EP3244072B1 - Hydrostatic valve assembly and hydrostatic lifting device with the valve assembly - Google Patents

Description

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

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

In a ship lifting device, in particular those with rack and pinion systems, for example, several hydraulic motors connected in parallel are connected to the hydraulic pump or pumps via lines and, in particular, hoses for supplying pressure medium. In the event of a break in the line or hose, the undesirable and dangerous effect can occur that the load, the ship, sinks unexpectedly. This poses a significant risk that must be avoided. In addition, there is the negative effect of escaping pressure medium.

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

When the load is lifted, the pending pump pressure opens the check valve and releases the pressure medium 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 there is a lockable directional control valve with two additional switching positions for fast and slow lowering of the load. A back space of the check valve, which is otherwise loaded with load pressure, is relieved of pressure via the switch position for rapid lowering, so that pressure medium can flow from the floor space via the check valve into the tank. In the slow switch position, the non-return valve remains closed because its back space has the load pressure and the lowering only takes place slowly via the bypass line.

The disadvantage of this solution is that in the event of a break in the working line between the pressure medium source and the non-return valve, there is no shut-off of the consumer supply, but only the lowering of the load takes place slowly instead of quickly. Associated with this is constant emptying of the floor space, i.e. leakage, and that the load is not held in the event of a break.

This disadvantage is shown, for example, in the publication U.S. 4,353,286 countered solution shown. There a continuous casting plant with two differential cylinders for holding down a press roll is disclosed. The bottom spaces of the differential cylinders can be connected to a pressure medium source or a tank via a safety valve arrangement. A pressure-loaded check valve is arranged between the pressure medium source and the floor spaces. In the closing direction, this is permanently loaded with the pressure in the bottom space of the cylinder and a spring force. Alternatively, the rear space can be loaded with high pressure medium that is held in a hydraulic accumulator. A control of the pressurization of the pressure medium of the rear chamber takes place via a complex switching valve, which is pressurized with control pressure in a position in which the rear chamber is connected to the working line carrying the pump pressure. If this working line breaks, a resulting leakage flow can be detected via a volume flow detection unit and a signal can be sent to a switching valve to relieve a control pressure line via which the pressure selection valve is controlled to select the pressure in the rear chamber. If the working line breaks, the control pressure line is relieved, whereby the pressure selection valve connects the return space to the "emergency pressure medium source" of the hydraulic accumulator and thus the pressure acting in the return space closes of the check valve is maintained. Due to the fact that the pressure in the working line and opening on the check valve has dropped due to the rupture, the check valve closes.

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

The pamphlet US 2013 209 276 A1 shows a hydrostatic valve arrangement which is provided for supplying pressure medium to a hydrostatic consumer and for shutting it off in the event of a leak or breakage.

In contrast, the invention is based on the object of creating a hydrostatic valve arrangement for supplying pressure medium to at least one hydrostatic consumer, in particular a lifting device, and for shutting it off in the event of leakage or breakage, which is simple in terms of device or control technology. Another object is to create 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 patent claim 15.

Advantageous developments of the valve arrangement are described in 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 shutting it off in the event of a leak or breakage, has a first working flow path from a first pressure connection via a first shut-off valve to a first consumer connection of the valve arrangement. A valve body of the first shut-off valve can be acted upon, in particular acted upon, with a closing pressure in the closing direction. According to the invention, the valve arrangement has a pressurized first flow path, which via a throttle point to the first consumer connection is provided. The closing pressure can be increased as a function of a pressure downstream of the throttle point, in particular to a value at which the first shut-off valve shuts off.

A break in a line or a hose downstream of the first working connection leads to a pressure drop at the latter and, due to the pressurization of the first flow path, to a volume flow in the latter. Due to the throttling effect of the throttle point, the pressure downstream of the throttle point also drops, which then serves as a suitable and reliable signal for increasing the closing pressure sufficiently, up to and including the closing of the first shut-off valve.

According to the invention, 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 connection, via a second shut-off valve to a second consumer connection, wherein the closing pressure can be applied to a valve body of the second shut-off valve in the closing direction is. In order to provide the described shut-off functionality also for the break of a line connected to the second consumer connection, the valve arrangement has a pressurized second flow path via the throttle point to the second consumer connection.

The pressure connection or connections can be fluidically 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 opened as a function of a pressure or pressure gradient at the first consumer connection and is otherwise closed. In particular, the first flow path is closed above a predetermined pressure value at the first consumer connection and is only opened when the pressure drops below this value. The drop below the value is then the signal to open the first flow path and the formation of the pressure medium volume flow therein, and thus causes at least the first consumer connection to be shut off.

In a further development, the second flow path can be opened and otherwise closed depending on a pressure or pressure gradient at the second consumer connection.

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 opening and closing the first flow path. This has an open position in which the throttle connects to the first working connection fluidically connectable or connected, and a closed position in which the throttle is fluidically separated from the first working connection.

Of course, this type of development is also suitable if the second flow path is present, in that a second valve, in particular a 2/2-way switching valve, is provided downstream of the throttle and has an open position in which the throttle can be fluidically connected to the second working connection , and which has a closed position in which the throttle is fluidically separated from the second working connection.

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

In a further development, a valve body of the first valve is loaded into the open position with a predetermined pressure equivalent, in particular that of a spring, and into the closed position with the pressure present at the first consumer connection. If the pressure at the first consumer connection falls below the setpoint value of the predetermined pressure equivalent, the volume flow through the throttle point and ultimately the shut-off of at least the first shut-off valve is caused in this way with the simplest technical means (spring).

Here, too, this type of further development is available if the second flow path is present, in that a valve body of the second valve is loaded into the open position with a predetermined pressure equivalent, in particular that of a spring, and into the closed position with the pressure present at the second consumer connection.

In a further development, a damping orifice or damping throttle is provided in the first flow path and outside the first working flow path, between the first valve and the first consumer connection, to prevent accidental, negative pressure peaks / pressure drops at the first consumer connection, which are not caused by a break, but purely operationally related and are not permanent, attenuate. In this way, incorrect activation of the barrier can be prevented.

This development is also formed for designs with a second working flow path and flow path in that a damping orifice 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 connection.

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

In order to be able to change the closing pressure in a very targeted manner and thus to perform the shut-off reliably, a pressure selection valve is provided in a further development, via which the increased closing pressure or a lower closing pressure can be selected depending on 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. It also 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 can be fluidically connected to a control surface of the valve body of the first shut-off valve that is effective in the closing direction, or in the case of the development with a shut-off valve each for flow and return, the first and second shut-off valve.

In a further development, the pressure selection valve has a working position in which it is loaded with the pressure downstream of the throttle, and in which the closing pressure connection is connected to the low pressure connection and separated from the high pressure connection. 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 connection is connected to the high pressure connection and from the low pressure connection, so that the increased closing pressure on the control surface or surfaces of the Check valves is effective.

In one development, the pressure medium source is formed by the first pressure connection or by that one of the first and second pressure connections which has the higher pressure. In the second case, the valve arrangement preferably has a shuttle valve, in particular a check valve arrangement through which the higher of the two pressures can be selected. 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 kept at a defined value. The pressure reducing valve or the pressure regulating valve is preferably connected upstream of the throttle.

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

So that the pressure downstream of the throttle point drops safely and sufficiently if the pressure at the first or second consumer connection drops in the event of a break, a respective pressure loss or flow resistance of the first or the first and second valve in the mentioned open position is smaller in a development , as a pressure loss or flow resistance of the throttle point. For this purpose, an opening cross section of the first or of the first and the second valve can be larger than that of the throttle point.

In a further development, the valve arrangement has at least one first working flow path, a first pressure port, a first shut-off valve, a first load port, and a valve body of the respective first shut-off valve, which is in each case at least one first working flow path, a first pressure connection, and a valve body of the respective first shut-off valve for each consumer Closing direction can be acted upon by the closing pressure.

In order to be able to provide the throttle point with a pressure medium source with the highest possible pressure, the valve arrangement in a development has a shuttle valve arrangement for selecting a highest one of the pressures of the first pressure connections, or the first and second pressure connections, of the consumers.

In a further development with several consumers, the first flow paths or the first and the second flow paths are fluidically parallel downstream of the throttle point. In this way, only one throttle point is necessary to detect the pressure medium volume flow caused by the break 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 shut-off valves, the valve arrangement has a collecting line via which the control surfaces of the shut-off valves (first and / or second) that 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 exemplary embodiments of a hydrostatic lifting device according to the invention, each with a valve arrangement according to the invention, are shown in the drawings. The invention will now be explained in more detail using the two figures of these drawings.

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

Figure 1

a hydrostatic lifting device with a consumer and a hydrostatic valve arrangement for supplying pressure medium and isolating the consumer in the event of breakage or leakage, according to a first exemplary embodiment, and

Figure 2

a hydrostatic lifting device with several consumers and a hydrostatic valve arrangement for supplying pressure medium and isolating the consumers in the event of breakage or leakage, according to a second embodiment.

The Figures 1 and 2 each show a hydrostatic lifting device 1; 101, such as can be used for lifting ships, for example. In principle, the lifting devices 1; 101 does not, however, restrict the lifting of ships; in principle, they can be used to lift loads where a breakage or sudden leakage of a working line must be safely handled. This naturally applies in particular to applications in which a load is lifted via hydrostatic consumers and the load threatens to drop if the working line breaks.

According to Figure 1 the hydrostatic lifting device has a hydrostatic consumer 2, which has a hydraulic motor 4 which can be operated in both directions of rotation and has a constant displacement volume. This drives a lifting mechanism 8 with a rack 10 by rotating its drive shaft 6. Notwithstanding the exemplary embodiments shown, the Consumer 2 instead of the hydraulic motor 4, for example, have a hydraulic cylinder, in particular a synchronous 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. A hydrostatic valve arrangement 14 is connected between the hydraulic pump 12 and the hydraulic motor 4, which on the one hand enables the supply of pressure medium and, on the other hand, shuts off the pressure medium supply to the consumer in the event of a break in a working line or serious leakage. The valve arrangement 14 has a first pressure connection a and a second pressure connection b, which is connected to a respective connection of the hydraulic pump 12. On the consumer side, the valve arrangement 14 has a first consumer connection A and a second consumer connection B, both of which are connected to a respective connection 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 hose section 20, the second consumer line 18 has a second hose section 22. In particular, the hose sections 20, 22 are particularly vulnerable to breakage due to their construction.

In order to prevent the load lifted by the rack 10, for example a ship, from sagging if one of the hose sections 20, 22 breaks and too large a quantity of pressure medium escapes, the valve arrangement 14 is provided. In the valve arrangement 14, the first pressure connection a can be fluidically connected to the first consumer connection A via a first shut-off valve 24, so that a first working flow path 26 can be formed. Correspondingly, the second pressure connection b can be fluidically connected to the second consumer connection B via a second shut-off valve 28, so that a second working flow path 30 can be formed. The working flow paths 26, 30 with their check valves 24, 28 are of identical design in the exemplary embodiment shown. The check valve 24 or 28 has a valve body 32 or 34, which is acted upon in the opening direction by a pressure at the first pressure port a and first consumer port A or second pressure port b and second consumer port B. In the closing direction, the valve body 32 or 34 can be acted upon, in particular acted upon, by a closing pressure present in a rear chamber 36 or 38. If, for example, one of the hose sections 20, 22 or one of the consumer lines 16, 18 breaks, the valve arrangement 14 increases the closing pressure in the rear spaces in such a way that both shut-off valves 24, 28 close.

The following components are used to control the closing process when the hose sections 20, 22 or consumer lines 16, 18 break: The rear spaces 36, 38 are fluidically connected to one another via a control pressure line 40. A control pressure line 42 opens into the latter. This in turn is connected to a closing pressure connection S of a pressure selection valve 44. The pressure selection valve 44 is designed as a 3/3-way valve in the exemplary embodiment shown. In addition to the closing pressure connection S, it has two inlets, a high pressure connection D and a low pressure connection T. It also has a central locking position a, in which all connections S, D, T are shut off. It also 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 a third position, it has a "blocking position" c, in which the high pressure connection D is connected to the closing pressure connection S and the low pressure connection T is blocked. A valve body of the pressure selection valve 44 is loaded with the pressure equivalent of a spring 46 in the direction of the “blocking position” c. In the opposite direction of the working position b, the valve body is subjected to a pressure downstream of a throttle point 48 which is fixed in the exemplary embodiment shown. The low-pressure connection T is connected to a low-pressure or leakage connection T of the valve arrangement 14 via a control pressure line 50.

The first pressure connection a and second pressure connection b are connected to an annular space of the first shut-off valve 24 or second shut-off valve 28 via a line section 52 or 54, respectively. The line section 52 or 54 is fluidically connected to an inlet 56 or 58 of a check valve arrangement 60. The check valve arrangement 60 has the functionality of a shuttle valve or pressure selection valve, which reports the higher of the two pressures of the line sections 52, 54 present at the inputs 50, 58 to an output 62 of the check valve arrangement 60. The output 62 is connected to the high pressure connection D of the pressure selection valve 44 via a control pressure line 52. Furthermore, the output 62 is connected to a pressure reducing valve 64, the output 66 of which is in turn connected to the throttle point 48. In this sense of direction, a tap 68 is provided downstream of the throttle point 48, via which the pressure can be tapped off downstream of the throttle point 48 and reported to a control surface 70 of the valve body of the pressure selection valve 44. In this way, the pressure present downstream of the throttle 48 acts on the control surface 70 and acts in the direction of switching to the working position b.

The tap 68 is connected to a first valve 74 via a control pressure line 72, whereby a first flow path 88 is formed. In addition, it is connected to a second valve 76 via the control pressure line 72, whereby a second flow path 89 is formed. The valves 74, 76 are fluidically connected in parallel to the control pressure line 72. Upstream of them is a check valve 72 which opens towards the respective valve 74, 76. The valves 74, 76 are each connected to the associated consumer connection A or B via a damping orifice 80. Furthermore, they are identical to each other, designed as a 2/2-way switching valve.

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

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

When the ship lifting device 1 is in operation, it lifts a boat or ship, for example via the rack 10. For this purpose, the hydraulic pump 12 conveys pressure medium via, for example, the first pressure connection a, the line section 52 to the annular space of the first shut-off valve 24. A pressure thus builds up in the line section 52. In the line section 54, which functions as a return in this case, on the other hand, a comparatively low pressure is present, since the load of the ship is only effective in the first working flow path 26, which causes the uplift. In this case, the second working flow path 30 is the return line and is essentially load-free.

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

At this point in time, the first shut-off valve 24 is still closed. By further conveying the hydraulic pump 12, the pressure in the line section 52 continues to rise until the valve body 32 lifts out of its valve seat and releases the pressure medium connection to the first consumer connection A. The load pressure applied to the damping diaphragm 80 has the effect that the first valve 74 is held in its blocking position a. The pressure in the second consumer line 18, although this only functions as a return, is sufficiently high to load the second valve 76 into its blocking position a. In the exemplary embodiment shown, the return pressure in the second consumer line 18, and in the opposite direction of movement in the first consumer line 16, is kept sufficiently high so that the valves 74, 76 always have their blocking position a during operation. As a result, the pressure at the tap 68 remains high and the pressure selection valve 44 is loaded into its working position b by the pressure on the control surface 70.

The rear spaces 36, 38 are thus connected to the low-pressure connection T of the pressure selection valve 44 via the closing pressure connection S and have low pressure. In this way, the pressures present in the power sections 52 and 54 are sufficient to keep the two shut-off valves 24, 28 open.

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

In the event of a break, for example, of the first hose section 20, a sudden drop in pressure occurs at the first consumer connection 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 means that the spring force of the spring 82 predominates and is sufficient to switch the first valve 74 into its open position b. In this case, the pressure at the outlet 66 set via the pressure reducing valve 64 is sufficient to effect 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, i.e. 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, drops noticeably. As a result, the control surface 70 of the pressure selection valve 44 is loaded with much less pressure, whereby the said valve 44 is moved into its "blocking position" c via the spring force of the spring 46. Then the closing pressure connection S is connected to the high pressure connection D and the low pressure connection T of the pressure selection valve 44 is blocked. As a consequence, the high pressure of the first line section 52 determined at the outlet 62 is present in the control pressure line 42 and in the control pressure line 40, and thus in the rear spaces 36 and 38. This is sufficient to move both valve bodies 32, 34 into their blocking position on their valve seat. At that moment, the pressure medium connection from the first pressure connection a to the first consumer connection A, and the pressure medium connection from the second consumer connection B to the second pressure connection b, are blocked. A leakage caused by the breakage of the hose section 20 is thus eliminated.

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 connection A is detected. The control of this mechanism is not shown.

In the previously described blocking of the working flow paths 26, 30 via the valve arrangement 14, following the blocking there is only a very small leakage flow via the throttle point 48, the control pressure line 72 and that due to the low pressure at the first consumer port A, as before First valve 74 switched to open position b. The volume flow via this first flow path 88 is very small.

If the direction of movement is reversed, that is, when the high or load pressure of the ship to be lifted is effective in the second working flow path 30, the second hose section 22 can break, for example. In this case, the outlined blocking of the working flow paths 26, 30 takes place in a manner analogous to that described for the previous direction of rotation or direction of movement. However, the second valve 76, which opens due to the low pressure at the second consumer connection B and which is switched to its open position b, then serves as the starting point for the shut-off. In the following, the pressure downstream of the throttle 48 at the tap 68 drops so sharply that the pressure selection valve 44, as already described, is switched into its "blocking position" c. As already mentioned, this leads to the pressurization of the rear spaces 36, 38 with the sufficiently high pressure of the high-pressure connection D and the closing of the shut-off valves 24, 28.

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

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

A pressure equivalent of the springs 82 is approximately 8 bar in this and in the other embodiment shown. A pressure difference between the return pressure and the pressure equivalent of the springs 82, then approximately 7 bar, provides sufficient security that the valves 74, 76 are held in their blocking position a with sufficient security during regular working operation. In this way, an unintentional triggering of the shut-off process of the shut-off valves 24, 28 - which should only take place in the event of a break in the area of one of the consumer lines 16, 18 and not due to operational pressure fluctuations - is ensured.

So that, in particular, negative pressure peaks in the respective consumer line 16, 18 do not lead to the inadvertent triggering of the shut-off process of the shut-off valves 24, 28, the damping diaphragms 80 are provided. The respective negative pressure peak, i. That is, the drop in pressure at the respective consumer connection A, B is only passed on to a reduced extent to the valve body of the valves 74, 76, so that the valves 74, 76 each remain in their blocking position a more reliably.

The hydraulic accumulator 84 is provided against pressure fluctuations at the tap 68, which could, for example, lead to the unintentional adjustment of the pressure selection valve 44 via the spring 46 into the "blocking position" c.

The two hydraulic machines 4, 12 can each be operated in four quadrant operation.

In order to switch the hydraulic motor 4 affected by the break into a free-wheeling mode, the valve arrangement 14 has a free-wheeling valve arrangement 90 Figure 2 shows a ship lifting device with several hydraulic motors 4, 4a, 4b and racks 10, 10a, 10b driven by these. The hydraulic pump is not shown. All first pressure connections a are connected together with one pressure connection of the hydraulic pump and the second pressure connections b are connected together with another pressure connection of the hydraulic pump (not shown). The lifting device 101 has a hydrostatic valve arrangement 114, which has the valve arrangement 14 according to the first exemplary embodiment as a sub-unit. As already described, this is assigned to the hydraulic motor 4 and the rack 10. Furthermore, the valve arrangement 114 has two additional valve units 14a, 14b, which are assigned to the hydraulic motors 4a, 4b with the toothed racks 10a, 10b driven by them. The valve units 14a, 14b largely correspond to the hydrostatic valve arrangement 14, which is illustrated by the use of the same reference symbols. However, the valve units 14a, 14b each lack the components for controlling the shut-off of the shut-off 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 named components of the hydrostatic valve arrangement 14 take on the function of controlling the shut-off of all consumer connections A, B, that is to say 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 which connects the outlets 62 of the respective check valve assemblies 60. A check valve 61, which opens towards the pressure selection line 188, is connected between the outputs 62 of the valve unit 14a, 14b and the pressure selection line 188. In this way, the highest of the pressures of all pressure connections a, b is reported to the output 62 of the hydrostatic valve arrangement 14.

Furthermore, the hydrostatic valve arrangement 114 according to FIG Figure 2 a closing pressure distributor line 190 which is connected to all of the rear spaces 36, 38 and to the closing pressure connection S of the pressure selection valve 44. In this way, the closing pressure selected by the pressure selection valve 44 is available in all rear spaces 36, 38. The result is that all shut-off valves close as soon as a significant pressure drop occurs at only one of the consumer connections A, B.

Furthermore, the hydrostatic valve arrangement 114 according to FIG Figure 2 a connecting line 192, via which all control pressure lines 72 of the hydrostatic valve arrangement 14 and the hydrostatic valve units 14a, 14b are connected. In this way, the described functionality of the throttle 48 is effective when only one of the valves 74, 76 of the respective hydrostatic consumers 4, 4a, 4b is triggered. As a consequence, the rupture of one of the hose sections 20, 22, 20a, 22a, 20b, 22b is sufficient to effect the shut-off of the shut-off valves 24, 28 described above. This means that all hydraulic motors 4, 4a, 4b are automatically stopped, which is useful, for example, if stopping only one of the hydraulic motors 4, 4a, 4b that is affected by the break would endanger the balance of the ship to be lifted or the load-bearing capacity would decrease in a safety-threatening manner would.

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

A detection of the rupture due to a pressure drop downstream of the throttle point 48 takes place very reliably due to the very high flow resistance of the throttle point 48 when the first 88 and / or second flow path 89 is formed 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 safe, fluidic separation in the event of a break in a working line on the consumer side. For this purpose, the valve arrangement has a separate flow path which is opened when there is sufficient pressure drop on the consumer side and the resulting pressure loss is a control signal via which a shut-off valve can be activated to shut off the consumer.

A lifting device with at least one hydrostatic consumer and the valve arrangement via which it can be supplied and shut off is also disclosed.

List of reference symbols

1; 101

Ship lifting device

2; 2a, 2b

hydrostatic consumer

4; 4a, 4b

Hydraulic motor

6th

Drive shaft

8th

Hoist

10

Rack

12

Hydraulic pump

14; 114

hydrostatic valve assembly

14a, 14b

hydrostatic valve unit

16

first consumer line

18th

second consumer line

20th

first hose section

22nd

second hose section

24

first shut-off valve

26th

first working flow path

28

second shut-off valve

30th

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

Throttling point

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

Attenuator

82

feather

84

Hydraulic accumulator

86; 86a, 86b

Blocking device

88

first flow path

89

second flow path

90

One-way valve assembly

188

Print selection line

190

Closing pressure distribution line

192

Connecting line

Claims (15)

1. Hydrostatic valve arrangement for the pressure medium supply of a hydrostatic consumer (2; 2, 2a, 2b), in particular of a lifting device (1; 101), and for shutting it off in the case of leakage or fracture, with a first working flow path (26) from a first pressure connector (a) via a first shut-off valve (24) towards a first consumer connector (A), it being possible for a valve body (32) of the first shut-off valve (24) to be loaded with a closing pressure in the closing direction, a pressurized first flow path (88) being provided via a throttle point (48) towards the first consumer connector (A), and it being possible for the closing pressure to be increased in a manner which is dependent on a pressure downstream of the throttle point (48), characterized by a second working flow path (30) from a second pressure connector (b) via a second shut-off valve (28) towards a second consumer connector (B), it being possible for a valve body (34) of the second shut-off valve (28) to be loaded with the closing pressure in the closing direction, and a pressurized second flow path (89) being provided via the throttle point (48) towards the second consumer connector (B).
2. Valve arrangement according to Claim 1, it being possible for the first flow path (88) to be opened in a manner which is dependent on a pressure or pressure gradient at the first consumer connector (A) or a pressure which is dependent thereon, and the said first flow path (88) otherwise being closed.
3. Valve arrangement according to Claim 1 or 2, a first valve (74) being provided downstream of the throttle point (48), which first valve (74) has an open position (b), in which the throttle point (48) can be connected fluidically to the first working connector (A), and which first valve (74) has a closed position (a), in which the throttle point (48) is disconnected fluidically from the first working connector (A).
4. Valve arrangement according to Claim 3, a valve body of the first valve (74) being loaded into the open position (b) with a predefined pressure equivalent (82) and into the closed position (a) with the pressure which prevails at the first consumer connector (A), or with the pressure which is dependent thereon.
5. Valve arrangement according to Claim 3 or 4, a damping orifice plate (80) or damping constriction being provided in the first flow path (88) and outside the first working flow path (26), between the first valve (74) and the first consumer connector (A).
6. Valve arrangement according to one of Claims 3 to 5, with a hydraulic accumulator (84) for damping at least negative pressure peaks, which hydraulic accumulator (84) is connected downstream of the throttle point (48) to the first flow path (88).
7. Valve arrangement according to one of the preceding claims, with a pressure selector valve (44), via which the increased closing pressure or a low closing pressure can be selected in a manner which is dependent on the pressure downstream of the throttle point (48).
8. Valve arrangement according to Claim 7, the pressure selector valve (44) having a low pressure connector (T), to which a pressure medium sink (T) can be connected, and the pressure selector valve (44) having a high pressure connector (D) which can be connected to a pressure medium source (52, 54), and the pressure selector valve (44) having a closing pressure connector (S) which can be connected fluidically to a control face of the valve body (32) of the first shut-off valve (24), which control face acts in the closing direction.
9. Valve arrangement according to Claim 8, the pressure selector valve (44) having a working position (b), into which it is loaded with the pressure downstream of the throttle point (48), and in which the closing pressure connector (S) is connected to the low pressure connector (T) and is disconnected from the high pressure connector (D), and the pressure selector valve (44) having a "shut-off position" (c), into which it is loaded with a predefined pressure equivalent (46), and in which the closing pressure connector (S) is connected to the high pressure connector (D) and is disconnected from the low pressure connector (T).
10. Valve arrangement according to Claim 8 or 9, the pressure medium source being formed by the first pressure connector (a), or the pressure medium source being formed by that one of the first (a) and second pressure connector (b) which is at the higher pressure.
11. Valve arrangement according to Claim 3 or a claim which refers back to it, a pressure loss or flow resistance of the first valve (74) in its open position (b) being smaller than a pressure loss or flow resistance of the throttle point (48).
12. Valve arrangement according to one of the preceding claims for the pressure medium supply of a plurality of hydrostatic consumers (2, 2a, 2b) and for shutting them off in the case of leakage or fracture, in each case with a first working flow path (26), a first pressure connector (a), a first shut-off valve (24), a first consumer connector (A), and a valve body (32) of the respective first shut-off valve (24) which can be loaded with the closing pressure in the closing direction.
13. Valve arrangement according to Claim 12 with a shuttle valve arrangement or pressure selector valve arrangement (60) for the selection of a highest one of the pressures of the first pressure connectors (a) of the consumers as pressure medium source.
14. Valve arrangement according to Claim 12 or 13, the first flow paths (88) beginning downstream of the throttle point (48) and being in parallel fluidically.
15. Hydrostatic lifting apparatus (1; 101), in particular ship lift device, with at least one hydrostatic valve arrangement (14) which is configured according to one of the preceding claims, and with at least one hydrostatic consumer (2) which is connected fluidically to the first consumer connector (a).

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