EP0103549A1 - Überlastungsschutz für hydraulische Zylinder - Google Patents

Überlastungsschutz für hydraulische Zylinder Download PDF

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Publication number
EP0103549A1
EP0103549A1 EP83830172A EP83830172A EP0103549A1 EP 0103549 A1 EP0103549 A1 EP 0103549A1 EP 83830172 A EP83830172 A EP 83830172A EP 83830172 A EP83830172 A EP 83830172A EP 0103549 A1 EP0103549 A1 EP 0103549A1
Authority
EP
European Patent Office
Prior art keywords
cylinder
rod
protected
hydraulic cylinder
piston
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Withdrawn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
EP83830172A
Other languages
English (en)
French (fr)
Inventor
Aurelio Ortelli
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.)
Riva Calzoni SpA
Original Assignee
Riva Calzoni 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 Riva Calzoni SpA filed Critical Riva Calzoni SpA
Publication of EP0103549A1 publication Critical patent/EP0103549A1/de
Withdrawn legal-status Critical Current

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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
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/02—Installations or systems with accumulators
    • 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
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1423—Component parts; Constructional details
    • F15B15/1447—Pistons; Piston to piston rod assemblies
    • 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
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1423—Component parts; Constructional details
    • F15B15/1457—Piston rods

Definitions

  • the present invention relates to a device for protecting a hydraulic cylinder against overloading which could damage its structure.
  • a hydraulic cylinder is normally used for moving an object in a straight line by means of a rod connected to its piston, and for maintaining the object firmly in position at a desired point along its line of movement.
  • the object so moved is kept in position by cutting off the two chambers of the cylinder by means of the distributor .of the pressurised working fluid, or by means of suitable valves connected in the supply and discharge ducts of the chambers.
  • the incompressibility of the working fluid generally oil
  • the prior art makes use of maximum pressure valves connected to the working chambers of the cylinder, which, by opening at a maximum predetermined pressure, allow part of the pressurised fluid to leave one of the chambers.
  • the problem behind the present invention is thus to provide a protection device for a hydraulic cylinder which avoids the failure of the cylinder and the apparatus hydraulically connected thereto when'overloading arises due to any external disturbing forces, and which at the same time allows the rod of the cylinder and hence the object controlled by this rod to be returned automatically to the initial position where the disturbing forces arose.
  • a protection device which is characterised in that it comprises an auxiliary hydraulic cylinder in which each working chamber defined by its piston is in constant hydraulic communication through a respective duct with a corresponding chamber of the hydraulic cylinder to be protected, and in that the rod is connected to a resilient member which yields in a direction opposite the direction of any displacement of the rod itself resulting from the surpassing of a force of predetermined value acting on the piston due to the pressure differential created in the hydraulic cylinder to be protected by the exceeding of the maximum pressure allowable within the cylinder to be protected.
  • a conventional hydraulic cylinder 1 has its interior divided into working chambers 2, 3 by a piston 4 which slides in a straight line within the cylinder 1.
  • a conventional sealing ring 5 is located on the piston 4.
  • the piston 4 is rigid with a rod 6 which, in the example illustrated, is of the type which projects from both ends 7, 8 of the cylinder 1 through respective apertures provided with conventional seals 9, 10.
  • the working chambers 2, 3 are provided with respective ducts 11, 12 for alternating hydraulic connection to a source of pressurised fluid, generally oil, and to a discharge vessel, not illustrated, through a distributor, also not illustrated since it is conventional.
  • the rod 6 has a cylindrical cavity 13 within which is slidable a piston 14 with a seal 15.
  • This piston divides the cylindrical cavity 13 into two working chambers 16, 17.
  • the whole thus. constitutes an auxiliary hydraulic cylinder.
  • a duct 18 effects a constant hydraulic connection between the chamber 16 and the chamber 2 of the cylinder 1 to be protected, while a second duct 19 effects a constant hydraulic connection between the chamber 17 and the working chamber 3 of the cylinder 1.
  • the rod 6 of the cylinder 1 also has a cylindrical cavity 20 coaxial with the cavity 13.
  • This cavity 20 in the preferred embodiment shown in the drawings, communicates hydraulically with the working chamber 17 of the auxiliary hydraulic cylinder.
  • a rod 21 is connected to the piston 14 and, in the embodiment illustrated, projects only from the side facing the chamber 17.
  • This rod 21 is extended by a coaxial section 22 which extends longitudinally within the cavity 20 of the side 6.
  • a coaxial section 22 which extends longitudinally within the cavity 20 of the side 6.
  • annular shoulder 23 At the junction between the rod 21 and its extension 22 there is an annular shoulder 23, while at the free end within the cavity 20 there is a head 24 defining an annular shoulder 25 facing the shoulder 23.
  • a helical spring 26 is mounted on the extension 22 and will yield only on the surpassing of a predetermined compression value, the spring being located between two annular elements 27, 28 which, when the spring 26 is not operative, bear against the shoulders 23, 25 of the extension rod 22, respectively. The latter may slide freely axially of the said annular elements 27, 28.
  • the cavity 20 of the rod 6 is provided, in its turn, with two opposing annular projections 29, 30 against which the annular elements 27, 28 engage when the spring 26 is in its non-operative condition.
  • the operation of the device is as follows.
  • the piston 14 is thus returned to its initial position and, with the return of the previously-displaced hydraulic fluid to the chamber 3 of the cylinder 1, the piston 4 is also returned automatically to the initial position.
  • the object (not illustrated) controlled by the rod 6 of the cylinder 1 is also automatically re-positioned exactly in its initial position.
  • auxiliary cylinder is formed within a cavity in the rod of the cylinder to be protected and the resiliently yielding member con--stituted by the spring 26 is also housed within a coaxial cavity in the same rod of the cylinder to be protected
  • the auxiliary cylinder and its resiliently yielding member may clearly also be formed separately from the rod of the cylinder to be protected without departing from the scope of the invention.
  • the basic advantage of the device according to the invention is that of achieving suitable protection against possible overloading and, at the same time, returning the rod of the cylinder to be protected automatically to the initial position where the overloading occurred, without having recourse to special operations.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
EP83830172A 1982-09-10 1983-09-05 Überlastungsschutz für hydraulische Zylinder Withdrawn EP0103549A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT8223204A IT1152387B (it) 1982-09-10 1982-09-10 Dispositivo di protezione contro sovraccarichi in un cilindro idraulico
IT2320482 1982-09-10

Publications (1)

Publication Number Publication Date
EP0103549A1 true EP0103549A1 (de) 1984-03-21

Family

ID=11204858

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83830172A Withdrawn EP0103549A1 (de) 1982-09-10 1983-09-05 Überlastungsschutz für hydraulische Zylinder

Country Status (2)

Country Link
EP (1) EP0103549A1 (de)
IT (1) IT1152387B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3606148A1 (de) * 1986-02-26 1987-08-27 Bbc Brown Boveri & Cie Gefederte aufhaengung eines steuerkolbens
DE4424927A1 (de) * 1994-07-14 1996-01-18 Kaup Gmbh & Co Kg Hydraulik-Antriebsaggregat mit Kolbenstange
DE10027731C1 (de) * 2000-06-03 2001-11-29 Festo Ag & Co Durch Fluidbeaufschlagung aktivierbare Betätigungseinrichtung
DE102015118839A1 (de) * 2015-11-03 2017-05-04 Tkr Spezialwerkzeuge Gmbh Hydraulikeinheit für ein mobiles Hydraulikwerkzeug
CN109854282A (zh) * 2019-03-11 2019-06-07 中铁二局第四工程有限公司 自动压紧装置及隧道防水板铺装机器人

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1347730A (fr) * 1962-10-26 1964-01-04 Vérin hydraulique à simple effet
FR1555347A (de) * 1967-04-26 1969-01-24
US4007667A (en) * 1975-08-15 1977-02-15 Fauchon Engineering Works Limited Hydraulic positioning and shock-absorbing apparatus
FR2414130A1 (fr) * 1978-01-09 1979-08-03 Leduc & Fils Rene Verin a double effet avec limitation de pression
WO1981003527A1 (en) * 1980-06-05 1981-12-10 Tampella Oy Ab Hydraulic piston cylinder device with a valve element

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1347730A (fr) * 1962-10-26 1964-01-04 Vérin hydraulique à simple effet
FR1555347A (de) * 1967-04-26 1969-01-24
US4007667A (en) * 1975-08-15 1977-02-15 Fauchon Engineering Works Limited Hydraulic positioning and shock-absorbing apparatus
FR2414130A1 (fr) * 1978-01-09 1979-08-03 Leduc & Fils Rene Verin a double effet avec limitation de pression
WO1981003527A1 (en) * 1980-06-05 1981-12-10 Tampella Oy Ab Hydraulic piston cylinder device with a valve element

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
OELHYDRAULIK UND PNEUMATIK, vol. 6, no. 10, October 1962, page 379, Mainz, DE. *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3606148A1 (de) * 1986-02-26 1987-08-27 Bbc Brown Boveri & Cie Gefederte aufhaengung eines steuerkolbens
US4774876A (en) * 1986-02-26 1988-10-04 Bbc Brown, Boveri Ltd. Sprung suspension of an actuating piston
DE4424927A1 (de) * 1994-07-14 1996-01-18 Kaup Gmbh & Co Kg Hydraulik-Antriebsaggregat mit Kolbenstange
DE4424927C2 (de) * 1994-07-14 1998-06-04 Kaup Gmbh & Co Kg Teleskop-Spreader für die Container-Verladung
DE10027731C1 (de) * 2000-06-03 2001-11-29 Festo Ag & Co Durch Fluidbeaufschlagung aktivierbare Betätigungseinrichtung
DE102015118839A1 (de) * 2015-11-03 2017-05-04 Tkr Spezialwerkzeuge Gmbh Hydraulikeinheit für ein mobiles Hydraulikwerkzeug
DE102015118839B4 (de) * 2015-11-03 2017-06-01 Tkr Spezialwerkzeuge Gmbh Hydraulikeinheit für ein mobiles Hydraulikwerkzeug
CN109854282A (zh) * 2019-03-11 2019-06-07 中铁二局第四工程有限公司 自动压紧装置及隧道防水板铺装机器人

Also Published As

Publication number Publication date
IT1152387B (it) 1986-12-31
IT8223204A0 (it) 1982-09-10

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Legal Events

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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

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB LI LU NL SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19841122

RIN1 Information on inventor provided before grant (corrected)

Inventor name: ORTELLI, AURELIO