WO1999054123A1 - Procede de fonctionnement d'une presse hydraulique - Google Patents

Procede de fonctionnement d'une presse hydraulique Download PDF

Info

Publication number
WO1999054123A1
WO1999054123A1 PCT/EP1999/002301 EP9902301W WO9954123A1 WO 1999054123 A1 WO1999054123 A1 WO 1999054123A1 EP 9902301 W EP9902301 W EP 9902301W WO 9954123 A1 WO9954123 A1 WO 9954123A1
Authority
WO
WIPO (PCT)
Prior art keywords
cylinder
press
pressure
acting
force
Prior art date
Application number
PCT/EP1999/002301
Other languages
German (de)
English (en)
Inventor
Manfred Breckner
Original Assignee
Mannesmann Rexroth 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
Priority claimed from DE19822436A external-priority patent/DE19822436A1/de
Application filed by Mannesmann Rexroth Ag filed Critical Mannesmann Rexroth Ag
Publication of WO1999054123A1 publication Critical patent/WO1999054123A1/fr

Links

Classifications

    • 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
    • B30B1/32—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 plungers under fluid pressure
    • B30B1/323—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 plungers under fluid pressure using low pressure long stroke opening and closing means, and high pressure short stroke cylinder 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
    • B30B15/16—Control arrangements for fluid-driven presses
    • B30B15/161—Control arrangements for fluid-driven presses controlling the ram speed and ram pressure, e.g. fast approach speed at low pressure, low pressing speed at high pressure

Definitions

  • the invention relates to a method for operating a hydraulic press, in which the force required for the deformation of a workpiece is applied by the piston of a double-acting hydraulic cylinder and this force is transmitted via mechanical intermediate elements from the piston to a press tool, the press tool only after driving through a first distance and the workpiece is deformed while driving through a second distance, as well as a hydraulic press operated according to this method with a synchronous cylinder arranged between the frame and the pressing tool with two cylinder chambers, of which the the first is assigned to the opening direction of the press and the second to the closing direction of the press, and in which the press is closed by lowering the pressing tool.
  • the press tool moves between a first, e.g. B. upper end position and a second, z. B. lower end position. If the pressing tool is in the upper end position, a blank can be inserted into the press. Then the press tool is lowered until it hits the blank. During the lowering of the pressing tool from its upper end position until it hits the blank, a path is traveled through without a counterforce acting on the pressing tool. If the pressing tool has reached the blank, the blank begins to deform. During the deformation of the blank, the pressing tool only has a short distance to reach its lower end position. However, a large force must be applied to deform the blank.
  • the required relationship between the distance traveled by the press tool and the force exerted by the press tool on the blank is determined in an eccentric press by a motor-driven disk on which the press tool is articulated so that the rotary movement of the motor into the desired pushing movement of the press tool is formed.
  • a toggle press the relationship between the distance traveled by the press tool and the force exerted by the press tool on the blank is determined by the geometry of a toggle lever. With such presses, the course of movement and force are the same for each stroke. The force is built up according to the mechanics of the press. With such presses, high cycle rates can be achieved.
  • hydraulic presses are only suitable to a limited extent, since a force drop occurs due to the compressibility of the oil used as pressure medium when changing from rapid traverse to the press speed. If hydraulic presses are to be used not only as test presses but also for series production, the pressure build-up during the transition from rapid traverse to the press speed must be improved. In order to improve the pressure build-up and thereby increase the pressing speed, large drive powers are required. These drive powers are mostly achieved by oversized storage drives with correspondingly long loading times.
  • the invention has for its object to provide a method for operating a hydraulic press and a press operated according to this method, which reduces the drop in force during the transition from rapid traverse to the pressing speed without requiring an increase in drive power.
  • This object is achieved with regard to the method by the features characterized in claim 1 and with regard to the hydraulic press by the features characterized in claim 7. While the press tool travels the first distance, the piston of the double-acting cylinder is clamped hydraulically, the pressure medium in the cylinder chambers is already compressed. For the build-up of the force acting on the pressing tool, only the pressure reduction of the cylinder chamber associated with the opening process is decisive.
  • Figure 2 shows the upper part of Figure 1 in an enlarged view.
  • Figure 1 shows a press operated according to the inventive method in a schematic representation.
  • Three hydraulic cylinders 3 to 5 are arranged between a frame 1 and a press beam 2.
  • the frame 1 carries a table 6 which, in a lower tool, not shown in FIG. 1, receives a workpiece, also not shown, as a blank to be deformed.
  • a press tool 7 is held on the press beam 2.
  • the pressing tool provided with the reference number 7 is the upper tool of the press.
  • the letter F denotes the force exerted by the press tool 7 on the workpiece or the force acting on the press tool.
  • the press beam 2 serves as a mechanical intermediate member between the cylinders 3 to 5 and the press tool 7.
  • the ' cylinders 3 and 4 are each identical synchronous cylinders.
  • the cylinder 5 is designed as a differential cylinder. Details of cylinders 3 to 5 are described below with reference to FIG. 2.
  • the reference numerals 8 and 9 denote lines which connect two chambers of the cylinder 3 to a first control device 10.
  • Reference lines 11 and 12 denote further lines which connect two chambers of the cylinder 4 to the control device 10.
  • the control device 10 is connected via a line 13 to a tank 14 and via a line 15 to a Pressure accumulator 16 connected.
  • the two chambers of the cylinder 5 are connected via lines 17 and 18 to a second control device 19.
  • a line 20 leads from the control device 19 to a further chamber of the cylinder 3 and a line 21 to a further chamber of the cylinder 4.
  • a motor 22 drives an adjustable pump 23.
  • the pump 23 supplies the pressure accumulator 16 and the control device 19 with pressure medium via a valve device 24.
  • the valve device 24 is connected to the tank 14 via a line 25.
  • a line 26 leads from the valve device 24 to the control device 19.
  • a controllable valve 27 with three positions is arranged between the lines 8 and 9. In the middle position, the valve 27 acts as a check valve, a pressure medium flow being possible only from line 8 to line 9. In the left position, the valve 27 blocks the connection between the lines 8 and 9. In the right position of the valve 27, pressure medium can flow between the lines 8 and 9 in both directions.
  • the middle position of the valve 27 is its rest position, the left " and the right position of the valve is a working position. Between the lines 11 and 12 there is a further valve 28 with likewise three switch positions.
  • Valve 28 As a non-return valve, pressure medium flow being possible only from line 11 to line 12.
  • valve 28 blocks the connection between lines 11 and 12.
  • lines 11 and Pressure medium flows in both directions 12.
  • the middle position of the valve 27 is its rest position, in the left and the right position the valve is a working position.
  • a suction tank 29 is located above the frame 1 and is connected to the tank 14 via a line 30.
  • Reference number 31 denotes a ventilation device for the suction tank 29.
  • Five chambers of cylinders 3 to 5 are connected to the suction tank 29 via suction valves 32 to 36 and lines 37 to 41.
  • FIG. 2 shows the upper part of FIG. 1 on an enlarged scale.
  • the individual chambers of the cylinders 3 to 5 are provided with the reference numerals 3.1, 3.2, 3.3, 4.1, 4.2, 4.3, 5.1 and 5.2.
  • the pressurized surfaces of the pistons of cylinders 3 to 5 are correspondingly referred to as A3.1, A3.2, A3.3, A4.1, A4.2, A4.3, A5.1 and A5.2.
  • the support beam 2 is in its upper position.
  • the holding pressure acts on the surface A5.1 of the chamber 5.1 of the cylinder 5.
  • This pressure is chosen so large that the force exerted by it on the surface A5.1 is at least as large as the total weight of the press beam 2 and the press tool 7 attached to it. This ensures that the press beam 2 with the press tool 7 is in a safe position.
  • the chamber 3.3 of the cylinder 3, the chamber 4.3 of the cylinder 4 and the chamber 5.2 of the cylinder 5 are depressurized, that is, for. B. via the control device 19 with the
  • the valve 27 is in the right switch position, so the lines 8 and 9 are connected to each other.
  • the control device 10 ensures that the Chambers 3.1 and 3.2 of the cylinder 3 via the lines 8 and 9, respectively, are pressurized with the pressure of the accumulator 16 (e.g. 320 bar).
  • the valve 28 is also in its right-hand switching position, the lines 11 and 12 are also connected to one another.
  • the chambers 4.1 and 4.2 are pressurized via lines 11 and 12 with the pressure of the accumulator 16. The forces exerted by the pressures acting on the surfaces A3.1 and A3.2 and the forces exerted by the pressures acting on the surfaces A4.1 and A4.2 cancel each other out.
  • the downward movement of the pressing tool 7 takes place in two areas.
  • the press tool 7 sinks in rapid traverse. Shortly before hitting the table 6, the sinking speed is reduced to the pressing speed.
  • the changeover from rapid traverse to the pressing speed takes place as a function of the output signal of a path converter which is arranged between the frame 1 and the pressing beam 2 and is not shown in the figures for reasons of space.
  • the chamber 5.1 is depressurized via the control device 19 to the ' tank 14. Now the dead weight of the press beam 2 and the press tool 7 attached to it predominate.
  • Pressure medium flows from the chamber 3.1 via the valve 27 into the chamber 3.2.
  • the control device 10 keeps the pressure in the chambers 3.1 and 3.2 at the storage pressure.
  • pressure medium flows from the chamber 4.1 via the valve 28 into the chamber 4.2, and the control device 10 also maintains the pressure in the chambers 4.1 and 4.2 on the memory print.
  • the pressure medium is compressed both in the chambers 3.1 and 3.2 and in the chambers 4.1 and 4.2, the pistons of the cylinders 3 and 4 are clamped hydraulically at the full pressure.
  • pressure medium is sucked out of the suction tank 29 via the suction valves 32, 36 and 34.
  • the pressing tool 7 is braked from rapid traverse to the pressing speed.
  • pressure is built up again in the chamber 5.1 by the control device 19.
  • the valves 27 and 28 are each switched to the middle position and the chambers 3.1 and 4.1 are relieved via the control device 10 to the tank 14. The pressure in chambers 3.2 and 4.2 is maintained.
  • Both the pistons of the cylinder 3 and the pistons of the cylinder 4 are now acted upon by a force supporting the dead weight of the press beam 2 and the press tool 7.
  • the usual way of generating a force that supports the dead weight of the press beam 2 and the press tool 7 is to build up pressure in the chambers 3.2 and 4.2 with the chambers 3.1 and 4.1 relieved of the load on the tank 14.
  • a pressure build-up requires more time than the decompression of the pressure medium in the chambers 3.1 and 4.1 provided in accordance with the invention while maintaining the pressure in the chambers 3.2 and 4.2. This measure eliminates the drop in the pressing force that otherwise occurs in hydraulic presses when changing from rapid traverse to the pressing speed.
  • Chambers 3.3, 4.3 and 5.2 additionally supplied with pressure medium via the control device 19.
  • the clamping of the pistons of the cylinders 3 and 4 and the decompression of the chambers 3.1 and 3.2 is carried out via the control device 10.
  • the pressing speed and the maximum pressing force are driven via the control device 19 and the adjustable pump 23.
  • the valves 27 and 28 are switched to the left position.
  • the connections between lines 7 and 8 and between lines 11 and 12 are thus interrupted.
  • the chambers 3.2 and 4.2 are relieved of pressure via the control device 10 to the tank 14.
  • the chambers 3.3, 4.3 and 5.2 are relieved of pressure via the control device 19 to the tank 14.
  • a retraction pressure is built up in the chamber 5.1 of the cylinder 5 by the adjustable pump 23 via the control device 19. This force is normally sufficient to raise the press beam 2 with the press tool 7.
  • an increased retraction force is required, e.g. B. to tear the press tool from the workpiece, an additional force can be generated briefly by building pressure in the chambers 3.1 and 4.1, which supports the retraction force generated by the cylinder 5.
  • the cylinder 5 is a differential cylinder.
  • a differential cylinder instead of a differential cylinder, a synchronous cylinder can be used. It is also possible to use a single-acting cylinder instead of a double-acting cylinder. In this case, the cylinder 5 only serves to hold the press beam 2 and the press tool 7.
  • the double-acting cylinders 3 and 4 are synchronous cylinders. So that the forces acting on the piston surfaces from opposite sides cancel each other out, the chambers of the synchronous cylinders are each pressurized when the press is lowered.
  • differential cylinders as double-acting cylinders instead of synchronous cylinders. So that the forces acting on the piston surfaces from opposite sides cancel each other out, the ratio of the pressures supplied to the chambers of the differential cylinder must be kept in accordance with the reciprocal of the pressurized surfaces, so that the product of surface and pressure is equal in each case. 12
  • the press tool moves in the vertical direction.
  • the press can also be constructed so that the press tool moves in the horizontal direction.
  • the chambers 3.1 and 4.1 are connected to the tank 14 before the beginning of the deformation of the workpiece in order to relieve pressure, as described above.
  • the pressure medium is first passed from the chambers 3.1 and 4.1 into the chamber 5.2.
  • This pressure medium supply to the chamber 5.2 takes place in addition to the pressure medium supply from the control device 19 via the line 18 described above.
  • the additional pressurization of the chamber 5.2 increases the force acting on the pressure beam 2. Only when the pressure in the chambers 3.1 and 4.1 (from e.g. 320 bar) has dropped to a predeterminable value (from e.g.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Control Of Presses (AREA)
  • Press Drives And Press Lines (AREA)

Abstract

Dans le cas de presses hydrauliques, pour lesquelles la force nécessaire à la déformation d'une pièce est appliquée par le piston d'un cylindre hydraulique à double action, une baisse de la force de compression survient lors de la transition du mouvement rapide à la vitesse de compression en raison de la compression de l'agent de pression lors de l'établissement de pression. Pour atténuer cette baisse de force, une certaine quantité de l'agent de compression est évacuée de la première chambre cylindre (3.1, 4.1) qui est affectée au sens d'ouverture de la presse, pendant le premier parcours, et est acheminée jusqu'à une deuxième chambre de cylindre (3.2, 4.2) qui est affectée au sens de fermeture de la presse. La pression maintenue dans les chambres de cylindres est telle que les forces agissant sur les surfaces de piston du cylindre s'annulent entre elles. Avant le début de la déformation de la pièce, la première chambre de cylindre (3.1, 4.1) est déchargée de telle façon que la pression régnant dans la deuxième chambre de cylindre (3.2, 4.2) exerce sur la pièce une force agissant sur sa déformation.
PCT/EP1999/002301 1998-04-07 1999-04-03 Procede de fonctionnement d'une presse hydraulique WO1999054123A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19815428.3 1998-04-07
DE19815428 1998-04-08
DE19822436A DE19822436A1 (de) 1998-04-08 1998-05-19 Verfahren zum Betrieb einer hydraulischen Presse
DE19822436.2 1998-05-19

Publications (1)

Publication Number Publication Date
WO1999054123A1 true WO1999054123A1 (fr) 1999-10-28

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1999/002301 WO1999054123A1 (fr) 1998-04-07 1999-04-03 Procede de fonctionnement d'une presse hydraulique

Country Status (1)

Country Link
WO (1) WO1999054123A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010046087A1 (fr) 2008-10-21 2010-04-29 Voith Patent Gmbh Entraînement hydraulique pour presse et procédé de fonctionnement d'un entraînement hydraulique pour presse
AT509239B1 (de) * 2009-12-17 2013-03-15 Trumpf Maschinen Austria Gmbh Antriebsvorrichtung für eine biegepresse
DE102013109490A1 (de) * 2013-08-30 2015-03-05 Siempelkamp Maschinen- Und Anlagenbau Gmbh Hydraulische Taktpresse
CN105751560A (zh) * 2016-05-06 2016-07-13 福州大学 长行程楔式节能型液压机及其工作方法
EP3115190A1 (fr) * 2015-07-06 2017-01-11 Feintool International Holding AG Dispositif et procede de commande de l'entrainement principal d'une presse pour decoupage de precision
DE102005041252B4 (de) * 2005-08-31 2019-11-21 Bosch Rexroth Aktiengesellschaft Elektrohydraulischer Pressenantrieb

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2386414A1 (fr) * 1977-04-05 1978-11-03 Smg Sueddeutsche Maschb Presse comportant une course a vide avant la course de travail
JPS5581100A (en) * 1978-12-14 1980-06-18 Samu Denshi Kikai:Kk Hydraulic compressor and control device thereof
JPS6330200A (ja) * 1986-07-21 1988-02-08 Kobe Steel Ltd 油圧プレスの実加圧力制御方法
DE4037848A1 (de) * 1990-11-28 1992-06-04 Eckehart Schulze Hydraulisch angetriebene maschine mit zwei antriebszylindern
DE4436666A1 (de) * 1994-10-13 1996-04-18 Rexroth Mannesmann Gmbh Hydraulisches Antriebssystem für eine Presse

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2386414A1 (fr) * 1977-04-05 1978-11-03 Smg Sueddeutsche Maschb Presse comportant une course a vide avant la course de travail
JPS5581100A (en) * 1978-12-14 1980-06-18 Samu Denshi Kikai:Kk Hydraulic compressor and control device thereof
JPS6330200A (ja) * 1986-07-21 1988-02-08 Kobe Steel Ltd 油圧プレスの実加圧力制御方法
DE4037848A1 (de) * 1990-11-28 1992-06-04 Eckehart Schulze Hydraulisch angetriebene maschine mit zwei antriebszylindern
DE4436666A1 (de) * 1994-10-13 1996-04-18 Rexroth Mannesmann Gmbh Hydraulisches Antriebssystem für eine Presse

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 004, no. 123 (M - 029) 30 August 1980 (1980-08-30) *
PATENT ABSTRACTS OF JAPAN vol. 012, no. 236 (M - 715) 6 July 1988 (1988-07-06) *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005041252B4 (de) * 2005-08-31 2019-11-21 Bosch Rexroth Aktiengesellschaft Elektrohydraulischer Pressenantrieb
WO2010046087A1 (fr) 2008-10-21 2010-04-29 Voith Patent Gmbh Entraînement hydraulique pour presse et procédé de fonctionnement d'un entraînement hydraulique pour presse
AT509239B1 (de) * 2009-12-17 2013-03-15 Trumpf Maschinen Austria Gmbh Antriebsvorrichtung für eine biegepresse
US9688041B2 (en) 2009-12-17 2017-06-27 Trumpf Maschinen Austria Gmbh & Co. Kg. Drive device for a bending press
DE102013109490A1 (de) * 2013-08-30 2015-03-05 Siempelkamp Maschinen- Und Anlagenbau Gmbh Hydraulische Taktpresse
DE102013109490B4 (de) * 2013-08-30 2015-08-06 Siempelkamp Maschinen- Und Anlagenbau Gmbh Hydraulische Taktpresse
EP3115190A1 (fr) * 2015-07-06 2017-01-11 Feintool International Holding AG Dispositif et procede de commande de l'entrainement principal d'une presse pour decoupage de precision
KR20170005768A (ko) * 2015-07-06 2017-01-16 페인툴 인터내셔널 홀딩 에이쥐 미세 블랭킹 프레스의 1차 드라이브를 제어하기 위한 장치 및 방법
KR102349812B1 (ko) 2015-07-06 2022-01-11 페인툴 인터내셔널 홀딩 에이쥐 미세 블랭킹 프레스의 1차 드라이브를 제어하기 위한 장치 및 방법
CN105751560A (zh) * 2016-05-06 2016-07-13 福州大学 长行程楔式节能型液压机及其工作方法

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