Device for Ultrasonic Welding of Composite Material

Abstract

A device is shown and described for ultrasonic welding of composite material, in particular composite material of package sleeves and/or packages, including at least two tools for ultrasonic welding, in particular a sonotrode and an anvil. Each tool has a functional surface for contact with the material to be welded. The functional surfaces of the tools are aligned approximately parallel to one another in such a way that a gap with an approximately horizontal seam direction is created between the functional surfaces. The tools are mounted in such a way that the width of the gap can be changed by at least one of the tools being movable along a feed direction, and at least one joint having at least one axis of rotation about which one of the tools is rotatable. In order to enable optimal adaptation of the movably mounted tool for example the sonotrode to the materials to be welded and their size, it is proposed that the position of the axis of rotation can be changed.

Claims

1-10. (canceled)

11. A device for ultrasonic welding of composite material, in particular composite material of package sleeves and/or packages, comprising: at least two tools for ultrasonic welding, in particular a sonotrode and an anvil, wherein each tool has a functional surface for contact with the material to be welded, wherein the functional surfaces of the tools are aligned approximately parallel to one another such that a gap with a preferably approximately horizontal seam direction is created between the functional surfaces, wherein the tools are mounted in such a way that the width of the gap can be changed by moving at least one of the tools along a feed direction, at least one joint with at least one axis of rotation about which one of the tools can be rotated, and wherein the position of the axis of rotation can be changed, wherein the position of the axis of rotation can be displaced along the seam direction and in that the displaceability is achieved in that the joint can be displaced relative to the rest of the device and can be locked in different positions.

12. The device according to claim 11, wherein the axis of rotation runs orthogonal to the feed direction and/or orthogonal to the seam direction.

13. The device according to claim 11, wherein the distance between the axis of rotation and the gap is less than 50 cm, in particular less than 10 cm, preferably less than 5 cm.

14. The device according to claim 11, wherein the joint has a hinge joint.

15. The device according to claim 11, wherein the joint has a solid-state joint, in particular a leaf spring.

16. The device according to claim 11, wherein the joints form a multi-part gearbox.

17. The device according to claim 16, wherein the gearbox has a plurality of solid-state joints, in particular a plurality of leaf springs.

18. The device according to claim 11, wherein the tool rotatably mounted around the joint has an instantaneous centre of rotation, the distance of which from the gap is less than 10 cm, in particular less than 5 cm, preferably less than 1 cm.

19. The device according to claim 11, wherein the tool rotatably mounted around the joint has an instantaneous centre of rotation, the distance of which from the gap is less than the distance between the axis of rotation and the gap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The invention will be explained in more detail below with reference to a drawing which represents only one preferred exemplary embodiment, in which:

[0028] FIG. 1A is a first embodiment of a device according to the invention in a perspective view,

[0029] FIG. 1B: shows the device from FIG. 1A in a side view,

[0030] FIG. 1C: shows the device from FIG. 1A in a plan view from the view shown in FIG. 1B viewing direction IC,

[0031] FIG. 2A: is a second embodiment of a device according to the invention in a perspective view,

[0032] FIG. 2B: shows the device from FIG. 2A in a side view,

[0033] FIG. 2C: shows the device from FIG. 2A in a plan view from the view shown in FIG. 2B viewing direction IIC,

[0034] FIG. 3A: is a third embodiment of a device according to the invention in a perspective view,

[0035] FIG. 3B: shows the device from FIG. 3A in a side view and

[0036] FIG. 3C: shows the device from FIG. 3A in a plan view from the view shown in FIG. 3B viewing direction IIIC.

DESCRIPTION OF THE INVENTION

[0037] FIG. 1A shows a first embodiment of a device 1 according to the invention in a perspective view. FIG. 1B shows the device 1 from FIG. 1A in a side view. FIG. 1C shows the device 1 from FIG. 1A in a plan view from the view shown in FIG. 1B viewing direction IC. In the case of the device 1 shown in FIG. 1A to FIG. 1C, it is a device for ultrasonic welding of composite material, in particular composite material of a package 2. In particular, seams of the package 2 can be welded and thus sealed in a manner that is liquid-tight, for example a seam 3 in the gable region 4 of the package 2. The device 1 has two tools for ultrasonic welding, in the present case a sonotrode 5 and an anvil 6. Both toolsi.e. both the sonotrode 5 and the anvil 6have a functional surface 5A, 6A for contact with the material to be welded. The functional surfaces 5A, 6A of the tools (sonotrode 5, anvil 6) are aligned approximately parallel to one another in such a way that a gap 7 with an approximately horizontal seam direction 8 is created between the functional surfaces 5A, 6A (the seam direction 8 is represented by a dashed line). Both tools (sonotrode 5, anvil 6) are also mounted in such a way that the width B (see FIG. 1C) of the column 7 can be changed by moving at least one of the tools along a feed direction 9. The device 1 shown in FIG. 1A to FIG. 1C also has a joint 10 with an axis of rotation 11A, about which one of the tools can be rotated. The position of the axis of rotation 11A can be displaced along the seam direction 8 (represented by arrows in FIG. 1C), so that the sonotrode 5 can be optimally positioned.

[0038] The joint 10 is designed as a hinge joint 10A and the axis of rotation 11A runs through the hinge joint 10A. As a result, the movably mounted tool (in this case: the sonotrode 5) can be rotated around the hinge joint 10A and its axis of rotation 11A and thus has an instantaneous centre of rotation M.sub.A which lies on the axis of rotation 11A. There is a distance 12A between the hinge joint 10A or its axis of rotation 11A or the instantaneous centre of rotation M.sub.A and the gap 7. The distance 12A therefore represents a radius about which the sonotrode 5 can rotate back and forth (in sections) (indicated by the dashed outline of the sonotrode 5 in FIG. 1C). The greater the distance 12A, the greater the translational portion of the movement of the sonotrode 5 in the area of the weld seam, so that even a small rotational angle results in a rather large movement in the circumferential direction along a circular path around the instantaneous centre of rotation M.sub.A. This means that even a small angle correction of the sonotrode 5 during the welding process would result in a rather large displacement of the sonotrode 5 in the seam direction 8. Since the permissible displacement along the seam direction 8 is limited but an angle correction of the sonotrode 5 is nevertheless desired, a distance 12A that is as small as possible is the goal.

[0039] FIG. 2A shows a second embodiment of a device 1 according to the invention in a perspective view. FIG. 2B shows the device 1 from FIG. 2A in a side view. FIG. 2C shows the device 1 from FIG. 2A in a plan view from the view shown in FIG. 2B viewing direction IIC. Corresponding reference symbols are used in FIG. 2A to FIG. 2C for those regions of the device 1 which are already in described in connection with FIG. 1A to FIG. 1C. A significant difference between the first embodiment of the device 1 (FIG. 1A to FIG. 1C) and the second embodiment of the device 1 (FIG. 2A to FIG. 2C) lies in the type and position of the joint 10. Instead of the hinge joint 10A described above, the joint 10 is designed as a solid-state joint, in particular as a leaf spring 10B, in the second embodiment of the device 1. In addition to their simple and robust design, leaf springs have the advantage that they generate return forces in the opposite direction to the deflection direction when deflected, which moves the leaf spring back to the non-deflected initial position. A further difference lies in the fact that the leaf spring 10B is arranged closer to the gap 7 in such a way that a reduced distance 12B is achieved compared to the first embodiment.

[0040] In the second embodiment, the axis of rotation 11B also runs through the joint 10, i.e. the leaf spring 10B. This also has the consequence here that the sonotrode 5 can be rotated about the leaf spring 10B and its axis of rotation 11B and the sonotrode 5 thus has an instantaneous centre of rotation M.sub.B, which lies on the axis of rotation 11B. There is a distance 12B between the leaf spring 10B or its axis of rotation 11B or the instantaneous centre of rotation M.sub.B and the gap 7. The distance 12B represents a radius about which the sonotrode 5 can rotate back and forth (in sections).

[0041] FIG. 3A shows a third embodiment of a device 1 according to the invention in a perspective view. FIG. 3B shows the device 1 from FIG. 3A in a side view. FIG. 3C shows the device 1 from FIG. 3A in a plan view from the view shown in FIG. 3B viewing direction IIIC. Corresponding reference symbols are used in FIG. 3A to FIG. 3C for those regions of the device 1 which are already in described in connection with FIG. 1A to FIG. 2C. A significant difference between the third embodiment of the device 1 (FIG. 3A to FIG. 3C) and the two previously described embodiments (FIG. 1A to FIG. 2C) in turn lies in the type and position of the joint 10.

[0042] In the third embodiment of the device 1, the joint 10 has four solid-state joints, which are formed as leaf springs 10C. Together, the leaf springs 10C form a four-part gearbox, which enables a particularly advantageous movement of the sonotrode 5. Leaf springs are characterised by a simple and robust design and move automatically back from any deflected position to the non-deflected starting position. Another difference lies in the position of the instantaneous centre of rotation M.sub.C of the sonotrode 5. In contrast to the embodiments previously described, the instantaneous centre of rotation M.sub.C of the sonotrode 5 in the third embodiment of the device 1 does not lie on one of the axes of rotation 11C of the individual leaf springs 10C, but rather much closer to the gap 7, whereby the distance 12C can be significantly reduced and even be zero (the instantaneous centre of rotation M.sub.C would then lie in the gap 7). The position of the instantaneous centre of rotation M.sub.C can be clarified using FIG. 3C: the instantaneous centre of rotation M.sub.C lies at the intersection of the connecting axes V of the axes of rotation 11C of the individual leaf springs 10C. The position and alignment of the individual leaf springs 10C or their axes of rotation 11C can thus specifically influence and optimise the position of the instantaneous centre of rotation M.sub.C of the sonotrode 5. An instantaneous centre of rotation M.sub.C which is very close to the gap 7 or even in the gap 7 has the consequence that the sonotrode 5 behaves as if it were mounted on a pivoting joint which is in the weld seam. This enables the sonotrode 5 to rotate about the weld seam without performing an undesired displacement in the seam direction. In other words, in the area of the weld seam, the sonotrode 5 performs almost exclusively a rotational movement (desired for an angle correction); however, it performs almost no translational movement there (undesired due to a deterioration of the welding outcome).

LIST OF REFERENCE NUMERALS

[0043] 1, 1, 1: Device for ultrasonic welding [0044] 2: Packaging [0045] 3: Seam [0046] 4: Gable area [0047] 5: Sonotrode [0048] 5A: Functional surface (of the sonotrode 5) [0049] 6: Anvil [0050] 6A: Functional surface (of the anvil 6) [0051] 7: Gap [0052] 8: Seam direction [0053] 9: Feed direction [0054] 10: Joint [0055] 10A: Hinge joint [0056] 10B, 10C: Leaf spring [0057] 11A, 11B, 11C: Axis of rotation [0058] 12A, 12B, 12C: Distance [0059] B: Width (of the gap 7) [0060] M.sub.A, M.sub.B, M.sub.C: Instantaneous centre of rotation [0061] V: Connecting axis