EP0199833B1 - Hydraulic pump - Google Patents

Hydraulic pump Download PDF

Info

Publication number
EP0199833B1
EP0199833B1 EP19850105181 EP85105181A EP0199833B1 EP 0199833 B1 EP0199833 B1 EP 0199833B1 EP 19850105181 EP19850105181 EP 19850105181 EP 85105181 A EP85105181 A EP 85105181A EP 0199833 B1 EP0199833 B1 EP 0199833B1
Authority
EP
European Patent Office
Prior art keywords
flow
valve
hydraulic pump
prolongation
spool
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.)
Expired
Application number
EP19850105181
Other languages
German (de)
French (fr)
Other versions
EP0199833A1 (en
Inventor
René Dr. Schulz
Heinz Teubler
Peter Breuer
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.)
Cessione luk Fahrzeug - Hidraulik & Co KG GmbH
Original Assignee
Vickers Systems GmbH
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 Vickers Systems GmbH filed Critical Vickers Systems GmbH
Priority to EP19850105181 priority Critical patent/EP0199833B1/en
Priority to DE8585105181T priority patent/DE3564603D1/en
Priority to CA000506074A priority patent/CA1253771A/en
Priority to JP61095925A priority patent/JPH0749797B2/en
Publication of EP0199833A1 publication Critical patent/EP0199833A1/en
Application granted granted Critical
Publication of EP0199833B1 publication Critical patent/EP0199833B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
    • F04C14/24—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • F04C14/26—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels

Definitions

  • the invention relates to a hydraulic pump, in particular for steering assistance, with the features of the preamble of claim 1.
  • Power steering pumps are usually designed as vane pumps and rigidly connected to the drive motor of the vehicle in which the power steering is used. Accordingly, the pump delivery flow increases with increasing engine speed. However, strong steering assistance is usually not required at higher engine speeds. For this reason, a flow control valve is usually used to regulate part of the pump delivery flow, while the remaining regulated useful flow is fed back to the tank via the steering valve.
  • the hydraulic fluid under the so-called dynamic pressure relaxes, which leads to a corresponding loss of performance if the power is not absorbed by the steering.
  • Such a high power consumption does not occur practically in the high speed range because you cannot turn in sharply when driving fast. In the high speed range of the pump, a constant readiness to perform is maintained, the level of which is not required and thus leads to an unnecessary loss of performance.
  • the invention is based on the object of designing a hydraulic pump of the generic type in such a way that a small range of falling characteristic curve branches of the useful flow pump speed characteristic can be generated by slight changes to the flow control valve. It should therefore be possible to generate a characteristic adapted to the application.
  • the annular space formed on the extension of the slide piston has a certain overlap width with respect to the orifice bore and the discharge channels, which are preferably duplicated.
  • the annular space is fed by a cavity in the extension of the slide piston.
  • the current divides in the annulus in terms of the useful flow and the regulated flow. The latter is quickly discharged into the pump inlet so that there is little flow loss.
  • the division of the current in the annular space has the further advantage that the impulse forces exerted are opposite to each other, so that the flow forces on the slide piston are largely compensated for.
  • the utility flow bore channel has a second inlet, formed by an annular gap between the extension of the valve slide and the valve bore wall in the range of movement of this extension.
  • This inlet cross-section is smaller than the normal opening cross-section between the annulus and the utility flow bore channel.
  • the extension of the slide piston can have different geometrical configurations in order to influence the course of the useful current / pump speed characteristic.
  • the vane pump has a main housing part 1 and a housing cover 2, which enclose an interior 1 a pressure-tight.
  • an interior 1 sit - arranged fixed to the housing - a pressure plate 4 and a cam ring 5, which are secured against rotation by pins 6.
  • a rotor 7 is arranged within the cam ring 5 and between the housing cover 2 and the pressure plate 4, which rotor (FIG. 3) has a series of radial guide slots. Wings 8 are radially displaceably mounted within these guide slots.
  • the rotor 7 can be driven via a shaft 9 which is mounted in a bearing bore in the housing cover 2.
  • the rotor 7 is cylindrical, while the cam ring 5 has an approximately oval inner contour, the small axis of which corresponds approximately to the diameter of the rotor, while the large axis determines the extension length of the vanes 8.
  • the cam ring 5 and the rotor 7 there are two crescent-shaped displacement regions 11, 12, which are divided into a number of cell spaces by the vanes 8. The cell spaces increase on the suction side of the system and decrease on the pressure side.
  • Hydraulic fluid is supplied from a tank 14 (FIG. 3) and a distribution area 16 via two slightly sloping bores 17 (FIG. 2), knee-shaped feed channel sections 18 and inlet openings 20 into the respective displacement areas of the pump.
  • the knee-shaped feed channel sections 18 each have a radial leg which opens into an unloading channel 19 (FIGS. 2 and 4).
  • the hydraulic fluid is removed via outlet openings 33 (FIG. 1) through the pressure plate 4 into a pressure chamber 35 on its rear side.
  • a flow control valve 40 the pump delivery flow is divided into a regulated useful flow flowing via a bore 38 to an outer pump outlet 37 (FIG. 2) and a regulated delivery flow flowing through the discharge channels 19.
  • the bore 38 represents a useful current channel and at the same time part of a measuring orifice 36 through which the useful current flows and whose voltage drop is tapped.
  • the useful flow reaches the pump outlet 37 (FIG. 2) via an inclined discharge duct 39 (FIG. 1). From this, a connection leads to a control chamber 47 of the flow control valve 40 via a damping throttle 48.
  • the flow control valve 40 has a slide piston 41 guided in a valve bore 55, which is pushed by the force of a spring 42 in the direction of the pressure plate 4 and, if necessary, to abut there brought.
  • the slide piston 41 has a first and second piston surface 53, 54 and two piston collars 43, 44, between which an annular groove 45 extends.
  • the piston collar 43 is narrower than the discharge channels 19 (FIG. 2) which meet the annular groove 45.
  • a partially radially and partially axially extending channel 46 leads from the annular groove 45 through the slide piston 41 into the control chamber 47, and the channel 46 is dominated by a cone valve which responds when a certain permissible pressure in the control chamber 47 is exceeded and discharges this chamber, so that the spool 41 acts as a controlled pressure relief valve, as is known.
  • the valve 40 assumes the position shown in FIG. 4.
  • the slide piston 41 has an extension 49 in which a cavity 50 is accommodated. This is connected via a series of bores 51 to an annular space 52 of width b.
  • the annular space 52 is delimited by the first piston surface 53 and a third piston surface 56, which work in cooperation with the discharge channels 19 and the useful flow bore channel 38 as control edges, so that the valve 40 represents a two-edge controller.
  • the radial bore 38 and the radial unloading channel 19 are shown in FIG. 4 in the same axial plane of the valve 40, while in reality they lie in different axial planes which, for example, form an angle of 90 ° to one another. Projected onto the axial sectional plane shown in FIG.
  • the pump operates as follows: the rotor 7 is driven by the shaft 9 and the vanes 8 pass through the displacement areas 11 and 12, so that the liquid via the liquid outlet system 33, 35, 50, 38, 39 to the outer pump outlet 37 is fed and liquid is sucked in via the outer pump inlet 16 and the liquid supply system 17, 18, 20. If the liquid flow through the bore 38 exceeds the desired value, the pressure drop across this bore 38 is sufficiently large to overcome the force of the valve spring 42, i.e. the compressive force on the piston surface 53 is greater than the compressive force on the piston surface 54 plus the spring force 42. Now part of the pumped flow is regulated via the discharge channel 19, while the useful flow continues to be withdrawn via the bore 38. Their effective cross-sectional area decreases due to the control edge 56 moving in the closing direction, i.e. the orifice 36 becomes narrower and the pressure drop in the useful flow increases.
  • a slide piston 41 is shown, the extension 49 is slightly conical.
  • the annular space 52 therefore extends to a certain extent up to the front edge 57 of the slide piston 41. Accordingly, if the slide piston 41 moves against the force of its valve spring 42, the opening width of the annular gap between the extension 49 and the valve bore 55 becomes narrower, the narrowing speed as it approaches the edge 57 to the valve bore 55 increases sharply, so that the proportion of the useful current that flows over the annular gap between the extension 49 and the valve bore 55 decreases sharply.
  • a certain proportion of the useful flow remains, as is shown in the assigned characteristic.
  • Fig. 7 shows a slide piston 41 with a Extension 49, which is composed of the shapes of the extension according to FIGS. 5 and 6, that is to say has a cylindrical region 58 and a conical region 59.
  • a certain proportion of the useful flow can flow through the annular gap between the conical region 59 and the valve bore 55 into the bore 38 until one certain position of the slide piston 41, the cylindrical portion 58 enters the valve bore 55.
  • a larger or smaller remaining useful flow is then achieved, as is indicated in the assigned useful flow speed characteristic.
  • Fig. 8 shows an embodiment of the slide piston 41 with an extension 49, which has a spherical surface. This shape approximates the design according to FIG. 7, and accordingly a similar useful current-speed characteristic is achieved.
  • the gap width, minus d z 0.21 to 0.71 mm, was varied.
  • a constant useful current could be achieved regardless of the pump speed n.
  • the dimension b was varied between 7.7 and 8.7 mm, whereby higher useful current values were achieved at higher values of b, ie the falling branch of the characteristic dropped less strongly or remained constant.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Details And Applications Of Rotary Liquid Pumps (AREA)
  • Rotary Pumps (AREA)
  • Reciprocating Pumps (AREA)

Description

Die Erfindung bezieht sich auf eine Hydraulikpumpe, insbesondere zur Lenkhilfe, mit den Merkmalen des Oberbegriffs des Anspruchs 1.The invention relates to a hydraulic pump, in particular for steering assistance, with the features of the preamble of claim 1.

Lenkhilfpumpen sind gewöhnlich in der Bauart als Flügelzellenpumpen ausgebildet und mit dem Antriebsmotor des Fahrzeugs starr verbunden, in welchem die Lenkhilfe angewendet wird. Mit steigender Motordrehzahl nimmt demnach der Pumpenförderstrom zu. Bei höheren Drehzahlen des Motors wird aber gewöhnlich keine starke Lenkunterstützung benötigt. Deshalb wird meist ein Stromregelventil dazu verwendet, einen Teil des Pumpenförderstroms abzuregeln, während der verbleibende geregelte Nutzstrom über das Lenkventil zurück zum Tank geleitet wird. Dabei entspannt sich die unter dem sogenannten Staudruck stehende Hydraulikflüssigkeit, was zu einem entsprechenden Leistungsverlust führt, wenn die Leistung nicht von der Lenkung aufgenommen wird. Eine derart hohe Leistungsaufnahme kommt praktisch im hohen Drehzahlbereich nicht vor, weil man bei rascher Fahrt nicht scharf einlenken kann. Im hohen Drehzahlbereich der Pumpe wird demnach eine ständige Leistungsbereitschaft aufrecht erhalten, die in ihrer Höhe nicht benötigt wird und somit zu einem unnötigen Leistungsverlust führt.Power steering pumps are usually designed as vane pumps and rigidly connected to the drive motor of the vehicle in which the power steering is used. Accordingly, the pump delivery flow increases with increasing engine speed. However, strong steering assistance is usually not required at higher engine speeds. For this reason, a flow control valve is usually used to regulate part of the pump delivery flow, while the remaining regulated useful flow is fed back to the tank via the steering valve. The hydraulic fluid under the so-called dynamic pressure relaxes, which leads to a corresponding loss of performance if the power is not absorbed by the steering. Such a high power consumption does not occur practically in the high speed range because you cannot turn in sharply when driving fast. In the high speed range of the pump, a constant readiness to perform is maintained, the level of which is not required and thus leads to an unnecessary loss of performance.

Um diesen Nachteil zu beheben, ist es bereits bekannt, das Stromregelventil für einen fallenden Kennlinienast der Nutzstrom-Pumpendrehzahl-Charakteristik auszulegen und zu gestalten (DE-A-2 265 097 und DE-A-2 652 707). Die Druckeinlassöffnung zum Stromregelventil ist dabei radial angeordnet, ebenso der Entladekanal, während der Nutzstromauslass axial, in Richtung der Bewegung des Schiebekolbens des Stromregelventils, angeordnet ist. Der Fortsatz am Schieberkolben ist als Ventilnadel mit Nadelkopf ausgebildet, wobei sich die Ventilnadel durch den axialen Auslass erstreckt, so dass eine Messblende gebildet wird, deren Weite von der Stellung des Nadelkopfes zum axialen Auslass abhängt. Nachteilig ist dabei der Umstand, dass bereits sehr geringe Änderungen der Stellung zu erheblichen Änderungen der durchströmten Querschnittsfläche des axialen Auslasses führen.In order to remedy this disadvantage, it is already known to design and design the flow control valve for a falling characteristic curve branch of the useful current pump speed characteristic (DE-A-2 265 097 and DE-A-2 652 707). The pressure inlet opening to the flow control valve is arranged radially, as is the discharge channel, while the useful flow outlet is arranged axially in the direction of the movement of the sliding piston of the flow control valve. The extension on the slide piston is designed as a valve needle with a needle head, the valve needle extending through the axial outlet, so that a measuring orifice is formed, the width of which depends on the position of the needle head relative to the axial outlet. The disadvantage here is the fact that even very small changes in position lead to considerable changes in the cross-sectional area of the axial outlet through which flow passes.

Der Erfindung liegt die Aufgabe zugrunde, eine Hydraulikpumpe der oberbegrifflichen Art so zu gestalten, dass durch geringfügige Änderungen am Stromregelventil ein breiter Bereich von fallenden Kennlinienästen der Nutzstrom-Pumpendrehzahl-Charakteristik erzeugt werden kann. Es soll also eine für den Anwendungsfall angepasste Charakteristik erzeugt werden können.The invention is based on the object of designing a hydraulic pump of the generic type in such a way that a small range of falling characteristic curve branches of the useful flow pump speed characteristic can be generated by slight changes to the flow control valve. It should therefore be possible to generate a characteristic adapted to the application.

Die gestellte Aufgabe wird aufgrund der Massnahmen des Hauptanspruchs gelöst.The task is solved on the basis of the measures of the main claim.

Der an dem Fortsatz des Schieberkolbens ausgebildete Ringraum hat eine gewisse Überdeckungsbreite mit Bezug auf die Messblenden-Bohrung und die vorzugsweise doppelt vorhandenen Entladekanäle. Der Ringraum wird von einem Hohlraum im Fortsatz des Schieberkolbens gespeist. Im Ringraum teilt sich der Strom im Sinne des Nutzstroms und des abgeregelten Förderstromes. Letzterer wird auf kurzem Wege wieder in den Einlass der Pumpe entladen, so dass geringe Strömungsverluste entstehen. Die Aufteilung des Stromes im Ringraum hat den weiteren Vorteil, dass die ausgeübten Impulskräfte einander entgegengesetzt sind, so dass eine weitgehende Kompensation der Strömungskräfte auf den Schieberkolben eintritt.The annular space formed on the extension of the slide piston has a certain overlap width with respect to the orifice bore and the discharge channels, which are preferably duplicated. The annular space is fed by a cavity in the extension of the slide piston. The current divides in the annulus in terms of the useful flow and the regulated flow. The latter is quickly discharged into the pump inlet so that there is little flow loss. The division of the current in the annular space has the further advantage that the impulse forces exerted are opposite to each other, so that the flow forces on the slide piston are largely compensated for.

Nach einer Weiterbildung der Erfindung besitzt der Nutzstrombohrungskanal einen zweiten Zulauf, gebildet durch einen Ringspalt zwischen dem Fortsatz des Ventilschiebers und der Ventilbohrungswand im Bewegungsbereich dieses Fortsatzes. Dieser Zulaufquerschnitt ist kleiner als der normale Öffnungsquerschnitt zwischen Ringraum und Nutzstrom-Bohrungskanal.According to a development of the invention, the utility flow bore channel has a second inlet, formed by an annular gap between the extension of the valve slide and the valve bore wall in the range of movement of this extension. This inlet cross-section is smaller than the normal opening cross-section between the annulus and the utility flow bore channel.

Nach weiteren Ausgestaltungen der Erfindung kann der Fortsatz des Schieberkolbens verschiedene geometrische Gestaltungen aufweisen, um Einfluss auf den Verlauf der Nutzstrom-Purnpendrehzahl-Charakteristik zu nehmen.According to further refinements of the invention, the extension of the slide piston can have different geometrical configurations in order to influence the course of the useful current / pump speed characteristic.

Die Erfindung wird anhand der Zeichnung beschrieben. Dabei zeigt:

  • Fig. 1 einen vertikalen Längsschnitt durch eine Flügelzellenpumpe, teilweise abgebrochen;
  • Fig. 2 einen horizontalen Längsschnitt entlang der Linie 11-11 in Fig. 1, teilweise abgebrochen;
  • Fig. 3 einen Querschnitt gemäss Linie III-III in Fig. 1;
  • Fig. 4 eine vergrösserte Einzelheit aus Fig. 1, 2, schematisiert;
  • Fig. 5-8 Kolbenformen und zugehörige Diagramme des abgegebenen Nutzstroms über der Pumpendrehzahl.
The invention is described with reference to the drawing. It shows:
  • 1 shows a vertical longitudinal section through a vane pump, partially broken off.
  • Figure 2 is a horizontal longitudinal section along the line 11-11 in Figure 1, partially broken away.
  • 3 shows a cross section along line III-III in FIG. 1;
  • 4 shows an enlarged detail from FIGS. 1, 2, schematized;
  • Fig. 5-8 piston shapes and associated diagrams of the emitted useful current over the pump speed.

Die Flügelzellenpumpe weist ein Gehäusehauptteil 1 und einen Gehäusedeckel 2 auf, die einen Innenraum 1 a druckmitteldicht einschliessen. Im Innenraum 1 sitzen - gehäusefest angeordnet - eine Druckplatte 4 und ein Nockenring 5, die durch Stifte 6 drehgesichert sind. Innerhalb des Nockenrings 5 und zwischen dem Gehäusedeckel 2 und der Druckplatte 4 ist ein Rotor 7 angeordnet, der (Fig. 3) eine Reihe von radialen Führungsschlitzen besitzt. Innerhalb dieser Führungsschlitze sind Flügel 8 radial verschieblich gelagert. Der Rotor 7 ist über eine Welle 9 antreibbar, die in einer Lagerbohrung des Gehäusedeckels 2 gelagert ist. Der Rotor 7 ist zylindrisch geformt, während der Nockenring 5 einen angenähert ovalen Innenumriss aufweist, dessen kleine Achse etwa dem Durchmesser des Rotors entspricht, während die grosse Achse die Auszugslänge der Flügel 8 bestimmt. Auf diese Weise liegen zwischen dem Nockenring 5 und dem Rotor 7 zwei sichelförmige Verdrängerbereiche 11, 12, die von den Flügeln 8 in eine Anzahl von Zellenräumen unterteilt werden. Bei der Saugseite des Systems vergrössern sich die Zellenräume, und bei der Druckseite verkleinern sie sich.The vane pump has a main housing part 1 and a housing cover 2, which enclose an interior 1 a pressure-tight. In the interior 1 sit - arranged fixed to the housing - a pressure plate 4 and a cam ring 5, which are secured against rotation by pins 6. A rotor 7 is arranged within the cam ring 5 and between the housing cover 2 and the pressure plate 4, which rotor (FIG. 3) has a series of radial guide slots. Wings 8 are radially displaceably mounted within these guide slots. The rotor 7 can be driven via a shaft 9 which is mounted in a bearing bore in the housing cover 2. The rotor 7 is cylindrical, while the cam ring 5 has an approximately oval inner contour, the small axis of which corresponds approximately to the diameter of the rotor, while the large axis determines the extension length of the vanes 8. In this way, between the cam ring 5 and the rotor 7 there are two crescent-shaped displacement regions 11, 12, which are divided into a number of cell spaces by the vanes 8. The cell spaces increase on the suction side of the system and decrease on the pressure side.

Die Zufuhr von Hydraulikflüssigkeit erfolgt von einem Tank 14 (Fig. 3) und einem Verteilbereich 16 über zwei leicht schräg fallende Bohrungen 17 (Fig. 2), knieförmige Zufuhrkanalabschnitte 18 und Eingangsöffnungen 20 in die jeweiligen Verdrängerbereiche der Pumpe. Die knieförmigen Zuführkanalabschnitte 18 weisen jeweils einen radialen Schenkel auf, der in einen Entladekanal 19 (Fig. 2 und 4) einmündet.Hydraulic fluid is supplied from a tank 14 (FIG. 3) and a distribution area 16 via two slightly sloping bores 17 (FIG. 2), knee-shaped feed channel sections 18 and inlet openings 20 into the respective displacement areas of the pump. The knee-shaped feed channel sections 18 each have a radial leg which opens into an unloading channel 19 (FIGS. 2 and 4).

Die Abfuhr der Hydraulikflüssigkeit erfolgt über Auslassöffnungen 33 (Fig. 1) durch die Druckplatte 4 hindurch auf deren Rückseite in einen Druckraum 35. Bei einem Stromregelventil 40 teilt sich der Pumpenförderstrom auf in einen über eine Bohrung 38 fliessenden, geregelten Nutzstrom zu einem äusseren Pumpenauslass 37 (Fig 2) und einen durch die Entladekanäle 19 abfliessenden, abgeregelten Förderstrom. Die Bohrung 38 stellt einen Nutzstromkanal und gleichzeitig einen Teil einer Messblende 36 dar, die vom Nutzstrom durchflossen wird und dessen Spannungsabfall abgegriffen wird. Der Nutzstrom gelangt über einen schräg verlaufenden Abfuhrkanal 39 (Fig. 1) zum Pumpenauslass 37 (Fig. 2). Von diesem führt eine Verbindung zu einem Steuerraum 47 des Stromregelventils 40 über eine Dämpfungsdrossel 48. Das Stromregelventil 40 weist einen in einer Ventilbohrung 55 geführten Schieberkolben 41 auf, der durch die Kraft einer Feder 42 in Richtung auf die Druckplatte 4 gedrängt und gegebenenfalls dort zur Anlage gebracht wird. Der Schieberkolben 41 weist eine erste und zweite Kolbenfläche 53, 54 sowie zwei Kolbenbunde 43, 44 auf, zwischen denen sich eine Ringnut 45 erstreckt. Der Kolbenbund 43 ist schmäler als die Entladekanäle 19 (Fig. 2), welche auf die Ringnut 45 treffen. Von der Ringnut 45 führt ein teilweise radial und teilweise axial sich erstreckender Kanal 46 durch den Schieberkolben 41 in den Steuerraum 47, und der Kanal 46 wird von einem Kegelventil beherrscht, welches beim Überschreiten eines bestimmten zulässigen Drucks im Steuerraum 47 anspricht und diesen Raum entlädt, so dass der Schieberkolben 41 als gesteuertes Druckbegrenzungsventil wirkt, wie es bekannt ist. Ob als Stromregelventil oder als Druckbegrenzungsventil, beim Ansprechen nimmt das Ventil 40 die in Fig. 4 dargestellte Lage ein.The hydraulic fluid is removed via outlet openings 33 (FIG. 1) through the pressure plate 4 into a pressure chamber 35 on its rear side. In the case of a flow control valve 40, the pump delivery flow is divided into a regulated useful flow flowing via a bore 38 to an outer pump outlet 37 (FIG. 2) and a regulated delivery flow flowing through the discharge channels 19. The bore 38 represents a useful current channel and at the same time part of a measuring orifice 36 through which the useful current flows and whose voltage drop is tapped. The useful flow reaches the pump outlet 37 (FIG. 2) via an inclined discharge duct 39 (FIG. 1). From this, a connection leads to a control chamber 47 of the flow control valve 40 via a damping throttle 48. The flow control valve 40 has a slide piston 41 guided in a valve bore 55, which is pushed by the force of a spring 42 in the direction of the pressure plate 4 and, if necessary, to abut there brought. The slide piston 41 has a first and second piston surface 53, 54 and two piston collars 43, 44, between which an annular groove 45 extends. The piston collar 43 is narrower than the discharge channels 19 (FIG. 2) which meet the annular groove 45. A partially radially and partially axially extending channel 46 leads from the annular groove 45 through the slide piston 41 into the control chamber 47, and the channel 46 is dominated by a cone valve which responds when a certain permissible pressure in the control chamber 47 is exceeded and discharges this chamber, so that the spool 41 acts as a controlled pressure relief valve, as is known. Whether as a flow control valve or as a pressure limiting valve, when activated, the valve 40 assumes the position shown in FIG. 4.

Der Schieberkolben 41 weist einen Fortsatz 49 auf, in welchem ein Hohlraum 50 untergebracht ist. Dieser steht über eine Reihe von Bohrungen 51 mit einem Ringraum 52 der Breite b in Verbindung. Der Ringraum 52 wird von der ersten Kolbenfläche 53 sowie einer dritten Kolbenfläche 56 begrenzt, welche im Zusammenwirken mit den Entladekanälen 19 und dem Nutzstrom-Bohrungskanal 38 als Steuerkanten arbeiten, so dass das Ventil 40 einen Zweikantenregler darstellt. Die radiale Bohrung 38 und der radiale Entladekanal 19 sind in Fig. 4 in der gleichen Axialebene des Ventils 40 dargestellt, während sie in Wirklichkeit in unterschiedlichen Axialebenen liegen, die beispielsweise einen Winkel von 90° zueinander einschliessen. Projiziert auf die in Fig. 4 dargestellte axiale Schnittebene ergibt sich ein Achsabstand a zwischen dem Entladekanal 19 und der Bohrung 38 mit einer Stegdicke c. Die Kanäle 19 und 38 brauchen nur eine allgemeine radiale Richtung zum Ventil 40 einzunehmen, wichtig ist, dass ein Stegabstand c gebildet wird. Wie ersichtlich, ist der Abstand b grösser als der Abstand c, d.h. der Ringraum 52 vermag in einer bestimmten Stellung des Schieberkolbens 41 die Bohrung 38 mit dem Entladekanal 19 zu verbinden. Der Durchmesser des Fortsatzes 49 ist mit d2 bezeichnet, während die Ventilbohrung 55 im Bereich dieses Fortsatzes einen Durchmesser von di hat.The slide piston 41 has an extension 49 in which a cavity 50 is accommodated. This is connected via a series of bores 51 to an annular space 52 of width b. The annular space 52 is delimited by the first piston surface 53 and a third piston surface 56, which work in cooperation with the discharge channels 19 and the useful flow bore channel 38 as control edges, so that the valve 40 represents a two-edge controller. The radial bore 38 and the radial unloading channel 19 are shown in FIG. 4 in the same axial plane of the valve 40, while in reality they lie in different axial planes which, for example, form an angle of 90 ° to one another. Projected onto the axial sectional plane shown in FIG. 4, there is an axial spacing a between the unloading channel 19 and the bore 38 with a web thickness c. The channels 19 and 38 need only take a general radial direction to the valve 40, it is important that a web spacing c is formed. As can be seen, the distance b is greater than the distance c, ie the annular space 52 can connect the bore 38 to the unloading channel 19 in a certain position of the slide piston 41. The diameter of the extension 49 is denoted by d 2 , while the valve bore 55 has a diameter of di in the region of this extension.

Der Betrieb der Pumpe geht wie folgt vor sich: Der Rotor 7 wird über die Welle 9 angetrieben, und die Flügel 8 durchwandern die Verdrängerbereiche 11 und 12, so dass die Flüssigkeit über das Flüssigkeitsauslasssystem 33, 35, 50, 38, 39 dem äusseren Pumpenauslass 37 zugeführt und über den äusseren Pumpeneinlass 16 sowie das Flüssigkeitszufuhrsystem 17, 18, 20 Flüssigkeit nachgesaugt wird. Wenn der Flüssigkeitsstrom durch die Bohrung 38 den gewünschten Wert übersteigt, ist das Druckgefälle an dieser Bohrung 38 genügend gross, die Kraft der Ventilfeder 42 zu überwinden, d.h. die Druckkraft auf die Kolbenfläche 53 ist grösser als die Druckkraft auf die Kolbenfläche 54 plus die Federkraft 42. Nunmehr wird ein Teil des geförderten Pumpenstroms über den Entladekanal 19 abgeregelt, während der Nutzstrom weiterhin über die Bohrung 38 entnommen wird. Deren wirksame Querschnittsfläche nimmt infolge der sich in Schliessrichtung bewegenden Steuerkante 56 ab, d.h. die Messblende 36 wird enger und der Druckabfall des Nutzstromes grösser.The pump operates as follows: the rotor 7 is driven by the shaft 9 and the vanes 8 pass through the displacement areas 11 and 12, so that the liquid via the liquid outlet system 33, 35, 50, 38, 39 to the outer pump outlet 37 is fed and liquid is sucked in via the outer pump inlet 16 and the liquid supply system 17, 18, 20. If the liquid flow through the bore 38 exceeds the desired value, the pressure drop across this bore 38 is sufficiently large to overcome the force of the valve spring 42, i.e. the compressive force on the piston surface 53 is greater than the compressive force on the piston surface 54 plus the spring force 42. Now part of the pumped flow is regulated via the discharge channel 19, while the useful flow continues to be withdrawn via the bore 38. Their effective cross-sectional area decreases due to the control edge 56 moving in the closing direction, i.e. the orifice 36 becomes narrower and the pressure drop in the useful flow increases.

Fig. 4 zeigt ein Diagramm des geregelten Nutzstroms Q gegenüber der Pumpendrehzahl n bei d1 = d2. Solange der Ringraum 52 nur mit der Bohrung 38 in Verbindung steht, steigt der Nutzstrom linear mit der Drehzahl n an. Danach wird ein immer grösserer Anteil des Pumpenstroms abgeregelt, bis schliesslich die Steuerkante 56 den Nutzstrom ganz absperrt. Durch entsprechende Bemessung der Grössen a, b, c, d3, d4 kann der Verlauf des fallenden Astes der Charakteristik beeinflusst werden, d.h. der Wert n bestimmt werden, bei dem der Nutzstrom Q auf Null geht.4 shows a diagram of the regulated useful current Q versus the pump speed n at d 1 = d 2 . As long as the annular space 52 is only connected to the bore 38, the useful current increases linearly with the speed n. Thereafter, an ever larger proportion of the pump current is reduced until finally the control edge 56 completely blocks the useful current. The course of the falling branch of the characteristic can be influenced by appropriate dimensioning of the variables a, b, c, d 3 , d 4 , ie the value n can be determined at which the useful current Q goes to zero.

Fig. 5 zeigt einen Schieberkolben 41, dessen Fortsatz 49 einen Durchmesser d2 aufweist, der kleiner als der Durchmesser d1 der Ventilbohrung 55 ist. Dadurch wird ein Ringspalt zwischen Fortsatz 49 und Ventilbohrung 55 gebildet, durch den - unabhängig von der Stellung des Schieberkolbens 41 - ein Strom zwischen Druckkammer 35 und Bohrung 38 fliessen kann. Deshalb geht der Nutzstrom Q nicht auf Null zurück, wenn die Kante 56 die Bohrung 38 absperrt. Es versteht sich, dass die durch den Ringspalt fliessende Menge vom auftretenden Druckgefälle abhängt, was im zugeordneten Diagramm durch eine gestrichelte bzw. strichpunktierte Linie angedeutet ist.5 shows a slide piston 41, the extension 49 of which has a diameter d 2 which is smaller than the diameter d 1 of the valve bore 55. As a result, an annular gap is formed between the extension 49 and the valve bore 55, through which — regardless of the position of the slide piston 41 — a current can flow between the pressure chamber 35 and the bore 38. Therefore, the useful current Q does not go back to zero when the edge 56 blocks the bore 38. It goes without saying that the amount flowing through the annular gap depends on the pressure drop that occurs, which is indicated in the associated diagram by a dashed or dash-dotted line.

In Fig. 6 ist ein Schieberkolben 41 dargestellt, dessen Fortsatz 49 leicht konisch ausgebildet ist. Der Ringraum 52 erstreckt sich deshalb gewissermassen bis zur Vorderkante 57 des Schieberkolbens 41. Wenn sich demnach der Schieberkolben 41 entgegen der Kraft seiner Ventilfeder 42 bewegt, wird die Öffnungsweite des Ringspaltes zwischen dem Fortsatz 49 und der Ventilbohrung 55 enger, wobei die Verengungsgeschwindigkeit bei der Annäherung der Kante 57 an die Ventilbohrung 55 stark zunimmt, so dass der Anteil des Nutzstroms, der über den Ringspalt zwischen Fortsatz 49 und Ventilbohrung 55 fliesst, stark abnimmt. Je nachdem, um wieviel der Innendurchmesser d1 der Ventilbohrung 55 grösser ist als der Aussendurchmesser d2 des Fortsatzes 49, bleibt jedoch ein gewisser Anteil des Nutzstromes vorhanden, wie dies in der zugeordneten Charakteristik dargestellt ist.In Fig. 6, a slide piston 41 is shown, the extension 49 is slightly conical. The annular space 52 therefore extends to a certain extent up to the front edge 57 of the slide piston 41. Accordingly, if the slide piston 41 moves against the force of its valve spring 42, the opening width of the annular gap between the extension 49 and the valve bore 55 becomes narrower, the narrowing speed as it approaches the edge 57 to the valve bore 55 increases sharply, so that the proportion of the useful current that flows over the annular gap between the extension 49 and the valve bore 55 decreases sharply. Depending on how much the inner diameter d 1 of the valve bore 55 is larger than the outer diameter d 2 of the extension 49, however, a certain proportion of the useful flow remains, as is shown in the assigned characteristic.

Fig. 7 zeigt einen Schieberkolben 41 mit einem Fortsatz 49, der aus den Formen des Fortsatzes nach Fig. 5 und 6 zusammengesetzt ist, also einen zylindrischen Bereich 58 und einen konischen Bereich 59 aufweist. Wenn die Fläche 53 mit dem Entladekanal 19 in Verbindung kommt, wird ein immer grösserer Anteil des geförderten Pumpenstroms abgeregelt, jedoch kann ein bestimmter Anteil des Nutzstromes durch den Ringspalt zwischen dem konischen Bereich 59 und der Ventilbohrung 55 in die Bohrung 38 fliessen, bis bei einer bestimmten Stellung des Schieberkolbens 41 der zylindrische Bereich 58 in die Ventilbohrung 55 eintritt. Je nachdem, um wieviel der Aussendurchmesser d2 des zylindrischen Bereiches 58 kleiner ist als der Innendurchmesser d, der Ventilbohrung, wird dann noch ein grösserer oder kleinerer restlich verbleibender Nutzstrom erzielt, wie dies in der zugeordneten Nutzstrom-Drehzahl-Charakteristik angedeutet ist.Fig. 7 shows a slide piston 41 with a Extension 49, which is composed of the shapes of the extension according to FIGS. 5 and 6, that is to say has a cylindrical region 58 and a conical region 59. When the surface 53 comes into contact with the discharge channel 19, an ever larger proportion of the pumped flow is reduced, but a certain proportion of the useful flow can flow through the annular gap between the conical region 59 and the valve bore 55 into the bore 38 until one certain position of the slide piston 41, the cylindrical portion 58 enters the valve bore 55. Depending on how much the outside diameter d 2 of the cylindrical area 58 is smaller than the inside diameter d of the valve bore, a larger or smaller remaining useful flow is then achieved, as is indicated in the assigned useful flow speed characteristic.

Fig. 8 zeigt ein Ausführungsbeispiel des Schieberkolbens 41 mit einem Fortsatz 49, der eine Kugeloberfläche besitzt. Diese Form ist der Ausbildung nach Fig. 7 angenähert, und demgemäss wird eine ähnliche Nutzstrom-Drehzahl-Charakteristik erzielt.Fig. 8 shows an embodiment of the slide piston 41 with an extension 49, which has a spherical surface. This shape approximates the design according to FIG. 7, and accordingly a similar useful current-speed characteristic is achieved.

In den durchgeführten Versuchen wurden die Grössen a, b, c, di, d2, d3, d4 variiert, womit der Verlauf der dargestellten Charakteristiken noch weiter beeinflusst werden konnte. In der Ausführungsform nach Fig. 4 war a = 10,3 mm, d4 = 5,5 mm, d3 = 3,1 bis 6,0 mm und b = 7,7 bis 10,7 mm.In the tests carried out, the variables a, b, c, d i , d 2 , d 3 , d 4 were varied, which allowed the course of the characteristics shown to be influenced even further. In the embodiment according to FIG. 4, a = 10.3 mm, d 4 = 5.5 mm, d 3 = 3.1 to 6.0 mm and b = 7.7 to 10.7 mm.

Mit d3 nahm auch der Nutzstrom Q zu, d.h. der maximale Nutzstrom wurde statt bei n = 10001/min erst bei n = 1700 1/min erreicht und war demgemäss höher. Von dort fiel der Nutzstrom Q auf 0 bei etwa n = 6 - 8000 1 /min ab, wobei die höheren Werte bei höheren Drücken erreicht wurden. Bei relativ kleinen Werten von b fiel der fallende Ast der Charakteristik stärker ab als bei relativ grösserem b.The useful current Q also increased with d 3 , ie the maximum useful current was only reached at n = 1700 1 / min instead of n = 10001 / min and was accordingly higher. From there, the useful current Q dropped to 0 at about n = 6-8000 1 / min, the higher values being reached at higher pressures. With relatively small values of b, the falling branch of the characteristic dropped more than with a relatively larger b.

In der Ausführungsform nach Fig. 5 wurde die Spaltweited, minus dz = 0,21 bis 0,71 mm variiert. Je grösser die Spaltweite, umso weniger steil neigte sich der abfallende Ast der Charakteristik gegen die Nullinie. Bei höheren Drücken konnte auch ein konstanter Nutzstrom unabhängig von der Pumpendrehzahl n erzielt werden. Das Mass b wurde zwischen 7,7 und 8,7 mm variiert, wobei bei höheren Werten von b höhere Nutzstromwerte erzielt wurden, d.h. der fallende Ast der Charakteristik fiel weniger stark ab oder blieb konstant.In the embodiment according to FIG. 5, the gap width, minus d z = 0.21 to 0.71 mm, was varied. The larger the gap width, the less steep the sloping branch of the characteristic inclined towards the zero line. At higher pressures, a constant useful current could be achieved regardless of the pump speed n. The dimension b was varied between 7.7 and 8.7 mm, whereby higher useful current values were achieved at higher values of b, ie the falling branch of the characteristic dropped less strongly or remained constant.

Es kann somit festgestellt werden, dass die Charakteristik des geregelten Nutzstromes Q derart beeinflusst werden kann, dass nach Ansprechen des Ventils bei einer bestimmten Pumpendrehzahl die Höhe des geregelten Nutzstromes Q wie folgt abgesenkt wird:

  • a) bei steigender Drehzahl n langsam abfallend auf Null;
  • b) bei steigender Drehzahl n langsam abfallend auf einen Mindestwert, und
  • c) bei steigender Drehzahl n zunächst konstant, dann abfallend auf Null oder einen Mindestwert. In allen Fällen sind die Strömungskräfte auf den Ventilkolben 41 teilweise gegeneinander gerichtet, so dass eine weitgehende Kompensation stattfindet.
It can thus be determined that the characteristic of the regulated useful current Q can be influenced in such a way that after the valve has responded at a certain pump speed, the level of the regulated useful current Q is reduced as follows:
  • a) slowly increasing to zero as the speed n increases;
  • b) slowly increasing to a minimum value with increasing speed n, and
  • c) initially increasing with increasing speed n, then falling to zero or a minimum value. In all cases, the flow forces on the valve piston 41 are partially directed towards one another, so that extensive compensation takes place.

Claims (8)

1. Hydraulic pump, intended especially for power steering systems and exhibiting the following features:
the hydraulic pump has a rotor (7), driven at varying rotation speeds (n) and, with stationary pump components, forming one or more displacement regions (11, 12), to which inlet openings (20) and outlet openings (33) lead;
the inlet openings (20) of each displacement region are connected to a supply system (17, 18) and the outlet openings (33) of each displacement region are connected to a pressure chamber (35);
the pressure chamber (35) and the supply system intercommunicate via a flow-regulating valve (40) which discharges an unregulated delivery flow into a discharge duct (19) associated with the supply system (17, 18), and which releases a regulated, usable flow (Q) to an external pump outlet (37); the flow-regulating valve (40) comprises a valve spool (41) which is guided in a valve bore (55), this valve spool (41) having a first spool face (53), which is subjected to relatively high pressure, and a second spool face (54), which is subjected to relatively low pressure, this flow-regulating valve (40) further comprising a valve spring (42) and a metering orifice (36) at which a a pressure drop associated with the regulated, usable flow (Q) is tapped off and supplied to the two faces (53,54) of the valve spool (41); the valve spool (41) has a prolongation (49), the position of this prolongation reducing the effective width of the metering orifice (36) as the pump rotation-speed (n) rises, thus generating a negative-slope portion of the usable flow versus pump rotation-speed characteristic, i.e. a portion that exhibits a negative slope overall, characterized in that the metering orifice (36) is formed on a bore (38) which constitutes the usable flow duct and extends in a generally radial orientation towards the flow-regulating valve (40), in that the said flow-duct bore (38) is separated from the associated discharge duct (19) by an axial distance (c) which, reckoned in the direction in which the valve spool (41) slides, is smaller than the width (b) of an annular space (52) that is formed on the valve spool (41), between the first spool face (53) and a third spool face (56); and in that the annular space (52) is connected to the pressure chamber (35) via a cavity (50) in the valve spool (41).
2. Hydraulic pump according to Claim 1, characterized in that the prolongation (49) associated with the valve spool (41) has an outside diameter (d2) that is smaller, by a small measured margin, than the diameter (di) of the valve bore (55) within the range over which this prolongation (49) moves.
3. Hydraulic pump according to Claim 2, characterized in that the small measured margin amounts to between 0.1 and 1 mm.
4. Hydraulic pump according to Claim 2, characterized in that the small measured margin amounts to between 0.2 and 0.7 mm.
5. Hydraulic pump according to any one of the preceding Claims, characterized in that the prolongation (49) is designed with a conical taper, its surface
(59) contracting in the direction towards the annular space (52).
6. Hydraulic pump according to any one of the preceding Claims, characterized in that the prolongation (49) has a spherical surface, sloping towards the annular space (52).
7. Hydraulic pump according to any one of the preceding Claims, characterized in that the annular space (52) continues in the form of a clearance at the outer periphery of the prolongation (49) associated with the valve spool (41).
EP19850105181 1985-04-27 1985-04-27 Hydraulic pump Expired EP0199833B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP19850105181 EP0199833B1 (en) 1985-04-27 1985-04-27 Hydraulic pump
DE8585105181T DE3564603D1 (en) 1985-04-27 1985-04-27 Hydraulic pump
CA000506074A CA1253771A (en) 1985-04-27 1986-04-08 Hydraulic pump
JP61095925A JPH0749797B2 (en) 1985-04-27 1986-04-26 Hydraulic pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19850105181 EP0199833B1 (en) 1985-04-27 1985-04-27 Hydraulic pump

Publications (2)

Publication Number Publication Date
EP0199833A1 EP0199833A1 (en) 1986-11-05
EP0199833B1 true EP0199833B1 (en) 1988-08-24

Family

ID=8193470

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19850105181 Expired EP0199833B1 (en) 1985-04-27 1985-04-27 Hydraulic pump

Country Status (4)

Country Link
EP (1) EP0199833B1 (en)
JP (1) JPH0749797B2 (en)
CA (1) CA1253771A (en)
DE (1) DE3564603D1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3623421A1 (en) * 1986-07-11 1988-01-14 Vickers Systems Gmbh STEERING PUMP
JPH0729267Y2 (en) * 1989-06-02 1995-07-05 株式会社ユニシアジェックス Vane pump
US5220939A (en) * 1991-05-21 1993-06-22 Koyo Seiko Co., Ltd. Flow control apparatus
WO1999067534A1 (en) * 1998-06-24 1999-12-29 Luk Fahrzeug-Hydraulik Gmbh & Co. Kg Hydraulic delivery device
AT520109B1 (en) * 2017-07-11 2019-09-15 Avl List Gmbh Reversible pump

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE619219C (en) * 1934-10-14 1935-09-27 Fortuna Werke Spezialmaschinen Adjustable throttle valve with flushing device
US2145533A (en) * 1936-07-06 1939-01-31 Caterpillar Tractor Co Fluid transfer mechanism
DE1108027B (en) * 1959-08-19 1961-05-31 Bosch Gmbh Robert Automatic control valve influenced by the flow rate of a pressure medium
US3033221A (en) * 1960-04-29 1962-05-08 Hough Co Frank Priority valve
US3185178A (en) * 1962-10-15 1965-05-25 Armand A Bonnard Cylindrical squeeze-type directional valve
JPS5838536B2 (en) * 1975-08-01 1983-08-23 帝人株式会社 Manufacturing method of polyester fiber material for rubber reinforcement
DE3033388A1 (en) * 1980-09-05 1982-04-22 Robert Bosch Gmbh, 7000 Stuttgart Multiposition multiway control valve for e.g. vehicle door actuator - has slide locking device in end position released only dependent on pressure
DE3211948C2 (en) * 1982-03-31 1984-07-26 Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen Control device for a positive displacement pump, in particular a vane pump

Also Published As

Publication number Publication date
JPH0749797B2 (en) 1995-05-31
JPS61250391A (en) 1986-11-07
CA1253771A (en) 1989-05-09
DE3564603D1 (en) 1988-09-29
EP0199833A1 (en) 1986-11-05

Similar Documents

Publication Publication Date Title
DE2938743C2 (en)
DE1528951C3 (en) Positive displacement pump for pumping a liquid that contains a lot of vapor and bubbles
DE4090852C2 (en) Power steering
DE1580479C3 (en) Hydraulic system
DE2328658C2 (en) Spool assembly
DE2441662B2 (en) Flow control valve
DE3313390A1 (en) OIL PUMP ARRANGEMENT
DE3327119A1 (en) AIR BEARING ARRANGEMENT FOR A DENTAL HANDPIECE
DE3237380C2 (en)
EP0199833B1 (en) Hydraulic pump
DE2124068A1 (en) Hydraulic regulating device, in particular for motor vehicles
WO1988001958A1 (en) Rotary gate valve for hydraulic servo-assisted steering systems
WO1993009349A1 (en) Vane cell pump
EP0151657A1 (en) Vane pump, especially for power steering
DE2838789C2 (en) Steering valve with closed center for actuating the servo motor of a vehicle power steering system
DE3303492C2 (en)
DE2418275A1 (en) PUMPING DEVICE
EP0509077B1 (en) Piston pump, especially a radial piston pump
DE2835816A1 (en) Rotary piston pump outwardly loads seal strips - by outlet pressure during part-revolution via ducts throttle-connected to inlet pressure
DE2402017A1 (en) ROTARY PISTON PUMPS, IN PARTICULAR FOR POWER STEERING IN MOTOR VEHICLES
DE3789189T2 (en) Fluid control and damped fluid path.
DE4235698C2 (en) Hydrostatic drive system
DE3211948C2 (en) Control device for a positive displacement pump, in particular a vane pump
DE2600918C2 (en) Control pump
DE3407827C2 (en) Diaphragm seal

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): DE FR GB IT SE

17P Request for examination filed

Effective date: 19861129

17Q First examination report despatched

Effective date: 19880209

ITF It: translation for a ep patent filed

Owner name: DE DOMINICIS & MAYER S.R.L.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT SE

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
REF Corresponds to:

Ref document number: 3564603

Country of ref document: DE

Date of ref document: 19880929

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
REG Reference to a national code

Ref country code: GB

Ref legal event code: 732

ITPR It: changes in ownership of a european patent

Owner name: CESSIONE;LUK FAHRZEUG - HIDRAULIK GMBH & CO. KG

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19940315

Year of fee payment: 10

EAL Se: european patent in force in sweden

Ref document number: 85105181.3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19950428

EUG Se: european patent has lapsed

Ref document number: 85105181.3

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20020328

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: 20020423

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: 20020503

Year of fee payment: 18

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 NON-PAYMENT OF DUE FEES

Effective date: 20030427

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: 20031101

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031231

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST