Roller leveler

Abstract

A roller leveler is provided having a substantially uniform pitch of leveling rolls arranged in a zigzag manner. The roller leveler is provided with a first roll group having first leveling rolls arranged with a pitch “P 1 ” in the carrying direction of a steel plate, a second roll group having five pieces of second leveling rolls which are arranged with the pitch “P 1 ” in the carrying direction of the steel plate and have a zigzag arrangement with respect to the first leveling rolls, a first retract mechanism for retracting the middle first leveling rolls from the pass line, and second retract mechanisms for retracting the pairs of end second leveling rolls from the pass line. The second roll group has third leveling rolls disposed with the pitch “P 1 ” in the carrying direction of the steel plate with respect to the outermost second leveling rolls.

1 . A roller leveler in which a steel plate is flattened while being carried, comprising:
 a first roll group, which is provided with “n” pieces of first leveling rolls (“n” is an integer of 4 or more) which are arranged with a predetermined first pitch in a carrying direction of the steel plate;   a second roll group, which is provided with “n+1” pieces of second leveling rolls which are arranged with the first pitch in the carrying direction of the steel plate and are disposed in a zigzag manner with respect to the first leveling rolls, which is disposed so as to face the first roll group through a pass line where the steel plate is passed;   a first retract mechanism which makes some pieces of the first leveling rolls retract from the pass line for changing a number of the first leveling rolls which are used for flattening the steel plate; and   a second retract mechanism which makes some pieces of the second leveling rolls retract from the pass line for changing a number of the second leveling rolls which are used for flattening the steel plate;   wherein the second roll group is provided with at least a third leveling roll which is disposed on at least one of an upstream side and a downstream side in the carrying direction of the steel plate and which is disposed with the first pitch or with a pitch of “m” times of the first pitch (“m” is an integer of 2 or more) with respect to the second leveling roll in the carrying direction of the steel plate.   
     
     
         2 . The roller leveler according to  claim 1 , wherein the third leveling roll is disposed on both of the upstream side and the downstream side in the carrying direction of the steel plate. 
     
     
         3 . The roller leveler according to  claim 2 , wherein the third leveling roll which is disposed on both of the upstream side and the downstream side in the carrying direction of the steel plate is one (1) in number. 
     
     
         4 . The roller leveler according to  claim 3 , wherein
 the first roll group is provided with “4+3k” pieces of the first leveling rolls (“k” is an integer of 0 or more),   the second roll group is provided with “5+3k” pieces of the second leveling rolls,   the third leveling roll is disposed with the first pitch with respect to the second leveling roll in the carrying direction of the steel plate,   the first retract mechanism makes two adjacent first leveling rolls retract from the pass line for changing a pitch of the first leveling rolls which are used for flattening the steel plate, and   the second retract mechanism makes two adjacent second leveling rolls retract from the pass line for changing a pitch of the second leveling rolls which are used for flattening the steel plate.   
     
     
         5 . The roller leveler according to  claim 1 , further comprising a first holding roll and a second holding roll for holding the steel plate on the pass line on at least one of the upstream side and the downstream side with respect to the first roll group in the carrying direction of the steel plate,
 wherein the first holding roll and the second holding roll are disposed in a shifted state each other in the carrying direction of the steel plate.   
     
     
         6 . The roller leveler according to  claim 5 , further comprising
 a first holding member which rotatably holds the first holding roll,   a second holding member which rotatably holds the second holding roll,   a first moving mechanism by which the first holding roll is moved toward the pass line and retracted from the pass line, and   a second moving mechanism by which the second holding roll is moved toward the pass line and retracted from the pass line,   wherein the second holding member is turnably connected to the first holding member, and the second moving mechanism is attached to the first holding member to turn the second holding member.   
     
     
         7 . The roller leveler according to  claim 2 , further comprising a first holding roll and a second holding roll for holding the steel plate on the pass line on at least one of the upstream side and the downstream side with respect to the first roll group in the carrying direction of the steel plate,
 wherein the first holding roll and the second holding roll are disposed in a shifted state each other in the carrying direction of the steel plate.   
     
     
         8 . The roller leveler according to  claim 3 , further comprising a first holding roll and a second holding roll for holding the steel plate on the pass line on at least one of the upstream side and the downstream side with respect to the first roll group in the carrying direction of the steel plate,
 wherein the first holding roll and the second holding roll are disposed in a shifted state each other in the carrying direction of the steel plate.   
     
     
         9 . The roller leveler according to  claim 4 , further comprising a first holding roll and a second holding roll for holding the steel plate on the pass line on at least one of the upstream side and the downstream side with respect to the first roll group in the carrying direction of the steel plate,
 wherein the first holding roll and the second holding roll are disposed in a shifted state each other in the carrying direction of the steel plate.   
     
     
         10 . The roller leveler according to  claim 7 , further comprising
 a first holding member which rotatably holds the first holding roll,   a second holding member which rotatably holds the second holding roll,   a first moving mechanism by which the first holding roll is moved toward the pass line and retracted from the pass line, and   a second moving mechanism by which the second holding roll is moved toward the pass line and retracted from the pass line,   wherein the second holding member is turnably connected to the first holding member, and the second moving mechanism is attached to the first holding member to turn the second holding member.   
     
     
         11 . The roller leveler according to  claim 8 , further comprising
 a first holding member which rotatably holds the first holding roll,   a second holding member which rotatably holds the second holding roll,   a first moving mechanism by which the first holding roll is moved toward the pass line and retracted from the pass line, and   a second moving mechanism by which the second holding roll is moved toward the pass line and retracted from the pass line,   wherein the second holding member is turnably connected to the first holding member, and the second moving mechanism is attached to the first holding member to turn the second holding member.   
     
     
         12 . The roller leveler according to  claim 9 , further comprising
 a first holding member which rotatably holds the first holding roll,   a second holding member which rotatably holds the second holding roll,   a first moving mechanism by which the first holding roll is moved toward the pass line and retracted from the pass line, and   a second moving mechanism by which the second holding roll is moved toward the pass line and retracted from the pass line,   wherein the second holding member is turnably connected to the first holding member, and the second moving mechanism is attached to the first holding member to turn the second holding member.