Electronic system for azimuth adjustment in a fixing device

Abstract

The invention relates to an electronic system (1) intended for a tire fastening device comprising: - An electronic card including a printed circuit board (5) on which is fixed: o A radio frequency antenna (2); - The electronic card being contained in an encapsulation device (20) of cylindrical shape around an axis (21) normal to the printed circuit board (5); - The encapsulation device (20) comprising a first (22) and second (23) surfaces; and characterized in that the surface (23) has two details (30, 31) angularly equidistant around the axis (21), one of which (30) has a specific geometry, and in that the radio frequency antenna (2), having a gain vector G whose projection onto the plane (40) of the printed circuit board (5) defines a center (41) and an end (42) and has an angle α with respect to the vector defined by the center (41) and the projection (43) of the detail (30). Fig. 2

Description

Title of the invention: Electronic system for azimuth adjustment in a mounting device. Field of the invention

[0001] The present invention relates to the field of electronic systems embedded on a mounted assembly whose purpose is the transmission of information such as the identity of the electronic chip but potentially also the measurement of the parameters of the pressurized fluidic cavity of a mounted assembly delimited by at least one tire and one wheel or even deformation parameters of the tire, and particularly the field of electronic systems positioned on the tire. Technological background

[0002] In the transportation sector, vehicles are often required to monitor the inflation pressure of tire assemblies when these are pressurized by a fluid at a pressure higher than atmospheric pressure. This is to ensure proper tire performance and, consequently, vehicle performance, thereby guaranteeing the safety of vehicle passengers and other road users. Electronic systems mounted on the wheel rim are often subjected to temperature fluctuations due to their proximity to potentially hot components such as the braking system, including brake discs, shoes, and drums. These thermal changes also affect the accuracy of measurements of the physical parameters of the fluidic cavity within the tire assembly.However, the transmission of this data is increasingly done via radio frequency transmission, which requires a transmitting antenna and encoding of the information into radio waves emitted by the antenna. Most radio frequency antennas are directional, meaning that transmission power is concentrated in a specific direction. Furthermore, the rim is often metallic, which creates electromagnetic interference with the radio waves used to operate such electronic systems. This necessitates positioning the electronic system at a distance from these hot, metallic components. Once positioned on the tire, the electronic system can record tire deformations, allowing for the analysis of other tire usage parameters, such as the number of rotations or the applied static load.And, while inserting an electronic system is undoubtedly a straightforward operation, optimizing its positioning within the mounting device is not so easy in order to maximize radio frequency communication. In [the following section / text]. Indeed, an angular orientation of the electronic system is necessary, firstly, to record tire deformation measurements along a non-radial direction, and secondly, the orientation of the radio frequency antenna must also be optimized if the antenna is not omnidirectional, which is the case for most antennas. Furthermore, the electronic system must be able to undergo easy and reliable positioning without compromising the durability of either the electronic system or the mounting device in which it is inserted.

[0003] The object of the following invention is to propose an economical technical solution for ideally positioning, that is to say in a simple and efficient way, an electronic radio communication system in a tire fixing device. Description of the invention

[0004] The invention relates to an electronic system intended to be positioned in a tire mounting device comprising: - An electronic card comprising a printed circuit board on which are fixed: • A radio frequency antenna; • A source of energy; • A microcontroller; the electronic card being contained in an encapsulation device of cylindrical shape around an axis of revolution normal to the printed circuit; the encapsulation device comprising a first surface intended to be arranged inside the fixing device and a second surface intended to be open to the outside of the fixing device;and 1 e electronic system is characterized in that the second surface of the encapsulation device has on its contour at least two structural details distributed angularly around the axis of revolution of the encapsulation device, preferably they are equidistant, and extending axially, in that one of the structural details has a specific geometry with respect to at least one other structural detail and in that the radio frequency antenna being directional and having a maximum gain along a vector G, whose orthogonal projection onto the plane of the printed circuit board, defines a center and an end on the plane, has a constant angle α with respect to the vector defined by the center and the orthogonal projection of the structural detail with specific geometry, preferably the angle α is 90 degrees modulo 90 degrees. ;

[0005] The technical problem is solved firstly through the structural details on the contour of the second surface of the encapsulation device. In fact, the second surface of the encapsulation device is accessible when the electronic system is positioned in the tire mounting device. Therefore, it is possible to position a rigid object bearing on these structural details since Accessibility is ensured. Furthermore, these structural details are located on the contour of the second surface, which is centered on the axis of revolution of the encapsulation device. Consequently, the lever arm is maximized to exert maximum torque, enabling rotation of the electronic system around the axis of revolution of the encapsulation device. Thus, the angular positioning of the electronic system within the tire mounting device is easy and efficient. Moreover, these structural details extend axially, that is, along the axis of revolution of the encapsulation device, which ensures stress distribution over a larger surface area, thereby improving the durability of the encapsulation device and, consequently, the electronic system.Furthermore, the structural component gripping tool is not in contact with the fastening device, which ensures increased durability of the fastening device with respect to the rotation of the electronic system within the fastening device. Preferably, if the structural components are evenly distributed, this ensures that the moment generated by external forces is pure, i.e., without generating any force, on the axis of rotation of the encapsulating device, which promotes the rotation of the electronic system within the fastening device.

[0006] Now, to align the preferred radio frequency communication axis of the electronic system with the preferred radio frequency communication direction in the environment of the assembled unit, it suffices to align the gain vector G of the antenna with the preferred communication plane of the tire. To this end, either by design or by measurement, it is possible to define the angle α that this vector G makes with respect to a particular structural detail, called a structural detail with specific geometry. Indeed, this structural detail is visually distinguished from other structural details by a particular geometric shape, such as the addition of a specific visual pattern associated only with that particular detail, or a shape or dimension different from the other structural details, which would otherwise all be identical.Knowing this angle at the level of the radio frequency antenna's radiation pattern in an electronic system environment allows us to define the rotation angle to be applied to the electronic system in its mounting device for the gain vector G, i.e., within the efficient communication plane of the tire. This efficient plane consists of a radial direction of the tire and a second direction perpendicular to this radial direction, which will therefore be a combination of the axial and circumferential directions of the assembled system. Thus, the degree of angular positioning of the cylindrical electronic system will be optimized for the same placement of the radio frequency antenna on the electronic board. While it is entirely possible to define a detail with a specific geometry to accommodate the angular positioning of the radio frequency antenna on the second surface of the encapsulation device, the sharing of this angular reference frame with... The structural details used to drive the rotation of the electronic system prevent errors from accumulating during angle summing and avoid excessively constraining the contour of the second surface, which is limited due to the desired miniaturization of the electronic system. Indeed, it must be compact, lightweight, easy to handle, and durable. The precision of the detail for angularly locating the radio frequency antenna of the electronic system is enhanced when the detail is located radially outside the rotation axis of the encapsulation device, thus improving the accuracy of the angle measurement. An angle of 90 degrees modulo 90 degrees—that is, among the values ​​90, 180, 270, and 360 degrees—allows for easy orientation of the electronic system within the tire mounting device.

[0007] According to a first embodiment, the at least two structural details are elements projecting from the second surface.

[0008] This embodiment facilitates the attachment of the tool to the structural details. In fact, it is sufficient to present the tool parallel to the second surface of the electronic system and then direct the tool towards the second surface to bear against these structural elements. Next, the tool is rotated to align its recesses with the protruding structural details of the second surface. Once the connection is made, a torque can be applied to the electronic system by rotating the tool. The connection between the second surface and the tool is facilitated since these protruding structural details are accessible when the electronic system is placed in the mounting device.However, the resistance of these structural elements to the forces exerted by the tool is proportional to the cross-section of these structural details, since they function as a beam fixed at its base within the electronic system. Therefore, the applied torques are limited. Furthermore, protruding structural details are also susceptible to breakage during handling, for example, during a fall.

[0009] According to a second embodiment, the at least two structural details are recessed elements with respect to the second surface.

[0010] In this case, the connection between the tool and the electronic system is more difficult, but this connection only needs to be established when the electronic system is installed in the tire mounting device. The tool, equipped with protruding elements, is parallel to the second surface. The tool is then rotated to ensure the connection between the protruding elements of the tool and the recessed structural details. The most tedious phase remains in locating the first recessed structural detail. The advantage of this embodiment is that the forces applied by the tool to rotate the electronic system in the mounting device are absorbed by the encapsulation device. Consequently, for the same material, the stresses are more homogeneous and more widely distributed than in the first embodiment. Because the protruding element is present in this embodiment at the tool level, it is possible to choose a more resilient material for the tool than the material of the encapsulation device, which must handle other functions. Furthermore, the recessed element removes material, thus reducing the final mass of the electronic system. This therefore limits the centrifugal forces acting on the electronic system and consequently on the fastening device during high and very high-speed tire operation.

[0011] Advantageously, the structural elements have a unidirectional geometric shape whose section is included in the group comprising circle, semicircle, ellipse, semi-ellipse, rectangle, square, triangle.

[0012] All these shapes are unidirectional and oriented along the axis of revolution of the encapsulation device, which allows the external force to be distributed over a larger area to cause the electronic system to rotate. When the details are positioned precisely on the contour of the second surface, the section can be open, such as a semicircle, a semi-ellipse, or a rectangle with one side unmade of material. If the detail, being positioned on the contour of the second surface, has a closed geometry such as a circle or an ellipse, it will then be radially closer to the axis of revolution of the encapsulation device. Furthermore, some geometries are naturally rounded, which avoids creating angular points that could concentrate stress and facilitates the connection between the tool component and the structural detail. These shapes are preferable for this reason.For straight sections, it is possible to blunt the angles using radii of curvature to avoid stress concentrations. This wide range of section geometry also allows for differentiation, through a specific section choice, of the single structural detail serving as the angular reference for the gain vector G of the radio frequency antenna of the electronic system, among all the structural details used to rotate the electronic system.

[0013] Preferably, the structural detail with specific geometry is differentiated by the dimension of the section compared to at least one other structural detail.

[0014] As previously mentioned, several cross-sectional geometries of the structural detail are possible, with some being preferred for reasons of mechanical strength. To visually distinguish the structural detail with a specific geometry, it is possible, while maintaining the same geometric shape, to modify the characteristic dimension of the structural detail used for the angular positioning of the radio frequency antenna. Of course, it is possible to combine the dimension of the geometric shape with a specific geometric shape to quickly identify the structural detail intended for the complementary function of angular positioning of the radio frequency antenna.

[0015] According to a specific embodiment, the electronic card includes at least one sensor for measuring a physical parameter of fluid having an active part sensitive to the physical parameter and the encapsulation device has an orifice on the second surface extending to the active part of at least one measuring sensor.

[0016] According to a complementary embodiment, the electronic card includes at least one measuring sensor capable of measuring at least one physical parameter of the electronic system along a direction parallel to a direction D contained in the plane of the printed circuit board, the direction D has a constant angle [3] with respect to the vector defined by the center and the orthogonal projection of the structural detail with specific geometry, preferably the angle [3] is 90 degrees modulo 90 degrees.

[0017] Preferably, at least one physical parameter of the electronic system is included in the group comprising acceleration, velocity, displacement, curvature, deformation, deformation rate.

[0018] These are complementary functionalities that the electronic system may include. In the first case, the through-hole can also serve as a complementary angular reference frame to the structural detail with specific geometry, in order to index an angular orientation on the electronic system. In the second case, the presence of a sensor measuring a quantity along a specific direction of the printed circuit board plane requires defining the axis of this measurement relative to the structural detail with specific geometry in order to define a coordinate system transformation matrix for the quantity measured using the sensor in the electronic system's coordinate system. As such, knowledge of the angle [3] is essential for a high-quality measurement of the quantity measured in the electronic system's coordinate system.An angle [3 of 90 degrees modulo 90 degrees, that is, among the values ​​90, 180, 270 and 360 degrees, allows for the creation of simple and elementary coordinate transformation matrices, thus minimizing potential rounding errors on the values ​​recalculated by the initial measurement system.

[0019] Specifically, there are four structural details.

[0020] It has been observed that dividing the system into four structural elements, preferably equally spaced, around the contour of the second surface provides the best match between the angular portion of the electronic system to be moved and the number of attachments. This amounts to considering the best quality / cost ratio of the electronic system for this functionality. Indeed, reducing the number of structural details to two or three does not allow for such easy rotation of the electronic system within the mounting device, which can lead to the tool detaching from the electronic system and potentially damaging the mounting device. Furthermore, the external force to be applied to each structural detail increases with There is a risk of locally damaging the encapsulation device at the level of the structural details. Conversely, increasing the number of structural details reduces the stress applied to each detail, but the miniaturization of the electronic system limits the number of structural details that can be implanted on the second surface to which the tool can attach. Furthermore, a sufficient amount of material must be maintained between each structural detail to avoid increasing stress and deformation on the encapsulation device, which could lead to its failure.

[0021] According to another particular embodiment, the central area of ​​the second surface of the encapsulation device is equipped with a visual support allowing at least the identification of the electronic system.

[0022] The central area of ​​the second surface is not affected by structural details or potentially by the fluidic connection orifice between the exterior of the electronic system and the fluidic parameter measurement sensor. This area can therefore be used to implement a visual element enabling the identification of the electronic system. This visual element may include a serial number or a barcode to ensure at least the identification function.

[0023] According to a first embodiment, the encapsulation device consists of: • A first rigid casing, comprising the second surface; • A second rigid housing suitable for being connected in a watertight manner to the first rigid housing on a closed contour; Preferably, the first housing is provided with a through orifice extending into a through orifice of an elastic seal bearing on one side on the first housing and on the other side on the sensor measuring a physical parameter of fluid.

[0024] According to a second embodiment, the encapsulation device consists of a coating plastic and the minimum distance, along the normal to the first surface of the encapsulation device, between the first surface of the encapsulation device and the electronic board is between 0.5 millimeter and 3 millimeters, preferably the encapsulation device has an orifice on the second surface extending into the material to the active part of at least one sensor for measuring a physical parameter of fluid.

[0025] These are two embodiments of the electronic system encapsulation device that are compatible with the structural details of the invention. The preferred versions relate to electronic systems equipped with a sensor for measuring a physical fluid parameter, which is becoming increasingly common. Brief description of the drawings

[0026] 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 attached figures. in which the same reference numbers designate identical parts everywhere and in which: • Fig. 1 presents a cross-section of an example of an electronic system used according to the invention in perspective. • Fig. 2 presents a perspective view of another example of an electronic system according to the invention; • Figure 3 presents a plan view of the example electronic system from Figure 2. • Fig. 4 presents the diagram representing the orientation of the radio frequency antenna in relation to the structural detail with specific geometry. • Fig. 5 presents a cross-section of a mounting device intended to accommodate the electronic system of the invention in perspective. • Fig. 6 presents a cross-sectional view of a tire receiving the electronic system of the invention in perspective. Detailed description of the implementation methods

[0027] Fig. 1 illustrates, in perspective, a cross-section of an electronic component 1 of the invention intended to be integrated into the tire fixing device.

[0028] This electronic system 1 consists here of an electronic card 6 and an encapsulation device 20 for the electronic card 6.

[0029] The electronic board 6 comprises a printed circuit board 5 on which various components are mounted, including a power source 4 in the form of a battery connected to the printed circuit board 5 by means of conductive arms. The conductive arms ensure that the battery 4 is held in place relative to the printed circuit board 5 and also ensure the conduction of electrical particles from the battery to the printed circuit board, and in particular to its electronic components connected by conductive traces of the printed circuit board 5. The printed circuit board 5 is also electrically connected to a microcontroller 3, which constitutes the brain of the electronic system 1. The printed circuit board 5 also includes a radio frequency antenna enabling the communication of information between the electronic component 1 and external transmitting / receiving means of the electronic system 1.Here, the electronic system 1 includes a sensor 7 for measuring a physical parameter of the electronic system's movement, such as an accelerometer, but also a sensor for measuring a physical parameter of the fluid, such as a pressure sensor and / or a temperature sensor. These sensors are fixed to the printed circuit board 5 and electrically connected to the microcontroller 3.

[0030] The encapsulation device 20 here consists of a plastic coating that solidifies the electronic components of the circuit board 6 together. Other designs for the circuit board encapsulation device exist, such as the combination of two rigid housings, joined together at their The edges are joined using standard techniques such as gluing and soldering. In this example, the electronic system 1 is rigid due to the absence of voids, allowing for thin walls at the periphery of the electronic board 6 without compromising the system's durability. Thus, the thinnest layer of plastic, representing the encapsulation device 20, between the exterior of the electronic system 1 and the electronic board 6, is approximately 0.5 millimeters. This reduction in thickness, resulting from the complete encapsulation of the electronic board 6, allows the use of larger electronic components within the same volume occupied by the electronic system 1. This improves the energy efficiency of the electronic system 1 by using, for example, a larger diameter battery with a higher power output, thereby extending the system's autonomy while maintaining the same functions.

[0031] This encapsulation device 20 is delimited by two surfaces 22 and 23 which together form a right cylinder around an axis 21 that is perpendicular to the printed circuit board 5. The first surface 22 is intended to be placed inside a tire mounting device, while the second surface 23 is intended to be open to the environment external to the mounting device and, in particular, to be open to the internal cavity of the assembled unit. This second surface 23 includes an orifice 25 that passes through the material to the active part of the sensor for measuring the fluid physical parameter in order to perform the measurement at the level of this sensor. The second surface 23, the most distal of the energy source 4, has a shoulder. On this shoulder are three structural details 30 equally distributed around the contour of the second surface 23, extending over the entire height of the shoulder.The two other structural details are located at approximately 120 degrees from the structural detail 30 shown. Similarly, the external surface of the encapsulation device 20, at the level of the first surface 22, has a recessed pattern 35 near the cylindrical base of the encapsulation device 20 proximal to the energy source 4. The structural detail 30, as well as the two other structural details not shown, of the encapsulation device 20 of the electronic system 1, is essential for rotating the electronic system 1 within the tire mounting device. Indeed, these details 30 are accessible to the operator when the electronic system 1 is placed in the mounting device since they are located on the second surface 23 of the encapsulation device 20.

[0032] Figure 2 illustrates another electronic system 1 of the invention in perspective, focusing on the second surface 23, which will be visible from inside the closed cavity of the assembled unit. This electronic system 1 is contained in an encapsulation device 20 cylindrical about an axis of revolution 21. This encapsulation device 20 comprises a lateral external surface and a base cylindrical sections intended to be inserted into the tire mounting device. This constitutes the first surface 21, which will be contained within the mounting device. It also includes a surface external to the mounting device, which is the second surface 23. This second surface includes a contour on which structural details 30 and 31 are positioned, evenly distributed around the entire contour of the second surface 23.

[0033] Here, details 30 and 31 are recessed elements relative to the second surface 23, of which there are four. The angle separating two consecutive details around the axis 21 is 90 degrees. The three details 31 are axially extending along the axis 21 with a rectangular cross-section that varies in height along the axis 21. In contrast, detail 30, with its specific geometry, extends axially along the axis 21 with a constant rectangular cross-section and has a larger surface area. To more clearly distinguish this detail 30 from the other details 31, two recesses are placed in the immediate vicinity of detail 30. Finally, the central square area 26 on the second surface 23 is designed to accommodate a visual element enabling the identification of the electronic system 1, such as a barcode.

[0034] Figure 3 shows a top view of the example electronic system 1 of Figure 2. A hollow disk located radially externally, which forms part of the first surface 21 of the encapsulation device 20, is thus visible. A solid disk centered on the hollow disk, representing the second surface 23, is also visible. The separation between the two disks is formed by the variation in height along the axis of the encapsulation device 20.

[0035] The second surface 23 comprises on its contour, i.e. as far radially as possible from the axis of the encapsulation device 20, four structural details 30, 31 equidistant from each other, i.e. spaced apart from each other at an angle of 90 degrees around the axis of the encapsulation device 20. The motifs 31 are identical; they are recessed elements from the second surface 23 to the first surface 22. The cross-section of these axial elements is rectangular, and the width of the rectangle decreases with the height of the detail 31.

[0036] The structural detail 30 is generally identical in shape, namely a hollow element extending along the axis of the encapsulation device 20 from the second surface 23 to the first surface 22. Here, the cross-section of the detail 30 has a constant surface area over its entire height. Furthermore, the cross-sectional area is slightly larger than the largest cross-sectional area of ​​the details 31. To further distinguish this detail 30 from the other details 31, two non-through cylindrical hollow elements are located near the detail 30. All of these differences result in a specific geometry for the detail 30 compared to the other details 31.

[0037] Finally, the central square-shaped area 26 is suitable for receiving a visual support, whether it is engraved directly on the surface of the central area 25 or juxtaposed on top of it by a suitable bonding technique.

[0038] Fig. 4 presents a three-dimensional view of the radiation pattern of a radio frequency antenna 2 of an electronic system according to the invention.

[0039] The radio frequency antenna 2 is here directional, that is to say that the radiation pattern is predominantly oriented towards a specific spatial area of ​​space relative to the radio frequency antenna 2, that is to say that in this area, radio frequency communication is better in transmission / reception compared to the rest of the space surrounding the radio frequency antenna 2.

[0040] Here, only the main lobe, the most energetic, is visualized. This main lobe describes a three-dimensional spatial region in an orthonormal coordinate system. The point of convergence of the main lobe is the radio frequency antenna 2. Within this main lobe, the gain vector G corresponding to the maximum radio frequency transmission / reception amplitude of the main lobe is identified.

[0041] An orthonormal coordinate system is defined, consisting of the plane 40 of the printed circuit board 5 of the electronic board of the electronic system and the normal 21 to this plane 40. The vector G is decomposed in this orthonormal coordinate system into two distinct projections. A first projection along the normal 21 to the plane, which is generally called the "elevation," and a second projection in the plane 40, which is simply the orthogonal projection of the vector G along the axis 21 of the encapsulation device of the electronic system onto the plane 40. This projection defines a center 41 and an endpoint 42, which is the orthogonal projection of the endpoint of the vector G onto the plane 40. The structural detail 30 with specific geometry of the encapsulation device is also projected along the axis 21 of the encapsulation device onto the plane 40. Here, the structural details 30 and 31 protrude from the second surface 23, represented by its dashed outline.The detail with specific geometry 30 is distinguished from the other structural details by the dimension of the half-cylinder which is larger than that of the half-cylinder of the other details 31. .

[0042] Finally, the angle α described by the intersection of two lines d and d' in plane 40 is calculated. Line d passes through the center 41 and the endpoint 42, while line d' passes through the center 41 and the point 43, which is the orthogonal projection of the structural detail 30 with specific geometry onto plane 40. The orientation of angle α is evaluated in the trigonometric direction with respect to the normal 21 running away from the plane of the printed circuit board 5 towards the second surface 23 of the electronic system, originating on line d'. Here, the value of angle α is therefore negative.

[0043] Similarly, if the electronic system is equipped with a sensor for measuring the physical parameter of the movement of the electronic system along a contained direction D In plane 40, this measurement direction D describes a straight line d” in plane 40. The angle [3 defined by the lines d' and d” is therefore the angle of rotation of the measurement direction D with respect to the direction of the structural detail 30 with specific geometry. The orientation of the angle [3 is evaluated in the trigonometric direction with respect to the normal 21 moving away from the plane of the printed circuit board 5 towards the second surface 23 of the electronic system, taking its origin on the line d'.

[0044] Figure 5 illustrates a tire fastening device 50. The device Fixation 50 is visualized in cross-section in a three-dimensional way.

[0045] The fastening device 50 is made of rubber so that it can deform elastically. The connection between the fastening device 50 and the tire is achieved by means of the sole 11, which is intended to be in contact with the inner surface of the tire using its outer surface, and by applying one of the various fastening techniques known to those skilled in the art for securely fastening rubber compounds together.

[0046] The device 50 also includes a retaining wall 12 extending perpendicularly to the sole 11 from the sole 11 to a free edge 13. The retaining wall 12 is closed and is cylindrical in shape around an axis 51. Here, the cylindrical shape of the retaining wall 12 is circular having identical dimensions along two directions perpendicular to each other. The free edge 13 defines an opening 17 capable of deforming to allow the insertion or extraction of an electronic system within the fastening device 50. The electronic system is housed within a cavity 18 open to the external environment by the opening 17. This cavity 18 is delimited by the internal surface 15 of the sole 11 and the internal surface 16 of the retaining wall 12. The electronic component is intended to come into contact with the internal surface 15 of the sole 11 during the rolling of the tire by the effect of centrifugal forces.Similarly, the elastic deformation of the retaining wall 12 ensures on the one hand the insertion and extraction of the electronic system from the volume 18. Moreover, in service, the retaining wall 12 rests on the first surface of the electronic system in order to ensure the retention of the electronic system within the fixing device 50.

[0047] Figure 6 shows a three-dimensional cross-section of a tire 100 comprising A vertex S extended by two flanks F and terminating in two ridges 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 ridges B. This defines a closed cavity, containing at least one pressurized fluid, delimited both by the radially inner surface 130 of the tire 100 and by the outer surface of the wheel. The tire 100 also includes a surface 140 radially external to the tire 100.

[0048] The reference axis 201, corresponding to the reference axis or natural axis of rotation of the tire 100, and the median plane 211, perpendicular to the reference axis 201 and equidistant from the two bead ribs B, shall be noted. The intersection of the reference axis 201 by the median plane 211 determines the center of the tire 200. A Cartesian coordinate system shall be defined at the center of the 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.

[0049] Every material point of the 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.

[0050] This tire 100 has on its radially inner surface 130 a fastening device 50 which is attached to the surface 130 by bonding according to conventional prior art techniques when the fastening device 50 is made of elastomeric material. The fastening device 50 is fixed at the apex S of the tire casing 100, which improves its durability since the fastening device thus positioned causes fewer problems during the mounting or dismounting of the wheel on the tire casing 100. Indeed, the fastening device 50 is located in an area away from the beads B of the tire casing 100. Here, the fastening device 50 is equipped with an electronic system 1 according to the invention positioned within its open volume, which constitutes a housing adapted to receive the electronic system 1. As a result, the tire casing 100 is ready to be mounted on a wheel to form a complete assembly.The electronic system 1 can deliver various functions such as the identification of certain components like the electronic system itself, the pneumatic system.

[0051] But the electronic system 1 can also be equipped with a pressure and / or temperature sensor in order to evaluate the inflation pressure or the temperature of the cavity The fluidic properties of the assembled vehicle are also measured. Finally, it can also be equipped with sensors that directly measure the curvature of the tire, such as an accelerometer or a flexometer, allowing for the analysis of tire usage parameters like angular velocity, mileage, and applied static load. All or some of these parameters can be used to identify the performance of the tire and therefore the assembled vehicle, such as its wear, grip, or intrinsic properties of the surface on which the vehicle travels.

Claims

Demands

1. Electronic system (1) intended to be positioned in a fastening device (50) for a tire (100) comprising: - An electronic card (6) comprising a printed circuit board (5) on which are fixed: • A radio frequency antenna (2); • A power source (4); • A microcontroller (3); - The electronic card (6) being contained in an encapsulation device (20) cylindrical in shape around an axis of revolution (21) normal to the printed circuit board (5); - The encapsulation device (20) comprising a first surface (22) intended to be arranged inside the fastening device (50) and a second surface (23) intended to be open to the outside of the fastening device (50);and Characterized in that the second surface (23) of the encapsulation device (20) has on its contour at least two structural details (30, 31) distributed angularly around the axis (21) of the encapsulation device (20), preferably they are equidistant, and extending axially, in that one of the structural details (30) has a specific geometry with respect to at least one other structural detail (31) and in that the radio frequency antenna (2) being directional and having a maximum gain along a vector G whose orthogonal projection onto the plane (40) of the printed circuit board (5), defines a center (41) and an end (42) on the plane (40), has a constant angle α with respect to the vector defined by the center (41) and the orthogonal projection (43) of the structural detail (30) with specific geometry, preferably the angle α is 90 degrees modulo 90 degrees.;

2. Electronic system (1) according to claim 1 in which the at least two structural details (30, 31) are elements projecting from the second surface (23).

3. Electronic system (1) according to claim 1 in which the at least two structural details (30, 31) are recessed elements with respect to the second surface (23).

4. Electronic system (1) according to any one of claims 1 to 3 wherein the structural elements (30, 31) have a unidirectional geometric shape whose cross-section is included in the group comprising circle, semicircle, ellipse, semi-ellipse, rectangle, square, triangle.

5. Electronic system (1) according to claim 4 in which the structural detail (30) with specific geometry differs in the dimension of the section from at least one other structural detail (31).

6. Electronic system (1) according to any one of claims 1 to 5 wherein the electronic board (6) comprises at least one measuring sensor (2) of a fluid physical parameter having an active part sensitive to the physical parameter and the encapsulation device (20) having an orifice (25) on the second surface (23) extending to the active part of at least one measuring sensor (2).

7. Electronic system (1) according to any one of claims 1 to 6 wherein the electronic board 6) comprises at least one measuring sensor (7) capable of measuring at least one physical parameter of the electronic system (1) along a direction parallel to a direction D contained in the plane (40) of the printed circuit board (5), the direction D has a constant angle [3] with respect to the vector defined by the center (41) and the orthogonal projection (43) of the structural detail (30) with specific geometry, preferably the angle [3] is 90 degrees modulo 90 degrees.

8. Electronic system (1) according to claim 7 in which at least one physical parameter of the electronic system is included in the group comprising acceleration, velocity, displacement, curvature, deformation, deformation rate.

9. Electronic system (1) according to any one of claims 1 to 8 wherein the structural details (30, 31) are four in number.

10. Electronic system (1) according to any one of claims 1 to 9 wherein the central area of ​​the second surface (23) of the encapsulation device (20) is equipped with a visual support (35) allowing at least the identification of the electronic system (1).

11. An electronic system (1) according to any one of claims 1 to 10 in which the encapsulation device (20) is constituted by:

12. - A first rigid casing, comprising the second surface (23); - A second rigid housing suitable for being connected in a watertight manner to the first rigid housing on a closed contour; - Preferably, the first housing is provided with a through orifice (25) extending into a through orifice of an elastic seal bearing on one side on the first housing and on the other side on the sensor measuring (2) of a physical parameter of fluid. Electronic system (1) according to any one of claims 1 to 10 wherein the encapsulation device (20) is made of a coating plastic and the minimum distance, along the normal to the first surface (22) of the encapsulation device (20), between the first surface (22) of the encapsulation device (20) and the electronic board (6) is between 0.5 millimeter and 3 millimeters, preferably the encapsulation device (20) has an orifice (25) on the second surface (23) extending into the material to the active part of at least one sensor for measuring a physical parameter of fluid.

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