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EP0716916B1 - Method for adjusting the impact of upper and lower tools in a press, damping the noise, and slide drive with a device using the method - Google Patents

Method for adjusting the impact of upper and lower tools in a press, damping the noise, and slide drive with a device using the method Download PDF

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Publication number
EP0716916B1
EP0716916B1 EP95117302A EP95117302A EP0716916B1 EP 0716916 B1 EP0716916 B1 EP 0716916B1 EP 95117302 A EP95117302 A EP 95117302A EP 95117302 A EP95117302 A EP 95117302A EP 0716916 B1 EP0716916 B1 EP 0716916B1
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EP
European Patent Office
Prior art keywords
braking
ram
pressure
cylinders
pressure oil
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.)
Expired - Lifetime
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EP95117302A
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German (de)
French (fr)
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EP0716916A1 (en
Inventor
Wieland Dr. Petter
Markus Dr. Müller
Gregor Geist
Andreas Schlag
Steffen Schmidt
Siegfried Klavehn
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Umformtechnik Erfurt GmbH
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Umformtechnik Erfurt GmbH
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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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B1/00—Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen
    • B30B1/26—Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by cams, eccentrics, or cranks
    • B30B1/265—Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by cams, eccentrics, or cranks using a fluid connecting unit between drive shaft and press ram
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/0076—Noise or vibration isolation means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/14—Control arrangements for mechanically-driven presses

Definitions

  • the invention relates to a method for noise and Low impact adjustment of the upper and lower tools from mechanical seizures, in particular presses for forming Sheet metal parts with high stroke rates according to the generic term of Claim 1.
  • the invention is also a Ram drive for mechanical presses with one device to carry out the above Process with the characteristics of Preamble of claim 4.
  • DD 279 639 A1 and DD 295 798 A5 are two solutions known in which the adjustment process is controlled by Lift cylinder between the pressure points and the tappet are arranged, was realized.
  • the object of the invention is a method and To propose establishment, after which with simple means and high efficiency of the adjustment process when closing of the tool is safely mastered.
  • a plunger drive with a device for the implementation of the method according to claims 1 or 2 is in claim 4 described.
  • Claims 5 to 7 contain further advantageous Embodiments of the device according to claim 4.
  • the alignment process is divided into two areas - in the braking and acceleration process. If the process and die cushion forces are negligible, so become the same size for braking and accelerating Paths provided, i.e. half the relative stroke.
  • the following can be used to influence the braking process in a targeted manner model considerations are used as a basis.
  • the dominant variable when braking is the kinetic energy of the Plunger by the plunger mass and the current Ram speed is marked.
  • the pestle will opposed to a defined force during braking (Pressure of the hydraulic oil in the pressure oil reservoir) and The kinetic energy is largely via the braking distance converted into potential energy (spring tension work). Flow-related losses occur.
  • the Ram movement can be simplified using the equation of motion a weakly damped, vibratory Describe 2nd order systems.
  • the solution to the differential equation is the relative path, which the tappet travels in the direction of the pressure point.
  • At Initiation of the braking process is the tappet from the drive "uncoupled” and slows down its speed until the desired impact speed has been reached.
  • Dependence on the braking force becomes a certain one Braking distance covered.
  • the braking distance and the braking speed are a function of time and the Braking force can be represented as an equation system.
  • the solution of the Equation system gives the required braking force and the associated braking time that the plunger needs to reach the desired impact speed after half To achieve relative path. This allows the crank angle specify at the time of impact.
  • the starting point e.g. by cams
  • the acceleration process is initiated immediately after touchdown. Pose with the acceleration the circuit-related constraints on.
  • the plunger takes on the premise of Equal area of brake and pressure point cylinders Half of the current drive speed. So that is the inner stop reached.
  • the adjustment process is not carried out by setting the Braking force and the coordinated triggering of the Braking process made, but the adjustment process through the target function specification and control with the Steady valve 10 "forced" on the hybrid drive. Since the Hybrid drive between two opposite, hydraulic Forces is clamped, the adjustment process with constantly acting braking force through discharge control affect the oil from the pressure point cylinders. The braking energy must be greater than that by Press stroke number certain kinetic energy of the ram be and results from the movement characteristics of the Alignment process. For energy reasons, it makes sense to adjust the braking force to the changing number of press strokes. The duration of the entire alignment process is depending on the number of press strokes and also on the desired impact speed.
  • any movement functions of the Specify rest-in-rest kinematics for the hybrid drive In principle, any movement functions of the Specify rest-in-rest kinematics for the hybrid drive.
  • the at Accelerate against the die cushion and die cushion Process forces influence the alignment process not as long as the pressure in the pressure point cylinders has not yet reached its limit.
  • the check valve is activated when the press coupling is switched on 11 unlocked so that under the preload of the pressure oil reservoir 8, the short-stroke pistons 1 spread before the plunger 4 closes with the upper tool. Locking the valve 5 causes a rapid braking of the Tappet 4 by removing the oil from the upper spaces of the Brake cylinder 3 is displaced into the pressure oil reservoir 8. At the same time, the short-stroke pistons 1a push the oil into the lower spaces of the brake cylinder 3. If necessary, oil from the Pressure oil reservoir 7 sucked in via the check valve 6.
  • the tappet 4 sets at a significantly reduced speed with the upper tool on the board 19.
  • the rest of the oil the pressure point cylinders 1a become the lower rooms the brake cylinder 3 pressed.
  • the stroke of the short-stroke pistons 1a represents the adjustment path, which the plunger 4 needs to hit the impact speed slowed down and after putting on the Board 19 to be accelerated again.
  • This approximation is composed of the braking distance and the acceleration distance together.
  • the ratio of braking distance to acceleration distance is 1: 1 if no external forces act on the plunger 4, while this is accelerating.
  • the control process it provides for the process and acting on the plunger 4 Pillow forces by changing the relationship of braking and acceleration distance to be taken into account.
  • the area of the short-stroke pistons 1a depends on the maximum Accelerating force that the plunger 4 at a certain Can apply maximum pressure.
  • the housing of the brake cylinder 3 are fixed with the plunger 4 connected. So that all elements of the hydraulic Circuit arranged in or on the plunger 4, so that none flexible hydraulic lines are required hydraulic connections between fixed and manufacture moving parts of the press.
  • the piston rods 2 the brake cylinder 3 are fixed at least at one end connected to the press frame.
  • the brake cylinder 3 must be designed as a synchronous cylinder, since both Cylinder chambers are shorted together when the Adjustment process does not take place. Is the piston area of the Piston of the brake cylinder 3 equal to the area of the Short stroke piston 1a, the speed of the tappet 4 at the end of the alignment process half the size of the current one Connecting rod speed. At this speed the inner stop is reached. This velocity can be reduced by the area of the Piston of the brake cylinder 3 is dimensioned smaller than that the short-stroke piston 1a of the pressure points. From energetic However, reasons should be striven for equal area.
  • This seat valve interrupts the short circuit between Cylinder top and bottom of the brake cylinder 3 during of the entire alignment process. It conducts with his Activate the braking process and must at the end of Acceleration process when the oil volume from the Pressure point cylinders 1 displaced into the brake cylinder 3 was reactivated. This happens at a Overfilling the pressure oil reservoir 8 and spraying the excess oil through the accumulator safety valve avoid.
  • the oil comes out of the upper ones during braking Broaching the brake cylinder 3 in the pressure oil reservoir 8. At the same time, for the lower rooms Brake cylinder 3 a volume requirement, which via the check valve 6 is covered by the pressure oil reservoir 7.
  • the Check valve 6 prevents backflow of the for the pressure point cylinder 1 determined amount of oil in the Pressure oil accumulator 7 when the "spreading" of the hydraulic drive is initiated.
  • the pressure oil reservoir 7 designed as a piston accumulator serves as an "oil reservoir” for the entire hydraulic circuit of the Hydraulic drive and covers that during the alignment process occurring volume requirement.
  • the pressure oil reservoir 7 is biased so far that the briefly occurring large volume flows do not lead to negative pressure in the system to lead.
  • the pressure oil reservoir 8 designed as a bladder accumulator is pre-tensioned so far that the in it prevailing pressure causes the required braking force. He takes out the amount of oil during the adjustment process the brake cylinders 3 is displaced and gives this amount of oil when "spreading" the hydraulic drive to the pressure point cylinder 1 off again. Are the surfaces of the pistons the Brake cylinder 3 is the same as that of the short-stroke piston Pressure oil reservoir 8 via the pump no additional oil be fed.
  • the pressure relief valve 9 is preferably as Continuous valve runs and serves within one Storage charge control in addition to the setting of the required brake pressure. Is the pressure oil reservoir 8 on filled the required amount, the pump is on pressureless circulation.
  • the unlockable check valve 11 is activated when the drawing process is complete and the plunger 4 again must be brought into its starting position. That is, the Pressure point cylinders (1) are refilled by via the unlockable check valve 11 with the Pressure oil reservoir 8 are connected.
  • the braking process takes place of the plunger 4 with the upper tool analogous to the circuit arrangement 2 with the check valve 11 open.
  • This unlockable check valve 11 is also during of the acceleration process first opened. It will closed before the short-stroke piston 1a the end position achieved.
  • the continuous valve 10 acts until it stops the short-stroke piston 1a as a damping valve.
  • the Balancing device designed to be controllable and brakes the plunger 4 to the required waypoint and with sufficient intensity after decoupling the power flow temporarily in the pressure points. This is between the balancing cylinder 13 and the surge tank 14 at least one valve 15 is arranged. At the pressure room of the Balancing cylinders 13 are on the one hand to avoid impermissible pressures pressure relief valves 16 and the other at least one check valve 17 for prevention a vacuum installed.
  • the short-stroke pistons 1a can cover their stroke if that Oil trapped in the pressure point cylinders 1 via the Switching or continuous valve 18 in the pressure oil reservoir 7 is pressed.
  • the plunger 4 By initiating the stroke via the drive, not shown the plunger 4 goes into the closed position with the upper tool. Depending on the crank angle, the valve becomes 15 in Locked position switched so that there is an increased Pressure increase in the pressure chamber of the balancing cylinder 13 sets. This also increases the hydraulic pressure in the pressure point cylinders 1, since the valve 18 is also is in the locked position. Before the upper tool on the Board 19 hits, the valve 18 is dependent on the crank angle open. The increased balancing power is able the plunger 4 to brake effectively, the drive via the Short-stroke piston 1a the pressure oil from the pressure point cylinders 1 presses into the pressure oil reservoir 7 via the valve 18. The The signal is given so that the stroke of the short-stroke piston 1a has not yet been completed before the upper tool Board 19 reached. As a result of the tappet braking progressive tappet movement reduces Impact speed clearly.
  • the piston rods 24 can be coupled with the plunger 4 or through Adjustment spindles, not shown here, acted upon become.
  • the working cylinder 23 can on the lower Tool carrier, the machine table, in the side stand or be arranged on the head piece 27.
  • the continuous valve 25 is activated via control cam so that the upper tool on the circuit board 19 hits before the short-stroke piston 1a its stroke have traveled. Once the stroke has been completed, the Pressure chamber of the working cylinder 23 are depressurized. About the check valve 26, the pressure chamber during the Run-up of the tappet 4 filled again, so that the piston rods 24 reach their starting position.
  • this is Housing of the brake cylinder 3 mounted on the plunger 4, the Piston rod is articulated on the head piece 27.
  • the valve 5 is open and the volume deficit is canceled by means of expansion tank 28.
  • the expansion tank 28 is biased.
  • a Pressure relief valve 29 secures the rod side Pressure chamber of the brake cylinder 3 against impermissible Operating pressures.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Presses And Accessory Devices Thereof (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Punching Or Piercing (AREA)

Description

Die Erfindung betrifft ein Verfahren zum Lärm- und stoßarmen Angleichen des Ober- und Unterwerkzeuges von mechanischen Fressen, insbesondere Pressen zum Umformen von Blechteilen bei hohen Hubzahlen gemäß dem Oberbegriff des Anspruchs 1. Gegenstand der Erfindung ist weiterhin ein Stößelantrieb für mechanische Pressen mit einer Einrichtung zur Durchführung des o. g. Verfahrens mit den Merkmalen des Oberbegriffs des Anspruchs 4.The invention relates to a method for noise and Low impact adjustment of the upper and lower tools from mechanical seizures, in particular presses for forming Sheet metal parts with high stroke rates according to the generic term of Claim 1. The invention is also a Ram drive for mechanical presses with one device to carry out the above Process with the characteristics of Preamble of claim 4.

Bei mechanischen Kurbel- bzw. Exzenterpressen entstehen bei hohen Hubzahlen und großen Ziehtiefen durch den Auftreffstoß negative Auswirkungen auf die Teilequalität und eine unzulässige Lärmbelastung für den Werker.With mechanical crank or eccentric presses arise at high stroke rates and large drawing depths due to the impact impact negative impact on part quality and a impermissible noise pollution for the worker.

Die kostenaufwendigen Gelenk- bzw. Hebelpressen haben den Auftreffstoß gemindert, dennoch sind insbesondere beim Einsatz von Pneumatikkissen in vielen Fällen zusätzlich noch Einrichtungen zum Vorbeschleunigen der bewegten Massen erforderlich. Bei Schneidarbeiten ohne Kissen im Tisch kann auf diese Einrichtungen nicht zurückgegriffen werden.The costly articulated or lever presses have that Impact impact reduced, but are especially in the In many cases, pneumatic cushions are also used still devices for pre-accelerating the moving masses required. When cutting without a pillow in the table these facilities are not used.

Es wurden auch Lösungen für den Stößelantrieb vorgeschlagen, die die werkzeugabhängigen Angleichvorgänge durch eine geeignete Gestaltung der Kinematik im Antriebsmechnismus (DE 41 30 004 A1) realisieren. Die Variabilität des Aufsetzpunktes führt dabei konstruktiv zu außerordentlich hohen Anforderungen.Solutions for the tappet drive have also been proposed, which the tool-dependent adjustments by a suitable design of the kinematics in the drive mechanism (DE 41 30 004 A1). The variability of the The point of contact leads constructively to extraordinary high demands.

Bei einem weiteren Vorschlag (DE 41 12 942 A1) ist der Stößelantrieb als Innen- und Außenstößel ausgebildet. Dabei wird der Innenstößel durch steuer- und regelbare Hubzylinder angetrieben, die am Außenstößel befestigt sind.In another proposal (DE 41 12 942 A1) Tappet drive designed as an inner and outer tappet. Here the inner tappet is controlled by controllable lifting cylinders driven, which are attached to the outer plunger.

Aus den DD 279 639 A1 und DD 295 798 A5 sind zwei Lösungen bekannt, bei denen der Angleichvorgang durch gesteuerte Hubzylinder, die zwischen den Druckpunkten und dem Stößel angeordnet sind, realisiert wurde. DD 279 639 A1 and DD 295 798 A5 are two solutions known in which the adjustment process is controlled by Lift cylinder between the pressure points and the tappet are arranged, was realized.

Keine der vorgeschlagenen Lösungen erfüllt die Anforderungen, mit einfachen Mitteln ein leistungsfähiges und robustes Verfahren für den Angleichvorgang zu schaffen unter Beachtung eines hohen Wirkungsgrades der Maschine.None of the proposed solutions meet the requirements a powerful and simple tool to create a robust process for the alignment process considering the high efficiency of the machine.

Die Aufgabe der Erfindung ist es, ein Verfahren und eine Einrichtung vorzuschlagen, nach dem mit einfachen Mitteln und hohem Wirkungsgrad der Angleichvorgang beim Schließen des Werkzeuges sicher beherrscht wird.The object of the invention is a method and To propose establishment, after which with simple means and high efficiency of the adjustment process when closing of the tool is safely mastered.

Erfindungsgemäß wird das durch die Abarbeitung der Verfahrensschritte gemäß den kennzeichnenden Merkmalen des Anspruchs 1 erreicht. Durch die Merkmale des Anspruchs 2 ist eine noch bessere Anpassung der Bewegungscharakteristik möglich. Im Anspruch 3 wird ein Verfahren angegeben, nach dem die optimalen Einstellparameter zur Durchführung des Verfahrens nach den Ansprüchen 1 und 2 ermittelt werden können.According to the invention, this is done by processing the process steps according to the characteristic features of the Claim 1 reached. By the features of claim 2 is an even better adjustment of the movement characteristics possible. In claim 3, a method is specified according to which the optimal setting parameters for carrying out the Method according to claims 1 and 2 are determined can.

Ein Stößelantrieb mit einer Einrichtung zur Durchführung des Verfahrens nach den Ansprüchen 1 oder 2 ist im Anspruch 4 beschrieben. Die Ansprüche 5 bis 7 enthalten weitere vorteilhafte Ausgestaltungen der Einrichtung nach Anspruch 4.A plunger drive with a device for the implementation of the method according to claims 1 or 2 is in claim 4 described. Claims 5 to 7 contain further advantageous Embodiments of the device according to claim 4.

Als Angleichvorgang wird die Bewegung des Stößels in Bezug zur Druckpunktfläche des Pleuels bezeichnet. Dieser Angleichvorgang kann nur über den begrenzten Hub der Druckpunktzylinder erfolgen. Der Angleichvorgang gelingt, wenn folgende Bedingungen erfüllt werden:

  • 1. Der Angleichvorgang muß mit einer ausreichend großen Geschwindigkeit erfolgen. Da die Richtung der Angleichbewegung der Antriebsbewegung des Stößels entgegengesetzt ist, verlangsamt sich die Bewegung des Stößels bezüglich des Pressengestells im gleichen Maße.
  • 2. Die Geschwindigkeit des Stößels muß beim Auftreffen auf das Blechteil ausreichend klein sein, d.h. die Relativgeschwindigkeit gegenüber den Pleuelstangen soll möglichst ihr Maximum erreichen.
  • 3. Nach dem Aufsetzen des Stößels auf das Blechteil soll der Stößel in Richtung des Blechteils wieder ausreichend beschleunigt werden, damit am Ende des Angleichvorgangs der innere Anschlag mit einer reduzierten Geschwindigkeit erreicht wird.
    • The movement of the tappet in relation to the pressure point surface of the connecting rod is called the adjustment process. This adjustment process can only take place via the limited stroke of the pressure point cylinder. The alignment process succeeds if the following conditions are met:
  • 1. The adjustment process must be carried out at a sufficiently high speed. Since the direction of the alignment movement is opposite to the drive movement of the ram, the movement of the ram with respect to the press frame slows down to the same extent.
  • 2. The speed of the tappet must be sufficiently low when it hits the sheet metal part, ie the relative speed compared to the connecting rods should reach its maximum if possible.
  • 3. After placing the plunger on the sheet metal part, the plunger should be accelerated sufficiently in the direction of the sheet metal part so that the inner stop is reached at a reduced speed at the end of the alignment process.

    • Zur Beeinflussung des Angleichvorgangs stehen mit der in Fig. 2 dargestellten Schaltungsanordnung folgende Variablen zur Verfügung:

    • Nocken zum Einschalten und Ausschalten des Bremsvorgangs,
    • Nocken zur Einleitung und Beendigung des Beschleunigungsvorgangs,
    • Drucksollwert für den Druckölspeicher zur Einstellung der erforderlichen Bremskraft.
    The following variables are available with the circuit arrangement shown in FIG. 2 to influence the adjustment process:
    • Cams to switch the braking process on and off,
    • Cams for initiating and ending the acceleration process,
    • Pressure setpoint for the pressure oil reservoir for setting the required braking force.

    Damit soll der Hybridantrieb an unterschiedliche Hubzahlen, verschiedene Ziehtiefen, variable Oberwerkzeugmassen und an verschiedene Ziehkissen- und Verfahrenskräfte anpaßbar sein.With this, the hybrid drive at different stroke rates, different drawing depths, variable upper tool dimensions and various die cushion and process forces adaptable be.

    Die Ermittlung der optimalen Einstellparameter wird in nachfolgend beschriebener Verfahrensweise vorgenommen.The determination of the optimal setting parameters is in procedure described below.

    Der Angleichvorgang wird in zwei Bereiche unterteilt - in den Brems- und in den Beschleunigungsvorgang. Sind die Verfahrens- und Ziehkissenkräfte vernachlässigbar klein, so werden für das Bremsen und das Beschleunigen gleichgroße Wege vorgesehen, also jeweils der halbe Relativhub.The alignment process is divided into two areas - in the braking and acceleration process. If the process and die cushion forces are negligible, so become the same size for braking and accelerating Paths provided, i.e. half the relative stroke.

    Zur gezielten Beeinflussung des Bremsvorgangs können folgende modellhafte Überlegungen zugrunde gelegt werden. Die dominante Größe beim Bremsen ist die kinetische Energie des Stößels, die durch die Stößelmasse und die momentane Stößelgeschwindigkeit gekennzeichnet ist. Dem Stößel wird während des Bremsvorgangs eine definierte Kraft entgegengesetzt (Druck des Hydrauliköls im Druckölspeicher) und über den Bremsweg wird die kinetische Energie größtenteils in potentielle Energie (Federspannarbeit) umgewandelt. Dabei treten strömungsbedingte Verluste auf. Die Stößelbewegung läßt sich vereinfacht mit der Bewegungsgleichung eines schwach gedämpften, schwingungsfähigen Systems 2. Ordnung beschreiben. The following can be used to influence the braking process in a targeted manner model considerations are used as a basis. The The dominant variable when braking is the kinetic energy of the Plunger by the plunger mass and the current Ram speed is marked. The pestle will opposed to a defined force during braking (Pressure of the hydraulic oil in the pressure oil reservoir) and The kinetic energy is largely via the braking distance converted into potential energy (spring tension work). Flow-related losses occur. The Ram movement can be simplified using the equation of motion a weakly damped, vibratory Describe 2nd order systems.

    Die Lösung der Differentialgleichung ist der Relativweg, den der Stößel in Richtung des Druckpunktes zurücklegt. Bei Einleitung des Bremsvorgangs wird der Stößel vom Antrieb "abgekoppelt" und verlangsamt seine Geschwindigkeit, bis die gewünschte Auftreffgeschwindigkeit erreicht ist. In Abhängigkeit von der Bremskraft wird dabei ein bestimmter Bremsweg zurückgelegt. Der Bremsweg und die Bremsgeschwindigkeit sind als Funktion von der Zeit und der Bremskraft als Gleichungssytem darstellbar. Die Lösung des Gleichungssystems gibt die erforderliche Bremskraft und die dazugehörige Bremszeit an, die der Stößel benötigt, um die gewünschte Auftreffgeschwindigkeit nach dem halben Relativweg zu erreichen. Damit läßt sich der Kurbelwinkel zum Zeitpunkt des Auftreffens angeben. Unter der Voraussetzung, daß sich die Hubzahl der Presse während der Abwärtsbewegung des Stößels nicht ändert, kann der Startpunkt (z.B. durch Nocken) für die Einleitung des Bremsvorgangs exakt ermittelt werden.The solution to the differential equation is the relative path, which the tappet travels in the direction of the pressure point. At Initiation of the braking process is the tappet from the drive "uncoupled" and slows down its speed until the desired impact speed has been reached. In Dependence on the braking force becomes a certain one Braking distance covered. The braking distance and the braking speed are a function of time and the Braking force can be represented as an equation system. The solution of the Equation system gives the required braking force and the associated braking time that the plunger needs to reach the desired impact speed after half To achieve relative path. This allows the crank angle specify at the time of impact. Provided, that the number of strokes of the press during the Downward movement of the ram does not change, the starting point (e.g. by cams) for initiating the braking process can be determined exactly.

    Die Einleitung des Beschleunigungsvorgangs erfolgt unmittelbar nach dem Aufsetzen. Mit dem Beschleunigen stellen sich die schaltungstechnisch bedingten Zwangsverhältnisse ein. Der Stößel nimmt unter der Vorraussetzung der Flächengleichheit von Brems- und Druckpunktzylinder die Hälfte der aktuellen Antriebsgeschwindigkeit an. Damit ist der innere Anschlag erreicht.The acceleration process is initiated immediately after touchdown. Pose with the acceleration the circuit-related constraints on. The plunger takes on the premise of Equal area of brake and pressure point cylinders Half of the current drive speed. So that is the inner stop reached.

    Muß während des Angleichvorgangs mit Ziehkissen- und Verfahrenskräften gerechnet werden, so spielt die Federsteifigkeit des eingeschlossenen Hydrauliköls eine Rolle. Der hydraulische Zwanglauf wird erst dann voll wirksam, wenn das Öl in den Rohrleitungen ausreichend vorgespannt ist. Die Folge ist eine Verzögerung des Beschleunigungsvorgangs, so daß u.U. der innere Anschlag mit einer größeren Geschwindigkeit als vorgesehen, erreicht wird. In diesem Fall muß das Verhältnis zwischen Brems- und Beschleunigungsweg derart geändert werden, daß sich der Beschleunigungsweg verlängert und der Bremsweg sich verkürzt. Must be done with die cushion and Process forces are expected, so the spring stiffness plays of the enclosed hydraulic oil play a role. The hydraulic forced operation only becomes fully effective if the oil in the pipes is sufficiently pre-stressed is. The result is a delay in Acceleration process, so that possibly the inner stop at a higher speed than intended becomes. In this case, the ratio between braking and Acceleration path are changed so that the Acceleration distance extends and the braking distance increases shortened.

    Nach der in Fig. 3 dargestellten Schaltungsordnung läßt sich der Angleichvorgang ebenfalls mit drei veränderbaren Parametern an unterschiedliche Hubzahlen, Ziehtiefen und Kräfte anpassen:

    • Nocken zum Ein- und Ausschalten des Bremsvorgangs,
    • Drucksollwert für den Druckölspeicher zur Einstellung der Bremskraft,
    • Sollwert für das Stetigventil zur Regelung der Angleichgeschwindigkeit.
    According to the circuit arrangement shown in FIG. 3, the adjustment process can also be adapted to three stroke numbers, drawing depths and forces with three changeable parameters:
    • Cams for switching the braking process on and off,
    • Pressure setpoint for the pressure oil reservoir for setting the braking force,
    • Setpoint for the continuous valve for regulating the adjustment speed.

    Im Unterschied zu der in Fig. 2 beschriebenen Schaltung wird der Angleichvorgang nicht durch Einstellung der Bremskraft und durch die darauf abgestimmte Auslösung des Bremsvorgangs vorgenommen, sondern der Angleichvorgang wird durch die Soll-Funktionsvorgabe und Regelung mit dem Stetigventil 10 dem Hybridantrieb "aufgezwungen". Da der Hybridantrieb zwischen zwei entgegengerichteten, hydraulischen Kräften eingespannt ist, läßt sich der Angleichvorgang bei ständig wirkender Bremskraft durch Abflußregelung des Öls aus den Druckpunktzylindern beeinflussen. Die Bremsenergie muß hierbei größer als die durch die Pressenhubzahl bestimmte kinetische Energie des Stößels sein und ergibt sich aus der Bewegungscharakteristik des Angleichvorgangs.Aus energetischen Gründen ist es sinnvoll, die Bremskraft an die sich ändernde Pressenhubzahl anzugleichen. Die Zeitdauer des gesamten Angleichvorgangs ist abhängig von der Pressenhubzahl und zusätzlich von der gewünschten Auftreffgeschwindigkeit.In contrast to the circuit described in FIG. 2 the adjustment process is not carried out by setting the Braking force and the coordinated triggering of the Braking process made, but the adjustment process through the target function specification and control with the Steady valve 10 "forced" on the hybrid drive. Since the Hybrid drive between two opposite, hydraulic Forces is clamped, the adjustment process with constantly acting braking force through discharge control affect the oil from the pressure point cylinders. The braking energy must be greater than that by Press stroke number certain kinetic energy of the ram be and results from the movement characteristics of the Alignment process. For energy reasons, it makes sense to adjust the braking force to the changing number of press strokes. The duration of the entire alignment process is depending on the number of press strokes and also on the desired impact speed.

    Prinzipiell lassen sich beliebige Bewegungsfunktionen der Rast-in-Rast-Kinematik dem Hybridantrieb vorgeben. Die beim Beschleunigen gegen das Ziehkissen auftretenden Ziehkissen- und Verfahrenskräfte beeinflussen den Angleichvorgang solange nicht, wie der Druck in den Druckpunktzylindern seinen Grenzwert noch nicht erreicht hat.In principle, any movement functions of the Specify rest-in-rest kinematics for the hybrid drive. The at Accelerate against the die cushion and die cushion Process forces influence the alignment process not as long as the pressure in the pressure point cylinders has not yet reached its limit.

    Die Erfindung wird nachfolgend an mehreren Ausführungsbeispielen näher erläutert. Die zugehörigen Zeichnungen zeigen:

    Fig. 1:
    den Verfahrensablauf zur Ermittlung der optimalen Einstellparameter als Blockschaltbild,
    Fig. 2:
    eine Einrichtung zum Bremsen und Beschleunigen durch reversierbare Energiewandlung,
    Fig. 3:
    eine Einrichtung zum Bremsen und Beschleunigen durch Verdrängersteuerung über ein Stetigventil und die
    Fig. 4-6:
    weitere Varianten für die Ausgestaltung des Stößelantriebes.
    The invention is explained in more detail below using several exemplary embodiments. The associated drawings show:
    Fig. 1:
    the process sequence for determining the optimal setting parameters as a block diagram,
    Fig. 2:
    a device for braking and accelerating through reversible energy conversion,
    Fig. 3:
    a device for braking and accelerating through displacement control via a continuous valve and
    Fig. 4-6:
    further variants for the design of the tappet drive.

    Bei einer Einrichtung zur Durchführung des Verfahrens sind nach Fig. 2 in den Druckpunkten des Stößels 4 zwischen den Pleuelstangen und dem Stößel 4 zusätzliche hydraulisch betätigbare Druckpunktzylinder 1 mit einfachwirkenden Kurzhubkolben 1a angeordnet. Am Kopfstück 27 sind die Kolbenstangen 2 von Bremszylindern 3 (mit beiderseitigen Kolbenstangen) angelenkt, während das Gehäuse am Stößel 4 befestigt ist. Die oberen und unteren Räume der Bremszylinder 3 können durch das Ventil 5 bei Erfordernis gegeneinander abgesperrt werden. Über ein Rückschlagventil 6 wird bei Bedarf Öl aus dem mit Niederdruck beaufschlagten, als Kolbenspeicher ausgeführten Druckölspeicher 7 gesaugt. Der Druckölspeicher 8 dient als Energiewandler des zu bremsenden und zu beschleunigenden Stößels 4.At a facility to carry out the procedure 2 in the pressure points of the plunger 4 between the Connecting rods and the tappet 4 additional hydraulic actuatable pressure point cylinder 1 with single-acting Short-stroke piston 1a arranged. At the head 27 are the Piston rods 2 of brake cylinders 3 (with both sides Piston rods) articulated while the housing on the tappet 4 is attached. The upper and lower rooms of the Brake cylinder 3 can through the valve 5 if necessary locked against each other. Via a check valve 6 If necessary, oil from the low pressure, designed as a piston accumulator 7 sucked. The pressure oil reservoir 8 serves as an energy converter of the ram to be braked and accelerated 4.

    Mit den Einschalten der Pressenkupplung wird das Rückschlagventil 11 entsperrt, so daß unter dem Vorspanndruck des Druckölspeichers 8 die Kurzhubkolben 1 gespreizt werden, bevor der Stößel 4 mit dem Oberwerkzeug schließt. Das Sperren des Ventils 5 bewirkt ein zügiges Bremsen des Stößels 4, indem das Öl aus den oberen Räumen der Bremszylinder 3 in den Druckölspeicher 8 verdrängt wird. Gleichzeitig schieben die Kurzhubkolben 1a das Öl in die unteren Räume der Bremszylinder 3. Bei Bedarf wird Öl vom Druckölspeicher 7 über das Rückschlagventil 6 angesaugt.The check valve is activated when the press coupling is switched on 11 unlocked so that under the preload of the pressure oil reservoir 8, the short-stroke pistons 1 spread before the plunger 4 closes with the upper tool. Locking the valve 5 causes a rapid braking of the Tappet 4 by removing the oil from the upper spaces of the Brake cylinder 3 is displaced into the pressure oil reservoir 8. At the same time, the short-stroke pistons 1a push the oil into the lower spaces of the brake cylinder 3. If necessary, oil from the Pressure oil reservoir 7 sucked in via the check valve 6.

    Mit deutlich reduzierter Geschwindigkeit setzt der Stößel 4 mit Oberwerkzeug auf die Platine 19 auf. Das restliche Öl aus den Druckpunktzylindern 1a wird in die unteren Räume der Bremszylinder 3 gepreßt. Dadurch erfahren der Stößel 4 mit Oberwerkzeug, die Platine 19, der Blechhalter 20, die Druckbolzen 21 sowie die nicht dargestellte Druckbolzenplatte des Ziehkissens eine Beschleunigungskraft gegen das Kopfstück 27, die solange wirkt, bis die Kurzhubkolben 1a ihren unteren mechanischen Anschlag erreichen.The tappet 4 sets at a significantly reduced speed with the upper tool on the board 19. The rest of the oil the pressure point cylinders 1a become the lower rooms the brake cylinder 3 pressed. This causes the tappet 4 to experience with upper tool, the board 19, the sheet metal holder 20, the Push pin 21 and the push pin plate, not shown of the die cushion against an acceleration force the head piece 27, which acts until the short-stroke pistons 1a reach its lower mechanical stop.

    Die Wirkungsweise der Schaltung nach Fig. 2 wird nachstehend an Hand der Funktionen der einzelnen Bauteile näher erläutert.The operation of the circuit of FIG. 2 is below based on the functions of the individual components explained in more detail.

    1. Kurzhubkolben 1a1. Short stroke piston 1a

    Der Hub der Kurzhubkolben 1a repräsentiert den Angleichweg, den der Stößel 4 benötigt, um auf die Auftreffgeschwindigkeit abgebremst und nach dem Aufsetzen auf die Platine 19 wieder beschleunigt zu werden. Diese Angleichung setzt sich also aus dem Bremsweg und dem Beschleunigungsweg zusammen. Das Verhältnis von Bremsweg zu Beschleunigungsweg ist 1:1 wenn keine äußeren Kräfte auf den Stößel 4 wirken, während dieser beschleunigt wird. Das Steuerungsverfahren sieht es vor, die auf den Stößel 4 wirkenden Verfahrens- und Kissenkräfte durch eine Veränderung des Verhältnisses von Brems- und Beschleunigungsweg zu berücksichtigen. Die Fläche der Kurzhubkolben 1a richtet sich nach der maximalen Beschleunigungskraft, die der Stößel 4 bei einem bestimmten Maximaldruck aufbringen kann.The stroke of the short-stroke pistons 1a represents the adjustment path, which the plunger 4 needs to hit the impact speed slowed down and after putting on the Board 19 to be accelerated again. This approximation is composed of the braking distance and the acceleration distance together. The ratio of braking distance to acceleration distance is 1: 1 if no external forces act on the plunger 4, while this is accelerating. The control process it provides for the process and acting on the plunger 4 Pillow forces by changing the relationship of braking and acceleration distance to be taken into account. The The area of the short-stroke pistons 1a depends on the maximum Accelerating force that the plunger 4 at a certain Can apply maximum pressure.

    2. Bremszylinder 32.brake cylinder 3

    Die Gehäuse der Bremszylinder 3 sind mit dem Stößel 4 fest verbunden. Damit sind alle Elemente der hydraulichen Schaltung in bzw. am Stößel 4 angeordnet, so daß keine flexiblen Hydraulikleitungen erforderlich sind, die hydrauliche Verbindungen zwischen feststehenden und bewegten Teilen der Presse herstellen. Die Kolbenstangen 2 der Bremszylinder 3 sind mindestens an einem Ende fest mit dem Pressengestell verbunden. Die Bremszylinder 3 müssen als Gleichgangzylinder ausgebildet sein, da jeweils beide Zylinderkammern miteinander kurzgeschlossen sind, wenn der Angleichvorgang nicht stattfindet. Ist die Kolbenfläche der Kolben der Bremszylinder 3 gleich der Fläche der Kurzhubkolben 1a, so ist die Geschwindigkeit des Stößels 4 am Ende des Angleichvorgangs halb so groß wie die momentane Geschwindigkeit der Pleuelstangen. Mit dieser Geschwindigkeit wird der innere Anschlag erreicht. Diese Anschlaggeschwindigkeit läßt sich verringern, indem die Fläche der Kolben der Bremszylinder 3 kleiner bemessen wird als die der Kurzhubkolben 1a der Druckpunkte. Aus energetischen Gründen ist jedoch Flächengleichheit anzustreben.The housing of the brake cylinder 3 are fixed with the plunger 4 connected. So that all elements of the hydraulic Circuit arranged in or on the plunger 4, so that none flexible hydraulic lines are required hydraulic connections between fixed and manufacture moving parts of the press. The piston rods 2 the brake cylinder 3 are fixed at least at one end connected to the press frame. The brake cylinder 3 must be designed as a synchronous cylinder, since both Cylinder chambers are shorted together when the Adjustment process does not take place. Is the piston area of the Piston of the brake cylinder 3 equal to the area of the Short stroke piston 1a, the speed of the tappet 4 at the end of the alignment process half the size of the current one Connecting rod speed. At this speed the inner stop is reached. This velocity can be reduced by the area of the Piston of the brake cylinder 3 is dimensioned smaller than that the short-stroke piston 1a of the pressure points. From energetic However, reasons should be striven for equal area.

    3. Ventil 5 ("Bremsen")3. Valve 5 ("braking")

    Dieses Sitzventil unterbricht den Kurzschluß zwischen Zylinderober- und -unterseite der Bremszylinder 3 während des gesamten Angleichvorgangs. Es leitet mit seiner Betätigung den Bremsvorgang ein und muß am Ende des Beschleunigungsvorgangs, wenn das Ölvolumen aus den Druckpunktzylindern 1 in die Bremszylinder 3 verdrängt wurde, wieder aktiviert werden. Dies geschieht um ein Überfüllen des Druckölspeichers 8 und das Abspritzen des überschüssigen Öles über das Speichersicherungsventil zu vermeiden.This seat valve interrupts the short circuit between Cylinder top and bottom of the brake cylinder 3 during of the entire alignment process. It conducts with his Activate the braking process and must at the end of Acceleration process when the oil volume from the Pressure point cylinders 1 displaced into the brake cylinder 3 was reactivated. This happens at a Overfilling the pressure oil reservoir 8 and spraying the excess oil through the accumulator safety valve avoid.

    4. Rückschlagventil 6 ("Nachsaugen")4. Check valve 6 ("suction")

    Während des Bremsvorgangs gelangt das Öl aus den oberen Räumen der Bremszylinder 3 in den Druckölspeicher 8. Gleichzeitig ergibt sich für die unteren Räume der Bremszylinder 3 ein Volumenbedarf, der über das Rückschlagventil 6 durch den Druckölspeicher 7 gedeckt wird. Das Rückschlagventil 6 verhindert jedoch ein Rückfließen der für die Druckpunktzylinder 1 bestimmten Ölmenge in den Druckölspeicher 7, wenn das "Spreizen" des Hydraulikantriebes eingeleitet wird.The oil comes out of the upper ones during braking Broaching the brake cylinder 3 in the pressure oil reservoir 8. At the same time, for the lower rooms Brake cylinder 3 a volume requirement, which via the check valve 6 is covered by the pressure oil reservoir 7. The Check valve 6 prevents backflow of the for the pressure point cylinder 1 determined amount of oil in the Pressure oil accumulator 7 when the "spreading" of the hydraulic drive is initiated.

    5. Druckölspeicher 75. Pressure oil reservoir 7

    Der als Kolbenspeicher ausgeführte Druckölspeicher 7 dient als "Ölreservoir" für die gesamte hydrauliche Schaltung des Hydraulikantriebs und deckt den während des Angleichvorgangs auftretenden Volumenbedarf. Der Druckölspeicher 7 ist soweit vorgespannt, daß die kurzzeitig auftretenden großen Volumenströme nicht zu Unterdruck in der Anlage führen.The pressure oil reservoir 7 designed as a piston accumulator serves as an "oil reservoir" for the entire hydraulic circuit of the Hydraulic drive and covers that during the alignment process occurring volume requirement. The pressure oil reservoir 7 is biased so far that the briefly occurring large volume flows do not lead to negative pressure in the system to lead.

    6. Druckölspeicher 86.Pressure oil reservoir 8

    Der als Blasenspeicher ausgeführte Druckölspeicher 8 ist vor dem Angleichvorgang soweit vorgespannt, daß der in ihm herrschende Druck die erforderliche Bremskraft bewirkt. Er nimmt während des Angleichvorgangs die Ölmenge auf die aus den Bremszylindern 3 verdrängt wird und gibt diese Ölmenge beim "Spreizen" des Hydraulikantriebs an die Druckpunktzylinder 1 wieder ab. Sind die Flächen der Kolben der Bremszylinder 3 gleich denen der Kurzhubkolben, muß dem Druckölspeicher 8 über die Pumpe kein zusätzliches Öl zugeführt werden.The pressure oil reservoir 8 designed as a bladder accumulator is pre-tensioned so far that the in it prevailing pressure causes the required braking force. He takes out the amount of oil during the adjustment process the brake cylinders 3 is displaced and gives this amount of oil when "spreading" the hydraulic drive to the pressure point cylinder 1 off again. Are the surfaces of the pistons the Brake cylinder 3 is the same as that of the short-stroke piston Pressure oil reservoir 8 via the pump no additional oil be fed.

    7. Druckbegrenzungsventil 97. Pressure relief valve 9

    Das Druckbegrenzungsventil 9 ist vorzugsweise als Stetigventil ausgeführt und dient innerhalb einer Speicherladeregelung zusätzlich der Einstellung des erforderlichen Bremsdruckes. Ist der Druckölspeicher 8 auf das erforderliche Maß gefüllt, wird die Pumpe auf drucklosen Umlauf gestellt.The pressure relief valve 9 is preferably as Continuous valve runs and serves within one Storage charge control in addition to the setting of the required brake pressure. Is the pressure oil reservoir 8 on filled the required amount, the pump is on pressureless circulation.

    8. Entsperrbares Rückschlagventil 11 ("Spreizen")8. Unlockable check valve 11 ("spreading")

    Das entsperrbare Rückschlagventil 11 wird aktiviert, wenn der Ziehvorgang abgeschlossen ist und der Stößel 4 wieder in seine Ausgangslage gebracht werden muß. D.h., die Druckpunktzylinder (1) werden wieder gefüllt, indem sie über das entsperrbare Rückschlagventil 11 mit dem Druckölspeicher 8 verbunden werden.The unlockable check valve 11 is activated when the drawing process is complete and the plunger 4 again must be brought into its starting position. That is, the Pressure point cylinders (1) are refilled by via the unlockable check valve 11 with the Pressure oil reservoir 8 are connected.

    9. Wegeventil 30 ("Beschleunigen")9. Directional control valve 30 ("accelerate")

    Mit Hilfe des Wegeventils 30 wird das "Beschleunigen", also die zweite Phase des Angleichvorgangs eingeleitet. Dabei wird durch Umschalten auf ein höheres Druckniveau dafür gesorgt, daß das aus den Druckpunktzylindern 1 austretende "überschüssige" Öl nicht mehr über ein Druckbegrenzungsventil in den Druckölspeicher 7, sondern zwangsweise in die unteren Räume der Bremszylinder 3 gelangt. Somit wird eine "hydrauliche Übersetzung" aktiviert, die den Stößel 4 mit der halben Geschwindigkeit der Pleuelstangen gegen das Werkzeug bewegt.With the help of the directional valve 30, the "acceleration", ie the second phase of the alignment process is initiated. Here is done by switching to a higher pressure level worried that the emerging from the pressure point cylinders 1 "Excess" oil no longer has a pressure relief valve in the pressure oil reservoir 7, but inevitably in the lower spaces of the brake cylinder 3 arrives. Thus one "hydraulic translation" activated, the plunger 4 with half the speed of the connecting rods against that Tool moves.

    Im Ausführungsbeispiel nach Fig. 3 erfolgt der Bremsvorgang des Stößels 4 mit Oberwerkzeug analog der Schaltungsanordnung nach Fig. 2 bei geöffneten Rückschlagventil 11. Dieses entsperrbare Rückschlagventil 11 ist auch während des Beschleunigungsvorgangs zunächst geöffnet. Es wird geschlossen, bevor die Kurzhubkolben 1a die Endlage erreicht haben. Das Stetigventil 10 wirkt bis zum Anschlag der Kurzhubkolben 1a als Dämpfungsventil.3, the braking process takes place of the plunger 4 with the upper tool analogous to the circuit arrangement 2 with the check valve 11 open. This unlockable check valve 11 is also during of the acceleration process first opened. It will closed before the short-stroke piston 1a the end position achieved. The continuous valve 10 acts until it stops the short-stroke piston 1a as a damping valve.

    Bei der Ausführung gemäß Fig. 4 ist die Ausbalancierungseinrichtung steuerbar ausgeführt und bremst den Stößel 4 zum erforderlichen Wegpunkt und mit ausreichender Intensität nach Entkopplung des Kraftflusses in den Druckpunkten vorübergehend ab. Hierzu ist zwischen dem Ausbalancierungszylinder 13 und dem Ausgleichsbehälter 14 mindestens ein Ventil 15 angeordnet. Am Druckraum der Ausbalancierungszylinder 13 sind einerseits zur Vermeidung unzulässiger Drücke Druckbegrenzungsventile 16 und andererseits mindestens ein Rückschlagventil 17 zur Verhinderung eines Unterdrucks eingebaut.4 is the Balancing device designed to be controllable and brakes the plunger 4 to the required waypoint and with sufficient intensity after decoupling the power flow temporarily in the pressure points. This is between the balancing cylinder 13 and the surge tank 14 at least one valve 15 is arranged. At the pressure room of the Balancing cylinders 13 are on the one hand to avoid impermissible pressures pressure relief valves 16 and the other at least one check valve 17 for prevention a vacuum installed.

    Die Kurzhubkolben 1a können ihren Hub zurücklegen, wenn das in den Druckpunktzylindern 1 eingeschlossene Öl über das Schalt- bzw. Stetigventil 18 in den Druckölspeicher 7 gedrückt wird.The short-stroke pistons 1a can cover their stroke if that Oil trapped in the pressure point cylinders 1 via the Switching or continuous valve 18 in the pressure oil reservoir 7 is pressed.

    Durch die Hubeinleitung über den nicht dargestellten Antrieb geht der Stößel 4 mit Oberwerkzeug in Schließstellung. Kurbelwinkelabhängig wird das Ventil 15 in Sperrstellung geschaltet, so daß sich ein erhöhter Druckanstieg im Druckraum der Ausbalancierungszylinder 13 einstellt. Dadurch erhöht sich auch der Hydraulikdruck in den Druckpunktzylindern 1, da das Ventil 18 sich ebenfalls in Sperrstellung befindet. Bevor das Oberwerkzeug auf die Platine 19 trifft, wird das Ventil 18 kurbelwinkelabhängig geöffnet. Die erhöhte Ausbalancierkraft ist in der Lage, den Stößel 4 wirksam zu bremsen, wobei der Antrieb über den Kurzhubkolben 1a das Drucköl aus den Druckpunktzylindern 1 über das Ventil 18 in den Druckölspeicher 7 drückt. Die Signalgabe erfolgt so, daß der Hub des Kurzhubkolbens 1a noch nicht zurückgelegt ist, bevor das Oberwerkzeug die Platine 19 erreicht. Infolge der Stößelbremsung bei fortschreitender Stößelbewegung reduziert sich die Auftreffgeschwindigkeit deutlich.By initiating the stroke via the drive, not shown the plunger 4 goes into the closed position with the upper tool. Depending on the crank angle, the valve becomes 15 in Locked position switched so that there is an increased Pressure increase in the pressure chamber of the balancing cylinder 13 sets. This also increases the hydraulic pressure in the pressure point cylinders 1, since the valve 18 is also is in the locked position. Before the upper tool on the Board 19 hits, the valve 18 is dependent on the crank angle open. The increased balancing power is able the plunger 4 to brake effectively, the drive via the Short-stroke piston 1a the pressure oil from the pressure point cylinders 1 presses into the pressure oil reservoir 7 via the valve 18. The The signal is given so that the stroke of the short-stroke piston 1a has not yet been completed before the upper tool Board 19 reached. As a result of the tappet braking progressive tappet movement reduces Impact speed clearly.

    Mit reduzierter Geschwindigkeit werden der Blechhalter 20 mit den Druckbolzen 21 und die massebehafteten Elemente des Ziehkissens beschleunigt und gleichzeitig die Kissenkraft überwunden. Während des Ziehvorganges wird das Ventil 15 geöffnet, so daß sich die Drücke im Ausbalancierzylinder 13 und Ausgleichsbehälter 14 angleichen können. In Tiefstlage wird das Ventil 15 erneut geschlossen. Durch den Druckzusammenbruch in den Ausbalancierungszylindern 13 kann der Stößel 4 nicht mehr der Bewegung des Antriebs der Kurzhubkolben 1a folgen. Dadurch entsteht ein Sog in den Druckpunktzylindern 1 und über das Rückschlagventil 22 bzw. Ventil 18 gelangt das Öl aus dem Druckölspeicher 7 wieder in die Druckpunktzylinder 1 zurück.The sheet metal holder 20 with the pressure pin 21 and the mass elements of Die cushion accelerates and at the same time the cushion force overcome. During the drawing process, the valve 15 opened so that the pressures in the balancing cylinder 13 and equalize reservoir 14. In the lowest position the valve 15 is closed again. By the Pressure collapse in the balancing cylinders 13 can the plunger 4 no longer the movement of the drive Follow short-stroke piston 1a. This creates a pull in the Pressure point cylinders 1 and via the check valve 22 or Valve 18 returns the oil from the pressure oil reservoir 7 back into the pressure point cylinder 1.

    Es ist auch denkbar, alternativ die pneumatischen Ausbalancierzylinder 13 und den Ausgleichsbehälter 14 durch hydrauliche Arbeitszylinder und hydrauliche Druckspeicher mit zwischengeschalteten Hydraulikventilen zu ersetzen.It is also conceivable, alternatively the pneumatic one Balancing cylinder 13 and the expansion tank 14 through hydraulic working cylinders and hydraulic pressure accumulators to be replaced with intermediate hydraulic valves.

    Im Ausführungsbeispiel nach Fig. 5 wirken hydrauliche Arbeitszylinder 23 kurz vor dem Auftreffen des Oberwerkzeuges auf das Unterwerkzeug auf den Stößel 4. Die Kolbenstangen 24 können mit dem Stößel 4 gekoppelt oder durch hier nicht dargestellte Verstellspindeln beaufschlagt werden. Die Arbeitszylinder 23 können auf dem unteren Werkzeugträger, dem Maschinentisch, im Seitenständer oder am Kopfstück 27 angeordnet sein. Das Stetigventil 25 wird über Steuernocken so aktiviert, daß das Oberwerkzeug auf die Platine 19 trifft, bevor die Kurzhubkolben 1a ihren Hub zurückgelegt haben. Ist der Hub zurückgelegt, kann der Druckraum der Arbeitszylinder 23 drucklos gemacht werden. Über das Rückschlagventil 26 wird der Druckraum während des Hochlaufs des Stößels 4 wieder gefüllt, so daß die Kolbenstangen 24 ihre Ausgangsstellung erreichen.5 act hydraulically Working cylinder 23 shortly before the upper tool hits on the lower tool on the tappet 4. The piston rods 24 can be coupled with the plunger 4 or through Adjustment spindles, not shown here, acted upon become. The working cylinder 23 can on the lower Tool carrier, the machine table, in the side stand or be arranged on the head piece 27. The continuous valve 25 is activated via control cam so that the upper tool on the circuit board 19 hits before the short-stroke piston 1a its stroke have traveled. Once the stroke has been completed, the Pressure chamber of the working cylinder 23 are depressurized. About the check valve 26, the pressure chamber during the Run-up of the tappet 4 filled again, so that the piston rods 24 reach their starting position.

    Bei einem weiteren Ausführungsbeispiel gemäß Fig. 6 ist das Gehäuse der Bremszylinder 3 am Stößel 4 montiert, dessen Kolbenstange am Kopfstück 27 angelenkt ist. Im Vorhub des Stößels 4 erfolgt ein Volumenaustausch des Öles aus dem stangenseitigen in den anderen Kolbenraum des Bremszylinders 3. Dabei ist das Ventil 5 geöffnet und das Volumendefizit wird mittels Ausgleichsbehälter 28 aufgehoben. Um den erforderlichen Füllgrad des Zylinderraumes zu sichern, wird der Ausgleichsbehälter 28 vorgespannt. Ein Druckbegrenzungsventil 29 sichert den stangenseitigen Druckraum des Bremszylinders 3 gegen unzulässige Betriebsdrücke ab. Zum Abbremsen des Stößels 4 vor dem Aufsetzen des Oberwerkzeuges auf den Blechhalter 20 wird das Ventil 5 geschlossen. Über die eingeschlossene Ölsäule wird eine Bremswirkung auf den Stößel 4 ausgeübt. Die Relativbewegung zwischen dem Kurzhubkolben 1a und dessen Anschlag wird erreicht, indem das Ventil 18 geöffnet wird.In a further exemplary embodiment according to FIG. 6, this is Housing of the brake cylinder 3 mounted on the plunger 4, the Piston rod is articulated on the head piece 27. In the preliminary stroke of the Ram 4 is a volume exchange of the oil from the rod-side in the other piston chamber of the brake cylinder 3. The valve 5 is open and the volume deficit is canceled by means of expansion tank 28. To the required degree of filling of the cylinder space too secure, the expansion tank 28 is biased. A Pressure relief valve 29 secures the rod side Pressure chamber of the brake cylinder 3 against impermissible Operating pressures. To brake the plunger 4 before Placing the upper tool on the sheet metal holder 20 valve 5 closed. About the enclosed oil column a braking effect is exerted on the tappet 4. The Relative movement between the short-stroke piston 1a and its Stop is achieved by opening the valve 18.

    Claims (7)

    1. A method of low noise and impact coordination of the upper and lower dies of mechanical presses, in which the sinusoidal motion characteristic produced by the crank or eccentric drive is superposed during particular stages of the ram stroke, preferably shortly before the upper die comes into contact with the sheet metal blank (blank holder), by relative motion produced by means of additional hydraulic working cylinders controllable as a function of the ram path or crank angle of the press and acting in the opposite direction from the motion of the crank or eccentric drive,
      characterised in that
      a) shortly before positioning of the upper die on the sheet metal part, in order to produce a braking force acting in the opposite direction from the ram motion, the compressed air outflow or pressure oil discharge from at least one braking cylinder (3) arranged between the ram (4) and the press frame (bed, press column, die holder or head piece) is halted or delayed or the braking cylinder (3) is connected with a pressure oil reservoir,
      b) pressure oil is discharged, optionally via valves, from the hydraulic centre of pressure cylinders (1) provided at each centre of pressure between connecting rod and ram (4) by forcing the pressure oil located in the centre of pressure cylinders (1) into a pressure oil reservoir (8) or at least in part into the lower cylinder chamber of the braking cylinder or cylinders (3) by the further downwards movement of the connecting rods when the ram is braked (4),
      c) after completion of the coordinating operation, the pressure in the braking cylinder or cylinders (3) is relieved by reversing the valves and
      d) during the ram return stroke, the short-stroke pistons (1a) of the centre of pressure cylinders (1) are brought back into the starting position by pressurising said short-stroke pistons (1a) or by applying a force acting in the opposite direction from the ram motion by means of the braking cylinders (3).
    2. A method of low noise and impact coordination of the upper and lower dies of mechanical presses according to claim 1,
      characterised in that
      a) the coordinating operation is subdivided into a braking operation, in which the ram speed is reduced relative to the connecting rod speed, and an accelerating operation, in which the ram speed once again approaches the connecting rod speed, wherein
      b) the ratio of braking distance to acceleration distance is such that the braking distance and the acceleration distance each correspond to approximately half the stroke distance of the short-stroke piston (1a) and the braking operation is completed before the upper die comes into contact with the sheet metal blank (19), and
      c) once the die has come into contact with the sheet metal blank (19), further oil discharge from the centre of pressure cylinders (1) is delayed by means of switchable or controllable valves in order to accelerate the ram (4), including the blank holder with the actively connected components of the die cushion, to the coordination speed and the pressure build-up in the die cushion, wherein the accelerating operation is completed when the short-stroke piston (1a) has travelled over its full stroke distance.
    3. A method of determining the optimum adjustment parameters for carrying out the method according to claims 1 and 2,
      characterised by the execution of the following steps, wherein individual steps are interchangeable within the sequence:
      a) setting of the braking force, the current drawing depths, the ratio of braking distance to the accelerating distance and the required impact speed,
      b) determination of the braking time required to reach impact speed,
      c) determination of the braking distance required to reach impact speed,
      d) comparison of the parameters,
      e) determination of the starting cam for initiating the accelerating operation,
      f) determination of the starting cam for initiating the braking operation and
      g) establishment of the switch-off point for the braking and accelerating operation.
    4. A ram drive for mechanical presses comprising an apparatus for carrying out the method according to claim 1, in particular for presses for shaping sheet metal parts which operate with high numbers of strokes, the rams of which are connected by means of connecting rods to the crank or eccentric drive, wherein, to achieve a relative motion of the ram acting in the opposite direction from the stroke motion of the connecting rods in each centre of pressure between the connecting rods and the ram, an additional, pressure oil-loadable piston is arranged in a cylinder chamber which is in turn actively connected via an on-off valve to a pressure oil reservoir,
      characterised in that
      the pistons (1) arranged in the centre of pressure cylinders (1) take the form of single-acting short stroke pistons (1a) and in that at least one hydraulically or pneumatically acting braking cylinder (3) serving as a temporarily acting ram brake is arranged between the ram (4) and the press frame (bed, lateral columns, die holder or head piece), wherein, by means of valves, the compressed air outflow or the pressure oil discharge from the braking cylinder (3) may be halted or throttled or the braking cylinder (3) may be actively connected to a pressure oil reservoir (8) in order to build up pressure during the coordination process.
    5. A ram drive for mechanical presses according to claim 4,
      characterised in that
      hydraulic cylinders with pistons loadable from two sides may be provided as braking cylinders (3), which pistons are preferably attached in or on the ram (4) and the piston rods (2) of which are mounted on the press frame, wherein the lower cylinder chambers of the braking cylinders (3) are connected directly or may be connected via a continuous valve (10) to the centre of pressure cylinders (1) and are connected in by-passing manner via an on-off valve (5) to the upper cylinder chambers of the braking cylinder (3) during (normal) ram motion to achieve oil circulation and the upper cylinder chambers are actively connected to the pressure oil reservoir (8) via a pilot-controlled check valve (11) during the coordination phase after closing of the on-off valve for the purpose of building up braking force acting in the opposite direction to the ram motion.
    6. A ram drive for mechanical presses according to claim 5,
      characterised in that
      a valve (10 or 30) delaying oil discharge to the centre of pressure cylinders (1) during the accelerating operation and a pressure oil reservoir (7) with relatively low oil pressure together with a check valve (11) upstream of the pressure oil reservoir (7) for blocking pressure oil discharge from the pressure oil reservoir (8) into the pressure oil reservoir (7) during expansion are arranged between the centre of pressure cylinders (1) and the lower cylinder chambers of the braking cylinders (3).
    7. A ram drive for mechanical presses according to claim 4, the ram and die mass of which is compensated by means of a hydraulically or pneumatically acting balancing device,
      characterised in that
      the balancing cylinders (13) are also used as braking cylinders, wherein, in order specifically to increase the pressure in the balancing cylinders (13) during the coordination process, a valve (15) blocking outflow of the compressed air in this stage or delaying discharge of the pressure oil is arranged between the balancing cylinders (13) and the equalising reservoirs (14).
    EP95117302A 1994-11-23 1995-11-03 Method for adjusting the impact of upper and lower tools in a press, damping the noise, and slide drive with a device using the method Expired - Lifetime EP0716916B1 (en)

    Applications Claiming Priority (2)

    Application Number Priority Date Filing Date Title
    DE4441569A DE4441569A1 (en) 1994-11-23 1994-11-23 Process for low-noise and shock-free alignment of the upper and lower tools of mechanical presses and ram drives with a device for carrying out the process
    DE4441569 1994-11-23

    Publications (2)

    Publication Number Publication Date
    EP0716916A1 EP0716916A1 (en) 1996-06-19
    EP0716916B1 true EP0716916B1 (en) 1999-08-25

    Family

    ID=6533874

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP95117302A Expired - Lifetime EP0716916B1 (en) 1994-11-23 1995-11-03 Method for adjusting the impact of upper and lower tools in a press, damping the noise, and slide drive with a device using the method

    Country Status (3)

    Country Link
    EP (1) EP0716916B1 (en)
    DE (2) DE4441569A1 (en)
    ES (1) ES2134984T3 (en)

    Families Citing this family (1)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE102015016773B4 (en) 2015-12-23 2024-12-24 Wieland Petter Processes for processing and shaping metallic and other materials

    Family Cites Families (8)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    FR1062187A (en) * 1952-08-25 1954-04-20 Dorstener Eisengiesserei U Mas Method of controlling mechanically driven punch presses
    DD279639A1 (en) * 1989-01-27 1990-06-13 Warnke Umformtech Veb K DRIVE FOR MECHANICAL PRESSES
    EP0417753B1 (en) * 1989-09-12 1993-09-22 Maschinenfabrik Müller-Weingarten AG Mechanical or hydraulic press with drawing or pressing station for multiple stage press
    DD295798A5 (en) * 1990-06-26 1991-11-14 Umformtechnik Erfurt Gmbh I G DRIVE WITH CONTROL FOR MECHANICAL PRESSES
    DE4112942A1 (en) * 1991-04-20 1992-10-22 Schuler Gmbh L MECHANICAL-HYDRAULIC PRESS
    DE4130004A1 (en) 1991-09-10 1993-03-11 Erfurt Umformtechnik Gmbh DRIVE FOR THE PUSHER OF MECHANICAL PRESSES
    DE69313585T2 (en) * 1992-11-05 1998-02-19 Toyota Motor Co Ltd Die cushion and method for optimizing its cylinder pin pressure
    DE4302263A1 (en) * 1993-01-28 1994-08-04 Horst Baltschun Mechanical transfer press with hydraulic units

    Also Published As

    Publication number Publication date
    EP0716916A1 (en) 1996-06-19
    ES2134984T3 (en) 1999-10-16
    DE59506687D1 (en) 1999-09-30
    DE4441569A1 (en) 1996-05-30

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