EP3244072A1 - Hydrostatic valve assembly and hydrostatic lifting device with the valve assembly - Google Patents

Abstract

Disclosed is a hydrostatic valve arrangement for the pressure medium supply of a hydrostatic load, in particular a lifting device, and its shut-off in case of leakage or breakage, with a first working flow path from a first pressure port, via a first shut-off valve to a first consumer port, wherein a valve body of the first shut-off valve in Closing direction can be acted upon by a closing pressure. Also disclosed is a hydrostatic lifting device with at least one such hydrostatic valve arrangement and with at least one hydrostatic consumer which is fluidically connected to the first consumer connection.

Description

The invention relates to a hydrostatic valve arrangement according to the preamble of patent claim 1, as well as to a hydrostatic lifting device with this valve arrangement according to claim 15.

A hydraulic or hydrostatic jack, such as a hydrostatic jack, has one or more hydrostatic pumps from which one or more hydrostatic or hydrostatic cylinders are pressurizable. The hydraulic motors or the cylinders can move a lifting mechanism when pressure medium is applied, so that the load, in particular a ship, for example, is moved against gravity.

In a ship lifting device, in particular those with rack and pinion systems, for example, a plurality of hydraulically connected in parallel hydraulic motors with the hydraulic pump or pumps via lines and in particular hoses for pressure medium supply. In the event of breakage of the pipe or hose, the undesirable and dangerous effect of causing a sudden drop in the load of the ship may occur. This poses a considerable danger which must be avoided. Added to this is the negative effect emerging pressure medium.

For example, the document shows US 6253 658 B1 a valve arrangement having a pressure medium source and a pressure medium sink, which can be connected via a directional valve with a working line, via which a bottom space of a lifting cylinder can be supplied with pressure medium. In the working line a control pressure loaded check valve is used.

When lifting the load, the pending pump pressure opens the check valve and releases the fluid connection. In addition, the valve arrangement has a bypass flow path, via which the floor space can be connected to the outlet of the directional valve, bypassing the check valve. In the bypass flow path a lockable directional control valve with two additional switch positions for fast and slow lowering of the load is arranged. By means of the switch position for rapid lowering, a back space of the check valve, which is otherwise loaded with load pressure, is depressurized so that pressure medium can flow from the floor space via the check valve into the tank. In the slow switching position, the check valve remains closed because the back space has the load pressure and the lowering is done only slowly via the bypass line.

A disadvantage of this solution is that in the case of breakage of the working line between the pressure medium source and the check valve no shut-off of the consumer supply takes place, but then only the onset of lowering the load slowly instead of fast. This is associated with a constant emptying of the floor space, so leakage, and that the load is not maintained in the event of breakage.

This disadvantage is for example in the of the document US 4353 286 countered shown solution. There, a continuous casting plant with two differential cylinders for holding down a press roll is disclosed. The bottom chambers of the differential cylinders are connected via a safety valve arrangement with a pressure medium source or a tank. Between the pressure medium source and the floor spaces a pressure-loaded check valve is arranged. In the closing direction this is permanently loaded with the pressure in the bottom space of the cylinder and a spring force. Alternatively, the back space can be loaded with pressure medium of high pressure, which is kept in a hydraulic accumulator. A control of the pressurizing agent of the back space is carried out via a complex switching valve, which is acted upon in working mode with control pressure in a position in which the rear space is connected to the pump pressure leading working line. By means of a volumetric flow rate detection unit, a leakage current resulting therefrom can be detected upon breakage of this working line and a signal sent to a switching valve to relieve a control pressure line via which the pressure selection valve for selecting the pressure in the rear space is relieved. In case of breakage of the working line consequently the control pressure line is relieved, whereby via the pressure selection valve the back space is connected to the "emergency pressure medium source" of the hydraulic accumulator and thus closing in the back space acting pressure the check valve is maintained. Due to the fact that the pending in the working line and opening to the check valve pressure has dropped due to the break, closes the check valve.

A disadvantage of this solution is that it is expensive in terms of device technology and control engineering. In particular, this solution requires the provision of an "emergency pressure source", for example in the form of a hydraulic accumulator, to ensure the shut-off of the consumer in the said break.

On the other hand, the object of the invention is to provide a hydrostatic valve arrangement for supplying pressure medium to at least one hydrostatic consumer, in particular a lifting device, and to shut it off in the event of leakage or breakage, which is designed to be simple in terms of device technology or control technology. Furthermore, the object is to provide a hydrostatic lifting device with such a valve arrangement.

This first object is achieved by a hydrostatic valve arrangement with the features of patent claim 1, the second, by a hydrostatic lifting device with the features of claim 15.

Advantageous developments of the valve assembly are described in the claims 2 to 14.

A hydrostatic valve arrangement for supplying pressure medium to a hydrostatic consumer, in particular that of a lifting device, and for blocking it in the event of leakage or breakage, has a first working flow path from a first pressure port, via a first shut-off valve to a first consumer port of the valve arrangement. In this case, a valve body of the first check valve in the closing direction can be acted upon, in particular acted upon, by a closing pressure. According to the invention, the valve arrangement has a pressurized first flow path which is provided via a throttle point to the first consumer port. In this case, the closing pressure in response to a pressure downstream of the throttle point, in particular to a value to which the first check valve shuts off, can be increased.

A breakage of a pipe or a hose downstream of the first working connection leads to a pressure drop at the latter and to a volume flow in the latter due to the pressurization of the first flow path. Due to the throttling effect of the throttle point thereby also decreases the pressure downstream of the throttle point, which then serves as a suitable and reliable signal for sufficiently increasing the closing pressure, to closing the first check valve.

In a development, in particular for connecting the consumer to the valve arrangement with flow and return, the valve arrangement has a second working flow path from a second pressure port, via a second shut-off valve to a second consumer port, wherein a valve body of the second shut-off valve in the closing direction with the Closing pressure can be acted upon. In order to provide the described shut-off functionality also for the breakage of a line connected to the second consumer connection, this development has a pressurized second flow path via the throttle point to the second consumer connection.

The one or more pressure ports are fluidly connected, in particular connected to a pressure medium source, for example a hydraulic machine, in particular a hydraulic pump.

In a further development, the first flow path can be controlled in dependence on a pressure or pressure gradient at the first consumer connection and otherwise controlled. In particular, the first flow path is controlled above a predetermined pressure value at the first consumer port and only opened when the pressure drops below this value. The drop below the value is then the signal for controlling the first flow path and the formation of the pressure medium volume flow therein, thus causing the barrier of at least the first consumer port.

In a further development, the second flow path can be controlled in a manner analogous to a pressure or pressure gradient at the second consumer connection and otherwise controlled.

In a further development, a first valve, in particular a 2/2-way switching valve, is provided downstream of the throttle for the purpose of establishing and controlling the first flow path. This has an open position in which the throttle with the first working port is fluidically connectable or connected, and a closed position in which the throttle is fluidically isolated from the first working port.

Of course, this type of training is also in the presence of the second flow path, by downstream of the throttle, a second valve, in particular a 2/2-way switching valve, is provided which has an open position in which the throttle is fluidically connected to the second working port , and which has a closed position in which the throttle is fluidically isolated from the second working port.

Both last-mentioned developments have the advantage that the respective flow path (first, second) is completely closed in normal operation, whereby leakage through it is largely prevented.

In a development, a valve body of the first valve is loaded in the open position with a predetermined pressure equivalent, in particular that of a spring, and in the closed position with the pressure applied to the first consumer port. If the pressure at the first consumer connection drops below the desired value of the predetermined pressure equivalent, the volume flow through the throttle point and finally the shut-off of at least the first shut-off valve is caused in this way with the simplest device-technical means (spring).

Again, this type of training in the presence of the second flow path offers by a valve body of the second valve is loaded in the open position with a predetermined pressure equivalent, in particular that of a spring, and in the closed position with the pressure applied to the second consumer port.

In a further development, a damping orifice or Dämfungsdrossel is provided in the first flow path and outside the first working flow path, between the first valve and the first load port to random, negative pressure peaks / pressure drops on the first consumer connection, which does not cause a break, but purely operationally and are not permanent, damp. Thus, a false triggering of the barrier can be prevented.

This development also forms for designs with a second working flow path and flow path, in that a damping diaphragm or damping throttle is provided in the second flow path and outside the second working flow path, between the second valve and the second consumer port.

With the same aim, to avoid false triggering, in a further development, a hydraulic accumulator is provided for damping negative pressure peaks / pressure drops downstream of the throttle, which is connected to the first or the first and second flow paths.

In order to be able to change the closing pressure in a very targeted manner and thus to be able to reliably perform the shut-off, a pressure selection valve is provided in a development, via which the increased closing pressure or a lower closing pressure can be selected as a function of the pressure downstream of the throttle.

In a further development, the pressure-selection valve has a low-pressure connection, to which a pressure-medium sink or a tank can be connected. In addition, it has a high-pressure connection, to which a pressure medium source can be connected. As a third connection, it has a closing pressure connection, which is fluidically connectable to a control surface of the valve body of the first shut-off valve which acts in the closing direction, or in the case of further development with a respective shut-off valve for flow and return, of the first and the second shut-off valve.

In a further development, the pressure selector valve has a working position, in which it is loaded with the pressure downstream of the throttle, and in which the closing pressure port is connected to the low pressure port and separated from the high pressure port. In addition, it has a "blocking position" in which it is loaded with a predetermined pressure equivalent, in particular that of a spring, and in which the closing pressure port is connected to the high-pressure port and the low-pressure port, so that the increased closing pressure on the or the control surfaces of or Check valves is effective.

In one development, the pressure medium source is formed by the first pressure port or by the first and second pressure port which has the higher pressure. In the second case, the valve arrangement preferably has a shuttle valve, in particular a check valve arrangement over which the higher of both pressures is selectable. In particular, a pressure-reducing or pressure regulating valve is connected to an output of the shuttle valve or the check valve arrangement, via which an inlet pressure of the throttle point is maintained at a defined value. Preferably, the pressure reducing or the pressure control valve upstream of the throttle is upstream.

In terms of device technology, the throttle point is designed to be fixed in a further development.

Thus, the pressure downstream of the throttle point safely and sufficiently decreases, if in the case of fracture, the pressure at the first or second load port drops, in a development, a respective pressure loss or flow resistance of the first or the first and second valves in said open position smaller , as a pressure drop or flow resistance of the orifice. For this purpose, an opening cross section of the first or the first and the second valve may be greater than that of the throttle point.

In a further development, the valve arrangement for pressure medium supply of several hydrostatic consumers and their shut-off in case of leakage or breakage, each consumer at least a first Arbeitsströmungspfad, a first pressure port, a first shut-off valve, a first consumer port, and a valve body of the respective first check valve, the Closing direction is acted upon by the closing pressure on.

In order to provide the throttle point then a pressure medium source with the highest possible pressure, the valve assembly in a development, a shuttle valve assembly for selecting a highest of the pressures of the first pressure ports, or the first and second pressure ports, the consumer.

In a further development with several consumers, the first flow paths or the first and the second flow paths downstream of the throttle point are then fluidly parallel. In this way, only one throttle point is necessary for detecting the pressure medium volume flow caused by breakage in one of the first or the second flow paths.

In order to use the pressure selection valve to control the shut-off of all check valves, the valve arrangement has a collecting line, via which the control surfaces of the check valves (first and / or second) which are effective in the closing direction are connected to the closing pressure connection.

A hydrostatic lifting device, in particular a ship lifting device, has at least one hydrostatic valve arrangement, which is designed according to one of the preceding claims, and at least one hydrostatic consumer, which is fluidically connected to the first consumer connection.

Two embodiments of a hydrostatic lifting device according to the invention, each with a valve arrangement according to the invention are shown in the drawings. Based on the two figures of these drawings, the invention will now be explained in more detail.

Figur 1

eine hydrostatische Hebevorrichtung mit einem Verbraucher und einer hydrostatischen Ventilanordnung zur Druckmittelversorgung und Isolierung des Verbrauchers bei Bruch oder Leckage, gemäß einem ersten Ausführungsbeispiel, und

Figur 2

eine hydrostatische Hebevorrichtung mit mehreren Verbrauchern und einer hydrostatischen Ventilanordnung zur Druckmittelversorgung und Isolierung der Verbraucher bei Bruch oder Leckage, gemäß einem zweiten Ausführungsbeispiel.

Show it

FIG. 1

a hydrostatic lifting device with a consumer and a hydrostatic valve arrangement for pressure medium supply and insulation of the consumer in case of breakage or leakage, according to a first embodiment, and

FIG. 2

a hydrostatic lifting device with a plurality of consumers and a hydrostatic valve arrangement for pressure medium supply and insulation of the consumer in case of breakage or leakage, according to a second embodiment.

The FIGS. 1 and 2 each show a hydrostatic lifting device 1; 101, as it can be used, for example, for lifting ships. In principle, the lifting devices shown are 1; 101 but not limited to the lifting of ships, but they can in principle be used for lifting loads in which a break or sudden leakage of a working line must be handled safely. Of course, this applies in particular to applications in which a load is lifted via hydrostatic loads and the load drops when the working line breaks.

According to FIG. 1 the hydrostatic lifting device has a hydrostatic consumer 2, which has a hydraulic motor 4 with a constant displacement volume which can be operated in both directions of rotation. This drives by means of rotation of its drive shaft 6 a hoist 8 with a rack 10 at. Deviating from the embodiments shown, the Consumers 2 instead of the hydraulic motor 4, for example, have a hydraulic cylinder, in particular a Gleichgangss- or differential cylinder.

The hydraulic motor 4 is arranged in a closed circuit with a second hydraulic machine 12, which is designed as a hydraulic pump. Between the hydraulic pump 12 and the hydraulic motor 4, a hydrostatic valve assembly 14 is connected, on the one hand enables the pressure medium supply and on the other hand, the shut-off of the pressure medium supply of the consumer takes place in case of breakage of a working line or serious leakage. The valve assembly 14 has a first pressure port a and a second pressure port b, which is connected to a respective port of the hydraulic pump 12. On the consumer side, the valve assembly 14 has a first consumer port A and a second consumer port B, both of which are connected to a respective port of the hydraulic motor 4. The consumer connection A or B is fluidically connected to the hydraulic motor 4 via a first consumer line 16 or a second consumer line 18. The first consumer line 16 has a first tube section 20, the second consumer line 18 a second tube section 22. In particular, the tube sections 20, 22 are structurally particularly vulnerable to breakage.

To avoid that lifted by the rack 10 load, for example, a ship, in case of breakage of one of the tube sections 20, 22 sags and exits an excessive amount of pressure medium, the valve assembly 14 is provided. In the valve arrangement 14, the first pressure port a can be fluidically connected to the first consumer port A via a first shut-off valve 24, so that a first working flow path 26 can be formed. Accordingly, the second pressure port b is fluidically connectable via a second shut-off valve 28 to the second consumer port B, so that a second working flow path 30 can be formed. The Arbeitsströmungspfade 26, 30 with their check valves 24, 28 are configured identical in the embodiment shown. The check valve 24 or 28 has a valve body 32 and 34 which is acted upon in the opening direction with a pressure at the first pressure port a and the first load port A and second pressure port b and the second consumer port B. In the closing direction of the valve body 32 and 34 can be acted upon with a pending in a rear space 36 and 38 closing pressure, in particular acted upon. In the event of breakage of, for example, one of the hose sections 20, 22 or one of the consumer lines 16, 18, the closing pressure in the rear chambers is increased via the valve arrangement 14 such that both shut-off valves 24, 28 close.

To control the closing operation in case of breakage of the tube sections 20, 22 or consumer lines 16, 18, the following components are used: The return chambers 36, 38 are fluidly connected to one another via a control pressure line 40. In the latter opens a control pressure line 42 a. This in turn is connected to a closing pressure port S of a pressure selection valve 44. The pressure selection valve 44 is configured in the illustrated embodiment as a 3/3-way valve. It has in addition to the closing pressure connection S two inputs, a high pressure port D and a low pressure port T. It also has a central blocking position a, in which all ports S, D, T are shut off. Furthermore, it has a working position b, in which the low-pressure connection T is connected to the closing pressure connection S and the high-pressure connection D is shut off. As the third position, it has a "blocking position" c, in which the high pressure port D is connected to the closing pressure port S and the low pressure port T is shut off. In the direction of the "blocking position" c, a valve body of the pressure-selection valve 44 is loaded with the pressure equivalent of a spring 46. In the opposite direction of the working position b of the valve body with a pressure downstream of a fixed in the embodiment shown, restrictor 48 is acted upon. The low-pressure connection T is connected via a control pressure line 50 to a low-pressure or leakage connection T of the valve arrangement 14.

The first pressure port a or second pressure port b is connected via a line section 52 or 54 with an annular space of the first stop valve 24 and the second stop valve 28. The line section 52 or 54 is fluidly connected to an input 56 or 58 of a check valve assembly 60. The check valve arrangement 60 has the functionality of a shuttle valve or pressure selection valve, which signals the higher of the two at the inputs 50, 58 pending pressures of the line sections 52, 54 to an output 62 of the check valve assembly 60. The output 62 is connected via a control pressure line 52 to the high pressure port D of the pressure selection valve 44. Furthermore, the output 62 is connected to a pressure reducing valve 64 whose output 66 is in turn connected to the throttle point 48. In this direction sense downstream of the throttle point 48, a tap 68 is provided, via which the pressure downstream of the throttle point 48 can be tapped off and 44 to a control surface 70 of the valve body of the pressure selector valve. In this way, the pressure applied downstream of the throttle 48 acts on the control surface 70 and acts in the direction of the circuit of the working position b.

The tap 68 is connected via a control pressure line 72 to a first valve 74, whereby a first flow path 88 is formed. In addition, it is connected via the control pressure line 72 with a second valve 76, whereby a second flow path 89 is formed. The valves 74, 76 are fluidly connected in parallel to the control pressure line 72. They are preceded by a check valve 72 which opens to the respective valve 74, 76. The valves 74, 76 are each connected via a damping orifice 80 with the associated consumer port A and B respectively. Furthermore, they are identical to each other, designed as a 2/2-way switching valve.

In this case, the first valve 74 or the second valve 76 is loaded by the pressure at the first consumer port A and second consumer port B in a blocking position a. In the opposite direction, the respective valve 74, 76 loaded in a flow position b by means of a spring 82. In the respective flow position b, the control pressure line 72 is fluidically connected via the first valve 74 and the second valve 76 to the first consumer port A and the second consumer port B, respectively.

In addition, to the control pressure line 72, a comparatively small hydraulic accumulator 84, for damping of, in particular negative, pressure peaks in the control pressure line 72 is connected.

In working mode of the ship lifting device 1 lifts this example, the rack 10 a boat or ship. For this purpose, the hydraulic pump 12 promotes pressure medium via, for example, the first pressure connection a, the line section 52 to the annular space of the first stop valve 24. In the line section 52 so builds up a pressure. By contrast, in the line section 54 functioning as a return in this case, a comparatively low pressure prevails, since the load of the ship is effective only in the first working flow path 26 which effects the lifting. The second working flow path 30 is in this case the return and substantially free of load.

Accordingly, the check valve assembly 60 selects the pending at the input 56 of the higher pressure of the line sections 52, 54 and reports it to the output 62. About the pressure reducing valve 64, this pressure is reduced to a set on the pressure reducing valve 64 setpoint, which then at the output 66 of the pressure reducing valve 64 is pending.

At this time, the first check valve 24 is still closed. By further conveying the hydraulic pump 12, the pressure in the line section 52 continues to increase until the valve body 32 lifts off from its valve seat and releases the pressure medium connection to the first consumer port A. The load applied to the damping panel 80 load pressure causes the first valve 74 is held in its blocking position a. Also, the pressure in the second consumer line 18, although only acting as a return, is sufficiently large to load the second valve 76 in its blocking position a. In the illustrated embodiment, the return pressure in the second consumer line 18, and in the reverse direction of movement in the first consumer line 16, kept sufficiently high, so that in the operating mode, the valves 74, 76 always have their blocking position a. As a result, the pressure at the tap 68 remains high and the pressure selection valve 44 is loaded by the pressure acting on the control surface 70 pressure in its working position b.

Thus, the back spaces 36, 38 are connected via the closing pressure port S to the low pressure port T of the pressure selection valve 44 and have low pressure. In this way, the pressures present in the power sections 52 and 54 are sufficient to keep the two check valves 24, 28 open.

In this way, via the pressure medium volume flow in the first working flow path 26, the hydraulic motor 4 is set in rotation, which results in an elevation of the ship. The return flow volume via the second working flow path 30 then leads via the second consumer connection B, the second shut-off valve 28 and the second pressure connection b back to the hydraulic pump 12.

In the case of a break, for example, of the first tube section 20, a sudden pressure drop occurs at the first consumer port A. As a result, the valve body of the first valve 74 is loaded with a much lower pressure in the blocking position a, which causes the spring force of the spring 82 outweighs and sufficient to switch the first valve 74 in its open position b. In this case, the pressure set at the outlet 66 via the pressure reducing valve 64 is sufficient to cause a pressure medium volume flow via the throttle 48, the tap 68, the control pressure line 72, the check valve 78 to the first consumer port A, ie to form the first flow path 88.

Since a flow resistance of the throttle point 48 is greater than a flow resistance of the first valve 74, the pressure at the tap 68, downstream of the throttle point 48, decreases markedly. As a result, the control surface 70 of the pressure selection valve 44 but charged with much lower pressure, whereby the said valve 44 is moved by the spring force of the spring 46 in its "blocking position" c. Then, the closing pressure port S is connected to the high pressure port D, and the low pressure port T of the pressure selecting valve 44 is locked. As a consequence, in the control pressure line 42 and in the control pressure line 40, and thus in the return spaces 36 and 38, in each case the high pressure of the first line section 52 ascertained at the outlet 62 is present. This is sufficient to move both valve bodies 32, 34 in their blocking position, on their valve seat. At the moment, the pressure medium connection from the first pressure port a to the first consumer port A, and the pressure fluid connection of the second consumer port B toward the second pressure port b is respectively blocked. This is a caused due to the breakage of the tube portion 20 leakage is turned off.

To fix the lifted load (ship), the ship lifting device 1 has a blocking device 86, which retracts as soon as the previously discussed pressure loss at the first consumer port A is detected. The control of this mechanism is not shown.

In the previously described shut off the working flow paths 26, 30 via the valve assembly 14, there is only a very small leakage flow through the restrictor 48, the control pressure line 72 and due to the low pressure at the first load port A still in his Opening position b switched, the first valve 74. The volume flow through this first flow path 88 is very small.

In the reverse direction of movement, that is, when the high or load pressure of the ship to be lifted is effective in the second working flow path 30, for example, the second hose section 22 may break. In this case, the outlined blocking of the working flow paths 26, 30 takes place in an analogous manner as described in the preceding direction of rotation or direction of movement. However, the starting point of the shut-off is then the second valve 76 which opens on the second consumer port B due to the low pressure at the second consumer port B and which is switched to its open position b. In the following, the pressure downstream of the throttle 48 at the tap 68 drops again so much that the pressure selection valve 44, as already described, is switched to its "blocking position" c. This leads, as already mentioned, to act on the return chambers 36, 38 with the sufficiently high pressure of the high pressure port D and to close the check valves 24, 28th

A pressure equivalent of the spring 46 is in this and in the other embodiment shown at least 5 bar higher than the pressure equivalent of the springs 82 of the valves 74, 76th

In this and in the other embodiment shown, a pressure in the working flow path functioning as a return 26 and 30 is set to at least 15 bar.

A pressure equivalent of the springs 82 is about 8 bar in this and in the other embodiment shown. A pressure difference of return pressure and pressure equivalent of the springs 82, then about 7 bar, provides sufficient assurance that the valves 74, 76 are held in the normal operating mode with sufficient certainty in its blocking position a. In this way, an unwanted triggering of said shut-off of the check valves 24, 28 - which is supposed to take place only in the event of breakage in the region of one of the consumer lines 16, 18 and not due to operational pressure fluctuation - ensured.

Thus, in particular negative pressure peaks in the respective consumer line 16, 18 do not lead to unwanted triggering of the shut-off of the check valves 24, 28, the damping panels 80 are provided. Over them, the respective negative pressure peak, d. h., The drop in pressure at the respective consumer port A, B only reduced reduced to the valve body of the valves 74, 76 passed so that the valves 74, 76 respectively depend more reliably in their blocking position a.

Against pressure fluctuations at the tap 68, which could lead to the unintentional adjustment of the pressure selector valve 44 via the spring 46 in the "blocking position" c, the hydraulic accumulator 84 is provided.

The two hydraulic machines 4, 12 are each operable in four quadrant operation.

In order to switch the hydromotor 4 affected by fracture into a freewheeling mode, the valve arrangement 14 has a freewheel valve arrangement 90 FIG. 2 shows a ship lifting device with a plurality of hydraulic motors 4, 4a, 4b and driven by these racks 10, 10a, 10b. On a representation of the hydraulic pump has been omitted. In this case, all first pressure ports a are connected in common with a pressure port of the hydraulic pump and the second pressure ports b are connected in common with another pressure port of the hydraulic pump (not shown). The lifting device 101 has a hydrostatic valve arrangement 114, which has as a subassembly the valve arrangement 14 according to the first exemplary embodiment. This is, as already described, associated with the hydraulic motor 4 and the rack 10. Furthermore, the valve assembly 114 has two additional valve units 14a, 14b associated with the hydraulic motors 4a, 4b with the racks 10a, 10b driven by them. The valve units 14a, 14b correspond in many parts of the hydrostatic valve assembly 14, which is illustrated by the use of the same reference numerals. However, the valve units 14a, 14b lack the components for controlling the shutoff of the check valves 24, 28, such as the pressure selection valve 44, the throttle 48, the pressure reducing valve 64, and the associated control pressure lines. Instead, the said components of the hydrostatic valve arrangement 14 assume the function of controlling the shut-off of all consumer connections A, B, that is also for those of the valve units 14a, 14b.

For this purpose, the hydrostatic valve arrangement 114 has three additional control pressure lines. One of these is a pressure selection line 188 connecting the outlets 62 of the respective check valve assemblies 60. In this case, between the outputs 62 of the valve unit 14a, 14b and the pressure selection line 188 each one, to the pressure selection line 188 opening check valve 61 is connected. In this way, the highest of the pressures of all pressure ports a, b is reported to the output 62 of the hydrostatic valve assembly 14.

Furthermore, the hydrostatic valve assembly 114 according to FIG. 2 a closing pressure distribution line 190 which is connected to all the back spaces 36, 38 and to the closing pressure port S of the pressure selection valve 44. In this way, the closing pressure selected by the pressure selection valve 44 is present in all the return spaces 36, 38. The result is that all check valves close as soon as a significant pressure drop occurs at only one of the consumer connections A, B.

Furthermore, the hydrostatic valve assembly 114 according to FIG. 2 a connection line 192 through which all control pressure lines 72 of the hydrostatic valve assembly 14 and the hydrostatic valve units 14a, 14b are connected. In this way, the described functionality of the throttle 48 is effective in response of only one of the valves 74, 76 of the respective hydrostatic consumers 4, 4a, 4b. As a consequence, even the breakage of one of the tube sections 20, 22, 20a, 22a, 20b, 22b is sufficient to effect the shutoff valves 24, 28 previously described. This automatically stops all hydraulic motors 4, 4a, 4b, which makes sense, for example, if stopping just one of the hydraulic motors 4, 4a, 4b affected by the break would jeopardize the balance of the ship to be lifted or reduce the carrying capacity to endanger safety would.

The shut-off shown works, as shown, regardless of a working direction or direction of rotation of the hydraulic machines 4, 4a, 4b and 12th

A detection of the break by pressure drop downstream of the throttle body 48 is due to the very high flow resistance of the throttle body 48 in training the first 88 and / or second flow path 89 very reliable and thus independent of the actual working pressure medium volume flow.

Disclosed is a hydrostatic valve arrangement for supplying pressure medium to a hydrostatic consumer and for its secure, fluidic separation when a consumer-side working line breaks. For this purpose, the valve arrangement has a separate flow path, which is controlled at a sufficient, consumer-side pressure drop and its resulting pressure loss is a control signal via which a check valve for shutting off the consumer can be activated.

Also disclosed is a lifting device with at least one hydrostatic consumer and the valve arrangement, by means of which it can be supplied and shut off.

LIST OF REFERENCE NUMBERS

1; 101

Ship lifting device

2; 2a, 2b

hydrostatic consumer

4; 4a, 4b

hydraulic motor

6

drive shaft

8th

hoist

10

rack

12

hydraulic pump

14; 114

hydrostatic valve arrangement

14a, 14b

hydrostatic valve unit

16

first consumer line

18

second consumer line

20

first hose section

22

second hose section

24

first shut-off valve

26

first working flow path

28

second shut-off valve

30

second working flow path

32

first valve body

34

second valve body

36

first back room

38

second back room

40

Control pressure line

42

Control pressure line

44

Pressure selection valve

46

feather

48

restriction

50

Control pressure line

52

line section

54

line section

56, 58

entrance

60

Check valve assembly

61

check valve

62

output

64

Pressure reducing valve

66

output

68

tap

70

control surface

72

Control pressure line

74

first valve

76

second valve

78

check valve

80

damping orifice

82

feather

84

hydraulic accumulator

86; 86a, 86b

blocking device

88

first flow path

89

second flow path

90

Freewheel valve assembly

188

Pressure selection line

190

Closing pressure distribution line

192

connecting line

Claims (15)

Hydrostatic valve arrangement for supplying pressure medium to a hydrostatic consumer (2, 2a, 2b), in particular a lifting device (1; 101), and for blocking it in case of leakage or breakage, with a first working flow path (26) from a first pressure port (a) first shut-off valve (24) towards a first consumer port (A), wherein a valve body (32) of the first shut-off valve (24) in the closing direction is acted upon by a closing pressure, characterized in that a pressurized first flow path (88) via a throttle point (48 ) is provided to the first consumer port (A), and that the closing pressure in response to a pressure downstream of the throttle point (48) can be increased. Valve arrangement according to claim 1, wherein the first flow path (88) in response to a pressure or pressure gradient at the first load port (A), or a pressure dependent thereon, aufsteubar and otherwise controlled. Valve arrangement according to claim 1 or 2, wherein downstream of the throttle point (48) a first valve (74) is provided which has an open position (b) in which the throttle point (48) is fluidically connectable to the first working port (A), and having a closed position (a), in which the throttle point (48) from the first working port (A) is fluidically separated. Valve arrangement according to claim 3, wherein a valve body of the first valve (74) in the open position (b) with a predetermined pressure equivalent (82) and in the closed position (a) with the pressure at the first consumer port (A), or the pressure dependent thereon , is loaded. Valve arrangement according to claim 3 or 4, wherein in the first flow path (88) and outside the first working flow path (26), between the first valve (74) and the first load port (A), a damping orifice (80) or damping throttle is provided. Valve arrangement according to one of claims 3 to 5, with a hydraulic accumulator (84) for damping at least negative pressure peaks, which is connected downstream of the throttle point (48) with the first flow path (88). Valve arrangement according to one of the preceding claims, comprising a pressure selection valve (44) via which, depending on the pressure downstream of the throttle point (48), the increased closing pressure or a lower closing pressure is selectable. Valve arrangement according to claim 7, wherein the pressure selection valve (44) has a low pressure port (T) to which a Druckmittelsenke (T) is connectable, and wherein the pressure selection valve (44) has a high pressure port (D) connected to a pressure medium source (52, 54 ), and wherein the pressure-selection valve (44) has a closing pressure port (S) which is fluidically connectable to a control surface of the valve body (32) of the first shut-off valve (24) that acts in the closing direction. Valve arrangement according to claim 8, wherein the pressure selection valve (44) has a working position (b), in which it is loaded with the pressure downstream of the throttle point (48), and in which the closing pressure port (S) to the low pressure port (T) and connected from the High pressure port (D) is separated, and wherein the pressure-selection valve (44) has a "blocking position" (c), in which it is loaded with a predetermined pressure equivalent (46), and in which the closing pressure port (S) with the high-pressure port (D) connected and separated from the low pressure port (T). Valve arrangement according to claim 8 or 9, wherein the pressure medium source from the first pressure port (a) is formed, or wherein the pressure medium source is formed by that of the first (a) and second pressure port (b) having the higher pressure. Valve arrangement according to claim 3 or claim dependent thereon, wherein a pressure loss or flow resistance of the first valve (74) in its open position (b) is smaller than a pressure drop or flow resistance of the throttle point (48). Valve arrangement according to one of the preceding claims for pressure medium supply to a plurality of hydrostatic consumers (2, 2a, 2b) and their shut-off in case of leakage or breakage, each having a first working flow path (26), a first pressure port (a), a first shut-off valve (24), a first consumer connection (A), a Valve body (32) of the respective first check valve (24), which can be acted upon in the closing direction with the closing pressure. Valve arrangement according to claim 12 with a shuttle valve or pressure selector valve arrangement (60) for selecting a highest of the pressures of the first pressure connections (a) of the consumer as a pressure medium source. Valve arrangement according to claim 12 or 13, wherein the first flow paths (88) begin downstream of the throttle point (48) and are fluidly parallel. A hydrostatic lifting device (1; 101), in particular a ship lifting device, comprising at least one hydrostatic valve arrangement (14) designed according to one of the preceding claims and at least one hydrostatic consumer (2) which is fluidically connected to the first consumer connection (a) ,

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