EP0283694B1 - Locking device for fluid actuator - Google Patents

Locking device for fluid actuator Download PDF

Info

Publication number
EP0283694B1
EP0283694B1 EP88101899A EP88101899A EP0283694B1 EP 0283694 B1 EP0283694 B1 EP 0283694B1 EP 88101899 A EP88101899 A EP 88101899A EP 88101899 A EP88101899 A EP 88101899A EP 0283694 B1 EP0283694 B1 EP 0283694B1
Authority
EP
European Patent Office
Prior art keywords
pressure
pressure medium
braking
cylinder
switch valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP88101899A
Other languages
German (de)
French (fr)
Other versions
EP0283694A1 (en
Inventor
Peter Pick
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Knorr Bremse AG
Original Assignee
Knorr Bremse AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Knorr Bremse AG filed Critical Knorr Bremse AG
Priority to AT88101899T priority Critical patent/ATE45012T1/en
Publication of EP0283694A1 publication Critical patent/EP0283694A1/en
Application granted granted Critical
Publication of EP0283694B1 publication Critical patent/EP0283694B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/082—Characterised by the construction of the motor unit the motor being of the slotted cylinder type
    • 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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/26—Locking mechanisms
    • F15B15/261—Locking mechanisms using positive interengagement, e.g. balls and grooves, for locking in the end positions
    • 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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/26—Locking mechanisms
    • F15B15/262—Locking mechanisms using friction, e.g. brake pads
    • 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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/26—Locking mechanisms
    • F15B15/265—Locking mechanisms specially adapted for rodless pistons or slotted cylinders

Definitions

  • the invention relates to a braking device for pressure medium cylinders, in particular rodless cylinders, with a brake element which can be tightened by means of pressure medium application and whose pressure medium application is monitored by a switching valve.
  • Such braking devices are shown, for example, in EP-A 104 364 for rodless cylinders, the braking member being arranged integrated in the power take-off member.
  • the known brake devices mentioned have the defect to solve in the event of an undesired loss of pressure, which often cannot be permitted for safety reasons.
  • spring-loaded brakes that is to say to apply them with spring force and to release them by means of pressure medium.
  • a pressure medium accumulator which can be charged via a check valve from a pressure medium source is arranged between a pressure medium source and the switching valve, which is designed as a 3/2-way valve, in that the pressure of the pressure medium source acts on a pressure switch which, when the pressure falls below a first one , high pressure threshold switches the switching valve to opening an otherwise closed connection from the pressure medium store to the braking element, that a spring-loaded cylinder acted upon from the pressure medium memory is provided, which activates a mechanical movement lock arranged in parallel with the braking element when subjected to a pressure exceeding a second, medium pressure threshold, and that the braking member is designed to hold the nominal load of the pressure medium cylinder until the pressure drops below a third, low pressure threshold.
  • a pressure medium connection 2 leads from a pressure medium source 1, here a compressed air source, through a check valve 3 to a pressure medium reservoir 4 designed as a container.
  • a pressure switch 5 is connected to the pressure medium connection 2, which is above a relatively high spring 6 by an adjustable spring 6 adjustable pressure threshold in the pressure medium connection 2 closes a switch 7 and keeps it open below this pressure threshold.
  • a switching valve designed as a solenoid valve 8 and representing a 3/2-way valve, is connected to the pressure medium accumulator and connects the pressure medium accumulator 4 to a pressure medium connection 10 leading to braking elements 9 in the de-energized state; in the de-energized state, the solenoid valve 8 blocks this connection and keeps the pressure medium connection 10 depressurized, for example in the illustrated pneumatic system, vented to the atmosphere.
  • the switch 7 is arranged in an electrical connection 11 from a current source symbolized only by a plus sign to the excitation coil of the solenoid valve 8. Furthermore, the pressure chamber 12 of a spring-loaded cylinder 13 is connected to the pressure medium reservoir 4, the piston rod 14 of which extends under the force of the spring 15 when the pressure falls below a second, medium pressure threshold in the pressure chamber 12. In the retracted state, the piston rod 14, which represents a locking pin, ends in front of a perforated strip 16 located in front of the spring-loaded cylinder 13; in the extended state, the piston rod 14 can engage in the holes 17 in the perforated strip 16. The piston rod 14 thus forms, together with the perforated strip 16, a mechanical, switchable movement lock 14, 16.
  • the braking device described above is arranged on a pressure medium cylinder (not shown in FIG. 1) with at least one fixed part and one part that can move under pressure medium in such a way that the check valve 3, the pressure monitor 5, the pressure medium accumulator 4, the solenoid valve 8, the braking members 9 and the Spring cylinder 13 on one and the perforated strip 16 on the other of the two parts.
  • the perforated strip 16 is expediently fixed, in a conventional piston rod cylinder vice versa to arrange the perforated strip 16 movably with the piston rod.
  • the braking members 9 are constructed in the usual way as a friction brake; they can, as can be seen from EP-A 104 364 already mentioned at the beginning, each have a cylinder or bellows which can be pressurized by the pressure medium connection 10 and which, when pressurized, has a friction element, in particular a brake shoe or presses a brake lining onto the other part of the pressure cylinder which is relatively displaceable for this purpose.
  • the pressure medium cylinder can be equipped with a further, customary brake, for example according to EP-A 104 364 mentioned, which is used as a service brake in normal operation of the pressure medium cylinder.
  • the braking device according to Fig. 1 acts as follows:
  • the switch 7 is closed and the solenoid valve 8 is thus energized when the current source is functioning.
  • the pressure medium reservoir 4 is filled by the check valve 3 from the pressure medium source 1, but the energized solenoid valve 8 keeps the braking members 9 depressurized and thus released.
  • the spring-loaded cylinder 13 is acted upon from the pressure medium reservoir 4, so that its piston rod 14 is retracted and out of engagement with the perforated strip 16. If the pressure at the pressure medium source 1 drops due to any damage, the switch 7 of the pressure switch 5 opens when the pressure falls below a first, still relatively high pressure threshold and thus interrupts the excitation of the solenoid valve 8.
  • the solenoid valve 8 therefore switches to the switch position shown um, whereby it separates the braking members 9 from the atmosphere and instead connects to the pressure medium accumulator 4.
  • the braking elements 9 are therefore pressurized from the pressure medium store 4 and tighten, so that the pressure medium cylinder is braked in its current position. Since the pressure drop in the pressure medium source 1 via the check valve 3 means that there is no further pressure make-up in the pressure medium reservoir 4, a compensating pressure is established between the pressure medium reservoir 4 and the pressurized spaces of the braking members 9, which, however, is considerably higher than the pressure level by appropriately dimensioning the volume of the pressure medium reservoir 4 which is required to safely brake the pressure medium cylinder under its nominal load.
  • the spring-loaded cylinder 13 remains in its tensioned position, the piston rod 14 thus remains disengaged from the perforated strip 16.
  • the compensating pressure prevailing in these rooms gradually drops. If the pressure falls below a second, medium pressure threshold, the storage spring 15 of the spring-loaded cylinder 13 pushes out the piston rod 14 so that it engages with the perforated strip 16. In general, the piston rod 14 will not yet engage in one of the holes 17 in the perforated strip 16, but will stand on the surface 18 of the perforated strip 16 facing the spring accumulator 13. At this medium pressure threshold mentioned, the application pressure is still sufficient to securely apply the braking elements 9. If the leak continues, the pressure in the pressure medium reservoir 4 and the spaces connected to it further decreases.
  • the pressure medium cylinder is thus locked in a form-fitting manner, so no further movement can take place. If, by chance, the piston rod 14 immediately engages in one of the holes 17 when it is extended, the aforementioned slipping of the pressure medium cylinder is of course not required; the pressure medium cylinder is locked in a positive manner without slipping.
  • the storage spring 15 is only slightly loaded when the piston of the spring storage cylinder 13 is suitably dimensioned, and can therefore be designed to be fatigue-free and unbreakable.
  • a further switch 19 indicated only by dashed lines, in the electrical connection between the current source and the switch 7, possibly also in the connection 11:
  • this switch 19 can be used for serve the operational actuation of the braking members 9, so no further service brake is required in this case.
  • the switch 19 is to be closed, the excitation of the solenoid valve 8 keeps the brake members 9 depressurized and thus released, while when the switch 19 is opened the excitation of the solenoid valve 8 is interrupted and the brake members are pressurized to brake will.
  • the switch 19, as is customary for service brakes, can be switched by any stops or a control program for the pressure medium cylinder.
  • FIG. 2 shows a braking device corresponding to that of FIG. 1, but the braking members are designed as a dual-circuit brake with the braking members 9 and 9 'for one braking circuit each, this dual-circuiting serves to further increase operational safety.
  • the parts corresponding to FIG. 1 are given the same reference numerals in FIG. 2 and therefore require no further explanation.
  • a pressure medium connection 20 leads from solenoid valve 8 to an inlet of a 5/3-way valve. 21, which is stabilized in its middle switching position by two springs 22.
  • the two output connections of the directional control valve 21 are each connected to the braking members 9 and 9 'via a pressure medium connection 10' and 23, respectively.
  • Branch channels lead from the pressure medium connections 10 'and 23 to the end-side loading chambers of the directional control valve 21, which switch these directional control valve 21 into one of its two end positions when the pressure medium is acted on unevenly.
  • the directional control valve 21 connects the pressure medium connection 20 to the two pressure medium connections 10 'and 23, so that both braking circuits are pressurized during braking operations, as described above for FIG. 1, and thus the braking members 9 and 9' have been applied .
  • the directional control valve 21 is therefore pressurized on one side via the branch channels and switches to one of its lateral limit switch positions, in which the pressure medium connection 20 alone with the intact brake circuit for the braking members 9 or 9 'connects while the other, defective brake circuit is kept depressurized.
  • the function of the braking device is thus ensured even in the case of a defective brake circuit. Otherwise, the function of the braking device according to FIG. 2 corresponds to that according to FIG. 1.
  • FIG. 3 To use the braking elements provided for the braking device also for the service braking of the pressure medium cylinder required in normal operation, an arrangement according to FIG. 3 can be provided in a further modification:
  • the check valve 3, the pressure switch 5, the air container 4 and the spring accumulator 13 combined into a structural unit, which is symbolized by a square 24, to which on the one hand the pressure medium source 1 and on the other hand a solenoid valve 8 'is connected.
  • the line 10 or 20 extends from the solenoid valve 8 'according to FIG. 1 or 2.
  • the solenoid valve 8 'does not connect the pressure medium connection 10 or 20 to the atmosphere, but rather to a further solenoid valve 25; in the de-energized state, the connections and functions described in FIGS. 1 and 2 are effected.
  • the solenoid valve 25 is designed as a 3/2-way valve, in the unexcited state it connects a pressure medium source 1 ', which may correspond to the pressure medium source 1, to the solenoid valve 8', in the excited state it keeps the connection to the solenoid valve 8 'depressurized.
  • p3 means the pressure applied to the braking elements, that is to say the pressure prevailing in the pressure medium connection 10 or 20, p2 the pressure in the pressure medium reservoir 4, p v the pressure of the pressure medium source 1 and I the excitation current for the solenoid valve 8 or 8 '.
  • the time course is plotted on the abscissa.
  • T the pressure medium and the current source are intact.
  • T occurs during the period between the times t 1 and tz a controlled by closing the switch 19 release process, the solenoid valve 8 picks up during this period, so that the pressure p 3 drops and the braking members 9 release.
  • the pressure in the pressure medium reservoir 4 has dropped to a value at which the spring-loaded cylinder 13 responds and the piston rod 14 extends; however, the braking members 9 are still securely applied. If there is a further loss of pressure, the pressure drops below the pressure in the braking elements 9 at which they begin to slip under load with the nominal load of the pressure medium cylinder, at the latest immediately after this point in time, the piston rod 14 engages in a hole 17 in the perforated strip 16 and locks the pressure medium cylinder in a form-fitting manner . It can thus be seen that if the pressure medium source fails, the frictional braking elements 9 are actuated and if there is a subsequent pressure loss due to leakage, a positive locking takes place.
  • a rodless cylinder 26 is indicated in front view, top view and side view with broken lines, which cylinder is provided with a slide or force output element 27 shown in solid lines.
  • the force output element 27 includes a braking element, as is known, for example, from EP-A mentioned at the beginning. From FIG. 5B, which shows a section along the line A-B in FIG. 5A, it can be seen that the force output element 27 contains cavities 28 which serve as pressure medium stores. Furthermore, a recess 29 for receiving a check valve and a further recess 30 for receiving a pressure switch 31 are provided, the pressure switch 31, in contrast to FIG.
  • the spring storage cylinder 13 with the storage spring 15 and the piston rod 14 is arranged in the center of the force output member 27, the piston rod 14 extends transversely to the longitudinal direction of the cylinder 26.
  • a solenoid valve 32 is provided, which corresponds to the solenoid valve 25 according to FIG.
  • the above-mentioned functional parts are connected by means of bores and channels running in the walls of the power output member 27.
  • clamping grooves 33 On the outside of the cylinder 26 there are clamping grooves 33, one of which is clamped with a stop 35 by means of a clamping device 34.
  • the stop 35 protrudes only when the piston rod is extended in its path of motion when the force output member 27 is moving. Overall, this results in a rodless cylinder which, with little additional effort and little increase in the required installation space, also has a frictional braking device which acts in emergencies and has a positive, has adjustable emergency stop by the clamping device 34.
  • the braking device is also suitable for hydraulic pressure medium cylinders, the pressure medium accumulator must be designed accordingly and return lines must be provided instead of venting.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valves And Accessory Devices For Braking Systems (AREA)
  • Braking Arrangements (AREA)
  • Braking Systems And Boosters (AREA)
  • Lock And Its Accessories (AREA)

Abstract

1. Braking device for pressure medium cylinders, especially cylinders (26) without a piston rod, having a braking element (9, 9') which can be operated on by pressure medium, this pressure medium operation being monitored by a switch valve (8, 8'), characterised in that between a pressure medium source (1) and the switch valve (8, 8'), constructed at least as a 3/2-way valve, there is arranged a pressure medium reservoir (4) which can be charged by means of a non-return valve (3) from the pressure medium source, in that the pressure of the pressure medium source (1) acts on a pressure monitor (5) which, when a first high pressure threshold is not reached, switches the switch valve (8, 8') so that it opens an otherwise closed connection from the pressure medium reservoir (4) to the brake element (9, 9'), in that a spring-loaded cylinder (13), acted on by the pressure medium reservoir (4), is provided which, when acted on by a pressure which falls below a second mean pressure threshold, activates a mechanical movement lock (14, 16) arranged in parallel to the braking element (9, 9'), and in that the braking element (9, 9') is designed to maintain the nominal load of the pressure medium cylinder until its actuation pressure falls below a third, low pressure threshold.

Description

Die Erfindung betrifft eine Bremseinrichtung für Druckmittelzylinder, insbesondere kolbenstangenlose Zylinder, mit einem durch Druckmittelbeaufschlagung zuspannbaren Bremsorgan, dessen Druckmittelbeaufschlagung durch ein Schaltventil überwacht ist.The invention relates to a braking device for pressure medium cylinders, in particular rodless cylinders, with a brake element which can be tightened by means of pressure medium application and whose pressure medium application is monitored by a switching valve.

Derartige Bremseinrichtungen zeigt beispielsweise die EP-A 104 364 für kolbenstangenlose Zylinder, wobei das Bremsorgan im Kraftabnahmeorgan integriert angeordnet ist.Such braking devices are shown, for example, in EP-A 104 364 for rodless cylinders, the braking member being arranged integrated in the power take-off member.

Bei derartigen Zylindern ist es des weiteren bekannt, am Zylinderkörper außenseitig Klemmnuten anzubringen, an welchen hubabhängig schaltende Schalter justierbar anklemmbar sind.In such cylinders, it is also known to provide clamping grooves on the outside of the cylinder body, to which stroke-dependent switches can be adjustably connected.

Die erwähnten, bekannten Bremsorgane weisen den Mangel auf, bei ungewolltem Druckverlust zu lösen, was aus Sicherheitsgründen oftmals nicht zugelassen werden kann. Zum Vermeiden dieses Mangels ist es bekannt, die Bremsorgane als Federspeicherbremsen auszubilden, sie also mit Federkraft zuzuspannen und durch Druckmitteldruck zu lösen. Hierbei ist es jedoch schwierig, Federn, die bei ausreichendem Hub ausreichend kräftig sind, in den beengten Einbauräumen unterzubringen; außerdem können diese hoch beanspruchten Federn erlahmen oder brechen, wodurch das Bremsorgan ausfällt.The known brake devices mentioned have the defect to solve in the event of an undesired loss of pressure, which often cannot be permitted for safety reasons. To avoid this deficiency, it is known to design the braking members as spring-loaded brakes, that is to say to apply them with spring force and to release them by means of pressure medium. Here, however, it is difficult to accommodate springs that are sufficiently strong with a sufficient stroke in the cramped installation spaces; in addition, these highly stressed springs can slacken or break, causing the braking element to fail.

Es ist somit Aufgabe der Erfindung, eine Bremseinrichtung der eingangs genannten Art zu schaffen, welche bei einfachem Aufbau eine sichere Funktion aufweist.It is therefore an object of the invention to provide a braking device of the type mentioned at the outset, which has a safe function with a simple structure.

Diese Aufgabe wird nach der Erfindung dadurch gelöst, daß zwischen eine Druckmittelquelle und das wenigstens als 3/2-Wegventil ausgebildete Schaltventil ein über ein Rückschlagventil aus einer Druckmittelquelle aufladbarer Druckmittelspeicher eingeordnet ist, daß der Druck der Druckmittelquelle einen Druckwächter beaufschlagt, der bei Unterschreiten einer ersten, hohen Druckschwelle das Schaltventil auf Öffnen einer ansonsten geschlossenen Verbindung vom Druckmittelspeicher zum Bremsorgan schaltet, daß ein aus dem Druckmittelspeicher beaufschlagter Federspeicherzylinder vorgesehen ist, der beim Beaufschlagen mit einem eine zweite, mittlere Druckschwelle überschreitenden Druck eine mechanische, zum Bremsorgan parallel angeordnete Bewegungssperre aktiviert, und daß das Bremsorgan die Nennlast des Druckmittelzylinders bis zum Unterschreiten einer dritten, niedrigen Druckschwelle ihres Beaufschlagungsdruckes haltend ausgebildet ist.This object is achieved according to the invention in that a pressure medium accumulator which can be charged via a check valve from a pressure medium source is arranged between a pressure medium source and the switching valve, which is designed as a 3/2-way valve, in that the pressure of the pressure medium source acts on a pressure switch which, when the pressure falls below a first one , high pressure threshold switches the switching valve to opening an otherwise closed connection from the pressure medium store to the braking element, that a spring-loaded cylinder acted upon from the pressure medium memory is provided, which activates a mechanical movement lock arranged in parallel with the braking element when subjected to a pressure exceeding a second, medium pressure threshold, and that the braking member is designed to hold the nominal load of the pressure medium cylinder until the pressure drops below a third, low pressure threshold.

Hierdurch wird erreicht, daß bei ungewolltem Druckabfall oder -ausfall der Druckmittelquelle anfänglich das Bremsorgan aus dem Druckmittelspeicher zu seiner Betätigung druckbeaufschlagt wird, fällt auch dieser Druck unzulässig ab, so schaltet der Federspeicherzylinder die mechanische Bewegungssperre ein, wozu die Feder des Federspeicherzylinders nur eine geringe Leistung aufbringen muß; der Druckmittelzylinder wird also sodann durch die mechanische Bewegungssperre in seiner Stellung verriegelt und kann keine ungewollte Bewegung ausführen.This ensures that in the event of an undesired pressure drop or failure of the pressure medium source, the brake member is initially pressurized from the pressure medium store to actuate it, this pressure also drops inadmissibly, the spring-loaded cylinder switches on the mechanical movement lock, for which purpose the spring of the spring-loaded cylinder only has a low output must muster; the pressure medium cylinder is then locked in position by the mechanical movement lock and cannot carry out any unwanted movement.

Nach der weiteren Erfindung vorteilhafte Ausgestaltungsmöglichkeiten der Bremseinrichtung sind den Unteransprüchen entnehmbar.According to the further invention, advantageous design options for the braking device can be found in the subclaims.

In der Zeichnung sind Ausführungsbeispiele für nach der Erfindung ausgebildete Bremseinrichtungen dargestellt, und zwar zeigen

  • Fig.1 u. 2 zwei unterschiedliche Ausführungsformen in schematischer Darstellung,
  • Fig.3 eine Ergänzung der Bremseinrichtung mit einer direkten Bremssteuerung in ebenfalls schematischer Darstellung,
  • Fig.4 ein Funktionsdiagramm und
  • Fig.5 A bis D ein Kraftabnahmeorgan eines kolbenstangenlosen Zylinders mit integrierter Bremseinrichtung in drei Ansichten und einem Schnittbild.
In the drawing, exemplary embodiments of braking devices designed according to the invention are shown, namely
  • Fig.1 u. 2 shows two different embodiments in a schematic representation,
  • 3 shows a supplement to the braking device with a direct brake control, likewise in a schematic representation,
  • 4 shows a functional diagram and
  • 5 A to D a force take-off element of a rodless cylinder with an integrated braking device in three views and a sectional view.

Gemäß Fig.1 führt von einer Druckmittelquelle 1, hier einer Druckluftquelle, eine Druckmittelverbindung 2 durch ein Rückschlagventil 3 zu einem als Behälter ausgebildeten Druckmittelspeicher 4. An die Druckmittelverbindung 2 ist ein Druckwächter 5 angeschlossen, welcher oberhalb einer relativ hohen, durch eine verstellbare Feder 6 einstellbaren Druckschwelle in der Druckmittelverbindung 2 einen Schalter 7 geschlossen und unterhalb dieser Druckschwelle geöffnet hält. An den Druckmittelspeicher ist ein als Magnetventil 8 ausgebildetes, ein 3/2-Wegeventil darstellendes Schaltventil angeschlossen, welches im unerregten Zustand den Druckmittelspeicher 4 mit einer zu Bremsorganen 9 führenden Druckmittelverbindung 10 verbindet; im unerregten Zustand sperrt das Magnetventil 8 diese Verbindung und hält die Druckmittelverbindung 10 drucklos, beispielsweise bei der dargestellten, pneumatischen Anlage in die Atmosphäre entlüftet.According to FIG. 1, a pressure medium connection 2 leads from a pressure medium source 1, here a compressed air source, through a check valve 3 to a pressure medium reservoir 4 designed as a container. A pressure switch 5 is connected to the pressure medium connection 2, which is above a relatively high spring 6 by an adjustable spring 6 adjustable pressure threshold in the pressure medium connection 2 closes a switch 7 and keeps it open below this pressure threshold. A switching valve, designed as a solenoid valve 8 and representing a 3/2-way valve, is connected to the pressure medium accumulator and connects the pressure medium accumulator 4 to a pressure medium connection 10 leading to braking elements 9 in the de-energized state; in the de-energized state, the solenoid valve 8 blocks this connection and keeps the pressure medium connection 10 depressurized, for example in the illustrated pneumatic system, vented to the atmosphere.

Der Schalter 7 ist in eine elektrische Verbindung 11 von einer lediglich durch ein Pluszeichen symbolisierten Stromquelle zur Erregungsspule des Magnetventils 8 eingeordnet. Weiterhin ist an den Druckmittelspeicher 4 der Beaufschlagungsraum 12 eines Federspeicherzylinders 13 angeschlossen, dessen Kolbenstange 14 bei Unterschreiten einer zweiten, mittleren Druckschwelle im Beaufschlagungsraum 12 unter der Kraft der Speicherfeder 15 ausfährt. Im eingefahrenen Zustand endet die einen Raststift darstellende Kolbenstange 14 vor einer vor dem Federspeicherzylinder 13 befindlichen Lochleiste 16, im ausgefahrenen Zustand vermag die Kolbenstange 14 in die Löcher 17 der Lochleiste 16 einzugreifen. Die Kolbenstange 14 bildet also zusammen mit der Lochleiste 16 eine mechanische, schaltbare Bewegungssperre 14,16.The switch 7 is arranged in an electrical connection 11 from a current source symbolized only by a plus sign to the excitation coil of the solenoid valve 8. Furthermore, the pressure chamber 12 of a spring-loaded cylinder 13 is connected to the pressure medium reservoir 4, the piston rod 14 of which extends under the force of the spring 15 when the pressure falls below a second, medium pressure threshold in the pressure chamber 12. In the retracted state, the piston rod 14, which represents a locking pin, ends in front of a perforated strip 16 located in front of the spring-loaded cylinder 13; in the extended state, the piston rod 14 can engage in the holes 17 in the perforated strip 16. The piston rod 14 thus forms, together with the perforated strip 16, a mechanical, switchable movement lock 14, 16.

Die vorstehend beschriebene Bremseinrichtung ist an einem in Fig.1 nicht dargestellten Druckmittelzylinder mit wenigstens einem feststehenden und einem unter Druckmittelbeaufschlagung beweglichen Teil derart angeordnet, daß sich das Rückschlagventil 3, der Druckwächter 5, der Druckmittelspeicher 4, das Magnetventil 8, die Bremsorgane 9 und der Federspeicherzylinder 13 am einen und die Lochleiste 16 am anderen der beiden Teile befinden. Bei einem kolbenstangenlosen Zylinder mit einem zumeist schlittenartig ausgebildeten Krafabnahmeorgan ist die Lochleiste 16 zweckmäßig feststehend, bei einem üblichen Kolbenstangenzylinder umgekehrt die Lochleiste 16 mit der Kolbenstange beweglich anzuordnen. Die Bremsorgane 9 sind in üblicher Weise als Reibungsbremse aufgebaut, sie können, wie aus der eingangs bereits erwähnten EP-A 104 364 ersichtlich, jeweils einen durch die Druckmittelverbindung 10 druckmittelbeaufschlagbaren Zylinder oder Balg aufweisen, der bei seiner Druckbeaufschlagung ein Reibelement, insbesondere eine Bremsbacke bzw. einen Bremsbelag an das hierzu relativ verschiebliche, andere Teil des Druckmittelzylinders andrückt.The braking device described above is arranged on a pressure medium cylinder (not shown in FIG. 1) with at least one fixed part and one part that can move under pressure medium in such a way that the check valve 3, the pressure monitor 5, the pressure medium accumulator 4, the solenoid valve 8, the braking members 9 and the Spring cylinder 13 on one and the perforated strip 16 on the other of the two parts. In a rodless cylinder with a mostly sled-like force-absorbing element, the perforated strip 16 is expediently fixed, in a conventional piston rod cylinder vice versa to arrange the perforated strip 16 movably with the piston rod. The braking members 9 are constructed in the usual way as a friction brake; they can, as can be seen from EP-A 104 364 already mentioned at the beginning, each have a cylinder or bellows which can be pressurized by the pressure medium connection 10 and which, when pressurized, has a friction element, in particular a brake shoe or presses a brake lining onto the other part of the pressure cylinder which is relatively displaceable for this purpose.

Zusätzlich zur in Fig.1 dargestellten Bremseinrichtung kann der Druckmittelzylinder mit einer weiteren, üblichen Bremse beispielsweise gemäß der erwähnten EP-A 104 364 ausgestattet sein, welche als Betriebsbremse im normalen Betrieb des Druckmittelzylinders genutzt wird.In addition to the brake device shown in FIG. 1, the pressure medium cylinder can be equipped with a further, customary brake, for example according to EP-A 104 364 mentioned, which is used as a service brake in normal operation of the pressure medium cylinder.

Die Bremseinrichtung nach Fig.1 wirkt wie folgt:The braking device according to Fig. 1 acts as follows:

Solange die Druckmittelquelle 1 ausreichenden Druck aufweist, ist der Schalter 7 geschlossen und bei funktionsfähiger Stromquelle das Magnetventil 8 somit erregt. Aus der Druckmittelquelle 1 wird durch das Rückschlagventil 3 der Druckmittelspeicher 4 gefüllt, das erregte Magnetventil 8 hält die Bremsorgane 9 jedoch drucklos und damit gelöst. Aus dem Druckmittelspeicher 4 wird der Federspeicherzylinder 13 beaufschlagt, so daß dessen Kolbenstange 14 eingefahren und außer Eingriff zur Lochleiste 16 ist. Sinkt nun der an der Druckmittelquelle 1 anstehende Druck durch irgendwelche Schäden bedingt ab, so öffnet bei Unterschreiten einer ersten, noch relativ hohen Druckschwelle der Schalter 7 des Druckwächters 5 und unterbricht damit die Erregung des Magnetventils 8. Das Magnetventil 8 schaltet daher in die dargestellte Schaltstellung um, wobei es die Bremsorgane 9 von der Atmosphäre abtrennt und stattdessen an den Druckmittelspeicher 4 anschließt. Aus dem Druckmittelspeicher 4 werden daher die Bremsorgane 9 druckbeaufschlagt und spannen zu, so daß der Druckmittelzylinder in seiner augenblicklichen Lage festgebremst wird. Da durch die Druckminderung der Druckmittelquelle 1 über das Rückschlagventil 3 keine Drucknachspeisung mehr in den Druckmittelspeicher 4 erfolgt, stellt sich zwischen dem Druckmittelspeicher 4 und den Beaufschlagungsräumen der Bremsorgane 9 ein Ausgleichsdruck ein, welcher jedoch durch entsprechendes Bemessen des Volumens des Druckmittelspeichers 4 beachtlich über derjenigen Druckhöhe liegt, welche zum sicheren Festbremsen des Druckmittelzylinders unter dessen Nennlast erforderlich ist. Der Federspeicherzylinder 13 verbleibt hierbei in seiner gespannten Stellung, die Kolbenstange 14 verbleibt also au-Ber Eingriff zur Lochleiste 16.As long as the pressure medium source 1 has sufficient pressure, the switch 7 is closed and the solenoid valve 8 is thus energized when the current source is functioning. The pressure medium reservoir 4 is filled by the check valve 3 from the pressure medium source 1, but the energized solenoid valve 8 keeps the braking members 9 depressurized and thus released. The spring-loaded cylinder 13 is acted upon from the pressure medium reservoir 4, so that its piston rod 14 is retracted and out of engagement with the perforated strip 16. If the pressure at the pressure medium source 1 drops due to any damage, the switch 7 of the pressure switch 5 opens when the pressure falls below a first, still relatively high pressure threshold and thus interrupts the excitation of the solenoid valve 8. The solenoid valve 8 therefore switches to the switch position shown um, whereby it separates the braking members 9 from the atmosphere and instead connects to the pressure medium accumulator 4. The braking elements 9 are therefore pressurized from the pressure medium store 4 and tighten, so that the pressure medium cylinder is braked in its current position. Since the pressure drop in the pressure medium source 1 via the check valve 3 means that there is no further pressure make-up in the pressure medium reservoir 4, a compensating pressure is established between the pressure medium reservoir 4 and the pressurized spaces of the braking members 9, which, however, is considerably higher than the pressure level by appropriately dimensioning the volume of the pressure medium reservoir 4 which is required to safely brake the pressure medium cylinder under its nominal load. The spring-loaded cylinder 13 remains in its tensioned position, the piston rod 14 thus remains disengaged from the perforated strip 16.

Falls nun am Druckmittelspeicher 4 oder den mit diesem verbundenen Räumen eine Undichtigkeit vorhanden ist oder auftritt, sinkt der in diesen Räumen herrschende Ausgleichsdruck allmählich ab. Bei Unterschreiten einer zweiten, mittleren Druckschwelle schiebt die Speicherfeder 15 des Federspeicherzylinders 13 die Kolbenstange 14 aus, so daß diese in Eingriff zur Lochleiste 16 gelangt. Im allgemeinen wird dabei die Kolbenstange 14 noch nicht in eines der Löcher 17 der Lochleiste 16 eingreifen, sondern auf der dem Federspeicher 13 zugewandten Oberfläche 18 der Lochleiste 16 aufstehen. Bei dieser erwähnten, mittleren Druckschwelle reicht der Beaufschlagungsdruck immer noch aus, um die Bremsorgane 9 sicher zuzuspannen. Bei weiter anhaltender Undichtheit sinkt der im Druckmittelspeicher 4 und den mit diesem verbundenen Räumen anstehende Druck weiter ab. Sobald dieser Druck eine dritte, relativ niedrige Druckschwelle unterschreitet reicht die Zuspannkraft der Bremsorgane 9 nicht mehr aus, um den Druckmittelzylinder bei dessen Belastung mit einer Nennlast abzubremsen, die Kolbenstange bzw. das Kraftabnahmeorgane des Druckmittelzylinders beginnt also bei Belastung mit Nennlast durchzurutschen. Bei diesem Durchrutschen verschiebt sich die Lochleiste 16 in ihrer Längsrichtung relativ zum Federspeicherzylinder 13, so daß alsbald eines der Löcher 17 vor die Kolbenstange 14 gelangt und die Kolbenstange 14 somit in dieses Loch 17 einrastet, wie es in Fig.1 dargestellt ist. Bei geringer, weiterer Verschiebung gelangt die Lochleiste 18 mit der Wandung des Loches 17 zur Anlage an der Kolbenstange 14 und wird hierdurch formschlüssig an einer weiteren Verschiebung gehindert. Damit ist der Druckmittelzylinder formschlüssig gesperrt, es kann also keine weitere Bewegung erfolgen. Sollte zufälligerweise die Kolbenstange 14 sogleich bei ihrem Ausfahren in eines der Löcher 17 eingerasten, so bedarf es selbstverständlich des vorerwähnten Durchrutschens des Druckmittelzylinders nicht, der Druckmittelzylinder wird hierbei sofort ohne Durchrutschvorgang formschlüssig gesperrt.If a leak is present or occurs on the pressure medium reservoir 4 or the rooms connected to it, the compensating pressure prevailing in these rooms gradually drops. If the pressure falls below a second, medium pressure threshold, the storage spring 15 of the spring-loaded cylinder 13 pushes out the piston rod 14 so that it engages with the perforated strip 16. In general, the piston rod 14 will not yet engage in one of the holes 17 in the perforated strip 16, but will stand on the surface 18 of the perforated strip 16 facing the spring accumulator 13. At this medium pressure threshold mentioned, the application pressure is still sufficient to securely apply the braking elements 9. If the leak continues, the pressure in the pressure medium reservoir 4 and the spaces connected to it further decreases. As soon as this pressure falls below a third, relatively low pressure threshold, the application force of the braking elements 9 is no longer sufficient to brake the pressure medium cylinder when it is loaded with a nominal load, so the piston rod or the force-taking elements of the pressure medium cylinder begin to slip under load with a nominal load. During this slipping, the perforated strip 16 shifts in its longitudinal direction relative to the spring-loaded cylinder 13, so that one of the holes 17 immediately reaches the piston rod 14 and the piston rod 14 thus snaps into this hole 17, as shown in FIG. With a slight, further displacement, the perforated strip 18 comes into contact with the piston rod 14 with the wall of the hole 17 and is thereby positively prevented from further displacement. The pressure medium cylinder is thus locked in a form-fitting manner, so no further movement can take place. If, by chance, the piston rod 14 immediately engages in one of the holes 17 when it is extended, the aforementioned slipping of the pressure medium cylinder is of course not required; the pressure medium cylinder is locked in a positive manner without slipping.

Die Speicherfeder 15 wird bei geeigneter Dimensionierung des Kolbens des Federspeicherzylinders 13 nur gering belastet, sie kann daher ermüdungsfrei und bruchsicher ausgebildet werden.The storage spring 15 is only slightly loaded when the piston of the spring storage cylinder 13 is suitably dimensioned, and can therefore be designed to be fatigue-free and unbreakable.

In Abänderung der vorstehend vorbeschriebenen Ausführung ist es möglich, in die elektrische Verbindung zwischen der Stromquelle und dem Schalter 7, gegebenenfalls auch in die Verbindung 11, einen weiteren, nur gestrichelt angedeuteten Schalter 19 einzuordnen: Bei intakter Druckmittel-und Stromquelle kann dieser Schalter 19 zum betriebsmäßigen Betätigen der Bremsorgane 9 dienen, es ist in diesem Falle also keine weitere Betriebsbremse erforderlich. Zum Lösen bzw. Gelösthalten der Bremsorgane 9 ist der Schalter 19 zu schließen, durch die Erregung des Magnetventiles 8 werden hierbei die Bremsorgane 9 drucklos und damit gelöst gehalten, während beim Offnen des Schalters 19 die Erregung des Magnetventils 8 unterbrochen und die Bremsorgane zum Einbremsen druckmittelbeaufschlagt werden. Der Schalter 19 kann, wie für Betriebsbremsen üblich, durch irgendwelche Anschläge oder ein Steuerprogramm für den Druckmittelzylinder schaltbar sein.In a modification of the above-described embodiment, it is possible to place a further switch 19, indicated only by dashed lines, in the electrical connection between the current source and the switch 7, possibly also in the connection 11: With an intact pressure medium and current source, this switch 19 can be used for serve the operational actuation of the braking members 9, so no further service brake is required in this case. To release or hold the brake members 9, the switch 19 is to be closed, the excitation of the solenoid valve 8 keeps the brake members 9 depressurized and thus released, while when the switch 19 is opened the excitation of the solenoid valve 8 is interrupted and the brake members are pressurized to brake will. The switch 19, as is customary for service brakes, can be switched by any stops or a control program for the pressure medium cylinder.

Die Fig.2 zeigt eine Bremseinrichtung entsprechend derjenigen nach Fig.1, wobei jedoch die Bremsorgane als Zweikreisbremse mit den Bremsorganen 9 und 9' für jeweils einen Bremskreis ausgebildet sind, diese Zweikreisigkeit dient der weiteren Steigerung der Betriebssicherheit. Die zu Fig.1 übereinstimmenden Teile sind in Fig.2 mit den gleichen Bezugszeichen versehen und bedürfen daher keiner weiteren Erläuterung. In Abänderung zu Fig.1 führt vom Magnetventil 8 eine Druckmittelverbindung 20 zu einem Eingang eines 5/3-Wegeventils . 21, das in seiner mittleren Schaltstellung durch zwei Federn 22 stabilisiert ist. Die beiden Ausgangsanschlüsse des Wegeventils 21 sind über je eine Druckmittelverbindung 10' bzw. 23 mit den Bremsorganen 9 bzw. 9' verbunden. Von den Druckmittelverbindungen 10' und 23 führen Zweigkanäle zu endseitigen Beaufschlagungskammern des Wegeventils 21, welche bei ungleicher Druckmittelbeaufschlagung dieses Wegeventil 21 in eine seiner beiden Endstellungen schalten. In der dargestellten, mittleren Schaltstellung verbindet das Wegeventil 21 die Druckmittelverbindung 20 mit den beiden Druckmittelverbindungen 10' und 23, so daß während Einbremsvorgängen, wie sie vorstehend zu Fig.1 beschrieben wurden, beide Bremskreise druckbeaufschlagt und damit die Bremsorgane 9 und 9' zugespannt wurden. Falls einer der beiden Bremskreise durch Undichtigkeit ausfällt, vermag sich während Bremsungen in ihm kein Druck aufzubauen, das Wegeventil 21 wird daher über die Zweigkanäle einseitig druckbeaufschlagt und schaltet in eine seiner seitlichen Endschaltstellungen, in welcher es die Druckmittelverbindung 20 allein mit dem jeweils intakten Bremskreis für die Bremsorgane 9 oder 9' verbindet, während der andere, defekte Bremskreis drucklos gehalten wird. Auch bei einem defekten Bremskreis wird somit die Funktion der Bremseinrichtung sichergestellt. Im übrigen entspricht die Funktion der Bremseinrichtung nach Fig.2 derjenigen nach Fig.1.2 shows a braking device corresponding to that of FIG. 1, but the braking members are designed as a dual-circuit brake with the braking members 9 and 9 'for one braking circuit each, this dual-circuiting serves to further increase operational safety. The parts corresponding to FIG. 1 are given the same reference numerals in FIG. 2 and therefore require no further explanation. 1, a pressure medium connection 20 leads from solenoid valve 8 to an inlet of a 5/3-way valve. 21, which is stabilized in its middle switching position by two springs 22. The two output connections of the directional control valve 21 are each connected to the braking members 9 and 9 'via a pressure medium connection 10' and 23, respectively. Branch channels lead from the pressure medium connections 10 'and 23 to the end-side loading chambers of the directional control valve 21, which switch these directional control valve 21 into one of its two end positions when the pressure medium is acted on unevenly. In the middle switching position shown, the directional control valve 21 connects the pressure medium connection 20 to the two pressure medium connections 10 'and 23, so that both braking circuits are pressurized during braking operations, as described above for FIG. 1, and thus the braking members 9 and 9' have been applied . If one of the two brake circuits fails due to a leak, no pressure can build up in it during braking, the directional control valve 21 is therefore pressurized on one side via the branch channels and switches to one of its lateral limit switch positions, in which the pressure medium connection 20 alone with the intact brake circuit for the braking members 9 or 9 'connects while the other, defective brake circuit is kept depressurized. The function of the braking device is thus ensured even in the case of a defective brake circuit. Otherwise, the function of the braking device according to FIG. 2 corresponds to that according to FIG. 1.

Zum Benutzen der für die Bremseinrichtung vorgesehenen Bremsorgane auch für die im normalen Betrieb erforderlichen Betriebsbremsungen des Druckmittelzylinders kann in weiterer Abänderung eine Anordnung gemäß Fig.3 vorgesehen werden: In Fig.3 sind das Rückschlagventil 3, der Druckwächter 5, der Luftbehälter 4 und der Federspeicher 13 zu einer Baueinheit zusammengefaßt, welche durch ein Viereck 24 symbolisiert ist, an welches einerseits die Druckmittelquelle 1 und andererseits ein Magnetventil 8' angeschlossen ist. Vom Magnetventil 8' geht die Leitung 10 bzw. 20 gemäß Fig.1 bzw. 2 aus. In Abänderung zu Fig.1 und 2 verbindet das Magnetventil 8' im erregten Zustand die Druckmittelverbindung 10 bzw. 20 nicht mit der Atmosphäre, sondern mit einem weiteren Magnetventil 25; im unerregten Zustand werden die zu Fig.1 und 2 beschriebenen Verbindungen und Funktionen bewirkt. Das Magnetventil 25 ist als 3/2-Wegeventil ausgebildet, im unerregten Zustand schließt es eine Druckmittelquelle 1', welche der Druckmittelquelle 1 entsprechen kann, an das Magnetventil 8' an, im erregten Zustand hält es die Verbindung zum Magnetventil 8' drucklos. Es ergibt sich somit, daß bei intakter Druckmittelquelle und Stromversorgung mittels des Magnetventiles 25 eine direkte Steuerung der Druckbeaufschlagung der Bremsorgane möglich ist, wobei bei unerregtem Magnetventil 25 die Bremsorgane betätigt und bei erregtem Magnetventil 25 die Bremsorgane gelöst sind.To use the braking elements provided for the braking device also for the service braking of the pressure medium cylinder required in normal operation, an arrangement according to FIG. 3 can be provided in a further modification: In FIG. 3, the check valve 3, the pressure switch 5, the air container 4 and the spring accumulator 13 combined into a structural unit, which is symbolized by a square 24, to which on the one hand the pressure medium source 1 and on the other hand a solenoid valve 8 'is connected. The line 10 or 20 extends from the solenoid valve 8 'according to FIG. 1 or 2. 1 and 2, the solenoid valve 8 'does not connect the pressure medium connection 10 or 20 to the atmosphere, but rather to a further solenoid valve 25; in the de-energized state, the connections and functions described in FIGS. 1 and 2 are effected. The solenoid valve 25 is designed as a 3/2-way valve, in the unexcited state it connects a pressure medium source 1 ', which may correspond to the pressure medium source 1, to the solenoid valve 8', in the excited state it keeps the connection to the solenoid valve 8 'depressurized. It thus follows that with an intact pressure medium source and power supply by means of the solenoid valve 25 direct control of the pressurization of the braking members is possible, the braking members being actuated when the solenoid valve 25 is not energized and the braking members released when the solenoid valve 25 is energized.

Im Diagramm nach Fig.4 ist die Funktion der Bremseinrichtung nach Fig.1,2 oder 3 verdeutlicht. In Fig.4 bedeutet p3 den Beaufschlagungsdruck der Bremsorgane, also den in der Druckmittelverbindung 10 bzw. 20 herrschenden Druck, p2 den Druck im Druckmittelspeicher 4, pv den Druck der Druckmittelquelle 1 und I den Erregungsstrom für das Magnetventil 8 bzw. 8'. Auf der Abszisse ist jeweils der Zeitablauf aufgetragen. Während der Zeitspanne T sind die Druckmittel- und die Stromquelle intakt. Während dieser Zeitspanne T erfolgt während der zwischen den Zeitpunkten t1 und tz liegenden Zeitspanne ein durch Schließen des Schalters 19 gesteuerter Lösevorgang, das Magnetventil 8 zieht während dieser Zeitspanne an, so daß der Beaufschlagungsdruck p3 abfällt und die Bremsorgane 9 lösen. Zum Zeitpunkt t3 erfolgt ein neuer Lösevorgang, welcher an sich bis zum Zeitpunkt t4 anhalten soll. Zum Zeitpunkt ts fällt jedoch die Druckmittelquelle 1 aus, ihr Druck fällt gemäß pv rasch ab und der Schalter 7 des Druckwächtes 5 öffnet sich alsbald. Das Magnetventil 8 fällt ab und beaufschlagt die Bremsorgane 9 aus den Druckmittelspeicher 4, so daß dessen Druck, wie aus dem Druckverlauf des p2 ersichtlich, geringfügig abfällt; der abgefallene Druck reicht jedoch zum sicheren Einbremsen aus. Zum Zeitpunkt t6 sollen zusätzlich die Bremsorgane 9 undicht werden, so daß ihr Beaufschlagungsdruck zusammen mit dem Druck des Druckmittelspeichers 4, wie aus den Druckverläufen p3 und p2 ersichtlich, abzufallen beginnt. Zum Zeitpunkt t? ist der Druck im Druckmittelspeicher 4 auf einen Wert abgefallen, bei welchem der Federspeicherzylinder 13 anspricht und die Kolbenstange 14 ausfährt; die Bremsorgane 9 sind jedoch noch sicher zugespannt. Bei weiterem Druckverlust wird zum Zeitpunkt ts in den Bremsorganen 9 eine Druckschwelle unterschritten, bei welcher sie unter Belastung mit der Nennlast des Druckmittelzylinders durchzurutschen beginnen, spätestens unmmittelbar nach diesem Zeitpunkt rastet die Kolbenstange 14 in ein Loch 17 der Lochleiste 16 ein und verriegelt formschlüssig den Druckmittelzylinder. Es ist also ersichtlich, daß bei Ausfall der Druckmittelquelle die reibschlüssigen Bremsorgane 9 betätigt werden und bei nachfolgendem, undichtheitsbedingtem Druckverlust eine formschlüssige Verriegelung erfolgt. Damit ist für den Druckmittelzylinder eine große Sicherheit gegen unerwünschte Bewegungen gegeben. Zum Zeitpunkt tg wird die Druckmittelquelle 1 wieder druckführend, der Druckwächter 5 schließt alsbald seinen Schalter 7, so daß das Magnetventil 8 zwischen dem Zeitpunkt ts bis t4 wieder erregt wird, die Bremsorgane 9 während dieser Zeit also drucklos gehalten werden. Beim Druckaufbau im Druckmittelspeicher 4 zieht zugleich der Federspeicherzylinder 13 seine Kolbenstange 14 aus dem Loch 17 der Lochleiste 16 zurück, so daß die formschlüssige Verriegelung aufgehoben wird und der Druckmittelzylinder wieder bewegungsfrei ist. Zum Zeitpunkt t4 wird der Schalter 19 geöffnet, die Erregung des Magnetventils 8 somit unterbrochen und die Bremsorgane 9 zum Einbremsen aus dem wiederaufgeladenen Druckmittelspeicher 4 druckbeaufschlagt.The function of the braking device according to FIGS. 1, 2 or 3 is illustrated in the diagram according to FIG. In FIG. 4, p3 means the pressure applied to the braking elements, that is to say the pressure prevailing in the pressure medium connection 10 or 20, p2 the pressure in the pressure medium reservoir 4, p v the pressure of the pressure medium source 1 and I the excitation current for the solenoid valve 8 or 8 '. The time course is plotted on the abscissa. During the period T, the pressure medium and the current source are intact. During this period T occurs during the period between the times t 1 and tz a controlled by closing the switch 19 release process, the solenoid valve 8 picks up during this period, so that the pressure p 3 drops and the braking members 9 release. At time t 3 there is a new release process, which should continue until time t 4 . At time ts, however, the pressure medium source 1 fails, its pressure drops rapidly according to p v , and the switch 7 of the pressure monitor 5 opens immediately. The solenoid valve 8 drops and acts on the braking elements 9 from the pressure medium reservoir 4, so that its pressure, as can be seen from the pressure curve of p 2 , drops slightly; the drop in pressure is sufficient for safe braking. At time t 6 , the braking members 9 should additionally leak, so that their pressure of application begins to drop together with the pressure of the pressure medium reservoir 4, as can be seen from the pressure profiles p 3 and p 2 . At time t? the pressure in the pressure medium reservoir 4 has dropped to a value at which the spring-loaded cylinder 13 responds and the piston rod 14 extends; however, the braking members 9 are still securely applied. If there is a further loss of pressure, the pressure drops below the pressure in the braking elements 9 at which they begin to slip under load with the nominal load of the pressure medium cylinder, at the latest immediately after this point in time, the piston rod 14 engages in a hole 17 in the perforated strip 16 and locks the pressure medium cylinder in a form-fitting manner . It can thus be seen that if the pressure medium source fails, the frictional braking elements 9 are actuated and if there is a subsequent pressure loss due to leakage, a positive locking takes place. This provides great security against undesired movements for the pressure medium cylinder. At the point in time tg, the pressure medium source 1 becomes pressurized again, the pressure switch 5 soon closes its switch 7, so that the solenoid valve 8 is energized again between the points in time ts to t 4 , so that the braking members 9 are kept depressurized during this time. When pressure builds up in the pressure medium accumulator 4, the spring-loaded cylinder 13 simultaneously pulls its piston rod 14 out of the hole 17 in the perforated strip 16, so that the positive locking is released and the pressure medium cylinder is again free of movement. At time t 4 , the switch 19 is opened, the excitation of the solenoid valve 8 is thus interrupted and the braking members 9 are pressurized for braking from the recharged pressure medium reservoir 4.

In den Figuren 5 A-C ist in Stirnansicht, Aufsicht und Seitenansicht mit gestrichelten Linien ein kolbenstangenloser Zylinder 26 angedeutet, der mit einem ausgezogen dargestellten Schlitten bzw. Kraftabgabeorgan 27 versehen ist. Das Kraftabgabeorgan 27 beinhaltet ein Bremsorgan, wie es beispielsweise aus der eingangs erwähnten EP-A bekannt ist. Aus der einen Schnitt gemäß der Linie A-B in Fig.5 A darstellenden Fig.5 B ist ersichtlich, daß das Kraftabgabeorgan 27 Hohlräume 28 beinhaltet, welche als Druckmittelspeicher dienen. Weiterhin ist eine Ausnehmung 29 zur Aufnahme eines Rückschlagventils sowie eine weitere Ausnehmung 30 zur Aufnahme eines Druckwächters 31 vorgesehen, der Druckwächter 31 ist abweichend zu Fig.1 als 3/2-Wegeventil ohne Schalter 7 ausgebildet und erfüllt damit zugleich die Funktion des Magnetventils 8 nach Fig.1. Mittig ist im Kraftabgabeorgan 27 der Federspeicherzylinder 13 mit der Speicherfeder 15 und der Kolbenstange 14 angeordnet, die Kolbenstange 14 verläuft quer zur Längsrichtung des Zylinders 26. Schließlich ist noch ein Magnetventil 32 vorgesehen, welches dem Magnetventil 25 nach Fig.3 entspricht. Die Verschaltung der erwähnten Funktionsteile erfolgt durch in den Wandungen des Kraftabgabeorgans 27 verlaufende Bohrungen und Kanäle. Am Zylinder 26 sind außenseitig Klemmnuten 33 vorgesehen, an deren einer mittels einer Klemmvorrichtung 34 ein Anschlag 35 angeklemmt ist. Der Anschlag 35 ragt nur bei ausgefahrener Kolbenstange in deren Bewegungsbahn bei sich bewegendem Kraftabgabeorgan 27. Insgesamt ergibt sich somit ein kolbenstangenloser Zylinder, der bei geringem Mehraufwand und geringer Vergrößerung des erforderlichen Einbauraumes zusätzlich zu einer Betriebsbremse eine reibungsbehafte, in Notfällen wirkende Bremseinrichtung mit einem formschlüssigen, durch die Klemmvorrichtung 34 justierbar gehaltenen Notanschlag aufweist.In FIGS. 5 A-C, a rodless cylinder 26 is indicated in front view, top view and side view with broken lines, which cylinder is provided with a slide or force output element 27 shown in solid lines. The force output element 27 includes a braking element, as is known, for example, from EP-A mentioned at the beginning. From FIG. 5B, which shows a section along the line A-B in FIG. 5A, it can be seen that the force output element 27 contains cavities 28 which serve as pressure medium stores. Furthermore, a recess 29 for receiving a check valve and a further recess 30 for receiving a pressure switch 31 are provided, the pressure switch 31, in contrast to FIG. 1, is designed as a 3/2-way valve without a switch 7 and thus also fulfills the function of the solenoid valve 8 Fig. 1. The spring storage cylinder 13 with the storage spring 15 and the piston rod 14 is arranged in the center of the force output member 27, the piston rod 14 extends transversely to the longitudinal direction of the cylinder 26. Finally, a solenoid valve 32 is provided, which corresponds to the solenoid valve 25 according to FIG. The above-mentioned functional parts are connected by means of bores and channels running in the walls of the power output member 27. On the outside of the cylinder 26 there are clamping grooves 33, one of which is clamped with a stop 35 by means of a clamping device 34. The stop 35 protrudes only when the piston rod is extended in its path of motion when the force output member 27 is moving. Overall, this results in a rodless cylinder which, with little additional effort and little increase in the required installation space, also has a frictional braking device which acts in emergencies and has a positive, has adjustable emergency stop by the clamping device 34.

Die Bremseinrichtung ist auch für hydraulische Druckmittelzylinder geeignet, der Druckmittelspeicher ist hierbei entsprechend auszubilden und statt Entlüftungen sind Rückleitungen vorzusehen.The braking device is also suitable for hydraulic pressure medium cylinders, the pressure medium accumulator must be designed accordingly and return lines must be provided instead of venting.

BezugszeichenlisteReference symbol list

  • 1,1' Druckmittelquelle1.1 'pressure medium source
  • 2 Druckmittelverbindung2 pressure medium connection
  • 3 Rückschlagventil3 check valve
  • 4 Druckmittelspeicher4 accumulators
  • 5 Druckwächter5 pressure switches
  • 6 Feder6 spring
  • 7 Schalter7 switches
  • 8,8' Magnetventil8.8 'solenoid valve
  • 9,9' Bremsorgan9.9 'braking element
  • 10,10' Druckmittelverbindung10.10 'pressure medium connection
  • J 1 VerbindungJ 1 connection
  • 12 Beaufschlagungsraum12 pressurization room
  • 13 Federspeicherzylinder13 spring-loaded cylinders
  • 14 Kolbenstange14 piston rod
  • 15 Speicherfeder15 spring
  • 16 Lochleiste16 perforated strip
  • 17 Loch17 holes
  • 18 Oberfläche18 surface
  • 19 Schalter19 switches
  • 20 Druckmittelverbindung20 pressure medium connection
  • 21 Wegeventil21 way valve
  • 22 Feder22 spring
  • 23 Druckmittelverbindung23 Pressure fluid connection
  • 24 Viereck24 square
  • 25 Magnetventil25 solenoid valve
  • 26 Zylinder26 cylinders
  • 27 Kraftabgabeorgan27 power transmission element
  • 28 Hohlraum28 cavity
  • 29 Ausnehmung29 recess
  • 30 Ausnehmung30 recess
  • 31 Druckwächter31 pressure switches
  • 32 Magnetventil32 solenoid valve
  • 33 Klemmnut33 clamping groove
  • 34 Klemmvorrichtung34 clamping device
  • 35 Anschlag35 stop
  • p3 Beaufschlagungsdruckp3 pressurization pressure
  • p2 Druckp2 pressure
  • Pv DruckP v pressure
  • 1 Erregungsstrom1 excitation current
  • T ZeitspanneT time span
  • tiZeitpunktt i time
  • tzZeitpunkttz time
  • t3Zeitpunktt 3 time
  • t4 Zeitpunktt 4 time
  • ts Zeitpunktts time
  • ts Zeitpunktts time
  • t7 Zeitpunktt 7 time
  • t8 Zeitpunktt 8 time
  • t9 Zeitpunktt 9 time
  • A-B LinieA-B line

Claims (8)

1. Braking device for pressure medium cylinders, especially cylinders (26) without a piston rod, having a braking element (9, 9') which can be operated on by pressure medium, this pressure medium operation being monitored by a switch valve (8, 8'), characterised in that between a pressure medium source (1) and the switch valve (8, 8'), constructed at least as a 3/2-way valve, there is arranged a pressure medium reservoir (4) which can be charged by means of a non-return valve (3) from the pressure medium source, in that the pressure of the pressure medium source (1) acts on a pressure monitor (5) which, when a first high pressure threshold is not reached, switches the switch valve (8, 8') so that it opens an otherwise closed connection from the pressure medium reservoir (4) to the brake element (9, 9'), in that a spring-loaded cylinder (13), acted on by the pressure medium reservoir (4), is provided which, when acted on by a pressure which falls below a second mean pressure threshold, activates a mechanical movement lock (14, 16) arranged in parallel to the braking element (9, 9'), and in that the braking element (9, 9') is designed to maintain the nominal load of the pressure medium cylinder until its actuation pressure falls below a third, low pressure threshold.
2. Braking device according to claim 1 characterised in that the movement lock is formed as a stop (14, 16 or 35) which can be switched by the spring-loaded cylinder (13).
3. Braking device according to claim 2, characterised in that the stop has a stop pin which can be moved by means of the spring-loaded cylinder (13) and may be formed from the piston rod (14), and a plurality of stop surfaces, possibly walls of bores (17), arranged in a spaced fashion in the stroke direction of the pressure medium cylinder, and possibly commonly arranged in a perforated strip (16).
4. Braking device according to one of claims 1 to 3, characterised in that the pressure monitor (5) has a switch (7) interrupting the excitation of the switch valve formed as a solenoid valve (8, 8') when the pressure falls below the first pressure threshold.
5. Braking device according to claim 4, characterised in that a further switch (19) is electrically connected in series with the switch (7).
6. Braking device according to claim 4, characterised in that the switch valve (8') connects the braking element (9) alternately to the pressure medium reservoir (4) or a further switch valve (25) controlling the connection to a pressure medium source (1 or to a return.
7. Braking device according to claim 1, characterised in that two braking elements (9 and 9'), pneumatically separate from each other, are provided which are connected to the switch valve (8, 8') by means of a 5/3-way valve (21), the 5/3-way valve (21) being acted on in opposite switching directions by the operating pressures of the two braking elements (9 and 9'), in the end switching positions connecting respectively that braking element (9 or 9') loading it with its operating pressure in the switching direction to the switch valve, and in its spring-stabilised middle switch position connecting both braking elements (9 and 9') to the switch valve (8, 8').
8. Braking device according to one or more of the preceding claims, for a cylinder (26) without a piston rod in whose power output element (27) the braking element (9, 9') is integrated, characterised in that the switch valve (8, 8'), the pressure medium reservoir (4) and the spring-loaded cylinder (13) are also arranged to be integrated in the power output element (27).
EP88101899A 1987-03-20 1988-02-10 Locking device for fluid actuator Expired EP0283694B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88101899T ATE45012T1 (en) 1987-03-20 1988-02-10 BRAKE DEVICE FOR PRESSURE MEDIUM CYLINDER.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3709164 1987-03-20
DE19873709164 DE3709164A1 (en) 1987-03-20 1987-03-20 BRAKE DEVICE FOR PRESSURE CYLINDER

Publications (2)

Publication Number Publication Date
EP0283694A1 EP0283694A1 (en) 1988-09-28
EP0283694B1 true EP0283694B1 (en) 1989-07-26

Family

ID=6323573

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88101899A Expired EP0283694B1 (en) 1987-03-20 1988-02-10 Locking device for fluid actuator

Country Status (3)

Country Link
EP (1) EP0283694B1 (en)
AT (1) ATE45012T1 (en)
DE (2) DE3709164A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE465787B (en) * 1990-02-09 1991-10-28 Bo Granbom FIXING DEVICE FOR FIXING A RAIL AT A MANOEVER CYLINDER
DE102009034721A1 (en) * 2009-07-24 2011-01-27 Dr. Ing. H.C. F. Porsche Aktiengesellschaft pneumatic system
CN102392845B (en) * 2011-11-28 2014-08-20 巨力索具股份有限公司 Passive locking hydraulic system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0104364A1 (en) * 1982-08-05 1984-04-04 Knorr-Bremse Ag Rodless fluidic motor with brake means

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2932282A (en) * 1957-07-08 1960-04-12 Roe L Mckinley Fluid actuated systems for operating and locking control elements
US3033171A (en) * 1960-09-07 1962-05-08 Sperry Rand Corp Interlocking means for hydraulic servomotor systems
US3654833A (en) * 1970-06-29 1972-04-11 Eaton Yale & Towne Hydraulic control circuit
DE2610692C2 (en) * 1976-03-13 1986-11-27 L. Schuler GmbH, 7320 Göppingen Drive device for a mechanically driven press
DE2633322C2 (en) * 1976-07-24 1985-07-18 L. Schuler GmbH, 7320 Göppingen Safety control
DE2814163A1 (en) * 1978-04-01 1979-10-11 Teves Gmbh Alfred EMERGENCY SUPPLY SYSTEM
DE3328292A1 (en) * 1983-08-05 1985-02-21 Robert Bosch Gmbh, 7000 Stuttgart WORK CYLINDER WITH BRAKE DEVICE

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0104364A1 (en) * 1982-08-05 1984-04-04 Knorr-Bremse Ag Rodless fluidic motor with brake means

Also Published As

Publication number Publication date
EP0283694A1 (en) 1988-09-28
ATE45012T1 (en) 1989-08-15
DE3860001D1 (en) 1989-08-31
DE3709164A1 (en) 1988-09-29

Similar Documents

Publication Publication Date Title
EP2238004B1 (en) Parking brake
DE102008015249B4 (en) Pressure medium-operated brake system of a vehicle with at least one bistable slide valve
EP0877693B1 (en) Combined service and parking brake system
WO2002064409A2 (en) Electrohydraulic brake system for motor vehicles
DE2142552C2 (en) Pressure control valve for an anti-lock control system
DE3629776A1 (en) HYDRAULIC BRAKE SYSTEM FOR MOTOR VEHICLES
DE1218891B (en) Pressure medium brake system for vehicles, in particular motor vehicles
EP0283694B1 (en) Locking device for fluid actuator
EP0881134B1 (en) Power accumulator
DE3517958C2 (en) Pressure-controlled valve, in particular for motor vehicle brake systems with brake slip control
DE3608567A1 (en) ELECTROMAGNETICALLY OPERATING PRESSURE MODULATOR
DE2121162C3 (en) Brake lining wear indicator for disc brakes that can be acted upon on both sides in a vehicle
DE2616851A1 (en) BRAKE SYSTEM FOR VEHICLES
WO1988006684A1 (en) Lockable clamping cylinder-piston unit
DE19851251C2 (en) Brake system for rotating and / or translationally moving parts
DE2738948C2 (en) Pressure control valve for controlling the front axle brake pressure in pneumatic dual-circuit vehicle brake systems
EP0457030A1 (en) Spring brake cylinder for compressed air operated vehicle brakes
DE2528838C3 (en) Brake system for an articulated rail vehicle
DE2645471C2 (en) Power boosters for hydraulic systems, in particular braking systems
DE2708629A1 (en) PRESSURE BRAKE DEVICE, IN PARTICULAR FOR RAIL VEHICLES
DE3736750C2 (en)
WO1991019108A1 (en) Piston-cylinder control device
DE3137438A1 (en) Directional control valve for loading an accumulator
WO2004020864A1 (en) Brake caliper
DE2544172C2 (en) Pressure control device for an anti-lock control system

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE GB IT LI NL SE

17P Request for examination filed

Effective date: 19880812

17Q First examination report despatched

Effective date: 19890110

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO ROMA S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE GB IT LI NL SE

REF Corresponds to:

Ref document number: 45012

Country of ref document: AT

Date of ref document: 19890815

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3860001

Country of ref document: DE

Date of ref document: 19890831

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19911220

Year of fee payment: 5

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

Ref country code: BE

Payment date: 19911227

Year of fee payment: 5

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

Ref country code: CH

Payment date: 19911230

Year of fee payment: 5

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

Ref country code: AT

Payment date: 19920204

Year of fee payment: 5

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

Ref country code: DE

Payment date: 19920210

Year of fee payment: 5

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

Ref country code: NL

Payment date: 19920229

Year of fee payment: 5

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

Ref country code: SE

Payment date: 19920312

Year of fee payment: 5

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

Ref country code: GB

Effective date: 19930210

Ref country code: AT

Effective date: 19930210

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

Ref country code: SE

Effective date: 19930211

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

Ref country code: LI

Effective date: 19930228

Ref country code: CH

Effective date: 19930228

Ref country code: BE

Effective date: 19930228

BERE Be: lapsed

Owner name: KNORR-BREMSE A.G.

Effective date: 19930228

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

Ref country code: NL

Effective date: 19930901

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930210

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: DE

Effective date: 19931103

EUG Se: european patent has lapsed

Ref document number: 88101899.8

Effective date: 19930912

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

Ref country code: IT

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

Effective date: 20050210