WO2022028879A1 - Procédé de soudage laser d'électrodes - Google Patents

Procédé de soudage laser d'électrodes Download PDF

Info

Publication number
WO2022028879A1
WO2022028879A1 PCT/EP2021/070258 EP2021070258W WO2022028879A1 WO 2022028879 A1 WO2022028879 A1 WO 2022028879A1 EP 2021070258 W EP2021070258 W EP 2021070258W WO 2022028879 A1 WO2022028879 A1 WO 2022028879A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrodes
partial beams
laser beam
laser
positions
Prior art date
Application number
PCT/EP2021/070258
Other languages
German (de)
English (en)
Inventor
Markus Kogel-Hollacher
Original Assignee
Precitec Gmbh & 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 Precitec Gmbh & Co. Kg filed Critical Precitec Gmbh & Co. Kg
Publication of WO2022028879A1 publication Critical patent/WO2022028879A1/fr

Links

Classifications

    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/21—Bonding by 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/03—Observing, e.g. monitoring, the workpiece
    • B23K26/032—Observing, e.g. monitoring, the workpiece using optical means
    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/0604—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams
    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/067—Dividing the beam into multiple beams, e.g. multifocusing
    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/067—Dividing the beam into multiple beams, e.g. multifocusing
    • B23K26/0673—Dividing the beam into multiple beams, e.g. multifocusing into independently operating sub-beams, e.g. beam multiplexing to provide laser beams for several stations
    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/08—Devices involving relative movement between laser beam and workpiece
    • B23K26/082—Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/0056—Manufacturing winding connections
    • H02K15/0068—Connecting winding sections; Forming leads; Connecting leads to terminals
    • H02K15/0081—Connecting winding sections; Forming leads; Connecting leads to terminals for form-wound windings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/04—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of windings, prior to mounting into machines
    • H02K15/0414—Windings consisting of separate elements, e.g. bars, hairpins, segments, half coils
    • H02K15/0421—Windings consisting of separate elements, e.g. bars, hairpins, segments, half coils consisting of single conductors, e.g. hairpins

Definitions

  • the present invention relates to a method for the material connection, in particular for laser welding, of electrodes, in particular rod-shaped electrodes, also called rod electrodes, and a processing device that is set up to carry out the method.
  • a laser processing system for processing a workpiece using a laser beam
  • the laser beam emerging from a laser beam source or from one end of a laser conducting fiber is focused or bundled onto a workpiece to be processed with the aid of beam guidance and focusing optics in order to locally heat the workpiece to melting temperature.
  • the processing can in particular include laser welding.
  • the laser processing system can include a laser processing device, for example a laser processing head, in particular a laser welding head.
  • a laser beam 10 is directed onto ends 1a, 2a of two adjacent hairpins 1, 2 and driven with a 2D scanner in a circular path (dashed arrow) over both ends 1a, 2a in order to form a common weld pool.
  • insulation material 3 surrounding a lower part of the hairpins for insulation can be melted.
  • the adjacent hairpins 1, 2 are at different heights or z-positions, ie if the distance from the laser processing head is different, the ends 1a, 2a of the two adjacent hairpins are melted unevenly. This can cause spatter and pinholes, resulting in poor electrical connection or high resistance.
  • the 2D scanner required for this is relatively expensive.
  • the present invention is based on the idea of generating a separate weld pool on at least two electrodes to be connected to one another by a so-called twin or multi-spot welding process in which the laser beam is divided into at least two partial beams. These separate weld pools then combine to form a common weld pool, in order to achieve the material connection or the electrical connection to make contact.
  • a laser beam any other high-energy processing beam, such as an electron beam, can also be used.
  • the present invention is described below using the example of welding by means of a laser beam, but is not limited to this.
  • a method for cohesively connecting at least two electrodes using a high-energy processing beam comprises: determining a processing point on each of the electrodes; splitting the processing beam into at least two partial beams; and irradiating the at least two partial beams onto one of the processing points of the at least two electrodes in order to form a common melt pool for welding the electrodes or for establishing an electrical connection between the electrodes.
  • the number of partial beams preferably corresponds to the number of electrodes.
  • a step of detecting the positions of the electrodes can be carried out before the machining points are determined.
  • a processing device for materially connecting two electrodes by means of a high-energy processing beam comprises: a detection unit for determining a processing point on each of the electrodes; and a processing head for radiating at least two partial beams onto one of the processing points, the processing head comprising splitting optics for splitting the processing beam into the at least two partial beams.
  • the splitting optics can also be referred to as multi-spot optics.
  • the processing device can also include a control unit that is set up to carry out a method according to one of the embodiments described in this disclosure.
  • the number of partial beams preferably corresponds to the number of electrodes.
  • the detection unit can also be set up to detect the positions of the electrodes.
  • the method and the processing device can have one or more of the following preferred features.
  • Each of the processing points preferably lies on a surface of the respective electrode.
  • the processing point can be used to designate that point on the respective electrode to which a partial beam (at least temporarily or at the beginning of the irradiation process) is judged.
  • the processing point on each of the electrodes is determined such that the processing point is at the center of a surface of the electrode facing the laser processing device.
  • At least one of the partial beams can be radiated perpendicularly onto the corresponding electrode or onto its surface containing the processing point.
  • the position of each electrode can be sensed to determine the corresponding processing point.
  • the position of the electrode may include a position of the electrode in a plane perpendicular to a laser beam propagating direction, i.e., x- and y-directions.
  • the position of the electrode can be a position of the electrode in a laser beam propagation direction (i.e. in the z-direction) and/or a distance between a surface of the electrode and a laser processing device executing the method, and/or a location or position of the electrode in three-dimensional space encompass space.
  • the positions of the electrodes can be detected by optical coherence tomography and/or by a camera and/or by at least one photodiode.
  • the detection unit can include a scanning device for surface scanning, an optical coherence tomograph or a camera, or can include a photodiode sensor that is sensitive to a wavelength of the laser beam. Detecting the positions of the electrodes can include irradiating the laser beam or the at least two partial beams onto the electrodes along a measurement path and detecting a reflected portion of the irradiated laser beam or the irradiated partial beams, in particular by means of a photodiode. The positions of the electrodes can then be determined based on the detected reflected portion.
  • the laser beam or the at least two partial beams can be radiated onto the electrodes along at least one first measuring path and along at least one second measuring path.
  • the first measurement path can have a predetermined angle to the second measurement path.
  • the positions of the at least two electrodes in a plane perpendicular to the laser beam propagation direction, ie in the x and y plane, can be detected or determined based on the reflected portion of the irradiated laser beam or the irradiated partial beams.
  • the method may further include positioning the electrodes in a positioning device, wherein a reflectivity of the positioning device differs from a reflectivity of the electrodes.
  • the measuring path preferably comprises a first and a second area, which lie on the positioning device, as well as an area on at least one of the electrodes between the first and the second area.
  • the positioning device and the electrodes can be of different chemical material and/or have different surface roughness so that they have different reflectivities.
  • the surface of the positioning device can consist of brushed, sandblasted and/or matt metal, in particular aluminum, and the surface of the electrodes can consist of smooth, shiny or polished metal, in particular copper.
  • a laser power of the irradiated laser beam can be selected that is lower than a laser power for welding the electrodes and/or a speed that is higher than a speed during the formation of melt pools on the electrodes.
  • the laser power or the speed can be selected in such a way that the laser beam is not coupled into the material of the electrodes, but is only reflected.
  • a power density of the laser beam on a surface of the electrodes and/or the positioning device can be selected such that it is below a threshold value at which the laser beam couples into the electrodes or the positioning device.
  • the electrodes can be illuminated to detect the positions.
  • the detection unit can include at least one light source, such as a VCSEL or a laser diode.
  • the VCSEL can emit light at a wavelength of e.g. 680nm, 850nm or 940nm.
  • the laser diode can have a wavelength of 630nm-640nm or 808nm-810nm.
  • At least one of the following parameters can also be detected: a size of the surface on which the processing point lies; a distance between the electrodes (i.e. in a plane perpendicular to the beam propagation direction of the laser beam or the partial beams or perpendicular to an optical axis of the laser processing head or the focusing optics); and a size and/or depth of the separate melt pools and/or the common melt pool.
  • a distance (ie on the electrodes) and/or an angle and/or an intensity distribution between the partial beams can be adjustable, for example depending on a distance between the processing points in a plane perpendicular to the optical axis of the laser beam or the partial beams or to an optical axis Axis of the focusing optics.
  • the intensity of the laser beam can be divided unequally among the partial beams. So if the processing point of one electrode is closer to the laser processing head than the processing point of the other electrode, the intensity of one partial beam that is directed at one electrode can be lower than the intensity of the other partial beam that is directed at the other electrode that is further away is directed, are set the.
  • the intensities of the two partial beams can preferably be changed steplessly in a ratio of 80:20 to 50:50.
  • the distance between the processing points is preferably larger than a focus diameter of at least one of the partial beams or larger than a diameter of at least one of the partial beams on the respective electrode or larger than a narrow side of one of the electrodes.
  • the distance between the processing points can be between 0.3 mm and 3 mm, for example.
  • Each partial beam is therefore preferably directed onto the processing point of one of the electrodes, so that the partial beams or points of impingement of the partial beams on the electrodes are spaced apart or separated from one another.
  • the splitting optics or multi-spot optics can comprise at least one beam-shaping optics, at least one diffractive optical element, at least one free-form optics, at least one wedge plate and/or at least one mirror.
  • the splitting optics can be set up to set a distance and/or an angle and/or an intensity distribution between the partial beams.
  • the splitting optics can be insertable into the beam path of the laser beam and removable from the beam path of the laser beam. In other words, the division of the laser beam into a plurality of partial beams can be switched on and off.
  • the laser processing device can also contain collimation optics for collimating the laser beam and/or focusing optics for focusing the partial beams.
  • the splitting optics can be arranged before or after the focusing optics in the beam propagation direction.
  • the splitting optics can be arranged between the collimating optics and the focusing optics.
  • the collimated laser beam is preferably divided into the partial beams.
  • the partial beams can be focused by common focusing optics or by separate focusing optics. Accordingly, a focal position can be set jointly for the two partial beams or separately for each partial beam.
  • the focus position is preferably set separately for each partial beam.
  • the necessary power density can also be generated at different levels, for example if the electrodes have a different position in the beam propagation direction of the laser beam or the partial beams or along an optical axis of the focusing optics.
  • a focal position of the at least two partial beams and/or at least one partial beam can be adapted to the detected position of the respective electrode or to the position of the respective processing point.
  • the focus of at least one of the partial beams can be at least temporarily on the processing point and/or on the surface of the respective electrode.
  • the focal position of the at least two partial beams or of at least one partial beam is preferably changed during the irradiation of the partial beams, in particular continuously or in steps.
  • at least one of the partial beams can be directed onto the respective electrode in a defocused manner during the irradiation of the partial beams in a first step.
  • the focus position of the at least one partial beam can be adjusted.
  • the focus position of the at least one partial beam can be approached or removed from the processing point on the respective electrode, in particular continuously or step by step.
  • a joint of the electrodes or the separate weld pool or the common weld pool can be modified in such a way that the coupling of the laser beam is improved.
  • the respective electrode surface is heated by the defocused irradiation of the partial beam(s), so that the coupling of the laser beam is also improved for long wavelengths, e.g. in the IR range.
  • the absorption of IR laser radiation by copper in the molten phase is almost identical to that at shorter wavelengths.
  • Each partial beam preferably remains on the respective electrode during irradiation.
  • a first of the two sub-beams preferably remains directed only at a first of the two electrodes, and the second of the two sub-beams only at the second of the two electrodes.
  • a partial beam falls into an intermediate space or gap between the electrodes and heats up insulation or other material there.
  • separate melt pools can be generated as a result. Once the electrode material, eg the copper, has been brought into the molten phase, the separate flow melt pools together to form a common melt pool. As a result, the formation of pores in the materially bonded connection or in the weld seam can be reduced.
  • the partial beams can preferably be deflected on the respective electrode, in particular linearly.
  • the deflection can be parallel to or along an edge or side of the electrode.
  • the partial beams can be moved back and forth on the respective electrode, for example in a direction perpendicular to a straight line connecting the electrodes or parallel to the opposite sides of the electrodes.
  • each sub-beam can be moved back and forth or oscillated along a predetermined path on the corresponding electrode.
  • the oscillating movement or the predetermined path can be linear, circular, zig-zag, wavy, helical, 8-shaped or the like.
  • the partial beams can be deflected by deflecting the laser beam before it is divided into the two partial beams.
  • the partial beams can be deflected after the laser beam has been divided.
  • the laser processing device can comprise a deflection unit for deflecting the laser beam and/or the partial beams.
  • the deflection unit is preferably a linear or ID deflection unit, ie set up for a linear deflection in only one direction.
  • a one-dimensional (ID) deflection unit is significantly less expensive and more compact than a deflection unit that is set up for a 2D deflection or for a deflection in two mutually perpendicular directions.
  • the deflection unit can be arranged between the collimation optics and the splitting optics.
  • the deflection unit can be arranged between the splitting optics and the focusing optics in order to deflect the partial beams directly.
  • the partial beams can be deflected independently of one another.
  • the deflection unit can, for example, be an oscillation module, an ID scanner or a 2D scanner and/or comprise at least one mirror, in particular a galvanometer mirror.
  • the deflection of the partial beams is preferably repeated regularly or periodically.
  • the deflection of the partial beams can be referred to as position modulation of the partial beams.
  • a position modulation amplitude or deflection amplitude and/or a position modulation frequency or deflection frequency and/or a position modulation speed or deflection speed can be set based on at least one of the following parameters: the positions of the electrodes; a size of the surface on which the edit point lies; a gap between the electrodes; a size and/or depth of the separate weld pools and/or the common weld pool; a radiation duration of the partial beams on the electrodes; a wavelength of the laser beam; and a power of the laser beam.
  • the electrodes are preferably arranged in such a way that the processing points or the surfaces of the electrodes which comprise the processing points lie on a plane perpendicular to the beam propagation direction of the laser beam.
  • the electrodes can be arranged parallel or antiparallel to one another.
  • ends of the electrodes can point in the same direction, but in the case of an anti-parallel arrangement, ends of the electrodes can point in opposite directions.
  • Ends of the electrodes are preferably arranged next to and/or adjacent to one another.
  • the partial beams can be radiated onto the ends of the electrodes at the front.
  • a beam propagation direction of the partial beams can be arranged essentially parallel to the longitudinal axis of the electrodes.
  • the electrodes are preferably rod-shaped electrodes.
  • the electrodes can have at least one flat side or plane surface and/or have a rectangular or square cross-section.
  • two flat sides of the electrodes are arranged opposite each other.
  • one end or a cross-section of the electrodes can have a width (or narrow side) of about 1 mm and a length (or long side) of about 5 mm.
  • the electrodes can be made of copper and/or aluminum or contain copper and/or aluminum.
  • the electrodes are or include hairpins or winding segments of a stator coil or a stator winding.
  • the laser beam preferably has wavelengths in the infrared range, for example between 780 nm and 1400 nm, in particular between 1000 nm and 1100 nm. This has the advantage that an inexpensive IR laser source can be used.
  • the laser beam can also have a wavelength in the visible green or blue range, in particular in the range between 400 nm and 450 nm or between 510 nm and 550 nm.
  • An irradiated power of the two partial beams can be modulated or set based on at least one of the following parameters: a position modulation amplitude or deflection amplitude, a position modulation frequency or deflection frequency, a position modulation speed or deflection speed, the positions of the electrodes; a size of the surface on which the edit point lies; a gap between the electrodes; a size and/or depth of the separate weld pools and/or the common weld pool; one Radiation duration of the partial beams on the electrodes; a wavelength of the laser beam; and a power of the laser beam.
  • FIG. 1 schematically shows a conventional scanner laser welding method
  • FIG. 2 schematically shows a processing device according to an embodiment of the present invention
  • FIG. 3 shows a diagram of a method according to an embodiment of the present invention
  • FIG. 4 schematically shows a processing device with an ID scanner according to an embodiment of the present invention.
  • 5A and 5B schematically show alternative arrangements of the two electrodes.
  • FIG. 2 shows a processing device for the integral connection of workpieces with a high-energy processing beam according to an embodiment of the present invention.
  • the invention is explained below using the example of a laser processing device for laser welding of two rod-shaped electrodes, but is not limited to this.
  • the processing device can also use an electron beam for the material connection.
  • the electrodes can have a different shape.
  • the laser processing device comprises a laser processing head 100 for radiating a laser beam 10 onto the workpieces 1, 2.
  • the laser beam 10 generated by a laser source can be coupled into the laser processing head 100 via an optical fiber 11.
  • the laser beam 10 is arranged in the laser processing head 100 splitting optics 50, such as at least one optical wedge plate, at least one diffractive optical element, at least one free form Optics or at least one beam shaping optics, divided into two partial beams 10a, 10b.
  • the splitting optics 50 are preferably arranged in the collimated laser beam 10 so that the splitting into the two partial beams 10a, 10b takes place based on the collimated laser beam 10.
  • the splitting optics 50 can be arranged after a collimation optics 20 of the laser processing head 100 in the laser beam propagation direction.
  • the two partial beams 10a, 10b can then be focused by focusing optics 60 for the machining process or the laser welding.
  • separate focusing optics 60 can be provided for each partial beam 10a, 10b in order to set the focal positions of the two partial beams 10a, 10b independently of one another.
  • the focusing optics 60 can also be arranged in front of the splitting optics 50 in the laser beam propagation direction, so that the splitting into the two partial beams 10a, 10b takes place based on the focused laser beam 10.
  • the laser beam 10 can be divided into two or more partial beams.
  • the number of electrodes is not limited to two, but the method can be used for welding two or more electrodes.
  • the number of partial beams preferably corresponds to the number of electrodes to be welded to one another.
  • the focal position of the two partial beams 10a, 10b is preferably adjustable.
  • the focal position can be adjusted, for example, by moving at least one of the following elements: the optical fiber 11, the collimating optics 20 and the focusing optics 60.
  • the focal positions of the two partial beams 10a, 10b can be set together, i.e. both partial beams 10a, 10b can have the same focal position .
  • the focal positions of the two partial beams 10a, 10b can be set independently of one another, i.e. the focal positions of the two partial beams 10a, 10b can be different. In this way, a different distance between the electrodes and the laser processing head 100 can be compensated for.
  • the laser processing device also includes a detection unit 40 for detecting positions of the two electrodes 1, 2.
  • the detection unit 40 can include, for example, an optical sensor, a photodiode, a camera and/or an optical coherence tomograph.
  • the detection unit 40 can detect the position of the two electrodes 1, 2 in at least one direction perpendicular to the optical axis of the focusing optics 60 or perpendicular to a laser beam propagation direction.
  • the optical axis of the focusing optics 60 or the laser beam propagation direction extends in the z direction.
  • An optical beam The path of the detection unit 40 can be coupled into the laser beam path of the laser processing head 100 via a beam splitter 30, for example.
  • the optical beam path of the detection unit 40 can be arranged outside of the laser processing head 100 and run at least partially inclined or parallel to the laser beam propagation direction.
  • the detection unit 40 can also detect a position of the electrodes 1, 2 along the optical axis of the focusing optics 60 or in the laser beam propagation direction (z-direction). In other words, a distance from each of the electrodes 1, 2 to the laser processing head 100 can be determined, for example in order to set a laser power or a focus position of the partial beams 10a, 10b based thereon.
  • the detection unit 40 can be set up for process observation or monitoring, for example for pre-process or post-process monitoring.
  • an illumination unit (not shown) can also be provided.
  • the lighting unit can be arranged on the detection unit 40 in order to couple light coaxially into the optical beam path of the detection unit.
  • the electrodes are illuminated by the illumination unit independently of or outside of the laser processing head and/or the detection unit.
  • the two partial beams 10a, 10b are each directed onto one of the two rod-shaped electrodes 1, 2.
  • the rod-shaped electrodes 1, 2 can in particular be hairpin electrodes or winding segments of a stator coil for an electric motor.
  • the rod-shaped electrodes 1, 2 can be made of copper and/or aluminum.
  • the rod-shaped electrodes 1, 2 are arranged parallel to one another in FIG. 2, ie the end faces or the ends 1a, 2a of the rod-shaped electrodes 1, 2 point in the same direction.
  • Each rod-shaped electrode is melted separately by the two partial beams 10a, 10b in order to form a separate melt pool on each rod-shaped electrode 1, 2. Due to the high surface tension of the electrode material, in particular copper, the two separate molten pools combine to form a common molten pool above a certain size, without essentially flowing into the gap 30 . In this way, an integral connection or a conductive contact between the rod-shaped electrodes can be produced with little formation of pores and without spatter.
  • the detection unit 40 is set up to determine a respective processing point A, B on each of the electrodes, onto which the respective partial beam 10a, 10b is directed.
  • the processing point A, B can be determined on the respective electrode 1, 2 in such a way that it lies centrally on a surface of the electrode facing the laser processing head 100, in particular an end face.
  • the processing points A and B are determined based on the detected position of the respective electrode 1, 2.
  • the laser processing device also includes a control unit 90 for controlling the laser processing device, ie for controlling at least one of the following components of the laser processing device: the laser processing head 100, a laser source, and the detection unit 40.
  • the control unit 90 and the detection unit 40 can be integrated in one unit or separately be provided.
  • the control unit 90 can receive data from or send data to the laser processing head 100 and the detection unit 40 .
  • the control unit 90 is set up in particular to carry out a method according to embodiments of the present invention.
  • the control unit 90 can exchange data with the detection unit 40 and/or the laser processing head (double arrow).
  • FIG. 3 schematically shows a flowchart of a method for materially connecting or welding two electrodes according to embodiments of the present invention.
  • step S1 the positions of the electrodes 1, 2 are detected and a processing point A, B on each electrode 1, 2 is determined.
  • a laser beam 10 is divided into two partial beams 10a, 10b.
  • step S3 each partial beam 10a, 10b is directed onto the respective processing point A, B of the electrodes 1, 2 in order to form a separate melt pool on each electrode.
  • the separate melt pools then combine to form a common melt pool. After solidification or cooling of the shared melt pool, there is a conductive contact with low resistance between the two electrodes.
  • the detection of the positions of the electrodes 1, 2 in step S1 preferably includes the detection of a lateral position of the two electrodes 1, 2 in at least one direction perpendicular to the optical axis of the focusing optics 60 or perpendicular to a laser beam propagation direction.
  • the position and extent of a surface facing the laser processing head can be determined for each electrode.
  • the examples shown are rod-shaped electrodes with a rectangular cross section.
  • Step S1 can additionally irradiate the laser beam 10 along a measurement path and to detect the positions of the electrodes 1, 2 Detecting a portion of the laser beam reflected by the electrodes.
  • the detection of the positions of the electrodes 1, 2 in step S1 takes place here based on an intensity of the reflected portion of the laser beam detected along the measurement path.
  • the electrodes 1, 2 are arranged in a positioning device.
  • the positioning device has a different reflectivity than the electrodes, so that based on the intensity of the reflected portion it can be distinguished whether the laser beam is on the positioning device or on one of the electrodes.
  • the processing points A, B can be defined on the surface.
  • the processing point A, B is fixed centrally on the surface of the electrode 1, 2 facing the laser processing head 100.
  • detecting the positions of the electrodes 1, 2 in step S1 can include determining a distance from the respective electrode 1, 2 or from the respective processing point A, B.
  • a focal position of at least one of the partial beams 10a, 10b can be set based on the axial positions of the electrodes 1, 2, which can differ from one another.
  • the laser beam 10 or the partial beams 10a, 10b preferably have a wavelength in the infrared range, in particular 1 ⁇ m.
  • IR laser radiation couples less well into reflective materials such as copper or aluminum at room temperature than laser radiation with shorter wavelengths, e.g. in the visible range, they are much cheaper.
  • the absorption of IR laser radiation is comparable to laser radiation with shorter wavelengths.
  • a focal position of at least one of the partial beams 10a, 10b can be changed.
  • the focal position can be moved from a first position, in which the partial beam is defocused on the electrode, to a second position, in which the partial beam is focused on the electrode, ie the focus of the partial beam is on the electrode.
  • the focal position at the first position, ie the defocused focal position can be a focal position between the electrode and the laser processing head, ie above the electrode, or a focal position within the Electrode.
  • the focal position of the partial beams 10a, 10b can be the same and can be adjusted together. For example, a rapid focusing movement can generate the necessary laser power density at different levels in order to increase the surface temperature of the electrodes for better coupling of the laser beam or to compensate for different distances between the electrodes and the laser processing head 100 .
  • step S2 the focus position of at least one of the partial beams 10a, 10b is preferably changed from a position that is focused on the respective electrode to a defocused position. In this way, a surface of the welded connection can be smoothed.
  • FIG. 4 shows a processing device according to a further exemplary embodiment.
  • the processing device of FIG. 4 essentially corresponds to the processing device of FIG. 2, with the exception of the following differences.
  • the laser beam 10 in FIG. 4 is coupled into the processing head 100 from the side.
  • neither the processing head shown in FIG. 2 nor the processing head shown in FIG. 4 are restricted to the respective coupling arrangement of the laser beam 10 .
  • the processing device comprises a deflection unit 70 for deflecting the laser beam 10 so that the partial beams 10a, 10b can be moved back and forth on the electrodes 1, 2 (see arrows in FIG. 4).
  • the deflection unit 70 can include an ID or 2D scanner. As a rule, however, an ID scanner is preferred because it is cheaper and a linear deflection is usually sufficient.
  • the partial beams can be directed onto the respective processing points A, B in step S3 and then linearly deflected around the processing points A, B on the respective electrodes 1, 2.
  • the linear deflection can take place parallel to or along an edge or side, in particular parallel to a longitudinal side or longitudinal axis, of a surface of the electrode 1, 2.
  • the linear deflection preferably takes place parallel to opposite sides or surfaces of the electrodes or perpendicular to an imaginary connecting line between the two electrodes 1, 2.
  • Each of the two rod-shaped electrodes preferably has at least one flat or level side on which the two electrodes 1, 2 opposite.
  • the deflection unit 70 can be arranged in front of the focusing optics 60 or in front of the splitting optics 50 in the laser beam propagation direction. In particular, as in FIG. 4 , the deflection unit 70 can be arranged between the collimation optics 20 and the splitting optics 50 in order to deflect the laser beam 10 . In this case, the partial beams are deflected synchronously or parallel to one another on the respective electrodes 1, 2.
  • the deflection unit 70 can also be arranged after the splitting optics 50 in the laser beam propagation direction, in particular between the splitting optics 50 and the focusing optics 60 .
  • the deflection unit 70 can be set up to deflect the two partial beams 10a, 10b independently of one another.
  • the two rod-shaped electrodes 1, 2 are preferably arranged, as shown in FIGS.
  • the partial beams 10a, 10b are directed onto the electrodes 1, 2 at the front.
  • the partial beams 10a, 10b can be radiated onto an end face or end face of the electrodes 1, 2.
  • the longitudinal axes of the two rod-shaped electrodes 1, 2 can also be aligned perpendicularly to the laser beam propagation direction or to the optical axis of the focusing optics 60.
  • the processing points A, B can be set on side faces of the rod-shaped electrodes, not on the end faces.
  • the rod-shaped electrodes 1, 2 are aligned parallel to one another, so that their ends 1a, 2a point in the same direction.
  • FIG. 5A shows an antiparallel arrangement of the electrodes, in which the ends 1a, 2a point in opposite directions.
  • the bar-shaped electrodes 1, 2 are arranged parallel to each other, but the processing points A, B are on side faces of the bar-shaped electrodes 1, 2.
  • a partial beam of a machining beam is irradiated separately on each electrode.
  • This allows a separate weld pool to be formed on each electrode. Due to the surface tension, the molten pools can combine to form a common molten pool and thus create a welded connection or weld seam. In this way spatter formation can be avoided and a pore-free welded connection with low contact resistance between the electrodes can be produced.
  • the inventive Methods are provided inexpensively.
  • a deflection unit or at least a 2D scanner can be dispensed with.
  • An IR laser source can also be used.

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Power Engineering (AREA)
  • Laser Beam Processing (AREA)

Abstract

L'invention concerne un procédé de soudage de deux électrodes en forme de barre au moyen d'un faisceau laser, comprenant : la détection des positions des électrodes en forme de barre et la détermination d'un point de traitement sur chacune des électrodes en forme de barre; la séparation du faisceau laser en deux faisceaux partiels; et l'émission des deux faisceaux partiels respectivement sur l'un des points de traitement des deux électrodes en forme de barre et la formation d'un bain de fusion commun pour souder les électrodes en forme de barre.
PCT/EP2021/070258 2020-08-05 2021-07-20 Procédé de soudage laser d'électrodes WO2022028879A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102020120643.7A DE102020120643A1 (de) 2020-08-05 2020-08-05 Verfahren zum Laserschweißen von Elektroden
DE102020120643.7 2020-08-05

Publications (1)

Publication Number Publication Date
WO2022028879A1 true WO2022028879A1 (fr) 2022-02-10

Family

ID=77071573

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2021/070258 WO2022028879A1 (fr) 2020-08-05 2021-07-20 Procédé de soudage laser d'électrodes

Country Status (2)

Country Link
DE (1) DE102020120643A1 (fr)
WO (1) WO2022028879A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022125492A1 (de) 2022-10-04 2024-04-04 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Verfahren zur Herstellung einer Statoranordnung

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022109740A1 (de) 2022-04-22 2023-10-26 Lessmüller Lasertechnik GmbH Verfahren und Vorrichtung zur Durchführung optischer Kohärenzmessungen für eine Überwachung eines Bearbeitungsprozesses eines Werkstücks

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110814519A (zh) * 2019-10-18 2020-02-21 西安交通大学 基于超声波驻场防止熔池下榻的发卡式接头焊缝控形系统
US10717153B2 (en) * 2016-08-02 2020-07-21 Toyota Jidosha Kabushiki Kaisha Laser welding method for flat wires

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITBO20150187A1 (it) 2015-04-16 2016-10-16 Magneti Marelli Spa Metodo di saldatura laser tra due elementi metallici adiacenti di un avvolgimento statorico con barre rigide per una macchina elettrica

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10717153B2 (en) * 2016-08-02 2020-07-21 Toyota Jidosha Kabushiki Kaisha Laser welding method for flat wires
CN110814519A (zh) * 2019-10-18 2020-02-21 西安交通大学 基于超声波驻场防止熔池下榻的发卡式接头焊缝控形系统

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TRUMPFTUBE: "TRUMPF Lasersystems: Paint stripping and welding of hairpins with TruLaser Cell 3000 and VisionLine", 16 October 2018 (2018-10-16), XP055862719, Retrieved from the Internet <URL:https://www.youtube.com/watch?v=xwtlLkxYei4> *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022125492A1 (de) 2022-10-04 2024-04-04 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Verfahren zur Herstellung einer Statoranordnung

Also Published As

Publication number Publication date
DE102020120643A1 (de) 2022-02-10

Similar Documents

Publication Publication Date Title
DE60131935T2 (de) Ein Laserstrahlbearbeitungskopf und eine Laserbearbeitungsvorrichtung mit einem solchen Laserstrahlbearbeitungskopf
DE4429913C1 (de) Vorrichtung und Verfahren zum Plattieren
EP0313594B1 (fr) Dispositif et procede d&#39;assemblage par rayonnement laser
WO2022028879A1 (fr) Procédé de soudage laser d&#39;électrodes
DE102015104411B4 (de) Laserstrahlfügeverfahren und Laserbearbeitungsoptik
EP0835715A1 (fr) Dispositif et procédé de traitement d&#39;une pièce avec un laser à diode
DE3427611A1 (de) Laserstrahl-lithograph
DE102007020748A1 (de) Vorrichtung und Verfahren zum Bearbeiten einer Oberfläche eines Werkstücks mittels Laserstrahlung
WO2013110467A1 (fr) Tête d&#39;usinage au laser pourvue d&#39;une commande de mise au point
DE112006000949T5 (de) Laserschweisssystem
DE10113471B4 (de) Verfahren zum Hybridschweißen mittels eines Laserdoppelfokus
DE102016201418A1 (de) Vorrichtung und Verfahren zur thermischen Bearbeitung
DE19846532C1 (de) Einrichtung zur Strahlformung eines Laserstrahls und Hochleistungs-Diodenlaser mit einer solchen Einrichtung
WO2019233944A1 (fr) Dispositif de traitement au laser de pièces difficilement accessibles
DE102008063614B4 (de) Laser-Lichtbogen-Hybrid-Schweißkopf
DE10037109C2 (de) Verfahren und Vorrichtung zur Schweißnahtglättung beim Strahlschweißen
DE3626944A1 (de) Verfahren und vorrichtung zum fokussieren und steuern einer hochleistungsenergiequelle
DE102021103206A1 (de) Verfahren zum Optimieren einer Bearbeitungszeit eines Laserbearbeitungsprozesses, Verfahren zum Durchführen eines Laserbearbeitungsprozesses an einem Werkstück und Laserbearbeitungssystem, welches eingerichtet ist, um diese durchzuführen
DE4339661C2 (de) Verfahren zum Herstellen von röhrenförmigen Rohlingen aus Fein- oder Feinstblech
DE112017003592T5 (de) Materialbearbeitung unter Verwendung eines Lasers mit variabler Strahlform
WO2022029073A1 (fr) Procédé de détermination d&#39;une position d&#39;une pièce pour un processus d&#39;usinage laser et système d&#39;usinage laser
DE102004050819B4 (de) Verfahren und Vorrichtung zum Laserstrahlbearbeiten
JP7326617B2 (ja) バスバーおよびバスバーの製造方法
EP3247528B1 (fr) Tête d&#39;usinage servant à l&#39;usinage de matériaux, munie d&#39;une unité d&#39;éclairage comprenant plusieurs sources lumineuses et éléments de renvoi
DE102021103881A1 (de) Verfahren und Laserbearbeitungssystem zum Analysieren einer durch einen Laserschweißprozess ausgebildeten Schweißnaht

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21746479

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21746479

Country of ref document: EP

Kind code of ref document: A1