阅读说明：本技术 托盘集装箱 (Pallet container ) 是由 D.魏劳赫 于 2018-07-13 设计创作，主要内容包括：本发明涉及一种用于存放和运输液态的填充物品的托盘集装箱(10),带有薄壁的刚性的由热塑性塑料制成的内部容器(12),带有作为支撑罩紧密地包围所述塑料内部容器(12)的由相互焊接的水平的以及竖直的管棒(18,20)组成的管式格栅框架(14),并且带有矩形的底部托盘(16),所述塑料内部容器(12)安放在该底部托盘上并且所述管式格栅框架(14)与该底部托盘固定地连接,其中在交叉区域(26)中相互焊接的管棒(18,20)分别具有封闭的空心型材。为了提高管式格栅框架(14)的刚度,至少一个管棒(18,20)的最初的基础型材构造成以伸延通过相互焊接的水平的和竖直的管棒(18,20)的交叉区域(26)的方式构造成升高了可预设的一段或者设有升高的背部区域(30)。(The invention relates to a pallet container (10) for storing and transporting liquid filling materials, comprising a thin-walled, rigid inner container (12) made of thermoplastic, a tubular grid framework (14) consisting of welded-together horizontal and vertical tubular rods (18,20) which tightly surrounds the plastic inner container (12) as a supporting shell, and a rectangular base pallet (16) on which the plastic inner container (12) rests and to which the tubular grid framework (14) is fixedly connected, wherein the tubular rods (18,20) welded together in a cross-over region (26) each have a closed hollow profile. In order to increase the rigidity of the tubular grid framework (14), the initial base profile of at least one pipe stick (18,20) is designed in such a way that it extends through the intersection region (26) of the horizontal and vertical pipe sticks (18,20) welded to one another by a predetermined distance or is provided with a raised back region (30).)

1. A pallet container (10) for storing and transporting liquid or flowable filling materials, having a thin-walled, rigid inner container (16) made of thermoplastic, having a tubular grid framework (14) which tightly surrounds the plastic inner container (16) as a supporting shell and consists of horizontal and vertical tubular rods (18,20) welded to one another in the intersection region, and having a rectangular base pallet (12) on which the plastic inner container (12) rests and to which the tubular grid framework (14) is fixedly connected,

it is characterized in that the preparation method is characterized in that,

the initial base profile of at least one horizontal and/or vertical pipe stick (18,20) is designed in such a way that it extends in the pipe stick longitudinal direction through the intersection region (26) of the horizontal and vertical pipe sticks (18,20) welded to one another by a predefinable length or is provided with a raised back region (30), wherein the initial base profile is deformed in the region of the raised back region (30) into an approximately triangular hollow profile.

2. The pallet container of claim 1,

it is characterized in that the preparation method is characterized in that,

the raised back region (30) is formed by the initial base profile by mechanical deformation by means of lateral pressure effects and has a narrow back extending in the longitudinal direction of the pipe rod.

3. The pallet container of claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the raised back region (30) is arranged on the side of the tube strand (18,20) which is directed outwards or inwards with respect to the tubular grid framework (14).

4. The pallet container of claim 1, 2 or 3,

it is characterized in that the preparation method is characterized in that,

the elevated back region (30) is formed in vertically running pipe rods (20) on the side pointing inwards with respect to the tubular grid framework (14) and/or is arranged in horizontally running pipe rods (18) on the side pointing outwards with respect to the tubular grid framework (14).

5. The pallet container of claim 1, 2, 3 or 4,

it is characterized in that the preparation method is characterized in that,

the raised back region (30) has a limited extension in the longitudinal direction of the pipe rod.

6. The pallet container of claim 1, 2, 3, 4 or 5,

it is characterized in that the preparation method is characterized in that,

the raised back region (30) extends in the longitudinal direction of the pipe rod over a length of between 2 and 10 times, preferably 5 times, the pipe rod width or pipe rod diameter.

7. The pallet container of claim 6,

it is characterized in that the preparation method is characterized in that,

the initial base profile is designed as a square tube profile.

8. The pallet container of any of the preceding claims 1 to 7,

it is characterized in that the preparation method is characterized in that,

the elevated back region (30) is arranged exclusively in the vertical tube strand (20) in the intersection region (26).

9. The pallet container of any of the preceding claims 1 to 8,

it is characterized in that the preparation method is characterized in that,

the square profile of the pipe stick (18,20) has a wall thickness of 0.8mm to 1.0 mm.

10. The pallet container of any of the preceding claims 1 to 9,

it is characterized in that the preparation method is characterized in that,

the square profile of the vertical pipe stick (20) has a wall thickness of 0.8mm and the square profile of the horizontal pipe stick (18) has a wall thickness of 0.9 mm.

11. The pallet container of any of the preceding claims 1 to 10,

it is characterized in that the preparation method is characterized in that,

the square profile has two opposite parallel straight side walls and two opposite parallel slightly curved side walls, wherein one curved side wall is configured to be slightly concave inward and the other curved side wall is configured to be slightly convex outward.

12. The pallet container of any of the preceding claims 1 to 11,

it is characterized in that the preparation method is characterized in that,

the initial base profile is configured as a round tube profile.

13. The pallet container of any of the preceding claims 1 to 7,

it is characterized in that the preparation method is characterized in that,

the triangular hollow profile in the raised back region (30) has a profile height of at least 20 mm.

14. The pallet container of any of the preceding claims 1 to 13,

it is characterized in that the preparation method is characterized in that,

the elevated back region (30) in the intersection region (26) is preferably realized in the region of the side walls of the tubular grid framework (14) with the greatest bulge, i.e. in the region of the tubular grid framework (14) in the middle of the second and third horizontal tube rods (18) starting from below.

15. Method for producing triangular hollow profiles from square base profiles in a grid tube bar for a tubular grid frame of a pallet container according to at least one of the preceding claims 1 to 14,

it is characterized in that the preparation method is characterized in that,

in order to form the central back section for the intersection region of the tube rods, pressure is simultaneously applied from two opposite parallel side walls in a direction parallel to the plane of the grid wall to the provided region of the base tube profile by means of a correspondingly shaped die.

16. The method of claim 15, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the pressure is applied essentially only to the two opposite, parallel, straight side walls in the region or section of the square base profile, i.e. the region or section is immediately adjacent to or slightly convexly curved side walls.

17. The method according to claim 15 or 16,

it is characterized in that the preparation method is characterized in that,

the pressure acting on the two opposite, parallel side walls is achieved in that the forward beveled tips of the dies moving toward each other in the end position produce a V-shaped gap between the tips of the dies, and in the deformed region of the tube strand a triangular tube cross section with an increased tube profile height is formed.

Technical Field

The invention relates to a tray container (Pallet container) for storing and transporting liquid or flowable filling materials, having a thin-walled inner container made of thermoplastic plastic, having a tubular grid frame consisting of welded-together horizontal and vertical tubular rods, which tightly surrounds the plastic inner container as a support shell, and having a rectangular base tray on which the plastic containers rest and to which the tubular grid frame is fixedly connected.

Background

The problems are as follows:

in the chemical industry, pallet containers (commonly known by the name "intermediate bulk containers" or "IBCs"; hereinafter also referred to as "IBCs" or "IBCs" for short) are widely used primarily for transporting liquid chemicals. These chemical products are mostly classified as dangerous liquid filling materials. For the transport and storage of products of this type, therefore, only packaging containers with corresponding authorization for hazardous materials are allowed to be used. In order to obtain a hazardous-goods authorization, the pallet container is subjected to a structural-type check, for which tests relating to different load states have to be passed, such as, for example, internal pressure tests, drop tests, stacking load tests, vibration tests on vibration tables and more. Upon the occurrence of the internal pressure, the cuboid-shaped plastic inner container filled with the liquid filling product tries to expand and bulge in its four side walls and in its upper bottom (Oberboden). The filled IBCs are usually transported in double stacks, for example on trucks, so that the lower IBC additionally has to carry (abtragen) the stacked load of the upper IBC. In particular, during the transport of filled IBCs by trucks, considerable wave motion of the liquid filling material occurs due to the transport shocks and movements of the transport vehicle, in particular on bad roads, whereby constantly changing pressure forces are exerted on the walls of the interior container, which in turn, in the case of rectangular pallet containers, lead to radial oscillation movements of the tubular grid framework and represent dynamic, constant oscillations with changing tensile/compressive loads acting on the welding points in the intersection of the grid bars. In the case of overloading or after a long period of loading, fatigue fractures and fractures of the weld points in the intersection can result for the tube rods. In pallet containers with a license for hazardous goods, special measures are often provided to reduce this type of damage.

Disclosure of Invention

Task:

the aim of the invention is to increase the rigidity of the tubular grid framework of pallet containers (ICBs) and thus to ensure increased safety of large containers of this type when used in particular for dangerous liquid filling materials.

The solution is as follows:

this object is achieved by the special features of claim 1. Further advantageous design possibilities of the pallet container according to the invention are described by the features in the dependent claims.

The technical teaching proposed clarifies how the feasibility of increasing the rigidity of the tubular grid framework of a pallet container can be achieved with comparatively simple constructional measures. According to the invention, the initial base profile of the at least one horizontal and/or vertical pipe rod is designed in such a way that it extends in the longitudinal direction of the pipe rod through the intersection region of the horizontal and vertical pipe rods welded to one another in such a way that a predefinable section is raised or a raised back region is provided.

In contrast to all known solutions, the base profile of the pipe rod is not recessed and weakened, but rather is configured to be reinforced and reinforced by a raised back region extending through the intersection region of the horizontal and vertical pipe rods welded to one another. The initial base profile is formed from the initial base profile in the elevation of the base pipe profile by mechanical deformation by means of lateral pressure effects and has a relatively narrow back line running in the longitudinal direction of the pipe rod. By increasing the height over the structure of the tube profile in the intersection region from the original base profile to the deformed approximately triangular hollow profile, the bending stiffness of the tube rod in this region is increased considerably. This then leads in an advantageous manner as a whole also to an increased or improved rigidity of the entire tubular grid framework. This, in turn, significantly reduces the bulging of the side walls of the tubular grid frame due to the effect of the hydrostatic pressure of the filled pallet container. Likewise, the stiffer sidewalls of the tubular grid frame are better resistant to internal pressures that occur due to temperature changes, for example, through thermal expansion in the case of insolation. In addition, the vibrations of the side walls of the tubular grid framework in the event of transport shocks and wave loads due to the liquid filling material are reduced. This results in overall lower stress loads on the tube bars themselves and on the individual welds in the intersection of the grid tube bars. By this structural measure, the rigidity of the tubular grid framework of the pallet container is not reduced but increased, and in connection therewith an increased safety of the IBCs according to the invention is ensured, in particular for dangerous liquid filling materials.

In one embodiment of the invention, it is provided that the raised back region is arranged exclusively on the outwardly pointing side of the tube strand with respect to the tubular grid framework at the horizontal tube strand and/or exclusively on the inwardly pointing side of the tube strand with respect to the tubular grid framework at the vertical tube strand. For improving the rigidity of the tubular grid framework, it is important to increase or enlarge the height of the tube profiles in the radial direction or perpendicular to the side walls of the tubular grid framework. Thus, as long as the raised back region is arranged on the vertical bars, it should be formed on the side pointing inwards with respect to the tubular grid framework. If the elevation is arranged on a horizontal pipe rod, the elevated back region should be formed on the outwardly pointing side. In this embodiment, no problems of welding in the intersection area for the horizontal and vertical tube rods lying one on top of the other arise.

In a further embodiment of the invention, it is provided that the raised back region has a limited elongation in the longitudinal direction of the tube rod. An optimum performance increase or strength increase of the tubular grid framework is achieved when the length of the raised back region in the longitudinal direction of the tubes extends between two and ten times, preferably five times, the tube rod width or the tube rod diameter. For the simplest and most efficient process technology for forming the raised back region, tube rods with a square cross section (also referred to below as "square profile") are particularly suitable, wherein the profile does not have to be perfectly square. For example, square profiles are also particularly suitable in this sense, for example with slightly different profiles in terms of the height of the side walls or with side walls that are not completely parallel.

The invention is distinguished by the following special features for the preferred embodiments:

the raised back is realized substantially only in the intersection area of the tube rods;

the raised back is realized at the vertical tube bars essentially only (with respect to the tubular grid frame) pointing outwards;

the raised back is realized at the horizontal tube bars essentially only (with respect to the tubular grid framework) pointing inwards;

the raised back is realized in the intersection area, preferably in the area of the lower half of the side wall of the tubular grid framework;

the raised back is realized in the intersection region, preferably in the region of the tubular grid framework with the largest raised side walls, which is the middle region of the second and third horizontal bars in the tubular grid framework starting from below.

Drawings

The invention is further explained and described below with the aid of exemplary embodiments which are schematically illustrated in the drawings. Wherein:

figure 1 shows an IBC according to the invention in a front view,

figure 2 shows in cross-section a preferred embodiment of a pipe bar base profile BP with a substantially square cross-section,

figure 3 shows in cross-section the pipe bar profile according to figure 1 after deformation with a substantially triangular cross-section,

figure 4 shows in cross-section another embodiment of a pipe bar base profile with a circular cross-section,

figure 5 shows in cross-section the pipe bar profile according to figure 4 after a first deformation stage into a 4-point supported weldable cross-section with crossing pipe bars,

figure 6 shows in cross-section the pipe bar profile according to figure 4 after further deformation into a triangular cross-section,

FIG. 7 shows a partial view of the side of a vertical pipe stick with a square cross section, an

Fig. 8 shows a partial top view of a vertical pipe stick with a square cross section, viewed from the inside of a tubular grid frame.

Detailed Description

Fig. 1 shows a pallet container according to the invention for storing and transporting, in particular, dangerous liquid or flowable filling materials, with reference numeral 10. For storing and/or transporting dangerous filling materials, the pallet container 10 meets special inspection standards and is provided with corresponding official hazardous material licenses. In one embodiment for a filled product volume of about 1000 l, the pallet container 10 has standardized dimensions with a length of about 1200mm, a width of about 1000mm and a height of about 1150 mm. The essential elements of the pallet container 10 consist of a thin-walled, rigid inner container 12 made of thermoplastic plastic in a blow molding process, a steel-tube grid framework 14 which tightly surrounds the plastic inner container 12 as a support shell, and a base pallet 16 on which the plastic inner container 12 is placed and to which the steel-tube grid framework 14 is fixedly connected. The outer tubular grid framework 14 is comprised of horizontal and vertical steel tube rods 18,20 welded to each other. The closed base profiles BP of the horizontal and vertical pipe rods 18,20 have no profile or recess at all transversely to the longitudinal direction of the pipe rods, which reduces the profile height.

The base tray 16 is constructed in the variant shown as a composite tray. On the front side of the tubular grid frame 14, a label plate 22 made of thin steel plate is fastened for marking the respective liquid filling material. A removal fitting 24 is connected in the middle of the bottom of the plastic inner container 12 for removing the liquid filling product.

The horizontal tube rods 18 are fixedly welded in the intersection region 26 to the vertical tube rods 20 of the tubular grid framework 14 by means of conventional resistance pressure welding by means of a 4-point bearing. In the present case, the steel-tube grid framework 14 is composed of eighteen vertical pipe rods 20 each having a length of approximately 1000mm and six circumferential horizontal pipe rods 18, which are each constructed as a rectangular pipe ring by four 90 ° arcs, each with a total length of approximately 4400mm and a connection of two pipe ends. Within the tubular grid frame 14 there are 72 pure crossover sites 26 and 18 upper and 18 lower crossover junctions 28. At the cross-butt 28, the upper and lower ends of the vertical pipe stick 20 are fixedly welded to the uppermost and lower horizontally encircling pipe sticks 18, respectively. The pallet container 10 can also be implemented as a large container in different volume sizes between 500 l and 1300 l.

Fig. 2 shows a cross-sectional view of a pipe bar base profile BP with an approximately square pipe cross section as a preferred embodiment. The initial base profile BP of the vertical pipe rod 20, which is a square profile, has no profiling or recess at all transversely to the pipe rod longitudinal direction. The outer dimensions are about 16x16mm, thusHeight H (of the length of the side of the square profile)_Q) Again 16 mm. The previously 1.0mm wall thickness of the tubular rods can be reduced by the inventive increase in the rigidity of the steel-tube grid framework, wherein the square profile then has a reduced wall thickness of 0.7mm to 1.0mm, preferably 0.9 mm.

In a preferred embodiment, it is provided that the square profile of the vertical pipe stick 20 has a wall thickness of 0.8mm and the square profile of the horizontal pipe stick 18 has a wall thickness of 0.9 mm. The weight and material expenditure of the pallet container can thereby be reduced while maintaining a high wall rigidity.

The basic square profile BP preferably has two opposite parallel straight side walls 32 and two opposite approximately parallel slightly curved side walls 34,36, wherein one curved side wall 34 is configured to be slightly concave inwards and the other curved side wall 36 is configured to be slightly convex outwards. The slightly concavely curved side walls of the tube rods 18,20 each have a flat back line 40 running in the longitudinal direction of the tube rod at the outer edge of their two sides.

In the intersection 26, the horizontal tube strand 18 and the vertical tube strand 20 are each stacked on top of one another with their slightly inwardly concavely curved side walls 34 or with their two outer, longitudinally extending back lines 40 and form the necessary 4-point support for welding the tube strands 18, 20. The slightly convexly configured side walls 36 of the square base profile can be deformed relatively easily into the triangular deformed profile with the intermediate shaped back section 30 in the region of the intersection 26 (which is desired and provided for the intersection) by the pressure applied on both sides. The back-type elevation is produced by cold-forming the base profile square tube by means of simple hydraulic pressure clamps.

The pipe rod profile 30 according to the invention, which is shaped and deformed in this way in the region of the intersection point 26, with a substantially triangular cross section and an intermediate shaped back section can be seen in fig. 3 in a cross-sectional view.

For a side length or height H (with 16 mm)_Q) In the case of a square base profile, the base profile is curved slightly inwardsWall-identical side walls for the 4-point contact points for welding the intersecting pipe rods up to the triangular cross-sectional area of the apex of the intermediate back section 30, in accordance with the size of the radius at the apex of the back, result in a height H of the triangular pipe rod profile of approximately 20.5mm (H: (_D). In this case, two opposite parallel straight side walls 32 and a slightly outwardly convex arched side wall 36 are each formed in half as two equilateral triangular side walls 38.

During the deformation process, two outwardly pointing bulges 48 are produced in the two deformed triangular side walls 38 from the two 90 ° arcs between the two oppositely situated parallel straight side walls 32 and the slightly outwardly convex arched side walls 36 in the cross-sectional view. The square base profile BP is initially deformed in the roll stand from a round steel tube into a square profile. In this case, four 90 ° arcs between two adjacent side walls are formed by cold forming. During cold deformation, a local increase in strength occurs due to the structural change in the steel material. In the region of the deformed triangular cross section, the two 90 ° arcs adjacent to the slightly outwardly convex arched side walls 36 are again curved upwards (aufbiegen). Due to the increased strength in the two 90 ° arcs, the reverse bending is not completely achieved and two peaks 48 remain in the two equilateral triangular side walls 38.

In contrast to the previously known solutions, the processing and deformation of the base profile tube strand is not carried out in a direction perpendicular to the plane of the grid wall, but in a direction parallel to the plane of the grid wall, wherein for the formation of the central back section 30, pressure is simultaneously applied from two opposite side walls to the provided region of the tube strand by means of a correspondingly shaped die. The pressure is applied to two opposite side walls 32 extending straight in parallel, that is to say starting in a region or section of the square base profile which is immediately adjacent to or slightly convexly curved side wall 36. This can be produced, for example, by means of a die with two punches which are moved toward one another and whose tips are correspondingly beveled on the front, so that in the end position a V-shaped gap is obtained between the tips of the punches and a tube cross section with an increased tube profile height to an approximately triangular or triangular-like deformed region with a tube rod is obtained. In a corresponding manner, the deformation process can also be carried out by means of a pressure jaw tool, wherein the two jaws act via a rotation point on two opposing, parallel, straight side walls 32. Here, the side walls 34, which are only slightly concavely curved inward, remain undeformed for the 4-point welding in the intersection region 26 of the horizontal and vertical tube bars 18,20, respectively.

The base profile square tube has a base side wall that is slightly inwardly arched, thereby creating an outer longitudinal bead for 4-spot resistance welding. During cold forming, the two 90 ° arcs opposite the base side walls are bent upwards and run as close to a straight line as possible, while the straight side walls opposite the base side walls are deformed in the middle into relatively narrow arcs with a small radius.

Another embodiment of the known pipe bar base profile is shown in a cross-sectional view in fig. 4. The initial tube-rod base profile is designed as a round-tube profile 42 and has an outer diameter D (D) of approximately 18mm_AR) And a wall thickness of 1.0 mm. In order to obtain a corresponding mutual support of the tube rods for the 4-point welding in the intersection region, in a first deformation phase, as illustrated in the following fig. 5, one side of the round tube profile is profiled radially with small segments, so that slightly concave or slightly inwardly arched wall segments 44 are formed with outer longitudinal ribs or longitudinal peaks, which form the 4-point support in the intersecting tube sections. The rigidity or bending moment of the round tubes of the known pallet container is greatly lost due to the recessing of the round tubes in order to form four welding contact points. The stiffness loss can be compensated again well by deforming in a further deformation phase with the introduction of the raised back region 30 into an approximately triangular cross-sectional profile, as can be seen in fig. 6. This embodiment with triangular hollow profiles also has a profile height H of at least 20mm in the region of the raised back region 30_D。

Fig. 7 shows a partial view of the side of a vertical tube rod 20 with a square cross section in the intersection region 26. The horizontal pipe rods 18 have the same square cross section of the base profile BP. In the intersection region 26, the initially square base profile BP of the vertical tube strand 20 is deformed into an approximately triangular hollow profile with a central raised back region 30. The central raised back region 30, which is formed by mechanical deformation by means of lateral pressure effects from the initial base profile, has a narrow back extending in the longitudinal direction of the pipe rod, wherein the raised back region 30 is limited to a defined extension in the longitudinal direction of the pipe rod. The length of the raised back region 30 extending in the longitudinal direction of the pipe rod should be between 2 and 10 times, preferably 5 times, the pipe rod width or pipe rod diameter (in the case of round pipes).

A transition region 46 running obliquely is produced on both sides between the original undeformed base profile and the central raised back region 30 formed by the deformation. This obliquely running transition region 46 is produced in that, for the formation of the raised back region of the intersection region for the tube strand, pressure is simultaneously applied by means of a correspondingly shaped die from two opposite parallel side walls in a direction parallel to the plane of the grid wall to the provided region of the base profile. In this case, the pressure is applied essentially only to the two opposite, parallel, straight-running side walls in the region or section of the square base profile, i.e. this region or section is immediately adjacent to or slightly convexly curved side walls. The deformation is carried out in such a way that a pressure is applied to the two opposing parallel side walls, for example by two tips of two punches of a die that are moved toward one another and are beveled at the front end or pivotable jaws of a pressure jaw, wherein in the end position a V-shaped gap is formed between the tips of the punches or jaws of the pressure jaw and thus an approximately triangular tube cross section with an increased height of the tube profile is formed in the undeformed region of the tube rod.

To this end, fig. 8 shows a deformed triangular cross-sectional area of the vertical pipe stick 20 with a middle raised back area 30 configured by deformation and with immediate transition areas 46 on both sides, in a partial top view of the vertical pipe stick 20 with a square base cross section, viewed from the inner pipe of the tubular grid framework. The longitudinal extent of the angled transition region 46 should be approximately one to two times the height of the side walls of the square base profile, that is to say between 15 and 35mm, preferably approximately 20 mm.

If the specific case of an IBC filled with a liquid filling product is observed, in which the filling product is shaken back and forth due to the transport load and thus acts with varying pressure on the side walls of the grid tube frame, this causes dynamic continuous loading in the tube profile with continuously increasing and decreasing tensile and compressive stresses, which over time can lead to cracks in the region of the most stressed tube profile and to fracture of the weld in the intersection. The bulging of the side walls to the outside of the tubular grille frame caused by the internal pressure in the plastic inner container is approximately twice the "indentation" or the spring-back to the inside of the tubular grille frame caused by the elastic restoring force. Bending loads of different magnitudes are thus generated in the radial direction in this case on the tube bars (bending beams) of the tubular grid framework.

The measure of resistance to bending is known as the resistive moment in the axial directionWOr also bending moment. The resistive moment is in the technical mechanism a quantity derived solely from the geometry (shape and size) of the beam cross-section, which is a measure for the resistance a bending beam resists when subjected to a load resulting from internal stresses. In this case, the maximum stress σ is assumed_maxAlways occurs in the edge fiber of the bending beam, which has the furthest distance from the neutral fiber. Moment of resistance of beam cross sectionWMoment of inertia in planeIIn a simple geometric relationship, the deformation is calculated at the time of cross-sectional dimensioning by means of this geometric relationship for determining the flexural rigidity of the beam under load. Moment of resistanceWIs defined as plane moment of inertiaIAnd maximum stress σ_maxThe quotient of (a). The unit of the moment of resistance is m³。

The following results have been obtained when comparing the measurement of the flexural rigidity of square base profiles and deformed triangular tube cross sections with an elevated back region: the square base profile has a size of approximately 1610mm⁴Plane moment of inertia ofI _x And about 2000mm is obtained for a triangular cross-sectional profile⁴Plane moment of inertia ofI _x . This results in a significant increase of about 24%.

In a corresponding comparative measurement, approximately 1770mm results for the undeformed circular tube profile of the known pallet container⁴Plane moment of inertia ofI _x This planar moment of inertia is also significantly reduced with the profiling and cross-sectional reduction in the intersection region implemented up to now. In contrast, the circular tube cross section is here deformed into a triangular profile with an elevated back region and a planar moment of inertiaI _x Increase to over 2000mm⁴Also a high performance boost results.

And (4) conclusion:

the invention thus provides a simply applicable, problem-free and inexpensive solution for advantageously increasing the rigidity of the tubular grid framework of a pallet container. No additional material is required, but only a special and local deformation of the tube and rod basic profile is applied. And even conversely material and cost savings can be achieved by reducing the wall thickness of the pipe stick.

This ensures increased safety against damage due to excessively high transport loads when using such large containers, in particular for dangerous liquid filling materials.

List of reference numerals

10 tray container

12 Plastic inner container

14-tube type grid framework

16 bottom tray

18 horizontal tube bar (14)

20 vertical tube stick (14)

22 Label plate

24 take-out fitting

26 intersection region (14)

28 cross butt-joint area (14)

30 raised back area (18,20)

32 parallel straight side walls

34 concave side wall

36 convex side wall

38 triangular side wall

40 lateral back line (18,20)

42 round tube foundation section bar (28)

44 concave wall segment (42)

46 transition region (BP,30)

48 convex peak (38)

H(_Q) Height of side length

H(_D) Height of triangle

WS(_R) Wall thickness of round tube

D(_R) Diameter of the circular tube

WS(_Q) Wall thickness of square tube

D(_AR) Outer diameter of round tube

BP square basic section bar