Search

EP-4740706-A1 - METHOD FOR PROTECTING AN ELECTRONIC HOUSING AND ASSOCIATED ELECTRONIC HOUSING, MEASUREMENT SYSTEM AND AIRCRAFT

EP4740706A1EP 4740706 A1EP4740706 A1EP 4740706A1EP-4740706-A1

Abstract

The invention relates to a method for protecting an electronic housing, comprising the steps of: - injecting at least one liquid or semi-liquid filling product into the housing (1) via at least one first injection opening provided in one of the walls of the housing; - stopping injection of the product when the product is present in at least one portion of at least one first opening and/or of at least one second opening provided in one of the walls of the housing; and - curing the product. The invention also relates to a corresponding housing, measurement system and aircraft.

Inventors

  • CLAUDON, Jérôme Alain Robert
  • BERNHARD, AXEL
  • GUICHON, Etienne Gérard Gilbert
  • BAILLY, Éric

Assignees

  • SAFRAN ELECTRONICS & DEFENSE

Dates

Publication Date
20260513
Application Date
20240705

Claims (13)

  1. 1. Method for protecting an electronic box comprising the steps of: Injection of at least one liquid or semi-liquid filling product inside the housing (1) via at least one first orifice (17) provided in one of the walls of the housing, Stopping the injection of the product when the first orifice is at least partially filled with the product and, if the housing has one or more additional orifices provided in one or more walls of the housing, when the additional orifice(s) are also partially filled with the product, Curing of the product, the process being defined so that at the end of the protection process, the housing has at least one air gap inside the housing between at least one of the walls of the housing and the cured product.
  2. 2. Method according to claim 1, comprising an additional step of removing one of the walls of the housing (1) once the product has hardened to replace it with a wall making it possible to define an air gap (21) inside the housing between said wall and the hardened product.
  3. 3. Method according to one of the preceding claims, in which the filling product is a resin and/or a foam.
  4. 4. Method according to claim 3, in which the resin is an elastomeric and/or silicone and/or epoxy resin.
  5. 5. A method according to claim 3 or claim 4, wherein the resin is an RTV resin.
  6. 6. Method according to one of claims 3 to 5, in which the filling product is composed of at least two different by-products.
  7. 7. Method according to one of claims 3 to 6, comprising a step of prior degassing of the resin before its injection into the housing (1).
  8. 8. Method according to one of the preceding claims, in which the hardening of the product is carried out by heating the housing (1).
  9. 9. Electronic housing comprising walls jointly defining a housing (6), at least one of the walls being pierced with at least one additional orifice, the housing being furthermore filled at least in part with a filling product.
  10. 10. Housing according to claim 9, comprising a substrate (7) on which at least one antenna (9) is mounted, the substrate being mounted on a wall (4) of the housing so that the antenna faces said wall.
  11. 11. Housing according to claim 10, comprising at least one sealing element (12) compressed between the substrate (7) and the wall (4) carrying the substrate, the sealing element externally surrounding the antenna (9).
  12. 12. Pressure measuring system (101) of a tire (102) comprising a housing (1) according to one of claims 9 to 11.
  13. 13. Aircraft (100) equipped with a measuring system (101) according to claim 12.

Description

METHOD FOR PROTECTING AN ELECTRONIC BOX, ELECTRONIC BOX, MEASURING SYSTEM AND ASSOCIATED AIRCRAFT The invention relates to a method for protecting an electronic housing. The invention also relates to an electronic housing thus protected. The invention also relates to a tire pressure measuring system comprising such an electronic box. The invention also relates to an aircraft equipped with such a measuring system. BACKGROUND OF THE INVENTION In the aeronautical field, it is known to measure the tire pressure of the landing gears of an aircraft using one or more pressure measurement sensors. The data they generate are provided to a remote computer of the landing gears via at least one electronic box, the communication between the pressure sensors and the box being carried out by radio link. Such a box is generally arranged in a sensitive area of the aircraft, such as at the level of one of the holds provided in the fuselage of the aircraft to receive at least one of the landing gears. Regardless of its position in the aircraft, such a box is subject to very strong environmental and mechanical constraints. Consequently, such a box must meet many constraints (lightning resistance, explosion resistance, etc.) in order to protect the aircraft in the event of a failure. Added to this is the fact that the radio link between the pressure sensors and the box must not be disrupted by the presence of one or more protections to meet such constraints. This implies, when designing the housing, respecting electrical insulation distances and significant dielectric levels between the different electronic elements of the housing by using generously sized connectors and/or mechanical parts. The size of the case is greatly increased. This also means that the case must comply with explosion resistance constraints. For this purpose, a first technique is to use explosion-proof enclosures. An explosion-proof enclosure is designed to withstand an explosion occurring inside it and to prevent the ignition of combustible materials surrounding the enclosure. Explosion-proof enclosures must also ensure an external temperature (skin temperature) lower than that which is sufficient to ignite the surrounding materials. However, such boxes are very bulky. A second technique is to protect the housing with a purge system providing a protective gas around and/or in the housing to limit the presence of flammable gases around and/or in the housing. However, purge systems are relatively complex and involve the addition of a gas supply source. One could imagine using intrinsically safe electrical circuits (limiting the energy used so that the circuit cannot provide enough energy to trigger a fire or explosion). Unfortunately, this technique is difficult to apply to the aeronautical field, given that the box is directly powered by the aircraft's electrical network. SUBJECT OF THE INVENTION The invention aims in particular to respond at least in part to the aforementioned problems. SUMMARY OF THE INVENTION For this purpose, the invention provides a method for protecting an electronic housing comprising the steps of: injecting at least one liquid or semi-liquid filling product into the electronic housing via at least one first orifice provided in one of the walls of the housing, stopping the injection of the product when the first orifice is at least partially filled with the product and, if the housing comprises one or more additional orifices provided in one or more walls of the housing, when the additional orifice(s) are also partially filled with the product, hardening the product. Thus, the product fills most of the gaps present in the housing (or even all of the gaps) and also helps to limit or even eliminate the presence of air bubbles in the housing. This prevents the presence of gas inside the enclosure, gas which could potentially ignite when using the enclosure in the presence of a flame or spark. The invention therefore makes it possible to effectively protect an electronic box and thus better preserve its performance. Furthermore, the invention proves to be advantageously simple to implement. In addition, the invention makes it possible to obtain a relatively compact protected housing. It is noted that the housing thus protected is of simple construction. It is also compact. It thus complies with constraints of electrical insulation, lightning resistance and resistance to explosive atmospheres (in particular in a confined environment). Advantageously, even if the housing were to explode, the hardened product would also make it possible to greatly limit or even eliminate a risk of material projections into the environment of the housing. Furthermore, the invention makes it possible to significantly reduce insulation distances and creepage lines inside the electronic housing compared with an electronic housing of the prior art. By "liquid" or "semi-liquid" product we mean any product that is fluid enough to be able to move inside the hou