EP3943246B1 - Device and method for machining panel-shaped workpieces - Google Patents

Description

The invention relates to a device and a method for processing plate-shaped workpieces according to the preamble of claim 1.

Many panel-shaped workpieces are provided with a carrier layer and a top layer, especially when processing wood. Such a configuration often occurs in the manufacture of kitchen worktops. Openings often have to be milled out in the worktop in order to be able to integrate sinks or the like into the worktop. Some of these devices to be used are inserted into the worktop from the underside. To do this, an opening often has to be made in the worktop from the underside using a milling unit. The top layer is often left with an overhang, under which the sink is then arranged. So-called underfloor milling units are therefore often used during the milling process, which mill out the carrier layer down to the top layer. A problem that arises is that the top layer is relatively thin, often less than 1mm thick. Therefore, during the milling process, this top layer often tends to vibrate. Of course, this has a negative effect, since the milling cutter can then no longer be precisely controlled and there is a risk of damaging the top layer. EP 3 278 923 A1 belongs to the state of the art and DE 10 2016 213841A1 describes a device according to the preamble of claim 1.

The present invention has therefore set itself the task of providing a device and a method for processing to create plate-shaped workpieces, with the help of which these disadvantages are avoided as far as possible or at least significantly reduced.

This object is achieved by a device having the features of claim 1 and a method having the features of claim 15. Advantageous embodiments can be found in the dependent claims.

The device according to the invention for processing panel-shaped workpieces, which can in particular be those made of wood and/or wood substitutes and/or plastics and/or as a honeycomb panel, has a controlled and displaceable processing tool. This can preferably be a drilling or milling tool. The device according to the invention further comprises a suction device located opposite the processing tool.

If the workpiece is then processed with the processing device and, in particular, removed by cutting down to the top layer, the suction device ensures that it sucks in the top layer. This ensures that any vibrations of the top layer caused by the processing unit are dampened or avoided by their suction. In this way, the processing of the workpiece can be controlled much more precisely, since vibrations in the top layer can no longer cause the processing unit to possibly damage parts of the top layer.

It is preferably provided that the machining tool is part of an underfloor machining unit, in particular an underfloor milling unit. Viewed in the vertical direction, this unit is fed onto the workpiece from below. In contrast, the suction device according to the invention is a device that is brought up to the workpiece from above in relation to the vertical direction.

The suction device is preferably also only arranged in the region of the machining tool. This means that the suction device does not assume a suction clamping function or the like, but is only used more or less locally at the point on the upper side of the workpiece where the corresponding processing unit is located on the underside. The device according to the invention is designed in such a way that the suction device can be displaced as a function of the displacement of the processing tool. This displacement preferably runs in a direction parallel to the top layer of the workpiece. More preferably, a control device is provided for this purpose, which can be part of the device according to the invention and causes the displacement of the suction device depending on the movement of the processing tool or the underfloor processing unit.

According to a preferred embodiment of the invention, it is provided that the suction device is a suction gripper working according to the Bernoulli effect and/or a suction gripper with a vacuum ejector. Of course, other suction devices can also be used; the suction devices mentioned have the advantage that the workpiece can still be moved horizontally relative to the suction device during the process, so that a relative movement of the workpiece with respect to the processing unit is possible.

The suction device is preferably located opposite the tip of the processing tool. During the process, the cover layer is therefore located between the tip of the processing tool on the one hand and the suction device on the other. In this way, a particularly precise relative movement between the workpiece and the tool can be controlled via the machine control.

Advantageously, the main suction direction of the suction device runs parallel to the axis of rotation of the processing tool. Since the tool is moved in the direction of the top layer during the machining process during chip removal, the distance between the top layer held or sucked in by the suction device and the tip of the machining tool can be determined and controlled particularly easily.

The processing tool can preferably be displaced in at least a first spatial direction in the direction of the suction device or in the opposite direction thereto. Of course, the processing tool can also be displaceable in at least one, preferably two, further spatial direction(s). The number of degrees of freedom ultimately depends on the intended processing of the workpiece. If recesses for accommodating sinks or the like are to be produced in kitchen worktops, a relative movement of tool and workpiece in three spatial directions is preferred.

Of course, it is important in the process that the movement of the tool relative to the workpiece can be carried out as precisely as possible. The distance between the top layer on the one hand and the tool on the other hand plays a decisive role. It is therefore necessary for the tool to be positioned as precisely as possible relative to the suction device sucking on the top layer of the cover layer. For this purpose it can be provided that the suction device comprises a suction section and the device, in particular the suction device, further comprises at least one feeler shoe spaced apart from the suction section for resting on a surface of the workpiece to be machined. The feeler shoe then serves as a reference for controlling the position of the machining tool. Such a feeler shoe can be realized in different ways, for example it can be provided that the device according to the invention comprises two feeler shoes, which are arranged on both sides and at a distance from the suction section. Alternatively, it is also possible for the feeler shoe to run around the suction section at least partially, preferably completely.

According to a preferred embodiment of the present invention, it is provided that it comprises a control device which is set up to control and/or move the processing tool and/or to actuate and/or move the suction device. The device according to the invention can be used both in the continuous process as part of a continuous machine, of course it is also a preferred variant that the device according to the invention is part of a machining center.

So that the suction section does not have to lie directly on the surface of the workpiece, it can be provided that it has a support element or a plurality of support elements for supporting the suction section on a workpiece surface. According to an alternative variant, the suction section itself can be designed as a support element. At least one, preferably a plurality, of the support elements can/can be designed to be exchangeable. For example, an adaptation to corresponding workpiece surfaces can take place.

1. a. Bereitstellen eines plattenförmigen Werkstücks mit einer eine Deckschicht aufweisenden ersten Seite,
2. b. Bearbeiten des Werkstücks mit dem Bearbeitungswerkzeug, indem mit diesem von der der ersten Seite gegenüberliegenden zweiten Seite des Werkstücks aus in Richtung der ersten Seite Material abgetragen wird,
3. c. wobei während des Bearbeitungsvorgangs b. die Saugeinrichtung die Deckschicht an ihrer Außenseite ansaugt.

The invention further relates to a method as described in claim 15. The device described above is used in the method according to the invention. The following steps, among others, are carried out:

1. a. Providing a panel-shaped workpiece with a first side having a cover layer,
2. b. Machining the workpiece with the machining tool, in that material is removed with it from the second side of the workpiece, opposite the first side, in the direction of the first side,
3. c. wherein during the machining process b. the suction device sucks the cover layer on its outside.

The suction can take place in such a way that a relative movement between the workpiece and the suction device is still possible. Provision can preferably be made for the cover layer to be pulled by the suction device in an area adjacent to the material to be removed by the machining tool being held. In this way, an oscillation or vibration of the cover layer is prevented precisely in those areas where the tool acts on the workpiece from the side of the cover layer facing away from the suction device.

Provision is preferably made for the material to be removed by the processing tool until the inside of the cover layer, which is opposite the outside, is reached. The machine control constantly determines the distance of the tool tip to the top layer, in particular to a feeler shoe lying on the top layer, so that the further feed of the tool in the direction of the top layer is controlled by the machine control depending on a defined minimum distance, which ideally corresponds exactly to the thickness of the top layer and can be stopped if necessary. According to a preferred embodiment, a depth for the removal of material is specified as a target value, with the actual distance between the suction device acting on the cover layer and/or a feeler shoe resting on the cover layer on the one hand and the processing tool on the other hand being determined and the actual distance being compared with the target value will. Step b is preferred. terminated when the setpoint is reached.

• b1) Die Vorrichtung wird an das Werkstück herangefahren. Dies kann aus verschiedenen Richtungen erfolgen.
• b2) Mit der Saugeinrichtung erfolgt auf der Deckschicht eine Tastung. Die Saugeinrichtung wird dabei über oder an der Deckschicht platziert und tastet die Oberfläche ab, so dass zwischen der Saugeinrichtung und dem Bearbeitungswerkzeug jederzeit ein definierter bzw. über die Maschinensteuerung ermittelbarer Abstand besteht, der sich mit einem vorgegebenen Schwellenwert vergleichen lässt.
• b3) Das Bearbeitungswerkzeug wird in Richtung auf die Deckschicht bis zu einer vorgegebenen Stelle bewegt.
• b4) Die Vorrichtung wird parallel zur Deckschicht verfahren und trägt dabei Material ab.

If the device according to the invention described above is used, in step b. In particular, the following sub-steps are carried out, preferably in the following order:

• b1) The device is moved up to the workpiece. This can be done from different directions.
• b2) The suction device is used to feel the surface layer. The suction device is placed above or on the top layer and scans the surface so that there is always a defined distance between the suction device and the processing tool, or one that can be determined via the machine control, which can be compared with a predetermined threshold value.
• b3) The machining tool is moved toward the top layer to a predetermined location.
• b4) The device is moved parallel to the top layer and removes material in the process.

Upon completing step b. it can be provided that the processing tool is moved away from the cover layer. The workpiece can then be removed from the fixture.

As already indicated above, according to the invention the processing tool is moved in a direction parallel to the top layer. In this way it can be ensured that only at the point at which the greatest vibrations can occur in the top layer is it held securely so that the workpiece can be machined precisely with the machining tool, in particular with a milling cutter that is part of an underfloor machining unit , is ensured. According to the invention, the suction device is carried along with the movement of the processing tool in the same direction parallel to the top layer.

• Figur 1 zeigt eine Schnittdarstellung durch ein beispielhaftes durch das erfindungsgemäße Verfahren hergestelltes Werkstück.
• Figur 2 zeigt eine Draufsicht auf das in Figur 1 dargestellte Werkstück.
• Figur 3 zeigt eine Seitenansicht der Bearbeitung eines in Figur 1 oder 2 dargestellten Werkstücks nach dem Stand der Technik.
• Figur 4 zeigt eine zu Figur 3 ähnliche Darstellung bei der Bearbeitung des in den Figuren 1 und 2 dargestellten Werkstücks mittels der erfindungsgemäßen Vorrichtung nach dem erfindungsgemäßen Verfahren.
• Figur 5 zeigt ein Detail der erfindungsgemäßen Vorrichtung nach einer ersten erfindungsgemäßen Ausführungsform.
• Figur 6 zeigt ein Detail der erfindungsgemäßen Vorrichtung nach einer zweiten erfindungsgemäßen Ausführungsform.
• Figur 7 zeigt ein Detail der erfindungsgemäßen Vorrichtung nach einer dritten erfindungsgemäßen Ausführungsform.
• Figur 8 zeigt ein Detail der erfindungsgemäßen Vorrichtung nach einer vierten erfindungsgemäßen Ausführungsform.
• Figur 9 zeigt ein Detail der erfindungsgemäßen Vorrichtung nach einer fünften erfindungsgemäßen Ausführungsform.

The invention is based on the Figures 1 to 9 explained in more detail.

• figure 1 shows a sectional view through an exemplary workpiece produced by the method according to the invention.
• figure 2 shows a plan view of the in figure 1 shown workpiece.
• figure 3 shows a side view of the machining of an in Figure 1 or 2 shown workpiece according to the prior art.
• figure 4 shows one to figure 3 similar representation when editing in the Figures 1 and 2 illustrated workpiece by means of the device according to the invention according to the method of the invention.
• figure 5 shows a detail of the device according to the invention according to a first embodiment of the invention.
• figure 6 shows a detail of the device according to the invention according to a second embodiment of the invention.
• figure 7 shows a detail of the device according to the invention according to a third embodiment of the invention.
• figure 8 shows a detail of the device according to the invention according to a fourth embodiment of the invention.
• figure 9 shows a detail of the device according to the invention according to a fifth embodiment of the invention.

In the Figures 1 and 2 an exemplary workpiece 1 is shown, which with the device according to the invention or the process according to the invention can be produced. Z designates the vertical direction, X and Y are the two spatial directions that run parallel to the workpiece surface or parallel to its cover layer 10 .

The workpiece 1 itself is a panel-shaped workpiece, for example made of wood or wood substitutes, but can also be made of plastics or, for example, be a lightweight panel or honeycomb panel. In the example shown here, a recess 12 is to be made in the workpiece, in which, in the example shown, a sink, for example, is to be mounted on the workpiece 1 from the underside of the workpiece. 14 designates the actual core layer or carrier layer of the plate, 10 is a cover layer applied to the upper side, which can usually be a few tenths of a millimeter to a few millimeters thick. The cover layer 10 has a recess 11 below which a sink, not shown here, is to be attached. For this purpose, an opening 13 must be made in the core layer 14 from the underside of the panel, which then ultimately becomes the recess 12 via a processing tool when the material of the core layer 14 has been removed in this area up to the cover layer 11 . Of course, the method according to the invention can also be used for other workpieces 1, which do not necessarily have to be kitchen worktops, but in which a recess 12 is to be made close to a top layer 10.

Conventionally, this recess 12 is produced by using a processing tool 20, for example a milling cutter, which is in particular part of an underfloor processing unit or underfloor milling unit, and bringing it close to the top layer, this is in figure 3 shown. Usually, the slab is placed on supports 4 resting on a machining base 3. In the example shown figure 3 the milling unit 20 is applied from above and the top layer 10 is at the bottom in the example shown. The thinner the material thickness of the core layer 14 becomes in this area, ie the further the machining tool 20 approaches the cover layer 10, the more the relatively thin cover layer 10 begins to vibrate in the area of the recess 12. This causes the distance between the tip of the tool 20 and the cover layer 10 to change periodically. However, the machine control is not able to evaluate this periodic change and transfer it to the feed of the tool 20 . Consequently, it can happen that the tip of the tool 20 gets too close to the cover layer 10 and damages it.

The solution according to the invention is figure 4 pictured. There the workpiece 1 lies on the supports 4 and the cover layer 10 lies on top in the example shown. As part of the device 2 according to the invention, the tool 20 is advanced from the underside in the direction Z of the cover layer 10, as a result of which the opening 13 and the recess 12 are formed. A recess 11 is contained in the cover layer 10 in this example. However, this does not have to be included.

The detail A is in various embodiments of the invention in the Figures 5 to 9 shown.

In figure 5 one recognizes the processing tool 20 and a suction device 21, which acts on the cover layer 10 of the workpiece 1 and on the core layer or carrier layer 14 is attached. The suction device 21 preferably uses the Bernoulli effect by blowing air through a channel 22 in the direction of the arrow P1 into the area between the suction section 23 serving as the outer wall and the suction section 24 serving as the inner wall. The annular gap between the suction sections 23 and 24 tapers towards the underside (towards the object to be sucked--in this case towards the cover layer 10--) and exits again laterally above the cover layer (P2, P3). As a result, the cover layer is sucked in in the area 10a that protrudes over the core layer 14 here, so that a force F is exerted on the cover layer 10 or 10a away from the tool 20 by the resulting negative pressure. In the example shown, support elements 23a and 23b designed as spacers are provided on the underside of the suction section 23, which create a minimum gap between the suction section 23 and the cover layer 10, 10a, so that the air P2 blown into the suction device 21 via the channel 22 escapes parallel to the cover layer 10 can.

In this way, the suction device 21 holds the top layer 10 during the machining process, so that vibration caused by the machining unit 20 is largely suppressed.

In figure 6 is the only difference to the embodiment in figure 5 that the support members 23a and 23b are not provided here. Instead, the central part 24, which forms the inner wall of the annular gap, rests on the cover layer 10, 10a. The section 23 does not rest on the cover layer 10, 10a, so that the air can still escape at P2 and P3.

At the in figure 7 The variant shown are provided on both sides and at a distance from the suction section 23 feeler shoes 25 . However, these feeler shoes 25 can also be a single circumferential feeler shoe, which partly or completely surrounds the suction section 23 . Such a feeler shoe 25 rests on the surface of the cover layer 10 and defines a zero line from which the machine control continuously detects and determines the distance between the tip of the tool 20 and this zero line. In this way, it can be ensured that the top layer 10 that is sucked in is not damaged by the tip of the tool 20 when the material is removed. Supporting elements 23a and 23b can also be provided in this variant, but do not have to be. In the example shown figure 7 the recess 12 is located between two sections of the carrier layer 14.

Of course, the device according to the invention can also be used to process areas in which material is to be removed at the edge of a plate-shaped workpiece 1, so that at the end of the process a cover layer 10a protruding at the edge is formed. Such an example is in figure 8 shown. The remaining components shown correspond to those of the previous embodiments. In this machining with a lateral overhang, the in figure 8 double feeler shoe or circumferential feeler shoe still shown is not absolutely necessary. Rather, it is sufficient, as in the embodiment of figure 9 is shown, a feeler shoe 25 for resting on the cover layer 10 is only provided on the side on which the carrier layer 14 is also present.

It applies to all embodiments according to the invention that the machining tool 20 or the underfloor machining unit having it can be moved parallel to the cover layer 10 by means of a control device in the directions X, Y. The control device of the device according to the invention is designed in such a way that the suction device is also carried along with the movement of the processing tool 20 or the underfloor processing unit that has it, so that the area on which the processing takes place on the underside of the workpiece 1 is always on the corresponding opposite Top of the cover layer 10 is also the suction device. This ensures that vibrations in the immediate vicinity of the machining tool 20 are dampened or avoided by the suction device 21 .

Claims (21)

1. Device (2) for machining panel-shaped workpieces (1), in particular those made of wood and/or of wood substitutes and/or of plastics and/or designed as honeycomb plates, having a controlled displaceably mounted machining tool (20), in particular a drilling or milling tool, wherein the device (2) further comprises a suction device (21) opposite the machining tool (20), wherein the suction device (21) is displaceable in dependence on the movement of the machining tool (20), characterised in that the suction device (21) is further designed so that it is entrained in the same direction (X, Y) with the movement of the machining tool (21).
2. Device (2) according to claim 1 characterised in that the machining tool (20) is part of an underfloor machining assembly, in particular an underfloor milling assembly.
3. Device (2) according to claim 1 or 2 characterised in that the suction device (21) is arranged only in the region of the machining tool (20).
4. Device (2) according to claim 1 characterised in that the suction device (21) is a suction gripper with vacuum ejector and/or a suction gripper operating according to the Bernoulli effect.
5. Device (2) according to one of the preceding claims characterised in that the suction device (21) is opposite the tip of the machining tool (20).
6. Device (2) according to one of the preceding claims characterised in that the main suction direction (Z) of the suction device (21) runs parallel to the axis of rotation of the machining tool (20).
7. Device (2) according to one of the preceding claims characterised in that the machining tool (20) is displaceable in at least one first spatial direction (Z) in the direction of the suction device (21) towards or in the direction opposite to the latter.
8. Device (2) according to claim 7 characterised in that the machining tool (20) is displaceable in at least one, preferably two, further spatial directions (X, Y).
9. Device (2) according to one of the preceding claims characterised in that the suction device (21) comprises a suction section (23, 24) and the device (2), in particular the suction device (21), further comprises at least one scanning head (25), spaced from the suction section (23, 24), for resting on a surface of the workpiece which is being machined.
10. Device (2) according to claim 9 characterised in that it comprises two scanning heads (25) which are arranged on either side and spaced from the suction section (23, 24).
11. Device (2) according to claim 9 characterised in that the scanning head (25) encircles the suction section at least in part and preferably completely.
12. Device (2) according to one of the preceding claims characterised in that it comprises a control device which is set up to control and/or move the machining tool (20), and /or to actuate and/or move the suction device (21).
13. Device (2) according to one of the preceding claims characterised in that the suction section (23) has a support element (24) or a number of support elements (23a, 23b) for supporting the suction section (23) on a workpiece surface, or is itself configured as the support element.
14. Device (2) according to claim 13 characterised in that at least one, preferably a number of the support elements (23a, 23b) is/are designed to be replaceable.
15. Method for machining a panel-shaped workpiece (1), in particular of wood and/or of wood substitutes and/or of plastics and/or is formed as a honeycomb plate, by using a device (2) for machining panel-shaped workpieces (1) which has a controlled displaceable machining tool (20) and further comprises a suction device (21) opposite the machining tool (20), wherein the suction device (21) is displaceable in dependence on the displacement of the machining tool (20), and wherein the method comprises the following:

    a. providing a panel-shaped workpiece (1) with a first side having a cover layer (10);

    b. machining the workpiece (1) with the machining tool (20) whereby material is removed by the machining tool from the second side of the workpiece opposite the first side, in the direction (Z) of the first side;

    c. wherein during the machining process b., the suction device (21) sucks up the cover layer (10) on its outer side,

    characterised in that the machining tool (20) is moved in a direction (X, Y) parallel to the cover layer (10), wherein the suction device (21) is entrained with the movement of the machining tool (21) in the same direction thereof (X, Y).
16. Method according to claim 15 characterised in that the cover layer (10) is held firm by the suction device (21) in a region adjacent the material which is to be removed by the machining tool (20).
17. Method according to claim 15 or 16 characterised in that the removal of the material is carried out by the machining tool (20) until the inside of the cover layer (10) opposite the outer side is reached.
18. Method according to one of claims 15 to 17 characterised in that a depth is predetermined as the target value for the material removal, wherein the actual distance between the suction device (21) engaging on the cover layer (10) and/or a scanning head (25) resting on the cover layer (10) on the one side and the machining tool (20) on the other side is detected and the actual distance is compared with the target value.
19. Method according to claim 15 characterised in that step b. is terminated when the target value is reached.
20. Method according to one of claims 15 to 19 characterised in that a device according to one of claims 1 to 12 is used, and in step b. the following sub-steps are carried out:

    b1) the device (2) is moved up to the workpiece (1)

    b2) the cover layer (10) is scanned with the suction device (21)

    b3) the machining tool (20) is moved in the direction (Z) to a predetermined position on the cover layer (10)

    b4) the device (2) is moved parallel to the cover layer (10) and material is then removed.
21. Method according to claim 20 characterised in that at the end of step b. the machining tool (2) is moved away from the cover layer (10).

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