EP3034714B1 - Clamping device for reinforcing hollow profiles and use of the same - Google Patents

Description

The invention relates to a hollow profile according to the preamble of claim 1, as well as a use of a tensioning device for stiffening such hollow profiles according to claim 16.

For the removal of loads such as glass loads, dead loads and wind and snow loads are special for large-area frame structures

Mullion-transom constructions and roof rafter constructions Hollow sections with correspondingly large cross-section values are used as a static load-bearing construction.

• die Spannweite zwischen 2 Befestigungspunkten zu groß ist.
• die auftretenden Lasten (Glasgewicht, Wind- und Schneelasten) zu groß sind.
• die bauliche Situation den Einbau entsprechend großer Profile nicht erlaubt
• aus optischen Gründen eine filigrane Konstruktion mit geringen Ansichtsbreiten und Profiltiefen gefordert wird.

Often, the cross-sectional values of commercial profiles are not sufficient to accommodate the loads because:

• the span between 2 attachment points is too large.
• the occurring loads (glass weight, wind and snow loads) are too large.
• the structural situation does not allow the installation of correspondingly large profiles
• For reasons of appearance, a filigree design with low view widths and profile depths is required.

Usually, insert profiles are used in the hollow profiles to achieve the necessary rigidity. Especially with bolt profiles, the moments of resistance are often not sufficient because of the low profile heights, so often on Steel profiles with a correspondingly high weight is used. However, this increases the load problem in most cases even more.

Another known possibility for stiffening is to install behind the profile devices that allow a lattice-shaped bracing and stiffening of the profiles, as shown in EP 1 020 574 A2 is known. Such constructions require a high assembly cost and result in a visually bulky construction. Therefore, they often can not be used for the respective requirements.

An initially mentioned hollow profile with an arranged inside the same clamping device to its stiffening is from the US-A-5,301,482 known. The US-A-5,301,482 discloses a hollow profile with the features of the preamble of claim 1. In the interior of the hollow profile at least one tension element is arranged and connected at its ends to the ends of the hollow profile such that a tensile force is exerted on the tension element, wherein the at least one tension element via a arranged in the interior of the hollow profile clamping element is connected to the hollow profile. A disadvantage of this construction is that, after the assembly of a structure having such a hollow profile, a subsequent adjustment of the prestressing in the interior of the hollow profile is no longer possible, since the screws located at the ends of the tensioning device are no longer accessible for applying the clamping force.

The invention is therefore an object of the invention to provide a tensioning device which is disposed within a hollow profile and allows a subsequent bias of the profile, which counteracts the expected acting on the hollow profile loads and the profile stiffened such that the deformation of the profiles in the frame the regulations allowed limits and the appearance of the frame construction is not affected.

This object is achieved with a hollow profile according to claim 1.

According to the invention, the tensile stress is applied by wedge-shaped intermeshing clamping elements, which are stretched over a screw connection arranged outside the hollow profile. A subsequent adjustment can hereby also be done after installation of the profiles. For this purpose, the clamping element is designed as a wedge-clamping device and the voltage by means of a clamping screw on the tension element can be applied.

A particularly elegant type of bracing results from the fact that the wedge-tensioning device has a base element fixedly arranged on the hollow profile and at least one wedge element adjustable in the longitudinal direction of the tension element.

The use of wedge-type tensioners has long been known. The British patent GB-A-710 089 describes a wedge-type clamping device for concrete anchors used in prestressed concrete structures.

• Durchführen einer statischen Vorbemessung für ein bestimmtes Profil unter Berücksichtigung der bekannten statischen Lasten,
• Berechnung der theoretischen lastabhängigen Durchbiegung,
• Vorspannung des Hohlprofils auf einen spezifischen Wert, zur Vermeidung einer übergroßen Durchbiegung im Einbauzustand.

With regard to the use of such a tensioning device, the object is achieved by the following steps:

• Performing a static pre-design for a particular profile taking into account the known static loads,
• Calculation of the theoretical load-dependent deflection,
• Pre-tensioning of the hollow section to a specific value, to avoid excessive deflection in the installed state.

The tension elements allow this to adjust the bias of the respective profile individually to the expected utility and service loads.

The necessary tension is preferably applied by a threaded connection to the tension elements. For this purpose, according to a further teaching of the invention, the at least one tension element has a thread at least at one end.

Since the at least one tension element is connected at least at one end via a clamping element with the preferably made of aluminum hollow profile, it is possible to laterally clamp a one-sided firmly clamped tension element at its free end to meet the expected loads. For this purpose, according to another teaching of the invention, the clamping element as an abutment and the voltage is applied directly to the tension element.

According to another teaching of the invention, the base element has at least one wedge surface and is a clamping body in the direction transverse to the tension element by means of a clamping screw relative to the base element adjustable so that the tension element can be braced.

To achieve a uniform and running in the central axis of the hollow profile layer of the tension element this is attached with at least one end directly on the wedge element.

In order to reduce the play of the tensioning device to a minimum, a further teaching of the invention provides that the base element and the tensioning body engage in order to achieve a positive guidance. Preferably, a groove / spring connection between the base member and the clamping body is provided for this purpose.

According to a further embodiment of the invention, at least one support element for fixing the position of the tension element in the free cross section of the hollow profile is provided over the length of the tension element in the interior of the hollow profile. Preferably, however, a plurality of support elements are arranged in the hollow profile, so that the tension element is clamped in the interior of the hollow profile as a supporting structure. In this way, side loads (for example, by wind loads) can be reliably countered.

Due to the versatility of the clamping device according to the invention, the hollow profile can be designed as a bar profile, ie as a horizontally arranged profile, as a post profile, ie as a vertically arranged profile, or as a rafter profile with any inclination.

The tension element can be designed as a pull rod or as a pull rope.

Finally, it is provided according to a further embodiment of the invention that the clamping device according to the invention constructed in a modular manner and is optimally suited in this way for retrofitting purposes in existing frame structures.

The maximum permissible deflection at dead load is included in the product standard for facades EN 13830. There it says under 4.2 dead load:
"Curtain wall facades must carry their own weight and all the additional connections included in the original design, and they must be securely transferred to the building structure via the fasteners provided.

The dead load shall be determined according to EN 1991-1-1.

The maximum deflection of any horizontal primary beam through vertical loads shall not exceed L / 500 or 3 mm, whichever is the smaller. "

The invention is able to achieve the maximum allowable deflection in a simple manner by corresponding prestressed profiles. This will be explained in more detail below to the exemplary embodiments.

Fig. 1

ein erstes Ausführungsbeispiel der erfindungsgemäßen Spannvorrichtung für ein Riegelprofil in schematischer Seitenansicht,

Fig. 2A, 2B

vergrößerte Darstellungen der beiden Kreisausschnitte IIA und IIB aus Fig. 1,

Fig. 3

den Gegenstand aus Fig. 1 in perspektivischer Darstellung.

Fig. 4

einen vergrößerten Ausschnitt einer ersten Keil-Spannvorrichtung für ein Riegelprofil,

Fig. 5

die Spannvorrichtung aus Fig. 4 in vergrößerter Explosionsdarstellung,

Fig. 6

einen vergrößerten Ausschnitt einer anderen Keil-Spannvorrichtung für ein Riegelprofil,

Fig. 7

die Spannvorrichtung aus Fig. 6 in vergrößerter Explosionsdarstellung,

Fig. 8

ein zweites Beispiel einer erfindungsgemäßen Spannvorrichtung für ein Pfostenprofil,

Fig. 9

ein weiteres Beispiel einer erfindungsgemäßen Spannvorrichtung für ein Dachsparrenprofil,

Fig. 10A, 10B

eine schematische Darstellung eines erfindungsgemäßen Riegelprofils in Seitenansicht und im Vertikalschnitt und

Fig. 11

einen Ausdruck einer statischen Vorbemessung für das Riegelprofil aus Fig. 10A/10B.

The invention will be explained below with reference to an exemplary embodiments illustrative drawings. In the drawing show

Fig. 1

A first embodiment of the clamping device according to the invention for a transom profile in a schematic side view,

Fig. 2A, 2B

enlarged views of the two sections IIA and IIB from Fig. 1 .

Fig. 3

the object out Fig. 1 in perspective view.

Fig. 4

an enlarged detail of a first wedge-clamping device for a bolt profile,

Fig. 5

the clamping device off Fig. 4 in an enlarged exploded view,

Fig. 6

an enlarged detail of another wedge-clamping device for a bolt profile,

Fig. 7

the clamping device off Fig. 6 in an enlarged exploded view,

Fig. 8

A second example of a clamping device according to the invention for a post profile,

Fig. 9

another example of a tensioning device according to the invention for a rafter profile,

10A, 10B

a schematic representation of a bar profile according to the invention in side view and in vertical section and

Fig. 11

an expression of a static pre-design for the bolt profile Fig. 10A / 10B ,

In Fig. 1 In the illustrated preferred embodiment, a clamping device for a (horizontally arranged) bolt profile 1 is shown. In this case, the bolt profile 1 is formed as a hollow profile and extends between two only partially shown post profiles 2. According to the invention now provides a running inside the hollow profile tension element 3, which is connected at its outer ends via clamping elements 4 with the bolt profile 1, for a tensile force can be applied in the interior of the bar profile 1. While in the illustrated embodiment, the two clamping elements clamp the tension element 3 in the upper region of the free cross section of the latch profile 1, provide further inside the bolt profile 1 arranged support elements 5 that the tension element 3 is performed there in the lower part of the free cross section of the latch profile 1. In this way, a structural structure can be achieved, which is optimally designed for the expected loads.

In the FIGS. 2A and 2B are enlarged representations of the clamping elements 4 and 5 Tragelemente shown. Fig. 2A clearly shows that the clamping element 4 in preferred embodiment, the end of the tension element 3, which is provided with a thread 6 receives, whereby the tension element 3 can be braced by means of a nut 7 and a washer 8 against the clamping element 4. It is clear that while the clamping element 4 must be firmly connected to the end of the bar profile 1.

In the preferred embodiment, the clamping element 4 has two holes 9, which pass into an enlarged recess 10 in order to be particularly versatile.

Fig. 2B shows a spaced from the end of the locking bar 1 support element 5, which is provided on its underside with a bore 11 which is designed as a threaded bore, so that the tension elements 3, which in turn at least at their ends have a thread 6, in a defined Screw depth into the support element 5.

Fig. 3 shows the previously described in more detail bolt profile with the clamping device according to the invention in a perspective view. This makes it clear that by the arrangement of the clamping elements 4 and 5 supporting elements, the tension element 3 can not only form a supporting structure in a vertical plane, but also, for example, in addition occurring wind loads, even a bias with horizontal component allowed, in which the Clamping elements 4 or support elements 5 not, as shown, are all arranged on one side of the inner cross section of the latch profile 1, but offset accordingly laterally.

A disadvantage of the clamping device as shown in FIG Fig. 2A is that the tensile force on the nut 7 can be applied to the tension element 3 only from within the hollow profile. Therefore, in the 4 and 5 a first alternative embodiment shown, in which the tensioning device is a wedge-clamping device 12, which is a change in the tensile force in the tension element 3 from outside the Hollow profiles allowed. For this purpose, in a first embodiment, the individual parts of the wedge-clamping device 12 in Fig. 5 shown individually. This is a base element 13, which, like the clamping element 4, is firmly connected to the end of the hollow profile. Opposite a clamping body 14 is arranged. Both the base element 13 and the clamping body 14 have an unspecified wedge surface, which come into contact with a wedge element 15 having two corresponding wedge surfaces. The adjustment of the wedge-clamping device 12 via a clamping screw 16. The clamping screw 16 is passed through a hole 17 in the base member 13 and screwed her threaded end into a threaded bore 18 in the clamping body. In this way, base element 13 and clamping body 14 can be moved by turning the clamping screw 16 relative to each other. In order to avoid jamming or jamming, in the preferred embodiment, the clamping body 14 is designed with a groove 19 and the base member 13 with a spring 20, which mesh and allow a defined uniform opposite movement of both structural parts.

The arrows in Fig. 4 show the mode of action. If the clamping screw 16 is actuated in the clockwise direction from the outside, then the movable clamping body 14 is used on the fixed base member 13, so that the wedge surfaces of both parts also approach and the wedge element 15 disposed therein is moved towards the end of the bar profile 1. To accommodate the tension element 3 while the wedge member 15 is provided with unspecified threaded holes and the spring 20 of the base member 13 with corresponding slots, also not specified. Fig. 5 shows for better understanding, the individual components of the wedge clamping device in the non-installed state.

Another embodiment of a wedge-clamping device 12 ', in which the tension takes place in another surface of the locking bar 1' is in the 6 and 7 shown. In this case, a base member 13 'is arranged in the interior of a bolt profile 1', which is designed as a threaded sleeve with an inner and an outer thread. On Clamping body 14 'and a wedge element 15' are provided with corresponding wedge surfaces. By means of a screw 16 ', which extends through a bore 17' in the clamping body 14 'and the threaded sleeve 13', there is a force on the wedge surfaces and thus a tension of the tension element 3 ', namely upon rotation of the clamping screw 16' in a clockwise direction, such as with the arrows in Fig. 6 indicated.

The Fig. 8 and 9 show 2 further embodiments of the clamping device according to the invention, wherein in Fig. 8 a post profile 2 is shown, which makes it possible to achieve in a vertical post an inner structure by the structure previously detailed by the example of the bar profile 1. In Fig. 9 the same installation situation is shown as it can be realized in a rafter profile 21. The inclination of the roof plays no role, as can be achieved by appropriate arrangement and geometry of the clamping elements 4 and support members 5, connected to the stepless adjustability, an optimal bias.

Due to its modular design, the tensioning device according to the invention can also be used for existing frame structures, because retrofitting already installed hollow sections is possible with relatively little effort.

In the calculation example reproduced below is assumed that a horizontal bar profile, as in the Fig. 1 to 7 is shown. Such a bar profile is used with vertical posts not shown here for fixing vertically arranged glass panes, for example, a facade.

A corresponding arrangement is in Fig. 10A shown in the - schematically - the forces and torque distribution and the deflection d are shown.

und ein vorgegebenes Flächenträgheitsmoment in x-Richtung von $$\mathrm{Ix}=\mathrm{45,73}{\mathrm{cm}}^4.$$

The bar shown in the example has a length of $$\mathrm{L}=2.5\mathrm{m}$$

and a predetermined area moment of inertia in the x direction of $$\mathrm{ix}=45.73{\mathrm{<figure-callout\; id="4"\; label="cm"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">cm</figure-callout>}}^4,$$

As a static load is assumed that a 300 kg glass, so $${\mathrm{F}}_{\mathrm{G}}=3\mathrm{kN},$$

The specific data of such a bolt go out Fig. 10B in which the profile is out Fig. 10A shown in vertical section.

In order to reliably prevent contact between the infill and the latch (or its extended left-pointing U-legs) and to ensure adequate ventilation, the deflection d must be limited to 3 mm (cf the already cited EN 13830).

To determine the value for a sufficient deflection d, first the mathematical determination of the - theoretical - deformation by means of a static program (such as AutoCAD).

Such a "static preliminary design" is in Fig. 11 shown.

The ACAD calculation shows that in this case an areal moment of inertia Ix of 83.314 cm ⁴ would be required in order to avoid a deflection of the transom profile downwards due to the glass load to be supported. Since this value is higher than the area moment of inertia Ix = 45.73 cm ^{4 of} the bar profile to be used, this must be preloaded.

The ACAD calculation also shows that the bar would deflect downwards by 5.465 mm given the glass load used.

In order to remain within the required tolerance of <3 mm, sufficient preload must be generated by the prestressing applied via the tensioning device in the transom profile.

For this purpose, it is possible with the construction according to the invention, to actively condition the bar for this case (to bias). By a corresponding bias in this case, a deformation of up to 3-3.5 mm produced on the bolt and installed in the element. After installation and glazing on the construction site results in a permanent deformation of <3 mm. The technical guidelines is thus done by the inventively applied bias sufficient.

The actual application of the bias voltage via an actuation of both arranged at the ends of the bolt tensioners by applying a torque M _A. By appropriately chosen clamping devices, these should always be designed so that a tightening in the clockwise direction causes a tightening of the tightening torque and a counterclockwise rotation causes a reduction of the same. In this way, for known profiles and known loads once determined optimum deflections (top) can be read using tables and generated using appropriate gauges only by pressing the jigs in the middle of the bar profile.

Claims (16)

1. Hollow profile with a tensioning device arranged inside the same for reinforcing the hollow profile, in particular for extensive frame constructions, wherein in the interior of the hollow profile at least one tensile element (3, 3') is arranged and is connected at its ends to the ends of the hollow profile such that a tensile force is exerted on the tensile element (3, 3'), wherein the tension can be applied by means of a tensioning screw (16, 16') on the tensile element (3, 3') from outside of the hollow profile, characterised in that the at least one tensile element (3, 3') is connected to the hollow profile via a tensioning element (4) arranged in the interior of the hollow profile, wherein the tensioning element (4) is configured as a wedge tensioning device (12, 12') and in that the wedge tensioning device (12, 12') has a base element (13, 13') fixedly attached to the hollow profile and at least one wedge element (15, 15') adjustable against it in the longitudinal direction of the tensile element (3, 3').
2. Hollow profile according to claim 1, characterised in that the at least one tensile element (3, 3') has a thread (6) at least at one end.
3. Hollow profile according to claim 1 or 2, characterised in that the tensioning element (4) serves as a counter bearing and the tension is applied directly to the tensile element (3, 3').
4. Hollow profile according to claim 1, characterised in that the base element (13, 13') has at least one wedge surface and in that a tensioning body (14, 14') is adjustable in the direction transverse to the tensile element (3, 3') by means of the tensioning screw (16, 16') relative to the base element (13, 13') such that the tensile element (3, 3') can be tensioned.
5. Hollow profile according to claim 1 or 4, characterised in that the end of the tensile element (3, 3') is fastened directly to the wedge element (15, 15').
6. Hollow profile according to claim 4 or 5, characterised in that the base element (13,13') and the tensioning body (14,14') engage into one another to achieve a forced guidance.
7. Hollow profile according to claim 6, characterised in that the base element (13) and the tensioning body (14) engage into one another by means of a tongue and groove connection (19/20).
8. Hollow profile according to any one of claims 1 to 7, characterised in that over the length of the tensile element (3, 3') in the interior of the hollow profile at least one support element (5) is provided to fix the position of the tensile element (3, 3') in the free cross-section of the hollow profile.
9. Hollow profile according to claim 8, characterised in that in the hollow profile a plurality of support elements (5) are present such that the tensile element (3, 3') can be tensioned in the hollow profile as a support structure.
10. Hollow profile according to any one of claims 1 to 9, characterised in that the hollow profile is a transom profile (1, 1').
11. Hollow profile according to any one of claims 1 to 9, characterised in that the hollow profile is a post profile (2).
12. Hollow profile according to any one of claims 1 to 9, characterised in that the hollow profile is a rafter profile (21).
13. Hollow profile according to any one of claims 1 to 12, characterised in that the tensile element (3, 3') is designed as a tensile rod.
14. Hollow profile according to any one of claims 1 to 12, characterised in that the tensile element is designed as a traction rope.
15. Hollow profile according to any one of claims 1 to 14, characterised by a modular structure.
16. Use of a tensioning device to reinforce hollow profiles according to any one of claims 1 to 15 to calculate and set a desired load-dependent pre-tension in a hollow profile to be installed, characterised by the following steps:

    - carrying out a static pre-dimensioning for a determined profile taking into account the known static loads,

    - calculating the theoretic load-dependent bending,

    - pre-tensioning the hollow profile to a specific value (d) to avoid excessive bending in the installation state.

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