Cutting device for cutting extruded plastic profiles

Abstract

The invention relates to a device for cutting plastic profiles extruded along an extrusion axis (7), at least comprising: a tool (10) arranged on a tool holder (14); a pivot arm (9) by means of which the tool holder (14) can be moved together with the tool (10) towards and away from the extrusion axis (7); means (19) for pivoting said pivoting arm (9). According to the invention, the tool (10) is connected to a tool holder (14) and can be oriented in a plane at right angles to the extrusion axis (7) via an adjustment (15), and / or the tool (10) is connected to the tool holder (14) and a pivot arm (9), the pivot arm (9) being arranged on a device (19) for pivoting, the device (19) for pivoting being an electromechanical drive, and the device (19) for pivoting being arranged on the pivot arm (9). The electromechanical drive comprises at least one cycloidal gear (11) which is directly connected to the actuator (21). The invention also includes a method for cutting.

Description

Technical Field

[0001] The present invention relates to a device for cutting a plastic profile extruded along an extrusion axis, the device comprising at least: a tool arranged on a tool holder; a pivot arm, by means of which the tool holder can move together with the tool toward or away from the extrusion axis; a device for pivoting the pivot arm; and the present invention relates to a method related thereto. Background Art

[0002] Cutting devices are known from the prior art. For example, DE 10 2020 181 144.7 describes a device for cutting extruded plastic pipes to length by means of a cutting device and a cutting unit that can rotate about the extrusion axis of the extruded pipe, wherein the cutting unit is rotatably supported and the cutting is carried out using a cutting tool arranged on the cutting unit, wherein energy can be transmitted in order to move the cutting tool, for this purpose, elements are arranged for transmitting energy to the moving parts, which elements are operatively connected to a rotating receiving unit arranged in the cutting unit. Summary of the invention

[0003] According to the invention, it is provided that at least one electrical component is additionally mounted on a rotating receiving unit, via which energy and control commands are transmitted to at least one electromechanical unit for moving at least one carrier and a cutting tool arranged thereon, wherein the space occupied by the electromechanical unit, the carrier and the cutting tool arranged thereon is configured to be smaller than the hydraulic unit required to generate the same force, and the electromechanical unit, the carrier or the cutting tool is arranged so that a force opposing the cutting force can be avoided as long as this force is greater than the required cutting force.

[0004] In this way, the entire system can be evaded in the event of an overload to avoid damage. This may be necessary when there are out-of-roundnesses, for example, in plastic pipes.

[0005] However, this does not allow a specific cutting process to be reproduced in a targeted manner, and the cutting tool is therefore not moved towards the plastic profile or away from it at different feed speeds.

[0006] The object of the present invention is to further develop the known cutting device in such a way that it is smaller and comprises fewer components; furthermore, the object is to enable a more precise positioning of the cutting tool and to maintain this positioning after a stop.

[0007] The solution to the problem is characterized in combination with the preamble of claim 1 in that the tool is connected to the tool holder and can be aligned via an adjustment portion to a plane at a right angle to the extrusion axis, and / or the tool is connected to the tool holder and a pivot arm, wherein the pivot arm is arranged on a device for pivoting, the device for pivoting is an electromechanical drive device, which includes at least one cycloid transmission device, which is directly connected to the actuator.

[0008] A great advantage of using a cycloid transmission with a direct drive via an actuator is its extremely strong internal transmission support. It is therefore possible in the device according to the invention to also use it as a pivoting support for the separating arm of the cutting device. In this way, the costs and space (construction space) for additional supports for the separating arm can be minimized or saved. Direct drive via an actuator also saves on additional transmissions and / or deflection devices. The actuator comprises at least a frequency converter and an electric motor, wherein the electric motor ensures the pivoting movement of the separating arm and thus the feed of the cutting device.

[0009] According to a further development, it is provided that a plurality of devices for pivoting with the pivot arms arranged thereon as well as the tool carrier and the tool are arranged around the extrusion axis.

[0010] A cutting device designed in this way provides a device with a smaller design, whereby more cutting tools (more than two) can be arranged on one device than is known in the prior art. By using an electromechanical drive, precise positioning is possible. In addition, it is possible, for example, to maintain the position of the pivoting arm after it has stopped, which cannot be guaranteed in a hydraulic system due to the pressure increase.

[0011] Advantageously, the device also includes a device for identifying which tool is connected to the tool holder. By means of this identification, it can be identified via the control device whether the tool is suitable for the process to be performed. If not, an alarm can be output via the control device or even the execution can be stopped or refused. This check can be carried out, for example, based on the pipe diameter or pipe thickness, where the identification can involve the inserted clamp and the cutting knife or only the cutting tool for chamfering.

[0012] According to a further development, the tool is fixed in the tool holder by means of a quick-release clamp. This quick-release clamp can be an eccentric or a screw connection. In each case, it is ensured that the connection tolerances are very precise, thereby ensuring a good fit. In order to minimize the wear of these components, the relevant components are hardened.

[0013] The solution associated with this method is presented in claim 7. Advantageous further developments are given in the dependent claims.

[0014] In addition to precise positioning, the method according to the invention also enables motor-driven feeding of the mold and a high degree of flexibility in adjusting the feeding speed. Thus, for example, it is conceivable that the knife first enters the plastic tube to be cut slowly so that the blade does not deflect. As soon as the knife has penetrated deep enough into the plastic tube and can no longer deflect, the speed can be increased again. Shortly before the knife breaks through the inner side of the plastic tube, the speed can be reduced again to avoid so-called "white cracks" or other types of material cracking (for example due to material brittleness).

[0015] According to a further development, it is provided that the feed rate depends on the torque. It is therefore provided that the feed rate is coupled to the torque of the actuator and thus different requirements are taken into account when cutting extruded profiles, preferably pipes in this case. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The device according to the invention is schematically shown in the accompanying drawings:

[0017] Figure 1 Showing a typical extrusion line

[0018] Figure 2 A cutting unit showing the prior art

[0019] Figure 3 An alternative embodiment of the cutting unit according to the invention is shown

[0020] Figure 4 Shown in accordance with Figure 3 Perspective

[0021] Figure 5 to Fig.11 Different views showing pivot arms with different designs

[0022] Figures 12 to 15 Different views showing the pivot arm according to the invention

[0023] Fig.16 A perspective view showing a cutting unit according to the invention DETAILED DESCRIPTION

[0024] Figure 1 A typical extrusion line is shown, as it is used today for extruding profiles, whether for producing window profiles or pipes. The figure shows an extruder 1 in which the plastic is melted and continuously fed to an extrusion die 2 for shaping. This is followed by a calibration and cooling station 3, and further cooling stations can be used depending on the profile. The cooling station is followed by a drawing device 4. In order to cut the continuous profile 6 into the desired length, a cutting device 5 is then arranged. The extrusion axis is marked with position numbers 7.

[0025] Figure 2The known prior art is shown in which two hydraulic systems 8 are arranged on a disk 22 rotatable about the extrusion axis, by means of which two pivot arms 9 with knives 10 arranged thereon can be moved towards the extrusion axis or away from it for cutting.

[0026] Figure 3 An alternative embodiment of the device is shown. Here, too, the device 19 for pivoting is arranged on a disk 22 that can be rotated about the extrusion axis 7. The tool 10 arranged on a pivot arm 9 is pivoted toward the extrusion axis 7 via these drives. In this case, however, the device 19 for pivoting is an electromechanical drive. The pivot arm and the drive are designed to be significantly smaller in size, so that, as in the present example, these units are arranged fourfold on the rotatable disk 22. As can be seen from the graphic representation, the tools 10 used can be different. Here, one is a saw blade provided with teeth, one is similar to a pizza cutter, one is a round cutting knife or a tool with which, for example, chamfers can be made.

[0027] Figure 4 Show Figure 3 , wherein the same positions are again referenced with the same position numbers. Due to the perspective view, other components of the device 19 for pivoting can be illustrated diagrammatically, so that the cycloid gear 11, the servomotor 12 and the angular gear 13 can be seen.

[0028] FIG. 5 shows the pivot arm 9 with the cycloid drive 11, the servo motor 12 and the angular drive 13; the tool holder 14 with the quick-release clamping device 20 can also be seen. Figure 6a The tool 10 arranged on the pivot arm 9 is reproduced in a and b.

[0029] In accordance with Figure 7a , 7b In the views of 7c and 7d, the pivot arm 9 with the tool holder 14 and the tool 10 is partially reproduced in a sectional view. Figure 7a The adjustment device 16 shown by the arrow in the diagram shows the adjustment of the tool holder 14 in the direction of the extrusion axis. The adjustment can be realized via the adjustment part 15, here a hexagonal screw. This mechanism is used to orient a plurality of tools relative to each other. This can be necessary, for example, when there are tolerance deviations in the components. Thus, all components can be oriented in a plane perpendicular to the extrusion axis and thus describing the cutting plane and thus ensure a clean cutting process for all arranged cutting tools. Figure 7b The suspension device on the slide rail and the lever for adjustment are shown in detail, and Figure 7c The complete pivot arm 9 is shown.

[0030] exist Figure 8a and 8bThe connection possibilities of the tool 10 and the tool holder 14 are emphasized in FIG. 1. The eccentric 17 is actuated via a quick-release clamp 20, which puts the tool 10, once secured via an adjusting screw, back into exactly the same position even after release. The two different positions of the quick-release clamp 20 are respectively Figure 8a and 8b as well as Figure 9a and 9b Shown in.

[0031] Fig.10 An alternative connection of the tool support 14 to the pivot arm 9 is shown. Here, a quick-action clamping device is dispensed with and exact positioning is ensured by determining precise manufacturing tolerances.

[0032] according to Fig.11 The view of FIG. 1 once again illustrates in detail that the tool support 14 has a stop edge 18 , via which an exact positioning of the tool support 14 is additionally ensured.

[0033] Fig.12 The cutting tool is arranged on a carrier which is connected to the cycloid gear 11 via an adjustment part 15. Figures 5a to 11 The difference between the embodiment shown in FIG. 1 and FIG. 2 is that the cycloid transmission 11 is directly connected to the actuator 21. Therefore, neither the servo motor 12 nor the angular transmission 13 is used. The actuator 21 includes at least one motor and one frequency converter.

[0034] Fig.13 With different views and Fig.12 Correspondingly, identical components are again labeled with the same reference numerals.

[0035] Fig.14 also with Fig.12 2, but a two-dimensional view is selected here. Here, the same parts are marked with the same reference numerals again. This also applies to the other two-dimensional view. Fig.15 .

[0036] Fig.16 Basically Figure 4 Correspondingly, here with Figure 4 In contrast, the servomotor 12 and the angular transmission 13 are not shown, but the pivot arm 19 with the actuator 21 is shown:

[0037] List of reference numerals:

[0038] 1 Extruder

[0039] 2 Extrusion die

[0040] 3Calibration and cooling chamber

[0041] 4Pull-out device

[0042] 5. Cutting device

[0043] 6 Profiles

[0044] 7 Extrusion axis

[0045] 8. Hydraulic system

[0046] 9 Pivoting arms

[0047] 10 Knives

[0048] 11Cycloid transmission

[0049] 12 Servo motors

[0050] 13 Angle gear

[0051] 14 tool holder

[0052] 15 is used for the adjustment part of 14

[0053] 16 Adjustment device

[0054] 17 Eccentric piece

[0055] Stop edge on 1814

[0056] 19 Means for pivoting

[0057] 20 Quick clamping device

[0058] 21 Actuator

[0059] 22 Rotatable disc

Claims

1. Equipment for cutting extruded plastic profiles along the extrusion axis (7), at least include: A tool (10) arranged on a tool support (14); A pivot arm (9), a tool holder (14) being able to move together with the tool (10) towards or away from the extrusion axis (7) by means of the pivot arm; a device (19) for pivoting the pivot arm (9); characterized in that the tool (10) is connected to the tool holder (14) and can be oriented in a plane at right angles to the extrusion axis (7) via an adjustment portion (15), and / or the tool (10) is connected to the tool holder (14) and the pivot arm (9), wherein the pivot arm (9) is arranged on the device (19) for pivoting, and the device (19) for pivoting is an electromechanical drive device, which includes at least one cycloid transmission device (11) which is directly connected to an actuator (21).

2. The device according to claim 1, It is characterized in that A plurality of devices (19) for pivoting, together with the pivot arms (10) arranged thereon, as well as the tool holder (14) and the tool (10) are arranged around the extrusion axis (7).

3. The device according to claim 2, It is characterized in that A device for identifying a tool (10) is provided.

4. The device according to any one of claims 1, 2 or 3, It is characterized in that The tool (10) is fixed in the tool holder (14) by means of a quick clamping device (20).

5. The device according to claim 3 or 4, It is characterized in that The quick clamping device (20) is an eccentric member (17).

6. The device according to claim 3 or 4, It is characterized in that The quick clamping device (20) is a bolt connection device.

7. A method for cutting an extruded plastic profile along an extrusion axis (7), in, Use of the device according to claim 1 for cutting, wherein the pivoting of the device (19) for pivoting is controlled by means of a controller, thereby influencing the feed speed at which the tool (10) is fed radially toward the profile (6) to be cut and is guided through the profile, wherein the feed speed of the pivoting is mapped by a graph.

8. The method according to claim 7, It is characterized in that The feed rate is a straight line equation or multiple straight line equations in a stepped manner.

9. The method according to claim 7, It is characterized in that The feed rate first increases until the tool reaches the outer region of the profile, then flattens out until the tool reaches a predetermined penetration depth, and then increases again until the cutting process is complete.

10. The method according to any one of claims 7 to 9, It is characterized in that The feed speed depends on the torque.

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