EP3150344B1 - Alignment device for aligning workpieces and processing machine - Google Patents

Description

Technical area

The invention relates to a method for feeding preferably plate-shaped workpieces, according to the preamble of claim 1. Such a method is known from the document US6189682 B1 known.

Furthermore, the invention relates to a processing machine.

State of the art

Alignment devices and methods of the type mentioned above are used, for example, when feeding workpieces, particularly plate-shaped ones, to processing machines.

The known embodiments of alignment devices and methods use, for example, transport roller systems when aligning the workpiece. When using these systems, slippage often occurs between the transport system and the workpiece due to the inertia of the mass when the workpiece is accelerated or decelerated. This results in deviations in the time interval from component to component. and the part spacing between two consecutive workpieces (usually recorded as the distance between the rear edge of a leading workpiece and the front edge of a trailing workpiece). These deviations from required target values inevitably lead to a reduction in the performance of the downstream processing machine. In the prior art, an alignment ruler positioned transversely to the transport direction is used to align a workpiece. Such a device and method are based on the workpiece being brought to a standstill on the alignment ruler during movement/feeding and immediately in front of the processing machine in order to be aligned at an angle. After alignment, the alignment ruler clears the transport path of the workpiece again by moving it out of the transport plane. The transport plane refers to the plane in which the workpieces are moved. Because the workpiece is braked during movement/feeding and must then be accelerated again, incalculable time losses arise that can no longer be compensated before feeding into the processing machine.

The state of the art presented can no longer meet the constantly increasing performance requirements regarding the output of the entire system as required and is therefore not future-proof.

Furthermore, the document WO 2005/113206 A1 which relates to a device and a method for a planing machine.

The US6,189,682 B1 shows a conveyor that allows blocks to be placed on each loader of the conveyor.

Subject of the invention

The object of the present invention is to efficiently arrange the feeding of workpieces, in particular plate-shaped workpieces, to a processing machine at previously defined distances or time intervals and the alignment of said workpieces in front of the processing machine. Preferably, high productivity should also be ensured by a constant flow of parts and a high variability in terms of workpiece sizes with a structurally simple design.

This object is achieved according to the invention by a method having the features of claim 1. Further preferred embodiments can be found in the subclaims.

The workpieces conveyed by the method according to claim 1 can be components such as floor panels, doors, table tops, furniture fronts, kitchen worktops or the like. Such workpieces, preferably in the form of plates, can be fed to a processing machine in order to machine them, for example.

According to the invention, an alignment device, which can be used as a feed device, for example, comprises a conveyor device for moving workpieces with an initial speed v ₀ in a transport direction to an alignment section. The transport direction from the conveyor device, for example to the processing machine or another transport path or from the alignment section into a compensation section explained in more detail below, is referred to as the transport direction.

The alignment section has at least one alignment device for aligning the workpieces moved by the conveyor device on a workpiece edge running transversely to the transport direction. The at least one alignment device is arranged on a circumferential support element so that it can be moved in sections in the transport direction.

For example, the rotating carrier element can be guided over deflection rollers spaced apart in the transport direction. At least one of the deflection rollers can be driven. Furthermore, it is preferred that the deflection rollers are arranged in a horizontal plane.

The movement of the carrier element can be characterized by its rotational speed, which corresponds to the first speed v ₁ . The first speed v ₁ is usually selected such that it is smaller than the initial speed v ₀ of the workpieces. In this case, a front edge of a workpiece moved by the conveyor device would come into contact with the alignment device, which in a specific example is formed by a cam, and would be aligned due to the speed difference.

Alternatively, it is possible that the first speed v ₁ (speed of the alignment device) is selected to be greater than the initial speed v ₀ of the workpiece. This variant is used when the alignment device engages a rear edge of a workpiece and this contact is used to align the workpiece.

The movable alignment device eliminates the need to stop the workpiece for alignment and to then release and accelerate again so that the time loss due to alignment is controlled and regulated.

Furthermore, according to the invention, the conveyor device runs in sections adjacent to the rotating support element, with an end section of the conveyor device being located beyond an end section of the rotating support element in the transport direction. In this way, an advantageous transfer of the workpiece to a processing machine or another transport path is provided. Furthermore, a compensation section can be formed, for example, directly adjacent to the alignment section.

According to a preferred embodiment, a compensation section for changing the speed of the workpiece is provided after the alignment section on the side facing the processing machine and comprises at least one conveyor device, in particular a conveyor belt. The target speed of the workpiece that is given to the workpiece in the compensation section is a second speed v ₂ , which can usually be selected to be higher than a first speed v ₁ . Adjusting the speed of the aligned workpiece enables a correction of the time interval between workpieces or an adjustment of the part distance and contributes to the exact adherence to a pre-determined/pre-calculated time interval and therefore to increasing the performance of the processing machine.

According to a preferred embodiment, the movable alignment device can be formed by at least one cam that projects into the plane of the transport. The plane of the transport refers to the plane in which the workpieces are moved The cam is arranged on the carrier element rotating in the transport direction at the first speed v _1. Alignment takes place through the contact of the first edge of the workpiece in the transport direction with the movable cam.

In a preferred embodiment, the carrier element is provided with two or more cams for aligning the workpiece. Since the carrier element has several cams, a receiving position for the subsequent workpiece can be reached more quickly with a further cam compared to a carrier element with one cam and/or the alignment can be carried out more precisely due to a greater guide length between the plurality of cams.

Furthermore, it is preferable to arrange the cams on the carrier element in such a way that they are equidistant from one another in relation to the total length of the carrier element. This configuration can increase the efficiency of the alignment device, since the carrier element does not have to be moved as far between the neutral position described later and the receiving position for a subsequent workpiece.

According to a further embodiment, a plurality of belts are provided in the alignment section, which circulate in the transport direction and are spaced apart from one another transversely to the transport direction. The belts are preferably driven synchronously with one another, so that the cams on the belts arranged next to one another together form the alignment device for the workpiece. When using several belts, the guide length for alignment can be increased, so that the accuracy of the alignment process is improved. For example, it is It is possible to align workpieces with high precision that have a relatively large width in the transverse direction (perpendicular to the conveying direction).

The alignment device preferably has a control device for setting and changing the rotational speed of the carrier element, which corresponds to the first speed, and optionally the second speed. With regard to the adjustment of the speed of the workpiece in the compensation section by the said control device, a distinction can be made, for example, between a positive and a negative correction. The first case of a positive correction is carried out when the current batch change time is greater than the required batch change time. This means that the part distance between the workpieces must be reduced. This is done by increasing the second speed within the compensation section. In the second case, a negative correction, the workpiece is transported within the compensation section at a lower second speed, so that the part distance is increased. If the current batch change time corresponds to the required batch change time, there is no need for a further positive or negative correction.

The invention also includes a processing machine, in particular an edge processing machine with an alignment device, which can have both the preceding features and the advantages mentioned, wherein the processing machine provides a subordinately arranged processing section with a processing tool, in particular a milling cutter.

According to a further variant, the alignment device can be coupled to a transport device by means of which workpieces are moved. In this case, the alignment device can be used to align and, if necessary, buffer workpieces. At the output of such a transport device, a packaging unit for packaging the workpieces, a stacking device for stacking the workpieces or the like can be provided.

• Bereitstellen eines Werkstücks mit einer Ausgangsgeschwindigkeit in Transportrichtung mittels einer Fördereinrichtung;
• Ausrichten des Werkstücks durch Kontakt einer Kante (insbesondere einer in Transportrichtung vorderen oder hinteren Kante) des Werkstücks mit einer Ausrichteinrichtung, die abschnittsweise in der Transportrichtung durch ein umlaufendes Trägerelement bewegbar ist, sodass das Werkstück durch die Fördereinrichtung mit der Ausrichteinrichtung in Kontakt kommt und dabei ausgerichtet wird;
• Freigeben des Werkstücks von der Ausrichteinrichtung, insbesondere durch Bewegen der Ausrichteinrichtung aus der Ebene des Transports in vertikaler Richtung nach unten.

According to the invention, a method for feeding preferably plate-shaped workpieces is provided, with an alignment device according to claim 1, which method comprises the steps:

• Providing a workpiece with an initial speed in the transport direction by means of a conveyor device;
• Aligning the workpiece by contact of an edge (in particular a front or rear edge in the transport direction) of the workpiece with an alignment device which is movable in sections in the transport direction by a rotating carrier element, so that the workpiece comes into contact with the alignment device through the conveyor device and is thereby aligned;
• Releasing the workpiece from the alignment device, in particular by moving the alignment device out of the plane of transport in a vertical direction downwards.

• Nach der Freigabe des Werkstücks von der Ausrichteinrichtung, Ändern der Geschwindigkeit des Werkstücks auf eine zweite Geschwindigkeit v₂ in einer Kompensationssektion, insbesondere zur Korrektur einer Loswechselzeit und/oder zum Justieren des Teileabstandes.

Preferably, the method may further comprise the steps:

• After releasing the workpiece from the alignment device, changing the speed of the workpiece to a second speed v ₂ in a compensation section, in particular to correct a batch change time and/or to adjust the part spacing.

After the workpiece is released, the alignment device can be moved against the transport direction and advanced upwards by a movement in a vertical direction in order to engage with a workpiece.

Short description of the drawings

Fig. 1

eine perspektivische Ansicht der Zuführeinheit mit einer Ausricht- und einer Kompensationssektion;

Fig. 2

eine Seitenansicht der Ausrichtsektion mit einem Werkstück; eine Nocke ist in der Aufnahmeposition;

Fig. 3

eine Seitenansicht der Ausricht- und der Kompensationssektion mit dem Werkstück; die Nocke ist in der neutralen Position nach der Freigabe des Werkstücks;

A described embodiment of the alignment device according to the invention is explained in more detail below. Shown are:

Fig.1

a perspective view of the feed unit with an alignment and a compensation section;

Fig. 2

a side view of the alignment section with a workpiece; a cam is in the receiving position;

Fig.3

a side view of the alignment and compensation sections with the workpiece; the cam is in the neutral position after the workpiece is released;

Detailed description of a preferred embodiment

Fig.1 shows a perspective view of an exemplary embodiment of an alignment device with an alignment section 10 and a compensation section 20. In the present embodiment, the alignment device is used as a feed device with which workpieces are conveyed into an edge processing machine and aligned in the process. The alignment device comprises several in one transport direction 50 (in Fig.1 illustrated by an arrow) for conveying plate-shaped workpieces. The conveying devices 21, 22 (here: conveyor belts) are driven by a common motor 24.

In the present embodiment, the extension direction of the conveyor devices 21 and the conveyor devices 22 is different in the transport direction 50. However, the conveyor devices 21, 22 can also have the same extension in the transport direction.

In the alignment section 10, in the present embodiment, seven belts 11 (support elements) are shown, which are spaced apart from one another transversely to the transport direction 50. However, the number of belts can deviate from the number mentioned. The belts 11 are driven by a common motor 13.

Each of the belts 11 has two cams 12 (alignment devices) which are attached to the belt 11 at equal distances. The dashed line in Figure 1 , which is created by the conceptual connection of the cams adjacent in the transverse direction, represents the totality of the movable cams with a certain guide length. In this way, a workpiece can be placed on several cams arranged next to one another in order to align it.

The conveyor devices 21, 22 (conveyor belts) are arranged in the compensation section 20, but not the belts 11 with the cams 12. An upstream transport and a downstream processing machine are not shown.

A side view of the alignment device is shown in Fig. 2 shown. In the situation shown, the workpiece 40 is introduced into the alignment section 10 by the upstream transport (not shown) at the initial speed v _0. In the present example, the initial speed v ₀ corresponds to the rotational speed of the conveyor devices 21, 22. At the same time, the belt 11 and thus also the cam 12 located thereon, which points upwards in a vertical direction, is moved at a first speed v ₁ in the transport direction 50. The position shown of the cam 12 protruding into the plane of the transport is referred to as the receiving position.

In order to align a workpiece, the initial speed v ₀ is greater than the first speed v ₁ (v ₀ > v ₁ ). Thus, when the workpiece is introduced into the alignment section 10, the first (front) edge 41 of the workpiece 40 in the transport direction comes into contact with the cam 12. The workpiece 40 is conveyed by the upstream transport and the conveyor belts 21, 22 against the cams 12, which are moved at the first speed v ₁ . By pressing the workpiece 40 against the cam 12, the workpiece 40 is aligned in the alignment section 10 on at least one cam 12.

The alignment takes place over a certain distance within the alignment section 10, as long as the cam 12 projects into the plane of the transport 50 and/or the first speed v ₁ is less than the initial speed v ₀ or less than the second speed v _2. The alignment distance in the embodiment shown is approximately 450 mm.

When the aligned workpiece 40 has reached the end of the alignment section 10, the first speed v ₁ of the belt 11 is increased to such an extent that the cam 12 detaches from and removes the first edge 41 of the workpiece 40 in the transport direction 50. This releases the workpiece 40. As soon as the cam 12 has reached the neutral position, shown in Fig.3 , the belt 11 is braked. The neutral position is characterized in the embodiment shown in that both cams 12 arranged on the belt 11 are in a plane parallel to the plane of the transport 50. The speed of the belt 11 or the belts 11 can be reduced to as low as 0 m/s in the neutral position. At the same time, the workpiece 40 is conveyed further by the conveyor belts 21, 22. These devices impose the desired speed v ₂ on the released workpiece 40. The second speed v ₂ is selected so that the required batch change time or the required part distance is maintained.

The second speed v ₂ can be equal to the speed v _0. This means that the conveyor devices 21, 22 are not accelerated or decelerated by the cams after the workpiece 40 is released.

However, according to an alternative, it is also possible that the second speed v ₂ (speed within the compensation section 20) differs from the speed v ₀ and the workpiece is slowed down or accelerated again after release from the cams 12.

After the second, rear edge 42 of the workpiece in the transport direction 50 has passed a certain area of the alignment section 10, the belt 11 is moved so that the cam 12 is in the receiving position which is the position of Fig. 2 The certain area of the alignment section 10 preferably includes the first 120 mm of the alignment section.

In a preferred embodiment, a maximum distance of 400 mm is available for correcting the batch change time within the compensation section 20. On this compensation distance, a second speed v ₂ of a maximum of 50 m/min or a maximum acceleration of 5 m/s ² can be applied to the workpiece 40 by the conveyor belt 21, 22.

According to an alternative embodiment not shown in the figures, the first speed v ₁ (speed of the cams 12) is selected to be greater than the initial speed v ₀ of the workpiece. This variant is used when the cams 12 engage a rear edge 42 of the workpiece 40 and thereby push the workpiece in the transport direction.

Claims (14)

1. Method for feeding preferably planar workpieces with an alignment device for aligning the workpieces (40), which preferably consist at least in part of wood, wood-based materials, plastics material or the like, wherein the alignment device comprises

   a conveying means (21, 22) for moving workpieces (40) in a transport direction (50) and

   an alignment section (10) having at least one alignment means (12) for aligning an edge of a workpiece (40) that extends transversely to the transport direction (50),

   wherein the at least one alignment means (12) is arranged on a circulating support element (11), in particular a belt, such that it can be moved at least in portions in the transport direction,

   characterised in that the conveying means (21, 22) extends at least in portions adjacently to the circulating support element (11), and wherein an end portion of the conveying means (21, 22) is beyond an end portion of the circulating support element (11) in the transport direction (50),

   wherein the method comprises the steps of:

   - providing a workpiece with a starting speed in the transport direction by means of the conveying means;

   - aligning the workpiece by contacting an edge, in particular a front or rear edge of the workpiece in the transport direction, with the alignment means, such that the workpiece comes into contact with the alignment means by means of the conveying means and is aligned in the process;

   - releasing the workpiece from the alignment means, in particular by moving the alignment means vertically downwards out of the transport plane.
2. Method according to claim 1, further comprising the step of:

   - after releasing the workpiece from the alignment means, changing the speed of the workpiece to a second speed (v2) in a compensation section, in particular to correct a batch change time and/or to adjust the spacing between parts.
3. Method according to claim 1, wherein the alignment device further comprises a compensation section (20) which comprises at least the conveying means (21, 22) for moving the workpiece (40) in the transport direction (50), in particular a conveyor belt.
4. Method according to any of the preceding claims, wherein the alignment means comprises at least one cam (12) which can project into the transport plane by means of the movement of the support element (11).
5. Method according to claim 4, wherein the alignment means comprises at least two cams (12) on the support element (11), wherein the cams (12) are equidistant from one another in relation to the total length of the support element (11).
6. Method according to any of the preceding claims, wherein the alignment section (10) comprises a plurality of circulating support elements (11) which are spaced apart from one another transversely to the transport direction (50) .
7. Method according to claim 6, wherein the support elements (11) are driven by means of a common motor (13).
8. Method according to any of the preceding claims, characterised in that the alignment device comprises a plurality of conveying means (21, 22), wherein a conveying means (21, 22) is arranged adjacently to a support element (11) .
9. Method according to claim 8, wherein the conveying means (21, 22) are driven by a common motor (24).
10. Method according to any of the preceding claims, characterised in that the speed of the conveying means (21, 22) is set to be less than the speed of the support element (11) .
11. Method according to any of claims 1 to 9, characterised in that the speed of the conveying means (21, 22) is set to be greater than the speed of support element (11) .
12. Method according to any of the preceding claims, characterised in that the alignment device comprises a control means for setting and, if necessary, changing the circulation speed of the at least one support element (11) and/or for setting and, if necessary, changing the speed of the at least one conveying means (21, 22).
13. Method according to any of the preceding claims, characterised in that the circulating support element (11) is guided over deflection rollers that are spaced apart in the transport direction and that are preferably located in a horizontal plane, wherein preferably at least one of the deflection rollers is driven.
14. Machining centre, in particular a machine for machining edges, comprising an alignment device which is configured to carry out a method according to any of the preceding claims, and at least one machining section that has a machining tool, in particular an edge machining tool such as a milling cutter, and that is arranged downstream in the transport direction.

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