Ultrasonic transducer, device with and use of an ultrasonic transducer, and corresponding method

Abstract

The invention relates to an ultrasonic transducer (1; 101; 201) for producing high-frequency vibrations, the ultrasonic transducer (1; 101; 201) being formed as a planar single piece with a thickness (D) in a thickness direction (DR), a length (L) in a length direction (LR) and a width (B) in a width direction (BR). According to the invention, the thickness (D) of said ultrasonic transducer is m·λ / 2, where m is a natural odd number, and the length (L) is n·λ / J2, where n is a natural number greater than or equal to 2, wherein the ultrasonic transducer (1; 101; 201) can be excited by initiating high-frequency mechanical vibrations to form one or more thickness vibrations, which then follow one another in the length direction (LR) of the ultrasonic transducer (1; 101; 201), with a wavelength λ measured in the length direction (LR) and also with vibration amplitudes which are substantially constant in the width direction (BR) as viewed over the length (L) of the ultrasonic transducer (1; 101; 201). Furthermore, the invention relates to a device (50) for producing high-frequency vibrations, said device having at least one ultrasonic converter (12) and at least one ultrasonic transducer (1; 101; 201) connected to the ultrasonic converter (12), and relates to the use of said transducer and to a method.

Description

[0001] 1 UMG-10429a-22 October 12, 2023 Ultrasonic oscillator, device with and use of an ultrasonic oscillator, and corresponding methods The present invention relates to an ultrasonic oscillator for generating high-frequency oscillations, wherein the ultrasonic oscillator is formed in one piece and is plate-shaped with a thickness in the thickness direction, a length in the length direction, and a width in the width direction. The invention also relates to a device with such an ultrasonic oscillator, as well as its use and corresponding methods. To date, plate-shaped ultrasonic oscillators have primarily been known for use in cleaning devices. In this case, a plate-shaped ultrasonic oscillator is immersed vertically into a cleaning bath, with a plurality of ultrasonic converters attached to its flat rear side, facing away from the cleaning bath.These cause the ultrasonic oscillator to vibrate non-harmonically, which is then transferred to the water. The resulting constant overpressure and underpressure in the water creates very small air bubbles that swell to many times their original diameter until they burst and release energy that, for example, removes dirt from surfaces. The well-known plate-shaped ultrasonic cleaning oscillators, which predominantly operate with surface waves, are all tuned to a quarter of their harmonic wavelength ^ / 4 in order to optimize the coupling to the cleaning medium, usually water or predominantly water. The dimensions of well-known ultrasonic oscillators are selected so that their length and width are significantly greater than their thickness. However, due to their design, the well-known ultrasonic oscillators have very limited applications. 2 UMG-10429a-22 12.10.2023 The object of the present invention is to provide a plate-shaped ultrasonic oscillator with which new fields of application can be opened up. Corresponding devices with such an ultrasonic oscillator, uses, and methods are also sought. This object is achieved by an ultrasonic oscillator having the features of the independent patent claims. The features of the other independent claims likewise solve the stated object. An ultrasonic oscillator is proposed, the thickness of the ultrasonic oscillator m. * ^ / 2, with m being a natural odd number, and whose length n *^ / 2, with n being a natural number ≥ 2. When excited externally by means of an ultrasonic converter that introduces high-frequency mechanical vibrations into the ultrasonic oscillator, the ultrasonic oscillator according to the invention oscillates in the form of one thickness oscillation or several thickness oscillations following one another in the length direction of the ultrasonic oscillator, wherein the thickness oscillations measured in the length direction of the ultrasonic oscillator have the wavelength ^. In particular, the ultrasonic oscillator according to the invention is characterized in that, viewed over its length, the oscillation amplitudes in the width direction are essentially constant.This results in a wave extending across the width of the ultrasonic oscillator with a constant oscillation amplitude in the width direction, which extends sinusoidally in the length direction and is characterized by expansion and contraction in the local thickness of the ultrasonic oscillator. In other words, wave crests and troughs do not alternate along a line in the width direction of the ultrasonic oscillator; instead, a common wavefront is essentially found along the said line. This allows for a more uniform energy transfer with a higher amplitude, for example, to media to be processed, which are guided past the ultrasonic oscillator in the length direction of the ultrasonic oscillator.The present invention thus proposes for the first time tuning a plate-shaped ultrasonic oscillator, at least in thickness and length, to a wavelength at which it oscillates sinusoidally in the form of thickness oscillations, with one or more thickness oscillations (then following one another in the length direction). In this way, surprisingly high energies can be derived from the ultrasonic oscillator, opening up a multitude of new application possibilities. The term "one-piece" is understood here to mean a coherent unit which, in particular, is not created by the material-to-material joining of two or more parts, but is manufactured as a single piece, in particular by milling from a single block of a suitable metal. The ultrasonic oscillator according to the invention advantageously has a uniform thickness of 1 / 2.In this case, no nodes are formed across the thickness of the ultrasonic oscillator, which is preferred for many applications. The ultrasonic oscillator according to the invention particularly preferably has a width of n. * ^ / 4, where n is a natural number. It has been found that with such a selection, the thickness vibrations and the constant vibration amplitudes in the width directions can be optimized. According to further advantageous embodiments, the width of the ultrasonic oscillator is n* ^ / 2, where n is a natural number and preferably a natural odd number. According to such an embodiment, the width of the ultrasonic oscillator is advantageously 1 / 2* ^ or ^ or 3 / 2 * ^ or 2 * ^ or 5 / 2 * ^ or 3 * ^ etc. and preferably 3 / 2 * ^ or 5 / 2 * ^ or 7 / 2 * ^ or 9 / 2 *^ ^etc. In particular, with an exact adjustment of the width of the ultrasonic oscillator, it has been shown that almost pure longitudinal waves are generated in the direction of the length or the length of the ultrasonic oscillator. In certain embodiments, it has proven advantageous for the width of the ultrasonic oscillator according to the invention to be at least ^. In certain embodiments that have proven advantageous, the length of the ultrasonic oscillator according to the invention is k* ^ / 2, where k is a natural even number greater than or equal to 2. The length in these cases is accordingly ^ or 2 * ^ or 3 *^ etc. With such a selection it has been shown that very uniform sine waves can be obtained in the length direction of the ultrasonic oscillator. But even with a length of 3 / 2* ^, 5 / 2* ^, 7 / 2* ^, 9 / 2* ^, i.e. when in the formula n* ^ / 2 for the length of the ultrasonic oscillator n is a natural odd number, the inventive effect can be achieved, namely that essentially constant oscillation amplitudes can be observed in the width direction over the length of the ultrasonic oscillator. In both cases the sine waves are superimposed by very little to no amplitude fluctuations in the width direction. The ultrasonic oscillator according to the invention is particularly preferably designed to be homogeneous throughout and in particular has no slits or completely enclosed recesses. This achieves a uniform oscillation excitation of the ultrasonic oscillator. From 5 UMG-10429a-22 12.10.2023 Plate oscillators in the form of welding sonotrodes are known in the prior art, in which only longitudinal waves are to be emitted from the ultrasonic oscillator. Transverse waves are to be suppressed by the previously known recesses and / or slots. The result of the prior art is plate-shaped welding sonotrodes that oscillate back and forth in a plane as a whole, thus no oscillations build up across the plate itself. In the present invention, longitudinal waves are also desired, but no slots or recesses are necessary. Rather, in the ultrasonic oscillators according to the invention, longitudinal oscillations build up that extend across the entire plate, thus preventing a plane back and forth oscillation of the ultrasonic oscillator as a whole.For all embodiments of the invention, it has proven advantageous for half the wavelength, i.e. λ / 2, to be in the range between 90 and 120 mm. The excitation frequency at such wavelengths is preferably in the range of 19 to 22 kHz, although finding the appropriate excitation frequency cannot be strictly calculated from the formula (frequency = speed of light / wavelength), but must be determined experimentally or by prior simulation. For a smaller wavelength λ, a higher excitation frequency must be selected to cause the ultrasonic oscillator to oscillate harmonically. For λ / 2 in the range of 80 mm, for example, the excitation frequency is roughly 30 kHz, and for λ / 2 in the range of 50 mm, it is roughly 35 kHz. An advantageous width of the ultrasonic oscillator according to the invention is at least 100 mm and preferably at least 500 mm.Larger widths are readily possible, for example, those of at least 1000 mm or 2000 mm or 3000 mm or even wider. Even with these very large widths, the excitation of an ultrasonic oscillator according to the invention with high oscillation amplitudes has been realized in corresponding experiments. The advantageous lengths of the ultrasonic oscillator according to the invention are also in the range of several hundred to several thousand millimeters. It has proven advantageous if, for smaller wavelengths ^, the external dimensions of the ultrasonic oscillator are also selected to be smaller than for longer wavelengths ^, in order to generate optimal excitation of the ultrasonic oscillator for harmonic oscillation in the longitudinal direction. According to advantageous embodiments, the ultrasonic oscillator according to the invention is cuboid-shaped.It has been shown that with this simple geometric design, ultrasonic oscillators with harmonic longitudinal waves with an oscillation amplitude that is constant in the width direction and sinusoidally extending in the length direction are possible, with which the energy of the longitudinal waves can be coupled out of the ultrasonic oscillator. According to other embodiments, it is advantageous if the one-piece ultrasonic oscillator comprises at least a first and a second cuboid section, wherein these two cuboid sections adjoin one another on their width sides and each have a width that is a multiple of ½. These two cuboid sections are arranged offset from one another in the width direction, whereby the first cuboid section on one side - viewed in the width direction - projects one cuboid section beyond the second cuboid section.On the other side of the ultrasonic oscillator—also viewed in its width direction—the relationships are reversed, i.e., the second cuboid section projects beyond the first cuboid section. The cuboid sections projecting in the width direction each have a width of ¼ or an odd multiple of ¼. Surprisingly, it has been found that with such a configuration, the oscillation peaks and troughs of longitudinal oscillations of one cuboid section excited in the length direction of the ultrasonic oscillator—as viewed across the width of the ultrasonic oscillator—can be largely or completely aligned with the corresponding oscillation peaks and troughs of the other cuboid section. Thus, a largely uniform sinusoidal wavefront is generated in the length direction of the ultrasonic oscillator across its width.Preferably, the at least two cuboid sections are of equal width, so that the two cuboid sections that project beyond the first and second cuboid sections are also of equal width. The width of the two cuboid sections is preferably 1 / 4 each. According to an alternative to a width-staggered arrangement of the cuboid sections - with an otherwise identical design of the ultrasonic oscillator - one of the two cuboid sections projects beyond the adjacent cuboid section at both its ends in the width direction by one cuboid section each. In this case, the two cuboid sections of the cuboid sections that project beyond in the width direction have a width of 1 / 4 or an odd multiple of 1 / 4. The advantage of the uniform waveform across the width of the ultrasonic oscillator, which arises in the previously described embodiment, is also realized in this embodiment.Advantageously, the length of each cuboid section is 1 / 2 or a multiple of 1 / 2. This configuration enables precise tuning of the oscillation waves propagating in the length direction of the ultrasonic oscillator. 8 UMG-10429a-22 12.10.2023 Furthermore, it is preferred that the at least two cuboid sections are of equal length. According to a further development of the embodiments described above, the ultrasonic oscillator consists of several block sections adjoining one another in the length direction, wherein each block section is formed from at least two of the aforementioned cuboid sections. This measure achieves a greater working length, for example when guiding material webs to be processed with the ultrasonic oscillator along the length direction of the ultrasonic oscillator. A preferred material for the ultrasonic oscillator according to the invention is aluminum.The one-piece, plate-shaped ultrasonic oscillator is then preferably milled from a single aluminum block. Alternative materials for the ultrasonic oscillator are steel, a steel alloy, or titanium. Here, too, the ultrasonic oscillator is preferably manufactured by milling. The invention also relates to a device for generating high-frequency oscillations with at least one ultrasonic converter and an ultrasonic oscillator, as described above, wherein the ultrasonic oscillator is connected to the at least one ultrasonic converter. The ultrasonic converter can be designed in particular as an electromechanical (e.g., piezoelectric or magnetostrictive) energy converter. The ultrasonic oscillator can then be used in particular as an ultrasonic tool.The converter serves to transform alternating electrical voltages into alternating mechanical strains and thus excite structural vibrations in the mechanically coupled ultrasonic transducer, which then transmits its vibrations to a workpiece connected to it. 9 UMG-10429a-22 12.10.2023 Furthermore, a so-called booster can advantageously be placed between the ultrasonic converter and the ultrasonic transducer, with which an amplitude translation from the ultrasonic converter to the ultrasonic transducer can be achieved. Both ultrasonic converters and boosters are widely known from the prior art. It is particularly advantageous for the at least one ultrasonic converter to be coupled to the at least one ultrasonic transducer from the top or bottom.The ultrasonic converter is preferably coupled at a vibration node (which becomes the antinode after half an oscillation) of the ultrasonic oscillator in order to achieve optimal energy input. The at least one ultrasonic converter is preferably coupled to the ultrasonic converter at a distance of 1 / 4 or a multiple of 1 / 4 from the width edge running in the width direction and also from the length edge of the ultrasonic oscillator running in the length direction. It has been shown that such a connection point for the ultrasonic converter to the ultrasonic oscillator allows optimal vibration excitation to be achieved. At a distance of 1 / 4 from the width edge or a multiple of 1 / 4, the ultrasonic converter couples to a point on the ultrasonic oscillator that oscillates with a maximum deflection amplitude.Particularly preferably, for the purpose of exciting said longitudinal waves, only a single ultrasonic converter is coupled to the ultrasonic oscillator from the top or bottom. Such a configuration contrasts particularly with cleaning oscillators, in which a plurality of ultrasonic converters are coupled to one side of the ultrasonic oscillator, usually on the side facing away from the cleaning bath. 10 UMG-10429a-22 12.10.2023 According to advantageous embodiments, the at least one ultrasonic oscillator is coupled to a device that resonates in the thickness direction of the ultrasonic oscillator, wherein this device can be an embossing tool, a punch, or an erosion tool. Due to the high amplitudes achievable by means of the invention and the high energy delivery to a workpiece to be machined, high efficiency can be achieved using a device designed in this way.For the processing of flat workpieces such as material webs, a transport device is preferably assigned to the underside or top side of the at least one ultrasonic oscillator, which transport device enables at least one material web to be passed through the device and in particular between the ultrasonic oscillator and the transport device. The transport device preferably comprises one or more actively and / or passively driven rollers or cylinders. According to an alternative, a withdrawal device is provided downstream of the ultrasonic oscillator, wherein a counterplate is assigned to the top or bottom side of the ultrasonic oscillator in order to guide one or more material webs between the ultrasonic oscillator acting as the working tool and the counterplate.The invention further relates to the use of an ultrasonic oscillator as described above for or in a device as described above. The invention likewise relates to a method for operating a device as described above, which is used for joining at least two material webs, for consolidating, drying, embossing or smoothing at least one material web, for heating, filtering, separating materials, cleaning sewage sludge, and / or for converting mechanical energy into electrical energy, in particular by means of piezoelectric transducers. 11 UMG-10429a-22 12.10.2023 A method according to the invention is characterized in that a flat, overall web comprising several material webs is joined together by means of a device according to the invention. This is preferably done by continuously transporting the overall web through the device in the length direction of the ultrasonic oscillator.The longitudinal direction of the ultrasonic oscillator therefore corresponds to the transport direction of the entire web. For example, an adhesive is applied to one of the material webs, either over a large area or only in certain regions, advantageously in a pattern, whereupon the entire web is passed between the underside or top side of the ultrasonic oscillator and a pressing counter-tool, in particular actively or passively driven rollers. With passive rollers arranged opposite the ultrasonic oscillator, the entire material web can be pulled through the device, for example, by downstream take-off rollers. Due to the high energy input, including the large vibration amplitude, which can be coupled in by the ultrasonic oscillator, the adhesive is melted in an optimal manner and the material webs are bonded together by pressure to form a complete web. The longer the ultrasonic oscillator (i.e.The longer the transport path along the ultrasonic oscillator, the greater the working length and the more even and reliable the connection of the material webs can be. Advantageous further developments are characterized by the features of the subclaims. The invention is explained in more detail below with reference to figures, wherein the same reference numerals are used for features that are identically designed and / or have the same effect. They show: 12 UMG-10429a-22 12.10.2023 Fig.1a-1c a plan view, a side view and a front view of a first embodiment of an ultrasonic oscillator according to the invention; Fig.2 a front view of the ultrasonic oscillator of Fig.1 with connected ultrasonic excitation devices; Figs.3a, 3b a simulated thickness oscillation of a second embodiment of an ultrasonic oscillator at a first and a second time point; Fig.4a, 4b show a simulated thickness oscillation of a third embodiment of an ultrasonic oscillator at a first and a second time; Fig. 5a-5c show a top view, a side view, and a front view of a fourth embodiment of an ultrasonic oscillator according to the invention; Fig. 6 shows a front view of the ultrasonic oscillator of Fig. 5 with connected ultrasonic excitation devices; Fig. 7a-7d show a top view, a side view, a front view, and a perspective top view of a fifth embodiment of an ultrasonic oscillator according to the invention; Fig. 8a, 8b show a simulated thickness oscillation of a sixth embodiment of an ultrasonic oscillator at a first and a second time; 13 UMG-10429a-22 12.10.2023 Fig. 9a, 9b show a simulated thickness oscillation of the sixth embodiment according to Fig. 8a, 8b at two times, shown with a connected booster; Fig.Fig. 10 is a plan view of a seventh embodiment of an ultrasonic oscillator; Fig. 11 is a plan view of an eighth embodiment of an ultrasonic oscillator; Fig. 12 is a plan view of a ninth embodiment of an ultrasonic oscillator; Fig. 13 is a side view of the ultrasonic oscillator of Fig. 1 with tools arranged on the underside and take-off rollers arranged downstream; Fig. 14 is a side view of the ultrasonic oscillator of Fig. 7 with transport rollers arranged on the underside, and Fig. 15 is a side view of the ultrasonic oscillator of Fig. 7 with a counterpressure plate arranged on the underside and take-off rollers arranged downstream. Figs. 1a-1c show a plan view, side view, and front view of an ultrasonic oscillator 1 according to the invention. The ultrasonic oscillator 1 is made from a piece of metal in the shape of a cuboid, preferably from aluminum and, according to advantageous alternatives, from steel or titanium.It has no slots or completely enclosed recesses, which are used in the prior art, particularly for suppressing transverse waves. However, in the ultrasonic oscillator 1 according to the invention, no transverse waves that disrupt the oscillation behavior occur in this respect due to its fundamentally different geometric structure, in particular the adjustment of the thickness to half the wavelength 1 / 2. The ultrasonic oscillator 1 has a thickness D in the thickness direction DR, a length L in the length direction LR, and a width B in the width direction BR. In the present case, the thickness D of the ultrasonic oscillator 1 shown in Fig. 1 is 1 / 2 and the length L is 2. * ^. In general, according to the invention, the thickness D m * ^ / 2, with m as a natural odd number, and the length (L) n *^ / 2, with n being a natural number greater than or equal to 2. The width B of the ultrasonic oscillator 1 in Fig.1 is 9 / 2 * ^. The wavelength ^ is considered in the longitudinal direction LR of the ultrasonic oscillator 1. ^ is the wavelength at which the ultrasonic oscillator 1 – with appropriate excitation – is capable of oscillating harmonically in the form of a longitudinal wave, which is reflected as thickness oscillations (see also below). All dimensions of the ultrasonic oscillator 1 in Fig. 1 are designed, as stated above, for half the wavelength ^ / 2 or a multiple of ^ / 2, namely the thickness D to ^ / 2, the length L to 2 * ^ and the width B to 9 / 2 *^. The said wavelength ^ is preferably between 180 mm and 240 mm, so that ^ / 2 is between 90 and 120 mm. The width B of the ultrasonic oscillator is advantageously at least 100 mm, preferably at least 500 mm, for example at least 1000 mm or at least 2000 mm. Fig. 2 shows a device 50 with an ultrasonic oscillator 1 and an ultrasonic converter 12 connected to the ultrasonic oscillator 1, which in turn is connected to a voltage supply 10. Furthermore, in the present case, a booster 14 is connected between the ultrasonic converter 12 and the ultrasonic oscillator 1 in order to amplify the amplitude provided by the converter 12 and to transmit it to the ultrasonic oscillator 1. However, such a booster 14 is not mandatory.The excitation frequency is advantageously selected in the range between 19 and 22 kHz for a wavelength ^ in the range of 90 and 120 mm, in such a way that the harmonic oscillations according to the invention are produced. The booster 14 is coupled to the ultrasonic oscillator 1 at the connection point 14a (see also Fig. 1a), which is spaced from its longitudinal edge 1a (i.e., the edge of the ultrasonic oscillator 1 extending in the longitudinal direction LR) ^ / 2 and from its lateral edge 1b (i.e., the edge of the ultrasonic oscillator 1 extending in the width direction BR). In general, the distance of the connection point 14a to the lateral edge and to the longitudinal edge is each selected to be ^ / 4 or a multiple thereof. Preferably, the device 50 comprises only a single ultrasonic converter 12, which is accordingly coupled - here via the booster 14 - to the top side of the ultrasonic oscillator 1, alternatively to its underside.The ultrasonic oscillators 1 according to the invention oscillate in the form of thickness oscillations with oscillation amplitudes that are essentially constant in the width direction BR over the length L of the ultrasonic oscillator 1. These oscillation characteristics can be seen, for example, in Figs. 3a and 3b, in which the thickness oscillations of a second embodiment of an ultrasonic oscillator 1 are shown at two different times in a three-dimensional computer simulation. In this simulation, the thickness D of the ultrasonic oscillator 1 was set to λ / 2, the length to λ / 2*, and the width to λ / 2. *^ + 5% is assumed. As can be seen from Figs. 3a and 3b, there are no vibration nodes in the width direction BR; the vibration amplitude is essentially the same for each length section (along the length direction LR) in the width direction BR. The number of vibrations in the length direction LR is 4.5* ^ or 9 / 2* ^ in accordance with the selected length L of the ultrasonic oscillator. Figs. 4a and 4b show a computational simulation of a third embodiment of an ultrasonic oscillator 1 according to the invention with a thickness of ^ / 2, a length L of 3 / 2 * ^ and a width of 9 / 2 *^ shown. Here too, it can be seen - using two different points in time as an example - that when the ultrasonic oscillator is excited in the length direction LR, thickness oscillations, which are also referred to as harmonic longitudinal waves extending in the length direction LR, are excited, with the respective amplitude in the width direction BR being essentially constant. A fourth embodiment of an ultrasonic oscillator 1 according to the invention is shown in Figs. 5a-5c. This ultrasonic oscillator 1 has a first and a second cuboid section 2, 3, which adjoin one another in one piece at their mutually facing broad sides 2a, 3a and each have a width B2 and B3, respectively. In the present case, these two widths B2 and B3 are each 9 / 4* ^ (generally: (n* ^ / 2 + ^ / 4) with n as a natural number).The special feature here is that the two cuboid sections 2, 3 are offset from one another in the width direction BR, with the cuboid sections 2', 3' projecting in the width direction BR each having a width B2, B3 of 5 / 4 (generally: m* 5 / 4, with m being a natural odd number). The two widths B2, B3 do not have to be identical, but in this case they are. The total width B of the ultrasonic transducer 1 is therefore 5 / 2. * ^. The length of the two cuboid sections 2, 3 is each ^ / 2, so that the length L of the ultrasonic oscillator 1 is ^. 17 UMG-10429a-22 12.10.2023 Fig. 6, similar to Fig. 2, shows a coupling of an ultrasonic converter 12 connected to a voltage source 10, with a booster 14 interposed, to a connection point 14a of the ultrasonic converter 1. The connection point 14a is 3 / 4 *^ from the longitudinal edge of the cuboid section 2. The selected distance of the connection point 14a to the width edge and to the length edge is each ^ / 4 or a multiple thereof. Figs. 7a-7d show a fifth embodiment of an ultrasonic vibrator 101 according to the invention. Here, two block sections 8 are arranged one behind the other in the length direction LR, wherein each block section 8 consists of an ultrasonic vibrator 1 according to Fig. 6 with two cuboid sections 2, 3 each. Two such block sections 8 adjoin one another in the length direction LR in the embodiment of Fig. 6. The ultrasonic vibrator 101 according to Fig. 7 also exhibits the vibration behavior according to the invention in the thickness direction, i.e. in particular the absence of vibration nodes in the width direction BR.8a and 8b show, again in a three-dimensional computer simulation, the thickness vibrations of a sixth embodiment of an ultrasonic oscillator 101 at two different times. The ultrasonic oscillator 101 in Fig. 8 is basically constructed in the same way as that in Fig. 7, i.e., it also consists of two block sections 8. For this ultrasonic oscillator 101, the thickness D was set at 1 / 2, the length L at 2* 1 / 2, and the width B at 9 / 2* 1 / 2. As with the embodiments in Figs. 3 and 4, there are no vibration nodes in the width direction BR in Figs. 8a and 8b, i.e., the vibration amplitude is essentially the same at every point along the length direction LR in the width direction BR. The number of vibrations in the length direction LR is 2* 1 / 2, corresponding to the selected length L of the ultrasonic oscillator. 18 UMG-10429a-22 12.10.2023 In Fig.9a and 9b show a slightly perspective view of the ultrasonic oscillator 101 of Figs. 8a and 8b with a connected booster 14. It can be seen that the booster 14 is attached to a connection point 14a of the ultrasonic oscillator 101, which has the maximum oscillation amplitude (cf. Figs. 9a and 9b). Figs. 10-12 show a seventh, eighth, and ninth embodiment of an ultrasonic oscillator 201 according to the invention. The seventh embodiment of Fig. 10 consists of two identical block sections 8, which follow one another in the length direction LR and are connected to one another in the width direction BR, each block section 8 in turn being constructed from two cuboid sections 2, 3 (cf. Fig. 7). The difference to the embodiment of Fig.7 consists in that the two cuboid sections 2, 3 each have a width B4, B5 of n* ^ / 2, with n being a natural number, whereby the cuboid section 3 extends beyond the adjacent cuboid section 2 at both its ends in the width direction by a cuboid sub-section 3' of width ^ / 4 (generally m. *^ / 4 with m being a natural odd number). The length of each cuboid section 2, 3 is ^ / 2 and thus the total length of the ultrasonic oscillator 201 is 2* ^, while its width B corresponds to the width B5 and is thus 7 / 2* ^. The thickness D of the ultrasonic oscillator 201 is, for example, ^ / 2, which is preferred, or 3 / 2* ^. An ultrasonic oscillator according to the invention, not shown here, can also consist of only one block section 8, as shown in Fig. 10. The eighth embodiment of an ultrasonic oscillator 201 according to the invention according to Fig. 11 has three cuboid sections 3, 2, 3, wherein the front and rear cuboid sections 3 - viewed in the length direction LR - are identical.These two cuboid sections 3 project beyond the central cuboid section 2 at their respective two ends in the width direction BR by a cuboid sub-section 3' of width ^ / 4 (generally m* ^ / 4 with m being a natural odd number). The length of each cuboid section 2, 3 is in this case ^ / 2 and thus the total length of the ultrasonic oscillator 201 is 3 / 2* ^, while its total width B is 7 / 2* ^. The thickness D of the ultrasonic oscillator 201 is, for example, ^ / 2 or 3 / 2* ^. The ninth embodiment of an ultrasonic oscillator 201 according to the invention according to Fig. 12 likewise has three integrally adjacent cuboid sections 2, 3, 2, wherein the front and rear cuboid sections 2—as seen in the length direction LR—are identical.The middle cuboid section 3 projects beyond the two cuboid sections 2 at its respective ends in the width direction BR by a cuboid section 3' of width ^ / 4 (generally: m* ^ / 4, where m is a natural odd number). The length of each cuboid section 2, 3 is presently ^ / 2, and thus the total length of the ultrasonic oscillator 201 is 3 / 2* ^, while its total width B is 7 / 2* ^. The thickness D of the ultrasonic oscillator 201 is, for example, ^ / 2 or 3 / 2* ^. In Fig. 13, an ultrasonic oscillator 1 connected to an ultrasonic converter 12, which in this case is designed according to Fig. 1, is arranged opposite two stationary tools 26 (voltage source 10 and possibly booster 14 are not shown), this tool 26 ending, for example, in an embossing tool, a punch, an erosion tool or one or more welding tips or edges.In this case, the free end of each of the two tools 26 is designed as a punch 27 and faces the underside of the ultrasonic transducer 1. A material web M is guided in the transport direction T between the ultrasonic transducer 1 and the two tools 26, where it is processed by the punches 27 and drawn from this working zone by a pair of draw-off rollers 24 arranged downstream. The pair of draw-off rollers 24 also guides the material web M along the entire device 50. Figure 14 shows a device 50 for joining two material webs M1 and M2. An ultrasonic oscillator 101 according to the invention, which is designed in the present case according to Fig.7, is excited (by means of an ultrasonic converter 12 not shown) to oscillate in the thickness direction, as shown for example in Figs.3a, 3b.In this case, a transport device 20 is provided as the counter-tool, consisting of four transport rollers 20a arranged one behind the other in the transport direction T, which perform two functions. Firstly, the ultrasonic oscillator 101 on each transport roller 20a and under the effect of its counter-pressure causes the two material webs M1, M2 to vibrate and weld them together; secondly, the transport rollers 20a serve to actively feed the two material webs M1, M2 and the resulting overall web GM. In Fig. 15, a counter-plate 22 forms a tool that extends over the entire length of the ultrasonic oscillator 101, which in this case is designed according to the embodiment of Fig. 7. Holes can also be provided in the counter-plate 22 (perforated plate) so that steam or liquids can escape from the space between the ultrasonic oscillator 101 and the counter-plate 22.Thus, two material webs M1, M2 fed one above the other can be welded together over a very long length to form a complete web GM, which in this case is in turn drawn off using a pair of draw-off rollers 24. 21 UMG-10429a-22 12.10.2023 Appropriately equipped devices according to the invention can be used in particular for joining at least two material webs, for consolidating, for drying, in particular for drying glue or adhesive, for embossing or smoothing at least one material web, for heating, filtering, separating materials, for separating chemical compounds, for cleaning sewage sludge, for separating sewage sludge, and for converting mechanical into electrical energy, in particular by means of piezoelectric transducers.

[0002] 22 UMG-10429a-22 12.10.2023 Reference numeral 1 Ultrasonic transducer 1a Longitudinal edge 1b Width edge 2 First cuboid section 2' First cuboid section 2a Wide side 3 Second cuboid section 3' Second cuboid section 3a Wide side 8 Block section 10 Power supply 12 Ultrasonic converter 14 Booster 14a Connection point for the ultrasonic converter or the booster 20 Transport device 20a Transport rollers 22 Counter plate 24 Pair of take-off rollers 26 Tool 27 Stamp 50 Device 101 Ultrasonic transducer 201 Ultrasonic transducer L Length of the ultrasonic transducer LR Length direction B Width of the ultrasonic transducer BR Width direction D Thickness of the ultrasonic transducer DR Thickness direction M Material web M1 First material web M2 Second material web GM Total web T Transport direction

Claims

1 UMG-10429a-22 12.10.2023 Patent claims 1. Ultrasonic oscillator (1; 101; 201) for generating high-frequency oscillations, wherein the ultrasonic oscillator (1; 101; 201) is formed in one piece and in the shape of a plate with a thickness (D) in the thickness direction (DR), a length (L) in the length direction (LR) and a width (B) in the width direction (BR), characterized in that its thickness (D) m * ^ / 2, with m as a natural odd number, and its length (L) n *^ / 2, with n being a natural number greater than or equal to 2, wherein the ultrasonic oscillator (1; 101; 201) can be excited by initiating high-frequency mechanical oscillations to one or more thickness oscillations which then follow one another in the length direction (LR) of the ultrasonic oscillator (1; 101; 201) with a wavelength ^ measured in the length direction (LR) and with oscillation amplitudes which are essentially constant in the width direction (BR) as seen over the length (L) of the ultrasonic transducer (1; 101; 201).

2. Ultrasonic oscillator (1; 101; 201) according to claim 1, characterized in that its thickness (D) is ^ / 2.

3. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that its width (B) is n* ^ / 4, where n is a natural number.

4. Ultrasonic oscillator (1; 101; 201) according to the preceding claim, characterized in that its width (B) is n *^ / 2, with n being a natural, preferably odd, number. 2 UMG-10429a-22 12.10.2023 5. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that its width (B) is at least ^.

6. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that it is designed as a continuous block without slots or completely enclosed recesses.

7. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that ^ / 2 is in the range between 90 and 120 mm.

8. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that its width (B) is at least 100 mm, preferably at least 500 mm, for example at least 1000 mm or at least 2000 mm.

9. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that it is cuboid-shaped. 10.Ultrasonic vibrator (101) according to at least one of claims 1 to 8, characterized in that it comprises at least a first and a second cuboid section (2, 3), wherein these two cuboid sections (2, 3) adjoin one another in one piece at their mutually facing broad sides (2a, 3a) and each have a width (B2, B3) for which (n* ^ / 2 + ^ / 4), with n as a natural number, wherein the two cuboid sections (2, 3) are arranged offset from one another in the width direction, and wherein the cuboid sub-sections (2', 3') which respectively project in the width direction (BR). 3 UMG-10429a-22 12.10.2023 a width of m *^ / 4, with m being a natural odd number, wherein the at least two cuboid sections (2, 3) advantageously have the same width (B2, B3).

11. Ultrasonic oscillator (201) according to at least one of claims 1 to 8, characterized in that it comprises at least a first and a second cuboid section (2, 3), wherein these two cuboid sections (2, 3) adjoin one another in one piece at their mutually facing broad sides and each have a width (B4, B5) of n* ^ / 2, with n being a natural number, wherein one of the two cuboid sections (3) projects beyond the adjacent cuboid section (2) at its two ends in the width direction (BR) by one cuboid sub-section (3'), and wherein the cuboid sub-sections (3') projecting in the width direction (BR) each have a width of m *^ / 4, with m being a natural odd number.

12. Ultrasonic oscillator (101; 201) according to claim 10 or 11, characterized in that it consists of a plurality of block sections (8) which adjoin one another in the length direction (LR), each block section (8) being formed from at least two of the aforementioned cuboid sections (2, 3).

13. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims, characterized in that it consists of aluminum.

14. Ultrasonic oscillator (1; 101; 201) according to at least one of the preceding claims up to the immediately preceding one, characterized in that it consists of steel, a steel alloy or titanium. 4 UMG-10429a-22 12.10.2023 15. A device (50) for generating high-frequency vibrations, comprising at least one ultrasonic converter (12) and at least one ultrasonic oscillator (1; 101; 201) connected to the ultrasonic converter (12) according to one of the preceding claims.

16. A device (50) according to the preceding claim, characterized in that the at least one ultrasonic converter (12) is coupled to the ultrasonic oscillator (1; 101; 201) at a distance of 1 / 4 or a multiple of 1 / 4 from the width edge (1b) extending in the width direction (BR) and from the longitudinal edge (1a) of the ultrasonic oscillator (1; 101; 201) extending in the length direction (LR).

17. Device (50) according to one of the two preceding claims, characterized in that the at least one ultrasonic converter (12) is coupled from the top or bottom to the at least one ultrasonic oscillator (1; 101; 201).Device (50) according to one of the three preceding claims, characterized in that only a single ultrasonic converter (12) is coupled from the top or bottom to an ultrasonic oscillator (1; 101; 201).

19. Device (50) according to at least one of the preceding device claims, characterized in that the at least one ultrasonic oscillator (1; 101; 201) is coupled to a tool and arranged opposite a stationary counter-tool, wherein the tool oscillates together with the ultrasonic oscillator (1; 101; 201) in the thickness direction and thus in the direction of the counter-tool, wherein the tool is selected from the following group: embossing tool, welding tip(s) or edge, punch, erosion tool. 5 UMG-10429a-22 12.10.2023 20. Device (50) according to at least one of the preceding device claims, characterized in that the at least one ultrasonic oscillator (1; 101; 201) is arranged opposite a stationary tool (26), said tool (26) having at its free end a processing device from the following group: embossing tool, welding tip(s) or welding edge, punch (27), erosion tool.

21. Device (50) according to one of the preceding device claims, characterized in that the tool according to claim 19 is arranged in a node of the ultrasonic oscillator (1; 101; 201), viewed in its longitudinal direction (LR), or the tool according to claim 19 is arranged opposite a node of the ultrasonic oscillator (1; 101; 201), viewed in its longitudinal direction (LR). 22.Device (50) according to at least one of the preceding device claims, characterized in that a transport device (20), preferably comprising one or more actively and / or passively driven transport rollers (20a), or a counter plate (22), is assigned to the underside or the top side of the at least one ultrasonic oscillator (1; 101; 201).

23. Use of an ultrasonic oscillator (1; 101; 201) according to at least one of claims 1 to 14 for or in a device (50) according to at least one of claims 15 to 22.

24. Method for operating a device (50) according to one of the preceding device claims, characterized in that it is used for joining at least two material webs, solidifying, drying, in particular drying glue or adhesive, embossing or. 6 UMG-10429a-22 12.10.2023 Smoothing at least one material web, heating, filtering, material separation, separation of chemical compounds, sewage sludge cleaning, sewage sludge separation, conversion of mechanical into electrical energy, in particular by means of piezo transducers.

25. Method for producing a flat, extending overall web (GM) from several material webs (M1, M2), which are connected to one another by means of the device (50) according to one of the preceding device claims.

26. Method according to the preceding claim, characterized in that the overall web (GM) is transported through the device (50) in the length direction (LR) of the ultrasonic oscillator (1; 101; 201).

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