EP1091836A1

EP1091836A1 - Chipping, method and device for producing said chipping and shaping a tree trunk and use thereof

Info

Publication number: EP1091836A1
Application number: EP99929270A
Authority: EP
Inventors: Hans Prof. Dr. Dietz
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-06-30
Filing date: 1999-06-18
Publication date: 2001-04-18
Anticipated expiration: 2019-06-18
Also published as: DE59901021D1; EP1091836B1; US6543497B2; DE19829112C1; ES2177292T3; CA2336337C; ATE214654T1; WO2000000331A1; CA2336337A1; US20010017171A1; DK1091836T3

Abstract

For use as a wood intermediary and the like in industry, an essentially wedge-shaped wood flake with opposite concave and convex surfaces that converge at an imaginary tip outside the flake dimensions. The tip is located beyond the flake a distance of typically between 40% and 100% of the flake length.

Description

Wood chips, method and device for producing a wood chip and for profiling a tree trunk and their uses

The invention relates to a wood chip with a first, concave surface and a second, convex surface, which delimit the substantially wedge-shaped wood chips between them, the surfaces converging in an imaginary tip outside the wood chip and the tip on a surface running between the surfaces Center line lies around a center line section outside the wood chip.

The invention further relates to a method for producing a substantially wedge-shaped wood chip, in which the wood chip is machined from the wood by means of a rotating chipping tool in such a way that it has a first, concave surface and a second, convex surface which between them Limit wood chips. The invention further relates to a method for profiling a tree trunk, in which, using a chipping tool, longitudinal corners are cut out of the tree trunk and side boards are sawn off the tree trunk, one narrow side of which is formed by one edge surface of the corner, a saw cut being made before the corners are removed is guided along the other edge surface.

The invention further relates to a device for producing a substantially wedge-shaped wood chip, in which the wood chip is machined from the wood by means of a rotating chipping tool in such a way that it has a first, concave surface and a second, convex surface which delimit the wood chips between them .

The invention also relates to a device for profiling a tree trunk, with a chipping tool for chipping longitudinal corners from the tree trunk, with means for sawing off side boards from the tree trunk, one narrow side of which is formed by one edge surface of the corner, and with a saw for guiding a saw cut along the other edge surface before removing the corners.

Finally, the invention relates to uses of the wood chips mentioned, the method mentioned and the device mentioned.

In woodworking technology, it is generally known to cut wood in whole or in part by means of so-called chipping tools. The chipper tools are usually rotating tools with chipper knives on their circumference. The cutting tools are usually spatially fixed ordered, and the wood to be cut or machined is guided along the chipper head in the axial direction of the wood.

Because of these conditions, the wood chips produced have a wing-like shape with an essentially wedge-shaped cross section. The wood chips are delimited on their two large surfaces by a concave or convex side, these sides leading from a thick end of the wood chip to a thin end or in the cross-sectional representation of a tip in which the two surfaces run tangentially into one another.

Wood chips are a valuable raw material in various branches of industry. This includes the pulp industry, the paper industry, but also the manufacturers of wood-based materials and so-called composite components, i.e. Panels, boards and beams made by gluing wood chips.

These processing companies accept wood chips according to a certain classification. Wood chips of medium size are particularly preferred because wood chips that are too large are difficult to process and that wood chips that are too small or too thin lead to losses or to no viable structures, particularly in the production of pulp, paper, wood-based materials and composite components.

The classification of the wood chips delivered is decisive for the price that a processing company is willing to pay for these wood chips. As a result, there is a significant one in the woodworking industry Desire in the production of wood chips to produce only those wood chips that achieve the highest prices within the classification of the processing industry.

If wood chips are produced by means of a rotating chipping tool in the manner described in more detail above, they have the thinly tapering end along their wedge-shaped cross section. This thin end is a disadvantage for the further processing of the wood chips, because this thin end either dissolves in the pulp or leads to areas that are not very stable in the production of composite components.

In practice, wood chips are produced either when wood is completely cut or when wood is partly cut out.

A partial removal of wood takes place e.g. when profiling tree trunks. This means the all-round processing of initially raw tree trunks in order to give them a cross-sectional shape (profile), in which the profiled tree trunk can be easily broken down into boards and beams by subsequent sawing. A corresponding method and a corresponding device are e.g. described in DE 29 28 949 A.

In these known methods and devices, the tree trunks are machined during profiling by means of so-called corner cutters, which mill corners in the axial direction out of the tree trunk, so that the previously or subsequently flattened on all sides Tree trunk is given a profile in which so-called side boards can be sawn off.

A corresponding method and a corresponding device are described in DE 37 02 980 C2. In the known method, a first, for example horizontal saw cut of predetermined depth is first made from one side of a tree trunk, in which case the axis of rotation of the saw blade runs vertically. After making the saw cut or (using a combined tool head) at the same time, a section of the wood above the saw cut is machined, whereby the axis of rotation of the chipping tool, or in the case of a combined tool head, the common axis of rotation, runs vertically. The removed area does not reach as far horizontally into the tree trunk as the first saw cut is deep. Then, in a further operation, the remaining area above the horizontal saw cut is machined using a cutting tool whose axis of rotation runs horizontally in the example mentioned. Afterwards or simultaneously with the chipping process, a second, vertical saw cut is made, the bottom of the gap created in this case being at the center where the first, horizontal saw cut ends in the wood. As a result, a whole area is worked out of the tree trunk that is corner-like, but is basically stepped at the corner. It is important that at no time does one of the two chipping tools intervene in an area that was previously sawn out. In this known method, as has already been described, only so-called "comma chips" are generated. EP 0 770 461 A2 discloses a method and a plant for dividing tree trunks into smaller wood products. In this method, a tree trunk is profiled by first sawing the corners completely using circular saw blades whose axes are inclined at 90 ° to one another. When sawing out, strips are created that are removed from the actual profiling system and completely cut in a separate chipper.

A method for processing tree trunks is known from EP 0 775 558 AI. In this method, a longitudinal cut is first made through the tree trunk by means of a band saw, this saw cut being made such that it separates a side board from the tree trunk. The saw blade is followed by a separating element in the sawn gap, with which the side board, which is still materially connected to the tree trunk, is kept at a distance from the remaining main goods. The separating element in turn is followed by a combined trimming tool which, in the manner already described, consists of a chipper and a circular saw blade connected to it. With this tool, the corner area above the narrow side of the side board to be produced is machined and at the same time the narrow side of the side board is machined with a high-quality surface using the circular saw blade. The cutting knife and the circular saw blade have the same radius in the cutting tool. The flight circle runs tangentially to the broad side of the separated side board, in other words, the saw teeth and the chipper blades do not run into the gap created by the leading band saw. Even if, in this known method, the flight circle of the span knife would extend into the gap, this would be irrelevant in connection with the present invention, because it is known that band saws are only extremely narrow Saw joints are generated, which are typically a maximum of 3 mm wide. This would only affect the outermost tips of the chips. However, this would only result in an economically insignificant change in the shape of the chips. With this known method, the "comma chips" already mentioned are generated in principle.

In all of the above-mentioned methods and devices, conventional wood chips with a tapered end are produced on the one hand and sawdust on the other hand.

DE 43 37 682 Cl discloses a method and a device for cutting a tree trunk.

In accordance with the known method, side boards are sawn from a tree trunk flattened at the side, which are still provided with forest edges at their edges. These side boards are bent out of the sawing plane as long as they are still materially connected to the tree trunk at the leading end and then run essentially parallel to the tree trunk at a distance. In this spaced-apart position, the side boards are machined on the narrow sides by means of a trimmer and thus trimmed. The cutting edges of the trimming cutter run through the wood in the area of the forest edges at a pressure angle of approx. 45 ° in the radial direction. The side boards thus run past the edger chipper almost in the area of the axis of rotation. This is possible because, as mentioned, the side boards are currently spaced from the main goods. The purpose of this measure is to produce so-called "equal-thickness chips" when trimming the previously bent side board, ie chips which, in contrast to the so-called "comma chips", are essentially one have a constant thickness parallel to the wood fiber. These "same-thickness chips" are approximately parallelogram-shaped in cross-section, the corner angle being approximately 45 ° (or 135 °) because, as mentioned, the plane of engagement of the chipper on the wood is less than approximately 45 ° to the direction of movement of the side boards.

The known method and the known device thus have the advantage of producing chips which are made more economical for subsequent processing in the cellulose industry, but this advantage has to be bought with considerable additional effort because the side boards are bent out of the sawing plane after sawing off and have to be trimmed there at a considerable distance from the main goods. This is not possible with all types of wood, at least not without damaging the side boards when bending in the fiber.

In contrast, the invention is based on the object of developing a wood chip and method and devices of the type mentioned at the outset or of specifying the uses mentioned in order to avoid the disadvantages mentioned above. In particular, wood chips should be produced in an economically optimal manner, the shape of which corresponds as closely as possible to those classes of wood chips that are most highly paid for by the processing industry.

In the case of a woodchip of the type mentioned at the outset, this object is achieved according to the invention in that the length of the central line section lying outside the woodchip is between 40% and 100% of the length of the central line section within the woodchip. In the method for producing a woodchip of the type mentioned in the introduction, the object is achieved in that the wood is removed prior to the removal in the area in which the surfaces converge in an imaginary tip.

In a method for profiling a tree trunk of the type mentioned at the outset, the object is achieved in that the cutting tool radius extends into the gap produced by the saw cut and runs empty therein.

In a device for producing a woodchip of the type mentioned in the introduction, the object is achieved in that means are provided for removing the wood before chipping in the area in which the surfaces converge in an imaginary tip.

In a device for profiling a tree trunk of the type mentioned, the object is achieved according to the invention in that the cutting tool extends with its circle radius into the gap created by the saw cut, in such a way that it runs empty therein.

The task is still solved by using the aforementioned wood chips as strands in the production of composite beams or boards.

Further solutions according to the invention consist in the use of the method mentioned above and the called device for chipping corners when profiling tree trunks.

The object underlying the invention is completely achieved in this way.

In contrast to conventional, wedge-shaped chips with a thinly tapering end or a thinly tapering tip, the invention provides for this thinly tapering end to be removed, so that only the thicker end of the chips remains.

Such a shortened wood chip has a much higher economic value and can therefore be processed in a much better way. The operator of a sawmill system can therefore expect a much higher economic yield during the recycling of the chips with such shaped chips.

The measure that the tip lies on a center line running between the surfaces around a center line section outside the chip, the length of which is between 40% and 100% of the length of the center line section inside the chip, has the advantage that a chip is produced which is just that it is much shortened that it represents an economic optimum.

It is further preferred if the center line of the wood chips intersects the wood chips in an interface in the transition between the center line sections. The interface preferably encloses a finite angle with the center line, so that further preferably the wood chip between the surfaces in the transition from the concave surface to the interface have a thickness between 2 and 10 mm.

This dimensioning information also has the advantage that wood chips which can be used in an economically optimal manner are produced.

Corresponding considerations to the exemplary embodiments described above apply in the same way to corresponding embodiments of the method according to the invention and of the device according to the invention.

It is also particularly preferred if the interface mentioned is flat. This is preferably done by making the interface by sawing.

The saw is preferably designed as a circular saw with a circular saw blade of more than 5 to 6 mm in thickness. The circular saw is further preferably followed by a riving knife which is arranged between the saw and the cutting tool.

This measure opens up the possibility of preparing the wood to be chipped or chipped in one and the same operation by means of a cut, in particular a saw cut, in such a way that the shortened wood chips mentioned arise immediately when the rotating chipper tool is subsequently engaged, since the area has already been removed beforehand, in which the tapered ends or tips would have been produced.

Further advantages result from the description and the attached drawing. It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination indicated in each case, but also in other combinations or on their own without departing from the scope of the present invention.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

Figure 1 is a sectional view through a wood chip, as it is produced with conventional chipping tools.

FIG. 2 shows an illustration, similar to FIG. 1, but for a wood chip produced in accordance with the invention;

3 shows a schematic, radial cross-sectional representation of a tree trunk to explain a profiling process;

FIGS. 4 and 5 are extremely schematic views of a device for producing wood chips of a conventional type;

FIG. 6 shows an illustration, similar to FIG. 5, but on an enlarged scale and illustrating an exemplary embodiment of a device according to the invention for producing wood chips according to the invention. In FIG. 1, 10 denotes a woodchip of a conventional type. The woodchip 10 has two sides or surfaces 12, 14 which are perpendicular to the plane of the drawing and form the essential surface of the woodchip 10. The left surface 12 in FIG. 1 is concave, and the right surface 14 is convex. The surfaces 12 and 14 converge tangentially at the bottom in FIG. 1 in a tip 16 or edge. A preferably flat end face 18 can be seen at the opposite end of the chips 10. Overall, the wood chips 10 thus have a thick end 20 and a thin end 22.

1 cause problems in further processing in the pulp industry or in the industry for the production of composite components, in particular beams or boards, because the thinner end 22 has hardly any stability of its own and is further processed in a liquid Medium also dissolves or is destroyed under greater mechanical stress, so that undefined fragments remain.

The economic value of the chips 10 can therefore be increased significantly if the thinner end 22 is removed.

This takes place in the embodiment of the invention shown in FIG. 2 in that a cut is made through the wood chips 10 along a parting plane 24, so that the thinner end 22 is removed.

The position of the parting plane 24 within the chips 10 'can be determined in different ways. Here, economic considerations are particularly important, ie the question in which remaining form the wood chips 10 'offers the best economic yield. The lateral distance of the parting plane 24 from the tip 16 is typically 6 mm, for example.

If one imagines between the surfaces 12 and 14, a center line 26, then, for example the center line portion 26a within the remaining wood flake 10 'with a length l _j _ and the imaginary center line portion 26b outside the remaining wood flake 10', namely until the tip 16 , with a length of 1 ₂ , the total length of the original wood chips being 10 l _x + 1 ₂ . An optimal position of the parting plane 24 is, for example, when 1 _{2 is} between 40% and 100% of 1 _: . Another possible definition is to define the thickness d of the remaining wood chips 10 ′ in the transition from the convex surface 24 to an interface 28 along the parting plane 24, for example between 2 and 10 mm.

In the arrangement shown in FIG. 2, the interface 28 forms an acute angle α with the center line 26, which e.g. can be between 15 ° and 50 °.

In preferred exemplary embodiments of the invention, the flat end face 18 is produced by machining or sawing and the interface 28 by sawing in the axial direction. They are therefore flat and run parallel to each other.

In FIG. 3, the essentially circular radial section through a tree trunk is indicated by dash-dotted lines. The so-called rinds 32, ie surface sections affected by forest edges, are located on the side of the tree trunk 30. So-called corners 34 are provided at four circumferential positions of the tree trunk 10, each offset by 90 ° to one another. When the rinds 32 (usually by machining) and the corners 34 (usually by milling or chipping) have been removed, a so-called model remains from which subsequent side boards 36 and then further boards and / or a so-called main item can be sawn.

In Fig. 3, 38 and 40 denote the two edge surfaces of the axially continuous corners 34.

4 again shows the area of a corner 34 of the tree trunk 30 on a greatly enlarged scale. A corner milling cutter 44, generally speaking a rotating chipping tool, is used to attach the corners. The corner milling cutter 44 can be rotated about an axis 46 in the direction of an arrow 48. The axis 46 runs perpendicular to the longitudinal axis of the tree trunk 30.

The corner milling cutter 44 is composed in a manner known per se from two tools, namely a chipper 50 and a saw blade 52 or a corresponding number of planing knives.

When the corner milling cutter 44 (arrow 48) rotates, the knives of the chipper 50 plunge into the corner 34 in the region of the first edge surface 38, while at the same time the second edge surface 40 of the corner 34 is treated by the saw blade 52 or the planing knives.

In this way, the second edge surface 40 receives a relatively high (sawn) surface quality, while the first edge surface 38 receives a wavy surface due to the rotary knife rotating with a rotary movement. FIG. 5 shows a top view of the arrangement according to FIG. 4. The arrow 54 indicates the rotary movement of the corner milling cutter 44 rotating around the axis 48. Its radius is denoted by r.

An arrow 56 indicates the direction of advance of the tree trunk 30 relative to the corner milling cutter 44 which is mounted in a fixed position (or vice versa). The plan view according to FIG. 5 also shows a flattened area 58 on the tree trunk 30, where the corresponding rind 32 was previously removed by flattening it sideways. The flattened area 58 is separated by an axially extending transition line 60 from the remaining forest-edged area 62, in which the corner 34 is to be worked out by means of the corner mill 44.

5, the wood chips 10 according to FIG. 1 are produced in this conventional manner.

In contrast, in the device according to the invention according to FIG. 6, a circular saw blade 70, which rotates about an axis 72, is arranged in front of the rotating corner milling cutter 44, as indicated by an arrow 74. The axis 72 extends perpendicular to the longitudinal axis of the tree trunk 30. The circular saw blade 70 thus saws a gap 76 along the transition line 60. The circular saw blade 70 typically has a thickness of more than 5 mm, preferably 6 mm and more, so that the gap 76 is correspondingly wide is, at least considerably wider than in the case of a band saw. Depending on the individual case, the circular saw blade 70 can also be provided with particularly wide teeth. A circular wedge 78 can follow the circular saw blade 70 and ends in the axial direction where the engagement area of the corner milling cutter 44 begins.

The arrangement is such that the gap 76 lies where the thin end 22 of the chips would lie in the conventional procedure (FIG. 5). Since the wood present there has already been removed in this area by the circular saw blade 70, the cutter blades of the cutter 50 of the corner milling cutter 44 as well as the saw blade 52 or the planing blades run empty.

As a result, the wood chips 10 ′ are produced without the thinner end 22, ie they only consist of the thicker end 20.

It goes without saying that the circular saw blade 70 is only to be understood as an example in this respect, and that other cutting tools can of course also be used, e.g. the width of the gap 76 should be larger.

The procedure shown in FIG. 6 also has the advantage that the first edge surface 38 is also designed with a saw-quality surface from the outset.

Claims

claims

1. Wood chips from wood with a first, concave surface (12) and a second, convex surface (14) which define between them the substantially wedge-shaped chips (10; 10 '), the surfaces (12, 14) in one converge the imaginary tip (16) outside the chip (10 '), and the tip (16) lies on a center line (26) running between the surfaces (12, 14) around a center line section (26b) outside the chip (10'), characterized in that the length (1 ₂ ) of the central line section (26b) lying outside the wood chip (10 ') is between 40% and 100% of the length (1 ₁ ) of the central line section (26a) within the wood chip (10').

2. Wood chips according to claim 1, characterized in that the center line (26) intersects the wood chips (10 ') in an interface (28) in the transition between the center line sections (26a, 26b).

3. Wood chips according to claim 2, characterized in that the interface (28) with the center line (26) includes a finite angle (α).

4. Wood chips according to claim 2 or 3, characterized in that it has a thickness (d) between 2 and 10 mm between the surfaces (12, 14) in the transition from the concave surface (14) to the interface (28). Wood chips according to one or more of claims 2 to 4, characterized in that the interface (28) is flat.

Wood chips according to one or more of claims 1 to 5, characterized in that the center line (26) cuts the wood chips (10 ") at the end opposite the interface (28) in an end face (18) which is parallel to the interface (28) runs.

Use of wood chips according to one or more of claims 1 to 6 as strands in the production of composite beams or boards, and wood-based materials.

Method for producing an essentially wedge-shaped wood chip (10; 10 '), in which the wood chip (10; 10') is machined from the wood by means of a rotating chipping tool (44 - 52) in such a way that it has a first, concave surface (12) and a second, convex surface (14) which delimit the wood chips (10; 10 ') between them, characterized in that the wood is removed prior to the removal in the area in which the surfaces (12, 14 ) converge in an imaginary tip (16).

Method according to Claim 8, characterized in that the region is removed in such a way that the tip (16) on a center line (26) running between the surfaces (12, 14) around a center line section (26b) outside the wood chip to be removed after removal 10 "), whose length (1 ₂ ) is between 40% and 100% of Length (l _x ) of the center line section (26a) within the wood chips (10 ').

10. The method according to claim 9, characterized in that the center line (26) in the transition between the center line sections (26a, 26b) cuts the chips to be removed after removal (10 ') in an interface (28).

11. The method according to claim 10, characterized in that the interface (28) is made such that it includes a finite angle () with the center line (26).

12. The method according to claim 10 or 11, characterized in that the chips (10 ') between the surfaces (12, 14) in the transition from the concave surface (14) to the interface (28) with a thickness (d) between 2 and 10 mm is machined.

13. The method according to one or more of claims 8 to 12, characterized in that the interface (28) is made flat.

14. The method according to claim 13, characterized in that the interface (28) is produced by sawing.

15. The method according to one or more of claims 9 to 14, characterized in that the center line (26) against the wood chips (10 ') at that of the interface (28) intersecting end in an end face (18) which runs parallel to the interface (28).

16. A method for profiling a tree trunk (30), in which, using a chipping tool, longitudinal corners (34) are cut out of the tree trunk (30) and side boards (36) are sawn off the tree trunk (30), one narrow side of which is cut off from one edge surface ( 40) of the corner (34) is formed, a saw cut being made along the other edge surface (38) before the corners (34) are machined, characterized in that the cutting tool with its radius of flight circle (r) extends into the gap produced by the saw cut (76) reaches in and runs empty.

17. Use of the method according to one or more of claims 8 to 15 for chipping corners (34) when profiling tree trunks (30).

18. Device for producing a substantially wedge-shaped chips (10; 10 '), in which the chips (10; 10') are machined from the wood by means of a rotating chipping tool (44-52) in such a way that they have a first, concave surface (12) and a second, convex surface (14) which delimit the wood chips (10; 10 ') between them, characterized in that means are provided for removing the wood before chipping in the area in which the Surfaces (12, 14) converge in an imaginary tip (16).

19. The apparatus according to claim 18, characterized in that the means comprise a saw.

20. The apparatus according to claim 19, characterized in that the saw is designed as a circular saw with a circular saw blade (70).

21. The apparatus according to claim 20, characterized in that the circular saw blade (70) is at least 5 mm, preferably at least 6 mm thick.

22. The device according to one or more of claims 19 to 21, characterized in that a saw wedge (78) aligned with the saw is provided between the saw and the cutting tool.

23. Device for profiling a tree trunk (30), with a chipping tool for chipping longitudinal corners (39) from the tree trunk (30), with means for sawing off side boards (36) from the tree trunk (30), one narrow side of which one Edge surface (40) of the corner (34) is formed, and with a saw for guiding a saw cut along the other edge surface (38) before removing the corners (34), characterized in that the cutting tool with its circle radius (r) up to the gap (76) created by the saw cut extends in such a way that it runs empty therein.

24. Use of the device according to one or more of claims 18 to 22 for chipping corners (34) when profiling tree trunks (30).