Pneumatic system equipped with an electronic system
The fastening device with geometric details and encapsulation device ensures precise angular positioning of electronic components in tires, addressing measurement and communication challenges, achieving accurate and efficient tire parameter monitoring.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
- Filing Date
- 2024-06-25
- Publication Date
- 2026-06-12
Smart Images
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Abstract
Description
Title of the invention: pneumatic system equipped with an electronic system Scope of the invention
[0001] The present invention relates to the field of electronic systems embedded on a mounted assembly, the purpose of which is to communicate information to the vehicle via radio frequency, such as the tire identifier, the measurement of parameters of the pressurized fluidic cavity of a mounted assembly delimited by at least one tire and one wheel, or tire deformation parameters, and particularly to the field of electronic systems positioned with a precise orientation on the tire. It is known that, in order to optimize radio frequency communication from an electronic system, it is sometimes necessary to orient the electronic component within the tire, particularly for directional antennas. Technological background
[0002] In the transportation sector, vehicles are often legally 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 frequently subjected to temperature spikes due to their proximity to components that can experience significant temperature increases, such as brake system components like brake discs, brake shoes, or brake drums. These temperature variations also affect the accuracy of measurements of the physical parameters of the fluidic cavity within the tire assembly. Therefore, the electronic system must be positioned away from these hot 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. Furthermore, to avoid constraining the electronic system's design, an angular orientation is necessary for measuring tire deformation in a non-radial direction. Additionally, the orientation of the radio frequency antenna must be optimized if it is not omnidirectional, which is the case for most antennas. Moreover, the system's orientation... Electronics potentially alters the measurement signals from the sensors of the electronic system.
[0003] The object of the following invention is to propose a simple, efficient and economical technical solution to guarantee control of the angular positioning of the electronic system in the pneumatic system in order to guarantee all the functionalities of the electronic system, in particular radio frequency communication. Description of the invention
[0004] The invention relates to an arrangement of a tire equipped with a fastening device and an electronic tire control unit in which: • The tire having an axis of rotation, being delimited by an external surface radially outside and an internal surface radially inside the tire, and comprising a vertex intended to come into contact with the ground, two sidewalls located on either side of the vertex and extended by two ridges intended to come into contact with a wheel rim; • The tire being equipped with a fastening device, located on the inner surface of the tire, and capable of deforming, the fastening device (10) comprising a sole whose outer surface is in contact with the tire, and a closed retaining wall, said retaining wall extending from the sole to a free edge and defining with the sole an open volume, the volume being defined by an inner surface of the sole and by an inner surface of cylindrical and convex shape of the retaining wall whose axis is carried by a radial direction of the tire, perpendicular to the axis of rotation (201), said inner surface of the retaining wall having an opening delimited by the free edge of the retaining wall; • An electronic component comprising an electronic board including a printed circuit on which are fixed a power source, a microcontroller, a radio frequency antenna, the electronic board being inserted in an encapsulation device having the shape of a right cylinder with an axis 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; The arrangement is characterized in that the second surface of the encapsulation device has a structural detail of revolution around the axis of the encapsulation device and extending axially on its contour, and in that the retaining wall of the fastening device has details on its external surface geometric, angularly equidistributed around the axis of the fastening device on an angular sector 0 of the retaining wall, in that at least one of the geometric details is arranged so that the line passing through at least one geometric detail and perpendicular to the axis of the retaining wall is parallel to the axial direction vector or the circumferential direction vector of the cylindrical frame associated with the intersection of the axis of the retaining wall with the internal surface of the tire, said geometric detail defining the origin of the angular frame,in that each geometric detail and the midpoint between two adjacent geometric details are particular geometric points, and in that a radial line perpendicular to the axis of the encapsulation device passing through the structural detail of the second surface of the encapsulation device and a radial line perpendicular to the axis of the retaining wall passing through a particular geometric point of the external surface of the retaining wall are parallel.
[0005] The technical problem is solved firstly by the presence of a structural detail on the external surface of the electronic component, at the level of the encapsulation device, which is visible from inside the fluid cavity of the assembled unit. Furthermore, this structural detail is associated with geometric details of the fastening device, which are also visible from inside the fluid cavity of the assembled unit. In particular, these geometric details are angularly equidistant, which allows the midpoint between two adjacent geometric details to be defined as a specific geometric point. Finally, the series of geometric details is equally distributed on either side of a differentiated geometric detail that defines the angular origin of the coordinate system at the level of the fastening device.Thus, the electronic component can be precisely positioned relative to the mounting device using its structural detail by aligning the structural detail with a specific geometric point on the mounting device. Locating it relative to the differentiated geometric detail allows the angle formed between the electronic component and the mounting device to be determined. Finally, the azimuthal position of the electronic component relative to the rotating frame of the tire is achieved by specifically positioning the mounting device within the tire using the differentiated geometric detail.
[0006] Angular precision is ensured, on the one hand, by the radial positioning of the structural detail on the electronic component and the radial positioning of the geometric details on the retaining wall. On the other hand, it is also guaranteed by the geometric shape of these details, and in particular the thinness of the cross-section in the circumferential direction around the axis of the two components. Finally, the coaxiality of the axis of the electronic component and the axis of the fastening device is guaranteed by the axisymmetric behavior of the retaining wall under deformation during the insertion of the component. The electronic component is molded under homogeneous deformation of the retaining wall of the mounting device. Of course, if the components have a specific geometry, such as a triangular cylinder for geometric components or a cone for structural components, allowing for greater precision in defining the positioning angle (here, via a vertex of the triangle or the apex of the cone), this provides an advantage in angular positioning. However, an accuracy of 6 degrees is sufficient to fully utilize the functionalities of the electronic component. Manufacturing the components using a simple molding process, whether for the mounting device or the encapsulation of the electronic component, makes the technical solution very cost-effective.
[0007] Preferably, the geometric details are elements projecting from the external surface of the retaining wall of the fastening device.
[0008] The geometric details must be visually observable from outside the fastening device. Due to the deformable, or even highly deformable, nature of the retaining wall, which is necessary to ensure easy insertion or removal of the electronic component of the fastening device, the thickness of the retaining wall, especially at the free edge, must be thin to tolerate large deformations under low stress. With a thin retaining wall, it is limiting for the geometric details to be recessed elements, which would reduce the thickness of the retaining wall at the level of these recessed elements.Since the geometric details occupy less than half the total surface area of the retaining wall at their level, it is preferable to project these geometric details to preserve the deformability and thermomechanical endurance qualities of the retaining wall, assuming the same material for this component.
[0009] Advantageously, one end of each geometric detail of the fastening device is part of the free edge of the retaining wall of the fastening device.
[0010] By starting the geometric detail from the free edge of the retaining wall, it is easier to position the structural detail of the electronic component encapsulation device relative to a geometric point on the retaining wall by visual continuity between these two details or by centering them between the two geometric details. Furthermore, the free edge of the retaining wall, which is a fragile area due to its reduced thickness and its exposure to external forces during the insertion or extraction of the electronic component from the mounting device, is thus reinforced by the geometric detail if this detail protrudes from the retaining wall.
[0011] Preferably, the angle X defined between two neighboring geometric details is at most 12 degrees.
[0012] If the angle formed by two adjacent geometric details is less than 12 degrees, then necessarily the angle formed between two adjacent geometric points is less than 6 degrees. However, an accuracy of less than 6 degrees on the angle allows the projections of this angle in an orthonormal coordinate system to be determined to within 10%. Therefore, this level of accuracy makes it possible to correct the signals from measurement sensors measuring the movement of the electronic component in a given orthonormal coordinate system to within 10% accuracy, thus enabling a high-quality measurement of the electronic component's movement in a plane parallel to the printed circuit board of the electronic component.Furthermore, knowing the initial angular position of the measuring sensor on the electronic board relative to the reference frame defined by the structural details of the electronic component's encapsulation device allows us to overcome all design constraints of the electronic board and therefore of the electronic component, resulting in a compact, lightweight, and ultimately inexpensive electronic component.
[0013] According to a preferred embodiment, the geometric details are distributed regularly on either side of the geometric detail defining the origin of the angular frame on an angular sector 0 of at least 120 degrees, preferably on an angular sector 0 of at least 180 degrees, preferably on an angular sector 0 of 360 degrees.
[0014] This design of the geometric details allows the origin of the angular coordinate system to be centered on the total angular sector 0. Furthermore, with a total angular sector 0 of at least 120 degrees, numerous angular positions of the electronic component within the mounting device are covered. The angular positioning of the electronic component on a geometric point is possible by defining a straight line passing through the geometric point and the axis of the mounting device. This is generally achieved by the volume of the internal cavity of the mounting device, which is deformed when the electronic component is present in the cavity, thus ensuring self-centering of the electronic component within the mounting device. That is to say, the axis of the mounting device is made coaxial with the axis of the encapsulating device of the electronic component by mounting.Therefore, the visual alignment of the structural detail of the electronic component with the geometric points of the mounting device ensures their angular position relative to each other. The larger the angular sector 0, the more degrees of freedom are allowed in the orientation of the electronic component within the mounting device. With an angular sector 0 of 360 degrees, it is possible to define an alignment line on the mounting device by taking two diametrically opposed geometric points, which facilitates the angular positioning of the electronic component within the mounting device via this visually defined line.
[0015] Advantageously, the geometric detail defining the origin of the coordinate system has a specific section compared to the section of the other geometric details.
[0016] In order to visually locate, via the human eye or an optical system, the origin of the angular reference frame of the fixing device, it is necessary to associate it with a differentiating visible geometry through its section for example.
[0017] Most advantageously, the specific section of the geometric detail defining the origin of the reference frame differs in shape and / or dimension from the section of the other geometric details.
[0018] Classically, the dimension or its shape of the section are effective and inexpensive visible differentiating elements for this purpose.
[0019] According to a specific embodiment, the electronic board comprising at least one measuring sensor capable of measuring at least two physical parameters of the electronic element along two perpendicular directions contained in the plane of the printed circuit board, a first direction D having a constant angle y with respect to the vector perpendicular to the axis of the encapsulation device and passing through the orthogonal projection of the structural detail on the plane of the printed circuit board and the structural detail of the electronic element aligned with the geometric detail defining the origin of the angular frame of the fixing device, the physical parameters of the electronic element expressed in the direct orthonormal frame associated with the origin of the angular frame of the fixing device are derived from a transformation of the measurements of at least one measuring sensor by a rotation matrix of angle y.
[0020] If no specific rotation of the electronic element with respect to the fixing device is carried out, i.e. the structural detail of the electronic element is aligned with the geometric detail defining the origin of the angular frame of the fixing device, the signals of the measuring sensor must be transformed by a rotation matrix of angle y to express the movement observed by the sensor in the direct orthonormal frame of the fixing device.
[0021] According to a second specific embodiment, the electronic card comprising at least one measuring sensor capable of measuring at least two physical parameters of the electronic organ along two perpendicular directions contained in the plane of the printed circuit, a first direction D having a constant angle y with respect to the vector perpendicular to the axis of the encapsulation device and passing through the orthogonal projection of the structural detail on the plane of the printed circuit, the structural detail is positioned at an angle - y with respect to the geometric detail defining the origin of the angular reference frame of the fixing device.
[0022] In this specific embodiment, the electronic element is rotated by an angle opposite to the angle formed by the specific directions of the measuring sensor in the angular frame of the electronic element relative to the detail. structural of the electronic component. As a result, the output signals of the electronic component's sensor are directly those expressed in the direct orthonormal coordinate system of the mounting device without any correction being applied to the output signals of the measuring sensor.
[0023] According to another particular embodiment, the radio frequency antenna of the electronic organ being directional and having a maximum gain along a vector G whose orthogonal projection onto the plane of the printed circuit board, having a first end and a second end on the plane, has a constant angle a with respect to the vector perpendicular to the axis of the encapsulation device and passing through the orthogonal projection of the structural detail onto the plane of the printed circuit board, the structural detail is positioned at an angle - a with respect to the geometric detail defining the origin of the angular frame of the fixing device.
[0024] Specifically, the physical parameters of the electronic organ expressed in the direct orthonormal frame associated with the origin of the angular frame of the fastening device are derived from a transformation of the measurements of at least one measuring sensor by a rotation matrix of angle -a.
[0025] If the radio frequency antenna is directional, a preferred communication direction of the antenna is chosen, and this direction must possibly coincide with the origin of the angular reference frame of the mounting device. To achieve this, knowing the angle α formed between this preferred communication direction and the direction defined by the structural detail of the electronic component, an opposite angle of the same magnitude must be applied to the electronic component during its installation in the mounting device. As a result, the preferred communication direction and the direction of the mounting device defined by its origin are aligned.
[0026] However, this affects the orientation of the sensor measuring the motion parameters of the electronic component, which have also undergone this rotation by an angle -a. Therefore, it is necessary to transform the measurement signals of said sensor using a transformation matrix that represents the rotation by an angle -a. This transformation may be added to the transformation associated with the rotation by an angle -y, which is linked to the angular position of the measurement sensor in the frame of reference of the electronic component and whether or not this position is taken into account during the installation of the electronic component in the mounting device, depending on the embodiment considered.
[0027] According to a second particular embodiment, the radio frequency antenna of the electronic component being directional and having a maximum gain along a vector G whose orthogonal projection onto the printed circuit board plane, having a first end and a second end on the plane, has a constant angle α with respect to the vector perpendicular to the axis of the encapsulation device passing through the orthogonal projection of the structural detail onto the printed circuit board plane, the structural detail is positioned at an angle of 90° - a with respect to the geometric detail defining the origin of the angular reference frame of the fixing device, a being expressed in degrees.
[0028] Specifically, the physical parameters of the electronic organ expressed in the direct orthonormal frame associated with the origin of the angular frame of the fastening device are derived from a transformation of the measurements of at least one measuring sensor by a rotation matrix of angle 90°-a.
[0029] If the radio frequency antenna is directional, a preferred communication direction of the antenna must be aligned with a specific direction of the angular coordinate system of the mounting device. This direction must be perpendicular to the direction defined by the geometric detail that establishes the angular origin of the mounting device's coordinate system. To achieve this, knowing the angle α formed between this preferred communication direction and the direction defined by the structural detail of the electronic component, a complementary angle must be applied to the electronic component during its installation in the mounting device so that the preferred communication direction is perpendicular to the direction defined by the angular origin of the mounting device's coordinate system. Consequently, the preferred communication direction and the direction of the mounting device, which is perpendicular to its origin, are aligned.
[0030] However, this affects the orientation of the sensor measuring the motion parameters of the electronic component, which have also undergone this rotation by an angle of 90-a. Therefore, it is necessary to transform the measurement signals of said sensor using a transformation matrix that reflects the rotation by an angle of 90-a. This transformation may be added to the transformation associated with the rotation by angle -y, which is linked to the angular position of the measurement sensor in the frame of reference of the electronic component and whether or not this position is taken into account during the installation of the electronic component in the mounting device, according to the embodiment considered.
[0031] According to a final particular embodiment, the radio frequency antenna of the electronic organ being directional and having a maximum gain along a vector G whose orthogonal projection onto the plane of the printed circuit board, having a first end and a second end on the plane, has a constant angle a with respect to the vector perpendicular to the axis of the encapsulation device and passing through the orthogonal projection of the structural detail onto the plane of the printed circuit board, the structural detail is positioned at an angle [3 - a with respect to the geometric detail defining at the origin of the angular frame of the fixing device.
[0032] Specifically, the physical parameters of the electronic component expressed in the direct orthonormal frame associated with the origin of the angular frame of the device fixation are derived from a transformation of the measurements of at least one measurement sensor by an angle rotation matrix [3-a.
[0033] If the radio frequency antenna is directional, a preferred communication direction of the antenna must be aligned, if necessary, with a direction of the angular coordinate system of the mounting device. This direction must form an angle [3] with the direction defined by the geometric detail defining the angular origin of the mounting device's coordinate system. To achieve this, knowing the angle α formed between this preferred communication direction and the direction defined by the structural detail of the electronic component, an angle [3-α] must be applied to the electronic component during its installation in the mounting device so that the preferred communication direction is correctly positioned relative to the tire's coordinate system via the coordinate system associated with the mounting device. Consequently, the preferred communication direction and the desired direction of the mounting device are aligned.
[0034] However, this affects the orientation of the sensor measuring the motion parameters of the electronic component, which have also undergone this rotation by an angle [3-a]. Therefore, it is necessary to transform the measurement signals of said sensor by a transformation matrix representing the rotation by an angle [3-a]. This transformation may be added to the transformation associated with the rotation by angle -y related to the angular position of the measurement sensor in the frame of reference of the electronic component and whether or not it is taken into account during the installation of the electronic component in the mounting device according to the embodiment considered. Brief description of the drawings
[0035] 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 cross-section of a tire mounting device in perspective view of the state of the art. • Fig. 2 presents a cross-section of an example of an electronic component used in the perspective view arrangement according to the invention. • Fig. 3 presents a top view of a device for fixing the arrangement according to the invention; • Fig. 4 presents a top view of an example of an assembly of a fastening device and an electronic component of the arrangement according to the invention. • Fig. 5 presents the diagram representing the orientation of a radio frequency antenna in relation to the structural detail of an electronic component. • Fig. 6 presents a perspective view of a cross-section of an arrangement according to the invention. Detailed description of the implementation methods
[0036] Figure 1 illustrates a state-of-the-art pneumatic mounting device 10. The mounting device 10 is shown in cross-section in perspective view.
[0037] The fastening device 10 is made of rubber so that it can deform elastically. The connection between the fastening device 10 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.
[0038] The device 10 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 cylindrical about an axis 21. Here, the cylindrical shape of the retaining wall 12 is circular. The free edge 13 defines an opening 17 capable of deforming to allow the insertion or extraction of an electronic component within the fastening device 10. The electronic component is housed within a cavity 20 open to the external environment through the opening 17. This cavity 20 is delimited by the inner surface 15 of the sole 11 and the inner surface 16 of the retaining wall 12. The electronic component is intended to come into contact with the inner surface 15 of the sole 11 during the rolling of the tire due to 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 component from the volume 20, and on the other hand, in service, the retaining wall 12 bears against the external surface of the electronic component in order to ensure the retention of the electronic component within the fixing device 10. The retaining wall 12 has an external surface 18 which is closed on itself.
[0039] Fig. 2 illustrates an electronic component 1 of the invention intended to be integrated into a tire fixing device whose volume corresponds to that of Fig. 1.
[0040] This electronic component 1 consists here of an electronic card 6 and an encapsulation device 30 for the electronic card 6.
[0041] The electronic board 6 comprises a printed circuit board 5 on which a power source 4 is mounted, in this case a battery connected to the printed circuit board 5 by means of conductive arms. The conductive arms ensure that the battery 4 is held by The printed circuit board 5 is connected to the printed circuit board and ensures 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 component 1. The printed circuit board 5 also includes a radio frequency antenna allowing the communication of information between the electronic component 1 and external transmitting / receiving means. Here, the electronic component includes a sensor 7 for measuring a physical parameter of the movement of the electronic component such as a three-dimensional accelerometer but also a sensor for measuring a physical parameter of the fluid such as a pressure sensor and / or a temperature sensor.Thus, the measuring sensor 7 measures both the movement of the electronic component in a direction perpendicular to the printed circuit board 5 and also in two directions perpendicular to each other in the plane of the printed circuit board 5. These sensors are fixed on the printed circuit board 5 and electrically connected to the microcontroller 3.
[0042] The encapsulation device 30 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 free edges by standard bonding techniques. This encapsulation device 30 is delimited by an external surface 32 in the form of a right cylinder around an axis 31 that is perpendicular to the printed circuit board 5. The external surface 33, which will be arranged so that it is open to the outside of the fastening device, includes an orifice 35 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 this sensor. This external surface 33 of the encapsulation device 30, the most distal to the energy source 4, has a shoulder.On this shoulder there is a hollow 34 extending over the entire height of the shoulder which represents a structural detail of the encapsulation device 30. This structural detail 34 of the encapsulation device 30 of the electronic organ 1 serves as a reference point for the angular orientation of the various components of the electronic organ 1 such as the radio frequency antenna or the sensor 7 measuring a physical parameter of the movement of the electronic organ 1.
[0043] Figure 3 shows a top view of a fastening device 10 of the arrangement according to the invention.
[0044] The fastening device 10 has a series of concentric discs around the axis of rotation 21, which corresponds to a material point in this representation. The disc furthest radially from the axis of rotation 21 corresponds to the base 11 of the fixing device 10. The adjacent light gray disc corresponds to the retaining wall 12 of the fixing device 10. On this second disc, a thin, imaginary line is observed, corresponding to the change in curvature of the retaining wall 12 between its predominantly vertical part, oriented along axis 21 and located radially external to axis 21, and its predominantly horizontal part, located radially furthest internally and ending at the free edge 13. Being located outside the fixing device 10, this hollow gray disc also represents the external surface 18 of the retaining wall 12 of the fixing device 10. Finally, the solid disc delimited by the free edge 13 corresponds both to the opening 17 allowing the insertion and / or extraction of the electronic component into the internal cavity of the fixing device 10 and also to a part of the internal surface 15 of the base 11 delimiting the internal cavity.Here, the fixing device 10 can be delimited by a cylinder of revolution around the axis 21.
[0045] On the right-hand side of the external surface 18 of the retaining wall 12, a series of geometric details 40, 41 are shown, angularly equidistant at an angle X, here on the order of 12 degrees, over an angular sector 0 of approximately 180 degrees. This distribution of the geometric details 40, 41 makes it possible to define geometric points 43 that correspond either to the centroid of the geometric details or to the midpoint between two neighboring centroids. This allows for a distribution of geometric points 43 angularly equidistant at an angle of approximately 6 degrees. Thus, an electronic component can be positioned angularly within the mounting device 10 with an accuracy of approximately 6 degrees.This minimizes errors in the measurement signals from the electronic device's sensors to less than 10%, which is sufficient to obtain accurate signals with respect to specific directions (U, V) of the mounting device 10, or even specific directions (Ut, Y) of the tire. Here, the mounting device 10 is assumed to be positioned so that the axis 21 is aligned with a radial direction of the tire.
[0046] In this series, a geometric detail 41 differs from the others due to its size relative to the other geometric details 40. This constitutes an angular reference frame for the fastening device 10. This geometric detail 41 is parallel to the tangential direction Ut in the cylindrical frame of the tire. All the geometric details 40, 41 of this fastening device 10 are parallelepiped elements projecting from the external surface 18 of the retaining wall 12, which ensures that the thickness of the retaining wall 12 is predominantly minimal to prevent any initiation or propagation of cracks during deformation of the retaining wall during the insertion or extraction of the electronic component. If these geometric details 40, 41 were recessed, this would impose an excess thickness on the retaining wall 12, which is detrimental to the Deformation of the retaining wall 12 to iso-material. Functionally, these geometric details must be visible with a suitable shape to define a specific point, which will ensure angular accuracy.
[0047] Fig. 4 presents a top view of an example of an assembly of a fastening device and an electronic component of the arrangement according to the invention.
[0048] In this figure, the fastening device 10 is similar to the fastening device of [Fig.3] with the following differences.
[0049] Here, the number of geometric details 40, 41, although angularly equidistant at an angle X close to 12 degrees, is greater in order to cover a total angular sector 0 of 360 degrees. Distributing the details over the entire retaining wall 12 makes it possible to geometrically define a diameter that facilitates the visual orientation of the electronic component 1 relative to the mounting device 10. Furthermore, the geometric detail 41 defining the angular reference frame of the mounting device is oriented along the axis U of the mounting device 10. However, in this case, this direction U corresponds to the axial direction Y of the tire.
[0050] In this figure, the fluidic cavity of the fastening device 10 accommodates an electronic element 1 of which only the external surface 33 of the encapsulation device is visible. This external surface 33 has an orifice 35 passing through the encapsulation device to a fluidic cavity related to the active part of a fluid parameter measurement sensor such as a pressure sensor and / or a pressure sensor.
[0051] The encapsulation device is circumscribed in a cylindrical axis 31 which is here coaxial with the axis 21 of the fixing device 10.
[0052] Finally, the external surface 33 has on its radial contour a structural detail 34 visible through the opening delimited by the free edge 13 of the retaining wall 12 of the fixing device 10. This structural detail 34 allows the electronic element 1 to be positioned angularly with respect to the angular reference frame of the fixing device 10 defined by the geometric detail 4L. In our case, the angle of rotation is here [3-a]. This ensures that the direction of the vector G of the directional radio frequency antenna of the electronic element, 1, defining an angle a with respect to the direction of the structural detail 34 makes either an angle [3 with respect to the vector U of the fixing device 10, or an angle [3 with respect to the axial direction Y of the tire.
[0053] Fig. 5 presents a three-dimensional view of the radiation pattern of a radio frequency antenna 2 of an example of an electronic component forming part of the arrangement according to the invention.
[0054] The radio frequency antenna 2 is directional here, that is to say that the radiation pattern is predominantly oriented towards a specific spatial region of space relative to the radio frequency antenna 2, that is to say that in this region, the Radio frequency communication is better in transmission / reception compared to the rest of the space surrounding the radio frequency antenna 2.
[0055] 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 is identified, corresponding to the maximum radio frequency transmission / reception amplitude of the main lobe.
[0056] An orthonormal coordinate system is defined, consisting of the plane 50 of the printed circuit board 5 of the electronic component and the normal 31 to this plane 50. The vector G is decomposed in this orthonormal coordinate system into two distinct projections. A first projection along the normal 31 to the plane 50, which is generally called the "elevation," and a second projection onto the plane 50, which is simply the orthogonal projection of the vector G along the axis 31 of the encapsulation device of the electronic component onto the plane 50. This projection defines a center 51 and an endpoint 52, which is the orthogonal projection of the endpoint of the vector G onto the plane 50. The structural detail 34 of the encapsulation device is also projected along the axis 31 of the encapsulation device onto the plane 50, which defines the point 53 on the plane 50.Here, the structural detail 34 protrudes from the second surface 33 of the electronic component encapsulation device, represented by its dotted outline.
[0057] Finally, the angle α described by the intersection of two lines d and d' in plane 50 is calculated. Line d passes through the center 51 and the endpoint 52, while line d' passes through the intersection of axis 31 with plane 50 and point 53, which is the orthogonal projection of structural detail 34 onto plane 50. The orientation of angle α is evaluated in the trigonometric direction with respect to the normal 31 running away from the plane of the printed circuit board 5 towards the second surface 33 of the electronic component, originating on plane 50. Here, the value of angle α is therefore negative.
[0058] Similarly, if the electronic element is equipped with a sensor for measuring the physical parameter of the movement of the electronic element along a direction D contained in the plane 50. This measurement direction D describes a straight line d” in the plane 50. 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 34 with respect to the intersection of the axis 31 with the plane 50. The orientation of the angle [3 is evaluated in the trigonometric direction with respect to the normal 31 moving away from the plane of the printed circuit board 5 towards the second surface 33 of the electronic element, taking its origin on the line d'.
[0059] Figure 6 shows a cross-section of a tire 100 in perspective of the arrangement according to the invention, comprising a vertex S extended by two sidewalls F and terminating in two bead 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 bead ridges B. This defines a closed cavity, containing at least one pressurized fluid, bounded 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.
[0060] 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.
[0061] 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.
[0062] This tire 100 has a fastening device 10 on its radially inner surface 130. This fastening device is attached to the surface 130 by bonding using conventional prior art techniques when the fastening device 10 is made of an elastomeric material. The fastening device 10 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 from the tire casing 100. Indeed, the fastening device 10 is located in an area away from the ridges B of the tire casing 100. Here, the fastening device 10 is equipped with an electronic component 1 positioned within its open volume, which provides a suitable housing for the electronic component. Therefore, the tire casing 100 is ready to be mounted on a wheel to form a complete assembly.Electronic component 1 can deliver. Various functions are performed, such as the identification of certain components like the electronic unit itself and the tire. To orient the electronic unit relative to the mounting device to account for the orientations of the electronic unit's components, the mounting device 10 must be positioned angularly with respect to the Frenet frame associated with the material point, which is the projection of the axis of the mounting device onto the inner surface 130 of the tire. The geometric detail with a specific cross-section, defining the angular origin of the mounting device 10, is positioned on the outer surface of the mounting device's retaining wall so that the line perpendicular to the axis of the mounting device 10 and passing through this geometric detail is parallel to the axis of rotation 201 of the tire 100, for example.
[0063] However, the electronic component 1 can also be equipped with a pressure and / or temperature sensor to evaluate the inflation pressure or the temperature of the fluidic cavity of the assembled vehicle. Finally, it can also be equipped with a sensor that directly measures the curvature of the tire, 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 the performance of the tire and therefore of the assembled vehicle, such as its wear, grip, or intrinsic properties of the surface on which the vehicle is traveling.
Claims
1. Demands Arrangement of a tire (100) equipped with a fastening device (10) and an electronic device (1) for tire: - The tire (100) having an axis of rotation (201), being delimited by an external surface (140) radially outward and an internal surface (130) radially inward, and comprising a top (S) intended to come into contact with a ground, two sidewalls (F) located on either side of the top (S) and extended by two ridges (B) intended to come into contact with a wheel rim; - The tire (100) being equipped with a fastening device (10), located on the inner surface (130) of the tire (100), and capable of deformation, the fastening device (10) comprising a base (11), the outer surface of which is in contact with the tire (100), and a closed retaining wall (12), said retaining wall (12) extending from the base (11) to a free edge (13) and defining with the base (11) an open volume (20), the volume (20) being defined by an inner surface (15) of the base (11) and by an inner surface (16) of cylindrical and convex shape of the retaining wall (12) the axis (21) of which is borne by a radial direction (R) of the tire (100), perpendicular to the axis of rotation (201), said inner surface (16) of the retaining wall (12) having an opening (17) delimited by the free edge (13) of the retaining wall (12); - An electronic component (1) comprising an electronic board (6) including a printed circuit board (5) on which are fixed a power source (4), a microcontroller (3), a radio frequency antenna (2), the electronic board (6) being inserted into an encapsulation device (30) having the shape of a right cylinder with axis (31) normal to the printed circuit board (5), the encapsulation device (30) comprising a first surface (32) intended to be arranged inside the fixing device (10) and a second surface (33) intended to be open to the outside of the fixing device (10); and the arrangement (100) being characterized in that the second surface (33) of the encapsulation device (30) has on its contour a structural detail (34) of revolution about the axis (31) of the encapsulation device (30) and extending axially, in that the retaining wall (12) of the fixing device (10) has on its external surface (18) geometric details (40, 41), angularly equidistant about the axis (21) of the fixing device (10) on an angular sector 0 of the retaining wall (12), in that at least one of the geometric details (41) is arranged such that the line passing through at least one geometric detail and perpendicular to the axis (21) of the retaining wall (12) is parallel to the axial direction vector (201) or to the circumferential direction vector of the cylindrical frame associated with the intersection of the axis (21) of the wall of retention (12) with the internal surface (130) of the tire (100),said geometric detail (41) defining the origin of the angular coordinate system, in that each geometric detail (40,41) and the midpoint between two neighboring geometric details are particular geometric points (43) and in that a radial line perpendicular to the axis (31) of the encapsulation device (30) passing through the structural detail (34) of the second surface (33) of the encapsulation device (30) and a radial line perpendicular to the axis (21) of the retaining wall (12) passing through a particular geometric point of the external surface (18) of the retaining wall (12) are parallel.
2. Arrangement according to claim 1 wherein the geometric details (40, 41) are elements projecting from the external surface (18) of the retaining wall (12) of the fastening device (10).
3. Arrangement according to any one of claims 1 to 2 wherein one of the ends of each geometric detail (40, 41) forms part of the free edge (13) of the retaining wall (12) of the fastening device (10).
4. An arrangement according to any one of claims 1 to 3 wherein the angle X defined between two adjacent geometric details (40,41) is at most 12 degrees.
5. An arrangement according to any one of claims 1 to 4 wherein the geometric details (40) are evenly distributed on either side of the geometric detail (41) defining the origin of the angular reference on an angular sector 0 of at least 120 degrees, preferably on an angular sector 0 of at least 180 degrees, preferably on an angular sector 0 of 360 degrees.
6. An arrangement according to any one of claims 1 to 5 wherein the geometric detail (41) defining the origin of the coordinate system has a specific section in relation to the section of the other geometric details (40).
7. Arrangement according to claim 6 wherein the specific section of the geometric detail (41) defining the origin of the reference frame differs in shape and / or dimension from the section of the other geometric details.
8. An arrangement according to any one of claims 1 to 7 wherein, the electronic board (6) comprising at least one measuring sensor (7) capable of measuring at least two physical parameters of the electronic element (1) along two perpendicular directions contained in the plane (50) of the printed circuit board (5), a first direction D having a constant angle y with respect to the vector perpendicular to the axis (31) of the encapsulation device (30) and passing through the orthogonal projection (53) of the structural detail (34) onto the plane (50) of the printed circuit board (5) and the structural detail (34) of the electronic element (1) aligned with the geometric detail (41) defining the origin of the angular coordinate system of the fastening device (10),The physical parameters of the electronic organ (1) expressed in the direct orthonormal frame associated with the origin of the angular frame of the fixing device (10) are derived from a transformation of the measurements of at least one measuring sensor (7) by a rotation matrix of angle y.
9. An arrangement according to any one of claims 1 to 7 wherein the electronic board (6) comprising at least one measuring sensor (7) capable of measuring at least two physical parameters of the electronic element (1) along two perpendicular directions contained in the plane (50) of the printed circuit board (5), a first direction D having a constant angle y with respect to the vector perpendicular to the axis (31) of the encapsulation device (30) and passing through the orthogonal projection (53) of the structural detail (34) onto the plane (50) of the printed circuit board (5), the structural detail (34) is positioned at an angle - y with respect to the geometric detail (41) defining the origin of the angular reference frame of the fastening device (10).
10. An arrangement according to any one of claims 1 to 9 wherein, the radio frequency antenna (2) of the electronic element (1) being directional and having a maximum gain along a vector G whose orthogonal projection onto the plane (50) of the printed circuit board (5), having a first end (51) and a second end (52) on the plane (50), has a constant angle α with respect to the vector perpendicular to the axis (31) of the encapsulation device (30) passing through the orthogonal projection (53) of the structural detail (34) onto the plane (50) of the printed circuit board, the structural detail (34) is positioned at an angle -α with respect to the geometric detail (41) defining the origin of the angular reference frame of the fixing device (10).
11. Arrangement according to the preceding claim wherein the physical parameters of the electronic element (1) expressed in the direct orthonormal frame associated with the origin of the angular frame of the fastening device (10) are derived from a transformation of the measurements of at least one measuring sensor (7) by a rotation matrix of angle -a.
12. An arrangement according to any one of claims 1 to 9 wherein, the radio frequency antenna of the electronic element (1) being directional and having a maximum gain along a vector G whose orthogonal projection onto the plane (50) of the printed circuit board (5), having a first end (51) and a second end (52) on the plane (50), has a constant angle α with respect to the vector perpendicular to the axis (31) of the encapsulation device (30) passing through the orthogonal projection (53) of the structural detail (34) onto the plane (50) of the printed circuit board, the structural detail (34) is positioned at an angle 90° - α with respect to the geometric detail (41) defining the origin of the angular reference frame of the fixing device (10), α being expressed in degrees.
13. Arrangement according to the preceding claim wherein the physical parameters of the electronic element (1) expressed in the direct orthonormal frame associated with the origin of the angular frame of the fastening device (10) are derived from a transformation of the measurements of at least one measuring sensor (7) by a rotation matrix of angle 90°-a.
14. An arrangement according to any one of claims 1 to 9, in which 1, the radio frequency antenna of the electronic component (1) being directional and having a maximum gain along a vector G whose orthogonal projection onto the plane (50) of the printed circuit (5), having a first end (51) and a second end (52) on the plane (50), has a constant angle a with respect to the vector perpendicular to the axis (31) of the encapsulation device (30) passing through the orthogonal projection (53) of the structural detail (34) onto the plane (50) of the printed circuit, the structural detail (34) is positioned at an angle [3 - a with respect to the geometric detail (41) defining at the origin of the angular frame of the fixing device (10).
15. Arrangement according to the preceding claim wherein the physical parameters of the electronic element (1) expressed in the direct orthonormal frame associated with the origin of the angular frame of the fastening device (10) are derived from a transformation of the measurements of at least one measuring sensor (7) by an angle rotation matrix [3-a.