EP0561301A1 - Integrierte Spann- und Führungseinheit mit hydrostatischen Lagern für eine hydraulische Presse - Google Patents

Integrierte Spann- und Führungseinheit mit hydrostatischen Lagern für eine hydraulische Presse Download PDF

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Publication number
EP0561301A1
EP0561301A1 EP93104073A EP93104073A EP0561301A1 EP 0561301 A1 EP0561301 A1 EP 0561301A1 EP 93104073 A EP93104073 A EP 93104073A EP 93104073 A EP93104073 A EP 93104073A EP 0561301 A1 EP0561301 A1 EP 0561301A1
Authority
EP
European Patent Office
Prior art keywords
guide
clamping
hollow body
head
cross
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP93104073A
Other languages
English (en)
French (fr)
Inventor
Alberto Rovetta
Giampaolo Spanio
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.)
Tcs Molding Systems SpA
Original Assignee
Tcs Molding Systems SpA
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 Tcs Molding Systems SpA filed Critical Tcs Molding Systems SpA
Publication of EP0561301A1 publication Critical patent/EP0561301A1/de
Withdrawn legal-status Critical Current

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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
    • B30B15/04—Frames; Guides
    • B30B15/041—Guides

Definitions

  • the present invention relates to the field of the hydraulic presses for press-moulding of plastic materials and more particularly relates to hydraulic presses for moulding fiber-reinforced or sheet plastic materials. More precisely, the invention relates to improvements to the clamping devices for locking the upper or movable platen or cross-head to the guidance columns of a short-stroke press, so as to ensure correct closing and opening of the mould.
  • Hydraulic presses for press-moulding of plastic materials are generally known for example from W-A-88/07447 and US-A-4,470,787. These hydraulic presses substantially comprise a lower base for a platen supporting a first mould member, from which four guidance columns extend for the sliding of a movable upper cross-head supporting a second mould member or cover to close the lower one.
  • the upper cross-head of the press is generally made to move vertically along guidance columns by means of suitable hydraulic actuating cylinders: furthermore in a short-stroke press it is locked in a predetermined working position before final closing of the mould which is performed for example by a further relative movement towards each other of the lower and upper mould members.
  • mould closing and opening operations give rise to considerable stresses and reaction forces which are transmitted, via the clamping devices for the upper platen, to the guidance columns.
  • stresses and the reaction forces may be constant during the entire moulding operation or may vary, depending from uncontrollable working conditions.
  • Opening and/or closing operations of mould, in presses of the kind mentioned, represent the most critical moments during which it is necessary to ensure that the mating surfaces of the two mould members are perfectly parallel, in order to prevent the occurrence of uncontrollable stresses and/or cross forces or torques which could damage both the clamping devices for the movable upper cross-head of the press, and the two mould members.
  • the main object of the present invention is to provide an integrated guide and clamping unit for the movable cross-head of a hydraulic press, which is able to overcome the abovementioned problems.
  • a further object of the present invention is to provide a hydraulic press for moulding plastic materials, of the short stroke type, comprising hydrostatic bearings to automatically compensate for any defects in the parallelism of the mould members which could result in misalignment of the mating surfaces and in arising dangerous cross-stresses, during either closing and opening of the same mould.
  • the press 10 substantially comprises a base 11 from which there extend four columns 12, only two of which are shown, for the sliding and guidance of a movable cross-head 13 actuated for example by a hydraulic cylinder 14.
  • 15 denotes the lower member of a mould suitably fixed to the platen of the base 11, while 16 denotes the upper mould member or closing cover fixed to the platen of the movable cross-head 13.
  • the cross-head 13 of the press is vertically movable between an upper or retracted position where the mould is open, shown in Figure 1, and a lower or advanced position where the mould is closed, being guided during its movement along the guide columns 12, by guiding units indicated in the drawings by 17.
  • Each guiding unit 17 for the movable cross-head 13 of the press in a manner known per se comprises clamping means 18 which may be of varying design and which are actuated for example by a suitable hydraulic control system for locking the cross-head 13 to the columns 12, of the press in a desired closing position; in the case of a dual-stroke press for moulding plastic material, the upper movable cross-head 13 is stopped and locked to columns 12 before the two mould members 15 and 16 are moved closer together during the moulding operation, until shouldering surfaces of the mould are brought almost into contact with each other.
  • a self-balancing hydrostatic bearing system for bearing the cross-head 13, designed to freely allow small relative floating displacements, in a plane perpendicular to the guide columns 12, between the cross-head 13 and each clamping device, thus preventing stresses or traverse forces from arising both during the closing, moulding operations and during opening of the same mould; this results in automatic self-centering action of the upper mould member 16 with respect to the lower mould member 15, which ensures in any working condition perfect parallel alignment of the mould shouldering surfaces.
  • a guide device 17 comprising a hollow cylindrical body 19 closed by a bottom wall 20 and by an upper cover 21; the bottom wall 20 and the cover 21 are provided with axially aligned holes 22, 23 through which the column 12 passes, the diameter of the holes being slightly greater than the external diameter of the column, for example of the order of few millimetres, so as to allow small relative movements of the entire cross-head 13 and thermal expansion of the same.
  • an axial clamping device 18 comprising, for example, a sleeve clamping element 24 surrounding the column 12 and which axially extends inside the hollow body 19.
  • the sleeve element 24 may have a varying configuration consisting of one or more parts and is provided with an internal frictional surface 25 designed to achieve a braking and locking action against the external surface of the column 12; therefore this sleeve element 24 is acted on so as to be elastically biased, in a radial direction, by means of a hydraulic pressure created in an annular chamber 26 formed between tubular elements 27 and 28 surrounding said clamping element 24, inside the tubular body 19.
  • the annular chamber 26 may be supplied from the exterior with a pressurised hydraulic fluid via a duct 29 or by other suitable means.
  • the design of the hydraulic clamping device shown in Figures 2 and 3 is supplied here purely and solely by way of example, without this restricting the innovative principle of the present invention.
  • connection between the clamping device 18 and the external body 19 of the guiding device is effected on upper and bottom sides by means of hydrostatic bearings able to transmit high forces axially to the columns 12, thus allowing a floating or relative displacement, without friction, or with transverse forces which are entirely negligible, in a plane perpendicular to the axis of the abovementioned columns.
  • the hydrostatic bearing means are provided in the form of flat hydrostatic bearings at both ends of the clamping device 18 so as to perform a bidirectional self-balanced hydrostatic bearing action, depending on the direction of the forces generated when the mould is closed or opened.
  • each hydrostatic bearing means is substantially defined by an annular element 30 which slidably surrounds the column 13 and which is accommodated in a corresponding annular seat 31 at each of the two ends of the clamping device, between the latter, the upper closing cover 21 and the bottom wall 20 of the hollow body 19, respectively.
  • the dimensions of the annular seat 31 are slightly greater than the corresponding dimensions of the annular element 30, so as to form around the ring 30 an annular gap which in conjunction with annular gaps 23 allow the desired relative movement.
  • the rings 30 rest directly, without any constraint, against the tubular elements 24 and 27 of the clamping device 18, with the disposition of suitable sealing gaskets 32 and 32' between the ring 30 and the tubular elements 27, 28 at each end of the annular chamber 26; additional sealing gaskets 33 and 33' are arranged on the opposite side between the ring 30 and the corresponding end closing walls 21,20 of the hollow body 19, keeping the annular seals 33 and 33' suitably spaced apart from one another in a radial direction so as to define between them a hydrostatic chamber 34 lying in a plane perpendicular to the axis of the corresponding column 12.
  • a pressurised hydraulic fluid is supplied into the hydrostatic chamber 34 via a supply duct 35 provided with a check valve 36, as shown in the drawings.
  • a hydrostatic bearing 34 able to transmit high axial forces while allowing a relative floating displacement of the cross-head 13 and hence of the upper mould member 16 with respect to the columns 12 and the lower mould member 15, resulting in a self-balancing action and in constant automatic and controlled alignment of the shouldering surfaces of the mould itself.
  • the value of the hydrostatic pressure of the fluid supplied to each of the chambers 34 may vary from case to case, depending on the specific applications; in general, the hydrostatic pressure of the fluid inside the chambers 34 must be such as to create a fluid film sufficient to prevent direct contact between the opposing surfaces of the ring 30 and the end closing walls 20 and 21 when acted upon by high loads which are transmitted to the head 13 in both the axial directions of the guide columns 12, upon closing and opening of the mould, without causing any force in the cross direction, and allowing to automatically compensate any misalignment in the three main directions between columns 12 and the integrated guide and clamping units of the cross-head 13, and therefore between the mould members.
  • the invention provides an integrated guide and clamping unit for an hydraulic press, provided with hydrostatic bearing means able to withstand high loads, while allowing a self-balancing and floating action to automatically compensate for any misalignment of the mould-shouldering surfaces, without causing damaging during closing and opening operation.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Mounting, Exchange, And Manufacturing Of Dies (AREA)
EP93104073A 1992-03-19 1993-03-12 Integrierte Spann- und Führungseinheit mit hydrostatischen Lagern für eine hydraulische Presse Withdrawn EP0561301A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI920653 1992-03-19
ITMI920653A IT1254835B (it) 1992-03-19 1992-03-19 Dispositivo di bloccaggio,con sostentamento idrostatico, e pressa idraulica incorporante tale dispositivo

Publications (1)

Publication Number Publication Date
EP0561301A1 true EP0561301A1 (de) 1993-09-22

Family

ID=11362523

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93104073A Withdrawn EP0561301A1 (de) 1992-03-19 1993-03-12 Integrierte Spann- und Führungseinheit mit hydrostatischen Lagern für eine hydraulische Presse

Country Status (2)

Country Link
EP (1) EP0561301A1 (de)
IT (1) IT1254835B (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004006126B4 (de) * 2004-02-07 2006-12-28 Horst Baltschun Presse mit verriegeltem Stößel
JP2013078786A (ja) * 2011-10-04 2013-05-02 Watanabe Kikai:Kk プレス装置
CN112846144A (zh) * 2021-01-07 2021-05-28 刘库 一种汽车发动机缸盖的压铸设备及其加工方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1136574B (de) * 1955-12-16 1962-09-13 Loewy Eng Co Ltd Schubuebertragende Einrichtung
US4470787A (en) * 1983-05-11 1984-09-11 Mts Systems Corporation Hydraulic press
EP0220634A2 (de) * 1985-10-31 1987-05-06 MASCHINENFABRIK HENNECKE GmbH Schliesseinheit für Formwerkzeuge, insbesondere solchen für die Herstellung von Polyurethan-Formteilen
WO1988007447A1 (en) * 1987-04-02 1988-10-06 Mts Systems Corporation Hydraulic press having integrated column clamps and actuators
EP0326980A2 (de) * 1988-01-30 1989-08-09 Umformtechnik ERFURT GmbH Hydraulische Presse

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1136574B (de) * 1955-12-16 1962-09-13 Loewy Eng Co Ltd Schubuebertragende Einrichtung
US4470787A (en) * 1983-05-11 1984-09-11 Mts Systems Corporation Hydraulic press
EP0220634A2 (de) * 1985-10-31 1987-05-06 MASCHINENFABRIK HENNECKE GmbH Schliesseinheit für Formwerkzeuge, insbesondere solchen für die Herstellung von Polyurethan-Formteilen
WO1988007447A1 (en) * 1987-04-02 1988-10-06 Mts Systems Corporation Hydraulic press having integrated column clamps and actuators
EP0326980A2 (de) * 1988-01-30 1989-08-09 Umformtechnik ERFURT GmbH Hydraulische Presse

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004006126B4 (de) * 2004-02-07 2006-12-28 Horst Baltschun Presse mit verriegeltem Stößel
JP2013078786A (ja) * 2011-10-04 2013-05-02 Watanabe Kikai:Kk プレス装置
CN112846144A (zh) * 2021-01-07 2021-05-28 刘库 一种汽车发动机缸盖的压铸设备及其加工方法
CN112846144B (zh) * 2021-01-07 2022-10-28 宁波豪若汽车零部件制造有限公司 一种汽车发动机缸盖的压铸设备及其加工方法

Also Published As

Publication number Publication date
IT1254835B (it) 1995-10-11
ITMI920653A1 (it) 1993-09-19
ITMI920653A0 (it) 1992-03-19

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