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1. EP2845659 - ROLLER LEVELER AND PLATE MATERIAL CORRECTION METHOD USING SAME

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

Claims

1. A roller leveler (100) for flattening a plate by passing the plate through a pass line, the roller leveler (100) comprising:

a leveling roll unit (20) including a plurality of leveling rolls (6, 8a, 8b) arranged on upper and lower sides of the pass line in a staggered manner and configured to rotate so as to pass the plate while flattening the plate sandwiched therebetween;

a pushing cylinder (4a, 4b) provided at each of an entrance side and a discharge side of the leveling roll unit (20), at which the plate enters and is discharged, respectively, and configured to press the plate via the leveling rolls (6, 8a, 8b); and

a driving mechanism (15) configured to rotate the leveling rolls (6, 8a, 8b) to pass the plate,

the roller leveler being characterized in that

at least one of the plurality of leveling rolls (8b) has a stepped structure, the at least one of the plurality of leveling rolls (8b) including a lateral center portion (21) with a large diameter, corresponding to a center portion of the plate with respect to a plate width direction, and a lateral end portion (22) with a small diameter, corresponding to an edge portion of the plate with respect to the plate width direction.


  2. The roller leveler (100) according to claim 1, wherein
the plurality of leveling rolls (6, 8a, 8b) include a plurality of upper leveling rolls (6) that are arranged above the pass line and a plurality of lower leveling rolls (8a, 8b) that are arranged below the pass line, wherein at least one of the lower leveling rolls (8b) has the stepped structure.
  3. The roller leveler (100) according to claim 2, wherein two or more of the lower leveling rolls (8b) from one end of the leveling roll unit (20) have the stepped structure.
  4. The roller leveler (100) according to any one of claims 1 to 3, wherein
the leveling roll unit (20) includes the leveling roll or rolls (8b) having the stepped structure at one end side of the leveling roll unit (20), and, at the other end side of the leveling roll unit (20), includes the leveling roll or rolls (6, 8a) having a straight form only.
  5. The roller leveler (100) according to any one of claims 1 to 4, wherein
length of the lateral center portion (21) of the leveling roll (8b) having the stepped structure and length of the lateral end portion (22) thereof are set according to width and material of the plate to be flattened, and a heat-treatment condition.
  6. The roller leveler (100) according to any one of claims 1 to 5, wherein
the leveling roll (8b) having the stepped structure is configured so that the lateral end portion (22) thereof is capable of being fitted with a ring (23) having a diameter the same as that of the lateral center portion (21) thereof so that length of the lateral center portion (21) thereof is adjustable with the use of the ring (23).
  7. A plate flattening method of flattening a plate with the use of a roller
leveler (100), in which the plate is passed through a pass line to flatten the plate, the roller leveler (100) including: a leveling roll unit (20) having a plurality of leveling rolls (6, 8a, 8b) arranged on upper and lower sides of the pass line in a staggered manner; a pushing cylinder (4a, 4b) provided at each of an entrance side and a discharge side of the leveling roll unit (20), at which the plate enters and is discharged, respectively, and configured to press the plate via the leveling rolls (6, 8a, 8b); and a driving mechanism (15) configured to rotate the leveling rolls (6, 8a, 8b) to pass the plate, the plate flattening method comprising:
sandwiching the plate between the plurality of leveling rolls (6, 8a, 8b); and
rotating the leveling rolls (6, 8a, 8b) while the pushing cylinder (4a, 4b) presses the plate via the leveling rolls (6, 8a, 8b) to pass and flatten the plate,
the plate flattening method being characterized in that
at least one of the plurality of leveling rolls (8b) has a stepped structure, the at least one of the plurality of leveling rolls (8b) including a lateral center portion (21) with a large diameter, corresponding to a center portion of the plate with respect to a plate width direction, and a lateral end portion (22) with a small diameter, corresponding to an edge portion of the plate with respect to the plate width direction,
whereby, when the plate is flattened, a pressing amount at the center portion of the plate with respect to the plate width direction is greater than a pressing amount at the edge portion of the plate with respect to the plate width direction to suppress occurrence of edge waves at the edge portion of the plate with respect to the plate width direction and/or eliminate edge waves present at the edge portion of the plate with respect to the plate width direction.
  8. The plate flattening method according to claim 7, wherein
the plurality of leveling rolls (6, 8a, 8b) include a plurality of upper leveling rolls (6) that are arranged above the pass line and a plurality of lower leveling rolls (8a, 8b) that are arranged below the pass line, wherein at least one of the lower leveling rolls (8b) has the stepped structure.
  9. The plate flattening method according to claim 8, wherein
two or more of the lower leveling rolls (8b) from one end of the leveling roll unit (20) have the stepped structure.
  10. The plate flattening method according to any one of claims 7 to 9, wherein
the leveling roll unit (20) includes the leveling roll or rolls (8b) having the stepped structure at one end side of the leveling roll unit (20), and, at the other end side of the leveling roll unit (20), includes the leveling roll or rolls (6, 8a) having a straight form only,
when a variation Δσ in yield stress in the plate in the plate width direction satisfies a relation, Δσ > 0.08 x σ MAX, and/or there are edge waves in the plate, flattening of the plate is performed with the one end side being the entrance side so that the pressing amount at the center portion of the plate with respect to the plate width direction is greater than the pressing amount at the edge portion of the plate with respect to the plate width direction to suppress occurrence of the edge waves at the edge portion of the plate with respect to the plate width direction and/or eliminate the edge waves present at the edge portion of the plate with respect to the plate width direction with the use of the leveling roll or rolls (8b) having the stepped structure, and,
when a relation, Δσ ≤ 0.08 x σ MAX, is satisfied and there is no edge wave in the plate, flattening of the plate is performed with the other end side being the entrance side so that the elongation of the center portion of the plate with respect to the plate width direction and the elongation of the edge portion of the plate with respect to the plate width direction are almost equal to each other,
wherein Δσ is equal to σ MAX - σ MIN, σ MAX is A maximum value of yield stress in the plate width direction, and σ MIN is a minimum value of yield stress in the plate width direction.
  11. The plate flattening method according to any one of claims 7 to 10, wherein
length of the lateral center portion (21) of the leveling roll (8b) having the stepped structure and length of the lateral end portion (22) thereof are set according to width and material of the plate to be flattened, and a heat-treatment condition.
  12. The plate flattening method according to any one of claims 7 to 11, wherein
the leveling roll (8b) having the stepped structure is configured so that the lateral end portion (22) thereof is capable of being fitted with a ring (23) having a diameter the same as that of the lateral center portion (21) thereof so that length of the lateral center portion (21) thereof is adjustable with the use of the ring (23) according to width and material of the plate to be flattened, and a heat-treatment condition.