US20100319299A1

US20100319299A1 - Profile arrangement with connecting elemet for sectional girders

Info

Publication number: US20100319299A1
Application number: US12/800,892
Authority: US
Inventors: Gabriel Schierscher; Lukas Mundwiler; Lorcan Kemple
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2009-05-27
Filing date: 2010-05-25
Publication date: 2010-12-23
Also published as: AU2010201916B2; DE102009026512A1; EP2256354A1; AU2010201916A1

Abstract

A profile arrangement (11) has two coaxially serially disposed sectional girders (12) and having a connecting element (16), the connecting element (16) having a value of its section modulus (Wy1) that differs maximally by 10% from the value of the corresponding section modulus (Wy2) of the sectional girders (12).

Description

This claims the benefit of German Patent Application DE 10 2009 026 512.0, filed May 27, 2009 and hereby incorporated by reference herein.
The present invention relates to a profile arrangement.

BACKGROUND

These types of profile arrangements are used, for example, as parts of a load-bearing structure that rests on a plurality of supports. In particular, in the case of solar park installations, frame structures having such profile arrangements are erected, upon which solar modules are mounted.
Since the sectional girders, i.e. profile supports, are mostly available in standard lengths, it is necessary to interconnect a plurality of coaxially serially disposed sectional girders at the butt joints thereof by a connecting element in order to construct longer sections.
A profile arrangement having two coaxially serially disposed sectional girders and having a connecting element that is introduced into the end regions of the sectional girders to join the same is known from the German Utility Model Patent 93 00 403 U1.
The disadvantage of the known approach is that the butt joints of the known profile arrangement have a lower load-carrying capacity than the sectional girders themselves. Therefore, for static reasons, it is not possible to select any given butt joint of the sectional girders, particularly in the case of a profile arrangement in the form of a multiple-span girder that rests on a plurality of supports, since, otherwise, the load on the connection that is created is too great.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a profile arrangement which will overcome the aforementioned disadvantages and which will be flexible in design.
The present invention provides a profile arrangement having at least two coaxially serially disposed sectional girders and having a connecting element for joining the sectional girders. In accordance with the present invention, the connecting element has a section modulus value that differs maximally by 10% from the corresponding section modulus value of the sectional girders.
Thus, the connecting element has essentially the same load-carrying capacity as that of the sectional girders joined by it. The section modulus of the connecting element is maximally 10% higher or lower than the corresponding section modulus of the sectional girders. The section modulus is the measure of the resistance by which a component of a given cross section opposes a bending moment.
Since the butt joint created essentially has the same load and deformation coefficients as a non-separated sectional girder, the position of the butt joint is selectable independently of the position of a support. As a result, more flexible profile arrangements are possible, and remainder pieces of already cut-to-length sectional girders may be used, which otherwise would have to be disposed of.
The outlay required for the installation, respectively for the assembly, as well as for planning is significantly reduced in comparison to conventional profile arrangements. This rules out any faulty installation with respect to the selection of the butt joints, which could otherwise lead to a loss of load-carrying capacity of the construction. Moreover, flexible girder structures may be erected without having to resort to using preset standard lengths or standard systems.
Preferably, the difference in the values of the corresponding section moduli is maximally 5%, whereby the load-carrying capacity of the connecting element is even closer to the load-carrying capacity of the sectional girders.
The connecting element is preferably a peripherally closed, hollow profile section, which, in comparison to a connecting element having a solid cross section, requires less material and, therefore, may be economically manufactured. In addition, a connecting element of this kind is lighter and, therefore, easier to manipulate. The connecting element advantageously has flexible wall sections which simplify its placement at the end regions of the sectional girders.
Material accumulations are preferably provided at the mutually opposing sides of the hollow profile section which extend in parallel to the corresponding resistance axis. The material accumulations render possible an optimized design of the basic cross-sectional area of the connecting element and thus a simple adaptation, respectively approaching of the section modulus of the connecting element to the corresponding section modulus of the sectional girders to be joined. The selectively configured material accumulations allow a greatest possible section modulus of the connecting element using as little material as possible. Particularly in the case of a connecting element having an asymmetrical cross section, correspondingly provided material accumulations are advantageous for optimizing the connecting element in terms of its section modulus. The material accumulations make it possible for the side walls of the hollow profile section to have a relatively thin design between the sides having the material accumulations, thereby simplifying the placement of self-drilling screws in this area.
Preferably, the connecting element is introduced into end regions of the sectional girders to join the same, and the insertion depth of the connecting element into one of the sectional girders is 50 to 500 mm, the lower value ensuring a minimal anchoring of the connecting element in the corresponding sectional girder for the transmission of forces, and the upper value ensuring the compensation of tolerances between the outside of the connecting element and the inside of the end region of the corresponding sectional girder. It is particularly advantageous that the depth of insertion of the connecting element into one of the sectional girders be 75 to 200 mm.
The sectional girders advantageously have at least one inwardly projecting crimping in at least one of the side walls thereof, the at least one crimping narrowing the interior cross section of the sectional girder in some areas. The connecting element advantageously has at least one stop shoulder on the outer side thereof that is configured in such a way that it is able to be brought into contacting engagement with one region of the at least one crimping; and the connecting element is still introducible into the sectional girder. In response to a displacement of the connecting element in the plane of the cross section, the stop shoulder grips behind the corresponding crimping region, thereby allowing the connection to be loaded with substantial forces in spite of tolerances between the connecting element and the sectional girder.
The connecting element mounted on the sectional girder is advantageously fixed thereto by a fixing means, such as a screw or a bonding agent, thereby providing a connection having a substantial load-carrying capacity for the sectional girders. The connecting element may be fixed, for example, to only one of the sectional girders, so that the subsequent sectional girder is still able to slide on a section of the connecting element. It is thus possible to compensate for longitudinal expansions of the sectional girders, caused, for example, by temperature fluctuations, within the structures without inducing tensile stress.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in greater detail below with reference to an exemplary embodiment. In the drawing,

FIG. 1: shows a profile arrangement in one view;

FIG. 2: is a detail view of a butt joint of two profiles; and

FIG. 3: illustrates a section along line III-III in FIG. 2 in an enlarged representation.

In general, identical or corresponding parts are provided with the same reference numerals in the figures.

DETAILED DESCRIPTION

FIG. 1 shows a load-bearing structure 6 for solar panels which have four profile arrangements 11 supported on supports 7. In this example, each profile arrangement 11 has two coaxially serially disposed sectional girders 12, which are joined at butt joints 13 thereof by a connecting element 16. Each connecting element 16 is introduced into the corresponding end region of sectional girders 12 to join the same. Sectional girders 12 are hollow profile sections which are formed as extruded sections of aluminum, for example.
Each connecting element 16 (see FIG. 3) has a value of its section modulus Wy1 that differs maximally by 10%, advantageously maximally by 5%, from the value of the corresponding section modulus Wy2 of sectional girders 12. Connecting element 16 is a peripherally closed, hollow profile section that is fabricated as an extruded section of aluminum, for example. Connecting element 16 has an asymmetrical cross section, which is designed for introduction into the end region of sectional girder 12 in conformance with interior cross-section 14 thereof. Material accumulations 19 and 20 are provided at mutually opposing sides 17 of the hollow profile section which extend in parallel to corresponding resistance axis 18, whereby the loadable cross-sectional area of connecting element 16 is optimized relative to section modulus Wy1.
At mutually opposing side walls, sectional girders 12 each have an inwardly projecting crimping 15 which narrows interior cross section 14 of sectional girder 12 in some areas. Connecting element 16 has relatively thin side walls 21, as well as at least one stop shoulder 22 on each outer side thereof. Stop shoulders 22 are configured in such a way that connecting element 16 is still introducible into sectional girders 12; and, in response to a displacement of connecting element 16 in the plane of the cross section, at least one of stop shoulders 22 is able to be brought into contacting engagement with one region of crimping 15, thereby at least partially gripping behind this region of crimping 15.
Depth of insertion T of connecting element 16 into one of sectional girders 12 is 50 to 200 mm, advantageously 75 to 200 mm. A section of connecting element 16 that is introduced into sectional girder 12 is fixed to a sectional girder 12 by a fixing means in the form of a screw 8 (see FIG. 2).

Claims

1. A profile arrangement comprising:

at least two coaxially serially disposed sectional girders; and

a connecting element for joining the sectional girders, the connecting element having a value of its section modulus differing maximally by 10% from a further value of the corresponding section modulus of the sectional girders.

2. The profile arrangement as recited in claim 1 wherein the difference in the values of the corresponding section moduli is maximally 5%.

3. The profile arrangement as recited in claim 1 wherein the connecting element is a peripherally closed, hollow profile section.

4. The profile arrangement as recited in claim 3 wherein material accumulations are provided at mutually opposing sides of the hollow profile section extending in parallel to a corresponding resistance axis.

5. The profile arrangement as recited in claim 1 wherein the connecting element is introduced into end regions of the sectional girders to join the sectional girders, and the insertion depth of the connecting element into one of the sectional girders is 50 to 500 mm.

6. The profile arrangement as recited in claim 5 wherein the insertion depth of the connecting element into the one of the sectional girders is 75 to 200 mm.