DE29622647U1 - High temperature insulation system - Google Patents

Description

GRÜNEECKER,

,$ SÜHWANHOUSES

LAW FIRM MAXIMIUANSTRASSE 58 D-80538 MUNICH GERMANY LAWYERS

DR. HERMANN SCHWANHÄUSSER
DR. HELMUT EICHMANN
GERHARD BARTH
OR. ULRICH BLUMENRÖDER, LL, M,
CHRISTA NIKLAS-FALTER

PATENT ATTORNEYS

EUROPEAN PATENT ATTORNEYS

AUGUST GRÜNEECKER

DR. HERMANN KINKELDEY

DR. WILFRIED STOCKMAIR, AE, E.

DR. KLAUS SCHUMANN

PETER H. JAKOB

DR. GUNTER BEZOLD

WOLFHARD MEISTER

HANS HILGERS

DR. HENNING MEYER-PLATH

ANNELIE EHNOLD

THOMAS SCHUSTER

DR. WALTER LANGHOFF

OR. KLARA GOLDBACH

MARTIN AUFENANGER

GOTTFRIED KLITSCH

DR. HEIKE VOGELSANG-WENKE

REINHARD KNAUER

DIETMAR KUHL

OR. FRANZ-JOSEF ZIMMER

BETTINA K. REICHELT

YOUR REF.

OUR REF.

G 3600-40/SW DATE

27.01.97

Applicant: G + H Montage GmbH

Mayor-Grünzweig-Straße 67059 Ludwigshafen

and

Daimler-Benz Aerospace AG Willy-Messerschmitt-Strasse 85521 Ottobrunn

HIGH TEMPERATURE DAMAGE SYSTEM

TEL 089 / 21 23 50 · FAX (GR 31 089 / 22 02 87 · FAX (GR 4) 89 / 21 86 92 93 ■ E MAIL [email protected] ■ TELEX 529 380 MONA D
MAXIMIUANSTRASSE 58 ■ D-80538 MUNICH DEUTSCHE BANK MUNICH, NO. 17 51734, BLZ 700 700 10

High temperature insulation system

The invention relates to an insulation system, in particular for protecting aircraft components against the effects of fire, with bulkhead elements for forming a firewall made of metal, insulating elements containing insulating material for forming an insulating shield arranged in front of the firewall in the direction of the fire impact, and respective covers for the insulating elements made of sheet metal or foil material.

In modern aircraft designs, lightweight materials such as aluminum or carbon fiber composites are increasingly being used for load-bearing components, such as fuselage frames. Components made of such materials do not adequately withstand the effects of flames and heat from engine fires, for example, and measures must be taken to protect the components in question against the effects of fire.

In an insulation system previously used for this purpose, a firewall made of bulkhead elements is first erected in front of the component to be protected, with steel or titanium sheet plates preferably being used as bulkhead elements. After the firewall has been erected, an insulation shield is attached to the firewall, which is made up of individual insulation elements with layers of insulation material. The insulation elements are covered on both sides with a film made of stainless steel, titanium or metal-coated plastic, with the insulation material layer being enclosed in the film material.

To install such a known insulation/bulkhead shield, the firewall and the insulation shield must be installed one after the other, whereby with regard to provisions for fastening the bulkhead and insulation elements to e.g.

Certain manufacturing tolerances must be observed for the support parts, the bulkhead elements and the insulation elements connected to the component to be shielded. The flexible insulation elements must also be attached at a relatively large number of points in order to ensure that the fire protection cover is sufficiently strong even when subjected to vibration.

The present invention provides an improved insulation system compared to this prior art, which is characterized in that a bulkhead element, an insulation element and a sheet metal/foil cover, including the insulation element, are integrated between the bulkhead element and the sheet metal/foil cover in an insulation/bulkhead element as a structural element for a fire protection cover.

This inventive solution significantly reduces the assembly effort required to erect the fire protection covers described above, as only the integrated insulation/bulkhead elements need to be assembled to form a protective wall. With regard to fastening provisions, such as fastening holes, manufacturing tolerances no longer need to be adhered to separately for bulkhead and insulation elements, which reduces the manufacturing costs for the insulation system. The integrated insulation/bulkhead elements are very stable, whereby strength problems caused by the flexibility of the insulation element are solved, in particular by enclosing the insulation element between the sheet metal/foil cover and the bulkhead element. The insulation system according to the invention also results in weight advantages, as a layer of foil is no longer required compared to the insulation system according to the state of the art, as the insulation elements no longer have to be covered with the sheet metal/foil cover on both sides, but only on one side.

Depending on the protection requirements and/or the maximum permissible weight of the fire protection cover, bulkhead elements made of titanium or stainless steel are preferably used. Titanium or stainless steel, in particular chrome-nickel steel, can also be used as the material for the sheet metal/foil cover.

Ceramic fiber materials, in particular based on Al ₂ O ₃ -SiO ₂ , can be considered as insulation material. In addition, a flexible, microporous insulating material, in particular based on SiO ₂ , can be used as insulation material.

In a preferred embodiment of the invention, the insulating elements are enclosed between opposing layers of glass fiber fabric, whereby the glass fiber fabric layers are sewn together to form containment sections for the insulation material. In particular, the division into containment sections ensures that even powdered insulation material is held in place even in the event of strong vibrations and thus remains homogeneously distributed over the insulation shield.

In a further preferred embodiment, the sheet metal/foil cover and the bulkhead element are welded to one another at their outer edges, preferably by means of a continuous, circumferential seam. If the material combinations for the bulkhead and cover are unsuitable for welding, the sheet metal/foil cover and the bulkhead element can be connected by a joining process, in particular by folding or riveting.

In a further preferred embodiment, the bulkhead element is designed as a sheet metal plate and the insulation element is set back from the edge of the sheet metal plate, whereby the sheet metal/foil cover is placed against the edge of the insulation element and is connected to the sheet metal plate to form a rear cover.

Settlement is connected to the edge gradation of the integrated insulation/ bulkhead element. This setting back of the insulation element means that there is enough space at the edge of the insulation/bulkhead element to connect the sheet metal/foil cover to the bulkhead element, so that, for example, the sheet metal/foil cover can be folded over a sufficient length around the edge of the bulkhead element.

In a further advantageous embodiment of the invention, it can be provided that the integrated insulation/bulkhead element has an overlapping film that protrudes beyond its edge to cover the joint area with an adjacent insulation/bulkhead element. This overlapping film, which is preferably welded to the sheet metal/foil cover, provides an additional shielding effect in the joint area, where joints must be left for reasons of thermal expansion. In particular, this overlapping film extends at least over the width of a groove formed between adjacent insulation/bulkhead elements, essentially by their edge gradations.

A ceramic fiber seal arranged between adjacent insulation/bulkhead elements also contributes to the additional insulation effect. This seal is designed in particular as a strand. The cross-section of the strand is preferably designed to correspond to the groove formed by the edge gradation. Such a flexible ceramic fiber seal can achieve effective insulation in the joint areas of the integrated insulation/bulkhead elements even when the width of the joints changes due to thermal expansion.

To further increase the degree of integration of the insulation system, the ceramic fiber seal can advantageously be connected to the insulation/bulkhead element, whereby a sealing strip used is connected to the insulation/bulkhead element in particular via

At least one foil strip can be connected to the sealing strip. The foil strip is advantageously welded to the edge of the insulation/bulkhead element at one end and to the overlap foil at the other end. Alternatively, the sealing strip can be clamped into the edge step by the overlap foil. By using such components that already contain the ceramic fiber seal, the assembly effort for installing insulation can be further reduced.

Preferably, the sheet metal/foil cover is provided with a ventilation opening through which air pressure can be equalized when using the integrated insulation/bulkhead elements in aircraft. This ventilation opening can be suitably grilled to prevent fibers from the insulation material from being washed out. In addition to the grilling or as the sole measure, a cover can be provided over the ventilation opening for this purpose, leaving only a narrow opening slot between the cover and the sheet metal/foil cover.

Further advantageous embodiments of the invention emerge from the subclaims.

The invention will now be explained and described in more detail using embodiments and the accompanying drawings relating to these embodiments. They show:

Fig. 1 shows an embodiment of an integrated insulation/bulkhead element according to the present invention;

Fig. 2 shows a fire protection cover composed of insulation/bulkhead elements according to the present invention;

Fig. 3 is a sectional view of an integrated insulation/bulkhead element according to the invention in its edge region along the line A-A of Fig. 2;

Fig. 4 shows a fastening point of an insulating/bulkhead element according to the invention on a support part connected to a component to be protected in a sectional view according to line B-B of Fig. 2;

Fig. 5 shows the fastening point of Fig. 4 in a sectional view perpendicular to the sectional view of Fig. 4;

Fig. 6 is a sectional view of a joint between the insulating/bulkhead elements according to the invention abutting in the insulating wall of Fig. 2 along line C-C of Fig. 2, the ceramic fiber seals arranged between the abutting insulating/bulkhead elements; and

Fig. 7 is a view similar to that of Fig. 6 with an alternative ceramic fiber seal to the ceramic fiber seals of Fig. 6.

In Fig. 1, reference number 1 designates a bulkhead element made from a titanium sheet plate 13, which in the embodiment shown has a rectangular shape. Instead of this rectangular shape, the sheet plate could have any shape according to the requirements of the component to be shielded. The use of a titanium bulkhead enables effective protection against the penetration of flames with low weight. Depending on the requirements of the insulation to be produced, the bulkhead could also be made from another material, such as stainless steel.

The reference number 2 in Fig. 1 designates a titanium foil which, as will be explained in more detail later with reference to Fig. 3,

is connected to the titanium sheet plate 13 by a seam connection running around its edge.

An insulating element 3 is enclosed between the titanium sheet plate 13 and the titanium foil 2. The insulating element 3 has an extension such that it is slightly set back from the edges of the titanium sheet plate 13, so that a circumferential edge step 4 is formed by the titanium foil 2 resting against the edge of the insulation layer and the folded connection of the titanium foil 2 with the titanium sheet plate 13. This setting back provides enough fold width at the edge of the titanium sheet plate 13 to be able to create a sufficiently stable connection between the titanium sheet plate 13 and the titanium foil 2 by folding.

In the embodiment shown, the insulation layer 3 contains an insulation material that is formed by a microporous SiO ₂ -based powder and is available under the trade name MINILEIT. The powdered insulation material is enclosed between opposing fabric layers made of glass fiber material, with the fabric layers being sewn together to form inclusion sections 5. By sewing the fabric material layers section by section, the powdered insulation material is held in place and remains evenly distributed over the surface of the insulation/bulkhead element shown, even when subjected to strong vibrations.

A ventilation opening 6 is provided in the titanium foil 2 approximately in the middle area of the insulation/bulkhead element. A cover plate 7, shown partially in section, is provided above this ventilation opening 6, which is barred in the embodiment shown, with only an edge slot opening 8 remaining, ensuring the connection between the outside environment and the barred ventilation opening 6. The ventilation opening 6 serves - when installing the shown

component into an aircraft - for pressure equalization. Both the grating, which is formed by a fine grid arranged on the inside of the component behind the titanium foil 2, and the sheet metal cover 7 help to ensure that the insulation material is not washed out by incoming and outgoing air currents.

As indicated at 9, the titanium foil 2 has an embossing formed by depressions, which contributes to the stability of the insulation/bulkhead element shown, in that on the one hand this embossing stiffens the titanium foil 2 and on the other hand knobs formed by the depressions and protruding inwards against the insulation layer 3 ensure secure holding of the enclosed insulation layer 3 within the insulation/building element.

Reference is now made to Fig. 2, where a fire protection cover composed of integrated insulation/bulkhead elements is shown for a fuselage frame of an aircraft with engines arranged in the fuselage. The insulation protects the fuselage frame against the effects of fire from the engine compartment and has insulation/bulkhead elements Ia-Ie which, in accordance with the spatial requirements, have different outlines compared to the rectangular insulation/bulkhead element shown in Fig. 1. The insulation/bulkhead elements Ib-Ie border on an air inlet opening 10, via which air can be supplied to an engine located behind the opening in the direction of flow. The cross signs + indicate fastening points for the insulation/bulkhead elements Ib, lc and ld, for example, at which these insulation/bulkhead elements are connected to support parts not visible in Fig. 1, which in turn are attached to the hull frame to be protected. The insulation/bulkhead elements lc and ld have openings for parts 11 and 12 protruding from the hull frame, which are not described in detail here.

Reference is now made to Fig. 3, where, as an example for all edge regions of the insulation/bulkhead elements Ia-Ie, an edge region of the insulation/bulkhead element Id is shown according to the section A-A shown in Fig. 2.

An insulating layer 3d is enclosed between a titanium sheet plate 13d serving as a bulkhead element and a titanium foil 2d. The titanium foil 2d has an embossing with depressions 9d. The insulating layer 3d is provided with opposing glass fiber fabric layers 14 and 15, which are connected to one another by seams, of which the seams 16 and 17 are visible in Fig. 3. The seams form sections filled with insulating material, which are filled with the insulating material described with reference to Fig. 1.

The reference number 18 in Fig. 3 designates a folded connection between the titanium sheet plate 13d and the titanium foil 2d. By setting the insulation layer 3d back from the edge of the titanium sheet plate 18d, there is enough space for the folded connection so that opposing folded legs 19 and 20 of the titanium foil 2d can be formed with sufficient width. Instead of the folded connection, a welded connection could also be made, for example, by a continuous or dotted seam or a connection by another joining method, such as riveting or a so-called Tog-L-Log method, between the titanium foil 2d and the titanium sheet plate 13d.

Reference is now made to Figures 4 and 5, wherein in Fig. 4, as an example of all fastening points, a fastening point is shown according to section B-B for the insulation/bulkhead element Id of Fig. 2.

At the fastening point, the insulation/bulkhead element ld has a recess 21 which is arranged coaxially to a fastening opening 22 of the insulation/bulkhead element ld. The recess 21 is formed by the insulation layer 3d being set back from the opening 22. The titanium foil 2d is connected to the titanium sheet plate 13d around the edge of the opening 22 in a similar manner by a folded connection as is produced according to Fig. 3 between the foil 2d and the titanium sheet plate 13d at the edge of the insulation/bulkhead element ld.

The reference number 23 in Fig. 4 designates a fastening bracket with legs 28 and 29, the leg 28 of which is connected via rivets 24 and 25 to a web 26 protruding from the fuselage frame (not shown otherwise). A layer 27 made of an insulating material is arranged between the leg 28 and the web 26. On the leg 29 there is a locking bracket 31 with a two-leg locking spring 32 at the exit of a hole 30 made in the leg 29. The locking bracket 31 is attached to the leg 29 via rivets 33 and 61. A fastening button 34 with a head part 35 and a pin part 36 is guided through the opening 22 of the insulation/bulkhead element 1d and the hole 30 in the leg 29. The pin part 36 has tangential locking grooves 38 and 39 for the legs of the locking spring 32 provided at one end of a conical tip part 37. The head 35 of the fastening button 34 is provided with a screwdriver engagement slot 40.

Between the leg 29 of the angle 23 and the insulation/bulkhead element Id, a further insulation layer 41 made of an insulating material with a passage for the pin part 36 of the fastening button 34 is arranged. Between the head 40 and the bottom of the recess having the fastening opening 22

21 of the insulation/bulkhead element ld a spring washer 42 is provided.

Reference is now made to Fig. 6, where a joint area between the abutting insulation/bulkhead elements Ib and Ic according to section C-C of Fig. 2 is shown as an example for all joint areas.

The reference number 26b in Fig. 6 designates a web protruding from the fuselage frame, to which a T-shaped support part 43 with a longitudinal leg 44 and a transverse leg 45 is attached via fastening means not shown. An insulating material layer 27b is arranged between the web 26b and the longitudinal leg 44.

As can be seen from Fig. 6, the insulation/bulkhead elements Ib and Ic each rest with their edges against the transverse leg 45 of the T-shaped support part 43, forming a butt joint 46.

47 and 48 designate sealing strands made of ceramic fiber material, which essentially fill a groove formed by the edge steps of the abutting insulation/bulkhead elements Ib and Ic. This groove is covered by overlapping foils 49 and 50, which extend from opposite edges of the insulation/bulkhead elements Ib and Ic and are connected to the titanium foil 2b and 2c of these insulation/bulkhead elements by spot welding. Between these overlapping foils 49, 50, which are also made of titanium foil, the sealing strand 47 and 49 can be clamped in the step section at the edge of the component and can be supplied in this state with the insulation/bulkhead element.

3.2·:

In the embodiment shown in Fig. 7 for a joint area, the same parts as in the embodiment shown in Fig. 6 are designated with the same reference number, but with a prime.

The embodiment differs from the previous embodiment in that a single sealing strip 60 is arranged between the abutting insulation/bulkhead elements Ib ¹ and Ic ^1. Furthermore, only a single overlapping film 51 is provided, which spans the groove formed by the edge step between the insulation/bulkhead elements Ib' and Ic'. The sealing strip 60 is connected to the insulation/bulkhead element Ic' via a film strip 52, which is welded at one end to the edge of the insulation/bulkhead element Ic' and at the other end to the overlapping film 51. The overlapping film 51 is connected to the insulation/bulkhead element IC by spot welding, whereby both the sealing strip 60 and the overlapping film 51 are an integral part of the insulation/bulkhead element Ic ¹ .

To produce the fire protection cover shown in Fig. 2, the insulation/bulkhead elements Ia-Ie are attached to appropriately prepared fastening points using fastening buttons 34, whereby these buttons only need to be pressed through the fastening opening and the bore 30 and the mentioned through-opening in the insulation layer 41 until the spring 32 snaps into the locking grooves 38 and 39. Fastening points corresponding to Figures 4 and 5 are provided in the appropriate number and arrangement, taking into account the given requirements for fastening. All dimensions of the components are provided in coordination with the fastening points so that the components rest with their edges against the cross leg of a T-shaped support element 43 with the formation of the joint 46 in a constant width.

If the sealing strips are already connected to the insulation/bulkhead elements to be assembled, no additional work is required to seal the joint area during assembly.

The insulating wall formed by assembling the insulating/bulkhead elements Ia-Ie can be easily dismantled by rotating the fastening button 34 by 90°, whereby the legs of the locking spring 32 can be released from engagement with the grooves 3 8 and 3 9 and the button can be pulled out of the bore 3 0 and the fastening opening 22.

The additional insulation layers 27 and 41 largely reduce the direct transfer of heat by conduction from the fire protection cover formed by the insulation/bulkhead elements to the hull frame to be shielded.

Depending on the choice of material and the material thickness for the bulkhead element, the insulation element and the sheet/foil cover, different fire protection standards can be met, such as the MIL-I-83294 standard for firewalls and the MIL-I-8776 standard for insulation shielding. For example, a fire protection cover constructed from the insulation/bulkhead elements according to the invention can withstand a flame of around 1,100 ⁰ C for a period of 5-15 minutes, with maximum surface temperatures of 100 ⁰ C occurring on the side to be protected.

Claims (25)

Protection claims 1. Insulation system, in particular for the protection of aircraft components against the effects of fire, with Bulkhead elements (13) for forming a fire bulkhead made of metal, Insulating elements (3) containing insulating material to form an insulating shield arranged in front of the fire barrier in the direction of fire impact, and respective covers (2) for the insulation elements (3) made of sheet metal or/and foil material, characterized, that a bulkhead element (13), an insulation element (3) and a sheet metal/foil cover (2) are integrated into an insulation/bulkhead element (1) as a structural element for a fire protection cover, including the insulation element (3) between the bulkhead element (13) and the sheet metal/foil cover (2). 2. Insulation system according to claim 1, characterized in that bulkhead elements comprising titanium and/or stainless steel are provided. 3. Insulation system according to claim 1 or 2, characterized in that covers made of titanium and/or stainless steel foil, in particular chrome-nickel steel foil, are provided. 4. Insulation system according to one of claims 1 to 3, characterized in that the insulation material comprises a ceramic ^I5 ': I: Fibre material, in particular based on AL ₂ O ₃ -SiO ₂ . 5. Insulation system according to one of claims 1 to 4, characterized in that the insulation material comprises a flexible microporous insulation material, in particular based on SiO ₂ . 6. Insulation system according to one of claims 1 to 5, characterized in that the insulation elements (3) have opposing layers (14, 15) of glass fiber fabric, between which the insulation material is enclosed. 7. Insulation system according to claim 6, characterized in that the glass fiber fabric layers (14, 15) are sewn together to form inclusion sections (5) for the insulation material. 8. Insulation system according to one of claims 1 to 7, characterized in that the sheet metal/foil cover and the bulkhead element are welded at their outer edges, preferably by a continuous circumferential seam. 9. Insulation system according to one of claims 1 to 8, characterized in that the integrated insulation/bulkhead element (1) has an overlapping film (49 to 51) projecting beyond its edge for covering a joint area with an adjacent insulation/bulkhead element. 10. Insulation system according to claim 9, characterized in that the overlapping film (49 to 51) is connected to the sheet metal/film cover (2), in particular by spot welding. 11. Insulation system according to claim 9 or 10, characterized in that the overlapping film (51) extends at least over the 'ie.: Width of a groove formed between adjacent insulation/bulkhead elements (1) essentially by edge gradations (5). 12. Insulation system according to one of claims 1 to 11, characterized in that a ceramic fiber seal, in particular designed as a sealing strip (47, 48, 60), is arranged between adjacent insulation/bulkhead elements of an insulation/bulkhead wall composed of insulation/bulkhead elements. 13. Insulation system according to claim 13, characterized in that the sealing strip (9, 48, 60) is adapted to the groove with respect to its cross section. 14. Insulation system according to claim 12 or 13, characterized in that the ceramic fiber seal (47, 48, 60) is connected to the integrated insulation/bulkhead element (Ib, lc, Ic ¹ ). 15. Insulation system according to one of claims 12 to 14, characterized in that the sealing strip (60) is connected to the insulation/bulkhead element (IC) via at least one foil strip (52) overlapping the sealing strip (60). 16. Insulation system according to claim 15, characterized in that the foil tape (IC) is welded at one end to the edge of the insulation/bulkhead element (IC) and at the other end to the overlap foil (51). 17. Insulation system according to one of claims 12 to 16, characterized in that the sealing strip (47, 48) is clamped in the edge step by the overlapping film (49, 50) •J·. 18. Insulation system according to one of claims 1 to 17, characterized in that the sheet metal/foil cover (2) is provided with at least one valve opening (6). 19. Insulation system according to claim 18, characterized in that the valve opening (6) is provided with a grille and/or a cover (7) to form a slot opening (8) between the sheet metal/foil cover (2) and the cover (7). 20. Insulation system according to one of claims 1 to 19, characterized in that the sheet metal/foil cover (2) has an embossed profile (9). 21. Insulation system according to one of claims 1 to 20, characterized in that the sheet metal/foil cover and the bulkhead element are connected by a joining process, in particular by folding or riveting. 22. Insulation system according to one of claims 1 to 21, characterized in that the integrated insulation/bulkhead element (Id) has fastening openings (22), wherein the sheet metal/foil cover is connected to the bulkhead element (Id) around the edge of the opening. 23. Insulation system according to claim 22, characterized in that for fastening the integrated insulation/bulkhead element (1) to a support part (23) through the fastening opening (22) a fastening button (34) with a pin part (36) having a locking groove (38, 39) can be pressed into locking engagement with a locking element (32) attached to the support part (23). 24. Insulation system according to claim 23, characterized in that the locking groove (3 8, 3 9) is designed as a tangential incision in such a way · · 18« is formed such that by turning the fastening knob (34)
the locking element (32) out of engagement with the locking groove (3 8,
39) is solvable. 25. Insulation system according to one of claims 1 to 24, characterized in that T-shaped support elements (43) are provided for supporting the integrated insulation/bulkhead elements (Ib, Ic) in the joint area.