阅读说明：本技术 木材连接件和包括多个这样的木材连接件的层压的木材塔 (Wood connector and laminated wood tower comprising a plurality of such wood connectors ) 是由 埃里克·多勒罗德 安德斯·维克斯特伦 于 2020-05-07 设计创作，主要内容包括：一种用于大的木制构造物的木材连接件(1),包括：第一木材模块(2)、第二木材模块(3)和穿孔钢板(4),该穿孔钢板(4)包括多个孔(12),其中,第一木材模块(2)和第二木材模块(3)包括多个层压的木材层(17),其中,每个木材层包括多个层压的单板层片(18),其中,穿孔钢板(4)的第一部分(14)利用胶水安装在第一木材模块(2)中,并且其中,穿孔钢板(4)的第二部分(15)利用胶水安装在第二木材模块(3)中,其中,穿孔钢板(4)的中心线(13)与位于第一木材模块(2)与第二木材模块(3)之间的分隔线对准,并且其中,穿孔钢板(4)具有超过700兆帕的抗拉强度,并且木材模块(2、3)至少是6cm厚并且具有超过20兆帕的抗拉强度。(A wood attachment (1) for large wooden structures comprising: a first wood module (2), a second wood module (3) and a perforated steel plate (4), the perforated steel plate (4) comprising a plurality of holes (12), wherein the first wood module (2) and the second wood module (3) comprise a plurality of laminated wood layers (17), wherein each wood layer comprises a plurality of laminated veneer plies (18), wherein a first portion (14) of the perforated steel plate (4) is mounted in the first wood module (2) with glue, and wherein a second portion (15) of the perforated steel plate (4) is mounted in the second wood module (3) with glue, wherein a centre line (13) of the perforated steel plate (4) is aligned with a separation line between the first wood module (2) and the second wood module (3), and wherein the perforated steel plate (4) has a tensile strength exceeding 700mpa, and the wood modules (2, b, 3) At least 6cm thick and having a tensile strength in excess of 20 mpa.)

1. A wood-connecting element (1) for large wooden constructions, comprising: a first wood module (2), a second wood module (3) and a perforated steel plate (4), the perforated steel plate (4) comprising a plurality of holes (12), wherein the first wood module (2) and the second wood module (3) comprise a plurality of laminated wood layers (17), wherein each wood layer comprises a plurality of laminated veneer plies (18), wherein a first portion (14) of the perforated steel plate (4) is mounted in the first wood module (2) with glue, and wherein a second portion (15) of the perforated steel plate (4) is mounted in the second wood module (3) with glue, wherein a centre line (13) of the perforated steel plate (4) is aligned with a separation line between the first wood module (2) and the second wood module (3), characterized in that the perforated steel plate (4) has a tensile strength exceeding 700mpa, and the wood modules (2, 3) are at least 6cm thick and have a tensile strength exceeding 20 mpa.

2. Wood connector according to claim 1, characterized in that the perforated steel sheet (4) is arranged perpendicular to the inner (21) and outer (22) surfaces of the laminated wood modules (2, 3).

3. A timber connection according to claim 1 or 2 wherein the timber modules (2, 3) are flat.

4. The wood connection according to claim 1 or 2, characterized in that the wood modules (2, 3) are curved in the longitudinal direction of the wood modules (2, 3).

5. The wood connection according to claim 4, wherein the laminated wood layer (17) comprises: a first set of plies (19), the first set of plies (19) comprising a plurality of veneer plies (18), and the wood grain of the first set of plies being oriented in a first direction; and a second set of plies (20), the second set of plies (20) comprising one or more veneer plies (18) arranged adjacent to each other and the wood grain of the second set of plies being oriented in a second direction, wherein the first direction is perpendicular to the second direction.

6. The wood connection according to any one of the preceding claims, characterized in that the first portion (14) and the second portion (15) of the perforated steel plate (4) are symmetrical with respect to the centre line (13) of the perforated steel plate (4), and wherein the width of the perforated steel plate is at least 60mm and the length of the perforated steel plate is at least 500 mm.

7. Wood connector according to any one of the preceding claims, characterised in that the holes (12) of the perforated steel plate (4) are circular, wherein the diameter of each hole is 10 mm.

8. The wood connection according to any one of the preceding claims, characterized in that the hole density of the perforated steel plate (4) adjacent to the centre line (13) of the perforated steel plate (4) is reduced.

9. Wood connector according to any one of the preceding claims, characterised in that each side edge of the perforated steel plate (4) comprises at least one protrusion (16), the at least one protrusion (16) extending 1mm over the surface of the perforated steel plate (4).

10. Wood connector according to any one of the preceding claims, characterized in that the distance from the centre line (13) to the hole (12) closest to the centre line (13) is at least 20 mm.

11. Wood connecting element according to any one of the preceding claims, characterized in that the perforated steel plate (4) comprises at least 6 holes (12).

12. Wood connector according to any one of the preceding claims, characterised in that the perforated steel plate (4) is at least 2mm thick.

13. The wood connection according to any one of the preceding claims, wherein the thickness of the ply (18) is between 1mm and 5 mm.

14. The wood connection according to any one of the preceding claims, characterized in that the laminated wood layer (17) comprises 5 to 15 plies.

15. A laminated wood tower, characterized in that the laminated wood tower (30) comprises a plurality of wood connectors (1) according to any one of claims 4 to 14.

Technical Field

The present invention relates to a joint for joining two wooden parts. Each wooden part is provided with at least one slit into which a perforated metal sheet is glued.

Background

Larger size wooden structures are becoming increasingly popular, whether for use in multi-story houses or other commercial wooden structures. Some buildings are designed to use steel or a combination of concrete and wood, and some are designed to use wood in both the load beam and the cladding.

One type of wooden building that is becoming more and more popular is a wooden tower, which can be used for many different purposes. For example, a wooden tower can be used as a transmitter mast or a wind power plant. A typical wind power plant is provided with a tower made of steel or concrete. The tower is attached to the ground by a foundation and is provided with a nacelle at the top of the tower for holding the generator, gearbox and rotor blades. Steel towers are typically assembled from steel rings bolted together or welded to each other. Concrete towers may be assembled from concrete parts that are joined together or may be cast by slip casting.

These conventional columns work well but have some drawbacks. One disadvantage is that they are heavy. Heavier towers require a very firm foundation which in turn requires a large amount of e.g. concrete. For efficiency reasons, wind power plants are often built in areas without roads, which complicates the transportation of the material to the site. Since the tower requires a large amount of material, a large amount of transportation is required. Another disadvantage is that the tower must be disassembled when the useful life of the tower is reached. In this case, all the material must be handled and transported again.

WO2010121733 proposes a wooden tower for a wind power plant. The proposed tower is built by using an inner frame made of planar elements to which the load-bearing coating is applied. The planar elements may be made of laminated plywood and/or wood composite. The planar elements may be connected by using perforated steel plates inserted into slits cut or arranged in the edges of the elements. Thereafter, the gap is filled with an adhesive which will glue the steel plate and the planar element together. A wood-steel connection of this type is described in detail in the German general construction administration approval No. Z-9.1-770 by DIBt (Deutsches institute fur Bautech ik, Germany institute of construction technology). This type of connection is suitable for transmitting tensile stresses up to 10 MPa.

US 5,966,892 shows a connector suitable for connecting two or more wooden elements to each other, where a metal plate is nailed and/or glued to the wooden elements, and where the wooden elements are connected with screws. US 5,660,492 shows a different type of wood connector, where the connector base is adhered in a wood pocket of a wood element.

These types of connectors are well suited for connections between wood elements where moderate forces are present, but there is still room for improvement in wood connectors with improved load bearing capabilities.

Disclosure of Invention

It is therefore an object of the present invention to provide an improved wood connecting piece for laminated wood modules, which comprises a veneer laminate. Another object of the invention is a laminated wood tower comprising a plurality of such wood connectors.

The solution to the problem according to the invention is described in the characterizing part of claim 1 for wood connectors and claim 15 for laminated wood towers. The other claims contain advantageous embodiments and further developments of the wood connecting element.

In a wood connector for a large wooden structure, the wood connector comprising: a first wood module, a second wood module and a perforated steel plate comprising a plurality of holes, wherein the first wood module and the second wood module comprise a plurality of laminated wood layers, wherein each wood layer comprises a plurality of laminated veneer plies, wherein a first part of the perforated steel plate is mounted in the first wood module with glue and wherein a second part of the perforated steel plate is mounted in the second wood module with glue, wherein a centre line of the perforated steel plate is aligned with a separation line between the first wood module and the second wood module, the invention achieves the object that the perforated steel plate has a tensile strength exceeding 700Mpa and the wood modules Mpa are at least 6cm thick and have a tensile strength exceeding 20 Mpa.

By this first embodiment of the wood connecting piece, a connecting piece is provided which can connect two laminated wood modules. By using high tensile strength perforated steel sheets with a tensile strength exceeding 700MPa, a connection is provided that is capable of handling the strength of a single-ply laminated lumber (LVL) module. Since the tensile strength of the single-plate laminate is in the range of 30MPa and the strength of the known DIBt connectors is in the range of 10MPa, the known DIBt connectors cannot exploit the full potential of the single-plate laminate. By using the known connecting element with a veneer laminate, the connecting element will be the limiting factor. The known connection is very suitable for connecting cross-laminated wood (CLT) modules having a tensile strength in the range of 10 MPa. Using the known connectors with laminated veneer lumber to transfer higher loads, the wall thickness of the module would have to be three times as thick as the known connectors to be able to handle loads up to 30 MPa. Such a solution would be impractical because an unnecessary amount of LVL would have to be used to allow the known connections to be able to handle higher loads, which would increase the weight and cost of the end construction. By using the wood connector of the present invention, the wood connector will match the tensile strength of the LVL module and will not limit the finished product. Thus, the wood connection will allow for example a higher laminated wood tower.

Tensile strength, also known as ultimate tensile strength, refers to the ability of a material or structure to withstand a load that tends to elongate the material or structure. In other words, tensile strength resists tensile forces. Tensile strength is measured by the maximum stress that a material can withstand before breaking when stretched or pulled. Tensile strength is determined by conducting tensile tests and recording engineering stress versus strain. Tensile strength is defined as stress, which is measured as force per unit area. In the international system of units (SI), the unit is pascal (Pa).

The wood module may be flat or may be curved in one direction and comprises a plurality of laminated wood layers, each layer comprising a plurality of laminated veneer plies. In a flat module, the orientation of the veneer layers may be selected as desired, for example, every other veneer layer is arranged in a perpendicular direction relative to the other veneer layers. Each layer may also comprise plies of veneer all oriented in the same direction, and wherein the plies of veneer of two adjacent layers are perpendicular.

For a curved module, each layer comprises a first set of plies, wherein the first set of plies comprises a plurality of plies arranged adjacent to each other, and wherein the wood grain is oriented in a first direction; and a second set of plies, wherein the second set of plies comprises one or more plies arranged adjacent to each other, and wherein the wood grain is oriented in a second direction, wherein the first direction is perpendicular to the second direction. By using a layer with a second set of plies with wood grain in a perpendicular direction with respect to the first set of plies, it is possible to bend the layers and in this way obtain a bent module with high tensile strength. In order to be able to connect the bent modules in a reliable and economical manner and at the same time to be able to maintain the tensile strength of the bent modules by means of the connections between the bent modules, perforated steel sheets with a tensile strength of more than 700MPa are used. By using the wood connecting piece of the invention, the total tensile strength of the veneer laminated wood module can be utilized in the finished product.

One advantage of the invention is that the wood modules can be connected to each other with connecting elements embedded in the wood modules. This simplifies the joining of the wood modules and allows for a smooth outside and a smooth inside of the finished product. Another advantage of embedding the connection is that the connection element is protected from the external environment. This is particularly advantageous for the outer surface of the finished product. It is also advantageous to have a smooth outer surface if the finished product is to be subjected to an external protective treatment, such as a protective film.

Wood, especially spruce or pine, is an inexpensive and strong material suitable for lamination of thin-ply sheets. Other fibers, such as bamboo fibers, may also be used, which may be laminated into a layer having fibers in a desired direction.

Each wood module is provided with a slot adapted to receive one half of a perforated steel sheet. Slits may be cut or arranged to the edges of the wood modules. In one example, the outer surface of the module is closed and the slit is provided from the closed wall of the outer surface to the inner surface. The perforated steel plate may be inserted from above or from the side of the wood module. The gap is slightly wider than the thickness of the perforated steel plate and preferably 2mm wider than the thickness of the perforated steel plate. During installation, the perforated steel sheet is further concentrated in the slits so that the glue can spread out evenly on both sides of the perforated steel sheet.

To this end, the perforated steel plate may be provided with a protrusion on each side, which protrusion will provide a distance means for the perforated steel plate. During manufacture, the protrusions are preferably stamped into the perforated steel sheet.

Each perforated steel plate includes a plurality of holes. Each hole may have a diameter of, for example, 10mm or more. The holes are positioned at a predetermined distance from the other holes and have a predetermined distance from the side of the perforated steel sheet. There is also a predetermined distance between the centerline of the perforated steel plate and the nearest hole. The apertures may be placed in rows and columns or may be positioned in an offset arrangement. The density of the holes in the perforated steel plate can also be varied. In one example, the hole density is reduced closer to the parting line between two wood modules.

When the perforated steel plate is positioned in the slit, glue is injected into the slit so that half of the steel plate is glued to the module. Preferably, the open side of the slit is covered before the glue is inserted, so that the slit is completely filled and the glue does not escape during hardening.

Preferably, the perforated steel plate is mounted to the wood module when the final product is assembled. The number of perforated steel plates used for the modules is determined by calculation of the required force that the joint must withstand.

The wood connectors can be used for different wood products made of laminated veneer layer modules. In one example, curved modules for a wind power plant are attached to each other using a plurality of wood connectors.

Drawings

The invention will be described in more detail below with reference to embodiments shown in the drawings, in which:

figure 1 shows an example of a wood joint according to the invention in a curved wood module,

figure 2 shows an example of a wood layer used in a wood module,

figure 3 shows an example of a perforated steel plate for use in a wood connecting piece according to the invention,

figure 4 shows another example of a perforated steel plate for use in a wood connecting piece according to the invention,

figure 5 shows an example of a laminated wood tower comprising a plurality of wood connectors according to the invention, an

Fig. 6 shows an example of a wind power tower according to the invention.

Detailed Description

The embodiments of the invention described below, which are further modified, are to be regarded only as examples and in no way limit the scope of protection provided by the patent claims. The directional references used refer to the direction of the wood modules that are bent when used in a laminated wood tower.

Fig. 1 shows a first example of a wood connecting piece. The wood connecting piece 1 comprises a first wood module 2, a second wood module 3 and a perforated steel plate 4. Both the first wood module 2 and the second wood module 3 comprise a plurality of laminated layers 17. Preferably, the first wood module 2 and the second wood module 3 have the same layout, with the same number of laminated layers of the same type. In one example, the module includes five layers. The layers are compression-bonded to each other to obtain solid wood modules 2, 3. The wood module is provided with an upper edge, a lower edge, a first side surface, a second side surface, an inner surface 21 and an outer surface 22. In the example shown, the wood modules are curved in one direction, but the wood modules may also be flat. The layer 17 comprises a plurality of laminated veneer plies 18. In the flat layer, the direction of the fibers of the veneer plies can be freely selected and can, for example, be oriented in the same direction. Some plies may also be arranged with the direction of their fibers oriented in a perpendicular direction when compared to other plies. In one example, every other ply is arranged in one direction, while the other plies are oriented perpendicular to the plies.

The wood layers of the module for bending are shown in fig. 2. In the wood layer 17 shown, the fibre directions of the veneer plies 18 of the first set of plies 19 are oriented in the same direction. The first set of plies 19 comprises a majority, preferably at least 80% of the number of plies. The layer also includes a second set of plies 20, the second set of plies 20 including one or more plies having the direction of their fibers oriented in a perpendicular direction when compared to the first set of plies. Preferably, the second set of plies comprises one ply, but may comprise two veneer plies arranged adjacent to each other.

The second set of plies 20, i.e. the set of plies having a direction perpendicular to the grain direction of the first set of plies 19 of the layer, may be arranged at any position of the layer, but is preferably arranged close to one side of the layer. In one example, the second set of plies is arranged as the outermost set of plies of the layer. In another example, the second set of plies is arranged within the first set of plies. Now, a first portion of the first set of plies is disposed on one side of the second set of plies and a second portion of the first set of plies is disposed on the other side of the second set of plies. The use of a single set of plies arranged in a transverse manner will reinforce the ply and will still allow the ply to be bent into a curved shape.

The wood modules are connected to each other by the use of perforated steel plates 4. A first example of a perforated steel sheet is shown in fig. 3. Each wood module is provided with a slit 11 for each perforated steel sheet. In the example shown, the slits 11 extend in the cross direction of the wood modules, i.e. from the outer surface to the inner surface of the wood module, perpendicular to the inner surface 21 and the outer surface 22 of the wood module. In other applications, in particular for flat modules, the slot may also extend parallel to the outer surface. The slits may be cut by, for example, a circular saw or router. One advantage of using a router is that the gap does not have to pass continuously through the entire wood module. In the case of a router, thin walls may be left at the outer surface of the wood module. In this way the outer surface of the wood module will be closed. This will allow the wood modules to have a smooth outer surface that does not have to be repaired to cover gaps in the outer surface.

The width of the slit is wider compared to a perforated steel plate. Preferably, a nominal gap of 1mm is provided between the perforated steel plate and each side wall of the slot. Preferably, the perforated steel plate 4 is provided with one or more protrusions 16, which protrusions 16 will provide distance means for the perforated steel plate such that the desired gap is created when the steel plate is positioned in the gap. Preferably, the protrusions extend 1mm in each direction from the surface of the perforated steel plate, corresponding to the nominal clearance of the slit. This will allow the perforated steel sheet to be centred in the slit during installation so that the glue can spread evenly on both sides of the perforated steel sheet. Preferably, the protrusions are pressed into the perforated steel sheet during manufacturing.

The perforated steel sheet may have different shapes, but is preferably rectangular in shape. The perforated steel sheet comprises a first section 14 and a second section 15 separated by a centre line 13. The perforated steel plate is symmetrical with respect to the center line such that the first portion and the second portion are identical. The first section is adapted to be mounted in a first wood module and the second section is adapted to be mounted in a second wood module, wherein the centre line 13 is arranged on the dividing line of the connection, in alignment with the upper edge of the first wood module 2 and the lower edge of the second wood module 3. The width of the perforated steel sheet will depend on the thickness of the wood module but is at least 60mm and the length is at least 500 mm. The thickness of the perforated steel plate is preferably between 2mm and 4 mm.

The perforated steel plate 4 comprises a plurality of holes 12. In the example shown, the holes are circular, but other shapes are also possible, such as elliptical holes or elliptical holes. Preferably, the circular holes have a diameter of 10mm, but other sizes are possible. The holes are positioned at a predetermined distance from the other holes and at a predetermined distance from the side of the perforated steel sheet. There is also a predetermined distance between the centerline of the perforated steel plate and the nearest hole. The apertures may be placed in rows and columns or may be positioned in an offset arrangement. The hole density of the perforated steel sheet may also be varied. Fig. 4 shows an example of a perforated steel sheet in which the hole density closest to the center line is reduced.

The perforated steel plate is mounted to the wood module by using glue. Preferably, glue is injected into the slit after the perforated steel sheet has been positioned in the slit. It is also possible to fill the gap with a predetermined amount of glue and thereafter insert the perforated steel plate. In this case, it is advantageous to vibrate the perforated steel sheet so that air can escape.

When the perforated steel plate is positioned in the slit, glue is injected into the slit so that half of the perforated steel plate is glued to the wood module. Preferably, the open side of the slit is covered before the glue is injected, so that the slit is completely filled and the glue does not escape during hardening. Adhesive tape or the like may be used to cover the gaps of the wood modules.

Preferably, the perforated steel plate is mounted to the wood module during assembly of the final product. The number of perforated steel plates used for the module is determined by counting the forces that the joint must withstand. Different types of glue may be used. A suitable glue is a two-component glue, for example based on epoxy, but other types, such as moisture-cured polyurethane, may also be used. Preferably, the glue is injected from the lowest part of the slit, so that the glue will be able to spread out evenly and so that the air bubbles are not closed. The glue may be injected through a drilled injection hole which is plugged after the injection has been performed.

The timber connector 1 can be used to connect veneer laminated timber modules of different sizes and shapes. In one example, a wood connector is used to mount a laminated wood tower 30, wherein curved modules 2, 3 are mounted to each other to form circular sections 31, wherein each circular section comprises a plurality of curved modules 2, 3. An example of a laminated wood tower is shown in fig. 5. The circular sections are then mounted to each other using wood connectors 1 to form a laminated wood tower. Mounting the bent modules to form the circle segment may be done with a specific joint, which may comprise, for example, a notch of a bent module, which cooperates with a notch of an adjacent bent module, wherein the bent modules may be locked to each other. Overlapping joints may also be used, where some layers of a bent module overlap with some layers of an adjacent bent module. Preferably, the curved modules are mounted to each other in the lateral direction with glue and screws. The bent modules can also be mounted to the circular section using perforated steel plates.

The circular sections are mounted to each other by using the wood connecting piece 1 of the invention. The wood connections can withstand tensile forces that occur when the wind turbine is subjected to air forces. One side of the tower will be subjected to a compressive force, which will be handled by the wood modules, and the other side will be subjected to a tensile force, which will be handled by the bent wood modules and wood connectors. Thus, the wood connectors are designed to correspond to the same tensile load capacity as the bent modules. The bending and torsional forces will be handled by the crossed laminate structure of the bent modules.

Fig. 6 shows an example of a wind power tower 40 comprising a laminated wood tower 30. The wind power tower shown may be up to 100 meters or more, and in the example shown, the wind power tower tapers slightly towards the top of the tower. The tower is fixed to a foundation 41, for example comprising steel bars extending upwards in the tower, to which the lower wooden section is attached with, for example, screws. The door may be provided in one of the lower curved modules. On top of the tower, a nacelle 42 is provided comprising a rotor 43 and a generator. Depending on the type of generator used, a transmission may also be installed.

The invention should not be regarded as being limited to the embodiments described above, many further variants and modifications being possible within the scope of the appended patent claims. The curved modules may be used for other round objects, such as wooden pipes, and may have various sizes. Straight wood sections can be used for larger walls in wooden shells, for example.

Reference numerals

1: wood connecting piece

2: first curved module

3: second curved module

4: perforated steel plate

11: gap

12: hole(s)

13: center line

14: the first part

15: the second part

16: projection part

17: wood layer

18: veneer sheet

19: a first set of plies

20: a second set of plies

21: inner surface

22: outer surface

30: laminated wood tower

31: circular segment

40: wind power generation tower

41: foundation

42: nacelle

43: and a rotor.