EP2155449A1 - Procédé et dispositif pour affaiblir une pièce - Google Patents

Procédé et dispositif pour affaiblir une pièce

Info

Publication number
EP2155449A1
EP2155449A1 EP08736304A EP08736304A EP2155449A1 EP 2155449 A1 EP2155449 A1 EP 2155449A1 EP 08736304 A EP08736304 A EP 08736304A EP 08736304 A EP08736304 A EP 08736304A EP 2155449 A1 EP2155449 A1 EP 2155449A1
Authority
EP
European Patent Office
Prior art keywords
tool
workpiece
force
weakening
support
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.)
Withdrawn
Application number
EP08736304A
Other languages
German (de)
English (en)
Inventor
Thorsten SCHÜPPSTUHL
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.)
KraussMaffei Technologies GmbH
Original Assignee
KraussMaffei Technologies GmbH
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
Priority claimed from DE200710024318 external-priority patent/DE102007024318B4/de
Application filed by KraussMaffei Technologies GmbH filed Critical KraussMaffei Technologies GmbH
Publication of EP2155449A1 publication Critical patent/EP2155449A1/fr
Withdrawn legal-status Critical Current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
    • B26D3/00—Cutting work characterised by the nature of the cut made; Apparatus therefor
    • B26D3/08—Making a superficial cut in the surface of the work without removal of material, e.g. scoring, incising
    • 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
    • B26D5/00—Arrangements for operating and controlling machines or devices for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting

Definitions

  • the present invention relates to a method and a device for weakening a workpiece with a tool according to the preambles of claims 1, 3 and 8.
  • weakening cuts For certain applications, it is necessary to bring in workpieces, for example in flat elements, weakening cuts. These can for example define a predetermined breaking point.
  • One area of application is given in the manufacture of dashboards with an integrated airbag in the automotive sector. When the airbag is triggered, the instrument panel is broken at the points of weakness, so that the airbag can escape.
  • the terms used in the present application such as workpiece, film, skin, etc. are usually free-form 3D workpieces to understand in which the goal is to cut the material on one side so that with a defined residual wall thickness regardless of possibly locally fluctuating Total wall thicknesses and tolerances a predetermined weakening arises. On the other side of the product, this weakening of the material must generally not be recognizable.
  • weakening cuts in automobile dashboards with integrated airbags which are to be regarded as safety components, a high accuracy of the cut or the residual wall thickness of significant importance to ensure the safe operation of the airbag.
  • a known device for introducing such weakening cuts can be found, for example, in DE 10 2006 034 287. Therein a device is described in which a workpiece is cut along a predetermined line with a cutting device, for example a cutting knife. In this case, the workpiece is supported against a support table or a support. The weakening will achieved in particular by the relative movement of the cutting blade and the defined spacing of the tip of the cutting blade to the support table or support.
  • a device is provided in DE 10 2006 034 287 with which the distance between the cutting blade and the support in the direction of the cutting axis can be formed constant.
  • the distance to be set between the tool tip and the support is currently determined by tests until the desired result is obtained.
  • the specified in DE 10 2006 034 287 setting the distance of the tool tip and counter bearing compression effects neither detect nor compensate.
  • the compression of an elastic workpiece depends on the total material thickness and the material properties, such as the material hardness, and in particular on any tool wear.
  • Object of the present invention is to provide a device mentioned above or a method mentioned, in which the desired weakening or a predetermined residual wall thickness can be accurately manufactured or safely monitored.
  • the invention is based on the finding that the fluctuations in material thickness, material properties or increasing tool wear have a direct effect on the forces occurring between the tool and the workpiece.
  • the workpiece is more or less compressed under the tool and forms depending on a certain residual wall thickness.
  • the above influencing variables can be kept almost constant with the exception of tool wear.
  • the forces and the resulting residual wall thickness change significantly under otherwise unchanged conditions. This is apparent from Figure 5, in which the difference in the force acting between the tool and the workpiece, with a new tool on the one hand and an old tool on the other hand, can be seen.
  • the force of a new tool in this example is in the range of 1, 5 to 2 N.
  • the force in an old tool is more than twice as high as the force of the new tool and moves between 4 and 5.5 N.
  • An idea of the present invention is therefore to be seen in that by the integration of a force or pressure sensor for continuous or discrete detection of the acting process forces between the tool and the workpiece or the tool and the anvil a statement about a change in the material thickness, the material properties and / or a tool wear can be made.
  • the force with which the tool presses against the workpiece is determined.
  • This force is compared with a predetermined force, and on this basis information can be generated which indicates whether the force thus determined is within predetermined limits of a predetermined force value. From this statement one can usually deduce whether the process step currently being performed is in order or if there is a fault or an abnormality.
  • the information obtained can be made visible to an operator, for example, so that the operating personnel can check this information.
  • the pressure or force sensor for a tactile measurement of the residual wall thickness produced.
  • the tool can be pulled in the axial direction, and indeed so far until just no axial force acts on the tool and the workpiece is no longer elastically deformed by the tool.
  • the distance between the support and the tool tip is increased up to this point.
  • a distance of the tool tip to the support has now been reached, which indicates the actual residual wall thickness (distance: support to tool tip).
  • All of these procedural positions may also be captured or stored via motion documentation of the robot as well as other active motion elements and retrieved on both the tool side and the counterpart side.
  • forces or pressures can be measured. Overall, it is only necessary to know the process forces between the tool and the workpiece or on the tool. Moreover, in determining the process forces or pressures, as a rule, measurement is made in the direction of the cutting axis. However, it is also possible to measure the force on the tool during the process of workpiece and tool parallel to the direction of travel. This allows conclusions about the state of wear of the tool, especially in comparison with earlier data, to be drawn directly via the blade geometry.
  • FIG. 1 shows a schematic representation of a cutting tool according to the invention according to a first embodiment
  • Figure 2 is a schematic detail view of a cutting tool according to the
  • FIG. 3 shows a schematic representation of a tool penetrating into an inflexible workpiece
  • 4 shows a schematic representation of a tool penetrating into a flexible workpiece
  • FIG. 3 shows a schematic representation of a tool penetrating into an inflexible workpiece
  • Figure 5 is a graph showing the difference in force between a partially worn and a new tool with respect to the force on the workpiece
  • Figure 6 is a schematic representation of the immersion of a tool in a
  • FIG. 7 is a graph showing the force variation over the path
  • Figure 8 is a schematic representation of the immersion of a tool in a
  • FIG. 9 is another graph showing the force relationships with respect to immersion in a tool.
  • Figure 10 is a schematic representation of a second embodiment of a cutting tool according to the invention according to the present invention.
  • Fig. 11 is a schematic representation of a third embodiment of a cutting tool according to the invention according to the present invention.
  • FIG. 1 shows a schematic representation of a cutting tool 10 for weakening plastic skins and similar flat workpieces shown schematically.
  • the cutting tool 10 in this embodiment comprises a U-shaped bracket 12 which is open at its right side.
  • a cutting blade 20 is arranged, which is aligned in the direction of a cutting axis 22.
  • the load cell can be installed between the knife and bracket. In that case, the force acting on the workpiece can be determined directly. In this case, the counter-holder 16 can move relative to the load cell in the cutting axis direction.
  • the bracket 12 has in the left area a Abstützlasche, which is connected via a coil spring 26 with a support block 28.
  • the bracket 12 can move as spring loaded relative to the support block 28.
  • the inherent elasticity of the workpiece can be used for tolerance compensation for the tool movement.
  • a workpiece 32 to be weakened is arranged on a support table 30, which rests on its underside on the roll 18 capable of rolling. About the axially biased displacement unit (24,26,28) of the tool will ensure that the ball is continuously applied to the support table.
  • the support table has a thickness which is designated by the reference numeral 36.
  • the residual wall thickness of the material after the weakening step results from the total distance of the tool tip from the upper end of the ball 18 minus the constant or path-dependent known support table thickness.
  • the force can be determined and transmitted to an evaluation or control and control unit.
  • the load cell determines the force with which the cutting blade 20 presses on the workpiece. This force depends on the material thickness, the material properties, the process parameters but also the state of wear of the tool.
  • Figure 2 a device of the prior art is shown in sections, wherein now an active adjustment of the cutting blade 20 'relative to the support table 30' by means of a motor drive is possible. This adjustment is achieved by means of the electric drive motor 25, which acts on an adjusting spindle 27.
  • the cutting tool 10 'thus illustrated can be accurately adjusted with respect to the distance of the tip of the tool 20' from the support table 30 '(reference numeral 37) or the depth of cut (reference numeral 39), wherein the total material thickness is defined by the reference numeral 40.
  • this adjustment as was made clear at the beginning, only with relatively hard and inflexible or inelastic materials readily possible.
  • this embodiment can be modified by installing a force measuring device in the region between the cutting blade tip and the holder (not shown).
  • the tip of the tool 50 is set at a distance s1 to the abutment 56.
  • a force between the tool 50 and the workpiece 54 ' acts by the compression of the workpiece, a force between the tool 50 and the workpiece 54 ', which also transmits to the support 56 and can be determined by the force sensor 58.
  • the relative cutting movement between workpiece 54 'and tool 50 is terminated first.
  • the tool 50 is pulled out of the workpiece by a distance ds1 until the force sensor 58 does not undergo any further force change upon further withdrawal of the tool from the workpiece can determine. If the force value no longer changes as the tool is pulled out further, this is the point at which there is no longer any compression of the material and the distance between the syringe of the cutting tool and the support now indicates the residual wall thickness.
  • s1 mark the distance between the cutting blade tip and the support during the weakening process and s2 the actual residual wall thickness; ds1 indicates the extent to which the material was compressed. It is also readily apparent in the graph of Fig.
  • FIG. 10 shows, partially and schematically, a further embodiment of a device according to the invention with which the method according to the invention can be carried out.
  • a cutting blade 120 is used, which is retracted via an adjusting spindle 126, which is acted upon by a motor 125, for weakening a workpiece 132 in this.
  • the workpiece 132 is again placed on a support table 130 and is shown by the arrow 134, relative to the tool 120 moves.
  • a weakening cut is made, resulting in a residual wall thickness.
  • a force is determined, which is generated by the cutting operation.
  • the sensor can not measure a cutting force directly because they are introduced into the support table.
  • This information about the force is provided via a line 174 of a control and control unit 150.
  • This control and control unit 150 is in turn connected to the motor 125 via a control line 162.
  • the adjustment of the cutting blade 120 in the direction of the support table 130 or away from it.
  • a displacement sensor is arranged, with which it can be determined how far the tip of the cutting blade 120 from the support table 130 is removed.
  • This distance represents in inelastic materials the residual wall thickness, which is composed of the difference of the distance of cutting blade tip to the button (reference numeral 138) minus the Auflagetischdicke designated by reference numeral 136.
  • the control and regulation device 150 possibly with the aid of data regarding material properties and / or thickness - conclude the process conditions.
  • tool wear or short-term variations in material thickness or material properties can be detected in this manner. It can be expected that tool wear will always change over the medium to long term. Fluctuations in the material thickness or the material properties are rather short-term events, which can also be determined as such due to the time course of the signal. Furthermore, it is possible, for example, to determine the material thickness with additional sensors and to include them in the analysis.
  • FIG. 1 Another embodiment of the present invention is shown schematically in FIG. This embodiment differs from that in FIG. 1, for example, in that the cutting arrangement as a whole is held on a robot arm 274, of which only its end is shown in FIG. 11. Between the robot arm 274 and the cutting device, a hinge 272 is arranged. On the one hand, the cutting blade 275 is fastened to the joint 272 in a rotatable manner to be taken from FIG. 11 and a holding arm 270. The support arm in turn holds a U-shaped bracket 212, which is configured similar to that in Fig. 1. Another difference in the embodiment of FIG. 1 lies in the fact that the cutting blade 275 can be rotated in a swivel mount 276 of the bracket.
  • a load cell 214 On the lower leg of the U-shaped bracket 212 are - as in the embodiment of FIG. 1 - a load cell 214, in counter-holder 216 and a trackball 218 are provided.
  • the trackball 218 now rolls off immediately at the bottom of the workpiece 232 and can absorb the force with which the tip 220 of the cutting blade presses into the workpiece. Laterally, the workpiece is clamped firmly in clamping devices and immovable.
  • the track ball 218 can be lowered by 50 mm by means of a precision actuator (not shown here) (Fig. 11 shows the raised state).
  • a precision actuator not shown here
  • Fig. 11 shows the raised state
  • the present invention gives the possibility of a material weakening to a well-defined residual wall thickness even with elastic materials under the action of the cutting tool deformed or compressed to achieve.
  • information about the state of the tool can be generated, in particular when the tool is to be replaced.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Automatic Control Of Machine Tools (AREA)

Abstract

L'invention concerne un dispositif et un procédé pour affaiblir une pièce au moyen d'un outil. À cet effet, la pièce est disposée entre l'outil et un support et affaiblie par déplacement relatif de la pièce par rapport à l'outil. Selon l'invention, pour qu'il soit possible de déterminer l'état d'usure de l'outil, la nature des matériaux de la pièce et/ou la profondeur d'affaiblissement effective, les forces exercées entre l'outil et la pièce sont déterminées, la force déterminée est comparée avec une valeur de force prédéterminée et une information est générée d'après cette comparaison, cette information indiquant si la force déterminée se situe dans des limites prédéterminées vis-à-vis de la valeur de force prédéterminée.
EP08736304A 2007-05-24 2008-04-17 Procédé et dispositif pour affaiblir une pièce Withdrawn EP2155449A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE200710024318 DE102007024318B4 (de) 2007-05-24 2007-05-24 Verfahren und Vorrichtung zum Einbringen eines Schwächungsschnittes in ein Werkstück
DE102007030517 2007-06-30
PCT/EP2008/054634 WO2008141877A1 (fr) 2007-05-24 2008-04-17 Procédé et dispositif pour affaiblir une pièce

Publications (1)

Publication Number Publication Date
EP2155449A1 true EP2155449A1 (fr) 2010-02-24

Family

ID=39431006

Family Applications (1)

Application Number Title Priority Date Filing Date
EP08736304A Withdrawn EP2155449A1 (fr) 2007-05-24 2008-04-17 Procédé et dispositif pour affaiblir une pièce

Country Status (2)

Country Link
EP (1) EP2155449A1 (fr)
WO (1) WO2008141877A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016123579A1 (de) * 2016-12-06 2018-06-07 Kraussmaffei Technologies Gmbh Verfahren zum Einbringen eines Applikationsmediums in einen Schwächungsspalt einer Abdeckung sowie bevorzugte Applikationsvorrichtung

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4624169A (en) * 1985-04-08 1986-11-25 Aerochem, Inc. Apparatus for automated cutting of thin films
FR2648274B1 (fr) * 1989-06-07 1994-07-29 Commissariat Energie Atomique Procede et dispositif de marquage et de clivage de plaquettes de materiaux semi-conducteurs monocristallins
US5831181A (en) * 1995-09-29 1998-11-03 The Regents Of The University Of California Automated tool for precision machining and imaging
US20020108477A1 (en) * 2001-02-09 2002-08-15 Seniff Dana W. Method for cutting coating blankets from sheet-type work material
DE102006034287B3 (de) * 2006-07-21 2008-02-28 Kraussmaffei Technologies Gmbh Vorrichtung zur Einbringung von Schwächungsschnitten in eine Folie oder Haut

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2008141877A1 *

Also Published As

Publication number Publication date
WO2008141877A1 (fr) 2008-11-27

Similar Documents

Publication Publication Date Title
DE102010018065B4 (de) Verfahren und Rheometer zur Bestimmung der rheologischen Eigenschaften von Materialien
EP2046541B1 (fr) Dispositif pour réaliser des fentes d'affaiblissement dans un film ou une peau
EP1961502B1 (fr) Procédé et dispositif destinés au pliage de pièces
EP2416941B1 (fr) Dispositif et procédé pour traiter un matériau d'emballage par ultrasons
DE19705462C2 (de) Verfahren zum Betreiben einer Elektropresse
DE2928153C2 (de) Bremsentestvorrichtung
EP2077938A1 (fr) Dispositif de soudage par ultrasons et machine de conditionnement comprenant un dispositif de soudage par ultrasons
AT510949B1 (de) Steuer- und regelvorrichtung für eine biegepresse
DE102014105667B4 (de) Drehtisch mit Anzugsmoment-Messeinrichtung
EP2092991B1 (fr) Matrice à plier pour une presse à plier, notamment presse plieuse et procédé de pliage d'une pièce
DE19950534B4 (de) Spritzgießmaschine
EP0399296A2 (fr) Justification automatique d'un laminoir universel après le changement des cylindres pour les profils neufs
DE10231742B3 (de) Vorrichtung zum Bearbeiten einer Materialbahn, Verfahren zum Steuern und Ermitteln der Lage und/oder der Anpresskraft einer Sonotrode sowie Verfahren zur Überwachung der in einem Bearbeitungsspalt bewegten Materialbahn
DE10331064B4 (de) Vorrichtung zum Bearbeiten einer Materialbahn
DE102017130873A1 (de) Vorrichtung und Verfahren zur Überwachung eines Keiltriebwerkzeugs
AT515672B1 (de) Biegepresse
DE102007024318B4 (de) Verfahren und Vorrichtung zum Einbringen eines Schwächungsschnittes in ein Werkstück
DE102010033001B3 (de) Prüfvorrichtung für eine Tiefziehpresse
EP3487647B1 (fr) Procede et dispositif pour cissailler le materiau d'une barre
WO2008141877A1 (fr) Procédé et dispositif pour affaiblir une pièce
AT517833B1 (de) Vorrichtung zur erzeugung eines eindruckes in einem prüfobjekt für eine härteprüfung
EP2181602A1 (fr) Surveillance de la pression d'un clip à l'aide d'un piezo-récepteur
EP1480767A1 (fr) Procede de reduction des erreurs d'angle de pliage lors du pliage
DE202009005394U1 (de) Fliess-Schneider mit Vorrichtung zur Messung der Schnittkräfte beim Schneiden von Papier, Pappe o.dgl.
DE102008025076A1 (de) Antriebsvorrichtung

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20091228

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20101102