EP3721094A1

EP3721094A1 - Valve device

Info

Publication number: EP3721094A1
Application number: EP19705145.1A
Authority: EP
Inventors: Peter Bruck; Frank Schulz; Christian Stauch; Jan Lübbert
Original assignee: Hydac Fluidtechnik GmbH
Current assignee: Hydac Fluidtechnik GmbH
Priority date: 2018-02-20
Filing date: 2019-02-07
Publication date: 2020-10-14
Anticipated expiration: 2039-02-07
Also published as: US20200378409A1; DE102018001303A1; EP3721094B1; WO2019162097A1

Abstract

A valve device having a feed connector (ZA) of a feed side for the supply of a hydraulic consumer which can be connected to the feed connector (ZA) with pressure fluid, an outlet connector (AA) of an outlet side for the discharge of pressure fluid from the consumer which can be connected, wherein, depending on the actuating direction of said consumer, the feed side changes into the outlet side and the outlet side changes into the feed side, a pressure supply connector (P), and a return flow connector (T), is characterized in that a pressure regulating device acts on the respective feed side and a volumetric flow regulating device acts on the respective outlet side.

Description

valve device

The invention relates to a valve device with an inlet port of an inlet side for the supply of a connector at the Anschlußba ren hydraulic consumer with pressurized fluid, with a drain port of a drain side for the discharge of pressurized fluid from the connectable consumer, depending on the driving direction of this consumer to running side in the Outlet side and the drain side changed to the inlet side, with a pressure supply connection and with a return connection. By EP 1 642 035 B1 a hydraulic system is known with a hydraulically controllable drive part as a hydraulic consumer with two opposite drive directions, at least one drive direction to at least one pressure regulator, in particular in valve form, seen before, and a throttle between the pressure regulator and the Drive part, wherein for detecting the load state of the drive part, a sensor is provided, in the form of a pressure sensor, which is connected for each drive direction of the drive part in the associated, fluid-carrying strand between the throttle and the drive part. The fact that in the known solution of the pressure transducer detects the instantaneous load situation on the drive part, that the pressure regulator in its basic position connects the secondary side of the system with a tank cap respectively return port, and that when controlling the pressure regulator the secondary pressure to the pressure of the proportional pilot control abzüg Lich the valve piston of the pressure regulator acting spring force is controlled, a control and control concept is reali-based, based on a basic system for hydraulically controllable drive parts or consumers, such as hydraulic power cylinder or Hydro-drive motors, a pressure, travel, speed and position measurement for the movable components of each selected th drive part can achieve. Via the respective pressure regulator, in particular in the form of a valve, dynamic and precise control processes can be implemented with the known system solution, depending on the hydraulic application. With the known hydraulic system using pressure regulators and corresponding throttles can be dispensed with the previously known conventional directional control valve technology for driving the movement of a hydraulic consumer, so that the loss of power and the susceptibility are reduced while shortening the reaction time for the hydraulic system.

Such hydraulic systems, be it in the form of stationary systems, be it in the form of mobile machines, are increasingly demanding in terms of productivity, flexibility and energy efficiency. With large machines, such as those used in the "mining area", for example, multi-circuit systems are increasingly gaining acceptance, ie hydraulic structures with associated pumps for the various consumers.The division of the power requirements has enormous ener- gy potential Such multi-circuit systems from an economic and constructive point of view, however, difficult to use.

Based on this prior art, the present invention seeks to simplify such known hydraulic structures and replace them with a more efficient control or valve concept, in order to lower the respective energy intake, in order not only to save operating costs, but also to make a relieving contribution to the increasingly stricter statutory exhaust gas regulations.

This object is achieved by a valve device having the features of patent claim 1 in its entirety. Characterized in that according to the characterizing part of claim 1 to the respective inlet side a pressure control device and the respective outlet side a Vo lumensstromregelungseinrichtung acts, a kind of decentralized valve control is created with so-called. Separate control edges, the possibility of a separate control of valve elements on the Zu - and drain side of a connectable to the valve device hydraulic consumer chers, such as a hydraulic cylinder offer. In addition to an individual actuation of inlet and outlet, circuit topologies can be set, which include, for example, swim or rapid traverse positions.

With the valve device according to the invention the requirements in the context of movement tasks for the hydraulic consumer he fills, on the one hand set a certain speed and on the other hand to ensure that the inlet side of the consumer in the case of un terstützender, so-called. Generational loads is sufficiently filled. For this purpose, the valve device according to the invention uses a hydraulic-mecha African regulation for the variables volume flow and pressure.

It is advantageous to put the volume flow control in each case on the ex-side of the consumer, because so motor and regenerative loads can be set with the same current controller to a defined speed. Accordingly, the pressure control is then on the inlet side, which filling deficiencies in lowering movements (generatori cal load) under the assumption of sufficient supply by hy-mechanical control of a sufficiently high filling pressure avoided the be avoided. Serves the valve device according to the invention for use in a hydraulic consumer, such as a hydraulic cylinder or a movable in opposite directions hydraulic motor, at egg nem change of movement or actuation direction the addressed inlet side then to the outlet side and the outlet side to the inlet side for the respective consumer. In that regard, the invention Ventilvorrich device ensures that with only one device even with changing Actuate transmission directions always on the inlet side with the pressure supply the pressure control device and on the respective outlet side a Volu menstromregelungseinrichtung acting on the fluid flow acts.

The valve device according to the invention is able to exploit the energetic, functional and structural potentials of separate control edges in valves while at the same time controlling the ensuing complexity at the component and control levels. The fiction, contemporary valve device can operate energetically low, which helps reduce Be operating costs and due to the improved control concept with the separate control edges can be within the Druckversor supply regularly provided by motorized hydraulic pumps, drive energy savings, which helps reduce exhaust emissions.

In a preferred embodiment of the device according to the invention Ventilvor direction is provided that the pressure control device and the Volu menstromregelungseinrichtung each have a proportional valve together with a pressure compensator and a pressure control valve of their function forth, which are interconnected and controlled such that at a supply of Ver supply connection from the side Pressure supply connection in a flow direction, the pressure control valve works and on the side of the drain port at a predetermined Sol l pressure on the other pressure control valve, this flow direction is reversed. The pressurized fluid flows over the other proportional valve and the associated pressure compensator, both of which function of their function as a flow control valve, in the direction of the return port from. In such a way, the valve device according to the invention can be realized in a "dissolved construction" with individual, structurally separated valve components.

It is particularly advantageous, however, the above-mentioned Ventilkompo components, in particular the respective pressure control valve and the respective associated levers pressure balance, summarize their functions in a single combination valve forth.

In a preferred manner, it is provided that the combination valve has two independently movable in a valve housing spool, in the form of a pressure control slide and in the form of a Druckwaa genschiebers that control the possible fluid-carrying connections between the pressure supply port, the return port and a Ar beitsanschluss, for the hydraulic consumer in one and the other opposite flow direction respectively forms the inlet and the drain port. In this way, with only one com bination valve with two independently movable in the valve housing slide a decentralized valve control realize with separate STEU erkanten, which also offers structural advantages in addition to an improved control geometry, in particular as regards the reduction of the tubing and Verrohrungsaufwandes with respect to known solutions with isolated , spatially separated individual valves.

Further advantageous embodiments of the invention Ventilvorrich device are the subject of the other dependent claims. In the following, the valve device according to the invention will be explained in more detail by means of embodiments according to the drawing. This show in principle and not to scale representation of the

Fig. 1 in the manner of a hydraulic circuit diagram, a first Ausfüh tion form of the valve device according to the invention in "dissolved" construction with a plurality of individual valve components;

Fig. 2 to 6, a second embodiment of the valve device according to the invention, with the function of the individual Ventilkom components according to FIG. 1 in a combination valve are summarized to sammengefasst.

The valve device shown in Fig. 1 has an inlet port ZA an inlet side for the supply of a closable at the inlet port ZA hydraulic consumer with pressurized fluid. Furthermore, a drain port AA of a drain side for the discharge of pressurized fluid from the connectable consumer is provided. Furthermore, the Ven tilvorrichtung a pressure supply port P for the supply of the valve device and the hydraulic consumer with pressure fluid presettable pressure and further comprises a return port T repek tive a tank port provided for the removal of displaced fluid from the hydraulic consumer and the valve device , The hyd raulische consumer is GE from a hydraulic cylinder AZ forms with a piston rod unit KSE, wherein the working cylinder AZ on its piston side permanently fluid leading to the inlet port ZA in connection and the rod side with the drain port AA as shown in FIG. If the piston side of the piston rod unit KSE supplied via the inlet port ZA with pressure fluid specifiable pressure, the piston rod unit KSE, as seen in the direction of FIG. 1, moves to the right and the fluid located in the rod space is AB via the drain port AA from the working cylinder AZ leads. In the opposite case, ie when retracting the piston rod unit KSE, as seen in the direction of Fig. 1 to the left, then the drain connection AA to the inlet port ZA and the supply in the Einfahrbewe movement of the piston rod unit KSE piston side displaced fluid leaves via a drain port AA, the originally formed in the extension movement of the inlet port ZA, the working cylinder AZ. The piston rod unit KSE of the working cylinder AZ thus performs depending on the supply state with pressurized fluid a reciprocating motion and extent a movement in opposite axial directions. Instead of Ar beitszylinders AZ could as a hydraulic consumer, a hydraulic motor unit (not shown) occur, which also, depending on the Befüllungszu his chambers, can rotate in opposite directions.

As shown in FIG. 1, both on the inlet side and on the downstream side of the valve device each have a 3/2-proportional valve PV with a pressure compensator DW available. As shown in FIG. 1, the input of the 3/2 proportional spool valve PV is connected via the pressure supply port P to a common pressure supply source such as a hydraulic pump. The output of the proportional valve PV is designed in the manner of a Nutzanschlusses and designated A. The proportional valve PV is, as shown, electromagnetically controllable and the valve spool is on its opposite control side with the control pressure from the user port A can be controlled. The pertinent volume flow, originating from the user port A, is directed to an input of the pressure compensator DW, which in the illustrated pressure compensator position leads the pressure at the user port A to the tank or return port T.

In another control position of the respective pressure compensator DW, this takes se a pertinent fluid path blocking position. Furthermore, a control side of the respective pressure compensator DW with a Energiespei cher, in particular in the form of a compression spring, acted upon and is further as control pressure of the return pressure, originating from the user port A, to, if the respective proportional valve PV ge further, in Fig. 1 ge showed slide position occupies, in which the fluid-carrying connection from the pressure supply port P to the user port A is suppressed and otherwise a fluid connection backward from the user port A in the direction of a control side of the pressure compensator DW exists. On the ge opposite control side of the respective pressure compensator DW the pressure PM is applied to a measuring port M, which is tapped at the inlet port ZA res pective at the outlet port AA of the working cylinder AZ.

Furthermore, according to the hydraulic circuit diagram of FIG. 1 in the usual manner, both the respective inlet port ZA and the respective drain port AA via an adjustable pressure relief valve DBV in the usual manner against excessive operating pressure in the direction of the return port T hedged. For the electromagnetic control of the respective pressure control valve DRV is an unspecified and shown control device that processed the pressure transducer DETA measuring pressure at the inlet connection ZA respectively at the running connection AA made clear and control signals to the pressure control valves DRV and the electromagnetically actuated proportional valves PV purpose of their Control forwards.

Now flowing fluid according to the illustration of FIG. 1 from bottom to top, ie from the pressure supply port P to the consumer A, the arranged on the inlet side 3/2 proportional valve acts as a pressure regulator. Now exceeds the pressure at the working port A of the pressure regulator on the discharge side of the set by means of the proportional solenoid DRV target pressure, the flow direction is reversed and the pressurized fluid (oil) flows into the working port A and from there through the pressure compensator DW shown on the right in FIG. 1 into the return port T. The right pressure compensator DW compares the pressure at the working port A with the pressure PM present at the measuring port M , In this return state then the right one acts

3/2-proportional valve DRV as a directional control valve, the control edge of user port A to the right pressure compensator DW is fully open. In combination with the shown right proportional valve PV between the terminals A and M, then the arrangement shown acts as a current control valve.

The valve device shown in Fig. 1 in so-called. Resolved design thus offers a hydraulic-mechanical control of the sizes of volume flow and pressure. As stated, the volume flow control was placed on the discharge side of the hydraulic consumer, because such motori cal and regenerative loads can be set with the same current controller to a defi ned speed. Consequently, then so far as the pressure control on the inlet side, whereby Befüllungsde ficits are avoided in lowering movements (regenerative load) assuming a sufficient supply by hydraulic-mechanical adjustment of a sufficiently high filling pressure. Now turn around the conditions, so drives according to the illustration of FIG. 1, the Kol benstangeneinheit KSE of the working cylinder AZ to the left, the previous her port ZA to the drain port AA and the previous From running connection AA to the inlet port ZA. The pressure regulating valve DRV shown on the right in FIG. 1 then forms the pressure regulator and the left Darge presented combination of proportional valve PV with the pressure compensator DW the current controller.

A possible construction of a so-called. Combination valve, the function of each of a pressure control valve DRV and the associated pressure compensator For an improved and simplified depicting ment the essential components of the combination valve are shown only in principle and simplified and also the combination valve is shown only with its upper half above its operating axis, wherein the rotationally symmetrical overall valve housing of the combination valve for the sake of simplicity is not shown, but of course the valve mimic explained in more detail below includes and releases passages to form the individual ports P, A, T, M accordingly.

The valve shown in Fig. 2 has two slides in the form of a pressure control slide DRS shown on the left and a pressure compensator slide DWS shown on the right. The pertinent two slide DRS and DWS control the fluid-carrying connections between the pressure supply port P, the working port A and the return flow port T, which forms the tank port. The further shown in Fig. 2 on the left return port T or tank port of a pre tax stage, formed from a pilot cone 18, which is actuated by a not shown nä forth actuating magnet of conventional design for the combination valve shown, with the main tank port shown on the right (return port T ), but this is not mandatory.

Furthermore, there are various spaces in the form of a pilot control chamber X, in which a control pressure px, which comes from the pressure supply port P, pending, said control pressure px proportional to the force of the energized actuating magnet or proportional solenoid acts from left to right on the pressure control slide DRS. For the connec tion between the pressure supply port P and pilot chamber X, a pilot channel 5 is provided which has a diaphragm 3 or an unspecified Darge notified flow control valve as a pressure divider of the pilot control. in this respect is the pilot pressure px to a reporting area 1, which, as seen in the direction of FIG. 2, the left end face of the pressure control slide DRS forms and in the illustrated in Fig. 2 displacement position of the pressure control slide DRS is the pilot chamber X, otherwise of the Valve housing is limited, essentially reduced to zero, except for a designated notch for the hydraulic end position of Druckregelschie bers DRS in his in Fig. 3a, 3b tion right end or stop posi. Furthermore, in FIG. 2, a compensation chamber E can be seen, which according to the representation according to FIG. 2 has likewise moved substantially to the volume zero. In this case, the compensation space E is bounded by the valve housing and by a compensation surface 4 as part of a collar, which is widened radially relative to the other diameter of the pressure regulating slide DRS. The compensation surface 4 against the opposite annular surface 4 'of the annular collar, provided in the present case the same diameter as the compensation surface 4, is directly the supply pressure px exposed at the pressure supply port P. Furthermore, the compensation chamber E is permanently connected in a fluid-conducting manner to the utility connection A via the compensation channel 6 shown in dashed lines in the pressure control slide DRS. Accordingly, the compensation channel 6 opens at a further or right annular surface 9 of the pressure control slide DRS, wherein the annular surface 9 has the same diameter as the annular surface 4, which serves as a compensation surface for the surface 9, which is for the function tion of particular importance. The right annular surface 9 is part of an annular collar with a further stop surface 9 'with the same diameter, which limits the pressure supply port P in the position shown. The diameters of the surfaces 4 'and 9 may be different voneinan, only the diameters of the surfaces 4 and 9 must be the same. Furthermore, a gap Z in the connection between Nutzan circuit A and return port T is present in which there is a resulting from this connection control pressure pz. In the extent parallel to the pressure control slide DRS extending gap Z open the user port A and the main return port T radially.

Further, an actual pressure reporting room Y is present, which, as seen in the direction of FIG. 2, is limited on the left side of a reporting area 1 1 for the actual pressure pA in pressure control mode and otherwise by a zy-cylindrical recess in the pressure compensator slide DWS with its left annular surface 12 engages over a right free end portion of the cylindrical pressure control slide DRS respectively comprises. While the Mel defläche 1 1 forms the right free end face of the pressure control slide DRS, opposite a circular surface 1 6 with the same diam water on the inside of the pressure compensator slide DWS available. An et waiger control pressure pA, which comes from the user port A, is thus effective pressure on the reporting area 1 1 as well as on the circular surface 16 of the pressure compensator slide DWS. In that regard, the reporting or control pressure PA in pressure compensator operation to the areas 1 1 and 1 6 is further reported. On the basis of the possible movement of movement of the two slides DRS and DWS, the free volume of the actual pressure reporting room Y changes. To the control pressure pA on the part of Nutzanschlusses in the Istdruck-reporting room Y wei terleiten can serve a dashed reproduced reporting channel 7, the a center collar or annular collar reduced in diameter relative to the annular surfaces 9, 9 ', which in this respect is permanently in fluid communication with the service port A in connection. At its other end of the pertinent message channel 7 opens for the actual or control pressure PA at the user port A in the actual pressure message room Y from. Furthermore, in the message channel 7 in an optional manner, so if necessary, a Dämp be fung aperture 8 connected. The pressure compensator slide DWS is supported by a widened end-side flange surface on an energy store in the form of a pressure spring 14 for the pressure compensator, wherein the pertinent compression spring 14 is made relatively hard. Furthermore, a stop 15 for the free Verfahrbewe movement of the pressure compensator slide DWS to the left in unspecified specifi cated valve housing available. In that regard, the spring 14 is supported with its the flange of the pressure compensator slide DWS gegenüberlie ing end of wall parts of a pertinent valve housing from. Fer ner is according to the illustration of FIG. 2 in the interior of the pressure control slide DRS another energy storage in the form of a compression spring 10 out, which agrees relatively soft the response of the pressure regulator mitbe. The pertinent compression spring 10 is supported with its one free end on the circular surface 1 6 of the pressure compensator slide DWS and with its other free end on the end face of a bore in the pressure control slide DRS.

Furthermore, a message room M in the valve housing is present, which, as seen in the direction of Fig. 2, on the left side of a reporting area 1 7 is limited, which forms the right free end face of Druckwaa genschiebers DWS in the region of its Flanschverbreiterung. In the pertinent message room M opens a measuring port 20, which leads in pressure compensator operation, the measuring pressure pM. In addition, it should be noted that in addition to the notch 2 for the hydraulic end position of Druckregelschie bers DRS for the pressure compensator DWS a relief notch 1 3 is introduced in the region of the main return port T on the left free end En de of the pressure compensator DWS, otherwise the thus free frontal End of the annular surface 12 is limited, which forwards the pressure pA on the user port A to the pressure balance slide DWS in pressure compensator operation. Furthermore, in the range of controllable with the actuating solenoid pilot cone 18, a conical seat 1 9 for the pertinent pilot cone in unspecified Valve housing available. The core idea of this valve concept according to the invention lies in the separation of the tasks pressure control and pressure compensator function, which are distributed to the two slides DRS and DWS, which are provided with independent energy storage in the form of the compression springs 10 and 14, wherein the compression spring 10 not only on the pressure compensator slide DWS on the circular area 1 6 acts, but also on a investment opportunity in the area of the other ring surface 9 'on the pressure control slide DRS.

The left slide or pressure control slide DRS realized the pressure control function, starting from the pressure supply port P to Druckan circuit A. The soft spring 10 holds him in the rest position on the left to beat. As already stated, the pressure control slide DRS has three channels, wherein the pilot control channel 5 supplies the pilot stage with fluid (oil) from the pressure supply connection P. For the pressure divider function of the pilot stage comes in the channel 5 either a diaphragm 3 used or integrated into the pressure control slide DRS miniature flow control valve (not shown). An advantage of the latter solution is the lower and constant pilot current. Thus, the control pressure in the control room before tax X from the supply pressure at port P is independent. However, this is offset by higher production costs. The message channel 7, however, reports the actual pressure pA at the working port A in the inner space Y between the two slides DRS and DWS. Optionally, a damping diaphragm 8 can be used here. The further existing channel 6 as a compensation channel causes a pressure equalization between the gap Z, which is disposed between the terminals A and T, and the compensation chamber E. With the help of the notch 2 a hydraulic end position is realized for the pressure control slide DRS. The right slide or pressure compensator DWS works so far as a pressure compensator, which compares the pressure at the user port A with the pressure at the measuring port 20 and with the pressure in the reporting room M. The resulting rule pressure difference is defined by the design of the hard spring 14 as the wide ren energy storage.

2, wherein in the following fi gures reference numerals are only as far as compared with the Fig. 2 are still indicated, as they are needed to explain the solution according to the invention in wesentli chen.

3a, 3b and 3c represent different resting states of the combinati onsventils, wherein the unloaded resting state as shown in FIG. 3a shows the same valve state, as it is given in Fig. 2 again, and Fig. 3b gives a loaded rest state for the Ven valve again, whereas Fig. 3c shows the valve in the loaded state of rest and vorbestromt.

In that regard, therefore, Figs. 3a, 3b and 3c concern the possible rest conditions of the combination valve according to the invention, i. the conditions in which no fluid (oil) flows over the flow paths P-A or A-T. In unloaded th idle state (Fig. 2 and 3a) all the connections shown are depressurized. The two slides DRS and DWS are located in the end positions defined by the springs 10 and 14 and the housing stops. In this case, the fluid-conducting connection between the pressure supply connection P and the utility port A is closed, the connection from the utility port A to the return port T fully open.

The loaded resting state according to the illustration of Fig. 3b is characterized by a load pressure at the measuring port 20 respectively in the notification room marked acts on the reporting area 1 7 on the right side of the carriage slide DWS on this. The pending on the reporting area 1 7 pressure moves the pressure compensator slide DWS as shown according to the Fig. 3b in the left end position, which is defined for example by means of the annular stop 15. The seat-tight holding of the load requires a seat-tight construction of a sealing point between the Mel deraum M to the return port T (not shown). The fluid leading de connection between the user port A to the return port T is closed except for the geometrically small failing relief notch 1 3.

To bridge the long dead zone of the pressure control slide DRS from the left end position out to the opening between Druckversorgungsan circuit P and user port A, a Vorbestromung the actuating magnet, not shown, which controls the pilot cone 18, makes sense. In this case, in the pilot control chamber X, a pilot pressure px adjusts, which acts on the reporting area 1 and shifts the pressure control slide DRS to the right until it closes the fluid-carrying connection from the utility A to the space Z. In this case, it is assumed that no fluid (oil) can flow out of the utility port A because the proportional or check valve PV (FIG. 1) connected to the utility port A is closed. During the mentioned movement, as seen in the direction of Fig. 3c to the right, the pressure control slide DRS displaced with its face 1 1 fluid or Ölvolu men from the Istdruck-reporting room Y, said fluid volume can flow through the reporting channel 7 in the working port A. , but from there due to the closed connection valve PV can not escape from the system. Therefore, the fluid (oil) is forced to flow into the space Z and on the relief notch 1 3 of the pressure balance in the form of the pressure balance slide DWS in the tank or Rücklaufan circuit T, namely until the pressure control slide DRS the fluidfüh-saving Connection between the user port A and the gap Z closes. This results in the pressure equilibrium between the two circular end faces 1 and 1 1, which are of equal size formed by their free diameter and the rest position shown in Figure 3c achieved, wherein the compensation chamber E and the gap Z are always pressure equalized via the compensation channel 6 in the pressure control slide DRS.

FIGS. 4a and 4b now show the actual pressure control operation. In this case, fluid (oil) flows from the pressure supply port P to Nutzan circuit A. The pressure at the user port A corresponds to the pre-control room X using the pilot stage set target pressure minus the pressure difference corresponding to the spring force, the biased pressure control spring 10 to the pressure control piston or Pressure control slide DRS exerts. The aforementioned pilot control stage is realized by components that are represented by the reference numerals 3, 5, 18 and 1 9. The actual pressure pA at the user port A is reported via the reporting message channel 7 in the pressure control slide DRS on the right end face 1 1 in the inner space in the form of Istdruck-reporting room Y and with the help of the same large face 1 on the left side of Druckre gelschiebers DRS with the pilot pressure px in Vorsteuerraum X compare. The geometry of the pressure control slide DRS is designed so that the space Y and thus the surface 1 1 is always connected via the message channel 7 with the user port A. Depending on the upcoming pressure at the measuring port 20 respectively in the message room M is the pressure Weigh ge in one of its two end positions or possibly in between. This only affects the spring force acting on the pressure control slide DRS and changes the control pressure at the utility connection A only minimally.

The following FIGS. 5a, 5b show the pressure control operation at saturation. If the setpoint pressure which is predetermined by the supply of the pilot solenoid at the pilot control valve 18 can not be achieved because a very large volume flow flows out of the utility connection A, no counterbalance action, even with full opening of the flow path from the pressure supply connection P to the utility connection A, is established. between the end faces 1 and 1 1 on the pressure control slide DRS. As a result, this moves so far to the right that he closes the angepro term fluid-carrying path P to A again, so that the payload connection pA continues to fall and the slider leaves the control range ver. This is prevented by means of the triangular notch 2 on the pressure control slide DRS. The triangular notch 2 opens a connection from the pilot chamber X in the relief space E and from there via the equalization channel 6 and the gap Z in the return port T. It is to ensure constructively that the connection of relief or compensation chamber E to the return port T is also maintained when the pressure compensator is located on the left stop, which is shown in Fig. 5b. In this case, the relief notch 1 3 remains as Restöff voltage from the gap Z to the tank or return port T. The effluent via the notch 2 fluid (oil) lowers the pilot pressure px so far that a determined by the Nutzanschlussdruck pA equilibrium between the Nutzanschlussdruck pA and the pilot pressure p _x . The pressure control slide DRS then remains in the effective range of the notch 2. The stability of this state depends essentially on the selected Ker gegege. It is additionally to ensure that the Strömungswi resistances on the equalization channel 6 and the relief notch 1 3 are significantly smaller than the resistance over the notch 2. Their resistance must not exceed that of the fully open pilot cam seat 19.

In the following Fig. 6 of the pressure compensator operation is shown. If the pilot pressure px in the pilot control chamber X is less than the working pressure at the user port A or in the space Y, then the shift at the surfaces 1 and

1 1 of the pressure control slide DRS resulting force the Druckre gelschieber DRS in the left end position as shown in FIG. 6. This opens the cross-section of user port A to the gap Z completely. The working pressure pA then acts directly on the left-hand ring surface

12 and the message channel 7 indirectly to the left circular surface 16 of the Pressure balance slide DWS as reporting pressure on. The pressure balance slide DWS then compares the working pressure pA with the measuring pressure pM, wel cher acts on the right circular surface 1 7 of the pressure compensator. The surface 1 7 corresponds to the sum of the areas 12 and 16. The pressure compensator slide DWS assumes a position in which the volume flow from the user port A to the tank or return port T at the throttle point between the gap Z and the return port T ge is throttled that adjusts the user port A, the measuring pressure pM minus the defined by the spring 14 control pressure difference DrM.

With the solution according to the invention, an electrohydraulic control system for hydraulic drives is created as a whole, which can operate in both directions in both motor and regenerative operation. Since a pilot operated Proportionalschieberventil is used, the function of a pressure reducer for the supply pressure control and a

Pressure balance for the flow control in a combined valve with each other.

Claims

Patent claims

1 . Valve device with a

Inlet connection (ZA) of an inlet side for the supply of a hydraulic consumer which can be connected to the inlet connection (ZA) with pressurized fluid,

- Drain port (AA) a drain side for the removal of pressure fluid from the connectable consumer, depending on the drive direction of this consumer, the inlet side changes in the drain side and the drain side in the inlet side,

- a pressure supply connection (P), and

a return connection (T),

characterized in that the respective

- Inlet side a pressure control device and

- Drain side a flow control device

acts.

2. A valve device according to claim 1, characterized in that the pressure control device and the volume flow control device each have a proportional valve (PV) and a pressure control valve (DRV) together with a pressure compensator (DW) of their function forth, which are interconnected and controlled such that at a Ver supply of the inlet port (ZA) of the Druckversorgungsan circuit (P) in a flow direction of a Druckregelven- valve (DRV) works as a pressure regulator and on the side of the Ablaufanschlus ses (AA) when a predetermined target pressure at the other pressure control valve (DRV) is exceeded the flow direction reverses and the pressure fluid flows in the direction of the return port (T) via the other proportional valve (PV) and the associated pressure compensator (DW), both of which function as a flow control valve.

3. A valve device according to claim 1 or 2, characterized in that the respective pressure control valve (DRV) is a Proportionalschieberven valve, preferably a 3/2-way proportional valve, which is controllable with means of at least one proportional solenoid (18) the A position of a target pressure specification at the pressure regulating valve (DRV).

4. Valve device according to one of the preceding claims, characterized in that the respective pressure control valve (DRV) and each Weil associated pressure compensator (DW) are combined in a combination valve of their functions.

5. Valve device according to one of the preceding claims, characterized in that the combination valve has tilgehäuse in a Ven independently movable spool, in the form of egg nes pressure control slide (DRS) and in the form of a Druckwaagenschie bers (DWS), the possible fluid-carrying connections between the pressure supply port (P), the return port (T) and a working port (A), the bil in connection with a Pro portionalventil (PV) in one and the other opposite flow direction the inlet or the drain port (ZA; AA) det.

6. Valve device according to one of the preceding claims, characterized in that the combination valve housing within the Ventilge having the following spaces: a

- Pilot chamber (X), in which a control pressure (px), which comes from the pressure supply port (P), according to the effect of the energized proportional solenoid acting on the pressure control slide (DRS),

- equalization chamber (E), - Interspace (Z) in the possible fluid-carrying connection between tween the user port (A) and the return port (T), in which a resulting from this compound control pressure (pz) acts,

- Actual pressure reporting chamber (Y), in which a control pressure (PA), which comes from the respective pressure at the user port (A), and

- Message room (M), in which a control pressure (PM) acts against the action of an energy storage device (14) on the pressure balance slide (DWS).

7. Valve device according to one of the preceding claims, characterized in that in the pressure control slide (DRS) a pilot channel (5) for a diaphragm (3) or a flow control valve for a pilot control is introduced, the pressure supply deadline (P) with a reporting surface ( 1) fluidly connecting, the pilot chamber (X) at least partially limited.

8. Valve device according to one of the preceding claims, characterized in that in the pressure control slide (DRS) a compensation channel (6) is introduced, which the utility connection (A) with the compensation chamber

(E) connects fluidly.

9. Valve device according to one of the preceding claims, characterized in that in the pressure control slide (DRS) a message channel (7) is introduced, with an optionally be arranged therein Dämpfungsblen de (8), the actual pressure (PA) at the user port (A) in the Istdruck- reporting room (Y) forwards, which is bounded by the pressure compensator valve (DWS), and a control side (1 1) of the pressure control slide (DRS), which is guided in the actual pressure message room (Y).

10. Valve device according to one of the preceding claims, characterized in that the pressure compensator slide (DWS) is supported on a further energy storage device (10), which engages the actual pressure reporting chamber (Y) by means of the pressure control slide (DRS).