a support (11) containing the electronic device (8) to a series of periodic deformations; and a reader (13) for detecting the operation of the electronic device (8) during the periodic deformation of the support (11); The testing system (9) is characterized in that the deformation unit (12) is constructed to periodically deform the area of ​​the support 11 in which the electronic device (8) is arranged in the following manner: the area of ​​the support (11) alternately presents a first shape (F1) presented by the component during use and a second shape (F2) presented by the component and different from the first shape (F1).

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