Stopper holder

Abstract

The invention relates to a stopper holder (1) for securing a stopper (2) for regulating the outflow rate from a bottom discharge opening (29) of a metallurgical casting vessel, wherein the stopper holder (1) has a stopper rod (3), and the lower face of the stopper rod (3), said lower face facing the casting vessel during use, has a stopper contact surface (5) for resting on a stopper (2). According to the invention, the stopper holder (1) has a gripper (6), which is provided on the stopper rod (3), for securing the stopper (2). The invention further relates to an assembly comprising a stopper holder (1) and a stopper (2) and to a method for positioning a stopper (2) in a stopper holder (1).

Description

[0001] Plug holder

[0002] The invention relates to a plug holder for a plug of a foundry plant, in particular for a plug for regulating the outflow velocity from a bottom pouring opening of a metallurgical vessel.

[0003] For pouring liquid metals and metal alloys, pouring vessels such as an intermediate vessel or a distribution trough are used in which the molten metal is collected before it flows into a mold via a bottom pouring opening.

[0004] To open or close the bottom pouring opening, a plug made of a refractory material is usually provided, which is held above the bottom pouring opening. The flow rate from the bottom pouring opening can be regulated during the pouring process by varying the distance between the bottom pouring opening and the plug held above it. Furthermore, the bottom pouring opening can be completely closed to fill the pouring vessel, after the pouring process, or in emergency situations.

[0005] The plug is held above the bottom pouring opening by a plug holder. The plug holder typically has a plug support arm extending above the metallurgical vessel, to which a plug rod is attached. The plug, in turn, is attached to the plug rod. This attachment is usually achieved by screwing the plug to the plug rod. Common plugs have a thread on their inside, and the plug rod has a corresponding thread on the outside.

[0006] Due to the rigid connection between the stopper rod and the stopper, it is necessary to position the stopper rod as precisely as possible relative to the bottom pouring opening. However, during preheating of the pouring vessel and during pouring, very high temperatures act on the stopper and stopper rod, which can lead to positional changes due to thermal expansion. For safety reasons, these positional changes cannot be corrected with conventional stopper holders, as this would require work in the high-temperature range. The stresses can be so great that the stopper breaks, forcing the pouring process to be aborted.

[0007] The high temperatures also cause damage to the thread of the stopper rod, making it impossible to separate the stopper and stopper rod after the casting process, and the stopper rod must be replaced frequently. The stopper is therefore knocked off and cannot be reused. Knocking off the stopper occurs at high temperatures and is therefore dangerous for personnel. The object of the invention is therefore to provide a stopper holder that enables a safe, reliable, and resource-efficient casting process. In particular, the object of the invention is to avoid working in high-temperature ranges, prevent the occurrence of stopper breakage, and reduce material wear.

[0008] This object is achieved in a plug holder for fastening a plug for regulating the outflow velocity of a bottom pouring opening of a metallurgical vessel, wherein the plug holder has a plug rod, wherein the plug rod has a plug contact surface for resting on a plug on its underside facing the pouring vessel in use, in that the plug holder has a gripper arranged on the plug rod for fastening the plug.

[0009] The gripper allows the plug to be attached to the plug rod without a screw connection by pressing the plug against the plug rod. The pressure with which the plug is pressed against the plug contact surface can be regulated by the gripper. Material stresses and position changes that occur during the casting process due to thermal changes in the plug or plug rod can therefore be easily compensated. By loosening the fastening, corrections can be made throughout the entire casting process, i.e. during preheating, the casting process, and the end of the casting. After the casting process is complete, the plug can be easily removed by opening the gripper. The plug is not damaged and can be reused. Furthermore, no work in the high-temperature range is necessary. The plug holder therefore enables a reliable and safe casting process.

[0010] Advantageous features are described in the dependent claims:

[0011] To achieve a uniform solidification structure of the cast product, it is important to avoid contamination of the melt, especially from reoxidation products, as otherwise non-metallic inclusions will be found in the product. For this purpose, inert gas is often introduced through the plug, especially near the bottom pouring opening. The escaping inert gas helps transport reoxidation products upwards, where they are absorbed into the covering powder layer of the melt. Furthermore, this prevents the formation of alumina deposits in the pouring channel, which could disrupt the flow there.

[0012] To enable the supply of inert gas to the stopper, the stopper rod can have a continuous central recess for conducting inert gas, wherein the recess opens into the stopper contact surface. The central recess extends along the longitudinal axis of the stopper rod. The stopper also typically has a central recess. The central recess of the stopper rod and the recess of the stopper enable continuous conduction of the inert gas. To enable the simplest and most central alignment of the stopper to the stopper rod, the stopper contact surface can be conical and / or curved, in particular convex or concave, in particular spherical.

[0013] To make it particularly easy to attach the plug, the gripper can be arranged coaxially with the plug rod and project beyond the plug rod on its underside. The gripper has at least one lower stop surface on its inner side, and the positioning of the lower stop surface relative to the plug contact surface can be adjusted by an adjustment means. The gripper can thus be opened and closed by the adjustment means.

[0014] The adjusting means can, for example, be designed as a conical element that can be moved up and down along the stopper rod in such a way that the conical element pushes the gripper away from the stopper rod to a greater or lesser extent. Alternatively, the adjusting means can be designed as a sleeve that can be moved along the stopper rod or as a reciprocating piston, in particular a spring-loaded one.

[0015] An upward or downward movement along the stopper rod can be achieved, for example, by arranging a thread on the outside of the stopper rod that interacts with a thread arranged on the inside of the adjusting means, so that the adjusting means can be displaced along the stopper rod by turning it. The turning can be done either manually or, preferably, by a drive, such as a toothed belt drive or a chain drive.

[0016] Alternatively, the movement of the adjusting means along the plug rod can be carried out by a toggle lever or fluid technology.

[0017] In order to enable automation of the casting process and to be able to centrally control the opening and closing of the gripper, the adjustment means can be connected to a control unit for controlling the gripper.

[0018] A particularly secure hold of the plug on the plug holder can be achieved by arranging the stop surface of the gripper parallel to the plug contact surface in the closed position of the gripper.

[0019] To reinforce the stopper's hold and compensate for loosening of the connection due to possible thermal expansion during the casting process, the gripper can be guided into a closed position by a spring element. In this case, the spring element provides additional security against accidental opening of the gripper.

[0020] To easily compensate for material stresses and position changes during the casting process, the gripper can be moved to at least one open position, one closed position, and one holding position. In the open position of the gripper, the plug can move completely freely relative to the plug holder. The plug holder does not support the weight of the plug in the open position.

[0021] In the closed position, the plug is secured in the plug holder. Slight displacement between the plug contact surface and the holder contact surface may be permitted to relieve stress.

[0022] In the holding position, the gripper is slightly open compared to the closed position. The plug is therefore pressed against the plug rod with less pressure. In the holding position, the gripper is positioned so that the plug is held by the plug holder. The holder contact surface can be easily moved relative to the plug contact surface, thus further preventing material wear. Material stresses caused by temperature changes can be relieved particularly easily by moving the gripper from the closed position to the holding position.

[0023] The gripper can move to the holding position as standard. If the gripper is adjustable by an adjustment device connected to a control unit, it can be specified, for example, that after a specified period of time has elapsed after the start of the heating phase, the gripper is moved from the closed position to the holding position and back to the closed position. Additionally or alternatively, sensors can be provided that detect the occurrence of material stresses, and their signal is forwarded to the control unit. If the value detected for the material stress exceeds a specified threshold, the control unit can in turn initiate a movement of the gripper from the closed position to the holding position and back.

[0024] Preferably, the plug contact surface and the holder contact surface are in contact with each other in the holding position, or a seal inserted between the contact surfaces is in contact with both the plug contact surface and the holder contact surface. However, displacement of the holder contact surface relative to the plug contact surface remains possible, and tensions between the plug holder and the plug can be relieved without causing a significant drop in the pressure of the inert gas in the central recess of the plug. Minor losses of inert gas can be compensated for by temporarily increasing the flow rate of the inert gas in the holding position.In order to minimize gas loss, the inert gas supply line can be connected to the control unit and controlled via the control unit, so that when the gripper is moved into the holding position, the flow rate of the inert gas is increased at the same time and is reduced to the initial level when the gripper is subsequently closed.

[0025] To facilitate easy correction of material stresses, the plug contact surface and / or the lower stop surface can have a smooth surface structure. A smooth surface structure in this context means that there are no structures intended to prevent the plug from shifting relative to the plug holder. The plug contact surface is therefore designed to be thread-free or groove-free, for example. The surface structure is therefore designed in such a way that, in the holding position, the plug can be shifted relative to the plug contact surface or the lower stop surface.

[0026] To ensure the plug is securely held in the plug holder while simultaneously allowing for easy adjustment of material tension, the gripper can have multiple gripper arms. Two or three gripper arms have proven particularly suitable. Each gripper arm has a lower stop surface for supporting the plug.

[0027] Furthermore, it is advantageous if the plug contact surface is conical or curved, in particular convexly curved, concavely curved, or spherical. This enables favorable spherical / spherical or spherical / conical pairings at the connection point. In the context of this application, spherical refers to the shape of a surface that corresponds to a portion of the surface of a sphere. Due to the curved or conical shape of the plug contact surface, the plug is automatically aligned in the plug holder when the gripper is closed, which supports the secure fastening of the plug in the gripper.

[0028] If the plug rod has a central recess for conducting inert gas, aligning the plug with the plug holder also aligns the central recess of the plug rod with the central recess of the plug. To facilitate alignment of the central recess of the plug rod with the central recess of the plug, the central recess can widen in a delta shape toward the plug contact surface.

[0029] To ensure that the plug holder is particularly easy to operate and that operating personnel can maintain a safe distance from the high-temperature areas at all times, the plug holder can have a plug support arm for mounting the plug holder outside the pouring vessel, with the plug rod being held by the plug support arm. To enable the plug to be easily positioned at the desired distance from the bottom pouring opening, the plug holder can comprise a lifting device for raising the plug support arm, with the lifting device preferably being connected to the control unit and controllable by the control unit. The lifting device allows the plug to be lowered and raised above the bottom pouring opening of the pouring vessel. The plug holder can therefore also be used with plugs of different lengths.

[0030] In order to provide a casting system whose operation does not require work in the high-temperature range, it is particularly advantageous if the movements of the stopper support arm, the gripper, and, if applicable, the supply of inert gas can be controlled by a control unit. In this case, the control unit can control the stopper holder in such a way that, without any additional action by the operating personnel, the gripper is positioned over a provided stopper, the gripper is opened and lowered, and then the gripper is closed. The gripper engages the stopper and encloses it, so that the central recess of the stopper rod is positioned over the central recess of the stopper, enabling a continuous line of inert gas. The gripper is then raised so that the stopper is held in the gripper.The control unit can then control the stopper support arm of the stopper holder such that the stopper is positioned over the bottom pouring opening of a pouring vessel. The stopper support arm can then be lowered to position the stopper in the bottom pouring opening. After the pouring process is complete, the stopper can be released from the stopper holder by opening the gripper and removed from the pouring vessel. The stopper holder and the stopper are available for the next pouring process after cleaning. Direct work on the stopper holder is not necessary during operation. Only maintenance and repair work, which is usually carried out in cold conditions, requires direct work on the stopper holder. This eliminates the need for work in the high-temperature range.

[0031] The invention further relates to a plug for regulating the outflow velocity from a bottom pouring opening of a metallurgical casting vessel. The plug has a lower plug end region for closing the bottom pouring opening, wherein the plug has an upper end region opposite the lower plug end region for attachment to a previously described plug holder. For this purpose, the plug has a fastening surface on its outer side for a positive connection to the gripper of the plug holder. Furthermore, a holder contact surface for supporting the plug holder, in particular the plug contact surface of the plug holder, is formed in the upper end region. The holder contact surface is arranged on the end face of the plug. The holder contact surface has, in particular, a smooth surface. Additionally or instead, the fastening surface can also have a smooth surface.A smooth surface is one that is free of engaging elements such as grooves, threads, pins, or similar. Because the support contact surface is conical or curved, i.e., convex or concave, especially spherical, the plug is particularly reliable and easy to install and adjust. This design allows the plug to interact with the plug holder in an articulated manner, creating a gas-tight and secure connection to the plug holder. The plug is particularly stable and reliable, allowing reuse.

[0032] In a preferred embodiment, the plug is formed in one piece. This makes the plug particularly stable and durable.

[0033] Alternatively, the plug can be composed of at least two connectable parts, for example, parts that can be screwed together. A plug has at one end the upper end region for attachment to the plug holder, at the other end the lower plug end region for closing the bottom pouring opening, and in between a plug body that has a constant diameter. A two-part plug is particularly advantageous if a first plug part forms the upper end region and a second plug part comprises the plug body and the lower plug end region. In this case, the plug can be particularly easily adapted to different plug holders and different casting vessels and is very flexible in use.

[0034] In order to enable the introduction of inert gas, it can be provided that the plug has a central recess for conducting inert gas, wherein the central recess extends along the longitudinal axis of the plug and opens centrally in the holder contact surface in the upper end region of the plug and ends and preferably opens in the lower plug end region.

[0035] According to the invention, an arrangement comprising a plug holder as described above and a plug, wherein the plug is connected to the plug holder in particular in an articulated manner.

[0036] The articulated connection can be achieved particularly well if at least the plug contact surface or the holder contact surface is curved, in particular convex, concave or spherical, and the opposite contact surface is conical or also curved.

[0037] A particularly tight connection can be achieved if the plug contact surface of the plug holder and the holder contact surface of the plug have an opposite curvature or an opposite pitch angle. The curvature or conical shape of the contact surfaces allows for easy centering. This enables simple, even automated, assembly of the plug to the plug holder, and equally simple release of the connection. At the same time, stresses in the components that could arise from heating are avoided, as they can be relieved by minimal displacement in the joint area. This makes the casting process safer and more reliable.

[0038] An arrangement comprising a plug as described above is particularly advantageous.

[0039] The positive connection between a plug and the gripper of the plug holder can be achieved, for example, by the fastening surface being located on the underside of an edge of the plug in which the diameter of the plug is larger than the diameter of the rest of the plug body. Alternatively, the fastening surface can also be located on the top side of a ring in which the diameter of the plug is smaller than in the rest of the plug body.

[0040] The plug, or rather the retaining contact surface, can thus be pressed against the plug contact surface. It is particularly advantageous if the lower stop surface and the fastening surface are arranged parallel to each other. To achieve a particularly good hold, the gripper can also have a lateral stop surface that rests against the edge of the plug. This allows the gripper to be clamped even more firmly against the plug.

[0041] To enable and precisely regulate the introduction of inert gas, the central recess of the plug and the central recess of the plug holder can be arranged at least partially in alignment with each other, allowing the inert gas to be directed from the plug holder into the plug. The central recess of the plug is arranged adjacent to the central recess of the plug holder.

[0042] To prevent inert gas leakage even more effectively, a sealing ring can be inserted between the plug contact surface and the holder contact surface. This can prevent inert gas leakage even more effectively, especially in the holding position. The sealing ring should be fireproof due to the high temperatures during the casting process.

[0043] According to the invention, a method for positioning a plug in a plug holder is further provided, wherein a plug holder, in particular a plug holder as described above, is provided, wherein a plug is fastened to the plug holder by arranging the gripper around the upper end region of the plug and moving it into a closed position, wherein the plug is subsequently arranged over the bottom pouring opening of a metallurgical vessel and subsequently the temperature of the vessel is changed, in particular the heating of the vessel and the plug takes place, wherein during the temperature change, in particular the temperature increase, or after reaching a target temperature, the gripper is moved into a holding position, wherein the plug is held in the holding position by the gripper, in particular between the plug rod and the bottom pouring opening,and wherein the gripper is moved back to the closed position after reaching the holding position. This reduces material stress and increases the durability of the plug holder and plug, while preventing plug breakage due to the improved positioning of the plug.

[0044] Any temporary escape of inert gas in the holding position can be compensated for by increasing the flow rate of the inert gas while the gripper is in the holding position or while moving it into or out of the holding position. This ensures that the inert gas flows out of the lower stopper end area at a virtually unchanged speed, preventing contaminants from penetrating the bottom pouring opening and deposits from forming in the pouring channel. Particularly advantageous embodiments of the invention are illustrated by way of example in the following drawings, without limiting the general inventive concept.

[0045] Fig. 1 a shows a first embodiment in open position above a plug.

[0046] Fig. 1 b shows a top view of the plug with a sealing ring.

[0047] Fig. 2 a shows the plug holder from Fig. 1 in open position (left) and closed position (right) on the plug.

[0048] Fig. 2 b shows the interaction of the plug with the bottom pouring opening.

[0049] Fig. 2 c shows the adjustment means of the plug holder from Fig. 1.

[0050] Fig. 2 d shows the connection of the plug support arm to the plug rod.

[0051] Fig. 3 shows a second embodiment.

[0052] Fig. 4 shows a third embodiment in open position in oblique view.

[0053] Fig. 5 shows a fourth embodiment in open and closed position.

[0054] Fig. 6 shows a fifth embodiment in the holding position.

[0055] Fig. 7 shows a sixth embodiment in the closed position.

[0056] Fig. 8 shows a seventh embodiment of the arrangement in closed position.

[0057] Fig. 1 a shows an exemplary plug holder 1, which is aligned over a plug 2 in order to fasten the plug 2 to the plug holder 1. The plug holder 1 comprises a plug support arm 12 to which a plug rod 3 is fastened. The plug rod 3 has a central recess 4 for conducting inert gas. The inert gas is introduced into the central recess 4 via the inert gas line 18. The central recess 4 opens into a plug contact surface 5, wherein in the embodiment shown, the central recess 4 widens in a delta shape towards the plug contact surface 5. The plug contact surface 5 is convexly curved in the embodiment shown.

[0058] The plug 2 has a holding contact surface 15, which serves to support the plug holder 1 and which, in the illustrated embodiment, is conical. A central recess 17 of the plug 2, which is provided for conducting inert gas, opens centrally into the holding contact surface 15. The upper end region of the plug 2 terminates at the end face, i.e., on the side facing the plug rod 3 during use, with the holding contact surface 15. A fastening surface 16 is arranged below the holding contact surface 15 in the upper end region of the plug 2. In the illustrated embodiment, the fastening surface 16 is formed on the underside of an edge whose diameter is larger than the diameter of the rest of the plug body.

[0059] In Fig. 1 a, the convex plug contact surface 5 interacts with the conically shaped support contact surface 15. This allows a centered alignment to be achieved when connecting the plug 2 to the plug rod 3, which allows the inert gas to flow continuously from the central recess of the plug rod 3 into the central recess 17 of the plug 2. In this way, the gas flow can be controlled to create an optimal flow that homogenizes the melt, with inclusions caking together and rising without disrupting the slag layer.

[0060] In Fig. 1 b it can be seen that a sealing ring 20 is inserted on the holder contact surface 15 in order to be able to prevent gas leakage between the plug holder 1 and the plug 2 even better and to be able to control the gas leakage at the lower plug end area 13 particularly precisely.

[0061] Fig. 1 a shows that the plug holder 1 has a gripper 6 which is attached to the plug rod 3, wherein the gripper 6 has two gripping arms 7 which project downwards beyond the plug rod 3.

[0062] The gripping arms 7 are designed as two-armed levers, with the pivot point located in the middle region of the gripping arms 7 resting on the outside of the stopper rod 3. The upper ends of the gripping arms 7 are in contact with an adjusting means 9. In this embodiment, the adjusting means 9 is conical or tapered and has an internal thread that interacts with a thread on the outside of the stopper rod 3 so that the conical adjusting means 9 can be moved up and down along the stopper rod 3. In the position shown, the gripper 6 is open. The adjusting element 9 is displaced upwards. At the upper ends of the gripping arms 7, an annular pretensioning means 10 is arranged, which presses the lower ends of the gripping arms 7 outwards.

[0063] The gripper 6 has a lower stop surface 8 at its lower end, which, in the illustrated embodiment, faces the plug contact surface 5. The lower stop surface 8 is spaced from the plug contact surface 5 such that the plug 2 can be clamped between the plug contact surface 5 and the lower stop surface 8. The gripper 6 can thus engage the plug 2 and hold the plug 2.

[0064] Fig. 2a shows an arrangement comprising the plug holder 1 from Fig. 1 and a plug 2. In this embodiment, the plug 2 is formed in one piece. On the left side in Fig. 2a, the gripper 6 is shown in the open position. On the right side in Fig. 2a, the gripper 6 is shown in the closed position of the plug holder 1, wherein the lower stop surfaces 8 of the gripper 6 are aligned parallel to the plug contact surface 5. The edge of the plug 2 is clamped between the lower stop surfaces 8 and the plug contact surface 5 as well as between the lateral stop surfaces 14, so that a positive connection is established between the plug holder 1 and the plug 2. The adjusting means 9 is moved completely downwards in the closed position.

[0065] To close the gripper 6, the adjusting means 9 is moved downward and, due to its conical shape, pushes the upper ends of the gripper arms 7 mounted on the stopper rod 3 outward, while their lower ends are moved inward into the closed position. At the same time, the annular preloading means 10 is preloaded. Upon opening, the upper ends are pulled back into the open position by the preloading means 10.

[0066] In the illustrated embodiment, the plug holder 1 can be operated by remote control, thus avoiding work in high-temperature areas. For this purpose, a chain drive is provided in the illustrated embodiment, which controls the rotation of the adjustment means 9 along the thread. To enable fully automatic operation, the adjustment means 9 and the plug support arm 12 can be connected to a control unit.

[0067] Fig. 2 b shows that the central recess 17 in the lower end region 13 of the plug 2 opens into the wall of the plug 2 and allows the introduction of the inert gas in the region of the bottom pouring opening 29. The plug 2 is arranged above the bottom pouring opening 29 so that the outflow of the melt from the casting vessel into a distributor can be regulated.

[0068] To enable adaptation of the plug holder 1 to plugs 2 of different lengths, in the illustrated embodiment, the height position of the plug rod 3 in the plug support arm 12 can be adjusted via the screw connection 19. This connection between the plug support arm 12 and the plug rod 3 is shown in detail in Fig. 2 d.

[0069] Fig. 3 shows a second exemplary embodiment of a plug holder 1. In contrast to the first embodiment, in this embodiment the gripper 6 is connected to the plug rod 3 via links 22. The adjusting means 9 in this embodiment is designed as a sleeve that can be moved along the plug rod 3. The illustrated embodiment has two gripper arms 7, which are pivotally mounted on the plug rod 3 via links 22 and are also articulated to the movable sleeve. The gripper arms 7 are guided by the links 22. If the adjusting means 9 is moved downwards, the gripper arms 7 are pressed by the links 22 into a position in which the lower ends of the gripper arms 7 protrude outwards from the plug rod 3. The gripper 6 is therefore opened by moving the adjusting means 9 downwards. If the adjusting means 9 is moved upwards, the gripper 6 is closed.At the same time, the spring element 11 is preloaded or released. The spring element 11 thus serves as an additional safety element for the tightness of the contact point and to compensate for the thermal expansion of the plug holder and protect it from deformation.

[0070] In this embodiment, too, the adjusting means 9 is connected to a control unit for opening and closing the gripper 6.

[0071] Fig. 4 shows a third exemplary embodiment of a plug holder 1. This essentially corresponds to the second embodiment, but the gripper 6 has three gripper arms 7 that can be actuated via a toggle lever 24. The plug holder 1 is shown with the gripper 6 in the open position. In the illustrated position, the plug contact surface 5 rests on the holder contact surface 15 of a plug 2. The gripper 6 of the plug holder 1 is open, and the lower stop surface 8 does not rest on the fastening surface 16.

[0072] Fig. 5 shows a further embodiment. In this embodiment, the adjusting means 9 is designed as a movable sleeve, with the sleeve being moved by a hydraulic or electric lifting drive 25 connected to a toggle lever 23 via a rod 26. The sleeve can be moved along the plug rod 3 by the toggle lever 23. The spring element 11 can be protected from overheating by a cooling system 27.

[0073] The gripping arms 7 of the gripper 6 are shown in the closed position of the gripper 6 and additionally the open position of the gripping arms 7 is shown in dashed lines.

[0074] In the closed position, the holder contact surface 15 and the plug contact surface 5 are arranged parallel to each other since they have an opposite curvature.

[0075] In this embodiment, automated operation of the casting system is possible. For this purpose, the stopper support arm 12 is pivotally mounted on a lifting and pivoting device 28. This is connected to a control unit, which can control the pivoting, raising, and lowering of the stopper support arm 12. Furthermore, the adjustment means 9 is connected to the control unit, so that the opening and closing of the gripper 6 can be controlled by the control unit. Furthermore, the flow rate of the inert gas supply line 18 is also regulated by the control unit.

[0076] If the plug holder 1 is mounted next to a metallurgical casting vessel, the casting process can be carried out without working in the high-temperature range. For this purpose, a plug 2 is first provided at a predetermined location. The control unit is designed such that the lifting and pivoting device 28, controlled by the control unit, pivots the plug support arm 12 over the provided plug 2 and then the gripper 6 is lowered so that the gripper arms 7 are arranged around the upper end region of the plug 2. The control unit then controls the adjusting means 9 such that the gripper 6 is brought into the closed position. The plug 2 is then lifted by the lifting and pivoting device and positioned over the casting vessel, in particular over the bottom pouring opening 29 of the casting vessel, and lowered.The control unit can be designed such that at a specific time, for example after preheating or during the casting process, the gripper 6 is briefly moved into a holding position to relieve material stresses. At the same time, the inert gas supply line 18 is increased so that the gas flow through the plug 2 remains as unchanged as possible. After the end of the casting process, the control unit controls the lifting and pivoting device 28 such that the plug 2 is returned to the specified location. Subsequently, the adjusting means 9 is controlled such that, by opening the gripper 6, the plug 2 is separated from the plug holder 1. This makes the plug 2 available for further use.

[0077] Fig. 6 shows another embodiment of the arrangement in the holding position of the gripper 6, in which the gripper 6 is slightly open compared to the closed position. The plug 2 rests with its fastening surface 16 on the lower stop surfaces 8 of the gripper arms 7 and is held by the plug holder 1. The lateral stop surfaces 14 are spaced from the edge of the plug 2, thus facilitating displacement of the plug 2 relative to the plug holder 1.

[0078] In the illustrated embodiment, a sealing ring 20 is inserted between the plug contact surface 5 and the holder contact surface 15. The sealing ring 20 prevents the inert gas from escaping, even when the gripper 6 is moved into a holding position to correct the position of the plug 2.

[0079] In this embodiment, the plug contact surface 5 is convexly curved. The holder contact surface 15 is concavely curved in this embodiment. The smooth surface structure of the plug contact surface 5 allows for easy movement between the plug 2 and the plug rod 1.

[0080] Fig. 7 shows another embodiment of the arrangement in the closed position. The plug 2 is held by the plug holder 1, with the gripping arms 7 encompassing the spherical fastening surface 16 on the plug edge. The plug contact surface 5 is concavely curved in this embodiment, while the holder contact surface 15 is convexly curved. Both contact surfaces 5, 15 have a smooth surface structure. In this embodiment, a sealing ring 20 is also arranged between the contact surfaces 5, 15, with the sealing ring 20 in this embodiment being adapted to the plug contact surface 5.

[0081] Fig. 8 shows another embodiment of the arrangement. In this embodiment, the plug 2 is constructed in two pieces. A first plug part comprises the upper end region for fastening the plug 2 to the plug holder 1. A second plug part comprises the plug body and the lower plug end region. The first plug part and the second plug part are screwed together.

[0082] All embodiments shown enable simple and safe assembly and disassembly of the plug 2.

Claims

Claims 1. Plug holder (1) for fastening a plug (2) for regulating the outflow rate from a bottom pouring opening (29) of a metallurgical casting vessel, wherein the plug holder (1) has a plug rod (3), wherein the plug rod (3) has a plug contact surface (5) on its underside facing the casting vessel in use for resting on a plug (2), characterized in that the plug holder (1) has a gripper (6) arranged on the plug rod (3) for fastening the plug (2).

2. Plug holder (1) according to claim 1, wherein the gripper (6) is arranged coaxially to the plug rod (3) and projects beyond the plug rod (3) on its underside, wherein the gripper (6) has at least one lower stop surface (8) on its inner side, wherein the positioning of the lower stop surface (8) relative to the plug contact surface (5) is adjustable by an adjusting means (9) and the gripper (6) can be brought into an open and a closed position by the adjusting means (9).

3. Plug holder (1) according to claim 1 or 2, wherein the adjusting means (9) is connected to a control unit for controlling the gripper (6).

4. Plug holder according to one of claims 1 to 3, wherein the gripper (6) can be brought into at least one open position, one closed position and one holding position, wherein the gripper (6) in the holding position has a position which is slightly open compared to the closed position, and in particular is arranged such that the plug (2) is held by the plug holder (1) and is displaceable relative to the plug holder (1).

5. Plug holder according to one of claims 1 to 4, wherein the plug contact surface (5) is conical and / or wherein the plug contact surface (5) is curved, in particular convex or concave, preferably spherical.

6. Plug holder according to one of claims 1 to 5, wherein the plug contact surface (5) and / or the lower stop surface (8) have a smooth surface structure, wherein it is provided in particular that the surface structure is designed such that, in the holding position, a displacement of the plug (2) relative to the plug contact surface (5) and / or the lower stop surface (8) is possible.

7. Plug holder according to one of claims 1 to 6, wherein the gripper (6) has several, preferably two or three, gripping arms (7), each of the gripping arms (7) having a lower stop surface (8).

8. Plug holder (1) according to one of claims 1 to 7, wherein the plug rod (3) is fastened to a plug support arm (12), wherein it is provided in particular that a lifting device (28) for lifting the plug support arm (12) is included, wherein the Lifting device (28) is preferably connected to the control unit and can be controlled by the control unit.

9. Plug holder (1) according to one of claims 1 to 8, wherein the plug rod (3) has a continuous central recess (4) for conducting inert gas, wherein the recess (4), in particular centrally, opens into the plug contact surface (5).

10. A plug (2) for regulating the flow from a bottom pouring opening (29) of a metallurgical casting vessel, wherein the plug (2) has a lower plug end region (13) for closing the bottom pouring opening (10), wherein the plug (2) has an upper end region opposite the lower plug end region (13) for fastening to a plug holder (1) according to one of claims 1 to 9, wherein the plug (2) has, in the upper end region, on its outer side a fastening surface (16) for positively connecting to a gripper (6), wherein the plug (2) has, in the upper end region, a holder contact surface (15) for supporting the plug contact surface (5) of the plug holder (1), wherein the holder contact surface (15) is curved and / or conical, and wherein it is provided in particular that the fastening surface (16) and / or the holder contact surface (15) have a smooth surface.

11. Arrangement comprising a plug holder (1) according to one of claims 1 to 9 and a plug (2), in particular a plug according to claim 10, wherein the plug (2) is connected to the plug holder (1), in particular in an articulated manner.

12. Arrangement according to claim 10 or 11, wherein the plug (2) is held in the gripper (6) in a form-fitting manner, wherein in particular the fastening surface (16) rests against the lower stop surface (8).

13. Arrangement according to one of claims 10 to 12, wherein the central recess (17) of the plug (2) and the central recess (4) of the plug holder (1) are arranged at least partially in register with one another.

14. A method for positioning a plug (2) in a plug holder (1), in particular according to one of claims 1 to 9, wherein the plug holder (1) is provided, wherein a plug (2) is fastened to the plug holder (1) by placing the gripper (6) around the upper end region of the plug (2) and moving the gripper (6) into a closed position, wherein the plug (2) is subsequently placed over the bottom pouring opening (29) of a metallurgical vessel, and the temperature of the vessel is subsequently changed, wherein during the temperature change or after reaching a target temperature, the gripper (6) is moved into a holding position, wherein the plug (2) is held in the holding position by the gripper (6) between the plug rod (3) and the bottom pouring opening, and wherein the plug (2) is refastened in the plug holder (1),by moving the gripper (6) back into the closed position after reaching the holding position., 15. The method according to claim 14, wherein in the closed position the material tension of the plug (2) and / or the plug holder (1) is detected by sensors, wherein the signal from the sensors is forwarded to the control unit, wherein when a predetermined threshold value of the material tension is exceeded, the control unit controls the adjusting means (9) such that the gripper (6) is moved into the holding position and then back into the closed position.

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