EP0153332B1 - Method and device for the vibratory operation of a working piston, particularly for working tools - Google Patents

Method and device for the vibratory operation of a working piston, particularly for working tools Download PDF

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Publication number
EP0153332B1
EP0153332B1 EP84902804A EP84902804A EP0153332B1 EP 0153332 B1 EP0153332 B1 EP 0153332B1 EP 84902804 A EP84902804 A EP 84902804A EP 84902804 A EP84902804 A EP 84902804A EP 0153332 B1 EP0153332 B1 EP 0153332B1
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EP
European Patent Office
Prior art keywords
piston
cylinder
control device
pressure fluid
pressure medium
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Expired
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EP84902804A
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German (de)
French (fr)
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EP0153332A1 (en
Inventor
Achim Graul
Elmar Niedermeier
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Individual
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Individual
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Priority to AT84902804T priority Critical patent/ATE31641T1/en
Publication of EP0153332A1 publication Critical patent/EP0153332A1/en
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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2203—Arrangements for controlling the attitude of actuators, e.g. speed, floating function
    • E02F9/221—Arrangements for controlling the attitude of actuators, e.g. speed, floating function for generating actuator vibration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/18—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency wherein the vibrator is actuated by pressure fluid
    • B06B1/183—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency wherein the vibrator is actuated by pressure fluid operating with reciprocating masses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
    • B25D9/06—Means for driving the impulse member
    • B25D9/12—Means for driving the impulse member comprising a built-in liquid motor, i.e. the tool being driven by hydraulic pressure
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/40—Dippers; Buckets ; Grab devices, e.g. manufacturing processes for buckets, form, geometry or material of buckets
    • E02F3/402—Dippers; Buckets ; Grab devices, e.g. manufacturing processes for buckets, form, geometry or material of buckets with means for facilitating the loading thereof, e.g. conveyors
    • E02F3/405—Dippers; Buckets ; Grab devices, e.g. manufacturing processes for buckets, form, geometry or material of buckets with means for facilitating the loading thereof, e.g. conveyors using vibrating means
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2217—Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
    • E21D9/01—Methods or apparatus for enlarging or restoring the cross-section of tunnels, e.g. by restoring the floor to its original level
    • 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
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/12—Fluid oscillators or pulse generators
    • F15B21/125—Fluid oscillators or pulse generators by means of a rotating valve

Definitions

  • the invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 2.
  • Such pulse-hydraulic methods and devices are used in particular for operating the working tools of earthmoving equipment, such as total power controlled excavators, bulldozers, loaders etc. are used. Due to the vibrating movement of the tools, they are relatively easy to penetrate into hard-to-work soil classes. Smaller machines than previously can be used, particularly in the case of chemically consolidated sands and gravels, in hard coal and lignite, in coral, chalk, banked limestone, and in heterogeneous or weathered hard rocks, since their working efficiency is significantly improved by the pulse hydraulics.
  • a hydraulic vibration exciter is known from DE-A-2 623 639 and JP-A-54/149 083, which consists of a piston-cylinder unit acted on on both sides, a separate liquid supply line and a liquid discharge line being arranged on each side of the piston are. These lines can be opened or closed alternately via a control device, and a rotary slide valve can also be used as the control device. With the separate line routing for supply and return of the pressure medium, a constant exchange of the pressure fluid in the cylinder and in the lines is effected.
  • a rotary valve controlled piston cylinder device for causing axial piston vibration is also known from DE-A-2 821 339.
  • the rotary valve is integrated directly into the working piston and rotates around the piston feed axis.
  • the working piston itself is acted on on both sides and moves relative to the fixed rotary valve, so that pressure medium is alternately applied to the front or the rear of the piston via corresponding bores in the working piston.
  • a disadvantage of known devices is that high pressure peaks occur when the pressure medium return is closed by the control device. Under certain circumstances, these pressure peaks can be a multiple of the feed pressure and lead to damage to the hydraulic system or possibly also to the working tool.
  • Another object of the invention is to provide a pulse hydraulic device in an optimal manner in an earth moving device, e.g. in an excavator. In terms of the method, this object is achieved with a method which has the features in the characterizing part of patent claim 1.
  • the resetting of the piston by the reaction forces on the tool enables a particularly simple construction of the cylinder.
  • the reaction forces depend on constantly changing external conditions. So z. B. at the moment of overcoming resistance in the clod-like breaking of rock, the tensile strength practically collapses to zero. With the method according to the invention, no harmful pressure peaks can occur in such a state.
  • the working piston immediately moves to its maximum piston stroke and only oscillates slightly in the area of the relief opening.
  • the digging force of the excavator bucket is optimally used regardless of whether the excavator bucket is moved by hydraulic movement of the excavator arm or by driving the excavator forward.
  • the tasks are solved with a device having the features in the characterizing part of claim 2.
  • the pressure medium is circulated in the working chamber of the cylinder via the supply line and the return line. Since reaction forces are used on the working tool to reset the piston, the restoring force cannot always be controlled.
  • the maximum working stroke of the piston must therefore be limited so that no harmful pressure peaks or impacts can act on the piston. This is achieved in a particularly simple manner through the relief opening on the cylinder. As soon as this opening is uncovered when the maximum piston stroke is reached, pressure medium can flow out of the cylinder bypassing the control unit, so that no more thrust is exerted on the piston.
  • the feed line and the return line between control unit and cylinder are connected to one another in a manner that communicates with one another independently of the piston position via the cylinder.
  • the pressure medium volume in the lines can be used as a hydraulic damper as soon as the control unit blocks the return line.
  • the pressure medium is compressed by the restoring force, so that one suddenly setting pressure peak in the system is avoided.
  • the compressed pressure medium serves as a piston accelerator for reversing the piston movement as soon as the control unit releases the flow line.
  • the performance of the device can be further optimized if the return line is throttled to build up pressure in the cylinder. In this way, regardless of the constantly changing external conditions such as e.g. Pressure medium quantity, pressure medium temperature, restoring force, etc., build up a feed pressure that causes the piston to move.
  • the piston can be struck against a mechanical damping device in both end positions. With large restoring forces on the piston, it is thus mechanically and hydraulically damped. At the same time, the mechanical damping device also supports the acceleration of the piston against the restoring force. On the other hand, the piston is also damped in the opposite direction if, for example, the restoring force is suddenly interrupted by the release of the work tool and the piston is exclusively exposed to the hydraulic pressure.
  • the relief opening in the cylinder can only be exposed against the resistance of the damping device, it is achieved in a particularly simple manner that the piston vibrates even when its maximum piston stroke is reached. As soon as the piston opens the relief opening, pressure is reduced in the cylinder even when the return line is closed, so that even if there is no restoring force, the piston is reset by the damping device, so that the relief opening is closed again. As soon as the control device releases the flow line, the damping device is compressed again or the relief opening is exposed, so that the process is repeated.
  • a particularly advantageous construction of the damping device can be achieved if it consists of two disks loosely mounted on a piston section with a reduced diameter, between which a spring element is arranged, the axial movement of each disk being arranged by a stop arranged in the cylinder on the side facing away from the spring element is limited.
  • the damping takes place in both directions by the same spring element.
  • the damping path is the same in both directions.
  • the damping path between the two disks can be limited by at least one spacer.
  • An advantageous use of a device described above for an excavator bucket with vibrating teeth is characterized according to the invention in that the hydraulic cylinder is flanged directly to the control device and that the unit consisting of hydraulic cylinder and control device is arranged in a raised floor below the bucket.
  • the direct assembly of the control unit and hydraulic cylinder means that unnecessary pipes are no longer required and the pressure pulses can be transmitted to the piston in the cylinder with practically no pressure loss.
  • By placing the hydraulic unit directly on the work tool complicated and fault-prone mechanical power transmission elements such as e.g. Rods etc. away. Due to this arrangement, the excavator bucket itself contains a larger mass, which also only has a positive effect in work.
  • the excavator bucket works particularly advantageously if it is provided with an approximately U-shaped mouth, the legs of which are articulated at their free ends in the upper region of the bucket, if the connecting piece between the legs forms the bucket edge on the front and supports the teeth and if the connector is in turn articulated to the piston. Since the teeth to be moved are all attached to the U-shaped mouth, a complicated individual guidance of the teeth is avoided. Due to the articulation of the legs in the upper area of the spoon, the teeth do not move in a straight line, but move on a circular path section. However, this only has a positive effect in work, since it moves the excavated soil against the spoon bowl.
  • Disruptive transverse forces on the piston can be eliminated if the connecting piece is connected to the piston via a joint piece with two ball joints, one bearing shell of which is attached to the piston and the other of which is attached to the connecting piece.
  • a particularly simple construction results if several units consisting of hydraulic cylinder and control device are arranged in a row under the tray bottom and if the control devices can be activated with a common control shaft. All control units carry out exactly the same control movement via the common control shaft, so that the cylinders vibrate at the same time at a uniform frequency.
  • a working piston 15 moves in a hydraulic cylinder 1.
  • the hydraulic cylinder is connected to a control unit 2 via a feed line 9 and via a return line 10 bound.
  • the cylinder is supplied with pressure medium by means of the pump 4 from a pressure medium tank 3 via the suction line 5 and pressure line 7, the continuation of which, according to the control unit 2, is the flow line 9.
  • a pressure compensation store 5 is connected to the pressure line 7 via a further pressure line 8.
  • the conversion of the hydrostatic into a pulsating pressure medium flow takes place.
  • the control device alternately closes or opens the flow line 9 and the return line 10.
  • a hydraulic impact force P H thus acts on the end face 14 of the working piston 15.
  • the connection is blocked from B to T.
  • the impact force PH thus causes the piston 15 to move against the restoring force R, which is a reaction force on the working tool.
  • the control device blocks the flow line, ie interrupts the connection from P to A and then immediately opens the connection in the control device from B to T, the restoring force R, if present, begins to reset the piston 15 again.
  • the pressure medium flows via the return line 10 and the control unit 2 through the tank line 12 back into the pressure medium tank 3.
  • the movement which the piston 15 executes in the cylinder 1 depends on the restoring force R. If there is no restoring force R, the piston 15 is moved over the entire piston stroke S by the hydraulic impact forces P H. In this position, the piston 15 first strikes a mechanical damping device 18. If the piston 15 is moved further by the path X ′ against the force of the damping device 18, the piston 15 opens a relief opening 17, which is arranged as an annular groove in the cylinder 1. Via this relief opening, pressure medium can flow back through the relief line 11, bypassing the control unit 2, directly into the tank line 12. This results in a pressure reduction in the cylinder 1, regardless of the control position of the control unit 2, so that the piston 15 is moved back again without a restoring force R by the force of the damping device 18.
  • the relief opening 17 is closed again so that a hydraulic impact force P H can act on the piston again as soon as the control unit 2 releases the flow line 9. Obviously, a vibrating movement of the piston is achieved even if there is no restoring force at all, or if this is permanently less than the hydraulic impact force P H. At the same time, the maximum piston travel is limited by hydraulic measures by this arrangement, sudden loads being avoided by the damping device 18.
  • a throttle 24 in the return line between cylinder 1 and pressure medium tank 3 causes pressure to build up in cylinder 1 even when the connection from B to T is open in control unit 2, so that abrupt resetting of piston 15 at high restoring forces R is avoided.
  • Fig. 2 shows the pressure medium flow in the system at the start of a work process, i.e. with the piston 15 reset.
  • the control unit 2 is flanged directly to one end of the hydraulic cylinder 1.
  • the control unit 2 works according to the rotary slide valve principle known per se.
  • a drive device driven by a drive device, not shown, rotates a rotor 29 at a specific speed, which determines the frequency of the hydraulic pulses.
  • Flow pockets 28 and return pockets 26 are arranged in the rotor 29, which, depending on their positions, open or close inlet bores 27 and outlet bores 25 in the housing of control unit 2. 2, the flow pockets 28 expose the inlet bores 27, while the rotor 29 closes the outlet bores 25, since the return pockets 26 are in this position approximately transverse to the axis of the outlet bores 25.
  • the connection P to A is released, so that the end face 14 of the piston 15 is acted upon by pressure medium.
  • another control unit could also be used instead of the rotary slide valve principle.
  • the control device could have a control slide, which does not rotate, but executes an exclusively axial movement.
  • the piston itself consists of an actual working piston 15 and a guide piston 23. Between the working piston 15 and the guide piston 23 there is a section 30 with a reduced piston diameter. Two disks 21 are axially displaceably mounted on this section 30. A spring element 20 is arranged between the two disks 21 and presses the two disks 21 apart. Each disc 21 has a stop in the cylinder 1 on the side facing away from the spring element 20, against which it is pressed by the spring element 20. The disks 21 and the spring element 20 thus form in the simplest manner a mechanical damping device 18, against which either the working piston ring surface 19 or the guide piston ring surface 22 can be struck. Spacer elements are provided to protect the spring element 20 and to limit the damping path X. These spacer elements preferably consist of an annular wall arranged on each disk, so that each disk has the configuration of a cup disk. Of course, other spacing elements are also conceivable.
  • the hydraulic cylinder 1 is provided with an annular groove 16 on its side facing the control unit 2.
  • This annular groove 16 is connected via the return line 10 to the outlet bores 25 in the control unit.
  • the annular groove 16 is arranged such that there is a communicating connection between the feed line 9 and the return line 10 even when the piston 15 is completely reset. On the ring groove 16 can also be dispensed with if it is not necessary for reasons of enlarging the damping chamber 13.
  • the outlet bores 25 have a reduced diameter compared to the inlet bores 27, so that they act as a throttle in the pressure medium flow.
  • FIG. 4 A particularly advantageous use of the pulse hydraulics described in an excavator bucket is shown in FIG. 4.
  • An excavator bucket 32 is attached to a stick joint 42 on a dipper stick 31.
  • An approximately U-shaped mouth 33 is arranged in front of the spoon 32 and has two lateral legs 34. These legs 34 are articulated at their upper free end with jaw joints 35 in the upper region of the spoon. On their underside, the two legs 34 are connected to one another with a connecting piece 36, which on the one hand forms the spoon cutting edge 37 and on the other hand carries the teeth 38.
  • the bucket 32 has a raised floor consisting of an upper sheet 39 and a lower sheet 40. Control device 2 and hydraulic cylinder 1 are accommodated in this raised floor, each forming a unit. Depending on the width of the excavator bucket, several such units can be arranged in a row one behind the other.
  • the power transmission from the piston 15 to the connecting piece 36 of the jaw 33 takes place via a joint piece 41.
  • This joint piece has two ball joints 47, a bearing shell 48 being arranged on the piston 15 and a second bearing shell 48 'on the connecting piece 36.
  • This articulated connection also ensures that the vibratory forces are correctly transmitted from the piston 15 to the mouth 33 when the latter is tilted or displaced under tensile forces and resistance to penetration. Therefore, no special measures have to be taken to stabilize the piston 15.
  • the teeth 38 on the mouth 33 do not perform an exactly linear movement. Rather, the teeth 38 move about the axis of the jaw joint 35.
  • An upper cover plate 49 and a lower cover plate 59 on the connecting piece 36 ensure a perfect transition of the material lifted from the cutting edge 37 into the interior of the spoon 32.
  • the unit consisting of control unit and hydraulic cylinder 1 is supported on an abutment 51 to the rear.
  • the spoon is not only connected to the arm 31 at the arm joint 42, but also to the arm arm 44 and the toggle lever 45 at the arm joint 43 becomes.
  • the ladle Steering 43 is mounted in a metal-rubber element, since reaction forces attack here from the vibration of the mouth. Forces and reaction forces exerted by bucket cylinder 46 are transmitted simultaneously via spoon joint 43 here. It has proven to be particularly advantageous if the lever arm 44 in the basic position of the spoon 32 extends essentially parallel to the dipper stick 31.
  • Fig. 5 shows a modified embodiment of a control device, in which in particular the cylinder 1 and the piston 15 have a different design.
  • the piston is provided with a central bore 53 which leads from the end face 14 to the level of a piston ring groove 55.
  • the piston ring groove and the central bore are connected to one another via connecting bores 54 running transversely to one another.
  • a pressure relief and thus a limitation of the maximum piston stroke takes place as soon as the piston ring groove 55 reaches the relief opening 17.
  • the backflow of the pressure medium then also takes place via the relief line 11. This solution allows the relief opening 17 to be moved back, which can be advantageous with regard to the overall length of the piston.
  • the reset piston closes the return line 10 or the annular groove 16.
  • the front of the piston is provided with a conical bevel 56 which prevents the return line from suddenly closing.
  • this version can also be provided with a damping device.

Abstract

The working piston (15) in the cylinder (1) is subjected to the force of the pressure medium only on one side, whereas the piston return travel results from reaction forces (R). The supply and discharge of the pressure medium are effected via separate conduits (9, 10), so that there is a continual replacement of the pressure medium within the cylinder (1). At the maximum of the pistons stroke, the pressure medium may be discharged out of the cylinder (1) independently of the control position of the control unit (2). In both end positions of the piston (15), the motion of the piston is braked by a mechanical dumping device (18).

Description

Die Erfindung betrifft ein Verfahren nach dem Oberbegriff von Patentanspruch 1 sowie eine Vorrichtung nach dem Oberbegriff von Patentanspruch 2. Derartige impulshydraulische Verfahren bzw. Vorrichtungen werden insbesondere zum Betrieb der Arbeitswerkzeuge von Erdbewegungsgeräten wie z.B. summenleistungsgeregelten Baggern, Planierraupen, Ladern usw. eingesetzt. Durch die vibrierende Bewegung der Werkzeuge vermögen diese relaiv leicht in schwer zu bearbeitende Bodenklassen einzudringen. Insbesondere bei chemisch verfestigten Sanden und Kiesen, in Stein- und Braunkohle, in Koralle, Kreide, bankigem Kalkgestein sowie in heterogenen bzw. verwitterten Hartgesteinen können kleinere Arbeitsmaschinen als bisher üblich eingesetzt werden, da deren Arbeitswirkungsgrad durch die lmpulshydraulik wesentlich verbessert wird.The invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 2. Such pulse-hydraulic methods and devices are used in particular for operating the working tools of earthmoving equipment, such as total power controlled excavators, bulldozers, loaders etc. are used. Due to the vibrating movement of the tools, they are relatively easy to penetrate into hard-to-work soil classes. Smaller machines than previously can be used, particularly in the case of chemically consolidated sands and gravels, in hard coal and lignite, in coral, chalk, banked limestone, and in heterogeneous or weathered hard rocks, since their working efficiency is significantly improved by the pulse hydraulics.

Durch die US-A-3 145 488 ist eine Baggerschaufel mit einem vibrierenden Schneidteil bekannt geworden, bei der hinter der Schaufel ein Arbeitskolben befestigt ist, der über ein Gestänge kraftschlüssig mit dem Schneidteil verbunden ist. Der Arbeitskolben wird zweiseitig mit Druckmittel beaufschlagt, wobei als Steuergerät ein mit Eigenmedium betätigter Ventilkolben dient. Der Arbeitskolben übernimmt dabei ebenfalls Steuerfunktionen, indem er die Vor-und Rücklaufleitungen öffnet bzw. verschliesst.From US-A-3 145 488 an excavator bucket with a vibrating cutting part is known, in which a working piston is attached behind the bucket, which is non-positively connected to the cutting part via a linkage. Pressure is applied to the working piston on both sides, a valve piston actuated with the own medium serving as the control device. The working piston also assumes control functions by opening or closing the supply and return lines.

Durch die DE-A-2 623 639 und die JP-A-54/ 149 083 ist ein hydraulischer Schwingungserreger bekannt geworden, der aus einer doppelseitig beaufschlagten Kolben-Zylindereinheit besteht, wobei an jeder Seite des Kolbens je eine separate Flüssigkeitszuleitung und eine Flüssigkeitsableitung angeordnet sind. Diese Leitungen sind über ein Steuergerät alternierend zu öffnen bzw. verschliessbar, wobei als Steuergerät auch ein Drehschieber eingesetzt werden kann. Mit der getrennten Leitungsführung für Vor- und Rücklauf des Druckmittels wird ein ständiger Austausch der im Zylinder und in den Leitungen befindlichen Druckflüssigkeit bewirkt.A hydraulic vibration exciter is known from DE-A-2 623 639 and JP-A-54/149 083, which consists of a piston-cylinder unit acted on on both sides, a separate liquid supply line and a liquid discharge line being arranged on each side of the piston are. These lines can be opened or closed alternately via a control device, and a rotary slide valve can also be used as the control device. With the separate line routing for supply and return of the pressure medium, a constant exchange of the pressure fluid in the cylinder and in the lines is effected.

Eine Drehschieber-gesteuerte Kolbenzylindervorrichtung zur Hervorrufung einer axialen Kolbenvibration ist auch durch die DE-A-2 821 339 bekannt geworden. Hier ist der Drehschieber jedoch unmittelbar in den Arbeitskolben integriert und dreht sich um die Vorschubachse des Kolbens. Der Arbeitskolben selbst ist doppelseitig beaufschlagt und bewegt sich gegenüber dem feststehenden Drehschieber, so dass über entsprechende Bohrungen im Arbeitskolben alternierend die Vor-oder die Rückseite des Kolbens mit Druckmittel beaufschlagt wird.A rotary valve controlled piston cylinder device for causing axial piston vibration is also known from DE-A-2 821 339. Here, however, the rotary valve is integrated directly into the working piston and rotates around the piston feed axis. The working piston itself is acted on on both sides and moves relative to the fixed rotary valve, so that pressure medium is alternately applied to the front or the rear of the piston via corresponding bores in the working piston.

Ein Nachteil bekannter Vorrichtungen besteht darin, dass im Augenblick des Schliessens des Druckmittelrücklaufes durch das Steuergerät hohe Druckspitzen auftreten. Diese Druckspitzen können unter Umständen ein Mehrfaches des Speisedruckes betragen und zu Beschädigungen am Hydrauliksystem oder evtl. auch am Arbeitswerkzeug führen.A disadvantage of known devices is that high pressure peaks occur when the pressure medium return is closed by the control device. Under certain circumstances, these pressure peaks can be a multiple of the feed pressure and lead to damage to the hydraulic system or possibly also to the working tool.

Schliesslich haben Versuche gezeigt, dass es insbesondere bei Baggerschaufeln schwierig ist, ohne übermässigen technischen Aufwand eine longitudinale Bewegung auf jeden einzelnen Zahn auszuüben. Ein Problem stellen auch die Vibrationskräfte dar, welche sich über den Löffelstiel auf den ganzen Bagger übertragen können.Finally, tests have shown that it is difficult, particularly with excavator buckets, to carry out a longitudinal movement on each individual tooth without undue technical effort. Vibration forces are also a problem, which can be transmitted to the entire excavator via the dipper stick.

Es ist daher eine Aufgabe der Erfindung, ein Verfahren und eine Vorrichtung der eingangs genannten Art zu schaffen, bei denen die bekannten Nachteile vermieden werden und bei denen mit möglichst geringem Aufwand ein vibrierend arbeitendes Werkzeug geschaffen werden kann. Eine weitere Aufgabe der Erfindung besteht darin, eine impulshydraulische Vorrichtung auf optimale Weise bei einem Erdbewegungsgerät, wie z.B. bei einem Bagger, einzusetzen. Diese Aufgabe wird in verfahrensmässiger Hinsicht mit einem Verfahren gelöst, welches die Merkmale im Kennzeichen von Patentanspruch 1 aufweist.It is therefore an object of the invention to provide a method and a device of the type mentioned at the outset in which the known disadvantages are avoided and in which a vibrating tool can be created with as little effort as possible. Another object of the invention is to provide a pulse hydraulic device in an optimal manner in an earth moving device, e.g. in an excavator. In terms of the method, this object is achieved with a method which has the features in the characterizing part of patent claim 1.

Die Rückstellung des Kolbens durch die Reaktionskräfte am Werkzeug ermöglicht eine besonders einfache Bauweise des Zylinders. Beim Vorschieben des Werkzeuges sind die Reaktionskräfte von ständig sich ändernden äusseren Bedingungen abhängig. So kann z. B. im Augenblick des Überwindens des Widerstandes beim schollenartigen Brechen von Gestein die Reisskraft praktisch auf Null zusammenbrechen. Mit dem erfindungsgemässen Verfahren können bei einem derartigen Zustand keine schädlichen Druckspitzen auftreten. Der Arbeitskolben fährt sofort auf seinen maximalen Kolbenhub und oszilliert nur noch geringfügig im Bereich der Entlastungsöffnung. Die Reisskraft der Baggerschaufel wird in jedem Fall optimal ausgenutzt und zwar unabhängig davon, ob die Baggerschaufel durch hydraulische Bewegung des Baggerarms oder durch Vorwärtsfahren des Baggers bewegt wird.The resetting of the piston by the reaction forces on the tool enables a particularly simple construction of the cylinder. When pushing the tool forward, the reaction forces depend on constantly changing external conditions. So z. B. at the moment of overcoming resistance in the clod-like breaking of rock, the tensile strength practically collapses to zero. With the method according to the invention, no harmful pressure peaks can occur in such a state. The working piston immediately moves to its maximum piston stroke and only oscillates slightly in the area of the relief opening. The digging force of the excavator bucket is optimally used regardless of whether the excavator bucket is moved by hydraulic movement of the excavator arm or by driving the excavator forward.

In vorrichtungsmässiger Hinsicht werden die gestellten Aufgaben mit einer Vorrichtung gelöst, welche die Merkmale im Kennzeichen von Patentanspruch 2 aufweisen. Über die Vorlaufleitung und die Rücklaufleitung erfolgt die Zirkulation des Druckmittels im Arbeitsraum des Zylinders. Da zur Rückstellung des Kolbens Reaktionskräfte am Arbeitswerkzeug eingesetzt werden, ist die Rückstellkraft nicht in jedem Fall kontrollierbar. Der maximale Arbeitshub des Kolbens muss daher so begrenzt werden, dass keine schädlichen Druckspitzen oder Schläge auf den Kolben einwirken können. Dies wird durch die Entlastungsöffnung am Zylinder auf besonders einfache Weise erreicht. Sobald diese Öffnung beim Erreichen des maximalen Kolbenhubes freigelegt wird, kann Druckmittel unter Umgehung des Steuergerätes aus dem Zylinder abfliessen, so dass auf den Kolben kein Schub mehr ausgeübt wird.In terms of the device, the tasks are solved with a device having the features in the characterizing part of claim 2. The pressure medium is circulated in the working chamber of the cylinder via the supply line and the return line. Since reaction forces are used on the working tool to reset the piston, the restoring force cannot always be controlled. The maximum working stroke of the piston must therefore be limited so that no harmful pressure peaks or impacts can act on the piston. This is achieved in a particularly simple manner through the relief opening on the cylinder. As soon as this opening is uncovered when the maximum piston stroke is reached, pressure medium can flow out of the cylinder bypassing the control unit, so that no more thrust is exerted on the piston.

Da die durch das Arbeitswerkzeug verursachten Rückstellkräfte relativ gross sein können, ist es erforderlich, die Rückstellbewegung des Kolbens zu dämpfen, um die eingangs erwähnten Druckspitzen im System zu vermeiden. Dies erfolgt konstruktiv auf einfachste Weise dadurch, dass die Vorlaufleitung und die Rücklaufleitung zwischen Steuergerät und Zylinder unabhängig von der Kolbenstellung über den Zylinder kommunizierend miteinander verbunden sind. Durch diese kommunizierende Verbindung der beiden Leitungen kann das Druckmittelvolumen in den Leitungen als hydraulischer Dämpfer eingesetzt werden, sobald das Steuergerät die Rücklaufleitung sperrt. Das Druckmittel wird durch die Rückstellkraft komprimiert, so dass eine schlagartig einsetzende Druckspitze im System vermieden wird. Gleichzeitig dient das komprimierte Druckmittel als Kolbenbeschleuniger für die Umkehr der Kolbenbewegung, sobald das Steuergerät die Vorlaufleitung freigibt.Since the restoring forces caused by the working tool can be relatively large, it is necessary to dampen the restoring movement of the piston in order to avoid the pressure peaks mentioned at the outset in the system. In terms of design, this is done in the simplest manner in that the feed line and the return line between control unit and cylinder are connected to one another in a manner that communicates with one another independently of the piston position via the cylinder. Through this communicating connection of the two lines, the pressure medium volume in the lines can be used as a hydraulic damper as soon as the control unit blocks the return line. The pressure medium is compressed by the restoring force, so that one suddenly setting pressure peak in the system is avoided. At the same time, the compressed pressure medium serves as a piston accelerator for reversing the piston movement as soon as the control unit releases the flow line.

Die Leistungen der Vorrichtung können weiter optimiert werden, wenn die Rücklaufleitung zum Aufbau eines Druckes im Zylinder gedrosselt ist. Auf diese Weise wird im Arbeitsraum des Zylinders unabhängig der sich ständig ändernden äusseren Bedingungen wie z.B. Druckmittelmenge, Druckmitteltemperatur, Rückstellkraft usw. ein Speisedruck aufgebaut, der eine Vorschubbewegung des Kolbens verursacht.The performance of the device can be further optimized if the return line is throttled to build up pressure in the cylinder. In this way, regardless of the constantly changing external conditions such as e.g. Pressure medium quantity, pressure medium temperature, restoring force, etc., build up a feed pressure that causes the piston to move.

Eine weitere Schonung des Kolbens bei zusätzlicher Begünstigung der Vibrationsbewegung kann dadurch erreicht werden, dass der Kolben in beiden Endstellungen an eine mechanische Dämpfungsvorrichtung anschlagbar ist. Bei grossen Rückstellkräften am Kolben wird dieser somit mechanisch und hydraulisch gedämpft. Gleichzeitig unterstützt auch die mechanische Dämpfungsvorrichtung die Beschleunigung des Kolbens entgegen der Rückstellkraft. Andererseits erfolgt auch eine Dämpfung des Kolbens in umgekehrter Richtung, wenn beispielsweise die Rückstellkraft durch Freiwerden des Arbeitswerkzeuges schlagartig aussetzt und der Kolben ausschliesslich dem hydraulischen Druck ausgesetzt ist.Further protection of the piston with additional favoring of the vibration movement can be achieved in that the piston can be struck against a mechanical damping device in both end positions. With large restoring forces on the piston, it is thus mechanically and hydraulically damped. At the same time, the mechanical damping device also supports the acceleration of the piston against the restoring force. On the other hand, the piston is also damped in the opposite direction if, for example, the restoring force is suddenly interrupted by the release of the work tool and the piston is exclusively exposed to the hydraulic pressure.

Wenn die Entlastungsöffnung im Zylinder nur gegen den Widerstand der Dämpfungsvorrichtung freilegbar ist, wird auf besonders einfache Weise erreicht, dass der Kolben auch beim Erreichen seines maximalen Kolbenhubes vibriert. Sobald der Kolben die Entlastungsöffnung freigibt, erfolgt nämlich auch bei geschlossener Rücklaufleitung ein Druckabbau im Zylinder, so dass selbst bei fehlender Rückstellkraft der Kolben durch die Dämpfungsvorrichtung wieder zurückgestellt wird, so dass die Entlastungsöffnung wieder verschlossen wird. Sobald das Steuergerät die Vorlaufleitung freigibt, wird die Dämpfungsvorrichtung wiederum zusammengepresst bzw. die Entlastungsöffnung freigelegt, so dass sich der Vorgang wiederholt.If the relief opening in the cylinder can only be exposed against the resistance of the damping device, it is achieved in a particularly simple manner that the piston vibrates even when its maximum piston stroke is reached. As soon as the piston opens the relief opening, pressure is reduced in the cylinder even when the return line is closed, so that even if there is no restoring force, the piston is reset by the damping device, so that the relief opening is closed again. As soon as the control device releases the flow line, the damping device is compressed again or the relief opening is exposed, so that the process is repeated.

Eine besonders vorteilhafte Konstruktion der Dämpfungsvorrichtung kann erzielt werden, wenn diese aus zwei lose auf einem Kolbenabschnitt mit reduziertem Durchmesser gelagerten Scheiben besteht, zwischen denen ein Federelement angeordnet ist, wobei die axiale Bewegung jeder Scheibe durch einen auf der dem Federelement abgewandten Seite im Zylinder angeordneten Anschlag begrenzt ist. Die Dämpfung erfolgt auf diese Weise in beiden Richtungen durch das gleiche Federelement. Ausserdem ist der Dämpfungsweg in beiden Richtungen gleich gross. Der Dämpfungsweg zwischen den beiden Scheiben kann dabei durch wenigstens einen Distanzhalter begrenzt werden.A particularly advantageous construction of the damping device can be achieved if it consists of two disks loosely mounted on a piston section with a reduced diameter, between which a spring element is arranged, the axial movement of each disk being arranged by a stop arranged in the cylinder on the side facing away from the spring element is limited. The damping takes place in both directions by the same spring element. In addition, the damping path is the same in both directions. The damping path between the two disks can be limited by at least one spacer.

Eine vorteilhafte Verwendung einer oben beschriebenen Vorrichtung für einen Baggerlöffel mit vibrierenden Zähnen ist erfindungsgemäss dadurch gekennzeichnet, dass der Hydraulikzylinder unmittelbar an das Steuergerät angeflanscht ist und dass die aus Hydraulikzylinder und Steuergerät bestehende Einheit in einem Doppelboden unterhalb des Löffels angeordnet ist. Durch den unmittelbaren Zusammenbau von Steuergerät und Hydraulikzylinder fallen unnötige Rohrleitungen weg und die Druckimpulse können praktisch ohne Druckverluste auf den Kolben im Zylinder übertragen werden. Es entsteht ausserdem eine kurze gedrungene Bauform, die sich leicht im Doppelboden des Löffels unterbringen lässt. Durch die Unterbringung der Hydraulikeinheit unmittelbar am Arbeitswerkzeug fallen auch komplizierte und störanfällige mechanische Kraftübertragungselemente wie z.B. Gestänge usw. weg. Der Baggerlöffel selbst enthält durch diese Anordnung eine grössere Masse, was sich im Arbeitseinsatz ebenfalls nur positiv auswirkt.An advantageous use of a device described above for an excavator bucket with vibrating teeth is characterized according to the invention in that the hydraulic cylinder is flanged directly to the control device and that the unit consisting of hydraulic cylinder and control device is arranged in a raised floor below the bucket. The direct assembly of the control unit and hydraulic cylinder means that unnecessary pipes are no longer required and the pressure pulses can be transmitted to the piston in the cylinder with practically no pressure loss. There is also a short, compact design that can be easily accommodated in the double bottom of the spoon. By placing the hydraulic unit directly on the work tool, complicated and fault-prone mechanical power transmission elements such as e.g. Rods etc. away. Due to this arrangement, the excavator bucket itself contains a larger mass, which also only has a positive effect in work.

Der Baggerlöffel arbeitet besonders vorteilhaft, wenn er mit einem etwa U-förmigen Maul versehen ist, dessen Schenkel an ihren freien Enden im oberen Bereich des Löffels angelenkt sind, wenn das Verbindungsstück zwischen den Schenkeln auf der Vorderseite die Löffelschneide bildet und die Zähne trägt und wenn das Verbindungsstück seinerseits mit dem Kolben gelenkig verbunden ist. Da die zu bewegenden Zähne alle gemeinsam am U-förmigen Maul befestigt sind, wird eine komplizierte Einzelführung der Zähne vermieden. Durch die Anlenkung der Schenkel im oberen Bereich des Löffels führen die Zähne keine geradlinige Bewegung aus, sondern bewegen sich auf einem Kreisbahnabschnitt. Dies wirkt sich jedoch im Arbeitseinsatz nur positiv aus, da dadurch das ausgebrochene Erdreich gegen die Löffelschale bewegt wird.The excavator bucket works particularly advantageously if it is provided with an approximately U-shaped mouth, the legs of which are articulated at their free ends in the upper region of the bucket, if the connecting piece between the legs forms the bucket edge on the front and supports the teeth and if the connector is in turn articulated to the piston. Since the teeth to be moved are all attached to the U-shaped mouth, a complicated individual guidance of the teeth is avoided. Due to the articulation of the legs in the upper area of the spoon, the teeth do not move in a straight line, but move on a circular path section. However, this only has a positive effect in work, since it moves the excavated soil against the spoon bowl.

Störende Querkräfte auf den Kolben können ausgeschaltet werden, wenn das Verbindungsstück mit dem Kolben über ein Gelenkstück mit zwei Kugelgelenken verbunden ist, deren eine Lagerschale am Kolben und deren andere Lagerschale am Verbindungsstück befestigt ist.Disruptive transverse forces on the piston can be eliminated if the connecting piece is connected to the piston via a joint piece with two ball joints, one bearing shell of which is attached to the piston and the other of which is attached to the connecting piece.

Eine besonders einfache Bauweise ergibt sich, wenn mehrere Einheiten bestehend aus Hydraulikzylinder und Steuergerät in einer Reihe unter dem Löffelboden angeordnet sind und wenn die Steuergeräte mit einer gemeinsamen Steuerwelle aktivierbar sind. Über die gemeinsame Steuerwelle führen sämtliche Steuergeräte exakt die gleiche Steuerbewegung durch, so dass die Zylinder immer gleichzeitig mit gleichförmiger Frequenz vibrieren.A particularly simple construction results if several units consisting of hydraulic cylinder and control device are arranged in a row under the tray bottom and if the control devices can be activated with a common control shaft. All control units carry out exactly the same control movement via the common control shaft, so that the cylinders vibrate at the same time at a uniform frequency.

Ein Ausführungsbeispiel der Erfindung ist in den Zeichnungen dargestellt und wird nachstehend genauer beschrieben. Es zeigen:

  • Fig. 1 eine schematische Darstellung des hydraulischen Systems bestehend aus Steuergerät und Zylinder,
  • Fig. 2 einen Querschnitt durch ein Steuergerät mit angeflanschtem Zylinder mit dem Kolben in rückgestellter Position,
  • Fig. 3 den Querschnitt gemäss Fig. 2 mit dem Kolben beim Erreichen des maximalen Kolbenhubes,
  • Fig. 4 die Verwendung einer erfindungsgemässen Vorrichtung in einer Baggerschaufel, und
  • Fig. 5 ein abgewandeltes Ausführungsbeispiel eines Steuergerätes.
An embodiment of the invention is shown in the drawings and will be described in more detail below. Show it:
  • 1 is a schematic representation of the hydraulic system consisting of control unit and cylinder,
  • 2 shows a cross section through a control unit with a flanged cylinder with the piston in the reset position,
  • 3 shows the cross section according to FIG. 2 with the piston when the maximum piston stroke is reached,
  • 4 shows the use of a device according to the invention in an excavator bucket, and
  • Fig. 5 shows a modified embodiment of a control device.

Wie in Fig. 1 dargestellt bewegt sich ein Arbeitskolben 15 in einem Hydraulikzylinder 1. Der Hydraulikzylinder ist über eine Vorlaufleitung 9 sowie über eine Rücklaufleitung 10 mit einem Steuergerät 2 verbunden. Die Speisung des Zylinders mit Druckmittel erfolgt mit Hilfe der Pumpe 4 aus einem Druckmitteltank 3 über die Saugleitung 5 und Druckleitung 7, deren Fortsetzung nach dem Steuergerät 2 die Vorlaufleitung 9 ist. An die Druckleitung 7 ist über eine weitere Druckleitung 8 ein Druckausgleichsspeicher 5 angeschlossen.As shown in FIG. 1, a working piston 15 moves in a hydraulic cylinder 1. The hydraulic cylinder is connected to a control unit 2 via a feed line 9 and via a return line 10 bound. The cylinder is supplied with pressure medium by means of the pump 4 from a pressure medium tank 3 via the suction line 5 and pressure line 7, the continuation of which, according to the control unit 2, is the flow line 9. A pressure compensation store 5 is connected to the pressure line 7 via a further pressure line 8.

Im nachstehend noch genauer beschriebenen Steuergerät 2 erfolgt die Umwandlung des hydrostatischen in einen pulsierenden Druckmittelstrom. Das Steuergerät verschliesst bzw. öffnet alternierend die Vorlaufleitung 9 und die Rücklaufleitung 10. Beim Öffnen der Vorlaufleitung 9 wirkt somit eine hydraulische Stosskraft PH auf die Stirnfläche 14 des Arbeitskolbens 15. Bei der Freigabe der Verbindung von P nach A im Steuergerät 2 ist die Verbindung von B nach T gesperrt. Die Stosskraft PH bewirkt somit eine Verschiebung des Kolbens 15 entgegen der Rückstellkraft R, welche eine Reaktionskraft am Arbeitswerkzeug ist. Sobald das Steuergerät die Vorlaufleitung versperrt, d.h. die Verbindung von P nach A unterbricht und unmittelbar anschliessend die Verbindung im Steuergerät von B nach T öffnet, beginnt die Rückstellkraft R, falls vorhanden, den Kolben 15 wieder zurückzustellen. Infolge der Rückstellkraft R fliesst das Druckmittel über die Rücklaufleitung 10 und das Steuergerät 2 durch die Tankleitung 12 zurück in den Druckmitteltank 3. Durch diese Anordnung der Druckmittelleitungen erfolgt ersichtlicherweise ein kontinuierlicher Austausch des Druckmittels mit jedem Druckimpuls.In the control unit 2 described in more detail below, the conversion of the hydrostatic into a pulsating pressure medium flow takes place. The control device alternately closes or opens the flow line 9 and the return line 10. When the flow line 9 is opened, a hydraulic impact force P H thus acts on the end face 14 of the working piston 15. When the connection from P to A is released in the control device 2, the connection is blocked from B to T. The impact force PH thus causes the piston 15 to move against the restoring force R, which is a reaction force on the working tool. As soon as the control device blocks the flow line, ie interrupts the connection from P to A and then immediately opens the connection in the control device from B to T, the restoring force R, if present, begins to reset the piston 15 again. As a result of the restoring force R, the pressure medium flows via the return line 10 and the control unit 2 through the tank line 12 back into the pressure medium tank 3. Obviously, this arrangement of the pressure medium lines results in a continuous exchange of the pressure medium with each pressure pulse.

Ersichtlicherweise ist die Bewegung, welche der Kolben 15 im Zylinder 1 ausführt, abhängig von der Rückstellkraft R. Wenn keine Rückstellkraft R vorhanden ist, wird der Kolben 15 durch die hydraulischen Stosskräfte PH über den gesamten Kolbenhub S bewegt. In dieser Stellung schlägt der Kolben 15 zuerst an einer mechanischen Dämpfungsvorrichtung 18 an. Wird der Kolben 15 entgegen der Kraft der Dämpfungsvorrichtung 18 um den Weg X' weiterbewegt, so gibt der Kolben 15 eine Entlastungsöffnung 17 frei, welche als Ringnut im Zylinder 1 angeordnet ist. Über diese Entlastungsöffnung kann Druckmittel durch die Entlastungsleitung 11 unter Umgehung des Steuergerätes 2 direkt in die Tankleitung 12 zurückfliessen. Dadurch erfolgt unabhängig von der Steuerstellung des Steuergerätes 2 ein Druckabbau im Zylinder 1, so dass der Kolben15 auch ohne Rückstellkraft R durch die Kraft der Dämpfungsvorrichtung 18 wieder zurückbewegt wird. Dabei wird die Entlastungsöffnung 17 wieder verschlossen, so dass erneut eine hydraulische Stosskraft PH auf den Kolben einwirken kann, sobald das Steuergerät 2 die Vorlaufleitung 9 freigibt. Ersichtlicherweise wird damit auch dann eine vibrierende Bewegung des Kolbens erzielt, wenn überhaupt keine Rückstellkraft vorhanden ist, oder wenn diese permanent kleiner ist als die hydraulische Stosskraft PH. Gleichzeitig wird durch diese Anordnung der maximale Kolbenweg durch hydraulische Massnahmen begrenzt, wobei durch die Dämpfungsvorrichtung 18 schlagartige Belastungen vermieden werden.Obviously, the movement which the piston 15 executes in the cylinder 1 depends on the restoring force R. If there is no restoring force R, the piston 15 is moved over the entire piston stroke S by the hydraulic impact forces P H. In this position, the piston 15 first strikes a mechanical damping device 18. If the piston 15 is moved further by the path X ′ against the force of the damping device 18, the piston 15 opens a relief opening 17, which is arranged as an annular groove in the cylinder 1. Via this relief opening, pressure medium can flow back through the relief line 11, bypassing the control unit 2, directly into the tank line 12. This results in a pressure reduction in the cylinder 1, regardless of the control position of the control unit 2, so that the piston 15 is moved back again without a restoring force R by the force of the damping device 18. The relief opening 17 is closed again so that a hydraulic impact force P H can act on the piston again as soon as the control unit 2 releases the flow line 9. Obviously, a vibrating movement of the piston is achieved even if there is no restoring force at all, or if this is permanently less than the hydraulic impact force P H. At the same time, the maximum piston travel is limited by hydraulic measures by this arrangement, sudden loads being avoided by the damping device 18.

Eine Drossel 24 in der Rücklaufleitung zwischen Zylinder 1 und Druckmitteltank 3 bewirkt einen Druckaufbau im Zylinder 1 auch bei geöffneter Verbindung von B nach T im Steuergerät 2, so dass ein schlagartiges Rückstellen des Kolbens 15 bei hohen Rückstellkräften R vermieden wird.A throttle 24 in the return line between cylinder 1 and pressure medium tank 3 causes pressure to build up in cylinder 1 even when the connection from B to T is open in control unit 2, so that abrupt resetting of piston 15 at high restoring forces R is avoided.

Anhand der Fig. 2 und 3 werden nachstehend Einzelheiten des Steuergerätes 2 und des Hydraulikzylinders 1 erläutert. Fig. 2 zeigt dabei den Druckmittelfluss im System bei Beginn eines Arbeitsvorganges, d.h. bei zurückgestelltem Kolben 15. Das Steuergerät 2 ist unmittelbar an eine Stirnseite des Hydraulikzylinders 1 angeflanscht. Beim dargestellten Ausführungsbeispiel arbeitet das Steuergerät 2 nach dem an sich bekannten Drehschieberprinzip.Details of the control unit 2 and the hydraulic cylinder 1 are explained below with reference to FIGS. 2 and 3. Fig. 2 shows the pressure medium flow in the system at the start of a work process, i.e. with the piston 15 reset. The control unit 2 is flanged directly to one end of the hydraulic cylinder 1. In the illustrated embodiment, the control unit 2 works according to the rotary slide valve principle known per se.

Dabei dreht sich, angetrieben von einer nicht näher dargestellten Antriebsvorrichtung, ein Rotor 29 mit einer bestimmten Drehzahl, welche die Frequenz der hydraulischen Impulse bestimmt. Im Rotor 29 sind Vorlauftaschen 28 und Rücklauftaschen 26 angeordnet, welche je nach ihren Stellungen Einlassbohrungen 27 und Auslassbohrungen 25 im Gehäuse des Steuergerätes 2 freigeben bzw. verschliessen. In Fig. 2 geben die Vorlauftaschen 28 die Einlassbohrungen 27 frei, während der Rotor 29 die Auslassbohrungen 25 verschliesst, da die Rücklauftaschen 26 in dieser Stellung etwa quer zur Achse der Auslassbohrungen 25 liegen. Dadurch erfolgt die Freigabe der Verbindung P nach A, so dass die Stirnfläche 14 des Kolbens 15 mit Druckmittel beaufschlagt wird. Selbstverständlich könnte anstelle des Drehschieberprinzips auch ein anderes Steuergerät eingesetzt werden. Beispielsweise könnte das Steuergerät einen Steuerschieber aufweisen, welcher nicht rotiert, sondern eine ausschliesslich axiale Bewegung ausführt.Here, driven by a drive device, not shown, rotates a rotor 29 at a specific speed, which determines the frequency of the hydraulic pulses. Flow pockets 28 and return pockets 26 are arranged in the rotor 29, which, depending on their positions, open or close inlet bores 27 and outlet bores 25 in the housing of control unit 2. 2, the flow pockets 28 expose the inlet bores 27, while the rotor 29 closes the outlet bores 25, since the return pockets 26 are in this position approximately transverse to the axis of the outlet bores 25. As a result, the connection P to A is released, so that the end face 14 of the piston 15 is acted upon by pressure medium. Of course, another control unit could also be used instead of the rotary slide valve principle. For example, the control device could have a control slide, which does not rotate, but executes an exclusively axial movement.

Der Kolben selbst besteht aus einem eigentlichen Arbeitskolben 15 und aus einem Führungskolben 23. Zwischen dem Arbeitskolben 15 und dem Führungskolben 23 ist ein Abschnitt 30 mit reduziertem Kolbendurchmesser angeordnet. Auf diesem Abschnitt 30 sind zwei Scheiben 21 axial verschiebbar gelagert. Zwischen den beiden Scheiben 21 ist ein Federelement 20 angeordnet, welches die beiden Scheiben 21 auseinanderpresst. Jede Scheibe 21 hat auf der dem Federelement 20 abgewandten Seite einen Anschlag im Zylinder 1, gegen den sie durch das Federelement 20 gepresst werden. Die Scheiben 21 und das Federelement 20 bilden so auf einfachste Weise eine mechanische Dämpfungsvorrichtung 18, an welche entweder die Arbeitskolbenringfläche 19 oder die Führungskolbenringfläche 22 anschlagbar ist. Zur Schonung des Federelementes 20 und zur Begrenzung des Dämpfungsweges X sind Abstandselemente vorgesehen. Vorzugsweise bestehen diese Abstandselemente aus einer an jeder Scheibe angeordneten Ringwand, so dass jede Scheibe die Konfiguration einer Topfscheibe erhält. Selbstverständlich sind jedoch auch andere Abstandselemente denkbar.The piston itself consists of an actual working piston 15 and a guide piston 23. Between the working piston 15 and the guide piston 23 there is a section 30 with a reduced piston diameter. Two disks 21 are axially displaceably mounted on this section 30. A spring element 20 is arranged between the two disks 21 and presses the two disks 21 apart. Each disc 21 has a stop in the cylinder 1 on the side facing away from the spring element 20, against which it is pressed by the spring element 20. The disks 21 and the spring element 20 thus form in the simplest manner a mechanical damping device 18, against which either the working piston ring surface 19 or the guide piston ring surface 22 can be struck. Spacer elements are provided to protect the spring element 20 and to limit the damping path X. These spacer elements preferably consist of an annular wall arranged on each disk, so that each disk has the configuration of a cup disk. Of course, other spacing elements are also conceivable.

Der Hydraulikzylinder 1 ist an seiner dem Steuergerät 2 zugewandten Seite mit einer Ringnut 16 versehen. Diese Ringnut 16 ist über die Rücklaufleitung 10 mit den Auslassbohrungen 25 im Steuergerät verbunden. Die Ringnut 16 ist derart angeordnet, dass auch bei ganz zurückgestelltem Kolben 15 zwischen der Vorlaufleitung 9 und der Rücklaufleitung 10 eine kommunizierende Verbindung besteht. Auf die Ringnut 16 kann auch verzichtet werden, wenn sie aus Gründen der Vergrösserung der Dämpfungskammer 13 nicht notwendig ist. Die Auslassbohrungen 25 weisen gegenüber den Einlassbohrungen 27 einen reduzierten Durchmesser auf, so dass sie im Druckmittelstrom als Drossel wirken.The hydraulic cylinder 1 is provided with an annular groove 16 on its side facing the control unit 2. This annular groove 16 is connected via the return line 10 to the outlet bores 25 in the control unit. The annular groove 16 is arranged such that there is a communicating connection between the feed line 9 and the return line 10 even when the piston 15 is completely reset. On the ring groove 16 can also be dispensed with if it is not necessary for reasons of enlarging the damping chamber 13. The outlet bores 25 have a reduced diameter compared to the inlet bores 27, so that they act as a throttle in the pressure medium flow.

Eine weitere Ringnut im Zylinder 1 ist mit einer Entlastungsöffnung 17 verbunden, welche jedoch nur dann freigegeben wird, wenn die Stirnfläche 14 dengesamten Kolbenhub S zurückgelegt hat und wenn der Kolben 15 dann noch zusätzlich gegen die Kraft der Dämpfungsvorrichtung 18 bewegt wird. Die Entlastungsöffnung 17 führt Druckmittel über die Entlastungsleitung 11 unabhängig von der Steuerposition des Steuergerätes 2 direkt zurück in den Druckmitteltank.Another annular groove in the cylinder 1 is connected to a relief opening 17, which is however only released when the end face 14 has covered the entire piston stroke S and when the piston 15 is then additionally moved against the force of the damping device 18. The relief opening 17 leads pressure medium directly back into the pressure medium tank via the relief line 11 regardless of the control position of the control unit 2.

Sobald der Rotor 29 die Verbindung P nach A freigibt, wird der Kolben 15 mit Druckmittel beaufschlagt. Ist die hydraulische Stosskraft PH grösser als die Rückstellkraft R, erfolgt eine Bewegung des Kolbens 15 entgegen der Rückstellkraft R. Diese Bewegung wird so lange fortgesetzt, bis der Rotor die Verbindung von P nach A wieder verschliesst. Nun erfolgt eine Rückstellung des Kolbens 15 durch die Rückstellkraft R, indem der Rotor 29 die Verbindung von B nach T freigibt, so dass das Druckmittel über die Rücklaufleitung 10 zurück in den Druckmitteltank fliessen kann. Auf diese Weise wird am Kolben 15 eine vibrierende Bewegung erzeugt, deren Frequenz von der Drehzahl des Rotors 29 abhängig ist.As soon as the rotor 29 releases the connection P to A, the piston 15 is acted upon by pressure medium. If the hydraulic impact force P H is greater than the restoring force R, the piston 15 moves against the restoring force R. This movement is continued until the rotor closes the connection from P to A again. The piston 15 is now reset by the restoring force R by the rotor 29 releasing the connection from B to T, so that the pressure medium can flow back into the pressure medium tank via the return line 10. In this way, a vibrating movement is generated on the piston 15, the frequency of which is dependent on the speed of the rotor 29.

Beim Schliessen des Druckmittelrücklaufs, d.h. beim Unterbrechen der Verbindung von B nach T wird der durch die Rückstellkraft R zurückbewegte Kolben 15 durch das Druckmittel abgebremst, da kein Druckmittel mehr über die Rücklaufleitung 10 abfliessen kann. Diese Verzögerung wird durch Komprimierung des Druckmittels hydraulisch gedämpft. Durch die kommunizierende Verbindung zwischen Vorlaufleitung und Rücklaufleitung ist das komprimierbare Druckmittelvolumen relativ gross. Das Druckmittelvolumen kann durch eine Dämpfungskammer 13 weiter vergrössert werden. Das komprimierte Druckmittel dient gleichzeitig als Kolbenbeschleuniger für die Umkehr der Kolbenbewegung infolge der Depressibilität des Druckmittels. Das anschliessend durch die Einlassbohrungen 27 einströmende Druckmittel kann somit optimal in Arbeit umgesetzt werden.When closing the pressure medium return, i.e. when the connection from B to T is interrupted, the piston 15 moved back by the restoring force R is braked by the pressure medium, since no pressure medium can flow off via the return line 10. This delay is hydraulically damped by compressing the pressure medium. Due to the communicating connection between the supply line and the return line, the compressible pressure medium volume is relatively large. The pressure medium volume can be further increased by a damping chamber 13. The compressed pressure medium also serves as a piston accelerator for reversing the piston movement due to the depressibility of the pressure medium. The pressure medium then flowing in through the inlet bores 27 can thus be optimally converted into work.

Für eine weitere Dämpfung der Rückstellkraft R sorgt auch die mechanische Dämpfungsvorrichtung 18, welche noch um den Dämpfungsweg X zusammengepresst werden kann, bevor der Kolben ganz anschlägt. Auch in diesem Fall bewirkt das Entspannen der Dämpfungsvorrichtung 18 eine Unterstützung der Umkehr der Kolbenbewegung gegen die Rückstellkraft R.The mechanical damping device 18, which can still be compressed by the damping path X before the piston strikes completely, also provides for further damping of the restoring force R. In this case too, the relaxation of the damping device 18 supports the reversal of the piston movement against the restoring force R.

Im Falle überwiegender hydraulischer Stosskraft PH beim Fehlen kompensierender Rückstellkräfte R legt der Kolben 15 den gesamten Kolbenhub S zurück bis zum Anschlagen der Arbeitskolbenringfläche 19 an die dem Arbeitskolben zugewandte Scheibe 21 der Dämpfungsvorrichtung 18. Diese Position des Arbeitskolbens 15 ist in Fig. 3 dargestellt. Die Stirnfläche 14 des Kolbens 15 ist relativ zur Entlastungsöffnung 17 derart angeordnet, dass bei an die Dämpfungsvorrichtung angeschlagenem Arbeitskolben 15 die Entlastungsöffnung 17 gerade noch verschlossen bleibt. Sobald infolge der hydraulischen Stosskraft PH die Stirnfläche 14 des Kolbens um den Weg X' gegen die Federkraft der Dämpfungsvorrichtung weiterbewegt wird, kann eine Teilmenge des Druckmittels direkt über die Entlastungsöffnung 17 und die Entlastungsleitung 11 unter Umgehung des Steuergerätes 2, bzw. unabhängig von der Steuerposition des Rotors 29, zum Druckmitteltank 3 zurückströmen. Dadurch wird der Kolben 15 in seiner Hubbewegung begrenzt. Da beim ungehinderten Abfliessen von Druckmittel über die Entlastungsöffnung 17 die Dämpfungsvorrichtung 18 den Kolben wieder zurückpresst, bewegt sich der Kolben 15 auch ohne Rückstellkraft R in seiner Endstellung vibrierend.In the event of predominant hydraulic impact force P H in the absence of compensating restoring forces R, the piston 15 covers the entire piston stroke S until the working piston ring surface 19 strikes the disk 21 of the damping device 18 facing the working piston. This position of the working piston 15 is shown in FIG. 3. The end face 14 of the piston 15 is arranged relative to the relief opening 17 such that when the working piston 15 is attached to the damping device, the relief opening 17 just remains closed. As soon as the end face 14 of the piston is moved by the path X 'against the spring force of the damping device as a result of the hydraulic impact force P H , a partial amount of the pressure medium can be passed directly via the relief opening 17 and the relief line 11 bypassing the control unit 2, or independently of that Control position of the rotor 29, flow back to the pressure medium tank 3. As a result, the piston 15 is limited in its stroke movement. Since the damping device 18 presses the piston back again when the pressure medium flows freely through the relief opening 17, the piston 15 moves vibratingly in its end position even without restoring force R.

Eine besonders vorteilhafte Verwendung der beschriebenen Impulshydraulik bei einem Baggerlöffel ist in Fig. 4 dargestellt. An einem Löffelstiel 31 ist ein Baggerlöffel 32 an einem Stielgelenk 42 befestigt. Vor dem Löffel 32 ist ein etwa U-förmig ausgebildetes Maul 33 angeordnet, welches zwei seitliche Schenkel 34 aufweist. Diese Schenkel 34 sind an ihrem oberen freien Ende mit Maulgelenken 35 im oberen Bereich des Löffels gelenkig befestigt. An ihrer Unterseite sind die beiden Schenkel 34 mit einem Verbindungsstück 36 miteinander verbunden, welches einerseits die Löffelschneide 37 bildet und welches anderseits die Zähne 38 trägt.A particularly advantageous use of the pulse hydraulics described in an excavator bucket is shown in FIG. 4. An excavator bucket 32 is attached to a stick joint 42 on a dipper stick 31. An approximately U-shaped mouth 33 is arranged in front of the spoon 32 and has two lateral legs 34. These legs 34 are articulated at their upper free end with jaw joints 35 in the upper region of the spoon. On their underside, the two legs 34 are connected to one another with a connecting piece 36, which on the one hand forms the spoon cutting edge 37 and on the other hand carries the teeth 38.

Der Löffel 32 hat einen Doppelboden bestehend aus einem oberen Blech 39 und aus einem unteren Blech 40. In diesem Doppelboden sind Steuergerät 2 und Hydraulikzylinder 1 untergebracht, welche jeweils eine Einheit bilden. Je nach Breite des Baggerlöffels können mehrere derartige Einheiten in einer Reihe hintereinander angeordnet sein. Die Kraftübertragung vom Kolben 15 auf das Verbindungsstück 36 des Mauls 33 erfolgt über ein Gelenkstück 41. Dieses Gelenkstück weist zwei Kugelgelenke 47 auf, wobei eine Lagerschale 48 am Kolben 15 und eine zweite Lagerschale 48' am Verbindungsstück 36 angeordnet ist. Durch diese gelenkige Verbindung erfolgt auch dann eine einwandfreie Übertragung der Vibrationskräfte vom Kolben 15 auf das Maul 33, wenn sich letzteres unter Reisskräften und Eindringwiderstand verkantet oder verschiebt. Es müssen daher keine besonderen Massnahmen getroffen werden, um den Kolben 15 zu stabilisieren.The bucket 32 has a raised floor consisting of an upper sheet 39 and a lower sheet 40. Control device 2 and hydraulic cylinder 1 are accommodated in this raised floor, each forming a unit. Depending on the width of the excavator bucket, several such units can be arranged in a row one behind the other. The power transmission from the piston 15 to the connecting piece 36 of the jaw 33 takes place via a joint piece 41. This joint piece has two ball joints 47, a bearing shell 48 being arranged on the piston 15 and a second bearing shell 48 'on the connecting piece 36. This articulated connection also ensures that the vibratory forces are correctly transmitted from the piston 15 to the mouth 33 when the latter is tilted or displaced under tensile forces and resistance to penetration. Therefore, no special measures have to be taken to stabilize the piston 15.

Ersichtlicherweise führen die Zähne 38 am Maul 33 keine exakt geradlinige Bewegung aus. Vielmehr bewegen sich die Zähne 38 um die Achse des Maulgelenks 35. Ein oberes Abdeckblech 49 und ein unteres Abdeckblech 59 am Verbindungsstück 36 gewährleisten einen einwandfreien Übergang des von der Schneide 37 abgehobenen Materials in das Innere des Löffels 32. Die Einheit bestehend aus Steuergerät und Hydraulikzylinder 1 stützt sich nach hinten an einem Widerlager 51 ab.As can be seen, the teeth 38 on the mouth 33 do not perform an exactly linear movement. Rather, the teeth 38 move about the axis of the jaw joint 35. An upper cover plate 49 and a lower cover plate 59 on the connecting piece 36 ensure a perfect transition of the material lifted from the cutting edge 37 into the interior of the spoon 32. The unit consisting of control unit and hydraulic cylinder 1 is supported on an abutment 51 to the rear.

Der Löffel ist nicht nur am Stielgelenk 42 mit dem Löffelstiel 31 verbunden, sondern auch am Löffelgelenk 43 mit dem Hebelarm 44 und dem Kniehebel 45. Am Kniehebel 45 greift ein Löffelzylinder 46 an, mittels dem die Kraft zum Verschwenken des Löffels um das Stielgelenk 42 aufgebracht wird. Das Löffelgelenk 43 ist in einem Metall-Gummi-Element gelagert, da hier Reaktionskräfte ausgehend von der Vibration des Mauls angreifen. Hier über dieses Löffelgelenk 43 werden einerseits vom Löffelzylinder 46 ausgeübte Kräfte und Reaktionskräfte gleichzeitig übertragen. Als besonders vorteilhaft hat es sich herausgestellt, wenn der Hebelarm 44 in der Grundstellung des Löffels 32 im wesentlichen parallel zum Löffelstiel 31 verläuft.The spoon is not only connected to the arm 31 at the arm joint 42, but also to the arm arm 44 and the toggle lever 45 at the arm joint 43 becomes. The ladle Steering 43 is mounted in a metal-rubber element, since reaction forces attack here from the vibration of the mouth. Forces and reaction forces exerted by bucket cylinder 46 are transmitted simultaneously via spoon joint 43 here. It has proven to be particularly advantageous if the lever arm 44 in the basic position of the spoon 32 extends essentially parallel to the dipper stick 31.

Fig. 5 zeigt ein abgewandeltes Ausführungsbeispiel eines Steuergerätes, bei welchem insbesondere der Zylinder 1 und der Kolben 15 eine andere Ausbildung aufweisen. Der Kolben ist mit einer zentralen Bohrung 53 versehen, welche von der Stirnfläche 14 aus bis auf die Höhe einer Kolbenringnut 55 führt. Kolbenringnut und zentrale Bohrung sind über quer zueinander verlaufende Verbindungsbohrungen 54 miteinander verbunden. Auf diese Weise herrscht in der Kolbenringnut 55 der gleiche Druck wie vor der Stirnfläche 14. Eine Druckentlastung und damit eine Begrenzung des maximalen Kolbenhubes erfolgt, sobald die Kolbenringnut 55 die Entlastungsöffnung 17 erreicht. Der Rückfluss des Druckmediums erfolgt dann ebenfalls über die Entlastungsleitung 11. Diese Lösung erlaubt ein Zurückversetzen der Entlastungsöffnung 17, was bezüglich der Baulänge des Kolbens vorteilhaft sein kann.Fig. 5 shows a modified embodiment of a control device, in which in particular the cylinder 1 and the piston 15 have a different design. The piston is provided with a central bore 53 which leads from the end face 14 to the level of a piston ring groove 55. The piston ring groove and the central bore are connected to one another via connecting bores 54 running transversely to one another. In this way, the same pressure prevails in the piston ring groove 55 as in front of the end face 14. A pressure relief and thus a limitation of the maximum piston stroke takes place as soon as the piston ring groove 55 reaches the relief opening 17. The backflow of the pressure medium then also takes place via the relief line 11. This solution allows the relief opening 17 to be moved back, which can be advantageous with regard to the overall length of the piston.

Beim dargestellten Ausführungsbeispiel verschliesst der zurückgestellte Kolben die Rücklaufleitung 10 bzw. die Ringnut 16. Um auch in diesem Fall eine gewisse Dämpfung zu erreichen, ist die Vorderseite des Kolbens mit einer konischen Anschrägung 56 versehen, welche ein schlagartiges Verschliessen der Rücklaufleitung verhindert. Selbstverständlich kann auch diese Ausführung mit einer Dämpfungsvorrichtung versehen werden.In the exemplary embodiment shown, the reset piston closes the return line 10 or the annular groove 16. In order to achieve a certain damping in this case as well, the front of the piston is provided with a conical bevel 56 which prevents the return line from suddenly closing. Of course, this version can also be provided with a damping device.

Claims (14)

1. A process for the vibratory operation of a tool such as an excavator shovel (32) and the like which can be advanced in at least one direction by means of a base machine, wherein the tool is supported against a hydraulic operating piston (15) or is force- lockingly connected to the operating piston (15) which is reciprocable in a cylinder (1). wherein a control device (2) allows pressure fluid into and out of the cylinder (1), characterised in that the operating piston (15) is acted upon by pressure fluid only on one side (PH) so that it moves in the direction of advance of the tool, and that the return movement of the piston (15) is effected by reaction forces (R) when the tool is advanced by means of the base machine, wherein in the absence of reaction forces or upon the attainment of the maximum operating stroke (S + X') of the operating piston (15), pressure fluid is removed from the cylinder, with the control device (2) being by-passed.
2. Apparatus for producing a vibratory movement at an operating piston (15) displaceable in a cylinder (1), with a pulse-generating control device (2) which allows pressure fluid into the cylinder (1) by way of a feed line (9) and allows pressure fluid out of the cylinder (1) by way of a return line (10), wherein said lines (9, 10) are alternately to be opened and closable with the control device (2), characterised in that the piston (15) can be acted upon with the pressure fluid only on one side, without a return means, and that arranged at the cylinder (1) is a relief opening (17) which is opened when the maximum piston stroke (S + X') is reached and by way of which pressure fluid can be drained from the cylinder (1) irrespective of the control position of the control device.
3. Apparatus according to claim 2, characterised in that the feed line (9) and the return line (10) between the control device (2) and the cylinder (1) are communicatingly interconnected by way of the cylinder (1) irrespective of the piston position.
4. Apparatus according to claim 3, characterised in that the return line (10) is throttled to build up a pressure in the cylinder (1).
5. Apparatus according to claim 4, characterised in that the piston (15) can abut against a mechanical damping means (18) in both limit positions.
6. Apparatus according to claim 5, characterised in that the relief opening (17) in the cylinder (1) can be opened only againstthe resistance of the damping means (18).
7. Apparatus according to claim 6, characterised in that the damping means (18) comprises two discs (21) which are loosely mounted on a piston portion (30) of reduced diameter and between which a spring element (20) is arranged, wherein the axial movement of each disc is limited by an abutment arranged in the cylinder on the side remote from the spring element.
8. Apparatus according to claim 7, characterised in that the damping travel (X) between the two discs (21) is limited by at least one spacer means, to protect the spring element (20).
9. Apparatus according to one of claims 2 to 8 for an excavator shovel (32) having vibrating teeth (38), characterised in that the hydraulic cylinder (1) is flanged directly on to the control device (2) and that the unit consisting of the hydraulic cylinder (1) and the control device (2) is arranged in a double bottom (39) beneath the shovel (32).
10. Apparatus according to claim 9, characterised in that the shovel (32) is provided with a substantially U-shaped mouth (33), the limbs (34) of which are pivoted at their free ends in the upper region of the shovel, that the connecting portion (36) between the limbs (34) on the front side forms the shovel cutting edge (37) and carries the teeth (38) and that the connection portion (36) is in turn pivotally connected to the piston (15).
11. Apparatus according to claim 10, characterised in that the connecting portion (36) is connected to the piston (15) by way of a pivot member (41) having two ball joints (47) of which one mounting socket (48) is fixed to the piston and the other mounting socket (48') is fixed to the connecting portion.
12. Apparatus according to claim 11, characterised in that a plurality of units consisting of a hydraulic cylinder (1) and a control device (2) are arranged in a row beneath the shovel bottom and that the hydraulic cylinders (1) can be activated synchronously or asynchronously by way of a common control shaft (52) in the control devices (2).
13. Apparatus according to one of claims 2 to 12, characterised in that the control device (2) has separate through-flow openings for the connection of the feed line (9) to a pressure fluid source (4)and for the connection of the return line (1 O)to a pressure fluid tank (3).
14. Apparatus according to claim 13, characterised in that the control device is a rotary spool valve and that the separate through-flow openings are feed pockets (28) and return pockets (26) which are arranged in axially displaced relationship with each other on the rotor (29).
EP84902804A 1983-08-06 1984-07-21 Method and device for the vibratory operation of a working piston, particularly for working tools Expired EP0153332B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84902804T ATE31641T1 (en) 1983-08-06 1984-07-21 METHOD AND DEVICE FOR THE VIBRATING OPERATION OF A WORKING PISTON, ESPECIALLY FOR ACTIVE WORKING TOOLS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3328426A DE3328426A1 (en) 1983-08-06 1983-08-06 WORK TOOL FOR EARTH MOVEMENT DEVICES
DE3328426 1983-08-06

Publications (2)

Publication Number Publication Date
EP0153332A1 EP0153332A1 (en) 1985-09-04
EP0153332B1 true EP0153332B1 (en) 1988-01-07

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EP84902804A Expired EP0153332B1 (en) 1983-08-06 1984-07-21 Method and device for the vibratory operation of a working piston, particularly for working tools

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US (1) US4715265A (en)
EP (1) EP0153332B1 (en)
JP (1) JPH0630845B2 (en)
AU (1) AU565964B2 (en)
CA (1) CA1237635A (en)
DE (2) DE3328426A1 (en)
FI (1) FI87150C (en)
IT (1) IT1177930B (en)
WO (1) WO1985000762A1 (en)
ZA (1) ZA846016B (en)

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US4959915A (en) * 1989-03-06 1990-10-02 Caterpillar Inc. Impact bucket apparatus
US5064005A (en) * 1990-04-30 1991-11-12 Caterpillar Inc. Impact hammer and control arrangement therefor
US6460276B1 (en) * 1996-09-18 2002-10-08 3786111 Canada Inc. Excavation bucket incorporating an impact actuator assembly
JP3724758B2 (en) * 1996-12-05 2005-12-07 株式会社小松製作所 Switching valve device
US6763661B2 (en) * 2002-05-07 2004-07-20 Husco International, Inc. Apparatus and method for providing vibration to an appendage of a work vehicle

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US2426409A (en) * 1944-03-31 1947-08-26 Chicago Pneumatic Tool Co Distributing valve for percussive tools
US2699756A (en) * 1950-09-15 1955-01-18 Leonidas C Miller Reciprocating pneumatic actuator for tools
US3145488A (en) * 1962-12-26 1964-08-25 Deere & Co Vibrating bucket
DE1634824A1 (en) * 1967-03-11 1971-02-25 Haynes Louis Eduard Device for digging out a suitcase or for digging out a sub-base, a subgrade or the like and for digging in the ground
SE322469B (en) * 1968-06-06 1970-04-06 Ilsbo Ind Ab
DE2008059A1 (en) * 1969-09-04 1971-09-09 Gunther Neumann Hydraulic, pneumatic and mechanical drive for oscillating movements
SE425468B (en) * 1974-11-22 1982-10-04 Ts Osrodek P K Maszyn Gorniczy HYDRAULIC SEAT MACHINE
DE2607190C3 (en) * 1976-02-23 1981-07-16 Koehring Gmbh - Bomag Division, 5407 Boppard Hydraulic vibration exciter for vibration compressors
DE2623639A1 (en) * 1976-05-26 1977-12-08 Kloeckner Humboldt Deutz Ag High frequency hydraulic vibrator - has double acting piston-cylinder unit connected to control unit by pipes with back pressure valves
DE2821339C3 (en) * 1977-05-18 1982-03-04 Kabushiki Kaisha Takahashi Engineering, Tokyo Hydraulic piston-cylinder device for generating axial piston oscillation
FR2554179B1 (en) * 1983-11-02 1986-01-03 Gtm Ets Sa METHOD FOR SUPPLYING HYDRAULIC FLUID, CONTINUOUSLY AND BY CONTROLLED PULSE, A HYDRAULIC CYLINDER NORMALLY WORKING CONTINUOUSLY, AND DEVICE FOR IMPLEMENTING THE PROCESS

Also Published As

Publication number Publication date
US4715265A (en) 1987-12-29
FI87150B (en) 1992-08-31
DE3468339D1 (en) 1988-02-11
AU565964B2 (en) 1987-10-01
FI851392L (en) 1985-04-04
WO1985000762A1 (en) 1985-02-28
ZA846016B (en) 1985-04-24
JPH0630845B2 (en) 1994-04-27
IT8448624A0 (en) 1984-07-24
CA1237635A (en) 1988-06-07
FI851392A0 (en) 1985-04-04
AU3157884A (en) 1985-03-12
IT1177930B (en) 1987-08-26
FI87150C (en) 1992-12-10
JPS60501959A (en) 1985-11-14
DE3328426A1 (en) 1985-02-21
EP0153332A1 (en) 1985-09-04

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