electronic component and elastic retaining device

Abstract

The invention relates to an arrangement of an electronic component (10) and a retaining device comprising: - a base (511), - a retaining wall (512), extending from the base (511) to an edge (513), - an open volume (520), defined by an internal surface (514) of said base (511) and by an internal surface (515) of said retaining wall (512), having an opening (516); - a radio transmitter coupled to a radio antenna; - a microprocessor powered by an energy source, - a memory space connected to the microprocessor, and - said elements encapsulated in a device (12) defining an external surface (30); Characterized in that the difference between the volume (520) and a volume delimited by the outer surface (30) defines a fluidic channel (19) from the inner surface (515) of the base (511) to one end (18') of the outer surface (30). Figure for the abbreviation: Fig. 5

Description

Title of the invention: Electronic component and elastic retention device Scope of the invention

[0001] The present invention relates to electronic components intended to be mounted via a retaining device on a pneumatic casing in order to convey identification information on the pneumatic casing or physical parameters of the pneumatic casing measured by the electronic component during the life of the pneumatic casing. Technological background

[0002] The development of electronic devices within pneumatic tires makes it possible to connect and link these tires, leading to the development of new services to optimize, for example, the use of the tire. However, these electronic components sometimes contain thermomechanically fragile elements, which necessitates integrating the electronic component after the tire has been manufactured. Furthermore, to prevent damage to the electronic component during the tire's use, the introduction of a fastening device as an interface between the electronic component and the tire has emerged. These fastening devices are generally elastic to avoid excessive stress on the tire, to accommodate the significant deformations it undergoes during use, and to dampen the stresses transmitted to the electronic component.One of the most commonly used device designs is a patch with a base that serves as a mounting point for the pneumatic casing and a self-enclosed wall extending from the base to an opening. This wall serves to grip or hold the electronic component in position within the device, the electronic component being tightly mounted inside the elastically deformable wall. The opening allows the electronic component to be inserted into and removed from the patch thanks to the elasticity of the opening material.

[0003] A patch of this nature is regularly illustrated in published documents. Firstly, this type of patch does not facilitate the insertion or extraction of the electronic component due to the tight fit of the electronic component within the patch. Thus, it is difficult to design an automatic tooling for inserting or extracting the electronic component within the pneumatically mounted fastening device that is both inexpensive and efficient, due to the manufacturing variations of the patch, the electronic component, and the tight fit of the component. The electronic component within the patch is essential. Furthermore, under high stress on the tire, the physical parameter measurements taken by the electronic component can be erroneous due to heating of the surrounding environment and the movement of the electronic component within the retaining device. Thus, the measurements become inoperable even with a measurement correction procedure, particularly during transient phases that occur when the tire is drifting or cambering, or during braking or high acceleration. Finally, this heating of the patch also reduces its mechanical endurance and consequently its lifespan. Therefore, removing the electronic component from the mounting device is crucial because the lifespan of the electronic component is greater than that of the tire and / or the patch.

[0004] The objects of the invention which follow have as their objective on the one hand to solve the problems of insertion and extraction of the electronic organ which are both economical, reliable and on the other hand to improve the endurance of the electronic organ in particular its exposure to strong thermomechanical stresses. Description of the invention

[0005] The invention relates to an arrangement of an electronic component and a retaining device suitable for being fixed to a wall of a pneumatic enclosure intended to form a pressurized assembly at a nominal operating pressure, said retaining device comprising: • a sole suitable for being fixed to the wall of the pneumatic casing via an external surface, • a retaining wall, capable of retaining said electronic component, extending from the base to a free edge and defining an open volume with said base, • said volume, suitable for accommodating at least a part of said electronic component, being defined by an internal surface of said base and by an internal surface of said retaining wall, having an opening delimited by the free edge of said retaining wall, suitable for deforming to introduce or extract said electronic component from said volume; The said electronic component comprising: • a radio transmitter coupled to at least one radio antenna; • a microprocessor located on a printed circuit board, coupled to the radio transmitter and powered by a power source, • a memory space connected to the microprocessor to store at least one identification piece of information, and • said elements encapsulated in an encapsulation device defining an external surface circumscribed within a cylinder whose axis of revolution is perpendicular to the median plane of the printed circuit and delimited by two parallel planes; The arrangement is characterized in that the difference between the volume of the retaining device and a volume delimited by the external surface of the electronic component defines at least one fluidic channel from the internal surface of the retaining device's base to one end of the external surface of the electronic component, in that the free edge of the retaining wall is in continuous contact with the external surface of the electronic component, and in that the portion of the retaining wall between the end of at least one fluidic channel and the free edge exhibits a critical elastic buckling load along the direction of the median plane of the portion of the retaining wall intended to be reached for a pressure in the at least one fluidic channel greater than one bar relative to the nominal operating pressure of the assembled unit.

[0006] Such a configuration of the arrangement ensures the desired dual functionality. Indeed, during the extraction or insertion phases of the electronic component into the retaining device, it is possible to elastically deform the retaining wall, particularly at the free edge. This deformation creates a fluidic connection between the environment outside the assembly and the free space formed between the electronic component and the retaining device. Consequently, this fluidic channel, connected to the outside during these two phases by the elastic deformation of the retaining wall (a mechanical process), prevents overpressure or underpressure within the fluidic channel. This naturally facilitates the extraction or insertion of the electronic component from the retaining device. This is particularly useful when these operations take place on the pneumatic casing, i.e., on a curved contour, within a confined space.

[0007] Furthermore, when the assembly consisting of the pneumatic casing equipped with the arrangement and a wheel is in operation under nominal pressure, a pressure imbalance already potentially exists between at least one channel of the arrangement and the environment outside the arrangement due to the seal formed by the continuous contact of the free edge of the retaining wall with the encapsulation device of the electronic component. However, when the assembly is rotated, the electronic component is subjected to centrifugal forces that will tend to press the electronic component against the tire when the arrangement is positioned on the inner surface of the tire tread. This will result in a decrease in the free volume of the arrangement, which will lead to an increase in pressure and temperature within the fluidic channel.

[0008] Similarly, when entering or exiting the contact patch, that is, the contact area between the tread and the ground where the tire rolls, The electronic component is subjected to a shock whose energy is directly proportional to the rotational speed. This then causes a potentially abrupt displacement of the electronic component within the retaining device. This displacement creates local pressure variations in the fluidic channel, which generate increased thermomechanical stresses on the electronic component.

[0009] Thanks to the arrangement, this overpressure, when applied at the end of the channel and generating a force exceeding the critical buckling load of the portion of the retaining wall between this end and the free edge, allows the retaining wall to blister, opening onto the environment outside the arrangement. This then causes a rebalancing of the pressures between the channel of the arrangement and the external environment, stabilizing them at the nominal operating pressure of the assembled unit. This localized buckling rebalances the pressures, which stabilizes the movement of the electronic component within the retaining device. The absence of excessive overpressure and the limitation of the electronic component's movement within the retaining device reduce the thermomechanical stresses exerted on the electronic component.In conclusion, this improves the thermomechanical endurance of the electronic component as well as the quality of any displacement measurements of the electronic component by limiting the relative movement of the electronic component within the retention device and therefore the movement relative to the tire.

[0010] This buckling is linked in particular to the channel which concentrates the fluidic forces related to the overpressure on a localized area of ​​the retaining wall at the end of the channel. This makes it possible to control the orientation and amplitude of the forces.

[0011] Next, the critical local buckling load of the retaining wall depends on the distance between the end of the channel and the free edge, the thickness of the retaining wall in this section, the stiffness of the retaining wall material, and also the nominal operating pressure of the assembled unit. The design of this area depends on all these parameters and the defined load threshold that will induce elastic buckling of the retaining wall. The elastic nature of the retaining wall and the transient nature of the phenomenon, due to the immediate pressure equilibrium that occurs when the seal between the retaining wall and the electronic component's encapsulation device is broken, allows for pressure equalization with each overpressure event related to the movement of the electronic component. This section of the retaining wall acts as an active check valve at a given overpressure value.

[0012] In conclusion, the presence of this channel addresses the problem raised. Other solutions exist for creating this fluidic connection between the exterior of the retaining device and the free space, such as an orifice passing through the retaining wall and / or the base of the retaining device. However, these solutions create areas of appropriate cracking within the restraint system, which is detrimental to the endurance of the restraint system.

[0013] According to a first embodiment, the end of at least one fluidic channel has a section whose normal is directed along the axis of revolution of the cylinder circumscribed to the outer surface of the encapsulation device.

[0014] In this first embodiment, the free edge of the retaining wall is located on the radially outer surface of the electronic component's encapsulation device. Consequently, the portion of the retaining wall that acts as a check valve extends primarily along the axis of revolution of the cylinder circumscribing the electronic component. The dimensions of this portion of the retaining wall are generally more rigid due to the necessary tight fit of the electronic component within the retaining device. For the same design parameters of this portion of the retaining wall acting as a check valve, the critical local buckling load is higher.

[0015] According to a second embodiment, the end of at least one fluidic channel has a section whose normal is directed along a direction D' of the base of the cylinder circumscribed to the outer surface of the encapsulation device.

[0016] Advantageously, the direction D' is a radial direction R to the axis of revolution of the cylinder circumscribed about the encapsulation device of the electronic organ.

[0017] In this second embodiment, the free edge of the retaining wall is located on the base of the cylinder circumscribing the encapsulation device for the electronic component. Consequently, the portion of the retaining wall that acts as a check valve extends primarily in a radial direction relative to the axis of revolution of the cylinder circumscribing the electronic component. The dimensioning of this portion of the retaining wall is generally more flexible due to the absence of a required tight fit of the electronic component in this axial direction. For the same design parameters of this portion of the retaining wall acting as a check valve, the critical local buckling load is lower. This is generally the desired design for positioning the electronic component within the retaining device.Furthermore, the lower structural rigidity of the portion of the retaining wall acting as a check valve allows for a wider range of parameter settings in this area for the same critical local buckling load. Preferably, direction D is radial with respect to the axis of revolution of the cylinder circumscribing the encapsulation device. This is advantageous if several channels exist in the arrangement and are regularly distributed around the axis of revolution.

[0018] According to a particular embodiment, at least one channel is partly formed by a groove on the outer surface of the encapsulation device of the electronic component.

[0019] According to another particular embodiment, at least one channel is partly formed by a groove on the internal surface of the retaining wall of the retaining device.

[0020] The fluidic channel can be implemented either through the encapsulation device of the electronic component, or at the internal surface of the retaining wall, or on both elements. The objective is to ensure that the end of the channel at the point where the retaining wall acts as a valve is not located at the neutral axis of that portion of the retaining wall, in order to induce buckling instability when the critical load is reached. Furthermore, the encapsulation device of the electronic component is more rigid than the retaining wall, which is inherently elastic. Consequently, a groove in the encapsulation device is more geometrically stable, regardless of the deformation of the part, than the retaining wall.The best compromise consists of a groove on the encapsulation device extending from the inner surface of the retaining device's base, which terminates in a groove on the retaining wall near the part of the retaining wall that acts as a flap. The groove at this point is then naturally offset from the neutral axis. Furthermore, the presence of a groove on the electronic component can serve as a gripping point for the electronic component during insertion or extraction, as well as an angular reference point for orienting the electronic component within the retaining device.

[0021] Advantageously, the difference between the volume of the retaining device and the external surface of the electronic organ defines several channels evenly distributed around the axis of revolution.

[0022] If one channel is sufficient to balance the pressures when the pneumatic is in service or during the insertion or extraction phases of the electronic component, the multitude of channels makes it possible to adapt the arrangement to any type of movement of the electronic component within the retention device.

[0023] An even distribution of the channels on the contour reinforces the homogeneity of the insertion and extraction forces at the radially external surface of the encapsulation device and the retaining wall, which ensures homogeneous clamping of the electronic element by the retaining wall and which ensures better endurance of the electronic element and the retaining device.

[0024] Preferably, the at least one channel has, in a plane perpendicular to the direction of the channel, a minimum width at the level of the internal surface of the retaining wall greater than or equal to the minimum depth of the at least one channel.

[0025] This channel shape, regardless of the geometry of the channel cross-section—square, rectangular, triangular, quadrilateral, semicircular, or elliptical—ensures that a channel is present. Furthermore, ensuring that the width is greater than the depth allows to minimize the thickness of the encapsulation device or retaining wall, unlike a design where the channel depth is greater than the width. This reduces the overall mass of the arrangement, thereby reducing the centrifugal forces acting on the arrangement when it is attached to a tire during operation.

[0026] According to a specific embodiment, at least one channel has a minimum cross-section in the plane perpendicular to the direction of the channel of at least 0.04 mm2, preferably of at least 0.09 mm2.

[0027] This minimum cross-section ensures that even under very high thermomechanical stresses potentially encountered in road use, the channel cross-section will not close, which is preferable for the durability of the retention device and the electronic component. Similarly, depending on the number of available channels and their minimum cross-sections, this minimum cross-section per channel defines a minimum effective fluid flow cross-section through the channel network. This fluid flow defines the rigidity characteristics of the fluid system under insertion and extraction stresses of the electronic component, which partially controls the torque consisting of the relative movement speed of the electronic component with respect to the retention device and the external force required to slide the electronic component within the open volume.The fact that the encapsulation device is rigid relative to the retaining wall of the retention device allows for smaller channel sections in the encapsulation device because the geometry is controlled.

[0028] Most preferably, the at least one channel has, in a plane perpendicular to the direction of the channel, a section whose shape is included in the group comprising semi-circular, semi-elliptic, circular, elliptic.

[0029] These are basic channel shapes that are easily produced by a molding process, whether at the level of the retention device or the encapsulation device for the electronic component. The rounded shapes help to limit instabilities during fluid movement in the channel, which promotes homogeneous pressure within the channel.

[0030] The invention also relates to an assembly comprising an arrangement according to the invention of a retaining device and an electronic element and a pneumatic casing comprising a top (S), two sides (F) extending from the top (S) and ending in two ridges (B) suitable for being linked to a wheel, in which the retaining device is fixed on one of the surfaces of the pneumatic casing, preferably on the radially inner surface of the pneumatic casing.

[0031] Most preferably, the retaining device is fixed on the radially inner surface of the pneumatic casing and at the top (S) of the pneumatic casing.

[0032] The primary purpose of the electronic component is to be associated with a tire via a retaining device, by positioning the retaining device on a surface of the tire. Preferably, the retaining device is attached to the surface delimiting the closed cavity formed by the tire and the wheel when the tire is mounted on the wheel. This ensures protection of the electronic component against external damage to the tire, whether mechanical or chemical, such as impacts on curbs or splashes of any kind. Advantageously, the retaining device is fixed to the inner wall of the tire at the crown, which facilitates mounting the tire equipped with the retaining device onto a wheel.The term "straight" here refers to the axial extent, along the tire's natural axis of rotation, of the retention device, which is included within the axial extent of the tire's crown. Furthermore, measuring certain crown parameters, such as its deformation by the electronic device, allows for the collection of useful physical parameters related to tire use, a function also sought by connected tires. These physical parameters can include, for example, the radial or longitudinal acceleration of the crown, used to determine the contact patch between the tire, when mounted and loaded, and the ground, or even the amount of water in hydroplaning conditions. Brief description of the drawings

[0033] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the accompanying figures in which the same reference numbers designate identical parts throughout and in which: - Fig. 1 presents a perspective view of an electronic component, suitable for being attached to a tire via a retaining device, representing the state of the art; - Fig. 2 presents a perspective view of a state-of-the-art electronic pneumatic component retaining device; - Fig. 3 presents a perspective view of an electronic component of the arrangement according to a first embodiment of the invention; - Fig. 4 presents a perspective view of an electronic component of the arrangement in a second embodiment of the invention; - Fig. 5 presents a perspective view of a fastening device according to a first embodiment of the invention; - Fig. 6 presents a perspective view of a fastening device in a second embodiment of the invention; - Fig. 7 presents a perspective and cross-sectional view of a pneumatic casing equipped with an electronic component housed in a retention device according to the invention; Detailed description of implementation methods

[0034] Fig. 1 is a perspective view of an electronic component 10, suitable for being fixed by means of a retaining device to a pneumatic casing, of the prior art.

[0035] The electronic element 10, shown here in grey, is delimited by an encapsulation device 12 enveloping all the electronic components of the electronic element 10. This encapsulation device 12 has an outer surface 30 circumscribed by a cylinder 17 having an axis of revolution 15 which is perpendicular to the printed circuit of the electronic element 10. This cylinder 17 is truncated by two parallel planes 16 and 16' which rest respectively on the outermost axial surfaces 14 and 14' of the encapsulation device 12.

[0036] This encapsulation device 12 is a combination of a cone and a parallelepiped. The conical shape facilitates its insertion into or removal from a retaining device. The cone has a parallelepiped on one of its axially external surfaces, which houses the radio antenna. The antenna is also encapsulated within the encapsulation device 12. The encapsulation device 12 is a monolithic piece or a piece assembled from several parts, the parts being welded together.

[0037] The parts or the monolithic piece are obtained, for example, using a molding process from a plastic material such as a thermoset. Low-temperature curing of the plastic results in the final formation of the outer surface 30 of the encapsulation device 12.

[0038] Figure 2 is a perspective view of a retaining device 510 for an electronic component intended to be attached to a prior art pneumatic casing. The retaining device 510 is of the open type, meaning that the insertion or extraction of the electronic component 10 from the retaining device 510 is carried out via an opening 516 accessible even when the retaining device 510 is attached to the pneumatic casing. Therefore, the insertion or extraction of the electronic component 10 from the retaining device 510 can be performed directly on the pneumatic casing.

[0039] This retaining device 510 has a base 511 whose external surface is designed to be fixed to the surface of a pneumatic casing using state-of-the-art technical solutions well known to those skilled in the art. The retaining device 510 rotates about an axis of rotation perpendicular to the base 511. A retaining wall 512, which is closed over 360 degrees, is attached to this base 511. This retaining wall 512 has an opening 516 delimited by a free edge 513 of the retaining wall 512 of the fixing device 510. The opening 516 leads to an open volume 520 delimited by the inner surface 514 of the base 511 and the inner surface 515 of the retaining wall 511. The opening 516 is deformable to allow the insertion or extraction of an electronic component 10 into or from the open volume 520.The elastic properties of the material of this retaining wall 512 allow this enlargement of the orifice 516 for the insertion and extraction phases. In addition, it also provides a holding or clamping force on the electronic component 10 when it is housed in the open volume 520.

[0040] Figure 3 shows an electronic element 10 according to a first embodiment of the invention obtained from the electronic element of Figure 1. The radially outer surface 13 of the encapsulation device 12 comprises two channels, here grooves 19a and 19b, extending from the outermost axial surface 14 of the encapsulation device 12. Each groove 19a, 19b has an end, named 18a and 18b respectively, on the axially outer surface 14 of the encapsulation device 12. And each groove 19a and 19b also has a second end, named 18'a or 18'b respectively, on the radially outer surface 13 of the encapsulation device 12 which is axially opposite to the first end 18a or 18b.

[0041] Each groove 19a and 19b constitutes a fluidic conduit between the upper part of the retaining device housing the electronic element 10 and the free space of the cavity housing the retaining device when the electronic element 10 is present in the retaining device. The free space is understood to be the difference between the initial volume of the cavity housing the electronic element within the retaining device and the volume occupied by the electronic element at each instant during the insertion or extraction phases of the electronic element in the retaining device. The smaller this free space, the greater the insertion or extraction force required on the electronic element, particularly in the absence of these grooves 19a and 19b. Here, the ends 18'a and 18'b do not open into the opening of the retaining device.

[0042] Here, the two grooves 19a and 19b are evenly distributed on the periphery of the radially outer surface 13 of the encapsulating device 12, in order to maximize the efficiency of the fluidic system by minimizing the risks of groove obstruction when the component is present in the retaining device. The cross-section of this groove is semi-circular here; it could be square, rectangular, oval, or elliptical, with a radius of approximately 0.2 millimeters. The cross-section is uniform by design here; it could be variable and have a value of approximately 0.06 square millimeters. This cross-section, which is the minimum cross-section, is sufficient to limit the insertion and extraction forces to reasonable levels for manual work by a person skilled in the art, particularly due to the presence of two grooves instead of one. Furthermore, this minimum cross-section ensures functionality even in the event of imperfect insertion or extraction of the electronic component 10 into the retaining device's housing cavity.In particular, this allows the maximum force required to extract or insert the electronic component 10 of the retaining device in cases of imperfect operation to be defined. This enables, on the one hand, the appropriate dimensioning of the electronic component 10 and the retaining device in terms of mechanical resistance, and on the other hand, the automation of insertion or extraction operations. Specifically, this allows the dimensioning of the portion of the retaining wall that acts as a valve.

[0043] Finally, obtaining these grooves 19a and 19b is easily accomplished industrially when the encapsulation device 12 is produced by a molding process. Indeed, it suffices to add, for example, two rods, here straight with a circular cross-section, having the inverse image of groove 19a or 19b, to the mold dies of the prior art encapsulation device, in order to generate these grooves 19a and 19b directly during the molding operation of the encapsulation device 12. This does not add any additional manufacturing time; the rods, which can be intimately bonded to the mold dies, are used to produce several parts since they are reusable. In the case of a square or elliptical groove section, it is necessary to add connecting radii to facilitate the demolding of the encapsulation devices 12. As a result, the technical solution is economically minimal compared to the realization of a state-of-the-art electronic component 10.Mechanically, the groove is obtained simultaneously with the encapsulation device using the same process, without any subsequent operation on the electronic component 10, such as cutting, which could weaken it. This ensures greater resistance to the electronic component 10 equipped with said groove.

[0044] Fig. 4 is a perspective view of an electronic organ 10 according to a variant of the second embodiment of the electronic organ 10 of the invention.

[0045] In this embodiment, the outermost axial surface 14 of the encapsulation device 12 comprises two main channels 21a and 21b that intersect each other. These channels delimit, in the case of [Fig. 4], the outermost axial surface 14 into four equal subspaces. Each subspace is delimited by the two main channels 21a and 21b and represents a portion of the outermost surface. axially external 14 of the encapsulation device 12 on an angular sector of 90 degrees. Indeed, the electronic element 10 of [Fig.4] is of revolution around its axis of rotation 15.

[0046] Each main channel 21a and 21b opens at each of its ends into a groove 19a, 19b, 19c, and 19d. These grooves are themselves evenly distributed over the outermost radial surface 13 of the encapsulation device 12. They divide the outermost radial surface 13 into four equal angular sectors of 90 degrees each. Thus, the remaining volume or free space of the receiving cavity, when the electronic element is inserted into a retaining device, is geographically evenly distributed around the axis of rotation of the electronic element 10. Here, the ends 18'a> 18'b, 18'c, and 18'd do not open into the opening of the retaining device.

[0047] When the electronic element 10 is inserted into the retaining device so that it comes into contact with the outermost axial surface 14 of the encapsulating device 12, which is common, the free space left by the electronic element 10 in the open volume 20, or receiving cavity, of the retaining device is reduced or even eliminated. As a result, the insertion and extraction forces of the electronic element 10 during the final moments of insertion and the initial moments of extraction, respectively, increase greatly despite the presence of the grooves 19a, 19b, 19c, and 19d. The presence of the main channels 21a and 21b allows on the one hand to create a residual void volume for the free space, which leads to a significant reduction in insertion or extraction efforts when the electronic organ 10 is intended to position itself up to the outermost axial surface 14 of the encapsulation device 12.For the efficiency of the fluidic circuit consisting of the grooves 19a, 19b, 19c and 19d, it is preferable that these main channels 21a and 21b open into the grooves at the level of the outermost axial surface 14 of the encapsulation device 12. .

[0048] Here, the cross-section of the main channels 21a and 21b is identical and semi-circular in shape; it could be square, rectangular, oval, or elliptical, with a radius of approximately 0.165 millimeters. The cross-section is uniform by design, but it could be variable, with a value of approximately 0.04 square millimeters. This cross-section, which corresponds to the minimum cross-section, is sufficient to limit the insertion and extraction forces to reasonable levels for manual operation by a person skilled in the art. In particular, it allows the maximum extraction or insertion force of the electronic component 10 of the retaining device to be defined in cases of imperfect operation, which allows it to be mechanically dimensioned. adequately the electronic component 10 and the retention device and on the other hand to automate the insertion or extraction operations.

[0049] This technical solution can be industrialized by integrating a shape representing the inverse image of each main channel 21a and 21b into one of the mold shapes of the protective housing. Thus, the main channels 21a and 21b are obtained simultaneously with the encapsulation device 12 of the electronic component 10 without any subsequent operation such as cutting, which could weaken it. This ensures greater resistance to the electronic component 10 equipped with said main channels 21a and 21b.

[0050] Figure 6 shows a retaining device 510 according to a first embodiment of the invention obtained from the retaining device of Figure 2. The retaining wall 512 comprises on its inner surface 515 two channels, here grooves 19a and 19b, extending from the inner surface 514 of the base 511 over the entire height of the retaining wall 512. Here, the free edge 513 of the retaining wall 512 is located radially internal to grooves 19a and 19b with respect to the axis of revolution of the encapsulation device of the electronic component.

[0051] Each groove 19a and 19b constitutes a fluidic conduit between the retaining device 510 and the electronic element. The fluidic conduit, or free space, is understood to be the difference between the initial volume of the open volume 520 of the retaining device 510 and the volume occupied by the electronic element at each instant during the insertion or extraction phases of the electronic element from the open volume 520. The smaller this free space, the greater the insertion or extraction force to be exerted on the electronic element, particularly in the absence of these grooves 19a and 19b.

[0052] Here, the two grooves 19a and 19b are evenly distributed around the periphery of the inner surface 515 of the retaining wall 512, and consequently around the periphery of the inner surface 514 of the base 511, in order to maximize the efficiency of the fluidic system while minimizing the risk of obstruction of the grooves 19a and 19b. The cross-section of these grooves is here semi-circular; it could be square, rectangular, oval, or elliptical, with a radius of approximately 0.3 millimeters. The cross-section is uniform by design; it could be variable, when the retaining device 510 is not equipped with the electronic component, and have a value of approximately 0.135 square millimeters. This section, which is the minimum section, is sufficient to limit the insertion and extraction efforts to reasonable values ​​for manual work by a skilled person, in particular by the presence of two grooves instead of one.Moreover, it ensures that even in the event of imperfect insertion or extraction of the electronic element from the open volume 520 of the retaining device 510, i.e. having a trajectory of the electronic element not perpendicular to the internal surface 514 of the base 511, the volume of the remaining fluidic conduit, made up of the grooves 19a and 19b, will be sufficient to facilitate the insertion operations. and extraction. In particular, this allows the maximum extraction or insertion force of the electronic component from the retaining device to be defined in cases of imperfect operations. This allows, on the one hand, for the appropriate dimensioning of the electronic component and the retaining device 510 in terms of mechanical resistance, and on the other hand, for the automation of the insertion or extraction operations. Note that the retaining wall 512 is elastic, and during the extraction or insertion phases of the electronic component, a significant deformation of the free edge 513 of the retaining wall 512 occurs to enlarge the orifice 516 to a size sufficient to allow the electronic component to pass through. Once the operation is complete, the release of the deformation forces on the retaining wall 512 causes the free edge 513 of the retaining wall 512 to continuously press against the encapsulating device of the electronic component.This movement then creates a seal between the free space of the arrangement and the fluidic medium external to the arrangement. This seal is achieved from the free edge 513 of the retaining device to the ends 18'a and 18'b of the grooves.

[0053] Finally, obtaining these grooves 19a and 19b is easily accomplished industrially when the retaining device 510 is produced by a molding process. Indeed, it suffices to add, for example, to the mold dies of a state-of-the-art retaining device, two rods, here straight with a circular cross-section, having the inverse image of groove 19a or 19b, in order to generate these grooves 19a and 19b directly during the molding operation of the retaining device 510. This does not add any additional manufacturing time, the rods can be intimately bonded to the mold dies and are used to produce several parts since they are reusable. In the case of a square or elliptical groove section, connecting radii should be added to facilitate the demolding of the 510 retention devices. As a result, the technical solution is economically minimal compared to the cost of producing a state-of-the-art 510 retention device.Mechanically, the groove is created simultaneously with the retaining device without any subsequent operation on the retaining device, such as cutting, which could weaken it. This ensures greater resistance for the 510 retaining device equipped with these grooves.

[0054] Figure 4 is an example of a retaining device 510 according to a second embodiment. In addition to the presence of grooves, here two in number 19a and 19b, on the internal surface 515 of the retaining wall 512, the internal surface 514 of the base 511 also has a main channel 21.

[0055] This main channel 21 opens at both ends into each of the grooves 19a and 19b since these are diametrically opposed. Here the grooves are evenly distributed on the internal surface 515 of the retaining wall 512 which is of revolution, and the main channel 21 is positioned so that the internal surface 514 of the base 511 is separated into two almost equal surfaces by the main channel 21.

[0056] When the electronic element is inserted into the retaining device 510 so that it comes close to the inner surface 514 of the base 511, which is common, the free space left by the electronic element in the open volume 520 of the retaining device 510 is reduced or even eliminated. Consequently, the insertion and extraction forces of the electronic element during the final moments of insertion and the initial moments of extraction, respectively, increase significantly despite the presence of the grooves 19a and 19b. The presence of the main channel 21 creates a residual void volume for the free space, thereby reducing the insertion and extraction forces when the electronic element is positioned as far as the inner surface 514 of the base 511.For the efficiency of the fluidic circuit formed by the grooves 19a and 19b, it is preferable that this main channel 21 open into the grooves 19a and 19b at the level of the internal surface 514 of the base 511. In another configuration, the retaining device 510 may have two main channels extending at its ends onto the internal surface 515 of the retaining wall 512. At only one of these ends does the main channel open into a groove. And the two main channels divide the internal surface 514 of the base 511 into three sub-surfaces of almost equal size. Thus, there is a statistically greater chance of finding an unobstructed fluidic conduit in potential fluidic connection with the outside via a groove, even when the electronic component is imperfectly positioned in the open volume 520 of the retaining device 510.

[0057] Here, the cross-section of the main channel 21 is semi-circular in shape; it could be square, rectangular, oval, or elliptical, with a radius of approximately 0.3 millimeters. The cross-section is uniform by design, but it could be variable, when the retaining device 510 is not equipped with the electronic component, and have a value of approximately 0.135 square millimeters. This cross-section, which corresponds to the minimum cross-section, is sufficient to limit the insertion and extraction forces to values ​​reasonable for manual operation by a person skilled in the art. This minimum cross-section can be smaller if the number of main channels is sufficient to ensure a satisfactory overall volume in the free space.In particular, this allows the maximum extraction or insertion force of the electronic component of the retaining device to be defined in cases of imperfect operations, which allows, on the one hand, the electronic component and the retaining device 510 to be mechanically dimensioned appropriately and, on the other hand, the insertion or extraction operations to be automated.

[0058] This technical solution can be industrialized by integrating a shape representing the inverse image of the main channel 21 into one of the shapes of the mold for the retaining device 510. Thus, the main channel 21 is obtained at the same time as the retaining device 510 without any further operation on the retaining device 510, such as a cutting that could weaken it. This ensures better resistance to the retention device 510 equipped with said main channel 21.

[0059] Figure 7 shows a cross-section of a pneumatic tire or casing 100 according to the invention, comprising a vertex S extended by two flanks F and terminating in two beadlets B. In this case, the tire 100 is intended to be mounted on a wheel, which is not shown in this figure, at the level of the two beadlets B. This defines a closed cavity, containing at least one pressurized fluid, delimited both by the second radially internal surface 130 of the pneumatic tire 100 and by the external surface of the wheel. The pneumatic casing 100 also includes a first radially external surface 140.

[0060] The reference axis 201, corresponding to the reference axis or natural axis of rotation of the pneumatic tire 100, and the median plane 211, perpendicular to the reference axis 201 and equidistant from the two ridges B, shall be noted. The intersection of the reference axis 201 by the median plane 211 determines the center of the pneumatic tire 200. A Cartesian coordinate system shall be defined at the center of the pneumatic tire 200, consisting of the reference axis 201, a vertical axis 203 perpendicular to the ground and a longitudinal axis 202 perpendicular to the other two axes. And, we will define the axial plane 212 passing through the reference axis 201 and the longitudinal axis 202, parallel to the ground plane and perpendicular to the median plane 211. Finally, we will call the vertical plane 213 the plane perpendicular to both the median plane 211 and the axial plane 212 passing through the vertical axis 203.

[0061] Every material point of the pneumatic tire 100 is uniquely defined by its cylindrical coordinates (Y, R, 0). The scalar Y represents the axial distance to the center of the tire 200 in the direction of the reference axis 201, defined by the orthogonal projection of the material point of the tire 100 onto the reference axis 201. A radial plane 214 is defined, making an angle of 0 with respect to the vertical plane 213 around the reference axis 201. The material point of the tire 100 is located in this radial plane 214 by the distance R to the center of the tire 200 in the direction perpendicular to the reference axis 201, identified by the orthogonal projection of this material point onto the radial axis 204. The unit vector perpendicular to the radial plane 214 and forming a right-handed trihedron with the unit vectors of the axial direction 201 and the radial direction 204 represents the circumferential direction of the tire 100.

[0062] This tire has on its radially inner surface 130 a retaining device 510 which is fixed to the surface 130 by bonding according to the usual prior art techniques when the retaining device is made of elastomeric material. The retaining device 510 is fixed at the apex S of the tire casing 100, which improves its durability since the retaining device 510 thus This positioning reduces problems during wheel mounting or dismounting operations on the tire 100. Indeed, the retaining device 510 is located away from the bead B of the tire 100. Here, the retaining device 510 is equipped with an electronic component 10 within its open volume, which provides a suitable housing for the electronic component 10. Therefore, the tire 100 is ready to be mounted on a wheel to form a complete assembly. The electronic component 10 can perform various functions, such as identifying certain components, including the electronic component itself and the tire.

[0063] However, the electronic component 10 can also be equipped with a pressure and / or temperature sensor to evaluate the inflation pressure of the assembled unit. Finally, it can also be equipped with a sensor that evaluates the curvature of the tire 10, such as an accelerometer or a flexometer, allowing the determination of tire usage parameters such as angular velocity, mileage, and applied static load. All or some of these parameters make it possible to identify tire performance characteristics such as wear, grip, or intrinsic properties of the surface on which the tire 100 travels.

Claims

1. Demands An arrangement of an electronic component (10) and a retaining device (510) suitable for being fixed to a wall of a pneumatic enclosure intended to form a pressurized assembly at a nominal operating pressure, said retaining device (510) comprising: - a sole (511) suitable for being fixed to the wall of the pneumatic casing via an external surface, - a retaining wall (512), capable of retaining said electronic component (10), extending from the base (511) to a free edge (513) and defining with said base (511) an open volume (520), - said volume (520), capable of receiving at least a part of said electronic component (10), being defined by an internal surface (514) of said base (511) and by an internal surface (515) of said retaining wall (512), having an opening (516) delimited by the free edge (513) of said retaining wall (512), capable of deforming to introduce or extract said electronic component (10) from said volume (520); Said electronic component (10) comprising: - a radio transmitter coupled to at least one radio antenna; - a microprocessor located on a printed circuit board, coupled to the radio transmitter and powered by a power source, - a memory space connected to the microprocessor to store at least one identification piece of information, and - said elements encapsulated in an encapsulation device (12) defining an outer surface (30) circumscribed within a cylinder (17) whose axis of revolution (15) is perpendicular to the median plane of the printed circuit board and delimited by two parallel planes (16, 16'); characterized in that the difference between the volume (520) of the retaining device (510) and a volume delimited by the outer surface (30) of the electronic component (10) defines at least one fluidic channel (19) from the inner surface (515) of the base (511) of the retaining device (510) to an end (18') of the outer surface (30) of the electronic component (10), in that the free edge (513) of the retaining wall (512) is in continuous contact with the outer surface (30) of the electronic component (10), in that the part of the retaining wall (512) between the end (18') of at least one fluidic channel (19) and the free edge (513) has a critical elastic buckling load along the direction of the median plane of the portion of the retaining wall (512) which is intended to be reached for a pressure in at least one fluidic channel greater than 1 bar relative to the nominal service pressure of the assembled assembly.

2. Arrangement of an electronic element (10) and a retaining device (510) according to claim 1, wherein the end (18') of at least one fluidic channel (19) has a section whose normal is directed along the axis of revolution (15) of the cylinder (17) circumscribed to the outer surface (30) of the encapsulation device (12).

3. Arrangement of an electronic element (10) and a retaining device (510) according to claim 1, wherein the end (18') of at least one fluidic channel (19) has a section whose normal is directed along a direction D' of the base (16') of the cylinder (17) circumscribed to the outer surface (30) of the encapsulation device (12).

4. Arrangement of an electronic element (10) and a retaining device (510) according to the preceding claim, wherein the direction D' is a radial direction R to the axis of revolution (15) of the cylinder (17) circumscribed about the encapsulation device (12) of the electronic element (10).

5. Arrangement of an electronic element (10) and a retaining device (510) according to any one of the preceding claims wherein at least one channel (19) is partly formed by a groove on the outer surface (30) of the encapsulation device (12) of the electronic element (10).

6. Arrangement of an electronic component (10) and a retaining device (510) according to any one of the preceding claims wherein at least one channel (19) is partly formed by a groove on the internal surface (515) of the retaining wall (512) of the retaining device (510).

7. Arrangement of an electronic element (10) and a retaining device (510) according to any one of the preceding claims wherein the difference between the volume (520) of the retaining device (510) and the external surface (30) of the electronic element (10) defines several channels (19a, 19b) evenly distributed around the axis of revolution (15).

8. Arrangement of an electronic component (10) and a retaining device (510) according to any one of the preceding claims, wherein the at least one channel (19a, 19b, 19c, 19d) has, in a plane perpendicular to the direction of the channel, a minimum width at the level of the internal surface (515) of the retaining wall (512) greater than or equal to the minimum depth of the at least one channel.

9. Arrangement of an electronic component (10) and a retaining device (510) according to the preceding claim, wherein at least one channel (19a, 19b, 19c, 19d) has a minimum cross-section in the plane perpendicular to the direction of the channel (19a, 19b, 19c, 19d) of at least 0.04 mm2, preferably of at least 0.09 mm2.

10. Arrangement of an electronic element (10) and a retaining device (510) according to any one of the preceding claims, wherein at least one channel (19a, 19b, 19c, 19d) has, in a plane perpendicular to the direction of the channel, a section whose shape is included in the group comprising semi-circular, semi-elliptic, circular and elliptic.

11. Assembly comprising an arrangement according to any one of claims 1 to 10 and a tire casing (100), comprising a top (S), two sides (F) extending from the top (S) and ending in two ridges (B) suitable for being linked to a wheel, in which the retaining device (510) is fixed on one of the surfaces (130, 140) of the tire casing (100), preferably on the radially inner surface (130) of the tire casing (100).

12. Assembly according to the preceding claim in which the retaining device (510) is fixed to the radially inner surface (130) of the pneumatic casing (100) and to the apex (S) of the pneumatic casing (100).