NO154789B - PROCEDURE FOR THE MANUFACTURE OF SELF-SURFACE SHEET SURFACES CONSTRUCTED BY MULTIPLE LAYERS. - Google Patents

Description

The invention relates to a method as stated in the introduction to claim 1.

By such a method, which is known from

DE-A 26 26 537, hollow profiles are combined into a section by means of assembly clamps which, before inserting the hollow profiles into the clamps, are plastically deformed in accordance with the desired contour determined by the rack and then connected to the corresponding section of the skeleton. The individual hollow profiles in this section are attached to the skeleton at points, e.g. using screws. Between the upper and lower sides of neighboring hollow profiles that collide with each other, an adhesive is arranged section by section to connect the hollow profiles in a section to each other after all or e.g. only every other hollow profile in a section is fixed on the stand. After the stand is completely covered with hollow profiles, these are connected to each other by means of thermosetting plastic filling material which at least partially penetrates between the upper and lower sides and hardens. Finally, a fibre-reinforced thermoplastic layer is placed on the formed surfaces and connected to them. In this way, a boat hull shell is obtained which has a relatively low weight and is very dimensionally stable and, due to its large air inclusions inside the hollow profiles, greatly improves the intended ability of the hull not to sink. With this method, boat hull shells of different shapes and dimensions can be produced in a simple way and without the use of expensive negative forms.

The skeleton used in this method is formed by the construction parts that are nevertheless used in the boat hull in addition to the shell, e.g. transoms, transoms or bulkheads, spars that form the esing of the boat hull shell, the keel beam and a bow. As with boat hulls of great length there is also a relatively large distance between the individual bulkheads, e.g. the last bulkhead and transom, it is difficult to arrange the hollow profiles to be laid on the rear bulkhead and transom, with regard to the desired contour and contour transition, as the hollow profiles tend to connect neighboring bulkheads with each other in the shortest way with unless mounting brackets are used. The hollow profiles used in this known method have a uniform cross-sectional shape, the upper side of which has the form of an outwardly open, obtuse-angled, V-shaped channel, while the lower side curves convexly outward in a U-shape. When the upper and lower sides of neighboring hollow profiles engage with each other, longitudinal grooves are obtained which are open to the inner surface and the outer surface of the base shell, respectively. In these grooves, the filling material must be introduced to connect the hollow profiles with each other and form the mainly smooth inner and outer surface of the base shell. Precisely when forming complicated contours of the boat hull shell, however, the neighboring hollow profiles in a section must be rotated relatively strongly in relation to each other, whereby the longitudinal grooves on either the inner or outer surface will admittedly become deeper or wider, but at the same time the longitudinal grooves on the other side are almost closed or may even disappear completely. Thereby, sufficient penetration of the filling material into at least one of the surfaces is not ensured, whereby the strength of the connection between neighboring hollow profiles can suffer in case of strong curvatures within a section of the hollow profiles.

In NO-B 148913, it has already been proposed for the production of such a boat hull shell to use hollow profiles with two different cross-sectional shapes, the first cross-sectional shape being mainly circular, while the second cross-sectional shape has contact surfaces with outwardly open obtuse-angled V-shaped grooves, the contact surfaces being interconnected by parallel side walls. At the free ends of the grooves in the second cross-sectional shape, protrusions are formed which extend mainly in the direction of the side walls to, together with the adjacent hollow profile of circular cross-section, form cavities with an approximate dovetail shape for receiving the filling material. On the other hand, these protrusions close the cavities almost completely against the inner surface and the outer surface of the boat hull shell, so that the connection between the plastic layer to be placed on the inner and outer rafts and the filling material is not optimal.

The purpose of the invention is to further develop the method stated in the introduction to claim 1, in such a way that a very reliable and form-locking connection can be ensured between neighboring profiles by means of the filling material to be inserted between the profiles, and the associated plastic layer, even when strong curvatures are to be formed between neighboring profiles when forming complicated contours of the enveloping surface.

Using a profile shape with a mainly

X-shaped cross-section, it is possible, despite the significant simplification in manufacturing and stocking that is obtained by using only one uniform profile type, to ensure that longitudinal grooves of sufficient width and depth are obtained on the inner and outer sides of the sheathing surface between the profiles, when neighboring profiles are mainly oriented 90° rotated in relation to each other. If a profile has its longitudinal midplane mainly vertically oriented, both of its neighboring profiles have a mainly horizontally oriented longitudinal midplane. As a result of the mainly X-shaped cross-section of the profiles, longitudinal grooves with dovetail-shaped cavities are obtained with this device, which have a large opening cross-section towards the inner and outer sides of the wrapping surface. Through this opening cross-section, the thermosetting plastic filling material can connect with the plastic layer, also consisting of thermosetting plastic, which is to be laid on the inside and outside. Such an intimate connection over the largest possible surface between the filler material penetrating the longitudinal cracks and the plastic layers is particularly important, as the connection between the thermosetting plastic layer and the profiles, which consist of any material, preferably, however, of thermoplastic or metal such as e.g. aluminium, can be critical. Preferably, hollow profiles are also used in the method according to the invention, and in that case the cross-section is preferably rounded and simplified so that the hollow profiles have an approximate "dog bone shape". This cross-sectional shape allows in a very free way a relatively strong turning of neighboring profiles in relation to each other for shaping even complicated contours in a simple way. The edges of the profiles are rounded below to exclude shearing effects (Kerbwirkungen) between neighboring profiles, especially also in case of a possible distortion of the individual profiles. These rounded profile edges facilitate the production of the profiles at the same time, which is preferable

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produced by extrusion. On the other hand, profiles of the desired cross-sectional shape can be controlled very well also as massive profiles, i.e. these too can e.g. twist for the case that successive sections in the longitudinal direction of an enveloping surface, e.g. a boat hull, must show different contours. On the other hand, a design of the profiles as hollow profiles is preferred, as these, as a result of the enclosed air, lead to a very low average mass density of the enveloping surface, e.g. of 0.3-0.4 g/cm calculated on the entire cross-section of the covering surface. This density is thus only about half the density of wood. The filling material used in the method according to the invention has a density of approx. 0.6 g/cm 3. According to a preferred embodiment of the method, assembly staples are also used there to produce the contours of the enveloping surface. The mounting clamps allow the method according to the invention to be carried out particularly easily and precisely.

These mounting clamps are preferably arranged in a frame which surrounds the clamp's U-profile, and which carries setting screws which serve to set the contour. The sides of the U-profile of the assembly brackets facing the profiles can also be provided with knob-like protrusions that facilitate the arrangement of the profiles in the assembly brackets, resp. secures the position of the profiles in the assembly brackets when these are at least partially unfoldable or expandable to be able to be folded around the profiles to be bent to a specific contour. On the other hand, the assembled j-clamps can also be pushed in over the profiles in a section, and the knob-like protrusions will then slide over the profiles that project furthest towards the inside and outside of the boat hull shell, as they then elastically dodge outwards. For this purpose, the knob-like protrusions, e.g. by means of coil springs, be elastically spring biased in the direction towards the longitudinal grooves' cavity or formed by adjustable screws.

Embodiments of the invention will be described in more detail with reference to the drawing.

Fig. 1 schematically shows the construction of a boat hull shell

which here forms the enveloping surface, from profiles.

Fig. 2 schematically shows the possible arrangement of the profiles used in the method according to the invention. Fig. 3 shows a possible cross-sectional shape of these profiles.

Fig. 4 schematically shows a mounting clamp for forming

of the contour of a section consisting of several profiles.

Fig. 5 shows a section of such a mounting bracket as

is provided with knob-like protrusions.

Fig. 6 schematically shows the application of the plastic layer on the profiles.

As schematically shown in fig. 1, a boat hull shell 1 is produced from a series of profiles 3, 3' using a skeleton 2. The skeleton 2 comprises a transom 2a, frames 2b or transverse walls 2c resp. bulkhead 2d, spars 2e which determine the esing of the boat hull shell, a keel or a keel beam 2f which connects these building elements on the underside, and a bow 2g which forms the bow. The elongated profiles, which consist of an arbitrarily suitable material, are placed on this skeleton and, as a result of their cross-sectional shape, will engage with each other on the upper and lower sides.

As shown in fig. 2 and 3, only one type of profile is used, which preferably has the one in fig. 3 showed a cross-sectional shape and is designed as a hollow profile with rounded edges. These profiles, which have an approximately "dog bone-shaped" cross-section, are arranged in the manner shown in fig. 2, so that a profile 3' lies with its longitudinal middle plane mainly horizontal, while the following neighboring profile 3 has a mainly vertical orientation of its longitudinal middle plane. As shown in the lower part of fig. 2, the thus arranged profiles are set obliquely or turned in relation to each other to form the desired contour of the boat hull shell. The approximately dovetail-shaped cavities that are formed between two successive, mainly horizontally arranged profiles 3' and a mainly vertical profile 3 lying between these profiles 3' are filled with thermosetting plastic filling material, since even when forming a specific contour, sufficient sizes are still obtained opening cross-section from the outside towards these cavities, which leads to an excellent joining between the thermosetting plastic filling material and the thermosetting plastic layers 4 which are applied to both the inside and the outside of the boat hull shell.

The rounded edges of the profiles prevent the formation of notches (Kerbwirkung) in neighboring profiles, even with a relatively strong slanting position of the profiles to each other when complicated contours of the boat hull shell are to be formed.

Although not shown in fig. 2, the mainly vertically oriented profiles when designing such contours can in extreme cases also be swung out of the overall cross-section of the shell on the inner or outer side, as the parts of the profiles that protrude outside the cross-section of the shell are ground away before the plastic layers are laid on the inner and outer surfaces of the shell . Open cavities that may be formed inside the profiles by such grinding away are likewise filled with thermosetting plastic filler material, so that neither the density nor the load-bearing capacity of the shell is reduced.

Although fig. 1 as an example of an enveloping surface shows

a boat hull shell produced by the method according to the invention, arbitrary, preferably three-dimensionally shaped covering surfaces which are made up of several layers and are self-supporting can of course be produced by the method according to the invention. The profiles can consist of an arbitrary, suitable, i.e. the lightest possible, material. Preferably, the profiles consist of a thermoplastic or a light metal such as e.g. aluminum. Other possible areas of application for the casing rafts lie in the area of construction technology, e.g. when building a hipped roof, silos,

aircraft etc.

In order to improve the connection between the profiles 3 and 3' as well as the thermosetting plastic filling material introduced in the cavities, especially when the profiles e.g. is made of aluminium, fibre-reinforced thermoplastic layers 4' can be applied to the mainly horizontally oriented profiles 3' in such a way that they cover the narrow side of the profiles and at least parts of the side surfaces of the mainly vertically oriented profiles 3', as schematically shown in fig. 6. After application of these plastic layers 4', the filling material is brought into the mainly dovetail-shaped cavities, after which the plastic layers 4 are applied to form outer and inner layers as also shown in fig. 2. Thereby, the connection of the filling material with the profiles can be improved, also when the profiles consist of a material that is of a different type to the filling material. On the other hand, even without these extra plastic layers 4', a sufficiently strong self-supporting structure of the sheathing rafts is obtained only as a result of the fact that, due to the special alternating arrangement of the profiles, mainly dovetail-shaped cavities are created into which the filling material is brought to form filling material wedges which, together with the outer layers, hold the self-supporting covering surface together.

However, the fibre-reinforced further hard plastic layers 4<1> can also serve as filling material themselves, as they have sufficient strength to form an anchorage body in the dovetail-shaped cavity. In this connection, it must be emphasized that the filling material does not exclusively have to be a mass that must be filled in the dovetail-shaped cavities, but also e.g. can consist of plastic layers that serve to form a body that rests against the limiting surfaces of the dovetail-shaped cavity or is connected to these, and which has sufficient strength that, together with the plastic layers that form the outer layers, it holds the self-supporting covering surface together. In this case, further "artificial" hollow profiles are formed in the dovetail-shaped cavities which, together with the plastic layers that form the outer layers, and the profiles form the enveloping surface.

In fig. 4 schematically shows an assembly clamp for producing contours on sections of profiles. These mounting brackets consist of a mainly U-shaped frame 13 which has side legs 113, 113' and a connecting step 113". As schematically shown at 15, the side legs 113, 113' can be pivotably supported on the connecting step 113" so that U- the profile of the actual assembly bracket 11 with the legs 111 and 111' must be able to be opened, which greatly facilitates the application of the assembly bracket on a section of profiles. After the mounting clip has been put on, the joint connection 15 between the legs 113, 113' and the connecting step 113" is locked, as they are held on the already covered part of the boat hull shell or on the esing. In the legs 113 and 113' of the frame 13, there are arranged a number setting screws 114 which are provided with wing heads 115. By setting the individual setting screws, the actual U-profile 11 of the mounting bracket can be adjusted elastically in the desired way to give the profiles 3, 3' which are inserted into the U-profile, the desired contour After the formation of this desired contour, the profiles 3, 3'

in the usual way attached to the skeleton and also connected to each other, for example, by means of spot welding, after which the mounting bracket is removed, the filler material is applied and the plastic laminates are applied.

The one in fig. 4 shown mounting clamps are suitable for producing a contour which has a concave shell shape which is open to the right in the drawing. If an inverted curved contour or a more complicated contour is to be produced, the frames 13 for these mounting brackets must be designed in a corresponding manner, since several differently designed mounting brackets are available for the formation of different contours on different sections and can of course also be simultaneously applied and set on the desired way on profile sections that follow each other in the longitudinal direction of the boat hull shell.

In order to facilitate the arrangement and orientation of the individual profiles in relation to each other and in the mounting bracket, knob-like projections 14, 14' can be arranged, the distances on the inside of the legs 111, 111' of the U-profile 11 are chosen so that the knobs project into the cavities of the longitudinal grooves formed. As schematically indicated in fig. 5, the projections 14' can also be spring-elastically displaceable in the outward direction,

something like e.g. can be achieved by means of coil springs 15, which bias a nail head-like projection in the direction towards the longitudinal grooves' cavities. However, the protrusions can also be formed by means of screws which can be set in the direction of the cavities, although this is not shown in the drawing. When the mounting clip cannot be folded around the profiles in a section when unfolding or opening the U-profile 11 as shown in fig. 4, the mounting clip can also be pushed in over the profiles in a section, as the knob-like projections then elastically dodge sideways when pushed over the mainly horizontally oriented profiles 3 '.

The self-supporting cladding surfaces produced by the method according to the invention have the further advantage that by using profiles consisting of a suitable material, accessories can be inserted into the cladding surface by welding and hot forming the profiles, or that holes can be created in the cladding surface, before the hard plastic filler is applied and the plastic layers are applied to the inside and outside.

Claims (5)

1. Method for producing self-supporting cladding surfaces that are built up from several layers, in particular a boat hull shell (1), using a skeleton (2) which determines the desired three-dimensional shape of the cladding surface, and as profiles (3,3') with the same cross-section is laid against under mutual tooth engagement and attached point by point, as the profiles are connected to each other by means of a thermosetting plastic filling material which partially penetrates between the profiles (3,3') and hardeners, after which fibre-reinforced thermosetting plastic layers (4,4') are applied to the formed surfaces and connected to these, characterized in that profiles (3,3') with a mainly X-shaped cross-section are used, and that the profiles (3,3') are arranged so that the cross-sections of neighboring profiles have a mutual, mainly 90° turn briefing. 2. Method as stated in claim 1, characterized in that hollow profiles with a mainly X-shaped cross-section are used as profiles, the legs of the X which limit a wide side of the hollow profile, forms a side wall which, seen from the outside, is concavely curved and the edges are rounded. 3. Method as stated in claim 1 or 2, characterized in that around the narrow sides of each mainly horizontally oriented profile a fibre-reinforced thermoplastic layer (4') is laid which extends to the side surfaces of the mainly vertically oriented profiles and itself forms the filling material or is applied before the placement of this. 4. Method as specified in one of the preceding claims, characterized in that plastic or metal profiles are used, e.g. aluminum. 5. Procedure as specified in one of the preceding claims, where several profiles are combined into one section by means of at least one mainly U-shaped mounting bracket (11), and where the profiles are adjusted by bending the mounting bracket (11) to the contour of the skeleton (2) to be covered, and then connected to the skeleton, after which the mounting bracket (11) or - the clamps are removed, preferably several assembly clamps are bent separately to different contours and fixed, characterized by the use of assembly clamps with knob-like protrusions (14,14') which are arranged on the sides facing the profiles (3,3') of The legs (111,111') of the U-profile (11) and protrude into each of the cavities formed by each of the mainly vertically oriented profiles (3) and mainly horizontally oriented neighboring profiles (3'), as well as touching the mainly vertically oriented profiles (3 ) for orientation of these.