Abstract:
In order to be able to carry out a multiplicity of continuously recurring activities at a continuous casting plant having at least one multifunction robot for implementing a plurality of different process-controlled or automated interventions at the continuous casting plant, at least one working region at the continuous casting plant and at least one multifunction robot assigned to each working region. The multifunction robot is arranged on a pivotable arm at a rotary column fastened to the pouring platform of the continuous casting plant and the robot can be pivoted with the pivot arm between a retraction position and a working position. The robot is also movable with respect to its arm.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a 35 U.S.C. §§371 national phase conversion of PCT/EP2006/005464, filed Jun. 8, 2006, which claims priority of Austrian Application No. A1035/05, filed Jun. 20, 2005. The PCT International Application was published in the German language. 
     The invention relates to a continuous casting plant having at least one multifunction robot, preferably having at least two multifunction robots, for carrying out a plurality of different process-controlled or automated actions on the continuous casting plant. At least one working region is defined on the continuous casting plant, and each working region is assigned at least one multifunction robot. The multifunction robot is arranged on a pivoting arm of a pivoting device. 
     BACKGROUND OF THE INVENTION 
     Multifunction robots are employed in continuous casting plants in order to carry out with high precision activities which are difficult and particularly hazardous for the operating personnel, in the region near liquid metal and under the effects of heat and dust. According to current demand in the operating situation, multifunction robots of this type are set up for carrying out a series of different activities in their effective range. The multifunction robot is preferably designed as a 6-axis robot. 
     The field of use embraces all types of continuous casting plants for the production of metal strands of any desired cross section from liquid metal, in particular from liquid steel. These are preferably single-strand or multistrand casting plants for the production of metal strands having slab, bloom or billet cross sections and of metal strands having any desired profile cross sections. 
     A multifunction robot of the generic type is already known from WO 2005/118182 A1. This robot is assigned a specific running gear and a runway, so that it can assume different positions of use. According to a particular embodiment, this running gear is additionally assigned a pivoting gear with a jib, on the projecting end portion of which a multifunction robot is positioned. By means of this arrangement, the multifunction robot can not only be brought into a position of use determined by the running gear, but can be pivoted between two or more working regions by means of the pivoting arm. 
     U.S. Pat. No. 5,360,051 or EP 0 371 482 B1 discloses a robot on the casting platform of a continuous casting plant, which robot is anchored in a stationary manner there and is equipped with an image acquisition and evaluation device for detecting its working surroundings in the region of a continuous mold. In particular, this robot is set up for the casting powder feed, for inert gas injection, for slag whisker removal and for the detection of bath level abnormalities. An essential disadvantage of this system is the stationary positioning in the region near the mold and the resulting obstruction of the operating personnel in the event of sudden faults in casting operation which require rapid intervention concentrated on the particular problem. 
     JP-A 5-169206 and JP-A 3-353900 disclose multifunction robots for sealing off a dummy strand in the mold of a continuous casting plant before the start of casting, each of these robots being movable between a position of use and a standby position on a railborne vehicle on the casting platform. JP-A 07-01639 likewise shows a multifunction robot which is placed on the running frame of a rail vehicle and is employed specially for the change of casting spouts. Further, it is known from JP-A 3-071959 to arrange movably on two separate rail tracks two robots which independently of one another carry out activities on the casting ladle and on the tundish. Although robots placed on a rail vehicle make it possible to displace the robots into a retraction region on the casting platform, with the result that access for the operating personnel is improved, the running rails nevertheless remain, which continue to constitute a stumbling place and the risk of accidents for the operating personnel. By being bound to the floor, railborne systems of this type are highly susceptible to faults in the event of casting faults caused by escaping liquid steel. 
     It is also known to arrange on the casting plant automated devices which, as a consequence of design, perform only a single activity. A device of this type is known for example, from U.S. Pat. No. 5,067,553, which comprises a casting powder feed device on the jib of a turret. After the hot bath level surface has been detected, the casting powder is conducted by means of a movable gripping arm out of a casting powder container through a flexible line onto the bath level surface. 
     SUMMARY OF THE INVENTION 
     The object on which the present invention is based is, therefore, to avoid the disadvantages of the known prior art and to propose a continuous casting plant having at least one multifunction robot, in which, with few multifunction robots being used, a multiplicity of continuously recurring activities can be carried out accurately and in an automated manner on a continuous casting plant, without access to the casting plant for the operating personnel being obstructed or an additional accident risk arising on account of the multifunction robots. Further, the multifunction robots are to be positioned such that, even in the event of operating faults, such as, for example, a run-out of liquid metal, they are subject to as low a risk of damage as possible. 
     Proceeding from a device of the type initially described, this object is achieved in that the or each multifunction robot is arranged on a pivoting arm of a rotary column fastened on the casting platform of the continuous casting plant and can be pivoted by means of the pivoting arm between a retraction position and a working position. 
     In defining a plurality of working regions on the continuous casting plant, it is important essentially to delimit these working regions spatially with respect to one another and fix the working position of the multifunction robot in each working region. A working position is to be understood here as meaning one or more basic positions which the multifunction robot assumes in relation to the casting plant. In this case, it is located on the pivoting arm of a rotary column, in a first embodiment of the pivoting arm the first axis of rotation of the multifunction robot running parallel to the axis of rotation of the pivoting arm of the rotary column and at a distance from this. In a second embodiment of the pivoting arm, the latter is formed by a parallel link system, and the first axis of rotation of the multifunction robot stands normally to the pivot axes of the parallel links. Even a combination of the two embodiments may be envisaged. By an appropriate choice of the pivoting arm length, the rotary column is anchored outside the immediate vicinity of the working region of the respective multifunction robot and, after the multifunction robot has been pivoted out into its retraction position, allows unobstructed access to this working region for the operating personnel of the casting plant. If a plurality of working positions are assigned to one multifunction robot, these are located on the pivoting circle of the pivoting arm which is determined by the position of the multifunction robot. 
     A plurality of basic forms of the design of a rotary column with a pivoting arm are expedient in this context: the pivoting arm may be connected rigidly to the rotatable rotary column, the rotary column being supported on a rotary bearing, and the rotary column being assigned a rotary drive comprising a motor and a gear. Further, the pivoting arm may be mounted rotatably on the rotary column, and the pivoting arm is assigned a rotary drive. Thirdly, there is the possibility that the pivoting arm is formed by a parallel link system, the parallel link system being assigned a pivoting drive. 
     Even two or more working regions may be assigned to one multifunction robot. As a result, on the one hand, it becomes possible for one multifunction robot to assume the function of another multifunction robot, for example in the event of its failure, and, on the other hand, if there is an appropriately overlapping range of adjacent multifunction robots, a regrouping of the activities of individual robots can be carried out as a function of the workload. 
     So that a plurality of multifunction robots can be positioned in optimal working positions, in an expedient embodiment at least one multifunction robot is arranged on a pivoting arm of a rotary column at a height which deviates from the height of a multifunction robot on a further pivoting arm of a rotary column. 
     The height of a multifunction robot may also be configured variably if the rotary column is designed as a lifting element. This may take place, for example, by means of the arrangement of lifting cylinders or by means of a telescopic construction of the lifting column. 
     Each multifunction robot is assigned a supply region for the reception and deposition of tools, operating stock and the like. This supply region comprises, for example, magazines, in which tools, materials to be used and operating stock are arranged unequivocally and in a grippable and detectable way for the gripping tools and the sensors of the multifunction robot and, if appropriate, can also be deposited there again. These supply regions are arranged in the multifunction robot range which is widened by means of the rotary column. 
     According to an expedient embodiment, the supply region may likewise be arranged on the pivoting arm of a rotary column, and this supply region is preferably pivotable between a position of use in the range of the multifunction robot and a loading position. In this case, the supply region may be arranged on a second pivoting arm of a rotary column which already has a pivoting arm with a robot, the two pivoting arms preferably being pivotable independently of one another. The supply region may, however, also be arranged on the pivoting arm of a separate rotary column, the position of use of this supply region lying in the range of one or more multifunction robots. 
     The selection of the working regions on the continuous casting plant takes place, on the one hand, according to spatial factors and, on the other hand, according to the prevailing time of use of the multifunction robot in the respective working region. Further, particularly in the retrofitting of existing continuous casting plants, it is influenced essentially by the existing structural conditions. 
     For example, working regions for essential core components and activity zones may be proposed:
         ladle turret surroundings,   casting ladle surroundings, in particular the region of the spout and of the ladle slide, etc.,   tundish surroundings, in particular the region of the immersion spout and of the ladle slide or of the tundish plug etc.,   mold surroundings, in particular bath level observation, casting powder feed, temperature measurement etc.,   flame-cutting machine, in particular burner guidance, local cooling, surface inspection, etc.,   deburring and marking surroundings, in particular whisker removal, placing of markings,   quality control in the run-out region of the continuous casting plants, in particular visual inspection, flame descaling, sampling, etc.       

     Where multistrand continuous casting plants are concerned, working regions of this type may be defined separately for each strand or else jointly for a plurality of strands. 
     A multiplicity of activities arise within the working regions for the assigned multifunction robot, for example, there are the following possible activities for the working regions “casting ladle surroundings”, “tundish surroundings” and “mold surroundings”: 
     Activities in the casting ladle surroundings:
         detection of the casting ladle position,   activation of the ladle slide shutter,   fastening and removal of the spout,   coupling and decoupling of the media lines and couplings.       

     Activities in the tundish surroundings:
         detection of the casting ladle position,   fastening and removal of the spout,   opening of the ladle with an oxygen lance,   cleaning of the spout,   changing of the spout,   temperature measurement in the tundish,   sampling in the tundish,   feed of casting powder in the tundish,   bath level measurement in the tundish.       

     Activities in the mold surroundings:
         detection of the tundish position,   sampling in the mold,   casting powder feed in the mold,   casting spout preheating,   casting spout change,   slag removal from the mold,   insertion of separating plates in sequential casting,   cooling of the strand end or mold cleaning at the end of casting,   placing and removal of splash protection devices,   execution of temperature measurements.       

     The partial overlap of activities in the assignment to the working regions makes it possible to bring together working regions or the processing in these by means of multifunction robots which are assigned to adjacent working regions. 
     Preferably, the multifunction robots and the rotary columns and pivoting arms carrying them are of modular construction. They form subassemblies which are interchangeable, as desired, with the result that a rapid change and maintenance of the assemblies becomes possible even during continuous casting operation. 
     Expediently, the multifunction robot is equipped with a data transmission and data reception device, and this is connected to a central management device or to a process computer of the continuous casting plant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages and features of the present invention may be gathered from the following description of unrestricting exemplary embodiments, reference being made to the accompanying figures in which: 
         FIG. 1   a  shows the liquid phase region of a continuous casting plant with the arrangement according to the invention of three multifunction robots in elevation in a diagrammatic illustration, 
         FIG. 1   b  shows the liquid phase region of a continuous casting plant with the arrangement according to the invention of three multifunction robots according to  FIG. 1   a  in horizontal projection in a diagrammatic illustration, 
         FIG. 2   a  shows the liquid phase region of a continuous casting plant with the arrangement according to the invention of four multifunction robots in elevation in a diagrammatic illustration, 
         FIG. 2   b  shows the liquid phase region of a continuous casting plant with the arrangement according to the invention of four multifunction robots according to  FIG. 2   a  in horizontal projection in a diagrammatic illustration, 
         FIG. 3  shows the rotary column with a pivoting arm in a possible basic form of the configuration, 
         FIG. 4  shows the rotary column with a pivoting arm in a further basic form of the configuration, 
         FIG. 5  shows a circuit diagram for incorporating the multifunction robots into the process management level of the plant control. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1   a  and  1   b  make clear in diagrammatic illustrations the situation on the casting platform of a continuous casting plant, such as is used, for example, in the production of a steel strand of slab cross section. 
     A ladle turret  2  is supported rotatably about a vertical axis  3  on the casting platform  1  of the continuous casting plant. Casting ladles  4 ,  5  for supplying the casting plant with steel melt are suspended in fork arms  2   a ,  2   b  directed away from one another. The casting ladle  5  is located, in the casting position, above a tundish  6 , and this, in turn, is located, in a casting position, above the continuous casting mold  7 . During the casting operation, steel melt flows out of the casting ladle  5  through a spout  8 , to which a slide shutter  9  is assigned, into the tundish  6  and from there through the immersion spout  10 , to which a slide shutter  11  is assigned, into the continuous casting mold  7 . An at least partially solidified steel strand, which is indicated by the curved center line  12 , emerges from the continuous casting mold  7  and runs in a known way through the strand guide of the continuous casting plant. 
     The continuous casting plant is assigned, on the casting platform  1 , three multifunction robots  20 ,  30 ,  40  which are designed as 6-axis robots and each of which is fastened independently on the assigned pivoting arm  21 ,  31 ,  41  of a rotary column  22 ,  32 ,  42 . The multifunction robot  20  is assigned a first axis of rotation  23  which is fixed at a distance A from the vertical axis of rotation  24  of the rotary column  22  and which fixes the position of the multifunction robot with respect to the axis of rotation  24 . In  FIG. 1   a , the multifunction robot  20  is illustrated in its retraction position, and in  FIG. 1   b  it is illustrated in its working position and in this working position can carry out manipulations in the working region  25  (casting ladle surroundings) of the casting ladle  4 , such as, for example, the detection of the casting ladle position or of the position of the ladle slide  9  and the fastening of the spout  8 . The rotary column  22  is fastened on the casting platform  1  preferably by means of a releasable screw connection, so that the rotary column, together with the multifunction robot, can easily be removed, as required. Magazines for the reception of tools and operating stock of the supply region  26  are arranged directly on the rotary column  22 . The basic structural set-up of the rotary column together with the pivoting arm and multifunction robot is identical for the robots  20 ,  30  and  40 . 
     The multifunction robot  30  is assigned to the working region  27  (tundish surroundings) and in this case can carry out activities in this region, such as, for example, the change of a spout  8  on the bottom of the casting ladle  5  or else sampling in the tundish  6 . According to its working region  27  on the continuous casting plant, the multifunction robot  30  is arranged at a height  28  elevated with respect to the multifunction robot  20 . It would be perfectly possible that the rotary column  32  is not fastened on a carrying frame  29 , as illustrated, but that the rotary column  32  extends onto the casting platform  1  and is fastened there. 
     The multifunction robot  40  is assigned to the working region  35  (mold surroundings) and can in this case carry out activities in this region, such as, for example, the change of the immersion spout  10  or the execution of sampling in the continuous casting mold  7 . Magazines of the supply region  26 ,  26   a  may be attached both directly on the rotary column  42  and to one side on the casting platform  1 , the supply region  26   a  being capable of being reached both by the multifunction robot  30  and by the multifunction robot  40 . 
       FIGS. 2   a  and  2   b  illustrate diagrammatically a possible arrangement of four multifunction robots on the casting platform of a continuous casting plant, which could be, here, on the one hand, a continuous casting plant for the production of very wide slabs or, on the other hand, a continuous casting plant for the casting of two or more steel strands. The reference symbols for components which occur both in the illustrations according to  FIG. 1   a  and  FIG. 1   b  and in the illustrations according to  FIGS. 2   a  and  2   b  are identical. 
     In  FIGS. 2   a  and  2   b , once again, a ladle turret  2  rotatable about a vertical axis  1  and carrying casting ladles  4 ,  5  is illustrated. The casting ladle  4  is assigned a multifunction robot  20  on the carrying arm  21  of a rotary column  22 , by means of which multifunction robot activities in the working region  25  (casting ladle surroundings) of the casting ladle  4  can be carried out, such as, for example, the detection of the casting ladle position or of the position of the ladle slide  9 . Circles  44 ,  45  outline the range of the multifunction robot in its retraction position and in its working position. 
     The robot  30  is supported on the pivoting arm  31  of the rotary column  32  and is assigned to the working region “tundish surroundings” and can in this case carry out activities in this region, such as, for example, the change of a spout  8  on the bottom of the casting ladle  5  or else sampling in the tundish  6 . 
     The multifunction robot  50  is supported on a pivoting arm  51  of the rotary column  52  and the multifunction robot  60  is supported on a pivoting arm  61  of the rotary column  62 . Both multifunction robots  50 ,  60  are assigned to the working region “mold surroundings” and can in this case carry out activities in this region, such as, for example, the change of the immersion spout  10  or the execution of sampling in the continuous casting mold  7 . It is clear from  FIG. 2   b  that the working regions, which are derived from the working position of the two robots  50 ,  60 , lie next to one another and correspondingly cover the working region on a very long tundish  6 , with, for example, two immersion spouts  10  arranged one behind the other in the image plane of  FIG. 2   a , or else the working regions of two continuous casting molds  7  arranged one behind the other in the image plane of  FIG. 2   a.    
       FIG. 3  illustrates a multifunction robot  20  in a working position (left image half) and in a retraction position (right image half) on the pivoting arm  21  of a rotary column  22 . The rotary column  22  is fastened releasably on the casting platform  1  by means of a baseplate  54  by a plurality of tension means  55 . The rotary column  22  is supported on the baseplate  54  rotatably about the vertical axis  24  via rotary bearings  56  and is connected to a drive device  57 , here especially to a drive motor (electric drive motor), via a gear, not illustrated in any more detail. Fastened on the rotary column is a pivoting arm  21  carrying the multifunction robot  20 , the first axis of rotation  23  of which is oriented parallel to the axis of rotation  24 . In a variant, illustrated by dashes, of the rotary column design, the rotary column  22  projects in a stationary manner upward from the baseplate  24 , and a rotary bearing  56 ′ is arranged just beneath the pivoting arm  21  or between the rotary column and the pivoting arm, so that only the pivoting arm  21  is moved by the drive device  57 ′, likewise depicted by dashes. 
     Both the multifunction robot  20  and the rotary column  22  with a pivoting arm  21  are designed as quick-changeable subassemblies. The multifunction robot is placed by means of a quick-action release mechanism  58  in the manner of a bayonet fastening on the projecting end of the pivoting arm  21  and, after the release of the bayonet fastening, can be lifted off by the indoor crane by means of the raising device  59  and set down at a service station or on another pivoting arm. The pivoting arm  21  is likewise equipped with a raising device  59   a  which, after the opening of the tension means  55 , makes it possible to manipulate the rotary column and the pivoting arm. 
       FIG. 4  shows a further variant of a rotary column  22  with a pivoting arm  21  for the reception of a multifunction robot  20 . The rotary column  22  is stationary and the pivoting arm  21  is formed by two parallel links  64 ,  65  which are supported, on the one hand, on the rotary column  22  pivotably about horizontal axes  64   a ,  65   a  and, on the other hand, on a carrying plinth  66  pivotably about horizontal axes  64   b ,  65   b . The drive device  57  is formed by a pressure medium cylinder and engages on one of the parallel links  65  and is itself supported on a bracket  67  of the rotary column  22 . The multifunction robot  20  is placed on the carrying plinth  66  and is fastened by means of a quick-action release mechanism  58 . 
       FIG. 5  shows the incorporation of the multifunction robots  20 ,  30  and of the drive devices  57  of the rotary columns  21 ,  31  into the process and plant control  71  of the continuous casting plant. By measuring and regulating devices  72 , not illustrated in any more detail, but conventional in multifunction robots, such as comprise, for example, image recorders, image evaluation devices, displacement transducers and drive assemblies for the individual axes of rotation of the robot, and also by the drive devices  57 , measurement signals are transmitted to a process computer of the plant control  71 , and are processed there, and control signals coordinated with the process management of the continuous casting plant are sent to the multifunction robots  20 ,  30  and the drive devices  57 .