EP1002198A1 - Shock-proof hydraulic cylinder - Google Patents
Shock-proof hydraulic cylinderInfo
- Publication number
- EP1002198A1 EP1002198A1 EP98922767A EP98922767A EP1002198A1 EP 1002198 A1 EP1002198 A1 EP 1002198A1 EP 98922767 A EP98922767 A EP 98922767A EP 98922767 A EP98922767 A EP 98922767A EP 1002198 A1 EP1002198 A1 EP 1002198A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- piston
- cylinder
- piston rod
- shock protection
- hydraulic cylinder
- 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.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/075—Constructional features or details
- B66F9/20—Means for actuating or controlling masts, platforms, or forks
- B66F9/22—Hydraulic devices or systems
-
- 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
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
- F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
- F15B15/223—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston with a piston extension or piston recess which completely seals the main fluid outlet as the piston approaches its end position
Definitions
- the invention relates to a hydraulic cylinder with shock protection, comprising
- piston rod has at least one opening in its lower region, which connects the piston rod outside with a hydraulic medium reservoir, and which is closed shortly before the upper piston end position is reached by the piston rod guide of the cylinder head.
- Such hydraulic cylinders are used, among other things, as lifting cylinders for industrial trucks.
- a hydraulic cylinder which has a shock protection, but which consists only of a simple hydraulic arrangement.
- the transport of sensitive goods requires that stroke impacts, which may result in a strong noise development and can cause damage to sensitive goods, are avoided as far as possible. This cannot be achieved with the hydraulic cylinder known from DE-OS 36 06 515.
- Another disadvantage of this hydraulic cylinder is that no further consumer can be connected downstream of the cylinder.
- the object of the present invention is to provide a hydraulic cylinder which enables improved shock protection.
- the cylinder chamber is connected to a hydraulic medium reservoir via a defined throttle point.
- FIGS. 1 and 2 represent two possible embodiments of the hydraulic cylinder according to the invention with shock protection.
- the cylinder housing 1 is closed on one of the end faces by a cylinder base 2.
- the cylinder base 2 has at least one inlet and outlet opening 3 for a hydraulic medium.
- This inlet and outlet opening 3 is connected to a hydraulic medium line, not shown in the figures.
- the inlet and outlet opening 3 comprises a section which is designed in the form of a central bore coaxially with a cylindrical bore of the cylinder housing 1.
- An axially displaceable piston 4 is arranged inside the cylinder housing 1 and is connected to a piston rod 10.
- piston 4 and piston rod 10 can of course also be formed in one piece.
- An annular gap of small width is provided between the piston 4 and the cylinder housing 1.
- the piston 4 can have a cylindrical bore 8 in which a hollow cylindrical damping piston 11 is arranged.
- the piston rod 10 has at least one opening in its lower region - which is preferably designed as a bore 21. This opening is closed when the upper piston end position is reached by the piston rod guide of the cylinder head 20.
- the (hydraulic) medium remaining in the annular cylinder chamber 7, which is defined by the inner surface of the cylinder housing 1, the outer surface of the piston rod, the underside of the piston rod guide of the cylinder head and the upper side of the piston, is removed from the annular cylinder chamber 7 via a defined throttle point displaced into a hydraulic medium reservoir.
- This hydraulic medium reservoir can be formed, for example, by a hollow piston rod 10. Adequate damping or shock protection can be achieved by means of the defined throttle point both during the downward and upward movement of the piston 4.
- a bore 18 can be provided in the piston 4, through which the (hydraulic) medium to be displaced is discharged from the annular cylinder chamber 7.
- a bore 18 can be provided in an existing damping piston 11.
- a seal 19 be provided between the cylinder housing 1 and the piston 4. Again alternatively or in addition to the piston bore 18 shown in FIG be trained.
- the piston rod 10, the piston 4 and - if present - the damping piston 11 are hollow cylindrical in the hydraulic cylinder with shock protection. It is thereby achieved that, regardless of the position of the piston 4 and the damping piston 11 within the cylinder housing 1, additional consumers can optionally be supplied with hydraulic medium, in particular with hydraulic oil.
- the embodiment of the hydraulic cylinder according to the invention shown in FIG. 2 has a hollow cylindrical damping piston 11. This has at least one opening 16 in its lower area facing the cylinder base 2; only for the sake of clarity, only one opening 16 is shown in FIG.
- the hollow cylindrical damping piston 11 is arranged axially displaceably in the cylindrical bore 8 of the piston 4.
- the piston 4 is also biased in the direction of the inlet and outlet opening 3 by means of a spring 15, which is preferably designed as a helical spring, as shown in FIGS. 1 and 2. Furthermore, the damping piston 15 has a stop 13, by means of which the maximum relative displacement of the damping piston 11 with respect to the piston 4 is limited.
- the spring 15 is supported at its upper end facing away from the cylinder base 2 on an annular part 9 of the piston rod 10. With a corresponding configuration of the piston rod 10, this annular part 9 can be dispensed with.
- the piston 4 has, on its side facing the cylinder base 2, a pressure-receiving surface 5 which determines or defines a cylinder chamber 6 arranged inside the cylinder bore and at the level of the inlet and outlet opening 3.
- Another annular cylinder chamber 7 is defined by the inner surface of the cylinder housing 1 and by the outer surface of the piston rod 10. If the piston 4 is moved downward in the direction of the cylinder base 2 via the piston rod 10, the underside of the damping piston 11 first hits the valve seat 17. This is formed at the innermost end of the bore of the inlet and outlet opening 3 in the cylinder base 2. While the piston rod 10 and piston 4 continue to move downwards, in contrast to the damping piston 11 which is already at rest, the cylinder chamber 6 is continuously reduced in size. The hydraulic medium located in the cylinder chamber 6 flows partially through the annular gap between the piston 4 and the cylinder housing 1 into the cylinder chamber 7.
- the remaining hydraulic medium in the cylinder chamber 6 can only pass through the opening 16 of the damping piston 11 into the cylindrical bore 14 and through this into the inlet and outlet opening 3. With an appropriate dimensioning of the opening (s) 16, this transfer of hydraulic medium from the cylinder chamber 6 into the cylindrical space 14 takes place such that the underside of the piston 4 comes to rest without impact on the stop 12 of the damping piston 11.
- a gap remains between the cylinder housing 1 and the piston 4.
- the lower end of the damping piston 11 is preferably spherical.
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- General Engineering & Computer Science (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Actuator (AREA)
- Fluid-Damping Devices (AREA)
- Lubricants (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE29707639U | 1997-04-28 | ||
DE29707639U DE29707639U1 (en) | 1997-04-28 | 1997-04-28 | Hydraulic cylinder with shock protection |
PCT/EP1998/002408 WO1998049451A1 (en) | 1997-04-28 | 1998-04-23 | Shock-proof hydraulic cylinder |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1002198A1 true EP1002198A1 (en) | 2000-05-24 |
EP1002198B1 EP1002198B1 (en) | 2003-03-12 |
Family
ID=8039638
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP98922767A Expired - Lifetime EP1002198B1 (en) | 1997-04-28 | 1998-04-23 | Shock-proof hydraulic cylinder |
Country Status (5)
Country | Link |
---|---|
US (1) | US6283008B1 (en) |
EP (1) | EP1002198B1 (en) |
JP (1) | JP2001522439A (en) |
DE (2) | DE29707639U1 (en) |
WO (1) | WO1998049451A1 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19802119A1 (en) * | 1998-01-21 | 1999-07-22 | Still Wagner Gmbh & Co Kg | Industrial truck with a lifting device |
US6557456B2 (en) | 2001-05-24 | 2003-05-06 | The Raymond Corporation | Cushioned actuator |
DE102004036424A1 (en) * | 2004-07-27 | 2006-03-23 | Still Gmbh | Hydraulic cylinder with end position damping |
DE102004039211A1 (en) * | 2004-08-12 | 2006-02-23 | Still Gmbh | Mast and hydraulic cylinder with a compensation device |
DE102007021052A1 (en) | 2007-05-04 | 2008-11-06 | Jungheinrich Ag | Hydraulic cylinder with variable end position damping |
DE202015009742U1 (en) * | 2014-06-12 | 2019-10-24 | Suzhou Roaring Precision Machinery Co., Ltd. | Fluid drive cylinder of hinged inner rod type |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3270626A (en) | 1963-07-01 | 1966-09-06 | Bradbury Farel | Fluid-powered linear actuators |
US3213760A (en) * | 1963-10-23 | 1965-10-26 | Flo Tork Inc | Fluid cushion |
DE2254495A1 (en) | 1972-11-07 | 1974-05-22 | Zettelmeyer Fa Hubert | DEVICE FOR DAMPING THE STRIKING OF EACH OTHER MOVING PARTS COUPLED BY HYDRAULIC CYLINDERS |
US4638717A (en) * | 1985-02-01 | 1987-01-27 | Flo-Tork, Inc. | Combination of cushion, adjuster and side ports in a single unit rotary actuator |
US4706781A (en) | 1985-02-28 | 1987-11-17 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Fluid-operated cylinder with cushioning flow rate control valve means |
IT1272114B (en) | 1993-03-19 | 1997-06-11 | Fiat Om Carrelli Elevatori Spa | FORK LIFTING UNITS IN FORKLIFTS |
-
1997
- 1997-04-28 DE DE29707639U patent/DE29707639U1/en not_active Expired - Lifetime
-
1998
- 1998-04-23 EP EP98922767A patent/EP1002198B1/en not_active Expired - Lifetime
- 1998-04-23 DE DE59807481T patent/DE59807481D1/en not_active Expired - Lifetime
- 1998-04-23 JP JP54657898A patent/JP2001522439A/en active Pending
- 1998-04-23 US US09/403,728 patent/US6283008B1/en not_active Expired - Fee Related
- 1998-04-23 WO PCT/EP1998/002408 patent/WO1998049451A1/en active IP Right Grant
Non-Patent Citations (1)
Title |
---|
See references of WO9849451A1 * |
Also Published As
Publication number | Publication date |
---|---|
DE29707639U1 (en) | 1997-08-21 |
EP1002198B1 (en) | 2003-03-12 |
US6283008B1 (en) | 2001-09-04 |
WO1998049451A8 (en) | 2000-01-06 |
DE59807481D1 (en) | 2003-04-17 |
WO1998049451A1 (en) | 1998-11-05 |
JP2001522439A (en) | 2001-11-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE68907578T2 (en) | Vehicle structure and assembly process. | |
DE69016218T2 (en) | Hydraulically lockable gas spring. | |
DE1256485B (en) | Hydraulic shock absorber | |
DE19918195C1 (en) | Tension/compression buffer for rail vehicle or automobile coupling has piston element displaced from neutral position in opposite directions with hydraulic damping of its return movement | |
DE3606515A1 (en) | FLUID-ACTUATED PISTON CYLINDER UNIT WITH SHOCK ABSORBER | |
DE2341352A1 (en) | LOCKABLE LIFTING UNIT WITH END SUSPENSION | |
DE2624475B2 (en) | Hydraulic shock absorber | |
DE19731139C2 (en) | Piston-cylinder unit, which is installed between a body and a wheel guide part of a vehicle | |
DE2905030B2 (en) | End stop damped gas spring | |
DE3335321A1 (en) | PNEUMATIC SPRING BALANCE | |
DE29816283U1 (en) | Improved hydraulic quick lifting unit of a jack | |
DE69007406T2 (en) | Pistons for pressure cylinders. | |
DE2636791C3 (en) | Hydraulic pit ram with rock check valve arrangement | |
EP1002198B1 (en) | Shock-proof hydraulic cylinder | |
DE2944831A1 (en) | HYDROPNEUMATIC SUSPENSION FOR MOTOR VEHICLES | |
DE102004047898B4 (en) | Self-pumping hydropneumatic strut | |
DE3911819A1 (en) | SHOCK ABSORBER WITH CHANGEABLE DAMPING CHARACTERISTICS | |
DE102018124353A1 (en) | Adjusting device for an axial piston machine | |
DE2852081A1 (en) | HYDRAULICALLY DRIVEN HAMMER | |
EP0051728A1 (en) | Hydraulic motor control system | |
WO1988007495A1 (en) | Hydraulic manually-operated single-piston pump | |
EP0066299A1 (en) | Hydraulic telescopic shock absorber for a motor vehicle | |
DE69203374T2 (en) | Hydraulic shock absorber. | |
DE4243667A1 (en) | Piston pump for hydraulic system with non-return type inlet valve | |
EP0516114B1 (en) | Hydraulic closing apparatus for an injection mould |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19991123 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB IT SE |
|
17Q | First examination report despatched |
Effective date: 20010522 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Designated state(s): DE FR GB IT SE |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REF | Corresponds to: |
Ref document number: 59807481 Country of ref document: DE Date of ref document: 20030417 Kind code of ref document: P |
|
REG | Reference to a national code |
Ref country code: SE Ref legal event code: TRGR |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) | ||
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20031215 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20100324 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20100427 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 20100423 Year of fee payment: 13 |
|
REG | Reference to a national code |
Ref country code: SE Ref legal event code: EUG |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20110423 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20110423 Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20110423 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20110424 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 18 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20150422 Year of fee payment: 18 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20150422 Year of fee payment: 18 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 59807481 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 59807481 Country of ref document: DE Representative=s name: PATENTSHIP PATENTANWALTSGESELLSCHAFT MBH, DE |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20161230 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20161101 Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20160502 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 59807481 Country of ref document: DE Representative=s name: PATENTSHIP PATENTANWALTSGESELLSCHAFT MBH, DE |