JP2011245520A - Tension leveler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tension leveler capable of obtaining a rolled material with a flat surface and with high quality without making a vertical line pattern to the rolled material, and reducing an exchanging frequency of rolls by elongating their lifetime.SOLUTION: The tension leveler includes work rolls contacting with a rolled material, and back-up rolls, wherein each back-up roll 4 is configured by connecting a plurality of small rolls 11 in a longitudinal direction, and an outer peripheral surface of each small roll 11 is formed in a crown shape by expanding its center portion of the longitudinal direction outside in a radius direction to form a convex shape, and gradually reducing outer diameter toward both ends.

Description

  The present invention relates to a tension leveler for correcting distortion caused by rolling of a copper alloy strip or the like.

Strict flatness is required for copper alloy strips used for lead frames and the like. For this reason, at the end of the rolling process, distortion caused by rolling is corrected by a tension leveler.
This tension leveler has a structure in which a roll unit in which a plurality of stages of work rolls, intermediate rolls, and backup rolls are stacked face each other, and a material to be rolled is passed between the work rolls of both roll units and rolled while applying tension. It is.

  As such a tension leveler, for example, as described in Patent Document 1, bridle portions composed of a plurality of rolls are provided on the entry side and the exit side of the tension leveler. The tension can be adjusted.

  Further, in Patent Document 2, as a normal multi-stage rolling mill instead of a strain correction tension leveler, the shore hardness of a rolled surface of a ceramic roll (work roll) for rolling a material to be rolled is set to 100 to 130, and the ceramic roll is used. The shore hardness of the rolling contact surface of the intermediate roll that is rolled back to the shore is set to 30 to 50 hardness lower than the shore hardness of the rolled surface of the ceramic roll. And by setting it as such a structure, even if a foreign material adheres to the rolling process surface of a ceramic roll, the adhered foreign material will be transferred to the rolling contact surface of an intermediate roll, and a foreign material mark will arise on a ceramic roll. It is said that there is nothing to do.

JP 2001-252719 A JP 2001-179212 A

  By the way, although rolling oil is used for lubrication in a normal multi-high rolling mill, the tension leveler has a plurality of rolls in contact with the material to be rolled, and can form a uniform oil film on all the rolls. Since it is difficult, rolling oil cannot be used for oil film formation. For this reason, if a small amount of foreign matter, wrinkles, or the like adheres to the roll, the oil film is not protected, so that they are easily transferred to the material to be rolled.

Usually, the work roll and the intermediate roll are composed of long rolls extending in the width direction of the material to be rolled, but the backup roll has a structure in which a plurality of small rolls are arranged with a slight gap in the width direction. . Therefore, both ends of each small roll of the backup roll come into contact with the surface of the intermediate roll, and there is a risk that the intermediate roll may be indented by both ends of the backup roll. When the indentation is applied to the intermediate roll, it is sequentially transferred to form a vertical stripe pattern along the rolling direction on the material to be rolled.
Each roll is periodically replaced and the surface is re-polished, but if an indentation is formed, it is necessary to replace it in a short time. This is particularly noticeable when a hardness difference is provided between the backup roll, the intermediate roll, and the work roll.
In addition, when equipped with a mechanism for reciprocally sliding the intermediate roll in the axial direction during rolling, the backup roll does not contact continuously at the same position, so there is an effect of preventing adhesion of indentation, but the number of rolls is large. A tension leveler is difficult to implement due to its complicated structure.

  The present invention has been made in view of the above-mentioned circumstances, and can provide a high-quality rolled material with a flat surface and a long life without adding a vertical stripe pattern or the like to the material to be rolled. It is an object of the present invention to provide a tension leveler that can reduce the replacement frequency.

  The tension leveler of the present invention is a tension leveler provided with a work roll in contact with a material to be rolled and a backup roll thereof, wherein the backup roll is connected to a plurality of small rolls in the length direction, and each small roll The outer peripheral surface is formed in a crown shape in which the central portion in the length direction is bulged outwardly in the radial direction and the outer diameter is gradually reduced toward both ends.

By making the outer shape of each small roll of the backup roll into a crown shape, both ends of the backup roll are separated from the surface of the adjacent roll. Therefore, it is possible to prevent the occurrence of indentation due to the tip of the small roll being pressed.
In this case, there is no indentation prevention effect to the extent that the small roll is formed in a columnar shape and both ends are chamfered, and the outer diameter gradually increases toward the both ends by causing the central portion to bulge outward in the radial direction. By using a reduced crown shape, indentation can be effectively prevented.

In the tension leveler of the present invention, each small roll of the backup roll has 1000 × (D−d) / L, where D is the maximum outer diameter, d is the minimum outer diameter at both ends, and L is the length. It is good that it is 1-10.
If the difference (D−d) between the maximum outer diameter and the minimum outer diameter of the small roll is small, the effect of preventing indentation cannot be expected. On the other hand, if the difference is large, the contact pressure at the center becomes too strong, Indentation problems may occur. In addition, when the length of the small roll is short, a larger pressure acts than that of the long small roll, and therefore, if the crown-shaped inclination (Dd) is small, an indentation may be generated. For this reason, when the length of the small roll is short, it is necessary to set the inclination of the crown shape larger than when using a long small roll.
Therefore, by setting the relationship between the maximum outer diameter D of the small roll, the minimum outer diameter d of both ends, and the length L so that 1000 × (D−d) / L is 1 to 10, the generation of indentation is generated. It can be surely prevented. When 1000 × (D−d) / L is less than 1, the effect of preventing indentation cannot be expected depending on the pressure of the backup and the like, and when it exceeds 10, the indentation at both ends can be prevented. There is a risk of indentation.

  In the tension leveler of the present invention, an intermediate roll is provided between the work roll and the backup roll, the Shore hardness of the rolled surface of the work roll is H1, and the intermediate roll of each small roll of the backup roll When the shore hardness of the contact surface to H2 is H2 and the shore hardness of the contact surface of the intermediate roll to the work roll is H3, it is preferable that the relationship is set such that H1> H2> H3.

By setting the shore hardness of each roll such that H1>H2> H3, even if foreign matter adheres to the work roll, it is transferred to the intermediate roll, so that it is suppressed from being transferred to the material to be rolled. Can do. And since this intermediate roll has a relatively low hardness, it is in a surface state in which indentations are likely to occur, but the small roll of the backup roll has a crown shape, so even if it is an intermediate roll with low hardness, Occurrence can be prevented.
Further, since the backup roll has a Shore hardness higher than that of the intermediate roll, the backup roll can be firmly backed up without causing deformation.

  According to the tension leveler of the present invention, it is possible to prevent the occurrence of indentation due to the backup roll, and to finish the rolled material with a flat surface having no vertical stripe pattern or the like with a high quality. The service life can be extended and the replacement frequency can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS (a) which shows embodiment of the work roll used for the tension leveler of this invention is a whole perspective view, (b) is a top view of one small roll. It is a front view showing typically an embodiment of a tension leveler of the present invention.

Hereinafter, an embodiment of the present invention will be described.
The tension leveler 1 of this embodiment includes a plurality of work rolls 2 arranged in a plane, a plurality of intermediate rolls 3 supporting the back of the work rolls 2, and these intermediate rolls, as shown in FIG. 2 sets of roll units 5 and 6 constituted by a plurality of backup rolls 4 supporting the back portion of 3. These roll units 5 and 6 are arranged to face each other in a state where the front and rear positions of the work rolls 2 are shifted, and the material 7 to be rolled is running between the work rolls 2 of both roll units 5 and 6. It is the composition which corrects.

  Moreover, although the work roll 2 and each intermediate roll 3 are each comprised by one roll of the length larger than the width | variety of the to-be-rolled material 7, the backup roll 4 is as shown to Fig.1 (a). The plurality of small rolls 11 shorter than the work rolls 2 and the like are connected at intervals. In this case, the outer peripheral surface 11a of each small roll 11 has the largest outer diameter at the central portion in the length direction, bulges outward in the radial direction, and the outer diameter decreases toward the both ends from the central portion. It is formed into a crown shape.

In this case, as shown in FIG. 1B, when the maximum outer diameter of each small roll 11 is D, the minimum outer diameter at both ends is d, and the length is L, 1000 × (D−d) / L Is set to a dimensional relationship of 1 to 10.
Since each small roll 11 of the backup roll 4 is shorter than the intermediate roll 3, both ends thereof are arranged on the surface of the intermediate roll 3. While both ends of the small roll are in contact with each other and continuously rolling, both ends of the small roll bite into the intermediate roll, and indentation is likely to occur in that portion, but the outer shape of each small roll 11 is formed in a crown shape. By doing so, both ends are separated from the surface of the intermediate roll 3, and the occurrence of indentation can be suppressed.
Also, if the difference (D−d) between the maximum outer diameter and the minimum outer diameter of the small roll is small, the indentation preventing effect cannot be expected. There may be a problem of indentation due to the central portion. Even in the case of an indentation caused by the center of the small roll, a vertical stripe pattern appears on the material 7 to be rolled.

By setting this crown shape to a dimensional relationship in which 1000 × (Dd) / L is 1 to 10, the generation of indentation can be reliably prevented, and 1000 × (Dd) / L is 1 If it is less than 1, the indentation preventing effect cannot be expected depending on the pressure of the backup and the like, and if it exceeds 10, the indentation at both ends can be prevented, but in the case of a high backup pressure, the indentation may occur at the center.
Although the specific dimension of each small roll 11 is not limited, for example, L is 50-100 mm and D is 25-25 with respect to the outer diameter of an intermediate roll of 25-35 mm and length of 400-700 mm. 35 mm and d are set to 24.00 to 34.95 mm.

Further, regarding the surface hardness of each of the rolls 2 to 4 of the roll units 5 and 6, the Shore hardness of the rolled surface of the work roll 2 is H1, and the shore of the contact surface of each small roll 11 of the backup roll 4 to the intermediate roll 3 is Shore. When the hardness is H2 and the Shore hardness of the contact surface of the intermediate roll 3 with the work roll 2 is H3, the relationship is set such that H1>H2> H3.
For example, the Shore hardness H1 of the work roll 2 is 90 to 130, the Shore hardness H3 of the intermediate roll 3 is 70 to 100, and the Shore hardness H2 of each small roll 11 of the backup roll 4 is 75 to 105. Are set to a relationship of H1>H2> H3. As the hardness difference, the hardness difference H1-H3 between the work roll 2 and the intermediate roll 3 is 20-45, and the hardness difference H2-H3 between each small roll 11 of the backup roll 4 and the intermediate roll 3 is 5-20. The
By setting the shore hardness of each of the rolls 2 to 4 to a relationship of H1>H2> H3, since H1> H3, even if foreign matter adheres to the work roll 2, it is immediately transferred to the intermediate roll 3. Therefore, it can suppress that the foreign material is transcribe | transferred to the to-be-rolled material 7. FIG. Further, since H2> H3, the backup roll 4 can be backed up firmly without deformation.

In the tension leveler 1 configured as described above, the material is rolled and corrected between the roll units 5 and 6 while applying tension to the material 7 to be rolled.
In the roll units 5 and 6, the backup roll 4 is configured by connecting a plurality of small rolls 11, and both ends of each small roll 11 are arranged on the surface of the intermediate roll 3 as indicated by a chain line in FIG. Is done. In this case, the shore hardness H1 of the work roll 2 surface, the shore hardness H3 of the intermediate roll 3 surface, and the shore hardness H2 of the small roll 11 surface of the backup roll 4 are in the relationship of H1>H2> H3. Since the shore hardness H3 of the surface is set lower than the shore hardness H2 of the surface of the small roll 11 of the backup roll 4, it is easy to receive an indentation from the backup roll 4, but the small roll 11 of the backup roll 4 The outer peripheral surface 11a is formed in a crown shape and is set in a dimensional relationship with 1000 × (D−d) / L being 1 to 10, whereby both ends of the small roll 11 are separated from the intermediate roll 3, The roll 3 is prevented from being indented by the small roll 11, and the surface of the intermediate roll 3 can be kept smooth.

Further, since the Shore hardness H3 of the surface of the intermediate roll 3 is lower than the Shore hardness H1 of the surface of the work roll 2, if foreign matter adheres to the surface of the work roll 2, it immediately bites into the intermediate roll 3 and transfers. Then, the foreign matter on the surface of the work roll 2 is removed.
As described above, the tension leveler 1 prevents the indentation from the backup roll 4 from being attached to the intermediate roll 3, so that the surface of the intermediate roll 3 can be kept smooth. Since the foreign matter adhering to the intermediate roller 3 is immediately transferred to the intermediate roll 3, it is possible to prevent the foreign matter from remaining on the surface of the work roll 2, and thereby the vertical streak pattern caused by the indentation on the material 7 to be rolled. The to-be-rolled material 7 can be finished to a smooth surface without any foreign matter marks or the like.

Hereinafter, a tension leveler similar to the structure shown in FIG. 2 is configured by changing various dimensions of the crown shape of the small roll in the backup roll, and a Cu—Fe—P type 0.15 mm thick copper alloy strip as a material to be rolled. The material was corrected almost continuously, the surface state thereof was observed, and the time until a vertical streak that required replacement of the roll was recognized on the surface was measured. The surface state of the copper alloy strip was monitored for an arbitrary plurality of observation regions with an optical microscope to determine whether or not a vertical streak pattern was generated.
The results are shown in Table 1.

  As shown in Table 1, when straightening was performed using the tension levelers of Comparative Example 1 and Comparative Example 2, vertical streak patterns occurred before reaching 100 hours. In the case of Comparative Example 3 and Comparative Example 4, although it was over 100 hours, the occurrence of a vertical streak pattern due to the indentation at the center of the backup roll was observed. In contrast to these comparative examples, in the case of the tension leveler of the example, the generation of the vertical streak pattern was not recognized even after 200 hours continuously. Therefore, by setting the backup roll in a dimensional relationship such that 1000 × (D−d) / L is 1 to 10, it is possible to extend the life of the roll and reduce the replacement frequency, thereby facilitating maintenance. it can.

In addition, using the backup roll having the shape of Example 2, the Shore hardness of each roll was changed, and the influence on the surface condition of the material to be rolled due to the inclusion of foreign matter was observed. A copper powder having a diameter of 80 to 120 μm was used as the foreign matter, and the copper powder was adhered to the work roll surface to observe whether or not a foreign matter mark was generated on the surface of the copper alloy strip.
The results are shown in Table 2.

  As can be seen from Table 2, even if foreign matter adheres to the work roll, it is possible to make the shore hardness of each work roll, each small roll of the backup roll, and each shore hardness of the intermediate roll H1> H2> H3. It is possible to prevent foreign matter marks from being generated on the material to be rolled by being transferred to the intermediate roll.

Although the embodiment of the present invention has been described above, the present invention is not limited to this description and can be appropriately changed without departing from the technical idea of the present invention.
For example, although the roll unit is composed of a work roll, an intermediate roll, and a backup roll, the intermediate roll may be divided into a first intermediate roll and a second intermediate roll and configured in multiple stages.

1 Tension Leveler 2 Work Roll 3 Intermediate Roll 4 Backup Roll 5, 6 Roll Unit 11 Small Roll 11a Outer Surface

Claims (3)

  A tension leveler comprising a work roll in contact with a material to be rolled and a backup roll thereof, wherein the backup roll is connected to a plurality of small rolls in the length direction, and the outer peripheral surface of each small roll has a length. A tension leveler characterized in that it is formed in a crown shape in which the central part in the direction is bulged outwardly in the radial direction and the outer diameter is gradually reduced toward both ends.   Each small roll of the backup roll has a maximum outer diameter of D, a minimum outer diameter of both ends of d, and a length of L, and 1000 × (D−d) / L is 1 to 10. The tension leveler according to claim 1, wherein   An intermediate roll is provided between the work roll and the backup roll, the Shore hardness of the rolled surface of the work roll is H1, and the Shore hardness of the contact surface of each small roll of the backup roll to the intermediate roll The relationship is set such that H1> H2> H3, where H2 is the thickness of the surface and the Shore hardness of the contact surface of the intermediate roll to the work roll is H3. The described tension leveler.

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