EP1648668B1 - Method and device for breaking down conical tree trunks - Google Patents

Abstract

The invention relates to a method and a device for breaking down conical tree trunks (42) with a conical angle ( alpha ) into wood products (58, 60). The sides of an optionally pre-treated tree trunk (42) are first laterally levelled (46), and the thus produced model (47) is centred (52), and then split by sawing (56). According to the invention, the sides of the tree trunk (42) are levelled parallel to a surface line (43), whereby a lateral guiding surface (50b) is created for the ensuing centring process, said surface being inclined in relation to the longitudinal axis (45) of the tree trunk (42) by the half conical angle ( alpha /2). The model (47) is sawn in a direction (41) parallel to the lateral guiding surface (50b).

Description

The invention relates to a method for cutting conical, cone-shaped tree trunks in wood products, in which a tree trunk laterally flattened, and the model generated thereby centered and finally divided by sawing.

The invention further relates to an apparatus for cutting conical, cone-shaped tree trunks into wood products, comprising a first station for laterally trimming a tree trunk, a second station for centering the model created by the trimming, and a third station for sawing the model ,

A method and a device of the aforementioned type are known, for example from DE 32 44 393.

According to the known method and associated apparatus, a conical tree trunk having a curved longitudinal axis is first brought to a lying position in which the plane of curvature of the tree trunk is vertical. The tree trunk is then led with the thicker end ahead over a chipper, which attacks from the bottom of the tree trunk at this and creates a straight surface at the bottom. The tree trunk then passes through a chipping station with two side chipper heads flattening the tree trunk on both sides. The tree trunk is thereby conveyed straight ahead, ie, that its longitudinal axis is aligned parallel to the conveying direction. As a result, approximately equal and equally shaped areas are machined on both sides of the conical tree trunk. The depth of engagement in cutting is set to correspond to the width of the tree trunk at the thin end. Behind the Zerspanerstation therefore remains a model, which is flattened from below and from the two sides in such a way that the width of the model from the front end to the back of the model is constant. This model is then fed to a centering station, which centers the model and feeds it to a sawing station. The sawing station exists from two circular saws, which laterally separate side boards.

In this known method and the associated device is a disadvantage that when lateral flattening a considerable amount of wood is machined, resulting in a relatively low yield.

From DE 33 43 953 A1 a method for processing curved logs is known. In this known method, a tree trunk is conveyed ahead with the thin end, wherein the plane of curvature of the tree trunk is horizontal. The tree trunk is conveyed on a roller conveyor and thereby scanned by means of lateral buttons, so that data on the shape of the tree trunk can be detected depending on its length. With this data, a Zerspanersterein arranged downstream of the roller conveyor and a downstream of the Zerspanerstation Bandägestation be driven, in such a way that the laterally attacking Zerspanerköpfe and running through the wood bandsaw blades are adjusted in the lateral direction so that from the curved tree trunk boards with be sawn out optimum yield.

In this known method has the disadvantage that a high expenditure on equipment must be driven in order to continuously detect the shape of the log on the roller conveyor and that complex control circuits including appropriate actuators must be present to both the Zerspanerköpfe as well as the band saws in the lateral direction to adjust.

The invention is the object of developing a method and an apparatus of the type mentioned in such a way that the above-mentioned disadvantages are avoided.

In particular, it should be possible to achieve a high wood yield in conical tree trunks with relatively manageable apparatus and control technology effort.

In a method of the type mentioned above, this object is achieved in that the possibly already pre-processed tree trunk is flattened parallel to a surface line when flattening, whereby a lateral guide surface for the subsequent centering arises, which is inclined to the longitudinal axis of the tree trunk by half the cone angle is, and that the model is sawn in a direction parallel to the lateral guide surface direction.

In a device of the type mentioned, the object is achieved in that first means are provided to flatten the tree trunk when flattening parallel to a surface line, whereby a lateral guide surface for the subsequent centering arises, to the longitudinal axis of the tree trunk by half the cone angle and second means for sawing the model in a direction parallel to the lateral guide surface.

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

By forming a guide surface parallel to the surface line and then sawing in a direction parallel to the guide surface, it becomes possible to produce in the region of this guide surface a side board or other wood product which passes over the entire length of the tree trunk. This is of considerable economic importance because long timber products have a disproportionately higher value than short timber products. In contrast to the procedure according to the aforementioned DE 32 44 393 C1, it is not necessary to go so deep into the tree trunk at the lateral Anflachen that the model produced in this way over its entire length is as wide as the tree trunk at the thinner end. Rather, the lateral penetration depth when flattening can be dimensioned so small that a lateral surface is created, the height of which is just as large as, for. the width of a tradable wooden strip or a narrow wooden board. Although this advantage is paid for by a greater penetration depth on the opposite side or a significantly shorter length of the wood product that can be produced there, profitability calculations have shown that the sum of the value of the wood products on both sides is greater than in known methods in which the Tree trunk is flattened on both sides in essentially symmentrischer way.

In a preferred embodiment of the method according to the invention, the model is guided during centering with the guide surface on a fixed space guide. This space-fixed guide preferably has first rollers.

This measure has the advantage that in this way already a stable guidance along the sawing direction available and the model can enter the subsequent sawing station immediately after centering.

In this context, it is further preferred if the spatially fixed guide faces a spatially movable guide for a surface of the model opposite the lateral guide surface.

This measure is for a safe, two-sided leadership advantage because the spatially movable guide makes it possible to guide the model on the opposite side also safe or to press against the space-tight leadership, the spatially movable leadership is able to follow the areas, which have a variable or a constant distance from the conveying direction and thus from the space-fixed guide.

This succeeds in a further embodiment of the invention particularly well, if the spatially movable guide has second rollers, which are each provided with an adjusting device for an adjustment perpendicular to the direction of sawing.

In further embodiments of the invention, the tree trunk is flattened before the side flattening on the top and on the bottom, for which purpose third means are provided.

This measure has the advantage that the promotion and centering of the tree trunk can be achieved in an even simpler and more reliable manner. If in this respect the term "top" and "bottom" is mentioned, then this of course the state at the moment of lateral flattening to understand. This does not exclude that the "top" and the "bottom" in a previous step also lie laterally, so the tree trunk is laterally flattened and then rotated by 90 ° before it is fed to the station for lateral flattening.

The invention is particularly suitable for tree trunks having a curved center line. In this case, the tree trunk is provided at the lateral flattening on a concave side with a curved guide surface which extends at a right angle to the plane of curvature of the tree trunk.

This measure has the advantage that the advantages already mentioned can be achieved to the full extent even with such curved tree trunks.

In further preferred embodiments of the invention, side panels are first separated from the model during sawing, preferably in the third station already mentioned.

This measure has the advantage already indicated above that lateral boards, strips or narrow wooden beams can be produced in this way, which in the area of the lateral guide surface over the entire length of the model, i. over the entire length of the tree trunk, go through. However, such long timber products are of disproportionately high economic value.

According to the invention, the model can be divided by circular saws or band saws.

Furthermore, it is alternatively possible to laterally flatten the tree trunk by cutting or by sawing.

Further advantages will become apparent from the description and the accompanying drawings.

Fig. 1

eine äußerst schematisierte Draufsicht auf eine Vorrichtung zum Zerlegen von konischen Baumstämmen;

Fig. 2

eine Darstellung, ähnlich Fig. 1, jedoch für ein Ausführungsbeispiel der Erfindung;

Fig. 3A bis 3C

in vergrößerter Darstellung einen geraden bzw. einen gekrümmten Baumstamm, wie sie auf der Vorrichtung gemäß Fig. 2 bearbeitet werden.

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

Fig. 1

a highly schematic plan view of an apparatus for disassembling conical tree trunks;

Fig. 2

a representation, similar to Figure 1, but for an embodiment of the invention.

Figs. 3A to 3C

in an enlarged view of a straight or a curved tree trunk, as they are processed on the apparatus of FIG. 2.

In the apparatus shown in Fig. 1, 10 designates a total of a processing line for cutting conical tree trunks.

Along a conveying direction 11, a tree trunk 12 is conveyed through the processing line 10. Indicated at 13 is that the tree trunk 12 may be preprocessed, i. may initially have been provided with a flattened top and also a corresponding flattened bottom, as is well known.

The tree trunk 12 is now preferably conveyed ahead with its thinner end 14, wherein the longitudinal axis 15 is aligned parallel to the conveying direction 11. The tree trunk 12 has a diameter d at the thinner end 14 and a diameter D at the rear, thick end. However, it is understood that the tree trunk 12 can also be conveyed ahead with the thicker end (the so-called "stick").

In the orientation shown on the left in Fig. 1, the tree trunk 12 is now fed to a Zerspanerstation 16, which may consist of two laterally arranged Zerspanerköpfen or two laterally arranged saws.

The Zerspanerstation 16 flattens the tree trunk 12 laterally, so that a model 17 is formed in which lateral areas 18a, 18b are removed and instead lateral guide surfaces 20a, 20b arise. The Zerspanerköpfe are adjusted so that the model 17 in the rear region has a diameter d ₁ , which is greater than the diameter d of the thinner end 14 of the tree trunk 12. Consequently, the lateral regions 18a, 18b and the lateral guide surfaces 20a, 20b do not extend over the entire length of the model 17, but terminate at a distance from the thinner tapered end 14.

The model 17 now enters a centering station 22, which consists of two spaced apart d ₁ roller tracks 24a, 24b. The model 17 runs first with its non-machined section in the region of the thinner end 14 in the centering station 22, so that initially no centering takes place, because the diameter of the model 17 in this non-machined section is smaller than the distance of the Roller tracks 24a, 24b. Only when the model 17 with the lateral guide surfaces 20a, 20b in engagement with the roller tracks 24a, 24b of the centering station 22, an exact centering takes place.

The model 17 now passes through a circular saw 26, which may alternatively be a band saw. The circular saw 26 generates saw cuts 27a, 27b at a distance from each other which corresponds to the distance d ₁ less twice the width of the side boards 28a, 28b to be produced. In the middle of the model 17 then remains a main product 30, which may be further divided into beams or boards.

Regarding the processing line 10 in FIG. 1, it should be noted that the side boards 28a, 28b produced at the end each have a length l ₁ which is significantly shorter than the total length L _{1 of} the model 17 and thus of the tree trunk 12.

In FIG. 2 and in FIGS. 3A to 3C, a further processing line 40 is now shown or the tree trunks processed thereon are illustrated.

In the processing line 40, a tree trunk 42 is conveyed and processed in a conveying direction 41. The tree trunk 42 has a cone angle α.

The tree trunk 42 is conveyed in the processing line 40 so that a lateral generatrix 43 of the tree trunk 42 is conveyed parallel to the conveying direction 41. Again, the tree trunk 42 is preferably supplied to the processing stations with the thinner end 44, in which case the tree trunk 42 may have been flattened in advance on the top in FIG. 2 and on the bottom side, as indicated by the reference numeral 49. Again, it is true that a conveying direction of the tree trunk 42 with the thicker end is also within the scope of the invention.

The longitudinal axis 45 of the tree trunk 42 is thus obliquely to the conveying direction 41 and although inclined by half the cone angle α / 2.

In this orientation, the log 12 is fed to a Zerspanerstation 46 or a sawing station, so that a model 47 is generated in which lateral portions 48 a, 48 b have been sawn or sawed off. As can be clearly seen by comparing FIGS. 1 and 2, in the procedure according to FIG. 2, the lateral areas 48a, 48b are not the same. On the contrary, the right-hand side region 48b extends in the conveying direction over the entire length of the model 47, while the left-hand region 48a in the conveying direction is substantially shorter in the longitudinal direction, but wider.

As a result of the stock removal or sawing off of the lateral areas 48a, 48b, lateral guide surfaces 50a, 50b are formed, wherein the lateral guide surface 50b passes over the entire length of the model 47, whereas the lateral guide surface 50a does not. In a conveying direction with the thicker end ahead, the guide surfaces 50a, 50b are immediately available when the model 47 enters subsequent stations.

The model 47 now passes into a centering station 52, in which laterally a left roller conveyor 54a in the conveying direction and a right roller conveyor 54b are provided. In contrast to the arrangement according to FIG. 1, only the right roller conveyor 54b is fixed in space in the centering station 52, while the left roller conveyor 54a consists of individual rollers which are individually adjustable laterally by means of an associated adjusting device 55.

Thus, when the model 47 in Fig. 2 enters the centering station 52 from left to right, the first roller of the roller conveyor 54a engages and advances at the forward end of the inclined lateral guide surface 50a 'until the straight lateral guide surface 50a reaches is. The following rollers follow this movement, so that the model 47 is guided on its left side in the conveying direction by all rollers of the roller conveyor 54a and pressed against the stationary roller conveyor 54b, regardless of whether the rollers of the movable roller conveyor 54a on the lateral guide surface 50a ' with varying width or abut the lateral guide surface 50 a with a constant width.

As a result, the model 47 is introduced into the circular saw 56 under contact with the spatially fixed guide of the roller conveyor 54b, whereby the right lateral guide surface 50b in the conveying direction is aligned parallel to the conveying direction 41.

As FIG. 2 shows on the right, this leads to two saw cuts 57a, 57b of different lengths being guided through the model 47, so that side boards 58a, 58b of different lengths are also formed, which include a main product 60 between them.

The side boards 58a, 58b have a width l ₂ and L _2, wherein L ₂ under otherwise identical conditions is slightly shorter than _L1. Nevertheless, the container produced in the procedure of FIG. 2 from a long side board 58b of length L ₂ and a short side board 58a of length l _{2 has} a higher economic value than the container produced in the procedure of FIG. 1 with two short side boards 28a, 28b of the same length l ₁ .

The conditions when processing and dividing the tree trunk 42 are again shown in principle in FIGS. 3A in a front view and in FIG. 3B in a plan view. 3C additionally shows the case of a tree trunk 42 'with a curved longitudinal axis 45'. It can be seen that the conditions are in principle the same as in the case of FIGS. 3A and 3B with an idealized tree trunk 42 with a straight longitudinal axis 45. In the case of a curved tree trunk 42 ', only care must be taken that the longer lateral guide surface 50b' is attached in the convex portion of the curvature.

Claims (20)

1. A method for dissecting conical logs (12; 42) having a cone angle (α), into wood products (28, 30; 58, 60), in which the log (12; 42) is flattened laterally to generate a profiled log (17; 47), the profiled log (17; 47) being centred and finally dissected by sawing, characterized in that the log (42) being already pre-treated (49), as the case may be, is flattened parallel to a surface line (43) during flattening, thereby creating a lateral guide surface (50b) for the subsequent centring, the guide surface (50b) being inclined by half the cone angle (α/2) relative to the longitudinal axis (45) of the log (42), and that the profiled log (47) is sawn in a direction parallel to the lateral guide surface (50b).
2. The method of claim 1, characterized in that during centring the profiled log (47) is guided with the guide surface (50b) along a stationary guide.
3. The method of claim 1 or 2, characterized in that prior to the lateral flattening, the log (42) is flattened on the upper side and on the lower side.
4. The method of one or more of claims 1 to 3, characterized in that the log (42') has a curved centre line (45'), and is provided on its concave side with a curved guide surface (50b') during the lateral flattening, the curved guide surface (50b') extending under right angles with respect to the plane of curvature of the log (42').
5. The method of one or more of claims 1 to 4, characterized in that during sawing, initially, lateral boards (58a, 58b) are dissected from the profiled log (47).
6. The method of one or more of claims 1 to 5, characterized in that the profiled log (47) is dissected by circular saws.
7. The method of one or more of claims 1 to 5, characterized in that the profiled log (47) is dissected by band saws.
8. The method of one or more of claims 1 to 7, characterized in that the log (42) is flattened by chipping.
9. The method of one or more of claims 1 to 7, characterized in that the log is flattened by sawing off.
10. An apparatus for dissecting conical logs (12; 42) having a cone angle (α), into wood products (28, 30; 58, 60), comprising a first station (16) for laterally flattening a log (12; 42), a second station (22; 52) for centring the profiled log (17; 47) generated during the flattening, and a third station (26; 56) for sawing up the profiled log (17; 47), characterized in that first means are provided for flattening the log (42) parallel to a surface line (43) during the flattening, whereby a lateral guide surface (50b) for the subsequent centring is generated, the guide surface (50b) being inclined relative to the longitudinal axis (45) of the log (42) by half the cone angle (α/2), and second means for sawing the profiled log (47) in a direction parallel to the lateral guide surface (50b).
11. The apparatus of claim 10, characterized in that the second means comprises a stationary guide for the lateral guide surface (50b)
12. The apparatus of claim 11, characterized in that the stationary guide comprises first rollers (54b)
13. The apparatus of claims 11 or 12, characterized in that the stationary guide is faced by a spatially displaceable guide for a surface (50a, 50a') of the profiled log (47) opposite the lateral guide surface (50b).
14. The apparatus of claim 13, characterized in that the spatially displaceable guide comprises second rollers (54a) being each provided with a displacement unit (55) for a direction of displacement perpendicular to the direction of sawing (41.
15. The apparatus of one or more of claims 10 to 14,
    characterized in that third means are provided for flattening the log (42) at the upper side and at the lower side prior to the lateral flattening.
16. The apparatus of one or more of claims 10 to 15,
    characterized in that the third station initially saws lateral boards (58a, 58b) from the profiled log (47).
17. The apparatus of one or more of claims 10 to 16,
    characterized in that the third station is configured as a circular saw station (56).
18. The apparatus of one or more of claims 10 to 16,
    characterized in that the third station is configured as a band saw station.
19. The apparatus of one or more of claims 10 to 18,
    characterized in that the first station is configured as a chipping station (46).
20. The apparatus of one or more of claims 10 to 18,
    characterized in that the first station is configured as a sawing station.

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