EP0027654A1 - Concrete pump with hydraulically relieved slide valve - Google Patents

Concrete pump with hydraulically relieved slide valve Download PDF

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Publication number
EP0027654A1
EP0027654A1 EP19800106348 EP80106348A EP0027654A1 EP 0027654 A1 EP0027654 A1 EP 0027654A1 EP 19800106348 EP19800106348 EP 19800106348 EP 80106348 A EP80106348 A EP 80106348A EP 0027654 A1 EP0027654 A1 EP 0027654A1
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European Patent Office
Prior art keywords
concrete
slide
control
connections
main control
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EP19800106348
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German (de)
French (fr)
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Karl Schlecht
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B7/00—Piston machines or pumps characterised by having positively-driven valving
    • F04B7/02—Piston machines or pumps characterised by having positively-driven valving the valving being fluid-actuated
    • F04B7/0233—Piston machines or pumps characterised by having positively-driven valving the valving being fluid-actuated a common distribution member forming a single discharge distributor for a plurality of pumping chambers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
    • F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
    • F04B9/10—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid
    • F04B9/109—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers
    • F04B9/117—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other
    • F04B9/1176—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other the movement of each piston in one direction being obtained by a single-acting piston liquid motor
    • F04B9/1178—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other the movement of each piston in one direction being obtained by a single-acting piston liquid motor the movement in the other direction being obtained by a hydraulic connection between the liquid motor cylinders

Definitions

  • the invention relates to a concrete pump with a hydraulically relieved slide valve according to the preamble of claim 1.
  • Such concrete pumps operate according to the so-called single-circuit control system because they are supplied by only one hydraulic pump.
  • DE-PS 2 441 831 describes a circuit in which the main control slide of the drive cylinder for the concrete delivery pistons has a spring-centered central position. With this circuit, the hydraulic connections of the concrete delivery cylinders are connected to each other and to the high-pressure connection at the same time, with the aim of relieving the pressure on the concrete slide during the switching process. The concrete delivery pistons come into the floating position, ie they briefly withdraw from the high pressure in the concrete line. This immediately relieves the load on the concrete slide valve and can then switch through with little effort and less friction and wear.
  • the object of the invention is to relieve the concrete shoot bers by ensuring a more effective floating position of the concrete delivery pistons.
  • this circuit brings about a real relief of the concrete slide valve during the reversing process while avoiding the disadvantages described above.
  • One is largely independent of the effects of the preload in the closed circuit and the more or less good centering effect of the centering spring in the main spool.
  • FIG. 1 shows a first embodiment of the circuit with a single drive cylinder for the concrete slide
  • Fig. 2 shows a second embodiment of the circuit with two drive cylinders for the concrete slide.
  • the control piston in the main control slide 11 moves hydraulically pushed out of its end position in the direction of the middle position. It can be assumed that the concrete slide can not be moved because it is clamped by the concrete pressure. However, as soon as the main hydraulic control piston in the main control slide 11 begins to plunge into its long central position 44, 43, 45, a connection of the connections of the concrete delivery cylinders to the low pressure line 10 enables the concrete delivery pistons 15, 16 to withdraw from the concrete pressure and thus a concrete pressure Bring relief.
  • two individual cylinders 31, 32 can also be used in a known manner, as shown in FIG. 2.
  • An additional switching pulse then occurs through lines 33, 34, which runs parallel to that of chokes 18, 19.
  • the throttles 18, 19 can initiate the switching operation of the main control slide 11 with a small opening. If the concrete slide valve switches through very quickly and without resistance due to the action of the drive cylinder 31, 32 with occasional low friction or low concrete pressure, after reaching the end position through the lines 33, 34, a step-by-pulse becomes parallel to that of the throttles 18, 19 given. In this way, an unnecessary increase in pressure and a waiting time for the hydraulic pump 3, and thus also the occurrence of pressure surges and energy loss, are avoided.
  • the check valves 37, 38 can optionally be used in the control lines 33, 34 are switched on in order to discharge the control pressure coming from the throttles 18, 19 through the drive cylinders 31, 32 of the concrete slide valve 39 to the tank 36, or, if there is no tank connection in the line 35, to the other cylinder side avoid.
  • these check valves 37, 38 can be omitted if the main control slide 11 also receives, as is known, additional centering springs. Then the lines 33, 34 are connected to the line 35 to the tank 36 while the drive cylinder 31, 32 of the concrete slide 39 is switched through. This allows a particularly soft switching setting for certain operating conditions and also allows large, dirt-resistant openings in the throttles 18, 19.
  • These throttles 18, 19 can both be adjustable, optionally only one adjustable and the other permanently adjustable.
  • the throttles 47, 48 in the rod-side connecting line 35 of the drive cylinders 31, 32 can cause a similarly rapid connection of the main control spool 11 by backwater in the rod space of these cylinders with exceptionally rapid switching of the concrete slide 39. This favors smooth running of the machine, smooth switching of the concrete slide and automatic, internal compensation of the control speeds with varying oil consistency as a result of temperature fluctuations, or even if the delivery rate of the hydraulic pump 3 changes significantly.
  • the reversing switching pulse can run in a known manner instead of the mechanical design via the rocker switch 14 and the reversing slide 13 also via electrical or hydraulic switching pulses which originate directly from the drive cylinder 1, be it through piston rod grooves or control bores on the cylinder jacket.
  • Such designs are known and can be operated as desired Conditions and conditions of use for the thick matter pump in question are used in connection with the subject matter of the invention.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)

Abstract

In order to connect the concrete slide valve through with low expenditure of force, the main control slide valve (11) has a central position (43, 44, 45) which is long relative to the travel of its actuating piston and in which the connections (23, 24) of the working cylinders (1) of the concrete delivery pistons are connected to the low pressure or tank connection (10) of the hydraulic circuit. <IMAGE>

Description

Die Erfindung betrifft eine Betonpumpe mit hydraulisch entlastetem Schieber nach dem Gattungsbegriff des Patentanspruchs 1. Solche Betonpumpen arbeiten nach der sogenannten Einkreissteuerung, weil sie von nur einer Hydropumpe versorgt werden.The invention relates to a concrete pump with a hydraulically relieved slide valve according to the preamble of claim 1. Such concrete pumps operate according to the so-called single-circuit control system because they are supplied by only one hydraulic pump.

Bei solchen Pumpen tritt der Nachteil auf, daß der hydraulisch betätigte Betonschieber beim Umschaltvorgang unter hohem Betondruck steht und deshalb stark angepresst wird. Dies erfordert hohe Schaltkräfte infolge hoher Reibung und verursacht hohen Verschleiß. Eine zu hohe Reibung vermag gelegentlich eine Durchschaltung sogar gänzlich unmöglich zu machen. In der DE-PS 2 441 831 wird eine Schaltung beschrieben, bei welcher der Hauptsteuerschieber der Antriebszylinder für die Betonförderkolben eine federzentrierte Mittelstellung aufweist. Bei dieser Schaltung werden die Hydroanschlüsse der Betonförderzylinder gleichzeitig miteinander und mit dem Hochdruckanschluß verbunden, mit dem Ziel, eine Entlastung des Betonschiebers beim Umschaltvorgang zu bewirken. Dabei kommen die Betonförderkolben in Schwimmstellung, d.h. sie weichen vor dem in der Betonleitung stehenden hohen Druck kurzfristig zurück. Dadurch wird der Betonschieber augenblicklich entlastet und kann dann mit geringem Kraftaufwand und weniger Reibung und Verschleiß durchschalten.The disadvantage of such pumps is that the hydraulically operated concrete slide valve is under high concrete pressure during the switching process and is therefore strongly pressed. This requires high shifting forces due to high friction and causes high wear. Excessive friction can even make switching through completely impossible. DE-PS 2 441 831 describes a circuit in which the main control slide of the drive cylinder for the concrete delivery pistons has a spring-centered central position. With this circuit, the hydraulic connections of the concrete delivery cylinders are connected to each other and to the high-pressure connection at the same time, with the aim of relieving the pressure on the concrete slide during the switching process. The concrete delivery pistons come into the floating position, ie they briefly withdraw from the high pressure in the concrete line. This immediately relieves the load on the concrete slide valve and can then switch through with little effort and less friction and wear.

In der Praxis hat sich gezeigt, daß die mit der vorgenannten Schaltung bewirkte Entlastung nicht unter allen Voraussetzungen zuverlässig eintritt. Dadurch, daß die Anschlüsse der Betonförderzylinder mit dem Hochdruckanschluß in Verbindung stehen, werden die Dichtungen der Kolbenstangen in den Betonförderzylindern stark angepresst. Die dadurch bedingte hohe Reibung verhindert weitgehend die Schwimmstellung. Außerdem sind die Rückstellfedern der Federmittelzentrierung im Hauptschieber bei hohen Drücken nur selten in der Lage, eine Federzentrierung herbeizuführen, insbesondere wenn in geschlossenem, vorgespanntem Hydrokreis gearbeitet wird.In practice it has been shown that the relief caused by the aforementioned circuit does not occur reliably under all conditions. Because the connections of the concrete delivery cylinders are connected to the high-pressure connection, the seals of the piston rods in the concrete delivery cylinders are strongly pressed. The resulting high friction largely prevents the floating position. In addition, the return springs of the spring centering in the main slide at high pressures are rarely able to bring about spring centering, especially when working in a closed, preloaded hydraulic circuit.

Aufgabe der Erfindung ist es, die Entlastung des Betonschiebers durch zuverlässige Herbeiführung einer wirkungsvolleren Schwimmstellung der Betonförderkolben sicherzustellen.The object of the invention is to relieve the concrete shoot bers by ensuring a more effective floating position of the concrete delivery pistons.

Diese Aufgabe wird mit den Merkmalen des kennzeichnenden Teils des Patentanspruchs 1 gelöst.This object is achieved with the features of the characterizing part of patent claim 1.

Gegenüber den bekannten Schaltungen bewirkt diese Schaltung eine echte Entlastung des Betonschiebers während des Umsteuervorgangs unter Vermeidung der oben geschilderten Nachteile. Dabei ist man von den Wirkungen der Vorspannung im geschlossenen Kreislauf und der mehr oder weniger guten Mittelzentrierwirkung der Zentrierfeder im Hauptsteuerschieber weitgehend unabhängig.Compared to the known circuits, this circuit brings about a real relief of the concrete slide valve during the reversing process while avoiding the disadvantages described above. One is largely independent of the effects of the preload in the closed circuit and the more or less good centering effect of the centering spring in the main spool.

Dies ist nicht nur dadurch gewährleistet, daß die Stopfbuchspackungen durch Beaufschlagung mit Niederdruck praktisch keine Reibung mehr auf die Kolbenstange ausüben, sondern auch dadurch, daß die Schwimmstellung im Verhältnis zur kurzen Überdeckungsphase des Hauptsteuerschiebers in seinen Endlagen besonders lang ist.This is ensured not only by the fact that the stuffing box packings practically no longer exert any friction on the piston rod due to the application of low pressure, but also by the fact that the floating position is particularly long in its end positions in relation to the short overlap phase of the main control spool.

In der Zeichnung sind in schematischer Weise zwei Ausführungsbeispiele der erfindungsgemäßen Schaltung dargestellt. Es zeigenIn the drawing, two exemplary embodiments of the circuit according to the invention are shown in a schematic manner. Show it

Fig. 1 ein erstes Ausführungsbeispiel der Schaltung mit einem einzigen Antriebszylinder für den Betonschieber,1 shows a first embodiment of the circuit with a single drive cylinder for the concrete slide,

Fig. 2 ein zweites Ausführungsbeispiel der Schaltung mit zwei Antriebszylindern für den Betonschieber.Fig. 2 shows a second embodiment of the circuit with two drive cylinders for the concrete slide.

Wird der Umsteuerimpuls der Betonförderkolben 15,16 in der jeweiligen Endlage der Kolben der Antriebszylinder 1 erreicht, dann bewegt sich der Steuerkolben im Hauptsteuerschieber 11 hydraulisch geschoben aus seiner Endlage in Richtung auf die Mittelstellung. Dabei kann vorausgesetzt werden, daß der Betonschieber noch nicht bewegt werden kann, weil er vom Betondruck festgeklemmt ist. Sobald jedoch der Haupthydraulik-Steuerkolben im Hauptsteuerschieber 11 in seine lange Mittelstellung 44,43,45 einzutauchen beginnt, wird durch eine Verbindung der Anschlüsse der Betonförderzylinder mit der Niederdruckleitung 10 ermöglicht, daß die Betonförderkolben 15,16 vor dem Betondruck zurückweichen und so eine Betondruck-Entlastung herbeiführen. Gleichzeitig wird durch Absperren des Hochdruckanschlusses der volle Druck und die volle Fördermenge der Hydropumpe 3 auf den Antriebszylinder 2 des Betonschiebers angestaut und dieser mit voller Kraft in die andere Endlage gedrückt. Dieser Duchsteuervorgang benötigt eine gewisse Zeit, die aufgrund der langen Mittelstellung 44,43,45 des Steuerkolbens im Hauptsteuerschieber 11 zur Verfügung steht. Der Steuerkolben hält über seinen infolge der Wirkung der Drosseln 18,19 gleichmäßig durchlaufenen Schaltweg die Kolben der Betonförderzylinder sehr lange in Schwimmstellung und zwar nach der Niederdruckseite bzw. dem Tank hin entlastet. Die Folge ist, daß die Anpressung der Stopfbuchsen in den Antriebszylindern 1 für die Betonförderkolben entfällt und sich die Kolbenstangen der Antriebszylinder und der Betonförderzylinder frei schwimmend ohne Reibung bewegen können.If the reversal impulse of the concrete delivery pistons 15, 16 is reached in the respective end position of the pistons of the drive cylinder 1, then the control piston in the main control slide 11 moves hydraulically pushed out of its end position in the direction of the middle position. It can be assumed that the concrete slide can not be moved because it is clamped by the concrete pressure. However, as soon as the main hydraulic control piston in the main control slide 11 begins to plunge into its long central position 44, 43, 45, a connection of the connections of the concrete delivery cylinders to the low pressure line 10 enables the concrete delivery pistons 15, 16 to withdraw from the concrete pressure and thus a concrete pressure Bring relief. At the same time, by shutting off the high-pressure connection, the full pressure and the full delivery rate of the hydraulic pump 3 are accumulated on the drive cylinder 2 of the concrete slide valve and this is pressed with full force into the other end position. This control process takes a certain amount of time, which is available in the main control slide 11 due to the long central position 44, 43, 45 of the control piston. The control piston keeps the pistons of the concrete delivery cylinder in the floating position for a very long time, namely after the low-pressure side or the tank, is relieved via its switching path, which is evenly traversed due to the action of the throttles 18, 19. The The consequence is that the pressure of the glands in the drive cylinders 1 for the concrete delivery pistons is eliminated and the piston rods of the drive cylinders and the concrete delivery cylinders can move freely floating without friction.

Anstelle des Antriebszylinders 2 für den Betonschieber können auch, wie in Fig. 2 dargestellt, zwei Einzelzylinder 31,32 in bekannter Weise verwendet werden. Sie können in der Endschaltstellung am Zylindermantel auf bekannte Weise eine Steuerbohrung aufweisen, welche vom Kolben nach Erreichen der neuen Endlage des Betonschiebers überfahren wird. Danach entsteht ein zusätzlicher Schaltimpuls durch die Leitungen 33,34, der parallel zu jenem der Drosseln 18, 19 verläuft. Die Drosseln 18,19 können bei geringer Öffnung den Durchschaltvorgang des Hauptsteuerschiebers 11 einleiten. Wenn dann der Betonschieber durch die Wirkung der Antriebszylinder 31,32 bei gelegentlich geringer Reibung bzw. geringem Betondruck sehr schnell und ohne Widerstand durchschaltet, wird nach Erreichen der Endlage durch die Leitungen 33,34 ein Weiterschalt-Impuls parallel zu jenem der Drosseln 18,19 gegeben. Auf diese Weise wird ein unnötiger Druckanstieg und eine Wartezeit für die Hydropumpe 3, und damit auch das Auftreten von Druckschlägen und Energieverlust vermieden.Instead of the drive cylinder 2 for the concrete slide valve, two individual cylinders 31, 32 can also be used in a known manner, as shown in FIG. 2. You can have a control bore in the end switch position on the cylinder jacket in a known manner, which is overrun by the piston after reaching the new end position of the concrete slide. An additional switching pulse then occurs through lines 33, 34, which runs parallel to that of chokes 18, 19. The throttles 18, 19 can initiate the switching operation of the main control slide 11 with a small opening. If the concrete slide valve switches through very quickly and without resistance due to the action of the drive cylinder 31, 32 with occasional low friction or low concrete pressure, after reaching the end position through the lines 33, 34, a step-by-pulse becomes parallel to that of the throttles 18, 19 given. In this way, an unnecessary increase in pressure and a waiting time for the hydraulic pump 3, and thus also the occurrence of pressure surges and energy loss, are avoided.

Die Rückschlagventile 37,38 können wahlweise in die Steuerleitungen 33,34 eingeschaltet werden, um ein Abströmen des von den Drosseln 18,19 kommenden Steuerdrucks durch die Antriebszylinder 31,32 des Betonschiebers 39 zum Tank 36 hin, bzw., wenn ein Tankanschluß in der Leitung 35 fehlt, zur anderen Zylinderseite hin zu vermeiden.The check valves 37, 38 can optionally be used in the control lines 33, 34 are switched on in order to discharge the control pressure coming from the throttles 18, 19 through the drive cylinders 31, 32 of the concrete slide valve 39 to the tank 36, or, if there is no tank connection in the line 35, to the other cylinder side avoid.

Wahlweise können diese Rückschlagventile 37,38 entfallen, wenn der Hauptsteuerschieber 11 noch, wie bekannt, zusätzliche Zentrierfedern erhält. Dann werden während des Durchschaltens der Antriebszylinder 31,32 des Betonschiebers 39 die Leitungen 33,34 mit der Leitung 35 zum Tank 36 verbunden. Dies erlaubt eine besonders weiche Schalteinstellung für bestimmte Betriebsbedingungen und erlaubt weiterhin große, schmutzunempfindliche Öffnungen der Drosseln 18,19. Diese Drosseln 18,19 können beide verstellbar, wahlweise auch nur eine verstellbar und die andere fest einstellbar, ausgeführt sein.Optionally, these check valves 37, 38 can be omitted if the main control slide 11 also receives, as is known, additional centering springs. Then the lines 33, 34 are connected to the line 35 to the tank 36 while the drive cylinder 31, 32 of the concrete slide 39 is switched through. This allows a particularly soft switching setting for certain operating conditions and also allows large, dirt-resistant openings in the throttles 18, 19. These throttles 18, 19 can both be adjustable, optionally only one adjustable and the other permanently adjustable.

Die Drosseln 47,48 in der stangenseitigen Verbindungsleitung 35 der Antriebszylinder 31,32 können durch Rückstau im Stangenraum dieser Zylinder bei ausnahmsweise schnellem Durchschalten des Betonschiebers 39 eine analog schnelle Durchschaltung des Hauptsteuerschiebers 11 bewirken. Dies begünstigt ruhigen Lauf der Maschine, weiches Umschalten des Betonschiebers und automatische, innere Ausgleichung der Steuergeschwindigkeiten bei variierender Ölkonsistenz infolge Temperaturschwankungen, oder auch bei starker Veränderung der Fördermenge der Hydropumpe 3.The throttles 47, 48 in the rod-side connecting line 35 of the drive cylinders 31, 32 can cause a similarly rapid connection of the main control spool 11 by backwater in the rod space of these cylinders with exceptionally rapid switching of the concrete slide 39. This favors smooth running of the machine, smooth switching of the concrete slide and automatic, internal compensation of the control speeds with varying oil consistency as a result of temperature fluctuations, or even if the delivery rate of the hydraulic pump 3 changes significantly.

Wie in Fig. 2 dargestellt, ist dieselbe Wirkung der erfindungsgemäßen Schaltung auch dann möglich, wenn die Hydroanschlüsse 23,24 der Antriebszylinder 1 der Betonförderkolben 15,16 nicht stangenseitig, sondern bodenseitig in die Antriebszylinder 1 münden. Dann sind deren stangenseitige Enden direkt über die Leitung 51 verbunden. Die Vorsteuerung des Schiebers 12 erfolgt hierbei auf an sich bekannte Weise über die Zylinderbohrungen 53,54 kurz vor der stangenseitigen Endlage der Kolben der Antriebszylinder 1. In Fig.2 sind der Einfachheit halber nicht alle hierfür notwendigen Hydroventile im Vorsteuersystem eingezeichnet.As shown in FIG. 2, the same effect of the circuit according to the invention is also possible if the hydraulic connections 23, 24 of the drive cylinders 1 of the concrete delivery pistons 15, 16 open into the drive cylinders 1, not on the rod side, but on the bottom side. Then their rod-side ends are connected directly via line 51. The pilot control of the slide 12 takes place in a manner known per se via the cylinder bores 53, 54 shortly before the rod-side end position of the pistons of the drive cylinder 1. For the sake of simplicity, not all of the hydraulic valves required for this are shown in the pilot control system.

Ebenso vorteilhaft funktioniert die Anordnung im sogenannten offenen Kreis, d.h. ohne die Speisepumpe 6, das Spülventil 8 usw.The arrangement in the so-called open circle works just as advantageously, i.e. without the feed pump 6, the flush valve 8, etc.

Wahlweise kann auf bekannte Weise der Umsteuer-Schaltimpuls anstelle der mechanischen Ausführung über den Wippschalter 14 und den Umsteuerschieber 13 auch über elektrische oder hydraulische Schaltimpulse laufen, welche direkt vom Antriebszylinder 1 ausgehen, sei es durch Kolbenstangennuten oder Steuerbohrungen am Zylindermantel. Solche Ausführungen sind bekannt und können nach Belieben entsprechend den Betriebsbedingungen und Einsatzbedingungen für die betreffende Dickstoffpumpe in Verbindung mit dem Erfindungsgegenstand angewendet werden.Optionally, the reversing switching pulse can run in a known manner instead of the mechanical design via the rocker switch 14 and the reversing slide 13 also via electrical or hydraulic switching pulses which originate directly from the drive cylinder 1, be it through piston rod grooves or control bores on the cylinder jacket. Such designs are known and can be operated as desired Conditions and conditions of use for the thick matter pump in question are used in connection with the subject matter of the invention.

Claims (6)

1. Betonpumpe mit hydraulisch entlastetem Schieber, bei welcher von einer Hydropumpe die Antriebszylinder für die Betonförderkolben und der Antriebszylinder für den Betonschieber selbsttätig in hydraulischer Folgeschaltung betätigt werden und die Steueranschlüsse des Hauptsteuerschiebers für die Antriebszylinder der Betonförderkolben mit dem Druckölanschlüssen des bzw. der Antriebszylinder für den Betonschieber über Verzögerungsdrosseln in Verbindung stehen, dadurch gekennzeichnet , daß der Hauptsteuerschieber (11) eine, relativ zum Weg seines Steuerkolbens, lange Mittelstellung (43,44,45) aufweist, bei welcher die Anschlüsse (23,24) der Antriebszylinder (1) der Betonförderkolben mit dem Niederdruck bzw. dem Tankanschluß (10) des Hydrokreislaufes in Verbindung stehen.1.Concrete pump with hydraulically relieved slide, in which the hydraulic cylinders for the concrete delivery pistons and the drive cylinders for the concrete slide are actuated automatically by a hydraulic pump in a hydraulic sequential circuit and the control connections of the main control spool for the drive cylinders of the concrete delivery pistons with the pressure oil connections of the or the drive cylinders for the Concrete slide valves are connected via delay throttles, characterized in that the main control slide valve (11) has a long central position (43, 44, 45) relative to the path of its control piston, in which the connections (23, 24) of the drive cylinder (1) of the Connect the concrete delivery piston to the low pressure or the tank connection (10) of the hydraulic circuit. 2. Betonpumpe nach Anspruch 1, dadurch gekennzeichnet , daß in den bei den äußeren Schaltstellungen (41,42) des Steuerkolbens des Hauptsteuerschiebers (11) die Länge der Überdeckung jeweils weniger als ein Drittel des Gesamtwegs des Steuerkolbens im Hauptsteuerschieber (11) beträgt.2. Concrete pump according to claim 1, characterized in that in the outer switching positions (41,42) of the control piston of the main Control spool (11) the length of the overlap is less than a third of the total travel of the control piston in the main control spool (11). 3. Betonpumpe nach Anspruch 1 oder 2, dadurch gekennzeichnet , daß zusätzlich zu den in den die Steueranschlüsse (25,26) des Hauptsteuerschiebers (11) mit den Antriebszylindern (31,32) für den Betonschieber (39) verbindenden Leitungen angeordneten Drosseln (18,19) parallel verlaufende Steuerleitungen (33, 34) vorgesehen sind, die mit Steuerbohrungen an den Antriebszylindern (31,32) in Verbindung stehen und von deren Kolben kurz vor bzw. bei Erreichen der Endlage des Schaltwegs am Betonschieber (39) überfahren werden.3. Concrete pump according to claim 1 or 2, characterized in that in addition to the in the control connections (25, 26) of the main control slide (11) with the drive cylinders (31, 32) for the concrete slide (39) connecting lines arranged throttles (18 , 19) parallel control lines (33, 34) are provided, which are connected to control bores on the drive cylinders (31, 32) and are driven over by their pistons shortly before or when the switching path on the concrete slide (39) is reached. 4. Betonpumpe nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet , daß in die Steuerleitungen (33,34) Rückschlagventile (37,38) eingebaut sind.4. Concrete pump according to one of claims 1 to 3, characterized in that check valves (37, 38) are installed in the control lines (33, 34). 5. Betonpumpe nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet , daß zwei zusammengehörige, beispielsweise stangenseitige Anschlüsse der Antriebszylinder (31,32) des Betonschiebers (39) miteinander durch eine Leitung (35) kleinen Querschnitts verbunden sind, wobei am Anschluß dieser Leitung (35) an die Antriebszylinder (31,32) Drosseln (47,48) vorgesehen sind.5. Concrete pump according to one of claims 1 to 4, characterized in that two associated, for example rod-side connections of the drive cylinder (31, 32) of the concrete slide (39) are connected to one another by a line (35) of small cross-section, with this Lei at the connection device (35) to the drive cylinder (31,32) throttles (47,48) are provided. 6. Betbnpumpe nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet , daß zwei zueinandergehörige, beispielsweise stangenseitige Anschlüsse der Antriebszylinder (31,32) des Betonschiebers (39) miteinander durch eine Leitung (35) verbunden und an einen Tank (36) angeschlossen sind, wobei am Anschluß der Leitung (35) an die Antriebszylinder (31,32) Drosseln (47,48) vorgesehen sind.6. Betbnpump according to any one of claims 1 to 4, characterized in that two related, for example rod-side connections of the drive cylinder (31,32) of the concrete slide (39) connected to each other by a line (35) and connected to a tank (36) , Throttles (47, 48) being provided at the connection of the line (35) to the drive cylinders (31, 32).
EP19800106348 1979-10-20 1980-10-18 Concrete pump with hydraulically relieved slide valve Ceased EP0027654A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19792942560 DE2942560A1 (en) 1979-10-20 1979-10-20 CONCRETE PUMP WITH HYDRAULICALLY RELEASED VALVE
DE2942560 1979-10-20

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EP0027654A1 true EP0027654A1 (en) 1981-04-29

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0167635A1 (en) * 1984-06-05 1986-01-15 COMPAGNIA ITALIANA FORME ACCIAIO S.p.A. Hydraulic circuit for the control of reciprocating pistons pump

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3333849A1 (en) * 1983-09-20 1985-04-11 Maschinenfabrik Walter Scheele GmbH & Co KG, 4750 Unna-Massen CONTROL FOR THE CONCRETE DISTRIBUTOR SWITCHING CYLINDER OF A CONCRETE PUMP
DE3509788A1 (en) * 1983-09-20 1986-10-02 Maschinenfabrik Walter Scheele GmbH & Co KG, 4750 Unna-Massen Braking control for the concrete-distributor switch-over cylinder of a concrete pump
DE102005008217A1 (en) * 2005-02-22 2006-08-31 Putzmeister Ag Hydraulic drive for two-cylinder thick matter pumps, has main pump, and blocking valve to block rinsing oil flow and to release oil flow after time delay, while diverting oil flow from low pressure side of hydraulic circuit into oil tank

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Publication number Priority date Publication date Assignee Title
CH224724A (en) * 1941-11-19 1942-12-15 Sulzer Ag Pump system for pumping liquids at high pressure.
DE2126446A1 (en) * 1971-05-27 1972-12-07 Wilhelm Reich Kg, 7900 Ulm Hydraulic twin piston drive, especially for concrete pumps
DE2447054A1 (en) * 1973-10-12 1975-04-17 Italiana Forme Acciaio THREE-WAY DISTRIBUTOR FOR CONCRETE DOUBLE PUMPS
DE2411391A1 (en) * 1974-03-09 1975-09-18 Scheele Maschf W Control system for piston pump delivering concrete - is separated from pump cylinder and piston for reducing wear

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH224724A (en) * 1941-11-19 1942-12-15 Sulzer Ag Pump system for pumping liquids at high pressure.
DE2126446A1 (en) * 1971-05-27 1972-12-07 Wilhelm Reich Kg, 7900 Ulm Hydraulic twin piston drive, especially for concrete pumps
DE2447054A1 (en) * 1973-10-12 1975-04-17 Italiana Forme Acciaio THREE-WAY DISTRIBUTOR FOR CONCRETE DOUBLE PUMPS
FR2247628A1 (en) * 1973-10-12 1975-05-09 Italiana Forme Acciaio Compagn Three-way distributor for twin-cylinder concrete pump - has rotatable S-shaped pipe section connecting with one or other cylinder
DE2411391A1 (en) * 1974-03-09 1975-09-18 Scheele Maschf W Control system for piston pump delivering concrete - is separated from pump cylinder and piston for reducing wear

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0167635A1 (en) * 1984-06-05 1986-01-15 COMPAGNIA ITALIANA FORME ACCIAIO S.p.A. Hydraulic circuit for the control of reciprocating pistons pump

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