WO1995024565A1 - Hydraulische antriebseinheit - Google Patents
Hydraulische antriebseinheit Download PDFInfo
- Publication number
- WO1995024565A1 WO1995024565A1 PCT/EP1995/000884 EP9500884W WO9524565A1 WO 1995024565 A1 WO1995024565 A1 WO 1995024565A1 EP 9500884 W EP9500884 W EP 9500884W WO 9524565 A1 WO9524565 A1 WO 9524565A1
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- WO
- WIPO (PCT)
- Prior art keywords
- control valve
- piston
- main control
- drive
- valve
- Prior art date
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Classifications
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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 hydraulic drive unit with a hydraulic motor designed as a power drive for high drive power and accordingly - if necessary - high throughput of hydraulic oil, a main control valve, by means of which an inflow of high-pressure hydraulic oil to the power drive and the outflow of at least one Part of the hydraulic oil supplied to the power drive, for example to the unpressurized reservoir of the pressure supply unit, can be controlled, a hydraulic servo drive designed as a double-acting linear cylinder for the actuation of the main control valve and with an electromotively controlled specification of the setpoint of the position and the control of the servo drive Movement speed of the movable element of the power hydraulic motor and mechanical feedback of the corresponding actual values of the follow-up control valve, which assumes a blocking position corresponding to the setpoint and actual value of the entered position, corresponding to the standstill of the power drive , which can be controlled by the position setpoint specification for taking the alternative drive directions of the power hydromotor assigned alternative flow positions, in which the effective flow cross-section varies monoton
- the follow-up control valve has an elongated rod-shaped piston which can be displaced in a pressure-tight manner in a central axially continuous bore of the piston of the main control valve and which, viewed in the axial direction, on both sides of the main control valve piston arranged drive pressure spaces penetrates, by means of whose alternative pressure application and relief, which can be controlled by means of the follow-up control valve, the servo drive of the main control valve piston is achieved, the piston of the follow-up control valve also in the axial limits of these two which are fixed to the housing End end walls of the housing of the main control valve forming drive pressure spaces must be displaceably guided in a pressure-tight manner.
- One end of the piston of the overrun control valve protrudes from the housing of the main control valve and is firmly connected at this end to a rack with which a pinion of the electromechanical position setpoint specification and actual value Feedback combs, which can be driven by means of a differential gear, which mediates the phase comparison required for the follow-up control between the setpoint specification and the actual value setting.
- the assembly of the assembly formed by the main control valve and the follow-up control valve is extremely complex in terms of the precision required for reliable function, since the respective end sections of the piston of the follow-up control valve receive bores in the housing of the main control valve and the central one Bore his valve pistons with the required, exactly aligned arrangement are very difficult to manufacture, and also the exact arrangement of control edges of the piston of the follow-up control valve to control edges of the piston of the main control valve, insofar as these have the most exact O-coverage possible in the locked position of the follow-up control valve should be, is very complex, with the result that the known drive unit is associated with high manufacturing costs.
- Another disadvantage is that the large-area limitations of the drive pressure spaces of the servo drive for the piston of the main control valve, which are each formed by one of the ring end faces of the piston itself, inevitably lead to large amounts of the control oil flows, which is particularly the case in highly dynamic operation of the servo motor is disadvantageous because a lot of energy is then required for the servo circuit.
- the object of the invention is therefore to improve a drive unit of the type mentioned at the outset such that a precise configuration of control edges of the follow-up control valve on the valve piston side and on the housing side can be achieved with significantly reduced outlay and the need for hydraulic control energy is considerably reduced .
- the follow-up control valve has two piston elements which are received from a through bore of the main control valve piston parallel to the central longitudinal axis of the main control valve piston, this bore being arranged at a radial distance from the central longitudinal axis of the main control valve;
- the axial distance between these piston elements is used to set a defined overlap of piston Control edges and housing-side control edges of the follow-up control valve arranged within the through bores of the piston of the main control valve, in particular for setting the O-coverage of such control edges suitable for sensitive control operation.
- the piston of the main control valve is provided with a central, axial through-hole, through which a setpoint input element, which is coupled in a rotationally fixed manner to the output shaft of the setpoint input motor but passes axially relative to the latter and the piston, passes through.
- This setpoint specification element is connected to an actual value feedback element which, due to the movable part of the power hydromotor, has a form-fitting correlation with its - rotational or translational - movements with the same sense of rotation as the setpoint specification element, but can be driven axially is immovably mounted on the housing of the main control valve, in the manner of a spindle-nut drive in thread-free engagement.
- the setpoint value element thereby experiences axial deflections with respect to a central position of the piston elements linked to the blocking position of the overrun control valve, these deflections being directly correlated with the difference between the setpoint and actual position of the movable part of the power hydraulic motor; these deflections convey the opening and closing operations of the overrun control valve via actuating elements which are rotationally decoupled from the setpoint input element, but which also carry out its axial movements.
- the drive cylinders thus implemented within the wall thickness of the main control valve piston, which together with their axially supported piston each form a single-acting hydraulic cylinder and, as a pair of cylinders, result in a double-acting hydraulic cylinder, are of relatively small control oil volume for carrying out the required Deflection strokes of the main control valve piston can be controlled and, using the operating pressure of the supply source, can easily develop the actuating forces required for highly dynamic operation of the main control valve.
- the hydraulic drive unit according to the invention is suitable both for volumetrically controlled rotary hydraulic motors such as Axial piston motors as well as for precise control of hydraulic linear motors, regardless of the speed at which they are operated, and is therefore also very suitable as a positioning drive.
- the advantageous properties of the drive unit according to the invention in this regard can be achieved by means of a structure that is provided according to claim 2 and its basic structure
- the design provided with two piston elements arranged in an axially continuous bore of the valve piston of the main control valve, which are arranged in an axially continuous bore of the valve piston of the main control valve, can be displaced in a pressure-tight manner , can be integrated in a simple manner, the adjustability of its axial distance, which is required for setting a specific, small positive overlap of the fine control valve desired in the basic position 0, being ensured in a preferred embodiment by the features of claim 4.
- the fine control valve is constructed by means of the two piston elements in a construction, as it were, as seen in claim 5, as two jointly operable 2/3-way valves, which are preferred in the piston of the main control valve with the feature specified in claim 6 Arrangement are provided diametrically opposite the follow-up control valve.
- the features of claim 7 indicate a design of the actuating cylinder provided for actuating both the main control valve and the fine control valve, with which, as indicated by the features of claim 8, it can in turn be integrated into the piston of the main control valve.
- the piston of the main control valve is provided with two from the opposite end faces of the main control valve piston in the blind bores, in which to limit one of its drive chambers relative to its bottom side, a piston is displaceable in a pressure-tight manner ⁇ is arranged on a on the housing of the main control valve If the fixed, optionally axially adjustable stop pin can be axially supported, these pistons can be inserted into these bores as free pistons, ie without a return element.
- the actuating cylinder can also have the characteristics of the claim
- the design of the actuating cylinder, or an actuating cylinder arrangement, possibly comprising several pairs of bores and pistons, as a differential cylinder unit or combination, has the advantage that the overrun control valve provided for actuating it / its control is a structurally simple 3 / 3-way valve can be formed, which in turn can be realized by two 2/3-way valves which can be actuated at the same time.
- the design of the piston of the main control valve which is provided according to claim 15, is particularly favorable in terms of production technology if the follower control valve, the fine control valve and also the actuating cylinder are in the main control valve piston are largely integrated and, if necessary, elements of the feedback device and the setpoint input device are received from a central bore of the central piston part, as a result of which small lengths of the oil columns which determine the hydraulic rigidity of the drive unit and high values of the control loop gain can be achieved .
- Position sensors provided and designed according to claims 16 to 18 can be used both for the adjustment of the main control valve and the fine control valve and of the follow-up control valve, and during operation of the drive unit also for the continuous detection of the follow-up travel of the control elements, i.e. be used to continuously determine the loop gain of the control loop.
- FIG. 1 is a hydraulic equivalent circuit diagram of a drive unit according to the invention with a double-acting linear hydraulic cylinder designed as a differential cylinder as a power drive, a main control valve and a fine control valve which can be actuated by means of an actuator also designed as a double-acting differential cylinder and with a follow-up control valve working with an electromotive-controlled setpoint specification and mechanical actual value feedback of the position of the drive piston of the power drive,
- FIG. 2 is a longitudinal sectional view of the main control valve and the integrated follow-up control valve and the actuating cylinder in two mutually right 4 and the power drive in a cutting plane containing its central longitudinal axis and the central longitudinal axis of the main control valve,
- FIG. 3 shows a longitudinal sectional view analogous to the representation of FIG. 2, which contains the central longitudinal axis of the fine control valve, along the trace line C-C of FIG. 4,
- FIGS. 2 and 3 shows the arrangement of bores of the piston of the main control valve provided for receiving pistons and actuating elements of the valves of the drive unit according to FIGS. 2 and 3 with respect to the central longitudinal axis of the main control valve in a sectional plane at right angles thereto along the line AA of FIG Fig. 2 and
- FIGS. 1 to 4 details of the arrangement and design of control channels and 5b th of the main control valve of the drive unit according to FIGS. 1 to 4 in a greatly enlarged sectional view along a line containing the central axis of the main control valve and the central axis of the power drive Radial plane of the main control valve.
- each designated 10 hydraulic drive unit consists of a hydraulic motor 11 designed for the development of high drive forces and a high drive power and a drive 12 provided for its drive control, designated overall 12
- Electrohydraulic control unit which is arranged in a housing shown in FIG. 1 as a frame 14 which is firmly connected to the housing 13 of the hydraulic motor 11 and which forms the geometric basis for the arrangement of a main control valve 16, a fine control valve 17 of a hydraulic actuator 18 and a follow-up control valve 19, from which the electro-hydraulic control unit 12 is constructed.
- the drive unit 10 is intended for applications in which high driving forces and high driving powers are important, in which correspondingly high hydraulic oil flows also occur and must be controllable as precisely as possible.
- possible uses of the drive unit 10 are, for example, the drive of punching, pressing and / or stamping tools and the positioning and displacement of heavy workpieces with respect to a machining station of a machining center, on which, for example, machining the workpiece while displacing it relative to a machine-fixed one arranged tool takes place.
- the hydraulic motor 11 provided as a power drive is designed as a double-acting linear cylinder with a piston rod 21 emerging from the housing on one side.
- the hydraulic cylinder 11 is switched as a differential cylinder which, when pressure is applied to both the rod-side drive chamber 22 of the hydraulic cylinder 11 and the bottom-side drive chamber 24, which is delimited so as to be movable in a pressure-tight manner by the piston 23, with the outlet pressure of the pressure supply unit 26, the outward stroke executes and, when pressurizing only the rod-side drive chamber 22 and relieving pressure on the bottom-side drive chamber 24, executes the pull-in stroke of the piston rod 21.
- the hydraulic cylinder 11 is controlled only by pressurizing and relieving its bottom drive chamber 24, while the stationary The drive chamber 22 on the opposite side is permanently acted upon by the outlet pressure of the pressure supply unit.
- the ratio ⁇ 1 / ⁇ 2 of the piston surface F ] _ on the bottom side, which can be pressurized, to the annular, rod-side piston surface F2 of the drive piston 23 of the hydraulic cylinder 11 is in the embodiment shown, in that in both alternative directions of movement of the piston 23 same feed forces should be able to be developed, 2/1.
- the pressurization and relief of the rod-side drive chamber 24 of the hydraulic cylinder 11 takes place by means of the main control valve 16 and the fine control valve 17, which are connected hydraulically in parallel and can be actuated together by means of the hydraulic actuator 18, which in turn is designed as a double-acting linear differential cylinder, the piston rod 28 emerging from its housing 27 on one side is rigidly connected to the movable valve elements of the main control valve 16 and the fine control valve 17, which can thus be pushed back and forth together along parallel axes 29 and 31.
- control valve 19 works with electrical, e.g. pulsed control of a stepper motor 36, which can be driven by rotation, controllable specification of the desired position of the piston 23 of the power hydraulic cylinder 11 and mechanical feedback of the actual position of the drive cylinder piston 23, on the one hand, and mechanical feedback of the position of the piston 32 of the actuating cylinder 18, on the other hand , which is achieved in that, in the exemplary embodiment shown, the housing 37 of the follow-up control valve
- the actuating device 42 of the follow-up control valve 19 comprises in a coaxial arrangement with respect to a common central longitudinal axis 43, which also includes the axis of rotation of the output shaft 44 of the stepping motor arranged on the right housing wall 46 as shown in FIG. 1 and the axis of rotation of one marks the opposite "left" housing wall 47 rotatably but axially immovably mounted threaded spindle 48, a hollow shaft 49 serving as a position setpoint specification element, which at its stepper motor end has a parallel toothing of the output shaft 44 of the stepper motor 36 in Intermeshing engagement and can thus be driven in rotation by means of the stepping motor 36.
- the hollow shaft 49 is provided with an internal thread 51, via which it is in meshing engagement with the thread 52 of the threaded spindle 48.
- the threaded spindle 48 can be driven in alternative directions of rotation by means of a toothed belt drive, designated overall by 53, which is assumed to be free of play.
- the toothed belt 54 is self-contained and runs over a toothed roller 56 connected to the threaded spindle 48 in a rotational test, and over a further toothed roller 57 which is rotatably mounted about an axis 58 fixed to the housing and running parallel to the axis of rotation 43 of the threaded spindle 48, the axis 58 of which is in the direction
- the central longitudinal axis 59 of the linear cylinder 11 provided as a power drive is significantly greater than the maximum stroke that the piston 23 of the drive cylinder 11 can carry out between its possible end positions from the axis of rotation 43 of the threaded spindle 48.
- the toothed belt drive 53 has a run 61 which runs exactly parallel to the central longitudinal axis 59 of the linear cylinder 11 and which is coupled in motion by means of a mechanically rigid connecting element 62 to the piston 21 of the drive cylinder 11 and experiences the same deflections as this.
- the toothed belt drive 53 thus converts the axial movements of the piston 21 into rotary feedback movements of the threaded spindle 48.
- the direction of rotation of the rotational position setpoint specification movements of the hollow shaft 49 by means of which a certain displacement speed of the piston 21, 23 of the drive cylinder 11 in the predetermined direction is to be achieved, and the direction of rotation by the feedback of the position Actual values of the drive cylinder piston 21, 23 resulting rotations of the feedback spindle 48 are selected such that, when the setpoint and actual values are identical, no displacement of the hollow shaft 49 with respect to the threaded spindle 48 occurs, whereas both at the beginning of the input Control of a position setpoint, which is accompanied by an enlargement of the difference between the setpoint and actual value, and upon completion of a change in the setpoint specification, which is accompanied by a reduction in the difference between the setpoint and actual value, relative opposite movements of the hollow shaft 49 and the threaded spindle 48 are linked such that the hollow shaft 49 experiences axial displacements in the two alternative directions.
- the follow-up control valve is in its function a 3/3-way valve which, as it were, is constructed by two 2/3-way valves 19 '. , 19 '' is realized, whose valve bodies 39 and 41, which are designed as pistons and are each represented by the valve symbol in FIG. 1, are guided so that they can be displaced in a pressure-tight manner in a through bore 63 of the valve housing 37.
- the two valve bodies 39 and 41 of the follow-up control valve 19 are pushed apart by a centrally arranged spring 64 and clamped between adjusting screws 66 and 67, which are screwed into threads of actuating arms 68 and 69 running radially to the central longitudinal axis 43 of the actuating device 42, which are connected axially displaceably to the hollow shaft 49 via a ball bearing 71 or 72, but are decoupled from their rotational movements.
- the two valve bodies 39, 41 of the two sub-valves 19, 19 ′′ of the follow-up control valve 19 can be adjusted by means of the adjusting screws 66, 67 in such a way that the axial distance from the control edges 73, 74 of the valve body of the valve body shown in FIG 1 and 2 "right” partial valve 19 'and the "left” partial valve 19''of the follow-up control valve 19 equal to the axial distance from the control edges 76, 77 of the valve tilgehause 37 of the follow-up control valve 19, through the relative movements of which in alternative directions, either a flow path 78 (FIG.
- the main control valve 16 is in the exemplary embodiment selected for explanation, in which the power drive cylinder 11 is operated as a differential cylinder, the rod-side drive chamber 22 of which is permanently acted upon by the output pressure of the pressure supply unit 26, as a 3/3-way Slider valve formed, the housing 86 is fixedly connected to the housing 13 of the drive cylinder 11.
- the piston 87 of the main control valve 16, which is represented in FIG. 1 by the 3/3-way valve symbol and in FIG. 2 and in FIG. 3, to which details are also referred to, in a technically realistic configuration of the main control valve 16 and the follow-up control valve 19 (FIG. 2) and the fine control valve 17 (FIG.
- the control output 94 of the main control valve 16 is formed by a radial housing channel which connects directly to the connecting channel 96 which is aligned with it and through which hydraulic oil can flow into the bottom-side drive chamber 24 of the drive cylinder and flow out of it again.
- the control channel 96 of the housing 86 of the main control valve 16 starts from an inner annular groove 97 of the valve housing 86, which between an annular groove 98 of the housing 86, which with the P-connection 83 is permanently in communication and an annular groove 99 of valve housing 86 is arranged, which is in permanent communication with T-connection channel 91.
- the piston 87 of the main control valve 16 is provided with a first outer annular groove 101, which always remains in communicating connection with the P-groove 98 of the valve housing 86 within the possible displacement range of the valve piston 87 and for coupling pressure into the bottom-side drive chamber 24 of the Drive cylinder 11 can be brought into overlap with the cross-sectional area of the central annular groove 97 of the housing 86 of the main control valve by displacing the valve body 87 as shown in FIG. 2 to the left, as a result of which the main control valve reaches the functional position I, in which the T-slot 99 is blocked against the control connection channel 94 of the main control valve 16.
- the piston 87 is provided with a second outer annular groove 102, which always remains in communicating connection with the T-groove 99 of the valve housing 86 of the main control valve and within the possible displacement range of the valve piston 87 and through axial displacement of the valve piston 87 2 to the right, can also be brought into a cross-sectional overlap with the central annular groove 97 of the valve housing 86, as a result of which hydraulic oil can flow out of the bottom-side drive chamber 24 of the drive cylinder 11 to the reservoir 92 of the pressure supply unit 26.
- the T-groove 94 is shut off against the control channel 94 of the main control valve 16.
- “Positive overlap” here means that, starting from the basic position 0 of the main control valve 16, the valve piston 87 must first be shifted in the axial direction by the amount e of the overlap before, depending on the shifting direction, that in the Flow path 112 or 113 to be released in the respective functional position I or II begins to open and, with increasing displacement, releases an increasing overflow cross section.
- a displacement of the valve piston 87 to the left is required, ie a pressure relief of the bottom-side drive chamber 33 of the actuating cylinder 18, which in turn has an - introductory - Displacement of the pistons 39 and 41 of the follow-up control valve 19 to the left requires that the partial valve 19 ′′ of the follow-up control valve 19 releases the flow path 82 which mediates the connection of the bottom-side drive chamber 33 of the actuating cylinder 18 to the unpressurized reservoir 92 of the pressure supply unit .
- the required displacement of the valve pistons 39 and 41 of the follow-up control valve 19 is achieved by the stepping motor 36, seen in the direction of the arrow 114 in FIG Is driven clockwise, in which the hollow shaft 49 also rotates and thereby experiences a displacement to the left due to your thread engagement with the threaded spindle 48, which the valve pistons 39 and 41 of the follow-up control valve 19 also carry out.
- the actuating cylinder 18 is thereby driven in the sense of a reduction in the previously released cross section of the flow path 112 of the main control valve 16, whereby on the one hand the inflow of hydraulic oil into the bottom-side drive chamber 24 of the drive cylinder 11 is reduced so that its extension speed decreases and on the other hand the housing 37 of the follow-up control valve is shifted again in the direction - to the right - in which the flow path 78 of the partial valve 19 'of the follow-up control valve 19 is blocked again and the inflow of hydraulic oil into the bottom-side drive chamber 33 of the actuating cylinder 18 is interrupted.
- the piston 32 of the actuating cylinder 18 then remains in a position corresponding to a reduced flow cross-section of the flow path 112 of the main control valve 16 which is still released and with which the lower movement speed v of the drive piston 23 of the hydraulic cylinder 11 is linked.
- the stroke that the piston 23 of the drive cylinder 11 is to perform in total is coded in the number of electrical control pulses with which the stepper motor 36 is used until the piston stroke has been completed must be controlled, the speed at which the piston executes this stroke, the frequency of the control pulses and the direction of rotation in which the stepper motor rotates, for example by the polarity of its control pulses or the phase relationship of two or more control pulse sequences with one another, with which excitation windings of the stepper motor, which is driven in a typical design to execute a 360 ° rotation of its drive shaft 44 with 400 step pulses, each of which leads to a rotation of the output shaft 44 by 0.9 °.
- the hydraulic drive unit 10 which is summarized in terms of its structure and function, contains two control loops coupled to one another via the overrun control valve 19, one of which is to be understood as a follow-up control loop for the actuator 18 and the second as a follow-up control loop for the drive cylinder 11.
- the control loop acting on the drive cylinder 11 here has a control loop gain K v , which is due to the relationship
- v denotes the - constant - speed of movement of the drive piston 23 in the steady - steady - state of the control
- s denotes a stopping distance which represents the "distance" difference - between the target, which was controlled, for example, by means of the stepping motor 36 -
- the value of the position of the piston 23 and its actual value are designated.
- a typical value for the loop gain K v of the power control loop is, for example, a value of 10 s _1 .
- the loop gain corresponding to the relationship (1) should not be greater than the natural frequency f 0 to be assumed for the fictitious damping-free case, taking into account a damping that is always present, which is caused by the relationship
- ⁇ 1 (2) is given, in which c denotes the hydraulic rigidity, which is essentially determined by the rigidity of the oil columns enclosed, while m denotes the mass driven by the drive circuit, for example the press bar of a press. From the relationship (2), on the other hand, it follows that the circuit gain of the actuator 18, the pressurization and relief of which is controlled by means of the follow-up control valve 19, can be very high because of the short length of the oil column enclosed the hydraulic rigidity of this control circuit is high and the mass to be moved, essentially the mass of the piston 87 of the main control valve 16, is low.
- the overrun control loop of the actuator can be operated with a loop gain K v2 , which can be 50 to 100 times higher than that of the drive control loop .
- FIG. 4 shows the arrangement of the through bore 63 of the follow-up control valve 19, a through valve bore 117 of the fine control valve 17 and two chamber bores 118 of the hydraulic actuator 18 inside the piston 87 of the main control valve 16, which in turn is received by the through bore 88 of the housing 86 of the main control valve 16.
- the central longitudinal axis 38 of the bore 63, the central longitudinal axes 119 of the two bores 118 for the actuator 18 and the central longitudinal axis 121 of the through bore 117 of the piston 87 of the main control valve 16 forming the housing for the overrun control valve 19 and the fine control valve 17 lie on a bore circle concentric with the central longitudinal axis 43 of a longitudinal bore 122 with the same diameter, apart from a small clearance, receiving the hollow shaft 49 of the actuating device 42 of the follower control valve and are along the same at equal azimuthal intervals of 90 ° arranged, the bores 63 and 117 for the follow-up control valve 19 and the fine control valve 17 being arranged diametrically opposite one another with respect to the central longitudinal axis 43 of the central bore 122 receiving the hollow shaft 49, likewise the bores 118 for the actuator 18.
- the purpose of the fine control valve 17 hydraulically connected in parallel with the main control valve 16 is to enable a high positioning accuracy of the power drive hydraulic motor 11 even if the piston-side control edges 107 and 108 of the piston 87 and the housing-side control edges 109 and 111 of the main control valve 16, seen in its basic position, have a relatively large positive overlap e, as explained above with reference to FIGS. 2 and 3 and shown on an enlarged scale in FIG. 5a, to which reference should also be made.
- the fine control valve 17 is designed such that it has a flow path 112 'which corresponds functionally to the flow path 112 of the main control valve 116 and via which the outlet pressure of the pressure supply unit 26 can be coupled into the bottom-side drive chamber 24 of the power hydraulic motor 11, or already opens a flow path 113 'corresponding to the flow path 113 of the main control valve 16 when the main control valve 16 assumes its function position I or its function position lung II is controlled.
- the fine control valve 17 is formed in analogy to the overflow control valve 19 as consisting of two sub-valves 17 'and 17'', each of which has a basic shape according to cylindrical pistons 129 and 131, respectively, from the through bore 117 of the through the piston 87 of the main control valve 16 formed "housing" of the fine control valve 17 are received.
- pistons 129 and 131 each have an annular groove 132 and 133, the radial groove cheeks of which are at a distance from one another and connect via the piston-side control edges 124 and 126 to the cylinder jacket surfaces, which are pressure-tight and slidable from the through bore 117 of the piston part forming the housing of the fine control valve of the main control valve piston 87 are received.
- the pistons 129 and 131 of the two fine control valve elements 17 'and 17 are urged by a preloaded, centrally arranged, preloaded spring 134 against a stop pin 136 or 137, which is coaxial with the central longitudinal axis 121 of the through bore 117 of the piston 87 of the main control valve, which forms the housing of the fine control valve 17.
- These stop pins 131 and 137 are designed as set screws which can be screwed into threaded bores of the housing 86 of the main control valve and by means of which the positions of the piston-side control edges 124 are formed and 126 the pistons 129 and 131 of the fine control valve can be adjusted with respect to the housing 86 of the main control valve 16.
- the fine control valve 17 can therefore, with the piston 87 of the main control valve 16 held, always adjusted such that the overlap of its piston-side control edges 124 and 126 with its housing-side control edges 127 and 128 is 0 or corresponds to any desired - small - value when the fine control valve 17 is in its basic position.
- the piston 87 which can be pushed back and forth in the housing 86, is constructed in two parts for manufacturing reasons and comprises an outer, thick-walled, jacket-shaped piston part 87 ', which is provided with the piston-side P and T grooves 101 and 102, and one inner, cylinder-block-shaped piston part 87 ", which has the central through-bore 122 penetrated by the hollow shaft 49 of the actuating device 42 of the follow-up control valve 19, the through-bore 63 of the follow-up control valve 19, the through-bore 117 of the fine control valve 17 and the cam ⁇ holes 118 is provided for the actuator 18.
- each designated 118 are formed as blind bores which, according to the representations of FIGS. 2 and 3, are introduced into the inner piston part 87 "from the right end face thereof Bores 118 each have a cylindrical piston 138, which can be moved in a pressure-tight manner relative to the piston element 87 ′′ of the main control valve piston 87 and which is located on one along the central longitudinal axis 119 of the respective bore 118 extending, housing-fixed slim stop pin 139 is axially supported.
- blind bores 118 ' are also made in the inner piston part 87' of the piston 87 of the main control valve 16, into each of which a cylindrical piston 138 'relative to the piston element 87 ′′ is slidably inserted, which is in turn axially supported on a stop pin 139 ′ fixed to the housing and extending along the central longitudinal axis 121 of the respective bore 118 ′.
- the drive unit 10 is equipped with an only schematically illustrated electronic position sensor 141, the output signal of which is a precise measure of deflections of the actuating device 42 of the follow-up control valve 19 in the direction of the central longitudinal axis 43 of the actuating device 42.
- the position sensor 141 is realized by a magnetic field sensor which is fixedly mounted on the housing 86 of the main control valve 16 and which detects the field strength of a permanent magnet 142 which is fixedly mounted on one of the actuating arms 68 or 69 of the follow-up control valve 19 and is arranged in this way that, under the occurring axial displacements of the actuating device 42, the field strength at the location of the magnetic field sensor varies linearly to a very good approximation, so that the output signal of the magnetic field sensor 141 directly corresponds to the deflection stroke of the actuating device 42, for example the hollow shaft 49 is proportional.
- the position sensor 141 can be calibrated in a simple manner by recording its path / output signal level characteristic and moving to the basic positions of the overrun control valve 19 and the fine control valve 17 or the main control valve 16 and can be used for a continuous determination of the overrun path s.
- a position sensor (not shown) can also be provided, which detects the deflections of the valve piston 87 of the main control valve 16 relative to its housing 86.
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Actuator (AREA)
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Abstract
Description
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Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE59502414T DE59502414D1 (de) | 1994-03-09 | 1995-03-09 | Hydraulische antriebseinheit |
US08/646,229 US5829336A (en) | 1994-03-09 | 1995-03-09 | Hydraulic drive unit |
EP95913076A EP0749535B1 (de) | 1994-03-09 | 1995-03-09 | Hydraulische antriebseinheit |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE4407765 | 1994-03-09 | ||
DEP4407765.3 | 1994-03-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1995024565A1 true WO1995024565A1 (de) | 1995-09-14 |
Family
ID=6512201
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1995/000884 WO1995024565A1 (de) | 1994-03-09 | 1995-03-09 | Hydraulische antriebseinheit |
Country Status (5)
Country | Link |
---|---|
US (1) | US5829336A (de) |
EP (1) | EP0749535B1 (de) |
AT (1) | ATE166951T1 (de) |
DE (2) | DE59502414D1 (de) |
WO (1) | WO1995024565A1 (de) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19536553A1 (de) * | 1995-09-30 | 1997-04-03 | Eckehart Schulze | Elektrohydraulische Steuerventilanordnung |
US6273000B1 (en) * | 1999-05-20 | 2001-08-14 | Aerobus International, Inc. | Rail switching system |
DE102007008092A1 (de) * | 2007-02-19 | 2008-08-21 | Robert Bosch Gmbh | Elektrohydraulische Antriebseinrichtung |
DE102007051857B3 (de) * | 2007-10-30 | 2009-04-23 | Siemens Ag | Regeleinrichtung zum Positionsregeln einer Hydraulikzylindereinheit mit Linearisierungseinheit |
CN102189482B (zh) * | 2011-03-23 | 2013-06-12 | 宁夏银川大河数控机床有限公司 | 珩磨机主轴往复随动控制装置 |
CN102192203A (zh) * | 2011-03-23 | 2011-09-21 | 宁夏银川大河数控机床有限公司 | 液压往复随动控制装置 |
WO2016122599A1 (en) * | 2015-01-30 | 2016-08-04 | Hewlett-Packard Development Company, L.P. | Selection valves of fluid supply systems |
RU2671928C1 (ru) * | 2017-12-18 | 2018-11-07 | Валерий Владимирович Бодров | Способ управления электрогидравлическим следящим приводом вибростенда |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2726350A1 (de) * | 1976-06-10 | 1977-12-22 | Nisshin Sangyo Co | Hydraulik-servomechanismus |
DE8711981U1 (de) * | 1986-09-04 | 1988-01-14 | Schulze, Eckehart, 7251 Weissach, De |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3614577A1 (de) * | 1985-04-30 | 1986-12-11 | Hartmann & Lämmle GmbH & Co KG, 71277 Rutesheim | Einrichtung zur einstellung der kreisverstaerkung eines nachlauf-regelkreises |
EP0279837B1 (de) * | 1986-09-04 | 1990-11-14 | Eckehart Schulze | Hydraulisches nachlauf-regelventil |
-
1995
- 1995-03-09 AT AT95913076T patent/ATE166951T1/de not_active IP Right Cessation
- 1995-03-09 EP EP95913076A patent/EP0749535B1/de not_active Expired - Lifetime
- 1995-03-09 US US08/646,229 patent/US5829336A/en not_active Expired - Fee Related
- 1995-03-09 WO PCT/EP1995/000884 patent/WO1995024565A1/de active IP Right Grant
- 1995-03-09 DE DE59502414T patent/DE59502414D1/de not_active Expired - Fee Related
- 1995-03-09 DE DE19508190A patent/DE19508190A1/de not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2726350A1 (de) * | 1976-06-10 | 1977-12-22 | Nisshin Sangyo Co | Hydraulik-servomechanismus |
DE8711981U1 (de) * | 1986-09-04 | 1988-01-14 | Schulze, Eckehart, 7251 Weissach, De |
Also Published As
Publication number | Publication date |
---|---|
EP0749535A1 (de) | 1996-12-27 |
ATE166951T1 (de) | 1998-06-15 |
EP0749535B1 (de) | 1998-06-03 |
US5829336A (en) | 1998-11-03 |
DE19508190A1 (de) | 1995-09-14 |
DE59502414D1 (de) | 1998-07-09 |
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