WO2012069515A1

WO2012069515A1 - Device for attaching a module to the internal wall of a tyre

Info

Publication number: WO2012069515A1
Application number: PCT/EP2011/070763
Authority: WO
Inventors: Julie Decore; Olivier Sejalon
Original assignee: Societe De Technologie Michelin; Michelin Recherche Et Technique S.A.
Priority date: 2010-11-24
Filing date: 2011-11-23
Publication date: 2012-05-31
Also published as: FR2967613B1; FR2967613A1

Abstract

Device for attaching a module (1) to the internal wall of a tyre, which device consists of a base (4) integral with the tyre, and of a flexible strip (6), the base (4) comprising means of attaching said strip, the ends of the flexible strip comprising at least two independent means of fastening the module (1), the flexible strip being positioned removably in the base (4) via two openings (5) in the base through which openings the strip (6) can pass, the flexible strip (6) having three portions: - a middle portion made of bi-elastic fabric; - two end portions, each one connected to the middle part and made of fabric of the hook and loop type.

Description

DEVICE FOR FIXING A MODULE ON THE INTERNAL WALL OF A

PNEUMATIC TECHNICAL FIELD OF THE INVENTION

The invention relates to a device for fixing a module on the inner wall of a tire and more specifically a device for fixing an electronic module consisting of a base, secured to the tire, and a strip flexible. The device is advantageously used on vehicles of the civil engineering type, and more particularly on dumper type vehicles.

STATE OF THE PRIOR ART

The use of electronic modules in tires can allow a multitude of applications to acquire, store and / or transmit information to monitor the use of the tire, including information on the evolution of tire performance during its service life.

Such electronic modules may comprise passive components such as identification chips or RFID, and / or active components connected to an autonomous power supply system such as batteries or an inductive coupling system. These electronic modules can be designed to exchange information with external modules, for example serving as an interface with the user, via radio waves whose frequency and power are carefully adjusted and according to specific transmission protocols. . They can also be provided for storing information for later interrogation, for example to analyze the use of the tire. The electronic modules are generally placed inside flexible or rigid protective housings, intended to preserve the electronic components of the aggressions related to shocks, and the atmosphere prevailing in the tire, in particular because of the presence of fluid, for example for antioxidant or puncture-resistant purposes, and its environment.

Such an electronic module can in particular be fixed inside the cavity formed by the tire once mounted on the wheel; for this it can be arranged on a large number of supports. Thus it can be fixed to the valve, fixed on the rim, fixed or glued on the inner wall of the tire or be integrated with the components of the tire. The choice of one of these solutions depends on the nature of the tire, the stresses it can endure, the nature of the energy source of the electronic module, the information that one wishes to follow and the desired accessibility. in case of maintenance. The invention relates to the case of an electronic module attached to the inner wall of the tire.

When the electronic module is thus associated with the tire, the selected mode of attachment must ensure the module in position regardless of the rotational speed and the conditions of use of the tire. Fixing solutions to meet these requirements have already been described for example in the publications EP 0 936 089, US 6 255 940, US 6 462 650 or WO 2005044600, which describe fastening systems of a module on the inner wall of a tire. These devices are composed of a flexible sole, one side of which serves as a connection with the inner wall of the tire and the other side of which has a fixing means cooperating with the fastening means arranged on the module.

[0007] Although not limited to this type of application, the invention will be more particularly described with reference to electronic modules whose thickness is greater than or equal to 2 cm and having a base of at least equal length. at 4 cm and at least 2 cm wide and intended to be inserted in vehicle tires of the dumper type and having an axial width greater than 37 inches.

In the case of this type of vehicle, especially for use in mines or quarries for the transport of loads, the dimensions of tires associated with the loads they support when driving lead to arrows tires of the order of 30%; they can in particular undergo load increases greater than 50% due to dynamic overloads linked for example to braking for loader type vehicles or for example to deformations of the traffic lanes in the case of dumper type vehicles.

The deflection of a tire is defined by the radial deformation of the tire, or variation of the radial height, when it moves from an uncharged state to a statically loaded state, under load conditions and nominal pressure.

It is expressed in the form of a relative arrow, defined by the ratio of this variation in the radial height of the tire to half the difference between the outer diameter of the tire and the maximum diameter of the rim measured on the hook. The outer diameter of the tire is measured statically in an uncharged state at the nominal pressure.

The tire thus undergoes in this zone radial stresses. These are combined with longitudinal stresses due in particular to the de-axialization of the tire in the area of the contact area. The combination of these constraints is reflected in particular by deformations of the walls of the tire.

These deformations combined for example with electronic modules such as those mentioned above whose thickness is relatively large require more suitable fixing means to ensure the durability of the attachment. Indeed, the aforementioned devices have weaknesses due to the particularly important stresses related to the type of module and the type of tire.

The inventors have thus given themselves the mission of defining a device for fixing an electronic module to ensure the durability of said fixation including in the case of a module such as that described above and having a thickness of at least 2 cm, the latter being fixed in a tire capable of supporting arrows of the order of 30%.

WO2007 / 1 13251 discloses a solution comprising a base and a flexible band adapted for fixing an electronic module. In one of the exemplary embodiments, the flexible strip is entirely made of self-gripping type fabrics.

This last device, like the others previously stated, are often used in the civil engineering sector, where they are impregnated with polypropylene glycol. This liquid is used to protect the wheel and the tire against the aggressions due to often extreme use constraints. Polypropylene glycol is, however, relatively aggressive towards certain components such as the means for fixing the module against the inner wall of the tire. In addition, it is likely to contribute to the degradation of the bielastic nylon used in known systems. Furthermore, in a humid or very hot environment or with the presence of liquid, the use of a complete Velcro tape, as in WO2007 / 1 13251, does not allow to perform and maintain a good tightening of the fixed element.

SUMMARY OF THE INVENTION [0016] To avoid being in such a context, and in particular to avoid any deterioration of the fixing of the electronic module against the wall of the tire due to use in the middle humide or with presence of liquid, and especially polypropylene glycol, the invention provides various technical means. First, a first object of the invention is to provide a fastening device that allows use in the current operating conditions of civil engineering vehicles. Another object of the invention to provide a device that retains its fastening properties even during regular contact and / or prolonged with polypropylene glycol and / or in a very hot and / or wet environment.

Yet another object of the invention is to provide a simple attachment device to use, with an easy and fast assembly.

To do this, the invention provides a device for fixing a module on the inner wall of a tire, consisting of a base, secured to the tire, and a flexible strip, the base comprising fastening means of said strip, the ends of the flexible strip comprising at least two independent means of attachment of the module, the flexible strip being removably disposed in the base by two openings in the base allowing the passage of the strip , the flexible band having three portions:

a medial portion made of a bielastic fabric;

two end portions, each connected to the middle part, and made of fabric provided with hooks and loops; and

in that the middle portion (1 1) and the end portions (13) are connected by a sewn yarn (12) covered with a protective or hydrophobic material.

[0021] The fact that the polytetrafluoroethylene is used to provide polytetrafluoroethylene is not readily available. Such a coating provides effective protection against polypropylene glycol. This avoids any degradation of the attachment at the connections between the portions.

According to another embodiment, the thread used to sew the parts of the strip is polyester. Polyester is a hydrophobic material that is relatively insensitive to liquids used in civil engineering tires.

The device thus described according to the invention makes it possible to keep the module in its location including during large stresses due to the use of the tire. The flexible configuration of the band in three portions, including an elastic, allows in particular to absorb certain stresses associated with attachment by independent means that can at least locally divide the stresses due to the solicitations, to ensure the durability of the attachment of the module in the tire. The specific configuration of the flexible band also ensures good support even when used in a humid environment, in a very hot environment and with polypropylene glycol.

According to an advantageous embodiment, the fastening system with hooks and loops provides a non-removable mounting. This type of fastening provides durable and reliable uses in wet environments, in which the conventional loops and hooks systems are often less efficient, due to a degraded attachment. If an electronic module that is not releasably attached has to be removed, it is possible to cut the flexible band. Then just use a new flexible band to reinstall a module.

According to an exemplary embodiment, the fastening system with hooks and loops is made of polyester. According to another embodiment, the fastening system with hooks and loops is metallic. According to an advantageous embodiment of the invention, the fastening means of the strip on the base are obtained by two openings in the base forming a loop and allowing the passage of the strip. This embodiment is particularly advantageous because of its simplicity of construction and its use. The openings in the base can for example be made at the time of manufacture of said base. When this is made of a polymeric material such as rubber, at the time of its crosslinking, or vulcanization, there is provided for example an insert on which the rubber does not adhere, which is then removed to reveal two openings forming said passing. Preferably, the attachment means of each end of the strip are perforations or openings. This preferred embodiment of the flexible strip makes it possible to hook one end of said strip to a protuberance of the module, to surround the module on either side, and to close the strip by hooking the other end on the protuberance.

A preferred embodiment of the invention further provides that the base is made of a crosslinked polymeric material on the tire.

Advantageously, the crosslinking of the base is obtained simultaneously with the crosslinking, in particular vulcanization, of the tire. According to this embodiment of the invention, the manufacture of the tire comprising a base is performed more quickly and the attachment of the base is perfectly integral with the inner wall of the tire.

DESCRIPTION OF THE FIGURES [0030] Other advantageous details and features of the invention will emerge below from the description of embodiments of the invention with reference to FIGS. 1 to 5 in which:

[0031] FIG 1 is a schematic perspective view of a device according to the invention, [0032] FIG 2 illustrates a flexible band according to the invention;

[0033] FIGS 3a to 3c schematically show the base seen from the side, from above and in perspective;

[0034] FIG. 4 shows the device according to the invention when the flexible strip is inserted into the base, before fixing an electronic module; [0035] FIG. 5 shows the device in use for fixing an electronic module. The figures are not shown in scale to simplify understanding.

Figures 1 and 5 show an electronic module 1 fixed on the inner wall 2 of a tire with a fixing device 3. The fixing device 3 is itself composed of a base 4 (Well visible in Figures 3a, 3b and 3c), integral with the tire, and provided with two openings 5 through which passes a flexible strip 6. The flexible strip is illustrated in detail in Figure 2.

The base 4 may for example be made during the manufacture of the tire, one or more layers of rubber constituting it being put in place and then cooked simultaneously with the baking of the tire. The formation of the two openings 5 can be obtained by the presence of an element set up during cooking. Such an element is made of any material known to those skilled in the art on which the rubber does not adhere, and is inserted between two layers of rubber and whose ends are positioned to obtain the two desired openings.

According to another embodiment, the base 4 may be made of rubber by prior molding and reported in the tire before baking thereof. The base 4 is then already fired and the connection is obtained by interposing an interface between the base 4 and the tire which will allow to obtain a connection between the base and the tire during cooking thereof.

According to a last embodiment, the base 4 may be made of rubber by molding before undergoing only a partial firing to maintain the base, that is to say the part of the base intended to come into contact with the tire, uncrosslinked. The base thus obtained is put in place on the tire before baking thereof and the connection between base and tire is thus obtained during the baking of the tire. According to this embodiment, however, it is prudent to limit the storage time prefabricated bases and partially crosslinked. The base 4 may advantageously be made of unreinforced rubber to better withstand all deformation of the tire. If the presence of reinforcing elements is required, these are advantageously elastic reinforcing elements. The strip 6 consists of three portions: a middle portion 1 1, made of fabric of bielastic material, surrounded on either side by end portions 13, made of material of the self-gripping fabric type. The end portions are advantageously fixed to the central portion 1 1 by sewn thread 12. The wire 12 is preferably covered with PTFE, providing protection against polypropylene glycol. It can also be polyester.

The flexible strip 6 has at each of its ends hooking means 8 of the electronic module 1. In the example shown in Figure 3, it is openings or perforations of substantially circular shape. The shape of the openings 8 is adapted to that of a measuring head 7 of the element to be fixed. Thus, other forms, such as hexagonal, oval or other forms can be used for these two elements.

According to a preferred embodiment, the closure of the attachment loop of the electronic module 1 is provided by the end portions 13 of the flexible strip 6. A portion 13 is provided with monofilament hooks, while the opposite portion is provided with unbrushed buckles. Thus, the end portions 13 allow attachment of one end of the strip 6 on the other in the overlap areas of these two ends. This attachment Velcro strips can be found in particular on both sides of the measuring head. This method of attachment allows an excellent distribution of the constraints that are exerted to block the module.

The flexible strip 6 is manufactured independently of the base 4 and reported during the introduction of the electronic module 1. It is slid by one of the openings 5 to emerge by the other so that the upper part of the base 4 located between the two openings 5 forms a loop which retains the flexible strip 6 which forms a closed loop from the top of the electronic module 1.

Tests carried out with the material hooks and loops marketed under the name APLIX 810, have achieved particularly high fixation performance, even in wet environments and / or with polypropylene glycol. The hooks remain attached to the loops, and the fastener thus obtained does not degrade. The tape retains its properties in a liquid or wet medium. The strip 6, with its central portion 1 1 made of a bielastic material, advantageously has elastic properties, which associated with the attachment system, are sufficient to block the electronic module 1. The respective dimensions of the end portions 13 and of the central portion 11 are provided so as to provide on the one hand a sufficient attachment surface, and on the other hand an elastic surface to secure the module, with a sufficient clamping to withstand the constraints of use.

Running tests in which the tire was subjected to significant stresses due to deformations during passages on stony soils made it possible to demonstrate that the electronic module remains in place and that the fixing device does not undergo damage. even with the presence of polypropylene glycol. The sewing attachment, with a protective coated thread, avoids any deterioration at the interface between the zones of the flexible band.

The electronic module 1 comprises a measuring head 7, for example pressure measurement, at its top. To ensure undisturbed measurements, it is preferable that the measuring head 7 is not covered by the fastening means connected to the flexible strip 6. Each of the ends of the flexible strip 6 comprising hooking means, in the illustrated example of the openings 8, it is possible to fix the module without covering the measuring head 7 of the electronic module 1. As shown in FIG. 2, the extremities of the strip 6 each comprise an opening 8 substantially of the size of the measuring head 7. In the case of FIG. 2, the measuring head is circular and the openings 8 are also circular and have a diameter substantially equivalent to that of the measuring head. Each end of the strip 6 is docked on the module 1 by hooking at the measuring head 7 without covering it. The figures and their descriptions made above illustrate the invention rather than limiting it. In particular, the invention and its various variants have just been described in connection with a particular example comprising a flexible band in three portions.

Nevertheless, it is obvious to a person skilled in the art that the invention can be extended to other embodiments in which, in variants, more than three portions are provided, or portions of which the profile is not necessarily parallelepipedic. The openings of the flexible strip as well as the corresponding portion of the electronic module may be configured with profiles different from that shown in the figures.

Furthermore, the openings 5 may be oriented at different angles relative to the longitudinal axis of the base 4. Finally, an electronic module provided with two or more protuberances may be used. The flexible band can then be hung from one side to a first protrusion, and from the other side to another protrusion.

The reference signs in the claims are not limiting in nature. The verbs "understand" and "include" do not exclude the presence of elements other than those listed in the claims. The word "a" preceding an element does not exclude the presence of a plurality of such elements.

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Claims

1. Device for fixing a module (1) on the inner wall of a tire, consisting of a base (4), integral with the tire, and a flexible band (6), the base (4) comprising fastening means for said strip, the ends of the flexible strip comprising at least two independent means (8) for fastening the module (1), the flexible strip being removably disposed in the base (4) by two openings (5) in the base allowing passage of the strip (6), characterized in that the flexible strip (6) has three portions:

a medial portion (1 1) made of bielastic fabric;

two end portions (13), each connected to the middle portion (1 1), and made of fabric provided with hooks and loops; and

2. Fixing device according to claim 1, wherein the wire (12) is a polyamide thread coated with polytetrafluoroethylene.

3. Fastening device according to claim 1, wherein the wire (12) is a polyester yarn.

4. Device according to any one of the preceding claims, wherein the fastening system with hooks and loops provides a non-removable mounting.

Fastening device according to any one of claims 1 to 4, wherein the fastening system hooks and loops is polyester.

6. Fastening device according to any one of claims 1 to 4, wherein the fastening system with hooks and loops is metallic.