U.S. patent application number 17/271884 was filed with the patent office on 2021-11-11 for encased pressure sensor for measuring pressure in an aircraft wheel.
The applicant listed for this patent is Compagnie Generale Des Etablissements Michelin, Safran, SAFRAN ELECTRONICS & DEFENSE, Safran Landing Systems. Invention is credited to Eric BAILLY, Jean-Christophe RIOU.
Application Number | 20210348977 17/271884 |
Document ID | / |
Family ID | 1000005925985 |
Filed Date | 2021-11-11 |
United States Patent
Application |
20210348977 |
Kind Code |
A1 |
RIOU; Jean-Christophe ; et
al. |
November 11, 2021 |
ENCASED PRESSURE SENSOR FOR MEASURING PRESSURE IN AN AIRCRAFT
WHEEL
Abstract
A pressure measurement device (1) comprising a housing (20)
extending around an electronic card (30) provided with a pressure
sensor (40); the housing (20) co-operating with a first face (31)
of the electronic card (30) to define a first sealed volume (3);
the housing (20) also co-operating with a second face (32) of the
electronic card (30) that is opposite from the first face (31) to
define a second sealed volume (4); the housing (20) including at
least one first channel (24) putting the medium (5) outside the
housing (20) into fluid flow communication with the first sealed
volume (3); the electronic card (30) including at least one second
channel (33) putting the first volume (3) into fluid flow
communication with the second volume (4); and the connection
between the housing (20) and the electronic card (30) being
arranged to allow relative movement between the housing (20) and
the electronic card.
Inventors: |
RIOU; Jean-Christophe;
(PARIS, FR) ; BAILLY; Eric; (PARIS, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAFRAN ELECTRONICS & DEFENSE
Compagnie Generale Des Etablissements Michelin
Safran Landing Systems
Safran |
PARIS
Clermont-Ferrand
Velizy-Villacoublay
Paris |
|
FR
FR
FR
FR |
|
|
Family ID: |
1000005925985 |
Appl. No.: |
17/271884 |
Filed: |
August 27, 2019 |
PCT Filed: |
August 27, 2019 |
PCT NO: |
PCT/EP2019/072890 |
371 Date: |
April 13, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01L 19/148 20130101;
G01L 19/0636 20130101; G01L 17/00 20130101; B60C 23/0493 20130101;
B60C 23/0411 20130101; G01L 19/04 20130101; G01L 19/0654
20130101 |
International
Class: |
G01L 17/00 20060101
G01L017/00; G01L 19/06 20060101 G01L019/06; G01L 19/14 20060101
G01L019/14; G01L 19/04 20060101 G01L019/04; B60C 23/04 20060101
B60C023/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2018 |
FR |
18 57877 |
Claims
1. A pressure measurement device comprising a housing extending
around an electronic card provided with a pressure sensor; the
housing co-operating with a first face of the electronic card to
define a first sealed volume; the housing also co-operating with a
second face of the electronic card that is opposite from the first
face to define a second sealed volume; the housing including at
least one first channel putting the medium outside the housing into
fluid flow communication with the first sealed volume; the
electronic card including at least one second channel putting the
first volume into fluid flow communication with the second volume;
and the connection between the housing and the electronic card
being arranged to allow relative movement between the housing and
the electronic card; wherein the second channel is metal-plated;
and wherein a conductive element is placed in the proximity of the
second channel and is connected to a first pole of a voltage
generator, the second channel being connected to a second pole of
said voltage generator.
2. The pressure measurement device according to claim 1, wherein
the pressure sensor extends in the first sealed volume.
3. The pressure measurement device according to claim 1, wherein
the pressure sensor defines a sealed measurement enclosure, said
sealed measurement enclosure being in fluid flow communication with
the second volume.
4. The pressure measurement device according to claim 1, including
processor means for processing the signal from the sensor and/or
communication means extending in the first sealed volume.
5. The pressure measurement device according to claim 1, wherein a
portion of the electronic card extends outside the housing.
6. The pressure measurement device according to claim 1, wherein
the first channel is circular in section with a first diameter
lying in the range 0.2 mm to 1.5 mm, preferably being 1 mm, and the
second channel is circular in section with a second diameter lying
in the range 100 .mu.m to 300 .mu.m, preferably being 200
.mu.m.
7. The pressure measurement device according to claim 1, wherein
the conductive element comprises a zone of the first face of the
electronic card that is provided with a conductive coating.
8. The pressure measurement device according to claim 1, wherein
the connection between the housing and the electronic card includes
means for damping vibration.
9. The pressure measurement device according to claim 1, wherein
the connection between the housing and the electronic card is an
adhesive connection.
10. The pressure measurement device according to claim 1, including
a heater device for heating the at least one second channel.
11. The pressure measurement device according to claim 10, wherein
the heater device comprises a resistive wire.
12. A tire including a pressure measurement device according to
claim 1.
13. A wheel including a tire according to claim 12.
14. An aircraft including a wheel according to claim 13.
15. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention relates to measuring pressure, and
more particularly to measuring pressure in an aircraft wheel.
BACKGROUND OF THE INVENTION
[0002] Conventionally, an aircraft wheel comprises a cylindrical
rim carrying a tire that co-operates with the rim to define an
inside volume filled with a fluid under pressure, generally air or
a fluid comprising a majority of nitrogen together with various
components of air. After each landing, the pressure of the air
contained in the wheel is measured by using a pressure measurement
device mounted on an inflation valve secured to the rim. The rim
generally contains a stack of brake disks called a heat pack that
gives off a significant amount of heat when braking the aircraft
(temperatures higher than 500 degrees Celsius). This heat requires
the use of specific materials and assembly techniques, which make
the manufacture of such a pressure sensor very expensive.
Furthermore, the exposure of the sensor to high temperature while
taking a measurement disturbs the accuracy of the measurement.
OBJECT OF THE INVENTION
[0003] The object of the invention is to improve the accuracy of a
pressure measurement device.
SUMMARY OF THE INVENTION
[0004] To this end, the invention provides a pressure measurement
device comprising a housing extending around an electronic card
provided with a pressure sensor. The housing co-operates with a
first face of the electronic card to define a first sealed volume.
The housing also co-operates with a second face of the electronic
card that is opposite from the first face to define a second sealed
volume. The housing includes at least one first channel putting the
medium outside the housing into fluid flow communication with the
first sealed volume. The electronic card includes at least one
second channel putting the first volume into fluid flow
communication with the second volume. The connection between the
housing and the electronic card is arranged to allow relative
movement between the housing and the electronic card.
[0005] A pressure measurement device is thus obtained that provides
effective mechanical decoupling and that also performs double
filtering of the particles contained in the fluid that is having
its pressure measured. The succession of channels through which the
fluid passes in order to reach the sensor also limits the effects
of pressure and temperature transients. The housing also improves
protection against mechanical aggression. It is thus possible to
select a pressure sensor that is more accurate than sensors of the
prior art, where selection has been based essentially on
constraints associated with effectively withstanding aggression
from the medium in which the device is placed.
[0006] Advantageously, the pressure sensor extends in the first
sealed volume.
[0007] The filtering of the fluid that is having its pressure
measured is improved when the pressure sensor defines a sealed
measurement enclosure, and when said sealed measurement enclosure
is in fluid flow communication with the second volume.
[0008] Also advantageously, the measurement device includes
processor means for processing the signal from the sensor and/or
communication means extending in the first sealed volume. It should
be observed that in this sensor, the electronic assembly, the
sensing element, and the support receiving the electronic
components are all under pressure while being protected by a thin
layer of Parylene having a thickness of 10 micrometers (.mu.m).
[0009] In a preferred embodiment, a portion of the electronic card
extends outside the housing.
[0010] The filtering of temperature and pressure transients, and
also the filtering of the particles present in the fluid that is
having its pressure measured is particularly effective when the
first channel is circular in section with a first diameter lying in
the range 0.2 millimeters (mm) to 1.5 mm, preferably being 1 mm,
and the second channel is circular in section with a second
diameter lying in the range 100 .mu.m to 300 .mu.m, preferably
being 200 .mu.m.
[0011] The second channel is provided with good protection when it
is metal plated.
[0012] The sensor is provided with improved protection against
freezing when a conductive element is placed in the proximity of
the second channel and is connected to a first pole of a voltage
generator, the second channel being connected to a second pole of
said voltage generator. Protection against freezing is further
improved when the pressure measurement device includes a heater
device for heating the at least one second channel. Such a heater
device can be made inexpensively when the heater device comprises a
resistive wire.
[0013] The conductive element can be made inexpensively when the
conductive element comprises a zone of the first face that is
provided with a conductive coating.
[0014] The robustness of the device is improved when the connection
between the housing and the electronic card includes means for
damping vibration. Such a connection can be made inexpensively when
it is made with adhesive.
[0015] The invention also provides a tire including a pressure
measurement device of the above type, a wheel provided with such a
tire, and also an aircraft equipped with such a wheel.
[0016] Other characteristics and advantages of the invention appear
on reading the following description of particular, nonlimiting
embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Reference is made to the accompanying figures, in which:
[0018] FIG. 1 is an exploded diagrammatic view in perspective of a
pressure measurement device in a first embodiment of the
invention;
[0019] FIG. 2 is a diagrammatic section view of the FIG. 1 pressure
measurement device;
[0020] FIG. 3 is a detail view of the FIG. 1 pressure measurement
device;
[0021] FIG. 4 is a fragmentary diagrammatic view in section of a
wheel in a first embodiment of the invention;
[0022] FIG. 5 is an exploded diagrammatic view in section of a
pressure measurement device in a second embodiment of the
invention;
[0023] FIG. 6 is a diagrammatic plan view of the FIG. 5 pressure
measurement device; and
[0024] FIG. 7 is a detail view of a third embodiment of the
pressure measurement device of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] With reference to FIGS. 1 to 3, the pressure measurement
device of the invention, given overall reference 1, comprises a
housing 20 made of phenolic resin, in this example in the shape of
a straight cylinder, that extends around an electronic card 30
provided with a pressure sensor 40 welded on the first face 31 of
the electronic card 30. The housing 20 comprises a top cover 21
screwed on a bottom cover 22. The top cover 21 and the bottom cover
22 are arranged to form a peripheral setback 23 in which the
electronic card 30 is fastened using a bead 2 of flexible
silicone-based adhesive.
[0026] The top cover 21 of the housing 20 co-operates with the
first face 31 of the electronic card 30 to define a first sealed
volume 3. The bottom cover 22 of the housing 20 co-operates with
the second face 32 of the electronic card 30 that is opposite from
the first face 31 to define a second sealed volume 4. The top cover
21 includes twenty first channels 24 that put the medium 5 outside
the housing 20 into fluid flow communication with the first volume
3. The first channels 24 are circular in section, having a first
diameter 24.1 of 1 mm. The electronic card 30 includes twenty
second channels 33 passing through it and putting the first volume
3 into fluid flow communication with the second volume 4. The
second channels 33 are circular in section, having a second
diameter 33.1 of 200 .mu.m.
[0027] The pressure sensor 40 extends in the first volume 3 and
includes a mechanical protection hood 41 (wirebonding) that defines
a sealed measurement enclosure 42. In this example, the pressure
sensor 40 is a capacitive sensor comprising a membrane 43 that
extends parallel to the first face 31 and that is provided with a
first electrode 44. The top portion of the hood 41 constitutes a
second electrode 45 of a capacitor 46. A third channel 33 puts the
enclosure 42 into fluid flow communication with the second volume
4. The third channel 34 is circular in section, having the second
diameter 34.1 of 200 .mu.m.
[0028] The device 1 includes a microcontroller 35 to which the
first electrode 44 and the second electrode 46 are connected, as is
a radio transceiver 36. The microcontroller 35 and the radio
transceiver 36 extend in the first volume 3. The first volume 3
also contains a kinetic energy recovery unit 37 secured to the
electronic card 30. The recovery unit 37 comprises a converter 38
that converts the kinetic energy it captures into electrical
energy, which it sends to a first rechargeable battery 39. In this
example, the energy recovery unit 37 comprises a ball 37.1 that is
made of ferromagnetic material and that can move freely in the air
gap of a coil 37.2. The first rechargeable battery 39 powers the
microcontroller 35 and the radio transceiver 36.
[0029] As can be seen in FIG. 3, the second channels 33 are
provided with metal coating 30 that is obtained by metal plating. A
ring 61 extends around each second channel 33 at a nonzero distance
therefrom. In this example, each ring 61 is made by depositing
copper in a groove 62 machined in the electronic card 30 and is
connected to a first pole 39.1 of the first rechargeable battery
39, specifically a negative pole. The coating 60 of each second
channel 33 is connected to a second pole 39.2 of the first
rechargeable battery 39, specifically a positive pole.
Advantageously, the top surface 61.1 of the ring 61 is set back
perceptibly from the first face 31 of the electronic card 30 so as
to create a retention zone.
[0030] As can be seen in FIG. 4, the pressure measurement device 1
is placed inside a wheel 50 of an aircraft 100. The wheel 50
comprises a rim 51 having a tire 52 mounted thereon. The tire 52
co-operates with the rim 51 to define an inside volume 53 of the
wheel 50 that is filled with air under pressure. The bottom 22 of
the pressure measurement device 1 is adhesively bonded on the
inside face of a sidewall 52.1 of the tire 52. For measurement
redundancy purposes, it is possible to envisage placing a plurality
of pressure measurement devices 1 in a single wheel 50.
[0031] The avionics equipment 101 of the aircraft 100 includes a
radio transceiver 102 tuned to the transmit/receive frequencies of
the transceiver 36 of the pressure measurement device 1.
[0032] In operation, the air under pressure in the inside volume 53
penetrates into the first volume 3 via the first channels 24. The
first channels 24 perform first filtering of particles (dust,
filings, etc.) that might be present in the inside volume 53.
Second filtering of the air under pressure in the inside volume 53
is performed by the second channels 33 when the air under pressure
passes from the inside volume 53 into the second channels 33. The
air present in the second volume 4 then penetrates into the
enclosure 42 and acts of the membrane 43. Under the effect of the
air pressure prevailing within the enclosure 42, the membrane 43
deforms, and the capacitance of the capacitor 46 is modified. The
microcontroller 35 converts the capacitance of the capacitor 46
into a pressure value for the wheel 50, which value is then sent
via the radio transceiver 36 to the radio transceiver 102 of the
aircraft 100.
[0033] The first rechargeable battery 39 establishes a voltage
between the metal coating 60 of the second channel 33 and the ring
61 that surrounds it, thereby electrolytically vaporizing any water
that might be obstructing the channel 33. The diameter of the
second channel 33 promotes water retention by capilarity and
contributes to preventing moisture in the air contained in the
inside volume 53 from penetrating as far as the second volume 4.
The retention of moisture in the second channel 33 and the
electrolysis device serves to limit the presence of water on the
membrane 43 and to protect the device 1 from the harmful
consequences of freezing while the aircraft 100 is in flight.
Specifically, water ice on the sensing element of a pressure sensor
generally makes it inoperative and usually causes it to be
destroyed.
[0034] During periods in which the wheel 50 is rotating, the
recovery unit 37 converts the kinetic energy to which the pressure
measurement device 1 is being subjected into electrical energy that
is stored in the first rechargeable battery 39.
[0035] The flexibility of the bead 2 of adhesive connecting
together the housing 20 and the electronic card 30 allows for
relative movement between the housing 20 and the electronic card
30, thereby serving to limit the transmission of vibration and of
impacts from the wheel 52 the electronic card 30. The inventors
have observed that the vibration, impacts, and mechanical stresses
to which the electronic card 30 is subjected are reduced by a
factor of at least 100 compared with the electronic card 30 being
adhesively bonded directly on the side wall 52.1 of the wheel 50.
The flexible adhesive generally presents hardness lying in the
range 30 on the Shore OO scale to 60 on the Shore A scale.
[0036] A pressure measurement device 1 is thus obtained that
provides effective mechanical decoupling and that also performs
double particle filtering on the air that is having its pressure
measured. The succession of channels through which the air passes
in order to reach the sensor 40 also limits the effect of pressure
and temperature transients. Finally, the pressure measurement
device 1 possesses improved resistance to freezing.
[0037] A second embodiment of the invention is shown in FIGS. 5 and
6. In this embodiment, the electronic card 30 possesses a portion
30.1, which is substantially triangular in this example, that
extends outside the housing 20 and that has extending therein an
antenna wire 36.1 that is connected to the radio transceiver
36.
[0038] In a third embodiment, shown in FIG. 7, the second of
channels 33 are associated with a heater device, specifically in
the form of a resistor wire 70 embedded in the card 30 and spiral
wound around each second channel 33. The wire 70 is connected to
the poles of a second rechargeable battery 71 via a current
regulator unit 72 that is controlled by the microcontroller 35.
Advantageously, the second rechargeable battery 71 is connected to
the converter 38. The resistor wire 70 thus serves to heat the
fluid passing through the second channels 33 from the first volume
3 to the second volume 4 and to keep its temperature above the dew
point. This heating thus serves to ensure that the fluid
penetrating into the enclosure 42 is dry, while concentrating any
zones of ice formation in the first volume 3 at the peripheries of
the first channels 33 where the fluid has not been heated.
[0039] Naturally, the invention is not limited to the embodiments
described, but covers any variant coming within the ambit of the
invention as defined by the claims.
[0040] In particular:
[0041] although above the pressure measurement device comprises a
housing made of phenolic resin, the invention applies equally to
housings of other types, e.g. such as a housing made of metal, of
carbon fiber, of thermoplastic material, of composite fiber, of
epoxy resin, or of other material;
[0042] although above the housing is cylindrical in shape, the
invention applies to housings of other shapes, e.g. such as a
housing that is egg-shaped, or of rectangular box shape, or of any
shape;
[0043] although above the housing comprises a top cover screwed
onto a bottom cover, the invention applies equally to other methods
of assembling elements of the housing, e.g. such as ultrasound
welding, adhesive bonding, soldering, or riveting. The housing may
equally well be made up of some other number of elements, e.g. such
as a single element, or more than two elements;
[0044] although above the housing comprises a top cover and a
bottom cover assembled to each other, the invention applies equally
to a housing comprising two or more portions connected directly to
the electronic card;
[0045] although above the antenna is a portion of the electronic
card onto which the sensor is fitted directly, the antenna could be
made on the faces of the two covers and connected internally to the
electronic card by means of a wire, of a braid, or of electrically
conductive adhesive;
[0046] although above the antenna is a portion of the electronic
card, the antenna could be constituted by one or more metal wires
that may be straight or else wound to form a spring or a
spiral;
[0047] although above the electronic card is fastened to the
housing by means of a bead of flexible silicone-based adhesive, the
invention applies equally to other types of bond between the
housing and the electronic card that allow the housing and the
electronic card to move relative to each other, e.g. such as a
synthetic or natural rubber or EPDM type gasket fitted by screw
fastening. Some of these materials also serve to damp the vibration
to which the device is subjected, e.g. bonding with neoprene
adhesive;
[0048] although above the top cover has twenty first channels, the
invention applies equally to some other number of first channels,
such as for example a single channel, two to nineteen channels, or
more than twenty;
[0049] although above the first channels are circular in section
with a first diameter equal to 1 mm, the invention applies equally
to first channels of other section, e.g. of section that is square
or arbitrary, and also to a first diameter lying in the range 0.2
mm to 1.5 mm or capable of being greater than or less than 1
mm;
[0050] although above the electronic card has twenty second
channels, the invention applies equally to some other number of
second channels, e.g. such as a single channel, two to nineteen
channels, or more than twenty;
[0051] although above the second channels are circular in section
with a second diameter equal to 200 .mu.m, the invention applies
equally to second channels of other section, e.g. such as a section
that is square or arbitrary, and to a second diameter lying in the
range 100 .mu.m to 300 .mu.m, or capable of being greater than or
less than 200 .mu.m;
[0052] although above the pressure measurement device includes a
microcontroller, the invention applies equally to other signal
processor means, e.g. such as a field programmable gate array
(FPGA), logic gates, or a microprocessor;
[0053] although above the microcontroller and the other components
are welded on an electronic card, the invention applies equally to
other means for connecting components to the control circuit, e.g.
such as connections via pins, by sintering, or by soldering on a
printed circuit board (PCB) type support, or components connected
by wires;
[0054] although above the pressure measurement device includes a
radio transceiver, the invention applies equally to wireless
transmission techniques of other types, e.g. such as a 2G, 3G, 4G,
or 5G protocol, or a protocol of long-range (LoRa), edge, Wi-Fi,
Bluetooth, ultrasound, or Internet of things (IoT) type;
[0055] although above the pressure measurement device includes a
kinetic energy converter unit that is inductive, the invention
applies equally to other types of energy converter, e.g. such as a
piezoelectric type kinetic energy converter or a thermal energy
converter or a device for recovering electromagnetic energy;
[0056] although above the measurement device is placed in an
aircraft wheel, the invention applies equally to wheels of other
types of vehicle, e.g. such as the wheels of trucks or cars;
[0057] although above the tire is filled with compressed air, the
invention applies equally to tires filled with other types of fluid
under pressure, e.g. such as gases or liquids;
[0058] although above the pressure sensor is of capacitive type,
the invention applies equally to other types of pressure sensor,
e.g. such as a sensor that is resistive, inductive, piezoresistive,
piezoelectric, or resonant;
[0059] although above the components of the device are all
implanted on the first face of the electronic card, the invention
applies equally to the components being arranged in some other way,
e.g. such as implanting some or all of the components of the device
on the second face of the electronic card;
[0060] although above the second channels are provided with a metal
coating obtained by metal plating, the invention applies equally to
other means for applying a metal coating in the second channels,
e.g. such as crimping metal sleeves or applying conductive
paint;
[0061] although above the copper ring received in a groove in the
first surface of the electronic card extends around each second
channel, the invention applies equally to other types of conductive
element placed in the proximity of the second channel, e.g. such as
a ring that is of square or arbitrary shape, metal plating on the
surface of the first electronic card, or printing using a
conductive ink;
[0062] although above the pressure measurement device includes a
rechargeable battery, the invention applies equally to other types
of voltage generator, e.g. such as a primary battery or a
capacitor;
[0063] although above 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 applies equally to the connection
polarities being inverted;
[0064] although above the sensor is placed in a tire, the pressure
measurement device may equally be used for measuring the pressure
prevailing in enclosures of other types, e.g. such as in a blower
or a ventilation duct;
[0065] although above the electronic card is received in a
peripheral setback of the housing, the invention applies equally to
other types of connection between the housing and the electronic
card, e.g. such as one or more of elastomer studs extending from
the first surface of the electronic card to the top cover of the
housing and one or more elastomer studs extending from the second
surface of the electronic card to the bottom cover of the
housing;
[0066] although above the portion of the card that extends outside
the housing is a rigid portion carrying an antenna, that portion of
the card could equally well be flexible and/or contain conductive
elements of other types associated with the components that are in
the protective housing;
[0067] the pressure measurement device may equally well include a
temperature sensor for transmitting its temperature and/or for
performing temperature compensation of the measurement of the
pressure sensor. Temperature may be measured by means of a
dedicated sensor, or indeed by means of a piezoresistive sensor
measuring the input resistance of the sensitive element, or by any
other combination of resistances of a piezoresistive sensor that
gives rise to providing an image of temperature only, with the
image of pressure being eliminated from the combination in question
(resistances operating longitudinally or transversely giving rise
respectively to positive and negative gauge factors);
[0068] although above all of the second channels include a
resistive wire, the invention applies equally to a measurement
device in which only some or only one of the second channels
include(s) a heater device. The heater device may also be fitted to
the third channel;
[0069] although above the resistive wire is embedded in the
electronic card, the invention applies equally to heater devices of
other types, e.g. such as a resistive track printed on the second
channel, or induction heating of the metal plating of the second
channel; and
[0070] although above the resistive wire is powered by a second
rechargeable battery connected to a current regulator unit, the
invention applies equally to other energy sources such as for
example the first rechargeable battery, and to other types of
control for regulating the heater device, e.g. such as servocontrol
of the device using a temperature sensor.
* * * * *