EP1389509B1 - Method and apparatus for processing solid wood cut blanks - Google Patents

Abstract

Method for sawing wood boards (12) in which the wood is to be cut into planks, whereby in a first step the wood is cut along a zero line (32) by placing the wood against a zero line so that the first cut is made in a section of the board that is essentially parallel to a transport plane (13). The invention also relates to a corresponding device for method implementation.

Description

The invention relates to a method and an apparatus for producing strips of solid wood blank.

In the production of wood blanks a sawing device is fed to a solid wood cut, which is usually cut by several saw blades at the same time. The solid wood cut consists for example of trimmed or unedged solid wood boards. The solid wood cutting can also include so-called boards and planks, which are made in the sawmill from logs. When cutting the trunks they are cut to a certain thickness before these boards or planks are dried, so that a residual moisture of, for example, 7 to 9% remains. In this state, the wood blanks are used in particular for interior work, for stairs, furniture, parquet as well as in building construction and other industries.

When drying the solid wood cut, the cut surface curves through the different tangential and radial shrinkage. As a result, the solid wood cut usually has a flat V-shaped cross-section or uneven, mostly curved sawing surfaces are formed.

From DE3839997 C1 a method for cutting a board longitudinally with a flat V-shaped or curved cross-section is known. Here, a first portion of the cross section of the board is held down with a clamping plate on a trolley. A second section of the cross-section of the board is made freely by the sawing device. Between the first and the second section a longitudinal section is attached. This method does not provide strips or edges with a square or rectangular cross-section.

From US 5 819 622 A a sawing device is known, which proposes an automatic alignment of a sawed material to saw blades. The shallow V-shaped or curved solid wood blank is fed to a sawing gate after the release of alignment by the operator to make the cuts so that the solid wood blank is cut into slats or edges. By fixing and conveying the solid wood blank between two pairs of transport rollers, the solid wood blank is positioned in an averaged position due to the flat V-shaped cross section or uneven surfaces. As a result, the cut strips or edges do not have a square or rectangular cross-section. Rather, the cut surfaces include an angle that is greater or less than 90 °, resulting in, for example, a trapezoidal cross-section. For further processing of the wood blanks, however, it is necessary that a high dimensional stability is given. Therefore, these strips or edges with an angle of the cut surfaces greater or smaller than 90 ° of further processing, such as planing, must be subjected to bring the blanks to measure.

The invention is therefore an object of the invention to provide a method and apparatus for the production of strips or edges of solid wood blank, which allows a high dimensional accuracy in the cutting of solid wood blanks.

This object is achieved by the method according to the features of claim 1 and the device according to the features of claim 8. Advantageous embodiments and embodiments of the invention can be found in the dependent claims.

According to the inventive method, at least a first longitudinal section is introduced into a first section of the solid wood section, which is held down between the pressure roller and the conveyor belt. Thus, the first longitudinal section is introduced substantially perpendicular to the already existing saw cut surfaces of Masslvholzschnittes, whereby a Maßhaltiges clippings, such as strips or edges, tailored and reworking by planing or the like is considerably reduced or may be unnecessary. By means of a second section of the solid wood section lying outside the section area, it is ensured that an increased dimensional accuracy is provided for the at least one first section.

At least a first longitudinal section is set in a region between a heartwood and an outer edge of the solid wood blank wherein the zero line is positioned in the cutting region in such a way that a section of the solid wood blank adjoining the heartwood rests substantially flat on a conveyor belt and passes through the sawing device. The positioning of the zero line for the first longitudinal section thus makes it possible, for example, for a leg of the flat V-shaped cross section of the solid wood blank to lie flat on the conveyor belt and for the solid wood blank to be cut in this position during the course of time by the pressure roller which at least partially covers the first section Longitudinal section is held down, whereby the first cut is formed substantially perpendicular to the support surface of the solid wood blank on the conveyor belt or to which abutting the pressure roller bearing surface. The second section of the flat V-shaped cross-section of the solid wood blank passes freely through the sawing device, without being influenced by the pressure roller or the conveyor belt. This makes it possible that the solid wood blank is not supplied in an averaged position for the blank, but a portion of the solid wood blank undergoes alignment, whereby the dimensional stability is increased. The zero line may alternatively be in a range between a right and left Edge of the conveyor belt lie, so that the solid wood cut is partially or completely passed through the cutting area. For this application, a pressure roller is provided, which is subdivided into several sections with different diameters or as a multi-part pressure roller is formed whose individual sections are adjustable at a distance from the support surface.

The same applies to a solid wood cut of a tree trunk, which lies outside the heartwood area. Due to the tangential and radial shrinkage, curved surfaces are formed when drying. The solid wood cut is carried out at least partially flat on the conveyor belt resting through the cutting area and at least another section is outside the cutting area or is not held down by a pressure roller or a pressure roller section, so that only lying in the cutting section or lying between conveyor belt and pressure roller and guided section rests flat on the conveyor belt.

Solid wood cutting Preferably, the saw good is positioned in the region of the heartwood to the zero line for a first dimensionally stable blank in order to achieve maximum yield. If only one cut was made in the first processing step, the two blanks can be fed again to the sawing device for further processing steps for cutting strips.

Advantageously, it may also be provided that when carrying out the first processing step when aligning the solid wood cuttings at the zero line, a plurality of further cuts are simultaneously made in the section, which rests essentially flat on the conveyor belt. As a result, in this first processing step, a first section of the solid wood blank can be completely cut to size, as far as possible, and the second section of the solid wood blank can be processed by re-feeding. When feeding the second section of the solid wood blank, it is advantageously taken into account that a new cut is made either near the first cut outside the heartwood area along the zero line since the first cut is near the heartwood area for the second section of the solid wood blank is not dimensionally stable and the heartwood is preferably completely removed or that the further cuts are provided such that the first cut near the heartwood along the zero line does not form a blank for the strip.

By carrying out the individual steps according to the invention it is possible that the cut strips and edges have a high dimensional stability and the loss by planing is substantially lower, whereby a reduction of the planing losses is given.

According to an advantageous embodiment of the invention, it is provided that the zero line is positioned opposite in an outer edge region of the cutting region, preferably the saw shaft drive, along which the solid wood blank is guided. As a result of this advantageous positioning of the zero line, one section of the solid wood blank can be positioned outside the cutting area and the other section can be passed through the cutting area without the pressure roller acting on the outside section. In this positioning of the zero line, the pressure roller, which is usually formed with a constant diameter, extend over the entire region of the conveyor belt. As a result, a simple construction of the sawing device can be maintained. At the same time an existing sawing device can be retrofitted by this positioning of the zero line, without any replacement or adaptation of the pressure rollers or the conveyor belt is required.

Alternatively, the zero line can also be positioned anywhere within the cutting area. Advantageously, pressure rollers are provided for this case, which extend sectionally, so that for a first half of the solid wood blanks a substantially planar system on the conveyor belt is made possible and the second half is carried out without affecting the pressure roller freely through the cutting area. The pressure rollers may also be formed in sections, so that, depending on the positioning of the zero line and within the cutting area a passage can be created, for example, by Lifting the pressure roller is formed upwards and allows passage of the other, not planed resting on the conveyor belt section through the cutting area.

According to a further advantageous embodiment of the invention, it is provided that in a first processing step, the zero line is provided in the outer edge region of the cutting area and hidden in a second processing step, the zero line or visualized as a further cutting line. Depending on the width of the solid wood blank as well as the geometry of the crop, the zero line can be hidden or provided as a further cutting line to allow further cutting. This advantageously also makes it possible for a small number of light sources, by means of which the zero line and the cutting line are visualized, to be required in order to equip the sawing device.

For example, in a curved solid wood blank, several successive cuts are made corresponding to the first cut. The zero line and the further cut line coincide so that the position of the further cut line corresponds to the zero line.

Advantageously, it is provided that a first and subsequent processing steps are programmable and retrieved via a control unit. By this control, the zero line and optionally at least one further cutting line for the first and for the further processing steps are adjusted, whereby a high flexibility and rapid conversion of the sawing device is also possible during the processing of solid wood blanks for different geometries of solid wood blanks. The zero line is preferably positioned on the side facing away from the drive side. The programming of the zero and optionally further cutting line can be done both for permanently provided on the drive shaft or adjustable blades. The positioning of the further cutting lines is done from the zero line as a reference.

In an advantageous embodiment of the method it is provided that a plurality of zero lines are provided in a cutting area, so that several solid wood blanks are fed simultaneously or successively the cutting area. In this case, a first zero line is advantageously arranged flush or at a small distance from the edge of the conveyor belt and the further zero line is positioned at a predetermined distance.

By means of the device according to the invention, in particular for carrying out the method according to the invention, a flexible arrangement of at least one zero line in the feed region for a first cut of the solid wood blank is provided, whereby the production of dimensionally stable cut material is made possible.

By the design of a free passage adjacent to the cutting area, it is made possible that the solid wood cut is fed with a first section of a cutting area and a second section outside the cutting area is guided past the saw blades. As a result, a substantially planar installation of the solid wood section in the region of the first section can be made possible, whereby a maximum dimensional accuracy is given. This applies to both solid wood cuts with and without core area.

The zero line is visualized by a light source and can be advantageously positioned by a positioning unit at least along the cutting area. As a result, the zero line can be provided both on a left and on a right edge of the cutting area, so that a region of the solid wood blank between the conveyor belt and the pressure roller passes through the sawing device and the other area is passed through without interference from the sawing device.

Alternatively it can also be provided that the zero line between the left and right edge or in a central region of the cutting area is adjustable, wherein the cutting of a solid wood blank, for example, a pressure roller is provided, which extends only partially regionally to the cutting area, so that one or individual sections of the substantially flat on the conveyor belt can rest.

According to an embodiment of the device according to the invention it is provided that viewed in the transport direction of the solid wood blank outside the cutting area laterally on the conveyor belt near the zero line a guide bar is provided which extends at least between the saw blade and the end of the conveyor belt. As a result, the portion of the solid wood blank outside the cutting area can be supported and guided during the first cutting. This ensures that the solid wood cut goes straight through to the end of the cut. The use of the guide bar is particularly provided when the zero line is positioned within the cutting area with a small distance to the lateral edge region of the transport roller and pressure roller. After the complete introduction of the cut, the section of the solid wood blank lying substantially outside the cutting area is still caught by the transport roller and pressure roll for removal, which is supported by the guide strip.

As an alternative to this embodiment of the invention, the invention provides that in an arrangement of the zero line substantially flush with the lateral edge of the conveyor belt, a further transport conveyor is provided, which laterally adjoins and extends at least from the saw blade to the end of the transport device of the saw. As a result, the portion of the solid wood blank lying outside the cutting area can be transported away after the cut along the zero line and, if appropriate, fed to the feed area for a subsequent processing step.

In the previous embodiments, the pressure rollers extend over the entire width of the conveyor belt, wherein the width of the conveyor belt corresponds to the cutting area. Deviations from this are possible, such as the pressure roller protrudes beyond the edge of the conveyor belt or does not extend to the edge and also allow the implementation of the method and the use of the device.

Figur 1

eine schematische Seitenansicht der erfindungsgemäßen Vorrichtung zur Durchführung des Verfahrens,

Figur 2

eine schematische Draufsicht auf die erfindungsgemäße Vorrichtung und deren Peripheriegeräte,

Figur 3

eine weitere schematische Seitenansicht der Vorrichtung gemäß Figur 1,

Figur 4

eine schematische Ansicht der Vorrichtung gemäß Figur 1 bei einem zweiten Bearbeitungsschritt,

Figur 5

eine schematische Ansicht einer alternativen Anordnung einer Nulllinie zu Figur 1,

Figur 6

eine schematische Draufsicht auf Figur 5 und

Figur 7

ein schematischer Querschnitt eines gekrümmten Sägegutes.

A preferred embodiment of the invention is given in the following description, drawings and claims. Show it

FIG. 1

a schematic side view of the device according to the invention for carrying out the method,

FIG. 2

a schematic plan view of the device according to the invention and its peripheral devices,

FIG. 3

FIG. 1 shows another schematic side view of the device according to FIG. 1, FIG.

FIG. 4

1 is a schematic view of the device according to FIG. 1 in a second processing step;

FIG. 5

1 is a schematic view of an alternative arrangement of a zero line to FIG. 1,

FIG. 6

a schematic plan view of Figure 5 and

FIG. 7

a schematic cross section of a curved Sägegutes.

In the figures 1 to 3, a device 11 for processing solid wood blanks 12 is shown in several perspectives. The device 11 has at least one conveyor belt 13, through which the solid wood blank 12 is fed to one or more saw blades 14. The solid wood blank 12 is held down by at least one pressure roller 16 before and after the saw blades 14, so that the surface of the conveyor belt 13 can engage the solid wood blank 12 and ensure transport.

The saw blades 14 are adjustable in their distance from each other within a cutting region 17 and are driven by a motor 19 via a common shaft 18. The saw blades 14 may be positioned with a fixed setting, a so-called fixed mount on the shaft 18 or be slidably disposed on the shaft 18 as a so-called Schiebeinhang by one sleeve. The shaft 18 may have an abutment on an end opposite the motor. Furthermore, alternative or further bearings may be provided to allow a low-vibration mounting of the saw blades 14 for a precise cut. The device 11 has a programmable control unit 21 for controlling the motor 19 and the cutting speed of the saw blades 14. The solid wood blank 12 is placed in a feed region 23 according to Figures 2 and 3 on the conveyor belt 13 and passes through the cutting area 17. By the conveyor belt 13th is the solid wood blank 12, which after passing through the cutting portion 17 at least one cut out of a first portion 26 and a second portion 27 led out of the device 11 and fed to a removal device 28. This removal device 28 carries the clippings, for example, cut strips that have an edge length of up to about 20 to 25 mm or edges, which have a larger edge length, for further processing or storage. The sections 26, 27 of the solid wood blank 12 which are to be cut further are conveyed via a conveyor 29 to the feed area 23 of the device 11 in order to feed them again to the device 11 for processing. Above the cutting area 17 light sources 31 are provided, which visualize a zero line 32 and further cutting lines 33, 34 and 36. The light source 31 is preferably formed by a laser operating in the visible wave spectrum to project the lines onto the feed region 23. The lines visualized by the light sources 31 are aligned with the saw blades 14 positioned on the shaft 18.

The light sources 31 are each connected to a positioning unit 37. The positioning units 37 are actuated by the control unit 21 so that the light source 31 is freely positionable and adjustable transversely to the cutting area 17, that is to say that the position of the light source 31 is assigned to a position of the saw blade 14. When using the Schiebeineinhanges the light source 31 and the respective saw blades 14 are moved in coordination with each other within the cutting area, serving as a reference for setting the distance, the zero line. The positioning unit 37 comprises, for example, a linear operation, by means of which the light source 31 is displaceably arranged on guides. Belt, chain, threaded, threaded spindle drives, pneumatic, electric, hydraulic drives or a combination of these can be used.

Advantageously, a light source 31 is provided for each saw blade 14. When programming the controller to the individual processing steps, the distances of the saw blades 14 to each other from the provided in the zero line 32 saw blade 14 are calculated from. Likewise, the positioning of the light sources 31 takes place analogously. In this case, the positioning of the zero line according to FIG. 1 or FIG. 5 is taken into account. However, it is also possible to provide fewer light sources 31, in which case a renewed method and positioning of the light sources 31 is required in each case depending on the desired work steps.

In Figure 1, for example, the solid wood blank 12 is shown in cross-section, which after drying usually has a flat V-shaped cross-section. The flat cut surfaces 38, 39, which are produced in the manufacture of the solid wood blank 12, change during drying of the solid wood blank 12th Thus, in a first processing step, a first cut with a high dimensional accuracy is introduced substantially at an angle of 90 ° to the cut surfaces 38, 39, it is provided that a zero line 32 is positioned in an outer edge region of the cutting region 17. In the exemplary embodiment, this is provided in Figure 1 on a side facing away from the motor 19. Alternatively, this may also be provided on a side facing the motor 19. The first section 26 of the solid wood blank 12 is fed to the saw blades 14. Due to the substantially planar system on the conveyor belt 13 rectangular cuts can be placed in this section 26. The first cut is adjacent to the heartwood 41, whereby a first and second section 26, 27 is formed, unless another cut is introduced simultaneously.

The curved solid wood blank 12, however, has no heartwood 41, as shown in Figure 7 in more detail. Due to the cut annual rings 43 undergoes the solid wood blank 12 during drying a radial and tangential shrinkage, whereby the curvature or bowl of the solid wood blank 12 is done. When machining a curved solid wood blank 12, the size of the section 26, 27, 27 ', 27' ', 27' ", etc. is advantageously chosen such that the largest part of a single section 26, 27, 27 ', 27" , 27 '' 'etc. rests flat on the conveyor belt 13. The adjacent sections are processed in subsequent processing steps analogous to the first processing step.

For example, in the first processing step, several cuts may be made by, for example, saw blades 14 adjacent to the zero line 32, as shown in FIG. 1, for example, whereby the outer edge 40 of the solid wood blank 12 is severed. So that the further section 27 can be passed outside the cutting area 17 through the device 11, a free passage 42 is provided adjacent to the cutting area 17.

In FIG. 1, the zero line 32 is positioned flush with the edge 44 of the conveyor belt 13. The solid wood blank 12 is preferably supplied in a flat V-shaped cross section such that the zero line 32 near the transition of the two legs in the region or at the area of the Kemholzes 41 is adjacent. The section 27, which lies outside the section area 17, is picked up by a conveying device 50 after the complete cut and transported further.

After the first processing step - as shown in Figure 1 - is carried out, the first portion 26, if completely cut, be transported via the removal device 28. If this section 26 is not completely cut, it can be returned together with the second section 27 via the conveyor 29 to the feed region 23. This is followed by one or more processing steps corresponding to the first processing step or, for example, as shown in FIG. 4.

In Figure 4, a fixed adjustment 54 is provided, which is formed by the outermost saw blade 14 and is visualized by the section line 36. The one or more arranged on the motor side adjacent saw blades 14 are set to the width of the crop to be produced. The sections 26, 27 are preferably applied to the cutting line 36 so that the trimmed or unedged edge is completely cut off and a plurality of the finished strips or edges are cut to size.

In the embodiment shown in Figure 5, the zero line 32 is offset from an edge 44 of the conveyor belt 13 by a distance 46 inwardly. This makes it possible that an area 47 of the section 27 of the solid wood blank 12 is held between the conveyor belt 13 and the pressure roller 16 and led out of the cutting area 17. Supporting a guide rail 51 for supporting and guiding the free portion 27 is provided in the rear region of the device 11. Advantageously, the further pressure roller 16 or a separate roller may have a region 52 which extends at least partially transversely to the guide rail 51 in order to ensure a removal of a portion 27 from the guide rail 51. The contact pressure is adjusted so that no effects on the clippings in the cutting area are given.

In the exemplary embodiment, the saw blades 14 are fixed on the shaft 18. Alternatively, it can also be provided that the saw blades 14 are provided on the shaft 18 movable between the individual processing steps. The change in the distances between the saw blades 14 is set and detected via the control unit 21, so that in analogy thereto the light sources 31 for visualizing the zero line 32 and the cutting line 33, 34, 36 are adapted accordingly.

Claims (14)

1. A method for machining a solid wood cut blank (12) with a flat V-shaped or curved cross-section, wherein the solid wood cut blank (12) is cut to strips or edgings by means of a sawing apparatus (11), wherein, in a first step of machining the solid wood cut blank (12), at least one first cut is made along a zero line (32), wherein,

   - with a flat V-shaped cross-section of the solid wood cut blank (12), said first cut is made in a first section (26) within a region between a heartwood (41) and an outer edge (40), or,

   - with a curved cross-section of the solid wood cut blank (12), said first cut is made in a first section (26) between an outer edge (40) and an interior region adjacent thereto, and

   - said first section (26) is placed flatly on a conveyor belt (13) and is pressed down by a pressure roll (16), and

   - a second section (27) of the flat V-shaped or curved cross-section of the solid wood cut blank (12) is freely passed through the sawing apparatus (11) while said first cut is being made, and

   - said second section (27) of the solid wood cut blank (12) is machined in a machining step following after the first machining step and analogously therewith.
2. A method according to Claim 1, characterized in that the zero line (32) is positioned in an outer marginal region of the conveyor belt (13) and that a section of the solid wood cut blank (12) that extends from the heartwood (41) to the lateral edge (40) of the solid wood cut blank (12) or a section (26, 27, 27', 27", etc.) of the solid wood cut blank (12) is positioned in the cutting region (17).
3. A method according to anyone of the preceding claims, characterized in that, in a first machining step, it is provided to position the zero line (32) in the marginal region of the conveyor belt (13) and that, in at least one second machining step, the zero line (32) is hidden or adjusted and visualized as a further cutting line (33, 34, 36).
4. A method according to anyone of the preceding claims, characterized in that, for said first and said further machining steps, the positioning of a light source (31) for the zero line (32) and/or at least one cutting line (33, 34, 36) can be programmed and said light source (31) is positioned and adjusted by means of a control unit (21).
5. A method according to anyone of the preceding claims, characterized in that the zero line (32) is adjusted flush with the edge (44) of the conveyor belt (13).
6. A method according to anyone of Claims 1 to 3, characterized in that the zero line (32) is set to be spaced apart from the outer edge (44) of the conveyor belt (13) by a distance (46).
7. A method according to anyone of the preceding claims, characterized in that, depending on the machining steps, the zero line (32) and the further cutting lines (33, 34, 36) are each rendered visible through a light source (31), preferably a laser, by means of an oscillating light beam within the feeding region (23).
8. An apparatus for machining solid wood cut blanks (12) with a flat V-shaped or curved cross-section, comprising at least one saw blade (14) and at least one conveyor belt (13) for feeding the solid wood cut blank (12) to a cutting region (17), comprising at least one light source (31) for visualizing at least one zero line (32) in the feeding region (23), which zero line (32) can be adjusted within the cutting region (17) for at least one first longitudinal cut of the solid wood cut blank (12) such that the at least one zero line (32) defines the positioning of a first section (26) of the solid wood cut blank (12) for the first longitudinal cut of the solid wood cut blank (12), wherein a first section (26) of the solid wood cut blank (12) crossing through the cutting region (17) and being that section in which the longitudinal cut is made is pressed down onto the conveyor belt (13) by at least one pressure roll (16) and wherein, adjacent to the cutting region (17), a free passage (42) is provided for the second section (27) which is to be passed through outside of the cutting region (17) and, within the passage (42) and in parallel to the conveyor belt (13), a conveyor assembly (50) for receiving and transferring the second section (27) or a guiding strip (51) for supporting and guiding the second section (27) is provided at least from the cutting region (17) to the end of the conveyor belt (13).
9. An apparatus according to Claim 8, characterized in that, for a first longitudinal cut of the solid wood cut blank (12), the zero line (32) defines the positioning of a region between the outer edge (40) and a heartwood (41) of the solid wood cut blank (12) or between an outer edge (40) and an interior adjacent region of the solid wood cut blank (12) and a first section of the solid wood cut blank (12) crossing through the cutting region (17) and being that section in which the at least one longitudinal cut is made in the first machining step is pressed down onto the conveyor belt (13) by at least one pressure roll (13).
10. An apparatus according to Claim 8 or 9, characterized in that the light source (31) for visualizing the zero line (32) is arranged at a positioning unit (37) and can be positioned at least along the cutting region (17).
11. An apparatus according to anyone of Claims 8 to 10, characterized in that at least one further light source (31) is provided for visualizing a cutting line (33, 34 and 36) and can be positioned in relation to the cutting region (17), preferably each by means of one positioning unit (37).
12. An apparatus according to anyone of Claims 8 to 11, characterized in that the positioning unit (37) and, preferably, the position of the saw blades (14) can be controlled by means of a control unit (21), preferably one at a time.
13. An apparatus according to anyone of Claims 8 to 12, characterized in that, for a first machining step, at least one cutting line (33, 34, 36) can be adjusted in parallel to the zero line (32).
14. An apparatus according to anyone of Claims 8 to 13, characterized in that the zero line (32) and the further cutting lines (33, 34, 36) can be adjusted separately from each other and can be programmed for a plurality of machining steps.

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