WO2021191166A1 - Device for measuring tyre pressure - Google Patents

Device for measuring tyre pressure Download PDF

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Publication number
WO2021191166A1
WO2021191166A1 PCT/EP2021/057313 EP2021057313W WO2021191166A1 WO 2021191166 A1 WO2021191166 A1 WO 2021191166A1 EP 2021057313 W EP2021057313 W EP 2021057313W WO 2021191166 A1 WO2021191166 A1 WO 2021191166A1
Authority
WO
WIPO (PCT)
Prior art keywords
channel
volume
housing
electronic card
face
Prior art date
Application number
PCT/EP2021/057313
Other languages
French (fr)
Inventor
Julien DESTRAVES
Lionel Fagot-Revurat
Eric BAILLY
Antoine Canu
David Vera
Eric-Carin NEBA
Michaël ARNOUX
Original Assignee
Safran
Safran Electronics & Defense
Safran Landing Systems
Compagnie Generale Des Etablissements Michelin
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FR2002782A external-priority patent/FR3108402B1/en
Priority claimed from FR2002783A external-priority patent/FR3108403B1/en
Application filed by Safran, Safran Electronics & Defense, Safran Landing Systems, Compagnie Generale Des Etablissements Michelin filed Critical Safran
Publication of WO2021191166A1 publication Critical patent/WO2021191166A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L17/00—Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
    • B60C23/0422—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver characterised by the type of signal transmission means
    • B60C23/0433—Radio signals
    • B60C23/0447—Wheel or tyre mounted circuits
    • B60C23/0452—Antenna structure, control or arrangement
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0491—Constructional details of means for attaching the control device
    • B60C23/0493—Constructional details of means for attaching the control device for attachment on the tyre
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
    • G01L19/02—Arrangements for preventing, or for compensating for, effects of inclination or acceleration of the measuring device; Zero-setting means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
    • G01L19/14—Housings
    • G01L19/142—Multiple part housings
    • G01L19/143—Two part housings
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
    • G01L19/14—Housings
    • G01L19/148—Details about the circuit board integration, e.g. integrated with the diaphragm surface or encapsulation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/2208—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems
    • H01Q1/2241—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems used in or for vehicle tyres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
    • H01Q9/20—Two collinear substantially straight active elements; Substantially straight single active elements
    • H01Q9/22—Rigid rod or equivalent tubular element or elements

Definitions

  • the present invention relates to a device for measuring the pressure of a tire intended to be fitted to an aircraft.
  • an aircraft wheel comprises a rim and a tire received on the rim, the rim and the tire delimiting an interior volume filled with a pressurized gas.
  • the regulations require that the pressure of the gas enclosed in the tire be measured at least once a day. If the tire is under-inflated, the airplane is not authorized to take off.
  • the pressure measurement of the gas enclosed in the tire is generally carried out manually using a pressure gauge connected to an inflation valve integral with the rim and in communication with the interior volume.
  • Tires are known equipped with a pressure measuring device on board inside the tire and intended to facilitate maintenance operations on the ground.
  • the pressure measuring device collects digital data relating to the pressure of the gas enclosed in the tire and transmits this data by radio waves to a reader arranged remotely, without having to touch the tire or perform any manual operation.
  • Such a pressure measuring device generally comprises a housing extending around an electronic card provided with a pressure sensor and electronic components distributed on the same face of the electronic card.
  • the housing comprises channels placing the pressure sensor in fluid communication with the outside and ensuring filtering of the gas enclosed in the tire. However, this filtering may prove to be insufficient to effectively protect the pressure sensor and the electronic components against particles present in the gas.
  • the object of the invention is therefore to propose a pressure measuring device making it possible to obviate at least in part the aforementioned problem.
  • a measuring device comprising:
  • an electronic circuit which is distributed over at least a first face of an electronic card and which comprises a pressure sensor mounted on the first face of the electronic card and comprising a mechanical protective cover defining a sealed enclosure at a reference pressure ;
  • a first housing part at least partially covering the first face in order to define therewith a first volume and comprising at least a first channel placing the first volume in fluid communication with the outside;
  • a second housing part at least partially covering a second face of the electronic card in order to define therewith a second volume and having a bottom intended to extend opposite an internal surface of the tire.
  • the electronic card comprises at least a second through channel placing the first volume in fluid communication with the second volume, and a third through channel placing the enclosure delimited by the cowling 35 in fluid communication with the second volume.
  • the first channel carries out a first filtering of the gas enclosed in the tire, while a second filtering of the gas is carried out by the second channel during its passage from the first volume to the second volume before its entry into the enclosure defined by the pressure sensor cover.
  • first channel and the second channel have a generally constant circular section, the diameter of the first channel being greater than that of the second channel.
  • first channel and the second channel have a generally constant circular section, the diameter of the first channel being smaller than that of the second channel.
  • the third channel has a generally constant circular section, the diameter of the third channel being greater than that of the second channel.
  • the diameter of the second channel is between 100 and 300 micrometers.
  • the diameter of the second channel is equal to 200 micrometers.
  • the second housing part is arranged such that the device has a center of gravity located in the second volume at a distance from the electronic card.
  • the device comprises at least a first antenna strand comprising one end galvanically connected to the electronic circuit and extending entirely in lateral projection of the housing, the housing comprising a projecting lateral portion substantially tangent to a proximal end section. of the first strand along a generatrix of said first strand.
  • the housing is generally cylindrical in shape.
  • the invention also relates to a tire comprising such a pressure measuring device.
  • the invention also relates to a wheel comprising such a tire.
  • the invention further relates to an aircraft landing gear comprising at least one such wheel.
  • FIG. 1A is a perspective view of a pressure measuring device according to a first embodiment of the invention
  • FIG. 1B is a schematic sectional view of the pressure measuring device illustrated in FIG. 1
  • FIG. 1C is a detail view of the electronic card of the pressure measuring device illustrated in FIG. 1;
  • FIG. 2 is a partial schematic sectional view of an aircraft wheel provided with the pressure measuring device illustrated in Figures IA, IB, IC;
  • - Figure 3 is a perspective view of a first variant of the pressure measuring device illustrated in Figures IA, IB, IC;
  • FIG. 4 is a perspective view of a second variant of the pressure measuring device illustrated in Figures IA, IB, IC;
  • FIG. 5 is a schematic sectional view of a third variant of the pressure measuring device illustrated in FIGS. IA, IB, IC;
  • FIG. 6 is a schematic sectional view of a fourth variant of the pressure measuring device illustrated in FIGS. IA, IB, IC;
  • FIG. 7 is a schematic sectional view of a fifth variant of the pressure measuring device illustrated in FIGS. IA, IB, IC;
  • FIG. 8 is a schematic sectional view of a pressure measuring device according to a second embodiment of the invention;
  • FIG. 9A is a perspective view of a pressure measuring device according to a third embodiment of the invention
  • FIG. 9B is a schematic sectional view of the pressure measuring device illustrated in FIG. 9A, housed in an elastomeric material
  • FIG. 9C is a top view of the electronic card of the pressure measuring device illustrated in FIG. 9A;
  • FIG. 10 is a perspective view of the pressure measuring device illustrated in FIG. 9B;
  • FIG. 11 is a perspective view of a patch made of elastomeric material making it possible to fix the overmolded pressure measuring device illustrated in FIG. 10 on an internal surface of a tire;
  • FIG. 12 is a schematic sectional view of an aircraft wheel provided with the pressure measuring device illustrated in FIG. 10 which is fixed to an internal surface of the tire using the patch illustrated in FIG. 11;
  • FIG. 13A is a first example of a spring antenna for the pressure measuring device illustrated in FIG. 9A;
  • FIG. 13B is a second example of a spring antenna for the pressure measuring device illustrated in FIG. 9A;
  • FIG. 14A is a perspective view of a variant of the pressure measuring device illustrated in FIG. 9A;
  • FIG. 14B is a schematic sectional view of the pressure measuring device illustrated in FIG. 14A;
  • FIG. 15A is a perspective view of a pressure measuring device according to a fourth embodiment of the invention;
  • FIG. 15B is a schematic sectional view of the pressure measuring device illustrated in FIG. 15A;
  • FIG. 16A is a perspective view of a variant of the pressure measuring device illustrated in FIG. 15A;
  • - Figure 16B is a schematic sectional view of the pressure measuring device illustrated in Figure 15A.
  • a pressure measuring device 1 according to a first embodiment of the invention comprises a housing 10 made of phenolic resin, here generally in the form of a right cylinder, extending along a vertical Z axis.
  • the housing 10 comprises a first part 10.1 and a second part 10.2 arranged on either side of an electronic card 20 extending in a horizontal XY plane.
  • the first part 10.1 of the housing 10 defines with a first face 20.1 of the electronic card 20 a first so-called “dirty” volume VI and forms a cover comprising an upper surface 11 of planar shape.
  • the first part 10.1 of the housing comprises first channels 12 putting the first volume VI in fluid communication with the outside.
  • the second part 10.2 of the housing 10 defines with a second face 20.2 of the electronic card 20 a second so-called “clean” volume V2 and forms a cover comprising a bottom 13 of planar shape.
  • the second part 10.2 of the housing 10 comprises an outer annular groove 14 forming a means for gripping the pressure measuring device 1 and delimiting with the bottom 13 an outer lateral surface 15 which is substantially convex in shape.
  • the outer lateral surface 15 has a profile having, in a plane passing through the Z axis, a first flat zone 15.1 and a second flat zone 15.2 slightly inclined with respect to each other but also with respect to the Z axis.
  • the first part 10.1 and the second part 10.2 of the housing 10 respectively have, along the Z axis, a height H1 and a height H2. It will be noted that the height H1 of the first part 10.1 is less than the height H2 of the second part 10.2 and that the volume VI is less than the volume V2.
  • the electronic card 20 comprises second through channels 21 placing the first volume VI in fluid communication with the second volume V2.
  • the second channels 21 have a circular section, the diameter of which is between 100 and 300 micrometers, preferably 200 micrometers.
  • the first channels 12 have a circular section, the diameter of which is here smaller than that of the second channels 21 so as to promote the circulation of air between the first volume VI and the second volume V2 and thus obtain better pressure dynamics between said first and second volume VI, V2.
  • an electronic circuit is distributed over the first face 20.1 and the second face 20.2 of the electronic card 20.
  • the electronic circuit comprises a pressure sensor 30, a radio transmitter / receiver 31, a microcontroller 32, a electromagnetic energy recuperator 33 and a battery 34.
  • the pressure sensor 30 and the radio transmitter / receiver 31 are mounted on the first face 20.1 of the electronic card 20 and extend into the first volume VI.
  • the microcontroller 32, the energy recovery 33 and the battery 34 are mounted on the second face 20.2 of the electronic card 20 and extend into the second volume V2.
  • the pressure sensor 30 comprises a mechanical protection cover 35 defining a sealed enclosure. a reference pressure.
  • the pressure sensor 30 is here a piezoelectric sensor comprising a membrane 36 which extends parallel to the first face 20.1 of the electronic card 20 and which is provided with a first electrode 37.1.
  • An upper part of the cowling 35 constitutes a second electrode 37.2 of a capacitor.
  • a third channel 22 passing through the electronic card 20 puts the enclosure delimited by the cowling 35 in fluid communication with the second volume V2.
  • the third channel 22 has a circular section, the diameter of which is here substantially equal to that of the second channels 21.
  • the energy recuperator 33 comprises a converter which converts the captured kinetic energy into electrical energy and sends it to the battery 34 for storage.
  • the energy recuperator 33 here comprises a ball made of ferromagnetic material which can move freely in the air gap of a coil.
  • the battery 34 supplies the microcontroller 32 and the radio transmitter / receiver 31.
  • the second channels 21 are provided with a metallic coating 23 obtained by metallization.
  • Each metallic coating 23 is connected to a pole of the battery 34, here a positive pole.
  • a ring 24 extends around each metal coating 23 at a non-zero distance therefrom.
  • Each ring 24 is here produced by depositing copper in a groove 25 machined in the electronic card 20 and is connected to a first pole of the battery 34, here a negative pole.
  • the ring 24 extends substantially set back from the first face 20.1 of the electronic card 20 in order to create a retention zone.
  • the electronic card 20 further comprises a first lateral portion 26.1 and a second portion 26.2 extending in lateral projection on either side of the housing 10 along a horizontal X axis perpendicular to the Z axis.
  • first portion 26.1 and the second portion 26.2 extends a wire or an antenna track 27.1, 27.2 connected to the radio transmitter / receiver
  • the first portion 26.1 and the second portion 26.2 are of substantially identical shape and are here triangular in shape.
  • the pressure measuring device 1 is placed inside a wheel R of an aircraft landing gear.
  • the wheel R comprises a rim J on which is mounted a tire P defining with the rim J an internal volume V filled with nitrogen under pressure.
  • a connecting element 40 made of elastomeric material makes it possible to fix the pressure measuring device 1 on an internal surface of a tread of the tire P and to at least partially absorb the shocks and the deformations undergone by said tire P when that - here rolls.
  • the connecting element 40 comprises a base 41 substantially of frustoconical shape, the large base of which is adhesively connected to the internal surface of the tread of the tire P and the small base of which forms a bottom 42.1 of a receptacle 42 of overall cylindrical shape.
  • the receptacle 42 comprises a side wall 42.2 having an internal surface arranged to cooperate with the external lateral surface 15 of the second part 10.2 of the housing 10, and an opening 42.3 for inserting the second housing part 10.2 of the measuring device 1. pressure in the receptacle 42.
  • the opening 42.3 is delimited by an annular flange 42.4 arranged to be engaged in the outer annular groove 14 so as to immobilize and retain said second housing part 10.2 in the receptacle 42.
  • the aircraft is equipped with a radio transmitter / receiver tuned to transmit and receive frequencies of the radio transmitter / receiver 31 of the pressure measuring device 1.
  • the pressurized air contained in the internal volume V defined by the rim J and the tire P enters through the first channels 12 of the housing 10 into the first volume VI.
  • the first channels 12 carry out a first filtering of the particles (dust, filings, grain of sand, etc.) which may be present in the internal volume V.
  • a second filtering of the air is carried out by the second channels 21 as it passes through the air.
  • the air present in the second volume V2 then enters the enclosure defined by the cowling 35 of the pressure sensor 30 and acts on the membrane 36. Under the effect of the air pressure prevailing in the enclosure, the membrane 36 is deformed and the capacitance of the capacitor associated with said membrane 36 is modified.
  • An analog-to-digital converter integrated into the microcontroller 32 converts the capacitance of the capacitor into a pressure value which is then sent to the radio transmitter / receiver of the aircraft using the radio transmitter / receiver 31 of the device 1 of pressure measurement.
  • the battery 34 establishes a voltage between the metal coating 23 of the second channels 21 and the copper rings 24 which surround it, carrying out a vaporization by electrolysis of the water which could come to obstruct the second channels 21.
  • the diameter of the second channels 21 promotes water retention by capillary action and helps prevent the passage of moisture from the air contained in the wheel R to the second volume V2.
  • the retention of moisture in the second channels 21 and the water electrolysis device make it possible to limit the presence of water on the membrane 36 and to protect the pressure measuring device 1 from the detrimental consequences of freezing when l aircraft is in flight. In Indeed, the presence of frozen water on the membrane 36 generally renders the pressure sensor 30 inoperative and most often causes its destruction.
  • the energy recuperator 33 converts the kinetic energy to which the device 1 is subjected into electrical energy which is stored in the battery 34.
  • the electronic card 20 is linked to the first part
  • the glue has a hardness of between 30 shore 00 and 60 shore A.
  • the pressure measuring device 1 to have a center of gravity G located in the second volume V2, at a distance from the electronic card 20.
  • the center of gravity G is located substantially on the central Z axis of the housing 10.
  • the pressure measuring device 1 makes it possible to limit the amplitude of the relative movements between the receptacle 42 and said pressure measuring device 1 caused during the rolling of the vehicle. wheel R, and therefore to limit the deterioration of the connecting element 40 of the device 1 stuck on the tread of the tire P.
  • the angular displacement of the device 1 is also limited, limiting the risk of the antenna striking the internal surface of the tire.
  • FIG. 3 illustrates a device 2 which is a first variant of the device 1 illustrated in FIGS. IA, IB, IC.
  • the pressure measuring device 2 differs from the device 1 in that the housing 10 comprises lugs formed by a first protuberance 16.1 and a second protuberance 16.2 which project sideways from an upper end of the second part 10.2 of the casing 10.
  • the first protuberance 16.1 and the second protuberance 16.2 are of substantially identical shape and cooperate with the second face 20.2 of the electronic card 20 at the level of the first portion 26.1 and the second portion 26.2 so as to limit the bending of said first and second portions 26.1, 26.2 caused by the rotation of the wheel R under the effect of their own weight.
  • FIG. 4 illustrates a device 3 which is a second variant of the device 1 illustrated in FIGS. IA, IB, IC.
  • the pressure measuring device 3 differs from the device 1 in that the first part 10.1 of the housing forms a cover having an upper surface 11 of convex shape outwardly while retaining a lower surface of planar shape. The length of the first channels 12 is thereby increased.
  • the domed upper surface 11 of the first part 10.1 of the housing 10 and the increase in the length of the first channels 12 makes it possible to limit the accumulation of pollutant in the immediate vicinity of the inlet orifices of the first channels 12.
  • FIG. 5 illustrates a device 4 which is a third variant of the device 1 illustrated in Figures IA, IB, IC.
  • the pressure measuring device 4 differs from the device 1 in that the first part 10.1 of the housing comprises an upper portion 11 of generally frustoconical shape having a flat upper wall traversed by the first channels 12 and connected to a frustoconical wall.
  • the addition of a slope to the upper portion 11 makes it possible, as for the device 3, to limit the accumulation of pollutant in the immediate vicinity of the inlet openings of the first channels 12.
  • FIG. 6 illustrates a pressure measuring device 5 which is a fourth variant of the device 1 illustrated in FIGS. IA, IB, IC.
  • the device 5 differs from the device 4 in that the first channels 12 cross obliquely the frustoconical wall of the upper portion 11.
  • the first channels 12 open inside the first volume VI through an orifice which is further from the card. electronic 20 as the inlet orifice through which they open to the outside of the volume VI.
  • the positioning of the first channels 12 makes it possible to limit the accumulation of pollutants in the immediate vicinity of the inlet openings of the first channels 12.
  • FIG. 7 illustrates a pressure measuring device 6 which is a fifth variant of the device 1 illustrated in FIGS. IA, IB, IC.
  • the device 6 differs from the device 1 in that the first channels 12 extend parallel to the first face 20.1 of the electronic card 20, which makes it possible, as for devices 3 to 5, to limit the accumulation of pollutant to immediate proximity to the inlet openings of the first channels 12.
  • FIG. 8 illustrates a device 7 for measuring pressure according to a second embodiment of the invention.
  • the device 7 differs from the device 1 in that the outer side surface 15 of the second part 10.2 of the housing 10 has an enlarged diameter in the vicinity of the bottom 13, so that the projected surface of the first part 10.1 of the housing 10 on the first face 20.1 of the electronic card 20 along the Z axis is inscribed in the projected surface of the second part 10.2 of the housing 10 on the same face 20.1 and along the same Z axis, the volume V2 remaining unchanged.
  • the center of gravity G is now located closer to the bottom 13 of the housing 10 than to the second face 20.2 of the electronic card 20.
  • the second housing part 10.2 thus includes an external bulge in the vicinity of the bottom. 13, a bulge which is matched by the wall of the receptacle 42 to ensure the attachment of the second housing part 10.2 to the internal surface of the tire.
  • FIGS. 9A, 9B, 9C illustrate a device 100 for measuring pressure according to a third embodiment of the invention.
  • the device 100 comprises a housing 110 made of phenolic resin, here generally in the form of a straight cylinder, extending along a vertical Z axis.
  • the housing 110 comprises a first part 110.1 and a second part 110.2 arranged on either side of an electronic card 120 extending in a horizontal XY plane.
  • the housing 110 thus defines an enclosure in which the electronic card 120 extends at least in part.
  • the first part 110.1 of the housing 110 defines a first volume VI with a first face 120.1 of the electronic card 120 and forms a cover having a surface upper plane.
  • the first part 110.1 of the housing comprises first through channels 111 placing the first volume VI in fluid communication with the outside.
  • the first channels 111 have a circular section, the diameter of which is between 0.2 and 1.5 millimeters, preferably 1 millimeter.
  • the second part 110.2 of the housing 110 delimits a second volume V2 with a second face 120.2 of the electronic card 120 opposite the first face 120.1, and forms a container having a bottom of planar shape.
  • the connection between the housing 110 and the electronic card 120 is arranged so as to allow relative movement between said housing. 110 and said electronic card 120, for example via a bead of flexible silicone-based adhesive.
  • the electronic card 120 comprises second channels 123 putting the first volume VI in fluid communication with the second volume V2.
  • the second channels are arranged in fluid communication with the second volume V2.
  • 123 have a circular section, the diameter of which is between 100 and 300 micrometers, preferably 200 micrometers.
  • an electronic circuit extends over the first face 120.1 of the electronic card 120 and comprises a passive pressure sensor 130 (substantially identical to the pressure sensor 30), a radio transmitter / receiver 131, a microcontroller 132, an electromagnetic energy recuperator and a battery (not shown).
  • the pressure sensor 130, the radio transmitter / receiver 131, the microcontroller 132, the electromagnetic energy recuperator and the battery are mounted on the first face 120.1 of the electronic card 120 and extend into the first volume VI.
  • the pressure sensor 130 comprises a mechanical protection cover 135 defining a sealed measurement enclosure.
  • the pressure sensor 130 is here a piezoresistive sensor comprising a membrane which extends substantially parallel to the first face 120.1 of the electronic card 120.
  • the sensor here is an electromechanical microsystem (or MEMS) with a Wheatstone bridge.
  • a third channel 124 passes through the electronic card 120 and places the enclosure delimited by the cowling 135 in fluid communication with the second volume V2.
  • the energy harvester includes a converter that converts the captured kinetic energy into electrical energy and sends it to the battery for storage.
  • the energy recovery here comprises a ball made of ferromagnetic material which can move freely in the air gap of a coil.
  • the battery powers the microcontroller and the radio transceiver.
  • the second channels 123 are provided with a metallic coating (not shown) obtained by metallization. Each metallic coating is connected to a pole of the battery, here a positive pole.
  • a ring (not shown) extends around each metal coating at a non-zero distance therefrom.
  • Each ring is produced here by depositing copper in a groove machined in the electronic card 120 and is connected to a first pole of the battery, here a negative pole.
  • the ring extends substantially set back from the first face 120.1 of the electronic card 120 in order to create a retention zone.
  • the electronic card 120 comprises a first pair of arms 121.1 extending as a lateral projection from the housing 110 along a horizontal X axis perpendicular to the Z axis.
  • the first pair of arms 121.1 forms a first notch.
  • the first strand 140.1 consists of a steel wire wound in a spring form helical at a pitch P and extends as a lateral projection from the housing 110 along the X axis. The projection of the first strand
  • the electronic card 120 further comprises a second notch 122.2 formed by a second pair of arms 121.2 identical to the first pair of arms 121.1 and being the opposite of said first pair of arms 121.1.
  • One end of a second strand 140.2 of identical spring antenna extends inside the second notch 122.2 and is galvanically connected to the radio transmitter / receiver 131.
  • the first strand 140.1 and the second strand 140.2 are substantially identical and constitute a dipole antenna.
  • the second housing part 110.2 comprises a first lug 112.1 projecting along the X axis.
  • the first lug 112.1 extends partly facing the first notch 122.1 and comprises a horizontal internal face 113.1 coming substantially tangent to a first section 141.1 of the first strand 40.1.
  • Two first fingers 114.1 extend parallel along the Z axis from a free end of the internal face 113.1 extending beyond the first notch 122.1 and form a space for receiving a second section 142.1 of the first strand
  • the first fingers 114.1 comprise an internal surface coming substantially vertically tangent to the second section 142.1 of the first strand 140.1.
  • the second housing part 110.2 further comprises a second protruding ear 112.2 identical to the first ear 112.1 and arranged opposite to said first ear 112.1.
  • the second lug 112.2 extends partly opposite the second notch 122.2 and comprises a horizontal upper face 113.2 coming substantially tangent to a first section 141.2 of the second strand 140.2.
  • Two second fingers 114.2 extend parallel along the Z axis from a free end of the upper face 113.2 extending beyond the second notch 122.2 and form a space for receiving a second section 142.2 of the second strand 140.2 .
  • Second fingers 114.2 include an interior surface coming substantially vertically tangent to the second section
  • the first ear 112.1 and the second ear 112.2 thus extend outside the enclosure delimited by the housing 110.
  • the second section 142.1 of the first strand 140.1 and the second section 142.2 of the second strand 140.2 respectively have a pitch smaller than that of the first section 141.1 of the first strand 140.1 and of the first section 141.2 of the second strand 140.2.
  • This difference in pitch makes it possible to increase in service the number of contact points between the strands 140.1, 140.2 and the second part 110.2 of the casing during the movement of said strands 140.1, 140.2, and therefore to reduce the local stresses to which the casing is subjected. 110, especially on the fingers
  • the device 100 is covered with a protective envelope 150 made of an elastomeric material, preferably crosslinking at a temperature below 100 ° C, for example based on polysiloxane or silicone, such as that called "silastene" which is an elastomeric material made from silicone.
  • the protective envelope 150 covers the first strand 140.1, the second strand 140.2, the housing 110 and the parts of the electronic card 20 not covered by the housing 110.
  • the protective envelope 150 electrically isolates the device 100 in that the electrical conductivity of the elastomeric material is below its threshold for percolation of the conductive charges, which improves the performance of the antenna in terms of transmission and reception.
  • the dielectric permittivity of the elastomer material will preferably be less than 10, advantageously less than 6, and very preferably less than 3, as is the case for “silastene”, the dielectric permittivity of which is equal to 2.83.
  • the elastomeric material is first deposited on the housing 110 in a semi-liquid state in order to facilitate the molding of the mechanical and electronic components of the device 100 and to allow air to escape, in particular at the level of the antenna strands 140.1, 140.2, the geometry of which favors the formation of air bubbles.
  • the elastomeric material is then stiffened during a crosslinking step preferably carried out at a temperature below 100 ° C. in order to avoid any deterioration of the electronic components.
  • the protective casing 50 is intimately linked in a homogeneous manner to the various mechanical and electronic components, which ensures robust performance of the antenna and of the anchoring of the mechanical and electronic components within of the protective enclosure 150.
  • the anchoring of the mechanical and electronic components within the protective envelope 150 is carried out in the absence of adhesion phenomenon in order to improve the endurance of the protective envelope 150, and therefore of the device 1, by minimizing the stress concentration at the origin of cracking phenomena.
  • Such anchoring is obtained by using a silicone-based elastomer such as "silastene” which is chemically inert with many materials.
  • the choice of elastomeric material depends on the material of the antenna strands 140.1, 140.2 with which the protective casing 50 will be in contact.
  • the “silastene” makes it possible for example to avoid this phenomenon of adhesion with strands 140.1, 140.2 of antenna made entirely of steel or having an outer coating layer of brass.
  • the protective envelope 150 is arranged to completely envelop the device 1 and limit the deformation of the antenna strands 140.1, 140.2 due to stresses external to the device 1, in particular along the X axis. Indeed, the elasticity of the antenna. elastomeric material allows movement of the antenna strands 140.1, 140.2 while limiting them, and limits the forces passing through said antenna strands 140.1, 140.2.
  • the envelope thus makes it possible to reduce the deflections of the antenna with respect to the air and to the stops of the lateral portions, and to offer other paths of the stresses and deformations resulting from the stresses exerted on the antenna in service. . A concentration of stresses is thus avoided by promoting homogenization of the latter over a larger surface.
  • the protective casing 150 makes it possible to reduce the stresses undergone in service by the strands 140.1, 140.2, in particular at the level of their galvanic link with the radio transmitter / receiver
  • the device 100 thus protected is placed inside a wheel R of an aircraft.
  • the wheel R comprises a rim J on which is mounted a tire P defining with the rim J an internal volume V filled with pressurized air.
  • a connecting patch 160 made of elastomeric material makes it possible to fix the device 1 covered with the protective casing 150 on an internal surface of the tire P, in particular on a sidewall of said tire. tire P.
  • the patch covers the device 100 and part of the internal surface around said device, while the bottom of the second part 110.2 of the housing 110 extends in the vicinity of the internal surface of the tire P.
  • the material in which is produced, the patch 160 is not cohesive with that in which the protective envelope 150 is made, which allows the device 100 to be reused, for example in another tire.
  • the aircraft is equipped with a radio transmitter / receiver tuned to transmission and reception frequencies of the radio transmitter / receiver 131 of the pressure measuring device 100.
  • the pressurized air contained in the internal volume V defined by the rim J and the tire P enters, via the first channels 111 of the housing 110, into the first volume VI.
  • the first channels 111 perform a first filtering of the particles at the inlet of the internal volume V.
  • a second filtering of the air is performed by the second channels 123 during the passage of the air from the first volume VI to the second volume V2.
  • the air present in the second volume V2 then enters the enclosure defined by the cowling 135 of the pressure sensor 130 via the third channel 124 and acts on the membrane.
  • An analog-to-digital converter built into the microcontroller 132 converts the capacitance of the capacitor into a pressure value which is then sent to the aircraft's radio transmitter / receiver using the radio transmitter / receiver 131 of the device 100. pressure measurement.
  • the first lug 112.1 and the second lug 112.2 of the housing 110 oppose, during the rotation of the tire P, deformations of the first sections 141.1, 141.2 and of the second sections 142.1, 142.2 of the strands 140.1, 140.2. They therefore make it possible to limit the stresses locally close to the proximal ends of said strands 140.1, 140.2 which are galvanically connected to the radio transmitter / receiver 31. The risks of breaking the strands 140.1, 140.2 at their connection with the electronic card 120 are thus limited.
  • FIGS. 13A and 13B respectively illustrate the dimensional characteristics of a first version and of a second version of right-wound strand 140.1, 140.2 here offering a good compromise between mechanical endurance and transmission / reception performance.
  • the strand 140.1, 140.2 has, by way of example, the following dimensional characteristics:
  • a first section comprising a turn extending over a length L1 equal to 1.1 mm;
  • a second section comprising five turns extending over a length L2 equal to 3.5 mm;
  • a third section comprising thirty turns extending over a length L3 equal to 33 mm;
  • the strand 140.1, 140.2 has, by way of example, the following dimensional characteristics: a diameter d ′ of wire equal to 0.225 mm; an outer winding diameter D 'equal to 1.8 mm; a total winding length L 'equal to 34.1 mm; a first section comprising a turn extending over a length L1 ′ equal to 1.1 mm; a second section comprising five turns extending over a length L2 ′ equal to 3.5 mm; a third section comprising thirty turns extending over a length L3 ′ equal to 27 mm; a rectilinear end portion of length l equal to 5 mm.
  • the first and third sections have a P / D ratio of less than 0.7.
  • the second section has a lower P / D ratio than that of the first and third sections.
  • FIGS. 14A and 14B illustrate a pressure measuring device 100 'which is a variant of the device 100 illustrated in FIG. 9A.
  • the device 100 ' differs from the device 100 in that the first ear 112.1' and the second ear 112.2 'are carried by the first part 110.1 of the housing 110 and not by the second part 110.2 of the housing 110.
  • FIGS. 15A and 15B illustrate a device 101 for measuring pressure according to a second embodiment of the invention.
  • the device 101 differs from the devices 100, 100 'in that the first part 110.1 and the second part 110.2 of the housing 110 each comprise two projecting ears 112.1, 112.1', 112.2, 112.2 'which extend two by two facing the 'one from the other.
  • the ears 112.1 ', 112.2' comprise an external surface extending the upper face of the housing 110 and the ears 112.1, 112.2 comprise an external surface extending the bottom of the housing 110.
  • the ears 112.1 ′, 112.2 ′ comprise a through hole forming an anchoring of the protective casing 150 to the casing 110, the elastomeric material of the protective casing 150 not adhering to the resin of the casing 110.
  • FIGS. 16A and 16B illustrate a pressure measuring device 101 'which is a variant of the device 101 illustrated in FIG. 15A.
  • the pressure measuring device 101 ' differs from the device 101 in that the outer surfaces of the ears 112.1', 112.2 'extend away from the upper surface of the housing 110.
  • the position of the device 1 in the casing of protection 150 is also modified.
  • the pressure measuring device comprises a phenolic resin housing
  • the invention also applies to other types of housings such as for example a metal case, carbon fiber, epoxy or other material.
  • housing is cylindrical in shape
  • the invention applies to other forms of housing such as for example an ovoid, parallelepiped or any shape.
  • the invention also applies to other types of connection between the case and the electronic card allowing relative movement. of the case and of the electronic card, such as for example a synthetic or natural gasket of the rubber or EPDM type.
  • first channels, the second channels and the third channel have a circular section
  • the invention also applies to first channels, second and / or a third channel of different section such as for example a square section or other.
  • the pressure measuring device comprises a microcontroller
  • the invention also applies to other signal processing means such as for example an FPGA, logic gates or a microprocessor.
  • the invention applies to all means for connecting the components to the electronic circuit, such as for example by wire connections, soldering / brazing, pinning or sintering on a support of the PCB type.
  • the invention applies to any means of connecting components to the electronic circuit such as for example by wire connections, soldering / brazing, pinning or sintering on a support of the PCB type.
  • the pressure measurement device comprises a radio transmitter / receiver (for example of the “RFID” type)
  • the invention applies to all types of wireless transmission techniques such as for example a 2G, 3G protocol. , 4G, 5G, “LoRa”, “edge”, “Wi-Fi”, “Bluetooth”, ultrasound or “IOT” type. Provision will be made to integrate a battery into the pressure measuring device if it is necessary to power the transmitter / receiver.
  • the pressure measuring device comprises an electromagnetic energy converter
  • the invention also applies to other types of energy converters such as for example an inductive kinetic energy converter or of the piezoelectric type or a thermal energy converter.
  • the measuring device is placed in an aircraft wheel
  • the invention also applies to other vehicles such as, for example, trucks or automobiles.
  • the tire is filled with nitrogen under pressure
  • the invention also applies to tires filled with other types of pressurized fluid such as, for example, air or inert gases other than nitrogen.
  • the pressure sensor is of the piezoelectric type
  • the invention also applies to other types of pressure sensors such as for example a resistive, inductive, piezoresistive, capacitive or resonant sensor.
  • the second channels are provided with a metallic coating obtained by metallization
  • the invention also applies to other means of applying a metallic coating to the second channels, such as for example a crimping of a metal jacket or the application of conductive paint.
  • the second channels may be devoid of a metallic coating.
  • the invention also applies to other type of conductive element placed at proximity of the second channel such as for example a ring of square or any shape, a metallization of the surface of the first electronic card or a printing using a conductive ink.
  • the pressure measuring device comprises a battery
  • the invention also applies to other types of voltage generator such as for example a battery or a capacitor.
  • the invention also applies to a reversal of the connection polarities.
  • the invention also applies to other types of connection between the housing and the electronic card such as for example one or more elastomeric pads extending from the first surface of the electronic card up to the first part of the housing and one or more elastomeric pads extending from the second surface of the electronic card to the second face of the housing.
  • first portion and the second portion of the electronic card extending outside the housing are rigid portions which carry an antenna
  • the first and second portions may also be flexible and / or contain other types of elements. conductors in relation to the components which are under the housing.
  • the electronic card is fixed to the housing using beads of flexible silicone-based glue
  • the invention also applies to other types of connection between the housing and the electronic card allowing a relative movement of the case and of the electronic card, such as for example a synthetic or natural gasket of the rubber or EPDM type.
  • the pressure measuring device can also include a temperature sensor for transmitting the temperature and / or for performing a temperature compensation of the measurement of the pressure sensor.
  • the temperature measurement can be carried out by a dedicated sensor or even be measured on a piezoresistive sensor by measuring the input resistance of the sensitive element or by any other combination of resistances of a piezoresistive sensor whose result does not would provide only an image of the temperature, that of the pressure being eliminated in the combination produced (resistors working in longitudinal or transverse direction giving respectively positive and negative gauging factors).
  • the protective envelope 150 may only partially cover the first and / or the second antenna.
  • the shape of the first and second portions of the electronic card is triangular in shape
  • the invention also applies to any other shape, such as, for example, portions of rectangular shape.
  • the base can also bear directly on said internal surface of the tread.
  • the bottom of the housing 110 can bear directly against the internal surface of the tire or indirectly via an interface such as a fixing or decoupling interface.
  • the measuring device comprises a pressure and / or temperature sensor, it can also include any type of sensor allowing measurement of an operating parameter of the tire such as a angular position, rotational speed, acceleration, magnetic field, humidity, corrosion ...
  • the volume VI can be equal to or greater than the volume V2 provided that the center of gravity G is located below the electronic card 20. It could for example be envisaged that the bottom 13 of the second part 10.2 of the housing 10 is thicker by so as to lower the center of gravity G and that the resulting volume V2 is substantially equal to the volume VI.
  • the diameter of the first channels 12 may be greater than that of the second channels 21 so as to improve the filtration of the air passing from the first volume VI to the second volume V2 to the detriment of its circulation between said first volume VI and the second volume V2 .
  • the diameter of the third channel 22 may be greater than that of the second channels 21 so that none of the particles filtered by the second channels 21 is able to block the third channel 22.
  • the electronic circuit may include other electronic components. instead of and / or in addition to the electronic components 31, 32, 33, 34. However, the so-called “critical” components, that is to say those liable to be damaged by particles contained in the internal volume V (dust, filings, grain of sand, etc.), will preferably be distributed over the second face 20.2 of the electronic card 20, in other words in the second volume V2, so as to benefit from the double filtration carried out by the first channels 12 and the second channels 21.

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
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  • Measuring Fluid Pressure (AREA)

Abstract

The invention relates to a pressure measuring device for a tyre, comprising: - an electronic circuit distributed over at least one first face of an electronic board and comprising a pressure sensor mounted on the first face of said electronic board and having a mechanical protective cowling defining a sealed enclosure at a reference pressure; - a first housing part covering the first face such that together they delimit a first volume, and comprising a first channel fluidically connecting the first volume to the outside; and - a second housing part covering a second face of the electronic board such that together they delimit a second volume, and having a base designed to extend with respect to an inner surface of the tyre; the electronic board comprising at least one second channel fluidically connecting the first volume to the second volume, and a third channel fluidically connecting the enclosure delimited by the cowling to the second volume.

Description

DISPOSITIF DE MESURE DE PRESSION D' UN PNEUMATIQUE TIRE PRESSURE MEASUREMENT DEVICE
La présente invention concerne un dispositif de mesure de pression d'un pneumatique destiné à équiper un aéronef. The present invention relates to a device for measuring the pressure of a tire intended to be fitted to an aircraft.
ARRIERE PLAN DE L'INVENTION Classiquement, une roue d'aéronef comprend une jante et un pneumatique reçu sur la jante, la jante et le pneumatique délimitant un volume intérieur rempli d'un gaz sous pression. La réglementation impose de mesurer la pression du gaz enfermé dans le pneumatique au moins une fois par jour. En cas de sous gonflage du pneumatique, l'avion n'est pas autorisé à décoller. BACKGROUND OF THE INVENTION Conventionally, an aircraft wheel comprises a rim and a tire received on the rim, the rim and the tire delimiting an interior volume filled with a pressurized gas. The regulations require that the pressure of the gas enclosed in the tire be measured at least once a day. If the tire is under-inflated, the airplane is not authorized to take off.
La mesure de pression du gaz enfermé dans le pneumatique est en général effectuée manuellement à l'aide d'un manomètre raccordé sur une valve de gonflage solidaire de la jante et en communication avec le volume intérieur. The pressure measurement of the gas enclosed in the tire is generally carried out manually using a pressure gauge connected to an inflation valve integral with the rim and in communication with the interior volume.
On connaît des pneumatiques équipés d'un dispositif de mesure de pression embarqué à l'intérieur du pneumatique et destiné à faciliter les opérations de maintenance au sol. Le dispositif de mesure de pression récolte des données numériques concernant la pression du gaz enfermé dans le pneumatique et transmet ces données par ondes radioélectriques à un lecteur agencé à distance, sans avoir besoin de toucher le pneumatique ou d'effectuer une quelconque opération manuelle. Un tel dispositif de mesure de pression comprend généralement un boîtier s'étendant autour d'une carte électronique pourvue d'un capteur de pression et de composants électroniques répartis sur une même face de la carte électronique. Le boîtier comporte des canaux mettant en communication fluidique le capteur de pression avec l'extérieur et assurant un filtrage du gaz enfermé dans le pneumatique. Cependant, ce filtrage peut s'avérer insuffisant pour protéger efficacement le capteur de pression et les composants électroniques contre des particules présentes dans le gaz. OBJET DE L'INVENTION Tires are known equipped with a pressure measuring device on board inside the tire and intended to facilitate maintenance operations on the ground. The pressure measuring device collects digital data relating to the pressure of the gas enclosed in the tire and transmits this data by radio waves to a reader arranged remotely, without having to touch the tire or perform any manual operation. Such a pressure measuring device generally comprises a housing extending around an electronic card provided with a pressure sensor and electronic components distributed on the same face of the electronic card. The housing comprises channels placing the pressure sensor in fluid communication with the outside and ensuring filtering of the gas enclosed in the tire. However, this filtering may prove to be insufficient to effectively protect the pressure sensor and the electronic components against particles present in the gas. OBJECT OF THE INVENTION
L'invention a donc pour objet de proposer un dispositif de mesure de pression permettant d'obvier au moins en partie au problème précité. RESUME DE L’INVENTION The object of the invention is therefore to propose a pressure measuring device making it possible to obviate at least in part the aforementioned problem. SUMMARY OF THE INVENTION
A cet effet, on prévoit, selon l'invention, un dispositif de mesure comprenant : To this end, there is provided, according to the invention, a measuring device comprising:
- un circuit électronique qui est réparti sur au moins une première face d'une carte électronique et qui comprend un capteur de pression monté sur la première face de la carte électronique et comportant un capotage de protection mécanique définissant une enceinte étanche à une pression de référence ; an electronic circuit which is distributed over at least a first face of an electronic card and which comprises a pressure sensor mounted on the first face of the electronic card and comprising a mechanical protective cover defining a sealed enclosure at a reference pressure ;
- une première partie de boîtier recouvrant au moins partiellement la première face pour délimiter avec celle-ci un premier volume et comportant au moins un premier canal mettant en communication fluidique le premier volume avec l'extérieur ; et a first housing part at least partially covering the first face in order to define therewith a first volume and comprising at least a first channel placing the first volume in fluid communication with the outside; and
- une deuxième partie de boîtier recouvrant au moins partiellement une deuxième face de la carte électronique pour délimiter avec celle-ci un deuxième volume et possédant un fond destiné à s'étendre en regard d'une surface interne du pneumatique. a second housing part at least partially covering a second face of the electronic card in order to define therewith a second volume and having a bottom intended to extend opposite an internal surface of the tire.
Selon l'invention, la carte électronique comporte au moins un deuxième canal traversant mettant en communication fluidique le premier volume avec le deuxième volume, et un troisième canal traversant mettant en communication fluidique l'enceinte délimitée par le capotage 35 avec le deuxième volume. Ainsi, le premier canal réalise un premier filtrage du gaz enfermé dans le pneumatique, tandis qu'un second filtrage du gaz est réalisé par le deuxième canal lors de son passage du premier volume vers le deuxième volume avant son entrée dans l'enceinte définie par le capotage du capteur de pression. Un tel dispositif permet ainsi de réaliser une double filtration protégeant le capteur de pression des particules présentes dans le gaz. According to the invention, the electronic card comprises at least a second through channel placing the first volume in fluid communication with the second volume, and a third through channel placing the enclosure delimited by the cowling 35 in fluid communication with the second volume. Thus, the first channel carries out a first filtering of the gas enclosed in the tire, while a second filtering of the gas is carried out by the second channel during its passage from the first volume to the second volume before its entry into the enclosure defined by the pressure sensor cover. Such a device thus makes it possible to perform double filtration to protect the pressure sensor from particles present in the gas.
De manière particulière, le premier canal et le deuxième canal ont une section circulaire globalement constante, le diamètre du premier canal étant supérieur à celui du deuxième canal. In particular, the first channel and the second channel have a generally constant circular section, the diameter of the first channel being greater than that of the second channel.
De manière particulière, le premier canal et le deuxième canal ont une section circulaire globalement constante, le diamètre du premier canal étant inférieur à celui du deuxième canal. In particular, the first channel and the second channel have a generally constant circular section, the diameter of the first channel being smaller than that of the second channel.
De manière particulière, le troisième canal a une section circulaire globalement constante, le diamètre du troisième canal étant supérieur à celui du deuxième canal. In particular, the third channel has a generally constant circular section, the diameter of the third channel being greater than that of the second channel.
De manière particulière, le diamètre du deuxième canal est compris entre 100 et 300 micromètres. In particular, the diameter of the second channel is between 100 and 300 micrometers.
De préférence, le diamètre du deuxième canal est égal à 200 micromètres. Preferably, the diameter of the second channel is equal to 200 micrometers.
De manière particulière, la deuxième partie de boîtier est agencée de telle manière que le dispositif ait un centre de gravité situé dans le deuxième volume à distance de la carte électronique. In particular, the second housing part is arranged such that the device has a center of gravity located in the second volume at a distance from the electronic card.
De manière particulière, le dispositif comprend au moins un premier brin d'antenne comportant une extrémité galvaniquement reliée au circuit électronique et s'étendant intégralement en saillie latérale du boîtier, le boîtier comprenant une portion latérale en saillie tangentant sensiblement un tronçon d'extrémité proximal du premier brin selon une génératrice dudit premier brin. In particular, the device comprises at least a first antenna strand comprising one end galvanically connected to the electronic circuit and extending entirely in lateral projection of the housing, the housing comprising a projecting lateral portion substantially tangent to a proximal end section. of the first strand along a generatrix of said first strand.
De manière particulière, le boîtier est de forme globalement cylindrique. In particular, the housing is generally cylindrical in shape.
L'invention concerne également un pneumatique comprenant un tel dispositif de mesure de pression. The invention also relates to a tire comprising such a pressure measuring device.
L'invention concerne aussi une roue comprenant un tel pneumatique. L'invention concerne en outre un train d'atterrissage d'aéronef comprenant au moins une telle roue. The invention also relates to a wheel comprising such a tire. The invention further relates to an aircraft landing gear comprising at least one such wheel.
L'invention sera mieux comprise à la lumière de la description qui suit, laquelle est purement illustrative et non limitative. The invention will be better understood in the light of the following description, which is purely illustrative and not limiting.
BREVE DESCRIPTION DES DESSINS Il sera fait référence aux dessins annexés, parmi lesquels : BRIEF DESCRIPTION OF THE DRAWINGS Reference will be made to the accompanying drawings, among which:
- la figure IA est une vue en perspective d'un dispositif de mesure de pression selon un premier mode de réalisation de l'invention ; la figure IB est une vue en coupe schématique du dispositif de mesure de pression illustré à la figure 1 ; la figure IC est une vue de détail de la carte électronique du dispositif de mesure de pression illustré à la figure 1 ; FIG. 1A is a perspective view of a pressure measuring device according to a first embodiment of the invention; FIG. 1B is a schematic sectional view of the pressure measuring device illustrated in FIG. 1; FIG. 1C is a detail view of the electronic card of the pressure measuring device illustrated in FIG. 1;
- la figure 2 est une vue schématique partielle en coupe d'une roue d'aéronef pourvu du dispositif de mesure de pression illustré aux figures IA, IB, IC ; - la figure 3 est une vue en perspective d'une première variante du dispositif de mesure de pression illustré aux figures IA, IB, IC ; - Figure 2 is a partial schematic sectional view of an aircraft wheel provided with the pressure measuring device illustrated in Figures IA, IB, IC; - Figure 3 is a perspective view of a first variant of the pressure measuring device illustrated in Figures IA, IB, IC;
- la figure 4 est une vue en perspective d'une deuxième variante du dispositif de mesure de pression illustré aux figures IA, IB, IC ; la figure 5 est une vue en coupe schématique d'une troisième variante du dispositif de mesure de pression illustré aux figures IA, IB, IC ; la figure 6 est une vue en coupe schématique d'une quatrième variante du dispositif de mesure de pression illustré aux figures IA, IB, IC ; la figure 7 est une vue en coupe schématique d'une cinquième variante du dispositif de mesure de pression illustré aux figures IA, IB, IC ; la figure 8 est une vue en coupe schématique d'un dispositif de mesure de pression selon un deuxième mode de réalisation de l'invention ; - Figure 4 is a perspective view of a second variant of the pressure measuring device illustrated in Figures IA, IB, IC; FIG. 5 is a schematic sectional view of a third variant of the pressure measuring device illustrated in FIGS. IA, IB, IC; FIG. 6 is a schematic sectional view of a fourth variant of the pressure measuring device illustrated in FIGS. IA, IB, IC; FIG. 7 is a schematic sectional view of a fifth variant of the pressure measuring device illustrated in FIGS. IA, IB, IC; FIG. 8 is a schematic sectional view of a pressure measuring device according to a second embodiment of the invention;
- la figure 9A est une vue en perspective d'un dispositif de mesure de pression selon un troisième mode de réalisation de l'invention ; la figure 9B est une vue en coupe schématique du dispositif de mesure de pression illustré à la figure 9A, logé dans un matériau en élastomère ; - la figure 9C est une vue de dessus de la carte électronique du dispositif de mesure de pression illustré à la figure 9A ; FIG. 9A is a perspective view of a pressure measuring device according to a third embodiment of the invention; FIG. 9B is a schematic sectional view of the pressure measuring device illustrated in FIG. 9A, housed in an elastomeric material; FIG. 9C is a top view of the electronic card of the pressure measuring device illustrated in FIG. 9A;
- la figure 10 est une vue en perspective du dispositif de mesure de pression illustré à la figure 9B ; - la figure 11 est une vue en perspective d'un patch en matériau élastomère permettant de fixer le dispositif de mesure de pression surmoulée illustré à la figure 10 sur une surface interne d'un pneumatique ; FIG. 10 is a perspective view of the pressure measuring device illustrated in FIG. 9B; FIG. 11 is a perspective view of a patch made of elastomeric material making it possible to fix the overmolded pressure measuring device illustrated in FIG. 10 on an internal surface of a tire;
- la figure 12 est une vue schématique en coupe d'une roue d'aéronef pourvue du dispositif de mesure de pression illustré à la figure 10 qui est fixé sur une surface interne du pneumatique à l'aide du patch illustré à la figure 11 ;FIG. 12 is a schematic sectional view of an aircraft wheel provided with the pressure measuring device illustrated in FIG. 10 which is fixed to an internal surface of the tire using the patch illustrated in FIG. 11;
- la figure 13A est un premier exemple d'antenne à ressort pour le dispositif de mesure de pression illustré à la figure 9A ; FIG. 13A is a first example of a spring antenna for the pressure measuring device illustrated in FIG. 9A;
- la figure 13B est un deuxième exemple d'antenne à ressort pour le dispositif de mesure de pression illustré à la figure 9A ; FIG. 13B is a second example of a spring antenna for the pressure measuring device illustrated in FIG. 9A;
- la figure 14A est une vue en perspective d'une variante du dispositif de mesure de pression illustré à la figure 9A ; la figure 14B est une vue en coupe schématique du dispositif de mesure de pression illustré à la figure 14A ; - la figure 15A est une vue en perspective d'un dispositif de mesure de pression selon un quatrième mode de réalisation de l'invention ; la figure 15B est une vue en coupe schématique du dispositif de mesure de pression illustré à la figure 15A la figure 16A est une vue en perspective d'une variante du dispositif de mesure de pression illustré à la figure 15A ; - la figure 16B est une vue en coupe schématique du dispositif de mesure de pression illustré à la figure 15A. FIG. 14A is a perspective view of a variant of the pressure measuring device illustrated in FIG. 9A; FIG. 14B is a schematic sectional view of the pressure measuring device illustrated in FIG. 14A; FIG. 15A is a perspective view of a pressure measuring device according to a fourth embodiment of the invention; FIG. 15B is a schematic sectional view of the pressure measuring device illustrated in FIG. 15A; FIG. 16A is a perspective view of a variant of the pressure measuring device illustrated in FIG. 15A; - Figure 16B is a schematic sectional view of the pressure measuring device illustrated in Figure 15A.
DESCRIPTION DETAILLEE DE L'INVENTION En référence aux figures IA et IB, un dispositif 1 de mesure de pression selon un premier mode de réalisation de l'invention comprend un boîtier 10 en résine phénolique, ici globalement en forme de cylindre droit, s'étendant selon un axe Z vertical. Le boîtier 10 comporte une première partie 10.1 et une deuxième partie 10.2 agencées de part et d'autre d'une carte électronique 20 s'étendant dans un plan XY horizontal. DETAILED DESCRIPTION OF THE INVENTION Referring to Figures IA and IB, a pressure measuring device 1 according to a first embodiment of the invention comprises a housing 10 made of phenolic resin, here generally in the form of a right cylinder, extending along a vertical Z axis. The housing 10 comprises a first part 10.1 and a second part 10.2 arranged on either side of an electronic card 20 extending in a horizontal XY plane.
La première partie 10.1 du boîtier 10 délimite avec une première face 20.1 de la carte électronique 20 un premier volume VI dit « sale » et forme un couvercle comportant une surface supérieure 11 de forme plane. La première partie 10.1 de boîtier comprend des premiers canaux 12 mettant en communication fluidique le premier volume VI avec l'extérieur. The first part 10.1 of the housing 10 defines with a first face 20.1 of the electronic card 20 a first so-called “dirty” volume VI and forms a cover comprising an upper surface 11 of planar shape. The first part 10.1 of the housing comprises first channels 12 putting the first volume VI in fluid communication with the outside.
La deuxième partie 10.2 du boîtier 10 délimite avec une deuxième face 20.2 de la carte électronique 20 un deuxième volume V2 dit « propre » et forme un capot comportant un fond 13 de forme plane. La deuxième partie 10.2 du boîtier 10 comprend une rainure 14 annulaire externe formant un moyen de préhension du dispositif 1 de mesure de pression et délimitant avec le fond 13 une surface latérale externe 15 sensiblement de forme convexe. La surface latérale externe 15 a un profil présentant dans un plan passant par l'axe Z une première zone plane 15.1 et une deuxième zone plane 15.2 légèrement inclinées l'une par rapport à l'autre mais aussi par rapport à l'axe Z. La première partie 10.1 et la deuxième partie 10.2 du boîtier 10 présente respectivement, selon l'axe Z, une hauteur H1 et une hauteur H2. On notera que la hauteur H1 de la première partie 10.1 est inférieure à la hauteur H2 de la deuxième partie 10.2 et que le volume VI est inférieur au volume V2. The second part 10.2 of the housing 10 defines with a second face 20.2 of the electronic card 20 a second so-called “clean” volume V2 and forms a cover comprising a bottom 13 of planar shape. The second part 10.2 of the housing 10 comprises an outer annular groove 14 forming a means for gripping the pressure measuring device 1 and delimiting with the bottom 13 an outer lateral surface 15 which is substantially convex in shape. The outer lateral surface 15 has a profile having, in a plane passing through the Z axis, a first flat zone 15.1 and a second flat zone 15.2 slightly inclined with respect to each other but also with respect to the Z axis. The first part 10.1 and the second part 10.2 of the housing 10 respectively have, along the Z axis, a height H1 and a height H2. It will be noted that the height H1 of the first part 10.1 is less than the height H2 of the second part 10.2 and that the volume VI is less than the volume V2.
La carte électronique 20 comporte des deuxièmes canaux 21 traversants mettant en communication fluidique le premier volume VI avec le deuxième volume V2. Les deuxièmes canaux 21 ont une section circulaire dont le diamètre est compris entre 100 et 300 micromètres, préférentiellement 200 micromètres. Les premiers canaux 12 ont une section circulaire dont le diamètre est ici inférieur à celui des deuxièmes canaux 21 de manière à favoriser la circulation de l'air entre le premier volume VI et le deuxième volume V2 et ainsi obtenir une meilleure dynamique en pression entre lesdits premier et deuxième volume VI, V2. The electronic card 20 comprises second through channels 21 placing the first volume VI in fluid communication with the second volume V2. The second channels 21 have a circular section, the diameter of which is between 100 and 300 micrometers, preferably 200 micrometers. The first channels 12 have a circular section, the diameter of which is here smaller than that of the second channels 21 so as to promote the circulation of air between the first volume VI and the second volume V2 and thus obtain better pressure dynamics between said first and second volume VI, V2.
Comme illustré à la figure IC, un circuit électronique est réparti sur la première face 20.1 et la deuxième face 20.2 de la carte électronique 20. Le circuit électronique comprend un capteur de pression 30, un émetteur/récepteur radio 31, un microcontrôleur 32, un récupérateur d'énergie 33 électromagnétique et une batterie 34. Le capteur de pression 30 et l'émetteur/récepteur radio 31 sont montés sur la première face 20.1 de la carte électronique 20 et s'étendent dans le premier volume VI. Le microcontrôleur 32, le récupérateur d'énergie 33 et la batterie 34 sont montés sur la deuxième face 20.2 de la carte électronique 20 et s'étendent dans le deuxième volume V2. As illustrated in Figure IC, an electronic circuit is distributed over the first face 20.1 and the second face 20.2 of the electronic card 20. The electronic circuit comprises a pressure sensor 30, a radio transmitter / receiver 31, a microcontroller 32, a electromagnetic energy recuperator 33 and a battery 34. The pressure sensor 30 and the radio transmitter / receiver 31 are mounted on the first face 20.1 of the electronic card 20 and extend into the first volume VI. The microcontroller 32, the energy recovery 33 and the battery 34 are mounted on the second face 20.2 of the electronic card 20 and extend into the second volume V2.
Le capteur de pression 30 comprend un capotage 35 de protection mécanique définissant une enceinte étanche à une pression de référence. Le capteur de pression 30 est ici un capteur piézoélectrique comprenant une membrane 36 qui s'étend parallèlement à la première face 20.1 de la carte électronique 20 et qui est munie d'une première électrode 37.1. Une partie supérieure du capotage 35 constitue une deuxième électrode 37.2 d'un condensateur. Un troisième canal 22 traversant la carte électronique 20 met en communication fluidique l'enceinte délimitée par le capotage 35 avec le deuxième volume V2. Le troisième canal 22 a une section circulaire dont le diamètre est ici sensiblement égal à celui des deuxièmes canaux 21. The pressure sensor 30 comprises a mechanical protection cover 35 defining a sealed enclosure. a reference pressure. The pressure sensor 30 is here a piezoelectric sensor comprising a membrane 36 which extends parallel to the first face 20.1 of the electronic card 20 and which is provided with a first electrode 37.1. An upper part of the cowling 35 constitutes a second electrode 37.2 of a capacitor. A third channel 22 passing through the electronic card 20 puts the enclosure delimited by the cowling 35 in fluid communication with the second volume V2. The third channel 22 has a circular section, the diameter of which is here substantially equal to that of the second channels 21.
Le récupérateur d'énergie 33 comprend un convertisseur qui convertit l'énergie cinétique captée en énergie électrique et l'envoie à la batterie 34 pour la stocker. Le récupérateur d'énergie 33 comporte ici une bille en matériau ferromagnétique pouvant se déplacer librement dans l'entrefer d'une bobine. La batterie 34 alimente le microcontrôleur 32 et l'émetteur/récepteur radio 31. The energy recuperator 33 comprises a converter which converts the captured kinetic energy into electrical energy and sends it to the battery 34 for storage. The energy recuperator 33 here comprises a ball made of ferromagnetic material which can move freely in the air gap of a coil. The battery 34 supplies the microcontroller 32 and the radio transmitter / receiver 31.
Comme visible à la figure IC, les deuxièmes canaux 21 sont pourvus d'un revêtement métallique 23 obtenu par métallisation. Chaque revêtement métallique 23 est relié à un pôle de la batterie 34, ici un pôle positif. Un anneau 24 s'étend autour de chaque revêtement métallique 23 à une distance non nulle de celui-ci. Chaque anneau 24 est ici réalisé par un dépôt de cuivre dans une rainure 25 usinée dans la carte électronique 20 et est relié à un premier pôle de la batterie 34, ici un pôle négatif.As visible in FIG. 1C, the second channels 21 are provided with a metallic coating 23 obtained by metallization. Each metallic coating 23 is connected to a pole of the battery 34, here a positive pole. A ring 24 extends around each metal coating 23 at a non-zero distance therefrom. Each ring 24 is here produced by depositing copper in a groove 25 machined in the electronic card 20 and is connected to a first pole of the battery 34, here a negative pole.
Avantageusement, l'anneau 24 s'étend sensiblement en retrait de la première face 20.1 de la carte électronique 20 afin de créer une zone de rétention. Advantageously, the ring 24 extends substantially set back from the first face 20.1 of the electronic card 20 in order to create a retention zone.
La carte électronique 20 comprend en outre une première portion 26.1 latérale et une deuxième portion 26.2 s'étendant en saillie latérale de part et d'autre du boîtier 10 selon un axe X horizontal perpendiculaire à l'axe Z. A l'intérieur de la première portion 26.1 et de la deuxième portion 26.2 s'étend un fil ou une piste d'antenne 27.1, 27.2 relié à l'émetteur/récepteur radioThe electronic card 20 further comprises a first lateral portion 26.1 and a second portion 26.2 extending in lateral projection on either side of the housing 10 along a horizontal X axis perpendicular to the Z axis. first portion 26.1 and the second portion 26.2 extends a wire or an antenna track 27.1, 27.2 connected to the radio transmitter / receiver
31. La première portion 26.1 et la deuxième portion 26.2 sont de forme sensiblement identique et sont ici de forme triangulaire. 31. The first portion 26.1 and the second portion 26.2 are of substantially identical shape and are here triangular in shape.
Comme illustré à la figure 2, le dispositif 1 de mesure de pression est placé à l'intérieur d'une roue R d'un train d'atterrissage d'aéronef. As illustrated in FIG. 2, the pressure measuring device 1 is placed inside a wheel R of an aircraft landing gear.
La roue R comprend une jante J sur laquelle est monté un pneumatique P définissant avec la jante J un volume interne V rempli d'azote sous pression. Un élément de liaison 40 en matériau élastomère permet de fixer le dispositif 1 de mesure de pression sur une surface interne d'une bande de roulement du pneumatique P et d'absorber au moins partiellement les chocs et les déformations subis par ledit pneumatique P lorsque celui-ci roule. The wheel R comprises a rim J on which is mounted a tire P defining with the rim J an internal volume V filled with nitrogen under pressure. A connecting element 40 made of elastomeric material makes it possible to fix the pressure measuring device 1 on an internal surface of a tread of the tire P and to at least partially absorb the shocks and the deformations undergone by said tire P when that - here rolls.
L'élément de liaison 40 comprend une embase 41 sensiblement de forme tronconique dont la grande base est reliée de manière adhésive à la surface interne de la bande de roulement du pneumatique P et dont la petite base forme un fond 42.1 d'un réceptacle 42 de forme globalement cylindrique. The connecting element 40 comprises a base 41 substantially of frustoconical shape, the large base of which is adhesively connected to the internal surface of the tread of the tire P and the small base of which forms a bottom 42.1 of a receptacle 42 of overall cylindrical shape.
Le réceptacle 42 comprend une paroi latérale 42.2 ayant une surface interne agencée pour coopérer avec la surface latérale externe 15 de la deuxième partie 10.2 du boîtier 10, et une ouverture 42.3 d'insertion de la deuxième partie de boîtier 10.2 du dispositif 1 de mesure de pression dans le réceptacle 42. L'ouverture 42.3 est délimitée par un rebord 42.4 annulaire agencé pour être engagé dans la rainure 14 annulaire externe de façon à immobiliser et retenir ladite deuxième partie de boîtier 10.2 dans le réceptacle 42. The receptacle 42 comprises a side wall 42.2 having an internal surface arranged to cooperate with the external lateral surface 15 of the second part 10.2 of the housing 10, and an opening 42.3 for inserting the second housing part 10.2 of the measuring device 1. pressure in the receptacle 42. The opening 42.3 is delimited by an annular flange 42.4 arranged to be engaged in the outer annular groove 14 so as to immobilize and retain said second housing part 10.2 in the receptacle 42.
L'aéronef est équipé d'un émetteur/récepteur radio accordé sur des fréquences d'émission et de réception de l'émetteur/récepteur radio 31 du dispositif 1 de mesure de pression. The aircraft is equipped with a radio transmitter / receiver tuned to transmit and receive frequencies of the radio transmitter / receiver 31 of the pressure measuring device 1.
En fonctionnement, l'air sous pression contenu dans le volume interne V défini par la jante J et le pneumatique P pénètre par les premiers canaux 12 du boîtier 10 dans le premier volume VI. Les premiers canaux 12 réalisent un premier filtrage des particules (poussière, limaille, grain de sable...) pouvant être présentes dans le volume interne V. Un second filtrage de l'air est réalisé par les deuxièmes canaux 21 lors de son passage du premier volume VI vers le deuxième volume V2. L'air présent dans le deuxième volume V2 pénètre ensuite dans l'enceinte définie par le capotage 35 du capteur de pression 30 et agit sur la membrane 36. Sous l'effet de la pression de l'air régnant dans l'enceinte, la membrane 36 se déforme et la capacité du condensateur associé à ladite membrane 36 est modifiée. Un convertisseur analogique-numérique intégré au microcontrôleur 32 convertit la capacité du condensateur en une valeur de pression qui est ensuite envoyée à l'émetteur/récepteur radio de l'aéronef à l'aide de l'émetteur/récepteur radio 31 du dispositif 1 de mesure de pression. In operation, the pressurized air contained in the internal volume V defined by the rim J and the tire P enters through the first channels 12 of the housing 10 into the first volume VI. The first channels 12 carry out a first filtering of the particles (dust, filings, grain of sand, etc.) which may be present in the internal volume V. A second filtering of the air is carried out by the second channels 21 as it passes through the air. first volume VI to second volume V2. The air present in the second volume V2 then enters the enclosure defined by the cowling 35 of the pressure sensor 30 and acts on the membrane 36. Under the effect of the air pressure prevailing in the enclosure, the membrane 36 is deformed and the capacitance of the capacitor associated with said membrane 36 is modified. An analog-to-digital converter integrated into the microcontroller 32 converts the capacitance of the capacitor into a pressure value which is then sent to the radio transmitter / receiver of the aircraft using the radio transmitter / receiver 31 of the device 1 of pressure measurement.
La batterie 34 établit une tension entre le revêtement métallique 23 des deuxièmes canaux 21 et les anneaux 24 de cuivre qui l'entourent, réalisant une vaporisation par électrolyse de l'eau qui pourrait venir obstruer les deuxièmes canaux 21. Le diamètre des deuxièmes canaux 21 favorise une rétention de l'eau par capillarité et contribue à empêcher le passage de l'humidité de l'air contenu dans la roue R vers le deuxième volume V2. La rétention de l'humidité dans les deuxièmes canaux 21 et le dispositif d'électrolyse de l'eau permettent de limiter la présence d'eau sur la membrane 36 et de protéger le dispositif 1 de mesure de pression des conséquences préjudiciables du gel lorsque l'aéronef est en vol. En effet, la présence d'eau gelée sur la membrane 36 rend généralement le capteur de pression 30 inopérant et provoque le plus souvent sa destruction. The battery 34 establishes a voltage between the metal coating 23 of the second channels 21 and the copper rings 24 which surround it, carrying out a vaporization by electrolysis of the water which could come to obstruct the second channels 21. The diameter of the second channels 21 promotes water retention by capillary action and helps prevent the passage of moisture from the air contained in the wheel R to the second volume V2. The retention of moisture in the second channels 21 and the water electrolysis device make it possible to limit the presence of water on the membrane 36 and to protect the pressure measuring device 1 from the detrimental consequences of freezing when l aircraft is in flight. In Indeed, the presence of frozen water on the membrane 36 generally renders the pressure sensor 30 inoperative and most often causes its destruction.
Au cours des phases de rotation de la roue R, le récupérateur d'énergie 33 convertit l'énergie cinétique à laquelle est soumis le dispositif 1 en énergie électrique qui est stockée dans la batterie 34. During the phases of rotation of the wheel R, the energy recuperator 33 converts the kinetic energy to which the device 1 is subjected into electrical energy which is stored in the battery 34.
La carte électronique 20 est liée à la première partieThe electronic card 20 is linked to the first part
10.1 et la deuxième partie 10.2 du boîtier 10 par un cordon de colle ayant une souplesse autorisant un mouvement relatif entre ladite carte électronique 20 et le boîtier 10, ce qui permet de limiter la transmission des vibrations et des chocs auxquels est soumis la roue R à la carte électronique 20. La colle présente une dureté comprise 30 shore 00 et 60 shore A. 10.1 and the second part 10.2 of the housing 10 by a bead of adhesive having a flexibility allowing relative movement between said electronic card 20 and the housing 10, which makes it possible to limit the transmission of vibrations and shocks to which the wheel R is subjected to the electronic card 20. The glue has a hardness of between 30 shore 00 and 60 shore A.
La répartition des composants électroniques 30, 31,The distribution of electronic components 30, 31,
32, 33, 34 sur la première face 20.1 et la deuxième face32, 33, 34 on the first side 20.1 and the second side
20.2 de la carte électronique 20, et la forme et les dimensions du boîtier 10 (notamment les hauteurs H1 et H2) permettent au dispositif 1 de mesure de pression de présenter un centre de gravité G situé dans le deuxième volume V2, à distance de la carte électronique 20. En outre, de par l'agencement symétrique de la première portion 26.1 et de la deuxième portion 26.2 de la carte électronique 20 hors du boîtier 10, le centre de gravité G se situe sensiblement sur l'axe Z central du boîtier 10. 20.2 of the electronic card 20, and the shape and dimensions of the box 10 (in particular the heights H1 and H2) allow the pressure measuring device 1 to have a center of gravity G located in the second volume V2, at a distance from the electronic card 20. In addition, by the symmetrical arrangement of the first portion 26.1 and of the second portion 26.2 of the electronic card 20 outside the housing 10, the center of gravity G is located substantially on the central Z axis of the housing 10.
En ayant un centre de gravité G situé en dessous de la carte électronique 20, le dispositif 1 de mesure de pression permet de limiter l'amplitude des mouvements relatifs entre le réceptacle 42 et ledit dispositif 1 de mesure de pression occasionnés lors du roulage de la roue R, et donc de limiter la détérioration de l'élément de liaison 40 du dispositif 1 collé sur la bande de roulement du pneumatique P. Le débattement angulaire du dispositif 1 est également limité, limitant le risque que l'antenne vienne percuter la surface interne du pneumatique. By having a center of gravity G located below the electronic card 20, the pressure measuring device 1 makes it possible to limit the amplitude of the relative movements between the receptacle 42 and said pressure measuring device 1 caused during the rolling of the vehicle. wheel R, and therefore to limit the deterioration of the connecting element 40 of the device 1 stuck on the tread of the tire P. The angular displacement of the device 1 is also limited, limiting the risk of the antenna striking the internal surface of the tire.
La figure 3 illustre un dispositif 2 qui est une première variante du dispositif 1 illustré aux figures IA, IB, IC. Le dispositif 2 de mesure de pression diffère du dispositif 1 en ce que le boîtier 10 comprend des oreilles formées par une première excroissance 16.1 et une deuxième excroissance 16.2 qui s'étendent en saillie latérale d'une extrémité supérieure de la deuxième partie 10.2 du boîtier 10. La première excroissance 16.1 et la deuxième excroissance 16.2 sont de forme sensiblement identique et coopèrent avec la deuxième face 20.2 de la carte électronique 20 au niveau de la première portion 26.1 et la deuxième portion 26.2 de façon à limiter la flexion desdites première et deuxième portions 26.1, 26.2 provoquées par la rotation de la roue R sous l'effet de leur propre poids. FIG. 3 illustrates a device 2 which is a first variant of the device 1 illustrated in FIGS. IA, IB, IC. The pressure measuring device 2 differs from the device 1 in that the housing 10 comprises lugs formed by a first protuberance 16.1 and a second protuberance 16.2 which project sideways from an upper end of the second part 10.2 of the casing 10. The first protuberance 16.1 and the second protuberance 16.2 are of substantially identical shape and cooperate with the second face 20.2 of the electronic card 20 at the level of the first portion 26.1 and the second portion 26.2 so as to limit the bending of said first and second portions 26.1, 26.2 caused by the rotation of the wheel R under the effect of their own weight.
La figure 4 illustre un dispositif 3 qui est une deuxième variante du dispositif 1 illustré aux figures IA, IB, IC. Le dispositif 3 de mesure de pression diffère du dispositif 1 en ce que la première partie 10.1 du boîtier forme un couvercle ayant une surface supérieure 11 de forme bombée vers l'extérieur tout en conservant une surface inférieure de forme plane. La longueur des premiers canaux 12 s'en trouvent ainsi augmentée. La surface supérieure 11 bombée de la première partie 10.1 du boîtier 10 et l'augmentation de la longueur des premiers canaux 12 permet de limiter l'accumulation de polluant à proximité immédiate des orifices d'entrée des premiers canaux 12. La figure 5 illustre un dispositif 4 qui est une troisième variante du dispositif 1 illustré aux figures IA, IB, IC. Le dispositif 4 de mesure de pression diffère du dispositif 1 en ce que la première partie 10.1 du boîtier comporte une portion supérieure 11 de forme générale tronconique ayant une paroi supérieure plane traversée par les premiers canaux 12 et raccordée à une paroi tronconique. L'ajout d'une pente à la portion supérieure 11 permet, comme pour le dispositif 3, de limiter l'accumulation de polluant à proximité immédiate des orifices d'entrée des premiers canaux 12. FIG. 4 illustrates a device 3 which is a second variant of the device 1 illustrated in FIGS. IA, IB, IC. The pressure measuring device 3 differs from the device 1 in that the first part 10.1 of the housing forms a cover having an upper surface 11 of convex shape outwardly while retaining a lower surface of planar shape. The length of the first channels 12 is thereby increased. The domed upper surface 11 of the first part 10.1 of the housing 10 and the increase in the length of the first channels 12 makes it possible to limit the accumulation of pollutant in the immediate vicinity of the inlet orifices of the first channels 12. FIG. 5 illustrates a device 4 which is a third variant of the device 1 illustrated in Figures IA, IB, IC. The pressure measuring device 4 differs from the device 1 in that the first part 10.1 of the housing comprises an upper portion 11 of generally frustoconical shape having a flat upper wall traversed by the first channels 12 and connected to a frustoconical wall. The addition of a slope to the upper portion 11 makes it possible, as for the device 3, to limit the accumulation of pollutant in the immediate vicinity of the inlet openings of the first channels 12.
La figure 6 illustre un dispositif 5 de mesure de pression qui est une quatrième variante du dispositif 1 illustré aux figures IA, IB, IC. Le dispositif 5 diffère du dispositif 4 en ce que les premiers canaux 12 traversent de manière oblique la paroi tronconique de la portion supérieure 11. Les premiers canaux 12 débouchent à l'intérieur du premier volume VI par un orifice qui est plus éloigné de la carte électronique 20 que l'orifice d'entrée par lequel ils débouchent à l'extérieur du volume VI. Le positionnement des premiers canaux 12 permet de limiter l'accumulation de polluants à proximité immédiate des orifices d'entrée des premiers canaux 12. FIG. 6 illustrates a pressure measuring device 5 which is a fourth variant of the device 1 illustrated in FIGS. IA, IB, IC. The device 5 differs from the device 4 in that the first channels 12 cross obliquely the frustoconical wall of the upper portion 11. The first channels 12 open inside the first volume VI through an orifice which is further from the card. electronic 20 as the inlet orifice through which they open to the outside of the volume VI. The positioning of the first channels 12 makes it possible to limit the accumulation of pollutants in the immediate vicinity of the inlet openings of the first channels 12.
La figure 7 illustre un dispositif 6 de mesure de pression qui est une cinquième variante du dispositif 1 illustré aux figures IA, IB, IC. Le dispositif 6 de diffère du dispositif 1 en ce que les premiers canaux 12 s'étendent parallèlement à la première face 20.1 de la carte électronique 20, ce qui permet, comme pour les dispositifs 3 à 5, de limiter l'accumulation de polluant à proximité immédiate des orifices d'entrée des premiers canaux 12. FIG. 7 illustrates a pressure measuring device 6 which is a fifth variant of the device 1 illustrated in FIGS. IA, IB, IC. The device 6 differs from the device 1 in that the first channels 12 extend parallel to the first face 20.1 of the electronic card 20, which makes it possible, as for devices 3 to 5, to limit the accumulation of pollutant to immediate proximity to the inlet openings of the first channels 12.
La figure 8 illustre un dispositif 7 de mesure de pression selon un deuxième mode de réalisation de l'invention. Le dispositif 7 diffère du dispositif 1 en ce que la surface latérale externe 15 de la deuxième partie 10.2 du boîtier 10 a un diamètre agrandi au voisinage du fond 13, de sorte que la surface projetée de la première partie 10.1 du boîtier 10 sur la première face 20.1 de la carte électronique 20 selon l'axe Z est inscrite dans la surface projetée de la deuxième partie 10.2 du boîtier 10 sur la même face 20.1 et selon le même axe Z, le volume V2 restant inchangé. Il en résulte que le centre de gravité G se trouve désormais plus proche du fond 13 du boîtier 10 que de la deuxième face 20.2 de la carte électronique 20. En outre, la deuxième partie de boîtier 10.2 comporte ainsi un renflement extérieur au voisinage du fond 13, renflement qui est épousé par la paroi du réceptacle 42 pour assurer la fixation de la deuxième partie de boîtier 10.2 à la surface interne du pneumatique. FIG. 8 illustrates a device 7 for measuring pressure according to a second embodiment of the invention. The device 7 differs from the device 1 in that the outer side surface 15 of the second part 10.2 of the housing 10 has an enlarged diameter in the vicinity of the bottom 13, so that the projected surface of the first part 10.1 of the housing 10 on the first face 20.1 of the electronic card 20 along the Z axis is inscribed in the projected surface of the second part 10.2 of the housing 10 on the same face 20.1 and along the same Z axis, the volume V2 remaining unchanged. As a result, the center of gravity G is now located closer to the bottom 13 of the housing 10 than to the second face 20.2 of the electronic card 20. In addition, the second housing part 10.2 thus includes an external bulge in the vicinity of the bottom. 13, a bulge which is matched by the wall of the receptacle 42 to ensure the attachment of the second housing part 10.2 to the internal surface of the tire.
Les figures 9A, 9B, 9C illustrent un dispositif 100 de mesure de pression selon un troisième mode de réalisation de l'invention. Le dispositif 100 comprend un boîtier 110 en résine phénolique, ici globalement en forme de cylindre droit, s'étendant selon un axe Z vertical. Le boîtier 110 comporte une première partie 110.1 et une deuxième partie 110.2 agencées de part et d'autre d'une carte électronique 120 s'étendant dans un plan XY horizontal. Le boîtier 110 délimite ainsi une enceinte dans laquelle s'étend au moins en partie la carte électronique 120. La première partie 110.1 de boîtier 110 délimite un premier volume VI avec une première face 120.1 de la carte électronique 120 et forme un couvercle ayant une surface supérieure de forme plane. La première partie 110.1 de boîtier comprend des premiers canaux 111 traversants mettant en communication fluidique le premier volume VI avec l'extérieur. Les premiers canaux 111 ont une section circulaire dont le diamètre est compris entre 0.2 et 1.5 millimètres, préférentiellement 1 millimètre. FIGS. 9A, 9B, 9C illustrate a device 100 for measuring pressure according to a third embodiment of the invention. The device 100 comprises a housing 110 made of phenolic resin, here generally in the form of a straight cylinder, extending along a vertical Z axis. The housing 110 comprises a first part 110.1 and a second part 110.2 arranged on either side of an electronic card 120 extending in a horizontal XY plane. The housing 110 thus defines an enclosure in which the electronic card 120 extends at least in part. The first part 110.1 of the housing 110 defines a first volume VI with a first face 120.1 of the electronic card 120 and forms a cover having a surface upper plane. The first part 110.1 of the housing comprises first through channels 111 placing the first volume VI in fluid communication with the outside. The first channels 111 have a circular section, the diameter of which is between 0.2 and 1.5 millimeters, preferably 1 millimeter.
La deuxième partie 110.2 de boîtier 110 délimite un deuxième volume V2 avec une deuxième face 120.2 de la carte électronique 120 opposée à la première face 120.1, et forme un récipient ayant un fond de forme plane. La liaison entre le boîtier 110 et la carte électronique 120 est agencée de façon autoriser un mouvement relatif entre ledit boîtier 110 et ladite carte électronique 120, par exemple via un cordon de colle souple à base de silicone. The second part 110.2 of the housing 110 delimits a second volume V2 with a second face 120.2 of the electronic card 120 opposite the first face 120.1, and forms a container having a bottom of planar shape. The connection between the housing 110 and the electronic card 120 is arranged so as to allow relative movement between said housing. 110 and said electronic card 120, for example via a bead of flexible silicone-based adhesive.
La carte électronique 120 comporte des deuxièmes canaux 123 mettant en communication fluidique le premier volume VI avec le deuxième volume V2. Les deuxièmes canauxThe electronic card 120 comprises second channels 123 putting the first volume VI in fluid communication with the second volume V2. The second channels
123 ont une section circulaire dont le diamètre est compris entre 100 et 300 micromètres, préférentiellement 200 micromètres . 123 have a circular section, the diameter of which is between 100 and 300 micrometers, preferably 200 micrometers.
Comme illustré à la figure 9C, un circuit électronique s'étend sur la première face 120.1 de la carte électronique 120 et comprend un capteur de pression 130 passif (sensiblement identique au capteur de pression 30), un émetteur/récepteur radio 131, un microcontrôleur 132, un récupérateur d'énergie électromagnétique et une batterie (non représentés). As illustrated in FIG. 9C, an electronic circuit extends over the first face 120.1 of the electronic card 120 and comprises a passive pressure sensor 130 (substantially identical to the pressure sensor 30), a radio transmitter / receiver 131, a microcontroller 132, an electromagnetic energy recuperator and a battery (not shown).
Le capteur de pression 130, l'émetteur/récepteur radio 131, le microcontrôleur 132, le récupérateur d'énergie électromagnétique et la batterie sont montés sur la première face 120.1 de la carte électronique 120 et s'étendent dans le premier volume VI. The pressure sensor 130, the radio transmitter / receiver 131, the microcontroller 132, the electromagnetic energy recuperator and the battery are mounted on the first face 120.1 of the electronic card 120 and extend into the first volume VI.
Le capteur de pression 130 comprend un capotage 135 de protection mécanique définissant une enceinte étanche de mesure. Le capteur de pression 130 est ici un capteur piézorésistif comprenant une membrane qui s'étend sensiblement parallèlement à la première face 120.1 de la carte électronique 120. Le capteur est ici un microsystème électromécanique (ou MEMS) avec un pont de Wheatstone. Un troisième canal 124 traverse la carte électronique 120 et met en communication fluidique l'enceinte délimitée par le capotage 135 avec le deuxième volume V2. Le troisième canalThe pressure sensor 130 comprises a mechanical protection cover 135 defining a sealed measurement enclosure. The pressure sensor 130 is here a piezoresistive sensor comprising a membrane which extends substantially parallel to the first face 120.1 of the electronic card 120. The sensor here is an electromechanical microsystem (or MEMS) with a Wheatstone bridge. A third channel 124 passes through the electronic card 120 and places the enclosure delimited by the cowling 135 in fluid communication with the second volume V2. The third channel
124 a une section circulaire dont le diamètre est sensiblement égal à celui des deuxièmes canaux 123. 124 has a circular section whose diameter is substantially equal to that of the second channels 123.
Le récupérateur d'énergie comprend un convertisseur qui convertit l'énergie cinétique captée en énergie électrique et l'envoie à la batterie pour la stocker. Le récupérateur d'énergie comporte ici une bille en matériau ferromagnétique pouvant se déplacer librement dans l'entrefer d'une bobine. La batterie alimente le microcontrôleur et l'émetteur/récepteur radio. Comme pour le dispositif 1, les deuxièmes canaux 123 sont pourvus d'un revêtement métallique (non représenté) obtenu par métallisation. Chaque revêtement métallique est relié à un pôle de la batterie, ici un pôle positif. Un anneau (non représenté) s'étend autour de chaque revêtement métallique à une distance non nulle de celui-ci. Chaque anneau est ici réalisé par un dépôt de cuivre dans une rainure usinée dans la carte électronique 120 et est relié à un premier pôle de la batterie, ici un pôle négatif. Avantageusement, l'anneau s'étend sensiblement en retrait de la première face 120.1 de la carte électronique 120 afin de créer une zone de rétention. The energy harvester includes a converter that converts the captured kinetic energy into electrical energy and sends it to the battery for storage. the energy recovery here comprises a ball made of ferromagnetic material which can move freely in the air gap of a coil. The battery powers the microcontroller and the radio transceiver. As for the device 1, the second channels 123 are provided with a metallic coating (not shown) obtained by metallization. Each metallic coating is connected to a pole of the battery, here a positive pole. A ring (not shown) extends around each metal coating at a non-zero distance therefrom. Each ring is produced here by depositing copper in a groove machined in the electronic card 120 and is connected to a first pole of the battery, here a negative pole. Advantageously, the ring extends substantially set back from the first face 120.1 of the electronic card 120 in order to create a retention zone.
La carte électronique 120 comprend une première paire de bras 121.1 s'étendant en saillie latérale du boîtier 110 selon un axe X horizontal perpendiculaire à l'axe Z. La première paire de bras 121.1 forme une première encocheThe electronic card 120 comprises a first pair of arms 121.1 extending as a lateral projection from the housing 110 along a horizontal X axis perpendicular to the Z axis. The first pair of arms 121.1 forms a first notch.
122.1 à l'intérieur de laquelle s'étend une extrémité d'un premier brin 140.1 d'antenne reliée galvaniquement à l'émetteur/récepteur radio 131. Le premier brin 140.1 est constituée d'un fil d'acier enroulé en ressort de forme hélicoïdale selon un pas P et s'étend en saillie latérale du boîtier 110 selon l'axe X. La projection du premier brin122.1 within which extends one end of a first strand 140.1 of antenna galvanically connected to the radio transmitter / receiver 131. The first strand 140.1 consists of a steel wire wound in a spring form helical at a pitch P and extends as a lateral projection from the housing 110 along the X axis. The projection of the first strand
140.1 sur un plan YZ perpendiculaire à l'axe X est circonscrit dans un cercle de diamètre D. Un rapport P/D inférieur à 0,7 permet d'améliorer les performances de l'antenne en termes d'émission et de réception mais aussi de diminuer la rigidité du brin hélicoïdal et donc de limiter les contraintes générées dans le premier brin 140.1, en particulier au niveau de sa connexion galvanique avec l'émetteur/récepteur radio 131. La carte électronique 120 comprend en outre une deuxième encoche 122.2 formée par une deuxième paire de bras 121.2 identiques à la première paire de bras 121.1 et s'entendant à l'opposé de ladite première paire de bras 121.1. Une extrémité d'un deuxième brin 140.2 d'antenne à ressort identique s'étend à l'intérieur de la deuxième encoches 122.2 et est reliée galvaniquement à l'émetteur/récepteur radio 131. Le premier brin 140.1 et le deuxième brin 140.2 sont sensiblement identiques et constituent une antenne dipôle. 140.1 on a YZ plane perpendicular to the X axis is circumscribed in a circle of diameter D. A P / D ratio of less than 0.7 makes it possible to improve the performance of the antenna in terms of transmission and reception but also to reduce the rigidity of the helical strand and therefore to limit the stresses generated in the first strand 140.1, in particular at the level of its galvanic connection with the radio transmitter / receiver 131. The electronic card 120 further comprises a second notch 122.2 formed by a second pair of arms 121.2 identical to the first pair of arms 121.1 and being the opposite of said first pair of arms 121.1. One end of a second strand 140.2 of identical spring antenna extends inside the second notch 122.2 and is galvanically connected to the radio transmitter / receiver 131. The first strand 140.1 and the second strand 140.2 are substantially identical and constitute a dipole antenna.
La deuxième partie 110.2 de boîtier comporte une première oreille 112.1 en saillie selon l'axe X. La première oreille 112.1 s'étend pour partie en regard de la première encoche 122.1 et comprend une face interne 113.1 horizontale venant sensiblement tangenter un premier tronçon 141.1 du premier brin 40.1. Deux premiers doigts 114.1 s'étendent parallèlement selon l'axe Z depuis une extrémité libre de la face interne 113.1 s'étendant au- delà de la première encoche 122.1 et forme un espace d'accueil d'un deuxième tronçon 142.1 du premier brinThe second housing part 110.2 comprises a first lug 112.1 projecting along the X axis. The first lug 112.1 extends partly facing the first notch 122.1 and comprises a horizontal internal face 113.1 coming substantially tangent to a first section 141.1 of the first strand 40.1. Two first fingers 114.1 extend parallel along the Z axis from a free end of the internal face 113.1 extending beyond the first notch 122.1 and form a space for receiving a second section 142.1 of the first strand
140.1. Les premiers doigts 114.1 comprennent une surface interne venant sensiblement tangenter verticalement le deuxième tronçon 142.1 du premier brin 140.1. 140.1. The first fingers 114.1 comprise an internal surface coming substantially vertically tangent to the second section 142.1 of the first strand 140.1.
La deuxième partie 110.2 de boîtier comporte en outre une deuxième oreille 112.2 en saillie identique à la première oreille 112.1 et agencée à l'opposé de ladite première oreille 112.1. La deuxième oreille 112.2 s'étend pour partie en regard de la deuxième encoche 122.2 et comprend une face supérieure 113.2 horizontale venant sensiblement tangenter un premier tronçon 141.2 du deuxième brin 140.2. Deux deuxième doigts 114.2 s'étendent parallèlement selon l'axe Z depuis une extrémité libre de la face supérieure 113.2 s'étendant au-delà de la deuxième encoche 122.2 et forme un espace d'accueil d'un deuxième tronçon 142.2 du deuxième brin 140.2. Les deuxièmes doigts 114.2 comprennent une surface intérieure venant sensiblement tangenter verticalement le deuxième tronçonThe second housing part 110.2 further comprises a second protruding ear 112.2 identical to the first ear 112.1 and arranged opposite to said first ear 112.1. The second lug 112.2 extends partly opposite the second notch 122.2 and comprises a horizontal upper face 113.2 coming substantially tangent to a first section 141.2 of the second strand 140.2. Two second fingers 114.2 extend parallel along the Z axis from a free end of the upper face 113.2 extending beyond the second notch 122.2 and form a space for receiving a second section 142.2 of the second strand 140.2 . Second fingers 114.2 include an interior surface coming substantially vertically tangent to the second section
142.2 du deuxième brin 140.2. 142.2 of the second strand 140.2.
La première oreille 112.1 et la deuxième oreille 112.2 s'étendent ainsi à l'extérieur de l'enceinte délimitée par le boîtier 110. The first ear 112.1 and the second ear 112.2 thus extend outside the enclosure delimited by the housing 110.
Le deuxième tronçon 142.1 du premier brin 140.1 et le deuxième tronçon 142.2 du deuxième brin 140.2 ont respectivement un pas inférieur à celui du premier tronçon 141.1 du premier brin 140.1 et du premier tronçon 141.2 du deuxième brin 140.2. Cette différence de pas permet d'augmenter en service le nombre de points de contact entre les brins 140.1, 140.2 et la deuxième partie 110.2 de boîtier lors du débattement desdits brins 140.1, 140.2, et donc de diminuer les contraintes locales auxquelles sont soumises le boîtier 110, notamment au niveau des doigtsThe second section 142.1 of the first strand 140.1 and the second section 142.2 of the second strand 140.2 respectively have a pitch smaller than that of the first section 141.1 of the first strand 140.1 and of the first section 141.2 of the second strand 140.2. This difference in pitch makes it possible to increase in service the number of contact points between the strands 140.1, 140.2 and the second part 110.2 of the casing during the movement of said strands 140.1, 140.2, and therefore to reduce the local stresses to which the casing is subjected. 110, especially on the fingers
114.1, 114.2. Elle permet également de former une certaine souplesse au niveau des deuxièmes tronçons 142.1, 142.2 des brins 140.1, 140.2, et donc de faciliter le débattement desdits brins 140.1, 140.2 tout en diminuant les efforts transitant au niveau leur connexion galvanique avec l'émetteur/récepteur radio 131. 114.1, 114.2. It also makes it possible to form a certain flexibility at the level of the second sections 142.1, 142.2 of the strands 140.1, 140.2, and therefore to facilitate the movement of said strands 140.1, 140.2 while reducing the forces passing through their galvanic connection with the transmitter / receiver. radio 131.
Si une augmentation du pas des deuxièmes tronçonsIf an increase in the pitch of the second sections
142.1, 142.2 permet d'améliorer les performances de l'antenne en radiofréquences, elle engendre aussi une augmentation de la rigidité des brins 140.1, 140.2 et donc une augmentation des efforts transitant au niveau leur connexion galvanique avec l'émetteur/récepteur radio 131. Dès lors, un compromis entre la tenue mécanique et la performance de l'antenne est à identifier selon l'usage final du dispositif 100. 142.1, 142.2 makes it possible to improve the performance of the radiofrequency antenna, it also generates an increase in the rigidity of the strands 140.1, 140.2 and therefore an increase in the forces passing through their galvanic connection with the radio transmitter / receiver 131. Therefore, a compromise between the mechanical strength and the performance of the antenna must be identified according to the end use of the device 100.
Comme illustré à la figure 10, le dispositif 100 est recouvert d'une enveloppe de protection 150 en un matériau élastomère, de préférence réticulant à une température inférieure à 100°C, par exemple à base de polysiloxane ou silicone, comme celui nommé « silastène » qui est un matériau élastomère à base de silicone. L'enveloppe de protection 150 recouvre le premier brin 140.1, le deuxième brin 140.2, le boîtier 110 et les parties de la carte électronique 20 non couvertes par le boîtier 110. As illustrated in FIG. 10, the device 100 is covered with a protective envelope 150 made of an elastomeric material, preferably crosslinking at a temperature below 100 ° C, for example based on polysiloxane or silicone, such as that called "silastene" which is an elastomeric material made from silicone. The protective envelope 150 covers the first strand 140.1, the second strand 140.2, the housing 110 and the parts of the electronic card 20 not covered by the housing 110.
L'enveloppe de protection 150 isole électriquement le dispositif 100 en ce que la conductivité électrique du matériau élastomère est inférieur à son seuil de percolation des charges conductrices, ce qui améliore les performances de l'antenne en termes d'émission et de réception. La permittivité diélectrique du matériau élastomère sera de préférence inférieure à 10, avantageusement inférieure à 6, et très préférentiellement inférieure à 3 comme c'est le cas pour le « silastène » dont la permittivité diélectrique est égale à 2,83. The protective envelope 150 electrically isolates the device 100 in that the electrical conductivity of the elastomeric material is below its threshold for percolation of the conductive charges, which improves the performance of the antenna in terms of transmission and reception. The dielectric permittivity of the elastomer material will preferably be less than 10, advantageously less than 6, and very preferably less than 3, as is the case for “silastene”, the dielectric permittivity of which is equal to 2.83.
Dans un mode de réalisation préféré, le matériau élastomère est tout d'abord déposé sur le boîtier 110 dans un état semi-liquide afin de faciliter le moulage des composants mécaniques et électroniques du dispositif 100 et permettre à l'air de s'échapper, notamment au niveau des brins 140.1, 140.2 d'antenne dont la géométrie favorise la formation de bulles d'air. Le matériau élastomère est ensuite rigidifié lors d'une étape de réticulation réalisée de préférence à une température inférieure à 100°C pour éviter toute détérioration des composants électroniques. En absence de bulle d'air, l'enveloppe de protection 50 est intimement liée de façon homogène aux différents composants mécaniques et électroniques, ce qui assure une robustesse des performances de l'antenne et de l'ancrage des composants mécaniques et électroniques au sein de l'enveloppe de protection 150. In a preferred embodiment, the elastomeric material is first deposited on the housing 110 in a semi-liquid state in order to facilitate the molding of the mechanical and electronic components of the device 100 and to allow air to escape, in particular at the level of the antenna strands 140.1, 140.2, the geometry of which favors the formation of air bubbles. The elastomeric material is then stiffened during a crosslinking step preferably carried out at a temperature below 100 ° C. in order to avoid any deterioration of the electronic components. In the absence of an air bubble, the protective casing 50 is intimately linked in a homogeneous manner to the various mechanical and electronic components, which ensures robust performance of the antenna and of the anchoring of the mechanical and electronic components within of the protective enclosure 150.
De préférence, l'ancrage des composants mécaniques et électroniques au sein de l'enveloppe de protection 150 est réalisé en l'absence de phénomène d'adhésion afin d'améliorer l'endurance de l'enveloppe de protection 150, et donc du dispositif 1, en minimisant la concentration de contraintes à l'origine de phénomènes de fissuration. Un tel ancrage est obtenu en utilisant un élastomère à base de silicone comme le « silastène » qui est inerte chimiquement avec de nombreux matériaux. Le choix du matériau élastomère dépend du matériau des brins 140.1, 140.2 d'antenne avec lequel l'enveloppe de protection 50 sera en contact. Le « silastène » permet par exemple d'éviter ce phénomène d'adhésion avec des brins 140.1, 140.2 d'antenne réalisés entièrement en acier ou possédant une couche de revêtement extérieure en laiton. Preferably, the anchoring of the mechanical and electronic components within the protective envelope 150 is carried out in the absence of adhesion phenomenon in order to improve the endurance of the protective envelope 150, and therefore of the device 1, by minimizing the stress concentration at the origin of cracking phenomena. Such anchoring is obtained by using a silicone-based elastomer such as "silastene" which is chemically inert with many materials. The choice of elastomeric material depends on the material of the antenna strands 140.1, 140.2 with which the protective casing 50 will be in contact. The “silastene” makes it possible for example to avoid this phenomenon of adhesion with strands 140.1, 140.2 of antenna made entirely of steel or having an outer coating layer of brass.
L'enveloppe de protection 150 est agencée pour envelopper complètement le dispositif 1 et limiter la déformation des brins 140.1, 140.2 d'antenne due à des sollicitations extérieures au dispositif 1, en particulier suivant l'axe X. En effet, l'élasticité du matériau élastomère autorise des déplacements des brins 140.1, 140.2 d'antenne tout en les limitant, et limite les efforts transitant dans lesdits brins 140.1, 140.2 d'antenne. L'enveloppe permet ainsi de réduire les débattements de l'antenne par rapport à l'air et aux butées des portions latérales, et d'offrir d'autres cheminements des contraintes et déformations résultant des sollicitations s'exerçant en service sur l'antenne. On évite ainsi une concentration des contraintes en favorisant une homogénéisation de celle-ci sur une surface plus grande. De par sa composition élastomérique, l'enveloppe de protection 150 permet de réduire les contraintes subies en service par les brins 140.1, 140.2, notamment au niveau de leur liaison galvanique avec l'émetteur/récepteur radioThe protective envelope 150 is arranged to completely envelop the device 1 and limit the deformation of the antenna strands 140.1, 140.2 due to stresses external to the device 1, in particular along the X axis. Indeed, the elasticity of the antenna. elastomeric material allows movement of the antenna strands 140.1, 140.2 while limiting them, and limits the forces passing through said antenna strands 140.1, 140.2. The envelope thus makes it possible to reduce the deflections of the antenna with respect to the air and to the stops of the lateral portions, and to offer other paths of the stresses and deformations resulting from the stresses exerted on the antenna in service. . A concentration of stresses is thus avoided by promoting homogenization of the latter over a larger surface. By virtue of its elastomeric composition, the protective casing 150 makes it possible to reduce the stresses undergone in service by the strands 140.1, 140.2, in particular at the level of their galvanic link with the radio transmitter / receiver
131, et de les répartir le long des génératrices desdits brins 140.1, 140.2. Le choix d'un matériau élastomère réticulant à température ambiante permet une cuisson de l'enveloppe de protection 150 en présence de la carte électronique 120 sans détérioration des composants électroniques qui la compose. 131, and to distribute them along the generatrices of said strands 140.1, 140.2. The choice of an elastomeric material crosslinking at room temperature allows baking of the protective envelope 150 in the presence of the card. electronic 120 without deterioration of the electronic components which compose it.
Comme illustré à la figure 12, le dispositif 100 ainsi protégé est placé à l'intérieur d'une roue R d'un aéronef. La roue R comprend une jante J sur laquelle est monté un pneumatique P définissant avec la jante J un volume interne V rempli d'air sous pression. De façon connue, un patch 160 de liaison en matériau élastomère (tel qu'illustré à la figure 11) permet de fixer le dispositif 1 recouvert de l'enveloppe de protection 150 sur une surface interne du pneumatique P, en particulier sur un flanc dudit pneumatique P. Le patch recouvre le dispositif 100 et une partie de la surface interne autour dudit dispositif, tandis que le fond de la deuxième partie 110.2 de boîtier 110 s'étend au voisinage de la surface interne du pneumatique P. Le matériau dans lequel est réalisé le patch 160 n'est pas cohésif avec celui dans lequel est réalisé l'enveloppe de protection 150, ce qui permet une réutilisation du dispositif 100, par exemple dans un autre pneumatique. As illustrated in FIG. 12, the device 100 thus protected is placed inside a wheel R of an aircraft. The wheel R comprises a rim J on which is mounted a tire P defining with the rim J an internal volume V filled with pressurized air. In a known manner, a connecting patch 160 made of elastomeric material (as illustrated in FIG. 11) makes it possible to fix the device 1 covered with the protective casing 150 on an internal surface of the tire P, in particular on a sidewall of said tire. tire P. The patch covers the device 100 and part of the internal surface around said device, while the bottom of the second part 110.2 of the housing 110 extends in the vicinity of the internal surface of the tire P. The material in which is produced, the patch 160 is not cohesive with that in which the protective envelope 150 is made, which allows the device 100 to be reused, for example in another tire.
L'aéronef est équipé d'un émetteur/récepteur radio accordé sur des fréquences d'émission et de réception de l'émetteur/récepteur radio 131 du dispositif 100 de mesure de pression. En fonctionnement, l'air sous pression contenu dans le volume interne V défini par la jante J et le pneumatique P pénètre, via les premiers canaux 111 du boîtier 110, dans le premier volume VI. Les premiers canaux 111 réalisent un premier filtrage des particules à l'entrée du volume interne V. Un second filtrage de l'air est réalisé par les deuxièmes canaux 123 lors du passage de l'air du premier volume VI vers le deuxième volume V2. L'air présent dans le deuxième volume V2 pénètre ensuite dans l'enceinte définie par le capotage 135 du capteur de pression 130 via le troisième canal 124 et agit sur la membrane. Sous l'effet de la pression de l'air régnant dans l'enceinte, la membrane se déforme et la résistance électrique associée à ladite membrane est modifiée. Un convertisseur analogique-numérique intégré au microcontrôleur 132 convertit la capacité du condensateur en une valeur de pression qui est ensuite envoyée à l'émetteur/récepteur radio de l'aéronef à l'aide de l'émetteur/récepteur radio 131 du dispositif 100 de mesure de pression. The aircraft is equipped with a radio transmitter / receiver tuned to transmission and reception frequencies of the radio transmitter / receiver 131 of the pressure measuring device 100. In operation, the pressurized air contained in the internal volume V defined by the rim J and the tire P enters, via the first channels 111 of the housing 110, into the first volume VI. The first channels 111 perform a first filtering of the particles at the inlet of the internal volume V. A second filtering of the air is performed by the second channels 123 during the passage of the air from the first volume VI to the second volume V2. The air present in the second volume V2 then enters the enclosure defined by the cowling 135 of the pressure sensor 130 via the third channel 124 and acts on the membrane. Under the effect of the air pressure prevailing in the enclosure, the membrane is deformed and the electrical resistance associated with said membrane is modified. An analog-to-digital converter built into the microcontroller 132 converts the capacitance of the capacitor into a pressure value which is then sent to the aircraft's radio transmitter / receiver using the radio transmitter / receiver 131 of the device 100. pressure measurement.
La première oreille 112.1 et la deuxième oreille 112.2 du boîtier 110 s'opposent, lors de la rotation du pneumatique P, à des déformations des premiers tronçons 141.1, 141.2 et des deuxièmes tronçons 142.1, 142.2 des brins 140.1, 140.2. Elles permettent donc de limiter les contraintes localement proches des extrémités proximales desdits brins 140.1, 140.2 qui sont reliées galvaniquement à l'émetteur/récepteur radio 31. Les risques de rupture des brins 140.1, 140.2 au niveau de leur connexion avec la carte électronique 120 sont ainsi limités. The first lug 112.1 and the second lug 112.2 of the housing 110 oppose, during the rotation of the tire P, deformations of the first sections 141.1, 141.2 and of the second sections 142.1, 142.2 of the strands 140.1, 140.2. They therefore make it possible to limit the stresses locally close to the proximal ends of said strands 140.1, 140.2 which are galvanically connected to the radio transmitter / receiver 31. The risks of breaking the strands 140.1, 140.2 at their connection with the electronic card 120 are thus limited.
Au fur et à mesure que l'on s'éloigne des extrémités proximales des brins 140.1, 140.2, il est avantageux de réajuster la raideur desdites antennes en modulant par exemple le pas de la forme hélicoïdale de celles-ci à iso diamètre d'enroulement afin d'améliorer leurs performances en termes d'émission et de réception sans pour autant dégrader leur endurance mécanique vis-à-vis des contraintes qu'elles subissent. Les figures 13A et 13B illustrent respectivement les caractéristiques dimensionnelles d'une première version et d'une deuxième version de brin 140.1, 140.2 à enroulement à droite offrants ici un bon compromis entre endurance mécanique et performance d'émission/réception. As one moves away from the proximal ends of the strands 140.1, 140.2, it is advantageous to readjust the stiffness of said antennas by modulating for example the pitch of the helical shape of the latter with iso winding diameter in order to improve their performance in terms of transmission and reception without degrading their mechanical endurance with respect to the stresses to which they are subjected. FIGS. 13A and 13B respectively illustrate the dimensional characteristics of a first version and of a second version of right-wound strand 140.1, 140.2 here offering a good compromise between mechanical endurance and transmission / reception performance.
Dans la première version (figure 13A), le brin 140.1, 140.2 présente à titre d'exemple les caractéristiques dimensionnelles suivantes : In the first version (figure 13A), the strand 140.1, 140.2 has, by way of example, the following dimensional characteristics:
- un diamètre d de fil égal à 0.225 mm ; - un diamètre d'enroulement externe D égal à 1.6 mm ;- a wire diameter d equal to 0.225 mm; - an external winding diameter D equal to 1.6 mm;
- une longueur totale L d'enroulement égale à 40.2 mm ;- a total winding length L equal to 40.2 mm;
- un premier tronçon comprenant une spire s'étendant sur une longueur L1 égale à 1.1 mm ; a first section comprising a turn extending over a length L1 equal to 1.1 mm;
- un deuxième tronçon comprenant cinq spires s'étendant sur une longueur L2 égale à 3.5 mm ; a second section comprising five turns extending over a length L2 equal to 3.5 mm;
- un troisième tronçon comprenant trente spires s'étendant sur une longueur L3 égale à 33 mm ; a third section comprising thirty turns extending over a length L3 equal to 33 mm;
- une portion d'extrémité rectiligne de longueur 1 égale à 5 mm. - a rectilinear end portion of length 1 equal to 5 mm.
Dans la deuxième version (figure 13B), le brin 140.1, 140.2 présente à titre d'exemple les caractéristiques dimensionnelles suivantes : un diamètre d' de fil égal à 0.225 mm ; un diamètre d'enroulement externe D' égal à 1.8 mm ; une longueur totale L' d'enroulement égale à 34.1 mm ; un premier tronçon comprenant une spire s'étendant sur une longueur Ll' égale à 1.1 mm ; un deuxième tronçon comprenant cinq spires s'étendant sur une longueur L2' égale à 3.5 mm ; un troisième tronçon comprenant trente spires s'étendant sur une longueur L3' égale à 27 mm ; une portion d'extrémité rectiligne de longueur l' égale à 5 mm. In the second version (FIG. 13B), the strand 140.1, 140.2 has, by way of example, the following dimensional characteristics: a diameter d ′ of wire equal to 0.225 mm; an outer winding diameter D 'equal to 1.8 mm; a total winding length L 'equal to 34.1 mm; a first section comprising a turn extending over a length L1 ′ equal to 1.1 mm; a second section comprising five turns extending over a length L2 ′ equal to 3.5 mm; a third section comprising thirty turns extending over a length L3 ′ equal to 27 mm; a rectilinear end portion of length l equal to 5 mm.
Dans ces deux exemples, les premier et troisième tronçons présentent un rapport P/D inférieur à 0,7. Le second tronçon présente un rapport P/D inférieur à celui des premier et troisième tronçons. In these two examples, the first and third sections have a P / D ratio of less than 0.7. The second section has a lower P / D ratio than that of the first and third sections.
Les figures 14A et 14B illustrent un dispositif 100' de mesure de pression qui est une variante du dispositif 100 illustré à la figure 9A. Le dispositif 100' diffère du dispositif 100 en ce que la première oreille 112.1' et la deuxième oreille 112.2' sont portées par la première partie 110.1 de boîtier 110 et non par la deuxième partie 110.2 de boîtier 110. Les figures 15A et 15B illustrent un dispositif 101 de mesure de pression selon un deuxième mode de réalisation de l'invention. Le dispositif 101 diffère des dispositifs 100, 100' en ce que la première partie 110.1 et la deuxième partie 110.2 de boîtier 110 comportent chacune deux oreilles en saillie 112.1, 112.1', 112.2, 112.2' qui s'étendent deux à deux en regard l'une de l'autre. FIGS. 14A and 14B illustrate a pressure measuring device 100 'which is a variant of the device 100 illustrated in FIG. 9A. The device 100 'differs from the device 100 in that the first ear 112.1' and the second ear 112.2 'are carried by the first part 110.1 of the housing 110 and not by the second part 110.2 of the housing 110. FIGS. 15A and 15B illustrate a device 101 for measuring pressure according to a second embodiment of the invention. The device 101 differs from the devices 100, 100 'in that the first part 110.1 and the second part 110.2 of the housing 110 each comprise two projecting ears 112.1, 112.1', 112.2, 112.2 'which extend two by two facing the 'one from the other.
Les oreilles 112.1', 112.2' comprennent une surface externe prolongeant la face supérieure du boîtier 110 et les oreilles 112.1, 112.2 comprennent une surface externe prolongeant le fond du boîtier 110. Les oreilles 112.1, 112.1', 112.2, 112.2', dépourvues de doigts en saillie, comprennent chacune une surface interne s'étendant horizontalement et venant sensiblement tangenter les brins 140.1, 140.2. The ears 112.1 ', 112.2' comprise an external surface extending the upper face of the housing 110 and the ears 112.1, 112.2 comprise an external surface extending the bottom of the housing 110. The ears 112.1, 112.1 ', 112.2, 112.2', devoid of fingers projecting, each comprise an internal surface extending horizontally and coming substantially tangent to the strands 140.1, 140.2.
Avantageusement, les oreilles 112.1', 112.2' comprennent un trou traversant formant un ancrage de l'enveloppe de protection 150 au boîtier 110, le matériau élastomère de l'enveloppe de protection 150 adhérant pas à la résine du boîtier 110. Advantageously, the ears 112.1 ′, 112.2 ′ comprise a through hole forming an anchoring of the protective casing 150 to the casing 110, the elastomeric material of the protective casing 150 not adhering to the resin of the casing 110.
Les figures 16A et 16B illustrent un dispositif 101' de mesure de pression qui est une variante du dispositif 101 illustré à la figure 15A. Le dispositif 101' de mesure de pression diffère du dispositif 101 en ce que les surfaces externes des oreilles 112.1', 112,2' s'étendent à distance de la surface supérieure du boîtier 110. La position du dispositif 1 dans l'enveloppe de protection 150 s'en trouve également modifiée. FIGS. 16A and 16B illustrate a pressure measuring device 101 'which is a variant of the device 101 illustrated in FIG. 15A. The pressure measuring device 101 'differs from the device 101 in that the outer surfaces of the ears 112.1', 112.2 'extend away from the upper surface of the housing 110. The position of the device 1 in the casing of protection 150 is also modified.
Bien entendu, l'invention n'est pas limitée au mode de réalisation décrit mais englobe toute variante entrant dans le champ de l'invention telle que définie par les revendications. Of course, the invention is not limited to the embodiment described but encompasses any variant coming within the scope of the invention as defined by the claims.
Bien qu'ici le dispositif de mesure de pression comprenne un boîtier en résine phénolique, l'invention s'applique également à d'autres types de boîtiers comme par exemple un boîtier métallique, en fibre de carbone, en matière époxy ou autre. Although here the pressure measuring device comprises a phenolic resin housing, the invention also applies to other types of housings such as for example a metal case, carbon fiber, epoxy or other material.
Bien qu'ici le boîtier soit de forme cylindrique, l'invention s'applique à d'autres formes de boîtier comme par exemple un boîtier ovoïde, parallélépipédique ou de forme quelconque. Although here the housing is cylindrical in shape, the invention applies to other forms of housing such as for example an ovoid, parallelepiped or any shape.
Bien qu'ici la carte électronique soit fixée au boitier à l'aide de cordons de colle souple à base de silicone, l'invention s'applique également à d'autres types de liaison entre le boîtier et la carte électronique autorisant un mouvement relatif du boitier et de la carte électronique, comme par exemple un joint synthétique ou naturel de type caoutchouc ou EPDM. Although here the electronic card is fixed to the case using flexible silicone-based adhesive beads, the invention also applies to other types of connection between the case and the electronic card allowing relative movement. of the case and of the electronic card, such as for example a synthetic or natural gasket of the rubber or EPDM type.
Bien qu'ici les premiers canaux, les deuxièmes canaux et le troisième canal aient une section circulaire, l'invention s'applique également à des premiers canaux, des deuxièmes et/ou un troisième canal de section différente comme par exemple une section carrée ou autre. Although here the first channels, the second channels and the third channel have a circular section, the invention also applies to first channels, second and / or a third channel of different section such as for example a square section or other.
Bien qu'ici le dispositif de mesure de pression comprenne un microcontrôleur, l'invention s'applique également à d'autres moyens de traitement du signal comme par exemple un FPGA, des portes logiques ou un microprocesseur . Although here the pressure measuring device comprises a microcontroller, the invention also applies to other signal processing means such as for example an FPGA, logic gates or a microprocessor.
L'invention s'applique à tous moyens de liaison des composants au circuit électronique comme par exemple par liaisons filaires, soudage/brasage, brochage ou frittage sur un support de type PCB. The invention applies to all means for connecting the components to the electronic circuit, such as for example by wire connections, soldering / brazing, pinning or sintering on a support of the PCB type.
L'invention s'applique à tout moyen de liaison des composants au circuit électronique comme par exemple par liaisons filaires, soudage/brasage, brochage ou frittage sur un support de type PCB. The invention applies to any means of connecting components to the electronic circuit such as for example by wire connections, soldering / brazing, pinning or sintering on a support of the PCB type.
Bien qu'ici le dispositif de mesure de pression comprenne un émetteur/récepteur radio (par exemple de type « RFID »), l'invention s'applique à tout type de techniques d'émission sans fil comme par exemple un protocole 2G, 3G, 4G, 5G, de type « LoRa », « edge », « Wi-Fi », « Bluetooth », ultrason ou « IOT ». On prévoira d'intégrer une batterie au dispositif de mesure de pression s'il est nécessaire d'alimenter l'émetteur/récepteur. Bien qu'ici le dispositif de mesure de pression comprenne un convertisseur d'énergie électromagnétique, l'invention s'applique également à d'autres types de convertisseurs d'énergie comme par exemple un convertisseur d'énergie cinétique inductif ou de type piézoélectrique ou un convertisseur d'énergie thermique. Although here the pressure measurement device comprises a radio transmitter / receiver (for example of the “RFID” type), the invention applies to all types of wireless transmission techniques such as for example a 2G, 3G protocol. , 4G, 5G, “LoRa”, “edge”, “Wi-Fi”, “Bluetooth”, ultrasound or “IOT” type. Provision will be made to integrate a battery into the pressure measuring device if it is necessary to power the transmitter / receiver. Although here the pressure measuring device comprises an electromagnetic energy converter, the invention also applies to other types of energy converters such as for example an inductive kinetic energy converter or of the piezoelectric type or a thermal energy converter.
Bien qu'ici le dispositif de mesure soit placé dans une roue d'aéronef, l'invention s'applique également à d'autres véhicules comme par exemple des camions ou des automobiles . Bien qu'ici le pneumatique soit rempli d'azote sous pression, l'invention s'applique également à des pneus remplis d'autres types de fluide sous pression comme par exemple l'air ou des gaz inertes autres que l'azote. Although here the measuring device is placed in an aircraft wheel, the invention also applies to other vehicles such as, for example, trucks or automobiles. Although here the tire is filled with nitrogen under pressure, the invention also applies to tires filled with other types of pressurized fluid such as, for example, air or inert gases other than nitrogen.
Bien qu'ici le capteur de pression soit de type piézoélectrique, l'invention s'applique également à d'autres types de capteurs de pression comme par exemple un capteur résistif, inductif, piézorésistif, capacitif ou résonnant. Although here the pressure sensor is of the piezoelectric type, the invention also applies to other types of pressure sensors such as for example a resistive, inductive, piezoresistive, capacitive or resonant sensor.
Bien qu'ici les deuxièmes canaux soient pourvus d'un revêtement métallique obtenu par métallisation, l'invention s'applique également à d'autres moyens d'application d'un revêtement métallique sur les deuxièmes canaux, comme par exemple un sertissage d'une chemise métallique ou la pose d'une peinture conductrice. Les deuxièmes canaux peuvent être dépourvus de revêtement métallique. Although here the second channels are provided with a metallic coating obtained by metallization, the invention also applies to other means of applying a metallic coating to the second channels, such as for example a crimping of a metal jacket or the application of conductive paint. The second channels may be devoid of a metallic coating.
Bien qu'ici un anneau en cuivre reçu dans une rainure de la première surface de la carte électronique s'étende autour de chaque deuxième canal, l'invention s'applique également à d'autre type d'élément conducteur placé à proximité du deuxième canal comme par exemple un anneau de forme carrée ou quelconque, une métallisation de la surface de la première carte électronique ou une impression à l'aide d'une encre conductrice. Bien qu'ici le dispositif de mesure de pression comprenne une batterie, l'invention s'applique également à d'autres types de générateur de tension comme par exemple une pile ou un condensateur. Although here a copper ring received in a groove of the first surface of the electronic card extends around each second channel, the invention also applies to other type of conductive element placed at proximity of the second channel such as for example a ring of square or any shape, a metallization of the surface of the first electronic card or a printing using a conductive ink. Although here the pressure measuring device comprises a battery, the invention also applies to other types of voltage generator such as for example a battery or a capacitor.
Bien qu'ici l'élément conducteur soit relié à un pôle négatif du générateur de tension et le revêtement de chaque deuxième canal soit relié au pôle positif du générateur de tension, l'invention s'applique également à une inversion des polarités de connexion. Although here the conductive element is connected to a negative pole of the voltage generator and the coating of each second channel is connected to the positive pole of the voltage generator, the invention also applies to a reversal of the connection polarities.
Bien qu'ici la carte électronique soit liée par des cordons de colle au boîtier, l'invention s'applique également à d'autres types de liaison entre le boîtier et la carte électronique comme par exemple un ou plusieurs plots élastomères s'étendant depuis la première surface de la carte électronique jusqu'à la première partie du boîtier et un ou plusieurs plots élastomères s'étendant depuis la deuxième surface de la carte électronique jusqu'au la deuxième face du boîtier. Although here the electronic card is linked by beads of adhesive to the housing, the invention also applies to other types of connection between the housing and the electronic card such as for example one or more elastomeric pads extending from the first surface of the electronic card up to the first part of the housing and one or more elastomeric pads extending from the second surface of the electronic card to the second face of the housing.
Bien qu'ici la première portion et la deuxième portion de la carte électronique s'étendant hors du boîtier soient des portions rigides qui portent une antenne, les première et deuxième portions peuvent également être flexible et/ou contenir d'autres types d'éléments conducteurs en relation avec les composants qui sont sous le boîtier. En outre, bien qu'ici la carte électronique soit fixée au boîtier à l'aide de cordons de colle souple à base de silicone, l'invention s'applique également à d'autres types de liaison entre le boîtier et la carte électronique autorisant un mouvement relatif du boîtier et de la carte électronique, comme par exemple un joint synthétique ou naturel de type caoutchouc ou EPDM. Le dispositif de mesure de pression peut également comprendre un capteur de température pour transmettre la température et/ou réaliser une compensation en température de la mesure du capteur de pression. La mesure de la température peut être réalisée par un capteur dédié ou encore être mesurée sur un capteur piézorésistif par la mesure de la résistance d'entrée de l'élément sensible ou par toute autre combinaison de résistances d'un capteur piézorésistif dont le résultat ne fournirait qu'une image de la température, celle de la pression étant éliminée dans la combinaison réalisée (résistances travaillant en longitudinal ou transversal donnant respectivement des facteurs de jauge positif et négatifs). Although here the first portion and the second portion of the electronic card extending outside the housing are rigid portions which carry an antenna, the first and second portions may also be flexible and / or contain other types of elements. conductors in relation to the components which are under the housing. In addition, although here the electronic card is fixed to the housing using beads of flexible silicone-based glue, the invention also applies to other types of connection between the housing and the electronic card allowing a relative movement of the case and of the electronic card, such as for example a synthetic or natural gasket of the rubber or EPDM type. The pressure measuring device can also include a temperature sensor for transmitting the temperature and / or for performing a temperature compensation of the measurement of the pressure sensor. The temperature measurement can be carried out by a dedicated sensor or even be measured on a piezoresistive sensor by measuring the input resistance of the sensitive element or by any other combination of resistances of a piezoresistive sensor whose result does not would provide only an image of the temperature, that of the pressure being eliminated in the combination produced (resistors working in longitudinal or transverse direction giving respectively positive and negative gauging factors).
Pour des raisons de redondances de la mesure, il est envisageable de placer plusieurs dispositifs de mesure de pression dans une même roue. For reasons of measurement redundancy, it is possible to place several pressure measurement devices in the same wheel.
L'enveloppe de protection 150 peut ne recouvrir qu'en partie la première et/ou la deuxième antenne. The protective envelope 150 may only partially cover the first and / or the second antenna.
Bien qu'ici la forme des première et deuxième portion de la carte électronique soit de forme triangulaire, l'invention s'applique également à toute autre forme, comme par exemple des portions de forme rectangulaire. Although here the shape of the first and second portions of the electronic card is triangular in shape, the invention also applies to any other shape, such as, for example, portions of rectangular shape.
Bien qu'ici le fond du boîtier 10 prenne appui indirectement sur la surface interne de la bande de roulement du pneumatique via un élément de liaison, le fond peut aussi prendre appui directement sur ladite surface interne de la bande de roulement. Although here the bottom of the housing 10 bears indirectly on the internal surface of the tread of the tire via a connecting element, the base can also bear directly on said internal surface of the tread.
Le fond du boîtier 110 peut prendre appui directement contre la surface interne du pneumatique ou indirectement via une interface comme une interface de fixation ou de découplage. The bottom of the housing 110 can bear directly against the internal surface of the tire or indirectly via an interface such as a fixing or decoupling interface.
Bien qu'ici le dispositif de mesure comprend un capteur de pression et/ou de température, il peut aussi comprendre tout type de capteur permettant une mesure d'un paramètre de fonctionnement du pneumatique tel qu'une position angulaire, une vitesse de rotation, une accélération, un champ magnétique, une humidité, une corrosion... Although here the measuring device comprises a pressure and / or temperature sensor, it can also include any type of sensor allowing measurement of an operating parameter of the tire such as a angular position, rotational speed, acceleration, magnetic field, humidity, corrosion ...
Le volume VI peut être égal ou supérieur au volume V2 à condition que le centre de gravité G soit situé en dessous de la carte électronique 20. On pourrait par exemple envisager que le fond 13 de la deuxième partie 10.2 du boîtier 10 soit plus épais de manière à abaisser le centre de gravité G et que le volume V2 résultant soit sensiblement égal au volume VI. The volume VI can be equal to or greater than the volume V2 provided that the center of gravity G is located below the electronic card 20. It could for example be envisaged that the bottom 13 of the second part 10.2 of the housing 10 is thicker by so as to lower the center of gravity G and that the resulting volume V2 is substantially equal to the volume VI.
Le diamètre des premiers canaux 12 peut être supérieur à celui des deuxièmes canaux 21 de manière à améliorer la filtration de l'air passant du premier volume VI vers le deuxième volume V2 au détriment de sa circulation entre lesdits premier volume VI et le deuxième volume V2. The diameter of the first channels 12 may be greater than that of the second channels 21 so as to improve the filtration of the air passing from the first volume VI to the second volume V2 to the detriment of its circulation between said first volume VI and the second volume V2 .
Le diamètre du troisième canal 22 peut être supérieur à celui des deuxièmes canaux 21 de manière à ce qu'aucune des particules filtrées par les deuxième canaux 21 soit en mesure de boucher le troisième canal 22. Le circuit électronique pourra comprendre d'autres composants électroniques en lieu et place et/ou en plus des composants électroniques 31, 32, 33, 34. Néanmoins, les composants dits « critiques », c'est-à-dire ceux susceptibles d'être endommagés par des particules contenues dans le volume interne V (poussière, limaille, grain de sable...), seront préférentiellement répartis sur la deuxième face 20.2 de la carte électronique 20, autrement dit dans le deuxième volume V2, de manière à bénéficier de la double filtration réalisée par les premiers canaux 12 et les deuxièmes canaux 21. The diameter of the third channel 22 may be greater than that of the second channels 21 so that none of the particles filtered by the second channels 21 is able to block the third channel 22. The electronic circuit may include other electronic components. instead of and / or in addition to the electronic components 31, 32, 33, 34. However, the so-called “critical” components, that is to say those liable to be damaged by particles contained in the internal volume V (dust, filings, grain of sand, etc.), will preferably be distributed over the second face 20.2 of the electronic card 20, in other words in the second volume V2, so as to benefit from the double filtration carried out by the first channels 12 and the second channels 21.

Claims

REVENDICATIONS
1. Dispositif (1, 2, 3, 4, 5, 6, 7, 100, 100', 101, 101') de mesure de pression destiné à équiper un pneumatique (P), comprenant : - un circuit électronique qui est réparti sur au moins une première face (20.1, 120.1) d'une carte électronique (20, 120) et qui comprend un capteur de pression (30, 130) monté sur la première face de la carte électronique et comportant un capotage (35, 135) de protection mécanique définissant une enceinte étanche à une pression de référence ; 1. Device (1, 2, 3, 4, 5, 6, 7, 100, 100 ', 101, 101') for measuring pressure intended to equip a tire (P), comprising: - an electronic circuit which is distributed on at least a first face (20.1, 120.1) of an electronic card (20, 120) and which comprises a pressure sensor (30, 130) mounted on the first face of the electronic card and comprising a cover (35, 135 ) mechanical protection defining a sealed enclosure at a reference pressure;
- une première partie (10.1, 110.1) de boîtier (10, 110) recouvrant au moins partiellement la première face pour délimiter avec celle-ci un premier volume (VI) et comportant au moins un premier canal (12, 111) mettant en communication fluidique le premier volume avec l'extérieur ; et - a first part (10.1, 110.1) of the housing (10, 110) at least partially covering the first face in order to define therewith a first volume (VI) and comprising at least a first channel (12, 111) putting in communication fluidizes the first volume with the exterior; and
- une deuxième partie (10.2, 110.2) de boîtier (10, 110) recouvrant au moins partiellement une deuxième face (20.2, 120.2) de la carte électronique pour délimiter avec celle-ci un deuxième volume (V2), et possédant un fond destiné à s'étendre en regard d'une surface interne du pneumatique ; la carte électronique (20, 120) comportant au moins un deuxième canal (21, 123) traversant mettant en communication fluidique le premier volume (VI) avec le deuxième volume (V2), et un troisième canal (22, 124) traversant mettant en communication fluidique l'enceinte délimitée par le capotage (35, 135) avec le deuxième volume (V2). - a second part (10.2, 110.2) of the housing (10, 110) at least partially covering a second face (20.2, 120.2) of the electronic card to define therewith a second volume (V2), and having a bottom intended in extending facing an internal surface of the tire; the electronic card (20, 120) comprising at least one second channel (21, 123) passing through placing the first volume (VI) in fluid communication with the second volume (V2), and a third channel (22, 124) passing through putting in fluid communication between the enclosure delimited by the cowling (35, 135) with the second volume (V2).
2. Dispositif (1, 2, 3, 4, 5, 6, 7, 100, 100', 101, 101') selon la revendication 1, dans lequel le premier canal (12, 111) et le deuxième canal (21, 123) ont une section circulaire globalement constante, le diamètre du premier canal étant supérieur à celui du deuxième canal. 3. Dispositif (1, 2, 2. Device (1, 2, 3, 4, 5, 6, 7, 100, 100 ', 101, 101') according to claim 1, wherein the first channel (12, 111) and the second channel (21, 123) have a generally constant circular section, the diameter of the first channel being greater than that of the second channel. 3. Device (1, 2,
3, 4, 5, 6, 7, 100, 100', 101, 101') selon la revendication 1, dans lequel le premier canal (12, 111) et le deuxième canal (21, 123) ont une section circulaire globalement constante, le diamètre du premier canal étant inférieur à celui du deuxième canal. 3, 4, 5, 6, 7, 100, 100 ', 101, 101') according to claim 1, wherein the first channel (12, 111) and the second channel (21, 123) have a generally constant circular section , the diameter of the first channel being smaller than that of the second channel.
4. Dispositif (1, 2, 3, 4, 5, 6, 7, 100, 100', 101, 101') selon la revendication 2 ou 3, dans lequel le troisième canal (22, 124) a une section circulaire globalement constante, le diamètre du troisième canal étant supérieur à celui du deuxième canal (21, 123). 4. Device (1, 2, 3, 4, 5, 6, 7, 100, 100 ', 101, 101') according to claim 2 or 3, wherein the third channel (22, 124) has a generally circular section. constant, the diameter of the third channel being greater than that of the second channel (21, 123).
5. Dispositif (1, 2, 3, 4, 5, 6, 7, 100, 100', 101, 101') selon l'une des revendications 2 à 4, dans lequel le diamètre du deuxième canal (21, 123) est compris entre 100 et 300 micromètres. 6. Dispositif (1, 2, 3, 4, 5, 5. Device (1, 2, 3, 4, 5, 6, 7, 100, 100 ', 101, 101') according to one of claims 2 to 4, wherein the diameter of the second channel (21, 123) is between 100 and 300 micrometers. 6. Device (1, 2, 3, 4, 5,
6, 7, 100, 100', 101, 101') selon la revendication 5, dans lequel le diamètre du deuxième canal (21, 123) est égal à 200 micromètres. 6, 7, 100, 100 ', 101, 101') according to claim 5, in which the diameter of the second channel (21, 123) is equal to 200 micrometers.
7. Dispositif (1, 2, 3, 4, 5, 6, 7) selon l'une quelconque des revendications précédentes, dans lequel la deuxième partie (10.2) de boitier (10) est agencée de telle manière que le dispositif ait un centre de gravité situé dans le deuxième volume (V2) à distance de la carte électronique. 7. Device (1, 2, 3, 4, 5, 6, 7) according to any one of the preceding claims, wherein the second part (10.2) of the housing (10) is arranged such that the device has a center of gravity located in the second volume (V2) at a distance from the electronic card.
8. Dispositif (100, 100', 101, 101') selon l'une quelconque des revendications là 6, comprenant au moins un premier brin (140.1, 140.2) d'antenne comportant une extrémité galvaniquement reliée au circuit électronique et s'étendant intégralement en saillie latérale du boîtier, le boîtier comprenant une portion latérale (112.1, 112.2) en saillie tangentant sensiblement un tronçon d'extrémité (141.1) proximal du premier brin selon une génératrice dudit premier brin. 8. Device (100, 100 ', 101, 101') according to any one of claims 1 to 6, comprising at least a first antenna strand (140.1, 140.2) having one end galvanically connected to the electronic circuit and extending integrally projecting from the side of the housing, the housing comprising a projecting lateral portion (112.1, 112.2) substantially tangent to an end section (141.1) proximal to the first strand along a generatrix of said first strand.
9. Dispositif (1, 2, 3, 4, 5, 6, 7, 100, 100', 101, 101') selon l'une quelconque des revendications précédentes, dans lequel le boîtier (10, 110) est de forme globalement cylindrique. 9. Device (1, 2, 3, 4, 5, 6, 7, 100, 100 ', 101, 101') according to any preceding claim, wherein the housing (10, 110) is generally shaped cylindrical.
10. Pneumatique (P) comprenant un dispositif (1, 2, 3, 4, 5, 6, 7, 100, 100', 101, 101') de mesure de pression selon l'une quelconque des revendications précédentes. 10. A tire (P) comprising a device (1, 2, 3, 4, 5, 6, 7, 100, 100 ', 101, 101') for measuring pressure according to any one of the preceding claims.
11. Roue (R) comprenant un pneumatique (P) selon la revendication 10. 11. Wheel (R) comprising a tire (P) according to claim 10.
12. Train d'atterrissage d'aéronef comprenant au moins une roue (R) selon la revendication 11. 12. Aircraft landing gear comprising at least one wheel (R) according to claim 11.
PCT/EP2021/057313 2020-03-22 2021-03-22 Device for measuring tyre pressure WO2021191166A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR2002782A FR3108402B1 (en) 2020-03-22 2020-03-22 Device for measuring an operating parameter of a tire
FR2002783A FR3108403B1 (en) 2020-03-22 2020-03-22 Tire pressure measuring device
FRFR2002783 2020-03-22
FRFR2002782 2020-03-22

Publications (1)

Publication Number Publication Date
WO2021191166A1 true WO2021191166A1 (en) 2021-09-30

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PCT/EP2021/057313 WO2021191166A1 (en) 2020-03-22 2021-03-22 Device for measuring tyre pressure

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130106597A1 (en) * 2011-10-31 2013-05-02 Hong Kong Applied Science and Technology Research Institute Company Limited Mount-free tire pressure monitoring system
WO2020043744A1 (en) * 2018-08-31 2020-03-05 Safran Electronics & Defense Encased pressure sensor
US20200070598A1 (en) * 2016-12-05 2020-03-05 Compagnie Generale Des Etablissements Michelin Method for manufacturing a patch equipped with a radiofrequency transponder and tire comprising such a patch

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130106597A1 (en) * 2011-10-31 2013-05-02 Hong Kong Applied Science and Technology Research Institute Company Limited Mount-free tire pressure monitoring system
US20200070598A1 (en) * 2016-12-05 2020-03-05 Compagnie Generale Des Etablissements Michelin Method for manufacturing a patch equipped with a radiofrequency transponder and tire comprising such a patch
WO2020043744A1 (en) * 2018-08-31 2020-03-05 Safran Electronics & Defense Encased pressure sensor

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