EP0613740B1 - Process and hydraulic press for the pressing of sheets - Google Patents
Process and hydraulic press for the pressing of sheets Download PDFInfo
- Publication number
- EP0613740B1 EP0613740B1 EP94103041A EP94103041A EP0613740B1 EP 0613740 B1 EP0613740 B1 EP 0613740B1 EP 94103041 A EP94103041 A EP 94103041A EP 94103041 A EP94103041 A EP 94103041A EP 0613740 B1 EP0613740 B1 EP 0613740B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sheet
- zero
- blank holder
- actuators
- pressing
- 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
Links
- 238000003825 pressing Methods 0.000 title claims description 19
- 238000000034 method Methods 0.000 title claims description 16
- 230000000452 restraining effect Effects 0.000 claims description 9
- 239000011159 matrix material Substances 0.000 claims description 6
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 230000000694 effects Effects 0.000 claims 1
- 239000004411 aluminium Substances 0.000 description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 10
- 229910052782 aluminium Inorganic materials 0.000 description 9
- 229910000831 Steel Inorganic materials 0.000 description 5
- 239000010959 steel Substances 0.000 description 5
- 230000010349 pulsation Effects 0.000 description 3
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 2
- 229910000399 iron(III) phosphate Inorganic materials 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000037237 body shape Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910001234 light alloy Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D24/00—Special deep-drawing arrangements in, or in connection with, presses
- B21D24/10—Devices controlling or operating blank holders independently, or in conjunction with dies
- B21D24/14—Devices controlling or operating blank holders independently, or in conjunction with dies pneumatically or hydraulically
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/20—Deep-drawing
- B21D22/26—Deep-drawing for making peculiarly, e.g. irregularly, shaped articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D24/00—Special deep-drawing arrangements in, or in connection with, presses
- B21D24/04—Blank holders; Mounting means therefor
- B21D24/08—Pneumatically or hydraulically loaded blank holders
Definitions
- the invention concerns a process for the pressing of metal sheets according to the preamble of claim 1, particularly the deep drawing (drawing) of motor vehicle body components.
- the invention also concerns a hydraulic press according to the preamble of claim 5, capable of implementing the above-mentioned pressing process.
- a sheet is installed between a matrix and a punch of the die, clamped with pre-determined force by a blank holder which has the task of restraining the sheet against the matrix in the course of the plastic deformation operation.
- the value of the clamping pressure exerted by the blank holder against the sheet in the pressing phase is fixed and is determined by trials working initially on a batch of test sheets, to be then kept constant for the entire production phase.
- the object of the invention is to provide an improved process of the pulsating pressure type disclosed above which enables the disadvantages of the latter to be overcome in a simple and economic manner thus enabling sheets, including aluminium sheets, to be processed in complex shapes at low cost.
- the pulsating pressure variation frequency is between zero and 20 Hz inclusive and is selected at a value that is higher, the lower the hardness of the sheet used. In this way even aluminium sheets become easy to process.
- the frequency of the said pulsating pressure is made to vary in the course of the pressing operation, particularly in the course of the active stroke of the punch and in any event so as to obtain at least one pressure variation cycle from zero to the maximum value for every 8-10 mm of depth of drawing of the sheet. In this way the rejects are reduced, substantially to zero, even where very complex pressings are involved.
- the process according to the invention can be implemented on a hydraulic press for the pressing of sheets, of the type comprising at least one blank holder controlled by actuators via a hydraulic control circuit comprising valve means for alternately pressurizing/depressurizing the blank holder actuators, as defined in claim 5
- press 1 represents a hydraulic press for the pressing of metal sheets 2, made of steel or aluminium or light alloy, for example, particularly to obtain body components of a vehicle which are known and not shown for reasons of simplicity;
- press 1 comprises a die 3 formed by least one matrix 4 and at least one punch 5 having a profile that is conjugate and shaped like the body component to be obtained, and a blank holder 6 capable of acting on the sheet 2 in correspondence with a perimetric portion 8 thereof.
- the blank holder 6, rather than being made of a single piece, consists of a multiplicity of restraining elements 10, four in number for example, one for each side of the sheet 8, which can be controlled independently of each other.
- press 1 comprises a hydraulic circuit 18 to control actuators 20 associated with the blank holder 6, particularly associated, singly or in pairs (or three or more according to need) with each restraining element 10.
- the circuit 18 comprises in its turn a valve assembly 22 controlled by an electronic microprocessor unit 23 and capable of controlling the inflow and outflow of control fluid to each actuator 20 associated with each element 10, independently for each said element 10.
- valve assembly 22 is of the same type as vehicle anti-lock brake systems (ABS) and so is not described for reasons of simplicity. Substantially, it is capable of selectively intercepting the flow supplied by a pump 24 towards each actuator 20 for very short periods of time and, possibly, of connecting the actuator to an outlet 25, so as to generate in the actuators 20 a control pressure variable with a periodic law or with a substantially stepwise profile between zero (corresponding to the point at which assembly 22 completely intercepts the said flow and then prevents it from reaching the actuator 20 and, if necessary, connects the actuator 20 to the outlet 25) and a pre-determined maximum value dependent on the characteristic of the pump 24 and, for example, adjustable via the assembly 22 by drawing under the control of the unit 23 (corresponding to the point at which the assembly 22 connects, directly or with drawing towards a pressure control valve which forms part of that assembly, the actuator 20 with the pump 24).
- ABS vehicle anti-lock brake systems
- the unit 23 is capable of controlling the assembly 22 (for example comprising a set of "on-off" type solenoid valves) so as to be able to vary on a continuous basis the periodicity, i.e. the frequency, of the periodic pressure variation law in the actuators 20, for example between a minimum frequency equal to zero (the pressure does not vary and remains constant) and a maximum frequency equal to approximately 20 Hz. Consequently, each element 10 is capable of applying to the sheet 2 a restraining pressure variable between zero (corresponding to the point at which the actuator/the actuators controlling this element 10 are at zero pressure) and a maximum pressure that is adjustable at will, with a frequency which can also be varied as desired between 0 and 20 Hz.
- the assembly 22 for example comprising a set of "on-off" type solenoid valves
- control circuit 18 is completed by a hydraulic accumulator 26 for supplying the assembly 22 at constant pressure, a filter 27 and a valve assembly 28 which controls an actuator 29 (not shown in Fig. 1) for raising the blank holder 6, and also exhaust valves 30 of actuators 20.
- the pulsating pressure must have a frequency selected according to the mechanical properties of the sheet to be pressed, particularly between zero and 20 Hz inclusive (the installation must be capable of achieving the zero value also, but the minimum operating frequency must be not less than 3 Hz) and of a value that is higher, the lower the hardness/strength of the sheet 2 being processed.
- a frequency selected according to the mechanical properties of the sheet to be pressed, particularly between zero and 20 Hz inclusive (the installation must be capable of achieving the zero value also, but the minimum operating frequency must be not less than 3 Hz) and of a value that is higher, the lower the hardness/strength of the sheet 2 being processed.
- FePO4 for example (designation according to UNI 5866/77 and EURONORM 130/77) between 0.8 and 1 mm thick the frequency must be relatively low, between 8 and 10 Hz inclusive for example; in contrast, for aluminium sheets 0.7-1 mm thick it is necessary to use higher frequencies, between 14 and 18 Hz inclusive.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
- Control Of Presses (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
Description
- The invention concerns a process for the pressing of metal sheets according to the preamble of
claim 1, particularly the deep drawing (drawing) of motor vehicle body components. - The invention also concerns a hydraulic press according to the preamble of claim 5, capable of implementing the above-mentioned pressing process.
- In known pressing processes a sheet is installed between a matrix and a punch of the die, clamped with pre-determined force by a blank holder which has the task of restraining the sheet against the matrix in the course of the plastic deformation operation. The value of the clamping pressure exerted by the blank holder against the sheet in the pressing phase is fixed and is determined by trials working initially on a batch of test sheets, to be then kept constant for the entire production phase.
- This method of working at "constant pressure" has a number of disadvantages particularly in the case of dies of complex shape and for deep drawing, which generally result in a relatively high percentage of rejects due to the formation of flaws on the sheet or the rupture of the sheet itself.
- To overcome these disadvantages EP patent application No. 0348774 by this Applicant proposes using a hydraulic press in which the blank holder is actuated with a clamping pressure that is pulsating or alternately variable with a pre-determined law between a minimum value and a maximum value. However, not even this system has proved to be totally effective in reducing rejects in the pressing of certain particularly complex components or pressing sheets which are made of aluminium or have properties that are different from those of steel sheet. Consequently some steel sheet body components have to be produced with special, very expensive so-called "back-hardening" sheets with a high work-hardening capability; and, however, it is not yet possible to produce vehicles with bodies entirely of aluminium on an industrial scale at acceptable cost unless they are restricted to body shapes that are extremely simple and unacceptable from the style point of view.
- The object of the invention is to provide an improved process of the pulsating pressure type disclosed above which enables the disadvantages of the latter to be overcome in a simple and economic manner thus enabling sheets, including aluminium sheets, to be processed in complex shapes at low cost.
- This object is achieved according to the invention by a process for the pressing of metal sheets as claimed in
claim 1. - In particular, the pulsating pressure variation frequency is between zero and 20 Hz inclusive and is selected at a value that is higher, the lower the hardness of the sheet used. In this way even aluminium sheets become easy to process.
- Furthermore, particularly when pressing sheets which require the higher frequencies, such as aluminium sheets, the frequency of the said pulsating pressure is made to vary in the course of the pressing operation, particularly in the course of the active stroke of the punch and in any event so as to obtain at least one pressure variation cycle from zero to the maximum value for every 8-10 mm of depth of drawing of the sheet. In this way the rejects are reduced, substantially to zero, even where very complex pressings are involved.
- The process according to the invention can be implemented on a hydraulic press for the pressing of sheets, of the type comprising at least one blank holder controlled by actuators via a hydraulic control circuit comprising valve means for alternately pressurizing/depressurizing the blank holder actuators, as defined in claim 5
- Further preferred features and advantages of the process and the press according to the invention will emerge from the detailed description which follows, supplied purely by way of example, with reference to the accompanying drawing, in which :
- Fig. 1 is a schematic perspective view of an embodiment of a press according to the invention; and
- Fig. 2 shows a block diagram of a control circuit for the blank holder of the press in Fig. 1.
- With reference to Figs. 1 and 2, in the
assembly 1 represents a hydraulic press for the pressing of metal sheets 2, made of steel or aluminium or light alloy, for example, particularly to obtain body components of a vehicle which are known and not shown for reasons of simplicity;press 1 comprises a die 3 formed by least onematrix 4 and at least one punch 5 having a profile that is conjugate and shaped like the body component to be obtained, and ablank holder 6 capable of acting on the sheet 2 in correspondence with aperimetric portion 8 thereof. - According to one of the main features of the invention, the
blank holder 6, rather than being made of a single piece, consists of a multiplicity ofrestraining elements 10, four in number for example, one for each side of thesheet 8, which can be controlled independently of each other. In fact,press 1 comprises ahydraulic circuit 18 to controlactuators 20 associated with theblank holder 6, particularly associated, singly or in pairs (or three or more according to need) with eachrestraining element 10. With reference to Fig. 2 also, thecircuit 18 comprises in its turn avalve assembly 22 controlled by an electronic microprocessor unit 23 and capable of controlling the inflow and outflow of control fluid to eachactuator 20 associated with eachelement 10, independently for each saidelement 10. - In particular, the
valve assembly 22 is of the same type as vehicle anti-lock brake systems (ABS) and so is not described for reasons of simplicity. Substantially, it is capable of selectively intercepting the flow supplied by apump 24 towards eachactuator 20 for very short periods of time and, possibly, of connecting the actuator to anoutlet 25, so as to generate in the actuators 20 a control pressure variable with a periodic law or with a substantially stepwise profile between zero (corresponding to the point at whichassembly 22 completely intercepts the said flow and then prevents it from reaching theactuator 20 and, if necessary, connects theactuator 20 to the outlet 25) and a pre-determined maximum value dependent on the characteristic of thepump 24 and, for example, adjustable via theassembly 22 by drawing under the control of the unit 23 (corresponding to the point at which theassembly 22 connects, directly or with drawing towards a pressure control valve which forms part of that assembly, theactuator 20 with the pump 24). - According to a further preferred feature of the invention the unit 23 is capable of controlling the assembly 22 (for example comprising a set of "on-off" type solenoid valves) so as to be able to vary on a continuous basis the periodicity, i.e. the frequency, of the periodic pressure variation law in the
actuators 20, for example between a minimum frequency equal to zero (the pressure does not vary and remains constant) and a maximum frequency equal to approximately 20 Hz. Consequently, eachelement 10 is capable of applying to the sheet 2 a restraining pressure variable between zero (corresponding to the point at which the actuator/the actuators controlling thiselement 10 are at zero pressure) and a maximum pressure that is adjustable at will, with a frequency which can also be varied as desired between 0 and 20 Hz. - Finally the
control circuit 18 is completed by ahydraulic accumulator 26 for supplying theassembly 22 at constant pressure, a filter 27 and a valve
assembly 28 which controls an actuator 29 (not shown in Fig. 1) for raising theblank holder 6, and alsoexhaust valves 30 ofactuators 20. - Working with the
press 1 described it is possible to implement a process of pressing the sheets 2 in which a sheet is drawn between thematrix 4 and the punch 5 in the shape of the component to be obtained, for example, a body component of a motor vehicle, restraining the sheet by means of theblank holder 6 exerting on it a pulsating pressure variable alternately between a minimum value equal to zero and a maximum value which can be pre-determined at will. Following experimental trials conducted by the applicant it has also been found that the pulsating pressure must have a frequency selected according to the mechanical properties of the sheet to be pressed, particularly between zero and 20 Hz inclusive (the installation must be capable of achieving the zero value also, but the minimum operating frequency must be not less than 3 Hz) and of a value that is higher, the lower the hardness/strength of the sheet 2 being processed. For example, if sheet 2 is steel, FePO4 for example (designation according to UNI 5866/77 and EURONORM 130/77) between 0.8 and 1 mm thick the frequency must be relatively low, between 8 and 10 Hz inclusive for example; in contrast, for aluminium sheets 0.7-1 mm thick it is necessary to use higher frequencies, between 14 and 18 Hz inclusive. - In the case of aluminium sheets for deep drawing, however, trials have shown that there continued to be a relatively high percentage of rejects (1 in 5) : this latter problem has been surprisingly resolved according to the invention by causing the frequency of the pulsating pressure to vary in the course of the pressing operation, an operation which the microprocessor 23 can easily be asked to perform by appropriate programming thereof; in practice the restraining pressure on the sheet 2 exerted by the blank holder 6 (or by any
component 10 of it) is caused to vary with frequency so as to achieve, in the course of the active stroke of the punch 5 (or in the course of that part of the stroke of the punch 5 in which the sheet 2 is actually in the course of plastic deformation) at least one complete cycle of pressure variation, from zero to the maximum value, for every 8-10 mm of depth of drawing which the sheet 2 undergoes. - Working with the parameters described, a percentage rejects figure practically in the vicinity of zero has been obtained, for both steel and aluminium components. For example, it has been possible to produce the rear door of the "FIAT UNO" vehicle from FePO4 with substantially no rejects whilst at the present time this component is made of a material that is much more expensive and valuable. Similarly, deep-drawn components (depth of drawing of the order of 200 mm) have been produced from sheet aluminium with substantially no rejects by causing the pressure pulsation frequency to vary between zero and the maximum value, between 18 Hz initially and 14 Hz finally. These trials were carried out using a press provided with a blank holder having the following properties :
- Working force : 1000 KN - Maximum working force : 2000 KN - Working speed : 25-50 mm/sec - Ascent speed : 100 mm/sec - Pressure pulsation frequency : 0-20 Hz - Pressure pulsation amplitude : 0-1,000 KN - Stroke 180 mm - Working pressure : 160 bars - Maximum pressure : 320 bars
Claims (5)
- Process for the pressing of metal sheets (2) comprising the steps of:- arranging a sheet (2) between a matrix (4) and a punch (5) of a die which are shaped in the shape of a component to be obtained; and- deforming the sheet (2) by means of the said matrix (4) and punch (5), restraining the sheet (2) between these latter exerting on the sheet (2), by means of a blank holder (6), a pulsating pressure alternately variable between a minimum value and a maximum value, the said pulsating pressure having a pre-determined frequency;
characterized in that said minimum value is equal to zero, said pre-determined frequency being selected according to the mechanical properties of the sheet (2) to be pressed and in such a manner to achieve, in the course of the active stroke of the punch (5), at least one pressure variation cycle from zero to the maximum value for every 8-10 mm of depth of drawing of the sheet (2). - Process according to Claim 1, characterized in that the frequency of the said pulsating pressure is between zero and 20 Hz inclusive and is selected at a value that is higher, the lower the hardness of the sheet (2) used.
- Process according to Claim 1 or 2, characterized in that the frequency of the said pulsating pressure is caused to vary in the course of the pressing operation.
- Process according to one of the preceding Claims, characterized in that a blank holder (6) is used, sub-divided into a multiplicity of restraining elements (10) which are independent of each other, by means of each of which a pulsating pressure variable with a different law from element to element, between zero and a maximum value, which may differ from element to element, is exerted on the sheet (2) in the pressing phase.
- Hydraulic press (1) for the pressing of sheets (2), for actuating the process according to anyone of the foregoing Claims, comprising at last one blank holder (6) controlled by actuators (20) via a hydraulic control circuit comprising valve means (22) for alternately pressurizing/depressurizing the actuators (20) of the blank holder (6), wherein said valve means (22) are capable of causing the pressure exerted by the blank holder (6) on the sheet (2) to vary between a pre-determined maximum value and a minimum value equal to zero; the said valve means (22) comprising timing means (23) for selectively varying on a continuous basis the alternate pressurizing/depressurizing frequency of the said actuators (20);
characterized in that the blank holder (6) is sub-divided into a multiplicity of restraining elements (10) independent of each other, each provided with at least one independent actuator (20) of its own controlled by the said valve means (22), in order to be able to be pressurized/depressurized with a law different from that of the other actuators (20); said actuators being operated by said valve means (22) and said timing means (23) in such a manner to achieve, in the course of the activity stroke of the punch (5), at least one pressure variation cycle from zero to the maximum value for every 8-10 mm of depth of drawing of the sheet (2).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ITTO930148 | 1993-03-02 | ||
ITTO930148A IT1260615B (en) | 1993-03-02 | 1993-03-02 | PROCEDURE AND HYDRAULIC PRESS FOR THE MOLDING OF SHEETS |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0613740A1 EP0613740A1 (en) | 1994-09-07 |
EP0613740B1 true EP0613740B1 (en) | 1997-09-10 |
Family
ID=11411217
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP94103041A Expired - Lifetime EP0613740B1 (en) | 1993-03-02 | 1994-03-01 | Process and hydraulic press for the pressing of sheets |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0613740B1 (en) |
JP (1) | JPH0747432A (en) |
DE (1) | DE69405426T2 (en) |
ES (1) | ES2105375T3 (en) |
IT (1) | IT1260615B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3880975B1 (en) * | 2018-11-13 | 2022-12-07 | Moog Luxembourg Sàrl | Electro-hydrostatic actuator system |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2776296B2 (en) * | 1995-05-01 | 1998-07-16 | トヨタ自動車株式会社 | Press working method, press working device, and pin transmitted load detecting device |
DK173519B1 (en) | 1999-06-21 | 2001-01-29 | Hydraulico As | Tool for press molding of metal plate and method for regulating a surface pressure using such a tool |
ES2297983B1 (en) * | 2005-08-03 | 2009-07-17 | Batz, S. Coop. | PROCEDURE TO EMBUTIRATE METAL SHEETS. |
JP4958721B2 (en) * | 2007-10-17 | 2012-06-20 | アイダエンジニアリング株式会社 | Servo motor driven press machine |
JP4832476B2 (en) * | 2008-07-18 | 2011-12-07 | サムテック株式会社 | Metal container manufacturing method and metal container manufacturing apparatus |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1481202A (en) * | 1976-03-29 | 1977-07-27 | Metal Box Co Ltd | Deep drawing |
US4745792A (en) * | 1986-10-14 | 1988-05-24 | Aluminum Company Of America | Blankholder for a draw press |
DD289723A5 (en) * | 1989-12-05 | 1991-05-08 | Fz Fuer Umform- Und Plastverarbeitungstechnik,De | METHOD FOR DEFLECTING SHEET MOLDING PARTS |
IT1239856B (en) * | 1990-01-24 | 1993-11-15 | Fiat Auto Spa | PROCEDURE FOR THE MOLDING OF SHEETS AND HYDRAULIC PRESS FOR THE REALIZATION OF THIS PROCEDURE. |
-
1993
- 1993-03-02 IT ITTO930148A patent/IT1260615B/en active IP Right Grant
-
1994
- 1994-03-01 DE DE69405426T patent/DE69405426T2/en not_active Expired - Fee Related
- 1994-03-01 EP EP94103041A patent/EP0613740B1/en not_active Expired - Lifetime
- 1994-03-01 ES ES94103041T patent/ES2105375T3/en not_active Expired - Lifetime
- 1994-03-02 JP JP6032229A patent/JPH0747432A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3880975B1 (en) * | 2018-11-13 | 2022-12-07 | Moog Luxembourg Sàrl | Electro-hydrostatic actuator system |
Also Published As
Publication number | Publication date |
---|---|
JPH0747432A (en) | 1995-02-21 |
DE69405426D1 (en) | 1997-10-16 |
DE69405426T2 (en) | 1998-02-12 |
EP0613740A1 (en) | 1994-09-07 |
IT1260615B (en) | 1996-04-22 |
ES2105375T3 (en) | 1997-10-16 |
ITTO930148A0 (en) | 1993-03-02 |
ITTO930148A1 (en) | 1994-09-02 |
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