Construction and arrangement of a dissipation device for suppressing vibrations in a rolling mill stand - Patents.com

Abstract

The invention relates to a dissipation device (1) for damping vibrations in a rolling mill stand for producing flat metal rolls, comprising a hydraulic inductor (21), a hydraulic resistor (22) and a hydraulic capacitor (23). The dissipation device (1) comprises an intermediate piece (20) with a first hydraulic interface (24) for direct hydro-mechanical connection to an adjustment cylinder (2) of the rolling mill stand. Via a second hydraulic interface (26), a valve block (6) with a control valve (11) for the adjustment cylinder (2) is directly hydro-mechanically connected to the dissipation device (2). The intermediate piece (20) is configured as a rigid block, to which the hydraulic resistor (22) and the hydraulic capacitor (23) are releasably fluidly connected. The hydraulic inductor (21) is preferably formed in the block as a tubular cavity and is fluidly connected to the first and second hydraulic interfaces (24, 26).

Description

[Technical field]

[0001] The invention relates to a dissipation device for damping vibrations in a rolling mill stand, which comprises as hydraulic components a hydraulic inductor, a hydraulic resistor and a hydraulic capacitor, the hydraulic capacitor and the hydraulic inductor each having a hydraulic volume for receiving a hydraulic fluid, the rolling mill stand being a rolling mill stand for producing flat metal rolled stock, in particular metal strip by hot rolling, the required rolling force being generated by means of at least one so-called adjusting cylinder acting on one of the rolls of the rolling mill stand, for example a backup roll. [Background technology]

[0002] A dissipative device is a device that is mechanically or fluidically coupled to a vibrating system and passively, i.e. without active control, draws vibration energy from the system, thereby damping or completely eliminating vibrations in the system. In contrast to actively controlled devices for vibration suppression, dissipative devices offer the advantage of a simpler mechanical structure, less susceptible to wear and allowing a more compact design due to the avoidance of moving parts.

[0003] The adjusting cylinder of the rolling mill stand is usually provided with a control valve, for example in the form of a servo valve for the hydraulic control circuit of the adjusting cylinder, by means of which the rolling force of the rolling mill stand is set, which can be connected to the adjusting cylinder via a hydraulic interface of the adjusting cylinder. The hydraulic interface is used for introducing the hydraulic fluid into the piston-side pressure chamber of the adjusting cylinder or discharging the hydraulic fluid from the piston-side pressure chamber. It may further be provided that the introduction of the hydraulic fluid into the ring-side pressure chamber of the adjusting cylinder or discharging the hydraulic fluid from the ring-side pressure chamber takes place via the hydraulic interface of the adjusting cylinder. This takes place, for example, in the case of a combined adjusting cylinder, through the same control valve, which also controls the inflow or outflow of the hydraulic fluid into the piston-side pressure chamber. In the case of a single-acting adjusting cylinder, the pressure of the hydraulic fluid in its ring-side pressure chamber is maintained at a constant pressure level, for example 30 bar, by means of a further pressure valve, and the hydraulic connection between the further pressure valve and the ring-side pressure chamber can likewise take place via the hydraulic interface of the adjusting cylinder. In both the case of single-acting and combined adjusting cylinders, the resulting rolling force is due to the pressure difference between the piston-side pressure chamber and the ring-side pressure chamber and can be set to the desired value by means of the provided control valve.

[0004] Typically, a so-called valve block is provided, into which the control valve and possibly a further pressure valve for the ring-side pressure chamber are integrated, which is releasably connected as a hydraulic unit to the hydraulic interface of the adjusting cylinder. A "releasable" hydraulic connection between two hydraulic components or hydraulic units is understood to mean a reversible mechanical-hydraulic connection, for example by means of a connecting means such as a screw connection, such that both connected components or units can be separated again without damage.

[0005] Rolling mills comprising several mill stands for producing flat rolled material (e.g. metal strip) may be configured as pure hot or cold mills or as combined cast-rolling plants (so-called ESP plants). In particular, in such mills, when rolling metal strip with a final thickness of 1 mm or less, many undesirable vibrations can occur, which, depending on the circumstances, can reduce the service life or duration of use of the parts of the rolling mill stands subjected to the vibrations, can have a negative effect on their production rate or can have a negative effect on the quality of the metal strip processed in the rolling mill stands concerned.

[0006] In particular, self-excited vibrations are often system specific, i.e. they inevitably arise at certain combinations of specific production parameters that are generally unknown, and therefore it is generally difficult or even impossible to predict the occurrence of such vibrations. Examples of production parameters that cause or promote such self-excited vibrations include high rolling speeds or large plate reductions in the rolling mill stands concerned. Self-excited vibrations in rolling mill stands for rolling metal strips often occur in the frequency range of 70 Hz to 130 Hz.

[0007] From EP 1 299 436 A1 it is known, in order to reduce pressure oscillations in a hydraulic system of a rolling mill stand of a cold or hot rolling mill, to determine the alternating component of the pressure oscillations and, based on the determined alternating component, to feed it to a control device which varies in real time the resonant volume of a dynamic vibration absorber connected to the hydraulic system in the form of a dissipation device. In this case, as a constructional solution, it is proposed to form the dynamic vibration absorber as a λ / 4 or Helmholtz resonator and to connect it to hydraulic valves and hydraulic cylinders of the hydraulic roll adjustment system. However, EP 1 299 436 A1 does not give any details regarding the construction and spatial arrangement of the dissipation device of the rolling mill stand.

[0008] From DE 10 200 03 133 A1 a hydraulic vibration damper in the form of a dissipation device is known, which has a frequency-dependent damping action tuned to the characteristic vibration frequencies of a rolling mill stand to be damped. According to a first embodiment, the vibration damper is directly fluidly connected to a hydraulic drive unit for the backup rolls of the rolling mill stand, but not to a control valve controlling the fluid pressure in the hydraulic drive unit. According to a second embodiment, the vibration damper is fluidly connected to the hydraulic drive unit and the associated control valve via a T-piece. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Austrian Patent No. 507087 [Patent Document 2] International Publication No. 2020 / 239589 Brochure Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is therefore to overcome the disadvantages of the dissipation devices known from the prior art and to describe a constructional solution which eliminates undesirable pressure fluctuations of characteristic vibration frequencies in the hydraulic circuit of the rolling mill stand as close as possible to the adjusting cylinder and allows for a construction which is as compact as possible, in which additional hydraulic lines and redirections are largely avoided. [Means for solving the problem]

[0011] According to the invention, this problem is solved by a dissipation device according to claim 1. Preferred embodiments of the dissipation device according to the invention are subject of the dependent claims.

[0012] The dissipation device according to the invention has a frequency-dependent damping effect, tuned to the characteristic vibration frequency of the rolling mill stand. This means that the design frequency of the dissipation device does not differ from the characteristic vibration frequency of the rolling mill stand by more than 10%. On the one hand, the damping effect is obtained by transferring part of the vibration energy from the hydraulic circuit to be damped to the dissipation device itself: in particular, the hydraulic capacitors and hydraulic inductors of the dissipation device receive part of the input vibration energy. This is also called the "tuned mass damper effect" of the dissipation device. In particular, the pressure fluctuations from the regulating cylinder are displaced to a large extent into the hydraulic volume of the dissipation device, where the pressure fluctuations may have a larger amplitude corresponding to their structure, but are not disturbing. Advantageously, the tuned mass damper effect is therefore used to spatially transfer a large part of the undesired pressure fluctuations from the system to be damped (the regulating cylinder) to the hydraulic volume of the dissipation device, without the need to actually reduce (dampen) these pressure fluctuations.

[0013] Furthermore, the tuned mass damping effect changes the vibration behavior of the damped system, the characteristic vibration frequency disappears, but two new vibration frequencies appear that are close to the original characteristic vibration frequency. However, the (undesirable, since theoretically unlimited) resonant behavior of these new vibration frequencies can be limited to a relatively small and in any case harmless resonant behavior by adding a dissipative element (for example in the form of a hydraulic resistor) to the dissipation device. In this case, only a small part of the vibration energy introduced into the dissipation device is broken down by the dissipative element and converted into thermal energy.

[0014] The resulting damping effect of the dissipation device as a whole depends on the one hand on its tuning mass-damper effect (by suitable design of the hydraulic capacitors and inductors of the dissipation device) and on the choice of hydraulic resistors. Furthermore, the damping effect of the dissipation device is essentially spread over a certain frequency band within the design frequency range of the dissipation device based on the action of its dissipation elements. The strength of the damping effect in relation to the frequency response curve is determined by the size of the hydraulic resistors. The tuning of the design frequency of the dissipation device to the characteristic vibration frequency of the dissipation device is brought about by the dimensional design of the corresponding structures of the hydraulic components of the dissipation device in relation to the further hydraulic components of the hydraulic network with which the dissipation device is fluidically connected, and is known for example from Prof. Dr. H. Murrenhoff, "Grundlagen der Fluidtechnik - Teil 1: Hydraulik" (1. Auflage 1997), in particular from the book points 2.3.1 to 2.3.4.

[0015] Furthermore, the dissipation device according to the invention comprises an intermediate piece which can be arranged fluidly between the adjusting cylinder of the rolling mill stand and a valve block with a control valve arranged on the adjusting cylinder. The intermediate piece comprises a first hydraulic interface in the above-mentioned sense for a direct hydro-mechanical connection of the dissipation device to the adjusting cylinder of the rolling mill stand. For this purpose, the first hydraulic interface of the intermediate piece comprises both a passage opening as a connection for a hydraulic line and any corresponding sealing means as well as a device for a mechanical connection means (such as a thread or a mating hole for a screw) by means of which the intermediate piece can be hydraulically coupled to the adjusting cylinder. This allows the passage of hydraulic fluid in both directions between the intermediate piece and the adjusting cylinder, and the intermediate piece can be mechanically connected to the adjusting cylinder. This also allows the intermediate piece to be mechanically fixed directly to the adjusting cylinder.

[0016] Within the scope of the present invention, a direct hydro-mechanical connection of a first hydraulic component or unit with a further hydraulic component or unit is understood to mean a direct fluidic and mechanical coupling of the first hydraulic component or unit with the further hydraulic component or unit without any intervening further fluidic or mechanical connecting elements, allowing a direct passage of liquid from the first hydraulic component or unit to the further hydraulic component or unit and vice versa.

[0017] The direct hydro-mechanical connection of the dissipation device according to the invention with the adjustment cylinder of the rolling mill stand is realized in that one of its hydraulic components, e.g. a hydraulic inductor, is directly fluidly coupled to the adjustment cylinder via a first hydraulic interface, the advantage of which is, on the one hand, the resulting compact design of the dissipation device, and, on the other hand, this avoids undesirable reflections of pressure waves and parasitic hydraulic inductances and capacitances, which would otherwise be caused by additional fluid connections (e.g. T-pieces, etc.), connecting lines or hydraulic redirections.

[0018] The intermediate piece of the dissipation device according to the invention additionally also has a second hydraulic interface for hydraulically connecting the valve block to the dissipation device, e.g. via one or more hydraulic connection lines. By means of the first and second hydraulic interfaces, the intermediate piece provides hydraulic ports or connection lines between the control valve (and possibly the pressure valve for the ring side pressure chamber of the adjusting cylinder) and the adjusting cylinder, so that the function of the valve block relative to the adjusting cylinder is not changed by the attachment of the intermediate piece to the adjusting cylinder.

[0019] By arranging the intermediate piece fluidically between the adjusting cylinder and the valve block, the dissipation device according to the invention can be arranged in a space-saving manner in the rolling mill stand. In addition, the dissipation device according to the invention, apart from the desired damping effect against undesired vibrations, exhibits a particularly neutral behavior with regard to the hydraulic behavior of the rolling mill stand, since the installation of the dissipation device only minimally changes the hydraulic line paths between the adjusting cylinder and the valve block with the control valve.

[0020] Furthermore, due to the presence of the first and second hydraulic interfaces, existing rolling mill stands can easily be retrofitted with a dissipation device without having to change the structure of the rolling mill stand itself. In this case, the valve block of the dissipation device with the control valve can be spatially separated from the adjustment cylinder and can be connected to the adjustment cylinder only via a corresponding hydraulic line. In some cases, it may be necessary to attach a fastening device of the intermediate piece of the dissipation device to the adjustment cylinder and / or to adapt existing hydraulic lines to a minimum.

[0021] It is further known that undesirable vibrations, for example caused by inherent vibrations in the roll sets of a rolling mill stand, generally lead to pressure fluctuations in the piston-side pressure chambers of the adjusting cylinders of the rolling mill stand, which pressure fluctuations are transmitted to the connected hydraulic circuit. By directly hydraulically connecting the dissipation device according to the invention to the adjusting cylinders, the undesirable pressure fluctuations in the associated hydraulic circuit are damped as close as possible to the source of the vibrations (the piston-side pressure chambers of the adjusting cylinders) and therefore do not propagate further into the connected hydraulic circuit. This avoids damage to the line elements of the hydraulic circuit or to the mechanical equipment of the associated rolling mill stand, such as bearings, gears, cardan shafts, roll surfaces, etc.

[0022] According to a further development of the dissipation device according to the invention, the second hydraulic interface is configured for a direct hydro-mechanical connection of the valve block to the dissipation device in the above-mentioned sense. This embodiment of the dissipation device according to the invention is particularly advantageously suitable as a space-saving retrofit for rolling mill stands, in which the valve block with the control valve arranged on the adjustment cylinder of the rolling mill stand is already fixed directly to the adjustment cylinder and is directly hydro-mechanically connected in the above-mentioned sense via the respective hydraulic interfaces of the adjustment cylinder and the valve block.

[0023] In this embodiment, the first hydraulic interface of the intermediate piece is configured identically to the hydraulic interface of the valve block and allows a direct hydro-mechanical connection between the intermediate piece or the dissipation device and the adjustment cylinder. The second hydraulic interface of the intermediate piece is also configured identically to the hydraulic interface of the adjustment cylinder and allows a direct hydro-mechanical connection between the valve block and the intermediate piece or the dissipation device. The intermediate piece thereby serves as a mechanical fixing seat for the valve block with the control valve.

[0024] According to a further preferred embodiment of the invention, the hydraulic resistor of the dissipation device is configured as an adjustable valve, which may for example be configured as a throttle valve, through which the cross section of the liquid flow is adjustable. Since the strength of the damping effect of the dissipation device is determined by its dissipation element, an optimal damping effect can be obtained by a suitable selection of the hydraulic resistor, which damping effect is almost independent of the vibration frequency within the frequency band covered by the damping effect and ensures the release of as much vibration energy as possible from the system to be damped.

[0025] The damping effect of a dissipation device depends primarily on its design frequency, but also to a certain extent on the peripheral hydraulic connection lines of the system to be damped, to which the dissipation device is connected when it is mounted on the rolling mill stand. It is therefore advantageous, especially during start-up, if a hydraulic resistor in the form of an adjustable valve can be set to a value corresponding to an optimum damping effect in the mounted state of the dissipation device.

[0026] The adjustable valve may be electrically adjustable, which allows the damping effect of the dissipation device in the installed state to be subsequently changed in an easy manner, for example by plant automation, to adapt to changed characteristic vibration frequencies of the rolling mill stand, which may be slightly influenced by, for example, a roll exchange or a change in production parameters such as the rolling speed, the sheet thickness or the set rolling force of the rolling mill stand.

[0027] Additionally, the adjustable valve may be fully closed, which allows the dissipation device to be turned off even when mounted on a rolling mill stand, since with the valve fully closed no vibration energy would be dissipated.

[0028] In a further preferred embodiment of the invention, the dissipation device has a design frequency in the range of 70 Hz to 130 Hz. The hydraulic register is then configured as a valve for a maximum flow rate of 300 liters of hydraulic fluid per minute and a maximum differential pressure of 5 bar. Unwanted vibrations of the rolling mill stand cause pressure fluctuations in the hydraulic circuit of the associated regulating cylinder, which are transferred to the hydro-mechanically directly connected dissipation device. The maximum differential pressure is the pressure difference that can occur between the inlet and outlet connections of the valve without damaging the valve. The hydraulic inductor is configured as a tubular cavity with a length of 600 mm to 800 mm and a maximum diameter of 50 mm to 65 mm. The hydraulic condenser of the dissipation device according to the invention is configured as a pressure vessel with a maximum pressure of 300 bar and a volume of 10 L to 20 L.

[0029] In this case, a "tubular cavity" is understood to be a cavity having a certain length along the longitudinal direction and a cross-sectional shape that is constant along the longitudinal direction. In this case, the cross-sectional shape extends perpendicular to the longitudinal direction and has a maximum diameter that corresponds to the diameter of a circumscribed circle around the cross-sectional shape. Furthermore, the length of the tubular cavity is at least twice its maximum diameter. The tubular cavity can thus be formed as a cylindrical bore in the simplest case, but in general as a prismatic cavity or a cavity whose cross section has any shape. A first end face and a second end face define the tubular cavity at the respective longitudinal ends.

[0030] The embodiment of the dissipation device according to the invention with the above-mentioned dimensions represents a good compromise between the damping effect of the dissipation device and its structural realization for damping the undesired vibrations of the rolling mill stand in the above-mentioned frequency range, since in order to obtain a good damping effect over the largest possible frequency range, it is better to select the volume of the hydraulic condenser as large as possible. However, if the pressure vessel of the hydraulic condenser exceeds a certain size, for space reasons it is no longer possible to mount the dissipation device on the adjustment cylinder of the rolling mill stand, and moreover the procurement costs of such a pressure vessel increase excessively with increasing volume.

[0031] Furthermore, the predominantly inductive nature of the tubular cavity is no longer obtainable with lengths below 600 mm, because the cross-sectional area of ​​the tubular cavity or the maximum diameter required for the abovementioned frequency range is so large that the tubular cavity may also have a component acting as a hydraulic capacitor. Finally, hydraulic inductors with lengths of the tubular cavity exceeding 800 mm are not realizable with a compact structure and would result in unfavorable mechanical loads on the connection between the dissipation device and the regulating cylinder.

[0032] According to a further preferred embodiment of the dissipation device according to the invention, the hydraulic condenser comprises a further pressure vessel which is hydro-mechanically connected directly to the hydraulic condenser in the sense defined above, said further pressure vessel comprising a clampable adjusting device by means of which the hydraulic volume of the further pressure vessel can be set to a value between 0% and 30% of the hydraulic volume of the hydraulic condenser.

[0033] The size of the hydraulic capacitor is proportional to its hydraulic volume. By directly hydro-mechanically connecting the further pressure vessel to the hydraulic capacitor of the dissipation device, its effective volume and therefore the value of the hydraulic capacitance are increased. This allows the frequency band of the damping action of the dissipation device and its design frequency, also in the mounted state, to be flexibly adapted to the vibration frequency of the rolling mill stand to be damped. The regulating device can, for example, have a piston displaceably mounted in the further pressure vessel, which piston is moved to the desired position via a further hydraulic regulating valve, thereby setting the hydraulic volume of the further pressure vessel.

[0034] The main property of the regulating device is its clampability, which means that the regulating device can be locked so that the hydraulic volume of the further pressure vessel does not change even in the case of a maximum expected pressure amplitude in the dissipation device or in its hydraulic capacitor. A clampable regulating device can for example be a piston with a piston rod displaceably mounted in the further pressure vessel and clampable in the desired displacement position of the piston by a clamping device.

[0035] In this case, the clamping device is preferably configured to hold the piston rod in the desired position without further energy supply, which means that no electrical or mechanical energy needs to be supplied to the clamping device in order to hold the piston rod in a set position, even if the axial load of the clamped piston rod remains constant or changes, in particular due to pressure waves in the dissipation device caused by undesirable vibration frequencies of the rolling mill stand.

[0036] For this purpose, the clamping device can comprise an energy-storing mechanical holding element which, upon the supply of mechanical energy, is displaced into an open position in which the piston rod is not clamped and is therefore freely displaceable, and which further dissipates the absorbed mechanical energy and thereby enters into a frictional connection with the piston rod, so that the piston rod is clamped in the desired position. The supply of mechanical energy or the release of the holding element can be effected, for example, by applying hydraulic pressure to the clamping device, which clamps the piston rod when the applied hydraulic pressure falls below a certain lower limit value.

[0037] The advantage of such a configuration of the clamping device lies in the fact that in order to adjust the frequency band of the damping or the design frequency of the dissipation device, it is only necessary to consume energy for a short time, and the clamping device can remain inactive most of the time, thereby ensuring that in the event of a lack of energy supply or hydraulic supply pressure to the associated rolling mill stand, the design frequency of the dissipation device or its damping will not change.

[0038] In a further preferred embodiment of the invention, the intermediate piece with the first and second hydraulic interfaces is formed as a rigid block, for example a metal block, to which the hydraulic register and the hydraulic capacitor of the dissipation device are releasably fluidly connected in the above-mentioned sense. Furthermore, the hydraulic inductor is fluidly connected to the hydraulic register or the hydraulic capacitor, so that the hydraulic inductor, the hydraulic register and the hydraulic capacitor of the dissipation device are fluidly connected in series with one another via the rigid block. This means that the hydraulic inductor, the hydraulic register and the hydraulic capacitor are fluidly connected to one another and arranged fluidly one behind the other.

[0039] Furthermore, the hydraulic inductor is formed in the intermediate piece as a tubular cavity. Furthermore, the tubular cavity is fluidly connected to the first and second hydraulic interfaces of the intermediate piece. In order to avoid or to minimize as much as possible undesirable reflections of pressure waves at the hydraulic inductor, the ratio of the cross-sectional area of ​​the tubular cavity of the hydraulic inductor in the rigid block to the cross-sectional area of ​​each of the fluid-passing openings of the first and second hydraulic interfaces preferably ranges between 4 and 1. In other words, the cross-sectional area of ​​the fluid-passing openings to the regulating cylinder or the valve block, respectively, is 25% to 100% of the cross-sectional area of ​​the hydraulic inductor in the rigid block.

[0040] Forming the intermediate piece as a rigid block allows for a particularly stable integration of the hydraulic components of the dissipation device, and a stable mechanical connection of the hydraulic capacitors and hydraulic resistors to the intermediate piece, for example via a screw connection. Furthermore, if the intermediate piece is formed as a rigid block, parasitic hydraulic capacitances or inductances within the dissipation device itself are largely avoided, since the individual hydraulic components are mechanically and hydraulically connected to one another in a compact manner, and no further fluid connection parts are required. This allows the desired design frequency of the dissipation device to be maintained with high precision.

[0041] Furthermore, forming the intermediate piece as a rigid block and connecting the hydraulic components in series allows a space-saving design of the dissipation device, which can be advantageously adapted to the space requirements available on the rolling mill stand. For example, the maximum longitudinal dimension of the intermediate piece, which extends in the direction of the tubular cavity for the hydraulic inductor and perpendicular thereto, can be twice (for example 3-5 times) the minimum longitudinal dimension extending between the first and second hydraulic interfaces for the adjusting cylinder or the control valve. As a result, a relatively small space is required between the control valve and the adjusting cylinder for mounting the dissipation device according to the invention on the rolling mill stand, while in the perpendicular direction thereto, the free volume generally present on the rolling mill stand can be advantageously utilized.

[0042] In a preferred embodiment of the dissipation device according to the invention, the hydraulic register is realized in the form of a so-called poppet or cartridge valve. Such a valve comprises an internal part through which the hydraulic fluid is passed. The internal part can be completely embedded (in the sense of being spatially insertable and connectable) in a further hydraulic part, for example the intermediate piece of the dissipation device according to the invention, so that the part of the cartridge valve remaining outside the further hydraulic part does not guide the hydraulic fluid and accommodates, for example, the actuator and / or the control electronics of the valve. This construction advantageously makes it possible to realize short hydraulic line paths through the hydraulic register and to avoid disruptive effects (such as, for example, the reflection of pressure waves inside the hydraulic register).

[0043] In the dissipation device, a flow of hydraulic fluid is passed through a cartridge valve, and the vibration energy of the system to be damped is dissipated by the cartridge valve. In this case, the cartridge valve is configured to redirect the flow of hydraulic fluid passing therethrough at a right angle and to fluidly connect a hydraulic inductor of the dissipation device with its hydraulic capacitor. In this case, the cartridge valve may be configured as an infinitely controllable proportional valve, the controllable opening position being 0% to 100% of a maximum opening position. Furthermore, the cartridge valve may be configured to report a set opening position. The set opening position of the proportional valve may correspond, for example, to a current position of a piston in the proportional valve. In this case, for example, the current position of the piston may be reported as a reference for the opening position of the proportional valve.

[0044] Cartridge valves of the above-mentioned kind offer the advantage that the flow of hydraulic fluid passing through them undergoes only one 90° change of direction. In contrast to this, in the case of so-called assembly valves, the flow of hydraulic fluid passing through them undergoes several changes of direction: once from the supply hydraulic line to be introduced into the assembly valve, then a 180° change of direction within the assembly valve itself, and finally a second change of direction in the direction of the hydraulic fluid flow when it is reintroduced into the hydraulic line. Such changes of direction are disadvantageous in the case of hydraulic components, since they can lead to undesirable reflections and turbulences of the hydraulic fluid flow.

[0045] Furthermore, the above-mentioned cartridge valve allows a compact mechanical construction of the dissipation device according to the invention, since the hydraulic fluid flow passing through it is redirected by 90°, and its hydraulic capacitor is arranged closer to the first hydraulic interface than when using conventional assembled valves, so that the first hydraulic interface of the dissipation device is subjected to less load during its installation, i.e., for example in the case of a direct hydraulic connection to the adjusting cylinder of a rolling mill stand.

[0046] According to a further preferred embodiment of the invention, the dissipation device comprises a cover cap which can be mechanically detached from the rigid block of the intermediate piece, which forms an end face of a tubular cavity in the intermediate piece forming the hydraulic inductor and thus defines the hydraulic inductor at one end. This construction allows a particularly precise dimensioning of the hydraulic inductance value, the tubular cavity being formed, for example, as a bore in the rigid block of the intermediate piece and sealed off with the cover cap. Furthermore, the cover cap can have a tubular insert which delimits the volume of the formed tubular cavity in a defined manner. This allows the hydraulic inductance to be set to a modified value even later, depending on the dimensions of the tubular insert.

[0047] The above-mentioned characteristics, features and advantages of the present invention, as well as the manner in which they are obtained, will become more clear and easier to understand in connection with the following description of an embodiment of the invention, which is given in more detail in conjunction with the drawings. [Brief description of the drawings]

[0048] [Figure 1] FIG. 1 is a hydraulic piping diagram of a valve block located directly on the adjustment cylinder of a rolling mill stand according to the prior art. [Diagram 2] FIG. 2 is a hydraulic piping diagram of a first embodiment of a dissipation device according to the present invention, which is arranged directly on the adjustment cylinder of a rolling mill stand. [Diagram 3] 3A to 3C are three diagrams showing the schematic structure and arrangement of the dissipation device according to the present invention shown in FIG. 2; [Figure 4] 3A to 3C are three diagrams showing the schematic structure and arrangement of the dissipation device according to the present invention shown in FIG. 2; [Diagram 5] 3A to 3C are three diagrams showing the schematic structure and arrangement of the dissipation device according to the present invention shown in FIG. 2; [Figure 6] FIG. 2 is a cross-sectional view along the XZ plane of the intermediate piece of the first embodiment of the dissipation device according to the present invention. [Figure 7] FIG. 4 shows a schematic diagram of a structure of an adjustable hydraulic capacitor of a dissipation device according to the present invention according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] FIG. 1 shows an adjusting cylinder 2, to which a valve block 6 with a control valve 11 and a pressure valve 12 is directly connected hydro-mechanically in the sense defined above, according to the prior art. The adjusting cylinder 2 has a cylinder housing 3 and a piston 4, which acts along a first longitudinal axis 5 of the piston 4, for example, on a backup roll of a rolling mill stand (not shown in FIG. 1). The adjusting cylinder 2 of FIG. 1 is exemplarily configured as a single-acting cylinder, whose piston-side pressure chamber 7 is connected via a first fluid line 13 to the control valve 11 and whose ring-side pressure chamber 8 is connected via a second fluid line 14 to the pressure valve 12. The first fluid line 13 and the second fluid line 14 are each fluid through-holes of the cylinder housing 3. Furthermore, the piston 4 of the adjusting cylinder 2 is sealed against the cylinder housing 3 by means of a sealing element 17, and the piston-side pressure chamber 7 is sealed against the ring-side pressure chamber 8 by means of a sealing element 18 surrounding the piston 4.

[0050] The control valve 11 and the pressure valve 12 are connected to further hydraulic lines via the valve block 6 (not shown in FIG. 1). To allow a compact construction of the valve block 6, the second fluid line 14 comprises a part guided along the first longitudinal axis 5 in the cylinder housing 3, a part on the outer surface of the cylinder housing 3 opening into a corresponding fluid interface of the pressure valve 12. Alternatively, there is also the possibility to fluidly connect the pressure valve 12 to the outer surface of the cylinder housing 3 at the level of the ring-side pressure chamber 8 via a directly guided connection 9 (not shown in FIG. 1). Vibrations in the rolling mill stand on which the adjusting cylinder 2 is mounted are transmitted primarily via the piston 4 of the adjusting cylinder 2 to the piston-side pressure chamber 7, causing corresponding pressure fluctuations 16 in the piston-side pressure chamber 7, which are transmitted undampened through the first fluid line 13 to the control valve 11.

[0051] FIG. 2 shows an exemplary adjusting cylinder 2 configured as a double-acting cylinder, in which a control valve 11 controls the inflow or outflow of hydraulic fluid to both the piston side pressure chamber 7 and the ring side pressure chamber 8.

[0052] The control valve 11 is arranged in a valve block 6 which is directly connected hydro-mechanically to the intermediate piece 20 of the dissipation device 1 according to the invention. For this purpose, the intermediate piece 20 has two fluid passage openings 33, 34 on the valve block side, corresponding to the piston side pressure chamber 7 and the ring side pressure chamber 8, respectively, which are mechanically connected to the intermediate piece 20 via a connecting means 29 (not shown in FIG. 2). The intermediate piece 20 itself is directly connected hydro-mechanically to the cylinder housing 3 of the adjusting cylinder 2. For this purpose, the intermediate piece 20 comprises on the cylinder side fluid passage openings 31, 32 to the first and second fluid lines 13, 14, respectively, which are mechanically connected to the cylinder housing 3 via a connecting means 30 (not shown in FIG. 2). The fluid passage openings 31, 32 on the cylinder side are part of the first hydraulic interface 24 of the intermediate piece 20, while the fluid passage openings 33, 34 on the valve block side form elements of its second hydraulic interface 26.

[0053] The fluid passage openings 32 and 34 corresponding to the ring side pressure chamber 8 are only fluidically connected to one another via a simple bore 36 in the intermediate piece. In contrast, the fluid passage openings 31 and 33 corresponding to the piston side pressure chamber 7 are fluidically connected to one another in the intermediate piece and to the hydraulic components of the dissipation device 1. This is symbolically shown in FIG. 2 by a branch line to the hydraulic capacitor 23 of the dissipation device 1. In other words, the intermediate piece 20 only forms a simple fluid connection between the ring side pressure chamber 8 of the regulating cylinder 2 and the control valve 11, whereas the piston side pressure chamber 7 and the control valve 11 are fluidically connected to one another and to the hydraulic components of the dissipation device 1 by the intermediate piece 20. The pressure fluctuations 16 in the piston side pressure chamber 7 due to the rolling mill stand are substantially damped by the dissipation device 1, so that the control valve 11 and the hydraulic lines or other hydraulic units connected thereto are at most exposed to significantly weakened pressure fluctuations 16'.

[0054] Figures 3, 4 and 5 respectively show cross sections along the YZ, XY and XZ planes of a schematic structure of a dissipation device 1 according to the invention according to a first embodiment, which is arranged on an adjustment cylinder 2 of a rolling mill stand as in Figure 2. The sizes of the individual parts shown in Figures 3 to 5 are not to scale and are used only to illustrate their arrangement. The relative orientation of the illustrated combination of the adjustment cylinder 2, the dissipation device 1 and the valve block 6 with respect to the Cartesian coordinate system of the likewise illustrated X-, Y- and Z-axes is the same in each of Figures 3 to 5.

[0055] The dissipation device 1 shown in Figures 3 to 5 comprises an intermediate piece 20 constructed as a rigid block, in which a hydraulic inductor 21 is formed in the form of a cylindrical bore along a second longitudinal axis 27. The cylindrical bore is fluidly connected via a fluid passage opening 33 to a control valve 11 mounted on the valve block 6 (not shown in Figures 3 to 5) and via a further fluid passage opening 31 to a first fluid line 13 of the regulating cylinder 2. Furthermore, the hydraulic inductor 21 is delimited at its ends close to the fluid passage openings 31 and 33 by a mechanically removable cover cap 28 and is fluidly connected at its opposite end to a hydraulic register 22.

[0056] The hydraulic register 22 is realized as a cartridge valve 22' configured to redirect the flow of hydraulic fluid passing therethrough at a right angle to the second longitudinal axis 27. Furthermore, the hydraulic register 22 is fluidly connected to a hydraulic capacitor 23, which is formed as a cylindrical fluid chamber for receiving hydraulic fluid and is fixed to the intermediate piece 20 in the direction of its cylinder axis at a right angle to the second longitudinal axis 27. The hydraulic capacitor 23 has a predetermined volume of 10 L to 20 L and is filled with hydraulic fluid while the dissipation device 1 is in operation. The hydraulic register 22 and the hydraulic capacitor 23 are each releasably fluidly connected to the intermediate piece 20. In the arrangement shown in Figures 3 to 5, the hydraulic inductor 21, the hydraulic register 22 and the hydraulic capacitor 23 are fluidly connected to each other in series.

[0057] Furthermore, the intermediate piece 20 of the illustrated embodiment is formed with a bore 36, which fluidly connects the second fluid line 14 of the adjusting cylinder 2 to the control valve 11 or pressure valve 12 (not shown in Figures 3 to 5) integrated in the valve block 6 via fluid passage openings 32 and 34. Furthermore, the intermediate piece 20 is provided with fitting holes 29 for connection means 30, such as screws (only shown in Figure 3 for clarity), by means of which the intermediate piece 20 can be mechanically fixed to the cylinder housing 3.

[0058] 6 shows a cross section of the intermediate piece 20 perpendicular to the hydraulic inductor 21 extending in the direction of the second longitudinal axis 27, which is connected to the fluid passage openings 31 and 33 via an obliquely extending bore 39 formed in the intermediate piece. The cylindrical bore forming the hydraulic inductor 21 along the second longitudinal axis 27 and the bore 36 extending in a plane perpendicular to said bore are formed in the intermediate piece 20 as interpenetrating bores, the bore 36 having a cross-sectional area perpendicular to its bore axis that is 25% to 100% of the cross-sectional area of ​​the hydraulic inductor 21. The bore 36 connecting the fluid passage openings 32 and 34 is formed in the intermediate piece 20 so as to extend obliquely parallel to the bore 39.

[0059] The intermediate piece 20 is formed with a mating hole 29 for receiving a screw 30 by means of which the intermediate piece 20 can be fixed to the cylinder housing 3 of the adjusting cylinder 2 (not shown in FIG. 6). Furthermore, the intermediate piece 20 has a threaded hole 25 which corresponds to the mating hole 29 for a further screw 30' in order to fix the valve block 6 (not shown in FIG. 6) to the intermediate piece 20. Furthermore, a holding device 35 in the form of an eyelet is attached to the intermediate piece 20, by means of which the dissipation device 1 can be positioned in the assembled state on the adjusting cylinder 2 of the rolling mill stand by means of a lifting device and connected to the adjusting cylinder 2 and to the valve block 6.

[0060] At the fluid passage openings 31 and 32, furthermore, recesses 38 for ring-shaped sealing means 37 are formed in the intermediate piece 20, which prevent the hydraulic fluid passing through the intermediate piece 20 from escaping when it enters the first and second fluid lines 13 and 14 of the adjusting cylinder 2. For the same purpose, at the fluid passage openings 33 and 34, ring-shaped sealing means 37 can be arranged between the intermediate piece 20 and the valve block 6 (this is not shown in FIG. 6). The fluid passage openings 31 and 32, together with the recesses 38 and the sealing means 37 and the mating hole 29, form the first hydraulic interface 24 of the dissipation device 1. Similarly, the fluid passage openings 33 and 34, together with the corresponding sealing means 37 and the threaded hole 25, form its second hydraulic interface 26.

[0061] The screw hole 25 has an offset 40 along the Z axis relative to the mating hole 29. Similarly, the fluid passage openings 33 and 34 on the valve block side have the same offset 40 along the Z axis relative to the corresponding passage openings 31 and 32 on the cylinder side. By thus arranging the screw 30 offset relative to the further screw 30' and the fluid passage openings 31 and 32 offset relative to the corresponding fluid passage openings 33 and 34, the dissipation device 1 according to the invention can be subsequently installed between the adjusting cylinder 2 and the valve block 6 hydraulically connected to the adjusting cylinder 2, without modifying the hydraulic interface of the adjusting cylinder 2 or the valve block 6.

[0062] FIG. 7 shows a cross-section of a dissipation device 1 according to the invention according to a second embodiment, in which a hydraulic capacitor 23 is configured to be adjustable and is fluidly connected in series with a hydraulic inductor 21 via a hydraulic resistor 22. The hydraulic resistor 22 is also configured as a cartridge valve 22' with an adjustable opening position 55, which is reported to the control electronics of the cartridge valve 22' through a corresponding electrical signal line (not shown in FIG. 7). In this case, the hydraulic capacitor 23 comprises a cylindrical fluid chamber 43 for receiving hydraulic fluid and has a further pressure vessel 41, which is directly connected hydro-mechanically to the cylindrical fluid chamber 43 via a third hydraulic interface 42 with a further fluid passage opening 44. In order to largely avoid undesired reflection of pressure waves at the fluid passage opening 44, its cross-sectional area is 25% to 100% of the axial cross-sectional area of ​​the cylindrical fluid chamber 43.

[0063] Furthermore, the hydraulic capacitor 23 has a clampable regulating device 45 which comprises a piston 46 with a piston rod 47 displaceably mounted in the further pressure vessel 41, a hydraulic clamping device 48 for clamping the piston rod 47, a hydraulic regulating valve 49 for moving the piston 46 and a hydraulic pressure valve 50 for opening the clamping device 48.

[0064] The clamping device 48 can be operated in a so-called "deactivated" state, in which the piston rod 47 is held by the clamping device 48 in a position in which no hydraulic or electrical energy is applied to the clamping device 48. In this case, the clamping force on the piston rod 47 is applied by an energy-storing mechanical retaining element. In the embodiment shown in Fig. 7, the mechanical retaining element is configured as a compressible conical seat 51, which is pressed by a compression spring 53 against the piston rod 47 by means of a complementary press-fit 52, thereby fixing the piston rod 47.

[0065] By operating the pressure valve 50, pressurized hydraulic fluid is supplied to the hydraulic chamber 54 opposite the compression spring 53, the press-fit part 52 is displaced against the compression spring 53, and the clamping of the conical seat 51 is thereby released. Furthermore, the displacement of the press-fit part 52 absorbs mechanical energy from the compression spring 53. By means of the hydraulic regulating valve 49, the piston 46 can then be moved to the desired position, and the hydraulic volume in the further pressure vessel 41 between the fluid passage opening 44 and the piston 46 can be set to a value between 0% and 30% of the hydraulic volume of the cylindrical fluid chamber 43. As soon as the piston 46 has reached the desired position, the pressure in the hydraulic chamber 54 can be reduced to a value below a lower limit value by deactivating the pressure valve 50, whereby the force of the compression spring 53 prevails, which presses the press-fit part 52 against the conical seat 51 based on the previously absorbed mechanical energy, which again locks the piston rod 47. [Explanation of symbols]

[0066] 1 Dissipation device 2 Adjustment cylinder 3 Cylinder housing 4 Piston 5 First Longitudinal Axis 6 Valve Block 7 Piston side pressure chamber 8 Ring side pressure chamber 9 Directly guided connections 11 Control valve 12 Pressure valve 13 First Fluid Line 14 Second Fluid Line 16, 16' Pressure Fluctuation 17 Sealing element 20 Intermediate Piece 21 Hydraulic Inductor 22 Hydraulic Resistor 22' Cartridge Valve 23 Hydraulic Condenser 24 First Hydraulic Interface 25 screw holes 26 Second Hydraulic Interface 27 Second Longitudinal Axis 28 Cover cap 29 Fitting hole 30, 30' Connection means, screw 31, 32, 33, 34 Fluid passage opening 35 Holding device 36 Bore 37 Sealing means 38 Recess 39 Bore 40 Offset 41 Further Pressure Vessels 42 3rd Hydraulic Interface 43 Cylindrical fluid chamber 44 Fluid passage opening 45 Clampable adjustment device 46 Piston 47 Piston rod 48 Clamping device 49 Regulating valve 50 Pressure valve 51 Cone Seat 52 Press-fit section 53 Compression spring 54 Hydraulic Room 55 Opening position

Claims

1. A dissipation device (1) for damping vibrations in a rolling mill stand for producing flat rolled metal stock, comprising: - the dissipation device (1) comprises a hydraulic inductor (21), a hydraulic resistor (22) and a hydraulic capacitor (23); the dissipation device (1) has a frequency-dependent damping action tuned to the characteristic vibration frequencies of the rolling mill stand; the dissipation device (1) comprises an intermediate piece (20) that is fluidly positionable between an adjustment cylinder (2) of said rolling stand and a valve block (6) that comprises a control valve (11) arranged in said adjustment cylinder (2), - said intermediate piece (20) has a first hydraulic interface (24) for directly hydro-mechanically connecting the dissipation device (1) to said adjusting cylinder (2); - said intermediate piece (20) having a second hydraulic interface (26) for hydraulically connecting said valve block (6) to the dissipation device (1).

2. The dissipation device (1) of claim 1, wherein the second hydraulic interface (26) is configured to directly hydro-mechanically connect the valve block (6) to the dissipation device (1).

3. 3. The dissipation device (1) according to claim 1 or 2, wherein the hydraulic resistor (22) is configured as an adjustable valve.

4. - the dissipation device (1) has a design frequency in the range of 70 Hz to 130 Hz, the hydraulic resistor (22) is configured as a valve corresponding to a maximum flow rate of 300 liters per minute and a maximum differential pressure of 5 bar; - the hydraulic inductor (21) is formed as a tubular cavity with a length of 600 mm to 800 mm and a maximum diameter of 50 mm to 65 mm; Dissipation device (1) according to any one of claims 1 to 3, wherein the hydraulic condenser (23) is formed as a pressure vessel with a maximum pressure of 300 bar and a volume of 10 to 20 L.

5. Dissipation device (1) according to any one of claims 1 to 4, wherein the hydraulic condenser (23) comprises a further pressure vessel (41) which is hydro-mechanically connected directly to the hydraulic condenser (23) and comprises a clampable adjusting device (45) by means of which the hydraulic volume of the further pressure vessel (41) can be set to a value between 0% and 30% of the hydraulic volume of the hydraulic condenser (23).

6. the intermediate piece (20) is formed as a rigid block to which the hydraulic resistor (22) and the hydraulic capacitor (23) are releasably and fluidly connected; - the hydraulic inductor (21) is fluidly connected to the hydraulic resistor (22) or to the hydraulic capacitor (23), such that the hydraulic inductor (21), the hydraulic resistor (22) and the hydraulic capacitor (23) are fluidly connected in series with each other; The dissipation device (1) according to any one of claims 1 to 5, wherein the hydraulic inductor (21) is formed in the intermediate piece (20) as a tubular cavity and is fluidly connected with a first hydraulic interface (24) and a second hydraulic interface (26).

7. 7. The dissipation device (1) of claim 6, wherein the hydraulic resistor (22) is a cartridge valve (22') configured to redirect the flow of hydraulic fluid passing therethrough at a right angle to fluidly connect the hydraulic inductor (21) with the hydraulic condenser (23).

8. 8. The dissipation device (1) according to claim 7, wherein the cartridge valve (22') is formed as an infinitely controllable proportional valve, the controllable opening position (55) being between 0% and 100% of a maximum opening position, and configured to report the set opening position (55).

9. 9. The dissipation device (1) according to any one of claims 6 to 8, comprising a mechanically removable cover cap (28) on the intermediate piece (20), said cover cap (28) delimiting the hydraulic inductor (21) at an end.

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