EP0012769B1 - Pressure raising hydropneumatic control device - Google Patents

Pressure raising hydropneumatic control device Download PDF

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Publication number
EP0012769B1
EP0012769B1 EP79900462A EP79900462A EP0012769B1 EP 0012769 B1 EP0012769 B1 EP 0012769B1 EP 79900462 A EP79900462 A EP 79900462A EP 79900462 A EP79900462 A EP 79900462A EP 0012769 B1 EP0012769 B1 EP 0012769B1
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EP
European Patent Office
Prior art keywords
piston
plunger
annular
cylinder
compressed air
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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
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EP79900462A
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German (de)
French (fr)
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EP0012769A1 (en
Inventor
Artur GRÜLLMEIER
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Individual
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Individual
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
    • F15B11/032—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force by means of fluid-pressure converters
    • F15B11/0325—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force by means of fluid-pressure converters the fluid-pressure converter increasing the working force after an approach stroke
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/16—Control arrangements for fluid-driven presses
    • B30B15/165—Control arrangements for fluid-driven presses for pneumatically-hydraulically driven presses
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
    • F15B2211/216—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being pneumatic-to-hydraulic converters
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/615—Filtering 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051—Linear output members
    • F15B2211/7053—Double-acting output members
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/775—Combined control, e.g. control of speed and force for providing a high speed approach stroke with low force followed by a low speed working stroke with high force, e.g. for a hydraulic press

Definitions

  • the invention relates to a pressure-translated hydropneumatic drive for rapid traverse and power stroke, in particular for driving punching tools, consisting of a cylinder housing with a transverse wall, a disc piston with a plunger, a working piston which can be pressurized with compressed air for return stroke and an annular piston comprising the plunger.
  • the cylinder spaces between the working piston and the annular piston on both sides of the transverse wall are filled with hydraulic oil.
  • the annular piston of the known drive Since the annular piston of the known drive is acted upon on one side with compressed air and on the other side with hydraulic oil, it has a special sealing arrangement, consisting of two sealing rings and a venting of the annular space between them. Experience has shown that this is unavoidable, since no seal is completely tight in the long run and air would therefore get into the hydraulic oil and foam it without venting the gap. The result of this would be that the desired force was not generated on the working piston and the drive could heat up excessively. However, since the ventilation opening in the cylinder housing does not move with the ring piston, the sealing rings must be moved apart by at least the stroke length of this piston. This entails an unfavorable extension of the entire cylinder housing of the drive according to US patent 3426530.
  • this known drive shows a complicated construction in that the plunger is a hollow body, into which a trunk-shaped extension of the cylinder end wall protrudes in a sealed manner.
  • a pressure-translated hydropneumatic drive of another type is known from US Pat. No. 4072013.
  • the working piston In order to move the working piston in rapid traverse, it has an annular surface which can be pressurized with compressed air in the feed direction. This will shorten the response time.
  • this known arrangement consumes a lot of drive compressed air, because compressed air is also applied to an annular piston surrounding the working piston and guided in its own cylinder housing.
  • the concentrically nested design of this known drive has significant manufacturing disadvantages, which also reveals the large number of individual parts required.
  • Such a drive consumes little drive compressed air per stroke, responds quickly, has a short overall length and is easy to manufacture.
  • the space containing the compression spring decreases and increases its volume with each work cycle during operation, air is expelled and sucked in again from the surroundings. This breathing process advantageously cools the drive.
  • the connection to the atmosphere is made via a filter.
  • the drawing shows a longitudinal section of a pressure-translated hydropneumatic drive with a working piston designed as a stepped piston.
  • the arrangement shown is composed of a high-pressure cylinder 1, in which a stepped working piston 2, which has a piston rod 3, can move, and a compressed-air cylinder 4, the cover 5 of which with the aid of several long clamping screws 6 distributed over the circumference with the high-pressure cylinder 1 is tense.
  • the compressed air cylinder 4 contains a disc piston 7, which is fixedly connected to a plunger 8, and an annular piston 9, which is sealed on the inside against the plunger and on the outside against the compressed air cylinder 4.
  • a compression spring 10 is clamped between the annular piston 9 and the disk piston 7.
  • the part of the compressed air cylinder interior in which this compression spring 10 is located is connected to the outside air via a filter 11.
  • the space between the annular piston 9 and the upper transverse wall 12 of the high-pressure cylinder is referred to as an oil reservoir 13, the space between the working piston 2 and this transverse wall as an oil chamber 14. Both are filled with hydraulic oil.
  • the transverse wall 12 In the transverse wall 12 there is an upwardly widening funnel-shaped opening 15 with a sealing ring which can be tightly closed by the plunger 8 going downwards.
  • the high-pressure cylinder 1 has two compressed air connections A and B.
  • the connection A is connected to the annular space 16 formed by the step, as a result of which an annular surface 16a of the working piston 2 can be acted upon.
  • the other compressed air connection B leads to the space 18 formed between the working piston 2 and a lower cover 17 of the high pressure cylinder.
  • the working piston 2 has an upwardly open central bore 19 for receiving the plunger 8, the diameter of this bore being significantly larger than the outside diameter of the Plungers 8 is.
  • the annular space 16 is connected via a connecting line 22 and a valve unit 23 to the space 24 between the disk piston 7 and the cover 5 of the compressed air cylinder.
  • the valve unit contains a pressure relief valve 25 that is only shown schematically and opens upward.
  • a quick exhaust valve 26 is provided in the valve unit, which establishes the connection between the connecting line 22 and the space 24 when pressure prevails in the connecting line 22 and the pressure relief valve 25 opens and which, on the other hand, allows the room 24 to be vented via an outlet 27 when the pressure in this connecting line 22 drops.
  • the quick exhaust valve 26 contains an up and down movable plate with a lip-like sealing edge.
  • the pressure relief valve 25 is connected in parallel as a bypass with a check valve which discharges the air pent up between the pressure relief valve 25 and the plate into the annular space 16, which in this phase is open to the outside.
  • the ring piston 9 stands still and the hydraulic oil in the oil chamber 14 is displaced by the penetration of the plunger 8, so that a very high pressure arises in the oil chamber, which the working piston 2 has the highest pressure Force moved down on his remaining commute.
  • the force generated corresponds essentially to the ratio of the cross section of the upper part of the working piston to the cross section of the plunger times the force exerted by the compressed air on the disk piston.
  • the compressed air continues to act on the annular surface 16a of the working piston 2.
  • the atmospheric air flowing in and out through the filter 11 is not compressed. It contributes significantly to cooling the arrangement, particularly in continuous operation.
  • the invention is implemented by a specific embodiment of a physical object, namely a piston-cylinder arrangement. It can therefore be exploited in particular through industrial production, through the sale or use of these objects and through the fact that the activities mentioned are permitted to third parties for a fee.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
  • Fluid-Damping Devices (AREA)

Abstract

For the hydropneumatic control of a fast motion and a driving travel, in particular for the control of stamping tools, there is provided a device comprising a cylinder (1, 4) provided with a transverse wall (12), a disc piston (7) with a plunger (8), a work piston (2) which may be actuated in a return direction by pressure air, and a ring-shaped piston (9) surrounding the plunger (8). The portions of the cylinder on either side of the transverse wall, between the work piston (2) and the ring-shaped piston (9) are filled with hydraulic fluid. In order to decrease the need for pressure air and to increase the reaction speed, as well as for simplification purposes, the work piston (2) is provided with an annular surface (16a) aimed at receiving pressure air which actuates said piston in the forward direction while, between the disc piston (7) and the annular piston (9), a pressure spring (10) is inserted. The part of the piston containing the spring (10) is permanently connected with the outside, preferably through a filter (11).

Description

Die Erfindung bezieht sich auf einen druckübersetzten hydropneumatischen Antrieb für Eilgang und Krafthub, insbesondere zum Antrieb von Stanzwerkzeugen, bestehend aus einem Zylindergehäuse mit Querwand, einem Scheibenkolben mit Plunger, einem zum Rückhub mit Druckluft beaufschlagbaren Arbeitskolben und einem den Plunger umfassenden Ringkolben. Die Zylinderräume zwischen dem Arbeitskolben und dem Ringkolben beiderseits der Querwand sind mit Hydrauliköl gefüllt.The invention relates to a pressure-translated hydropneumatic drive for rapid traverse and power stroke, in particular for driving punching tools, consisting of a cylinder housing with a transverse wall, a disc piston with a plunger, a working piston which can be pressurized with compressed air for return stroke and an annular piston comprising the plunger. The cylinder spaces between the working piston and the annular piston on both sides of the transverse wall are filled with hydraulic oil.

Zugrundeliegender Stand der Technik: US-A-3426530; US-A-4072013Prior Art: US-A-3426530; US-A-4072013

Bei einem aus der US-Patentschrift 3426530 bekannten Antrieb dieser Gattung wird beim Eilgang in den Raum zwischen dem Ringkolben und dem Scheibenkolben Druckluft eingeleitet. Dabei verschiebt der Ringkolben den Hydraulikölvorrat und bewegt mit dessen Hilfe den Arbeitskolben. Der erwähnte Raum ist gleichzeitig Hubraum des Scheibenkolbens beim Krafthub und stellt im Eilgang einen toten Luftraum dar, der verhältnismässig gross ist. Das hat die nachteilige Folge, dass beim Eilgang viel Antriebsdruckluft verbraucht wird. Auch erfordert der Druckauf- und -abbau in diesem grossen Raum eine verhältnismässig lange Zeit, was die Ansprechgeschwindigkeit dieses bekannten Antriebs herabsetzt. Dabei ist zu berücksichtigen, dass der Antriebsluftdruck des Eilgangs beim Kraufthub ganz abgebaut sein muss, da er der beginnenden Bewegung des Scheibenkolbens entgegenwirkt.In a drive of this type known from US Pat. No. 3,426,530, compressed air is introduced at rapid traverse into the space between the annular piston and the disk piston. The ring piston moves the hydraulic oil supply and moves the working piston with it. The space mentioned is also the displacement of the disk piston during the power stroke and represents a dead air space in the rapid traverse, which is relatively large. This has the disadvantageous consequence that a lot of drive compressed air is consumed in the rapid traverse. The pressure build-up and reduction in this large space requires a relatively long time, which reduces the response speed of this known drive. It must be taken into account that the drive air pressure of the rapid traverse must be completely reduced during the crank stroke, since it counteracts the incipient movement of the disc piston.

Da der Ringkolben des bekannten Antriebs auf einer Seite mit Druckluft und auf der anderen Seite mit Hydrauliköl beaufschlagt ist, weist er eine besondere Dichtungsanordnung auf, bestehend aus zwei Dichtungsringen und einer Entlüftung des dazwischen liegenden Ringraums. Dies ist erfahrungsgemäss unumgänglich, da keine Dichtung auf Dauer vollkommen dicht ist und deshalb ohne Belüftung des Zwischenraums Luft in das Hydrauliköl gelangen und dieses aufschäumen würde. Das hätte zur Folge, dass am Arbeitskolben die gewünschte Kraft nicht erzeugt werden und der Antrieb sich unzulässig erhitzen könnte. Da sich jedoch die Belüftungsöffnung im Zylindergehäuse nicht mit dem Ringkolben bewegt, müssen die Dichtungsringe um mindestens die Hublänge dieses Kolbens auseinandergerückt werden. Das bringt eine unvorteilhafte Verlängerung des ganzen Zylindergehäuses des Antriebs nach US-Patent 3426530 mit sich.Since the annular piston of the known drive is acted upon on one side with compressed air and on the other side with hydraulic oil, it has a special sealing arrangement, consisting of two sealing rings and a venting of the annular space between them. Experience has shown that this is unavoidable, since no seal is completely tight in the long run and air would therefore get into the hydraulic oil and foam it without venting the gap. The result of this would be that the desired force was not generated on the working piston and the drive could heat up excessively. However, since the ventilation opening in the cylinder housing does not move with the ring piston, the sealing rings must be moved apart by at least the stroke length of this piston. This entails an unfavorable extension of the entire cylinder housing of the drive according to US patent 3426530.

Schliesslich zeigt dieser bekannte Antrieb eine komplizierte Bauweise insofern, als der Plunger ein Hohlkörper ist, in den ein rüsselförmiger Ansatz der Zylinderstirnwand abgedichtet hineinragt.Finally, this known drive shows a complicated construction in that the plunger is a hollow body, into which a trunk-shaped extension of the cylinder end wall protrudes in a sealed manner.

Ein druckübersetzter hydropneumatischer Antrieb anderer Gattung ist aus der US-Patentschrift 4072013 bekannt. Um den Arbeitskolben im Eilgang zu bewegen weist dieser eine in Vorschubrichtung mit Druckluft beaufschlagbare Ringfläche auf. Hierdurch wird zwar die Ansprechzeit verkürzt. Diese bekannte Anordnung verbraucht aber viel Antriebsdruckluft, weil auch ein den Arbeitskolben umgebender, in einem eigenen Zylindergehäuse geführter Ringkolben mit Druckluft beaufschlagt wird. Im übrigen hat die konzentrisch verschachtelte Bauweise dieses bekannten Antriebs wesentliche fertigungstechnische Nachteile, was auch die grosse Zahl der erforderlichen Einzelteile erkennen lässt.A pressure-translated hydropneumatic drive of another type is known from US Pat. No. 4072013. In order to move the working piston in rapid traverse, it has an annular surface which can be pressurized with compressed air in the feed direction. This will shorten the response time. However, this known arrangement consumes a lot of drive compressed air, because compressed air is also applied to an annular piston surrounding the working piston and guided in its own cylinder housing. In addition, the concentrically nested design of this known drive has significant manufacturing disadvantages, which also reveals the large number of individual parts required.

Offenbarung der Erfindung:Disclosure of the Invention:

Die vorliegende Erfindung besteht darin, dass bei einem druckübersetzten hydropneumatischen Antrieb nach den Merkmalen a) bis g) des Anspruchs

  • - der Arbeitskolben eine in Vorschubrichtung mit Druckluft beaufschlagbare Ringfläche aufweist,
  • - zwischen dem Scheibenkolben und dem Ringkolben eine Druckfeder eingespannt ist und
  • - der die Druckfeder enthaltende Raum immer mit der Atmosphäre verbunden ist.
The present invention is that in a pressure-translated hydropneumatic drive according to features a) to g) of the claim
  • the working piston has an annular surface which can be pressurized with compressed air in the feed direction,
  • - A compression spring is clamped between the disc piston and the annular piston and
  • - The space containing the compression spring is always connected to the atmosphere.

Ein solcher Antrieb verbraucht wenig Antriebsdruckluft pro Hub, spricht schnell an, hat eine geringe Baulänge und ist einfach zu fertigen.Such a drive consumes little drive compressed air per stroke, responds quickly, has a short overall length and is easy to manufacture.

Eine wesentliche Verringerung des Druckluftverbrauchs ergibt sich zum einen aus dem Wegfall jeglichen toten Luftraumes und zum anderen aus dem Umstand, dass der Ringkolben gar nicht mehr mittels Druckluft angetrieben wird, sondern mittels der Druckfeder. Gleichzeitig ergibt sich eine Erhöhung der Ansprechgeschwindigkeit, d.h. eine Verkürzung des Zeitintervalls vom Startsignal bis zum Ende des Krafthubes, wozu vorteilhafterweise die Druckfeder beiträgt, denn der durch sie bewirkte Anfangsdruck im Ölspeicher unterstützt den pneumatischen Antrieb des Arbeitskolbens im Eilgang. Die bisher notwendige Doppeldichtung des Ringkolbens wird entbehrlich, da dieser nicht mehr mit Druckluft beaufschlagt ist. Vielmehr steht das Hydrauliköl wie erwähnt ständig unter Überdruck, so dass allenfalls Öl austreten, niemals aber Luft in das Öl gelangen kann. Der Wegfall der auf Abstand gesetzten Doppeldichtung erlaubt eine beträchtliche Verkürzung des Ringkolbens und damit des ganzen Zylindergehäuses. Schliesslich erreicht die Erfindung eine konstruktive Vereinfachung durch den Wegfall sowohl röhrenförmiger als auch mehrfach konzentrisch geschachtelter Elemente, was einen fühlbaren Fertigungs- und damit Preisvorteil ergibt.A significant reduction in compressed air consumption results on the one hand from the elimination of any dead air space and on the other hand from the fact that the annular piston is no longer driven by compressed air but by means of the compression spring. At the same time, the response speed increases, i.e. a shortening of the time interval from the start signal to the end of the power stroke, to which the compression spring advantageously contributes, because the initial pressure it causes in the oil reservoir supports the pneumatic drive of the working piston in rapid traverse. The previously required double seal of the ring piston is no longer necessary since it is no longer pressurized with compressed air. Rather, as mentioned, the hydraulic oil is constantly under pressure, so that at most oil can escape, but air can never get into the oil. The omission of the spaced double seal allows the ring piston and thus the entire cylinder housing to be considerably shortened. Finally, the invention simplifies the design by eliminating both tubular and multiply concentrically nested elements, which results in a tangible manufacturing and thus price advantage.

Da der die Druckfeder enthaltende Raum im Betrieb sein Volumen mit jedem Arbeitstakt verkleinert und wieder vergrössert, wird Luft ausgestossen und aus der Umgebung wieder eingesaugt. Dieser Atmungsvorgang bewirkt eine vorteilhafte Kühlung des Antriebs. Um den Luftströmungswiderstand gering zu halten und das Eindringen von Staub und Fremdkörpern in den Raum zu verhindern, wird in Weiterbildung der Erfindung vorgeschlagen, dass die Verbindung zur Atmosphäre über ein Filter erfolgt.Since the space containing the compression spring decreases and increases its volume with each work cycle during operation, air is expelled and sucked in again from the surroundings. This breathing process advantageously cools the drive. In order to keep the air flow resistance low and to prevent dust and foreign bodies from entering the room, it is proposed in a further development of the invention that the connection to the atmosphere is made via a filter.

Kurze Beschreibung der Zeichnung:Brief description of the drawing:

Die Zeichnung stellt einen Längsschnitt eines druckübersetzten hydropneumatischen Antriebes mit einem als Stufenkolben ausgebildeten Arbeitskolben dar.The drawing shows a longitudinal section of a pressure-translated hydropneumatic drive with a working piston designed as a stepped piston.

Bester Weg zur Ausführung der Erfindung:Best way to carry out the invention:

Die dargestellte Anordnung setzt sich zusammen aus einem Hochdruckzylinder 1, in dem sich ein gestufter Arbeitskolben 2, der eine Kolbenstange 3 aufweist, bewegen kann, und einem Druckluftzylinder 4, dessen Deckel 5 mit Hilfe mehrerer über den Umfang verteilter langer Spannschrauben 6 mit dem Hochdruckzylinder 1 verspannt ist. Der Druckluftzylinder 4 enthält einen Scheibenkolben 7, der mit einem Plunger 8 fest verbunden ist, und einen Ringkolben 9, der innen gegenüber dem Plunger und aussen gegenüber dem Druckluftzylinder 4 abgedichtet ist. Zwischen dem Ringkolben 9 und dem Scheibenkolben 7 ist eine Druckfeder 10 eingespannt. Der Teil des Druckluftzylinder-Innenraumes, in dem sich diese Druckfeder 10 befindet, steht über ein Filter 11 mit der Aussenluft in Verbindung. Der Raum zwischen dem Ringkolben 9 und der oberen Querwand 12 des Hochdruckzylinders wird als Ölspeicher 13 bezeichnet, der Raum zwischen dem Arbeitskolben 2 und dieser Querwand als Ölkammer 14. Beide sind mit Hydrauliköl gefüllt. In der Querwand 12 befindet sich eine nach oben trichterförmig aufgeweitete Durchtrittsöffnung 15 mit Dichtring, welche von dem nach unten gehenden Plunger 8 dicht verschlossen werden kann.The arrangement shown is composed of a high-pressure cylinder 1, in which a stepped working piston 2, which has a piston rod 3, can move, and a compressed-air cylinder 4, the cover 5 of which with the aid of several long clamping screws 6 distributed over the circumference with the high-pressure cylinder 1 is tense. The compressed air cylinder 4 contains a disc piston 7, which is fixedly connected to a plunger 8, and an annular piston 9, which is sealed on the inside against the plunger and on the outside against the compressed air cylinder 4. A compression spring 10 is clamped between the annular piston 9 and the disk piston 7. The part of the compressed air cylinder interior in which this compression spring 10 is located is connected to the outside air via a filter 11. The space between the annular piston 9 and the upper transverse wall 12 of the high-pressure cylinder is referred to as an oil reservoir 13, the space between the working piston 2 and this transverse wall as an oil chamber 14. Both are filled with hydraulic oil. In the transverse wall 12 there is an upwardly widening funnel-shaped opening 15 with a sealing ring which can be tightly closed by the plunger 8 going downwards.

Der Hochdruckzylinder 1 hat zwei Druckluftanschlüsse A und B. Der Anschluss A steht mit dem durch die Stufe gebildeten Ringraum 16 in Verbindung, wodurch eine Ringfläche 16a des Arbeitskolbens 2 beaufschlagt werden kann. Der andere Druckluftanschluss B führt zu dem zwischen dem Arbeitskolben 2 und einem unteren Deckel 17 des Hochdruckzylinders gebildeten Raum 18. Der Arbeitskolben 2 hat eine nach oben offene zentrale Bohrung 19 zur Aufnahme des Plungers 8, wobei der Durchmesser dieser Bohrung deutlich grösser als der Aussendurchmesser des Plungers 8 ist.The high-pressure cylinder 1 has two compressed air connections A and B. The connection A is connected to the annular space 16 formed by the step, as a result of which an annular surface 16a of the working piston 2 can be acted upon. The other compressed air connection B leads to the space 18 formed between the working piston 2 and a lower cover 17 of the high pressure cylinder. The working piston 2 has an upwardly open central bore 19 for receiving the plunger 8, the diameter of this bore being significantly larger than the outside diameter of the Plungers 8 is.

Die eventuell nach längerem Betrieb eintretende geringe Leckage der Medien Luft und Öl wird über eine Ringnut und eine Längsbohrung 20 im Arbeitskolben 2 und dessen Kolbenstange 3 nach aussen abgeführt. Über einen am Hochdruckzylinder 1 angebrachten Nippel 21 kann jederzeit Hydrauliköl in den Ölspeicher 13 nachgefülltwerden.The slight leakage of the media air and oil that may occur after prolonged operation is discharged to the outside via an annular groove and a longitudinal bore 20 in the working piston 2 and its piston rod 3. Hydraulic oil can be refilled into the oil reservoir 13 at any time via a nipple 21 attached to the high-pressure cylinder 1.

Der Ringraum 16 ist über eine Verbindungsleitung 22 und eine Ventileinheit 23 mit dem Raum 24 zwischen dem Scheibenkolben 7 und dem Dekkel 5 des Druckluftzylinders verbunden. Die Ventileinheit enthält ein nur schematisch dargestelltes, nach oben öffnendes Überdruckventil 25. Ferner ist in der Ventileinheit ein Schnellentlüftungsventil 26 vorgesehen, welches die Verbindung zwischen der Verbindungsleitung 22 und dem Raum 24 herstellt, wenn in der Verbindungsleitung 22 Druck herrscht und das Überdruckventil 25 öffnet und welches andererseits bei Druckabfall in dieser Verbindungsleitung 22 die Entlüftung des Raumes 24 über einen Auslass 27 ermöglicht. Das Schnellentlüftungsventil 26 enthält ein auf- und abbewegliches Plättchen mit einem lippenartigen Dichtrand. Damit dieses Plättchen beim Rücklauf des Scheibenkolbens nach unten zurückweichen kann, ist dem Überdruckventil 25 als Bypass ein Rückschlagventil parallel geschaltet, welches die zwischen dem Überdruckventif 25 und dem Plättchen aufgestaute Luft in den Ringraum 16 abführt, der in dieser Phase ins Freie geöffnet ist.The annular space 16 is connected via a connecting line 22 and a valve unit 23 to the space 24 between the disk piston 7 and the cover 5 of the compressed air cylinder. The valve unit contains a pressure relief valve 25 that is only shown schematically and opens upward. Furthermore, a quick exhaust valve 26 is provided in the valve unit, which establishes the connection between the connecting line 22 and the space 24 when pressure prevails in the connecting line 22 and the pressure relief valve 25 opens and which, on the other hand, allows the room 24 to be vented via an outlet 27 when the pressure in this connecting line 22 drops. The quick exhaust valve 26 contains an up and down movable plate with a lip-like sealing edge. So that this plate can move backwards when the disc piston returns, the pressure relief valve 25 is connected in parallel as a bypass with a check valve which discharges the air pent up between the pressure relief valve 25 and the plate into the annular space 16, which in this phase is open to the outside.

Der beschriebene Antrieb wirkt wie folgt: In der gezeigten Ruhestellung ist der untere Druckluftanschluss B mit Druckluft beaufschlagt. Der Arbeitskolben 2 steht infolgedessen in seiner oberen Stellung. Ebenso wird der Scheibenkolben 7 von der Druckfeder 10 in seiner oberen Stellung gehalten.The drive described works as follows: In the rest position shown, the lower compressed air connection B is pressurized with compressed air. As a result, the working piston 2 is in its upper position. Likewise, the disc piston 7 is held in its upper position by the compression spring 10.

Für den Eilgang wird der obere Druckluftanschluss A und damit die Ringfläche 16a beaufschlagt, während der Raum 18 entlüftet wird. Dadurch bewegt sich der Arbeitskolben 2 nach unten. Gleichzeitig drückt der Ringkolben 9 unter der Wirkung der Druckfeder 10 durch die geöffnete Durchtrittsöffnung 15 Hydrauliköl aus dem Ölspeicher 13 in die Ölkammer 14. Dieses Hydrauliköl drückt ebenfalls in Vorschubrichtung auf den Arbeitskolben 2.For the rapid traverse, the upper compressed air connection A and thus the annular surface 16a are acted upon, while the space 18 is vented. As a result, the working piston 2 moves downward. At the same time, the annular piston 9 presses hydraulic oil from the oil reservoir 13 into the oil chamber 14 through the open passage opening 15 under the action of the compression spring 10. This hydraulic oil also presses on the working piston 2 in the feed direction.

Stösst der Arbeitskolben 2 nun auf Widerstand, so baut sich in dem Ringraum 16 ein Druck auf, der das Überdruckventil 25 öffnet, so dass die Druckluft den Scheibenkolben 7 mit dem Plunger 8 gegen die Kraft der Druckfeder 10 nach unten bewegt.If the working piston 2 now encounters resistance, a pressure builds up in the annular space 16, which opens the pressure relief valve 25, so that the compressed air moves the disk piston 7 with the plunger 8 downward against the force of the compression spring 10.

Sobald der Plunger 8 die Durchtrittsöffnung 15 und deren Dichtring durchfährt, steht der Ringkolben 9 still und das Hydrauliköl in der Ölkammer 14 wird durch das Eindringen des Plungers 8 verdrängt, so dass in der Ölkammer ein sehr hoher Druck entsteht, der den Arbeitskolben 2 mit höchster Kraft auf seinem restlichen Arbeitsweg nach unten bewegt. Die entstehende Kraft entspricht im wesentlichen dem Verhältnis des Querschnitts des oberen Teils des Arbeitskolbens zum Querschnitt des Plungers mal der von der Druckluft auf den Scheibenkolben ausgeübten Kraft. Zusätzlich wirkt die Druckluft nach wie vor auf die Ringfläche 16a des Arbeitskolbens 2.As soon as the plunger 8 passes through the passage opening 15 and its sealing ring, the ring piston 9 stands still and the hydraulic oil in the oil chamber 14 is displaced by the penetration of the plunger 8, so that a very high pressure arises in the oil chamber, which the working piston 2 has the highest pressure Force moved down on his remaining commute. The force generated corresponds essentially to the ratio of the cross section of the upper part of the working piston to the cross section of the plunger times the force exerted by the compressed air on the disk piston. In addition, the compressed air continues to act on the annular surface 16a of the working piston 2.

Ist der Krafthub beendet, so wird die Druckluft wieder auf den Anschluss B umgeschaltet und der Arbeitskolben 2 in seine Ausgangsstellung zurückgedrückt. Gleichzeitig schiebt der oberhalb des Arbeitskolbens entstehende Öldruck den Plunger 8 zurück, wobei die Druckfeder 10 mitwirkt. Das schliesslich aus der Ölkammer 14 ausgestossene Öl wird vom Ölspeicher 13, der durch die Druckfeder 10 vorgespannt ist, luftblasenfrei aufgenommen.When the power stroke has ended, the compressed air is switched back to port B and the working piston 2 is pushed back into its starting position. At the same time, the oil pressure that arises above the working piston pushes back the plunger 8, with the compression spring 10 cooperating. The oil finally ejected from the oil chamber 14 is taken up by the oil reservoir 13, which is prestressed by the compression spring 10, without air bubbles.

Die durch das Filter 11 ein- und ausströmende atmosphärische Luft wird nicht komprimiert. Sie trägt besonders bei Dauerbetrieb wesentlich zur Kühlung der Anordnung bei.The atmospheric air flowing in and out through the filter 11 is not compressed. It contributes significantly to cooling the arrangement, particularly in continuous operation.

Nur als Beispiel werden nachfolgend die wichtigsten technischen Daten eines Prototyps eines solchen Antriebes gegeben: Pneumatischer Betriebsdruck 6 Bar, Eilgangkraft 430 kp, Arbeitskraft 10.000 kp, Rückzugskraft 780kp, Gesamthub 30mm, Arbeitshub 6mm, Hubzahl 40/min., Bauhöhe insgesamt 500mm. In Anbetracht der hohen Arbeitskraft ist der Luftverbrauch mit 1,81 Druckluft, entsprechend 10,81 angesaugter Luft je Hub, ausserordentlich gering. Hinzuweisen ist auch auf das optimale Verhältnis der Kräfte zueinander im Hinblick auf die Anwendung in der Stanzereitechnik, wo die Rückzugskraft des Arbeitskolbens im Verhältnis zur Arbeitskraft nicht zu klein sein darf.The most important technical data of a prototype of such a drive are given below as an example: Pneumatic operating pressure 6 bar, rapid traverse force 430 kp, work force 10,000 kp, retraction force 780kp, total stroke 30mm, working stroke 6mm, stroke rate 40 / min., Overall height 500mm. Given the high The labor force is the air consumption with 1.81 compressed air, corresponding to 10.81 intake air per stroke, extremely low. It is also important to note the optimal ratio of the forces to one another with regard to their use in stamping technology, where the retraction force of the working piston must not be too small in relation to the worker.

Gewerbliche Verwertbarkeit:Commercial usability:

Die Erfindung wird durch eine bestimmte Ausgestaltung eines körperlichen Gegenstandes, nämlich einer Kolben-Zylinder-Anordnung, verwirklicht. Sie ist daher durch insbesondere industrielle Herstellung, durch Verkauf oder Benutzung dieser Gegenstände sowie dadurch gewerblich verwertbar, dass die erwähnten Tätigkeiten Dritten gegen Entgelt gestattet werden.The invention is implemented by a specific embodiment of a physical object, namely a piston-cylinder arrangement. It can therefore be exploited in particular through industrial production, through the sale or use of these objects and through the fact that the activities mentioned are permitted to third parties for a fee.

Claims (2)

1. Boosted hydro-pneumatic drive for rapid traverse and power stroke, particularly for driving punching tools, having the following features:
a) a cylinder housing is provided with two sections separated from each other by a partition (12);
b) in the first cylinder section a pneumatically loadable disc piston (7), carrying a plunger (8) of small diameter, is supported in a sealed manner;
c) the plunger (8) can penetrate through the partition (12) in a sealed manner after a predetermined stroke;
d) in the second cylinder section a working piston (?) with a piston rod leading outwards in arranged;
e) for the return stroke the working piston (2) can be loaded with compressed air on the side of the piston rod;
f) in the first cylinder section an annular piston (9) surrounding the plunger (8) is provided and
g) the cylinder spaces (13, 14) on both sides of the partition (12), limited by the working piston (2) and by the annular piston (9), are filled with hydraulic oil;

characterized by the following features:
h) the working piston (2) is provided with an annular surface (16a) which can be loaded with compressed air in the direction of advance;
i) a compression spring (10) is clamped between the disc piston (7) and the annular piston (9) and
j) the space containing the compression spring (10) is always connected to the atmosphere.
2. Drive according to Claim 1, characterized in that the connection to the atmosphere is made via a filter (11).
EP79900462A 1978-04-26 1979-12-05 Pressure raising hydropneumatic control device Expired EP0012769B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2818337 1978-04-26
DE2818337A DE2818337C2 (en) 1978-04-26 1978-04-26 Hydropneumatic pressure intensifier

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EP0012769A1 EP0012769A1 (en) 1980-07-09
EP0012769B1 true EP0012769B1 (en) 1983-02-23

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US (1) US4300351A (en)
EP (1) EP0012769B1 (en)
AT (1) AT380542B (en)
CH (1) CH640312A5 (en)
DD (1) DD143296A5 (en)
DE (1) DE2818337C2 (en)
GB (1) GB2055972B (en)
IT (1) IT1112714B (en)
SE (1) SE433650B (en)
WO (1) WO1979000986A1 (en)

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Also Published As

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DD143296A5 (en) 1980-08-13
US4300351A (en) 1981-11-17
IT7922103A0 (en) 1979-04-24
GB2055972A (en) 1981-03-11
AT380542B (en) 1986-06-10
SE433650B (en) 1984-06-04
CH640312A5 (en) 1983-12-30
DE2818337B1 (en) 1979-10-18
EP0012769A1 (en) 1980-07-09
IT1112714B (en) 1986-01-20
GB2055972B (en) 1982-08-18
DE2818337C2 (en) 1980-07-17
WO1979000986A1 (en) 1979-11-29
ATA301279A (en) 1985-10-15
SE7910518L (en) 1979-12-20

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