U.S. patent application number 09/771887 was filed with the patent office on 2001-07-12 for process for producing a composite structural element.
This patent application is currently assigned to MOLLER PLAST GmbH. Invention is credited to Hesch, Rolf.
Application Number | 20010007269 09/771887 |
Document ID | / |
Family ID | 7802480 |
Filed Date | 2001-07-12 |
United States Patent
Application |
20010007269 |
Kind Code |
A1 |
Hesch, Rolf |
July 12, 2001 |
Process for producing a composite structural element
Abstract
A process for producing a composite structural element, which
includes the steps of providing a thin-section wall part, placing
the thin-section wall part into a mold, applying reinforcing
elements to the thin-section wall part, placing a counter-mold onto
the mold for forming a mold cavity, and introducing a binder having
a foaming agent into said mold cavity via one of injection cannulas
and nozzles, after a set time delay a foaming of the binder
occurring for encapsulating the reinforcing elements on all
sides.
Inventors: |
Hesch, Rolf; (Lemgo,
DE) |
Correspondence
Address: |
WERNER H. STEMER
P.O. Box 2480
Hollywood
FL
33022
US
|
Assignee: |
MOLLER PLAST GmbH
|
Family ID: |
7802480 |
Appl. No.: |
09/771887 |
Filed: |
January 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09771887 |
Jan 29, 2001 |
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09150707 |
Sep 10, 1998 |
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6207244 |
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09150707 |
Sep 10, 1998 |
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PCT/DE97/01239 |
Aug 13, 1996 |
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Current U.S.
Class: |
156/78 ;
264/46.5; 264/46.6 |
Current CPC
Class: |
Y10T 428/249986
20150401; B60J 5/042 20130101; Y10T 428/24744 20150115; Y10T
428/24504 20150115; Y10T 428/249984 20150401; Y10T 428/1366
20150115; Y10T 428/1376 20150115; Y10T 428/249982 20150401; Y10T
428/233 20150115; B60R 21/0428 20130101; Y10T 428/1372 20150115;
Y10T 428/1359 20150115; Y10T 428/161 20150115 |
Class at
Publication: |
156/78 ;
264/46.5; 264/46.6 |
International
Class: |
B32B 031/04; B29C
044/06 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 1996 |
DE |
196 32 550.1 |
Claims
I claim:
1. A process for producing a composite structural element, which
comprises: providing a thin-section wall part; placing the
thin-section wall part into a mold; applying reinforcing elements
to the thin-section wall part; placing a counter-mold onto the mold
for forming a mold cavity; introducing a binder having a foaming
agent into said mold cavity via one of injection cannulas and
nozzles, after a set time delay a foaming of the binder occurring
for encapsulating the reinforcing elements on all sides.
2. The process according to claim 1, which comprises introducing
the binder having the foaming agent into an open mold.
3. The process according to claim 1, which comprises using the
binder having the foaming agent with a set time delay of less than
5 seconds for foaming the binder.
4. The process according to claim 1, which comprises priming the
thin-section wall part on a foam application side to improve
adhesion before applying the binder.
5. The process according to claim 1, which comprises backing the
thin-section wall part with a hard shell formed with reinforcing
elements by one of compression molding and injection molding before
a formation of the mold cavity, and applying a second hard shell
subsequently to the free side of the molding.
6. The process according to claim 5, which comprises molding on
transverse cross-pieces to the hard shell during the application of
the hard shell.
7. The process according to claim 5, which comprises forming a
recycled core from one of a foam and a comparable light weight
material and placing the recycled core in the reinforcing elements
before the binder is injected.
8. A process for producing a composite structural element, which
comprises: producing moldings formed with reinforcing elements and
a binder by foaming of the binder for encapsulating the reinforcing
elements; producing hard shells formed with the reinforcing
elements and the binder by foaming of the binder for encapsulating
the reinforcing elements; and providing a thin-section wall part,
and bonding adhesively the moldings and the hard shells to the
thin-section wall part for forming a composite element.
9. The process according to claim 8, which comprises producing the
moldings with recycled cores.
10. The process according to claim 8, which comprises producing the
hard shells with transverse cross-pieces.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a division of U.S. application Ser. No.
09/150,707, filed Sep. 10, 1998, which was a continuation of
International Application Ser. No. PCT/DE97/01239, filed Aug. 13,
1996, which designated the United States.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The invention relates to a process for producing a composite
structural element, in particular for the body or parts of the body
of a motor vehicle. The wall or structural element provides
superior impact protection and increases the resistance to pressure
and bending, and improves heat-insulation.
[0004] In the construction of motor vehicles for passenger
transportation, occupant protection is becoming an increasingly
important consideration. For example, the problem of side impact
protection is solved by the installation of transverse members in
the doors. As known, shock absorbers made of foam are also fitted
into the cavities of the doors in order to distribute the forces
occurring during impact and absorb impact energy by deforming. Side
airbags are other known measures for the protection of vehicle
occupants. However, the known configurations contribute only to a
limited extent to the strength and rigidity of the body and
consequently to the safety of the occupants.
[0005] A further problem of modern vehicle construction is that of
heat insulation. More and more vehicles are being fitted with
air-conditioning systems. At the same time, inadequate heat
insulation results in wasted cooling energy on a large scale.
Better heat insulation could make a considerable contribution to
lowering energy consumption by reduced heating power in the winter
and lower fan power in the summer.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide a
process for producing a composite structural element which
overcomes the above-mentioned disadvantages of the prior art
devices and methods of this general type, and which provides a wall
or structural element, preferably for the body or parts of the body
of a motor vehicle, which offers the vehicle occupants a high level
of safety during accidents and, by improved heat insulation, lowers
energy consumption and improves traveling comfort.
[0007] With the foregoing and other objects in view there is
provided, in accordance with the invention, a structural element
for providing impact protection, increasing resistance to pressure
and bending, and increasing heat-insulation, including a composite
element having a sheet-like, thin-section wall part with a surface
area; and a molding formed with a binder embedded with reinforcing
elements and having a surface area adjoining the surface area of
the sheet-like, thin section wall part, the composite element
provided for dissipating impact forces and introducing the impact
forces into load-bearing parts of a body.
[0008] The composite element formed in this way, which can be used
variously as a wall element for the body or as a component for
bumpers, members or the like, but also in other regions as a wall
part or component of high flexural rigidity and heat insulation.
The composite element can be produced at low cost and with little
expenditure on primary raw materials. When used as a body wall
element, it offers outstanding occupant protection during
accidents, since the body or other components do not splinter and
no sharp or broken edges causing injuries are produced. Any impact
energy which is absorbed by the wall or structural element, such as
doors, members, body panels, bumpers and the like, is dissipated
and distributed over the surface area.
[0009] The expenditure on material for the body panel, in this case
used as a sheet-like, thin-section wall part, is inexpensive. As a
result, the vehicle weight can usually be reduced and consequently
the energy consumption and ultimately the emission of pollutants
can also be reduced. The climatic conditions in vehicles or other
interior spaces provided with the wall element according to the
invention can be improved considerably without having to use
sophisticated air-conditioning systems.
[0010] In accordance with an added feature of the invention, the
molding is either adhesively bonded over its entire surface area to
the wall part or foamed onto the wall part.
[0011] In accordance with an additional feature of the invention,
the reinforcing elements are renewable raw materials.
[0012] In accordance with another feature of the invention, the
renewable raw materials are disposed in the binder as uncut,
partially cut, and/or substantially cut in a form of stalks, stalk
sections, fibers, bundles of fibers, twisted yarns, filaments,
husks, nonwovens, wovens or rovings.
[0013] In accordance with another added feature of the invention,
the renewable raw materials are dicotyledons, including flax, hemp,
jute, and linume, and/or monocotyledons, including bamboo and giant
grasses.
[0014] In accordance with another additional feature of the
invention, the binder is a foamable synthetic, a biological derived
substance, a naturally derived substance, matrices of natural
substances or matrices of synthetic substances.
[0015] In accordance with yet another added feature of the
invention, there are low weight recycled cores provided in regions
of low tensile and compressive stress inside of the molding.
[0016] In accordance with yet another feature of the invention, the
recycled cores are unreinforced recycled products, formed from
foam, foam granules, preformed parts, prebonded parts, foam-textile
combinations or textiles.
[0017] Inside the molding or in regions of low tensile and
compressive stress, recycled cores of unreinforced or reinforced
recycled products, such as foam, foam granules or preformed or
prebonded parts of the latter, foam-textile combinations, textiles
or natural foams, for example sunflower pith, may be provided.
[0018] In accordance with yet another additional feature of the
invention, there is an insulating layer disposed between the
molding and the thin-section wall part, the insulating layer is
recycled foam and is adhesively bonded solidly to each of the
molding and the thin-section wall part.
[0019] In accordance with yet a further added feature of the
invention, the insulating layer includes a molded foam part, a foam
panel or foam flakes.
[0020] In accordance with yet a further additional feature of the
invention, a foamable material is admixed with the recycled foam
forming the insulating layer for adhesively bonding the insulating
layer with the thin-section wall part.
[0021] In accordance with yet another further feature of the
invention, the molding is at least two moldings produced separately
and bonded to one another in a sandwich type of construction.
[0022] In accordance with a further feature of the invention, each
of the at least two moldings has a shell with a cavity formed
therein, and the cavity receives an insulating core.
[0023] In accordance with an added feature of the invention, the
insulating core is formed with the binder and the reinforcing
elements.
[0024] In accordance with another feature of the invention, the
insulating core includes recycled products without reinforcing
elements.
[0025] In accordance with an additional feature of the invention,
the insulating core has regions for receiving functional elements,
actuating elements and cables.
[0026] In accordance with a further added feature of the invention,
the molding is constructed at least partially from a number of
shells in the sandwich type of construction for easy accessibility
to and exchangeability of functional and actuating elements.
Between the moldings there may be provided an insulating core
composed of a binder and reinforcing means or composed of recycled
products, it also being possible for clearances to be formed in the
insulating core for receiving actuating elements, cables or the
like.
[0027] In accordance with a further additional feature of the
invention, the thin-section wall part is formed with sheet metal or
a thin-layer, sheet-like decorative material.
[0028] In accordance with yet another added feature of the
invention, the wall part is formed with sheet metal for forming a
sheet-metal skin, and includes a hard shell formed by compression
molding or injection molding adjoined to and reinforcing the
sheet-metal skin, the hard shell also adjoining and solidly bonding
to the molding.
[0029] In accordance with yet another feature of the invention, the
hard shell includes the reinforcing elements for providing high
tensile stress strength.
[0030] In accordance with yet another additional feature of the
invention, the molding is adjoined on two sides by the hard shell.
Between the thin-section wall part and the molding there is
arranged a hard shell formed by compression molding or injection
molding and solidly bonded to both of them. The molding may be
covered on the side opposite the wall part by a solidly bonded
second hard shell, as a counter-chord. Cross-pieces extending in
the transverse direction may also be molded onto the first hard
shell, the cavities formed as a result are filled in the way
described above with reinforcing elements or recycled products, or
both, surrounded by binder.
[0031] In accordance with an added feature of the invention, the
hard shell covered molding includes at least one recycled core.
[0032] In accordance with another feature of the invention, there
are transverse cross-pieces extending in a transverse direction
which are molded onto the hard shell adjoining the wall part.
[0033] In accordance with an additional feature of the invention,
the hard shell provided with the transverse cross-pieces is formed
from a plurality of half-shells which are solidly bonded to the
wall part and to one another.
[0034] In accordance with a further added feature of the invention,
the half-shells have cavities formed therein, the cavities of the
half-shells are filled with one of the reinforcing elements and the
binder, unreinforced recycled material, and the reinforcing
elements and the binder with a recycled core.
[0035] In accordance with a further feature of the invention, the
composite element is one of a body part or parts of the body of a
motor vehicle.
[0036] With the foregoing and other objects in view there is also
provided, in accordance with the invention, a process for producing
a composite structural element, which includes providing a
thin-section wall part; placing the thin-section wall part into a
mold; applying reinforcing elements to the thin-section wall part;
placing a counter-mold onto the mold for forming a mold cavity;
introducing a binder having a foaming agent into the mold cavity
via one of injection cannulas and nozzles, after a set time delay a
foaming of the binder occurring for encapsulating the reinforcing
elements on all sides.
[0037] According to the process of the invention for producing the
structural element as a composite work piece, reinforcing elements,
preferably in the form of renewable raw materials or parts thereof,
are applied to the thin-section wall element, preferably consisting
of sheet metal, and, after the placing on of a counter-mold, the
binder with a delayed-action or immediately acting foaming agent
are introduced into the cavity thus formed via injection cannulas
or nozzles. The binder initially flows around the reinforcing
elements, in order to create during the subsequent foaming a solid
bond between the wall part and the foamed binder and between the
reinforcing elements and the foamed binder and at the same time to
fix the reinforcing elements in position. To improve the adhesion
between the wall part and the molding formed of the binder and
reinforcing elements, the side of the wall part facing the molding
may be primed in advance.
[0038] Before providing the reinforcing elements, the thin-section
wall part may be backed with a hard shell by compression molding or
injection molding, a second hard shell being applied as a
counter-chord once the molding has formed.
[0039] The first hard shell--provided with transverse
cross-pieces--may be produced separately and also in more than one
part and then be adhesively bonded on the wall part in an already
prefabricated form. A plurality of hard shells with transverse
cross-pieces also being held in positive engagement with respect to
one another and on the wall part may also form one complete hard
shell.
[0040] In accordance with an added feature of the invention, there
is the further step of introducing the binder having the foaming
agent into an open mold.
[0041] In accordance with another feature of the invention, there
is the further step of using the binder with the foaming agent
having a set time delay of less than 5 seconds for foaming the
binder.
[0042] In accordance with an additional feature of the invention,
there is the step of priming the thin-section wall part on a foam
application side to improve adhesion before applying the
binder.
[0043] In accordance with yet another added feature of the
invention, there is the step of backing the thin-section wall part
with a hard shell formed with reinforcing elements by compression
molding or injection molding before a formation of the mold cavity,
and applying a second hard shell subsequently to the free side of
the molding.
[0044] In accordance with yet another further feature of the
invention, there is the step of molding on transverse crosspieces
to the hard shell during the application of the hard shell.
[0045] In accordance with yet a further feature of the invention,
there is the step of forming a recycled core from one of a foam or
a comparable light weight material and placing the recycled core in
the reinforcing elements before the binder is injected.
[0046] With the foregoing and other objects in view there is
further provided, in accordance with the invention, a process for
producing a composite structural element, which includes: producing
moldings formed with reinforcing elements and a binder by foaming
of the binder for encapsulating the reinforcing elements; producing
hard shells formed with the reinforcing elements and the binder by
foaming of the binder for encapsulating the reinforcing elements;
and providing a thin-section wall part, and bonding adhesively the
moldings and the hard shells to the thin-section wall part for
forming a composite element. The moldings themselves may also be
produced separately from the thin-section wall part, to be precise
with or without recycled cores, and then be adhesively bonded to
the wall part or to the hard shell.
[0047] In accordance with an added feature of the invention, there
is the step of producing the moldings with recycled cores.
[0048] In accordance with a concomitant feature of the invention,
there is the step of producing the hard shells with transverse
cross-pieces.
[0049] Other features which are considered as characteristic for
the invention are set forth in the appended claims.
[0050] Although the invention is illustrated and described herein
as embodied in a process for producing a composite structural
element, it is nevertheless not intended to be limited to the
details shown, since various modifications and structural changes
may be made therein without departing from the spirit of the
invention and within the scope and range of equivalents of the
claims.
[0051] The construction and method of operation of the invention,
however, together with additional objects and advantages thereof
will be best understood from the following description of specific
embodiments when read in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 is a sectional view of a wall or structural element
of a composite type of construction bonded to a further composite
component, taking as an example a vehicle door of a motor vehicle
according to the invention;
[0053] FIG. 2 is a sectional view of a second embodiment of the
structural element serving as the vehicle door;
[0054] FIG. 3 is a sectional view of a third embodiment of the
structural element of the composite type used as part of the
vehicle door connected to a second composite component; and
[0055] FIGS. 4a and 4b are perspective, side-elevational views of
the vehicle door and of load-bearing parts of a passenger car in a
region of the vehicle door, with arrows representing dissipation to
all sides of forces generated during side impact onto the
load-bearing parts of the vehicle door and of a body of the motor
vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0056] Referring now to the figures of the drawing in detail and
first, particularly, to FIG. 1 thereof, there is shown a wall or
structural element produced as a composite in the example of a door
for a motor vehicle. The door includes two wall or structural
elements respectively produced as a composite type of construction
and secured to each other, but leaving a channel 5 free between
them because of a required fitting of a window pane 6 and a
mechanism required for moving it. A thin-section wall part 1 for an
outer skin of the motor vehicle door is formed of sheet metal, is
adjoined by a molding 4 formed of a foamed synthetic, biological or
naturally derived binder 2 and reinforcing elements 3 surrounding
the latter and thereby fixed in their position. The molding 4 is
bonded to a second molding 4a, or composite part, forming an
interior paneling of the vehicle door. Provided between the two
moldings 4, 4a is the channel 5 for receiving the window pane 6, a
guide rail 7 required for guiding the window pane 6, and further
actuating elements (not shown in the drawing) for moving the window
pane 6. The outside of the second molding 4a is covered by a
decorative layer 8 shown as a thin-layered wall part and is solidly
bonded to the molding 4a by foaming on, adhesion or the like. The
production of the wall or structural element shown in FIG. 1 takes
place by placing the wall part 1, serving as the outer door skin
formed of sheet metal, into a mold and covering its inner side
uniformly with a layer of the reinforcing element 3. Renewable raw
materials in the form of stalks and stalk sections or fibers and
bundles of fibers as well as nonwovens and the like produced from
the latter are used as the reinforcing elements 3. Preferably
considered here as renewable raw materials are monocotyledons and
dicotyledons, which are distinguished by outstanding mechanical
properties. In the case of dicotyledons, the periphery of the stalk
consists of a bast ring, which is composed of extremely long and
high-strength fibers, particularly in the case of bast fiber
plants. The cylindrical arrangement of the bast fibers represents
what is mechanically an ideal cross section for bringing about a
particularly high modulus of elasticity as well as a high flexural
strength and buckling resistance. Although monocotyledons do not
have a pronounced bast ring, they have a ring of shorter-fibered
sclerenchyma, adjoined in the case of many species by a
high-strength ring of vascular bundles, which are accompanied by
high-strength mechanical tissue. In addition to this, they have a
highly pronounced epidermis of great toughness.
[0057] The renewable raw materials used according to the invention
are also advantageous to the extent that their fibers are embedded
in a parenchyma matrix. The parenchyma is resistant to pressure and
has a large lumen and, in interaction with the peripheral
strengthening strands, allows considerable flexing. In the case of
dicotyledons, on the other hand, in the center of the stalk there
is instead of the parenchyma a core of wood, which is likewise
characterized by an extremely low wood density.
[0058] After applying the reinforcing elements 3 of renewable raw
materials to the wall part 1, a counter-mold (not shown) is placed
on and the binder 2 is introduced via corresponding cannulas or
injection nozzles into the hollow mold thus formed. The binder 2 is
free-flowing during injection process, with the result that it
flows completely around the reinforcing elements 3 and can
penetrate into all the intermediate spaces. After a time delay, the
binder 2 will foam and secure the reinforcing elements 3 in place.
The foaming process commences only after a certain time delay after
a corresponding distribution of the binder 2. The foamed binder 2
adheres solidly to the reinforcing elements 3 and fixing the latter
in its position.
[0059] Once the inner side of the wall parts 1 (door panel) has
been primed, if need be, before being placed into the mold, the
molding 4 including the foamed binder 2 and reinforcing elements 3
also undergoes a solidly adhering, full-area bond with the wall
part 1. The result being a one-piece composite is obtained after
removing the counter-mold.
[0060] In the case of the exemplary embodiment represented on the
basis of a vehicle door, the second molding 4a can be separately
produced in the same way as a thin-section wall part 1 onto an
interior paneling or the decorative layer 8.
[0061] The two composite parts subsequently being solidly bonded to
each other in a sandwich-like manner with recesses forming
intermediate spaces for receiving the window pane 6 and necessary
guiding and actuating elements.
[0062] With composites produced in this way, which may be
configured equally as a member or a wall element of the body or as
a bumper etc., outstanding side impact protection in the motor
vehicle is achieved by increasing the moment of resistance and the
deformation path. Since impact forces are uniformly distributed and
dissipated and introduced into the cage structure of the passenger
compartment, the impact energy is substantially absorbed. At the
same time, the heat insulation of the body is improved and
consequently the CO.sub.2 emission and the energy consumption are
reduced. Finally, the climatic conditions in the interior of the
vehicle are also improved. On account of the composite type of
construction including a sheet-like wall part 1 and the reinforced
molding 4 (foam element), the body panel can be made much thinner
than is generally customary, with the result that the expenditure
on material for the body panel, which is a high consumer of primary
energy, and ultimately the weight of the body can usually be
lowered. In addition, in the event of impact, no sharp edges are
produced, since the composite material does not splinter, and
consequently the safety of the vehicle occupants and other persons
involved in an accident is increased.
[0063] According to the invention, it is also possible, however,
contrary to the production process described above, to produce the
reinforced molding 4, 4a separately in a mold, i.e. separately from
the wall part 1 (or 8), and subsequently adhesively bond it to the
thin-section wall part 1. Even greater rigidity of the structural
element produced as a composite part can be achieved by using
integral foam, it being possible in this case to reduce further the
wall thickness of the thin-section wall part 1.
[0064] FIG. 2 shows a second variant of the invention also shown by
example as the door of a motor vehicle in which the impact
protection is further improved and the thickness of the wall part 1
is even further reduced.
[0065] The wall part or component differs from that represented in
FIG. 1 essentially in that the thin-section wall part 1, i.e. the
outer skin of the door, the body, a member etc., is backed by a
hard shell or insulating layer 9 formed by compression molding or
injection molding 9, preferably using reinforcing elements 3 of
renewable raw materials in the hard shell 9. In the way described
above, the molding 4 including the reinforced foam or integral foam
and reinforcing elements 3 are applied to the hard shell 9, in a
solid bond with the shell 9, and a further hard shell 9 is applied
to the molding 4 as a counter-chord.
[0066] It can also be seen from FIG. 2 that, to save primary
material, inside the molding 4 there is a recycled core or
insulating core 10 formed of a lightweight recycled material. The
size of this recycled core 10 is variable. It may ultimately reach
over the entire cross section of the molding 4 and, moreover, be
reinforced with renewable raw materials or other materials. It goes
without saying that this molding can also be produced separately,
as described with reference to FIG. 1, and then be adhesively
bonded to the thin-section wall part 1, in order to form the
composite in this way. In order to form the channel 5, the second
molding 4a, or the second structural element, is solidly joined
onto the structural element thus formed.
[0067] In FIG. 3, there is reproduced a third variant of a wall or
structural element, configured as a composite, for the motor
vehicle door. In this case, the wall or structural element is
reinforced by transverse cross-pieces 11a, which are part of
half-shells 11 produced separately and solidly bonded to the wall
part 1. The half-shells 11 are placed with positive engagement into
the wall part 1 and held against the latter and with respect to one
another by adhesion or foaming in.
[0068] The half-shells 11 with the transverse cross-pieces 11a
extending substantially perpendicularly away from the latter, are
produced with the preferred use of renewable raw materials as
reinforcing elements 3. The cavities formed by the half-shells 11
and transverse cross-pieces 11a are filled by reinforcing elements
3 composed of renewable raw materials and foam having a binder 2,
or else are provided with a recycled core or completely with a foam
filling. The half-shells 11 filled in this way are covered with a
hard shell 9. The hard shell 9 forms a solid bond with the
half-shells 11 or the transverse cross-pieces 11a, for example by
the foam-filling of the cavities. The hard shells 9 and the
half-shells 11 are produced by a compression-molding technique or
else an injection-molding or blow-molding technique, with or
without the use of reinforcing elements 3.
[0069] With the third variant, particularly high rigidity and
flexural strength can be achieved resulting in a further reduction
in the material thickness of the outer skin (wall part 1).
[0070] As already described above, the composite element
embodiments may be in the form of a vehicle door. There may be
connected to the composite element thus produced, the second
molding 4a, into which various functional elements (not shown),
such as map pockets, armrests or the like, may be integrated. In
this case, the thin-section inner wall part (decorative layer 8)
may also be configured as a thin sheet-metal skin, in 20 order to
bring about a further increase in the rigidity of the vehicle
door.
[0071] It can be seen from the representations of a passenger
vehicle door, or the part of the body receiving the latter,
reproduced in FIGS. 4a and 4b, how the door in the form of a rigid
shell covers over the fold of the door opening over its full
area--with the exception of the window region--and consequently the
energy generated during impact (large arrow) is dissipated over a
large area onto the entire door fold in the direction of the small
arrows. In addition, in combination with the dissipation of the
forces, the impact energy is absorbed by the compression of the
foam core extending over the entire door surface area.
* * * * *