Search

DE-202026101338-U1 - Sonotrode for an ultrasonic welding device

DE202026101338U1DE 202026101338 U1DE202026101338 U1DE 202026101338U1DE-202026101338-U1

Abstract

Sonotrode (10) for an ultrasonic welding device with at least one sealing surface (20) for contacting a workpiece, wherein a planar welding structure (30) is provided on the sealing surface (20) which is designed to introduce welding energy into the workpiece, wherein a suppression structure (40) is further provided on the sealing surface (20), wherein the suppression structure (40) extends around the welding structure (30) and has a closed contour.

Assignees

  • HERRMANN ULTRASCHALLTECHNIK GMBH & CO KG

Dates

Publication Date
20260513
Application Date
20260310
Priority Date
20260310

Claims (17)

  1. Sonotrode (10) for an ultrasonic welding device with at least one sealing surface (20) for contacting a workpiece, in which a planar welding structure (30) is provided on the sealing surface (20) which is configured to introduce welding energy into the workpiece, in which a suppression structure (40) is further provided on the sealing surface (20), wherein the suppression structure (40) extends around the welding structure (30) and has a closed contour.
  2. Sonotrode (10) after Claim 1 , wherein the suppression structure (40) has at least one ridge (42) which preferably extends perpendicularly from the sealing surface (20).
  3. Sonotrode (10) according to one of the preceding claims, wherein the ridge (42) is wedge-shaped in cross-section.
  4. Sonotrode (10) according to one of the preceding claims, wherein the ridge (42) has a rounded tip.
  5. Sonotrode (10) according to one of the preceding claims, wherein a maximum height H1 of the suppression structure (40) is less than a maximum height H2 of the welded structure (30).
  6. Sonotrode (10) according to one of the preceding claims, wherein the maximum height H1 of the suppression structure (40) corresponds to approximately half the maximum height H2 of the welded structure (30).
  7. Sonotrode (10) according to one of the preceding claims, wherein a maximum width B1 of the suppression structure (40) is less than a maximum width B2 of the welded structure (30) in at least one dimension.
  8. Sonotrode (10) according to one of the preceding claims, wherein the maximum width B1 of the suppression structure (40) in at least one dimension is less than 10% of the maximum width B2 of the welded structure (30).
  9. Sonotrode (10) according to one of the preceding claims, wherein a boundary region (22) between the suppression structure (40) and a boundary (24) of the sealing surface (20) slopes continuously from the suppression structure (40).
  10. Sonotrode (10) according to one of the preceding claims, wherein the weld structure (30) is uniform.
  11. Sonotrode (10) according to one of the preceding claims, wherein the welded structure (30) comprises a plurality of pyramid-shaped elements (32) which are preferably arranged in a grid.
  12. Sonotrode (10) according to one of the preceding claims, wherein the maximum width B1 of the suppression structure (40) is less in at least one dimension than a maximum width B3 of the pyramidal elements (32).
  13. Sonotrode (10) according to one of the preceding claims, wherein the welded structure (30) has a rectangular base area.
  14. Sonotrode (10) according to one of the preceding claims, wherein the sealing surface (20) is essentially flat.
  15. Sonotrode (10) according to one of the preceding claims, wherein the contour has at least one kink or curve (44).
  16. Sonotrode (10) for an ultrasonic welding device with at least one sealing surface (20) for contacting a workpiece, in which a welding structure (30) is provided on the sealing surface (20) which is configured to introduce welding energy into the workpiece, in which a suppression structure (40) is further provided on the sealing surface (20), wherein the suppression structure (40) extends along a path at least partially around the welding structure (30), the path deviating from a straight line.
  17. Sonotrode (10) after Claim 16 , wherein the track has at least one bend or curve (44).

Description

The present invention relates to a sonotrode for an ultrasonic welding device. In ultrasonic welding, sonotrodes are used to transfer the energy supplied by a converter into the workpiece being welded. The design of the sonotrode has a significant influence on the weld quality. Ultrasonic welding can be used to join a wide variety of materials. This includes both plastics and metals. One problem that arises with ultrasonic metal welding is the formation of flakes. These are small chips that are created when the tool penetrates the weld pool and during the ultrasonic process. These flakes are undesirable because they can break off or fall off during further handling and, for example, cause short circuits. They can also gradually contaminate the work area during production. Flakes can be removed by manual post-treatment (brushing), but this is very time-consuming. To prevent flake formation, the welding parameters can be adjusted. However, in this case, compromises must be made between flake prevention and weld quality. It is therefore an object of the present invention to avoid the formation of flakes without impairing the quality of the weld. This problem is solved by a sonotrode according to claim 1. Advantageous further developments are the subject of the dependent claims. The advantages of the invention are particularly evident in metal welding. In metal welding, flakes can, for example, cause short circuits, which is why suppressing flake formation is of particular importance. The sonotrode is therefore preferably a metal welding sonotrode and, in particular, has a coupling surface that is essentially perpendicular to the sealing surface. The sonotrode preferably has several sealing surfaces. The sealing surfaces can be identical or differently designed. Preferably, all sealing surfaces have a welding structure and a suppression structure. The inventors have determined that the suppression structure largely welds any flakes that form into the workpiece material. Post-processing is unnecessary, and there is no longer a risk of flakes detaching later. The welding parameters can be adjusted independently of flake formation. In advantageous embodiments, the suppression structure has at least one burr. A burr is an elongated projection. The burr preferably extends perpendicularly from the sealing surface. The burr allows any flakes formed to be efficiently incorporated into the workpiece. The burr is preferably wedge-shaped in cross-section. This ensures that the burr makes essentially linear contact with the workpiece. In advantageous embodiments, the burr has a rounded tip. This prevents unnecessary wear of the burr and allows it to retain its shape and thus its properties during flake suppression over a long period. The suppression structure has a maximum height H1, which is preferably defined by the burr. Particularly preferably, the maximum height H1 is the distance by which the burr projects perpendicularly from the sealing surface. The weld structure preferably has a maximum height H2, which is also measured perpendicular to the sealing surface. The maximum height H1 of the suppression structure is preferably less than the maximum height H2 of the weld structure. This ensures that the weld structure performs the actual welding process, i.e., introduces the welding energy into the workpiece, and that the suppression structure primarily fulfills its primary function of suppressing the flakes. If the maximum height H1 is too small, flake formation is not sufficiently suppressed. If H1 is too large, the contact between the suppression structure and the workpiece is too extensive, requiring additional welding energy. Preferably, the maximum height H1 of the suppression structure corresponds to approximately half the maximum height H2 of the weld structure. Deviations of 10% are acceptable. This achieves a good compromise between suppression effectiveness and the additional welding energy required. The maximum height H1 is preferably between 0.1 mm and 1 mm. The maximum height H2 is preferably between 0.3 mm and 3 mm. The welded structure preferably has a rectangular base area. The suppression structure has a maximum width B1, which is preferably a measure of the ridge. Particularly preferably, the maximum width B1 is the maximum width of the ridge perpendicular to the surface. The width follows the contour and is parallel to the sealing surface. In the case of a wedge-shaped ridge, the width is that of the ridge's base. The weld structure has a maximum width B2, which preferably corresponds to its overall width and can differ in several dimensions. For example, a weld structure with a rectangular base has two maximum widths B2 perpendicular to each other. The suppression structure can be significantly narrower than the weld structure, as it only performs an auxiliary function. Therefore, the maximum width B1 of the suppression structure is preferably less than the maximum width B2 of the weld structure in