Multi-chamber closed structure element and method for manufacturing a multi-

Abstract

The invention relates to a multi-cavity closed structural element and to a method for producing such an element, comprising the following steps: a) providing at least one cavity profile preform (2) comprising an inner wall (3) and an outer wall (4) made of sheet metal and arranged in parallel planes, wherein a ventilation opening (6) is arranged on at least one wall (3, 4); b) sealing the unconnected edges of the walls (3, 4) so as to form a closed, closed hollow interior space; c) connecting the end edges of at least one cavity profile preform (2) to each other in order to form a preform (9) of the multi-cavity closed structural element, said preform comprising a central cavity (8) surrounded by an inner wall of the preform (2); d) introducing a pressurized fluid into the interior space in order to form a deformed cavity profile (1).

Description

[0001] The invention relates to a multi-chamber closed structural element and a method for producing a multi-chamber closed structural element, which is used in particular as a vertical columnar support structure or as a profile in a frame structure. The subject matter of the invention can be used for producing vertical support structures in construction, mining or power engineering.

[0002] One of the most important structural elements used in a wide range of technical fields is the support column as a vertical independent structural support. As rods and columns, they are used to support and carry the loads of structures such as buildings, bridges, viaducts, etc. Supporting structural elements are also used in mining as roof supports in galleries or as structures used in small-scale architecture, for example in the construction of pavilions.

[0003] On the other hand, in frame structures used, for example, in vehicle body construction, profiles are used which, when properly connected to one another, form a frame having a desired shape and desired strength properties. An important factor of a frame structure is its strength, which depends inter alia on the strength of the components (i.e., the profiles) and on its empty weight, which is also related to the weight of the components.

[0004] PL224768B1 describes a mining load-bearing bar comprising: longitudinal layers, each longitudinal layer comprising a pair of outer beams substantially parallel to each other defining two longitudinal walls of the bar; transverse layers, each transverse layer comprising a pair of outer beams substantially parallel to each other defining two transverse walls of the bar, wherein the transverse layers are arranged alternately with the longitudinal layers, so that the outer beams of the transverse layers intersect with the adjacent outer beams of the longitudinal layers at four intersection points, and the outer beams of the transverse layers and the adjacent outer beams of the longitudinal layers are joined by recesses made in the upper and lower surfaces of the longitudinal beams and the transverse beams. Such structures are used as protective elements in deep-sea mining, supporting the roof in a mining tunnel or pulling the floor from the roof. Increasing the load-bearing capacity of the bar can be achieved by filling the interior of the bar with a self-hardening mixture (e.g., a mineral cement mixture) and forming a composite structure.

[0005] PL67807Y1 relates to a structural element, in particular a sheet metal section, intended for use in a sheet metal structure. The structural element has an inner wall with longitudinal edges that are preferably bent inwards at the center of the base. The inner wall is folded and inclined so that the edge walls are away from each other, preferably perpendicular to the side walls. Preferably, the edge is close to the surface of the side wall. In addition, the inner wall is connected by spot welding on the arc of the transition from the base plane.

[0006] Polish patent application P.432278 describes a method for manufacturing a multi-cavity structural element, wherein in order to form a multi-cavity structural element in which a cavity profile extends radially from a center defined by the connection of the cavity profiles, the method comprises the following steps: providing at least three cavity profile preforms, each cavity profile preform comprising two walls made of a metal material sheet and arranged in planes substantially parallel to each other, with a gap between the two walls, wherein the edges of the respective walls converge, wherein at least one wall is arranged with a vent; sealing the unconnected edges of the walls of each cavity profile preform by a seal to form a closed, airtight hollow interior space of the cavity profile preform; introducing a pressurized fluid into the interior space of the cavity profile preform through the vent to form a deformed cavity profile, at least three cavity profile preforms or cavity profiles are connected to each other in the region of the corresponding inner edges of the cavity profile preform or cavity profile along at least a portion of the inner edge, the edge being close to the connection axis. A multi-cavity structural element is also disclosed in the description of the invention.

[0007] The present invention intends to solve the technical problems behind it by providing a method for manufacturing a multi-cavity closed structural element, which will make it possible to manufacture a multi-cavity closed structural element, which has desired properties while maintaining the desired dimensional accuracy, especially in terms of strength and load capacity to weight ratio. It is expected that the method for manufacturing a multi-cavity closed structural element should be characterized by a limited number of technical steps, and can be achieved without the use of specialized and complex equipment, which will directly translate into the economic benefits of a simplified process of manufacturing a multi-cavity closed structural element that consumes less time and is therefore cheaper. In addition, it is expected that the method for manufacturing a multi-cavity closed structural element should be characterized by low material consumption, and it should be possible to manufacture a multi-cavity closed structural element with a wide range of geometric parameters (especially with different heights, spatial shapes, both symmetrical characteristics and asymmetric characteristics). It is also important to provide a method for manufacturing a multi-cavity closed structural element, which will make it possible to easily modify the shape of the multi-cavity closed structural element within a wide range of geometric parameters without the need to rearrange the equipment for manufacturing. Importantly, it is also expected to provide a multi-cavity closed structural element that will be easy to transport and assemble at the destination. The present invention also intends to solve the technical problems behind it by providing a multi-cavity closed structural element with the above-mentioned features and with desired performance parameters.

[0008] In one aspect, the present invention provides a method for manufacturing a multi-cavity closed structural element, characterized in that the method comprises the following steps:

[0009] a) providing at least one cavity profile preform comprising an inner wall and an outer wall made of a sheet of metal material and arranged in planes substantially parallel to each other with a gap therebetween, wherein the edges of the respective walls converge, wherein at least one wall is provided with a ventilation opening,

[0010] b) sealing the unconnected edges of the walls of the cavity profile preform by means of a seal to form a closed, airtight hollow interior space of the cavity profile preform, said space including the end edges of the cavity profile preform,

[0011] c) connecting the end edges of at least one cavity profile preform to each other to form a preform of a multi-cavity closed structural element, said preform comprising a central cavity surrounded by the inner wall of the cavity profile preform,

[0012] d) introducing a pressurized fluid into the interior space of at least one cavity profile preform through the vent to form a deformed cavity profile.

[0013] Preferably, after step a), the cavity profile preform is bent inwardly along the bending line, and an inner seal is formed along the bending line to form at least two cavity profile preforms, and the inner seal is formed to have fluid communication between the internal spaces of the obtained at least two cavity profile preforms.

[0014] Preferably, in step a), cavity profile preforms are provided in a number corresponding to the number of cavity profiles in the multi-cavity closed structural element.

[0015] Preferably, the cavity profile preforms in the preform of the multi-cavity closed structural element have a varying width.

[0016] Preferably, the central cavity is filled with a filler, preferably concrete, plastic or loose material. For example, sand, gravel or aggregate may be indicated as preferred loose materials.

[0017] Preferably, the cavity profile preform has regions of the inner wall and / or outer wall with increased sheet metal thickness.

[0018] Preferably, the cavity profile preform has regions of the inner wall and / or outer wall which are made of different materials.

[0019] Preferably, the cavity profile preform has at least one opening which is formed in the region of the inner wall and the outer wall and which is sealed by a seal to form a closed, airtight hollow interior of the cavity profile preform.

[0020] Preferably, step c) is performed simultaneously for all cavity profile preforms corresponding to cavity profiles in the multi-cavity closed structural element.

[0021] Preferably, the seal and / or the inner seal are produced by welding, pressure welding, gluing or extrusion.

[0022] Preferably, the fluid is air, water, oil, fluid concrete or fluid plastic.

[0023] On the other hand, the present invention provides a multi-cavity closed structural element, characterized in that the multi-cavity closed structural element comprises: at least three cavity profiles, which are deformed by introducing a pressurized fluid into their closed hollow spaces, wherein the cavity profiles are connected to each other along at least a portion of the seals through corresponding seals to form a multi-cavity closed structural element, and the multi-cavity closed structural element forms an annular structure in cross section including a central cavity surrounded by an inner wall of the cavity profile.

[0024] Preferably, at least one cavity profile has a greater or smaller width than the other cavity profiles.

[0025] Preferably, the central cavity is filled with a filler, preferably concrete, plastic or loose material. Sand, gravel or aggregate may be indicated as preferred loose materials.

[0026] Preferably, the chamber profile has regions of the inner wall and / or outer wall with increased sheet metal thickness.

[0027] Preferably, the chamber profile has regions of the inner wall and / or outer wall which are made of different materials.

[0028] Preferably, the chamber profile has at least one opening formed in the region of the inner wall and the outer wall, which at least one opening is sealed by a seal.

[0029] Preferably, the seal and / or inner seal is a weld, a pressure weld, a glue layer or a lap joint.

[0030] Preferably, the fluid is air, water, oil, fluid concrete or fluid plastic.

[0031] In the present description, a multi-cavity closed structural element is understood to be a structural element formed by cavity profiles which, when connected to one another, form in cross section an annular structure having a closed inner space, referred to as a central cavity, surrounded by the inner walls of the cavity profiles.

[0032] The method for manufacturing multi-cavity closed structural element according to the present invention makes it possible to make structural element, and the structural element has desired properties, especially in terms of stiffness and strength coefficient and load capacity to weight ratio of the structural element. In particular, by mainly using relatively thin metal sheets for the manufacture of multi-cavity closed structural element, the multi-cavity closed structural element manufactured by the method of the present invention can significantly improve load capacity to weight ratio compared with classical solutions known in the art. In addition, the method for manufacturing multi-cavity closed structural element according to the present invention is realized by using uncomplicated machinery, which is converted into economic benefits and significant simplification of the manufacturing process of multi-cavity closed structural element. A small amount of seals affects the speed of the manufacturing process of multi-cavity closed structural element and causes the labor consumption of reducing the manufacturing process. In addition, the manufacture of the single-cavity profile as the basic structural element of the multi-cavity closed structural element (described manufacture is based on introducing pressurized fluid into the airtight sealed internal space of the cavity profile preform) makes it possible to modify the parameters of the manufactured cavity profile and therefore the target multi-cavity closed structural element to a great extent, especially in terms of its final geometry. Importantly, by using a relatively thin cavity profile preform made of a sheet of metal material, and by using uncomplicated machinery, the multi-cavity closed structural element makes it possible to easily introduce the component into difficult-to-access places, such as into mine galleries, where the multi-cavity closed structural element can be made and erected using simple operations, thereby creating a support element for the roof structure. In addition, using areas with different thicknesses and / or material sheets made of different materials to construct the cavity profile preform makes it possible to additionally shape the geometry of the target multi-cavity closed structural element by affecting the degree of deformation of a given area under the influence of a pressurized fluid introduced into the interior of the cavity profile preform. In addition, filling the central cavity formed inside the multi-cavity closed structural element with a filler (e.g., concrete, plastic or loose material (such as sand, aggregate or gravel)) makes it possible to improve the strength characteristics of the resulting multi-cavity closed structural element, resulting in an increased stiffness or load capacity of the structural element.

[0033] The solution according to the invention is illustrated in the following embodiments and in the accompanying drawings, in which:

[0034] Figure 1 An embodiment of a multi-chamber closed structural element of the present invention is shown in a cross-sectional isometric view,

[0035] Figure 2 A to Figure 2 C shows various embodiments of the preform of the multi-cavity closed structural element of the present invention in cross-sectional view,

[0036] Figure 3 A to Figure 3 D shows various embodiments of the multi-cavity closed structural element of the present invention in a front view,

[0037] Figure 4 Another embodiment of the multi-chamber closed structural element of the present invention is shown in the front view.

[0038] Figure 5 Another embodiment of the multi-chamber closed structural element of the present invention is shown in the front view.

[0039] Figure 6 Another embodiment of the multi-chamber closed structural element of the present invention is shown in a cross-sectional isometric view.

[0040] Figure 7 A. Figure 7 B shows another embodiment of the multi-chamber closed structural element of the present invention in an axonometric view.

[0041] Example 1

[0042] Figure 1 A first embodiment of the multi-chamber closed structural element of the present invention is schematically shown in a cross-sectional axonometric view.

[0043] The illustrated embodiment of the multi-cavity closed structural element is manufactured by the method of the present invention, which comprises the following steps: providing at least one cavity profile preform 2, the at least one cavity profile preform comprising two walls 3, 4 made of metal sheet arranged in planes substantially parallel to each other, namely an inner wall 3 and an outer wall 4, with a gap between the two walls, wherein the edges of each wall 3, 4 converge. A vent 6 is arranged on at least one of the walls 3, 4. The vent 6 is a pneumatic or hydraulic attachment element and makes it possible to tightly attach a supply line 7 from an external pressurized fluid source. In some embodiments of the present invention, the vent 6 can be a valve, in particular a check valve. The position of the vent 6 does not limit the scope of the present invention, and therefore the vent 6 can be located in any area on the metal sheet, as long as the connection with the internal space of the cavity profile preform 2 is ensured.

[0044] exist Figure 2 In the embodiment shown in C, four cavity profile preforms 2 are provided to form a multi-cavity closed structural element comprising four cavity profiles 1. The number of cavity profiles 1 and therefore the number of cavity profile preforms 2 used in the method of manufacturing a multi-cavity closed structural element does not limit the scope of the present invention, and in alternative embodiments, the multi-cavity closed structural element may include a smaller or larger number of cavity profiles 1, but the number must be greater than three to form a closed annular structure including a central cavity 8 surrounded by the cavity profile 1 (its inner wall 3) in cross section. Figure 3 A to Figure 3 D shows various non-limiting embodiments of multi-cavity closed structural elements comprising different numbers of cavity profiles 1 in a front view, wherein Figure 3 A shows a multi-chamber closed structural element comprising three chamber profiles 1, Figure 3 B shows a multi-chamber closed structural element comprising four chamber profiles 1, Figure 3 C shows a multi-chamber closed structural element comprising five chamber profiles 1, and Figure 3 D shows a multi-chamber closed structural element comprising eight chamber profiles 1 .

[0045] In the present embodiment, the cavity profile preform 2 is formed by two walls 3, 4, each wall 3, 4 being a separate metal sheet. In an alternative embodiment, a single sheet of metal material may be provided, which is bent along one edge in a known cold bending operation to form two walls 3, 4 arranged in planes substantially parallel to each other. This embodiment of the invention has the advantage that as early as in the step of providing the sheet metal sheet, one edge of the manufactured cavity profile preform 2 is already sealed (at the location where the sheet metal sheet is bent), which reduces the number of subsequent sealing operations.

[0046] In the next step of the method for manufacturing a multi-cavity closed structural element, each cavity profile preform 2 is sealed to form a sealed closed interior space. The sealing is performed on the edges of the metal sheets forming the walls 3, 4 of the cavity profile preform 2 after the walls 3, 4 of the cavity profile preform 2 have been juxtaposed. In the present embodiment, all peripheral edges of the juxtaposed walls 3, 4 of each cavity profile preform 2 are thus sealed, wherein Figure 2 C shows the front longitudinal seal 5, which is also referred to as the end edge of the cavity profile preform 2. In the present embodiment, the sealing is performed by welding the corresponding edges together to form in particular a longitudinal weld. The edges of the juxtaposed walls 3, 4 on the front and rear sides of the cavity profile preform 2 are also sealed. The sealing of all said edges results in a sealed closed interior space in the cavity profile preform 2, such as Figure 2 C. In this case, the type of seal 5 does not limit the scope of the invention, and in alternative embodiments, any type of seal 5 may be used as long as a sealed inner space is formed in the cavity profile preform 2, such as by welding, brazing, gluing, bending or pressing.

[0047] In another step of the method for manufacturing a multi-cavity closed structural element of the present invention, the end edges of the four cavity profile preforms 2 are connected in series with each other, wherein the last end edge of the fourth cavity profile preform 2 is connected to the first end edge of the first cavity profile preform 2, thereby forming a ring structure in cross section. In this way, a preform 9 of a multi-cavity closed structural element is formed, which preform includes a central cavity 8 surrounded by the inner walls 3 of the four cavity profile preforms 2, such as Figure 2C. The connection of the end edges of the cavity profile preform 2 is achieved by any technical means that ensures a permanent connection of the metal sheets, including welding, pressure welding, brazing, gluing, etc. The connection can be achieved along the entire length of the end edge of the cavity profile preform 2, including partial connection or point connection. In this case, it is important that the connection of the cavity profile preform 2 will withstand the next step of introducing a pressurized fluid into the internal space of the cavity profile preform 2 and the associated deformation of the metal sheet. In an alternative embodiment of the present invention, the step of connecting the end edges of the cavity profile preform 2 can be achieved simultaneously with the step of sealing the cavity profile preform 2 (as described above). In this implementation, the advantage of reducing the number of operations required to manufacture the target multi-cavity closed structural element is obtained.

[0048] In another step, an external source of pressurized fluid is connected to the vent 6 via a supply line 7. In this embodiment, the fluid is air, the source of pressurized fluid is a compressor, and the supply line 7 and the vent 6 form a pneumatic attachment. The type of external source of pressurized fluid and the attachment equipment do not limit the scope of the present invention, and in alternative embodiments, fluids in the form of water, fluid cement, motor oil, fluid plastics such as one-component, two-component or three-component foams (e.g., flex 140 type) and the like, as well as attachment equipment and pressurized fluid sources suitable for these fluids, can be used. The less compressible the fluid, the more controllable the deformation conditions of the cavity profile preform 2.

[0049] In a further step of the method for manufacturing the multi-cavity closed structural element of the invention, a fluid is supplied at a specified pressure to the sealed inner space of the cavity profile preform 2. The technique of introducing a pressurized fluid into a closed sealed cavity element made of sheet metal in order to deform it and give it its final shape is known, in particular from patent application EP2110189A1. As a result of the supply of the pressurized fluid to the inner space of the cavity profile preform 2, the walls 3, 4 of the cavity profile preform 2 are deformed, wherein the maximum degree of deformation is located in the center of the cavity profile 1, as shown in FIG. Figure 3 B, which shows a cross section of a multi-cavity closed structural element, reveals a cavity profile 1 formed from cavity profile preforms 2. As can be observed, the walls 3, 4 of each cavity profile preform 2 are significantly deformed.

[0050] In the present embodiment, the step of introducing a fluid into the sealed internal space of the cavity profile preform 2 at a specified pressure is performed simultaneously for all cavity profile preforms 2 in the preforms 9 of the multi-cavity closed structural element. This results in a more homogeneous distribution of the deformation of the individual cavity profiles 1 constituting the target multi-cavity closed structural element. In alternative embodiments, this step may be performed in series, one by one for each cavity profile preform 2, or several cavity profile preforms 2 in groups.

[0051] It is worth mentioning that the introduction of the pressurized fluid into the inner space of the cavity profile preform 2 is carried out in a cold technology (ie at room temperature), but this does not limit the scope of the invention and in alternative embodiments this process may be performed at elevated or high temperature.

[0052] In one embodiment of the present invention, the step of introducing a pressurized fluid is performed under the following process parameters:

[0053] -Process temperature: 20℃,

[0054] - Working pressure: 5 bar,

[0055] - Deformation time: 1 minute, to equalize the pressure in the cavity profile preform 2,

[0056] -Pressure maintenance time: 30 seconds,

[0057] -Total deformation time: 1.5 minutes.

[0058] Example 2

[0059] Another embodiment of the method for manufacturing a multi-cavity closed structural element according to the present invention uses Figure 2 A schematically shown preform 9 of a multi-cavity closed structural element. The illustrated embodiment of the method of manufacturing a multi-cavity closed structural element is substantially the same as the method of manufacturing a multi-cavity closed structural element illustrated in Example 1, and therefore, for the sake of clarity of the present disclosure, the same steps will not be discussed in detail.

[0060] In this embodiment of the method for manufacturing a multi-cavity closed structural element, in a first step, a cavity profile preform 2 is provided, which is subjected to a series of processing steps before a step of sealing the edges of the cavity profile preform 2. The processing steps involve bending the cavity profile preform 2 inwardly along three bending lines 10. Figure 2In the embodiment shown in A, the bend is formed at a right angle and involves two walls 3, 4 of the cavity profile preform 2. Three right-angle bends are made along the bend line 10 to create a structure that is substantially rectangular in cross section. In the next step, an inner seal 11 is also formed along the bend line 10 to form four cavity profile preforms 2, wherein the inner seal 11 is formed to have fluid communication between the internal spaces of the resulting four cavity profile preforms 2. The inner seal 11 is made by a known technique that allows a seal to be formed by two metal sheets arranged at a short distance from each other. A non-limiting example of this technique is laser welding. The fluid communication between the resulting cavity profile preforms 2 can be provided by making a discontinuous inner seal 11. Maintaining the fluid communication between the cavity profile preforms 2 so formed is essential for providing pressurized fluid to each cavity profile preform 2 from only one vent 6. Alternatively, in the cavity profile preform 2, before the bending step, more ventilation openings 6 may be provided in areas corresponding to the individual cavity profiles 1 in a number corresponding to the number of target cavity profiles 1 in the multi-cavity closed structural element, wherein in this implementation, fluid connectivity does not need to be provided in the step of creating the inner seal 11.

[0061] In an alternative embodiment, in order to form a multi-cavity closed structural element including four cavity profiles 1, two cavity profile preforms 2 can also be provided, and a right-angle bending operation is performed on each of them, as described above, and then an operation of forming the inner seal 11 is performed. Then each of the two cavity profile preforms 2 is divided into another two cavity profile preforms 2, such as Figure 2 As shown in B.

[0062] In another alternative embodiment, in order to form a multi-cavity closed structural element including four cavity profiles 1, two cavity profile preforms 2 can also be provided, and two right-angle bending operations are performed on one of the cavity profile preforms along the bending line 10, as described above, and then two operations of making the inner seal 11 are respectively performed. Then, the cavity profile preform 2 bent twice to form a U-shaped structure in its cross section is divided into three other cavity profile preforms 2, wherein the preform 9 of the multi-cavity closed structural element is supplemented by the remaining cavity profile preforms 2. This embodiment is not shown in the drawings.

[0063] It should be emphasized that the bending angle, the number of bending portions and the number of inner seals 11 produced depend on the geometry of the target multi-chamber closed structural element, and in particular, depend on the number of chamber profiles 1 constituting the target multi-chamber closed structural element.

[0064] Example 3

[0065] Figures 4 to 7 Other non-limiting embodiments of multi-chamber closed structural elements are shown in various views.

[0066] Figure 4 The embodiment of the multi-cavity closed structural element shown in the front view differs from the previous embodiment in that the central cavity 8 is filled with a filler 12. After the multi-cavity closed structural element is made, that is, after the pressurized fluid is introduced into the closed internal space of each of the cavity profiles 1, the filler 12 is introduced into the central cavity 8. The filler 12 has a fluid form when introduced into the central cavity 8 and can solidify after a period of time. Non-limiting examples of fillers 12 are fluid concrete or fluid plastic. Introducing fillers 12 into the central cavity 8 can give the resulting multi-cavity closed structural element additional properties, which are associated with the type of filler 12 used, such as increased strength and stiffness, and in some cases, also attenuate the vibrations of the resulting structure (for example, the use of appropriately selected plastic foams makes it possible to absorb vibrations and prevent resonances from being undesirably induced in the multi-cavity closed structural element).

[0067] Figure 5 The embodiment of the multi-cavity closed structural element shown in cross section in FIG. 2 differs from the previous embodiments in that different materials are used to form the individual cavity profile preforms 2. In the illustrated embodiment, the inner wall 3 is formed of a material other than the material of the outer wall 4. The materials of the individual walls 3, 4 have different susceptibility coefficients to deformation under the influence of a pressurized fluid. In particular, the inner wall 3 is made of a material, such as non-alloy steel S235JR, which is easier to deform (more plastic) than the material, such as non-alloy steel S355JR, from which the outer wall 4 of each cavity profile preform 2 is made. Therefore, after the pressurized fluid is introduced into the closed internal space of each cavity profile preform 2, different degrees of deformation are obtained for the inner wall 3 and the outer wall 4. As can be seen from Figure 5It can be observed that the outer wall 4 made of a material with a lower deformation susceptibility deforms less than the inner wall 3 made of a material with a higher deformation susceptibility. The presented examples do not limit the invention, and in alternative embodiments, different materials may be used in each of the cavity profile preforms 2 to obtain the desired target shape of the multi-cavity closed structural element. An exemplary non-limiting list of structural materials for the inner wall 3 and the outer wall 4 of the preform of the multi-cavity closed structural element includes low carbon steel, S235JR to S355JR series steel, DC01-05 steel, DP500 to DP600 series steel, stainless steel such as 1.4301, 1.4404, HSS high speed steel, 1000 and 5000 series aluminum (e.g. 1050, 5754). Similar functionality can be achieved by using the same material for the inner wall 3 and the outer wall 4 of a given cavity profile preform 2 but with different metal sheet thicknesses. In this non-limiting embodiment, the inner wall 3 is made of 1 mm thick HSS steel, while the outer wall 4 is made of the same material, but its thickness is 1.5 mm. Therefore, by using a thicker metal sheet for the outer wall 4, the degree of deformation can be affected in a similar manner as described above. Likewise, the use of metal sheets of different thicknesses in a multi-cavity closed structural element does not limit the scope of the present invention.

[0068] Figure 6 The embodiment of the multi-cavity closed structural element shown in the cross-sectional axonometric view in FIG differs from the previous embodiment in that one of the cavity profiles 1 has a different width than the other cavity profile 1. The width dimension of the cavity profile 1 is to be understood herein as the minimum distance between the end (longitudinal) edges of the cavity profile 1. The result is a multi-cavity closed structural element that is similar to a trapezoid in cross section. In an alternative embodiment, a multi-cavity closed structural element can be formed from cavity profiles 1, some or even all of which have different widths, thereby adjusting the external dimensions of the multi-cavity closed structural element according to the construction requirements of the place of use.

[0069] Figure 7 The embodiment of the multi-cavity closed structural element shown in an axonometric view in A differs from the previous embodiments in that each cavity profile 1 making up the multi-cavity closed structural element comprises openings 13 formed (through) in the region of the inner wall 3 and the outer wall 4, which are sealed by seals 5. The openings 13 are arranged along the length of the respective cavity profile 1. Figure 7 A shows the openings 13 in a circular shape, but the shape of the openings 13, their number and their arrangement in the area of ​​a single cavity profile 1 or all cavity profiles 1 are not limiting, and in alternative embodiments, shapes other than a circle (e.g., a triangle ( Figure 7B), rectangular, polygonal (especially regular polygonal), irregular shape) and make a smaller or larger number of openings on one or more cavity profiles 1. The formation of the openings 13 in the multi-cavity closed structural element makes it possible to reduce the empty weight of the multi-cavity closed structural element without significantly losing strength properties. In addition, unlike the previous embodiment, in Figure 7 A and Figure 7 In the multi-cavity closed structural element shown in B, the ventilation openings are located on the inner wall 3 of each cavity profile 1 (not visible in the drawings).

[0070] It should be emphasized that the number of cavity profiles 1 that make up the multi-cavity closed structural element and the geometric shapes of the cavity profiles 1 that make up the multi-cavity closed structural element are not limited to the scope presented in the embodiment of the present invention, they are only exemplary and possible implementations of the present invention. In alternative embodiments, the multi-cavity closed structural element may include more than three cavity profiles 1, wherein the cavity profiles 1 may adopt shapes different from those shown, including combinations of shapes disclosed herein.

[0071] Example 4

[0072] Comparative tests (based on numerical calculations) were performed on the multi-cavity closed structural elements manufactured by the method of the present invention, which compared the elements with standard structural elements commonly used in the art. The results of the comparative tests are summarized in Table 1 below. The tested multi-cavity closed structural elements manufactured by the method of the present invention are marked as FIDU1 and FIDU2 in Table 1. The comparative structural element marked as STANDARD is a standardized structural element with geometric dimensions of 100mm x 100mm x1000mm and a wall thickness of 2mm. Figure 8 A to Figure 8 The numerical model used in the comparative simulation is shown in cross section and axonometric view in C, where Figure 8 A shows the STANDARD components, Figure 8 B shows the FIDU1 element, and Figure 8 C shows the FIDU2 element.

[0073] In the simulation of the profile, the material used is DC01 steel. The multi-cavity closed structural element according to the present invention (denoted as FIDU1) is composed of Figure 8The four cavity profiles 1 shown in B are formed. The FIDU1 multi-cavity closed structural element formed by the cavity profile 1 presents a square structure defined by the outer wall 4 of the cavity profile 1, and its external dimensions are similar to the external dimensions of the STANDARD element. Each constituent cavity profile 1 is formed from 1 mm thick material (inner wall 3 and outer wall 4) using the process parameters shown in Example 1. The FIDU2 multi-cavity closed structural element formed by the cavity profile 1 also presents a square structure defined by the outer wall 4 of the cavity profile 1, and its external dimensions are similar to the external dimensions of the STANDARD element. Each constituent cavity profile 1 has an inner wall 3 with a thickness of 0.8 mm and an outer wall 4 with a thickness of 1.2 mm, and has been formed using the process parameters shown in Example 1.

[0074] Table 1 - Performance parameters of structural elements

[0075]

[0076]

[0077] As can be seen from Table 1, all numerically tested elements have the same empty weight of 6.15 kg. The structural elements were analyzed for various performance parameters such as compression resistance, compression resistance under rigid plates, torsion resistance and bending resistance.

[0078] The stiffness is determined with a geometric and material linear analysis for 3 load states. The critical force / collapse torque is determined with a linear buckling analysis. These analyses are used to quickly estimate the load capacity of the object. The determined collapse load leads to a loss of stability. The strength of the profile is defined as the highest load during the test under given load conditions. A virtual quasi-static analysis is performed using explicit methods.

[0079] In this case, the two elements manufactured by the method of the invention, namely FIDU1 and FIDU2, show greater rigidity and strength relative to the STANDARD element. It is worth noting the critical force, which, for compression resistance, is more than twice that of the STANDARD element. In the case of the rigid plate compression resistance test, the FIDU1 and FIDU2 elements obtain greater strength relative to the STANDARD element. On the other hand, the collapse torque of the torsion test of the FIDU1 element and the FIDU2 element presents greater values ​​compared to the STANDARD element. In the case of bending resistance, the FIDU1 element is characterized by a critical force that is almost three times that of the STANDARD element, while the FIDU2 element is characterized by a critical force that is more than three and a half times that of the STANDARD element.

[0080] List of reference numerals:

[0081] 1 – Cavity Profile

[0082] 2 – Cavity Profile Preform

[0083] 3 – Inner wall

[0084] 4 – outer wall

[0085] 5 – Seals

[0086] 6 – Air Vents

[0087] 7-Opening

[0088] 8 – Center cavity

[0089] 9 – Preforms for multi-cavity closed structural elements

[0090] 10 – Bend Line

[0091] 11 – Inner seal

[0092] 12 – Filling

[0093] 13 – Opening

Claims

1. A method for manufacturing a multi-cavity closed structural element, characterized in that: The method comprises the following steps: a) providing at least one cavity profile preform (2), comprising an inner wall (3) and an outer wall (4) made of a sheet of metal material and arranged in planes substantially parallel to each other, with a gap between the inner wall and the outer wall, wherein the edges of the respective walls (3, 4) converge, wherein at least one wall (3, 4) is provided with a ventilation opening (6), b) sealing the unconnected edges of the walls (3, 4) of the cavity profile preform (2) by means of a seal (5) to form a closed, airtight hollow interior space of the cavity profile preform (2), the space including the end edges of the cavity profile preform (2), c) connecting the end edges of at least one cavity profile preform (2) to each other to form a preform (9) of the multi-cavity closed structural element, the preform comprising a central cavity (8) surrounded by the inner wall (3) of the cavity profile preform (2), d) introducing a pressurized fluid into the interior space of at least one cavity profile preform (2) through the vent (6) to form a deformed cavity profile (1).

2. The method for manufacturing a multi-cavity closed structural element according to claim 1, characterized in that: After step a), the cavity profile preform (2) is bent inwardly along the bending line (10), and an inner seal (11) is formed along the bending line (10) to form at least two cavity profile preforms (2), and the inner seal (11) is formed to have fluid communication between the internal spaces of the at least two cavity profile preforms (2) obtained.

3. The method for manufacturing a multi-cavity closed structural element according to claim 1, characterized in that: In step a), the cavity profile preforms (2) are provided in a number corresponding to the number of cavity profiles (1) in the multi-cavity closed structural element.

4. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 3, characterized in that: The cavity profile preform (2) in the preform (9) of a multi-cavity closed structural element has a varying width.

5. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 4, characterized in that: The central cavity (8) is filled with a filler (12), preferably concrete, plastic or loose material.

6. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 5, characterized in that: The cavity profile preform (2) has regions of the inner wall (3) and / or the outer wall (4) having an increased sheet metal thickness.

7. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 6, characterized in that: The cavity profile preform (2) has regions of the inner wall (3) and / or the outer wall (4) which are made of different materials.

8. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 7, characterized in that: The cavity profile preform (2) has at least one opening (13), which is formed in the region of the inner wall (3) and the outer wall (4) and is sealed by a seal (5) to form a closed, airtight hollow interior space of the cavity profile preform (2).

9. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 8, characterized in that: Step c) is performed simultaneously for all cavity profile preforms (2) corresponding to the cavity profiles (1) in the multi-cavity closed structural element.

10. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 9, characterized in that: The seal (5) and / or the inner seal (11) are produced by welding, pressure welding, gluing or extrusion.

11. The method for manufacturing a multi-cavity closed structural element according to any one of claims 1 to 10, characterized in that: The fluid is air, water, oil, fluid concrete or fluid plastic.

12. A multi-cavity closed structural element, characterized in that: The multi-cavity closed structural element comprises: at least three cavity profiles (1), which are deformed by introducing a pressurized fluid into their closed hollow spaces, wherein the cavity profiles (1) are connected to each other along at least a portion of the seals (5) via corresponding seals (5) to form the multi-cavity closed structural element, and the multi-cavity closed structural element forms an annular structure in cross section including a central cavity (8) surrounded by an inner wall (3) of the cavity profile (1).

13. The multi-cavity closed structural element according to claim 12, characterized in that: At least one cavity profile (1) has a greater or smaller width than the other cavity profiles (1).

14. The multi-cavity closed structural element according to claim 12 or 13, characterized in that: The central cavity (8) is filled with a filler (12), preferably concrete, plastic or loose material.

15. The multi-chamber closed structural element according to any one of claims 12 to 14, characterized in that: The chamber profile (1) has regions of the inner wall (3) and / or the outer wall (4) having an increased sheet metal thickness.

16. The multi-chamber closed structural element according to any one of claims 12 to 15, characterized in that: The cavity profile preform (1) has regions of the inner wall (3) and / or the outer wall (4) which are made of different materials.

17. The multi-chamber closed structural element according to any one of claims 12 to 16, characterized in that: The chamber profile (1) has at least one opening (13) formed in the region of the inner wall (3) and the outer wall (4), the at least one opening being sealed by a seal (5).

18. The multi-chamber closed structural element according to any one of claims 12 to 17, characterized in that: The seal (5) and / or the inner seal (11) is a weld, a pressure weld, a glued layer or a lap joint.

19. The multi-chamber closed structural element according to any one of claims 12 to 18, characterized in that: The fluid is air, water, oil, fluid concrete or fluid plastic.

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