EP0312809A2 - Presse à double effet pour emboutir d'elements en tôle - Google Patents

Presse à double effet pour emboutir d'elements en tôle Download PDF

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Publication number
EP0312809A2
EP0312809A2 EP88115856A EP88115856A EP0312809A2 EP 0312809 A2 EP0312809 A2 EP 0312809A2 EP 88115856 A EP88115856 A EP 88115856A EP 88115856 A EP88115856 A EP 88115856A EP 0312809 A2 EP0312809 A2 EP 0312809A2
Authority
EP
European Patent Office
Prior art keywords
force
sheet metal
hold
pressure
metal holder
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.)
Ceased
Application number
EP88115856A
Other languages
German (de)
English (en)
Other versions
EP0312809A3 (fr
Inventor
Oswald Ostrowski
Volker Dr. Thoms
Bernd Dr. Fugger
Werner Hezel
Thomas Hunyar
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.)
Daimler Benz AG
Original Assignee
Daimler Benz AG
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 Daimler Benz AG filed Critical Daimler Benz AG
Publication of EP0312809A2 publication Critical patent/EP0312809A2/fr
Publication of EP0312809A3 publication Critical patent/EP0312809A3/fr
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D24/00—Special deep-drawing arrangements in, or in connection with, presses
    • B21D24/10—Devices controlling or operating blank holders independently, or in conjunction with dies
    • B21D24/14—Devices controlling or operating blank holders independently, or in conjunction with dies pneumatically or hydraulically
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/20—Deep-drawing
    • B21D22/26—Deep-drawing for making peculiarly, e.g. irregularly, shaped articles

Definitions

  • the invention relates to a double-acting press for drawing sheet metal parts according to the preamble of claim 1, as is common in industrial manufacturing practice and is also used by the applicant.
  • the joints between the sheet metal holder and the drawing tappet on the one hand and the associated connecting rods are adjustable in height compared to the corresponding tappets and are accordingly movably guided relative to the tappets; in addition, at least in the sheet metal tappets between the connecting rod bearing and the tappet, a piston / cylinder unit charged with hydraulic fluid is interposed in the power flow; the force-determining pressure chamber of this piston / cylinder unit is placed under a presettable constant pressure. That is, a relatively low, controllable pneumatic pressure is converted into a correspondingly proportional fluid pressure by means of a stepped piston which acts as a pressure intensifier and has a very large area ratio between the small and large piston areas.
  • the Kraftbe is also indirect matching pressure chamber of the piston / cylinder unit pneumatically controlled.
  • the hydraulic system is only used passively as a pressure transmission medium; pressure is set pneumatically at the low pressure level.
  • the purpose of the intermediate short-stroke piston / cylinder unit is to limit the transferable force to a preset value; if the preset pressure or force value is exceeded, the stepped piston on the low-pressure side dodges, causing the machine to be switched off.
  • the object of the invention is to design the press on which it is based in such a way that it can be reproducibly and quickly reproducibly adjusted to the changed production conditions after a changeover to a changed sheet metal part or to a corresponding tool.
  • a changeover should be possible with significantly fewer test impressions than before.
  • the characterizing features of claim 1. Thanks to the direct servohydraulic control of the force-determining working space pressure in the intermediate piston / cylinder unit of each sheet metal connecting rod, the required sheet metal holder force can be precisely adjusted with high reproducibility, hysteresis-free and without inertia.
  • the servohydraulic plate holder force control is so precise, so precisely reproducible and so low inertia that the setpoint can be changed depending on the stroke or crank angle depending on a preset program even within a press cycle.
  • the sheet metal holder force can optionally be increased or decreased in a targeted and reproducible manner during the pressing process. In individual cases, this depends on the workpiece to be pressed and must be tried out on a case-by-case basis.
  • the double-acting press shown schematically in FIG. 1 in vertical section has a press stand 2 and a press table 10, on which the lower tool 9 for the sheet metal part 1 to be pressed is fastened.
  • a sheet metal plunger 4 is vertical performed, which is driven by a symmetrically arranged connecting rod 6 or 6 'stroke.
  • the actual plunger 3 is arranged inside the sheet metal holder 4 and is guided relative to the stroke relative to it and can be separately driven by several connecting rods 5 which are also arranged symmetrically.
  • the sheet metal holder 7 of the upper tool is attached to the sheet metal holder plunger 4 and the drawing die 8 of the upper tool is attached to the drawing plunger 3.
  • the sheet metal holder When the upper die comes down, the sheet metal holder first places on the still unpressed board resting on the lower die 9 with a defined force; only when the edge of the board is clamped in with a defined force does the drawing punch 8 come into contact with the sheet 1 and press it with defined sliding out of the sheet edge from the edge clamping into the die.
  • the extent of the sheet metal holder force is of particular importance here; Depending on the workpiece, the sheet metal holder force must be optimized on a case-by-case basis and kept to the found value as precisely as possible across all pressing cycles. The present invention is particularly concerned with this aspect, which will be discussed in more detail below.
  • this is shown in simplified form in the form of a connecting rod bearing, in each case Ram plunger bearing rod 12;
  • this connecting rod bearing boot is not stored or guided in the tappet, but in a press-proof vertical guide in the manner of a cross head.
  • an adjusting spindle 13 is arranged within the connecting rod bearing boot 12 and engages with a nut thread attached to the lower end of the connecting rod bearing boot.
  • the adjusting spindle in turn can be rotated by means of a worm wheel 28 which surrounds the adjusting spindle 13 in a rotationally fixed manner, as a result of which a change in the height position of the tappet relative to the connecting rod bearing occurs.
  • the worm wheel 28 in turn can be rotated in a defined manner by means of a worm drive (not shown) and a corresponding motor drive.
  • a worm drive not shown
  • a corresponding motor drive At the lower end of the adjusting spindle 13, the above-mentioned piston / cylinder unit 11 is attached, which encloses a pressure chamber 14 between the corresponding piston and the cylinder surrounding it, which is provided with a corresponding fluid connection.
  • the different circumferential areas 17, 17', 17 ′ and 17 ⁇ of the sheet holder are assigned.
  • Each of these circumferential areas is accordingly assigned a different piston / cylinder unit 11, 11 ', 11 ⁇ and 11 ′′′. It makes perfect sense not to tighten the edge of the sheet to be pressed to keep the entire scope constant, but also to set lower sheet metal holder forces in some areas; this depends individually on the respective workpiece or the tool designed for it. This also has to be tested individually. After this has been determined, however, the corresponding manufacturing parameters can be quickly set again with exact reproducibility thanks to the invention for batch sizes to be manufactured later.
  • the force transducers are formed by strain gauges 36 which are glued to the surface of the wall sections of the sheet metal holder 7 which are loaded by the sheet metal holder force. As shown in FIGS.
  • the wall 35 is to be weakened locally in terms of load-bearing capacity with a small notch effect, so that the remaining disc-shaped central web represents a type of compression spring which is deformed in a defined manner by the sheet metal holder force.
  • FIG. 6 Another possibility of a locally targeted weakening of the wall 35, which shows only a slight notch effect, is shown in FIG. 6: there are two bores 32 horizontally next to one another, which enclose between them a biconcave web 33 which is vertical, that is to say in the direction of force flow 37.
  • This web 33 also serves as a type of compression spring which can be loaded by the sheet metal holder force and whose deformation can be determined by the strain gauges 36 attached to the thinnest point of the web as a measure of the load.
  • the weak points worked out from the full wall 35 and covered with strain gauges have the advantage that there are no joints within the force flow which would cause a hysteresis phenomenon in the force measurement.
  • the force transducers worked out from the full wall 35 thus work completely free of hysteresis, which is important for the present application.
  • the servohydraulic plate holder force control will be described below with reference to the hydraulic diagram according to FIG. 7.
  • the top of the illustration shows the four piston / cylinder units 11, 11 ', 11 ⁇ and 11 ′′′ assigned to the different areas of the sheet metal holder circumference with the different pressure chambers 14, 14', 14 ⁇ and 14 ′′′.
  • the four different previously mentioned force sensors 15, 15 ', 15, and 15 15 are shown there; they are fed together from a uniform battery 38 and are parallel to one another in this regard.
  • the measuring taps of the elongation resistances of a force transmitter, each representing a Wheatstone bridge, are shown separately for each force transmitter.
  • Each individual piston / cylinder unit 11,11 '11 ⁇ and 11 ′′′ and each associated force sensor 15,15', 15 ⁇ and 15 ′′′ is assigned a controller 19,19 ', 19 ⁇ and 19 ′′′, on the input of which Measuring tap of the force transmitter 15 is switched.
  • Each of the four controllers 19 mentioned is assigned a setpoint adjuster 18, 18 ', 18 ⁇ and 18 ′′′, the output of which is also connected to the controller input.
  • the force generator and the setpoint adjuster both emit a similar and comparable electrical signal.
  • the controller 19 compares the target signal with the actual signal and emits a corresponding signal at its output in accordance with the difference between the two, with which a control intervention can be carried out which eliminates any established / actual deviation that has been found.
  • proportional valves 20, 20 ', 20 ⁇ and 20 ′′′ are provided for each of the four controlled systems.
  • the proportional valves can first of all Regulators are electrically piloted via an electro-hydraulic pilot valve.
  • the electrohydraulic pilot valve is supplied hydraulically from a control oil pump 21, which draws in from a separate control oil sump 24; With regard to the sensitivity of the electro-hydraulic pilot valves, this circuit is kept particularly clean, which is indicated by the filter 23.
  • the electro-hydraulic pilot valve is opened to a greater or lesser extent and, in accordance with this electro-hydraulic amplification, the proportional valve 20 is also opened to a greater or lesser extent.
  • the proportional valve is opened in the direction of the pressure source 22/25 and the pressure in the associated pressure chamber 14 is increased. If, on the other hand, the sheet metal holder force rises above the specified setpoint due to malfunction, the proportional valve opens in the direction of the working oil sump, so that the pressure is reduced in the force-determining pressure chamber 14. If the predetermined sheet metal holder force is reached again during such a control intervention, the associated proportional valve returns to the illustrated middle blocking position; the pressure then present in the force-determining pressure chamber 14 is retained.
  • each individual servo-hydraulic control circuit is provided with a pressure relief valve 26,26', 26 ⁇ and 26 ′′′. If the pressure in the work line is exceeded. In the associated pressure chamber 11, 14 ', 14 ⁇ and 14 ′′′ above a presettable maximum value, 26 working oil flows out at the pressure relief valve. This working oil, which is under high pressure, can be used to actuate an emergency stop switch 27 which is common to all four pressure relief valves and which stops the press.
  • the exemplary embodiment of the hydraulic diagram shown in FIG. 8 differs from that according to FIG. 7 in that instead of force transducers integrated in the sheet-metal holder, there is a separate pressure transducer 16, 16 ′, 16 in each force-determining pressure chamber 14, 14 ′, 14 ′ or 14 ′′ ⁇ or 16 ′′′ is assigned. This converts the pressure signal into a corresponding electrical signal, which is connected to the input of the associated controller 19, 19 ', 19 ⁇ or 19 ′′′. Otherwise, the operation of the hydraulics 8 quite analogous to the mode of operation of the diagram according to FIG.
  • FIG. 8 the possibility of a crank angle-dependent change of the target value is also indicated in FIG. 8.
  • An angle sensor 30 is coupled to the stylized crankshaft 29 of the press, which emits an electrical signal corresponding to the instantaneous rotational position of the crankshaft 29.
  • This is switched on four different function transmitters 31, 31 ', 31 ⁇ and 31 ′′′.
  • These function transmitters are designed in such a way that a different function value can be output as a function of the crank angles, with which the associated setpoint adjuster 18, 18 ', 18 ⁇ or 18 ′′′ can be changed. Thanks to the quick response of the controlled system, it can also follow a setpoint setting changed during the stroke relatively quickly.
  • the sheet metal holder forces can be gradually increased or decreased within a pressing cycle, as required.
  • the individual function transmitters 31, 31 ', 31 ⁇ and 31 ′′′ - after they have been individually optimized for a specific workpiece - can be removed and replaced with other function transmitters that have been optimized for another workpiece.
  • This exchange of functions can be effected by switching over to a control center, where all function transmitters optimized for different workpieces are installed in groups and kept on standby.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Presses (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
EP88115856A 1987-10-21 1988-09-27 Presse à double effet pour emboutir d'elements en tôle Ceased EP0312809A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3735582 1987-10-21
DE19873735582 DE3735582C1 (de) 1987-10-21 1987-10-21 Doppeltwirkende Presse zum Ziehen von Blechteilen

Publications (2)

Publication Number Publication Date
EP0312809A2 true EP0312809A2 (fr) 1989-04-26
EP0312809A3 EP0312809A3 (fr) 1989-10-18

Family

ID=6338758

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88115856A Ceased EP0312809A3 (fr) 1987-10-21 1988-09-27 Presse à double effet pour emboutir d'elements en tôle

Country Status (4)

Country Link
EP (1) EP0312809A3 (fr)
JP (1) JPH01130824A (fr)
DD (1) DD283085A5 (fr)
DE (1) DE3735582C1 (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0406792A1 (fr) * 1989-07-06 1991-01-09 L. SCHULER GmbH Couplage de réglage pour la course supérieure pour la jumelle de pression d'un dispositif d'emboutissage
EP0422491A1 (fr) * 1989-10-10 1991-04-17 L. SCHULER GmbH Dispositif pour emboutissage en passes d'emboutissage de presses
EP0453955A1 (fr) * 1990-04-23 1991-10-30 Maschinenfabrik Müller-Weingarten AG Dispositif pour emboutir des pièces de tôle dans une presse
EP0531140A1 (fr) * 1991-09-04 1993-03-10 Toyota Jidosha Kabushiki Kaisha Système de coussin hydraulique pour une presse, ayant une alimentation hydraulique comprenant des moyens pour régler la pression initiale des cylindres des boulons de pression
EP0585589A1 (fr) * 1992-09-01 1994-03-09 Mercedes-Benz Ag Procédé pour l'optimisation de processus d'emboutissage automatique et itératif aux presses
EP0596696A1 (fr) * 1992-11-05 1994-05-11 Toyota Jidosha Kabushiki Kaisha Procédé et dispositif pour contrôler, vérifier ou optimaliser la pression des goupilles des cylindres d'amortissement d'une presse par déchargement du fluide ou de la pression initiale
EP0622133A1 (fr) * 1993-04-28 1994-11-02 Toyota Jidosha Kabushiki Kaisha Procédé et appareil pour diagnostiquer le coussin de serre-flan d'un presse, pour la gamme optimale de la force du serre flan
US5457980A (en) * 1992-11-05 1995-10-17 Toyota Jidosha Kabushiki Kaisha Method and device for controlling, checking or optimizing pressure of cushion pin cylinders of press by discharging fluid or initial pressure
US5687598A (en) * 1994-07-15 1997-11-18 Toyota Jidosha Kabushiki Kaisha Press having cushioning cylinders each having two chambers whose pressure difference is adjustable to control blank-holding force
US5701778A (en) * 1994-03-03 1997-12-30 Toyota Jidosha Kabushiki Kaisha Press having gas cylinders of plastically deformable members for even distribution of blank-holding force on pressure member through cushion pins
US5735201A (en) * 1994-12-21 1998-04-07 Toyota Jidosha Kabushiki Kaisha Apparatus including mutually communicating hydraulic cylinders for even distribution of blank-holding force on pressing machine
NL1021738C2 (nl) * 2002-10-24 2004-04-27 Tno Werkwijze en inrichting voor het reduceren van plooivorming bij dieptrekken.
CN103697014A (zh) * 2013-12-17 2014-04-02 马钢(集团)控股有限公司 车轮油压机脱模缸

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3744177A1 (de) * 1987-12-24 1989-07-06 Audi Ag Verfahren zum tiefziehen von platinen, insbesondere von tiefziehblechen fuer karosserieelemente von kraftfahrzeugen
JP2501276Y2 (ja) 1989-03-17 1996-06-12 株式会社名機製作所 液圧プレス装置
DD289724A5 (de) * 1989-12-05 1991-05-08 Fz Fuer Umform- Und Plastverarbeitungstechnik,De Verfahren zur erhoehung des grenztiefziehverhaeltnisses
IT1239856B (it) * 1990-01-24 1993-11-15 Fiat Auto Spa Procedimento per lo stampaggio di lamiere e pressa idraulica per la realizzazione di tale procedimento.
DE4121869C2 (de) * 1991-07-03 2001-04-12 Erfurt Umformtechnik Gmbh Einrichtung zur Veränderung der Blechhaltekräfte an Tischkissen in Pressen während des Ziehprozesses
DE4405909A1 (de) * 1994-02-24 1995-08-31 Erfurt Umformtechnik Gmbh Verfahren und Schaltungsanordnung zum Unterbrechen und Fortführen des Ziehprozesses an zweifachwirkenden Pressen, insbesondere hydraulischen Pressen
ITPN20050061A1 (it) * 2005-09-06 2007-03-07 Silvano Bordignon "molla mista oleo-pneumatica con vaso di espansione"

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3406526A1 (de) * 1984-02-23 1985-09-12 Maschinenfabrik Müller-Weingarten AG, 7987 Weingarten Schiebetisch mit eingebautem blechhalterrahmen
EP0173755A1 (fr) * 1984-06-29 1986-03-12 L. SCHULER GmbH Dispositif d'étirage dans une presse
US4635466A (en) * 1984-04-27 1987-01-13 Kabushiki Kaisha Komatsu Seisakusho Die cushion apparatus for use in a press machine

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE735158C (de) * 1939-04-30 1943-05-07 Messerschmitt Boelkow Blohm Einrichtung zum Steuern des Druckes eines pneumatischen bzw. hydropneumatischen Faltenhalters einer Blechziehpresse
US3108470A (en) * 1960-03-28 1963-10-29 Danly Mach Specialties Inc High speed tonnage indicator for power press
JPS532423B2 (fr) * 1973-09-27 1978-01-27
DE2407864C3 (de) * 1974-02-19 1982-08-26 Maschinenfabrik Weingarten Ag, 7987 Weingarten Druckbolzenanordnung an einem Druckkissen für Pressen
DE2833829C2 (de) * 1978-08-02 1986-11-27 L. Schuler GmbH, 7320 Göppingen Schaltungsanordnung für einen Stellantrieb einer Stößelverstellung
JPS5949120B2 (ja) * 1978-12-14 1984-11-30 株式会社サム電子機械 油圧式圧縮装置
CS217858B1 (en) * 1981-02-09 1983-01-28 Jaroslav Pecha Method of the metal sheet shaping and device for executing the said method
JPS59193800A (ja) * 1983-04-18 1984-11-02 Toyota Motor Corp プレス荷重制御装置
JPS59212200A (ja) * 1983-05-18 1984-12-01 Toyota Motor Corp プレス荷重の動特性制御装置
JPS609526A (ja) * 1983-06-28 1985-01-18 Toyota Motor Corp ブランクホルダ加圧力制御方法およびその装置
DE3475889D1 (en) * 1984-02-03 1989-02-09 Schuler Gmbh L Pressure control apparatus in presses
JPS623720A (ja) * 1985-06-28 1987-01-09 中部電力株式会社 樹木切断装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3406526A1 (de) * 1984-02-23 1985-09-12 Maschinenfabrik Müller-Weingarten AG, 7987 Weingarten Schiebetisch mit eingebautem blechhalterrahmen
US4635466A (en) * 1984-04-27 1987-01-13 Kabushiki Kaisha Komatsu Seisakusho Die cushion apparatus for use in a press machine
EP0173755A1 (fr) * 1984-06-29 1986-03-12 L. SCHULER GmbH Dispositif d'étirage dans une presse

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0406792A1 (fr) * 1989-07-06 1991-01-09 L. SCHULER GmbH Couplage de réglage pour la course supérieure pour la jumelle de pression d'un dispositif d'emboutissage
EP0422491A1 (fr) * 1989-10-10 1991-04-17 L. SCHULER GmbH Dispositif pour emboutissage en passes d'emboutissage de presses
EP0453955A1 (fr) * 1990-04-23 1991-10-30 Maschinenfabrik Müller-Weingarten AG Dispositif pour emboutir des pièces de tôle dans une presse
US5299444A (en) * 1991-09-04 1994-04-05 Toyota Jidosha Kabushiki Kaisha Hydraulic cushioning system for press, having hydraulic power supply including means for adjusting initial pressure to be applied to pressure-pin cylinders
EP0531140A1 (fr) * 1991-09-04 1993-03-10 Toyota Jidosha Kabushiki Kaisha Système de coussin hydraulique pour une presse, ayant une alimentation hydraulique comprenant des moyens pour régler la pression initiale des cylindres des boulons de pression
US5450347A (en) * 1992-09-01 1995-09-12 Mercedes-Benz Ag Method for the automatic, interactive process optimization of drawing processes in presses
EP0585589A1 (fr) * 1992-09-01 1994-03-09 Mercedes-Benz Ag Procédé pour l'optimisation de processus d'emboutissage automatique et itératif aux presses
US5457980A (en) * 1992-11-05 1995-10-17 Toyota Jidosha Kabushiki Kaisha Method and device for controlling, checking or optimizing pressure of cushion pin cylinders of press by discharging fluid or initial pressure
EP0773075A3 (fr) * 1992-11-05 1997-10-15 Toyota Motor Co Ltd Procede et dispositif pour controler verifier ou optimaliser la pression des coupilles des cylinders d'amortissement d'une presse pour dechargement ou fluide ou de la pression initiale
EP0596696A1 (fr) * 1992-11-05 1994-05-11 Toyota Jidosha Kabushiki Kaisha Procédé et dispositif pour contrôler, vérifier ou optimaliser la pression des goupilles des cylindres d'amortissement d'une presse par déchargement du fluide ou de la pression initiale
EP0622133A1 (fr) * 1993-04-28 1994-11-02 Toyota Jidosha Kabushiki Kaisha Procédé et appareil pour diagnostiquer le coussin de serre-flan d'un presse, pour la gamme optimale de la force du serre flan
US5471861A (en) * 1993-04-28 1995-12-05 Toyota Jidosha Kabushiki Kaisha Method and apparatus for diagnosing press cushioning device, on optimum range of blank-holding force
US5701778A (en) * 1994-03-03 1997-12-30 Toyota Jidosha Kabushiki Kaisha Press having gas cylinders of plastically deformable members for even distribution of blank-holding force on pressure member through cushion pins
US5687598A (en) * 1994-07-15 1997-11-18 Toyota Jidosha Kabushiki Kaisha Press having cushioning cylinders each having two chambers whose pressure difference is adjustable to control blank-holding force
US5735201A (en) * 1994-12-21 1998-04-07 Toyota Jidosha Kabushiki Kaisha Apparatus including mutually communicating hydraulic cylinders for even distribution of blank-holding force on pressing machine
NL1021738C2 (nl) * 2002-10-24 2004-04-27 Tno Werkwijze en inrichting voor het reduceren van plooivorming bij dieptrekken.
WO2004037460A1 (fr) * 2002-10-24 2004-05-06 Nederlandse Organisatie Voor Toegepast-Natuurwe Tenschappelijk Onderzoek Tno Procede et appareil pour reduire la formation de plis dans une operation d'emboutissage profond
CN103697014A (zh) * 2013-12-17 2014-04-02 马钢(集团)控股有限公司 车轮油压机脱模缸
CN103697014B (zh) * 2013-12-17 2016-03-23 马钢(集团)控股有限公司 车轮油压机脱模缸

Also Published As

Publication number Publication date
EP0312809A3 (fr) 1989-10-18
JPH01130824A (ja) 1989-05-23
DD283085A5 (de) 1990-10-03
DE3735582C1 (de) 1988-04-28

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