Abstract
The invention relates to a device for pressing flat material, comprising means for transporting the flat material (15) in a transport direction and at least one pressing roller pair (9), which is stationary in the transport direction and acts on the flat material (15) on both sides, said device being characterized in that both pressing rollers (13, 14, 29, 34) of the pressing roller pair (9) or both pressing rollers (13, 14, 29, 34) of at least one of the pressing roller pairs (9) are elastically deformable in the radial direction at least at the circumference of said pressing rollers.
Claims
1.-17. (canceled)
18. A device for pressing processing flat material, comprising means for transporting the flat material in a transport direction and at least one pressing roller pair which is stationary in the transport direction and acts on the flat material on both sides, characterized in that, both pressing rollers of the pressing roller pair or both pressing rollers of at least one of the pressing roller pairs are elastically deformable in the radial direction at least at the circumference of said pressing rollers.
19. The device according to claim 18, characterized in that there are at least two pressing roller pairs arranged one behind the other in the transport direction.
20. The device according to claim 18, characterized in that the device is a double-belt press.
21. The device according to claim 18, characterized by heating means for heating the flat material.
22. The device according to claim 21, characterized in that the heating means act indirectly on the flat material via a double-belt press.
23. The device according to claim 21, characterized in that at least a number of the heating means act inductively.
24. The device according to claim 23, characterized in that at least a number of the heating means are designed to generate magnetic fields which have a predominant magnetic field component oriented perpendicular to a center plane of the flat material.
25. The device according to claim 21, characterized in that the heating means or at least a number of the heating means have a meandering course at least in sections.
26. The device according to claim 21, characterized in that at least a number of the heating means are designed to encompass a section of the fiat material to be heated in a shape.
27. The device according to claim 21, characterized by means for controlling or regulating a distance between the heating means and a center plane of the flat material running parallel to the transport direction and parallel to the axes of rotation of the pressing rollers.
28. The device according to claim 21, characterized by spacers to ensure a constant distance between the heating means and a center plane of the flat material running parallel to the transport direction.
29. The device according to claim 18, characterized in that at least two pressing roller pairs can be acted upon in a controllable or regulatable manner with different pressing forces.
30. The device according to claim 18, characterized in that at least one of the pressing rollers of at least one pressing roller pair comprises a cavity for the passage of a cooling fluid.
31. The device according to claim 18, characterized in that at least one of the pressing rollers of at least one roller pair is protected on the outer circumference by a heat-insulating layer.
32. The device according to claim 31, characterized in that the heat-insulating layer is part of the pressing roller.
33. The device according to claim 31, characterized in that the heat-insulating layer is formed by a separate belt guided around part of the circumference of the roller.
34. The device according to claim 18, characterized by cooling means which, during use, direct a cooling fluid from the outside onto the circumference of the pressing roller and/or onto the end faces of the pressing roller.
Description
[0026] Shown schematically are:
[0027] FIG. 1: a double-belt press,
[0028] FIG. 2: a pressing roller pair before and after the pressure build-up with heating elements and flat material to be processed without heating means tracking,
[0029] FIG. 3: a pressing roller pair before and after the pressure build-up with heating elements and flat material to be processed with heating element tracking,
[0030] FIG. 4: the principle of heating means tracking with spacers,
[0031] FIG. 5: the principle of the motorized heating element tracking,
[0032] FIG. 6: pressing roller with integrated heat-insulating layer,
[0033] FIG. 7: pressing roller with separate thermal insulation belt guided around a deflection roller,
[0034] FIG. 8: pressing roller with separate thermal insulation belt guided around two deflection rollers,
[0035] FIG. 9: a perspective view from the side of a workpiece with inductively acting heating elements and
[0036] FIG. 10: an inductive heating element encompassing the workpiece in a side view.
[0037] FIG. 1 shows schematically in a lateral cross section a double-belt press having an upper press belt 1 and a lower press belt 2. The endless press belts 1 and 2 are each guided around an upper drive roller 3 and lower drive roller 4 and around an upper deflection roller 5 and a lower deflection roller 6, respectively. Flat material to be processed, not shown here, is guided between a working strand 7 of the upper press belt 1 and a working strand 8 of the lower press belt 2, which is carried in a transport direction (from left to right in FIG. 1) by the revolving press belts 1 and 2. A plurality of pressing roller pairs 9 is arranged along the working strands 7 and 8, with which the upper working strand 7 and the lower working strand 8 are pressed against the flat material to be processed, not shown here. Furthermore, heating elements, not shown individually in FIG. 1, are arranged along the working strands 7 and 8 in a main heating zone 10 and in intermediate heating zones 11, which preferably act inductively. In this case, either the material of the press belts 1 and 2 is inductively coupled or the flat material to be processed. A temperature required for processing the flat material can be maintained over a long distance due to the plurality of heating elements and their positioning between the pressing roller pairs 9. The arrangement depicted here of one intermediate heating zone 11 between two pressing roller pairs 9 is only an example. The number of intermediate heating zones 11 and the arrangement of the pressing roller pairs 9 adjacent to the intermediate heating zones 11, for example, individually or in groups of two or more pressing roller pairs 9, can be designed differently depending on the requirements of the operation of the double-belt press. As seen in the transport direction, cooling sections 12 are optionally arranged at the end of the working strands 7 and 8.
[0038] FIG. 2 schematically shows a pressing roller pair 9 having an upper pressing roller 13 and a lower pressing roller 14, wherein in a) the situation before application of a pressing power and in b) the situation under a certain pressing power is shown. A workpiece 15 made of flat material to be processed is depicted schematically between the pressing rollers 13 and 14, wherein the press belts 7 and 8 (see FIG. 1) taking the workpiece 15 between them cannot be seen in the illustration. The pressing rollers 13 and 14 comprise an elastically deformable region 16 on their outer circumference. The contact pressure of the two pressing rollers 13 and 14 is built up symmetrically according to FIG. 2, that is, due to the flexibility of the elastically deformable region 16, the axes of rotation 17 and 18 of the pressing rollers 13 and 14 each move the same distance ΔI towards the workpiece 15; the vertical position of a center plane 19 of the workpiece 15 is therefore not changed by the application of the pressing power. FIG. 2 also schematically shows the position of heating elements 20, as they can be provided in the main heating zone 10 or in the intermediate heating zones 11 (see FIG. 1). The distance between these heating elements 20 perpendicular to the center plane 19 remains unchanged despite the shift in the positions of the axes of rotation 17 and 18 which is generated when the pressing power is applied. However, a considerable amount of regulation effort has to be carried out in order to achieve a movement of the pressing roller pair 13 and 14 symmetrical to the center plane 19.
[0039] FIG. 3 shows a situation similar to FIG. 2. The same reference numbers relate to the same device elements, so that reference can be made to the description of FIG. 2. The starting position of the pressing rollers 13 and 14 shown in partial figure a) is identical to the starting position in FIG. 2a). One difference is that the axis of rotation 18 of the lower pressing roller 14 is fixed in its position in the arrangement according to FIG. 3. In order to apply the pressing power, only the axis of rotation 17 of the upper pressing roller is thus moved by a distance 2ΔI in the direction of the lower axis of rotation 18. Since the deformation of the pressing rollers 13 or 14 is the same due to the otherwise matching structure, the center plane 19 of the workpiece 15 will move to the lower pressing roller 14 by the distance ΔI. In order to prevent the application of the pressing power from changing the effect of the heating elements 20 on the workpiece 15, provision is made not to change the distance between the heating elements 20 and the center plane 19 and also to move the heating elements 20 by the distance ΔI. With this measure, the advantage of the surface pressure achieved by means of the elastically deformable region 16 is achieved without restriction due to an otherwise only limitedly reproducible effect of the heating elements 20 on the workpiece 15.
[0040] FIG. 4 schematically shows, in a cross section perpendicular to the material transport direction, a double-belt press having two heating elements 20, one above and the other below the workpiece 15 and the press belts 1 and 2 receiving the workpiece 15 arranged between them. The heating elements 20 are held on brackets 21 such that the distance between the respective heating element 20 and the associated press belt 1 or 2 is as constant as possible during operation of the double-belt press. Spacers 23 are provided here by way of example for this purpose. In order to be able to follow a possible vertical movement of the respective press belt 1 or 2, the heating elements 20 are pressed with a force in the direction of the associated press belt 1 or 2, which force is symbolized here in each case by a spring element 22. For the upper one of the heating elements 20, said force can also be composed of its weight and a supporting force counteracting gravitation, wherein the supporting force is intended to reduce the load on the upper press belt 1. The spacers 23 are preferably fixed on the respective heating element 20 and can roll off the associated press belt 1 or 2. Of course, sliding spacers can also be provided as an alternative or in addition. Guide elements 24 are provided for guiding the brackets 21.
[0041] FIG. 5 also shows in cross section a double-belt press in which, unlike in FIG. 4, the distance between the heating elements 20 and the workpiece 15 arranged between the press belts 1 and 2 is set by means of electric motors 25 and linear guides 26. Sensor values from distance sensors 27, which, for example, measure mechanically, optically or capacitively, serve as the base variable for the control or regulation of the electric motors 25 taking place via a control or regulating device 28.
[0042] FIG. 6 shows schematically a pressing roller 29 which presses on the upper press belt 1 and has a heat-insulating layer 30 which is fixedly arranged on the outer circumference thereof and which is applied directly to an elastically deformable region 31 of the pressing roller. The elastically deformable region 31 in turn surrounds a hollow cylinder 33 made of a material that is rigid in comparison, for example, stainless steel. An inner cavity 32 of the hollow cylinder 33 can be used for the flow of a cooling fluid. The elastically deformable region 31, for example, made of silicone, can, for example, have a thickness of 1 to 20 mm, preferably 5 to 15 mm, and a hardness between, for example, 20 Shore A and 65 Shore A, preferably between 50 Shore A and 60 Shore A.
[0043] FIG. 7 shows a pressing roller 34 in which the heat-insulating layer is not fixed over the entire circumference but is implemented by a circumferential belt 35 which rests against the elastically deformable region 36 only on part of the circumference thereof and is otherwise guided at a distance from the pressing roller 34 via a deflection roller 37. There is an improved possibility of separate cooling of the belt 35 in the spaced-apart region between the pressing roller 34 and the deflection roller 37. In addition, the belt 35, which is subject to wear, is easily exchangeable. FIG. 8 shows a further variant similar to FIG. 7, in which the belt 35, however, is guided over two deflection rollers 37, whereby a smaller angle of wrap of the belt 35 with the press roller 34 is implemented and a better possibility for cooling can be provided. Reference is made to the description of FIG. 7 for further details.
[0044] The fact that the pressing rollers do not necessarily have to be hollow cylinders applies to all embodiments. Other shapes with or without passages for a cooling fluid are also conceivable.
[0045] FIG. 9 shows a perspective oblique top view of a workpiece 15 to be processed, wherein of the double belt press, only one inductively acting first heating element 38 having a connection element 42 arranged in a main heating zone 10 (see also FIG. 1) and a respective further inductively acting heating element 39, 40 or 41 having a collective connection element 43 arranged in intermediate heating zones 11 are shown schematically. In the main heating zone 10, the first heating element 38 is guided in a plurality of heating loops on the one hand above the workpiece 15 and on the other hand below the workpiece 15. In the intermediate heating zones 11, the second heating element 39, the third heating element 40 and the fourth heating element 41 each comprise a heating loop above and a heating loop below the workpiece 15. In the intermediate heating zones 11, more than one heating loop in each case and different numbers of heating loops in different intermediate heating zones 11 are also conceivable. The heating elements 39, 40 and 41 can, as shown in FIG. 9, be supplied with power and cooling water jointly via the collective connection element 43 by a preferably controllable alternating current source, not shown here, or without a collective connection element individually directly with one controllable alternating current source each. The latter offers the advantage of individual power regulation and thus individual heating in the heating zones 11.
[0046] FIG. 10 shows the first heating element 38 guided around the workpiece 15 with the connection element 42 in a side view. The representations of FIG. 9 and FIG. 10 differ slightly, particularly in connection element 42, but this is not intended to be of any significance here. The connection element 42 is, like the collective connection element 43 (FIG. 9), prepared for contacting a preferably controllable alternating current source, not shown here. The heating loops of the first heating element 38 are mechanically stabilized with respect to one another using two parallel cross connectors 44 made of an electrically insulating material.
[0047] The electrical connection between the upper loops and the lower loops of the first heating element 38 is implemented by two transition pieces 45 which are each guided around the edge of the workpiece 15 on the side facing the connection element 42. On the side facing away from the transition pieces 45, the first heating element 38 is open and can thus be guided laterally over the workpiece 15 or the workpiece 15 can be inserted laterally so that maintenance or replacement of the first heating module 38 is possible, even when the workpiece 15 is located in the double-belt press.
[0048] The illustrated course of the loops of the first heating element 38 above and below the workpiece leads to the magnetic fields generated during operation of the first heating element 38 being aligned perpendicular to the center plane of the workpiece 15, that is, magnetic transverse fields are generated. Such transverse fields can be technically and economically more efficient when heating flat material, that is, with a large ratio of material width to material thickness, than longitudinal fields running parallel to the center plane.
[0049] The statements relating to the first heating element 38 also apply in a corresponding manner to the further heating elements 39, 40 and 41 in the intermediate heating zones 11.
[0050] Of course, other design variants for the heating elements are also possible, for example, those in which the part running under the workpiece 15 and the part running above the workpiece can be moved independently of one another at least over a certain distance, for example, in order to be able to implement the embodiment according to FIG. 5. For this purpose, the two parts can be associated with separate connection elements, for example, or the electrical connection between the two components is made via flexible transition pieces or transition pieces that can be changed in length. It should be noted that the vertical movement of the heating elements only requires short distances in the mm or cm range to ensure a largely constant distance between the heating element and the workpiece (see, for example, FIGS. 4 and 5).
REFERENCE SYMBOLS LIST
[0051]
TABLE-US-00001 1 upper press belt 2 lower press belt 3 upper drive roller 4 lower drive roller 5 deflection roller 6 deflection roller 7 working strand upper press belt 8 working strand lower press belt 9 pressing roller pair 10 main heating zone 11 intermediate heating zone 12 cooling section 13 upper pressing roller 14 lower pressing roller 15 workpiece 16 elastically deformable region 17 axis of rotation 18 axis of rotation 19 center plane 20 heating element 21 bracket 22 spring element 23 spacers 24 guide element 25 electric motor 26 linear guide 27 distance sensors 28 control or regulating device 29 pressing roller 30 heat insulating layer 31 elastically deformable region 32 cavity 33 hollow cylinder 34 pressing roller 35 belt 36 elastically deformable region 37 deflection roller 38 first heating element 39 second heating element 40 third heating element 41 fourth heating element 42 connection element 43 collective connection element 44 cross connector 45 transition piece
