EP0822341A2 - Oleopneumatische Betätigungsvorrichtung für elektrische Schalter - Google Patents

Oleopneumatische Betätigungsvorrichtung für elektrische Schalter Download PDF

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Publication number
EP0822341A2
EP0822341A2 EP97111926A EP97111926A EP0822341A2 EP 0822341 A2 EP0822341 A2 EP 0822341A2 EP 97111926 A EP97111926 A EP 97111926A EP 97111926 A EP97111926 A EP 97111926A EP 0822341 A2 EP0822341 A2 EP 0822341A2
Authority
EP
European Patent Office
Prior art keywords
piston
pump
microswitch
pressure circuit
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.)
Withdrawn
Application number
EP97111926A
Other languages
English (en)
French (fr)
Other versions
EP0822341A3 (de
Inventor
Costante Piazza
Libero Sfrondini.
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.)
ABB Adda SpA
Original Assignee
ABB Adda 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 ABB Adda SpA filed Critical ABB Adda SpA
Publication of EP0822341A2 publication Critical patent/EP0822341A2/de
Publication of EP0822341A3 publication Critical patent/EP0822341A3/de
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
    • H01H33/30—Power arrangements internal to the switch for operating the driving mechanism using fluid actuator
    • 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
    • F15B1/027—Installations or systems with accumulators having accumulator charging devices
    • F15B1/033—Installations or systems with accumulators having accumulator charging devices with electrical control means

Definitions

  • the present invention relates to an oleo-pneumatic device or accumulator for actuating electric switches and more particularly a control system.
  • Control means or actuators capable of supplying considerable amounts of mechanical energy in a very short time are required in various applications to actuate switches.
  • Such energy must therefore be accumulated beforehand in devices which can be recharged slowly, i.e., with a small input of mechanical energy per unit time, and are then capable of quickly delivering this energy at the time of actuation.
  • a well-known device of this kind comprises steel springs of various kinds which are loaded in various ways.
  • Such a device has the fundamental drawback that its weight and bulk are very high as the energy to be accumulated increases.
  • Another conventional device uses oleo-pneumatic accumulators which, for the same weight and bulk, allow to store much more energy than spring-loaded devices, typically 10 to 15 times more.
  • the aim of the present invention is to overcome the above drawbacks of the prior art and particularly to provide an oleo-pneumatic device for actuating electric switches which has a simple construction and is capable of ensuring temperature-independence of the accumulated (and released) energy.
  • an oleo-pneumatic device for actuating electric switches which comprises: a cylinder inside which a free piston can slide so as to define a chamber containing a working fluid; a pump for applying pressurized oil to the piston of the cylinder in order to compress the working fluid; control means for stopping the pump when the compressed fluid reaches a preset volume; and means for discharging the oil towards a low-pressure circuit in order to quickly release the stored energy; characterized in that said control means comprise an actuation microswitch for stopping the pump, whose position is a function of the temperature of the working fluid, and in that the microswitch cooperates with a profiled actuation element driven by the piston compression movement.
  • the device according to the invention allows to precisely control the energy returned by an oleo-pneumatic accumulator in a temperature-independent manner and at the same time to provide a high-safety, high-precision control device.
  • the device according to the invention comprises a cylinder 1 which is closed by a bottom 22 at one end and by a head 3 at the other end.
  • a free piston 2 can slide inside the cylinder 1 and defines, together with the bottom 22, a variable-volume chamber 24 containing a fluid (generally a gas, particularly nitrogen) in which the energy is stored.
  • a fluid generally a gas, particularly nitrogen
  • this energy depends on the pressure P and on the volume V and on the gas temperature.
  • a union elbow 9 is fitted to the head 3; by means of the elbow, pressurized oil 21 can be applied to the surface of the piston 2 in order to compress the gas or can be discharged in order to use the energy stored in the compressed gas.
  • the pressurized oil 21 arrives from a high-pressure circuit AP which comprises a pump 20 and a reservoir 29.
  • a hole 25 is provided on the elbow 9 and a valve 8 is installed thereon; the valve comprises a T-shaped duct 26.
  • a needle 11 can move axially in the horizontal arm of the T-shaped duct, which is aligned with the hole 25; the needle has a ball 10 at one end, whilst the other end of the needle protrudes from the body of the valve through an appropriate seal.
  • the vertical arm of the T-shaped duct is connected by means of a tube 28 to a low-pressure circuit BP which is connected to a reservoir 29.
  • the diameter of the hole 25 is smaller than the diameter of the ball 10, so that the ball obstructs the hole when the ball moves to the left.
  • a rod 4 is directly and rigidly connected to the free piston 2 that separates the hydraulic circuit from the energy-accumulating volume of gas; the rod passes hermetically through the union elbow 9 and has, at its outer end, a slider 6 and a vane 7.
  • the slider 6 is shaped like a profiled body and has the purpose of actuating a microswitch 5, which stops the pump 20 and is fitted on the head 3 by means of an elastic support 12 and an assembly consisting of a rigid support 14 and a thermostatic element 13.
  • the microswitch 5 is provided with a contact 15 which is opened by the profile or inclined plane of the slider 6 when, during the compression movement, the piston 2 is moved forward by an extent c with respect to the maximum expansion position.
  • the rigid supporting element 14 is shaped like a bracket which is fixed to the head 3 at one end by means of a screw and is in any case in thermal contact with the head and thus with the cylinder 1.
  • the other end of the bracket 14 is fixed to the microswitch 5 by means of the thermostatic element 13, i.e., a temperature-sensitive component, for example a bimetallic strip.
  • the microswitch 5 is rigidly coupled to the head 3 by means of the element 12, which is for example shaped like an elastic spring and applies a return force to the microswitch 5.
  • the vertical position of the microswitch 5 is thus determined as a function of the temperature of the cylinder 1, i.e., of the temperature of the compressed gas. Accordingly, the opening of the contact 15 can be advanced or delayed as a function of the temperature both by acting on the adjustment of the thermostatic element 13 and by acting on the profile or inclined plane (or on the position) of the slider 6 or by acting on both.
  • the vane 7 can move the needle to the right; more specifically, when the piston 2 under compression has covered a distance d , the vane 7 pushes the needle 11 of the valve 8 to the right and the ball connects the hole 25 to 21, thus allowing fluid hydraulic connection between the cylinder and the low-pressure circuit.
  • the vane 7 discharges the excess pressure into the low-pressure circuit BP.
  • the pump 29 for replenishing the circuit AP feeds pressurized oil into the cylinder 1, causing the movement of the piston 2, gradually reducing the volume of the chamber 24 and thus compressing the gas contained therein; the microswitch 5 stops the pump when a preset pressure is reached as a function of the temperature.
  • the ball 10 is pushed so as to obstruct the duct 26 by the pressure of the oil 21 if the pump fails to stop.
  • the vane 7 pushes the ball 10 to the right, allowing pressure limitation by discharging the oil through the valve 8 into the reservoir 29.
  • the pressure P of the compressed fluid is a function of the stroke of the piston 2 and therefore of the stroke c , which in turn depends on the vertical position of the microswitch 5 determined by the temperature of the compressed fluid.
  • the hydraulic circuit AP is preferably provided with the pressure limiting valve 8, which is connected to the reservoir 29 and opens if the pressure in the circuit AP exceeds a safety value.
  • connection between the piston and an actuation rod 23 is provided by means of a traction element 16, i.e., an element capable of transmitting only traction forces but not compression forces, instead of by means of a rigid rod.
  • the traction element 16 advantageously consists of a metal wire or chain.
  • a curved duct 17 which covers an angle between 0 and 180 o , between the head 3 and a union 9 (similar to the union of figure 1) which is connected to the high-pressure circuit AP (not shown).
  • the chain or wire rests against the inner surface of the curved duct.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Lighting Device Outwards From Vehicle And Optical Signal (AREA)
  • Electrophonic Musical Instruments (AREA)
  • Radiation-Therapy Devices (AREA)
EP97111926A 1996-07-19 1997-07-14 Oleopneumatische Betätigungsvorrichtung für elektrische Schalter Withdrawn EP0822341A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT96MI001507A IT1283462B1 (it) 1996-07-19 1996-07-19 Dispositivo oleopneumatico per il comando di interruttori elettrici
ITMI961507 1996-07-19

Publications (2)

Publication Number Publication Date
EP0822341A2 true EP0822341A2 (de) 1998-02-04
EP0822341A3 EP0822341A3 (de) 1999-04-07

Family

ID=11374620

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97111926A Withdrawn EP0822341A3 (de) 1996-07-19 1997-07-14 Oleopneumatische Betätigungsvorrichtung für elektrische Schalter

Country Status (2)

Country Link
EP (1) EP0822341A3 (de)
IT (1) IT1283462B1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002001076A3 (de) * 2000-06-24 2002-07-18 Bosch Gmbh Robert Hydraulikenergiespeicher mit einem aus metall bestehenden faltenbalg
EP3503154A1 (de) * 2017-12-19 2019-06-26 E.G.O. ELEKTRO-GERÄTEBAU GmbH Verfahren zum verändern eines arbeitsfluids in einem ausdehnungssystem und ausdehnungssystem

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2795932A (en) * 1952-08-19 1957-06-18 S & C Electric Co Hydraulic actuating mechanism for operating electric circuit breakers and the like
DE1141193B (de) * 1961-02-24 1962-12-13 Daimler Benz Ag Regelvorrichtung fuer eine Druckmittelanlage zum Betaetigen von verstellbaren Kraftfahrzeugteilen
CH654444A5 (fr) * 1981-10-12 1986-02-14 Alsthom Atlantique Disjoncteur a gaz sous pression comprenant pour chaque phase deux chambres de coupure disposees en v.
FR2663780B1 (fr) * 1990-06-26 1992-09-11 Merlin Gerin Disjoncteur haute tension a isolement gazeux et a mecanisme de commande pneumatique.
FR2750246B1 (fr) * 1996-06-20 1998-09-04 Gec Alsthom T & D Sa Procede de surveillance d'un disjoncteur haute tension a circuit hydraulique de commande

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002001076A3 (de) * 2000-06-24 2002-07-18 Bosch Gmbh Robert Hydraulikenergiespeicher mit einem aus metall bestehenden faltenbalg
EP3503154A1 (de) * 2017-12-19 2019-06-26 E.G.O. ELEKTRO-GERÄTEBAU GmbH Verfahren zum verändern eines arbeitsfluids in einem ausdehnungssystem und ausdehnungssystem
US11761822B2 (en) 2017-12-19 2023-09-19 E.G.O. Elektro-Geraetebau Gmbh Method for changing a working fluid in an expansion system, and expansion system

Also Published As

Publication number Publication date
ITMI961507A0 (de) 1996-07-19
EP0822341A3 (de) 1999-04-07
IT1283462B1 (it) 1998-04-21
ITMI961507A1 (it) 1998-01-19

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