EP0641919A1 - Safety valve arrangement - Google Patents
Safety valve arrangement Download PDFInfo
- Publication number
- EP0641919A1 EP0641919A1 EP94112814A EP94112814A EP0641919A1 EP 0641919 A1 EP0641919 A1 EP 0641919A1 EP 94112814 A EP94112814 A EP 94112814A EP 94112814 A EP94112814 A EP 94112814A EP 0641919 A1 EP0641919 A1 EP 0641919A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- valves
- hydraulic
- pair
- valve
- hydraulic valves
- 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
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
- F01D21/20—Checking operation of shut-down devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
- F01D21/16—Trip gear
- F01D21/18—Trip gear involving hydraulic means
-
- 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
- F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
- F15B20/001—Double valve requiring the use of both hands simultaneously
Definitions
- the present invention relates to the field of mechanical engineering and plant engineering. It relates to a hydraulic safety circuit for a hydraulically controlled and / or regulated machine or system, in particular for the purpose of quick shutdown of a gas or steam turbine, in which safety circuit several hydraulic valves which can be actuated electrically by means of a solenoid and are closed when the solenoid is excited, between one for control or Control pressure line and a pressure relief line are arranged in such a way that, on the one hand, a continuous connection between the pressure line and the pressure relief line is established when one or more valves fall off as planned and, on the other hand, the function of the other valves can be taken over if some of the valves fail.
- Such a safety circuit is e.g. known from German Patent DE-C2-30 40 367 in the form of a so-called 2-of-3 system.
- the invention further relates to a method for operating such a safety circuit.
- Safety circuits For machines or systems which are controlled and / or regulated hydraulically by means of servomotors or the like, safety circuits have long been known which ensure immediate pressure release in the hydraulic system in the event of a malfunction. Safety circuits of this type are used in particular in gas or steam turbines in which, in the event of a rapid shutdown (so-called "trip" case), the fuel or steam supply is to be interrupted immediately by means of hydraulically operating actuators.
- the known safety circuits usually contain several hydraulic valves that are connected to the pressure line of the hydraulic system.
- the hydraulic valves are usually designed as valves which can be actuated electrically via a solenoid and which operate according to the closed-circuit principle, i.e. are closed when the solenoid is excited.
- the safety circuit responds, the voltage at the solenoid coils drops, the hydraulic valves open and establish a continuous connection from the pressure line to a pressure relief line, via which the hydraulic medium can flow into a tank or the like until the pressure in the hydraulic system is reduced Has.
- EP-B1-0 020 892 proposes three hydraulic valves connected in parallel for a safety circuit for a double-acting servo motor, each of which can effect pressure relief in itself (1-out-of-3 system).
- the three valves are also connected to each other by a cross line, so that if one of the valves opens when a safety signal arrives, the other two likewise open even if they do not respond to the signal themselves.
- This solution is problematic because if one of the valves fails, the entire safety circuit is deactivated.
- the object is achieved in a safety circuit of the type mentioned at the outset in that at least four hydraulic valves are provided, two of which are connected in parallel in a pair of valves, and in that the pairs of valves connected in parallel are connected in series between the pressure line and the pressure relief line.
- the essence of the invention is to provide two identical subsystems connected in series with a parallel valve pair, one of which is active in the safety circuit as a 1-out-of-2 system and the other can serve as a reserve pair. If a valve in the active pair fails, the reserve pair can be switched over so that the same reliability (1-out-2) is achieved again due to the identical configuration of the pairs.
- a first preferred embodiment of the safety circuit according to the invention is characterized in that the hydraulic valves are each equipped with only one through-channel and are designed as control valves with a valve seat.
- the method according to the invention for operating the safety circuit is characterized in that, in the normal operating state, the hydraulic valves of a first pair of valves are kept closed by energizing the corresponding solenoid coils, while the hydraulic valves of the second pair of valves are open, and for establishing a continuous connection between the pressure line and the pressure relief line in the event of a shutdown at least one of the two hydraulic valves of the first valve pair is opened.
- a first preferred embodiment of the method according to the invention is characterized in that in the event of a failure of one of the hydraulic valves of the first pair of valves, the two hydraulic valves of the second pair of valves are closed be that the other hydraulic valve of the first pair of valves is opened, and that in the event of a shutdown for establishing a continuous connection between the pressure line and the pressure relief line, at least one of the two hydraulic valves of the second pair of valves is opened.
- a pressure relief line runs next to the pressure line 8 17, via which the pressure existing in the pressure line 8 can be reduced if a continuous connection between the two lines is switched.
- the pressure relief line 17 can end, for example, in a tank 14 for the hydraulic medium.
- the safety circuit 1 itself comprises three hydraulic valves 2a-c, the exemplary internal structure of which can be seen from FIG. 2.
- Each of the hydraulic valves 2 or 2a-c has a solenoid 3 or 3a-c for actuation, which closes the valve against the pressure of a spring 5 or 5a-c when energized. If the voltage at the magnetic coil 3, 3a-c drops when a safety signal arrives, the respective valve opens due to the pressure of the spring 5, 5a-c.
- the position of the valve can be monitored by means of a built-in limit transmitter (10 in FIG. 2), which outputs the information to the controller (not shown) via suitable signal converters 4a-c.
- Each of the hydraulic valves 2a-c has two through channels, which are designated with the connections P and A or T and B (P indicates the pressure input, T indicates the tank output).
- the valves are cyclically connected so that each output A is connected to the input B of the next valve.
- All inputs P are connected to the pressure line 8 and all outputs T to the pressure relief line 17. In this way, a continuous connection between the pressure line 8 and the pressure relief line 17 is only possible if at least two valves open, ie fall off.
- the exemplary internal structure of one of the hydraulic valves 2a-c is shown in FIG. 2.
- the hydraulic valve 2 is shown in FIG. 2a in the closed position, but in FIG. 2b in the open position.
- the connection of the connections P and A or B and T takes place via a slide 12 accommodated in a valve housing 9, which is moved by the solenoid 3 via a piston 11.
- This circuit has at least four hydraulic valves 15a, b and 16a, b, two of which, namely 15a, b and 16a, b, are connected in parallel in a pair of valves by means of a connecting line 13.
- the parallel-connected valve pairs 15a, b and 16a, b in turn are connected in series between the pressure line 8 and the pressure relief line 17.
- Each of the hydraulic valves 15a-16b has only one through channel 22a-23b, which can be opened against a spring by energizing a solenoid 18a-19b.
- the hydraulic valves 15a-16b are preferably designed as control valves with a valve seat, which is particularly simple because of the one through-channel.
- the position of the hydraulic valves 15a, b of the upper pair of valves is sent via signal converters 20a, b as information to a monitoring circuit 24, which in turn is connected to a control circuit 25 for the solenoids 18a-19b.
- the circuit shown in FIG. 3 operates as follows: In the normal operating state, the hydraulic valves 15a, b of the upper (first) valve pair are kept closed by energizing the corresponding solenoid coils 18a, b. The hydraulic valves 16a, b of the lower (second) pair of valves are open and therefore play no role in the normal operating sequence. If there is a safety signal (shutdown), At least one of the two hydraulic valves 15a, b of the first valve pair is opened to establish a continuous connection between the pressure line 8 and the pressure relief line 17. This corresponds to a 1-out-of-2 system.
- one of the hydraulic valves 15a, b of the first valve pair fails, e.g. of the valve 15a, which is registered in the monitoring circuit 24, the two hydraulic valves 16a, b of the second valve pair are closed via the control circuit 25 and the other, functional hydraulic valve 15b of the first valve pair is opened.
- the system therefore still has the same reliability (1-out-2) after normal failure of one of the valves and is therefore clearly superior to the conventional 2-out-3 system.
- first and second pair of valves can also be interchanged by the first pair of valves 15a, b taking over the role of the reserve pair.
- the positions of the hydraulic valves 16a, b of the second pair of valves are reported to the monitoring circuit 24 via corresponding signal converters 21a, b.
- the possibility of a routine function test of all hydraulic valves 15a-16b during normal operation is particularly advantageous in a circuit according to FIG. 3.
- the sequence of such a complete functional test is as follows: In a first step, the hydraulic valves 15a, b of the first pair of valves are kept closed and the hydraulic valves 16a, b of the second pair of valves are first closed, then opened and then closed again. This completes the check on these valves. In a second step, the hydraulic valves 16a, b of the second valve pair is kept closed and the hydraulic valves 15a, b of the first valve pair are only opened and then closed again. The check of these valves is now complete. Finally, in a third step, the hydraulic valves 16a, b of the second valve pair are opened again, so that the original operating state of the circuit is restored.
- the invention results in a safety circuit that maintains its reliability even in the event of a valve failure, has a particularly simple design and enables a routine function test of all valves during normal operation.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Fluid-Pressure Circuits (AREA)
- Control Of Turbines (AREA)
Abstract
Description
Die vorliegende Erfindung bezieht sich auf das Gebiet des Maschinenbaus und der Anlagentechnik. Sie betrifft eine hydraulische Sicherheitsschaltung für eine hydraulisch gesteuerte und/oder geregelte Maschine oder Anlage, insbesondere zum Zwecke der Schnellabschaltung einer Gas- oder Dampfturbine, bei welcher Sicherheitsschaltung mehrere mittels einer Magnetspule elektrisch betätigbare und im erregten Zustand der Magnetspule geschlossene Hydraulikventile zwischen einer zur Steuerung bzw. Regelung führenden Druckleitung und einer Druckentlastungsleitung derart angeordnet sind, dass einerseits beim planmässigen Abfall eines oder mehrerer Ventile eine durchgehende Verbindung zwischen der Druckleitung und der Druckentlastungsleitung hergestellt und andererseits beim Ausfall eines Teils der Ventile die Funktion von den übrigen Ventilen übernommen werden kann.The present invention relates to the field of mechanical engineering and plant engineering. It relates to a hydraulic safety circuit for a hydraulically controlled and / or regulated machine or system, in particular for the purpose of quick shutdown of a gas or steam turbine, in which safety circuit several hydraulic valves which can be actuated electrically by means of a solenoid and are closed when the solenoid is excited, between one for control or Control pressure line and a pressure relief line are arranged in such a way that, on the one hand, a continuous connection between the pressure line and the pressure relief line is established when one or more valves fall off as planned and, on the other hand, the function of the other valves can be taken over if some of the valves fail.
Eine solche Sicherheitsschaltung ist z.B. aus der Deutschen Patentschrift DE-C2-30 40 367 in Form eines sogenannten 2-von-3-Systems bekannt.Such a safety circuit is e.g. known from German Patent DE-C2-30 40 367 in the form of a so-called 2-of-3 system.
Die Erfindung betrifft weiterhin ein Verfahren zum Betrieb einer solchen Sicherheitsschaltung.The invention further relates to a method for operating such a safety circuit.
Für Maschinen oder Anlagen, die hydraulisch mittels Servomotoren oder dgl. gesteuert und/oder geregelt werden, sind seit langem Sicherheitsschaltungen bekannt, die im Falle einer Betriebsstörung für einen sofortigen Druckablass im Hydrauliksystem sorgen. Derartige Sicherheitsschaltungen finden insbesondere Verwendung bei Gas- oder Dampfturbinen, bei denen im Falle einer Schnellabschaltung (sog. "trip"-Fall) die Brennstoff- bzw. Dampfzufuhr sofort mittels hydraulisch arbeitender Stellglieder unterbrochen werden soll.For machines or systems which are controlled and / or regulated hydraulically by means of servomotors or the like, safety circuits have long been known which ensure immediate pressure release in the hydraulic system in the event of a malfunction. Safety circuits of this type are used in particular in gas or steam turbines in which, in the event of a rapid shutdown (so-called "trip" case), the fuel or steam supply is to be interrupted immediately by means of hydraulically operating actuators.
Die bekannten Sicherheitsschaltungen enthalten üblicherweise mehrere Hydraulikventile, die an die Druckleitung des Hydrauliksystems angeschlossen sind. Die Hydraulikventile sind meist als über eine Magnetspule elektrisch betätigbare Ventile ausgebildet, die nach dem Ruhestromprinzip arbeiten, d.h. im erregten Zustand der Magnetspule geschlossen sind. Beim Ansprechen der Sicherheitsschaltung fällt die Spannung an den Magnetspulen ab, die Hydraulikventile öffnen und stellen eine durchgehende Verbindung von der Druckleitung zu einer Druckentlastungsleitung her, über die das hydraulische Medium solange in einen Tank oder dgl. abfliessen kann, bis sich der Druck im Hydrauliksystem abgebaut hat.The known safety circuits usually contain several hydraulic valves that are connected to the pressure line of the hydraulic system. The hydraulic valves are usually designed as valves which can be actuated electrically via a solenoid and which operate according to the closed-circuit principle, i.e. are closed when the solenoid is excited. When the safety circuit responds, the voltage at the solenoid coils drops, the hydraulic valves open and establish a continuous connection from the pressure line to a pressure relief line, via which the hydraulic medium can flow into a tank or the like until the pressure in the hydraulic system is reduced Has.
Obgleich grundsätzlich ein einzelnes Hydraulikventil für die beschriebene Druckentlastung ausreichen würde, sind aus Gründen der Redundanz üblicherweise mehrere Ventile vorgesehen, die ein Funktionieren der Schaltung auch dann sicherstellen sollen, wenn eines der Ventile ausfällt. So werden in der EP-B1-0 020 892 für eine Sicherheitsschaltung zu einem doppelt wirkenden Servomotor drei parallelgeschaltete Hydraulikventile vorgeschlagen, die jeweils für sich genommen die Druckentlastung bewirken können (1-aus-3-System). Die drei Ventile sind zusätzlich noch durch eine Querleitung untereinander verbunden, so dass, wenn beim Eintreffen eines Sicherheitssignals eines der Ventile öffnet, die anderen zwei gleichfalls öffnen, auch wenn sie selbst auf das Signal nicht ansprechen. Problematisch ist diese Lösung, weil bei einem fehlerhaften Abfallen bereits eines der Ventile die gesamte Sicherheitsschaltung ausser Betrieb gesetzt ist. Darüber hinaus ist es nicht möglich, einzelne Ventile während des Betriebes auf ihre Funktionstüchtigkeit hin zu testen.Although in principle a single hydraulic valve would suffice for the described pressure relief, several valves are usually provided for reasons of redundancy, which are intended to ensure the functioning of the circuit even if one of the valves fails. For example, EP-B1-0 020 892 proposes three hydraulic valves connected in parallel for a safety circuit for a double-acting servo motor, each of which can effect pressure relief in itself (1-out-of-3 system). The three valves are also connected to each other by a cross line, so that if one of the valves opens when a safety signal arrives, the other two likewise open even if they do not respond to the signal themselves. This solution is problematic because if one of the valves fails, the entire safety circuit is deactivated. In addition, it is not possible to test individual valves for their functionality during operation.
In der eingangs genannten Druckschrift wird demgegenüber ein mit drei Ventilen arbeitendes 2-aus-3-System vorgeschlagen. Hierbei sind die drei Ventile durch spezielle Stellmechanismen so untereinander verschaltet, dass eine Druckentlastung nur stattfindet, wenn wenigstens 2 der 3 Ventile auf das Sicherheitssignal ansprechen und abfallen. Diese Schaltung hat den Vorteil, dass der fehlerhafte Abfall eines Ventils die Entlastung noch nicht auslösen kann, und dass beim Ausfall eines der Ventile weiterhin die Schaltung funktionstüchtig bleibt. Nachteilig ist hier allerdings, dass sich nach dem Ausfall eines Ventils die Zuverlässigkeit drastisch ändert: Während ohne vorherigen Ausfall nur 2 von 3 Ventilen korrekt funktionieren müssen (2-aus-3), müssen nach einem Ausfall die verbleibenden 2 Ventile unbedingt funktionieren (2-aus-2), damit die Sicherheitsschaltung ihre Aufgabe erfüllen kann. Darüber hinaus ist für die Verschaltung der Ventile untereinander eine relativ komplizierte hydraulische Schaltung notwendig, die ein zusätzliches Sicherheitsrisiko darstellt, insbesondere, wenn anstelle von Stellventilen mit Ventilsitzen mit Leckagen behaftete Schieber eingesetzt werden.In contrast, in the publication mentioned at the outset, a 2-out-of-3 system working with three valves is proposed. The three valves are interconnected by special actuating mechanisms so that pressure relief only takes place if at least 2 of the 3 valves respond to the safety signal and drop out. This circuit has the advantage that the faulty drop of a valve cannot yet trigger the relief, and that if one of the valves fails, the circuit remains functional. The disadvantage here, however, is that the reliability changes drastically after the failure of a valve: While only 2 out of 3 valves have to work correctly (2-out-3) without a previous failure, the remaining 2 valves must work after a failure (2- from-2), so that the safety circuit can fulfill its task. In addition, a relatively complicated hydraulic circuit is necessary for the interconnection of the valves, which represents an additional safety risk, in particular if, instead of control valves with valve seats, leaky slides are used.
Es ist daher Aufgabe der Erfindung, eine hydraulische Sicherheitsschaltung zu schaffen, die auch nach Ausfall eines Ventils eine gleichbleibende Zuverlässigkeit aufweist, sowie ein Verfahren zu deren Betrieb anzugeben.It is therefore an object of the invention to provide a hydraulic safety circuit which has constant reliability even after a valve has failed, and to specify a method for its operation.
Die Aufgabe wird bei einer Sicherheitsschaltung der eingangs genannten Art dadurch gelost, dass wenigstens vier Hydraulikventile vorhanden sind, von denen jeweils zwei in einem Ventil-Paar parallelgeschaltet sind, und dass die parallelgeschalteten Ventil-Paare zwischen der Druckleitung und der Druckentlastungsleitung in Serie geschaltet sind.The object is achieved in a safety circuit of the type mentioned at the outset in that at least four hydraulic valves are provided, two of which are connected in parallel in a pair of valves, and in that the pairs of valves connected in parallel are connected in series between the pressure line and the pressure relief line.
Der Kern der Erfindung besteht darin, hintereinandergeschaltet zwei gleichartige Teilsysteme mit einem parallelen Ventil-Paar vorzusehen, von denen eines in der Sicherheitsschaltung als 1-aus-2-System aktiv ist und das andere als Reserve-Paar dienen kann. Beim Ausfall eines Ventils in dem aktiven Paar kann auf das Reserve-Paar umgeschaltet werden, so dass wegen der identischen Konfiguration der Paare wieder dieselbe Zuverlässigkeit (1-aus-2) erreicht wird.The essence of the invention is to provide two identical subsystems connected in series with a parallel valve pair, one of which is active in the safety circuit as a 1-out-of-2 system and the other can serve as a reserve pair. If a valve in the active pair fails, the reserve pair can be switched over so that the same reliability (1-out-2) is achieved again due to the identical configuration of the pairs.
Eine erste bevorzugte Ausführungsform der erfindungsgemässen Sicherheitsschaltung zeichnet sich dadurch aus, dass die Hydraulikventile jeweils mit nur einem Durchgangskanal ausgestattet und als Stellventile mit einem Ventilsitz ausgebildet sind.A first preferred embodiment of the safety circuit according to the invention is characterized in that the hydraulic valves are each equipped with only one through-channel and are designed as control valves with a valve seat.
Das erfindungsgemässe Verfahren zum Betrieb der Sicherheitsschaltung ist dadurch gekennzeichnet, dass im normalen Betriebszustand die Hydraulikventile eines ersten Ventil-Paares durch Erregung der entsprechenden Magnetspulen geschlossen gehalten werden, während die Hydraulikventile des zweiten Ventil-Paares offen sind, und dass zum Herstellen einer durchgehenden Verbindung zwischen der Druckleitung und der Druckentlastungsleitung im Abschaltfall wenigstens eines der beiden Hydraulikventile des ersten Ventil-Paares geöffnet wird.The method according to the invention for operating the safety circuit is characterized in that, in the normal operating state, the hydraulic valves of a first pair of valves are kept closed by energizing the corresponding solenoid coils, while the hydraulic valves of the second pair of valves are open, and for establishing a continuous connection between the pressure line and the pressure relief line in the event of a shutdown at least one of the two hydraulic valves of the first valve pair is opened.
Eine erste bevorzugte Ausführungsform des erfindungsgemässen Verfahrens zeichnet sich dadurch aus, dass bei einem Ausfall eines der Hydraulikventile des ersten Ventil-Paares die beiden Hydraulikventile des zweiten Ventil-Paares geschlossen werden, dass das andere Hydraulikventil des ersten Ventil-Paares geöffnet wird, und dass im Abschaltfall zum Herstellen einer durchgehenden Verbindung zwischen der Druckleitung und der Druckentlastungsleitung wenigstens eines der beiden Hydraulikventile des zweiten Ventil-Paares geöffnet wird.A first preferred embodiment of the method according to the invention is characterized in that in the event of a failure of one of the hydraulic valves of the first pair of valves, the two hydraulic valves of the second pair of valves are closed be that the other hydraulic valve of the first pair of valves is opened, and that in the event of a shutdown for establishing a continuous connection between the pressure line and the pressure relief line, at least one of the two hydraulic valves of the second pair of valves is opened.
Weitere Ausführungsformen ergeben sich aus den abhängigen Ansprüchen.Further embodiments result from the dependent claims.
Die Erfindung soll nachfolgend anhand von Ausführungsbeispielen im Zusammenhang mit den Figuren näher erläutert werden. Es zeigen
- Fig. 1
- eine bekannte 2-aus-3-Sicherheitsschaltung;
- Fig. 2
- ein als Schieber ausgebildetes, elektrisch betätigtes Hydraulikventil, wie es in der Schaltung nach Fig. 1 bevorzugt eingesetzt wird, in der geschlossenen (a) und in der geöffneten (b) Stellung; und
- Fig. 3
- ein Ausführungsbeispiel für eine Sicherheitsschaltung nach der Erfindung.
- Fig. 1
- a known 2-out-of-3 safety circuit;
- Fig. 2
- an electrically operated hydraulic valve designed as a slide, as is preferably used in the circuit according to FIG. 1, in the closed (a) and in the open (b) position; and
- Fig. 3
- an embodiment of a safety circuit according to the invention.
In den Fig. 1 und 2 ist eine bekannte Art einer hydraulischen Sicherheitsschaltung 1 nach dem 2-aus-3-System dargestellt. Eine Druckleitung 8, die über einen Zugang 6 mit einem unter Druck stehenden Hydraulikmedium, z.B. Oel, beaufschlagt wird, führt über einen Abgang 7 zu einem Servomotor oder einem vergleichbaren hydraulisch betätigten Stellglied, welches in einem Störungsfall die betroffenen Maschine oder Anlage abschaltet. neben der Druckleitung 8 verläuft eine Druckentlastungsleitung 17, über die der in der Druckleitung 8 vorhandene Druck abgebaut werden kann, wenn eine durchgehende Verbindung zwischen beiden Leitungen geschaltet wird. Die Druckentlastungsleitung 17 kann beispielsweise in einem Tank 14 für das Hydraulikmedium enden.1 and 2 show a known type of
Die Sicherheitsschaltung 1 selbst umfasst drei Hydraulikventile 2a-c, deren beispielhafter innerer Aufbau aus der Fig. 2 ersichtlich ist. Jedes der Hydraulikventile 2 bzw. 2a-c weist zur Betätigung eine Magnetspule 3 bzw. 3a-c auf, die bei Erregung das Ventil gegen den Druck einer Feder 5 bzw. 5a-c schliesst. Fällt die Spannung an der Magnetspule 3, 3a-c bei Eintreffen eines Sicherheitssignals ab, öffnet das jeweilige Ventil durch den Druck der Feder 5, 5a-c. Die Stellung des Ventils kann mittels eines eingebauten Grenzwertgebers (10 in Fig. 2) überwacht werden , der die Information über geeignete Signalwandler 4a-c an die (nicht dargestellte) Steuerung abgibt.The
Jedes der Hydraulikventile 2a-c hat zwei Durchgangskanäle, die mit den Anschlüssen P und A bzw. T und B bezeichnet sind (P deutet auf den Druckeingang, T auf den Tankausgang hin). Die Ventile sind zyklisch so verschaltet, dass jeder Ausgang A mit dem Eingang B des nächsten Ventils verbunden ist. Alle Eingänge P sind mit der Druckleitung 8 und alle Ausgänge T mit der Druckentlastungsleitung 17 verbunden. Auf diese Weise ist eine durchgehende Verbindung zwischen der Druckleitung 8 und der Druckentlastungsleitung 17 nur möglich, wenn wenigstens zwei Ventile öffnen, d.h. abfallen. Der beispielhafte innere Aufbau eines der Hydraulikventile 2a-c ist in Fig. 2 wiedergegeben. Das Hydraulikventil 2 ist dabei in Fig. 2a in der geschlossenen, in Fig. 2b dagegen in der geöffneten Stellung gezeigt. Die Verbindung der Anschlüsse P und A bzw. B und T erfolgt über einen in einem Ventilgehäuse 9 untergebrachten Schieber 12, der von der Magnetspule 3 über einen Kolben 11 bewegt wird.Each of the hydraulic valves 2a-c has two through channels, which are designated with the connections P and A or T and B (P indicates the pressure input, T indicates the tank output). The valves are cyclically connected so that each output A is connected to the input B of the next valve. All inputs P are connected to the
Wie bereits eingangs erwähnt worden ist, hat eine solche 2-aus-3-Sicherheitsschaltung den Nachteil, dass beim Ausfall eines Ventils die Zuverlässigkeit erheblich reduziert ist, weil dann die beiden übrigen Ventile sicher arbeiten müssen und eine Redundanz nicht mehr vorhanden ist. Weiterhin erfordert die zyklische Verschaltung der Ventile einen erheblichen Aufwand. Werden darüber hinaus auch noch Ventile mit Schiebern eingesetzt, ergeben sich zusätzliche unerwünschte Dichtigkeitsprobleme.As has already been mentioned at the beginning, such a 2-out-of-3 safety circuit has the disadvantage that if one valve fails, the reliability is considerably reduced, because then the other two valves have to work safely and redundancy is no longer present. Furthermore, the cyclical connection of the valves requires considerable effort. If valves with slide valves are also used, there are additional undesirable sealing problems.
Bei dem in Fig. 3 dargestellten Ausführungsbeispiel der erfindungsgemässen Sicherheitsschaltung treten derartige Probleme nicht auf. Bei dieser Schaltung sind wenigstens vier Hydraulikventile 15a,b und 16a,b vorhanden, von denen jeweils zwei, nämlich 15a,b bzw. 16a,b in einem Ventil-Paar mittels einer Verbindungsleitung 13 parallelgeschaltet sind. Die parallelgeschalteten Ventil-Paare 15a,b und 16a,b ihrerseits sind zwischen der Druckleitung 8 und der Druckentlastungsleitung 17 in Serie geschaltet. Jedes der Hydraulikventile 15a-16b weist nur einen Durchgangskanal 22a-23b auf, der durch Erregung einer Magnetspule 18a-19b gegen eine Feder geöffnet werden kann. Die Hydraulikventile 15a-16b sind aus Gründen der Dichtigkeit vorzugsweise als Stellventile mit einem Ventilsitz ausgebildet, was wegen des einen Durchgangskanals besonders einfach ist. Die Stellung der Hydraulikventile 15a,b des oberen Ventil-Paares wird über Signalwandler 20a,b als Information an eine Ueberwachungsschaltung 24 abgegeben, die ihrerseits mit einer Ansteuerschaltung 25 für die Magnetspulen 18a-19b verbunden ist.Problems of this type do not occur in the exemplary embodiment of the safety circuit according to the invention shown in FIG. 3. This circuit has at least four hydraulic valves 15a, b and 16a, b, two of which, namely 15a, b and 16a, b, are connected in parallel in a pair of valves by means of a connecting
Der Betrieb der in Fig. 3 gezeigten Schaltung läuft wie folgt ab: Im normalen Betriebszustand werden die Hydraulikventile 15a,b des oberen (ersten) Ventil-Paares durch Erregung der entsprechenden Magnetspulen 18a,b geschlossen gehalten. Die Hydraulikventile 16a,b des unteren (zweiten) Ventil-Paares sind offen und spielen damit für den normalen Betriebsablauf keine Rolle. Kommt nun ein Sicherheitssignal (Abschaltfall), wird zum Herstellen einer durchgehenden Verbindung zwischen der Druckleitung 8 und der Druckentlastungsleitung 17 wenigstens eines der beiden Hydraulikventile 15a,b des ersten Ventil-Paares geöffnet. Dies entspricht einem 1-aus-2-System.The circuit shown in FIG. 3 operates as follows: In the normal operating state, the hydraulic valves 15a, b of the upper (first) valve pair are kept closed by energizing the
Bei einem Ausfall eines der Hydraulikventile 15a,b des ersten Ventil-Paares, z.B. des Ventils 15a, der in der Ueberwachungsschaltung 24 registriert wird, werden über die Ansteuerschaltung 25 die beiden Hydraulikventile 16a,b des zweiten Ventil-Paares geschlossen und das andere, funktionstüchtige Hydraulikventil 15b des ersten Ventil-Paares geöffnet. Damit ist innerhalb des zweiten Ventil-Paares wieder eine 1-aus-2-Situation geschaffen; im Abschaltfall wird dann zum Herstellen einer durchgehenden Verbindung zwischen der Druckleitung 8 und der Druckentlastungsleitung 17 wenigstens eines der beiden Hydraulikventile 16a,b des zweiten Ventil-Paares geöffnet. Das System weist damit nach Ausfall eines der Ventile immer noch dieselbe Zuverlässigkeit (1-aus-2) auf wie im Normalzustand und ist damit dem herkömmlichen 2-aus-3-System deutlich überlegen. Selbstverständlich können die Rollen des ersten und zweiten Ventil-Paares auch vertauscht werden, indem das erste Ventil-Paar 15a,b die Rolle des Reserve-Paares übernimmt. In diesem Falle werden die Stellungen der Hydraulikventile 16a,b des zweiten Ventil-Paares über entsprechende Signalwandler 21a,b an die Ueberwachungsschaltung 24 weitergemeldet.If one of the hydraulic valves 15a, b of the first valve pair fails, e.g. of the valve 15a, which is registered in the
Besonders vorteilhaft ist bei einer Schaltung gemäss Fig. 3 die Möglichkeit einer routinemässigen Funktionsprüfung aller Hydraulikventile 15a-16b während des normalen Betriebes. Der Ablauf einer solchen vollständigen Funktionsprüfung läuft wie folgt ab: In einem ersten Schritt werden die Hydraulikventile 15a,b des ersten Ventil-Paares geschlossen gehalten und die Hydraulikventile 16a,b des zweiten Ventil-Paares erst geschlossen, dann geöffnet und anschliessend wieder geschlossen. Damit ist die Ueberprüfung dieser Ventile abgeschlossen. In einem zweiten Schritt werden die Hydraulikventile 16a,b des zweiten Ventil-Paares geschlossen gehalten und die Hydraulikventile 15a,b des ersten Ventil-Paares erst geöffnet und anschliessend wieder geschlossen. Damit ist die Ueberprüfung auch dieser Ventile abgeschlossen. Zum Schluss werden in einem dritten Schritt die Hydraulikventile 16a,b des zweiten Ventil-Paares wieder geöffnet, so dass der ursprüngliche Betriebszustand der Schaltung wiederhergestellt ist.The possibility of a routine function test of all hydraulic valves 15a-16b during normal operation is particularly advantageous in a circuit according to FIG. 3. The sequence of such a complete functional test is as follows: In a first step, the hydraulic valves 15a, b of the first pair of valves are kept closed and the hydraulic valves 16a, b of the second pair of valves are first closed, then opened and then closed again. This completes the check on these valves. In a second step, the hydraulic valves 16a, b of the second valve pair is kept closed and the hydraulic valves 15a, b of the first valve pair are only opened and then closed again. The check of these valves is now complete. Finally, in a third step, the hydraulic valves 16a, b of the second valve pair are opened again, so that the original operating state of the circuit is restored.
Insgesamt ergibt sich mit der Erfindung eine Sicherheitsschaltung, die auch bei Ausfall eines Ventils ihre Zuverlässigkeit beibehält, besonders einfach aufgebaut ist und einen routinemässigen Funktionstest aller Ventile während des Normalbetriebs ermöglicht.Overall, the invention results in a safety circuit that maintains its reliability even in the event of a valve failure, has a particularly simple design and enables a routine function test of all valves during normal operation.
- 11
- Sicherheitsschaltung (hydraulisch)Safety circuit (hydraulic)
- 2a-c2a-c
- HydraulikventilHydraulic valve
- 3,3a-c3,3a-c
- MagnetspuleSolenoid
- 4a-c4a-c
- SignalwandlerSignal converter
- 5a-c5a-c
- Federfeather
- 66
- Zugang (Druckleitung)Access (pressure line)
- 77
- Abgang (Druckleitung)Outlet (pressure line)
- 88th
- DruckleitungPressure line
- 99
- VentilgehäuseValve body
- 1010th
- GrenzwertgeberLimit transmitter
- 1111
- Kolbenpiston
- 1212th
- SchieberSlider
- 1313
- VerbindungsleitungConnecting line
- 1414
- Tank (Hydraulikmedium)Tank (hydraulic medium)
- 15a,b15a, b
- HydraulikventilHydraulic valve
- 16a,b16a, b
- HydraulikventilHydraulic valve
- 1717th
- DruckentlastungsleitungPressure relief line
- 18a,b18a, b
- MagnetspuleSolenoid
- 19a,b19a, b
- MagnetspuleSolenoid
- 20a,b20a, b
- SignalwandlerSignal converter
- 21a,b21a, b
- SignalwandlerSignal converter
- 22a,b22a, b
- DurchgangskanalThrough channel
- 23a,b23a, b
- DurchgangskanalThrough channel
- 2424th
- UeberwachungsschaltungMonitoring circuit
- 2525th
- AnsteuerschaltungControl circuit
- A,B,P,TA, B, P, T
- Anschluss (Ventil)Connection (valve)
Claims (7)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4330038 | 1993-09-06 | ||
| DE4330038A DE4330038A1 (en) | 1993-09-06 | 1993-09-06 | Hydraulic safety circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0641919A1 true EP0641919A1 (en) | 1995-03-08 |
| EP0641919B1 EP0641919B1 (en) | 1997-06-04 |
Family
ID=6496925
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP94112814A Expired - Lifetime EP0641919B1 (en) | 1993-09-06 | 1994-08-17 | Safety valve arrangement |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0641919B1 (en) |
| JP (1) | JP3592377B2 (en) |
| DE (2) | DE4330038A1 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2425369A (en) * | 2005-04-19 | 2006-10-25 | Emerson Process Management | Electronically controllable and testable turbine trip system |
| DE102005040039A1 (en) * | 2005-08-23 | 2007-03-01 | Abb Patent Gmbh | Valve arrangement for controlling a component |
| US7322270B2 (en) * | 2004-08-31 | 2008-01-29 | Hydac System Gmbh | Safety circuit for media-operated consumers and process for its operation |
| WO2008048290A1 (en) * | 2006-10-16 | 2008-04-24 | Elliott Company | Direct acting hydraulic trip block with majority voting |
| US7828008B1 (en) * | 2005-04-19 | 2010-11-09 | SafePlex Systems, Inc. | Online partial stroke testing system using a modified 2004 architecture |
| WO2011003506A1 (en) * | 2009-07-09 | 2011-01-13 | Robert Bosch Gmbh | Electro-hydraulic controller |
| CN106470935A (en) * | 2014-04-23 | 2017-03-01 | 普茨迈斯特工程有限公司 | Control system for the machine for doing work of hydraulic pressure |
| WO2017125247A1 (en) * | 2016-01-22 | 2017-07-27 | Hydac System Gmbh | Safety controller |
| US9903221B2 (en) | 2012-06-08 | 2018-02-27 | Emerson Process Management Power & Water Solutions, Inc. | Electronically controllable and testable turbine trip system and method with redundant bleed manifolds |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202011109158U1 (en) | 2011-12-15 | 2012-01-24 | Karl Morgenbesser | Electrohydraulic safety control |
| CN106414907B (en) * | 2014-06-03 | 2019-03-26 | 福伊特专利有限公司 | The hydraulic control device and steam turbine plant of quick-closing valve for steam turbine |
| JP6581499B2 (en) * | 2015-12-25 | 2019-09-25 | 株式会社東芝 | Steam valve drive |
| DE102016000643A1 (en) * | 2016-01-22 | 2017-07-27 | Hydac System Gmbh | safety control |
| CN112648021B (en) * | 2020-11-30 | 2022-12-27 | 华电电力科学研究院有限公司 | Online maintenance and transformation method for steam turbine AST electromagnetic valve activity test |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1212664A (en) * | 1969-01-21 | 1970-11-18 | Schwermaschb Nobas Nordhausen | An automatic hydraulic combining valve arrangement |
| DE3230056A1 (en) * | 1982-08-12 | 1984-02-16 | Herion-Werke Kg, 7012 Fellbach | Safety control system |
| JPS5949305A (en) * | 1982-09-13 | 1984-03-21 | Mitsubishi Heavy Ind Ltd | Multiple hydraulic circuit for turbine preservation apparatus |
| DE3340925A1 (en) * | 1983-04-13 | 1984-10-18 | Siemens AG, 1000 Berlin und 8000 München | CONTROL DEVICE FOR CONTROL VALVES OF TURBO MACHINES, ESPECIALLY FOR INDUSTRIAL TURBINES OF HIGH AVAILABILITY |
| US5133189A (en) * | 1991-07-15 | 1992-07-28 | Westinghouse Electric Corp. | System and method for individually testing valves in a steam turbine trip control system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE372055B (en) * | 1973-03-23 | 1974-12-09 | Stal Laval Turbin Ab | |
| US3943714A (en) * | 1975-01-23 | 1976-03-16 | The United States Of America As Represented By The Secretary Of The Navy | Fail-safe limit switch stopping system for air motor |
| US4001654A (en) * | 1975-07-31 | 1977-01-04 | General Electric Company | Testable protective system |
| FR2348523A1 (en) * | 1976-04-16 | 1977-11-10 | Telemecanique Electrique | Pneumatic shift register sequence control - has threshold gate to ensure interlock signal line pressure is below given pressure |
| JPS5842699Y2 (en) * | 1977-11-10 | 1983-09-27 | 株式会社小松製作所 | Dual valve failure detection device |
| CH636932A5 (en) * | 1979-06-22 | 1983-06-30 | Sulzer Ag | SAFETY CIRCUIT WITH A DOUBLE-ACTING, FLUID-OPERATED SERVO MOTOR. |
| DE3040367A1 (en) * | 1980-10-25 | 1982-05-27 | AEG-Kanis Turbinenfabrik GmbH, 8500 Nürnberg | Safety system for steam or gas turbines - uses combined hydraulic and electrical system with pressure switches and magnetic valves |
| CH666132A5 (en) * | 1984-07-20 | 1988-06-30 | Bbc Brown Boveri & Cie | DEVICE FOR MONITORING PHYSICAL QUANTITIES IN PLANTS. |
| DE3804784A1 (en) * | 1988-02-16 | 1989-08-24 | Huperz Adalbert | Multi-stage valve control |
-
1993
- 1993-09-06 DE DE4330038A patent/DE4330038A1/en not_active Withdrawn
-
1994
- 1994-08-17 DE DE59402992T patent/DE59402992D1/en not_active Expired - Lifetime
- 1994-08-17 EP EP94112814A patent/EP0641919B1/en not_active Expired - Lifetime
- 1994-09-05 JP JP21152894A patent/JP3592377B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1212664A (en) * | 1969-01-21 | 1970-11-18 | Schwermaschb Nobas Nordhausen | An automatic hydraulic combining valve arrangement |
| DE3230056A1 (en) * | 1982-08-12 | 1984-02-16 | Herion-Werke Kg, 7012 Fellbach | Safety control system |
| JPS5949305A (en) * | 1982-09-13 | 1984-03-21 | Mitsubishi Heavy Ind Ltd | Multiple hydraulic circuit for turbine preservation apparatus |
| DE3340925A1 (en) * | 1983-04-13 | 1984-10-18 | Siemens AG, 1000 Berlin und 8000 München | CONTROL DEVICE FOR CONTROL VALVES OF TURBO MACHINES, ESPECIALLY FOR INDUSTRIAL TURBINES OF HIGH AVAILABILITY |
| US5133189A (en) * | 1991-07-15 | 1992-07-28 | Westinghouse Electric Corp. | System and method for individually testing valves in a steam turbine trip control system |
Non-Patent Citations (1)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN vol. 8, no. 152 (M - 309)<1589> 14 July 1984 (1984-07-14) * |
Cited By (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7322270B2 (en) * | 2004-08-31 | 2008-01-29 | Hydac System Gmbh | Safety circuit for media-operated consumers and process for its operation |
| EP1630425A3 (en) * | 2004-08-31 | 2011-11-02 | Hydac System GmbH | Safety circuit for a fluid actuated user and method for using the same |
| GB2468431B (en) * | 2005-04-19 | 2010-12-22 | Emerson Process Management | Electronically controllable and testable turbine trip system |
| US7874241B2 (en) | 2005-04-19 | 2011-01-25 | Emerson Process Management Power & Water Solutions, Inc. | Electronically controllable and testable turbine trip system |
| GB2468431A (en) * | 2005-04-19 | 2010-09-08 | Emerson Process Management | Electronically controllable and testable turbine trip system |
| US7828008B1 (en) * | 2005-04-19 | 2010-11-09 | SafePlex Systems, Inc. | Online partial stroke testing system using a modified 2004 architecture |
| GB2425369A (en) * | 2005-04-19 | 2006-10-25 | Emerson Process Management | Electronically controllable and testable turbine trip system |
| GB2425369B (en) * | 2005-04-19 | 2011-01-12 | Emerson Process Management | Electronically controllable and testable turbine trip system |
| CN1854470B (en) * | 2005-04-19 | 2011-05-25 | 艾默生过程管理电力和水力解决方案有限公司 | Electronically controllable and testable turbine trip system |
| DE102005040039B4 (en) * | 2005-08-23 | 2013-01-31 | Abb Technology Ag | Valve arrangement for controlling a component |
| US7444920B2 (en) | 2005-08-23 | 2008-11-04 | Abb Patent Gmbh | Valve arrangement for the activation of a structural element |
| EP1757817A3 (en) * | 2005-08-23 | 2009-09-09 | ABB Technology | Valve arrangement for controlling a quick-acting valve of a gas or vapour turbine |
| DE102005040039A1 (en) * | 2005-08-23 | 2007-03-01 | Abb Patent Gmbh | Valve arrangement for controlling a component |
| EA014134B1 (en) * | 2006-10-16 | 2010-10-29 | Эллиотт Компани | Direct acting hydraulic trip block with majority voting |
| WO2008048290A1 (en) * | 2006-10-16 | 2008-04-24 | Elliott Company | Direct acting hydraulic trip block with majority voting |
| US7409965B2 (en) | 2006-10-16 | 2008-08-12 | Elliott Company | Direct acting hydraulic trip block |
| WO2011003506A1 (en) * | 2009-07-09 | 2011-01-13 | Robert Bosch Gmbh | Electro-hydraulic controller |
| CN102549273A (en) * | 2009-07-09 | 2012-07-04 | 罗伯特·博世有限公司 | Electro-hydraulic controller |
| CN102549273B (en) * | 2009-07-09 | 2016-03-23 | 罗伯特·博世有限公司 | Electrofluidic control device |
| US9903221B2 (en) | 2012-06-08 | 2018-02-27 | Emerson Process Management Power & Water Solutions, Inc. | Electronically controllable and testable turbine trip system and method with redundant bleed manifolds |
| CN106470935A (en) * | 2014-04-23 | 2017-03-01 | 普茨迈斯特工程有限公司 | Control system for the machine for doing work of hydraulic pressure |
| CN106470935B (en) * | 2014-04-23 | 2019-08-16 | 普茨迈斯特工程有限公司 | Control system for hydraulic machine for doing work |
| WO2017125247A1 (en) * | 2016-01-22 | 2017-07-27 | Hydac System Gmbh | Safety controller |
Also Published As
| Publication number | Publication date |
|---|---|
| DE59402992D1 (en) | 1997-07-10 |
| JPH0797902A (en) | 1995-04-11 |
| JP3592377B2 (en) | 2004-11-24 |
| DE4330038A1 (en) | 1995-03-09 |
| EP0641919B1 (en) | 1997-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2141371C3 (en) | Hydraulic servo control with multiple channels | |
| EP0641919B1 (en) | Safety valve arrangement | |
| EP1266147B1 (en) | Fluidic system with a safety function | |
| DE2921464A1 (en) | CONTROL SYSTEMS | |
| EP1834220B1 (en) | Redundant electrohydraulic valve system | |
| EP0433791B1 (en) | Actuator for a feeding valve | |
| DE1500459A1 (en) | Electro-hydraulic servo control system | |
| EP2276935B1 (en) | Control device and method for a quick-acting gate valve of a steam turbine | |
| EP0810136B1 (en) | Pressure installation | |
| DE10004605B4 (en) | Hydraulic logic crosstalk between separate redundant servo actuators | |
| EP0020892B1 (en) | Safety circuit | |
| DE112008003999T5 (en) | Fluid powered actuation system | |
| DE3441688A1 (en) | Fail-safe servo valve system | |
| DE2929578C2 (en) | ||
| EP0890030B1 (en) | Safety circuit | |
| DE102021213469B3 (en) | safety valve device | |
| DE2041681C2 (en) | Method and device for the electrohydraulic control of a hydraulic actuator | |
| EP1526289B1 (en) | Valve for a fluid system | |
| DE3800533C2 (en) | Main control spool for a hydraulic actuator of an airplane rudder | |
| DE2144086A1 (en) | Actuator, in particular motorized control drive for valves | |
| DE1751809A1 (en) | Arrangement for the electro-hydraulic control of a hydraulic tandem actuating piston | |
| EP1114918A2 (en) | Valve arrangement for an internal combustion engine and driving method | |
| CH642770A5 (en) | HYDRAULIC ACTUATOR FOR A HIGH VOLTAGE CIRCUIT BREAKER. | |
| DE102022002037A1 (en) | Hydraulic system | |
| DE1751419A1 (en) | Method and device for the electrohydraulic control of a hydraulic working piston, especially for aircraft and space vehicles |
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 |
|
| AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): CH DE GB LI NL |
|
| 17P | Request for examination filed |
Effective date: 19950817 |
|
| 17Q | First examination report despatched |
Effective date: 19960502 |
|
| 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 |
|
| RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: ASEA BROWN BOVERI AG |
|
| 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 |
Kind code of ref document: B1 Designated state(s): CH DE GB LI NL |
|
| REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
| REF | Corresponds to: |
Ref document number: 59402992 Country of ref document: DE Date of ref document: 19970710 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 19970901 Year of fee payment: 4 |
|
| GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 19970821 |
|
| 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 | ||
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19980831 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19980831 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19990301 |
|
| REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
| NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 19990301 |
|
| REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
| REG | Reference to a national code |
Ref country code: GB Ref legal event code: 732E |
|
| REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 59402992 Country of ref document: DE Representative=s name: ROESLER, UWE, DIPL.-PHYS.UNIV., DE Effective date: 20120621 Ref country code: DE Ref legal event code: R081 Ref document number: 59402992 Country of ref document: DE Owner name: ALSTOM TECHNOLOGY LTD., CH Free format text: FORMER OWNER: ALSTOM, PARIS, FR Effective date: 20120621 |
|
| REG | Reference to a national code |
Ref country code: GB Ref legal event code: 732E Free format text: REGISTERED BETWEEN 20120802 AND 20120808 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20130902 Year of fee payment: 20 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20130726 Year of fee payment: 20 |
|
| REG | Reference to a national code |
Ref country code: DE Ref legal event code: R071 Ref document number: 59402992 Country of ref document: DE |
|
| REG | Reference to a national code |
Ref country code: DE Ref legal event code: R071 Ref document number: 59402992 Country of ref document: DE |
|
| REG | Reference to a national code |
Ref country code: GB Ref legal event code: PE20 Expiry date: 20140816 |
|
| 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 EXPIRATION OF PROTECTION Effective date: 20140819 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20140816 |