EP0220248B1 - Device for adjusting the circuit amplification of a servo-regulating circuit - Google Patents

Device for adjusting the circuit amplification of a servo-regulating circuit Download PDF

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Publication number
EP0220248B1
EP0220248B1 EP19860902788 EP86902788A EP0220248B1 EP 0220248 B1 EP0220248 B1 EP 0220248B1 EP 19860902788 EP19860902788 EP 19860902788 EP 86902788 A EP86902788 A EP 86902788A EP 0220248 B1 EP0220248 B1 EP 0220248B1
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EP
European Patent Office
Prior art keywords
valve
flow
drive unit
servo
regulating
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
EP19860902788
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German (de)
French (fr)
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EP0220248A1 (en
Inventor
Dieter Jordan
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.)
Voith Turbo H and L Hydraulic GmbH and Co KG
Original Assignee
Hartmann and Lammle GmbH and Co KG
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Publication of EP0220248A1 publication Critical patent/EP0220248A1/en
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    • 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
    • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
    • F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
    • F15B9/08—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor
    • F15B9/12—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor in which both the controlling element and the servomotor control the same member influencing a fluid passage and are connected to that member by means of a differential gearing

Definitions

  • the invention relates to a device for setting the loop gain of a tracking control circuit provided for the movement control of a hydraulic feed drive unit, which is electrically, e.g. works by means of a stepper motor, controlled position setpoint value specification and mechanical position actual value feedback, and with the other generic features mentioned in the preamble of claim 1.
  • Follow-up control loops of the aforementioned type are used in a variety of ways, e.g. to control the feed and retraction movements of pressing or punching tools or to control the relative movements of workpieces and tools in machine tools that work with metal cutting, e.g. Lathes as well as in machine tools in which a more or less quickly routing driven tool such as a drill, a milling cutter, a grinding or a honing tool perform feed and retraction movements.
  • the loop gain K v of such electro-hydraulic control loops is given by the relationship defines, in which v denotes the speed of the controlled tool or workpiece movements, which is determined by the amount of the working medium flows supplied to or discharged from the drive unit via a follow-up control valve and is denoted by A s, the following error or following error, by which the actual position of the tool differs from the set target position if, in the steady state of the control, the run-on control valve is turned on to such an extent that the time-related delivery quantity required for a desired feed rate flows through the run-on control valve.
  • the loop gain K v is, in terms of amount, a measure of the sensitivity of the tracking control, which is greater the greater the loop gain.
  • This “switchover” to another circuit gain of the overrun control circuit is carried out by adjusting the gear ratio of a mechanical conversion device as required, by means of which the deflections of the valve piston of a main valve pressure-pilot-controlled by means of the overrun control valve are reported back to the valve actuating element of the follow-up control valve .
  • a disadvantage of this type of circuit gain switching or setting is the complicated structure of the mechanical implementation devices required for this and the relatively narrow area for structural reasons within which a variation of the circuit gain is possible. Such devices for adjusting the loop gain of a wake control loop are therefore only suitable for a limited group of applications.
  • the object of the invention is therefore to provide a device of the type mentioned, which is subject to no restrictions with regard to the area within which a setting of different loop amplifications should be possible, but is nevertheless of a considerably simpler design and can be implemented more cost-effectively. This object is achieved by the features mentioned in the characterizing part of claim 1.
  • the follow-up control valve is provided with at least one additional valve element which executes the actuating movements of a valve element used for movement control with the circuit gain K v1 , for example a cone seat valve.
  • a parallel flow path leads via this valve element to that flow path of the follow-up control valve, via which, in an operating phase running with the value K v1 of the circuit gain, the working medium flow determining the working speed of the drive unit flows, while working with the circuit gain K v1 , Is blocked.
  • This additional flow path can be released by activating a boost control valve arrangement, with the result that a working medium flow supplied to or flowing from the drive unit increases in accordance with the additionally released flow cross-section and thus results in a relative increase in the circuit gain to a value K v2 becomes.
  • a control device is provided with which the additional flow path can be opened or closed as required.
  • claims 2 and 3 alternatively as well as in combination implementable options for guiding the additional flow paths, by releasing them, the loop gain of the control loop can be changed.
  • the combinatorial implementation of the features of claims 2 and 3 is necessary if a double-acting hydraulic cylinder of the drive unit is designed as a differential cylinder.
  • the features of claim 4 provide a design of a device according to the invention in which large changes in the circular gain can be achieved with only a single additional flow path.
  • the features of claim 5 achieve a continuous adjustability of the loop gain between a lower limit value K v1 and an upper limit value K v2 .
  • the advantage of a device designed according to the features of claim 6 is that as a follow-up control valve, via the valve elements of which all working medium flows are led, which are used to change the circuit gain or to stabilize it to a certain value, the usual 4 / 3-way control valves of simple design can be used, the valve elements of which are designed as inserts which have different opening cross sections in relation to the unit of the adjustment path.
  • the design of a device according to the basic structure and specified in more detail by the features of claim 8 is suitable for a drive unit with a double-acting hydraulic cylinder, the working spaces of which are offset by the piston, alternatively with the regulated, high outlet pressure of the follow-up control valve or are connected to the tank of the pressure supply source via the valve elements of the follow-up control valve which are used in the return flow direction.
  • valves of the amplification control valve arrangement provided for releasing and blocking the additional flow paths, in an embodiment as electrically controllable solenoid valves, enable a program-controlled path-dependent switching of the overrun control circuit to the respectively appropriate values of the circuit amplification.
  • boost control valves as well as pressure-controlled valves can be formed, the control pressure spaces of which are communicatively connected to one of the working spaces of the hydraulic cylinder of the drive unit.
  • the design of the device according to the invention specified by the features of claim 9 has the advantage that both control options are available to the user with only little additional technical effort.
  • the device according to the invention fulfills as far as possible all the requirements that may exist on the user side and is therefore suitable as a standard device for a wide variety of applications.
  • One of the two control options can be used as a security measure against a malfunction of the other control type.
  • the working space 18, which is penetrated in the axial direction by the piston rod 13 and has an annular cross section, is continuously connected to the high pressure (P) supply connection 21 of the hydraulic pressure supply unit 22, which, for the sake of simplicity, is represented only by the hydraulic pump 23 and the tank (T) 24.
  • the working space 18 of the hydraulic cylinder 11, which is delimited by the smaller, annular piston surface 26 of the piston 27, is thus constantly subjected to the outlet pressure of the pressure supply unit 22.
  • the other, by the total cross-sectional area 28 of the piston 27 movable working space 19 of the hydraulic cylinder 11 is of a type known per se by a total control valve 29 designated, which with electrical or mechanical position setpoint value specification and mechanical position actual Value feedback works, alternatively connectable to the pressure outlet 21 of the pressure supply unit 22 or to its tank 24.
  • a total control valve 29 designated, which with electrical or mechanical position setpoint value specification and mechanical position actual Value feedback works, alternatively connectable to the pressure outlet 21 of the pressure supply unit 22 or to its tank 24.
  • the larger working space 19 of the hydraulic cylinder 11 e.g. Via the control outlet 31 (A outlet) of the overrun control valve 29 and thus connected via this to the pressure passage 21 of the pressure supply unit 22, the piston 27 and with it the tool head 14 moves in the direction of the arrow 16, according to FIG. 1 upwards, whereby working medium is forced out of the - upper - working space 18 back to the pump 23, while a working medium flow of the same amount flows into the - lower - working space 19.
  • the larger working chamber 19 is connected via the B control connection 32 of the follow-up control valve and via this to the tank 24 of the pressure supply unit, in which case the piston 27 of the hydraulic cylinder 11 moved in the direction of arrow 17 "down".
  • the follow-up control valve 29 comprises a total of 4 valve elements 34, 35, 36 and 37, the basic position shown being the blocking position in the special exemplary embodiment shown.
  • the conical valve bodies 38 which are urged in the direction of the respective, for example annular-edged valve seat 41 by return springs 39, have pin-shaped extensions 42, on the free ends of which a valve actuation member, generally designated 43, can engage, by means of its axial displacements in the arrows 44 and 46, in opposite directions, either lift the valve bodies of the two valve elements 34 and 35, which are arranged to the right of the valve actuator 43 according to FIG.
  • valve elements 34 - 37 are designed so that the valve gap or flow cross sections released by an actuation of the valve elements flow over the working medium flows supplied to or from the hydraulic cylinder 11, each proportional to the deflections e i and s 2 of the valve actuating member 43 or are approximately proportional, by which the valve bodies 38 of one “right” pair of valve elements 34, 35 or the valve bodies 38 of the other pair of valve elements 36, 37 are displaced in the direction of arrows 44 and 46, respectively.
  • the lower right valve element 34 according to FIG. 1 is the flow cross section of a first flow path, generally designated 47, via which working medium is directed from the P supply connection 21 of the pressure supply unit 22 to the A control output 31 of the follow-up control valve 29 and via this can flow into the working area 19 of the hydraulic cylinder having the larger cross section.
  • the lower valve element 36 on the left is the flow cross-section of a first drain flow path, designated overall by 48, via which working medium can flow out of the working space 19 of the hydraulic cylinder 11 to the tank 24.
  • the upper right valve element 35 according to FIG. 1 is the effective flow cross section of an additional inflow flow path, which is connected in parallel to the first inflow flow path 47 and is designated overall by 49, and which runs from the P supply outlet 21 of the pressure supply unit 22 to the B- Control port 32 of the follow-up control valve 29 and via this leads to the larger working space 19 of the hydraulic cylinder 11.
  • this additional inflow flow path 49 is blocked and released when the control valve 51 is controlled into its excited position 1.
  • the upper valve element 37 on the left is the effective flow cross-section of an additional drain flow path connected in parallel with the first drain flow path 48, designated overall by 52, which in the basic position 0 of a second 2/2-way Solenoid valve trained control valve 53 is blocked and released in the energized position 1 of this second control valve 53, so that 52 working medium can flow out of the larger working space 19 of the hydraulic cylinder 11 to the tank 24 through this additional drain flow path.
  • the control of the feed and retraction movements of the hydraulic cylinder 11 takes place by step-by-step or continuous specification of target position values in the embodiment shown play by turning a spindle nut 54 which is guided in the housing 33 of the follow-up control valve in the direction of arrows 44 and 46 to slide back and forth.
  • the spindle nut is in meshing engagement with a threaded spindle 56, which is rotatably mounted in the housing 33 of the follow-up control valve 29, but is secured against axial displacements.
  • a pinion 57 which is connected in a rotationally fixed manner to the threaded spindle 56, meshes with a toothed rack 58 which, for example, is coupled in motion to the piston rod 13 of the hydraulic cylinder 11 via a rigid connection 59.
  • the spindle nut 54 which passes freely through a central opening 61 of the valve actuating member 43, is connected to the valve actuating member 43 via axial ball bearings 62 and 63 arranged on both sides of the valve actuating member 43 such that the latter results in axial displacements of the spindle nut resulting from a rotation of the spindle nut relative to the threaded spindle 56, which, depending on the direction of rotation in the direction of arrow 44 or arrow 46, also carries out, but does not also have to carry out their rotational movements; the valve actuator 43, which is not specifically shown, is secured against rotation, guided on the valve housing 33 so as to be displaceable in the axial direction.
  • the tool head 14 should first perform an infeed movement in the direction of the arrow 16 “upwards” until it hits a workpiece (not shown) and then - under increased load - a working stroke s must execute, which corresponds to the machining depth of the workpiece. Then the tool head 14 is to be returned to the starting position shown.
  • the spindle nut is first rotated counterclockwise, as seen in the direction of arrow 64, as a result of which the spindle nut 54 and together with this the valve actuation element 43, since at the beginning of this control process the piston 27 of the hydraulic cylinder 11 practically does not yet move and so that the threaded spindle 56 does not yet rotate, undergoes a shift in the direction of the arrow 44, to the right, as a result of which the two valve elements 34 and 35, which are arranged to the right of the valve actuating element according to FIG. 1, are opened. It is assumed that the two control valves 51 and 53 are in the blocking position 0 shown.
  • the threaded spindle 56 is also rotated in the direction of arrow 64, also in the counterclockwise direction, via the rack / pinion drive 58, 57, depending on the conversion ratio, with where the speed v of the rack movement is converted into a proportional angular velocity of the threaded spindle 56, the angular velocity of which sooner or later becomes equal to that of the spindle nut, possibly after a phase in which the angular velocity of the threaded spindle 56 was greater than that of the spindle nut 54 and in the prevailing equilibrium state of the same angular velocities of the spindle nut 54 and the threaded spindle 56, that deflection ⁇ 1 of the valve actuating member 43 is reached, in which the valve element 37 is opened so far that it is introduced via the first flow path 47 into the larger working space 19 of the hydraulic cylinder 11
  • the working medium flow has the value at which the speed of the movement of the hydraulic
  • the specification of the setpoint of the speed of movement of the piston 27 of the hydraulic cylinder takes place in the special embodiment shown in a manner known per se with the aid of a stepper motor 67 which can be driven in alternative directions of rotation by output control pulses from an electronic control unit 66 and which has a toothed belt drive designated as 68 with the Spindle nut 54 is drive-coupled.
  • the rotational or angular speed of the spindle nut 54 is determined by the frequency of the respective control pulses by which the driven pinion 69 of the stepping motor 67 is rotated by a defined angular increment.
  • the time-related number of the control pulses fed to the stepper motor 67 which are used to control them in one or the opposite direction of rotation, thus predetermine a specific path s by which the piston 27 of the hydraulic cylinder 11 or the tool head 14 moves in the reference time period.
  • the caster or tracking error As, by which the current position of the tool head 14, that is to say the actual position thereof, differs from the desired position controlled by the toothed belt drive 68, then corresponds to the deflection ⁇ 1 or ⁇ characteristic of the stationary movement state 2 of the valve actuator 43 from its basic position, multiplied by the conversion ratio with which the mechanical feedback device comprising the threaded spindle 56, its drive pinion 57 and the rack 58 converts stroke paths of the piston 27 of the hydraulic cylinder into rotation angle amounts of the threaded spindle 56 which are proportional thereto.
  • the overrun control valve 29 reacts to this with an increase in the deflection ⁇ 1 of the valve actuating element 43, with the result that the loop gain K v - because of the increase in the overrun error As associated with the increase in the deflection ⁇ 1 - decreases.
  • the control becomes less sensitive, and therefore deviations of the actual position of the tool from the currently controlled target position become larger.
  • the additional inflow flow path 49 and the additional drain flow path 52 is provided. As long as these additional flow paths 49 and 52 are blocked in the basic positions 0 of the control valves 51 and 53, the loop gain of the overrun control loop is limited to a maximum value K v1 .
  • the maximum circuit gain of the overrun control circuit can be increased to the value K v2 for the feed operation of the hydraulic cylinder 11, that is to say when the piston 27 moves in the direction of the arrow 16, since now with a predetermined deflection ⁇ 1 of the valve actuating element 43, working medium can flow into the larger working space 19 of the hydraulic cylinder 11 via the two valve elements 34 and 35 of the parallel inflow flow paths 47 and 49.
  • the circuit gain of the wake control circuit can also be increased to a maximum value K v2 for the retracting operation of the hydraulic cylinder 11, that is to say when the piston 27 moves “downward” in the direction of the arrow 17 become, since with a given deflection s z the valve body 38 of the two valve elements 36 and 37 per unit time can flow a larger volume of working medium via the parallel discharge flow paths 48 and 52 to the tank 24.
  • valve-controlled release of an additional inflow flow path 49 and an outflow flow path 52 can be used both to increase the loop gain and to partially or completely compensate for a drop in the loop gain, the need being that Compensation for a drop in loop gain in practice which will be more common.
  • a throttle 71 with an adjustable flow resistance is provided between the first control valve 51 and the valve element 35 of the follow-up control valve 29; likewise, a throttle 72 with an adjustable flow resistance is provided in the additional outflow flow path 52 leading from the hydraulic cylinder 11 via the valve element 37 of the follow-up control valve 29, as seen in the flow direction, again between the valve element 37 and the second control valve 53.
  • the booster control valves 51 and 53 are controlled as required by the program by means of output signals from the electronic control unit 66, which also provide the position-target value output signals for controlling the stepping motor 67 generated, that is path-dependent.
  • FIG. 2 shows a drive device 10 'largely functionally analogous to the drive device 10 according to FIG. 1 with adjustable control loop gain, elements of the drive device 10' according to FIG. 2 and 10 according to FIG. 1 the same reference numerals are used and in this respect reference can be made to the relevant description of FIG. 1.
  • the drive device 10 'according to FIG. 2 differs from that according to FIG. 1 essentially only in the special design of the follow-up control valve 29', which is designed here as a spool valve.
  • the devices required for setting the desired position value and for reporting the actual position of the piston 27 of the hydraulic cylinder 11 can have the same design as that in connection with the achievement of the deflections ⁇ 1 and 82 of the valve actuator 43 of the follow-up control valve 29 ge 1 and are not shown for the sake of simplicity.
  • valve housing 74 of the follow-up control valve 29 ' which is only shown schematically, a total of six annular grooves 77-82, which radially widen the central housing bore, in which the valve piston 73 is displaceably guided, are provided, which are equidistant along the central longitudinal axis 83 of the valve housing 74 are arranged, the width w of these annular grooves 77-82, measured in the same direction, corresponding to the thickness of the annular intermediate ribs 85-89 of the valve housing 74, which thickness is also measured in this direction, and which each offset two of these annular grooves.
  • the valve piston 73 has between its end sections 91 and 92, with which it is guided in the corresponding end sections of the housing bore 76, a total of 4 annular grooves 93-96, each in pairs through one of the three piston flanges 97-99, whose diameter D is the diameter of the central housing bore 76, are offset from one another, the annular grooves 93-96 of the valve piston 73, viewed in the direction of its longitudinal axis 83, being twice the width ww of the annular grooves 77-82 of the valve housing 74 and the thicknesses of the piston flanges 97 measured in the same direction, 98 and 99 correspond to the axial widths w of the ring grooves 77 - 82 of the valve housing 74.
  • the arrangement of the housing ring grooves and the arrangement of the piston ring grooves 93 - 96 are thus symmetrical with respect to the transverse central plane 101 of the valve housing or the transverse central plane 102 of the valve piston 73, the basic position of the valve piston 73 shown in dashed lines with the transverse central plane 101 of the valve housing 73 coincides.
  • the annular groove 80 arranged to the right of the plane of symmetry 101 of the valve housing 73 according to FIG. 2 is communicatively connected to the P supply connection 21 of the pressure supply unit 22, the annular groove 79 arranged to the left of the plane of symmetry 101 to the tank supply connection 103.
  • the two Ring grooves 78 and 81, between which the ring grooves 79 and 80 communicating with the tank supply connection 103 and the P supply connection 21 are arranged, are both via the B control output 32 and the A output 31 of the follow-up control valve 29 '. connected to the working space 19 of the hydraulic cylinder 11 delimited by the larger piston area 28.
  • the outer annular groove 77 of the valve housing 74 is via the amplification control valve 51, which is blocked in its basic position 0, in its excited position 1 is switched from passage to the P supply output 21 of the pressure supply unit 22 and via this connected to the work chamber 18 of the hydraulic cylinder 11, which is smaller in cross section.
  • the outer annular groove 82 on the right of the valve housing 74 is connected to the supply connection 103 communicating with the tank 24 of the pressure supply unit 22 via the second boost control valve 53, the basic position 0 of which is the blocking position and the excited position I is the flow position.
  • the possible deflections ⁇ 1 and s 2 of the valve piston 73 in the alternative deflection directions 44 and 46 are limited to values which are less than half the width w of the annular grooves 77-82 of the valve housing 74.
  • the valve piston (shown in dashed lines) 73 are both the ring grooves 78 which are in constant communication with the larger working space 19 of the hydraulic cylinder 11 and also the two outermost ring grooves 77 and 82, which are connected to one of the control valves 51 and 52, against which one of the P - or T-supply connections 21 or 103 communicating annular grooves 80 or 79 of the valve housing 74 blocked.
  • the blocking position of the follow-up control valve 29 '- the piston 27 of the hydraulic cylinder 11 stops.
  • the annular groove 79 which constantly communicates with the tank supply connection 103 and also the further annular groove 82 which only communicates with the tank in the open position of the second boost control valve 53 are at a deflection ⁇ 1 of the valve piston 73 against the respectively adjacent annular grooves 78 and 81 cordoned off.
  • FIG. 3 shows a further embodiment of a hydraulic drive device 100 with a device for adjusting the loop gain that is subject to the inventive concept.
  • the basic structure and function of the drive device 100 according to FIG. 3 is largely analogous to that of the drive device 10 according to FIG. 1, and the elements of the drive devices 10 shown in FIGS. 1 and 3 are therefore identical or have the same construction and function or 100 used the same reference numerals, so that reference can be made to the relevant parts of the description of FIG. 1.
  • the characteristic difference of the drive device; 100 compared to the drive device 10 according to FIG. 1 consists in that in both working directions of movement 16 and 17 of the piston 27 of the double-acting hydraulic cylinder 11 provided as the power drive unit, one of its two working spaces 19 or 18 via the a total of 29 "follow-up control valve are connected to the P pressure supply connection 21 of the pressure supply unit 22 and the respective other working space 18 or 19, also via follow-up control valve 29" to the tank 24 of the pressure supply unit 22.
  • the piston 27 of the hydraulic cylinder 11 moves in the feed direction 16 when its working space 19 with the larger cross section via the A control connection 31 of the follow-up control valve 29 'with the P supply connection 21 of the pressure supply unit 22 and its cross section is smaller Working space 18 are connected to the tank 24 of the pressure supply unit 22 via the B control connection 32 of the follow-up control valve 29 ".
  • the working space 18 of the hydraulic cylinder 11, which is smaller in cross section is via the B control connection 32 of the follow-up control valve 29 "with the pressure supply connection of the pressure supply unit 22 and the cross-sectionally larger working space 19 of the hydraulic cylinder 11 via the A control connection 31 of the follow-up control valve 29" with the tank 24 of the pressure supply unit 22.
  • valve elements 104, 105, 106 and. are in the context of the follow-up control valve 29 ", the structure of which, apart from the number of valve elements, is analogous to that of the follow-up control valve 29 according to FIG. 1 107 are provided which, in turn, can alternatively be controlled in pairs to release the inflow or outflow flow paths to be steered in the respective movement directions 16 and 17.
  • valve elements 108 and 109 as well as 111 and 112 and associated amplification control valves 113 and 114 or 116 and 117, additional supply and discharge flow paths can be released, by means of which the effective circuit amplification of the overrun provided for movement control of the hydraulic cylinder piston 27 is enabled
  • Control loop be it to increase the loop gain or to compensate for a load-related reduction thereof, can be released.
  • Due to the deflection ⁇ 1 and ⁇ 2 of the valve actuating member 43 ' which, in the same way as explained with reference to FIG. 1, from the target value control and the position-actual value feedback via the stepper motor-controlled rotation of the spindle nut 54 or the rotation of the threaded spindle 56, 4 of the total of 8 valve elements are opened.
  • valve elements 104, 105, 108 and 109 which, according to FIG. 3, are arranged to the right of the valve actuating member 43'.
  • valve elements 106, 107 and 111 and 112 arranged on the left thereof are opened.
  • the control valve can be actuated 113 in its flow position 1, an additional inflow flow path 118 is released, through which an additional working medium flow into the larger working area is provided by the P supply connection 21 via the control valve 113 and the valve element 108 connected to it aum 19 of the hydraulic cylinder 11 can flow, resulting in a relative increase in the circular gain K v is achieved.
  • an additional drain flow path 119 can be released, which leads from the smaller working chamber 18 of the hydraulic cylinder 11 via the B control connection 32, the valve element 109 of the follow-up control valve 29 "and the additional boost control valve 114 leads back to the tank 24 of the pressure supply unit 22.
  • additional flow path 119 is a relative Er Increasing the loop gain K v of the wake control loop can be achieved.
  • additional inflow and outflow flow paths 118 and 119 respectively correspond to additional flow paths 121 and 122 which are suitable for setting desired values of the loop gain and which can be used when the hydraulic cylinder 11 is operated in the retracting mode, ie with movement in the direction of the arrow 17 , can be activated by actuation of the further boost control valves 116 and 117.
  • control valves 113 and 114 or 116 and 117 are expediently carried out by output signals from the electronic control unit 66 ', which also generates the control pulses for the stepper motor 68 which are used for specifying the desired value.
  • the control of the boost control valves 113 and 114 or 116 and 117 is path-dependent, that is to say program-controlled.
  • boost control valves 113 and 114 or 116 and 117 pressure-controlled actuation of the same is also possible, as in the upper part of FIG. 3 for the boost Control valves 114 and 117 shown, which, if the pressure in that work space 18 or 19, from the working medium to flow out to the tank 24, exceeds a threshold value, are controlled in their flow positions and thereby the additional drain flow path 119 or 122 is released .
  • boost control valves 113 and 116 can also be provided in connection with the boost control valves 113 and 116, respectively, which release the additional inflow flow paths 118 and 121, respectively.
  • valve elements 34-37 of the follow-up control valve 29 according to FIG. 1 and likewise the valve elements 104-109 as well as 111 and 112 of the follow-up control valve 29 "according to FIG. 3 have what the schematic representations of FIGS. 1 and 3 do not can be seen, pressure-balanced valve body 38, which regardless of how the pressure conditions are on different sides of the valve seat, are reliably held in their locking position by the return springs 39 when the respective valve actuator 43 or 43 'is in its neutral basic position.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

A servo-regulating circuit for a hydraulic forward drive unit (10), which operates with an electrically-controlled set value of the position and with mechanical feed-back of the actual position. The flows of the working medium to and from the drive unit (10), whose value determines the speed v of the tool movements, are fed via valve elements (34, 36) of a servo-regulating valve (29) which can be jointly controlled via the regulating distances epsilon1 and epsilon2 according to the pre-set value. The circuit amplification Kv can be switched by valve-controlled operation of a switching system. In the servo-regulating circuit, the servo-regulating valve (29) has at least one additional valve element (35, 37) which effects the positioning movements of the valve element serving to control the movement with the circuit amplification Kv1; through this element runs a flow-path, parallel to the flow-path of the servo-regulating valve (29), which can be opened up by the operation of an amplification control valve arrangement (51, 53); as a result the circuit amplification Kv2 is adjusted. A device (66) is provided with which the control-valve system can be controlled as required as regards its throughflow setting, which enables operation with the modified value, Kv2.

Description

Die Erfindung betrifft eine Einrichtung zur Einstellung der Kreisverstärkung eines zur Bewegungssteuerung einer hydraulischen Vorschub-Antriebseinheit vorgesehenen Nachlauf-Regelkreises, der mit elektrisch, z.B. mittels eines Schrittmotors, gesteuerter Positions-Soll-Wert-Vorgabe und mechanischer Positions-Ist-Wert-Rückmeldung arbeitet, und mit den weiteren, im Oberbegriff des Patentanspruchs 1 genannten, gattungsbestimmenden Merkmalen.The invention relates to a device for setting the loop gain of a tracking control circuit provided for the movement control of a hydraulic feed drive unit, which is electrically, e.g. works by means of a stepper motor, controlled position setpoint value specification and mechanical position actual value feedback, and with the other generic features mentioned in the preamble of claim 1.

Nachlauf-Regelkreise der vorerwähnten Art werden in vielfältiger Weise eingesetzt, z.B. zur Steuerung der Vorschub- und Rückzugsbewegungen von Press- oder Stanzwerkzeugen oder zur Steuerung der Relativbewegungen von Werkstück und Werkzeug bei Werkzeugmaschinen, die spanabhebend arbeiten, z.B. Drehbänken sowie auch bei Werkzeugmaschinen, bei denen ein mehr oder weniger schnell routierend angetriebenes Werkzeug wie ein Bohrer, ein Fräser, ein Schleif- oder ein Honwerkzeug Vorschub- und Rückzugsbewegungen ausführen.Follow-up control loops of the aforementioned type are used in a variety of ways, e.g. to control the feed and retraction movements of pressing or punching tools or to control the relative movements of workpieces and tools in machine tools that work with metal cutting, e.g. Lathes as well as in machine tools in which a more or less quickly routing driven tool such as a drill, a milling cutter, a grinding or a honing tool perform feed and retraction movements.

Die Kreisverstärkung Kv solcher elektrohydraulischer Regelkreise ist dabei durch die Beziehung

Figure imgb0001
definiert, worin v die Geschwindigkeit der gesteuerten Werkzeug- bzw. Werkstückbewegungen bezeichnet, die durch den Betrag der über ein Nachlauf-Regelventil der Antriebseinheit zugeleiteten bzw. von dieser abfließenden Arbeitsmediumströme bestimmt ist und mit A s, der Schlepp- bzw. Nachlauffehler bezeichnet ist, um den sich die Ist-Position des Werkzeugs von der eingesteuerten Soll-Position unterscheidet, wenn im stationären Zustand der Regelung das Nachlauf-Regelventil so weit aufgesteuert ist, daß die für eine erwünschte Vorschubgeschwindigkeit benötigte, zeitbezogene Fördermenge über das Nachlauf-Regelventil strömt. Die Kreisverstärkung Kv ist dem Betrage nach ein Maß für die Empfindlichkeit der Nachlaufregelung, die um so größer ist, je größer die Kreisverstärkung ist. Im Zuge der vorgenannten Werkzeug- bzw. Werkstückbewegungen können erhebliche Lastwechsel auftreten mit der Folge, daß sich die Kreisverstärkung - und damit die Empfindlichkeit der Nachlauf-Regelung bzw. der Positionssteuerung - erheblich ändern kann mit der Folge, daß Abweichungen z. B. der Kontur des bearbeiteten Werkstücks von einer durch die Bearbeitung zu erzielenden «Soll-Kontur» Beträge annehmen, die außerhalb der Toleranzgrenzen liegen; was natürlich nicht hingenommen werden kann.The loop gain K v of such electro-hydraulic control loops is given by the relationship
Figure imgb0001
 defines, in which v denotes the speed of the controlled tool or workpiece movements, which is determined by the amount of the working medium flows supplied to or discharged from the drive unit via a follow-up control valve and is denoted by A s, the following error or following error, by which the actual position of the tool differs from the set target position if, in the steady state of the control, the run-on control valve is turned on to such an extent that the time-related delivery quantity required for a desired feed rate flows through the run-on control valve. The loop gain K v is, in terms of amount, a measure of the sensitivity of the tracking control, which is greater the greater the loop gain. In the course of the above-mentioned tool or workpiece movements, considerable load changes can occur, with the result that the loop gain - and thus the sensitivity of the tracking control or the position control - can change significantly with the result that deviations z. B. the contour of the machined workpiece from a "target contour" to be achieved by machining assume amounts that are outside the tolerance limits; which of course cannot be accepted.

Eine Möglichkeit, diese Schwierigkeiten zu vermeiden, besteht darin, eine Antriebseinheit mit bedrafsgerecht einstellbarer bzw. umschaltbarer Kreisverstärkung des Nachlauf-Regelkreises zu verwenden, die in der eigenen, älteren, nicht vorveröffentlichten Patentanmeldung P 3 436 356.4 DE-A-3 535 258 unter besonderer Berücksichtigung der bei Pressen-und Stanzmaschinen-Antrieben vorliegenden Verhältnisse vorgeschlagen. Bei den dort beschriebenen hydraulischen Antriebseinheiten ist im Rahmen der zur Positionen-Ist-Wert-Rückmeldung vorgesehenen - mechanischen - Rückmeldeeinrichtung eine selbsttätig arbeitende Umschalteinrichtung vorgesehen, mit der das Verhältnis, mit dem Abweichungen der Regelgröße in Querschnittsänderungen der Durchfluß-Strömungspfade des Nachlauf-Regelventils umgesetzt werden, z.B. bei einem Übergang von Eilvorschub- auf Lastvorschub-Betrieb auf einen größeren Wert umgeschaltet wird. Diese «Umschaltung» auf eine andere Kreisverstärkung des Nachlauf-Regelkreises erfolgt dabei durch bedarfsgerechte Einstellung des Übersetzungsverhältnisses einer mechanischen Umsetzungs-Einrichtungs, mittels deren die Auslenkungen des Ventilkolbens eines mittels des Nachlauf-Regelventils druck-vorgesteuerten Hauptventils auf das Ventilbetätigungsglied des Nachlauf-Regelventils rückgemeldet werden. Nachteilig an dieser Art der Kreisverstärkungs-Umschaltung bzw. -Einstellung ist der komplizierte Aufbau der dafür erforderlichen mechanischen Umsetzungseinrichtungen und der aus konstruktiven Gründen relativ enge Bereich, innerhalb dessen eine Variation der Kreisverstärkung möglich ist. Derartigen Einrichtungen zur Einstellung der Kreisverstärkung eines Nachlauf-Regelkreises sind daher nur für eine beschränkte Gruppe von Einsatzfällen geeignet.One way of avoiding these difficulties is to use a drive unit with a circuit gain of the overtravel control circuit that can be adjusted or switched as required, which is described in particular in the own, older, unpublished patent application P 3 436 356.4 DE-A-3 535 258 Consideration of the conditions proposed for press and punching machine drives. In the hydraulic drive units described there, as part of the mechanical feedback device provided for the position actual value feedback, an automatically operating changeover device is provided, with which the ratio with which deviations in the controlled variable are converted into cross-sectional changes in the flow-through flow paths of the follow-up control valve be, e.g. is switched to a larger value during a transition from rapid feed to load feed operation. This “switchover” to another circuit gain of the overrun control circuit is carried out by adjusting the gear ratio of a mechanical conversion device as required, by means of which the deflections of the valve piston of a main valve pressure-pilot-controlled by means of the overrun control valve are reported back to the valve actuating element of the follow-up control valve . A disadvantage of this type of circuit gain switching or setting is the complicated structure of the mechanical implementation devices required for this and the relatively narrow area for structural reasons within which a variation of the circuit gain is possible. Such devices for adjusting the loop gain of a wake control loop are therefore only suitable for a limited group of applications.

Aufgabe der Erfindung ist es daher, eine Einrichtung der eingangs genannten Art zu schaffen, die hinsichtlich des Bereiches, innerhalb dessen eine Einstellung verschiedener Kreisverstärkungen möglch sein soll, keinerlei Beschränkungen unterworfen ist dabei trotzdem wesentlich einfacher aufgebaut und preisgünstiger realisierbar ist. Diese Aufgabe wird erfindungsgemäß durch die im kennzeichnenden Teil des Patentanspruchs 1 genannten Merkmale gelöst.The object of the invention is therefore to provide a device of the type mentioned, which is subject to no restrictions with regard to the area within which a setting of different loop amplifications should be possible, but is nevertheless of a considerably simpler design and can be implemented more cost-effectively. This object is achieved by the features mentioned in the characterizing part of claim 1.

Hiernach ist das Nachlauf-Regelventil mit mindestens einem zusätzlichen, die Stellbewegungen eines zur Bewegungssteuerung mit der Kreisverstärkung Kv1 ausgenutzten Ventilelements, z.B. eines Kegel-Sitzventils, mit ausführendem Ventilelement versehen. Über dieses Ventilelement führt ein zu demjenigen Strömungspfad des Nachlauf-Regelventils, über den in einer mit dem Wert Kv1 der Kreisverstärkung ablaufenden Betriebsphase der die Arbeitsgeschwindigkeit der Antriebseinheit bestimmende Arbeitsmedium-Strom fließt paralleler Strömungspfad geführt, der, während mit der Kreisverstärkung Kv1 gearbeitet wird, gesperrt ist. Dieser zusätzliche Strömungspfad ist durch Ansteuerung einer Verstärkungs-Steuerventilanordnung freigebbar, mit der Folge, daß ein der Antriebseinheit zugeleiteter bzw. von dieser abströmender Arbeitsmedium-Strom entsprechend dem zusätzlich freigegebenen Strömungsquerschnitt vergrößert und damit im Ergebnis eine relative Erhöhung der Kreisverstärkung auf einen Wert Kv2 erzielt wird. Zur Ansteuerung der Verstärkungs-Steuerventilanordnung ist eine Steuerungseinrichtung vorgesehen, mit der bedarfsgerecht der zusätzliche Strömungspfad aufsteuerbar bzw. absperrbar ist.According to this, the follow-up control valve is provided with at least one additional valve element which executes the actuating movements of a valve element used for movement control with the circuit gain K v1 , for example a cone seat valve. A parallel flow path leads via this valve element to that flow path of the follow-up control valve, via which, in an operating phase running with the value K v1 of the circuit gain, the working medium flow determining the working speed of the drive unit flows, while working with the circuit gain K v1 , Is blocked. This additional flow path can be released by activating a boost control valve arrangement, with the result that a working medium flow supplied to or flowing from the drive unit increases in accordance with the additionally released flow cross-section and thus results in a relative increase in the circuit gain to a value K v2 becomes. To control the booster control valve arrangement, a control device is provided with which the additional flow path can be opened or closed as required.

Hierdurch werden zumindest die folgenden technischen Vorteile erzielt:

  • die zur bedarfsgerechten Umschaltung der Kreisverstärkung von einem Wert Kv1 auf einen Wert Kv2 vorgesehene Steuerventilanordnung ist im einfachsten Falle, das heißt wenn nur ein zusätzlicher Strömungspfad vorgesehen ist, mittels eines einfachen, mechanisch, hydraulisch oder elektrisch betätigbaren, marktüblichen Ventils, realisiert werden, das keinen nennenswerten zusätzlichen technischen Aufwand bedeutet. Dasselbe gilt sinngemäß auch dann, wenn mehrere zusätzliche Strömungspfade vorgesehen sind, die einzeln oder zu mehreren freigebbar bzw. absperrbar sind. Der Bereich, innerhalb dessen Änderungen der Regelkreis-Verstärkung Kv möglich sind bzw. im Verlauf der Bearbeitung eines Werkstückes auftretende Erniedrigungen der Kreisverstärkung kompensiert werden können, kann durch die Auslegung der auf einen bestimmten Stellweg bezogenen Öffnungsquerschnitte der Ventilelemente des Nachlauf-Regelventils in weiten Grenzen variiert werden. Es sind ohne weiteres Änderungen der Kreisverstärkung im Bereich 1 : 50 möglich.
This achieves at least the following technical advantages:
  • In the simplest case, that is to say if only one additional flow path is provided, the control valve arrangement provided for the need-based switching of the loop gain from a value K v1 to a value K v2 can be actuated by means of a simple, mechanically, hydraulically or electrically ren, commercially available valve, which means no significant additional technical effort. The same applies mutatis mutandis if several additional flow paths are provided which can be released or blocked individually or in groups. The range within which changes in the control loop gain K v are possible or reductions in the loop gain that occur in the course of machining a workpiece can be compensated for within wide limits by designing the opening cross sections of the valve elements of the follower control valve related to a specific travel range can be varied. Changes in the loop gain in the range 1:50 are possible without further notice.

Durch die Merkmale der Ansprüche 2 und 3 sind alternativ wie auch in Kombination realisierbare Möglichkeiten der Führung der zusätzlichen Strömungspfade angegeben, durch deren Freigabe die Kreisverstärkung des Regelkreises geändert werden kann. Die kombinatorische Realisierung der Merkmale der Ansprüche 2 und 3 ist erforderlich, wenn ein doppelt wirkender Hydrozylinder der Antriebseinheit als Differential-Zylinder ausgebildet ist.The features of claims 2 and 3 alternatively as well as in combination implementable options for guiding the additional flow paths, by releasing them, the loop gain of the control loop can be changed. The combinatorial implementation of the features of claims 2 and 3 is necessary if a double-acting hydraulic cylinder of the drive unit is designed as a differential cylinder.

Durch die Merkmale des Anspruchs 4 ist eine Gestaltung einer erfindungsgemäßen Einrichtung angegeben, bei der mit nur einem einzigen zusätzlichen Strömungspfad betragsmäßig große Änderungen der Kreisverstärkung erzielbar sind.The features of claim 4 provide a design of a device according to the invention in which large changes in the circular gain can be achieved with only a single additional flow path.

In Verbindung hiermit wird durch die Merkmale des Anspruchs 5 eine stufenlose Einstellbarkeit der Kreisverstärkung zwischen einem unteren Grenzwert Kv1 und einem oberen Grenzwert Kv2 erzielt.In connection with this, the features of claim 5 achieve a continuous adjustability of the loop gain between a lower limit value K v1 and an upper limit value K v2 .

Der Vorteil einer gemäß den Merkmalen des Anspruchs 6 gestalteten erfindungsgemäßen Einrichtung besteht darin, daß als Nachlauf-Regelventil, über dessen Ventilelemente sämtliche Arbeitsmedium-Ströme geleitet sind, die zu Änderungen der Kreisverstärkung oder zu deren Stabilisierung auf einen bestimmten Wert ausgenutzt werden, übliche 4/3-Wege-Regelventile einfacher Bauart verwendet werden können, deren Ventilelemente als Einsätze ausgebildet sind, die auf die Einheit des Verstellweges bezogen, unterschiedliche Öffnungsquerschnitte haben.The advantage of a device designed according to the features of claim 6 is that as a follow-up control valve, via the valve elements of which all working medium flows are led, which are used to change the circuit gain or to stabilize it to a certain value, the usual 4 / 3-way control valves of simple design can be used, the valve elements of which are designed as inserts which have different opening cross sections in relation to the unit of the adjustment path.

Die durch die Merkmale des Anspruch 7 ihrem grundsätzlichen Aufbau nach angegebene und durch die Merkmale des Anspruchs 8 näher spezifizierte Gestaltung einer erfindungsgemäßen Einrichtung eignet sich für eine Antriebseinheit mit einem doppelt wirkenden Hydrozylinder, dessen durch den Kolben gegeneinander abgesetzte Arbeitsräume alternativ mit dem geregelten, hohen Ausgangsdruck des Nachlauf-Regelventils beaufschlagt bzw. über die in Rückflußrichtung ausgenutzten Ventilelemente des Nachlauf-Regelventils an den Tank der Druckversorgungsquelle angeschlossen sind.The design of a device according to the basic structure and specified in more detail by the features of claim 8 is suitable for a drive unit with a double-acting hydraulic cylinder, the working spaces of which are offset by the piston, alternatively with the regulated, high outlet pressure of the follow-up control valve or are connected to the tank of the pressure supply source via the valve elements of the follow-up control valve which are used in the return flow direction.

Die zur Freigabe und Absperrung der zusätzlichen Strömungspfade vorgesehenen Ventile der Verstärkungs-Steuerventilanordnung ermöglichen in einer Ausbildung als elektrisch ansteuerbare Magnetventile eine programmgesteuert-wegabhängige Umschaltung des Nachlauf-Regelkreises auf die jeweils zweckmäßigen Werte der Kreisverstärkung.The valves of the amplification control valve arrangement provided for releasing and blocking the additional flow paths, in an embodiment as electrically controllable solenoid valves, enable a program-controlled path-dependent switching of the overrun control circuit to the respectively appropriate values of the circuit amplification.

Alternativ können solche Verstärkungs-SteuerVentile als auch druckgesteuerte Ventile ausgebildet sein, deren Steuerdruckräume mit je einem der Arbeitsräume des Hydrozylinders der Antriebseinheit kommunizierend verbunden sind. Bei einer derartigen Ausbildung kann eine druckgesteuert-selbsttätige Umschaltung der Einrichtung auf den jeweils bedarfsgerechten Wert der Kreisverstärkung erzielt werden.Alternatively, such boost control valves as well as pressure-controlled valves can be formed, the control pressure spaces of which are communicatively connected to one of the working spaces of the hydraulic cylinder of the drive unit. With such a configuration, a pressure-controlled automatic switchover of the device to the value of the loop gain that is appropriate to the needs can be achieved.

Die durch die Merkmale des Anspruchs 9 angegebene Gestaltung der erfindungsgemäßen Einrichtung hat den Vorteil, daß mit nur geringem technischem Mehraufwand beide Steuerungsmöglichkeiten dem Anwender zur Verfügung stehen.The design of the device according to the invention specified by the features of claim 9 has the advantage that both control options are available to the user with only little additional technical effort.

Die erfindungsgemäße Einrichtung erfüllt in dieser letztgenannten Gestaltung in einem weitestmöglichen Umfang alle Anforderungen, die anwenderseitig bestehen können und ist insofern als eine Standardeinrichtung für die verschiedensten Anwendungsfälle geeignet. Dabei kann jeweils eine der beiden Steuerungsmöglichkeiten gleichsam als Sicherheitsmaßnahme gegen eine Fehlfunktion der anderen Steuerungsart ausgenutzt werden.In this latter design, the device according to the invention fulfills as far as possible all the requirements that may exist on the user side and is therefore suitable as a standard device for a wide variety of applications. One of the two control options can be used as a security measure against a malfunction of the other control type.

Es versteht sich, daß in Fällen, in denen die Antriebseinheit einen Hydrozylinder mit mehr als zwei Arbeitsräumen umfaßt, auch Nachlauf-Regelventilanordnungen mit entsprechender Multiplizität von Ventilelementen, das heißt im Querschnitt regelbaren Durchlaß-Strömungspfaden, vorgesehen werden müssen, wobei eine Integration dieser Ventilelemente in ein einziges 4/3-bzw. 8/3- oder allgemein 2n/3-Ventil, wobei n auch Werte größer/= 3 annehmen kann, besonders vorteilhaft ist, da der für die Betätigung der Ventilelemente und die Positions-Ist-Wert-Rückmeldung erforderliche technische Aufwand bei solchen Ventilen nicht größer ist als z.B. bei einem 4/3-Nachlauf-Regelventil.It is understood that in cases in which the drive unit comprises a hydraulic cylinder with more than two work spaces, follow-up control valve arrangements with corresponding multiplicity of valve elements, that is to say cross-section flow passage paths, must be provided, with an integration of these valve elements in a single 4/3 or. 8/3 or generally 2n / 3 valve, where n can also assume values greater than / = 3, is particularly advantageous since the technical effort required for the actuation of the valve elements and the feedback of the actual position value for such valves is not is greater than e.g. with a 4/3 wake control valve.

Weitere Einzelheiten und Merkmale der Erfindung ergeben sich aus der nachfolgenden Beschreibung spezieller Ausführungsbeispiele anhand der Zeichnung. Es zeigen:

  • Fig. 1 eine hydraulische Antriebsvorrichtung mit einer als Differentialkolben-Hydrozylinder ausgebildeten Leistungs-Antriebseinheit mit einem zur Bewegungssteuerung der Leistungs-Antriebseinheit vorgesehenen Nachlauf-Regelkreis, der mit einer erfindungsgemäßen Einrichtung zur Einstellung der Kreisverstärkung ausgerüstet ist, in vereinfachter, schematischer Schaltbild-Darstellung,
  • Fig. 2 eine funktionell der Vorrichtung gemäß Fig. 1 entsprechende hydraulische Antriebsvorrichtung, bei der im Rahmen des Nachlauf-Regelkreises ein als Schieberventil ausgebildetes Nachlauf-Regelventil eingesetzt ist und
  • Fig. 3 ein weiteres Ausführungsbeispiel einererfindungsgemäßen Einrichtung zur Einstellung der Kreisverstärkung eines Nachlauf-Regelkreises für eine hydraulische Antriebsvorrichtung, bei der als Leistungs-Antriebseinheit ein doppelt wirkender Hydrozylinder in Normalschaltung ausgenutzt ist, in einer der Fig. 1 entsprechenden, schematischen Darstellung.
Further details and features of the invention result from the following description of special exemplary embodiments with reference to the drawing. Show it:
  • 1 shows a hydraulic drive device with a power drive unit designed as a differential piston hydraulic cylinder with a follow-up control loop provided for movement control of the power drive unit, which is equipped with a device according to the invention for adjusting the loop gain, in a simplified, schematic circuit diagram representation,
  • FIG. 2 shows a hydraulic drive device corresponding to the device according to FIG. 1, in which a follow-up control valve designed as a slide valve is used in the context of the follow-up control circuit and
  • 3 shows a further exemplary embodiment of a device according to the invention for setting the loop gain of a follow-up control circuit for a hydraulic drive device, in which a double-acting hydraulic cylinder in normal circuit is used as the power drive unit, in a schematic illustration corresponding to FIG. 1.

Bei der in der Fig. 1, auf deren Einzelheiten ausdrücklich verwiesen sei, dargestellten, insgesamt mit 10 bezeichneten hydraulischen Antriebsvorrichtung, ist als Leistungs-Antriebseinheit ein Differentialkolben-Hydrozylinder 11 vorgesehen, an dessen einseitig aus dem Zylindergehäuse 12 austretender Kolbenstange 13 ein lediglich schematisch angedeuteter Werkzeugkopf 14 montiert ist, der im Verlauf einer z.B. spanabhebenden Bearbeitung eines nicht dargestellten Werkstückes in den durch die Pfeile 16 und 17 repräsentierten Richtungen Vorschub- und Rückzugs-Bewegungen ausführt, die durch zweckgerechte Druckbeaufschlagung der Arbeitsräume 18 und 19 des Hydrozylinders 11 gesteuert werden.In the case of the hydraulic drive device shown in FIG. 1, to the details of which reference is expressly made, designated as a whole, there is a difference as the power drive unit tialkolben hydraulic cylinder 11 is provided, on the one side of the cylinder housing 12 emerging from the piston rod 13 a merely schematically indicated tool head 14 is mounted, the feed and retraction during the course of, for example, machining a workpiece, not shown, in the directions represented by arrows 16 and 17 -Executes movements that are controlled by appropriate pressurization of the working spaces 18 and 19 of the hydraulic cylinder 11.

Entsprechend der zur Antriebs-Steuerung des Hydrozylinders 11 vorgesehenen Differentialschaltung ist der von der Kolbenstange 13 in axialer Richtung durchsetzte, im Querschnitt ringförmige Arbeitsraum 18 ständig an den Hochdruck (P) Versorgungsanschluß 21 des hydraulischen Druck-Versorgungsaggregats 22 angeschlossen, das, der Einfachheit halber, lediglich durch dessen Hydraulikpumpe 23 und den Tank (T) 24 repräsentiert ist. Der durch die kleinere, ringförmige Kolbenfläche 26 des Kolbens 27 beweglich begrenzte Arbeitsraum 18 des Hydrozylinders 11 ist somit ständig mit dem Ausgangsdruck des Druckversorgungsaggregates 22 beaufschlagt. Der andere, durch die Gesamtquerschnittsfläche 28 des Kolbens 27 beweglich begrenzte Arbeitraum 19 des Hydrozylinders 11 ist über ein insgesamt mit 29 bezeichnetes Nachlauf-Regelventil für sich bekannter Bauart, das mit elektrischer oder mechanischer Positions-Soll-Wert-Vorgabe und mechanischer Positions-Ist-Wert-Rückmeldung arbeitet, alternativ an den Druckausgang 21 des Druckversorgungs-Aggregats 22 bzw. an dessen Tank 24 anschließbar. Ist der größere Arbeitsraum 19 des Hydraulikzylinders 11, z.B. über den Steuerausgang 31 (A-Ausgang) des Nachlauf-Regelventils 29 und damit über dieses an den Druckgang 21 des Druckversorgungs-Aggregats 22 angeschlossen, so bewegt sich der Kolben 27 und mit diesem der Werkzeugkopf 14 in Richtung des Pfeils 16, gemäß Fig. 1 nach oben, wobei Arbeitsmedium aus dem - oberen - Arbeitsraum 18 zurück zur Pumpe 23 gedrängt wird, während ein Arbeitsmedium-Strom gleichen Betrages in den - unteren - Arbeitsraum 19 einströmt.Corresponding to the differential circuit provided for the drive control of the hydraulic cylinder 11, the working space 18, which is penetrated in the axial direction by the piston rod 13 and has an annular cross section, is continuously connected to the high pressure (P) supply connection 21 of the hydraulic pressure supply unit 22, which, for the sake of simplicity, is represented only by the hydraulic pump 23 and the tank (T) 24. The working space 18 of the hydraulic cylinder 11, which is delimited by the smaller, annular piston surface 26 of the piston 27, is thus constantly subjected to the outlet pressure of the pressure supply unit 22. The other, by the total cross-sectional area 28 of the piston 27 movable working space 19 of the hydraulic cylinder 11 is of a type known per se by a total control valve 29 designated, which with electrical or mechanical position setpoint value specification and mechanical position actual Value feedback works, alternatively connectable to the pressure outlet 21 of the pressure supply unit 22 or to its tank 24. Is the larger working space 19 of the hydraulic cylinder 11, e.g. Via the control outlet 31 (A outlet) of the overrun control valve 29 and thus connected via this to the pressure passage 21 of the pressure supply unit 22, the piston 27 and with it the tool head 14 moves in the direction of the arrow 16, according to FIG. 1 upwards, whereby working medium is forced out of the - upper - working space 18 back to the pump 23, while a working medium flow of the same amount flows into the - lower - working space 19.

In einer zu diesem Betriebszustand alternativen Betriebszustand der Leistungs-Antriebseinheit 11 ist der größere Arbeitsraum 19 über den B-Steueranschluß 32 des Nachlauf-Regelventils und über dieses mit dem Tank 24 des Druckversorgungs-Aggregats verbunden, wobei sich in diesem Falle der Kolben 27 des Hydrozylinders 11 in Richtung des Pfeils 17 «nach unten» bewegt.In an operating state of the power drive unit 11 which is alternative to this operating state, the larger working chamber 19 is connected via the B control connection 32 of the follow-up control valve and via this to the tank 24 of the pressure supply unit, in which case the piston 27 of the hydraulic cylinder 11 moved in the direction of arrow 17 "down".

Das Nachlauf-Regelventil 29 umfaßt in einem lediglich schematisch angedeuteten Gehäuse 33 insgesamt 4, beim dargestellten, speziellen Ausführungsbeispiel als Kegel-Sitzventile ausgebildete Ventilelemente 34, 35, 36 und 37, deren dargestellte Grundstellung die Sperrstellung ist. Die kegelförmigen Ventilkörper 38, die durch Rückstellfedern 39 in Richtung auf den jeweiligen, z.B. ringkantenförmigen Ventilsitz 41 gedrängt werden, haben stiftförmige Fortsätze 42, an deren freien Enden ein insgesamt mit 43 bezeichnetes Ventilbetätigungsglied angreifen kann, durch dessen axiale Verschiebungen in den durch die Pfeile 44 und 46 repräsentierten, entgegengesetzten Richtungen entweder die Ventilkörper der beiden Ventilelemente 34 und 35, die gemäß Fig. 1 rechts von dem Ventil-Betätigungsglied 43 angeordnet sind, von ihren Ventilsitzen 41 abheben, während die beiden anderen Ventilelemente 36 und 37 in ihrer Sperrstellung bleiben, oder die Ventilkörper 38 dieser letztgenannten Ventilelemente 36 und 37 von ihren Ventilsitzen 41 abheben, während die beiden vorgenannten Ventilelemente 34 und 35 in ihrer Sperrstellung verharren. Die Ventilelemente 34 - 37 sind so ausgebildet, daß die durch eine Öffnungsbetätigung der Ventilelemente freiwerdenden Ventilspalt bzw. Strömungsquerschnitte über die dem Hydrozylinder 11 zugeleitete bzw. von diesem abfließende Arbeitsmedium-Ströme fließen, jeweils den Auslenkungen ei bzw. s2 des Ventilbetätigungsgliedes 43 proportional oder annähernd proportional sind, um die die Ventilkörper 38 des einen «rechten» Ventilelementpaares 34, 35 bzw. die Ventilkörper 38 des anderen Ventilelementpaares 36, 37, in Richtung der Pfeile 44 bzw. 46 verschoben werden.In a housing 33, which is only indicated schematically, the follow-up control valve 29 comprises a total of 4 valve elements 34, 35, 36 and 37, the basic position shown being the blocking position in the special exemplary embodiment shown. The conical valve bodies 38, which are urged in the direction of the respective, for example annular-edged valve seat 41 by return springs 39, have pin-shaped extensions 42, on the free ends of which a valve actuation member, generally designated 43, can engage, by means of its axial displacements in the arrows 44 and 46, in opposite directions, either lift the valve bodies of the two valve elements 34 and 35, which are arranged to the right of the valve actuator 43 according to FIG. 1, from their valve seats 41, while the other two valve elements 36 and 37 remain in their blocking position, or lift the valve bodies 38 of these latter valve elements 36 and 37 from their valve seats 41, while the two aforementioned valve elements 34 and 35 remain in their blocking position. The valve elements 34 - 37 are designed so that the valve gap or flow cross sections released by an actuation of the valve elements flow over the working medium flows supplied to or from the hydraulic cylinder 11, each proportional to the deflections e i and s 2 of the valve actuating member 43 or are approximately proportional, by which the valve bodies 38 of one “right” pair of valve elements 34, 35 or the valve bodies 38 of the other pair of valve elements 36, 37 are displaced in the direction of arrows 44 and 46, respectively.

Das gemäß Fig. 1 untere, rechte Ventilelement 34 ist das den Durchflußquerschnitt eines ersten, insgesamt mit 47 bezeichneten Strömungspfades, über den vom P-Versorgungsanschluß 21 des Druck-Versorgungsaggregates 22 Arbeitsmedium zum A-Steuerausgang 31 des Nachlauf-Regelventils 29 geleitet ist und über diesen in den den größeren Querschnitt aufweisenden Arbeitsraum 19 des Hydrozylinders einströmen kann.The lower right valve element 34 according to FIG. 1 is the flow cross section of a first flow path, generally designated 47, via which working medium is directed from the P supply connection 21 of the pressure supply unit 22 to the A control output 31 of the follow-up control valve 29 and via this can flow into the working area 19 of the hydraulic cylinder having the larger cross section.

Das gemäß Fig. 1 linke, untere Ventilelement 36 ist das den Durchflußquerschnitt eines ersten, insgesamt mit 48 bezeichneten Abfluß-Strömungspfades, über den Arbeitsmedium aus dem Arbeitsraum 19 des Hydrozylinders 11 zum Tank 24 hin abströmen kann.1, the lower valve element 36 on the left is the flow cross-section of a first drain flow path, designated overall by 48, via which working medium can flow out of the working space 19 of the hydraulic cylinder 11 to the tank 24.

Das gemäß Fig. 1 obere, rechte Ventilelement 35 ist das den wirksamen Durchflußquerschnitt eines zusätzlichen, zu dem ersten Zufluß-Strömungspfad 47 parallel geschalteten, insgesamt mit 49 bezeichneten Zufluß-Strömungspfades, der vom P-Versorgungsausgang 21 des Druckversorgung-Aggregates 22 zum B-Steueranschluß 32 des Nachlauf-Regelventils 29 und über diesen zum größeren Arbeitsraum 19 des Hydrozylinders 11 führt. Dieser zusätzliche Zufluß-Strömungspfad 49 ist in der Grundstellung 0 eines als 2/2-Wege-Magnetventil ausgebildeten ersten Steuerventils 51 gesperrt und freigegeben, wenn das Steuerventil 51 in seine erregte Stellung 1 gesteuert ist.The upper right valve element 35 according to FIG. 1 is the effective flow cross section of an additional inflow flow path, which is connected in parallel to the first inflow flow path 47 and is designated overall by 49, and which runs from the P supply outlet 21 of the pressure supply unit 22 to the B- Control port 32 of the follow-up control valve 29 and via this leads to the larger working space 19 of the hydraulic cylinder 11. In the basic position 0 of a first control valve 51 designed as a 2/2-way solenoid valve, this additional inflow flow path 49 is blocked and released when the control valve 51 is controlled into its excited position 1.

Das gemäß Fig. 1 linke, obere Ventilelement 37 ist das den wirksamen Durchflußquerschnitt eines zu dem ersten Abfluß-Strömungspfad 48 parallel geschalteten, insgesamt mit 52 bezeichneten zusätzlichen Abfluß-Strömungspfades, der in der Grundstellung 0 eines zweiten, als 2/2-Wege-Magnetventil ausgebildeten Steuerventils 53 gesperrt und in der erregten Stellung 1 dieses zweiten Steuerventils 53 freigegeben ist, so daß auch über diesen zusätzlichen Abfluß-Strömungspfad 52 Arbeitsmedium aus dem größeren Arbeitsraum 19 des Hydrozylinders 11 zum Tank 24 hin abströmen kann.1, the upper valve element 37 on the left is the effective flow cross-section of an additional drain flow path connected in parallel with the first drain flow path 48, designated overall by 52, which in the basic position 0 of a second 2/2-way Solenoid valve trained control valve 53 is blocked and released in the energized position 1 of this second control valve 53, so that 52 working medium can flow out of the larger working space 19 of the hydraulic cylinder 11 to the tank 24 through this additional drain flow path.

Die Steuerung der Vorschub- und Rückzugsbewegungen des Hydrozylinders 11 erfolgt durch schrittweise oder kontinuierliche Vorgabe von Positions-Soll-Werten, beim dargestellten Ausführungsbeispiel durch Verdrehen einer Spindelmutter 54, die in dem Gehäuse 33 des Nachlauf-Regelventils in Richtung der Pfeile 44 und 46 hin- und herverschiebbar geführt ist. Die Spindelmutter steht in kämmendem Eingriff mit einer Gewindespindel 56, die im Gehäuse 33 des Nachlauf-Regelventils 29 drehbar gelagert, jedoch gegen axiale Verrückungen gesichert ist. Ein mit der Gewindespindel 56 drehfest verbundenes Ritzel 57 kämmt mit einer Zahnstange 58, die z.B. über eine starre Verbindung 59 mit der Kolbenstange 13 des Hydrozylinders 11 bewegungsgekoppelt ist. Die durch eine zentrale Öffnung 61 des Ventilbetätigungsgliedes 43 frei hindurchtretende Spindelmutter 54 ist über beidseits des Ventilbetätigungsgliedes 43 angeordnete Axial-Kugellager 62 und 63 derart mit dem Ventilbetätigungsglied 43 verbunden, daß dieses aus einer Verdrehung der Spindelmutter gegenüber der Gewindespindel 56 resultierende axiale Verschiebungen der Spindelmutter, die, je nach der Drehrichtung in Richtung des Pfeils 44 oder des Pfeils 46 erfolgen, mit ausführt, jedoch nicht auch deren Rotationsbewegungen mit ausführen muß; das Ventilsbetätigungsglied 43 ist, was nicht eigens dargestellt ist, gegen Verdrehung gesichert, am Ventilgehäuse 33 in axialer Richtung verschiebbar geführt.The control of the feed and retraction movements of the hydraulic cylinder 11 takes place by step-by-step or continuous specification of target position values in the embodiment shown play by turning a spindle nut 54 which is guided in the housing 33 of the follow-up control valve in the direction of arrows 44 and 46 to slide back and forth. The spindle nut is in meshing engagement with a threaded spindle 56, which is rotatably mounted in the housing 33 of the follow-up control valve 29, but is secured against axial displacements. A pinion 57, which is connected in a rotationally fixed manner to the threaded spindle 56, meshes with a toothed rack 58 which, for example, is coupled in motion to the piston rod 13 of the hydraulic cylinder 11 via a rigid connection 59. The spindle nut 54, which passes freely through a central opening 61 of the valve actuating member 43, is connected to the valve actuating member 43 via axial ball bearings 62 and 63 arranged on both sides of the valve actuating member 43 such that the latter results in axial displacements of the spindle nut resulting from a rotation of the spindle nut relative to the threaded spindle 56, which, depending on the direction of rotation in the direction of arrow 44 or arrow 46, also carries out, but does not also have to carry out their rotational movements; the valve actuator 43, which is not specifically shown, is secured against rotation, guided on the valve housing 33 so as to be displaceable in the axial direction.

Zur Erläuterung der Funktion der insoweit erläuterten Antriebsvorrichtung 10 sei der Fall betrachtet, daß der Werkzeugkopf 14 zunächst eine Zustellbewegung in Richtung des Pfeils 16 «nach oben» ausführen soll, bis er auf ein nicht dargestelltes Werkstück trifft und danach - unter erhöhter Last - einen Arbeitshub s ausführen muß, der gleichsam der Bearbeitungstiefe des Werkstückes entspricht. Danach soll der Werkzeugkopf 14 in die dargestellte Ausgangslage zurückgebracht werden.To explain the function of the drive device 10 explained so far, consider the case that the tool head 14 should first perform an infeed movement in the direction of the arrow 16 “upwards” until it hits a workpiece (not shown) and then - under increased load - a working stroke s must execute, which corresponds to the machining depth of the workpiece. Then the tool head 14 is to be returned to the starting position shown.

Um diese Bewegungen zu steuern, wird die Spindelmutter zunächst, in Richtung des Pfeils 64 gesehen, im Gegenuhrzeigersinn gedreht, wodurch die Spindelmutter 54 und mit dieser zusammen das Ventilbetätigungsglied 43, da sich am Beginn dieses Steuerungsvorganges der Kolben 27 des Hydrozylinders 11 praktisch noch nicht bewegt und damit die Gewindespindel 56 sich auch noch nicht dreht, eine Verschiebung in Richtung des Pfeiles 44, nach rechts, erfährt, wodurch die beiden Ventilelemente 34 und 35, die gemäß Fig. 1 rechts von dem Ventil- betätigungsglied angeordnet sind, aufgesteuert werden. Dabei sei vorausgesetzt, daß sich die beiden Steuerventile 51 und 53 in der dargestellten Sperrstellung 0 befinden. Es fließt damit zunächst nur über das eine Ventilelement 34, das heißt über den ersten Zuführungs-Strömungspfad 47 Arbeitmedium in den größeren Arbeitsraum 19 des Hydrozylinders, wodurch dessen Zustellbewegung einsetzt. Der Einfachheit halber sei vorausgesetzt, daß die Spindelmutter 54 mit konstanter, einem bestimmten Erwartungswert der Vorschubgeschwindigkeit v entsprechenden Winkelgeschwindigkeit angetrieben sei. Sobald die Aufwärtsbewegung des Kolbens 27 des Hydrozylinders 11 einsetzt, wird über den Zahnstangen-/Ritzei-Antrieb 58, 57 auch die Gewindespindel 56, in Richtung des Pfeils 64 gesehen, ebenfalls im Gegenuhrzeigersinn, in Rotation versetzt, wobei je nach dem Umsetzungsverhältnis, mit dem die Geschwindigkeit v der Zahnstangenbewegung in eine dazu proportionale Winkelgeschwindigkeit der Gewindespindel 56 umgesetzt wird, deren Winkelgeschwindigkeit früher oder später gleich derjenigen der Spindelmutter wird, ggf. nach einer Phase, in der die Winkelgeschwindigkeit der Gewindespindel 56 größer war als diejenige der Spindelmutter 54 und in dem sich einspielenden Gleichgewichtszustand gleicher Winkelgeschwindigkeiten der Spindelmutter 54 und der Gewindespindel 56 diejenige Auslenkung ε1 des Ventilbetätigungsgliedes 43 erreicht ist, bei welcher das Ventilelement 37 soweit aufgesteuert ist, daß der über den ersten Strömungspfad 47 in den größeren Arbeitsraum 19 des Hydrozylinders 11 eingeleitete Arbeitsmedium-Strom denjenigen Wert hat, bei dem die Geschwindigkeit der Bewegung des Hydrozylinderkolbens 27 dem durch Verdrehen der Spindelmutter 54 eingesteuerten Sollwert entspricht.In order to control these movements, the spindle nut is first rotated counterclockwise, as seen in the direction of arrow 64, as a result of which the spindle nut 54 and together with this the valve actuation element 43, since at the beginning of this control process the piston 27 of the hydraulic cylinder 11 practically does not yet move and so that the threaded spindle 56 does not yet rotate, undergoes a shift in the direction of the arrow 44, to the right, as a result of which the two valve elements 34 and 35, which are arranged to the right of the valve actuating element according to FIG. 1, are opened. It is assumed that the two control valves 51 and 53 are in the blocking position 0 shown. First of all, working medium flows into the larger working chamber 19 of the hydraulic cylinder only via one valve element 34, that is to say via the first feed flow path 47, as a result of which the feed movement begins. For the sake of simplicity, it may be assumed that the spindle nut 54 is driven at a constant angular speed corresponding to a certain expected value of the feed speed v. As soon as the upward movement of the piston 27 of the hydraulic cylinder 11 begins, the threaded spindle 56 is also rotated in the direction of arrow 64, also in the counterclockwise direction, via the rack / pinion drive 58, 57, depending on the conversion ratio, with where the speed v of the rack movement is converted into a proportional angular velocity of the threaded spindle 56, the angular velocity of which sooner or later becomes equal to that of the spindle nut, possibly after a phase in which the angular velocity of the threaded spindle 56 was greater than that of the spindle nut 54 and in the prevailing equilibrium state of the same angular velocities of the spindle nut 54 and the threaded spindle 56, that deflection ε 1 of the valve actuating member 43 is reached, in which the valve element 37 is opened so far that it is introduced via the first flow path 47 into the larger working space 19 of the hydraulic cylinder 11 The working medium flow has the value at which the speed of the movement of the hydraulic cylinder piston 27 corresponds to the setpoint value that is set by turning the spindle nut 54.

Die Vorgabe des Sollwertes der Bewegungsgeschwindigkeit des Kolbens 27 des Hydrozylinders erfolgt beim dargestellten, speziellen Ausführungsbeispiel in an sich bekannter Weise mit Hilfe eines durch Ausgangs-Steuerimpulse einer elektronischen Steuereinheit 66 in alternativen Drehrichtungen antreibbaren Schrittmotors 67, der über einen insgesamt mit 68 bezeichneten Zahnriementrieb mit der Spindelmutter 54 antriebsgekoppelt ist. Die Rotations- bzw. Winkelgeschwindigkeit der Spindelmutter 54 ist dabei durch die Frequenz der jeweiligen Steuerimpulse bestimmt, durch die das Abtriebritzel 69 des Schrittmotors 67 um jeweils ein definiertes Winkel-Inkrement gedreht wird. Durch die zeitbezogene Anzahl der dem Schrittmotor 67 zugeleiteten, zu dessen Ansteuerung in der einen oder der entgegengesetzten Drehrichtung ausgenutzten Steuerimpulse ist somit ein bestimmter Weg s vorgegeben, um den sich der Kolben 27 des Hydrozylinders 11 bzw. der Werkzeugkopf 14 in der Bezugszeitspanne bewegt.The specification of the setpoint of the speed of movement of the piston 27 of the hydraulic cylinder takes place in the special embodiment shown in a manner known per se with the aid of a stepper motor 67 which can be driven in alternative directions of rotation by output control pulses from an electronic control unit 66 and which has a toothed belt drive designated as 68 with the Spindle nut 54 is drive-coupled. The rotational or angular speed of the spindle nut 54 is determined by the frequency of the respective control pulses by which the driven pinion 69 of the stepping motor 67 is rotated by a defined angular increment. The time-related number of the control pulses fed to the stepper motor 67, which are used to control them in one or the opposite direction of rotation, thus predetermine a specific path s by which the piston 27 of the hydraulic cylinder 11 or the tool head 14 moves in the reference time period.

Der Nachlauf- oder Schleppfehler As, um den sich die momentane Position des Werkzeugkopfes 14, das heißt die Ist-Position desselben von der über den Zahnriementrieb 68 angesteuerten Soll-Position unterscheidet, entspricht dann der für den stationären Bewegungszustand charakteristischen Auslenkung ε1 bzw. ε2 des Ventilbetätigungsgliedes 43 aus seiner Grundstellung, multipliziert mit dem Umsetzungsverhältnis, mit dem die die Gewindespindel 56, deren Antriebsritzel 57 und die Zahnstange 58 umfassende, mechanische Rückmeldeeinrichtung HubWege des Kolbens 27 des Hydrozylinders in dazu proportionale Drehwinkel-Beträge der Gewindespindel 56 umsetzt.The caster or tracking error As, by which the current position of the tool head 14, that is to say the actual position thereof, differs from the desired position controlled by the toothed belt drive 68, then corresponds to the deflection ε 1 or ε characteristic of the stationary movement state 2 of the valve actuator 43 from its basic position, multiplied by the conversion ratio with which the mechanical feedback device comprising the threaded spindle 56, its drive pinion 57 and the rack 58 converts stroke paths of the piston 27 of the hydraulic cylinder into rotation angle amounts of the threaded spindle 56 which are proportional thereto.

Die durch die Beziehung Kv = v/As definierte Kreisverstärkung des Nachlauf-Regelkreises der Antriebsvorrichtung 10 ist somit um so niedriger, je größer die Auslenkungen ε1 bzw. F2 sind, um die die Ventilkörper 38 der Ventilelemente 34 bzw. 36 ausgelenkt werden müssen, damit bei vorgegebenem Ausgangsdruck des Druckversorgungsaggregates 22 der für die Erzielung einer bestimmten Vorschub- bzw. Rückzugsgeschwindigkeit des Werkzeugkopfes 14 erforderliche Arbeitsmedium-Strom über den Strömungspfad 47 dem Hydrozylinder 11 zuströmen bzw. von diesem über den Abfluß-Strömungspfad 48 zum Tank 24 hin abströmen kann.The circular gain of the overtravel control loop of the drive device 10 defined by the relationship K v = v / As is therefore lower, the greater the deflections ε 1 and F2 by which the valve bodies 38 of the valve elements 34 and 36 must be deflected So that at a given output pressure of the pressure supply unit 22, the working medium flow required to achieve a certain feed or retraction speed of the tool head 14 can flow via the flow path 47 to the hydraulic cylinder 11 or can flow out of the latter via the discharge flow path 48 to the tank 24 .

Tritt im Verlauf einer z.B. in Richtung des Pfeils 16 erfolgenden Vorschubbewegung des Werkzeugkopfes 14 ein Lastwechsel auf, derart, daß sich der Widerstand, gegen den der Kolben 27 des Hydrozylinders 11 verschoben werden muß, vergrößert, wobei jedoch die Geschwindigkeit v der Vorschubbewegung konstant bleiben soll, so reagiert das Nachlauf-Regelventil 29 hierauf mit einer Vergrößerung der Auslenkung ε1 des Ventilbetätigungsgliedes 43, mit der Folge, daß die Kreisverstärkung Kv - wegen der mit der Vergrößerung der Auslenkung ε1 verknüpften Vergrößerung des Nachlauffehlers As - abnimmt. Die Regelung wird unempfindlicher, und es werden daher Abweichungen der Ist-Position des Werkzeuges von der momentan angesteuerten Soll-Position größer.If a load change occurs in the course of a feed movement of the tool head 14, for example in the direction of arrow 16, such that the resistance against which the piston 27 of the hydraulic cylinder 11 has to be displaced increases, but the speed v of the feed movement should remain constant , the overrun control valve 29 reacts to this with an increase in the deflection ε 1 of the valve actuating element 43, with the result that the loop gain K v - because of the increase in the overrun error As associated with the increase in the deflection ε 1 - decreases. The control becomes less sensitive, and therefore deviations of the actual position of the tool from the currently controlled target position become larger.

Dasselbe gilt sinngemäß, wenn im Verlauf einer in Richtung des Pfeils 17 erfolgenden Rückzugsbewegung des Werkzeugkopfes 14 ein Lastwechsel im Sinne einer Vergrößerung des Widerstandes auftritt, gegen den der Kolben 27 des Hydrozylinders 11 zurückgeschoben werden muß, in welchem Falle das Nachlauf-Regelventil mit einer Vergrößerung der Auslenkung ε2 des Ventilbetätigungsgliedes 43 in Richtung des Pfeils 46 reagiert.The same applies analogously if, in the course of a retraction movement of the tool head 14 in the direction of arrow 17, a load change occurs in the sense of an increase in the resistance, against which the piston 27 of the hydraulic cylinder 11 must be pushed back, in which case the follow-up control valve with an increase the deflection ε 2 of the valve actuator 43 in the direction of arrow 46 reacts.

Um derartige, z.B. lastabhängige Änderungen der Kreisverstärkung des Nachlauf-Regelkreises vermeiden oder zumindest weitgehend kompensieren zu können, aber auch um bedarfsweise gezielt einen anderen Wert der Kreisverstärkung einstellen zu können, sind bei der Antriebsvorrichtung 10 gemäß Fig. 1 der zusätzliche Zufluß-Strömungspfad 49 und der zusätzliche Abfluß-Strömungspfad 52 vorgesehen. Solange diese zusätzlichen Strömungspfade 49 und 52 - in den Grundstellungen 0 der Steuerventile 51 und 53 gesperrt sind, ist die Kreisverstärkung des Nachlauf-Regelkreises auf einen maximalen Wert Kv1 begrenzt.In order to be able to avoid or at least largely compensate for such, for example, load-dependent changes in the loop gain of the wake control loop, but also in order to be able to selectively set a different value of the loop gain, the additional inflow flow path 49 and the additional drain flow path 52 is provided. As long as these additional flow paths 49 and 52 are blocked in the basic positions 0 of the control valves 51 and 53, the loop gain of the overrun control loop is limited to a maximum value K v1 .

Durch ventilgesteuerte Freigabe des zusätzlichen Zufluß-Strömungspfades 49 kann für den Vorschub- betrieb des Hydrozylinders 11, das heißt wenn sich dessen Kolben 27 in Richtung des Pfeils 16 bewegt, die maximale Kreisverstärkung des Nachlauf-Regelkreises auf den Wert Kv2 erhöht werden, da nunmehr bei vorgegebener Auslenkung ε1 des Ventilbetätigungsgliedes 43 über die beiden Ventilelemente 34 und 35 der parallelen Zufluß-Strömungspfade 47 und 49 Arbeitsmedium in den größeren Arbeitsraum 19 des Hydrozylinders 11 einströmen kann.By valve-controlled release of the additional inflow flow path 49, the maximum circuit gain of the overrun control circuit can be increased to the value K v2 for the feed operation of the hydraulic cylinder 11, that is to say when the piston 27 moves in the direction of the arrow 16, since now with a predetermined deflection ε 1 of the valve actuating element 43, working medium can flow into the larger working space 19 of the hydraulic cylinder 11 via the two valve elements 34 and 35 of the parallel inflow flow paths 47 and 49.

Desgleichen kann durch ventilgesteuerte Freigabe des zusätzlichen Abfluß-Strömungspfades 52 die Kreisverstärkung des Nachlauf-Regelkreises auch für den Rückzugsbetrieb des Hydrozylinders 11, das heißt, wenn sich dessen Kolben 27 in Richtung des Pfeils 17 «abwärts» bewegt, auf einen maximalen Wert Kv2 erhöht werden, da bei vorgegebener Auslenkung sz der Ventilkörper 38 der beiden Ventilelemente 36 und 37 pro Zeiteinheit ein größeres Arbeitsmedium-Volumen über die parallelen Abfluß-Strömungspfade 48 und 52 zum Tank 24 hin abströmen kann.Likewise, by valve-controlled release of the additional discharge flow path 52, the circuit gain of the wake control circuit can also be increased to a maximum value K v2 for the retracting operation of the hydraulic cylinder 11, that is to say when the piston 27 moves “downward” in the direction of the arrow 17 become, since with a given deflection s z the valve body 38 of the two valve elements 36 and 37 per unit time can flow a larger volume of working medium via the parallel discharge flow paths 48 and 52 to the tank 24.

Es versteht sich, daß die erfindungsgemäß vorgesehene Möglichkeit der ventilgesteuerten Freigabe eines zusätzlichen Zufluß-Strömungspfades 49 und eines Abfluß-Strömungspfades 52 sowohl zu einer Erhöhung der Kreisverstärkung als auch zu einer teilweisen oder vollständigen Kompensation eines Abfalles der Kreisverstärkung ausgenutzt werden kann, wobei der Bedarfsfall der Kompensation eines Abfalls der Kreisverstärkung in praxi der häufigere sein wird.It is understood that the possibility according to the invention of the valve-controlled release of an additional inflow flow path 49 and an outflow flow path 52 can be used both to increase the loop gain and to partially or completely compensate for a drop in the loop gain, the need being that Compensation for a drop in loop gain in practice which will be more common.

In dem zusätzlichen Zufluß-Strömungspfad 49 ist, in Strömungsrichtung des vom Druckversorgungsaggregat 22 zum Hydrozylinder 11 fließenden Arbeitsmedium-Stromes gesehen, zwischen dem ersten Steuerventil 51 und dem Ventilelement 35 des Nachlauf-Regelventils 29 eine Drossel 71 mit einstellbarem Strömungswiderstand vorgesehen; desgleichen ist in dem vom Hydrozylinder 11 über das Ventilelement 37 des Nachlauf-Regelventils 29 führenden zusätzlichen Abfluß-Strömungspfad 52, in Strömungsrichtung gesehen wiederum zwischen dem Ventilelement 37 und dem zweiten Steuerventil 53 eine Drossel 72 mit einstellbarem Strömungswiderstand vorgesehen. Durch bedarfsgerechte Einstellung der Strömungswiderstände dieser Drosseln 71 und 72 können die im Vorschub-Betrieb und im Rückzugs-Betrieb maximal ausnutzbaren Werte Kv2 und Kv2' stufenlos eingestellt werden.In the additional inflow flow path 49, as seen in the flow direction of the working medium stream flowing from the pressure supply unit 22 to the hydraulic cylinder 11, a throttle 71 with an adjustable flow resistance is provided between the first control valve 51 and the valve element 35 of the follow-up control valve 29; likewise, a throttle 72 with an adjustable flow resistance is provided in the additional outflow flow path 52 leading from the hydraulic cylinder 11 via the valve element 37 of the follow-up control valve 29, as seen in the flow direction, again between the valve element 37 and the second control valve 53. By adjusting the flow resistances of these throttles 71 and 72 as required, the maximum usable values K v2 and K v2 ' in the feed mode and in the retract mode can be set continuously.

Beim dargestellten Erläuterungsbeispiel der Antriebsvorrichtung 10 mit einem Differentialkolben-Hydrozylinder 11 als Leistungs-Antriebseinheit erfolgt die bedarfsgerechte Ansteuerung der Verstärkungs-Steuerventile 51 und 53 programmgesteuert durch Ausgangssignale der elektronischen Steuereinheit 66, die auch die Position-Soll-Wert-Ausgabesignale zur Ansteuerung des Schrittmotors 67 erzeugt, das heißt wegabhängig.In the illustrated explanatory example of the drive device 10 with a differential piston hydraulic cylinder 11 as the power drive unit, the booster control valves 51 and 53 are controlled as required by the program by means of output signals from the electronic control unit 66, which also provide the position-target value output signals for controlling the stepping motor 67 generated, that is path-dependent.

Die Fig. 2, auf deren Einzelheiten nunmehr ausdrücklich verwiesen sei, zeigt eine funktionell der Antriebsvorrichtung 10 gemäß Fig. 1 weitestgehend analoge Antriebsvorrichtung 10' mit einstellbarer Regelkreisverstärkung, wobei für bau- und funktionsgleiche bzw. -analoge Elemente der Antriebsvorrichtung 10' gemäß Fig. 2 und 10 gemäß Fig. 1 jeweils dieselben Bezugszeichen verwendet sind und insoweit auf die diesbezügliche Beschreibung zu Fig. 1 verwiesen werden kann.2, to the details of which reference is now expressly made, shows a drive device 10 'largely functionally analogous to the drive device 10 according to FIG. 1 with adjustable control loop gain, elements of the drive device 10' according to FIG. 2 and 10 according to FIG. 1 the same reference numerals are used and in this respect reference can be made to the relevant description of FIG. 1.

Die Antriebsvorrichtung 10' gemäß Fig. 2 unterscheidet sich von derjenigen gemäß Fig. 1 im wesentlichen nur durch die spezielle Gestaltung des Nachlauf-Regelventils 29', das hier als Kolben-Schieberventil ausgebildet ist.The drive device 10 'according to FIG. 2 differs from that according to FIG. 1 essentially only in the special design of the follow-up control valve 29', which is designed here as a spool valve.

Auch bei der Antriebsvorrichtung 10' gemäß Fig. 2 werden durch Auslenkungen ε1 und 82 eines insgesamt mit 73 bezeichneten Ventilkolbens, die aus dessen gestrichelt angedeuteter Grundstellung in den durch die Pfeile 44 und 46 repräsentierten, alternativen Richtungen erfolgen, die in Richtung der Pfeile 16 bzw. 17 ablaufenden Vorschub- und Rückzugs- bewegungen des Kolbens 27 des Hydrozylinders 11 gesteuert.Also in the drive device 10 ′ according to FIG. 2, deflections ε 1 and 82 of a valve piston, designated overall by 73, which, from its basic position indicated by dashed lines, take place in the alternative directions represented by the arrows 44 and 46, in the direction of the arrows 16 or 17 running feed and retraction movements of the piston 27 of the hydraulic cylinder 11 controlled.

Zur Erzielung der erforderlichen Auslenkungen ε1 und 82 des Ventilkolbens 73 erforderliche Einrichtungen zur Positions-Soll-Wert-Vorgabe und zur Rückmeldung der Ist-Position des Kolbens 27 des Hydrozylinders 11 können dieselbe Ausbildung haben wie die diesbezüglich in Verbindung mit der Erzielung der Auslenkungen ε1 und 82 des Ventilbetätigungsgliedes 43 des Nachlauf-Regelventils 29 gemäß Fig. 1 vorgesehenen Funktionselemente und sind der Einfachheit halber nicht dargestellt.In order to achieve the required deflections ε 1 and 82 of the valve piston 73, the devices required for setting the desired position value and for reporting the actual position of the piston 27 of the hydraulic cylinder 11 can have the same design as that in connection with the achievement of the deflections ε 1 and 82 of the valve actuator 43 of the follow-up control valve 29 ge 1 and are not shown for the sake of simplicity.

In dem lediglich schematisch dargestellten Ventilgehäuse 74 des Nachlauf-Regelventils 29' sind insgesamt sechs die zentrale Gehäusebohrung, in welcher der Ventilkolben 73 verschiebbar-dicht geführt ist, radial erweiternde Ringnuten 77 - 82 vorgesehen, die, entlang der zentralen Längsachse 83 des Ventilgehäuses 74 äquidistant angeordnet sind, wobei die in derselben Richtung gemessene Weite w dieser Ringnuten 77 - 82 der ebenfalls in dieser Richtung gemessenen Dicke der ringförmigen Zwischenrippen 85 - 89 des Ventilgehäuses 74 entspricht, die je zwei dieser Ringnuten gegeneinander absetzen.In the valve housing 74 of the follow-up control valve 29 ', which is only shown schematically, a total of six annular grooves 77-82, which radially widen the central housing bore, in which the valve piston 73 is displaceably guided, are provided, which are equidistant along the central longitudinal axis 83 of the valve housing 74 are arranged, the width w of these annular grooves 77-82, measured in the same direction, corresponding to the thickness of the annular intermediate ribs 85-89 of the valve housing 74, which thickness is also measured in this direction, and which each offset two of these annular grooves.

Der Ventilkolben 73 hat zwischen seinen Endabschnitten 91 und 92, mit deren er in den entsprechenden Endabschnitten der Gehäusebohrung 76 geführt ist, insgesamt 4 Ringnuten 93 - 96, die paarweise durch je einen der insgesamt drei Kolbenflansche 97 - 99, deren Durchmesser D dem Durchmesser der zentralen Gehäusebohrung 76 entspricht, gegeneinander abgesetzt sind, wobei die Ringnuten 93 - 96 des Ventilkolbens 73, in Richtung dessen Längsachse 83 gesehen, die doppelte Weite ww der Ringnuten 77 - 82 des Ventilgehäuses 74 haben und die in derselben Richtung gemessenen Dicken der Kolbenflansche 97, 98 und 99 den axialen Weiten w der Ringnuten 77 - 82 des Ventilgehäuses 74 entsprechen. Die Anordnung der Gehäuse-Ringnuten und die Anordnung der Kolben-Ringnuten 93 - 96 sind somit symmetrisch bezüglich der Quermittelebene 101 des Ventilgehäuses bzw. der Quermittelebene 102 des Ventilkolbens 73, die in der gestrichelt eingezeichneten Grundstellung des Ventilkolbens 73 mit der Quermittelebene 101 des Ventilgehäuses 73 zusammenfällt.The valve piston 73 has between its end sections 91 and 92, with which it is guided in the corresponding end sections of the housing bore 76, a total of 4 annular grooves 93-96, each in pairs through one of the three piston flanges 97-99, whose diameter D is the diameter of the central housing bore 76, are offset from one another, the annular grooves 93-96 of the valve piston 73, viewed in the direction of its longitudinal axis 83, being twice the width ww of the annular grooves 77-82 of the valve housing 74 and the thicknesses of the piston flanges 97 measured in the same direction, 98 and 99 correspond to the axial widths w of the ring grooves 77 - 82 of the valve housing 74. The arrangement of the housing ring grooves and the arrangement of the piston ring grooves 93 - 96 are thus symmetrical with respect to the transverse central plane 101 of the valve housing or the transverse central plane 102 of the valve piston 73, the basic position of the valve piston 73 shown in dashed lines with the transverse central plane 101 of the valve housing 73 coincides.

Die gemäß Fig. 2 rechts von der Symmetrieebene 101 des Ventilgehäuses 73 angeordnete Ringnut 80 desselben ist mit dem P-Versorgungsanschluß 21 des Druckversorgungsaggregats 22 kommunizierend verbunden, die links von der Gehäuse-Symmetrieebene 101 angeordnete Ringnut 79 mit dem Tank-Versorgungsanschluß 103. Die beiden Ringnuten 78 und 81, zwischen denen die mit dem Tank-Versorgungsanschluß 103 bzw. dem P-Versorgungsanschluß 21 kommunizierenden Ringnuten 79 und 80 angeordnet sind, sind beide über den B-Steuerausgang 32 bzw. den A-Ausgang 31 des Nachlauf-Regelventils 29' an den durch die größere Kolbenfläche 28 begrenzten Arbeitsraum 19 des Hydrozylinders 11 angeschlossen.The annular groove 80 arranged to the right of the plane of symmetry 101 of the valve housing 73 according to FIG. 2 is communicatively connected to the P supply connection 21 of the pressure supply unit 22, the annular groove 79 arranged to the left of the plane of symmetry 101 to the tank supply connection 103. The two Ring grooves 78 and 81, between which the ring grooves 79 and 80 communicating with the tank supply connection 103 and the P supply connection 21 are arranged, are both via the B control output 32 and the A output 31 of the follow-up control valve 29 '. connected to the working space 19 of the hydraulic cylinder 11 delimited by the larger piston area 28.

Die gemäß Fig. 2 linke, äußere Ringnut 77 des Ventilgehäuses 74 ist über das Verstärkungs-Steuerventil 51, das in seiner Grundstellung 0 gesperrt, in seiner erregten Stellung 1 aus Durchlaß geschaltet ist, an den P-Versorgungsausgang 21 des Druckversorgungsaggregats 22 und über diesen an den im Querschnitt kleineren Arbeitsraum 18 des Hydrozylinders 11 angeschlossen.2, the outer annular groove 77 of the valve housing 74 is via the amplification control valve 51, which is blocked in its basic position 0, in its excited position 1 is switched from passage to the P supply output 21 of the pressure supply unit 22 and via this connected to the work chamber 18 of the hydraulic cylinder 11, which is smaller in cross section.

Die gemäß Fig. 2 rechte, äußere Ringnut 82 des Ventilgehäuses 74 ist über das zweite Verstärkungs-Steuerventil 53, dessen Grundstellung 0 die Sperrstellung und dessen erregte Stellung I die DurchflußStellung ist, an den mit dem Tank 24 des Druckversorgungsaggregats 22 kommunizierenden Versorgungsanschluß 103 angeschlossen.2, the outer annular groove 82 on the right of the valve housing 74 is connected to the supply connection 103 communicating with the tank 24 of the pressure supply unit 22 via the second boost control valve 53, the basic position 0 of which is the blocking position and the excited position I is the flow position.

Die möglichen Auslenkungen ε1 und s2 des Ventilkolbens 73 in den alternativen Auslenkungsrichtungen 44 und 46 sind auf Werte beschränkt, die kleiner sind als die Hälfte der Weite w der Ringnuten 77 - 82 des Ventilgehäuses 74. In der - gestrichelt eingezeichneten - Grundstellung des Ventilkolbens 73 sind sowohl die mit dem größeren Arbeitsraum 19 des Hydrozylinders 11 ständig in kommunizierender Verbindung stehenden Ringnuten 78 als auch die beiden äußersten Ringnuten 77 bzw. 82, die an je eines der Steuerventile 51 bzw. 52 angeschlossen sind, gegen die mit je einem der P- bzw. T-Versorgungsanschlüsse 21 bzw. 103 kommunizierenden Ringnuten 80 bzw. 79 des Ventilgehäuses 74 abgesperrt. In dieser Stellung des Ventilkolbens 73 - der Sperrstellung des Nachlauf-Regelventils 29' - bleibt der Kolben 27 des Hydrozylinders 11 stehen.The possible deflections ε 1 and s 2 of the valve piston 73 in the alternative deflection directions 44 and 46 are limited to values which are less than half the width w of the annular grooves 77-82 of the valve housing 74. In the basic position of the valve piston (shown in dashed lines) 73 are both the ring grooves 78 which are in constant communication with the larger working space 19 of the hydraulic cylinder 11 and also the two outermost ring grooves 77 and 82, which are connected to one of the control valves 51 and 52, against which one of the P - or T-supply connections 21 or 103 communicating annular grooves 80 or 79 of the valve housing 74 blocked. In this position of the valve piston 73 - the blocking position of the follow-up control valve 29 '- the piston 27 of the hydraulic cylinder 11 stops.

Bei einer Auslenkung ε1 des Ventilskolbens 73 in Richtung des Pfeils 44, gemäß Fig. 2 nach rechts, gelangt die an den P-Versorgungsanschluß 21 angeschlossene Ringnut 80 in kommunizierende Verbindung mit der mit dem A-Steueranschluß 31 kommunizierenden Ringnut 81, an dem der größere Arbeitsraum 19 des Hydrozylinders angeschlossen ist, so daß über den ersten Zuführungs-Strömungspfad 47 Arbeitsmedium zu dem größeren Arbeitsraum 19 des Hydrozylinders strömen kann und dessen Kolben 27 sich in Richtung des Pfeils 16 bewegt; desgleichen gelangt auch die zweite, über den B-Steueranschluß 32 in ständiger kommunizierender Verbindung mit dem größeren Arbeitsraum 19 des Hydrozylinders 11 stehende Ringnut 78 in kommunizierender Verbindung mit der, gemäß Fig. 2 linken, äußeren Ringnut 77, so daß, wenn das erste Verstärkungs-Steuerventil 51 in seine Durchlaß-Stellung 1 gesteuert wird, auch über den zu dem ersten Zuführungs-Strömungspfad 47 parallelen, zusätzlichen Strömungspfad 49 Arbeitsmedium vom P-Versorgungsanschluß 21 in den größeren Arbeitsraum 19 des Hydrozylinders 11 strömen kann. Die ständig mit dem Tank-Versorgungsanschluß 103 kommunizierende Ringnut 79 und auch die weitere, lediglich in der Durchlaßstellung des zweiten Verstärkungs-Steuerventils 53 mit dem Tank kommunizierende Ringnut 82 sind bei einer Auslenkung ε1 des Ventilkolbens 73 gegen die jeweils benachbarten Ringnuten 78 bzw. 81 abgesperrt.With a deflection ε 1 of the valve piston 73 in the direction of arrow 44, as shown in FIG. 2 to the right, the annular groove 80 connected to the P supply connection 21 comes into communicating connection with the annular groove 81 communicating with the A control connection 31, on which the Larger working space 19 of the hydraulic cylinder is connected, so that working medium can flow to the larger working space 19 of the hydraulic cylinder via the first feed flow path 47 and its piston 27 moves in the direction of arrow 16; likewise, the second annular groove 78, which is in constant communicating connection with the larger working chamber 19 of the hydraulic cylinder 11 via the B control connection 32, also communicates with the outer annular groove 77, as shown in FIG. 2 on the left, so that when the first reinforcement Control valve 51 is controlled in its passage position 1, can also flow from the P supply connection 21 into the larger working chamber 19 of the hydraulic cylinder 11 via the additional flow path 49, parallel to the first feed flow path 47. The annular groove 79 which constantly communicates with the tank supply connection 103 and also the further annular groove 82 which only communicates with the tank in the open position of the second boost control valve 53 are at a deflection ε 1 of the valve piston 73 against the respectively adjacent annular grooves 78 and 81 cordoned off.

Bei einer in Richtung des Pfeils 46 erfolgenden Auslenkung des Ventilkolbens 73 aus seiner Grundstellung wird die mit dem P-Versorgungsanschluß 21 werden sowohl die mit dem P-Versorgungsanschluß 21 kommunizierende Ringnut 80 als auch die gemäß Fig. 2 linke, äußere Ringnut 77 gegen die jeweils benachbarten Ringnuten 79 und 81 bzw. 78 abgesperrt; dafür gelangt die ständig mit dem Tank 24 kommunizierende Ringnut 79 in kommunizierende Verbindung mit der über den B-Steueranschluß 32 mit dem größeren Arbeitsraum 19 des Hydrozylinders 11 verbundenen Ringnut 78 des Ventilgehäuses 74 und gleichzeitig auch mit dessen gemäß Fig. 2 rechter, äußerer Ringnut 82, die über das zweite Verstärkungs-Steuerventil 53 an den T-Versorgungsanschluß 103 angeschlossen ist.When the valve piston 73 is deflected in the direction of arrow 46 from its basic position, the ring groove 80 communicating with the P-supply connection 21 and the outer ring groove 77 on the left according to FIG adjacent ring grooves 79 and 81 and 78 blocked; for this purpose, the annular groove 79, which communicates constantly with the tank 24, comes into communicating connection with the annular groove 78 of the valve housing 74, which is connected to the larger working chamber 19 of the hydraulic cylinder 11 via the B control connection 32, and at the same time also with its outer annular groove 82, which is the right one according to FIG. 2 connected to the T supply port 103 via the second boost control valve 53.

Bei einer Auslenkung s2 des Ventilkolbens 73 in Richtung des Pfeils 46 kann somit in jedem Falle über den ersten Abfluß-Strömungspfad 48 Arbeitsmedium aus dem größeren Arbeitsraum 19 des Hydrozylinders 11 zum Tank 24 hin abströmen und, wenn das zweite Verstärkungs-Steuerventil 53 in seine Durchlaß-Stellung 1 gesteuert ist, auch über den zusätzlichen Abfluß-Strömungspfad 52.With a deflection s 2 of the valve piston 73 in the direction of the arrow 46 can thus in any case the first outflow flow path 48 outflow working medium from the larger working space 19 of the hydraulic cylinder 11 to the tank 24 and, if the second boost control valve 53 is controlled in its passage position 1, also via the additional outflow flow path 52.

Die jeweils zur Änderung bzw. Einstellung der Kreisverstärkung des Nachlauf-Regelkreises erforderliche alternative oder gemeinsame Ansteuerung der beiden Verstärkungs-Steuerventile 51 und 53 erfolgt bei der Antriebsvorrichtung 10' gemäß Fig. 2 wie anhand der Fig. 1 für die Antriebsvorrichtung 10 beschrieben.The alternate or common actuation of the two amplification control valves 51 and 53, which is required in each case for changing or adjusting the loop gain of the overrun control loop, takes place in the drive device 10 ′ according to FIG. 2 as described with reference to FIG. 1 for the drive device 10.

Die Fig. 3, auf deren Einzelheiten nunmehr verwiesen sei, zeigt eine weitere Ausgestaltung einer hydraulischen Antriebsvorrichtung 100 mit einer dem Erfindungsgedanken unterfallenden Einrichtung zur Einstellung der Kreisverstärkung.FIG. 3, to the details of which reference should now be made, shows a further embodiment of a hydraulic drive device 100 with a device for adjusting the loop gain that is subject to the inventive concept.

Die Antriebsvorrichtung 100 gemäß Fig. 3 in ihrem grundsätzlichen Aufbau und ihrer Funktion nach der Antriebsvorrichtung 10 gemäß Fig. 1 weitgehend analog, und es sind daher für bau- und funktionsgleiche bzw. -analoge Elemente der in den Fig. 1 und 3 dargestellten Antriebsvorrichtungen 10 bzw. 100 jeweils dieselben Bezugszeichen verwendet, so daß insoweit auf die diesbezüglichen Beschreibungsteile zu Fig. 1 verwiesen werden kann.The basic structure and function of the drive device 100 according to FIG. 3 is largely analogous to that of the drive device 10 according to FIG. 1, and the elements of the drive devices 10 shown in FIGS. 1 and 3 are therefore identical or have the same construction and function or 100 used the same reference numerals, so that reference can be made to the relevant parts of the description of FIG. 1.

Der charakteristische Unterschied der Antriebsvorrichtung; 100 gemäß Fig. 3 gegenüber der Antriebsvorrichtung 10 gemäß Fig. 1 besteht darin, daß in beiden Arbeits-Bewegungsrichtungen 16 und 17 des Kolbens 27 des als Leistungs-Antriebseinheit vorgesehenen, doppelt-wirkenden Hydrozylinders 11 jeweils einer seiner beiden Arbeitsräume 19 oder 18 über das insgesamt mit 29" bezeichnete Nachlauf-Regelventil an den P-Druckversorgungsanschluß 21 des Druckversorgungsaggregats 22 und der jeweils andere Arbeitsraum 18 bzw. 19, ebenfalls über Nachlauf-Regelventil 29" an den Tank 24 des Druck- versorgungsaggregats 22 angeschlossen sind. Der Kolben 27 des Hydrozylinders 11 bewegt sich in Vorschub-Richtung 16, wenn sein Arbeitsraum 19 mit dem größeren Querschnitt über den A-Steueranschluß 31 des Nachlauf-Regelventils 29' mit dem P-Versorgungsanschluß 21 des Druck-Versorgungsaggregats 22 und sein im Querschnitt kleinerer Arbeitsraum 18 über den B-Steueranschluß 32 des Nachlauf-Regelventils 29" mit dem Tank 24 des Druck-Versorgungsaggregats 22 verbunden sind. In der dazu alternativen Rückzugs-Bewegungsrichtung 17 sind der im Querschnitt kleinere Arbeitsraum 18 des Hydrozylinders 11 über den B-Steueranschluß 32 des Nachlauf-Regelventils 29" mit dem DruckVersorgungsanschluß des Druck-Versorgungsaggregats 22 und der im Querschnitt größere Arbeitsraum 19 des Hydrozylinders 11 über den A-Steueranschluß 31 des Nachlauf-Regelventils 29" mit dem Tank 24 des Druck-Versorgungsaggregats 22 verbunden.The characteristic difference of the drive device; 100 compared to the drive device 10 according to FIG. 1 consists in that in both working directions of movement 16 and 17 of the piston 27 of the double-acting hydraulic cylinder 11 provided as the power drive unit, one of its two working spaces 19 or 18 via the a total of 29 "follow-up control valve are connected to the P pressure supply connection 21 of the pressure supply unit 22 and the respective other working space 18 or 19, also via follow-up control valve 29" to the tank 24 of the pressure supply unit 22. The piston 27 of the hydraulic cylinder 11 moves in the feed direction 16 when its working space 19 with the larger cross section via the A control connection 31 of the follow-up control valve 29 'with the P supply connection 21 of the pressure supply unit 22 and its cross section is smaller Working space 18 are connected to the tank 24 of the pressure supply unit 22 via the B control connection 32 of the follow-up control valve 29 ". In the alternative direction of retraction movement 17, the working space 18 of the hydraulic cylinder 11, which is smaller in cross section, is via the B control connection 32 of the follow-up control valve 29 "with the pressure supply connection of the pressure supply unit 22 and the cross-sectionally larger working space 19 of the hydraulic cylinder 11 via the A control connection 31 of the follow-up control valve 29" with the tank 24 of the pressure supply unit 22.

Zur Steuerung der insoweit erläuterten Arbeitsbewegungen des Hydrozylinderkolbens 27 sind im Rahmen des Nachlauf-Regelventils 29", dessen Aufbau, abgesehen von der Zahl der Ventilelemente, demjenigen des Nachlauf-Regelventils 29 gemäß Fig. 1 analog ist, die Ventilelemente 104, 105, 106 und 107 vorgesehen, die zur Freigabe der in den jeweiligen Bewegungs-Richtungen 16 und 17 aufzusteuernden Zufluß- bzw. Abfluß-Strömungspfade wiederum paarweise alternativ aufsteuerbar sind.In order to control the working movements of the hydraulic cylinder piston 27 explained so far, the valve elements 104, 105, 106 and. Are in the context of the follow-up control valve 29 ", the structure of which, apart from the number of valve elements, is analogous to that of the follow-up control valve 29 according to FIG. 1 107 are provided which, in turn, can alternatively be controlled in pairs to release the inflow or outflow flow paths to be steered in the respective movement directions 16 and 17.

Mittels weiterer Ventilelemente 108 und 109 sowie 111 und 112 und diesen zugeordneter Verstärkungs-Steuerventile 113 und 114 bzw. 116 und 117 können zusätzliche Zuführungs- und Abfluß-Strömungspfade freigegeben werden, mittels derer die wirksame Kreisverstärkung des zur Bewegungssteuerung des Hydrozylinder-Kolbens 27 vorgesehenen Nachlauf-Regelkreises, sei es zur Erhöhung der Kreisverstärkung oder zur Kompensation einer lastbedingten Verminderung derselben, freigebbar sind. Durch die Auslenkung ε1 und ε2 des Ventilbetätigungsgliedes 43', die, in derselben Weise wie anhand der Fig. 1 erläutert, aus der Soll-Wert-Einsteuerung und der Positions-Ist-Wert-Rückmeldung über die Schrittmotor-gesteuerte Verdrehung der Spindelmutter 54 bzw. die Rotation der Gewindespindel 56 resultieren, werden jeweils 4 der insgesamt 8 Ventilelemente aufgesteuert. Bei einer Auslenkung si des Ventilbetätigungsgliedes 43' in Richtung des Pfeils 44 sind dies die Ventilelemente 104, 105, 108 und 109, die gemäß Fig. 3 rechts von dem Ventilbetätigungsglied 43' angeordnet sind. Bei einer Auslenkung s2 des Ventilbetätigungsgliedes 43' werden die links von diesem angeordneten Ventilelemente 106, 107 sowie 111 und 112 aufgesteuert.By means of further valve elements 108 and 109 as well as 111 and 112 and associated amplification control valves 113 and 114 or 116 and 117, additional supply and discharge flow paths can be released, by means of which the effective circuit amplification of the overrun provided for movement control of the hydraulic cylinder piston 27 is enabled Control loop, be it to increase the loop gain or to compensate for a load-related reduction thereof, can be released. Due to the deflection ε 1 and ε 2 of the valve actuating member 43 ', which, in the same way as explained with reference to FIG. 1, from the target value control and the position-actual value feedback via the stepper motor-controlled rotation of the spindle nut 54 or the rotation of the threaded spindle 56, 4 of the total of 8 valve elements are opened. In the event of a deflection s i of the valve actuating member 43 'in the direction of the arrow 44, these are the valve elements 104, 105, 108 and 109 which, according to FIG. 3, are arranged to the right of the valve actuating member 43'. In the event of a deflection s 2 of the valve actuating member 43 ', the valve elements 106, 107 and 111 and 112 arranged on the left thereof are opened.

Im «normalen» Vorschubbetrieb des Hydrozylinders 11 in der durch den Pfeil 16 repräsentierten Bewegungsrichtung fließt Arbeitsmedium vom P-Versorgungsanschluß 21 über das eine Ventilelement 104 des Nachlauf-Regelventils 29" zum größeren Arbeitsraum 19 des Hydrozylinders 11, während Arbeitsmedium aus seinem im Querschnitt kleineren Arbeitsraum 18 über das ebenfalls aufgesteuerte Ventilelement 105 zum Tank 24 des Druckversorgungsaggregats 22 zurückströmt. Wird im Verlauf der Vorschub-Bewegung des Hydrozylinderkolbens 27 eine Erhöhung der Kreisverstärkung Kν oder eine zur Kompensation eines Kreisverstärkungsabfalles geeignete Einstellung der Kreisverstärkung Kv erforderlich, so kann durch Ansteuerung des Steuerventils 113 in dessen Durchflußstellung 1 ein zusätzlicher Zufluß-Strömungspfad 118 freigegeben werden, durch den vom P-Versorgungsanschluß 21 über das Steuerventil 113 und das an dieses angeschlossene Ventilelement 108 ein zusätzlicher Arbeits-Medium-Strom in den größeren Arbeitsraum 19 des Hydrozylinders 11 einströmen kann, wodurch im Ergebnis eine relative Erhöhung der Kreisverstärkung Kv erzielt wird. Desgleichen kann durch gleichzeitig oder alternativ zur Ansteuerung des Steuerventils 113 erfolgende Ansteuerung eines weiteren Verstärkungs-Steuerventils 114 in dessen Durchflußstellung 1 ein zusätzlicher Abfluß-Strömungspfad 119 freigegeben werden, der von dem kleineren Arbeitsraum 18 des Hydrozylinders 11 über den B-Steueranschluß 32, das Ventilelement 109 des Nachlauf-Regelventils 29" und das weitere zusätzliche Verstärkungs-Steuerventil 114 zurück zum Tank 24 des Druck-Versorgungsaggregats 22 führt.In the "normal" feed operation of the hydraulic cylinder 11 in the direction of movement represented by the arrow 16, working medium flows from the P supply connection 21 via the one valve element 104 of the follow-up control valve 29 "to the larger working chamber 19 of the hydraulic cylinder 11, while working medium flows from its smaller working chamber in cross section 18 flows back to the tank 24 of the pressure supply unit 22 via the likewise actuated valve element 105. If, in the course of the feed movement of the hydraulic cylinder piston 27, an increase in the circular gain Kν or a suitable adjustment of the circular gain K v to compensate for a decrease in the circular gain is required, the control valve can be actuated 113 in its flow position 1, an additional inflow flow path 118 is released, through which an additional working medium flow into the larger working area is provided by the P supply connection 21 via the control valve 113 and the valve element 108 connected to it aum 19 of the hydraulic cylinder 11 can flow, resulting in a relative increase in the circular gain K v is achieved. Likewise, by simultaneously or alternatively actuating a further boost control valve 114 in the flow position 1 thereof, an additional drain flow path 119 can be released, which leads from the smaller working chamber 18 of the hydraulic cylinder 11 via the B control connection 32, the valve element 109 of the follow-up control valve 29 "and the additional boost control valve 114 leads back to the tank 24 of the pressure supply unit 22.

Auch durch die Freigabe dieses weiteren zusätzlichen Strömungspfades 119 ist eine relative Erhöhung der Kreisverstärkung Kv des Nachlauf-Regelkreises erzielbar. Diesen zusätzlichen Zufluß- bzw. Abfluß-Strömungspfaden 118 bzw. 119 entsprechende zusätzliche, zur Einstellung erwünschter Werte der Kreisverstärkung geeignete Strömungspfade 121 bzw. 122, die ausnutzbar sind, wenn der Hydrozylinder 11 im Rückzugsbetrieb, d.h. mit Bewegung in Richtung des Pfeils 17 betrieben wird, sind durch Ansteuerung der weiteren Verstärkungs-Steuerventile 116 bzw. 117 aufsteuerbar.Also by releasing this additional flow path 119 is a relative Er Increasing the loop gain K v of the wake control loop can be achieved. These additional inflow and outflow flow paths 118 and 119 respectively correspond to additional flow paths 121 and 122 which are suitable for setting desired values of the loop gain and which can be used when the hydraulic cylinder 11 is operated in the retracting mode, ie with movement in the direction of the arrow 17 , can be activated by actuation of the further boost control valves 116 and 117.

Die bedarfsgerechte Ansteuerung der Steuerventile 113 und 114 bzw. 116 und 117 erfolgt zweckmäßigerweise durch Ausgangssignale der elektronischen Steuereinheit 66', die auch die für die Soll- Wert-Vorgabe ausgenutzten Steuerimpulse für den Schrittmotor 68 erzeugt. Die Ansteuerung der Verstärkungs-Steuerventile 113 und 114 bzw. 116 und 117 erfolgt in diesem Falle wegabhängig, das heißt programmgesteuert.The need-based control of the control valves 113 and 114 or 116 and 117 is expediently carried out by output signals from the electronic control unit 66 ', which also generates the control pulses for the stepper motor 68 which are used for specifying the desired value. In this case, the control of the boost control valves 113 and 114 or 116 and 117 is path-dependent, that is to say program-controlled.

Bei der Antriebsvorrichtung 100 gemäß Fig. 3 ist, alternativ oder in Kombination mit einer wegabhängigen, elektrischen Ansteuerung der Verstärkungs-Steuerventile 113 und 114 bzw. 116 und 117 auch eine druckgesteuerte Betätigung derselben möglich, wie im oberen Teil der Fig. 3 für die Verstärkungs-Steuerventile 114 und 117 dargestellt, die, wenn der Druck in demjenigen Arbeitsraum 18 oder 19, aus dem Arbeitsmedium zum Tank 24 hin abströmen soll, einen Schwellenwert überschreitet, in ihre Durchflußstellungen gesteuert werden und dadurch den zusätzlichen Abfluß-Strömungspfad 119 bzw. 122 freigegeben.3, alternatively or in combination with a path-dependent, electrical actuation of the boost control valves 113 and 114 or 116 and 117, pressure-controlled actuation of the same is also possible, as in the upper part of FIG. 3 for the boost Control valves 114 and 117 shown, which, if the pressure in that work space 18 or 19, from the working medium to flow out to the tank 24, exceeds a threshold value, are controlled in their flow positions and thereby the additional drain flow path 119 or 122 is released .

Es versteht sich, daß eine derartige druckgesteuerte Umschaltung der Verstärkungs-Steuerventile auch in Verbindung mit den die zusätzlichen Zufluß-Strömungspfade 118 bzw. 121 freigebenden Verstärkungs-Steuerventilen 113 bzw. 116 vorgesehen sein kann.It goes without saying that such a pressure-controlled switchover of the boost control valves can also be provided in connection with the boost control valves 113 and 116, respectively, which release the additional inflow flow paths 118 and 121, respectively.

Die Ventilelemente 34 - 37 des Nachlauf-Regelventils 29 gemäß Fig. 1 und ebenso die Ventilelemente 104 - 109 sowie 111 und 112 des Nachlauf-Regelventils 29" gemäß Fig. 3 haben, was den schematischen Darstellungen der Fig. 1 und Fig. 3 nicht zu entnehmen ist, druckausgeglichene Ventilkörper 38, die unabhängig davon wie die Druckverhältnisse auf verschiedenen Seiten des Ventilsitzens sind, durch die Rückstellfedern 39 zuverlässig in ihrer Sperrstellung gehalten werden, wenn sich das jeweilige Ventilbetätigungsglied 43 bzw. 43' in seiner neutralen Grundstellung befindet.The valve elements 34-37 of the follow-up control valve 29 according to FIG. 1 and likewise the valve elements 104-109 as well as 111 and 112 of the follow-up control valve 29 "according to FIG. 3 have what the schematic representations of FIGS. 1 and 3 do not can be seen, pressure-balanced valve body 38, which regardless of how the pressure conditions are on different sides of the valve seat, are reliably held in their locking position by the return springs 39 when the respective valve actuator 43 or 43 'is in its neutral basic position.

Claims (9)

1. Device for adjusting the circuit amplification of a servo-regulating circuit provided for controlling the movements of a hydraulic forward drive unit (11), which operates with an electrically controlled set value of the position and with mechanical feedback of the actual positions, the control being achieved - for example - by means of a step motor (67), and where the flows of the working medium from a pressure source (22) to the drive unit (11) and from the drive unit to the tank (24) of the pressure source, whose magnitude determines the speed v with which the movements of a tool operated by the drive unit (11) are carried out, are fed via valve elements (34, 36) of a servo-regulating valve (29, 29', 29"), which can be jointly controlled via the pre-set values of the regulating distances ε1 and E2 required to obtain a desired working speed, and where the circuit amplification Kv of the regulating circuit can be switched by valve-controlled operation of a switching system from a first value Kv1 of the regulating circuit amplification to at least one other value Kv2, characterized in that the servo-regulating valve (29; 29'; 29") is provided with at least one additional valve element (37, 39; 108, 109, 111, 112) which follows the positioning movements of the valve element(s) (34 and 36; 104, 105, 106, 107) serving to control the movement with the circuit amplification Kvi, the said valve element being traversed by a flow-path (49, 52; 118, 119, 121, 122) parallel to the flow-path of the servo-regulating valve (29; 29'; 29"), through which, in an operating phase taking place with the value Kv1 of the circuit amplification, there flows the working medium that determines the working speed of the drive unit (11 ), and which can be opened up by the operation of an amplification control valve arrangement (51, 53; 113, 114, 116, 117), whose basic position is the closed position, and, further, that there is provided a control device (66; 66') with which the throughflow setting(s) of the amplification control valve arrangement (51, 53; 113, 114, 116,117) can be controlled as required to permit the drive unit (11) to be operated with the modified value(s) Kv2.
2. Device according to Claim 1, characterized in that the additional flow-path (49) leads from the outlet (21) of pressurization unit (22) via the additional valve element (35) to the particular working area of the drive unit (11) in which, during the operating phase of the drive unit carried out with the circuit amplification Kvi, there prevails the regulated output pressure of the servo-regulating valve (29; 29').
3. Device according to Claim 1 or 2, characterized in that there is provided a flow-path (52) that passes through an additional valve element (37) of the servo-regulating valve (29; 29') and can be either opened or closed by means of the amplification control valve arrangement (51, 53), this flow-path being switched parallel to the particular flow-path (48) by means of which, during an operating phase of the drive unit (11) carried out with the circuit amplification Kvi, working medium is either displaced or evacuated from a working area (19) of the drive unit (11 ).
4. Device according to any one of the preceding Claims 1 - 3, characterized in that the aperture cross section corresponding to the regulating distances ε1 or s2 of the additional valve element(s) (35, 37; 108, 109, 111, 112) of the servo-regulating valve (29; 29', 29"), through which - in an operating phase carried out with the modified circuit amplification Kv2 - there passes the working medium, is greater than the aperture cross section corresponding to the regulating distance of those valve elements (34, 36; 104, 105, 106, 107), through which - in an operating phase carried out with the circuit amplification Kvi, there pass the working medium flows that either flow to the drive unit or have been displaced or evacuated from it.
5. Device according to any one of the preceding claims, characterized in that the additional flow-path(s) (49 and/or 52) is (are) provided with a throttle (71 and/or 72) opposing an adjustable resistance to the flow.
6. Device according to any one of the preceding claims, where the drive unit is designed as a double-acting hydraulic cylinder (11) with a double diameter piston, the working area (18) of the said cylinder, which is delimited in a mobile manner by the smaller piston surface (26), being permanently connected to the outlet of the pressurization unit (22), while the working area (19), which is delimited in a mobile manner by the larger piston surface (28), can be connected, via one of two valve elements provided within the servo-regulating valve (29), alternatively to either the outlet of the pressurization unit (22) or to its tank (24), characterized in that the servo-regulating valve (29) is designed as a by itself known four/three-way valve, where the set value of the position is provided by means of a defined setting of the turning distance of a nut (54) relative to a threaded shaft (56) provided for the feedback of the actual position, and the said shaft, in its turn, can be rotated alternatively in either direction by the forward and backward movements of the hydraulic cylinder drive unit (11) acting, for example, via a rack-and-pinion mechanism (58, 57), and where there is provided a valve-operating element (43) that follows the axial displacements ε1 or s2 of the nut (54) resulting form a rotation of the nut with respect to the shaft, the movements of this element triggering the changes - proportional to the deviations to be corrected - in the aperture cross sections through which there pass the working-medium flow-paths of the drive unit (11), and where the displacements ε1 or 82 of the valve-operating element (43), which take place in alternative directions, are controlled in either case by two valve elements (34 and 35, or 36 and 37) acting as a pair, and where the two flow-paths that lead to the larger working area (19) of the hydraulic cylinder (11) with the double-diameter piston and thus permit this area to be connected to the outlet (21) of the pressurization unit (22) pass through the valve elements (34 and 35) of the one pair of valve elements, while the flow-paths that permit the larger working area (19) to be connected to the tank (24) pass through the valve elements (36 and 37) of the other pair of valve elements, and where in either case one of these pressure-applying or pressure-relieving flow-paths is provided with an amplification control valve (51 or 53) that can be controlled in such a way as to move from its basic position, which blocks the flow-path in which the valve is inserted, into the particular throughflow position associated with the operation of the device at the higher circuit amplification Kv2.
7. Device in accordance with any one of the preceding Claims 1 - 5, where the drive unit is designed as a double-acting hydraulic cylinder (11), with either identical or different areas of the piston surfaces that delimit the two working areas (18, 19), and where, depending on the alternative directions of motion of the piston (27), one of the working areas is always connected to a pressure outlet and the other to the backflow tank of the servo-regulating valve (29") and the flow-paths by means of which the working medium, passing through the servo-regulating valve, reaches the drive unit and/or is evacuated therefrom have a throughflow cross section that is proportional to the regulating deflection ε1 or s2 of the valve bodies of the valve elements of the servo-regulating valve, characterized in that the particular flow-paths that, during operation of the drive unit (11) with the circuit amplification Kv1, are controlled in such a way that their aperture cross section is proportional to the regulating distance of a valve-operating element (43) can be made to receive the flow of other, parallel flow-paths (118, 119, 121, 122), these flows being released by controlling the valves (113, 114, 116, 117) of the control valve arrangement, and that the receiving flow-paths pass through additional valve elements (108, 109, 111, 112) of the servo-regulating valve, the valve bodies of these elements being subject to the same cross- section-changing deflections as the valve bodies of the particular valve elements (104, 105, 106 and 107) through which there pass the flow-paths that are exploited only while the device is being operated at the - lower - value Kv1 of the cicuit amplification.
8. Device according to Claim 7, characterized in that the servo-regulating valve (29") is designed as an eight/three-way valvethat contains two groups of four valve elements (104, 105, 108, 109 and 106, 107, 111, 112), the four elements in each group being capable of joint operation, and where each of the two groups is correlated with one of the alternative directions of motion of the drive unit (11).
9. Device according to Claim 7 or Claim 8, characterized in that the valves (113, 114, 116, 117) of the amplification control valve arrangement provided for controlling or blocking the additional flow-paths (118, 119, 121, 122) are designed as electrically or hydraulically controlled reversing valves that can be controlled by means of the outlet pressure of the working area (18 or 19) of the drive unit connected to the valve once this outlet pressure has exceeded a certain threshold value.
EP19860902788 1985-04-30 1986-04-30 Device for adjusting the circuit amplification of a servo-regulating circuit Expired EP0220248B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3515566 1985-04-30
DE3515566 1985-04-30

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EP0220248A1 EP0220248A1 (en) 1987-05-06
EP0220248B1 true EP0220248B1 (en) 1989-07-26

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DE (2) DE3614577A1 (en)
WO (1) WO1986006445A1 (en)

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Publication number Priority date Publication date Assignee Title
DE3706160A1 (en) * 1987-02-26 1988-09-08 Eumuco Ag Fuer Maschinenbau LIFTING BAR AUTOMATIC FOR DIE FORGING PRESSES AND THE LIKE
FR2653243B1 (en) * 1989-10-12 1992-02-07 Laudinet Chrisitan
DE4038270C2 (en) * 1990-12-05 1993-11-18 Yoshikawa Iron Works Lift control device
DE59502414D1 (en) * 1994-03-09 1998-07-09 Eckehart Schulze HYDRAULIC DRIVE UNIT
CN115213255B (en) * 2022-07-15 2024-06-07 上汽通用五菱汽车股份有限公司 Stamping part size deviation adjusting method, electronic equipment and storage medium

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Publication number Priority date Publication date Assignee Title
US2733688A (en) * 1956-02-07 badenoch
US3183785A (en) * 1963-06-26 1965-05-18 Cadillac Gage Co Adaptive gain servo actuator
DE2062134C3 (en) * 1970-12-17 1974-03-28 Hartmann & Laemmle Ohg, 7000 Stuttgart-Bad Cannstatt Control device with a measuring spindle L connected to a piston of a working cylinder
JPS52151496A (en) * 1976-06-10 1977-12-15 Nisshin Sangyo Co Hydraulic servo mechanism

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EP0220248A1 (en) 1987-05-06
DE3614577A1 (en) 1986-12-11
DE3664667D1 (en) 1989-08-31
WO1986006445A1 (en) 1986-11-06

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