Abstract:
A method of and an installation for exchange of roll sets ( 5, 6 ) contemplate provision of a number of separate transversely displaceable carriages ( 9, 10, 11 ), whereby individual worn-out working roll sets ( 6 ) are displaced along a single connection track ( 14 ) by a single locomotive ( 21 ) in a roll workshop ( 20 ), and a new working roll set ( 6   a ) is displaced back to an installation position, and wherein during formation of a gap ( 12 ) in front of a rolling mill stand ( 2, 3, 4 ), a withdrawn backup roll set ( 5 ) is transported by a crane in the roll workshop and back.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a method of and an installation for exchanging roll sets in rolling mill stands of a rolling mill train with several rolling mill stands which include respective backup and working roll sets, by displacing a working roll set or a backup roll set, which are supported on top of each other, in an axial direction, on an operator&#39;s side, into a roll workshop and subsequently displacing back and mounting new roll sets. 
     2. Description of the Prior Art 
     Such method of exchanging roll sets is disclosed in DE 43 21 663 A1. Firstly, on the operator&#39;s side of the rolling mill stands, there are provided support plates that are supported on a carriage, are displaced transverse to the roll axes, and are equipped with at least two rail pairs arranged adjacent to each other. The working roll sets themselves are supported on rolls. In front of the rolling mill stands, there are formed pits on the bottom of which draw-out rails for backup roll sets are provided. The pits are closed with swing covers that likewise carry rails along which the working roll sets are drawn out or inserted. Neither the construction with pits nor the use of rails over the pits are particularly convenient. 
     U.S. Pat. No. 4,772,626 discloses transportation of backup roll sets and working roll sets together on a carriage. The transfer of different roll sets depends on a tall construction of roll exchange carriages having a large bearing capacity, and the method is very complicated. 
     The object of the present invention is to provide with small constructional modifications, a flexible method of exchanging roll sets in selected rolling mill stands and which would correspond to the operating cycle in a roll workshop. 
     SUMMARY OF THE INVENTION 
     The object of the invention is achieved, according to the invention, in that on the operator&#39;s side, individual worn-out working roll sets are brought on a number of separate transversely displaceable carriages that corresponds to a number of the rolling mill stands, one after another along a single connection track by a single locomotive into the roll workshop and, therefrom, new working roll sets are displaced back and are set at exchange distances on respective transversely displaceable carriages between the rolling mill stands, and in that after unblocking of the operator&#39;s side by the transversely displaceable carriages, after dismantled respective worn-out working roll sets, the worn-out backup roll sets are withdrawn and are brought with a crane in the roll workshop, are serviced, are transported back, and are again mounted in corresponding rolling mill stands. The method separates exchange of the working roll sets from the exchange of the backup roll sets and, for that reason alone, is more flexible. The method is more economical because of smaller expenses. The process is applicable to separate rolling mill stands and to the exchange of roll sets. 
     The simplification of the inventive method and its adaptation to the operation in roll workshop, as well as time saving, is achieved in that in a start position, in front of each rolling mill stand, simultaneously, the transversely displaceable carriage is adjusted to the exchange distance, worn-out working roll sets are removed, after transverse displacement, new working roll stands are placed on another carriage half, and the worn-out working roll sets are displaced, respectively, by their transversely displaceable carriages, over slides on the chock in the roll workshop, are dismantled, and new working roll sets are brought again in the start position. 
     A further simplification is achieved in that in the start position, a respective worn-out set is pulled onto associated carriage half, and a new working roll set, which is delivered form the roll workshop, is pushed onto the other carriage half at a distance from the axis that corresponds to the exchange distance in front of the rolling mill stand. 
     A timely and localized exchange of the to-be-exchanged roll sets in respective rolling mill stands can be achieved in that the transversely displaceable carriages are displaced in a rolling direction one after another from their defined positions for rolling mill stand dismantling or installation positions. Thereby, corresponding premises for exchange of backup roll sets can be provided. 
     According to an embodiment of the invention, with respective intermediate plates pivotal in a horizontal plane precisely reproducible distances and exchange positions with respect to adjacent rolling mill stands are established between the transversely displaceable carriages, and established exchange distances are compensated during pivoting or vertical displacement of the intermediate plates and/or closing plates. Thereby, a precise start of installation of working roll sets in a rolling mill stand is facilitated. 
     According to a further development of the invention, for exchanging backup roll sets, transversely displaceable carriages are displaced away, and in front of respective rolling mill stands, respective gaps are provided, and worn-out backup roll sets are removed with a crane, and new refurbished backup roll sets are installed with the crane. Thereby, the movements of transportation means for the working roll sets and the backup roll sets are adapted to each other. 
     As soon as the backup roll sets are displaced to their operational position and are locked in respective rolling mill stands, the gaps in front of the rolling mill stands are closed again by pivoting the intermediate plates, and the transversely displaceable carriages are again displaced in the exchange space. 
     According to a further embodiment, empty transversely displaceable carriages, with the intermediate plates being pivoted away, are displaced in respective parking positions at one and/or another end of the rolling mill train and are parked. 
     The installation for exchanging roll sets in rolling mill stands of a rolling mill strain with several rolling mill stands proceeds from the state of the art that provides for connection of respective backup and working roll sets with a drive for transverse dismantling or transverse installation of roll sets, wherein parallel to a rolling direction, rails for transversely displaceable carriages in a foundation and a connection track toward a roll workshop are provided, and the transporting carriages are connected with a drive. 
     The object of the invention is achieved according to the invention in that the transversely displaceable carriages are displaceable along continuous rails placed in the foundation parallel to the rolling direction at fixed spacings between the rolling mill stands which are controlled with pivotal intermediate plates, and that only one connection track runs, transverse to the rails, in the roll workshop and on which only one locomotive, to which a respective working roll set is attachable or detachable, runs. 
     The space saving in front of the rolling mill stand is achieved in that the intermediate plates are, respectively, height-adjustable or pivoted away in a vertical plane or are adjustable in a horizontal plane. 
     Despite the artificial free space in front of the rolling mill stands, advantageously, the transversely displaceable carriages, the intermediate plates pivotal in the horizontal plane, and closing plates, which are provided at the ends of a foundation pit, are fixed against rotation but are pivotal in the horizontal plane and are vertically adjustable, form a continuous accessible working surface. The constructional units can also be operated automatically, so that use of the crane is avoided or it need be used only rarely. 
     A further automatic step is achieved in that at the ends of the rails that run parallel to the rolling direction, respective fixedly and pivotally supported closing plates are arranged and which provide for movement of the transversely displaceable carriages together with the pivotal intermediate plates, by at least half of the transversely displaceable carriage. 
     The drawings show an embodiment of the invention that will be described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings show: 
         FIG. 1  a side view of a rolling mill train with three rolling mill stands; 
         FIG. 1A  a roll housing with a working roll set and a backup roll set in an operational position; 
         FIGS. 2-9  a plan view of different phases of exchange of the working roll set; 
         FIG. 9A  parking positions of transversely displaceable carriages; and 
         FIG. 10  a plan view of the phase “pivoting of intermediate plates” with return to a start position according to  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In  FIGS. 1 and 1A , the rolling mill train  1  is formed, e.g., of three rolling mill stands  2 ,  3 , and  4 . Each rolling mill stand  2 ,  3 ,  4  has a backup roll set  5  located in an operational position, and worn-out working roll sets  6  with chocks. In  FIG. 1 , the working roll and backup roll sets  6 ,  5  are already dismantled and are located, respectively, on first transversely displaceable carriage  9 , second transversely displaceable carriage  10 , and third transversely displaceable carriage  11 . The working roll sets  6  (or  6   a ) consist, respectively, of upper and lower rolls which support each other by means of chocks, just as backup rolls  5  (not shown in detail in the dismantled phase).  FIG. 1  shows a start position  1   a  in which the roll exchange is carried out on an operator&#39;s side  1   b . A worn-out working roll set  6  is shown in side view ( FIG. 1 ) and in plan view in  FIGS. 2-8  and is shown in the drawings with hatching, and a new working roll set  6   a  is shown without hatching. 
     On the operator&#39;s side  1   b , there are located a number of separate transversely displaceable carriages  9 ,  10 ,  11  which correspond to the number of the rolling mill stands  2 ,  3 ,  4  and which carry new working roll sets  6   a  delivered from a roll workshop  20 . The worn-out working roll sets  6  are withdrawn with a working roll-draw-out cylinder  8  and a locomotive  21 . The separate transversely displaceable carriages  9 ,  10 ,  11 , which are equipped with their own drives, respectively, are displaceable over a single connection track  14   a  toward the roll workshop  20 , and the transversely displaceable carriages  9 ,  10 ,  11  are displaceable in a rolling direction  13  on rails  14 . Further transportation from the rails  14  onto the connection track  14   a  takes place over slides on respective chocks. The displacement along the connection rail  14   a  is effected with a single locomotive  21 . The transversely displaceable carriages  9 ,  10 ,  11  are controlled by spacer means  7 . After operator&#39;s side  1   b  becomes free upon displacement of the transversely displaceable carriages  9 ,  10 ,  11  after dismantling of respective worn-out working roll sets  6 , the worn-out backup roll sets  5  are dismantled and are brought in the roll workshop  20  by a crane, and new ground rolls are brought back in associated rolling mill stands  2 ,  3 ,  4 , are mounted there, and are locked. The displacement of the transversely displaceable carriages  9 ,  10 ,  11  over the rails  14  in the foundation pit  15   a  of the foundation  15  provides for respective gaps  12  (see also  FIG. 9A ) for dismantling or mounting of the backup roll sets  5 . 
     The transversely displaceable carriages  9 ,  10   11  are arranged with a right half for worn-out working roll sets  6  at respective exchange distances  2   a ,  3   a ,  4   a  (with three rolling mill stands) and with left half for new working roll sets  6   a . The spacer means  7  consists, in the embodiment shown, of pivotal intermediate plates  7   a . The intermediate plates  7   a  are relatively light and thin, so that a crane for their manipulation is not necessary. 
     The working roll sets  6   a  are just delivered, as shown in  FIGS. 2 and 3 , from the remotely located roll workshop  20 . The working roll sets  6   a  are attached to the locomotive  21  and are transferred onto the transversely displaceable carriages  9 ,  10 ,  11 . 
       FIG. 2  shows a start position  1   a  in front of each rolling mill stand  2 ,  3 ,  4 , with the transversely displaceable carriages  9 ,  10 ,  11  being adjusted with the intermediate plates  7   a  pivotal in a horizontal plane. The worn-out working roll sets  6  are then moved away ( FIG. 3 ). After the transverse displacement onto the other carriage halves, the new working roll sets  6   a  are mounted in respective rolling mill stands  2 ,  3 ,  4 . The worn-out working roll sets  6  are then displaced into the roll workshop  20  for maintenance. A new working roll set  6   a  is again brought to a start position ( FIG. 2 ), and the cycle begins anew. 
     A particular feature here is that in the start position  1   a , respective worn-out working roll sets  6  are pulled onto associated carriage halves, and new working roll sets  6   a  are located at the exchange distance  2   a ,  3   a ,  4   a  in front of the respective rolling mill stands  2 ,  3 ,  4 , placed on the other carriage halves, whereby a precise adjustment is carried out. 
     According to  FIG. 3 , respective transversely displaceable carriages  9 ,  10 ,  11  are aligned with distances  2   a ,  3   a ,  4   a  with respect to each other with the intermediate plates  7   a  having been pivoted out. The transversely displaceable carriages  9 ,  10 ,  11  are displaced out of these predetermined mounting or dismantled positions in the rolling direction  13  one after another. 
     According to  FIG. 4 , all of the new working roll sets  6   a  are located in their mounting position with respect to the rolling mill stands  2 ,  3 ,  4  and are pushed in with the working roll push-in cylinder  8  and the locomotive  21  and are secured in the stands. 
     In  FIG. 5 , the new working roll sets  6   a  are pushed in the working roll stands  2 ,  3 ,  4  and are secured in the operational position. With separate movements, the transversely displaceable carriages  9 ,  10 ,  11  are repeatedly precisely adjusted, respectively, by the intermediate plates  7   a  pivotal in the horizontal plane, relative to each other at the distances and in the exchange positions relative to the adjacent rolling mill stands  2 ,  3 ,  4 , with the stationary arranged closing plates  18  at the ends of rails  14  closing the remaining gaps. The distances between the transversely displaceable carriages  9 ,  10 ,  11  can be adjusted, respectively, by pivotal movements or transverse movements of the intermediate plates  7   a  and/or the closing plates  18 , as shown in  FIG. 6 . 
     The transverse arrangement of the intermediate plates  7   a  and of the closing plate  18  provides free space so that for the exchange of the backup roll sets  5 , in front of respective rolling mill stands  2 ,  3 ,  4 , respective gaps  12  are formed by moving the transversely displaceable carriages  9 ,  10 ,  11  away (see also  FIG. 9A ). A worn-out backup roll set  5  can be removed by a crane, and a new refurbished backup roll set  5  can be again installed with the crane. 
     According to  FIG. 7 , the transversely displaceable carriages  9 ,  10 ,  11  are connected one after another to the locomotive  21  displaceable along the connection track  14   a . Respective worn-out working roll sets  6  are displaced in the roll workshop  20  and are exchanged there for new working roll sets  6   a.    
     As shown in  FIG. 8 , respective worn-out working roll sets  6  are displaced into the roll workshop  20  with the locomotive  21 , are exchanged there for respective new working roll sets  6   a , and are displaced back, as also shown in  FIG. 8 . 
     According to  FIG. 9 , the second working roll set  6  is already displaced back from the roll workshop  20 , together with a new working roll set  6   a . Only the third worn-out working roll set  6  has to be displaced in the roll workshop  20 . 
       FIG. 9A  shows that empty transversely displaceable carriages  9 ,  10 ,  11  are displaced, at the pivoted-out or transversely lifted intermediate plates  7   a  and closing plates  18 , in a left parking position (transversely displaceable carriages  9 ,  10 ) and in a right parking position (transversely displaceable carriage  11 ), with the intermediate plates  7   a  being pivoted out and the closing plates  18  being lifted in order to save space. Thereby, the gaps  12  in front of rolling mill stands  3  and  4  remain free for other manipulations. 
     As further shown in  FIG. 9A , the intermediate plates  7   a  are pivotally supported on respective transversely displaceable carriages  9 ,  10 ,  11  and are displaced toward and away with displaceable on the carriage, pneumatic or hydraulic piston-cylinder drives  17 . The piston-cylinder drives  17  are provided on the closing plates  18 , doubly on the first transversely displaceable carriage  9 , and on one side, on the right, on the second and third transversely displaceable carriages  10  and  11 . 
     After being loaded with a new working roll set  6   a , the transversely displaceable carriages  9 ,  10 ,  11  are displaced, as shown in  FIG. 10 , again in the mounting position in front of the rolling mills stands  2 ,  3 ,  4 . Finally, the intermediate plates  7   a  are displaced into a horizontal plane, and the closing plates  18  are lowered in the horizontal plane. The new working roll sets  6   a  are located in a position for a rapid replacement of worn-out working rolls sets  6 . The invention also provides for exchange of separate worn-out working roll sets  6 . 
     The transversely displaceable carriages  9 ,  10 ,  11 , together with the pivotal in the horizontal plane, intermediate plates  7   a  and arranged at the ends of a foundation pit  15   a , liftable and horizontally pivotal, stationary closing plates  18 , form, in the horizontal plane, a continuous accessible working surface  19 . 
     In  FIGS. 1 ,  2 - 5  and  10 , at the ends of the rails  14 , there are arranged, parallel to the rolling, direction  13 , stationary, pivotally and vertically adjustable, closing plates  18  that form, together with the intermediate plates  7   a , the working surface  19 . 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1 . Rolling mill train 
               1   a . Start position 
               1   b . Operator&#39;s side 
               2 . Roll stand 
               2   a . Exchange distance 
               3 . Roll stand 
               3   a . Exchange distance 
               4 . Roll stand 
               4   a . Exchange distance 
               5 . Set of backup rolls 
               6 . Worn-out work roll set (Drawings; with hatching) 
               6   a . New work roll set (Drawings: without hatching) 
               7 . Spacer means 
               7   a . Pivotal intermediate plate 
               8 . Work roll-draw-out cylinder 
               9 . First transversely displaceable carriage 
               10 . Second transversely displaceable carriage 
               11 . Third transversely displaceable carriage 
               12 . Gap in front of a roll stand 
               13 . Rolling direction 
               14 . Rails 
               14   a . Connection track 
               15 . Foundation 
               15   a . Foundation pit 
               16 . Spacings 
               17 . Piston-Cylinder drive 
               18 . Stationary secured closing plate 
               19 . Accessible Working surface 
               20 . Roll workshop 
               21 . Locomotive