EP1183136B1 - Method and device for transversally gluing veneer strips - Google Patents

Abstract

The invention relates to a method and a device for transversally gluing veneer strips (1) in order to produce a butt-glued veneer carpet (2). According to the invention, a first sensor unit (4) and a second sensor unit (7) are provided for aligning a front edge or a back edge (5) of a veneer strip (1) or a veneer carpet (2) by means of several conveyor belts (8 to 11) or (12 to 17) in such a way that said edge is located exactly in a centre line of a heating area (3).

Description

The invention relates to a method and a device for cross-bonding of veneer strips to a butt-glued Veneer carpet.

From the prior art it is known to veneer strip glue their edges to a larger veneer carpet to create.

For this purpose, from the prior art so-called Querzusammensetzmaschinen for butt bonding of wood veneers known. These machines are pre-glued veneer strips transferred to a heating zone and there under pressure and heat glued together at their edges. It understands itself, that it is necessary, the joining areas of the Orient each veneer strip so that it is in the heating zone lie.

The exact alignment of the trailing edge of the previous one Veneer strip is in known devices characterized achieved that the veneer strip across the heating zone transported and then a reversing countermovement is subjected. Before this countermovement begins, in the area of the heating zone stop pins are extended, against which of the veneer strips is mechanically applied. Of the each next veneer strip to be glued is meanwhile supplied and also aligned against stop pins. Subsequently, the other veneer strip against the still located in the heating zone stop pins and driven thus aligned accordingly. For bonding the two Veneer strip is then closed the heating zone, the Stop pins are withdrawn. The previous veneer strip is held tight while the new, additional Veneer strips against the edge of the previous one Veneer strip is pushed and held on tension until the joining process is finished.

A disadvantage of this method, on the one hand, proves to be that by the reversing movement of the preceding veneer strip a considerable amount of time required is. Furthermore, wavy or warped veneer strips exist the danger that these are not exactly against the stop pins be created. The veneer strip would thus not lying flat before the pins, but wrinkles and others Have deformations. The same applies to the new veneer strip, after removing the stop pins against the Edge of the previous veneer strip is pushed. Also here there is a risk that this shift process is not exactly.

A similar process in which a veneer strip by means Pendulum stops and first leaf stops, is described in the Utility Model 93 01 196.2. The case used attacks lead to the disadvantages described above.

From the prior art, it is also known, the resulting Veneer carpet after the joining process by one Continue to transport veneer strip width and fix it. There is a risk that tolerances in the veneer strip widths as well as the transport mechanics with increasing Add the number of joints so far that the one to be glued Edge of the veneer strips no longer in the area of the heating zone lies.

EP 0 199 841 A (closest prior art) describes a device for coating of veneers with carrier material. For positioning the individual Veneer sheets provided a pendulum stop, the the leading edge of a respective next veneer sheet opposite the rear edge of the last inserted veneer sheet aligns. This expiring edge of the last inserted Veneer sheet is scanned by means of a scanning device. Should not the expiring, rear veneer edge correct, it is by means of a straightening device aligned. The straightening device is at the press outlet in Arranged portion of the guide roller and includes a pressure roller, which in terms of their right or left end stronger pressed or lowered.

Another device for aligning a material web, in particular a veneer sheet, is known from DE 29 16 828 A. Also in this device is already created and in the device located veneer sheet aligned or twisted, wherein the alignment process to the expiring Edge of the previous veneer sheet applies. in this connection a monitoring device is provided, by means of which a Holding device or an additional drive device operable is. In this case, the main drive device is corresponding off.

Another machine for gluing together veneer sheets describes the DE 89 07 631 U. Also in this machine provided a pendulum stop, against which a subsequent Veneer sheet is created. This will be together with the shuttle stop to the rear end of the previously formed Veneer path continues to move in this way the leading edge of the next veneer parallel to the trailing edge of the bis aligned veneer sheet parallel to it.

The invention is based on the object, a method and to provide a device of the type mentioned, which with a simple structure and simple, reliable applicability the extensive automatic butt gluing of Enable veneer strips.

According to the invention, the object is achieved by the two independent Claims 1 and 7 are solved, the respective subclaims show Further advantageous embodiments of the invention.

The inventive method is characterized by a series significant benefits. First of all, completely refrain from using mechanical slings use, at least in the area of the heating zone. Thus separates the danger that the edge of a veneer strip is insufficient or correctly applied against slings, completely out. In addition, the mechanical structure is simplified the device since on the mechanical stop means as well whose drive and control can be completely dispensed with.

By the several transport devices independently To control, there is the possibility of the veneer strip even then to align very precisely, if this one wrong or if the veneer strip is bent or warped. Thus, according to the invention, it is possible to to position a veneer strip exactly and if necessary bend out while doing this in parallel to align to the heating zone and to position in this. On a reversing movement can be dispensed with.

The inventive method is thus both on the alignment to apply the trailing edge of a first veneer strip as well as on the respective leading edges of the following Veneer strips. It is thus possible to have an optimized and perform fault-free joining, regardless of the number of veneer strips and minor deviations.

Depending on the desired Precision of the gluing process can be sufficient many measuring points are used.

To avoid mistakes after passing through the first sensor unit could occur, it is particularly advantageous if by means of a second sensor unit in the area the heating zone determines the position of the edge of the veneer strip and, if necessary, a position correction of the veneer strip is made. It is thus possible within Once again check the heating zone to see if the edge of the veneer strip is exactly positioned and, if necessary, a correction perform.

In order to achieve a uniform formation of the veneer carpet, to ensure a high-quality, precise joining process, It is particularly advantageous if the edge of the Veneer strip parallel to the perpendicular to the transport direction arranged heating zone is positioned. The joining area is thus always in optimal alignment with the heating zone.

Especially with longer or larger veneer strips the danger that these warp or bend. Around To compensate for such errors is provided according to the invention, that by means of the first and / or the second sensor unit a bending of the veneer strip is detected and that the multiple transport devices for straight alignment the veneer strip are operated separately. It can It may be particularly beneficial if individual areas of the veneer strip be clamped to the straight alignment of the same. Other areas may continue by means of the transport facilities be moved, so that there is a straight joint edge.

It is particularly advantageous if the veneer strip in Transport direction reversibly movable behind the heating zone is. This is especially the case with a first veneer strip possible to optimize this after passing its trailing edge Align way in the heating zone.

With regard to the device is based on the invention lying task solved by the features of claim 7.

The device according to the invention is also characterized a number of significant benefits. First of all, the whole Construction of the device relatively easy, because on the plane the veneer strip retractable stop elements according to the State of the art can be completely dispensed with. contamination or damage to the stop elements and their Drives can therefore no longer occur. Simplified the manufacture of the device. In addition will the maintenance effort is greatly reduced.

To the individual veneer strips exactly straight to the heating zone to be able to align and thereby also rotational movements To be able to perform, it is particularly advantageous if the first group of transport devices several in the transport direction juxtaposed, separately operable Includes conveyor belts. The same applies to the second group of transport facilities.

The first and / or the second group of transport facilities are preferably counterpressure for contacting associated with the surface of the veneer strips. through This counter pressure means it is possible to put the veneer strips in to clamp individual areas to compensate for bending. The counter-pressure means preferably comprise ball elements, which only lead to a selective clamping and thus allow twisting of the veneer strip.

The first and second sensor units comprise according to the invention preferably optical sensors. The optical sensors thus form in a favorable embodiment of the invention vertical Light barriers. The passage of a leading edge or a Behind edge of a veneer strip can thus be detected very accurately and be registered. Because transverse to the transport direction a plurality of such light barriers are formed, it is special reliably possible, the veneer strip exactly in terms capture its original position and subsequently align.

The first and / or the second group of transport facilities is designed in a particularly advantageous manner so that They both in the transport direction and against the transport direction is operable.

The heating zone advantageously comprises upper and lower Pressure elements around the veneer strips during the joining process to keep exactly.

Fig. 1

eine schematische Seitenansicht eines Ausführungsbeispiels der erfindungsgemäßen Vorrichtung,

Fig. 2

eine vergrößerte Detailansicht des Heizzonenbereichs der erfindungsgemäßen Vorrichtung,

Fig. 3

eine Ansicht, ähnlich Fig. 2, eines weiteren Ausführungsbeispiels der Erfindung,

Fig. 4

eine Darstellung analog Fig. 3 in detaillierterer Darstellung,

Fig. 5

eine schematische, vereinfachte Draufsicht auf einen Teilbereich der erfindungsgemäßen Vorrichtung,

Fig. 6

eine perspektivische Teildarstellung eines oberen Bereichs der Heizzone und der zugeordneten Elemente,

Fig. 7

ein Zeitdiagramm des Ablaufs der Ausrichtung eines ersten Furnierstreifens parallel zur Heizzone,

Fig. 8 bis 10

Detaildarstellungen der Ausrichtung des Furnierstreifens gemäß dem Ablaufdiagramm der Fig. 7,

Fig. 11

ein Zeitdiagramm des Ablaufs der Ausbiegung des ersten Furnierstreifens parallel zur Heizzone,

Fig. 12 bis 14

Detailansichten zu den Abläufen gemäß Ablaufdiagramm der Fig. 11,

Fig. 15

ein Zeitdiagramm des Ablaufs der Ausrichtung eines Furnierteppichs parallel zur Heizzone, und

Fig. 16 und 17

Detaildarstellungen des Ablaufs gemäß Ablaufdiagramm der Fig. 15.

In the following the invention will be described by means of embodiments in conjunction with the drawing. Showing:

Fig. 1

a schematic side view of an embodiment of the device according to the invention,

Fig. 2

an enlarged detail view of the heating zone region of the device according to the invention,

Fig. 3

a view, similar to FIG. 2, of a further embodiment of the invention,

Fig. 4

a representation analogous to FIG. 3 in more detail,

Fig. 5

a schematic, simplified plan view of a portion of the device according to the invention,

Fig. 6

a partial perspective view of an upper portion of the heating zone and the associated elements,

Fig. 7

a time chart of the process of alignment of a first veneer strip parallel to the heating zone,

Fig. 8 to 10

Detailed views of the orientation of the veneer strip according to the flowchart of Fig. 7,

Fig. 11

a time chart of the course of the deflection of the first veneer strip parallel to the heating zone,

Fig. 12 to 14

Detailed views of the processes according to the flowchart of FIG. 11,

Fig. 15

a time chart of the course of the alignment of a veneer carpet parallel to the heating zone, and

FIGS. 16 and 17

Detailed views of the sequence according to the flowchart of FIG. 15.

In Fig. 1 is a simplified, schematic side view an embodiment of the device according to the invention shown. The device is divided into a transport area I for feeding individual veneer strips to be glued by means of conveyor belts or transport belts, one Joining area II with a heating zone 3, a transport area III with transport belts or conveyor belts for alignment the veneer carpet, a cutting area IV and a delivery area V to the outlet of the cut veneer sheets, too their transfer to storage or stacking facilities.

In Fig. 1, the transport direction is shown by an arrow 6. Simplified is a veneer strip 1 is shown which by conveyor belts 8 to 11 a first group of Transport devices is supplied. To clarify the Representation, the respective transport facilities are open shown. With 2 a veneer carpet is called, the consists of several glued veneer strips.

In the area of joining area II it can be seen that the heating zone 3 of an upper 18 and a lower 19 pressure element consists. Following the heating zone 3 are lower conveyor belts 12-15 of a second group of transport facilities shown. Above the conveyor belts 12 to 15 are located Counterpressure 16 with ball elements 17.

The joining area is shown enlarged in FIG. 2. there is particularly apparent that the conveyor belts 8 to 11 at least one friction shaft 20 is arranged downstream, the respective veneer strip 1 moves into the heating zone 3.

Fig. 2 shows schematically a first sensor unit 4. The illustration shows in particular the vertical one Photoelectric sensor formed by the first sensor unit 4 becomes.

The reference numeral 7 shows a second sensor unit, which is located in the area of the heating zone 3. The distance the two sensor units 4 and 7 is for example 60 mm.

In the transport direction behind the second sensor unit 7 is a line 21, which is the ideal position for a trailing edge 5 of a preceding veneer strip 1 forms.

From Fig. 2 is further seen that above the conveyor belts 12 to 15 of the second group of transport facilities Counterpressure 16 is arranged with ball elements 17 are adjustable in height.

The first and the second sensor unit 4, 7 thus form a Number of light sensors or other detection elements which the position and parallelism of veneer strips 1 as well detect the curvature of a first veneer strip. The values the sensor units are stored and controlled by means of a control and control unit using controlled, intelligent Transport equipment used the veneer strips to align exactly and especially bends to correct a first veneer strip.

In the inventive method and to be used Device according to the invention is the transport speed a veneer strip detected or accordingly set. In one pass through the first sensor unit thus results in a given transport path or a predetermined transport time until achievement a desired, optimal position in the area of Heating zone 3, for example on line 21. For straight veneer strips is thus a further correction or alignment not mandatory. Due to the exact control of the transport device can on stops or the like to the mechanical Alignment altogether be waived.

FIGS. 3 and 4 each show analogous representations of one Embodiment similar to Fig. 2. Here were the individual technical components clarified pointed out. It can be seen in particular that the location of the first Sensor unit 4 may vary, depending on the structural conditions the device.

Above the friction shaft 20, a pressure wave 22 is arranged. This serves for the exact transport of veneer strips. In particular, from the illustration of FIG. 6 it follows that a plurality of such pressure waves 22 are provided in a modular manner, to ensure a targeted supply of veneer strips.

The heater with the upper 18 and the lower 19 pressure element is known from the prior art, so to further explanations can be waived. It is important to mention in that the second sensor unit 7 is arranged in the region of the heating zone is. For this purpose, the heating zone has a plurality of vertical recesses on.

Fig. 5 shows a plan view of an inventive Veneer carpet 2, which consists of several individual veneer strips 1 was made. A trailing edge 5 of a last processed Veneer strip is doing just in the field of first sensor unit 4 (there are two light barriers 4a and 4b shown). Fig. 5 shows that the trailing edge 5 of the veneer strip is oriented obliquely. With 7a and 7b are two light barriers of the second sensor unit 7 in FIG Area of the heating zone 3 shown. Furthermore, it is shown that the second group of transport facilities in this Embodiment comprises a total of eight conveyor belts (12a to 15a and 12b to 15b). By different control this single belt or conveyor belts is it possible, the rear edge 5 of the veneer carpet. 2 in the region of the second sensor unit 7 and thus the heating zone 3 exactly perpendicular to the transport direction 6 align.

More specifically, this alignment process is as follows. It was Assume that the last illustrated veneer strip 1 is straight was glued to the veneer carpet 2. The conveyor belts 12 to 15 of the second group of transport facilities thus transport the veneer carpet 2 in the transport direction 6. For this purpose, all conveyor belts are operated synchronously. When passing through the first sensor unit 4, however, it is determined that the rear edge 5 of the veneer strip 1 in a not desired angle is aligned. The running values the trailing edge 5 through the first sensor unit 4 become stored in the rule or control unit. With the help of the parallel recorded transport path is thus the distance of the veneer strip 1 still to be covered is calculated. In the further course of the conveyor belts are now too Both sides of the center line so regulated that the still to be covered Value up to the middle of heating zone 3 up to one completed time. Because the back edge 5 is not aligned parallel to the heater center line takes place now the correction by the calculation and execution two different path-time functions of the transport facilities. In a particularly advantageous embodiment of the invention is structurally provided that the individual conveyor belts 12 to 15 each driven by its own servo motor become. To a corresponding adhesion between the veneer carpet 2 and the conveyor belts 12 to 15 is to ensure from above by means of the ball elements 17th a force applied to the veneer carpet 2 to this against to press the conveyor belts 12 to 15. With the help of Ball elements 17, however, is a rotation of the veneer carpet possible to achieve the desired parallelism of the trailing edge 5 too the center line of the heating zone 3 to achieve. The calculated Time-travel functions are provided by the servomotors of the conveyor belts generated and via the conveyor belts or conveyor belts transferred to the veneer carpet 2. It is on it to point out that instead of spherical elements also normal Rollers, pressure rollers or ball press rollers are used.

To additional disturbing influences in this transport process exclude and make sure the back edge 5 is aligned exactly to the heating zone 3, the second sensor unit 7 provided. This is just before the midline arranged the heating zone 3 and again performs a measurement of Pass through the rear edge 5 by. Look for this after Event of path covered and the distance of the second Sensor unit 7 from the center line of the heating zone 3 is again the residual deviation is calculated. If this one exceeds to be defined tolerance value, so is again on the Conveyor belts corrected this difference. By a reversing movement It is thus possible, the veneer carpet 2 if necessary, to transport back the calculated difference value.

Figs. 7 to 10 show the sequence of alignment of a first Veneer strip parallel to the heating zone 3. At the time Ta are the first and the second sensor unit 4, 7 free. In the representation, the first sensor unit 4 by the Photoelectric sensors 4a and 4b, while the second sensor unit 7 relates to the photocells 7a and 7b.

To start the process, the light barriers 4a, 4b, 7a, 7b free, a veneer strip 1 is through the conveyor belts. 8 to 11 and the friction shaft 20 transported. At the time Tb is the veneer in the ball pressure rollers 17. The friction shaft 21 stops, the counter-pressure roller 22 moves up while the ball pressure rollers 17 by means of the back pressure 16 are lowered. At time Tc occurs a start of the conveyor belts 12 to 15 of the second Group of transport facilities. At the time Td detects the light barrier 7a of the second sensor unit 7, the veneer trailing edge 5 and stops the corresponding conveyor belts the second group of transport facilities, for example the left conveyor belts. At the time Te recognizes the Photocell 7b of the second sensor unit 7, the rear edge 5 of the veneer strip 1 and stops the corresponding conveyor belts the second group of transport facilities, for example the right conveyor belts. At the time Tf takes place the positioning of the trailing edge 5 parallel to the Heating zone 3 by reversing movement of the conveyor belts 12th to 15. At the time Tg detect the photocells 7a and 7b the back edge 5 of the veneer strip 1. The positioning is stopped. The areas A1 and A2 shown in FIG. 7 correspond the values returned by the respective right or left conveyor belts. FIGS. 8 to 10 show in the plan view the process described again. In Fig. 8, the time Ta is shown. Fig. 9 shows the times Td or Te after passing the light barriers 7a and 7b, respectively. The conveyor belts 12 and 13 are stopped while the conveyor belts 14 and 15 continue to operate become. In Fig. 10, the time Tf is shown. It takes place a reversal of the movement of the veneer strip 1 until it is exactly aligned, that is the one shown Distance X = 0.

It is understood that also considerably more photoelectric than the two photocells shown can be used to the parallelism of the rear edge 5 of the veneer strip 1 at to record additional measuring points. This is special then pertinently, if with very long veneer strips 1 the There is a risk that these are wavy or bent. The quality The deflection and positioning can also be done by the number of conveyor belts can be increased.

Fig. 11 shows the flow of the deflection of a first veneer strip parallel to the heating zone. FIGS. 12 to 14 show the respective processes in an enlarged view.

At time Ta (Fig. 12), the respective area is the trailing edge 5 of the veneer strip 1 at the light barriers 7a and 7b. At time Tb (FIG. 13), the Rebend the curved veneer strip 1. To do this in the field of light barriers 7a and 7b pressure pieces 16a against pressed the veneer strip 1 to fix this. In the area the photocells 7c and 7d is a holder by means of the ball elements 17, which have a corresponding friction pressure on the conveyor belts 13 and 14 exercise. By a reversing movement of the conveyor belts 13 and 14 (see Arrows in Fig. 13) becomes the central portion of the veneer strip 1 in the direction of the center line of the heating zone 3 moves. At time T c (FIG. 14), the light barriers 7 c and 7d the rear edge 5 of the veneer strip 1. The movement of the Conveyor belts 13 and 14 is stopped, the veneer strip 1 is fixed and is thus for the subsequent joining process prepared.

Figs. 15 to 17 show the sequence of alignment of a Veneer carpet parallel to the heating zone. It is assumed that similar to Fig. 5, the rear edge 5a obliquely is aligned to the transport direction 6.

At time Ta (FIG. 16), the start of the transport movement takes place. The photoelectric barriers 4a, 4b, 7a and 7b are each occupied, that is covered by the veneer strip 1. At the time Tb detects the light barrier 4a, the trailing edge 5 of Veneer strip 1. At time Tc detects the photocell 4b, the rear edge 5 of the veneer strip 1. Here starts the Positioning process. At time Td (Fig. 17) is the positioning operation completed. The veneer back edge 5 is aligned parallel to the center line of the heating zone 3, the Photocells 7a and 7b recognize the rear edge 5.

The areas A1 and A2 shown in FIG. 15 correspond to those traveled Because of the right or left conveyor belts.

The invention is not limited to the embodiments shown limited, but rather arise within the scope of the invention various modifications and modifications.

In summary, the following can be stated:

The invention relates to a method and a device for cross-bonding of veneer strips 1 to a butt-glued Veneer carpet 2. According to the invention, a first sensor unit 4 and a second sensor unit 7 are provided to by means of several conveyor belts 8 to 11 and 12, respectively to 17 a leading edge and a rear edge 5, respectively a veneer strip 1 or veneer carpet 2 align so that this edge is exactly in a centerline a heating zone 3 is located.

Claims (15)

1. A method for transversely gluing veneer strips (1) to form a butt-glued veneer carpet (2), wherein single veneer strips (1) are supplied, aligned in their position with respect to each other and with respect to a heating zone (3) and glued,
   wherein one veneer strip (1) is transported, wherein the passage of an edge (5) of said veneer strip (1) transverse to the direction of transportation (6) is determined at a plurality of measuring points by means of a first sensor unit (4) comprising a plurality of sensors arranged adjacently in a series transversely to the direction of transportation (6), wherein respectively one transportation means of a first group of transportation means being arranged adjacently in a direction of transportation and being separately operable is assigned to said sensors,
   wherein the transportation path respectively required for the portion of the respective transportation means towards a target position of the edge (5) of the veneer strip (1) in the area of the heating zone (3) is calculated dependent on the determined values of the single sensors of the first sensor unit (4),
   and wherein, on the basis of the determined values, the sequences of movements of the respective transportation means of the first group of transportation means are controlled independent of each other, in particular in view of the transportation speeds and/or the transportation times.
2. The method according to claim 1, characterized in that the position of the edge (5) of the veneer strip (1) is determined by means of a second sensor unit (7) in the area of the heating zone (3) and that a position correction of the veneer strip (1) is performed if necessary.
3. The method according to one of claims 1 or 2, characterized in that the edge (5) of the veneer strip (1) is positioned parallel to the heating zone (3) being arranged at a right angle to the direction of transportation (6).
4. The method according to one of claims 1 to 3, characterized in that a bending of the veneer strip (1) is determined by the first (4) and/or second (7) sensor unit and that the plurality of transportation means can be operated separately for a straight alignment of the veneer strip (1).
5. The method according to claim 4, characterized in that portions of said veneer strip (1) can be clamped for a straight alignment.
6. The method according to one of claims 1 to 5, characterized in that said veneer strip (1) is movable reversingly in the direction of transportation behind the heating zone (3).
7. An apparatus for transversely gluing veneer strips (1) to form a butt-glued veneer carpet (2), comprising

   a first group of transportation means for supplying veneer strips (1),

   a first sensor unit (4) comprising a plurality of sensors being arranged adjacently in the direction of transportation (6), wherein respectively one transportation means of the first group of transportation means is assigned to said sensors within their area,

   a heating zone (3) arranged transversely to the direction of transportation (6),

   a second sensor unit (7) comprising a plurality of sensors arranged adjacently in the direction of transportation (6) in the area of the heating zone (3),

   a second group of transportation means arranged downstream of the heating zone (3), and

   a control unit.
8. The apparatus according to claim 7, characterized in that the first group of transportation means comprises a plurality of conveyor belts (8, 9, 10, 11) being arranged adjacently in the direction of transportation and being separately operable.
9. The apparatus according to one of claims 7 or 8, characterized in that the second group of transportation means comprises a plurality of conveyor belts (12, 13, 14, 15) being arranged adjacently in the direction of transportation and being separately operable.
10. The apparatus according to claim 9, characterized in that the second group of transportation means and/or the first group of transportation means have upper counterpressure means (16) assigned thereto for contacting the surfaces of the veneer strips (1).
11. The apparatus according to claim 10, characterized in that the counterpressure means (16) comprise ball elements (17) or spherical rollers.
12. The apparatus according to one of claims 7 to 11, characterized in that the first (4) and the second (7) sensor units respectively comprise optical sensors.
13. The apparatus according to claim 12, characterized in that the optical sensors form vertical light barriers.
14. The apparatus according to one of claims 7 to 13, characterized in that the first and/or the second group of transportation means are operable in the direction of transportation (6) or against the direction of transportation (6).
15. The apparatus according to one of claims 7 to 14, characterized in that the heating zone (3) comprises upper and lower pressure members (18, 19).

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