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
  • B23K11/00—Resistance welding; Severing by resistance heating
  • B23K11/002—Resistance welding; Severing by resistance heating specially adapted for particular articles or work
• • 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
  • B23K11/00—Resistance welding; Severing by resistance heating
  • B23K11/10—Spot welding; Stitch welding
  • B23K11/11—Spot welding
  • B23K11/115—Spot welding by means of two electrodes placed opposite one another on both sides of the welded parts
• • 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
  • B23K11/00—Resistance welding; Severing by resistance heating
  • B23K11/16—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded
• • 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
  • B23K11/00—Resistance welding; Severing by resistance heating
  • B23K11/34—Preliminary treatment

Definitions

• the invention relates to a method for resistance welding a sandwich panel with at least one further component, wherein the sandwich sheet has two metallic cover layers and a thermoplastic layer disposed between the metallic cover layers, wherein the welded portion of the sandwich sheet is heated so that the thermoplastic resin layer softens and through Compressing the cover layers is displaced from the welding area and the cover layers with the further component by an electric current flow for welding in a first power source having a first circuit via a first, arranged on the side of the sandwich sheet welding electrode and a second, on the side of the further component arranged welding electrode are welded together.
• the invention relates to a device for resistance welding of a sandwich sheet, which has a thermoplastic plastic layer arranged between metallic cover layers, with at least one further component, with a first, on the side of the
• Sandwich plate arranged weld electrode, with a second, can be arranged on the side of the further component welding electrode, with means for providing a first power source having a first circuit, which conduct a current flow for welding at least over the first and the second welding electrode, and means for displacement of the thermoplastic layer of the sandwich sheet from the welded area of the sandwich sheet.
• Sandwich panels have a thermoplastic layer between two metallic thin cover layers.
• sandwich panels can provide different, often-exclusive properties that open up new weight-saving potential. So have sandwich panels due to the Plastic layer significantly lower weight than solid sheets and at the same time provide high strength values.
• the Plastic layer significantly lower weight than solid sheets and at the same time provide high strength values.
• sandwich panels is that they have an electrically insulating layer, which in welding process problems in terms of training a
• sandwich panels are therefore often glued or mechanically joined together.
• Sandwich panel with a further component in which the intermediate layer is melted in the connection region and displaced from the connection region, so that subsequently by establishing an electrical contact between the component and the cover layers of the sandwich sheet a
• Welded connection can be generated. It is proposed to carry out the heating of the joining regions by means of temperature-controllable electrodes or pressing elements.
• the welding electrodes or pressing elements are provided for this purpose, for example, with heating elements. Due to the necessary modifications to the welding electrode, the structure of the welding electrodes thus becomes relatively complex. In addition, the speed of heating the thermoplastic resin layer is in need of improvement, so that shorter cycle times can be achieved. From US Patent US 4,650,951 is also a method for
• Welding electrodes are used, which are heated and so heat and displace the plastic layer lying between the cover layers before the actual
• Plastic layer in need of improvement to achieve shorter cycle times.
• Welding electrode and the sandwich sheet arranged electrical conductor and a second power source comprises.
• heating of the area to be welded can be effected without further modification merely by activating or deactivating the second current source, which is of the first power source is different can be achieved.
• the second current source which is of the first power source is different
• Welding electrode and the sandwich sheet arranged electrical conductor achieved an efficient heating of the area to be welded, for example by a correspondingly designed, specific electrical resistance of the electrical conductor. As a result, therefore, a method is provided which allows a simple operation and also can achieve short cycle times.
• the further component can be, for example, a metal solid sheet, for example a steel sheet. In principle, however, it is also possible for the other component to be integrated as well Sandwich sheet is. Also, other components may be provided, which are welded, such as an arranged between the sandwich plate and the further metallic component in particular additional metallic component.
• the first and / or the second current source may be, for example, DC or preferably AC sources. In this case, the dedicated current sources of the first and the second circuit can be designed as needed and independently of each other.
• the first circuit preferably comprises, in particular, the first current source, the first welding electrode, the second welding electrode, first electrical lines connected to the first and the second welding electrodes, the sandwich panel and the further component.
• the second circuit preferably comprises, in particular, the second current source, the electrical conductor and second electrical lines connected to the electrical conductor.
• the second circuit preferably does not comprise the sandwich panel, the further component, the first welding electrode and / or the second welding electrode. If according to an embodiment of the method according to the invention, the second current source is first activated, so that the current flow for preheating in the second circuit, and then the first current source is activated, so that the current flow for welding in the first circuit, an unnecessarily early activation of the first Power sources avoided and the first power source is activated only when needed. This will cause unwanted interactions between the
• the first current source is activated with or after the deactivation of the second current source.
• the first current source is already activated before the deactivation of the second current source.
• Power sources for example, by a controller, which includes, for example, a trigger circuit.
• a trigger circuit is a sufficient, for example, complete displacement of the thermoplastic layer from the welding area, the triggering event, whereby a switching pulse or a switching edge for the first and / or second power source is generated.
• thermoplastic layer can begin from the welding area.
• Welding range representative measured value for example, can be concluded continuously on the progress of the displacement. It is also possible to select a measurement value representative of the displacement of the thermoplastic polymer layer from the welding region, from which only individual discrete information about the progress of the displacement can be deduced, for example whether the displacement has already been completed or not. For example, the representative measured value can be compared with a reference value.
• the measured value representative of the displacement of the thermoplastic polymer layer from the welding region is based on an electrical property of at least the
• Sandwich plate In this way, a contact of the metallic cover layers of the sandwich sheet in the area to be welded can be determined in a simple and reliable manner. For example, a measurement of the representative for the displacement of the thermoplastic resin layer from the welding area is carried out
• the cover layers of the sandwich panel Compression of the cover layers of the sandwich panel.
• an electrical resistance measurement takes place, so that for the displacement of the thermoplastic layer from the welding area representative measured value is an electrical resistance value and the electrical resistance between the cover layers of the sandwich sheet comprises.
• the electrical resistance can be measured, for example, between the first and the second welding electrode. If the cover layers have metallic contact, the resistance decreases at any rate locally abruptly, so that a sufficient displacement of the
• thermoplastic material can be closed from the area to be welded.
• a resistance value can be selected, which is measured between the welding electrodes in direct contact of the cover layers
• the measured value representative of the displacement of the thermoplastic polymer layer from the welding region is based on a position of a welding electrode, preferably of the first welding electrode. If the position of the welding electrode detected anyway, can be easily determined automatically when a sufficient amount of the thermoplastic polymer layer from the welding region.
• Displacement of the thermoplastic layer from the welding area is done without, for example, a resistance measurement needs to be performed.
• a resistance measurement needs to be performed.
• thermoplastic layer that is, the welding electrode has moved by the thickness of the thermoplastic layer, can on a
• thermoplastic resin layer As a reference value can serve the thickness of the thermoplastic resin layer.
• a conductor strip is used as the electrical conductor disposed between the first welding electrode and the sandwich plate.
• a conductor band or contacting band can simply be guided around or surround the first welding electrode, so that the contact region of the welding electrode, which
• the conductor strip normally would contact the sandwich sheet to be welded, such as for example, the electrode cap, is covered by the conductor strip at least partially.
• the conductor strip is arranged with a band holder between the first welding electrode and the sandwich sheet.
• the conductor strip can be particularly compact and reliable between the first welding electrode and the
• the tape holder may be formed so that the conductor strip can be moved to the renewal with respect to the first welding electrode. This allows different points of the conductor strip between the first welding electrode and the sandwich sheet, so that a change in the
• the tape holder can be mounted, for example, on the welding tongs or integrated into the welding tongs.
• the electrical conductor arranged between the first welding electrode and the sandwich sheet contacts the first welding electrode and / or the sandwich sheet directly.
• the electrical conductor has a first region with a first specific electrical resistance and a second region with a second specific electrical resistance, which is greater than the first specific electrical resistance, for heating the region of the sandwich sheet to be welded ,
• the second area there is the first area of copper or a copper alloy.
• the second region consists of tungsten or a tungsten alloy. While the preheating flow through the copper or copper alloy in the first area is less
• Heat is conducted can be carried out by the tungsten or the tungsten alloy in the second region efficient heat development.
• the preheating current can pass over the first to the second region.
• the conductor in particular the conductor strip, at least partially be formed two- or multi-layered, for example with one of the first welding electrode and a sandwich sheet facing layer.
• the layer facing the sandwich sheet at least partially corresponds to the first area with the first specific electrical resistance.
• the layer facing the first welding electrode at least partially corresponds to the second region with the second specific electrical resistance.
• the second region is arranged in the contact region of the first welding electrode with the sandwich metal sheet, the proximity of the second region to the latter can be achieved
• the electrical conductor has an area for insulation, in particular for insulation of the first one
• Area opposite to the first welding electrode can be undesirable
• Branch currents, in particular via the first welding electrode can be avoided.
• the area for isolation may consist, for example, of electrically insulating material. Alternatively or additionally, an area for isolation at the first welding electrode
• Welding electrode or be provided on the tape holder can be provided on the tape holder.
• the object mentioned is achieved in that a second circuit is provided, wherein the second circuit comprises an arranged between the first welding electrode and the sandwich sheet electrical conductor and a second power source.
• Power source can be enabled. Neither extensive modifications to the welding electrode nor provision of additional conductors on the sandwich panel or the second welding electrode are necessary. At the same time, efficient heating of the area to be welded is achieved by the electrical conductor arranged between the first welding electrode and the sandwich panel. As a result, therefore, a device is provided which allows a simple operation and also can achieve short cycle times.
• the device may be particularly suitable for carrying out the method.
• a controller is provided, which is coupled to the first and the second current source and configured such that first the second current source is activated, so that the current flow for preheating in the second circuit takes place, and then the first current source is activated, so that the current flow for welding takes place in the first circuit. This will be an unnecessarily early activation of the first
• the controller is set up for activating the first current source and / or
• thermoplastic plastic layer from the welding area representative To take into account the measured value. This allows a precise and needs-based
• the electrical conductor arranged between the first welding electrode and the sandwich panel is a conductor band. This can simply be led around or surround the first welding electrode, so that the contact region of the welding electrode is at least partially covered by the conductor strip.
• a method for resistance welding of a sandwich sheet is disclosed with at least one further component, wherein the sandwich sheet has two metallic cover layers and a thermoplastic layer disposed between the metallic cover layers, wherein the welded portion of the sandwich sheet is heated so that the thermoplastic
• Softened plastic layer and is displaced by compression of the outer layers of the welding area and the outer layers with the other component by an electric current flow for welding in a first current source having first circuit via a first, arranged on the side of the sandwich sheet welding electrode and a second, on the Side of the further component arranged welding electrode are welded together, wherein the welded area of the sandwich sheet by a current flow for preheating in a second circuit is heated, wherein the second circuit comprises an arranged between the first welding electrode and the sandwich sheet electrical conductor.
• a device for resistance welding of a sandwich panel which has a thermoplastic plastic layer disposed between metallic cover layers, disclosed with at least one further component, with a first, arranged on the side of the sandwich sheet welding electrode and a second, which can be arranged on the side of the other component welding electrode , comprising means for providing a first current source having a first
• Sandwich panel a second circuit is provided, wherein the second circuit comprises an arranged between the first welding electrode and the sandwich sheet electrical conductor.
• the first and the second circuit can have a common current source.
• the second circuit may have, for example, the first current source, the electrical conductor, the first welding electrode and second electrical lines connected to the electrical conductor.
• Embodiments of the method and the device can be as described above.
• a conductor strip may be used as the electrical conductor disposed between the first welding electrode and the sandwich panel.
• the electrical conductor may have a first region having a first electrical resistivity and a second region having a second electrical resistivity which is greater than the first specific electrical resistance for heating the region to be welded
• Fig. La, b is a schematic representation of a first embodiment of a device according to the invention for carrying out a first
• FIG. 2 is a schematic representation of the embodiment of FIG. 1
• FIG. 3 is a schematic representation of the embodiment of FIG. 1
• Fig. 6 is a schematic representation of another device for
• Fig. La shows a schematic representation of a first embodiment of a device 1 according to the invention for carrying out a first embodiment of a method according to the invention during the preheating.
• the device 1 is used for resistance welding of a sandwich panel 2 with at least one further, for example, metallic component 4.
• the sandwich panel 2 has a thermoplastic arranged between metallic cover layers 2a, 2b
• the device has a first, on the side of the Sandwich plate 2 arranged welding electrode 6 and a second, arranged on the side of the further metallic component 3 welding electrode 8.
• 12 means for providing a first circuit are provided with the first power source 10 and the first electrical lines. This allows a current flow to the welding I s are guided via the first and the second welding electrode 6, 8 (shown in Fig. 2).
• the first welding electrode 6 serves as a means for displacing the first welding electrode 6
• Applying force such as a welding gun, be provided (not shown).
• a second electric circuit which comprises an electrical conductor 14 arranged between the first welding electrode 6 and the sandwich panel 2, a second current source 16 and second electrical lines 18.
• the arranged as between the first welding electrode 6 and the sandwich panel 2 electrical conductor 14 is formed as a conductor strip and by means of a
• the electrical conductor strip 14 contacts the first welding electrode 6 and the sandwich sheet 2 directly.
• the electrical conductor strip 14 has a first region 14a with a first electrical resistivity and a second region 14b with a second electrical resistivity for heating the region of the sandwich sheet 2 to be welded.
• the first region 14a is made of copper, for example, and the second region 14b of tungsten. As a result, the second specific electrical resistance is greater than the first specific electrical resistance.
• the electrical conductor strip 14 has a region 14c for insulating the first region 14a with respect to the welding electrode 6.
• FIG. 1b shows an enlargement of the conductor strip 14 in the region of the contact with the first welding electrode 6.
• the region of the sandwich sheet to be welded can be welded 2 be heated particularly efficiently, so that the thermoplastic resin layer 2c softens quickly and is displaced from the welding area by compressing the cover layers 2a, 2b. This is done by a current flow for preheating I v in the second circuit, which is shown in Fig. La by the arrows. The electrical energy is thereby converted into heat by the electrical resistance of the second region 14b and the contact resistance between the first region 14a and the second region 14b.
• a controller 20 which comprises a trigger circuit and is coupled to the first and the second current source 10, 16.
• the controller is set up such that initially the second current source 16 is activated so that the current flow for preheating I v takes place in the second circuit.
• thermoplastic resin layer 2c is softened and displaced, so that the cover layers 2a, 2b have metallic contact, is determined by the consideration of a measurement value representative thereof. This may, for example, a decrease in the electrical resistance between the welding electrodes 6, 8 or one of the thickness of the thermoplastic resin layer 2c corresponding to the first
• Welding electrode 6 be covered path.
• Fig. 2 shows a schematic representation of the embodiment of Fig. 1 during welding.
• the controller 20 the second power source 16 has been deactivated and the first power source 10 is activated.
• the welding current I s flows in the first circuit via the electrical leads 12, the first and second welding electrode 6, 8, the further component 4 and the sandwich sheet 2.
• the cover layers 2a, 2b become thereby welded to the further component 4 by the electric current flow for welding I s .
• Fig. 3 shows a schematic representation of the embodiment of Fig. 1 during a Mehrticianwiderstandssch spaens. In contrast to the case shown in FIGS. 1 and 2, a welded connection 24 has already taken place in FIG. 3.
• FIG. 4a shows a schematic representation of a second exemplary embodiment of a device according to the invention for carrying out an exemplary embodiment of a method according to the invention during preheating.
• the device and the method performed therewith are similar to the device 1 and the method performed therewith. In this respect, reference is first made to the description of FIGS. 1 to 3.
• the device 1 'in turn has an electrical conductor 14', which is formed as a conductor strip and by means of the band holder 22 'between the first welding electrode 6 and the sandwich plate 2 this is arranged directly contacting.
• the electrical conductor strip 14 'in turn has a first region 14a', a second region 14b 'with a higher electrical resistivity for heating the region to be welded, and a region 14c' for insulating the first region 14a 'from the welding electrode 6.
• the regions of the electrical conductor strip 14 'of the device 1' are arranged differently. In the contact area of the electrical
• Conductor 14 'with the sandwich sheet 2 only the second region 14 b' is arranged with the higher electrical resistivity, which in contact with the first welding electrode 6 and the sandwich sheet 2 is. This is followed on each side by the first region 14a '.
• the insulating region 14c ' prevents direct electrical contact between the first region 14a' and the first welding electrode 6.
• the conductor strip 14 ' has no insulating region in the region of the band holder 22' 14c 'on, since the tape holder 22' already has a region 26 for insulating the welding electrode 6 relative to the electrical conductor strip 14 '.
• the second region 14b 'in the contact region of the first welding electrode 6 with the sandwich sheet 2 can be heated particularly efficiently, so that the thermoplastic resin layer 2c quickly softens and passes through
• Compressing the cover layers 2a, 2b is displaced from the welding area. This is done by a current flow for preheating I v in the second circuit, which is shown by the arrows in Fig. 4a.
• Fig. 6 shows a schematic representation of a further device 1 "to
• the device 1 is constructed similarly to the device 1 'and the same electrical conductor strip 14' is used
• the device 1 “does not have a second current source, but rather the preheating current I v is also provided by the first current source 10.
• an electrical bridge 28 is provided which underlies the first current source 10 Bridging the second welding electrode 8, the other component 4 and the sandwich sheet 2 via the tape holder 22 "with the conductor strip 14 'connects.
• the second preheating circuit comprises the first current source 10, a portion of the first electrical leads 12, the first Welding electrode 6, the electrical conductor strip 14 'and the electrical bridge 28. The preheating current can then flow as shown by the arrows in Fig. 6.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Resistance Welding (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=54542262

Family Applications (1)

Country Status (7)

Families Citing this family (2)

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• 2015
  • 2015-01-21 DE DE102015100849.1A patent/DE102015100849B4/de not_active Expired - Fee Related
  • 2015-11-13 KR KR1020177023098A patent/KR101948461B1/ko active IP Right Grant
  • 2015-11-13 CN CN201580074197.6A patent/CN107206538B/zh not_active Expired - Fee Related
  • 2015-11-13 JP JP2017538197A patent/JP6383499B2/ja not_active Expired - Fee Related
  • 2015-11-13 WO PCT/EP2015/076542 patent/WO2016116188A1/de active Application Filing
  • 2015-11-13 EP EP15794565.0A patent/EP3247526A1/de not_active Withdrawn
  • 2015-11-13 US US15/544,283 patent/US20180009057A1/en not_active Abandoned

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