JP2017508440A - Lattice mast with open framework structure, in particular mast for transmission lines or communication lines, and method for enhancing the stability of grid mast with open framework structure - Google Patents

Abstract

The present invention relates to a lattice mast (1) having an open framework structure composed of a cornered profile (3), and particularly to a mast for a transmission line or a communication line. The lattice mast includes one or more cladding profiles (9a, 9b) extending over at least a portion of the length of at least one angular profile (3), the at least one cladding profile having a curved inflow The inflow shielding portion of the window exposed edge of the angular profile (3) is formed, and the inflow surface is curved in a substantially spherical shape and is not shielded. The flow resistance coefficient is smaller than the flow resistance coefficient.

Description

  The present invention relates to a lattice mast having an open framework structure composed of an angled profile (hereinafter also referred to as an angled profile), and more particularly to a power transmission line or communication line mast.

  The invention further relates to a method for increasing the stability of a grid mast having an open framework structure of angled profiles, in particular a transmission line or communication line mast.

  In the gist of the present invention, a lattice mast should be understood as a mast for holding, for example, an overhead power transmission line. Similarly, the communication line mast should be understood as a lattice mast in the spirit of the invention. In any case, the lattice mast having an open framework structure may be a lattice mast in a bridge or a steel tower. Finally, the lattice mast may be a mast for holding the wind power generator in the spirit of the invention.

  An open framework structure is to be understood in the context of the present invention as a framework structure that is not used for continuous residence or residential purposes, whose struts are not provided with gap filling.

  The aerodynamic cladding according to the invention is provided for an open framework structure with an angular profile.

  The framework structure including the angular profile has the following advantages. That is, they are particularly lightweight and furthermore the individual profile struts have the advantage that they can be interconnected relatively easily, for example by rivets, welds or bolts.

  Such grid masts are usually constructed from a series of structural elements arranged one above the other, where each stage has three or more trapezoidal framework panels, each with a reinforced angular support. A framework structure consisting of the body is formed. These angular supports are configured as angular profiles, and the struts connecting them may also be partially configured as angular profiles and partially as plate profiles.

  The design of such a framework structure is generally dependent on the requirements for supporting loads and wind loads acting on the building.

  The distribution or dimensions of the components forming the framework structure depend on the one hand on the free buckling length of the individual elements, i.e. on the tensile or compressive stress that dominates in them, and on the other hand, for example by wind loads. Depends on the interaction of longitudinal and lateral stresses on the building.

  For the stabilization of this type of grid structure or framework structure, many bracing systems are known that are optimized with respect to the arrangement of framework struts and with respect to the total weight of the grid structure. Such a system is described, for example, in British Patent Application Publication No. 675859.

  When creating a new framework structure, the optimal design of the framework structure for the wind and support loads expected in connection with weight optimization is usually not a problem. In the case of existing framework structures, for example in the case of existing grid masts for overhead transmission lines, it is sometimes necessary to modify and / or replace part of the structure. This may require new stability proofs in some cases. Existing equipment may fail to meet increased stability requirements, in some cases, especially due to increased load requirements or due to structural weakening expected over a relatively long lifetime.

  In such a case, it may be necessary to perform troublesome holding and wire fixing in some cases.

  The problem on which the present invention is based is to provide a lattice mast having a design that can be manufactured relatively easily in the course of a later upgrade.

  It is a further object of the present invention to provide a suitable method for increasing the stability of the lattice mast in the course of later upgrades.

  The problem is solved in particular by the characterizing part of claim 1 and the characterizing part of claim 11.

  Preferred variant embodiments of the lattice mast according to the invention as well as preferred variant embodiments of the method according to the invention for increasing the stability of the lattice mast emerge from the dependent claims.

  According to one aspect of the present invention, a grid mast having an open framework structure composed of a cornered profile, in particular a mast for a power transmission line or a communication line, over a part of the length of at least one cornered profile. One or more cladding profiles extending in this case, where at least one cladding profile has an inflow surface and forms an inflow shield at the window exposed edge of the angular profile, where the inflow surface is The flow resistance coefficient is smaller than the flow resistance coefficient of the unshielded angular profile.

  Preferably, the inflow surface is at least approximately spherically curved or has a polygonal or faceted contour approximating a spherical or elliptical arc contour. Faceted shape is to be understood in the context of the present invention as meaning a polygonal surface approximating an arc contour.

  In the present invention, the angled profile should be understood to mean, for example, a T-shaped profile, an L-shaped profile, an I-shaped profile, a Z-shaped profile, a U-shaped profile, a C-shaped profile, and the like.

  The present invention utilizes the fact that the wind load on the building is determined from the product of the reference pressure using the flow resistance coefficient and the exposed area of the building. The reference pressure depends on air density and wind speed. The flow resistance coefficient here represents the characteristics of the wind flow around the structural elements of the relevant framework structure, for example the angular profile. The sharp edges of the profile tend to generate turbulence and are therefore more prone to wind loads than faceted or rounded edges or circular or tubular profiles. The octagon, for example, has a flow resistance coefficient of Cw = 1.3 compared to the flow resistance coefficient Cw = 2.0 in the case of a sharp edged angular profile.

  If the fluid velocity of the laminar flow initially increases and the laminar flow characteristics change independently and then unstably, then the initial orderly flow transitions to a wavy state. As a result, the flow resistance coefficient is greatly increased. At sharp profile edges, the flow resistance coefficient Cw (dimensionless) can be as large as about 2.0. In contrast, the flow resistance coefficient for rounded elements, for example including spherical elements, is between about 0.176 and 0.48, depending on the Reynolds number. For very large Reynolds numbers, the resistance coefficient of the sphere increases, whereas for relatively small Reynolds numbers it can take a low value.

  The present invention makes use of these per se known flow mechanism relationships. By providing a correspondingly coated grid mast, the flow resistance coefficient of at least a portion of the exposed angular profile can be significantly reduced, thereby reducing wind loads on the building as well. Is done. In the simplest case, this can be achieved, for example, by shielding at least one exposed critical edge of the angled profile with a cladding profile. In this case, the cladding profile has a rounded or curved inflow surface. In the case of a lattice mast, for example, all or part of the corner posts or corner profiles can be provided so as to be shielded by the corresponding cladding profile. These cladding profiles may for example be fixed only over a part of the length of the relevant angular profile, or the angular profile may be shielded only over a part of the respective length. Good. Similarly, within the framework of the invention, it is also possible to cover only the framework node points accordingly.

  According to a further aspect of the invention, the cladding profile has a variable cross-section along the angled profile to be coated in order to prevent the possibility of eddy current triggering or to optimize aerodynamic damping. It may be implemented together.

  In the case of a lattice mast structure, for example, the associated cladding profile may be arranged such that it shields the top of the angular profile that forms, for example, an isosceles triangle in cross section.

  In the case of a lattice mast structure with three or four corner posts, the configuration is usually selected so that the corner posts are configured as a cornered profile having a substantially isosceles triangular cross section. The vertices of the relevant angular profile in that case are directed outwards. These vertex coatings provide a substantial reduction in wind loads.

  Preferably, the curved inflow surface of at least one cladding profile is arranged symmetrically with respect to the associated profile edge.

  The cladding profile includes particularly lightweight plastic, aluminum or steel profiles, which may be configured as complete profiles as well as shell-like elements.

  According to a preferred variant embodiment of the grating mast according to the invention, the at least one cladding profile is at most 60%, preferably at most 40%, even more than the maximum projected area of the uncoated angular profile. Preferably, it has a maximum projected area that is up to 20% larger. This ensures that the inflow surface for the calculation of the wind load does not increase so as to completely eliminate the advantages of the reduced flow resistance coefficient compared to the uncoated profile.

  For example, in the case of a cladding profile having a generally arcuate inflow surface, the diameter of the associated cladding profile can be up to 20% larger than the diagonal of the angled profile configured as a corner corner profile.

  It should be understood that an approximately spherically curved inflow surface in the context of the present invention also means an elliptical, parabolic or asymmetrically curved inflow surface.

  Variations of the grating mast according to the invention are characterized in that the at least one cladding profile forms a structural unit with at least one angular profile.

  In the context of the present invention, a structural unit is to be understood that the cladding profile and the associated angular profile complement each other to form a part that accepts and supports the load.

  At least one cladding profile is said at least one angled using one or more fixed types selected from the group comprising adhesion, rivet, welding, clamping, hook-and-loop fastening, fastening, screwing, stapling or forming Can be connected with a profile. Combinations of these fixed types are also possible. For example, one clad profile can be bonded to an associated angular profile, but these can also be fastened simultaneously using a strap, band, etc. to clamp and fix the angular profile and the cladding profile.

  According to a preferred embodiment of the present invention, the at least one cladding profile complements the angled profile to form one closed profile cross section. It should also be understood here that, for example, the cladding profile closes or covers only one open side of the angular profile.

  Instead of the cornered profile being complemented to form a closed profile cross-section, the at least one cladding profile also partially or more completely surrounds the angled profile and is a closed or nearly closed profile. A cross section may be formed. For this purpose, for example, the cladding profile may comprise a plurality of elements interconnected via hinges, for example film hinges.

  Alternatively, the plurality of cladding profiles may form a closed or substantially closed contour profile that at least partially surrounds the angular profile. These clad profiles may be connected to each other, for example, releasably, or alternatively secured thereto in a manner that grips the angular profiles using a clamping element in such a way that they partially overlap, for example. May be. According to a preferred advantageous variant of the coating, the cladding profiles are complemented to form a closed or nearly closed spherical or elliptical cross section. A profile cross-section formed by one or more cladding profiles can completely encompass the angular profile. This contour cross-section does not necessarily have to be symmetrical, but rather these cladding profiles can also form an asymmetric elliptical cross-section.

  This can be achieved, for example, by providing two clad profiles configured as shell-like profile segments with different radii of curvature, in which case one clad with a first radius of curvature. The profile and the second cladding profile with the second radius of curvature are complemented to form one closed profile cross-section to encompass the angular profile. In this case, the first radius of curvature is preferably smaller than the second radius of curvature, and the first radius of curvature surrounds the exposed edge of the angular profile to be closed.

  If the angular profile to be covered is, for example, an angular profile with two profile legs and one apex, the apex is defined by a first cladding profile with a first small radius of curvature. While the open side of the angular profile can be shielded, it is shielded by a second cladding profile with a second large radius of curvature. In this way, an inflow surface is defined by the first angled profile, through which air flow is drawn through the free ends of the legs of the angled profile.

  At least one or more cladding profiles can be configured as a shell-like profile segment, as described above, and alternatively, in particular, one or more cladding profiles are each one of the contour cross-sections of the angular pull file. If complements are to be formed, they may also be configured as a complete profile.

  The shell-like profile segment may be placed at a distance with respect to the associated angular profile, for example the shell-like profile segment may be attached at a distance to the angular profile via the web. it can.

  According to a preferred variant embodiment of the invention, at least one or more cladding profiles are backformed, in which case the foam simultaneously provides a means of adhesion to the associated angular profile.

  The at least one or more cladding profiles can be configured as shell-like profile segments, and their free edges are extended by fringe, fiber or perforated profiles. In particular, such a configuration of the profile leg can prevent the formation of vortex flow at the free end of the profile leg. This also provides a relatively good aerodynamic effect.

  According to a further aspect of the present invention, there is provided a method for increasing the stability of a grid mast having an open framework structure of angled profiles, in particular a transmission line or communication line mast, using at least one cladding profile. Proposed and in this case the method comprises a coating of at least one angular profile having a cladding profile, said cladding profile having at least one inflow surface which is at least approximately spherically curved or faceted, At least one window exposed edge of the angular profile is shielded by an associated cladding profile, the angular profile being at least partially, at least partially and at least partially closed or substantially closed. Approximately circular It is complemented or coated so as to form a faceted profile sections.

  This method is preferably characterized by a later version upgrade of the lattice mast to form an aerodynamically coated lattice mast with any of the features described above.

  According to a preferred variant embodiment of the method according to the invention, the angular profile is such that the cladding profile, in particular the cladding profile configured as a structural unit with such an angular profile, overlaps at the node points of the framework structure. And / or connected to each other by frictional bonding, shape bonding, or material bonding, for example, by gluing, insertion, clamping, bolting, or screwing. In this way, the entire support function of the original framework structure can be replaced by an exoskeleton comprising a plurality of cladding profiles.

  In such a variant embodiment of the method, the cladding profiles are preferably connected to each other and / or to the angular profiles only at the node points of the framework structure.

  Although the above description has referred to various variant embodiments of the aerodynamic coating of a plurality of grid masts, in this case the variant embodiments of the coating described above can also be applied in combination in a single grid mast. It is.

  Also, within the framework of the present invention, it is possible to aerodynamically cover all profiles and profile struts of the framework structure, and in this case as well, only a part of the grid mast or framework Only these nodes can be covered accordingly.

  The cladding profile can be formed as individual profile shell segments, as individual complete profile elements, or from a plurality of profile segments closely connected to one another.

  The method preferably includes fixing the cladding profile in a lattice mast having a framework structure using at least one climbing robot.

  Hereinafter, the present invention will be described based on an embodiment shown in the drawings.

Schematic diagram of a grid mast as an overhead power transmission mast for holding overhead power lines 1 is a cross-sectional view of the corner support member of the lattice mast shown in FIG. 1 with an aerodynamic coating according to a first variant embodiment of the invention 1 is a cross-sectional view of a corner mast of the lattice mast shown in FIG. 1 with an aerodynamic coating according to a second variant embodiment of the invention as an exploded view.

Detailed Description of the Invention The lattice mast 1 of Fig. 1 is configured as a conventional open framework structure with four corner posts 2, which in the case of the present invention are two legs of the same length. It is configured as an open angular profile 3 with a part 4 and a vertex 10.

  As can be seen in FIG. 1, the lattice mast requires a relatively large installation area in its installation region, and the four corner corner struts 2 of the lattice mast 1 converge toward the mast tip 5 direction. Two corner support posts each form a mast stage trapezoidal panel together with the cross strut 6. Each mast stage is represented by a total of four trapezoidal panels, and the plurality of mast stages extend in the height direction from the base portion of the lattice mast 1 toward the mast tip 5 thereof. Each panel of the grid mast 1 stage is configured as a framework structure with diagonally extending struts, which function as push rods or tension rods depending on the level of lateral load of the grid mast 1 To do. The shape of the grid mast 1 that tapers in the direction of the mast tip 5 bears the bending stress of the grid mast 1 estimated based on the wind load and the track support load. The track 7 is suspended from the mast cross arm 8 by a known method. The geometric shape of the mast cross arm 8 is adapted to the bending moment distribution estimated due to the weight of the line 7.

  FIG. 2 showing the first embodiment according to the present invention shows a cross-sectional view of the corner support 2 of the lattice mast 1 as the angular profile 3 in the gist of the present invention.

  The cross struts 6 provided on the grid mast 1, the diagonal struts provided thereon and other components can likewise be correspondingly aerodynamically coated as a angular profile within the spirit of the invention.

  Two cladding profiles are fixed to the corner post 2 as an aerodynamic coating, and the first cladding profile 9a of them is configured as a profile shell segment having a first radius of curvature, The second cladding profile 9b is configured as a second profile shell segment having a second radius of curvature.

  Both the first cladding profile 9a and the second cladding profile 9b may be configured, for example, in the form of a plastic shell, which can be glued, screwed, riveted, stapled or otherwise formed with the angular profile 3. Connectable. The first cladding profile 9a is configured as a curved profile shell with a first relatively small radius of curvature, while the second cladding profile 9b has a second relatively large radius of curvature. Similarly designed as a curved profile shell. These two cladding profiles 9a, 9b completely surround the angular profile and form a closed, asymmetric elliptical cross section.

  The first cladding profile 9a forms an inflow surface that shields and surrounds the apex 10 of the angular profile 3 that is configured symmetrically. The first cladding profile 9a is connected to or fixed to the angular profile in the end region of the leg 4 of the symmetrical angular profile 3. The second clad profile 9b covering and shielding the open side opposite to the apex 10 of the angular profile 3 has a relatively large radius of curvature, and similarly, the leg 4 of the angular profile 3 It is fixed to the angular profile 3 in the end region.

  In the embodiment shown in FIG. 2, the flow shield of the apex 10 is mainly provided, and the first cladding profile 9a is accordingly arranged symmetrically with respect to the apex 10, and the flow profile winds. The upper side is formed, while the second cladding profile 9b forms the leeward side.

  In the drawing, the covering surrounding the angled profile 3 as a whole is configured to be closed, but it should be understood that the present invention does not necessarily require the profile surface to be completely closed. On the contrary, this profile surface can also be configured such that the leeward side (second cladding profile 9b) is only partially closed.

  As can be seen in particular in the depiction of FIG. 2, the maximum diameter of the first cladding profile 9 a, and thus the maximum diameter of the contour profile of the entire coating, is 1.. 2 times bigger. In other words, the projected area of the completely covered angular profile 3 is 1.2 times larger than the projected area of the uncovered angular profile 3.

  Also in the variant embodiment of the aerodynamic coating shown in FIG. 3, a first cladding profile 9a and a second cladding profile 9b are provided, each configured as a complete profile, Similarly, it is connected to the leg portion 4 of the angular profile 3 in a shape coupling or material coupling manner. The clad profiles 9a and 9b according to the second embodiment are asymmetrical elliptical shapes and complement the symmetrical angular profile 3 so as to form a contour that approximates a circular cross section.

DESCRIPTION OF SYMBOLS 1 Lattice mast 2 Corner corner support 3 Angled profile 4 Leg 5 Mast tip 6 Cross strut 7 Line 8 Mast cross arm 9a 1st clad profile 9b 2nd clad profile 10 vertex

From DE 1509022, a crane structure is known which is at least partially covered by a freely flowable, rotatably supported hollow profile, whereby the direction of wind flow is set. It is.
From British Patent Application No. 8700379.1, a support for a radio communication mast with a protective covering made of concrete in the leg region is known.
Further prior art is known from Japanese Patent Application Laid-Open No. 2002-276200 and Chinese Patent Application No. 102155106.
The problem on which the present invention is based is to provide a lattice mast having a design that can be manufactured relatively easily in the course of a later upgrade.

  The at least one cladding profile is configured as a shell-shaped profile segment, as described above, and alternatively, in particular, the one or more cladding profiles are each complementary to one contour cross-section of the angular pull file. If a body is to be formed, they may also be configured as a complete profile.

  According to the invention, at least one cladding profile is backformed, in which case the foam simultaneously provides a means of adhesion to the associated angular profile.

Claims (15)

Lattice mast (1) having an open framework structure consisting of an angular profile (3), in particular for a transmission line or a communication line mast,
One or more cladding profiles (9a, 9b) extending over at least part of the length of the at least one angular profile (3),
At least one cladding profile (9a, 9b) has an inflow surface and forms an inflow shield at the window exposed edge of said angular profile (3);
Lattice mast (1), characterized in that the inflow surface has a flow resistance coefficient smaller than the flow resistance coefficient of the angular profile (3) which is not shielded.   The lattice mast according to claim 1, wherein the inflow surface is at least substantially spherically curved or has a polygonal outline at least approximating a spherical or elliptical arc outline.   The grating mast according to claim 1 or 2, wherein the curved inflow surface of the at least one cladding profile (9a, 9b) is arranged symmetrically with respect to the edge.   Said at least one cladding profile (9a, 9b) is at most 60%, preferably at most 40%, even more preferably at most 20% than the maximum projected area of the unwrapped angular profile (3) The lattice mast according to any one of claims 1 to 3, wherein the lattice mast has a large maximum projected area.   The grating mast according to any one of claims 1 to 4, wherein the at least one cladding profile (9a, 9b) forms a structural unit with the at least one angular profile (3).   Said at least one clad profile (9a, 9b) using one or more fixed types selected from the group comprising adhesive, rivet, weld, clamp, hook-and-loop fastener, fastening, screwing, stapling or forming The lattice mast according to claim 1, wherein the lattice mast is fixed to the at least one angular profile.   A plurality of cladding profiles (9a, 9b) form a structural unit with each other and / or with the at least one angular profile (3) of the framework structure across the nodes of the framework structure The lattice mast according to any one of claims 1 to 6, which is connected.   Lattice mast according to any one of the preceding claims, wherein the at least one cladding profile (9a, 9b) complements the angled profile (3) to form a closed profile cross section.   The plurality of cladding profiles (9a, 9b) form a closed or substantially closed contour profile that at least partially encompasses the angular profile. The lattice mast described in the section.   The grating according to any one of the preceding claims, wherein the plurality of cladding profiles (9a, 9b) are complemented to form a closed or substantially closed spherical or elliptical cross section. mast.   The lattice mast according to any one of claims 1 to 10, wherein at least one of the cladding profiles (9a, 9b) is configured as a shell-like profile segment.   The lattice mast of claim 11, wherein the at least one cladding profile (9a, 9b) is backformed.   The at least one shell-like profile segment includes a profile leg, and at least one free end of the at least one profile leg is worn or has a plurality of bands or holes 13. A grid mast according to claim 11 or 12, having at least one additional hole profile that reduces flow resistance and / or increases aerodynamic damping. A method for improving the stability of a grid mast having an open framework structure consisting of a cornered profile, particularly a transmission line or communication line mast, using at least one cladding profile,
Comprising at least one angular profile coating having the cladding profile;
The cladding profile has at least one inflow surface curved at least approximately spherically, at least one window exposed edge of the angled profile is shielded by the cladding profile, and the angled profile is at least partially A method characterized in that it is supplemented or covered so as to form at least partly a circular or faceted profile cross-section, which is substantially closed or substantially closed.   15. The method of claim 14, wherein a later version upgrade of the lattice mast is performed to form an aerodynamically coated lattice mast according to the method of any one of claims 1-13.

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