EP1910103A2

EP1910103A2 - Tire tread support element comprising a recess for an electronic module, and an electronic module adapted thereto

Info

Publication number: EP1910103A2
Application number: EP06764203A
Authority: EP
Inventors: Jean-Charles Lacour; Mickael Résidence les Cézeaux LION; Jonathan Champredonde
Original assignee: Michelin Recherche et Technique SA Switzerland; Michelin Recherche et Technique SA France; Societe de Technologie Michelin SAS
Current assignee: Michelin Recherche et Technique SA Switzerland; Michelin Recherche et Technique SA France; Societe de Technologie Michelin SAS
Priority date: 2005-07-19
Filing date: 2006-07-19
Publication date: 2008-04-16
Also published as: FR2888779A1; US20080295933A1; WO2007010001A2; CN101223045A; WO2007010001A3; JP2009501666A

Abstract

The invention relates to a tread support element (10) of a tire (1) comprising a recess (40) for an electronic module (50) radially opening inside relative to the support. The support element (10) comprises a blocking part (18) for blocking one of the beads (5) of the tire on its wheel seat, and the recess (40) is placed in the part (18) for blocking the bead (5). The recess (40) has an essentially parallelepiped shape and comprises means for holding the electronic module in place, having a number of wedges (401, 402) with triangular cross-sections and placed on the sidewalls (53) of the recess. The support element comprises a tire tread (14) with a set of reinforcements (142). The electronic module is characterized in that the emitting antenna (55) is placed closest to the outer face (52).

Description

Tread support support comprising a housing for an electronic module, adapted electronic module

The present invention relates to a tread support support comprising a housing for an electronic module and a suitable electronic module.

Already known in the state of the art tread support supports comprising housing for electronic modules intended, in particular, for monitoring the pressure of the tires.

EP 0 775 601 B1 discloses a tread support support of a tire intended to be disposed around the bearing surface of a wheel and comprising a housing for an electronically radially inwardly emitting electronic module relatively in support in which the housing is a circumferential groove. The electronic module is held in place by tightening the support on the rim and is protected by two lips of the circumferential groove.

The invention relates to a similar support tread support, characterized in that the housing of the electronic module has a substantially parallelepiped shape and comprises means for holding in place the electronic module comprising a plurality of shims substantially triangular cross section disposed on the side walls of the housing.

Preferably, the shims disposed on the side walls of the housing have a wall intended to come into contact with the electronic module which has a slight undercut.

This against clearance allows to block in position the electronic module without prohibiting its introduction into the housing.

Advantageously, the housing comprises a bottom with a set of bottom ribs. These bottom ribs have the advantage of removing the electronic module from the bottom of the housing and thus to form a layer of air at the bottom of the housing between the support and the electronic module, this layer of air can be used thermal barrier to limit the transmission of calories between the support and the module during a run flat. These ribs also allow, in connection with the shims arranged on the side walls, a constant air flow around the electronic module.

The bottom ribs can be arranged parallel and oriented in the smallest dimension of the bottom of the housing.

This has the advantage of facilitating the fluidic continuity between the air layers separating the different walls of the housing and the electronic module and the tire cavity defined by the rim and the tire.

The bottom of the housing also preferably comprises at least one radial opening for placing in fluid communication the housing with the internal cavity of the tire. These openings or conduits contribute to homogenize the temperature all around the electronic module and its housing.

The invention also relates to a similar support EP 0 775 601 B1 wherein, the support comprising a sole with a set of reinforcements substantially inextensible and oriented substantially circumferentially, none of said circumferential reinforcements is located axially in the housing area.

The circumferential reinforcements are advantageously arranged axially on either side of the housing.

Preferably, the support comprises a support portion for supporting the load of the tire in the event of running flat and an axially adjacent blocking portion for locking one of the beads of the tire on its wheel seat. and the housing is disposed in the bead blocking portion.

The establishment of the electronic module in this part of the support which is not intended to carry the load but only to lock on its seat a bead tire ensures that the mechanical stresses likely to be transmitted to the electronic module during an impact or during a run flat are greatly minimized. This is a longevity factor for this electronic module.

As the locking portion is practically not used to carry the load in the event of running flat, it has a much smaller mass than the support portion of the load and thus a much smaller number of circumferential reinforcements is sufficient for ensure good resistance to centrifugation of the support in this part.

The support of the invention can be used with a wheel in two parts as described in EP 0 363 639. It is preferably intended to be threaded around a wheel rim having a first rim seat of maximum diameter Φsimax, and a second rim seat of maximum diameter Φs2maχ greater than the maximum diameter of said first seat Φsim _a x, the second seat being extended axially towards the first seat by a circumferential groove and a bearing surface whose outside diameter is substantially equal to the maximum diameter of the first seat Φsim _a x- This support is such that the support portion of the support is adapted to be arranged around the bearing surface and the locking portion is adapted to be disposed radially outwardly relative to the circumferential groove.

Similarly, the housing of the electronic module is intended to be disposed radially outwardly relative to the circumferential groove. This enhances the protection of the electronic module in case of shock or run flat.

Preferably, the second seat being extended towards the first seat by a flank of the circumferential groove, the locking portion of the support is adapted to bear against the side of the groove.

According to a very preferred embodiment, the wheel comprises a rim and a disk attached to the rim of the side of said second seat.

[0021] Advantageously, when a tire with a first bead and a second bead is intended to be mounted on the first and second seats of the rim, the second bead having circumferentially oriented reinforcements of outside diameter Φτ2m _a χ, the housing is inscribed in a cylinder of revolution of diameter ΦLmax less than the outside diameter Φτ2maχ-

This further strengthens the mechanical protection of the electronic module in use. Indeed, the bottom of the housing of the module is protected during shocks by the seat of the rim of larger diameter but also by the reinforcements, such as rods, which ensure the maintenance of the bead on its seat in operation because these reinforcements have an outer diameter greater than that of the revolution cylinder in which the housing is inscribed.

The invention also relates to an electronic module intended to be disposed in a housing of a tire tread support support. This electronic module comprises in particular an electronic component support (PCB), a pressure sensor, a transmitter and an emission antenna and is characterized in that it has a substantially parallelepiped shape with an inner face and an outer face and that the electronic component support is arranged closest to the inner face and in that the transmitting antenna is disposed closest to the outer face.

This organization of the components of the electronic module can greatly reduce the total volume of the module while obtaining a good electromagnetic operation.

Advantageously, the antenna is a wire antenna with a U-shape, it is arranged in a plane parallel to the plane defined by the component support (PCB) and it substantially follows the edges of the electronic module.

The area occupied by the U is therefore maximum to emit a maximum of field lines and is as far as possible from the ground plane which corresponds to the component support (PCB) to limit the capacitive coupling with the PCB and improve its performances. This antenna is mechanically fixed to the component support by at least one end.

The antenna consists of a conductor wire and has tuning capabilities so that it resonates at a UHF frequency, for example of the order of 315 MHz.

The fact of using a "wire" antenna and not a metal surface has the advantage of not blocking any low frequency communications useful for transmitting specific instructions to the electronic module, in particular to ask him to transmit more quickly, etc., by means of initiators arranged near the wheel-tire assembly, for example in the wheel arches of the vehicle.

Preferably, the straight sections of the electronic module normal to the outer and inner faces are trapezoidal and the larger surface area is the outer face intended to be disposed radially outwardly relative to the axis of the support.

The inner face preferably has a concavity adapted to the inner profile of the support. This concavity also corresponds to the internal profile of the wheel and significantly improves the mechanical strength of the electronic module in case of heap nests or roll flat.

The side walls of the module thus have an inclination adapted to that of the lateral holding wedges of the housing. The cooperation of the two allows excellent retention of the electronic module in its housing whatever the driving conditions.

Advantageously, the pressure sensor is in fluid communication with the outside of the module by a chimney opening into the outer face.

This outer face is intended to be disposed against the bottom of the housing. The bottom ribs cooperate with the shims of the side walls and the throat circumferential circumference to ensure fluidic continuity and good pressure and temperature measurements where applicable.

Other features and advantages of the invention appear from the description given hereinafter with reference to the accompanying drawings which show, by way of non-limiting examples, embodiments of the subject of the invention:

- Figure 1 shows a partial meridian sectional view of a support assembly, sensor, rim and tire according to the invention;

- Figure 2 shows a partial view of a support according to the invention illustrating the position of the housing; - Figure 3 shows a partial meridian sectional view of a support illustrating the support partitions of the support of Figure 1;

- Figure 4 shows a meridian sectional view of the housing of the support of Figure i;

- Figure 5 is similar to Figure 4 including the electronic module; - Figures 6 and 7 show schematic views of an electronic module according to the invention illustrating the position and shape of the main electronic components; and

- Figure 8 is a partial longitudinal sectional view of the support including the electronic module.

By meridian or axial plane is meant any plane passing through the axis A of the wheel and the rim and in longitudinal or circumferential section a section through a plane perpendicular to the axis of rotation A of the wheel, the rim and support.

In Figure 1 is shown, seen in partial meridian section or axial, a support assembly 10, 20 rim and tire 1 according to the invention. The rim 20 forms with a disc 21 a monoblock wheel. The disc can also be manufactured independently of the rim and joined thereafter. The rim 20 comprises a first seat 22 and a second seat 24 intended to serve as a bearing surface for the first 3 and second 5 beads of the tire 1. The first seat 22 comprises a frustoconical bottom 221 locally confused with a cone of revolution coaxial with the rim and open towards the second seat 24, a safety boss 222 extending the bottom 221 of the first seat 22 towards the second seat 24, and an outer edge 223 extending the bottom 221 of the first seat away from the second seat 24. The maximum diameter of the first seat 22 is Φsim _a x- This diameter corresponds to the maximum diameter of the safety boss 222.

The second seat 24 comprises a frustoconical bottom 241 locally confused with a cone of revolution coaxial with the rim and open towards the first seat 22, a safety boss 242 extending the bottom 241 of the second seat 24 to the first seat 22 and an outer edge 243 extending the bottom 241 of the second seat on the opposite side to the first seat 22. The maximum diameter of the second seat 24 is Φs2m _a χ- This diameter corresponds to the maximum diameter of the safety boss 242.

The maximum diameter of the second seat is greater than that of the first seat. In the example shown, the order of magnitude of the difference between the maximum diameters Φs2maχ - Φsimax is of the order of 20 mm. The gap between the minimum radii of the two seats is therefore of the order of 10 mm.

From the first seat 22 to the second seat 24, there is successively a circumferential groove 26, a bearing surface 28 and a second circumferential groove 30. The second circumferential groove 30 serves as a mounting groove for the second seat 24. The groove 30 includes a flank 301 adjacent to the safety boss 242. On the bearing surface 28 is a circumferential groove 281. The outer diameter of the bearing surface 28 substantially corresponds to the maximum diameter of the first seat 22 to allow to put the support 10 on this bearing surface 28 by crossing the first seat 22.

The tire 1 comprises two beads 3 and 5 intended to bear on the seats 22 and 24 of the rim 20, two sidewalls 7 and a tread 9. Each bead comprises annular reinforcements oriented substantially circumferentially and substantially inextensible . These reinforcements, such as rods 4 and 6, are intended for ensure in service the maintenance of the beads on the rim seats. The rod 6 of the bead 5 of the second seat 24 has an outside diameter Φτ2maχ-

The support 10 essentially comprises:

a substantially cylindrical apex 12 intended to come into contact with the tread 9 of the tire 1 in the event of loss of pressure, and leaving a guard with respect thereto at the nominal pressure,

- A substantially cylindrical sole 14 intended to fit around the rim 20, this sole comprises a plurality of wedges 141 arranged circumferentially, of substantially half-cylindrical section and intended to cooperate with the groove 281 to lock in position the support 10 on the bearing surface 28 of the rim 20, and

- An annular body 16 connecting the sole 14 and the top 12, this body comprises a set of partitions Y-shaped 160 substantially radially connecting the sole and the top and oriented substantially axially from one side to the other of the support .

This support comprises a housing 40 which opens radially internally relative to the support and which is intended to receive an electronic module 50. Such an electronic module is part of a tire pressure monitoring system such as the one presented. in WO 94/20317. The electronic module periodically measures the air pressure and temperature values of the cavity formed by the tire and the rim and periodically sends these values to a central unit where these values are analyzed and processed.

The sole 14 comprises circumferentially oriented reinforcements such steel son or high modulus textile reinforcements such as aramid. Their function is to oppose centrifugal forces sustained by the support during high speed running to allow the support to remain in abutment against the bearing surface without moving circumferentially. These reinforcements not shown in the figure are arranged axially on either side of the housing 40.

Figure 1 shows the tire assembly 1, support 10 and 20 mounted rim. It can be seen that the support is arranged around the bearing surface 28 of the rim 20 and extends axially radially externally relative to the groove 30 to abut against the flank 301 of this groove 30. The portion of the support disposed around the bearing surface 28 is the so-called "support"portion; it is this support portion 17 which carries the load mainly during a run flat with contact between the tread of the tire and the top of the support. The portion of the support disposed around the groove 30 is said "blocking" part. This blocking portion 18 serves to house the housing 40 and to lock in position on its seat 24 the second bead 5 of the tire 1. This anti-decoupling function of the locking portion 18 of the support completes the action. similar to the security boss 242 of the second seat 24.

It should be noted that the housing is inscribed in a cylinder of diameter of revolution ΦLm _a x- This diameter is greater than that of the adjacent seat 24 but is less than that of the bead wire 6 of the bead 5 1. In Consequently, during a particularly violent shock, the electronic module will be protected by the bead of the tire.

Figure 2 shows a view of the radially inner wall of the support including the housing 40. In this view we see the wedges 141 for locking the support on the bearing surface 28 and the ends of the partitions 160 of the annular body 16 on the side of the locking portion 18.

Figure 3 shows a view of the support in which the top 12 and the radially outer part of the partitions 160 have been removed. The partitions 160, in the example shown, have a general Y shape. The partitions 170 of the support portion 17 correspond to the V part of the Y. These partitions 170 are slightly inclined relative to the axial direction. The partitions 180 of the locking portion 18 correspond to the I-portion of the Y. Their direction is substantially axial. The thickness of the partitions 170 is significantly greater than that of the partitions 180 because of their load bearing function. It can be seen in these two figures 2 and 3 that the housing 40 extends circumferentially on two Y patterns. Figure 4 shows an axial section similar to that of Figure 1 but on a larger scale. This figure is centered on the housing 40. The side walls of the housing 40 have a slight clearance relative to the radial direction to facilitate the demolding of the support. We distinguish the blocking wedges 401 disposed on the two side walls of greater length. These wedges have a substantially triangular section that gives a slight undercut. This undercut has the function of allowing the locking in position of the electronic module 50. We also see the wedges 402 arranged on the side walls of the housing of smaller length. These wedges have the same geometry and the same function as the wedges 401. There is also a wedge 403 disposed on the bottom surface of the housing 40. This wedge is oriented parallel to the axis of the support. Its function is to separate the module from the bottom of the housing to create a layer of air that can freely circulate through the side shims. This air layer has a role of thermal protection barrier of the electronic module in use. It also allows the pressure sensor disposed in the electronic module to be in fluid communication with the cavity created by the tire and the rim to make correct measurements of the inflation pressure of the tire.

In the sole 14 of the support 10 are shown schematically the son circumferentially oriented reinforcements 142. These son are arranged on either side of the housing 40. The cut is made to the right of a partition 180 of the blocking part 18.

Figure 5 is identical to Figure 4 with just the module shown in the locking position. The module 50 has a trapezoidal section in axial section and in circumferential section, that is to say in a plane perpendicular to the axial plane passing through the housing 40. The wall of the smaller surface electronic module 51 is disposed radially internally relatively to the axis of the support that is to say is arranged facing the groove 30 of the rim. The wall of the larger surface electronic module 52 is disposed radially outwardly and is thus in contact with the wedges 403 disposed on the bottom of the housing. The side walls 53 have a slight against draft adapted to that of the wedges 401 and 402 to obtain effective blocking of the electronic module in use.

Figure 8 shows a longitudinal section of the support at the housing 40 with the electronic module 50 in the locking position. This FIG. 8 shows that the housing 40 extends axially over a distance corresponding to two Y patterns. Section three is seen in section 180. The housing 40 comprises three axially oriented bottom blocks 403 and two lateral shims 402. There are also two holes 404 disposed in the bottom wall of the housing to put in fluid communication the housing and the internal cavity of the tire. This figure also shows that the inner wall of the module 50 has a concavity adapted to the concavity of the support 10. This concavity significantly improves the fatigue strength and shocks of the electronic module.

The thicknesses of the partitions 170 and 180 are adapted so that near the azimuth of the housing 40, there is no change in the radial rigidity of the tread support support. Likewise at 180 ° of the housing 40, the geometry of the support is modified to balance the static unbalance of the support support.

The tread support support may be made of elastomeric materials, including rubber but also polyurethane elastomer PU or thermoplastic TPE. In all cases, the exact geometry of the blocking wedges of the electronic module will be adapted to allow easy assembly and disassembly of the module while maintaining excellent locking in the service position. In particular, it is possible to adapt the axial and circumferential widths of the shims as a function of the modulus of the material constituting the support.

Figures 6 and 7 show a side view and from above an electronic module according to the invention. These two views present the main electronic elements that make up the electronic module before their incorporation in a packaging such as a housing or a coating resin. The electronic module 50 comprises a PCB electronic components support 54, a UHF emission antenna 55, a pressure sensor 57 with a cylindrical chimney 58 intended to put in fluid communication the sensitive part of the sensor 57 with the pneumatic cavity defined by the tire and the rim, a battery 56, two receiving antennas LF 59 and several other components 60 such as the RF transmitter and a microprocessor for processing data and signals received and transmitted.

The support of electronic components PCB 54 is disposed substantially at the inner face of the module which is intended to be placed on the radially inner side of the housing 40 of the support support 10. The UHF emission antenna is disposed substantially at the outer surface 52 of the module 50. This outer face is intended to be disposed on the radially outer side of the housing 40 of the support support 10.

The transmitting antenna 55 is a U-shaped wire antenna and mechanically connected to the PCB by its ends. This antenna is mainly arranged in the plane of the outer face, the plane furthest radially from the plane defined by the ground plane of the module constituted by the PCB. This limits the capacitive coupling between the two and thus improve the performance of the antenna.

The area occupied by the U is almost maximal to capture a maximum of field lines.

The antenna consists of a conductive wire, such as a unitary copper wire. It is connected to the circuit of the module via appropriate tuning capabilities to make it resonate at a frequency of the order of 315 MHz, by way of example.

The advantage of a wire antenna instead of a patch antenna is that it is the perimeter of the antenna surface that is used to transmit the UHF waves, which makes it possible not to block communications. low frequencies and allows the passage of the chimney 58. It should be noted that the support assembly and module according to the invention has been subjected to extended tests of rolling flat and sidewalk or pothole impact tests and that at the end of those The electronic module was still in good working order.

The invention is not limited to the examples described and shown and various modifications can be made without departing from its scope only limited by the following claims.

Claims

1. Support (10) for tread support of a tire (1) intended to be arranged around the bearing surface (28) of a rim (20) and comprising a housing (40) for a module electronics (50) opening radially inwardly relative to said support, characterized in that said housing (40) has a substantially parallelepipedal shape and comprises means for holding in place said electronic module comprising a plurality of wedges (401, 402) of cross-section substantially triangular disposed on the side walls (53) of said housing.

2. Support (10) according to claim 1, wherein said shims (401, 402) disposed on the side walls (53) of said housing (40) have a wall intended to come into contact with said electronic module with a slight undercut .

3. Support (10) according to one of claims 1 and 2, wherein said housing (40) comprises a bottom with a set of bottom ribs (403).

4. Support (10) according to claim 3, wherein said bottom ribs (403) are arranged parallel and oriented along the smallest dimension of said bottom of said housing.

5. Support (10) according to one of claims 3 and 4, wherein the bottom comprises at least one radial opening (404) for putting in fluid communication housing (40) with the internal cavity of the tire.

6. Support (10) for tread support of a tire (1) intended to be arranged around the bearing surface of a rim (20) and comprising a housing (40) for an electronic module (50). ) opening radially internally relative to said support, characterized in that said support comprising a sole (14) with a set of reinforcements (142) substantially inextensible and oriented substantially circumferentially, none of said circumferential reinforcements (142) is located axially in the area of said housing.

7. Support (10) according to claim 6, wherein said circumferential reinforcements (142) are arranged axially on either side of said housing (40).

8. Support (10) according to any one of claims 1 to 7, wherein, said support (10) comprising a support portion (17) for supporting the load of said tire in the event of running flat and a portion axially adjacent blocking (18) for blocking one of the beads (5) of said tire on its wheel seat (24), the housing (40) is disposed in the locking portion (18) of the bead (5).

9. Support (10) according to claim 8, intended to be threaded around a wheel rim (20) having a first seat (22) rim (20) of maximum diameter Φsim _a x, and a second seat (24). ) rim of maximum diameter Φs2m _a χ greater than the maximum diameter of said first seat Φsim _a x, said second seat being extended axially towards the first seat by a circumferential groove (30) and a bearing surface (28) whose outer diameter is substantially equal to the maximum diameter of the first seat Φsim _a x, wherein said support portion (17) of said support is adapted to be disposed around said bearing surface (28) and said locking portion (18) is adapted to being disposed radially outwardly relative to said circumferential groove (30).

10. Support (10) according to claim 9, wherein said housing (40) is intended to be arranged radially outwardly relative to said circumferential groove (30).

11. Support (10) according to one of claims 9 and 10, wherein said second seat (24) being extended towards the first seat (22) by a flank (301) of said circumferential groove (30), said portion of blocking (18) of said support is adapted to bear against said side (301) of said groove (30).

12. Support (10) according to one of claims 9 to 11, wherein said wheel comprises a rim (20) and a disk (21) connected to said rim on the side of said second seat (24).

13. Support (10) according to claim 12, wherein, a tire (1) with a first bead (3) and a second bead (5) being intended to be mounted on said first (22) and second (24) seats of said rim, said second bead (5) having circumferentially oriented reinforcements (6) of outside diameter Φτ2m _a χ, said housing (40) is inscribed in a cylinder of revolution of diameter ΦLm _a x less than said outside diameter Φτ2maχ-

The support (10) according to claim 13, wherein said circumferential reinforcements (6) of said second bead (5) are a bead wire.

15. Electronic module (50) intended to be arranged in a housing (40) of a support (10) according to one of claims 1 to 14, said electronic module including an electronic component support (54), a sensor pressure transmitter (57), an emitter and a transmitting antenna (55), characterized in that the electronic module has a substantially parallelepipedal shape with an inner face (51) and an outer face (52) and that the support of electronic components (54) is arranged closest to the inner face (51) and in that the transmitting antenna (55) is arranged closest to the outer face (52).

The electronic module (50) of claim 15, wherein said antenna (55) is a U-shaped wire antenna and wherein said antenna substantially follows the edges of said outer face (52).

The electronic module (50) of claim 16, wherein said antenna (55) is mechanically attached to said component carrier (54) by at least one end.

18. Electronic module (50) according to one of claims 15 to 17, such that the straight sections of said normal module audited outer (52) and inner (51) are trapezoidal.

19. Electronic module (50) according to claim 18, wherein the larger surface area is the outer face (52) intended to be disposed radially outwardly relative to the axis A of said support.

20. Electronic module (50) according to one of claims 15 to 19, wherein the inner face (51) has a concave shape adapted to the inner profile of the support.

21. Electronic module (50) according to one of claims 15 to 20, wherein said pressure sensor (57) is in fluid communication with the outside of said module by a chimney (58) opening into said outer face (52). .