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BR-112022010609-B1 - Pressurized aircraft cabin door with a structure formed by beams of variable cross-section.

BR112022010609B1BR 112022010609 B1BR112022010609 B1BR 112022010609B1BR-112022010609-B1

Abstract

AIRCRAFT PRESSURIZED CABIN DOOR WITH STRUCTURE FORMED BY BEAMS OF VARIABLE CROSS SECTION. A pressurized aircraft cabin door (1) is disclosed comprising an outer panel (2) and a door structure (3) comprising: - two circumferential beams (4) fixed to the lateral edges of the door; - a plurality of longitudinal beams (5a, 5b) which are arranged substantially perpendicularly between the circumferential beams (4) and are fixed to the outer panel (2), each longitudinal beam (5a, 5b) extending from one circumferential beam (4) to the other. At least one longitudinal beam (5b) is a beam having a variable cross section which increases from the ends (B, M) of the beam to the center (H, L) of the beam, with two curved support bars.

Inventors

  • Miloslav KLISKY
  • JEAN MICHEL BORLOT
  • Josef KRENA

Assignees

  • LATECOERE

Dates

Publication Date
20260310
Application Date
20201130
Priority Date
20191202

Claims (7)

  1. 1. Pressurized aircraft cabin door, comprising an outer panel (2) and a door structure (3) comprising: - two circumferential beams (4) fixed to the lateral edges of the door; - a plurality of longitudinal beams (5a, 5b) arranged substantially perpendicular to the circumferential beams (4) and fixed to the outer panel (2), each longitudinal beam (5a, 5b) extending from one circumferential beam (4) to the other, and each longitudinal beam (5a, 5b) comprising: a first end coming into contact with one of the circumferential beams (4); and a second end that comes into contact with the other circumferential beam (4); characterized in that each longitudinal beam (5a, 5b) has an open cross-section whose opening is facing the outer panel (2), this opening being closed by the inner face of the outer panel (2) on which the longitudinal beam (5a, 5b) is fixed, at least one longitudinal beam (5b) of variable cross-section, in two directions (Y, Z) perpendicular to the direction in which the longitudinal beam (5b) extends, a cross-section that increases from the ends (B, M) of the beam towards the middle (H, L) of the beam, the longitudinal beam of variable cross-section (5b) having two support bars (6) fixed to the outer panel (2), these support bars (6) extending along the entire length of the longitudinal beam (5b), on each side of said opening, these two support bars being curved and each having a concavity facing the concavity of the other support bar (6).
  2. 2. Door according to claim 1, characterized in that the longitudinal beam of variable cross-section (5b) comprises two lateral flanges (11) extending obliquely towards each other from the two support bars (6), these two lateral flanges (11) being curved and each having a concavity facing the concavity of the other lateral flange (11).
  3. 3. Door according to claim 2, characterized in that each support bar (6) is formed by a bend of one of the side flanges (11).
  4. 4. Door according to one of claims 1 to 3, characterized in that the longitudinal beam of variable section (5b) comprises an upper flange (7), opposite the support bars (6), whose width, measured in a plane perpendicular to the longitudinal axis of the beam (5b), is less than or equal to the minimum distance separating the two support bars (6).
  5. 5. Door according to claim 4, characterized in that the upper flange (7) is a curved surface with the concavity facing the outer panel (2).
  6. 6. Door according to any of the preceding claims, characterized in that the door structure (3) comprises a frame formed by circumferential beams (4) and two longitudinal beams (5a, 5b) located at the ends of the circumferential beams (4).
  7. 7. Door according to any of the preceding claims, characterized in that the longitudinal beam of variable cross-section (5b) has a dimension that increases from the ends (B, M) of the beam towards the middle (H, L) of the beam, in the two directions (Y, Z) perpendicular to the direction in which the longitudinal beam (5b) extends.

Description

DESCRIPTION TECHNICAL FIELD [001] The invention relates to the field of aeronautics and relates to a pressurized aircraft cabin door. [002] Aircraft, and airplanes in particular, are generally equipped with doors that allow people and equipment to enter and exit the cabin. Because the cabin is pressurized, these doors must ensure that, during flight, the cabin remains closed and a significant pressure difference between the interior and exterior of the cabin is maintained. Pressurized cabin doors therefore include an outer panel, also called a "skin," which, when the door is closed, lies flush with the aircraft fuselage and acts as a barrier to maintain the pressure difference. In order for this outer panel to have an acceptable thickness despite the significant stresses due to the pressure difference, the door also comprises a door frame formed by beams fixed to the outer panel to ensure the rigidity of the latter. [003] In addition, cabin doors also typically support various equipment, such as door opening mechanisms or comfort and safety equipment. The door structure, in addition to ensuring the door's rigidity, must also be dimensioned to support these additional masses. [004] Pressurized cabin doors are fundamental to aircraft safety as they are responsible for maintaining pressure inside the cabin. The door panels and associated door structures are therefore dimensioned for a high level of safety. However, the mass of the door structure, and of the door in general, benefits from being reduced for reasons of production cost and aircraft lightness, in particular to allow for fuel savings. PREVIOUS TECHNIQUE [005] Patent application FR 2928620 describes an aircraft cabin door whose door structure comprises crossbeams and stringers that form a rigid structure. The crossbeams and stringers are IPN-type sections. In the example described by this document, four stringers and six crossbeams intersect at right angles and are fastened to each other, thus forming a highly rigid structure. [006] Such a door structure is difficult and expensive to manufacture, in particular due to the connections that must be made at the intersections between the stringers and the crossbeams. These connections require fasteners, additional parts or complex connections and also lead to increases in mass. [007] Furthermore, the intersections between the crossbeams and the stringers make it difficult to manufacture this door in composite materials, for which the creation of such intersections generates more difficulties in terms of assembly or molding. [008] US patent application 2007007390 proposes to solve some of the aforementioned drawbacks by proposing a monolithic aircraft door made in a single piece. Strong reinforcing ribs intersect at right angles across the entire inner surface of the door. Such a door is also highly rigid, which is appropriate for its use in aeronautics, but it remains highly complex and expensive to produce. Its mass is also substantial. [009] Patent application US2009/0078826 describes a pressurized cabin door made of composite materials and whose design is optimized for the use of these composite materials. The door comprises beams that are arranged at right angles to each other, but do not intersect. The manufacturing method of such a door is simplified compared to the methods mentioned above, and production using composite materials is facilitated. However, the skin support of such a door is inferior to that of cross-beam door structures. DESCRIPTION OF THE INVENTION [010] The invention aims to improve the cabin doors of pressurized aircraft, proposing such a door that combines high rigidity allowing its use for aircraft flying at altitude with simplicity of construction that allows rapid manufacturing at lower cost, by any process and materials, including composite materials. [011] For this purpose, the invention relates to a pressurized aircraft cabin door comprising an outer panel and a door frame. The door frame includes: - two circumferential beams fixed to the lateral edges of the door; - a plurality of longitudinal beams arranged substantially perpendicular to the circumferential beams and fixed to the outer panel, each longitudinal beam extending from one circumferential beam to the other and each longitudinal beam comprising: a first end coming into contact with one of the circumferential beams; and a second end coming into contact with the other circumferential beam. [012] Furthermore, each longitudinal beam has an open cross-section whose opening faces the outer panel, this opening being closed by the inner face of the outer panel on which the longitudinal beam is fixed, at least one longitudinal beam having a variable cross-section, in two directions perpendicular to the direction in which the longitudinal beam extends, a cross-section that increases from the ends of the beam to the middle of the beam, the longitudinal beam with a variable cross-section has two support bars fixed to the ou