Sonotrode for a device for deburring a workpiece by means of ultrasonic waves

Abstract

The present invention relates to a sonotrode (10) for a device (100) for deburring a workpiece (12) with ultrasonic waves, wherein the sonotrode (10) comprises: - a main body section (14) which defines a longitudinal axis (16) and is configured to vibrate along the longitudinal axis (16) with, in particular longitudinal, ultrasonic vibrations, - a coupling section (18) which can be coupled to an ultrasonic transducer (20) of the device (100), wherein the ultrasonic transducer (20) is configured to provide the ultrasonic vibrations, wherein ultrasonic vibrations coupled via the coupling section (18) can be transmitted to the main body section (14), and - a processing section (22) for emitting the ultrasonic waves for deburring the workpiece (12), wherein the processing section (22) is connected to the main body section (14).wherein the machining section (22) is formed with at least one machining projection (24) which extends from the main body section (14) substantially transversely to the longitudinal axis (16), and wherein the machining section (22), in particular the at least one machining projection (24), is designed to be inserted laterally into a recess (25) of the workpiece (12) to be machined for deburring.

Description

[0001] The present invention relates to a sonotrode for a device for deburring a workpiece with ultrasonic waves and a device for deburring a workpiece with ultrasonic waves, a method for operating the sonotrode and / or the device and a method for deburring a workpiece with a sonotrode.

[0002] Sonotrodes are tools that are set into resonant vibrations by introducing ultrasonic vibrations. A machining surface of the sonotrode is set into ultrasonic vibrations, from which ultrasonic waves are coupled out and can be used to process workpieces, for example for deburring.

[0003] To perform deburring with ultrasonic waves, the surface being worked, excited by ultrasonic vibrations, is immersed in a container filled with a liquid medium, in which the workpiece to be deburred is also at least partially positioned. The vibrating surface transmits ultrasonic vibrations into the liquid medium, which then propagate along the direction of vibration of the surface. This creates an ultrasonic "processing beam" or "processing area" within the liquid medium, in which the workpiece to be deburred can be positioned. The ultrasonic vibrations can induce cavitation in the liquid medium. Cavitation is the formation and dissolution of vapor-filled cavities (vapor bubbles) in liquids.The continuous alternation of higher and lower pressure ranges, for example caused by ultrasonic vibrations, can cause the vapor pressure of the liquid to drop locally. This leads to the spontaneous formation of vapor bubbles. If the ambient pressure increases, the vapor bubbles shrink and can implode, generating additional shock waves in the liquid. If these shock waves encounter a solid surface, any burrs present on the surface of the workpiece to be deburred can be blasted off. Cavitation can occur, for example, along the processing beam. As a result, the ultrasonic waves remove any burrs from previous processing steps from the workpiece, yielding precisely formed, burr-free edges and transitions.

[0004] In principle, sonotrodes and methods for deburring a workpiece with ultrasonic waves are already known from the prior art, for example from documents DE 10 2015 106 343 A1, DE 10 2019 006 919 B3, DE 10 2019 004 411 B4 and DE 10 2016 101 313 A1.

[0005] The inventors recognized that deburring workpieces with complex geometries using ultrasonic waves is difficult with previously used sonotrode geometries. Such workpieces with complex geometries can, for example, have areas with openings, bores, undercuts, and / or similar features into which ultrasonic waves are difficult to couple. These areas cannot be positioned within the processing beam due to the workpiece geometry. Similarly, conventional sonotrodes cannot be positioned sufficiently accurately relative to these areas.

[0006] Based on the prior art, the invention aims to enable the deburring of workpieces with complex geometries using ultrasound.

[0007] The object of the invention is achieved by a sonotrode for a device for deburring a workpiece with ultrasonic waves and a device for deburring a workpiece with ultrasonic waves, a method for operating the sonotrode and / or the device and a method for deburring a workpiece with a sonotrode, as described herein and defined in the claims.

[0008] The present invention provides for a sonotrode for a device for deburring a workpiece using ultrasonic waves. The sonotrode comprises a main body section defining a longitudinal axis and configured to vibrate along the longitudinal axis with, in particular longitudinal, ultrasonic vibrations; a coupling section that can be coupled to an ultrasonic transducer of the device, wherein the ultrasonic transducer is configured to provide the ultrasonic vibrations, wherein ultrasonic vibrations coupled via the coupling section can be transmitted to the main body section; and a machining section for emitting the ultrasonic waves for deburring the workpiece, wherein the machining section is connected to the main body section, wherein the machining section is formed with at least one machining projection extending from the main body section substantially transversely to the longitudinal axis, and wherein the machining section, in particular the at least one machining projection, is configured toto be inserted laterally into a recess in the workpiece to be processed for deburring.

[0009] Furthermore, the present invention provides a device for deburring a workpiece using ultrasonic waves. The device comprises a sonotrode according to the invention, an ultrasonic transducer configured to provide the ultrasonic vibrations and to which the sonotrode can be coupled, a liquid bath configured to hold a liquid medium and within which the workpiece can be arranged, and an alignment unit configured to position the sonotrode within the liquid bath and further configured to insert the processing section laterally into a recess of the workpiece to be processed for deburring.

[0010] A sonotrode designed with the features described above, along with a corresponding device, enables the deburring of even workpieces with complex geometries using ultrasound. Such workpieces with complex geometries, which could not be subjected to ultrasonic deburring with previously used sonotrode geometries, or only with difficulty, can now be deburred with sufficiently good results using the sonotrode and device according to the invention. The range of applications for deburring with ultrasonic waves can thus be expanded. In other words, a greater variety of workpieces, even those with complex geometries, can be made accessible for deburring with ultrasonic waves.

[0011] Previously used sonotrodes typically generate a processing beam or area that extends longitudinally along the sonotrode's longitudinal axis, originating from a section of the sonotrode's surface through which this longitudinal axis passes. The inventors have discovered that, unlike this, even a significant angling of sections of the sonotrode can achieve effective coupling of ultrasonic waves into the liquid medium. These angled sections can then be integrated, for example, into a recess in a workpiece with a complex geometry, such as a bore, an undercut, or similar features. This allows access to edges hidden within the workpiece, where a burr may have been left behind during a previous manufacturing step.Using the sonotrode according to the invention, such a hidden burr can now also be removed by ultrasonic waves. With conventional sonotrodes according to the prior art, such a burr was not accessible or difficult to access using ultrasonic waves. The recess containing the difficult-to-access burr can, for example, comprise a depression, a cut, an opening, a cavity, or the like in the workpiece. It can have been produced by various machining or separating processes such as milling, drilling, and / or punching.

[0012] In principle, the sonotrode can be specifically designed and / or intended for deburring a workpiece using ultrasonic waves. The sonotrode can be designed to be excited by ultrasonic vibrations and to vibrate accordingly. The ultrasonic waves for deburring can be emitted into the liquid medium and / or coupled out into it via the sonotrode. The sonotrode can be mechanically designed such that the amplitude of the ultrasonic waves provided by the device, in particular the ultrasonic transducer, and coupled into the sonotrode can be specifically influenced via the sonotrode geometry. The amplitude of the ultrasonic waves emitted by the sonotrode can differ from the amplitude of the ultrasonic waves coupled into the sonotrode. For example, it can be greater than the amplitude of the ultrasonic waves provided by the ultrasonic transducer.In other words, by appropriately selecting the sonotrode geometry, the amplitude of the ultrasound waves coupled into the sonotrode can be changed, in particular increased or amplified.

[0013] The term "main body section" refers to the basic body of the sonotrode. The main body section can be cylindrical and / or conical. Generally, the main body section tapers along its longitudinal axis towards the working section. This taper allows the sonotrode geometry to be specifically designed to influence the amplitude. The amplitude can be adjusted, in particular, to achieve a desired vibration amplitude of the working section.

[0014] This allows cavitation to be specifically adjusted within the recess of the workpiece, achieving a controlled deburring effect.

[0015] The main body section can extend distally from the coupling section. The term "distal" refers to a state in which the sonotrode is coupled to the device. According to one embodiment, the main body section can occupy a large portion of the volume and / or spatial extent of the sonotrode. "Large portion" means, for example, at least 70%, in particular at least 80%, preferably at least 90%, of the volume and / or spatial extent of the sonotrode. The main body section can have a principal direction of extension along the longitudinal axis of the sonotrode.

[0016] According to this disclosure, "oscillating along the longitudinal axis" means that the ultrasound waves coupled into the sonotrode propagate distally along the longitudinal axis. The main body section can be configured to oscillate, i.e., to "swing back and forth." At least in sections, the main body section can thus expand and compress periodically according to the frequency of the ultrasound oscillations. The amplitude of the ultrasound oscillations is in the micrometer range.

[0017] The coupling section can define a proximal portion of the sonotrode and / or connect proximally to the main body section. The term "proximal" refers to the sonotrode in a coupled state to the device and means spatially closer to the device. The coupling section allows the ultrasonic vibrations provided by the ultrasonic transducer to be coupled into the main body section. The coupling section can be excited to ultrasonic vibrations together with the main body section. For coupling to the device, the coupling section can have a recess or the like, which is shaped to be complementary to a counterpart of the device, in particular its ultrasonic transducer, in order to enable mechanical coupling.This allows the sonotrode to be securely held on the device and the ultrasonic waves from the transducer to be coupled into the sonotrode. The coupling section can, for example, be connected to the device, particularly the transducer, using a plug-and-socket connection and / or be attached to a projection of the transducer. The coupling section can be specifically designed for the virtually lossless transmission of ultrasonic waves.

[0018] The machining section can be configured to couple the ultrasonic waves for deburring the workpiece into the liquid medium. When the machining section, immersed in the liquid medium, vibrates, it excites the medium with ultrasonic waves. This can subsequently generate cavitation in the liquid medium. The machining section can be mechanically coupled to the main body section, in particular such that vibrations of the main body section can be transmitted to the machining section with virtually no loss. The machining section can be positively locked and / or materially locked to the main body section and / or be integrally formed with it.

[0019] The machining projection can be, for example, a raised section extending from the main body segment, a nose, a lateral projection, a beam running perpendicular to the main body segment and extending across the longitudinal axis, or the like. Viewed along the longitudinal axis, the machining projection can, for example, extend laterally beyond the main body segment perpendicular to the longitudinal axis, where "perpendicular" does not necessarily mean 90°, but rather encompasses any extension not parallel to the longitudinal axis. For example, the cross-section of the main body segment can be circular. The machining projection can extend laterally to the cross-section and / or project laterally beyond it. In cross-section, the machining projection can be circular, semicircular, elliptical, rectangular, or have another geometry.

[0020] The transitions between the individual sections of the sonotrode can be rounded or harmonic. Alternatively, sharp and rounded transitions can be provided.

[0021] The term "lateral" can also be understood as "radial". Both "radial" and "lateral" refer to the longitudinal axis and specify a direction that is at least primarily perpendicular to the longitudinal axis.

[0022] The machining section and / or the at least one machining projection can define a principal axis. The principal axis can extend along a principal direction of extension of the machining section and / or the at least one machining projection. The principal axis can be arranged at any angle transverse to the longitudinal axis, for example, also perpendicular to it. The machining section and / or the at least one machining projection can be elongated along the principal axis. This can mean that a longitudinal extension of the machining section and / or the at least one machining projection along the principal axis is greater than an extension of the machining section and / or the at least one machining projection transverse to the principal axis. The extension transverse to the principal axis can refer to a width of the machining section and / or the at least one machining projection.For example, the longitudinal extent can be at least twice, in particular at least three times, preferably at least four times, the extent perpendicular to the main axis or the width.

[0023] To further improve the inherent vibration stability of the sonotrode according to the invention, the machining section can extend from the main body section on two sides. The main body section and the machining section can be designed to be at least substantially mirror-symmetrical with respect to the longitudinal axis. According to some embodiments, the machining section thus has two machining projections. These two machining projections can extend in opposite directions with respect to the longitudinal axis, in particular mirror-symmetrically with respect to the longitudinal axis, i.e., originating from two opposite sides of the main body section with respect to the circumference of the main body section. In one embodiment, the sonotrode can therefore be designed in a "hammer-shaped" form.In a figurative sense, the main body section can form the hammer handle and the machining section the hammer head.

[0024] The machining section, in particular the at least one machining projection, can be designed to be inserted, at least partially, laterally into a recess, undercut, or other irregularly shaped sections of the workpiece with complex geometry for deburring. Care must be taken to ensure that there is no direct contact between the workpiece and the sonotrode; that is, the sonotrode must be held at a distance from the workpiece for deburring. By inserting the machining section into the workpiece with complex geometry, it can be positioned closer to a difficult-to-access area of ​​the workpiece, so that a hidden burr to be removed can be reached more effectively by emitted ultrasonic waves than is currently possible with sonotrodes known from the prior art.This allows ultrasound waves to be coupled into the liquid bath close to the burr, and cavitation can be generated in the immediate vicinity of the hidden burr.

[0025] The sonotrode can be moved transversely to the longitudinal axis, for example, via the device, to position the machining section relative to the workpiece. Furthermore, it can be provided that the machining section can be inserted into the recess of the workpiece via the device transversely to a vibration direction of the main body section defined by the ultrasonic vibrations. It can be provided that the machining section can be inserted into the recess such that, during deburring, its point nearest to the workpiece maintains a distance of, for example, at least 0.1 cm to a maximum of 5 cm, in particular at least 0.2 cm to a maximum of 3 cm, preferably at least 0.3 cm to a maximum of 1.5 cm.

[0026] The device according to the present invention can be configured to operate and position a sonotrode for deburring using ultrasonic waves. The device can include a corresponding control unit, a user interface, and optionally other components. For example, a user can use the user interface to define a workpiece geometry, in particular a position and / or a size of the recess in the workpiece to be deburred, for example, relative to a predetermined starting position of the sonotrode or in a coordinate system of the device. Alternatively or additionally, the workpiece geometry can be determined by the device, in particular a position and / or a size of the recess, for example, relative to a predetermined starting position of the sonotrode and / or in a coordinate system of the device.This can be achieved, for example, with the aid of a camera and / or a distance sensor, such as an ultrasonic sensor. Alternatively or additionally, the sonotrode can be controlled and / or positioned by the user via the user interface. For example, the user interface can include a joystick or other similar control unit, allowing the user to position the sonotrode within the liquid bath. This makes it user-friendly to insert the sonotrode, in particular with the machining section or at least one machining projection, laterally into the recess of the workpiece.

[0027] The ultrasound transducer can correspond to an ultrasound transducer known from the prior art. One operating principle of the ultrasound transducer is described, for example, in document DE 10 2015 106 343 A1. The ultrasound transducer can be configured, in particular, to generate and / or provide longitudinal ultrasound waves. The ultrasound transducer can be controllable by means of the control unit.

[0028] The liquid medium can be provided in the form of a liquid bath within a liquid basin, for example, designed as an open-topped tub. The workpiece can be inserted into the liquid bath through the opening of the tub, ensuring that at least the area to be deburred is covered by the liquid medium. It is important that all openings and undercuts are also filled or covered with liquid. Of course, the workpiece can also be completely immersed in the liquid bath. The workpiece can be placed on the bottom of the liquid bath or fixed at any point within the liquid bath using a clamping device.

[0029] The liquid bath may have an opening in one side wall through which the sonotrode, the ultrasonic transducer, and / or the alignment unit can protrude into the liquid bath. Alternatively or additionally, the ultrasonic transducer and / or an ultrasonic transducer-side coupling section, to which the sonotrode coupling section can be connected, may protrude into the liquid bath through the opening. The opening may be sealed fluid-tight from the surrounding environment, for example, by means of a rubber casing. The sonotrode may be articulated to the side wall and / or arranged to be angled.

[0030] The device may also include an additional ultrasonic transducer and / or at least one additional sonotrode, which may also be placed in the liquid bath. If multiple sonotrodes are used, they may be used either alternately or simultaneously. For example, the additional sonotrode may be a conventional sonotrode for providing an ultrasonic processing beam along the longitudinal axis of the sonotrode, or it may be a sonotrode of the type described above.

[0031] The liquid medium can comprise an ultrasonic transmission medium, a suspension, and / or a liquid. When using a suspension, it can consist of a liquid and suspended solid particles with an abrasive effect for deburring. The liquid medium can be specifically designed to enhance cavitation.

[0032] The alignment unit can be controlled by the control unit. The alignment unit can be configured to position the sonotrode in three spatial directions within the liquid bath. For this purpose, it can, for example, include at least one motor. The alignment unit can be used to adjust the angular position of the sonotrode. Furthermore, the alignment unit can be used to move the sonotrode along its longitudinal axis. The alignment unit can also be used to pivot or rotate the sonotrode in or around the opening in the side wall of the liquid bath. The opening can define a reference point about which the sonotrode experiences essentially no lateral displacement, particularly with respect to the longitudinal axis of the main body section.

[0033] Considering the machining section, in particular the at least one machining projection extending transversely to the longitudinal axis, it can be excited into bending vibrations by the ultrasonic vibrations of the main body section. Thus, longitudinal ultrasonic vibrations of the main body section can be converted into bending vibrations in the machining section. It is advantageous that the space required for the vibrating machining section to emit ultrasonic waves can be comparatively small, especially compared to a prior art sonotrode that vibrates longitudinally along its longitudinal axis.

[0034] According to a further development of the invention, the main body section can be excited with ultrasonic vibrations such that the machining section, in particular the at least one machining projection, can be excited to bending vibrations with a natural frequency. An ultrasonic vibration of the main body section with a comparatively small amplitude can thus lead to a bending vibration with a comparatively large amplitude at the machining section or machining projection. Furthermore, deburring can be carried out energy-efficiently, reproducibly, and reliably by means of the bending vibrations. In particular, the machining section or the at least one machining projection can be excited to bending vibrations at the first natural frequency. This applies especially if the machining projection and / or the machining section is beam-shaped.

[0035] Furthermore, according to a further development of the invention, the machining section can be designed such that a node of the bending vibrations of the machining section or of the at least one machining projection lies spatially within the machining section. This allows stable and reproducible bending vibrations to be achieved, enabling deburring to be carried out repeatedly, reliably, and safely. The node can represent a point and / or a region with minimal displacement. It is conceivable that the node is selected such that it oscillates along the longitudinal axis together with the main body section or a distal section of the main body section. However, if the bending vibrations of the machining section are considered conceptually in isolation, the node represents a region where the displacement is minimal or approximately zero.

[0036] Particularly efficient deburring can be achieved if a lateral end of the machining section or the at least one machining projection exhibits a maximum amplitude of bending vibration. The lateral end can refer to a point of the machining section or the at least one machining projection located radially furthest from the longitudinal axis. Furthermore, it can refer to a point located at any angular orientation transverse to the longitudinal axis and furthest from the longitudinal axis. According to one embodiment of the invention, the sonotrode can be designed such that cavitation generation is at its maximum in the immediate vicinity of the lateral end.

[0037] As already explained above, the machining section, in particular the at least one machining projection, can be beam-shaped. Advantageously, the machining section can be reliably inserted into comparatively narrow, deep and / or elongated recesses, boreholes or the like.

[0038] Furthermore, at least one machining projection can taper outwards along its longitudinal axis. Such a shape can be advantageous from a vibration mechanics perspective, increasing the vibration amplitude. Moreover, the mass of the machining projection can be precisely controlled. Reduced mass contributes to faster and more accurate positioning of the sonotrode.

[0039] Furthermore, the processing section and the coupling section can be arranged on opposite sides along the longitudinal axis of the main body section. Thus, the sonotrode can be mounted on the side wall of the liquid bath, with the processing section positioned within the liquid bath and the coupling section protruding outwards. Additionally, the amplitude of the ultrasonic waves provided by the ultrasonic transducer can be modulated by appropriate design of the main body section.

[0040] Furthermore, according to another embodiment of the invention, the machining section can have a length along the main axis that is greater than at least twice, and in particular at least three times, the diameter of the main body section in a region where the machining section is arranged on the main body section. Thus, an elongated machining section can be provided. By appropriately selecting its length, the machining section can be inserted into deeper recesses. The width of the machining section can correspond at least substantially to its diameter, but can also be larger or smaller. The width can be defined in a direction transverse to the longitudinal axis and transverse to the main axis.

[0041] Furthermore, the main body section can be excited by ultrasound vibrations in such a way that a node of the ultrasound vibrations lies on the longitudinal axis of the main body section. This allows for controlled, safe, stable, and reproducible ultrasound vibration of the main body section. The node is defined as the point of minimum displacement during the ultrasound vibrations of the main body section.

[0042] Regarding the design and / or material selection of the sonotrode, it should be noted that the sonotrode itself is subjected to forces through cavitation, which can lead to wear. Accordingly, in one embodiment of the invention, the sonotrode can be made of a wear-resistant material with sufficient hardness, particularly surface hardness, and / or fatigue strength. For example, the sonotrode, especially the machining section, the main body section, and / or the coupling section, can be made of steel, particularly stainless steel and / or hardened stainless steel, or of a titanium alloy or another correspondingly hard material.

[0043] One embodiment of a sonotrode according to the invention can be provided by forming the main body section, the coupling section, and / or the machining section as a single piece. This reduces or completely eliminates unwanted damping or parasitic effects resulting from material transitions that can restrict the propagation of ultrasonic vibrations. The sonotrode can be manufactured at least substantially from a single piece, for example, by turning and / or milling from a blank.

[0044] Furthermore, the present invention provides a method for operating a sonotrode or device according to the invention.

[0045] Furthermore, the present invention provides a method for deburring a workpiece with a sonotrode, in particular a sonotrode according to the invention, which comprises a processing section for emitting ultrasonic waves for deburring the workpiece, wherein the processing section is designed with at least one processing projection extending substantially transversely to the longitudinal axis from the main body section of the sonotrode defining a longitudinal axis. The method comprises the steps: Inserting the workpiece into a liquid medium, aligning the sonotrode with respect to the workpiece, laterally inserting the machining section into a recess of the workpiece to be machined, and exciting the machining section by means of an ultrasonic vibration to deburr the workpiece.

[0046] The invention is explained below by way of example with reference to the accompanying figures. They show: Fig. 1 a schematic representation of an axis-containing sectional view of a sonotrode according to the invention and a workpiece; Fig. 2 a side view of the sonotrode according to the invention; Fig. 3 a perspective view of the sonotrode according to the invention; Fig. 4 a schematic representation of the sonotrode according to the invention in a state of maximum deflection of a machining section; Fig. 5 a further schematic representation of the sonotrode in a state of maximum deflection; Fig. 6 a schematic representation of a device; and Fig. 7 a schematic flowchart of a method for deburring with ultrasonic waves.

[0047] Fig. 1 Figure 1 shows a schematic representation of an axis-containing sectional view of a sonotrode 10 along a longitudinal axis 16 of a main body section 14 of the sonotrode 10 and a workpiece 12 to be deburred. The sonotrode 10 defines a longitudinal axis 16 and can be coupled to and operated with a device (not shown, see Figure 1). Fig. 6 The workpiece 12 to be deburred can be processed using the sonotrode 10. The sonotrode 10 and the workpiece 12 to be deburred are located in a liquid bath containing a liquid medium suitable for coupling ultrasonic waves and supporting the deburring process, for example, a suspension. The sonotrode 10 is configured to be excited by ultrasonic vibrations via an ultrasonic transducer and to vibrate. In the liquid bath, the sonotrode 10 emits the ultrasonic waves to deburr the workpiece 12. The ultrasonic vibrations of the sonotrode 10 create cavitation in the liquid medium. The cavitation generated in the immediate vicinity of the workpiece 12 removes burrs from the workpiece 12.

[0048] In this example, workpiece 12 has a complex geometry. This means, for instance, that it has a recess 25 within which an undercut 29 and at least one bore 31 are arranged. During machining of workpiece 12, burrs 13 (schematically shown) can form within the recess 25 that are difficult to access and need to be removed. However, prior art sonotrodes for deburring with ultrasonic waves (not shown) cannot be inserted into the undercut 29 due to their bulky geometry. Therefore, to remove the burrs 13, they must be positioned close to the inner opening of the bore 31. Consequently, it is either impossible or extremely difficult and yields unsatisfactory results to treat these areas with ultrasonic waves for deburring.Therefore, a workpiece of such complex geometry cannot be effectively deburred using conventional sonotrodes.

[0049] The sonotrode 10 according to the present invention provides a remedy for this. It comprises the main body section 14, which defines the longitudinal axis 16 and is configured to be excited and vibrate along the longitudinal axis 16 with longitudinal ultrasonic vibrations. Furthermore, the sonotrode 10 comprises a coupling section 18, which is connected to an ultrasonic transducer (see Figure 1). Fig. 6 The device is couplingable to the main body section 14, wherein the ultrasonic transducer is configured to provide the ultrasonic vibrations, and wherein ultrasonic vibrations coupled via the coupling section 18 can be transmitted to the main body section 14. The sonotrode 10 also includes a machining section 22 for emitting the ultrasonic waves for deburring the workpiece 12. The machining section 22 is connected to the main body section 14 so that the ultrasonic waves are transmitted into the machining section 22. Furthermore, the machining section 22 is configured with, in this example, two machining projections 24 extending from the main body section 14 transversely to the longitudinal axis 16. The machining section 22 with its two machining projections 24 is configured like a crossbeam and is designed to be inserted into the recess 25 of the workpiece 12 to be machined for deburring.In the example shown, the lower machining projection 24 is inserted into the recess 25.

[0050] It goes without saying that workpieces with other shapes (not shown) can also be deburred using the sonotrode 10. The example shown of workpiece 12 serves only for illustrative purposes.

[0051] The coupling section 18 of the sonotrode 10 is arranged at a proximal end 46 of the main body section 14. The processing section 22 is arranged at a distal end 48 of the main body section 14. The processing section 22 and the coupling section 18 are thus arranged on opposite sides 30, 32 along the longitudinal axis 16 of the main body section 14. The main body section 14 is conically shaped and tapers along the longitudinal axis 16 from the coupling section 18 in a distal direction to the processing section 22, thus conserving material.

[0052] About one in Figur 1 The main body section 14 of the ultrasound transducer (not shown) can be excited by longitudinal ultrasound vibrations originating from the coupling section 18. The ultrasound waves propagate along the longitudinal axis 16 within the sonotrode 10. This means that the sonotrode 10 and / or the main body section 14 oscillates in the direction of arrow 50.

[0053] The coupling section 18 has a recess 52 that opens proximally and extends along the longitudinal axis 16 into the sonotrode 10. The recess 52 allows the sonotrode 10 to be attached to a mandrel (not shown) located on the ultrasonic transducer. In a coupled state with the ultrasonic transducer, the coupling section 18 thus forms a positive-locking connection. Flattened sections 66, described below, further contribute to this connection.

[0054] The machining section 22 is designed and configured to be inserted laterally into the recess 25 of the workpiece 12 shown in the example. Within the recess 25, the machining section 22 can be excited to bending vibrations by the ultrasonic vibrations of the main body section 14, thereby coupling ultrasonic waves into the liquid medium via the machining section 22 within the recess 25. This allows cavitation to be generated in the liquid medium. The sections to be deburred are thus subjected to ultrasonic waves and gravity. As a result, even remote areas within the recess 25, for example in the region of the undercut 29, can be subjected to ultrasonic waves and / or cavitation for deburring.

[0055] The main body section 14, the coupling section 18, and the machining section 22 of the sonotrode 10 are formed in one piece; that is, sections 14, 18, and 22 are manufactured together from a single piece, for example, by milling and turning. In this example, the sonotrode 10 is made of corrosion-resistant stainless steel.

[0056] Fig. 2 Figure 1 shows a schematic side view of the sonotrode 10. It can be seen that the machining section 22 has a length 34 transverse to the longitudinal axis 16, which is greater than at least three times the diameter 36 of the main body section 14 in the area where the machining section 22 is positioned on the main body section 14. The diameter 36 is, for example, 2 cm and the length 34 is, for example, 7 cm. The machining section 22 also has a height 56. The height 56 ​​is, for example, about one-fifth of the length 34, i.e., about 1.5 cm. A distal surface 60 of the machining section 22 is at least substantially flat. Edges of the distal surface 60 have a chamfer 64 or are rounded. A rear surface 58 of the machining projections 24 tapers outwards on both sides of the main body section 14 with increasing distance from the longitudinal axis 16.The transition from the main body section 14 to the machining section 22 is concave with a rounded transition 62. The coupling section 18 has four flattened surfaces 66 in the circumferential direction, each offset from the others by 90°. This design creates a circumferential profile that allows the coupling section 18 to be inserted into a receptacle of the device in a rotationally fixed manner.

[0057] Fig. 3 Figure 1 shows a perspective view of the sonotrode 10. It can be seen that the edges of the longitudinal side of the machining section 22 are provided with a rounded edge 64. The longitudinal side is the side that extends along the main axis 27. The width 68 of the machining section 22 and the machining projection 24 corresponds at least substantially to the diameter 36. Furthermore, the four flattened surfaces 66 on the coupling section 18 can be seen.

[0058] Fig. 4 und Fig. 5 Figures 1 and 2 each show a schematic representation of the sonotrode 10 in a state of maximum deflection of the free ends of the machining projections 24 in the proximal and distal directions with respect to the longitudinal axis 16, respectively. The oscillatory movement of these free ends of the machining projections 24 is indicated by double arrows. In the Fig. 4 In the state shown, the deflection in the distal direction along the longitudinal axis 16 is maximal. In the state shown in the Fig. 5 In the depicted state, the displacement in the proximal direction along the longitudinal axis 16 is at its maximum. For illustrative purposes, the displacements are shown significantly over-proportioned; in reality, they range from 5 µm to 50 µm. Due to the longitudinal ultrasonic vibrations of the main body section 14 along the longitudinal axis 16, represented by arrow 50, the machining section 22 can be excited to bending vibrations at its free ends of the machining projections 24. Both machining projections 24 therefore oscillate in the direction of arrow 50 parallel to the longitudinal axis 16, corresponding to the double arrows D shown in bold. A lateral end 28 of the machining section 22, or of the machining projection 24, exhibits a maximum amplitude of the bending vibration.

[0059] The main body section 14 can be excited to ultrasonic vibrations such that the machining section 22, with its lateral machining projections 24, can be excited to bending vibrations at a natural frequency. The machining projection 24 has a first natural frequency that is tuned to a natural frequency of the main body section 14. The main body section 14 is also excited to vibrate at a natural frequency during deburring with ultrasonic waves. It is understood that the natural frequency of the machining section 22 and that of the main body 14 depends on the overall structure of the sonotrode 10. Furthermore, it is understood that the natural frequency of the main body section 14, the machining section 22, and the machining projection 24 lies in the ultrasonic range. A node 26 of the bending vibrations of the machining projection 24 lies within the machining projection 24.Each of the machining projections 24 therefore exhibits a node 26 of its inherent bending vibration when excited by ultrasonic vibrations via the main body section 14. The main body section 14 can also be excited to ultrasonic vibrations such that a node 38 of the ultrasonic vibration lies on the longitudinal axis 16 of the main body section 14.

[0060] Fig. 6 Figure 1 shows a schematic representation of a device 100 for deburring a workpiece 12' using ultrasonic waves. The device 100 comprises the sonotrode 10, the ultrasonic transducer 20, which is configured to provide the ultrasonic vibrations and to which the sonotrode 10 is coupled, and a trough 42 for a liquid bath 42, which is configured to hold the liquid medium 40. The workpiece 12' is arranged in the liquid bath 42. A positioning unit 44 is also shown, which is configured to position the sonotrode 10 within the liquid bath 42 and, in particular, is configured to laterally insert the processing section 22 into a recess 25' of the workpiece 12' to be processed for deburring. The ultrasonic transducer 20 projects partially into the liquid bath 42.A passage 72 is provided in a side wall 70 of the tub 42, through which the ultrasonic transducer 20 extends into the tub 42. The sonotrode 10 is mounted on the ultrasonic transducer 20 inside the tub 42 and is located in the liquid medium 40. The passage 72 is sealed fluid-tight to the environment by means of a rubber seal 73.

[0061] The workpiece 12' is positioned in the liquid bath 42. The liquid bath 42 is filled with the liquid medium 40. The medium 40 is a suspension of water and solid particles that promote cavitation. The liquid medium 40 covers the workpiece 12' and the sonotrode 10. The sonotrode 10 is analogous to the Fig. 1 The workpiece 12' is inserted laterally into a recess 25' of the workpiece 12'. The workpiece 12' has an undercut 29' and bores 31' (for clarity, only one bore is shown with a reference numeral). Burrs to be removed are located within the recess 25', for example, on one of the bores 31' and / or within the undercut 29'. It can be seen that the workpiece 12' has a burr 77, for example, in a difficult-to-access area due to its previous machining. This burr is to be removed. The sonotrode 10 can be excited to longitudinal ultrasonic vibrations by means of the ultrasonic transducer 20.

[0062] The ultrasonic transducer 20 is arranged on the alignment unit 44. The alignment unit 44 allows the sonotrode 10 to be pivoted around the opening 72 and along the longitudinal axis of the sonotrode 10 (see figure). Fig. 1 The alignment unit 44 and the ultrasonic transducer 20 are linearly movable. They are connected to a control unit 74. The ultrasonic transducer 20 can be activated and controlled by means of the control unit 74. Furthermore, the alignment unit 44 can be controlled by means of the control unit 74. Deburring with ultrasonic waves can be performed automatically. Alternatively or additionally, the deburring can be controlled by a user via a user interface 76. For example, the user can align the sonotrode 10 by means of control commands via the user interface 76 and insert it laterally into the recess 25'. In an inserted state (as shown), the deburring can be started by activating the ultrasonic transducer 20.

[0063] Furthermore, in this example, the device 100 includes another sonotrode 78, which is configured to emit longitudinal ultrasonic waves. The device 100 also includes a positioning device 80, by means of which the workpiece 12' can be positioned in the liquid bath. Furthermore, the workpiece 12' can be aligned relative to the sonotrode 10 by means of the positioning device 80, for example, such that the sonotrode 10 can be inserted laterally into the recess 25'.

[0064] Fig. 7 Figure 1 shows a schematic flowchart of a method for deburring a workpiece 12 with a sonotrode 10 according to the invention. As described above, the sonotrode comprises the processing section 22 for emitting ultrasonic waves for deburring the workpiece 12 and is designed according to the embodiment described above. The method comprises the following steps: Step 1 - Reference numeral 90: Inserting the workpiece 12 into a liquid medium 40; Step 2 - Reference numeral 92: Aligning 92 of the sonotrode 10 with respect to the workpiece 12; Step 3 - Reference numeral 94: Laterally inserting the machining section 22 into a recess 25 of the workpiece 12 to be machined; and Step 4 - Reference numeral 96: Exciting 96 of the machining section 22 by means of an ultrasonic vibration to deburr the workpiece 12.

Claims

1. Sonotrode (10) for a device (100) for deburring a workpiece (12) with ultrasonic waves, wherein the sonotrode (10) comprises: a main body section (14) which defines a longitudinal axis (16) and is configured to vibrate along the longitudinal axis (16) with, in particular longitudinal, ultrasonic vibrations; a coupling section (18) which can be coupled to an ultrasonic transducer (20) of the device (100), wherein the ultrasonic transducer (20) is configured to provide the ultrasonic vibrations, wherein ultrasonic vibrations coupled via the coupling section (18) can be transmitted to the main body section (14);and a machining section (22) for emitting the ultrasonic waves for deburring the workpiece (12), wherein the machining section (22) is connected to the main body section (14), wherein the machining section (22) is formed with at least one machining projection (24) which extends from the main body section (14) substantially transversely to the longitudinal axis (16), and wherein the machining section (22), in particular the at least one machining projection (24), is configured to be inserted laterally into a recess (25) of the workpiece (12) to be machined for deburring.

2. Sonotrode (10) according to claim 1, wherein the machining section (22), in particular the at least one machining projection (24), can be excited to bending vibrations by the ultrasonic vibrations of the main body section (14).

3. Sonotrode (10) according to claim 1 or 2, wherein the main body section (14) can be excited such that the machining section (22), in particular the at least one machining projection (24), can be excited to bending vibrations with a natural frequency, in particular of the machining section (22) and / or of the at least one machining projection (24).

4. Sonotrode (10) according to one of the preceding claims, wherein a node (26) of the bending vibrations of the machining section (22), in particular of the at least one machining projection (24), is located in the machining section (22).

5. Sonotrode (10) at least according to claim 2 or 3, wherein a lateral end (28) of the machining section (22), in particular of the at least one machining projection (24), has a maximum amplitude of the bending vibration.

6. Sonotrode (10) according to one of the preceding claims, wherein the machining section (22), in particular the at least one machining projection (24), is beam-shaped.

7. Sonotrode (10) according to one of the preceding claims, wherein the at least one machining projection (24) tapers outwards with respect to the longitudinal axis (16).

8. Sonotrode (10) according to one of the preceding claims, wherein the machining section (22) extends on both sides from the main body section (14) and / or wherein the main body section (14) and the machining section (22) are together formed at least substantially mirror-symmetrical with respect to the longitudinal axis (16).

9. Sonotrode (10) according to one of the preceding claims, wherein the processing section (22) and the coupling section (18) are arranged on opposite sides (30, 32) along the longitudinal axis (16) of the main body section (14).

10. Sonotrode (10) according to one of the preceding claims, wherein the machining section (22) has a length (34) that is greater than at least twice, in particular at least three times, the diameter (36) of the main body section (14) in a region in which the machining section (22) is arranged on the main body section (14).

11. Sonotrode (10) according to one of the preceding claims, wherein the main body section (14) can be excited to the ultrasonic vibration such that a node (38) of the ultrasonic vibration lies on the longitudinal axis (16) of the main body section (14).

12. Sonotrode (10) according to one of the preceding claims, wherein the main body section (14) tapers along the longitudinal axis (16) in the direction of the processing section (22).

13. Sonotrode (10) according to one of the preceding claims, wherein the main body section (14) and / or the machining section (22) is configured to be immersed, at least partially, in a liquid medium (40) for deburring.

14. Sonotrode (10) according to one of the preceding claims, wherein the main body section (14), the coupling section (18) and / or the processing section (22) are formed jointly in one piece and / or in one piece.

15. Device (100) for deburring a workpiece (12) with ultrasonic waves, comprising: a sonotrode (10) according to one of the preceding claims; an ultrasonic transducer (20) configured to provide the ultrasonic vibrations and to which the sonotrode (10) can be coupled; a liquid bath (42) configured to receive a liquid medium (40) and within which the workpiece (12) can be arranged; and an alignment unit (44) configured to position the sonotrode (10) within the liquid bath (42) and further configured to insert the processing section (22) laterally into a recess (25) of the workpiece (12) to be processed for deburring.

16. Method for operating a sonotrode (10) according to one of claims 1 to 14 and / or a device (100) according to claim 15.

17. A method for deburring a workpiece (12) with a sonotrode (10), in particular according to one of claims 1 to 14, comprising a processing section (22) for emitting ultrasonic waves for deburring the workpiece (12), wherein the processing section (22) is formed with at least one processing projection (24) extending substantially transversely to the longitudinal axis (16) from the main body section (14) of the sonotrode (10), which defines a longitudinal axis (16), comprising the steps of: - placing the workpiece (12) in a liquid medium (40); - aligning the sonotrode (10) with respect to the workpiece (12); - laterally inserting the processing section (22) into a recess (25) of the workpiece (12) to be processed; and - exciting the processing section (22) by means of an ultrasonic vibration for deburring the workpiece (12).

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