U.S. patent application number 11/363496 was filed with the patent office on 2009-06-04 for process and tools for manufacturing composite ring frames.
This patent application is currently assigned to AIRBUS ESPANA, S.L.. Invention is credited to Aquilino Garcia Garcia, Jesus Manuel Martin, Pedro Nogueroles Vines.
Application Number | 20090139644 11/363496 |
Document ID | / |
Family ID | 38217702 |
Filed Date | 2009-06-04 |
United States Patent
Application |
20090139644 |
Kind Code |
A1 |
Nogueroles Vines; Pedro ; et
al. |
June 4, 2009 |
PROCESS AND TOOLS FOR MANUFACTURING COMPOSITE RING FRAMES
Abstract
The present invention relates to a process for manufacturing
composite ring frames for aeronautical fuselages by means of the
application of the RTM technology to two preforms with C- and
L-shaped sections manufactured using two tools (21, 55) in the
following steps: providing the material; hot-forming planar
rectangular laminates (41); hot-forming laminates of right angle
section (51) on one part of right angle section of the first tool
(21), placing an elastic membrane (55) and applying a temperature
and vacuum cycle; hot-forming the preforms into a C shape (11) and
L shape (13) on a second curved tool (55) by deforming said
laminates of right angle section (51) thereon, and applying a
temperature and vacuum cycle. The invention also relates to said
tools (21, 55)
Inventors: |
Nogueroles Vines; Pedro;
(Getafe, ES) ; Garcia; Aquilino Garcia; (Getafe,
ES) ; Martin; Jesus Manuel; (Getafe, ES) |
Correspondence
Address: |
Ladas & Parry LLP
26 West 61 Street
New York
NY
10023
US
|
Assignee: |
AIRBUS ESPANA, S.L.
|
Family ID: |
38217702 |
Appl. No.: |
11/363496 |
Filed: |
February 27, 2006 |
Current U.S.
Class: |
156/250 ;
156/538 |
Current CPC
Class: |
B29B 11/16 20130101;
B29C 33/308 20130101; Y10T 156/1031 20150115; Y10T 156/1052
20150115; B29C 70/342 20130101; Y10T 156/17 20150115; Y10T 156/1011
20150115; Y10T 156/1079 20150115 |
Class at
Publication: |
156/250 ;
156/538 |
International
Class: |
B32B 37/06 20060101
B32B037/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2005 |
ES |
PCT/ES05/70186 |
Claims
1. A process for manufacturing composite ring frames for
aeronautical fuselages by application of RTM technology to two
preforms with C- and L-shaped sections, wherein said preforms are
manufactured using a first tool and a second tool in the following
steps: a) providing the fabric for the preforms in pieces of
material cut according to preset patterns; b) hot-forming planar
rectangular laminates by placing overlapping layers of pieces of
material on a first tool in predetermined positions and number and
applying pressure and temperature so that the overlapped pieces of
material adhere to one another in local areas, and cutting the
laminate into parts; c) hot-forming laminates of right angle
section from segments of said planar laminates of predetermined
dimensions, obtained by cutting, on a part of a right angle section
of the first tool, arranging on its top side a part intended for a
flange of the preforms with a C- or L-shaped section, holding its
longitudinal edge on the first tool and allowing the rest to be
free, placing an elastic membrane on the first tool and applying a
temperature and vacuum cycle; d) hot-forming the preforms into a C
shape and an L shape on a second curved tool by deforming said
laminates of right angle section thereon, said deformation
including in the case of C-shaped preforms the bending of a second
flange, and applying a temperature and vacuum cycle.
2. A process for manufacturing composite ring frames for
aeronautical fuselages according to claim 1, wherein the preset
patterns for the pieces of material include rectangular patterns at
+/-45.degree. and unidirectional tape reinforcement for a
flange.
3. A tool (21) for carrying out steps b) and c) of the process
object of claim 1, characterized in that it comprises a central
module (25) and two side modules (23), which are joined together to
carry out step b) and are separated to carry out step c), and
heating heads (31) for carrying out the application of pressure and
temperature of step b), the central module (25) having heating
components (61) inside, vacuum inlets for carrying out step c) and
a hold-down plate (29) with a pneumatic actuator arranged on the
central module (25) to hold the laminates (51) during step c).
4. A tool (55) for carrying out step d) of the process object of
claim 1, characterized in that it comprises a curved male module
(57) with mortises (59, 60) for positioning the flange and flanges,
respectively, of the L- or C-shaped laminates (51) and a plurality
of elastic strips (71) for holding the laminates during
hot-forming.
5. A tool (21) for carrying out steps b) and c) of the process
object of claim 2, characterized in that it comprises a central
module (25) and two side modules (32), which are joined together to
carry out step b) and are separated to carry out step c), and
heating heads (31) for carrying out the application of pressure and
temperature of step b), the central module (25) having heating
components (61) inside, vacuum inlets for carrying out step c) and
a hold-down plate (29) with a pneumatic actuator arranged on the
central module (25) to hold the laminates (51) during step c).
6. A tool (55) for carrying out step d) of the process object of
claim 2, characterized in that it comprises a curded male module
(57) with mortises (59, 60) for positioning the flange and flanges,
respectively, of the L- or C-shaped laminates (51) and a plurality
of elastic strips (71) for holding the laminates during
hot-forming.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a process for manufacturing
composite aeronautical fuselage ring frames by means of the RTM
(resin transfer moulding) technology, and particularly to the steps
of that process in which the preforms subjected to the final resin
injection step are manufactured.
BACKGROUND OF THE INVENTION
[0002] In the aeronautical industry the resistance-weight ratio is
a fundamental aspect, and for this reason the tendency has gone
from using metal structures to using structures manufactured or
optimized with composites.
[0003] In the process of optimizing all types of aeronautical
structures, maximally reducing weight and integrating the largest
number of parts is sought so as to reduce both the duration of the
assembly process and the handling of smaller components.
[0004] The manufacture of ring frames in the known art is carried
out on the basis of machined metal structures or shaped sheet metal
structures, reinforcing the part bearing the most load with
machined parts. In the case of shaped sheet metal, the section
normally used is obtained in two pieces: on one hand the Z is
manufactured, and on the other hand the angle or babbetes which are
riveted to the previous section (see FIG. 1a), are
manufactured.
[0005] This process has the drawback of requiring long assembly
times and the resulting weight exceeds the weight obtained when
making the same section in an integrated manner.
[0006] The present invention has as an object providing a process
resolving the drawbacks from the prior art.
SUMMARY OF THE INVENTION
[0007] The present invention proposes a process for manufacturing
composite ring frames for aeronautical fuselages by means of
applying the RTM technology to two preforms with C- and L-shaped
sections, characterized in that said preforms are manufactured,
using a first and second tool, in the following steps: [0008]
Providing the fabric for the preforms in pieces of material cut
according to preset patterns. [0009] Hot-forming planar rectangular
laminates by placing layers of pieces of material on a first tool
in predetermined positions and number and applying pressure and
temperature so that the pieces of material adhere to one another
only locally, i.e. not on their entire surface, only along a
longitudinal strip where the unidirectional tape reinforcements are
arranged. [0010] Hot-forming laminates of right angle section from
segments of said planar laminates of predetermined dimensions,
obtained by means of cutting, on a part of right angle section of
the first tool, arranging on its top side the part intended for the
flange of the preforms with a C- or L-shaped section, holding one
longitudinal edge over the tool and allowing the rest to be free;
placing an elastic membrane on the tool and applying a temperature
and vacuum cycle. [0011] Hot-forming the preforms into a C and L
shape on a second curved tool by deforming said laminates of right
angle section thereon, said deformation including in the case of
C-shaped preforms the bending of the second flange, and applying a
temperature and vacuum cycle.
[0012] The present invention also relates to the two mentioned
tools.
[0013] The first tool is formed by a central module and two side
modules joined together so as to make the laminate of the preforms
as well as to perform the longitudinal joining of the patterns by
means of overlaps, and they are separated to carry out the step of
hot-forming the laminates of right angle section, and heating heads
for carrying out the application of pressure and temperature of the
step for hot-forming the planar laminates.
[0014] The central module has heating elements, vacuum intakes and
a hold-down plate with a pneumatic actuator arranged on the central
module for hot-forming the laminates of right angle section.
[0015] The second tool comprises a curved male module with
mortising to position the flange and flanges, respectively, of the
L- or C-shaped laminates and a plurality of elastic strips for
holding the laminates during their hot-forming process.
[0016] The manufacture of ring frame preforms which will
subsequently be injected in the RTM process is facilitated by means
of the process of the present invention with the following
advantages: [0017] Ring frames with complicated geometries and
integrated ring frames are manufactured, meeting the objective
sought in any structure. [0018] The one-sided only surface finish
problem is resolved by adding high dimensional precision without
any reduction of radiuses because the autoclave is not used. [0019]
Control of thicknesses is improved (reaching tolerances.ltoreq.0.2
mm), whatever these thicknesses may be, and therefore a good fit
between the outer flange of the ring frames with the overlay and
the stringer is obtained. [0020] The process is repetitive, with
short curing cycle times, reducing the duration of the
manufacturing process.
[0021] Other features and advantages of the present invention shall
be gathered from the following detailed description of an
illustrative embodiment of its object in relation to the attached
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1a shows a section of a ring frame made of metal and
FIG. 1b shows a section of a ring frame made of a composite
manufactured by means of the process object of the present
invention.
[0023] FIG. 2a shows a perspective view of the first tool used in
the process object of the present invention.
[0024] FIG. 2b schematically shows the components of the first tool
used in the process object of the present invention.
[0025] FIG. 3 schematically shows the different phases of the step
for hot-forming planar laminates of the process object of the
present invention.
[0026] FIG. 4 schematically shows the cuts made in the planar
laminate so as to obtain the laminates with the dimensions required
for the preforms with C- and L-shaped sections.
[0027] FIG. 5 schematically shows the different phases of the step
for forming planar laminates of the process object of the present
invention.
[0028] FIG. 6 schematically shows the different phases of the step
for hot-forming the preforms with C- and L-shaped sections.
[0029] FIG. 7 shows schematic section views of the second tool used
in the process object of the present invention.
[0030] FIGS. 8 and 9 show schematic section views of the central
module of the first tool.
DETAILED DESCRIPTION OF THE INVENTION
[0031] An embodiment of the process according to the invention for
manufacturing aeronautical fuselage ring frame preforms with
composites is described below.
[0032] The section to be manufactured is formed by a C shape 11 and
by an L-shaped angle iron 13 made from fabric and reinforced with a
unidirectional tape on the lower flange 15 to increase the moment
of inertia and therefore the stiffness. Ring frames of up to 8
meters long with radiuses of curvature of up to 250 mm can be
obtained with this invention.
[0033] Carrying out the process begins with providing the material
needed to manufacture the laminates; the patterns obtained from the
cutting process are manufactured in groups as per geometries, such
that the cutting machine works only once, obtaining the pattern
required from each one of them. An identification of each one of
the parts is not required by means of this process, and it is only
necessary to gradually take the required number of pieces of each
geometry to manufacture the laminate.
[0034] For its part, the laminate tool 21 of the C- and L-shaped
preforms (in each case with the suitable dimensions) is provided,
coupling the side modules 23 to the central module 25. Longitudinal
gibs 27 are fixed, positioned on the side modules 23 in the area
where the laminating is carried out (any of the two side modules 23
is suitable for this).
[0035] To begin the laminate 41, the hold-down plate 29 of the top
part of the tool 21 is removed. Then the rectangular patterns of
the pieces of material 30 are arranged at +/-45.degree. between the
central module 25 and the gibs 27 of the side module 23 chosen for
manufacture, longitudinally overlapping the patterns. The
measurements of the contour dimensions as well as the displacement,
cutting and overlap marks of the layers involved therein are shown
by means of laser projectors. In order to integrate the
reinforcements and overlap the pieces of material 30 until
obtaining the entire length of the ring frame section, pressure and
temperature are applied with a heating head 31 that can shift on
guides on the sides of the table 33. The lowering of the heating
head 31 above the laminate 41 is done by means of manually
controlled pneumatic actuation. The heater can rotate +45.degree.,
+90.degree., -90.degree., -45.degree. around the Z axis in order to
be able to adhere the reinforcements of the unidirectional tape or
overlaps, as the case may be. Once the laminate 41 is finished, it
is to be cut in the areas marked, identifying each one of the
resulting parts and the axes of symmetry with a white marker, thus
it is clear that four ring frames 43, 45, 47, 49 are manufactured
from the same laminate 41 at the same time.
[0036] The straight hot-forming of the C- and L-shaped preforms is
carried out in the laminate tool 21 following the steps shown in
FIG. 5. First a separating film 53 will be arranged so that the
starting laminate 51 (with the dimension required for hot-forming
the C- or L-shaped perform involved) does not adhere to the elastic
membrane 55 and contaminate the material. Then the hold-down plate
29 is placed, which is quickly anchored through a pneumatic
actuator to a projection on the central module 25, the cantilever
of which overlaps on only a 10 mm longitudinal strip of laminate 41
and presses on it enough so that it is not dragged by the elastic
membrane 55. Since the laminate 51 has longitudinal reinforcements
with variable thickness in the area to be heated, the hold-down
plate 29 must be discontinuous so as to couple to the different
heights. Once the hold-down plate 29 is in place, the side modules
23 are carefully removed so as to not drag the previously generated
laminate 41, and the ring frame with the elastic membrane 55 is
placed. This elastic silicone membrane is vacuum-deformed,
withstanding temperatures of 120.degree. as the working
temperature, and elongations of the order of 400%. Then with
everything assembled, the hot-forming (temperature+vacuum) process
is performed. The temperature is applied through the hot-forming
tool 21. The central module 25 has resistors 61 embedded therein to
heat the laminate 51. During hot-forming, these resistors heat the
horizontal area where the laminate 51 and 5 mm (at most) of the
vertical area is supported. To prevent the vertical area from being
heated, an FV material 63 is placed in the tool in this area acting
as a thermal insulator. The temperature to be reached locally is
100.degree. C. (with a tolerance of .+-.5.degree. C.) for 20
minutes as a reference. The vacuum is carried out through the table
33 of the tool 21, made in aluminum honeycomb panel form, and the
vacuum inlets are placed under the central module 25, which has
longitudinal mortising with transverse bypasses 67.
[0037] To carry out the second hot-forming cycle the curved
hot-forming tool 55 for the C- and L-shaped preforms is used. The
laminates 51 of right angle section obtained in the previous step
are placed on the hot-forming component 55 corresponding to the C-
and L-shaped preforms, manually deforming them in order to couple
them to the male part 55 without the occurrence of creases, first
placing the flanges shaped in the previous step into the mortises
59 and then adapting the rest of the laminate to the tool which, in
the case of the C-shaped preforms, means that in addition to the
curved deformation, the deformation required for hot-forming the
other flange must be carried out, using mortises 60 for that
purpose.
[0038] Then a separating film is placed on the preforms, making the
necessary cuts for the purpose of coupling it perfectly, and this
is all held with elastic strips 71 with fastening clips 73,
preventing the occurrence of creases in the radiuses and web.
Control thermocouples will be positioned on each one of the
preforms, in the middle of the flanges shaped in the first straight
hot-forming cycle, introduced in it about 5 mm deep. Finally, the
tool 55, formed by aluminum sheet metal 75 on a base sheet metal
77, also of aluminum, will be introduced in the hot-forming machine
(temperature+vacuum cycles).
[0039] Once the preforms are shaped the excess parts will be cut
away.
[0040] If it is necessary in the assembly to couple the outer
flange of the ring frame to a planar support, such as the overlay,
wedge-shaped accessories can be manufactured which are placed on
the ring frames, coupling them to the flanges by means of the
application of heat with an iron.
[0041] Now the preforms are ready for carrying out a ring frame of
a fully integrated section by means of a process known as RTM
injection.
[0042] Any modifications comprised within the scope defined by the
following claims can be introduced in the preferred embodiment
described above.
* * * * *