WO1996036814A1 - Arrangement in a pressing tool for sheet metal forming - Google Patents
Arrangement in a pressing tool for sheet metal forming Download PDFInfo
- Publication number
- WO1996036814A1 WO1996036814A1 PCT/SE1996/000647 SE9600647W WO9636814A1 WO 1996036814 A1 WO1996036814 A1 WO 1996036814A1 SE 9600647 W SE9600647 W SE 9600647W WO 9636814 A1 WO9636814 A1 WO 9636814A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- hydraulic cylinder
- piston unit
- accumulator
- designed
- flow
- Prior art date
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/10—Delay devices or arrangements
Definitions
- the present invention relates to an arrangement in a pressing tool for sheet metal forming in order to shut off or retard an oil flow in a hydraulic system in co ⁇ ordination with the closing and opening movements of the said tool.
- a passive hydraulic system in the pressing tool. This is done in order to be able to shift some of the pressing force to another position and another direction, for example in order to be able to perform yet another operation in the same tool.
- a passive hydraulic system can be achieved by arranging a primary hydraulic cylinder/piston unit in a lower tool half in such a way that the piston is pressed into the cylinder when the tool is closed.
- the oil flow from the primary hydraulic cylinder/piston unit can thus be used in order to produce a stroke in a secondary hydraulic cylinder/piston unit. The timing of the said stroke coincides with the closing of the tool.
- the gas-filled spring in the upper part of the sheet metal forming tool is compressed against the piston rod of the hydraulic cylinder/piston unit.
- the said piston rod is not pressed into the cylinder when the tool is being closed, but only when the valve is opened after predetermined delay.
- the gas-filled spring then presses the piston rod into the cylinder so that the oil flows from the latter to the secondary hydraulic cylinder/piston unit, which can then supply force and movement.
- the pressing tool must be in the fully closed position in order to be able to supply a satisfactory oil flow. This means that the time at which the secondary force/movement will act cannot be determined with complete freedom.
- the object of the present invention is to produce an arrangement which can shut off or retard an oil flow in a hydraulic system in a pressing tool for sheet metal forming for an arbitrarily chosen period.
- This object is achieved according to the invention in that it comprises: a non-return return valve designed, when the tool is being closed, to permit a flow in one direction from a primary hydraulic cylinder/piston unit, which is thereby compressed, to a pressurised accumulator; a first valve designed to selectively permit a flow between the accumulator and a secondary hydraulic cylinder/piston unit, which is designed as a consequence of such a flow to move from a compressed basic position to an expanded position; and parallel with the non-return valve a second valve, designed so that when the primary hydraulic cylinder/piston unit has been relieved by opening of the tool, it will selectively permit a return flow to the primary hydraulic cylinder/piston unit from the accumulator or, if the first valve is also made to open, from the secondary hydraulic cylinder/piston unit
- the pressure in the accumulator is always equal to or greater than the working pressure in the hydraulic system.
- the accumulator is of dimensions sufficient to accommodate the oil which is in the system when both the hydraulic cylinder/piston units are compressed.
- a piston which separates the oil from pressure generating means is located in the accumulator.
- gas is used as the pressure generating means.
- a coil spring is used as pressure generating means.
- the secondary hydraulic cylinder/piston unit is designed to be returned to the compressed basic position by means of a gas-filled spring.
- the secondary hydraulic cylinder/piston unit is designed to be returned to the compressed basic position by means of a coil spring. According to a further special characteristic of the invention, the secondary hydraulic cylinder/piston unit is designed to be returned to the compressed basic position by means of a gas under pressure.
- the piston in the accumulator is designed to rest against a stop when the system is not under load.
- Fig.l shows a passive hydraulic system with a retarding arrangement according to the prior art.
- Fig.2 shows a passive hydraulic system with a retarding arrangement according to the invention.
- 1 denotes a primary hydraulic cylinder/piston unit arranged in a lower tool half of a pressing tool for sheet metal forming.
- the primary hydraulic cylinder/piston unit 1 forms a passive system together with a secondary hydraulic cylinder/piston unit 2 and a flow element 3 connecting the cylinders.
- the passive system derives its driving force from an external action on the piston rod of the primary hydraulic cylinder/piston unit 1.
- the main function of the system is to convert a force in one direction at one point to a force in another direction at another point.
- the flow element 3 is provided with a valve 4, which is designed to selectively permit a flow between the primary and the secondary hydraulic cylinder/piston unit.
- the retardation of the oil flow is achieved by means of the valve 4 and a gas-filled spring 5, which is arranged in the upper part of the pressing tool and designed to act in opposition to the piston rod of the primary hydraulic cylinder/piston unit 1 when the tool is being closed.
- the valve 4 is kept closed when the tool is closing, for which reason the gas-filled spring 5 is compressed against the piston rod of the primary hydraulic cylinder/piston unit 1 , which remains in an extended position.
- the valve 4 is made to open at an arbitrary time, following which the piston rod of the gas-filled spring 5 presses the piston rod of the primary hydraulic cylinder/piston unit 1 in and oil flows from the latter to the secondary hydraulic cylinder/piston unit 2 so that its piston rod moves outwards.
- the tool In order for this to function satisfactorily, the tool must be fully closed when the valve 4 is being opened.
- Fig.2 shows an arrangement according to the invention for shutting off or retarding of an oil flow in a hydraulic system.
- the hydraulic system is a passive system of the same type as in Fig.1.
- a primary hydraulic system/piston unit 7 is ' arranged in a lower tool half of a pressing tool for sheet metal forming and connected to a primary flow connection of the retarding arrangement.
- a secondary hydraulic cylinder/piston unit 10 is connected to a secondary flow connection of the retarding arrangement and designed to perform another operation in the same tool.
- a non-return valve 6 is designed to permit a flow in one direction from the primary flow connection to a pressurised accumulator 8, for example a piston accumulator.
- a first two way valve 9 is designed to selectively permit a flow between the accumulator 8 and the secondary flow connection. This can occur at any time after the tool is closed and also after it is opened again.
- a second two-way valve 11 is arranged parallel with the non-return valve 6 and designed to selectively permit a return flow to the primary flow connection after a certain time or as a function of the position of the piston rod of the secondary hydraulic cylinder/piston unit 10.
- the secondary hydraulic cylinder/piston unit 10 has a built-in return force which can be achieved by means of a gas-filled or coil spring.
- the first two-way valve 9 can be opened so as to permit a flow between the accumulator 8 and the secondary hydraulic cylinder/piston unit 10. Its piston rod is made to move outwards as oil is forced in by the piston 12 of the accumulator 8.
- the accumulator 8 also functions as overload protection in case the piston rod is subjected to a required or unwanted stop. This is possible in that it is designed to accommodate the oil which is present in the system when the piston rods of both hydraulic cylinder/piston units 7,10 are pressed into the cylinders. In such cases the accumulator 8 takes up the excess oil in the system so that an undesirable pressure increase cannot occur.
- the system according to the invention can also be adapted to a situation in which strokes by the secondary hydraulic cylinder/piston unit 10 are not desirable.
- oil as previously described, is discharged from the primary hydraulic cylinder/piston unit through the non-return valve 6 to the accumulator 8. Oil is then quite simply discharged back to the relieved primary hydraulic cylinder/piston unit 7 by opening of the second valve 11 after the tool has been opened.
- the first two-way valve 9 is kept closed throughout the entire process. In this way a shutting-off of the secondary hydraulic cylinder/piston unit 10 is achieved.
- the piston 12 in the accumulator 8 can be designed to rest against a stop when the system is not under load. This means that the pressure in the unloaded system is zero in all parts outside the accumulator 8.
- the accumulator 8 can also consist of a spring-loaded piston rod in a hydraulic cylinder/piston unit.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP96914528A EP0870114B1 (en) | 1995-05-19 | 1996-05-15 | Arrangement in a pressing tool for sheet metal forming |
US08/952,606 US5855114A (en) | 1995-05-19 | 1996-05-15 | Arrangement in a pressing tool for sheet metal forming |
AU57861/96A AU5786196A (en) | 1995-05-19 | 1996-05-15 | Arrangement in a pressing tool for sheet metal forming |
JP53476196A JP4036245B2 (en) | 1995-05-19 | 1996-05-15 | Metal sheet forming equipment |
DE69614877T DE69614877T2 (en) | 1995-05-19 | 1996-05-15 | ARRANGEMENT IN A PRESSING TOOL FOR SHAPING SHEET PANELS |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE9501880A SE510202C2 (en) | 1995-05-19 | 1995-05-19 | Device for a hydraulic system |
SE9501880-0 | 1995-05-19 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1996036814A1 true WO1996036814A1 (en) | 1996-11-21 |
Family
ID=20398384
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/SE1996/000647 WO1996036814A1 (en) | 1995-05-19 | 1996-05-15 | Arrangement in a pressing tool for sheet metal forming |
Country Status (8)
Country | Link |
---|---|
US (1) | US5855114A (en) |
EP (1) | EP0870114B1 (en) |
JP (1) | JP4036245B2 (en) |
AU (1) | AU5786196A (en) |
DE (1) | DE69614877T2 (en) |
ES (1) | ES2162055T3 (en) |
SE (1) | SE510202C2 (en) |
WO (1) | WO1996036814A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7219601B2 (en) | 2004-12-03 | 2007-05-22 | Cosmopower, Inc. | Empty container pressing apparatus |
EP2005914A3 (en) * | 2000-07-20 | 2008-12-31 | Allegiance Corporation | Hand-actuated articulating surgical tool |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1025922B1 (en) * | 1999-02-05 | 2002-06-26 | Strömsholmen AB | Hydraulic arrangement for performing a secondary operation in a pressing tool for sheet metal forming |
CA2408408C (en) | 2000-05-12 | 2013-07-09 | Genzyme Corporation | Modulators of tnf- alpha signaling |
GB2464756B (en) * | 2008-10-28 | 2013-06-05 | Linval Rodney | Improvements in or relating to punches or presses |
DE102011001955B4 (en) | 2011-04-11 | 2020-01-23 | Audi Ag | Press tool with an additional tool and method for actuating an additional tool of a press tool |
US8978766B2 (en) * | 2011-09-13 | 2015-03-17 | Schlumberger Technology Corporation | Temperature compensated accumulator |
TWI684719B (en) * | 2019-02-27 | 2020-02-11 | 陳文彬 | Fluid control device |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2420890A (en) * | 1942-07-20 | 1947-05-20 | Bendix Aviat Corp | Fluid pressure control system |
US4253379A (en) * | 1979-10-01 | 1981-03-03 | American Standard Inc. | Fluid control system |
US5038598A (en) | 1990-09-07 | 1991-08-13 | Gene Pitzer | Method and apparatus for performing secondary operations in a press |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4209987A (en) * | 1978-07-18 | 1980-07-01 | Bocharov Jury A | Hydraulic screw press drive |
US4211078A (en) * | 1979-02-22 | 1980-07-08 | Bass Robert F | Dynamic power source |
NL8801644A (en) * | 1988-06-28 | 1990-01-16 | Applied Power Inc | HYDRAULIC CONTROL UNIT, PARTICULARLY FOR LIFTING A LOAD LIKE A HOSPITAL BED. |
US5361583A (en) * | 1993-09-30 | 1994-11-08 | Ethicon, Inc. | Pressurized fluid actuation system with variable force and stroke output for use in a surgical instrument |
-
1995
- 1995-05-19 SE SE9501880A patent/SE510202C2/en not_active IP Right Cessation
-
1996
- 1996-05-15 WO PCT/SE1996/000647 patent/WO1996036814A1/en active IP Right Grant
- 1996-05-15 EP EP96914528A patent/EP0870114B1/en not_active Expired - Lifetime
- 1996-05-15 AU AU57861/96A patent/AU5786196A/en not_active Abandoned
- 1996-05-15 ES ES96914528T patent/ES2162055T3/en not_active Expired - Lifetime
- 1996-05-15 JP JP53476196A patent/JP4036245B2/en not_active Expired - Lifetime
- 1996-05-15 US US08/952,606 patent/US5855114A/en not_active Expired - Lifetime
- 1996-05-15 DE DE69614877T patent/DE69614877T2/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2420890A (en) * | 1942-07-20 | 1947-05-20 | Bendix Aviat Corp | Fluid pressure control system |
US4253379A (en) * | 1979-10-01 | 1981-03-03 | American Standard Inc. | Fluid control system |
US5038598A (en) | 1990-09-07 | 1991-08-13 | Gene Pitzer | Method and apparatus for performing secondary operations in a press |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2005914A3 (en) * | 2000-07-20 | 2008-12-31 | Allegiance Corporation | Hand-actuated articulating surgical tool |
US7219601B2 (en) | 2004-12-03 | 2007-05-22 | Cosmopower, Inc. | Empty container pressing apparatus |
Also Published As
Publication number | Publication date |
---|---|
EP0870114B1 (en) | 2001-08-29 |
DE69614877D1 (en) | 2001-10-04 |
SE510202C2 (en) | 1999-04-26 |
JP4036245B2 (en) | 2008-01-23 |
ES2162055T3 (en) | 2001-12-16 |
SE9501880L (en) | 1996-11-20 |
US5855114A (en) | 1999-01-05 |
AU5786196A (en) | 1996-11-29 |
DE69614877T2 (en) | 2002-04-11 |
EP0870114A2 (en) | 1998-10-14 |
JP2000516539A (en) | 2000-12-12 |
SE9501880D0 (en) | 1995-05-19 |
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