Method for manufacturing a tubular screw foundation

Abstract

The invention relates to a method for producing a tubular screw foundation (1) for fastening elements in a substrate, wherein the tubular screw foundation (1) has a front section (1d) tapering conically to an insertion tip and wherein the front section (1d) is provided at least partially with a thread-like contour (7) for screwing into the substrate. The following procedural steps are planned: a) Providing at least two plate-shaped semi-finished products (2) as starting forms, b) Forming the plate-shaped semi-finished products (2) into a partially tubular blank (3,3') with a convex outer surface (3a) and an inner surface (3b) facing away from the outer surface (3a), wherein the respective blank (3,3') extends in a longitudinal direction (L) and has two edges (4,5) in the longitudinal direction (L), c) Introducing a thread-like partial contour (6) as a recess into the inner surface (3b) of the respective blank (3,3') by cold forming during and / or after step b), d) Joining the blanks (3,3') according to step c) to form the tubular screw foundation (1) in which the edges (4,5) of the two blanks (3,3') are joined together by material and / or form-fitting means.

Description

[0001] The invention relates to a method for producing a tubular screw foundation for fastening elements in a substrate, wherein the tubular screw foundation has a front section tapering conically to an insertion tip and wherein the front section is provided at least partially with a thread-like contour for screwing into the substrate.

[0002] Screw foundations are available in various designs. They can be designed at the rear end for inserting piles or rods, or alternatively, they can have a plate- or flange-like fastening element at the rear end to which other elements, e.g., frames or the like, can be attached.

[0003] A method with the features of the preamble of claim 1 is known from DE 10 2019 128 030 B3. In this method for manufacturing a screw foundation for securing elements in the ground, a cylindrical tube is provided as the starting form, to which a conical front section tapering to an insertion tip is formed without the use of chips. The front section is provided, at least in part, with a threaded outer contour for screwing into the ground. The essential feature of this method is that an inner contour for a screw-in tool is formed into a rear end of the tube by die rolling, and that the front section and the threaded outer contour are formed exclusively by die rolling. The screw foundation is thus manufactured solely by die rolling, which reduces manufacturing costs and allows for the production of precise and reproducible components.Either the inner contour can be formed first, followed by the front section and the thread-like outer contour, or vice versa.

[0004] Another method of this type is known from DE 10 2021 130 720 B3. Both known methods have in common that they require a tube as the starting form, which can be formed by means of flow forming. In some applications, however, such a manufacturing process with a tube as the starting form is not economical.

[0005] From DE 10 2021 121 427 B3, a method for manufacturing a tubular body as a support rod for carrying a headrest of a vehicle seat is known, the body having a lateral surface provided with at least one recess, wherein the recess has a first side surface, a second side surface opposite the first side surface, and a bottom surface, and wherein the recess has a first transition area between the first side surface and / or the second side surface and the lateral surface, and a second transition area between the first side surface and / or the second side surface and the bottom surface. The following process steps are provided: a) providing at least one plate-shaped semi-finished product; b) forming the semi-finished product into a blank having a convex shape, which has an outer surface and an inner surface facing away from the outer surface;c) Introducing at least one depression, having a predetermined width and depth, into the outer surface of the blank by means of cold forming during or after step b); d1) Producing at least one first shell-shaped segment, extending in a longitudinal direction and having two edges in the longitudinal direction, from the blank after step c); e1) Producing at least one second shell-shaped segment, extending in a longitudinal direction and having two edges in the longitudinal direction, from the blank after step b) or c);f1) Joining the first segment and the second segment according to step e1) to form the tubular body by connecting the edges of the first segment and the second segment along at least two seams. In this method for manufacturing a support rod for a headrest, two plate-shaped semi-finished products are thus transformed into shell-shaped segments into which recesses are made from the outside and which are finally joined together to form a tubular support rod. This method is not suitable for manufacturing tubular screw foundations with a thread-like outer contour.

[0006] The object of the invention is to create a method for producing a tubular screw foundation which does not require a pipe as its starting form.

[0007] This problem is solved in a process of the type described above according to the invention by the following process steps: a) Providing at least two plate-shaped semi-finished products as starting forms, b) Forming the plate-shaped semi-finished products into a partially tubular blank with a convex outer surface and an inner surface facing away from the outer surface, wherein the respective blank extends in a longitudinal direction and has two edges in the longitudinal direction, c) Introducing a thread-like partial contour as a recess into the inner surface of the respective blank by cold forming during and / or after step b). d) Joining the blanks according to step c) to form the tubular screw foundation, in which the edges of the two blanks are joined together by material and / or form-fitting means.

[0008] As a starting form, no tube is required; instead, at least two plate-shaped semi-finished products are used, each of which is formed into a partially tubular blank (e.g., half-tubular if two starting forms are used). Thread-like partial contours are formed into the inside of each blank as recesses, with the thread-like partial contours of the blanks being geometrically adapted to each other so that they form a continuous thread-like contour in the finished screw foundation. Preferably, the respective partial contour does not extend to the edges of the blanks, so that a gap without a threaded contour remains along the longitudinal edges of the connection, which facilitates the material-locking and / or form-fit connection of the two blanks. Furthermore, under certain soil conditions, the gaps along the connection edges also facilitate the screwing in of the screw foundation. The gaps can also be omitted, i.e.,The partial contours can extend to the edges of the blanks. It may be necessary to machine the edges of the two blanks before joining, for example by trimming, if the condition of the edges does not allow for a perfect fit.

[0009] In a preferred embodiment, it is provided that step b) and / or step c) is carried out by deep drawing, pressing or hydroforming.

[0010] Furthermore, it is advantageously provided that the joining after step d) is carried out by welding or clinching.

[0011] To simplify the production of the tapered front section of the screw foundation, it is provided that the plate-shaped semi-finished products each have a rectangular main area and an adjacent V-shaped tapered area.

[0012] In a particularly preferred embodiment, the following further procedural steps are provided: e) Providing at least two plate-shaped auxiliary semi-finished products as a second starting form, f) Forming the plate-shaped auxiliary semi-finished products into a partially tubular blank with a convex outer surface and an inner surface facing away from the outer surface, wherein the respective blank extends in a longitudinal direction and has two edges in the longitudinal direction, g) Joining the two blanks according to step f) to form a tubular screw foundation extension, in which the edges of the two blanks are joined together by material and / or form-fitting means.

[0013] In addition to the screw foundation, at least one screw foundation extension is also provided, which is inserted into the screw foundation from the rear and connected to it in a suitable rotationally fixed manner.

[0014] Preferably, the following additional process step is provided: h) Introducing a thread-like partial contour as a recess into the inner surface of the respective blank by cold forming during and / or after step f).

[0015] Step f) and / or step h) is preferably carried out by deep drawing, pressing or hydroforming.

[0016] The joining process according to step g) is preferably carried out by welding or clinching.

[0017] In a further advantageous embodiment, a star-shaped contour with internal and external serrations is formed into the rear end of the screw foundation. This contour is suitable for both a rotationally fixed connection with a screw-in tool and a rotationally fixed connection with a screw foundation extension.

[0018] It is advantageously provided that a star-shaped contour with internal and external teeth is formed into each of the two tubular ends of the at least one tubular screw foundation extension, wherein the contour at one end of the tubular screw foundation extension corresponds to the contour at the rear end of the screw foundation, and the contour at the other end of the tubular screw foundation extension is designed such that the other end of the tubular screw foundation extension can be inserted into or onto the rear end of the screw foundation in a force-fit and / or form-fit manner. A suitable star-shaped contour is described, for example, in DE 10 2021 121 427 B3.

[0019] The invention is explained in more detail below with reference to the drawing. This shows in Fig. 1 a plate-shaped semi-finished product as the starting form, Fig. 2 one from the semi-finished product to Fig. 1 manufactured semi-tubular blank, Fig. 3 a first blank after Fig. 2 with thread-like partial contour, Fig. 4. a second blank after Fig. 2 with thread-like partial contour, Fig. 5 one from the two blanks after Fig. 3 and Fig. 4 joined and welded screw foundations in perspective view, Fig. 6 a side view of the screw foundation according to Fig. 5 and in Fig. 7 a cut according to line VII - VII in Fig. 6.

[0020] To produce a tubular screw foundation 1 for fastening elements in a subsoil, the described process sequence uses two identical plate-shaped semi-finished products 2 as starting materials. Alternatively, more than two plate-shaped semi-finished products 2 can be provided, which may also be geometrically different.

[0021] Each plate-shaped semi-finished product 2 according to Fig. 1, in which only a semi-finished product 2 is shown, consists of a sheet metal blank with a rectangular main area 2a and an adjacent V-shaped tapered area 2b.

[0022] Each plate-shaped semi-finished product 2 is first processed according to Fig. 2 each are formed into a semi-tubular blank 3, 3' with a convex outer surface 3a and an inner surface 3b facing away from the outer surface 3a. This forming is carried out by deep drawing, pressing or hydroforming. The respective blank 3, 3' extends in a longitudinal direction L and has two edges 4, 5 in the longitudinal direction L.

[0023] During and / or after the production of the respective semi-tubular blank 3, 3', a thread-like partial contour 6 is introduced into the inner surface 3b of the respective blank 3, 3' as a recess by cold forming, e.g. also by deep drawing, pressing or hydroforming. As the Fig. 3 and Fig. As shown in Figure 4, the thread-like partial contours of both blanks 3, 3' protrude outwards beyond the outer surface 3a. As a comparison of the Fig. 3 and Fig. Figure 4 shows that the thread-like partial contours 6 of the two blanks 3, 3' are geometrically adapted to each other in such a way that they form a circumferential thread-like contour 7 in the finished screw foundation 1, i.e. viewed in the longitudinal direction L, the individual sections of the thread-like partial contours 6 are offset from each other.

[0024] The respective partial contour 6 preferably does not extend to the edges 4, 5 of the blanks 3, 3', so that a clearance 8 without a thread-like contour remains in the longitudinal direction L along the edges 4, 5, which facilitates the subsequent material-locking and / or form-locking connection of the two blanks 3, 3'. Furthermore, the clearances 8 along the edges 4, 5 also facilitate the screwing in of the screw foundation 1 under certain soil conditions.

[0025] In the next process step, the two blanks 3, 3' are joined to form the tubular screw foundation 1, in which the edges 4, 5 of the two blanks 3, 3' are connected to each other by material and / or form-fitting means. Fig. Figure 5 shows an example of a weld seam 9 extending in the longitudinal direction L.

[0026] The screw foundation 1, as completed, has a rear end 1a and a front end 1b. Adjacent to the rear end 1a in the longitudinal direction L, the screw foundation 1 has a cylindrical section 1c and, adjoining this to the front, a front section 1d that tapers conically to an insertion point at the front end 1b. In the exemplary embodiment, the thread-like contour 7 extends along both the cylindrical section 1c and the conical front section 1d, but can also extend only along the front section 1d.

[0027] A star-shaped contour for a screw-in tool and / or for connection to a screw foundation extension is subsequently formed into the rear, tubular end 1a. The front end 1b is formed into a preferably closed insertion tip.

[0028] The production of a screw foundation extension is carried out in an analogous manner to the production of the screw foundation 1, whereby at least two plate-shaped additional semi-finished products are provided as a second starting form. These additional semi-finished products are preferably rectangular sheet metal blanks.

[0029] Of course, the invention is not limited to the illustrated embodiments. Further embodiments are possible without departing from the basic concept. Instead of two plate-shaped semi-finished products, three or more plate-shaped semi-finished products can also be used. The individual blanks can also be joined by clinching. Reference symbol list: 1 screw foundation 1a behind the end 1b front end 1c cylindrical area 1d conical anterior segment 2 plate-shaped semi-finished products 2a rectangular main area 2b V-shaped tapered area 3.3' blank 3a convex outer surface 3b Inner surface 4 rand 5 Rand 6 thread-like partial contour 7 thread-like contour 8 Free space 9 weld seam L longitudinal direction QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 128 030 B3

[0003] DE 10 2021 130 720 B3

[0004] DE 10 2021 121 427 B3 [0005, 0018]

Claims

[1] Method for producing a tubular screw foundation (1) for fastening elements in a subsurface, wherein the tubular screw foundation (1) has a front section (1d) tapering to an insertion tip and wherein the front section (1d) is provided at least in regions with a thread-like contour (7) for screwing into the subsurface, characterized by following procedural steps: a) providing at least two plate-shaped semi-finished products (2) as starting form, b) forming the plate-shaped semi-finished products (2) into a partially tubular blank (3, 3') with a convex outer surface (3a) and an inner surface (3b) facing away from the outer surface (3a), wherein the respective blank (3, 3') extends in a longitudinal direction (L) and has two edges (4, 5) in the longitudinal direction (L), c) introducing a thread-like partial contour (6) as a recess into the inner surface (3b) of the respective blank (3, 3') by cold forming during and / or after step b), d) Joining the blanks (3,3') according to step c) to form the tubular screw foundation (1), in which the edges (4,5) of the two blanks (3,3') are connected to one another in a material and / or form-fitting manner. [2] Method according to claim 1, characterized by that step b) and / or step c) is carried out by deep drawing, pressing or hydroforming. [3] Method according to claim 1 or 2, characterized by that the joining after step d) is carried out by welding or clinching. [4] Method according to one or more of claims 1 to 3, characterized by that the plate-shaped semi-finished products (2) each have a rectangular main region (2a) and an adjacent V-shaped tapered region (2b). [5] Method according to one or more of claims 1 to 4, characterized by the following further procedural steps: e) providing at least two additional plate-shaped semi-finished products as a second starting form, f) forming the plate-shaped additional semi-finished products into a partially tubular blank with a convex outer surface and an inner surface facing away from the outer surface, wherein the respective blank extends in a longitudinal direction and has two edges in the longitudinal direction, g) Joining the two blanks according to step f) to form a tubular screw foundation extension by joining the edges of the two blanks together in a material and / or form-fitting manner. [6] Method according to claim 5, characterized by , characterized by following further procedural step: h) Introducing a thread-like partial contour as a recess into the inner surface of the respective blank by cold forming during and / or after step f). [7] Method according to claim 5 or 6, characterized by that step f) and / or step h) is carried out by deep drawing, pressing or hydroforming. [8] Method according to claim 5, 6 or 7, characterized by that the joining according to step g) is carried out by welding or clinching. [9] Method according to one or more of claims 1 to 8, characterized by that a star-shaped contour having internal and external teeth is formed into the rear end (1a) of the screw foundation (1). [10] Method according to one or more of claims 5 to 9, characterized byin that a star-shaped contour having an internal and external toothing is formed into each of the two tubular ends of the at least one tubular screw foundation extension, wherein the contour at one end of the tubular screw foundation extension corresponds to the contour at the rear end of the screw foundation and the contour at the other end of the tubular screw foundation extension is designed such that the other end of the tubular screw foundation extension can be inserted into or onto the rear end of the screw foundation in a force-fitting and / or form-fitting manner.

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