EP2331268B1 - Device for producing high-frequency vibrations and method for operating said device - Google Patents

Description

The present invention relates to a device for generating high-frequency oscillations according to the preamble of the independent claims. Furthermore, the invention relates to methods that make use of said device.

The use of ultrasound is now indispensable in the industry. Ultrasonic devices are used for welding material webs, for soldering, mixing, applying z. As multi-component adhesives, cleaning and separating, riveting, insertion, etc. used.

The WO 2008/037256 A2 describes a set in rotation sealing or welding sonotrode (ultrasonic oscillator), which protrudes with one end into a hollow shaft and is fixed to the inner wall by means of a sonotrode support. Also, a booster and a converter are arranged in the hollow shaft. The hollow shaft is mounted on the outside with ball bearings a fixed housing and can thus be offset together with sonotrode, booster and converter in rotary motion. The sealing or welding surface of the sonotrode is disposed outside of the hollow shaft to interact with the peripheral surface of a counter tool on a workpiece. Accordingly, the ultrasonic vibrator is partly housed in the hollow shaft (sleeve) while a portion outside the sleeve is arranged, namely the tool portion with the sealing or welding surface.

The same applies to the US 3,955,740 , which discloses a device for seam welding, the sonotrode is arranged laterally outside a rotatable cylindrical housing (sleeve). The sonotrode is connected via a coupling member arranged in the housing with a converter in connection, wherein the coupling member by means of metallic diaphragms with the Inside the housing is connected. The housing is rotatably mounted by means of ball bearings in vertical supports, so that with the housing and the converter, the coupling member and the sonotrode are rotated. The outside of the housing (sleeve) arranged sonotrode is placed in longitudinal vibrations and creates a weld on a workpiece, which is guided between the contact surface of the sonotrode and an anvil.

Another special device of this type is known from DE 103 43 325 A1 known. This describes a device for continuous bonding and / or solidification of material webs by means of ultrasound with a coupling pin formed as an ultrasonic vibrator and a peripheral sleeve on this (forming a total sonotrode), wherein the ultrasonic oscillator and the sleeve constitute a rotating roller. This roller radially opposite is a counter pressure tool. Axial to the said roller an amplitude transformation piece is attached, also called booster. The amplitude transformation piece is followed by an ultrasonic converter with a power supply. The length of the rotating roller corresponds to a λ / 2 wave of the imposed vibration or a multiple thereof. In a specific embodiment, the rotating roller is formed by a sleeve or a tube, which is closed by a respective end pin. The amplitude transformation pieces are connected to these trunnions.

A disadvantage of this known device is that a highly accurate adaptation of ultrasonic oscillator and vibrating element is necessary to be offset, the oscillation frequency is also limited to the frequency of the ultrasonic vibrator.

It is an object of the present invention to provide a device for generating high-frequency vibrations, which offers a more flexible and efficient use. The indication of appropriate Methods and uses for such a device is also an object of the present invention.

This object is achieved according to the features of the independent claims.

According to the invention, between the outer circumference of the ultrasonic vibrator and the inside of the sleeve, at least one coupling section fixedly connected thereto is arranged, the two ends of the sleeve projecting beyond the coupling section in each case. This construction enables the ultrasonic vibrator to be located entirely within the sleeve. It not only results in a space advantage, but it can also be realized a bearing of the sleeve independently of the ultrasonic vibrator. All that needs to be provided is a power supply from the ultrasonic converter to the ultrasonic oscillator. It has also been found that accommodating the ultrasonic vibrator in the sleeve allows an excellent, stable coupling to the sleeve by means of the at least one coupling section.

According to an advantageous embodiment of the invention, in which between the outer circumference of the ultrasonic vibrator and the inside of the sleeve at least one firmly connected to this coupling portion is arranged, the coupling length is at least 50% shorter than the axial extent of the ultrasonic vibrator. This is based on the finding that the previously known full-surface contact of the sleeve on the ultrasonic vibrator severely restricts the vibrations of the sleeve and impedes reliable storage of the sleeve during operation. So far, it has been assumed in the prior art that for optimum excitation of a vibration structure (such as a sleeve as in the DE 103 43 325 A1 described) this structure in terms of dimensions and coupling must meet certain requirements. For this purpose, the length of the vibration structure was tuned to the excitation wavelength (n · λ / 2, where n is a natural number is). Likewise, the largest possible contact surface of the vibration structure was realized at the ultrasonic vibrator, so that the vibration structure can be excited by the highest possible amplitude of the excitation frequency.

In contrast, it has been shown that an excitation of the sleeve can be realized most suitably by the short coupling length of the coupling section. It is particularly advantageous that no tuning of the sleeve length to a multiple of half the wavelength of the excited vibration of the sleeve must be made.

Particularly preferably, the coupling length of the coupling portion is at least 60% shorter than the axial extent of the ultrasonic transducer, preferably shorter than 75%, preferably shorter than 90%. The coupling length is therefore chosen to be very small, on the one hand to enable the sleeve to vibrate, on the other hand, but not to obtain a rigid coupling and thus movement restriction of the sleeve.

In order to enable the small-surface attachment between the sleeve and UI trasound oscillator by means of the at least one coupling portion, a gap between the inner wall of the sleeve and the outer periphery of the ultrasonic vibrator is expediently present. The gap width can be in the millimeter range. It is essential that sleeve and ultrasonic vibrator do not touch during operation, because then a detuning would result.

The term "sleeve" according to the present invention refers in the present case to a structure which, at least in the region of the ultrasonic vibrator, surrounds the latter circumferentially at least partially in order to ensure attachment to the circumference of the ultrasonic vibrator. The cross section of the sleeve can take various forms. It is also possible that the cross section varies in the axial direction. According to an exemplary embodiment the sleeve has a continuous round cross-section, is thus designed as a round tube and preferably extends linearly in the axial direction. Other cross sections are possible. The sleeve may be formed hollow or partially filled throughout. The ultrasonic vibrator according to the present invention may be formed in particular cylindrical, wherein the one or more coupling portions are arranged on the outer periphery.

According to a further advantageous development, between the outer circumference of the ultrasonic vibrator and the inside of the sleeve at least one firmly connected to this coupling portion arranged, the coupling length is so short and the coupling location chosen such that the transverse vibrations of the sleeve substantially no load on the Exert vibrations of the ultrasonic vibrator.

Thus, if the contact or attachment surface between the vibration structure and ultrasonic transducer selected sufficiently small and appropriately placed in the sleeve, the sleeve can be substantially transversal oscillations, where it exerts almost or even no effect on the ultrasonic transducer , The coupling is preferably carried out in a vibration extremum of the sleeve transversal oscillation. The sleeve and possibly coupled with her work tools (knives, stamping tools, etc.) are thus stimulated and then swing independently, without in turn to influence the ultrasonic transducer, such as an ultrasonic excitation pin in the sleeve. Significant amplitude losses do not occur with appropriate tuning.

It is therefore according to the aforementioned development surprisingly by means of the coupling on the narrow coupling sections managed to avoid a reaction of the vibrations of the sleeve on the ultrasonic oscillator almost or even completely. It has been shown in experiments that different and also in different numbers connected to the sleeve, the vibration exploiting elements (eg tools, piezo elements) leave the ultrasonic oscillator unaffected, ie no increased power supply is necessary to vibrate one or more of said elements. This discovery opens up a variety of possible applications, for example in energy conversion and generation.

With suitable circumferential coupling of the sleeve by means of at least one coupling section to the ultrasonic oscillator, the amplitude of the ultrasonic oscillator itself is preferably not or hardly influenced by the vibration of the sleeve.

According to an advantageous development, at least one coupling section fixedly connected thereto is likewise arranged between the outer circumference of the ultrasonic oscillator and the inside of the sleeve, in which case the sleeve is mounted on its inside and / or outside independently of the ultrasound oscillator. In such an embodiment, the sleeve and the bearing are coupled directly to each other. It is therefore not arranged as in the prior art, an ultrasonic transducer between sleeve and bearing. This embodiment increases the flexibility of use enormously. In addition, no mechanical stress on the ultrasonic oscillator, since it does not have to absorb any bearing forces.

A combination of the various developments in a device for generating high-frequency vibrations is readily possible and even preferred.

According to a preferred embodiment of the invention, the device is designed such that the ultrasonic vibrator excites the sleeve to a transversal vibration whose amplitude is greater by at least 50% than a possibly also excited longitudinal vibration, preferably greater than 75%, particularly preferably greater than 90%. In other words, it is preferable that transversal vibrations are realized mainly be unlike DE 103 43 325 A1 in which transversal and longitudinal waves have approximately equal amplitudes. Such vibration excitation can be achieved essentially by the at least one narrow coupling section.

As already mentioned above, the length of the sleeve is particularly preferably not harmoniously matched to the ultrasonic oscillator. It has been shown that such a vote is not necessary or even may cause worse vibration properties. There are therefore less design constraints in the choice of the sleeve length. This can rather be adapted to the respective application. In particular, it is not necessary, according to the prediction, that the length of the sleeve corresponds to a lambda-half (λ / 2) wave of the excited oscillation or a multiple thereof (L = x · λ / 2). The invention is in this case clearly from the above-mentioned prior art. In the previous experiments, wavelengths in the range of 30-80 mm were realized at frequencies of 20 kHz, the wavelengths in particular being influenced by the sleeve material and by the wall thickness of the sleeve.

It is even more preferable if the sleeve has a length of n · λ / 2 + 2 · x, where λ is the wavelength of the excited oscillation of the sleeve and x <λ / 2. It has been found that an extension of the sleeve over the in DE 103 43 325 A1 considered necessary length of n · λ / 2 by a distance x allows a much better excitation of transversal oscillations. In experiments, it has been found that a choice of x in the range of greater than λ / 30 and smaller than λ / 2 is possible, preferably λ / 15 <x <λ / 5. According to a preferred embodiment, x is chosen larger than 1 mm.

According to an advantageous embodiment, the sleeve is at one or both of its end faces in the inside and / or outside, ie at its inner or outer circumference, attacking bearings (radial bearings) stored. Such storage makes it possible to provide the bearings directly inside and / or outside circumference of the sleeve. Indirect storage via an intermediate ultrasonic transducer is unnecessary. In addition, the bearing seats can be precisely adapted to the excited transversal oscillations, on the one hand to allow optimum power and on the other hand largely avoid swinging the bearings in the transverse direction, ie axial direction of the sleeve, and also in the longitudinal direction.

It has proved to be particularly advantageous if the or the bearings are provided closer to the corresponding free end of the sleeve than the coupling portion between the ultrasonic oscillator and sleeve. In one related embodiment, the ultrasonic vibrator is in the sleeve axially between two end-side, on the inside of the sleeve attacking bearings (radial bearings).

Particularly preferably, the respective free ends of the sleeve are unsupported, so they can swing freely. The radially engaging bearings are in this case for example offset a little inwardly and preferably engage in the region of the outermost nodes of the transverse waves on the sleeve. Since the bearings and the sleeve have finite thicknesses, the center lines of the sleeve and the bearing points - which are for example designed as a bearing webs - can be used to realize an optimized coupling. In other words, in this case the center line of a bearing bar meets the center line of the sleeve in one of its transversal vibration nodes. The center lines correspond to the so-called "neutral fibers" or "neutral axes".

The wall thickness of the sleeve can be chosen according to the current knowledge in a wide range. It is preferably depending on the application in the range of 1 mm to 100 mm, more preferably in the range of 5 mm to 100 mm.

The frequency of the transverse vibration with which the sleeve is vibrated, advantageously deviates no more than 2% from the excitation frequency of the ultrasonic vibrator. The transmission of the excitation frequency from the ultrasonic oscillator via the at least one coupling section on the sleeve is thus effectively realized. It can be assumed that the sleeve is put into a natural vibration by the excitation. Typically, ultrasonic vibrators are excited at a frequency of 19.5 - 20.5 kHz.

For an effective coupling or transmission of the vibration amplitudes of the ultrasonic transducer to the sleeve is preferably provided that the coupling portion is provided in the region of a vibration, in particular in a vibration extremum, with respect to the transversal vibration of the sleeve.

It has proved to be preferred if the coupling portion has a length in the axial direction of 2-20 mm, along which it is firmly connected to the inside of the sleeve. It has been found in experiments that for generating the high frequency sleeve vibrations of the invention, the web thickness can be up to 30% of half the wavelength of the induced sleeve vibration.

In a preferred embodiment of the invention, the coupling portion is fixed continuously and radially circumferentially on the outer circumference of the ultrasonic vibrator. This coupling ensures a high energy transfer from the ultrasonic vibrator to the sleeve with a total small mounting surface. Alternatively, the at least one coupling section is provided only at spaced-apart regions along the circumference of the UI-traschall oscillator, these areas representing the coupling section as a whole. If here generally from coupling section the speech is, this may consist of a contiguous area or of several separate areas.

According to a related embodiment of the web on the circumference of the ultrasonic vibrator is provided (for example, unscrewed) and formed integrally therewith, and the sleeve shrunk onto this web and / or pressed.

An alternative embodiment for fastening the sleeve on the ultrasonic oscillator provides that the coupling portion is designed as a radially inwardly directed, one-piece web or collar of the sleeve, whose free end is attached to the ultrasonic oscillator. The web can thereby rotate closed or have interruptions. This design also allows the inventive, only over a narrow or small area extending attachment between the sleeve and ultrasonic vibrator. It is advisable to attach the web of the sleeve, for example by means of a shrink and / or press fit on the ultrasonic vibrator.

The web or collar itself can also be formed as a separate part, which is firmly connected on the one hand with the sleeve and on the other hand with the ultrasonic vibrator.

By means of the above-described web, which is expediently arranged on an end face of the sleeve, it is possible to provide the coupling point between sleeve and ultrasonic oscillator only along a short axial section of the ultrasonic vibrator. In this case, the web or collar thickness can then be substantially smaller than the length of the ultrasonic vibrator.

A particular advantage arises in certain applications, when a material is used for the sleeve, which has a high strength and little Has abrasion. Here, in particular offers steel. Prior art sonotrodes that contact workpieces are typically made of special aluminum or titanium. In the device according to the invention, however, a harder, more abrasion-resistant material can be selected, since no consideration has to be taken of the ultrasonic vibrator. In certain applications, however, it is also readily possible to resort to aluminum or titanium as material for the sleeve.

A particularly preferred development of the invention is characterized in that the ultrasonic oscillator and the sleeve attached to it are designed as rotating bodies. One thus obtains a rotating roller which offers a variety of possible uses, for example in the production of flat material webs, in which a plurality of webs are welded together. The roller can be directly driven or towed. In a direct drive, the ultrasonic vibrator and / or the sleeve can be driven.

In an embodiment as a roller with a counterpressure roller arranged parallel to it, the abovementioned steel construction of the sleeve is particularly advantageous since it then has only a very small deflection, so that even very long sleeves with a length of several meters and thus corresponding processing widths can be realized.

To use the excited vibrations, in particular the transversal oscillations, of the sleeve, various tools or energy converters can preferably be arranged on its outer circumference, in particular cutting edges, piezo transducers, embossing tools, welding pattern tools and / or welding edges. The amplitudes of the bending or transversal oscillations can thus be effectively utilized in a variety of ways. The sleeve may in this case be stationary or rotating.

If, for example, the sleeve has an embossing profiling on its outer circumference, various material webs can be processed in interaction with a counterpressure tool, for example webs for the production of corrugated cardboard. A solidification of webs is possible.

In alternative uses, the sleeve is coupled to a device which oscillates in the axial direction due to the vibration excitation of the sleeve. This device can also be designed as a tool of various designs, in particular as an axially movable knife, as a second UI-trasound oscillator (which is excited by the sleeve to vibrate, in which case its vibrations are used as exciter vibrations in a second sleeve), as an embossing tool , Stamp, drill or erosion tool.

In a specific embodiment in this respect, a device, for example a knife, which is set in oscillation in the axial direction, protrudes axially outwardly through a bearing supporting the sleeve. In this way, a high-frequency oscillating blade can be realized, which can still be used due to the above-described little or no existing feedback to the ultrasonic vibrator when the cutting edge has become shorter by a prolonged use. According to the prior art, this knife could then no longer be used due to the resulting detuning. In contrast, according to the invention, no such coordination is required, resulting in longer operating times and cost savings.

The cross section of the ultrasonic vibrator can take various geometric shapes. For example, it is circular, square, rectangular or elliptical. The same applies to the cross section of the sleeve.

For many applications, it is expedient if the sleeve - apart from its attachment portion on the ultrasonic oscillator - has a constant cross section over its entire length. An example of this is the above-mentioned tubular design as part of a rotating roll.

In a further development of the invention, an ultrasound oscillator, each with an optional amplitude transformation piece, ultrasonic converter and power supply, is provided on both sides of the sleeve. Thus, ultrasound from both end faces can be coupled into the sleeve, so that an overall higher power supply is possible. In a rotary arrangement of the two ultrasonic oscillator with the interposed sleeve one or both ultrasonic vibrators can be driven. The sleeve may also have its own drive.

When arranged on both sides of the sleeve ultrasonic transducers, it is expedient to stimulate them either with a phase shift or the distance between the two attachment points of the sleeve as an odd multiple of λ / 2 respect. Of the oscillation frequency of the sleeve to choose.

The invention also relates to a method for generating ultrasound and exploiting the vibrations obtained. In this case, ultrasound energy is transmitted to a sleeve by means of the device according to the invention described above. In this case, various uses of the device according to the invention are possible. These include, but are not limited to, heating (especially water), filtering, and pulping, including sewage sludge cleaning, cutting, drilling, joining, embossing, solidifying, or smoothing materials.

Particularly promising seems the conversion of mechanical Energy, ie the vibrations of the sleeve, into electrical energy, in particular by means of piezoelectric transducers, which are placed on the outer circumference of the sleeve. Since even with the placement of several piezo transducers on the outer surface of the sleeve no or almost no repercussions were observed on the ultrasonic vibrator, it seems possible to obtain high amounts of electrical energy by using a variety of piezo transducers.

Another promising field of application seems to be the warming of service water. For this purpose, for example, a metal tube, preferably made of brass, coupled to the sleeve and charged with circulating water. The coupling causes the brass tube to vibrate and thereby heat up, part of the heat being dissipated directly to the water.

Surprisingly, it has also been found that hardly any amplitude losses occur in the application of the device according to the invention in liquids. Compared to known devices in which the amplitude attenuation is sometimes considerable, therefore, the use in liquids is particularly advantageous, for example in the above sewage sludge cleaning or ultrasonic cleaning in liquids.

In the following the invention will be explained in more detail with reference to figures. The features shown in the figures and mentioned in the claims and the description may be essential to the invention individually or in combination.

Figur 1

einen Längsschnitt einer ersten Ausführungsform einer erfindungsgemäßen Vorrichtung zum Erzeugen von Ultraschall;

Figur 1a

eine ähnliche Ausführung wie in Figur 1, allerdings mit Lagern am Außenumfang der Hülse;

Figur 2

die Vorrichtung gemäß der Figur 1, zu Schwingungen angeregt;

Figur 3

einen weiteren Schwingungszustand der Vorrichtung gemäß der Figuren 1 und 2;

Figur 4

einen Längsschnitt einer zweiten Ausführungsform mit axial schwingendem Messer;

Figur 5

die Vorrichtung gemäß der Figur 4, zu Schwingungen angeregt;

Figur 6

einen weiteren Schwingungszustand der Vorrichtung gemäß der Figuren 4 und 5;

Figur 7

einen Längsschnitt einer dritten Ausführungsform mit axial schwingendem Messer;

Figur 8

die Vorrichtung gemäß der Figur 7, zu Schwingungen angeregt;

Figur 9

einen weiteren Schwingungszustand der Vorrichtung gemäß der Figuren 7 und 8;

Figur 10

eine schematische Seitenansicht einer vierten Ausführungsform mit Schneidkante entlang des Außenumfangs der Hülse;

Figur 11

eine schematische Seitenansicht einer fünften Ausführungsform mit zwei schematisch dargestellten Piezowandlern am Außenumfang der Hülse;

Figur 11a

eine Vorderansicht der Vorrichtung gemäß der Figur 11;

Figur 12

einen weiteren Schwingungszustand der Vorrichtung gemäß der Figur 11;

Figur 13

eine Vorderansicht einer fünften Ausführungsform mit vier Piezowandlern;

Figur 14

die Vorrichtung gemäß der Figur 13 im Längsschnitt entlang AA der Figur 13;

Figur 15

die Vorrichtung gemäß der Figuren 13 und 14 in perspektivischer Ansicht;

Figur 16

eine Vorderansicht der fünften Ausführungsform der Hülse mit 20 Piezowandlern;

Figur 17

die Vorrichtung gemäß der Figur 16 im Längsschnitt entlang AA der Figur 16;

Figur 18

die Vorrichtung gemäß der Figuren 16 und 17 in perspektivischer Ansicht;

Figur 19

einen Längsschnitt durch eine sechste Ausführungsform mit einem Adapter zur Flüssigkeitserwärmung (entlang A-A der Figur 20);

Figur 20

eine Vorderansicht der Vorrichtung gemäß der Figur 19, und

Figur 21

die Vorrichtung gemäß der Figuren 19 und 20 in perspektivischer Ansicht.

In the following figures, like reference numerals designate like or corresponding elements. Show it:

FIG. 1

a longitudinal section of a first embodiment of a device according to the invention for generating ultrasound;

FIG. 1a

a similar design as in FIG. 1 , but with bearings on the outer circumference of the sleeve;

FIG. 2

the device according to the FIG. 1 , excited to vibrate;

FIG. 3

a further vibration state of the device according to the Figures 1 and 2 ;

FIG. 4

a longitudinal section of a second embodiment with axially oscillating blade;

FIG. 5

the device according to the FIG. 4 , excited to vibrate;

FIG. 6

a further vibration state of the device according to the FIGS. 4 and 5 ;

FIG. 7

a longitudinal section of a third embodiment with axially oscillating blade;

FIG. 8

the device according to the FIG. 7 , excited to vibrate;

FIG. 9

a further vibration state of the device according to the FIGS. 7 and 8 ;

FIG. 10

a schematic side view of a fourth embodiment with cutting edge along the outer circumference of the sleeve;

FIG. 11

a schematic side view of a fifth embodiment with two schematically illustrated piezoelectric transducers on the outer circumference of the sleeve;

FIG. 11a

a front view of the device according to the FIG. 11 ;

FIG. 12

a further vibration state of the device according to the FIG. 11 ;

FIG. 13

a front view of a fifth embodiment with four piezo transducers;

FIG. 14

the device according to the FIG. 13 in longitudinal section along AA FIG. 13 ;

FIG. 15

the device according to the FIGS. 13 and 14 in perspective view;

FIG. 16

a front view of the fifth embodiment of the sleeve with 20 piezo transducers;

FIG. 17

the device according to the FIG. 16 in longitudinal section along AA FIG. 16 ;

FIG. 18

the device according to the FIGS. 16 and 17 in perspective view;

FIG. 19

a longitudinal section through a sixth embodiment with a liquid heating adapter (along AA of Figure 20);

FIG. 20

a front view of the device according to the FIG. 19 , and

FIG. 21

the device according to the FIGS. 19 and 20 in perspective view.

In the Figures 1-3 a first embodiment of a device 1 according to the invention is shown. The sectional view of the FIG. 1 shows a tubular sleeve 25 made of a metal, for example made of hardened steel or a steel alloy. The sleeve 25 has z. B. has a length of 4000 mm and has a wall thickness of 10 mm. The outer circumference of the sleeve 25 is for example 150 mm and the inner circumference accordingly 140 mm (no scale representation).

The sleeve 25 has at its two end faces in each case a bearing 30, which in the present case are each designed as pins and have a central, open at both ends of the tube 32, one part of which extends into the sleeve 25 and the other part of the sleeve 25 protrudes , The tube 32 has on the outer circumference side two axially mutually offset circumferential radial webs 34, whose free ends are fixedly connected to the inner wall of the sleeve 25, for example by press fits. The radial webs 34 are arranged in the sleeve 25 such that the free ends 26 of the sleeve 25 remain uncoupled. Furthermore, the shown bearing of the sleeve 25 has the consequence that the ultrasonic oscillator 20 and the bearings 30 are not directly connected to each other. This has the advantage that the bearings 30 can be positioned on the sleeve inner wall in such a way that they are not or hardly vibrated by the ultrasonic oscillator 20.

In the sleeve 25, a cylindrical ultrasonic vibrator 20 is arranged, which may also be made of a steel. The ultrasonic oscillator 20 is connected via a line 18 with one (or more) optional amplitude transformation piece 14 or booster and an adjoining ultrasonic converter 12. The ultrasonic converter 12 is connected to a power supply 10. The elements 10, 12, 14 are in the FIG. 1 shown only schematically. In the other figures, they were mainly not shown for the sake of simplicity, s. but Figs. 22 and 24. It should be noted that the ultrasonic converter 12 is also disposed in the sleeve can be, with an external arrangement easier cooling is possible. Also it can be changed more easily.

The ultrasonic oscillator 20 is fixedly connected to the inner wall of the sleeve 25 by means of a radially encircling, continuous, here designed as a web coupling portion 22. The coupling portion 22 may be formed, for example, from the solid material of the ultrasonic vibrator 20 by turning and be connected to the sleeve 25 by press fits. Alternatively, the coupling portion 22 is integrally connected to the sleeve 25. Other connection possibilities of coupling section 22, ultrasonic vibrator 20 and sleeve 25 are possible and are obvious to those skilled in the art.

The coupling length AL of the coupling portion 22 is substantially smaller than the axial extent AE of the ultrasonic vibrator 20 and has, for example, a length of 5 mm, along which it is firmly connected to the inside of the sleeve 25. The coupling length AL is in this case clearly below the wavelength λ, with which the sleeve 25 oscillates, preferably below 30% of λ / 2.

The ultrasonic oscillator 20 is excited, for example, in the known frequency range of 19.5 - 20.5 kHz and excites accordingly via the coupling portion 22, the sleeve 25 to oscillate. As in the FIGS. 2 and 3 shown, the sleeve oscillates in the illustrated representation substantially transversely with a frequency that differs only in the low percentage range of the excitation frequency of the ultrasonic vibrator 20. Die Frequenz ist in Fig. 1 dargestellt. The sleeve 25, however, hardly vibrates in the longitudinal direction; the corresponding amplitudes are only a fraction of those of the transverse vibrations, for example in the region of 10%.

The representations in the FIGS. 2 and 3 are schematic, in particular serve the deflections shown of the ultrasonic vibrator 20, the sleeve wall and the bearing 30 for illustrative purposes only. It becomes clear that the circumferential coupling section 22 is fixed in a vibration extremum of the transverse vibrations (corresponding to a vibration node of the small longitudinal vibrations, not shown). The movements of the ultrasonic vibrator 20 are thus transmitted with great effectiveness to the sleeve 25, so that they can be offset with correspondingly large amplitudes in transverse oscillations.

Also is out of the FIGS. 2 and 3 removable, that the bearings 30 are also influenced by the vibrations of the sleeve 25. However, their axial position remains almost unchanged. This is in particular due to the coupling of the radial webs 34 in nodes of the transverse oscillations of the sleeve 25, when the radial webs 34 and the sleeve are idealized as strokes (neutral fibers), these strokes then meet in a node of the transverse oscillations. In other words, the geometries of the elements involved are chosen such that the forces acting on the bearings 30 substantially cancel, so that they resonate only to an insignificant extent.

It has been shown that the free ends 26 of the sleeve 25 should actually not be coupled, since otherwise little or no excitation of the transverse vibrations is possible.

By means of the device according to the invention, by way of example on the embodiment of the FIG. 1 are shown, little or no Rückeinflüsse from the sleeve 25 on the ultrasonic vibrator 20 are observed. When tracking the electrical power no load influences are detected. Thus, when the ultrasonic vibrator 20 is operated at, for example, 1500 W, a variety of tools (see below) coupled to the sleeve 25 can be operated without requiring higher power to be supplied to the ultrasonic vibrator 20.

As a further particular advantage has been shown that the length of the sleeve 25 of this and the devices described below need not be harmonically tuned to the excited or excited transverse vibration of the sleeve 25, as described in the prior art (s. DE 103 43 325 A1 ). Instead of choosing the sleeve length as a multiple of λ / 2, a sleeve piece of length x with x in the range of λ / 30 to below λ / 2 is preferably selected on both sides of a vibration node of the transverse vibration, preferably in the range λ / 15 <x <λ / 5.

In the FIG. 1a is indicated schematically that the bearings 30 can also attack on the outer circumference of the sleeve 25.

In the FIGS. 4 to 6 a concrete application of a device 101 according to the invention is shown, in which an axially oscillating blade 40 is arranged in the concentrically extending tube 32 of a bearing 30. The bearing 30 on the opposite side of the sleeve 25 is opposite to the embodiment of FIG. 1 unchanged. The knife 40 has a radially encircling, full-surface disc 44, which is arranged inside the sleeve beyond the radial webs 34 and is fixed peripherally to the inner wall of the sleeve 25. The disk edge is in this case arranged in a vibration node of the transverse vibration of the sleeve 25. Of the disc 44 is perpendicular to a running along the sleeve axis rod 42 from at the free end of a cutting edge 46 is arranged.

If the ultrasonic vibrator 20 of the device 101 and thus the sleeve 25 is vibrated, the knife 40 leads into the FIGS. 6 and 7 shown linear reciprocating movements in the axial direction of the sleeve 25 from. The rest position of the cutting edge 46 is defined here by the vertical line S, which is passed by the cutting edge according to the high-frequency excitation. With a likewise usual excitation of approximately 35 kHz, the cutting frequency is correspondingly high.

In the Figures 7-9 a device 201 according to the invention is shown with a likewise oscillating blade in the axial direction 50, wherein in this embodiment, the sleeve 25 is mounted only on one side in a bearing 30. On the other sleeve side, a knife 50 is provided, which in turn has a disc 54 - fixed in a vibration node of the sleeve transversal oscillation - and an axially outwardly extending rod 52. At its free end 56, a cutting blade (not shown) can be attached with two screws. An attachment of a drill or a punch or a stamping tool are also possible.

In the FIGS. 8 and 9 the operation of the tool 50 is shown in operation. The rod 52 and thus its free end swing according to the transverse vibration of the sleeve 25 in the axial direction back and forth, so that the stroke of the cutting blade (or other corresponding end-mounted tool) can be exploited.

The FIG. 10 schematically shows an inventive device 301 with a tool 60 which extends in the axial direction on the outside of the sleeve 25 (s. Fig. 10a which is a schematic representation of an end face of the sleeve 25 is seen from). This tool 60 may be formed in particular as a cutting edge, but also as a welding edge or the like.

In the schematic front view according to the FIG. 10b a device 401 according to the invention is shown, in which a tool 70 is arranged circumferentially around the outer circumference and has, for example, an embossing pattern or welding pattern. The sleeve 25 is advantageously rotationally driven (drive not shown). For example, wallpaper patterns can be embossed with a corresponding embossing tool.

Other applications with rotated devices of the invention - possibly in conjunction with counter tools, such as counter-rollers - are of course possible, for. B. Materialbahnenverfestigen, material web welding, etc. For this purpose, for example, the device according to the FIG. 1 ,

In the Figures 11-18 three similar devices 501, 601 and 701 are shown in which on the outer circumference of the sleeve 25 Piezowandler devices 80 are placed on the antinodes of the sleeve transversal vibration, for example, glued or screwed. The FIGS. 11 and 11a Here are only schematic diagrams to illustrate the mode of action, wherein FIG. 11a a schematic frontal view is. The individual piezoelectric transducers 81 of the piezoelectric transducer devices 80 (in each case six piezo converters 81 arranged one above the other in the device 601, two each in the device 701, wherein the respective electrical leads of the piezoelectric transducers are not shown for simplicity) are compressed in accordance with the transversal vibrations of the sleeve 25 and stretched and convert this mechanical energy into electrical energy (the known to a person skilled in the art storage of the piezoelectric transducer devices 80 at their free ends is not shown here for the sake of simplicity). In the device 501, two piezo-transducer devices 80 are provided, in the device 601 four and in the device 701 twenty.

As repeatedly described above, no performance-reducing reaction by the coupled with the sleeve 25 tools or other elements on the ultrasonic vibrator 20, the individual piezoelectric transducers 81 in the three devices 501, 601, 701 (under otherwise constant conditions, such as Geometries, power supply, etc.) each have substantially equal electrical energies. This means that surprisingly, and for reasons not yet understood, in principle electrical energy can be obtained which is that of the one used Power to vibrational excitation of the ultrasonic vibrator 20 may exceed.

In the FIGS. 13-15 between the six piezoconductors 81 and sleeve 25 arranged one above the other are 1: 1 spacers 82 (which impart mechanical vibrations one to one further) made of steel, which are fastened in blind bores 89 of sleeve 25 by means of pins 88. On the spacers 82 trumpet-shaped centerpieces 83 are attached with an axial bore, in turn, the piezoelectric transducers 81 are stacked. On the uppermost piezoelectric transducer 81 is a counterpart 84, which also has an axial bore, placed. The counterpart 84, the piezoelectric transducer 81 and the middle piece 83 are connected to each other by means of a screw 85. Furthermore, a plurality of blind bores 89 spaced apart in the longitudinal direction of the sleeve 25 are present in order to arrange piezo transducer devices 80 at different points of the sleeve 25, ie at different oscillation bellies of the sleeve transversal oscillation. In addition, a total of four rows of such piezocransmitter devices 80 are arranged offset by 90 ° around the circumference of the sleeve 25, four piezocransmitter devices 80 each being arranged on a common transversal oscillation belly which arises at the same axial height on the circumference of the sleeve.

According to the Fig. 16-18 are on the sleeve 25 of the device 701, otherwise with those of Fig. 13-15 is identical, a total of twenty Piezowandler devices 80 attached, for example screwed. The piezo-transducer devices 80 each have two piezo-transducers 81, which are arranged between a relatively short intermediate piece 82 and a counterpart 84 placed from above. Spacer 82, piezoelectric transducer 81 and counterpart 84 have mutually aligned through holes through which a respective screw 87 is guided, whose free end is screwed into one of the blind holes 89.

The intermediate pieces 82 of the devices 601, 701 serve to transmit the mechanical vibrations from the sleeve 25 to the piezoelectric transducers 81. Since the sleeve 25 has a circular outer contour, whereas the piezoelectric transducers 81 have a flat pressure surface, the intermediate pieces 82 absorb the vibrations of the sleeve 25 and in the radial direction to the piezoelectric transducer 81 from. Due to the flat contact of the intermediate pieces 82 to the piezoelectric transducer 81, these are loaded and unloaded uniformly over their pressure surface.

It is also a spatially staggered arrangement of the piezoelectric transducer devices 80 possible. Instead of circular spacers 82 and counterparts 84 are also possible with square base. The electrical energy generated by the piezoelectric transducers 81 is advantageously tapped without the sleeve 25 serving as an electrical grounding line.

In the Fig. 19-21 a device 801 is shown with which a liquid, in particular water, can be heated or heated. It has been shown that the energy transfer or energy conversion from mechanical vibration energy to thermal energy is very efficient. In the device 801 according to the Fig. 19-21 a coupling piece 90 is arranged in the sleeve 25, which has an elongated cylindrical central part 92. At a free end of the central part 92, a circumferential radial web 94 is provided, which in turn is attached to the inner circumference of the sleeve 25, for example by means of a shrink fit. The other free end of the coupling piece 90 protrudes from the sleeve 25, there to be connected via a pin connection - possibly by means of shrink fit or welding or screwing, etc. - with a hollow body 95 made of brass or other suitable, good heat conducting metal , The hollow body 95 in the present case consists of a brass tube with brass lids placed on both sides. On the top side, an inlet connection 91 and a discharge connection 92 are provided in order to supply cold water and to remove heated water. The vibrations from the sleeve 25 are over the coupling piece 90 and the Transfer pin connection to the hollow body 95, which in turn is vibrated, which heat the water therein. The device 801 can be used in particular as a water heater.

It has also been found in the device 801 that no vote of the hollow body 95 on the vibrations of the sleeve 25 is necessary.

In principle, can be with a device that of the Fig. 19-21 corresponds, heat any media.

The devices according to the Figures 1-3 For example, they can be used for ultrasonic cleaning in liquids, for heating liquids, for filtration or the like. Here, a storage in the radial bearings 30 may be appropriate.

In all the illustrated devices 1, 101, 201, etc. may arise applications in which instead of steel aluminum or titanium can be used as a sleeve material. On the other hand, for an increase in hardness and carbide can be applied to a sleeve 25 made of steel.

Incidentally, the relative size ratios of the individual elements in the illustrated devices 1, 101, 201, etc. are only approximately shown.

The invention has been explained in more detail with reference to some embodiments. Modifications of the invention within the scope of the claims are readily possible. For example, the type of coupling of the sleeve to the ultrasonic oscillator can be varied. The sleeve itself may have different shapes and cross-sections, which also need not be homogeneous or uniform over the length. The described fields of application are not exhaustively enumerated. That's the way it is, for example possible to obtain the electrical energy to drive vehicles of any kind with the presented or on the principle similar working devices.

Claims (30)

1. A device (1; 101; 201; 301; 401; 501; 601; 701; 801) for generating high-frequency oscillations, having at least one ultrasound converter (12) and at least one ultrasound oscillator (20) connected to the ultrasound converter (12), wherein a sleeve (25) is attached at the periphery of the ultrasound oscillator (20) and wherein between the outer periphery of the ultrasound oscillator (20) and the inside of the sleeve (25), at least one coupling section (22) is disposed connected firmly to them, characterized in that the two ends of the sleeve (25) each protrude beyond the ultrasound oscillator (20).
2. The device according to claim 1, characterized in that the sleeve (25) is supported on its inside and/or outside independently of the ultrasound oscillator (20).
3. The device according to claim 1 or 2, characterized in that the coupling length (AL) is chosen so small and the coupling location is chosen such that the transverse oscillations of the sleeve (25) exert substantially no loading effects on the oscillations of the ultrasound oscillator (20).
4. The device according to one of the preceding claims, characterized in that the coupling length (AL) of the coupling section (22) is at least 50% shorter than the axial extension (AE) of the ultrasound oscillator (20).
5. The device according to one of the preceding claims, characterized in that the ultrasound oscillator (20) is able to excite the sleeve (25) to a transverse oscillation, the amplitude of which is greater by at least 50% than a possibly likewise excited longitudinal oscillation.
6. The device according to one of the preceding claims, characterized in that the length (L) of the sleeve (25) does not correspond to a λ/2 wave of the excited oscillation of the sleeve (25) or a multiple thereof (L ≠ n · λ/2, n = natural number).
7. The device according to one of the preceding claims, characterized in that the sleeve (25) has a length of n · λ/2 + 2 · x, wherein λ is the wavelength of the excited oscillation of the sleeve (25) and x < λ/2.
8. The device according to one of the two preceding claims, characterized in that λ/30 < x < λ/2, wherein λ is the wavelength of the excited oscillation of the sleeve (25).
9. The device according to the preceding claim, characterized in that x > 1 mm.
10. The device according to one of the preceding claims, characterized in that the sleeve (25) is supported on one or both of its end faces in internally and/or externally acting bearings (30).
11. The device according to claim 10, characterized in that the ultrasound oscillator (20), viewed in longitudinal section through the sleeve (25), is disposed without overlapping with the bearing(s) (30).
12. The device according to one of the preceding claims, characterized in that the one or both bearings (30) are provided closer to the corresponding free end of the sleeve (25) than said at least one coupling section (22).
13. The device according to one of the two preceding claims, characterized in that the respective free end of the sleeve (25) is unsupported.
14. The device according to one of the preceding claims, characterized in that the wall thickness of the sleeve (25) is in the range of 1 mm to 100 mm.
15. The device according to one of the preceding claims, characterized in that the frequency of the transverse oscillation, with which the sleeve (25) is set into oscillation, deviates by not more than 2% from the excitation oscillation of the ultrasound oscillator (20).
16. The device according to one of the preceding claims, characterized in that the coupling section (22) is provided in the region of an oscillation antinode with respect to the transverse oscillation of the sleeve (25).
17. The device according to one of the preceding claims, characterized in that the coupling section (22) has a length in the axial direction of 2-20 mm, along which it is firmly connected to the inside of the sleeve (25).
18. The device according to one of the preceding claims, characterized in that the coupling section (22) has a length in the axial direction of up to 30% of λ/2, wherein λ is the wavelength of the excited oscillation of the sleeve (25).
19. The device according to one of the preceding claims, characterized in that the coupling section (22) is implemented as a continuous circumferential ligament on the outer circumference of the ultrasound oscillator (20).
20. The device according to one of the preceding claims, characterized in that the coupling section (22) is implemented as an inwardly directed ligament of the sleeve (25).
21. The device according one of the preceding claims, characterized in that the sleeve (25) is manufactured from a material of the following group: steel, steel alloys, aluminum, titanium.
22. The device according to one of the preceding claims, characterized in that the ultrasound oscillator (20) and the sleeve (25) are implemented as a rotatably supported body.
23. The device according to the preceding claim, characterized in that the ultrasound oscillator (20) and/or the sleeve (25) are implemented such that they can be directly driven or towed.
24. The device according to one of the preceding claims, characterized in that at least one of the following devices is disposed on the outer periphery of the sleeve (25): cutting edge (60), mechanical to electrical energy transducer, embossing tool (70), welding pattern tool (70), welding edges (60).
25. The device according to one of the preceding claims, characterized in that the sleeve (25) is coupled with a device which oscillates in the axial direction, wherein this device is selected from the following group: axially movable knife (40; 50), second ultrasonic oscillator (90), which in turn is used as a an exciter in a second sleeve or is coupled with a hollow body (95) for heating a medium introduced therein, embossing tool, punch, drill, erosion tool.
26. The device according to one of the preceding claims, characterized in that a device (40, 90) set in oscillation in the axial direction projects axially outward through a bearing (30) supporting the sleeve (25).
27. A method for operating a device (1; 101; 201; 301; 401; 501; 601; 701; 801) according to one of the preceding claims, characterized in that it is used for heating, filtering, substance separating, sludge-cleaning, bonding, embossing or smoothing, drilling, converting from mechanical to electrical energy.
28. The method according to the preceding method claim with respect to the heating of water, characterized in that a metal tube made of brass is coupled with the sleeve (25), which is fed with circulating water, wherein the brass tube is set into oscillation by the coupling and thereby heated, wherein a portion of the heat is discharged directly to the water.
29. The method according to one of the preceding method claims, characterized in that the device is immersed in liquids and operated there.
30. The method according to one of the preceding method claims with respect to the conversion of mechanical into electrical energy, characterized in that the energy obtained by the conversion of mechanical energy into electrical energy is used to drive a vehicle.

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