EP1237688B1 - Device for generating a chip - Google Patents

Abstract

An apparatus for producing an essentially wedge-shaped wood flake comprises a chipping tool rotating about a first, horizontal axis for chipping the flake out of the wood such that the flake has a first, concave surface and a second, convex surface. The flake is delimited between the surfaces. A circular saw blade is provided rotating about a second, vertical axis for removing wood in an area in which the surfaces intersect in an imaginary tip, prior to the chipping out.

Description

The invention relates to a device for generating a in essential wedge-shaped wood chips, with one around a first horizontal axis rotating cutting tool for Removing the chips from the wood, so that the Wood chips a first, concave surface and a second, convex surface that has between them the wood chips limit, with the surfaces in an imaginary tip converge and the tip on one between the surfaces extending centerline around a midline section outside the wood chip, and with a second vertical axis rotatable circular saw blade to remove the Wood before cutting in the area where the surfaces converge in the imaginary peak.

Such a device is known from DE 3702 890-A.

It is well known in the art of woodworking Wood by means of so-called Zerspanerwerkzeuge wholly or partly to machine. The Zerspanerwerkzeuge are usually rotating tools having cutting blades at their periphery. The Zerspanerwerkzeuge are usually arranged spatially fixed, and the wood to be cut or to be sawn guided in the axial direction of the wood on the Zerspanerkopf.

Because of these circumstances, the wood chips produced have a wing-like shape with a substantially wedge-shaped cross-section. The wood chips are on their two big ones Surfaces bounded by a concave or convex side, These pages are from a thick end of the woodchip too a thin end or in the cross-sectional view of a Lead tip in which the two surfaces tangentially tangent.

Wood chips are a valuable source material in various Industries. These include, on the one hand, the pulp industry, the paper industry, but also the manufacturers of Wood materials and so-called composite components, i.

Plates, boards and beams by gluing wood chips getting produced.

These processing companies pick up wood chips a specific classification. Particularly preferred Wood chips of medium size, because too big wood chips poorly processed and too small or too thin wood chips, in particular in the production of pulp, Paper, wood-based materials and composite components to losses or lead to no viable structures.

The classification of delivered wood chips is crucial for the price of a processing company willing to pay for these chips. Consequently, there is in the woodworking industry a considerable Desire, in the production of wood chips as possible only to produce such chips within the classification the processing industry is the highest To achieve prices.

If wood chips by means of a rotating chipper tool be generated in the manner described in more detail, have They along their wedge-shaped cross-section, the thin expiring End up. This thin end poses for further processing the chips are a disadvantage because themselves this thin end dissolves either in the pulp or at the Production of composite components in less stable areas leads.

In practice, chips are either when completely machined of wood or even when partially removing wood generated.

Partial cutting of wood finds e.g. at the so-called Profiling of tree trunks instead. By this one understands the All-sided processing of initially raw tree trunks to this to give a cross-sectional shape (profile) in which the profiled tree trunk by subsequent sawing in simple Way in boards and beams can be decomposed. A corresponding Methods and a corresponding device are e.g. described in DE 29 28 949 A.

In these known methods and devices, the Tree trunks are processed during profiling by means of so-called corner cutters, milling out corners of the tree trunk in the axial direction, so that before or after flattened on all sides Tree trunk receives a profile, in the so-called side boards can be sawed off.

In DE 37 02 890 C2 a corresponding method and a corresponding device described. In the known Procedure is first from one side of a tree trunk first, for example, horizontal saw incision predetermined Depth made, in which case the axis of rotation the saw blade runs vertically. After introduction of the saw incision or (using a combined Tool head) at the same time so that a portion of the Wood above the Sägeeinschnitts herauspant, whereby also the Rotation axis of the Zerspanerwerkzeuges, or in a combined Tool head the common axis of rotation, vertical runs. The swept out area is not enough horizontally far into the tree trunk like the first saw incision deep is. Thereafter, in a further operation, the remaining area herausgespant above the horizontal Sägeeinschnitts, namely by means of a chipper tool whose axis of rotation in said Example case runs horizontally. After or at the same time with the Ausspanungsvorgang becomes a second, vertical Saw incision attached, with the reason of the generated Gap with its center lies there where the first, horizontal Saw incision in the wood ends. As a result, therefore, overall an area worked out of the tree trunk, which although corner-like educated, basically the corner is stepped but. Important is that at no time one of the two Spanerwerkzeuge engages in an area that has been sawed out before. In this known method, as well as this already was described, only so-called "Kommaspäne" generated.

From EP 0 770 461 A2 a method and a system for the Splitting tree trunks into smaller wood products known. In this method, a tree trunk is profiled in that first by means of circular saw blades whose axes are 90 ° to each other inclined, the corners are perfectly sawn out. When sawing out resulting strips that from the actual Profilieranlage removed and in a separate Zerspaner be completely machined.

From EP 0 775 558 A1 a method for processing of Known tree trunks. In this method, first by means of a band saw running in the vertical direction a longitudinal section guided by the tree trunk, and alternatively also Circular saws are proposed. The saw cut is in any case placed in a vertical plane so that it is a side board separated from the tree trunk. The saw blade follows in the sawn gap a separating element with which the material still with the tree trunk connected side board in the distance from the remaining main item is held. The separating element in turn is followed by a combined one Trimming tool that rotates about a vertical axis is and in the manner already described from a chipper and an associated circular saw blade. With this Tool is the corner area above the narrow side of the too generating side boards spanned and at the same time the narrow side of the side board by means of the circular saw blade in one processed high surface quality. It has in the Zerspanerwerkzeug the chipper knife and the circular saw blade same Circle radius. The circle is tangent to the Broadside of the severed side board, in other words, the saw teeth and the chipper knives do not run in the of the leading band saw generated gap into it. Even if in this known method, the circle of the Spanermesser would reach into the gap, this would be related irrelevant with the present invention, because with band saws it is known that only extremely narrow sawing lines are produced, the typically a maximum of 3mm wide. That would only then the most extreme tips of the chips will be affected. This would result but only an economically irrelevant change in the form of Chips. Thus, in principle also in this known method produced the already mentioned "Kommaspäne".

In all the above-mentioned methods and devices thus on the one hand conventional wood chips with thin tapered End and on the other hand generated sawdust.

DE 43 37 682 C1 discloses a method and a device known for cutting a tree trunk.

According to the known method are flattened from one side Tree trunk first by means of a circular saw side boards sawn off, which provided at their edges with forest edge are. These side boards will be as long as they are ahead End are still materially connected to the tree trunk, bent from the sawing plane and then run essentially in Distance parallel to the tree trunk. In this spaced position The side boards are attached by means of a trimming cutter the narrow sides abgespant and trimmed with it. The cutting of the Trimming chipper run under about 45 pressure angles in radial Direction through the wood in the area of the forest edges. The side boards run almost in the area of the axis of rotation of Besäumzerspaners past this. This is possible because because, as mentioned, the side boards at this moment in the lateral distance from the main product. Sense of this Measure is when trimming the previously bent side board so-called "equal-thickness chips", ie chips, which in contrast to the so-called "Kommaspänen" a substantially have constant thickness parallel to the wood fiber. These "equal-thickness chips" are approximately parallelogram-shaped in cross-section, where the corner angle is about 45 ° (or 135 °), because the cutting plane of the chipper on the wood, as mentioned, at about 45 ° to the direction of movement of the side boards lies.

Although the known method and the known device have thus having the advantage of producing chips for a subsequent one Processing in the cellulose industry cheaper However, this advantage must be considerable additional Effort be bought, because the side boards after sawing bent out of the sawing plane and there at a considerable distance must be trimmed by the main product. this is not for all woods in the required way possible, anyway not without the side boards when turning in the fiber to harm.

The invention is based on the object, Devices of the beginning further education to avoid the above-mentioned disadvantages. In particular, wood chips should be produced in an economically optimal manner be generated whose shape as closely as possible Classes of wood chips corresponds to those of the processing Industry are paid the highest

In a device of the type mentioned this is Task according to the invention with the characteristics of Claim 1 solved.

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

Unlike traditional, wedge-shaped chips with thin expiring end or thin leaking tip provided to remove this thinly tapering end, so that only the thicker end of the chips left remains.

Such a shortened wood chips has a significant higher economic value and can therefore in far be better processed. The operator of a Sawmill can therefore with such shaped chips with a much higher economic yield during Expect the utilization of wood chips.

The fact that in the inventive devices the Rotary axis of the circular saw blade vertically and the axis of rotation of the Chipper tool runs horizontally, has the advantage that smaller drives can be used, so economic and constructive advantages.

The circular saw blade is, unlike the device according to EP 775 558 A1, not according to the invention for separating a side board, but rather only to create a gap finite Depth.

The circular saw blade is preferably with a thickness of more than 5 formed to 6 mm thickness. The circular saw blade continues preferably a riving knife, between the circular saw blade and the cutting tool is arranged.

This measure opens up the possibility of being in one and the same Operation by the wood to be cut or auszuspanende by to prepare a cut, in particular a saw cut, so that during the subsequent engagement of the rotating Zerspanerwerkzeugs the abovementioned shortened wood chips arise immediately, since already the area was removed in advance, in which the thin tapered ends or tips would have been produced.

Further advantages will be apparent from the description and the attached Drawing.

Fig. 1

eine Schnittdarstellung durch einen Hackschnitzel, wie er mit herkömmlichen Zerspanerwerkzeugen hergestellt wird;

Fig. 2

eine Darstellung, ähnlich Fig. 1, jedoch für einen Hackschnitzel in erfindungsgemäßer Herstellung;

Fig. 3

eine schematisierte, radiale Querschnittsdarstellung eines Baumstamms zur Erläuterung eines Profiliervorganges;

Fig. 4 und 5

äußerst schematisierte Ansichten einer Vorrichtung zum Erzeugen von Hackschnitzeln herkömmlicher Art;

Fig. 6

eine Darstellung, ähnlich Fig. 5, jedoch in vergrößertem Maßstab und mit abweichender Achsanordnung, darstellend ein Ausführungsbeispiel einer erfindungsgemäßen Vorrichtung zum Erzeugen von erfindungsgemäßen Hackschnitzeln beim Profilieren von Baumstämmen; und

Fig. 7A bis 7D

vier Schaubilder zur Erläuterung der Wirkungsweise der Vorrichtung gemäß Fig. 6

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it:

Fig. 1

a sectional view of a wood chip, as it is produced with conventional Zerspanerwerkzeuge;

Fig. 2

a representation, similar to Figure 1, but for a wood chips in accordance with the invention.

Fig. 3

a schematic, radial cross-sectional view of a tree trunk for explaining a Profiliervorganges;

4 and 5

highly schematic views of a device for producing wood chips of conventional type;

Fig. 6

a representation, similar to Figure 5, but on an enlarged scale and with different axle assembly, showing an embodiment of an apparatus according to the invention for producing wood chips according to the invention in the profiling of logs. and

Figs. 7A to 7D

four diagrams for explaining the operation of the device according to FIG. 6

In Fig. 1, 10 denotes a woodchip of conventional type. The woodchip 10 has two sides or surfaces 12, 14 on, which are perpendicular to the plane and the essential Form surface of the wood chip 10. The left in Fig. 1 Surface 12 is concave, and the right surface 14th convex. The surfaces 12 and 14 run down in Fig. 1 in a tip 16 or edge tangentially together. At the opposite end of the wood chip 10 is a preferably flat end face 18 recognizable. Overall, the Wood chips 10 with a thick end 20 and a thin end 22nd

Preparing chips according to the type of woodchip 10 according to FIG. 1 during further processing in the pulp industry or the industry for producing composite components, in particular Beams or boards, problems because the thinner end 22 barely has its own stability and in a further processing in a liquid medium also dissolves or at a stronger mechanical stress is destroyed, so that undefined fragments remain.

The economic value of the woodchip 10 can therefore be significantly increased when the thinner end 22 removed becomes.

This is done in the embodiment shown in FIG the invention characterized in that along a parting plane 24th a section through the chips 10 is performed, so that the Thinner end 22 is removed.

The position of the parting plane 24 within the woodchip 10 ' can be determined in different ways. Here are before all economic considerations, i. the question, in which remaining shape of the chips 10 'the best offers economic yield.

If one thinks between the surfaces 12 and 14 a center line 26, one can eg the center line section 26a within the remaining wood chip 10 'with a length 1 ₁ and the imaginary center line section 26b outside the remaining wood chip 10', namely to the top 16, define with a length 1 ₂ , wherein the total length of the original woodchip 10 1 ₁ + 1 ₂ . An optimal position of the parting plane 24 is then present, for example, when 1 ₂ between 40% and 100% of 1 ₁ . Another definition is to define the thickness d of the remaining woodchip 10 'with eg between 2 and 10 mm in the transition of the convex surface 14 to an interface 28 along the parting plane 24.

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

In preferred embodiments of the invention, the flat face 18 by cutting or sawing and the interface 28 generated by sawing in the axial direction. They are therefore each level and parallel to each other.

In Fig. 3 is dash-dotted lines 30 of the substantially circular Radial section indicated by a tree trunk. Laterally on tree trunk 30 are the so-called rinds 32, i. forest edge-affected surface sections.

At four offset by 90 ° to each other circumferential positions of the tree trunk 10, so-called corners 34 are provided. If the Scales 32 (usually by machining) and the corners 34 are removed (usually by milling or Ausspäsen), remains a so-called model, from the following side boards 36 and then more boards and / or a so-called Main product can be sawed.

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

Fig. 4 shows this in a greatly enlarged scale again the Area of a corner 34 of the tree trunk 30. To attach the Corners 34 becomes a corner cutter 44, generally speaking rotating chipper tool used. The corner cutter 44 is about a vertical axis 46 in the direction of arrow 48 rotatable. The axis 46 extends to the longitudinal axis of the horizontal aligned tree trunk 30 vertically.

The corner cutter 44 is in a conventional manner of two Assembled tools, namely a chipper 50 and a Saw blade 52 or a corresponding number of planing knives.

Upon rotation of the corner cutter 44 (arrow 48) the knives dive of the chipper 50 in the area of the first edge surface 38 in the corner 34, while at the same time the second edge surface 40 of the corner 34 is treated by the saw blade 52 and the planing knives.

In this way, the second edge surface 40 receives a relative high (sawn) surface quality, while the first edge surface 38 as a result of rotating with a rotational movement Slicer knife receives a wavy surface.

5 shows a plan view of the arrangement according to FIG. 4. With an arrow 54 is the rotational movement of the vertical Axis 48 circumferential corner cutter 44 indicated. Its radius is denoted by r.

With an arrow 56, the feed direction of the tree trunk 30th opposite the spatially fixed corner cutter 44 (or vice versa) designated. The plan view of FIG. 5 shows on the Tree trunk 30 also has a flattened area 58, where previously through Side flattening removes the corresponding rind 32 has been. The flattened region 58 is characterized by an axially extending Transition line 60 from the remaining woodland area 62 separated, in which the corner 34 by means of the corner cutter 44 is to be worked out.

As can be seen clearly from FIG. 5, reference is made to this conventional one Way of the chips 10 produced in FIG. 1.

In contrast, in accordance with the device according to the invention Fig. 6, first, the orientation of the axis 46 'of the corner cutter 44 changed. This extends according to the invention horizontally. Further is in front of the peripheral corner cutter 44 a circular saw blade 70th arranged, which rotates about a vertical axis 72, as with an arrow 74 indicated. The axis 72 is perpendicular to Longitudinal axis of the turn horizontally aligned tree trunk 30. The circular saw blade 70 thus saws a horizontal gap 76 finite depth d (FIG. 7B) 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 accordingly wide, at any rate, significantly wider than in the case a band saw. The circular saw blade 70 may, depending on the individual case also be provided with extra-wide teeth.

On the circular saw blade 70, a riving knife 78 follow, which in axial direction ends where the engagement area of the corner cutter 44 begins.

The arrangement is made such that the gap 76 there where, in the conventional approach (Figure 5), the thin End 22 of the woodchip would be. Because in this area by the circular saw blade 70, the existing wood there already the Spaniards of the Spaniard are running 50 of the Corner cutter 44 as well as the saw blade 52 and the planer blades empty.

Consequently, the wood chips 10 'without the thinner end 22 made, so it consists only of the thicker end 20.

It is understood that the circular saw blade 70 so far only is to be understood as an example, and that, of course, too other cutting tools can be used, e.g. the width of the gap 76 should be larger.

In the procedure shown in Fig. 6 results at the same time nor the advantage that the first edge surface 38 'of designed in the beginning with a surface in sawing quality becomes.

In Figs. 7A to 7D, the sequence is again in four pictures the processing steps in the apparatus of FIG. 6 illustrated.

Fig. 7A shows the moment in which that in a horizontal plane circumferential circular saw blade 70 (vertical axis of rotation 72) dips laterally into the tree trunk 30a.

FIG. 7B shows that the circular saw blade 70 is in the tree trunk 30b has generated the horizontal gap 76 of finite width d.

FIG. 7C illustrates that now engaging tree trunk 30c Corner cutter 44 which extends about the horizontal axis 46 ' rotates. The corner cutter 44 spant while the chips 10 'in a shape of FIG. 6 from.

Finally, Fig. 7D shows the final state of the log 30d with milled corner 34 ', both edge surfaces 38 'and 40' are of high surface quality.

Claims (4)

1. An apparatus for producing an essentially wedge-shaped wood flake (10; 10'), comprising a chipping tool (44 - 52) rotating about a first, horizontal axis (46), for chipping the flakes (10; 10') out of the wood, such that the flake (10; 10') has a first, concave surface (12) and a second, convex surface (14), delimiting between them the flake (10; 10'), the surfaces (12, 14) intersecting in an imaginary tip (16), the tip (16) being located on a center line (26) extending between the surfaces (12, 14) and at a distance of a center line section (26b) outside the flake (10; 10'), and a circular saw blade (70) arranged rotatably about a second, vertical axis (72) for removing the wood prior to the chipping within the area in which the surfaces (12, 14) intersect at the imaginary tip (16), characterized in that the chipping tool (44 - 52) extends into the removed area so far that that in the produced flakes (10') the length (1₂) of the center line section (26b) lying outside the flake (10') has between 40% and 100% of the length (1₁) of the center line section (26a) lying within the flake (10').
2. The apparatus of claim 1, characterized in that the circular saw blade (70) generates a slot (76) of finite depth (d) within the wood.
3. The apparatus of claim 1 or 2, characterized in that the circular saw blade (70) has a thickness of at least 5 mm, preferably of at least 6 mm.
4. The apparatus of one or more of claims 1 through 3, characterized in that a wood cleaver (78) is arranged between the circular saw blade (70) and the chipping tool (44 - 52), the wood cleaver (78) being flush with the circular saw blade (70).

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