EP4558286A1 - Outil à ultrasons et procédé d'usinage d'une pièce à l'aide de vibrations mécaniques ultrasonores - Google Patents

Outil à ultrasons et procédé d'usinage d'une pièce à l'aide de vibrations mécaniques ultrasonores

Info

Publication number
EP4558286A1
EP4558286A1 EP22782462.0A EP22782462A EP4558286A1 EP 4558286 A1 EP4558286 A1 EP 4558286A1 EP 22782462 A EP22782462 A EP 22782462A EP 4558286 A1 EP4558286 A1 EP 4558286A1
Authority
EP
European Patent Office
Prior art keywords
sonotrode
converter
insulating
ultrasonic
amplitude amplifier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22782462.0A
Other languages
German (de)
English (en)
Inventor
Ulrich Vogler
Tobias Rosenkranz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Herrmann Ultraschalltechnik GmbH and Co KG
Original Assignee
Herrmann Ultraschalltechnik GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Herrmann Ultraschalltechnik GmbH and Co KG filed Critical Herrmann Ultraschalltechnik GmbH and Co KG
Publication of EP4558286A1 publication Critical patent/EP4558286A1/fr
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
    • B26D7/08—Means for treating work or cutting member to facilitate cutting
    • B26D7/086—Means for treating work or cutting member to facilitate cutting by vibrating, e.g. ultrasonically
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B3/00—Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
    • B06B1/0611—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements in a pile
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/10—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating making use of vibrations, e.g. ultrasonic welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/10—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating making use of vibrations, e.g. ultrasonic welding
    • B23K20/106—Features related to sonotrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/22—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded
    • B23K20/233—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating taking account of the properties of the materials to be welded without ferrous layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/08—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using ultrasonic vibrations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/814—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps
    • B29C66/8145—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps characterised by the constructional aspects of the pressing elements, e.g. of the welding jaws or clamps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/816—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the mounting of the pressing elements, e.g. of the welding jaws or clamps
    • B29C66/8167—Quick change joining tools or surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
    • B29C66/832—Reciprocating joining or pressing tools
    • B29C66/8322—Joining or pressing tools reciprocating along one axis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/87—Auxiliary operations or devices
    • B29C66/874—Safety measures or devices
    • B29C66/8742—Safety measures or devices for operators
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/30—Organic materials
    • B23K2103/42—Plastics other than composite materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/73—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/739—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/7392—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic
    • B29C66/73921—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic characterised by the materials of both parts being thermoplastics

Definitions

  • the present invention relates to an ultrasonic tool and a method for machining a workpiece using mechanical ultrasonic vibrations.
  • Ultrasonic tools are used, for example, to weld or separate workpieces, especially material webs.
  • ultrasonic tools have an ultrasonic vibration unit that includes a converter member and a sonotrode.
  • the sonotrode can be connected directly to the converter element or to the converter element via an amplitude amplifier.
  • the workpiece for example a plastic film
  • a counter tool anvil
  • the workpiece can also be conveyed continuously over the counter tool.
  • the workpiece is located between the sonotrode and the counter tool.
  • the converter element generally has a converter comprising several piezo elements, which converts the applied electrical alternating voltage, which is generally provided by a generator, into a mechanical movement of the same frequency.
  • Each piezo element is connected on the one hand to a phase conductor of the generator and on the other hand to a neutral conductor of the generator. If there is an alternating voltage on these conductors, the piezo elements alternately become longer and shorter and in this way generate an ultrasonic vibration.
  • the piezo elements are often arranged in a converter housing, which serves to protect the piezo elements as much as possible from environmental influences.
  • the converter housing is often connected to the neutral conductor, so it is at its potential. If the line between the generator and the neutral conductor fails, for example breaks, a fault can occur. The phase conductor continues to supply charge and the piezo elements are further excited. This creates a potential at the other end of each piezo element, which cannot be dissipated via the neutral conductor due to the error. This potential is then also applied to the converter housing. For reasons of occupational safety, this is undesirable as bystanders can come into contact with live components. The problem is usually solved by additionally grounding the converter housing using a protective conductor.
  • an ultrasonic tool for machining a workpiece by means of mechanical ultrasonic vibrations with a converter member and a sonotrode comprising a converter having at least one piezo element, the converter member having a phase conductor for a supply line of an electrical alternating voltage and a neutral conductor.
  • the phase conductor and the neutral conductor form the two poles for the converter or the at least one piezo element.
  • the at least one piezo element is set up to convert an electrical alternating voltage into a mechanical ultrasonic vibration.
  • the converter element can be set into a resonance oscillation with a mechanical ultrasonic oscillation of wavelength A and is mechanically coupled to the sonotrode.
  • the sonotrode and the converter member are coordinated with one another in such a way that the sonotrode can be set into a resonance oscillation with the mechanical ultrasonic oscillation of wavelength A.
  • the sonotrode points a sealing surface that is intended to come into contact with the workpiece to be processed.
  • the sealing surface of the sonotrode and the neutral conductor are galvanically separated. In the event of a fault, there may be a potential on the neutral conductor that is not dissipated. The galvanic isolation prevents this potential from being transferred to the sealing surface.
  • the phase conductor is also preferably galvanically isolated from the sealing surface of the sonotrode.
  • the piezo elements are usually arranged one behind the other along a converter axis.
  • the piezo disks are polarized so that they deform when voltage is applied.
  • the piezo disks have a positive side and a negative side.
  • the positive sides of all piezo disks are connected to the same pole, for example the phase conductor, and the negative sides are all connected to the other pole, in this example the neutral conductor. This ensures that the piezo disks all deform in the same way, i.e. all piezo disks are expanded (elongated) or contracted at a certain voltage.
  • the piezo disks are preferably arranged alternately in reverse polarization one behind the other along the converter axis so that two adjacent piezo disks can be contacted by the same electrode (contact disk) lying between them.
  • an alternating voltage source also called an ultrasound generator
  • the AC voltage source is connected to the phase conductor and the neutral conductor.
  • the converter member and sonotrode can be arranged one behind the other in a direction of propagation of the ultrasonic vibration.
  • Both the converter element and the sonotrode can have a length of A/2 or a multiple of A/2 in this direction of propagation. This ensures that in the event of an excitation with an oscillation of wavelength A, a standing wave with a oscillation maximum is formed at the interfaces of the sonotrode and converter element due to reflections of the ultrasonic oscillation at the end of the oscillating structure.
  • the direction of propagation can run along the converter axis, but it is also possible, for example, for the converter axis and propagation direction to be perpendicular to one another.
  • the entirety of the sonotrode and converter element as well as an amplitude amplifier optionally arranged between the sonotrode and converter element is also referred to as an oscillating structure. If an amplitude amplifier is used, it is also designed in such a way that it can be resonated with an oscillation with wavelength A.
  • the amplitude amplifier also advantageously has a length of A/2 or a multiple of A/2 in the propagation direction.
  • the oscillating structure is preferably held (clamped) in a holder, the holder preferably engaging on the sonotrode, in particular in the area of an oscillation node.
  • the holder can also engage the amplitude amplifier, the converter element or several of the components.
  • the ultrasonic vibration unit can be held in a known manner, for example as shown in WO 96/14202 A2. A large number of different holders are known to those skilled in the art, so that for reasons of clarity, a special holder has not been shown here.
  • the holder is also provided with a galvanic isolation in order to prevent the sonotrode from being grounded via the holder. It is particularly advantageous if the holder engages from the sealing surface of the sonotrode behind the galvanic isolation. This means that there is no need for additional insulation on the holder. In this case, the holder does not have any additional insulation.
  • Galvanic isolation is a device that prevents current from flowing between the neutral conductor and the sealing surface. This can and usually will be electrical insulation. However, it would also be conceivable for a line connected to the neutral conductor to be connected to the sealing surface of the sonotrode via electrically non-conductive coupling members, which allow the exchange of signals, for example by means of induction. With electrical insulation, however, the circuits have no effect on each other. In other words, we will speak of electrical insulation below if there is galvanic isolation and at the same time signal exchange is excluded.
  • the sonotrode has a signal connection for an electrical signal voltage that is electrically connected to the sealing surface, the neutral conductor and the signal connection being galvanically separated and preferably are electrically isolated from each other.
  • a signal voltage is applied in particular when a contact between the sealing surface of the sonotrode and another part, for example a counter tool (anvil), is to be detected (contact detection).
  • the galvanic isolation of the neutral conductor and the signal connection ensures that the signal voltage is not carried away through the neutral conductor and that, even in the event of a fault, the signal voltage and no other voltage is always present on the sealing surface. This protects the contact detection from disruptive influences and also prevents people from coming into contact with high potentials that do not correspond to the signal voltage via the sonotrode.
  • the holder engages the sonotrode, it preferably has a galvanic isolation, with a part of the holder being conductively connected to the sonotrode, in particular in the area of an oscillation node, and another part being galvanically isolated from this part.
  • the signal connection on the part of the holder that is conductively connected to the sonotrode instead of on the sonotrode. In this way, too, the signal voltage can be applied to the sealing surface of the sonotrode. If the signal connection is arranged on the sonotrode, it influences the vibration behavior of the oscillating structure. This is not the case with the holder, which is why the arrangement of the signal connection on the holder is particularly advantageous.
  • the converter member preferably has a converter housing in which the at least one piezo element is arranged.
  • the ultrasonic tool advantageously has a protective conductor, which is preferably arranged on the converter housing.
  • the protective conductor is connected or can be connected to the ground.
  • the ultrasonic tool then preferably has a first section, a second section and a third section.
  • the first section includes at least the neutral conductor.
  • the second section includes at least the protective conductor and the converter housing.
  • the third section includes the sealing surface of the sonotrode and can emit or receive a signal voltage via the signal connection.
  • the invention makes it possible to dispense with galvanic isolation of the first section and second section.
  • the second section and the third section are then galvanically isolated. This ensures that the signal voltage does not flow away via the protective conductor.
  • the invention makes it possible to additionally ground the converter housing using the protective conductor. In the event of a malfunction of the neutral wire it is prevented on the converter housing there is a potential because any potential is derived through the protective conductor. Thanks to the additional grounding, there is no longer any risk of injury to people if the converter housing is touched. There is also no risk that a signal voltage potential other than the desired one will be present on the sealing surface of the sonotrode. In this way, contact detection is possible despite the additional grounding of the converter housing.
  • the first section and the second section can also be galvanically separated and, best of all, electrically insulated from each other.
  • the second section is then galvanically isolated from the first and third sections.
  • the second section is advantageously located between the first section and the third section, so that there are two electrical insulations between the neutral conductor (first section) and the sealing surface of the sonotrode (third section). In this way, an additional section that is grounded is created between the first section, to which a high voltage can be applied in the event of a fault, and the third section, to which the signal voltage is applied.
  • An insulation housing made of electrically insulating material defining an insulation space can be provided within the converter housing, with the at least one piezo element and the neutral conductor being arranged in the insulation space.
  • the insulation housing then represents the galvanic isolation between the first and second sections.
  • the insulation housing is particularly preferably toroidal or hollow cylindrical.
  • the converter member in particular comprises a shaft, in particular a converter screw with a shaft, which is surrounded by the toroidal or hollow cylindrical insulation housing.
  • the insulation housing can consist of several insulation parts, in particular axially arranged insulation disks and radially insulating, cylindrical insulation parts. In this way, the piezo elements can continue to be compressed in the axial direction, thereby ensuring the transmission of the ultrasonic vibration.
  • the insulation housing serves in particular to provide basic insulation for the converter.
  • a counter tool with a sealing surface is advantageously provided, which is positioned in such a way that the workpiece to be machined can be arranged between the sealing surface of the sonotrode and the sealing surface of the counter tool during machining.
  • the sealing surface of the counter tool is preferably grounded.
  • the counter tool is preferably a roller, in particular a rotating roller, which conveys the workpiece during processing. This enables continuous welding of the workpiece.
  • the counter tool is at least partially electrically conductive.
  • the sonotrode or the oscillating structure as a whole is preferably movable along an adjustment direction, in particular by means of an adjustment device of the ultrasonic tool.
  • the adjusting device can be part of the holder. In this way, the sonotrode can be moved towards and away from the counter tool. In this way, the distance between the sonotrode and the counter tool can be adjusted at any time.
  • the sonotrode or the oscillating structure as a whole can also be gradually moved in the direction of the counter tool, especially if the machining consists of a cutting process.
  • a voltage source is provided with which the third section, in particular the signal connection, can be supplied with a signal voltage, with a sensor being provided for detecting electrical voltage applied to the third section or electrical voltage dissipated by the third section. If an electrical voltage is applied to or removed from the third section, this is detected by the sensor. From this detection it can be concluded that there is contact between the sealing surfaces.
  • the alternating voltage applied to the at least one piezo element is preferably between 500 V rm s (root mean square, effective voltage) and 3000 V rm s and preferably has a frequency between 20 kHz and 70 kHz. It has been shown that low voltages are advantageous for the signal voltage.
  • the distances between the sealing surfaces during processing and the contact times are very short due to the high frequencies and piezo technology. If the signal voltage is too high, voltage flashovers (arcs) occur before actual contact is made between the sealing surfaces, causing the sensor to detect a current flow. On the other hand, if the voltage is too low, hardly any current flows even with a minor contact, which makes early detection of the contacts more difficult.
  • the signal voltage is preferably a DC voltage and is further preferably less than 30 V, preferably less than 25 V and most preferably between 5 V and 12 V.
  • the inventors have determined that the range of 5 V from 12 V is best for contact detection suitable, with voltages up to 25 V also producing acceptable results lead. Above 30 V, however, in some applications voltage flashovers occur far too early.
  • the signal voltage can also be an alternating voltage, although a direct voltage is preferred because in the event of contact it leads to a uniform discharge that can be easily detected.
  • the sealing surfaces come into contact, a current flows between the sealing surfaces. If the contact ends, a potential is built up again by the voltage source of the signal voltage. Since the distances between the individual contacts can be very short, this construction should be extremely quick.
  • the electrical line with which the signal voltage is applied is shielded and/or does not exceed a predetermined total capacity.
  • the third section is therefore preferably connected to the voltage source by means of an electrical line, which is shielded and/or whose total capacity is ⁇ 2500 pF, in particular ⁇ 1500 pF. If the total capacity is ⁇ 1500 pF, contacts that occur very quickly one after the other can also be recognized and differentiated. At up to 2500 pF, sufficient contacts can still be detected, whereas detection suffers significantly above 2500 pF.
  • an insulation resistance between the second section and the third section is at least 5 kQ, in particular at least 7 kQ.
  • a limit of 100 MQ can therefore be viewed as the upper limit for the insulation resistance, although any larger value is also acceptable as long as no other boundary conditions speak against it.
  • An amplitude amplifier is preferably provided between the converter element and the sonotrode.
  • the converter member is mechanically coupled to the amplitude amplifier and the amplitude amplifier is mechanically coupled to the sonotrode.
  • the sonotrode, the amplitude amplifier and the converter element are coordinated with one another in such a way that the sonotrode can be set into a resonance oscillation with the mechanical ultrasonic oscillation of wavelength A.
  • the sonotrode, the amplitude amplifier and the converter element form the oscillating structure.
  • Sonotrode, amplitude amplifier and converter element can also be referred to as components that are connected to each other.
  • at least one insulation means is provided, which causes the sealing surface of the sonotrode and the neutral conductor to be galvanically separated, in particular electrically insulated.
  • Various design options for the at least one insulation means are described below.
  • At least one insulation means is provided at exactly two points, namely on the one hand at a direct contact point between two affected components, i.e. to be connected, i.e. where the ultrasonic vibration is transmitted from one component to the subsequent component in the direction of propagation, and on the other hand Others at a connection point at which the components are held together, which can happen in particular through frictional connection, but also through positive connection and/or material connection. Multiple connection points can also work together to hold the components together. Compressive forces in particular are transmitted at the contact point and tensile forces in particular are transmitted at the connection point.
  • the converter element and the sonotrode and/or the converter element and the amplitude amplifier and/or the amplitude amplifier and the sonotrode are preferably connected to one another via at least one connecting element.
  • the connecting element in particular causes a frictional connection along the direction of propagation.
  • the respective components are connected to one another in such a way that the ultrasonic vibration can propagate along the ultrasonic tool.
  • the connecting element is preferably a screw and/or a threaded bolt and/or a threaded bushing.
  • the at least one connecting element connects the respective components in particular with a clamping force of at least 20 kN and preferably less than 150 kN, in particular at least 30 kN and/or less than 90 kN.
  • the connecting element is preferably designed as an insulating means and is at least partially provided with an insulating coating and/or at least partially made of an insulating material. In this way, galvanic isolation is achieved where the adhesion between the respective components is closed.
  • the threaded bushing can also be a wire thread insert.
  • At least one insulating element in particular an insulating disk, is preferably provided, which is designed as an insulating means and at least partially consists of an insulating the material and/or is at least partially provided with an insulating coating.
  • the insulating disk particularly preferably has a hole through which the connecting element can protrude, for example, and is therefore preferably designed as an annular disk.
  • the insulating element causes in particular a galvanic isolation at a contact point between the affected components, where the ultrasonic vibration is transmitted to the subsequent component in the direction of propagation.
  • the connecting element and the insulation element are therefore particularly preferably used in combination.
  • the converter element and/or the amplitude amplifier and/or the sonotrode is designed as an insulating means and consists at least partially of an insulating material and/or is at least partially provided with an insulating coating.
  • galvanic isolation through the connecting element and/or the insulation element can be dispensed with.
  • the affected component is then coated at the contact point where the ultrasonic vibration is transmitted and/or where a frictional connection is generated, or consists of an insulating material there.
  • the number of components used can be reduced, which is particularly advantageous for ultrasonic tools, since additional components change the vibration behavior of the entire oscillating structure.
  • a coating has the particular advantage that it can be made so thin that the vibration behavior of the oscillating structure hardly or only slightly changes. If a component, for example an insulating disk, made of an insulating material is used, the component must generally have a thickness that is significantly greater than a coating. The component then has a significantly greater influence on the vibration behavior of the oscillating structure. This particularly applies to the contact point between two components.
  • a cascade of several components is provided as a connecting element, preferably a first cascade part being held by a second cascade part by means of a positive connection in the direction of propagation and the first cascade part and / or the second cascade part being provided with an insulating coating on the respective contact surface for the positive connection is.
  • at least one of the cascade parts can consist of an insulating material.
  • the cascade can also be used to implement the insulation means at the contact point or an insulating element, in particular an insulating disk, is used in addition to the cascade.
  • the connecting element has a smooth, in particular cylindrical, section which is provided with an insulating coating, this section being shrunk into the sonotrode or the converter member or the amplitude amplifier.
  • the sonotrode can be heated, causing a hole provided there to widen, whereupon the smooth section can be inserted into the hole. When it cools down, the bore shrinks again and then holds the connecting element in a frictional manner.
  • Smooth means in particular that the section has a constant cross section along its axial extent and in particular has no thread.
  • the cross section can be round, but also star-shaped or designed differently. Round has the advantage that the geometry is easier to produce, for example by grinding. When shrinking, very tight tolerances must be adhered to in order to achieve a sufficiently large adhesion, but at the same time not to overload the base material with tension due to excessive excess.
  • the main advantage of these embodiments is that no thread sections need to be coated.
  • the connecting element can comprise a smooth section and a threaded attachment which is shrunk onto the smooth section. The thread attachment then provides an external thread that can be screwed into an internally threaded hole in another component.
  • a through hole is provided in the amplitude amplifier, the amplitude amplifier having a section which is provided with an insulating coating.
  • a part of the converter member in particular a lower converter part, can also have the through hole and the section with the insulating coating.
  • a screw is further provided whose head rests on the coated section and is spaced from an inner surface of the through hole.
  • the screw can be screwed with its thread into the converter member or the sonotrode; in the case of the lower converter part with a through hole, the screw can be screwed with its thread into the amplitude amplifier or the sonotrode.
  • the screw can be a countersunk screw, which results in automatic centering of the connected components.
  • Additional insulating means can be provided on an inner wall of the through hole in order to still ensure sufficient insulation in the event of unplanned contact. There are no great demands placed on these insulating materials, as they do not transmit large forces, but only have to ensure electrical resistance. Therefore can These insulating materials are, for example, insulating sleeves, spray paint or insulating films.
  • a transverse bore which runs transversely to the direction of propagation, is provided in the converter element or the amplitude amplifier or the sonotrode, into which an at least partially coated transverse part with a threaded bore is inserted.
  • the cross part can be a cuboid groove piece or a bolt.
  • the converter member, the amplitude amplifier or the sonotrode then has, in addition to the transverse bore, a bore concentric to the threaded bore in which a screw or a threaded bolt is arranged, the screw or the threaded bolt being connected to the cross part by means of the threaded bore.
  • the screw or threaded bolt can then be connected to an adjacent part, i.e.
  • a coupling piece in particular a flange part, is provided as an insulating means, which is at least partially coated.
  • the coupling piece is attached to one of the components using screws, with the coupling piece being provided with the insulating coating where the screws rest.
  • no thread needs to be coated for the frictional connection.
  • the insulating coating and/or the insulating material preferably comprises at least one of the following components: ceramic, in particular chromium oxide (C ⁇ Os) and/or aluminum oxide (AI2O3), glass, polymer composite, in particular glass fiber reinforced plastic (GRP) and/or carbon fiber reinforced plastic ( CFRP). These materials have proven to be particularly advantageous both in terms of galvanic isolation and in terms of force and ultrasonic vibration transmission.
  • the coating can have an impact on the entire oscillating structure. At the point of contact between The coating changes the propagation/transmission of the ultrasonic vibration in the affected components. If the insulating coating is applied to a thread section, it changes the dimension of the thread, which must be taken into account when the thread was originally manufactured.
  • the insulating coating preferably has a thickness of at least 0.02 mm. Further preferably, the thickness is at most 0.5 mm. It has been shown that coatings below 0.02 mm sometimes have a sufficient insulating effect. However, particularly in the area of the threads, the insulation can be damaged by screwing in the corresponding counterpart (e.g. a screw).
  • the connecting element is a bolt with two external thread sections adjacent in the axial direction, each external thread section being provided with an external thread, the external threads being separated from one another and at least one of the external thread sections, in particular exactly one of the external thread sections, being coated with an insulating material.
  • the connecting element designed in this way therefore has two threaded sections arranged axially one behind the other, each with an external thread, with the external threads not merging into one another. If the connecting element is screwed into one of the components with one threaded section, the screwing-in process is possible up to the starting point of the second threaded section. There, the internal thread present in the component does not match the thread of the second thread section, which is why further screwing in is prevented.
  • a galvanic isolation between the components is achieved by the connecting element designed in this way.
  • a projection is provided between the thread sections, in particular a circumferential, radially projecting bead, which hinders further screwing beyond the projection. This projection is preferably also coated since it can come into contact with its uncoated counterpart.
  • the connecting element is a screw or a threaded bolt with an additional washer
  • the screw or the threaded bolt and the washer is designed either in one piece or in several parts, wherein the screw or the threaded bolt and the washer are each designed as an insulating means and consist at least partially of an insulating material and / or are at least partially coated with an insulating material.
  • the screw or the threaded bolt then causes galvanic isolation based on the adhesion between the two affected components and the washer causes galvanic isolation based on the contact surface between the two components.
  • These embodiments are comparatively easy to implement and in particular do not require any adaptation of existing components (sonotrode, amplitude amplifier, converter element).
  • the one-piece design makes the insulating component complex, but makes assembly of the components easier.
  • the ring disk must have a certain basic thickness, which can have a detrimental effect on the vibration behavior.
  • the connecting element is an element acting on an outer peripheral surface, in particular a union nut.
  • a union nut is that it is visible from the outside and, for example, damage to the coating or the union nut itself can be more easily recognized.
  • the converter member and the sonotrode and/or the converter member and the amplitude amplifier and/or the amplitude amplifier and the sonotrode are connected to one another via an insulating adhesive, in particular polyurethane and/or epoxy resin, in particular the connecting element being connected to the converter member and/or the sonotrode and/or the amplitude amplifier is connected via an insulating adhesive.
  • an adhesive offers the advantage that both galvanic isolation and the connection between the components can be achieved in one step.
  • the ultrasonic tool preferably comprises a control unit, which is in particular set up to carry out the contact detection.
  • the control unit is preferably connected to the adjusting device and the sensor for detecting electrical charge applied to the third section or electrical charge removed from the third section. This allows the control unit to control the adjusting device based on the sensor signal and move the sonotrode closer to or away from the counter tool.
  • the control unit can also be connected to the voltage source of the signal voltage, the voltage source of the alternating voltage, other sensors and/or output devices, such as a display or a signal lamp.
  • the voltage sources can also be controlled depending on the sensor signal, for example to reduce the amplitude of the alternating voltage if too many or too long contacts are detected, or to switch off the alternating voltage completely.
  • An output device enables the sensor signal to be output in a way that people can perceive, for example as a warning in the event of too many contacts or as a list of all detected contacts.
  • the object of the invention is also achieved by a method for machining a workpiece using mechanical ultrasonic vibrations using an ultrasonic tool according to the above description.
  • the method is characterized in that the workpiece is arranged for processing between the sonotrode and a counter tool and the workpiece is processed by means of the ultrasonic tool, that an electrical signal voltage, in particular a signal voltage less than 100, is present at a signal connection of the sonotrode that is electrically connected to the sealing surface of the sonotrode V, preferably less than 30 V and best between 5 and 25 V, is applied, whereby an electrical current flow between the neutral conductor and the signal connection is prevented and that it is determined at least temporarily whether a current flows between the sonotrode and the counter tool and / or a voltage drops between the sonotrode and the counter tool.
  • an electrical signal voltage in particular a signal voltage less than 100
  • the signal voltage and determining whether a current flows and/or a voltage drops it can be determined whether there is contact between the sonotrode and the counter tool.
  • the galvanic isolation in the ultrasonic tool prevents the signal voltage from being dissipated via the neutral conductor, so that contact detection is not impaired.
  • a force is preferably exerted on the sonotrode, which is transmitted from the sonotrode to the workpiece. This force ensures an even transmission of the ultrasonic vibration to the workpiece.
  • the alternating voltage (effective voltage) applied to the converter of the ultrasonic tool is preferably between 500 V rm s and 3000 V rm s and preferably has a frequency between 20 kHz and 70 kHz. With these voltages and these frequencies, it is effectively possible to generate an ultrasonic vibration for machining the workpiece.
  • the ultrasonic vibration on the sealing surface of the sonotrode preferably has a frequency of 20 kHz to 70 kHz and/or an amplitude of 5 pm to 50 pm.
  • the frequency of the ultrasonic oscillation corresponds to the frequency of the alternating voltage.
  • the amplitude is significantly influenced by the level of the alternating voltage, the structural design of the converter element, the amplitude amplifier and the sonotrode as well as the converter, i.e. the at least one piezo element itself.
  • the contact detection is particularly suitable for amplitudes from 5 pm to 50 pm.
  • the workpiece preferably comprises at least partially a polymer, in particular a thermoplastic polymer.
  • the workpiece particularly preferably consists entirely of a polymer in the area of a contact surface with the sonotrode.
  • the workpiece is preferably at least partially melted by the ultrasonic vibration in the area of a contact surface with the sonotrode.
  • the workpiece comprises a polymer, particularly in the area of the contact surface with the sonotrode.
  • the workpiece consists of several parts, in particular several material webs, which are joined together during processing. The material webs are preferably conveyed continuously through the area between the sonotrode and the counter tool, in particular by means of rollers.
  • the contact detection according to the invention is particularly advantageous for such thin components, since contact between the sonotrode and the counter tool often occurs due to the small thickness. Any contact affects the service life of the sonotrode and counter tool. Therefore, precise adjustment of the gap between the sonotrode and the counter tool is particularly advantageous. This setting can be achieved using the method according to the invention.
  • a duration is determined for at least one current flow and/or voltage drop between the sonotrode and counter tool and, if the duration exceeds a predefined time limit, the current flow and/or voltage drop becomes evaluated as contact between the sealing surfaces of the sonotrode and the counter tool with a contact time that corresponds to the duration of the current flow or the voltage drop.
  • the time limit is in particular >0.01 ps and particularly preferably >1 ps.
  • An upper limit of 1000 ps can be set for the time limit to exclude accidents. It has been shown that a current not only flows when the sonotrode and counter tool actually contact each other, but that a current flow can also occur when the sonotrode and the counter tool come very close to each other or partially touch each other.
  • a current intensity is determined for at least one current flow and/or voltage drop between the sonotrode and counter tool and, if the current intensity exceeds a predefined current limit value, the current flow and/or voltage drop is evaluated as contact between the sealing surfaces.
  • the current limit is preferably > 1 mA.
  • An upper limit of 300 ps can be set for the current limit to exclude accidents.
  • the current strength is also an indicator of how close the sealing surfaces actually come to each other. Therefore, a distinction can be made between contacts to be evaluated and non-contacts based on the current strength.
  • the sealing surfaces also have a surface area and a roughness - albeit slight.
  • both limit values are also suitable for assessing the quality of the contacts.
  • the determination of the current strength and the contact rating dependent on it can be used alternatively or in addition to the duration of the current flow and/or voltage drop.
  • a current flow and/or voltage drop is only considered a contact if both the time limit and the current limit are exceeded.
  • at least one of the following parameters is determined for at least a predetermined (past) period of time, in particular for the last millisecond, whereby the parameter is preferably stored and/or output:
  • the determination of these parameters serves to evaluate the contact detection. For example, if there are only a small number of contacts during the specified period of time or if the total contact time is very short despite a high number of contacts, it can be concluded that the sealing surfaces have not yet come very close to one another.
  • a limit value can be provided for each of the parameters, above which a specific action, for example a warning signal, takes place.
  • the parameters can be further processed by a control unit of the ultrasonic tool.
  • the ultrasonic tool can adjust the position of the ultrasonic tool or the oscillating structure, in particular the sonotrode, reduce or increase the force exerted on the sonotrode, issue a warning and/or stop the machining process.
  • Figure 1 schematically shows a first embodiment of an ultrasonic tool in a lateral cross section
  • FIGS 2 to 16 show schematically further embodiments of ultrasonic tools
  • the ultrasonic tool 100 shown in Figure 1 comprises a converter member 10 and a sonotrode 40.
  • the converter member 10 comprises a converter 20, a converter lower part 12, an annular disk-shaped cover plate 16 and a converter screw 18.
  • the converter 20 has four annular disk-shaped piezo elements 22, which are arranged one behind the other the converter lower part 12 and the cover plate 16 are arranged.
  • the converter 20 further includes a total of five electrodes, which are also referred to as contact disks: three neutral electrodes 24 and two phase electrodes 26, which are also designed in the shape of an annular disk.
  • the electrodes 24, 26 are arranged alternately with the piezo elements 22 along a converter axis K between the lower converter part 12 and the cover plate 16.
  • the electrodes 24, 26 alternate.
  • a neutral electrode 24 is therefore arranged at the bottom and top.
  • the converter screw 18 rests with its screw head on the cover plate 16 and runs through all the holes in the piezo elements 22, the electrodes 24, 26 and the cover plate 16.
  • the converter screw 18 is screwed into the lower converter part 12 and ensures that the piezo elements 22 and the Electrodes 24, 26 are kept compact. Unlike in the schematic representation of Figure 1, the piezo elements and the electrodes 24, 26 are in direct contact with one another and are kept compact by the converter screw 18.
  • the converter screw 18 is tightened with a sufficient preload force, for example 70 kN.
  • the converter element 10 further comprises a phase conductor 31 for supplying an electrical alternating voltage and a neutral conductor 33 for deriving it.
  • the phase conductor 31 and the neutral conductor 33 form the two poles for the converter 20.
  • the neutral electrodes 24 are connected to the neutral conductor 33 and the phase electrodes 26 are connected to the phase conductor 31.
  • the piezo elements 22 are polarized and each arranged in such a way that they are either all elongated or all compressed at any time with the exception of a zero position.
  • the piezo elements 22 convert the electrical alternating voltage into a mechanical ultrasonic oscillation, the converter member 10 being set into a resonance oscillation with a mechanical ultrasonic oscillation of wavelength A.
  • the ultrasonic vibration spreads in particular along a propagation direction R, which in the embodiment shown runs from the converter 20 to the sonotrode 40, i.e. downwards along the converter axis K.
  • the converter element 10 and the sonotrode 40 both have a length of A/2 along the propagation direction R.
  • the sonotrode 40 and the converter member 10 are coordinated with one another in such a way that the sonotrode 40 is set into a resonance oscillation with the mechanical ultrasonic oscillation of wavelength A.
  • the sonotrode 40 has a sealing surface 42 which is intended to come into contact with a workpiece 200 to be machined.
  • the workpiece 200 is shown schematically here.
  • the workpiece 200 often has several parts that are welded together, in particular several material webs are welded together, which then together form the workpiece 200.
  • the ultrasonic tool 100 further includes a counter tool 110 with a sealing surface 111.
  • the ultrasonic tool 100 is designed to process the workpiece 200 using mechanical ultrasonic vibration.
  • the workpiece 200 is placed between the sealing surfaces 42, 111 or passed through the gap between the sealing surfaces 42, 111, with the workpiece 200 touching the sealing surfaces 42, 111 in each case.
  • a force in the propagation direction R is also exerted on the workpiece 200, which can be generated by an adjusting device (not shown) of a holder. If an ultrasonic vibration is now generated, the workpiece 200 is processed, often with several parts, such as material webs, being connected to one another.
  • An insulation means 300 is arranged between the converter member 10 and the sonotrode 40.
  • the insulation means 300 comprises a threaded bolt-shaped connecting element 310 and an insulating element 350 in the form of an insulating disk-shaped section.
  • the connecting element 310 and the insulating element 350 are made in one piece.
  • the insulation means 300 consists entirely of a ceramic material.
  • the insulation means 300 is screwed with the connecting element 310 into both the converter lower part 12 and the sonotrode 40.
  • the converter lower part 12 and the sonotrode 40 do not touch each other because they are separated from one another by the insulation means 300. In this way, the sealing surface 42 of the sonotrode 40 and the first neutral conductor 33 of the converter 20 are electrically isolated. A current flow between the converter base 12 and the sonotrode 40 is prevented.
  • the converter member 10 includes a schematically illustrated converter housing 11, which in particular shields the piezo elements 22 and the electrodes 24, 26 from the outside.
  • a protective conductor 35 is provided on the converter housing 11 and is connected to the ground.
  • the converter housing 11 is connected to the converter lower part 12 in the area of an oscillation node.
  • the sonotrode 40 has a signal connection 44 for an electrical signal voltage that is electrically connected to the sealing surface 42.
  • the neutral conductor 33 and the signal connection 44 are galvanically separated from one another by the insulation means 300.
  • the ultrasonic tool 100 includes a voltage source 400, which is a DC voltage source.
  • the voltage source 400 is electrically connected on the one hand via a sensor 410 in the form of an ammeter to the signal connection 44 of the sonotrode 40 and on the other hand to the counter tool 110.
  • the voltage source 400 applies a direct voltage to the signal connection 44 and thus to the sealing surface 42. If the sealing surfaces 42, 111 come into contact during the processing of the workpiece 200, a current flows. This current flow can be detected using the sensor 410.
  • the sonotrode 40 and the counter tool 110 are designed to be conductive and are in particular made of a metallic material. The signal from the sensor 410 can therefore be used to conclude that there is contact between the sealing surfaces 42, 111 (contact detection).
  • the piezo elements 22 are further excited, whereby they then generate a potential on the neutral electrodes 24 and thus on the neutral conductor 33. This potential is then also present on the lower converter part 12.
  • the protective conductor 35 ensures that the potential is dissipated in the event of a fault and that touching the converter housing 11 does not result in injury.
  • the insulation means 300 also prevents this potential from being present on the sealing surface 42 of the sonotrode 40 in the event of a fault and influencing the contact detection.
  • the protective conductor 35 is galvanically isolated from the sealing surface 42 and the signal connection 44 by the insulation means 300 in order to prevent the signal voltage from being dissipated via the protective conductor 35.
  • the insulation means 300 can also consist of a non-ceramic, for example metallic, material. In these embodiments, the insulation means 300 is then provided with an insulating coating on at least one side or on the entire surface.
  • an amplitude amplifier 60 can also be provided between the converter base 12 and the sonotrode 40.
  • the insulation means 300 can then be arranged between the converter base 12 and the amplitude amplifier 60 or between the amplitude amplifier 60 and the sonotrode 40. 2 only shows a section of an ultrasonic tool 100, namely the area around a contact point 112 between sonotrode 40 and an amplitude amplifier 60.
  • two insulation means 300 are provided between the sonotrode 40 and the amplitude amplifier 60.
  • a connecting element in the form of a threaded bolt is provided, which is screwed into both the sonotrode 40 and the amplitude amplifier 60.
  • the threaded bolt is completely coated and connects the sonotrode 40 and the amplitude amplifier 60 to one another in a non-positive manner, thus representing the connection point between the components.
  • the connecting element is designed as an insulating means 300.
  • An insulating element 350 in the form of an insulating disk is also provided as a further insulating means 300.
  • the insulating disk is an annular disk and is arranged at the contact point 112 between the sonotrode 40 and the amplitude amplifier 60.
  • the insulating disk is also provided with an insulating coating, whereby the insulating coating can be present all the way around, or only on one of the axial sides, for example on the top 352 or the bottom 354.
  • the connecting element 310 and the insulating element 350 provide galvanic isolation of the Sonotrode 40 and the amplitude amplifier 60.
  • the insulation means 300 shown in FIG. 2 can also be used for a connection between the sonotrode 40 and the converter element 10 or for a connection between the amplitude amplifier 60 and the converter element 10.
  • the ultrasonic tool 100 comprises an insulating element 350 in the form of an annular disk-shaped insulating disk and a wire thread insert 320 as insulation means 300.
  • the wire thread insert 320 can consist entirely of an insulating material or be provided with an insulating coating.
  • the wire thread insert 320 is screwed into a threaded hole in the sonotrode 40.
  • a connecting element 310 in the form of a threaded bolt is also provided. The threaded bolt is screwed into the amplitude amplifier 60 at one end and into the wire thread insert 320 at the other end.
  • the insulating element 350 and the wire thread insert 320 represent a galvanic isolation between the sonotrode 40 and the amplitude amplifier 60.
  • This type of connection can also be used in other embodiments between the sonotrode 40 and the converter element 10 or between the amplitude amplifier 60 and the converter element 10.
  • FIG. 4 shows a section of an ultrasonic tool 100 around a contact point 112 between the sonotrode 40 and the amplitude amplifier 60.
  • Both the sonotrode 40 and the amplitude amplifier 60 have no bore in this embodiment.
  • An insulating element 350 in the form of an insulating disk without a hole is provided as an insulating means 300 between the components 40, 60. In other embodiments, the insulating disk can also have a hole here, for example if it is advantageous in terms of vibration or in terms of uniform force transmission.
  • the insulating element 350 represents a galvanic isolation at the contact point 112.
  • the sonotrode 40 has an external thread 46 and the amplitude amplifier 60 has a circumferential shoulder 62.
  • a connecting element 310 in the form of a union nut is also provided.
  • the union nut has a radially inwardly projecting projection 316 at its upper end and an internal thread 314 at its lower end.
  • the union nut rests with the projection 316 on the shoulder 62 and the internal thread 314 is screwed onto the external thread 46 and thereby connects the sonotrode 40 and the amplitude amplifier 60 in a non-positive manner at the connection point.
  • the union nut can consist entirely of an insulating material. However, it can also be provided with an insulating coating in individual areas, in particular in the area of the projection 316 and preferably wherever it rests on the shoulder 62. As a result, no current can flow from the amplitude amplifier 60 via the union nut to the sonotrode 40. In this way, the union nut and the insulating disk form two insulating means 300.
  • This type of galvanic isolation can also be used in other embodiments between the sonotrode 40 and the converter element 10 or between the amplitude amplifier 60 and the converter element 10.
  • the ultrasonic tool 100 shown in Figure 5 also includes a sonotrode 40 and an amplitude amplifier 60. Between the two components 40, 60, an insulating means 300 in the form of a flange part is provided at the contact point 112, which is an annular disk as an insulating element 350 and a threaded bolt connected to it as Connecting element 310 includes. Connecting element 310 and insulating element 350 are made in one piece. In the embodiment shown, the underside 354 of the insulating disk is included provided with an insulating coating. In other embodiments, the entire flange portion may be made of an insulating material, such as ceramic.
  • the insulating disk projects in the radial direction relative to the amplitude amplifier 60 and forms a flange shoulder 358 there.
  • the flange shoulder 358 is circumferential.
  • a union nut is also provided as a further connecting element 310.
  • the union nut has a radially inward projection 316 at the upper end and an internal thread 314 at the lower end. The projection 316 rests on the flange shoulder 358 and the thread 314 is screwed onto an external thread 46 of the sonotrode 40.
  • the insulating disk is also provided with an insulating coating where the union nut rests, i.e. on the top 352. This is not necessary if the flange part consists entirely of an insulating material.
  • the flange part is screwed into a threaded hole in the amplitude amplifier 60 with the threaded bolt.
  • the sonotrode 40 and the amplitude amplifier 60 are electrically isolated by the insulating coating.
  • This type of connection can also be used in other embodiments between sonotrode 40 and converter element 10 or between amplitude amplifier 60 and converter element 10.
  • FIG. 6 shows a further embodiment of an ultrasonic tool 100, here also in detail around the contact point 112 between the two components 40, 60.
  • Isolation means 300 are again arranged between the sonotrode 40 and the amplitude amplifier 60.
  • a flange part is provided which has an insulating disk as an insulating element 350 and a threaded bolt as a connecting element 310 in one piece.
  • the flange part consists of an insulating material, for example ceramic.
  • the insulation means 300 has bores arranged along a circular path, through which a flange screw 356 runs.
  • the insulation means 300 is connected to the sonotrode 40 with the flange screws 356.
  • the flange screws 356 are screwed into threaded holes in the sonotrode.
  • the amplitude amplifier 60 is screwed onto the threaded bolt.
  • the flange screws 356 are provided with an insulating coating.
  • the flange screws 356 therefore also represent insulation means 300 and connecting means 310.
  • the sonotrode 40 and the amplitude amplifier 60 are galvanically separated from one another by the insulating coating and the insulating material.
  • the flange part can only be provided with an insulating coating and/or the flange screws 356 can be made of an insulating material.
  • connection and insulation can also be used in other embodiments between the sonotrode and the converter element 10 or between the amplitude amplifier 60 and the converter element 10.
  • annular insulating disk is provided as an insulating element 350 between the sonotrode 40 and the amplitude amplifier 60.
  • the insulating disk forms the galvanic isolation at the contact point 112.
  • a threaded hole is provided in the amplitude amplifier 60.
  • a blind hole without thread is provided in the sonotrode 40. The two holes are concentric.
  • the ultrasonic tool 100 further includes a bolt as a connecting element 310, which is threaded at one end and has a smooth section 311 at the other end.
  • the bolt is glued to the sonotrode 40 using an adhesive 360, i.e. connected in a materially bonded manner.
  • the bolt then protrudes beyond the upper end of the sonotrode 40.
  • the adhesive 360 is insulating and causes galvanic isolation at the connection point between the sonotrode 40 and the amplitude amplifier 60.
  • the bolt can also be provided with a thread on its entire circumferential surface and/or the bore in the sonotrode 40 can be provided with an internal thread, with the bores not matching one another. If an adhesive 360 is introduced into the resulting gap, an undercut and thus a positive connection is achieved in addition to the cohesive connection.
  • galvanic isolation between sonotrode 40 and amplitude amplifier 60 described here can also be used in other embodiments for galvanic isolation between sonotrode 40 and converter element 10 or between amplitude amplifier 60 and converter element 10.
  • Figure 8 shows a section of an ultrasonic tool 100 according to a further embodiment.
  • the amplitude amplifier 60 has a throughput input bore 64, which ends in a shoulder 62 at its upper end.
  • a screw is arranged as a connecting element 310 in the through hole 64. The screw projects downwards out of the amplitude amplifier 60 or out of the through hole 64 and is screwed there into a threaded hole in the sonotrode 40.
  • Additional insulating means are provided on an inner wall of the through hole. These additional insulating means ensure sufficient insulation in the event of unplanned contact between the through hole 64 and the screw. These additional insulating means do not have to transmit large forces, but only ensure electrical resistance. In other embodiments, these additional insulating means can also be used where no insulating coating is provided between two components, but contact cannot be completely ruled out.
  • An insulating disk is also arranged as an insulating element 350 at the contact point 112 between the sonotrode 40 and the amplitude amplifier 60.
  • the insulating disk is provided with an insulating coating or consists entirely of an insulating material, for example ceramic, and therefore represents an insulating means 300.
  • the amplitude amplifier has an internal thread into which the lower converter part 12 is screwed.
  • the amplitude amplifier 60 has a through hole 64 which has a conical taper at the upper end.
  • a screw can be inserted into the through hole 64 from below as a connecting element 310, which rests on a shoulder surface 66 of a shoulder 62 of the conical taper. The connection point is there. In this position, the screw projects upwards out of the through hole 64 and is screwed there into a threaded hole in the lower converter part 12.
  • An annular insulating disk is arranged as an insulating element 350 between the converter lower part 12 and the amplitude amplifier 60.
  • An insulating coating is disposed on the shoulder surface 66 of the shoulder 62.
  • the amplitude amplifier 60 represents an isolation means 300.
  • the insulating disk is provided with an insulating coating or is constructed entirely of an insulating material and thus forms an insulating means 300. In this way, the amplitude amplifier 60 and the lower converter part 12 are galvanically isolated.
  • the ultrasonic tool 100 has a sonotrode 40, an amplitude amplifier 60 and a converter lower part 12.
  • the amplitude amplifier 60 has two concentric threaded holes, each with an internal thread.
  • the sonotrode 40 is screwed into the lower hole.
  • the converter lower part 12 has a through hole 13 which is concentric with the upper threaded hole in the amplitude amplifier.
  • An insulating disk is arranged as an insulating element 350 between the converter lower part 12 and the amplitude amplifier 60.
  • the insulating disk is made of an insulating material or is provided with an insulating coating and therefore represents an insulating means 300.
  • a screw can be inserted into the through hole 13 from above as a connecting element 310.
  • the screw then rests on a shoulder 15 of the lower converter part 12, the through hole 13 being provided with an insulating coating in the area of the shoulder 15.
  • the lower converter part 12 represents an insulating means 300.
  • the screw is screwed into the upper threaded hole of the amplitude amplifier and non-positively connects the amplitude amplifier 60 to the lower converter part 12.
  • the amplitude amplifier 60 and the lower converter part 12 are galvanic from the insulating coating and additionally the insulating disk separated.
  • the piezo elements 22 can only be added after the lower converter part 12 and the amplitude amplifier 60 have been connected and the converter 20 can be completely constructed.
  • the amplitude amplifier and the lower converter part 12 are galvanically isolated by the insulating disk and the coating in the area of the shoulder 15.
  • FIGS 11A, 11B and 11C show a further embodiment of an ultrasonic tool 100.
  • the area around the contact point 112 between the sonotrode 40 and the amplitude amplifier 60 is shown.
  • the amplitude amplifier 60 has a through hole 64, which has a shoulder 62 in the lower area having.
  • an insulating disk is arranged as an insulating element 350, which is annular.
  • the insulating pane is made of an insulating material or is provided with an insulating coating and thereby represents an insulating means 300.
  • a transverse bore 48 and a central blind bore 49 are provided in the sonotrode 40, the blind bore 49 opening into the transverse bore 48.
  • the transverse bore 48 is rectangular in cross section and the blind bore 49 is round.
  • a cuboid cross part 330 in the form of a groove piece can be inserted into the transverse bore 48 from the side.
  • the cross part 330 has a central threaded hole 332, which is arranged concentrically with the blind hole 49.
  • a screw can then be inserted from above through the through hole 64, which comes to rest on the shoulder 62 and can be screwed into the hole 332 of the groove piece.
  • the groove piece is pulled upwards until it rests on the ceiling of the transverse hole 48. If the screw is screwed in further, a clamping force is applied.
  • the cross member 330 is provided with an insulating coating, although the bore is not coated. In this way, the cross part 330 represents an insulating means 300. Since the cross part 330 rests with one top side on the top side of the transverse bore 48, a galvanic isolation is created.
  • the cross part 330 can also be cylindrical. If the transverse part 330 is designed to be cylindrical, the transverse bore 48 is preferably round or oval in cross section.
  • the insulating disk and the cross part 330 create a galvanic isolation between the sonotrode 40 and the amplitude amplifier 60.
  • the embodiment shown can also be used when connecting a sonotrode with a converter element 10 or an amplitude amplifier with a converter element 10.
  • the cross part 330 can also consist entirely of an insulating material.
  • the ultrasonic tool 100 has a converter base 12 and an amplitude amplifier 60, which come together at a contact point 112.
  • the converter lower part 12 has a through hole 13.
  • a cascade of several components is provided as the connecting element 310.
  • the cascade includes a threaded bolt with two separate threaded sections. With one threaded section, the threaded bolt is screwed into an internal thread of the converter lower part 12. The other end of the threaded bolt can be screwed into a first cascade part 340.
  • the first cascade part 340 holds a second cascade part 342 by means of positive locking in the propagation direction R.
  • the second cascade part 342 has an external thread, by means of which it is connected to an internal thread of the amplitude amplifier 60 is to be connected.
  • the second cascade part 342 is provided with an insulating coating on an upper side 344 and a lower side 346.
  • the second cascade part 342 represents an insulation means 300.
  • the second cascade part 342 touches the converter lower part 12 with the top 344.
  • the second cascade part 342 touches the first cascade part 340 with the bottom 346.
  • the threaded bolt does not touch the second cascade part 342.
  • additional insulating means such as an insulating sleeve, can be provided between the threaded bolt and the second cascade part 342. In this way, the converter base 12 and the amplitude amplifier 60 are galvanically isolated from one another.
  • Such a cascade can also be used for a connection between amplitude amplifier 60 and sonotrode 40 or between sonotrode 40 and converter element 10.
  • a cascade is also provided as a connecting element 310.
  • the main difference to the embodiment according to FIG. 12 is that the second cascade part 342 has a smaller diameter and ends at the top with the amplitude amplifier 60.
  • an insulating disk is provided as an insulating element 350 between the amplitude amplifier 60 and the converter lower part 12.
  • the insulating pane is made of an insulating material or is provided with an insulating coating and thereby represents an insulating means 300.
  • the second cascade part 342 is not coated.
  • the first cascade part 340 is provided with an insulating coating on an axial contact surface with the second cascade part 342.
  • the first cascade part 340 in this embodiment can also consist entirely of an insulating material, for example ceramic.
  • the first cascade part 340 forms an insulation means 300. In the radial direction, the first cascade part 340 and the second cascade part 342 do not touch each other.
  • additional insulating means such as an insulating sleeve, can be provided.
  • a bolt is provided as the connecting element 310, which has an external thread section and a smooth section 311.
  • the smooth section 311 is provided with an insulating coating and the bolt is with the smooth section 311 in a blind hole in the sonotrode 40 is shrunk.
  • the bolt forms an insulating means 300.
  • the threaded section of the bolt protrudes upwards from the sonotrode 40. In this way, the amplitude amplifier 60 can be screwed onto the threaded section using a threaded hole.
  • annular insulating disk is also provided as an insulating element 350, which consists of an insulating material or is provided with an insulating coating and thereby represents an insulating means 300.
  • an annular insulating disk is also provided as an insulating element 350, which consists of an insulating material or is provided with an insulating coating and thereby represents an insulating means 300.
  • the ultrasonic tool 100 has a sonotrode 40 and an amplitude amplifier 60.
  • An insulating disk is provided as an insulating element 350 at the contact point 112.
  • the insulating disk is ring-shaped.
  • the insulating pane is made of an insulating material or is provided with an insulating coating and thereby represents an insulating means 300.
  • the sonotrode 40 has a bolt 47 which is manufactured integrally with the sonotrode 40.
  • the bolt 47 projects upwards through the recess in the washer.
  • the bolt 47 of the sonotrode 40 is provided with an insulating coating. In this way, the sonotrode 40 forms an insulation means 300.
  • a threaded attachment 313 with an external thread as a connecting means 310 is shrunk onto the bolt 47.
  • the amplitude amplifier 60 is screwed onto the external thread of the threaded attachment 313 using a threaded hole.
  • the insulating disk can be dispensed with if the entire top of the sonotrode 40 is provided with an insulating coating.
  • this type of connection can also be used between the sonotrode 40 and the converter element 10 or between the amplitude amplifier 60 and the converter element 10.
  • At least one of two interconnected components can be provided with an insulating coating or can at least partially consist of an insulating material, in particular on the respective contact surface. Then either the insulating pane as a whole or its coating can be dispensed with. This applies to all versions with an insulating pane.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Apparatuses For Generation Of Mechanical Vibrations (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)

Abstract

L'invention concerne un outil à ultrasons et un procédé d'usinage d'une pièce au moyen de vibrations mécaniques ultrasonores.
EP22782462.0A 2022-09-05 2022-09-05 Outil à ultrasons et procédé d'usinage d'une pièce à l'aide de vibrations mécaniques ultrasonores Pending EP4558286A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2022/074657 WO2024051918A1 (fr) 2022-09-05 2022-09-05 Outil à ultrasons et procédé d'usinage d'une pièce à l'aide de vibrations mécaniques ultrasonores

Publications (1)

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EP4558286A1 true EP4558286A1 (fr) 2025-05-28

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Country Status (5)

Country Link
US (1) US11759968B1 (fr)
EP (1) EP4558286A1 (fr)
JP (1) JP2025531076A (fr)
CN (1) CN119768239A (fr)
WO (1) WO2024051918A1 (fr)

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CN117620717B (zh) * 2023-12-01 2026-04-03 齐鲁工业大学(山东省科学院) 一种预紧超声扭转振动刀柄
DE102024107854A1 (de) * 2024-03-19 2025-09-25 Herrmann Ultraschalltechnik Gmbh & Co. Kg Beschichtete Schraube sowie Ultraschallschwingsystem mit einer solchen
CN119733635A (zh) * 2024-12-30 2025-04-01 哈尔滨理工大学 一种用于高性能涂层制造的超声波辅助装置及其使用方法

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GB1232128A (fr) * 1968-11-12 1971-05-19
EP0790888B1 (fr) * 1994-11-07 1999-06-09 Herrmann Ultraschalltechnik GmbH & Co. KG Procede et dispositif d'usinage en continu par ultrasons d'une bande de materiau
US6171265B1 (en) * 1997-01-07 2001-01-09 Storz Endoskop Gmbh Handpiece for use with a multifunctional operating endoscopic instrument

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IT1145587B (it) 1981-11-05 1986-11-05 Roberto Perlini Dispositivo di stabilizzazione in marcia rettilinea e di modificazione di assetto su traiettorie predeterminate per assale di veicoli
DE4400210A1 (de) * 1994-01-05 1995-08-10 Branson Ultraschall Verfahren und Einrichtung zum Betrieb eines Generators zur HF-Energieversorgung eines Ultraschallwandlers
DE102005038344A1 (de) 2005-08-13 2007-02-15 Tetra Laval Holdings & Finance S.A. Vorrichtung zum Ultraschallbearbeiten von Werkstücken
US20110126686A1 (en) * 2009-11-30 2011-06-02 Manfred Geiss Machine tool, machine tool apparatus and method for operating a machine tool apparatus
DE102013225042A1 (de) 2013-12-05 2015-06-11 Branson Ultraschall Niederlassung Der Emerson Technologies Gmbh & Co. Ohg Ultraschallschweißvorrichtung und Ultraschallschweißverfahren zur Regelung von kontinuierlichen Ultraschallschweißprozessen
DE102015109451A1 (de) 2015-06-14 2016-12-15 Charles Rizk Sonotrodenvorrichtung und Gerät für akustische Levitation sowie Steuerungseinrichtung bzw. -verfahren dafür

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1232128A (fr) * 1968-11-12 1971-05-19
EP0790888B1 (fr) * 1994-11-07 1999-06-09 Herrmann Ultraschalltechnik GmbH & Co. KG Procede et dispositif d'usinage en continu par ultrasons d'une bande de materiau
US6171265B1 (en) * 1997-01-07 2001-01-09 Storz Endoskop Gmbh Handpiece for use with a multifunctional operating endoscopic instrument

Also Published As

Publication number Publication date
US11759968B1 (en) 2023-09-19
CN119768239A (zh) 2025-04-04
JP2025531076A (ja) 2025-09-19
WO2024051918A1 (fr) 2024-03-14

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