DE29719830U1 - pipe - Google Patents

Description

Pipe

The present innovation relates to a pipe with a cross-section that is constant over its entire length, which pipe must be attached to another part by means of a welded joint, comprising in cross-section at least one flattened part, which is provided with projections extending beyond this flattened part at the transition to the other part of the pipe.

Such pipes are generally known in the state of the art. For the manufacture of the lattice structures, it is proposed to use circular pipes and to connect them at the intersection with a friction weld.

However, it has been found that such a welded joint has insufficient strength under certain circumstances.

In addition, in certain applications it is desirable to keep the total thickness of a grid, formed by stacked horizontal and vertical tubes, as small as possible.

In order to solve this problem, it has long been known to make indentations in the pipe in the area of the weld that is to be made later. In addition to such indentations in the pipe wall, edges are then created and by providing both pipes with such edges and laying them on top of each other to connect two pipes, a more stable weld can be achieved. Reference is made to "Special print" from "Maschinenwelt und Elektrotechnik", XVth year, issue 6, 1960, "Some applications of projection or projection welding".

In addition, denting reduces the "height" of the pipe in the area of the weld, so that when two pipes are placed on top of each other, the total thickness of a grid thus formed can decrease.

It is understood that the local application of dents places high demands on work preparation. It is absolutely essential that the dents are placed in the right place and if, for example, a somewhat larger grid is to be produced, this causes considerable problems. In addition, the application of dents is a labor-intensive process. When moving to the rest of the pipe, the change in geometry in the axial direction (the dent) creates

·

Stress concentrations, which can lead to premature mechanical failure (cracking).

This has been observed particularly when subjected to alternating or vibrational loading.

The pipes described above are used, for example, for the manufacture of "intermediate bulk containers". These are structures consisting of a pallet-like support on which a latticework is attached, in which a plastic container is filled with the goods to be transported. Such packaging is particularly efficient to transport and can be stored in a particularly space-saving manner, both by stacking and by placing them next to each other. However, it has been found that the lattices used in such packaging are exposed to considerable vibrations during transport. In addition to the strength required in several internationally valid drop tests, it has been found that some lattices fail prematurely due to such vibrations.

It has also been found that the local dents in such pipes reduce the strength of the part of these dents.

The purpose of the present invention is to avoid these disadvantages and to provide a pipe that is easy to use.

This purpose is achieved in a pipe as described above, in that these projections comprise bends from the interior of this pipe, arranged in a continuous wall region, which is part of the closed profile, the apex angle of these projections being less than 180°.

In contrast to the tube described in "Sonderdruck", it is now proposed to use a profiled tube, whereby the tube is designed so that it is essentially ring-shaped with two projections between which there is a flattened part. This eliminates the problem of complicated steps to make the indentations at specific locations depending on the area of application. In addition, it is possible to make the projections described above directly during the manufacture of the tube.

By using a profiled tube according to the invention, potential local stress concentrations are no longer

given.

It will be understood that the remaining part of the tube may have any shape known in the art. It is even possible to provide another flattened part with projections on the other part of the tube.

In the applications of an IBC described above, the remaining part of the pipe will preferably be round or curved. This is particularly important because bending pipes with a round or curved cross-section is relatively easy.
It is also possible to increase the strength of the tube, for example by widening the profile or increasing the wall thickness, without increasing the height. This is important for the use of IBCs in order to keep the volume of the bottle as large as possible.

Although the flattened portion may have any conceivable curved or polygonal shape, it is preferred to make this portion substantially flat.

In addition, it is preferred to round off the projections to

to gradually run off towards the rest of the pipe. This also largely avoids stress concentrations. There is no regularity between the radius r of the profiled pipe in the area of the projection (the welding edge) and the radii in the rest of the round or curved part of the pipe. These radii are determined by the available space and the required strength, and the radius r of the welding edge is determined by the desired "height" and stability of the edge for welding.

As described above, the invention also relates to a packaging and a pipe grid that can be used for such a packaging.

The invention is explained in detail below with reference to the embodiments shown in the drawing.
It shows:

Figure 1 shows a packaging in which the tube according to the invention is used;

Figure 2 is a detail from Figure 1 showing, on an enlarged scale, two intersecting pipes;

Figure 3 is a cross-section through the welded joint of the two intersecting pipes in Figure 2;

Figure 4 shows a further variant of the pipe according to the invention;
and

Figure 5 shows a series of variants of the pipe according to the invention. In Figure 1, 1 represents a so-called "intermediate bulk container". This packaging consists of a pallet-like construction 2 on which a grid 3 is attached or, where this grid 3 is part of such a pallet-like construction 2. Such constructions are generally known in the prior art and reference is made to the international application WO 96/19397.

Inside the grid 3 there is a container 4 which contains the product to be packaged, which can be tapped, for example, by means of a filling opening 5.

The grid 3 is particularly important for the present innovation. This consists of vertical tubes 6 and horizontal tubes 8, whereby the details of the end connection of the vertical tubes 6 with the horizontally running tube are not discussed here.

All this is shown in more detail in Figure 2. It can be seen that the tubes 6 and 7 each consist of a circular part 10 which forms approximately a semicircle. A flattened part 8 is attached to this and between the flattened part and the circular part 10 there is a projection 9 on both sides.

When the tubes 6 and 7 are placed crosswise on top of each other, four contact points are formed by the projections. Resistance welding can be used to weld in the area of these contact points, as shown in Figure 3 and designated 11.

The projections preferably have a smaller height than width, as can be seen from the figures, in which the height is indicated by h and the width by b.

When used in packaging, as shown in Figure 1, when determining the radii of curvature R of the round or curved part 10, the available space for the grid and the desired rigidity of the grid are taken into account, while when determining the radius of curvature r of the rounding of the projections, in addition to the available space, the desired stability of the edge for the

Welding plays a role.

It is to be understood that the pipe according to the invention is not limited to the design shown here. All this becomes immediately apparent when studying Figure 4, in which 12 represents a different pipe profile that meets the above-mentioned requirements.

Apart from the variant according to Figure 4, it is understood that many other variants are conceivable for the prior art. Examples of these are shown in Figure 5 and these are all within the scope of the appended claims.

Claims (7)

PROTECTION CLAIMS 1. Pipe (6, 7, 12) comprising a closed profile with a cross-section that is constant over its entire length, which pipe (6, 7, 12) must be attached to another part (7, 6) by means of a welded connection, comprising in cross-section at least one flattened part which, at the transition to the other part of the pipe, is provided with projections (9) extending beyond this flattened part, characterized in that the projections (9) comprise bends made from the interior of this pipe in a continuous wall region that is part of the closed profile, the apex angle of these projections being less than 180°. 2. Pipe according to claim 1, wherein the height (h) of the projections is less than or equal to the width (b) of these projections. 3. A pipe according to any preceding claim, wherein the remaining portion comprises a substantially round portion (10). 4. Pipe according to one of the preceding claims, wherein the circular part comprises approximately a semicircle. 5. A tube according to any preceding claim, wherein said flattened portion is substantially flat. 6. Pipe grid comprising intersecting pipes (6, 7, 12) according to one of claims 1-5, wherein the projections (9) of the pipes are attached to each other by welding. 7. Packaging comprising a pallet-like construction (2) connected to a grid (3), within which grid a container (4) is mounted, said grid comprising a pipe grid according to claim 6.