Method for producing a bar element

Abstract

A bar element as a construction element includes strips preferably produced from bamboo and is hollow at least in certain regions. The hollow interior is formed at least in certain sections as a hollow fillet achieved by a plastic and/or resin introduced into the bar elements, using a shaped body movable through the interior. Producing bar elements from interconnected strips ensures that although produced from a natural raw material, the bar elements have a reproducible outer cross section. Using a shaped body movable through the interior to produce the inner cross section also ensures a defined inner cross section of the bar elements, with the result that in turn connections between a plurality of bar elements that are defined by suitable connection elements can be formed. In this way, the bar elements make it possible to produce lattice works, grid constructions, frameworks or other desired structures and/or three-dimensional bodies.

Claims

1. A method for producing a bar element for use as a construction element, the method comprising: (a) forming an at least partially hollow element comprising a plurality of strips and having an inner wall forming an interior; and either (b) coating the inner wall with at least one of a plastic or a resin to form a coated interior and moving a piston having a round outer cross-section through the coated interior; or (c) introducing into the interior an inner tube coated with a parting agent and an outer mantle comprising at least one of a plastic or a resin coated on the parting agent and removing the inner tube from the interior after hardening of the plastic or resin coated on the outer mantle, whereby the bar element is produced with an inner cross-section having defined dimensions in the form of a fillet.

2. The method according to claim 1, wherein glass fibers or carbon fibers are worked into the outer mantle in a longitudinal or transverse direction or a woven lattice structure of glass fibers or carbon fibers is wrapped around the outer mantle prior to performing step (c) and subsequently, upon performing step (c), the bar element becomes reinforced with the glass fibers or carbon fibers in the longitudinal or transverse direction or with the woven lattice structure.

3. The method according to claim 1, wherein each strip of the plurality of strips has a trapezoid cross-section.

4. The method according to claim 3, wherein the plurality of strips comprises six strips and the hollow element is formed by connecting, by an adhesive, longitudinal edges of the six strips, and wherein the bar element has a hexagonal cross-section.

5. The method according to claim 4, wherein the longitudinal edges are configured to be planar.

6. The method according to claim 3, wherein the plurality of strips comprises eight strips and the hollow element is formed by connecting, by an adhesive, longitudinal edges of the eight strips, and wherein the bar element has an octagonal cross-section.

7. The method according to claim 1, wherein the inner tube has a round, triangular, or square shape in at least some sections and, in step (c), impresses an inner contour into the bar element corresponding to the round, triangular, or square shape.

8. The method according to claim 7, wherein multiple bar elements are joined together by means of at least one internally hollow body provided with at least one connector piece to produce polygonal constructions, grid constructions, three-dimensional bodies, geometric bodies, or lattice works.

9. The method according to claim 1, further comprising, subsequent to step (b) or step (c), inserting an internally hollow body into the interior of the bar element.

10. The method according to claim 9, wherein the internally hollow body projects beyond a face side of the bar element, wherein another, subsequent bar element is set onto and/or otherwise connected with the internally hollow body with force fit and/or shape fit, and wherein at least an end section of the internally hollow body functions as a connector piece for the subsequent bar element.

11. The method according to claim 9, wherein the internally hollow body has an angled-away or cropped passage.

12. The method according to claim 9, wherein the internally hollow body has at least one articulated connection in a connection region of the internally hollow body between the bar element and a subsequent bar element connected to the bar element.

13. The method according to claim 9, wherein a separate connection element, comprising at least two cuff sections that are spaced apart from one another, is set onto the internally hollow body in such a manner that a face-side end section of the internally hollow body is held with shape fit in one of the cuff sections.

14. The method according to claim 13, wherein the internally hollow body, connection element, and/or cuff sections are produced using a 3D printing method or are die-cast.

15. The method according to claim 1, wherein the at least partially hollow element comprising a plurality of strips is half-open, resulting in a half-open bar element.

16. The method according to claim 1, wherein multiple bar elements are connected with one another along outer contours of the bar elements to form a composite bar arrangement.

17. The method of claim 16, wherein the multiple bar elements comprise open or closed bar elements and/or closed half-bar elements.

18. The method according to claim 16, wherein the composite bar arrangement has planks on one or both sides and/or is provided with an outer planking on both sides with insulating material and/or reinforcement materials interposed between the composite bar arrangement and the planking.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained below, using one or more exemplary embodiments.

(2) The figures show:

(3) FIG. 1: a bar element having an octagonal outer cross-section, in a perspective view,

(4) FIG. 2: a bar element having a hexagonal outer cross-section, having a fillet formation, in a perspective view,

(5) FIG. 3: a further bar element having an integrated, coated inner tube as well as a round outer cross-section, in a perspective view,

(6) FIG. 4: a bar element having a round outer cross-section, in an alternative embodiment, in a perspective view,

(7) FIG. 5: a bar element having an inner reinforcement, in a perspective view,

(8) FIG. 6: a bar element in a half-open embodiment,

(9) FIG. 7 a)-c): a connection of two bar elements in different connection stages, each in a perspective view,

(10) FIG. 8 a)-d): a right-angle connection of two bar elements in different connection stages, each in a perspective view,

(11) FIG. 9 a)-c): a cross-connection of two bar elements in different stages, each in a perspective view,

(12) FIG. 10: a honeycomb structure composed of bar elements connected with one another, in a perspective view, and

(13) FIG. 11: a honeycomb structure composed of bar elements connected with one another, in a deviating embodiment, in a perspective view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(14) FIG. 1, in a perspective view, shows a bar element 1 that consists of a plurality of strips 2 produced from bamboo, wherein the strips 2 each possess a trapezoid cross-section. In this regard, the strips 2 are connected with one another in the region of their longitudinal edges 3, by means of a suitable adhesive connection, in each instance. After the strips 2 are produced using an industrial cutting method, it is ensured that the longitudinal edges 3 are configured in planar manner, to form a strong connection, and furthermore so that the bar elements 1 produced by means of the method according to the invention are provided with reproducible cross-sections, in each instance.

(15) In a further work step, the bar elements 1 according to FIG. 2 can be coated with a plastic and/or resin on their inner walls, and in a further work step, a movable piston having a round outer cross-section can be guided through the bar element 1, at least in certain sections, with the result that a round inner cross-section 4 is impressed on the bar element 1, in other words a fillet is formed, which is also strong after the laminate material that was introduced has hardened. Accordingly, the bar elements 1 according to FIG. 2 also possess a reproducible inner cross-section with clearly defined dimensions.

(16) According to the representation in FIG. 3, the polygonal bar elements according to the representations in FIGS. 1 and 2 can also be worked in such a manner that bar elements 1 having a round outer cross-section 5 are produced from the polygonal ones. This can be implemented in that the polygonal pipes are lathed on their outside, until the desired round outer cross-section 5 has formed. The problem that exists in this connection, that of a reduced wall thickness due to the outer cross-section of the bar element 1 being lathed away on the outside, can be corrected, according to the representation in FIG. 3, in that a round inner tube 7, which is provided with an outer mantle 8, is introduced into the interior of the bar element 1. The outer mantle 8 is applied to the inner tube 7 from the outside, with the interposition of a parting layer, and usually consists of resin or plastic or of a composite of these materials, wherein in addition, glass fibers, or carbon fibers are worked into this outer mantle for further reinforcement, in a manner that is not shown in any detail. These fibers can be introduced into the outer mantle 8 in simple manner, in the form of a woven mat that is wound around the inner tube 7, but also worked into the outer mantle 8 as individual fibers, in the longitudinal and/or transverse direction. After the outer mantle 8 has hardened, the inner tube 7, due to the parting layer that lies in between, can simply be pulled out of the bar element 1, which then possess a round inner cross-section, and, due to the integrated fiber arrangement, possesses greater rigidity, by means of which the loss in rigidity that was brought about by lathing off the outer cross-section of the bar element is compensated or overcompensated.

(17) Alternatively, according to the representation in FIG. 4, the outer surface of the outer cross-section of the bar element 1 can be reinforced by means of application of a further bamboo strip 6, in each instance, and the bar element 1 can be lathed off only then, until once again, a round outer cross-section 5 is achieved. This occurs with the difference that the wall thickness of the bar element 1 achieved in this way is clearly reinforced as compared with the embodiment in FIG. 3.

(18) The bar elements 1 according to the representations in FIGS. 1-4 can be reinforced and stiffened by means of suitable inner reinforcements, if necessary, wherein according to the representation in FIG. 5, a triangular inner tube 7 was used, which is preferably also produced from bamboo and is produced, analogously, in that the bamboo strips for production of the inner tube 7 are connected with one another in the region of their longitudinal edges 3for example by means of a suitable adhesive connection. This inner tube 7 is introduced into the bar element 1 to reinforce it, in the sense of a press fit, and accordingly brings about greater strength of the bar element 1. Alternatively or in addition, the interior of the bar element 1 can also be filled with a filling compound, for example filled with foam, wherein in this connection, either only the interior of the inner tube 7 or the entire interior of the bar element 1 can be filled with compound or filled with foam.

(19) FIG. 6, also in a perspective view, shows a bar element that has not yet been completed.

(20) According to the perspective representation in FIG. 7, multiple bar elements 1 can be joined together by means of suitable connection elements. According to the representation in FIG. 7, internally hollow bodies 10, which can but do not have to be bar elements 1, 1 according to the invention, once again, can be pushed into the defined inner cross-section of a bar element 1, with shape fit, specifically in such a manner that the internally hollow body 10 according to the representation in FIG. 7 b) forms an excess length 11 as compared with the one bar element 1, before the other bar element 1 is then set onto the internally hollow body 10, and thereby a connection of the two bar elements 1, 1 is produced according to FIG. 7 c).

(21) In this regard, the internally hollow bodies 10 can be shaped more or less in any desired manner to produce the connection between two bar elements 1, 1, in other words as an angled element or as a curved element, for example, so that angular or curved connections between multiple bar elements 1, 1 according to the representation in FIG. 8 are also conceivable. In this regard, curved connections can be implemented only when using special connection elements, in any case elements not produced from bamboo, for example produced by die-casting or 3D printing. In detail, FIG. 8 shows the different connection stages between two bar elements 1, 1 that participate in the connection, in a perspective representation, in each instance, which elements can be connected with one another by means of an internally hollow body 10 according to the exploded representation or in the representation before the formation of the connection according to FIG. 8 a), which body is formed, in this case, as an angled element, with the formation of a right angle.

(22) In this regard, the internally hollow body 10 is introduced into the bar element 1, at least in certain sections, according to the representation in FIG. 8 b), before the other bar element 1 is then also set onto the internally hollow body 10, at least in part, according to FIG. 8 c), and finally a closed connection between the two bar elements 1, 1 is produced by means of completely setting on the two bar elements 1, 1 that participate in the connection, in such a manner that ultimately, an angled element is produced by means of the configuration of the connection.

(23) Any desired other constructions can also be produced by means of the selection of suitable connection elements. Thus, FIG. 9 shows the individual steps of the formation of a cross-connection, in that in detail, four bar elements 1 are connected, using a central cross-connector 12, in that the bar elements 1 are set onto the individual connection pieces of the cross-connector 12, in each instance.

(24) More or less any desired lattice works, grid constructions, frameworks, three-dimensional bodies or, in the case of connection elements having integrated articulations, also spatially changeable bodies or articulated connections can be produced by means of these and comparable constructions.

(25) In connection with the formation of more complex constructions, expansive constructions such as frameworks or three-dimensional bodies, it has proven itself if the individual connection elements are provided with cuffs for face-side accommodation of the bar elements 1 according to the invention, so that these are stabilized in their end region, and possible breakout of the bar element 1 in the end region is prevented or the connection is only insignificantly impaired by it. Such connections have proven to be strong also in connection with simple constructions.

(26) Furthermore, wall structures of any desired shape and wall thickness can be produced using the bar elements 1, 1 according to the invention, which can be joined together by means of suitable adhesive connections, to produce a composite arrangement or honeycomb arrangement 13 according to FIG. 10. In this regard, the individual bar elements 1, 1 for forming the wall structure, can once again be provided with reinforcements, if necessary, as explained above, or can be filled with reinforcement material or with insulation material, if necessary.

(27) In this regard, fundamentally closed bar elements 1, 1 do not necessarily have to be inserted into the honeycomb structure 13 according to the representation in FIG. 11. Instead, alternatively, open bar elements 14 or closed half-bars 15 can also be integrated, for example in order to be able to produce a defined wall end.

(28) The honeycomb arrangements 13 shown in FIGS. 10 and 11 are usually advantageously provided with planking on one or both sides, particularly in the construction sector, or produced using sandwich construction right from the start, with interposition of the honeycomb arrangement. In this regard, this sandwich construction can already take place with the interposition of insulating materials or insulation materials, if applicable leaving out any channels required for installation.

REFERENCE SYMBOL LIST

(29) 1, 1 bar element 2 strip 3, 3 longitudinal edge 4 round inner cross-section 5 round outer cross-section 6 further bamboo strip 7 inner tube 8 outer mantle 10 internally hollow body 11 excess length 12 cross-connector 13 honeycomb arrangement 14 open bar element. 15 half-bar