JPH0224604B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scale breaker that cracks the scale of a steel strip to facilitate scale removal.

The rolled steel strip is pickled to remove the oxide film (scale) produced during rolling. However, since it takes a considerable amount of time to remove scale by pickling alone, a scale breaker is used that creates cracks in the scale by creating distortion on the scale surface before pickling.
This creates cracks in the scale, which speeds up penetration of the pickling solution and promotes scale dissolution.

Conventionally, a scale breaker as shown in Fig. 1 has been used. That is, it is composed of a bridle 1 consisting of a set of bridle rolls 2, which applies tension to the strip 14, and a tension leveler 3, which causes distortion in the scale of the surface of the strip 14. The tension leveler 3 includes deflector rolls 4, 11, back-up rolls 6,
8, 10, bending rolls 5, 7, 9, and pinch rolls 12, 13.

However, with such a scale breaker, the pickling time is only shortened by about 15 to 20%, and the scale breaker shown in Figure 2 is used for the purpose of significantly shortening the pickling time and correcting the shape of strips that are not well shaped. is proposed.

The scale breaker shown in FIG. 2 is composed of a pair of bridle rolls 22 or 52, including an inlet bridle 21 that applies tension to the strip 53, an outlet bridle 51, and a bridle that causes distortion in the scale on the surface of the strip 53. It is composed of a leveler 23. The tension leveler 23 has the following configuration. A pair of work rolls 25 and 26 are provided sandwiching the strip 53, and backup rolls 34 and 35 are engaged with these work rolls 25 and 26, respectively. The work roll 25 is provided with an intermeshing (reduction amount) adjusting means for applying a bending force to the strip 53. That is, the work roll 25
A fixed shaft 15 and an eccentric shaft 41 are provided below, and by rotating the eccentric shaft 41, the work roll 25 and the back-up roll 34 are moved up and down. A pair of deflector rolls 32 are provided above the strip 53 on the transport direction side of the pair of work rolls 25 and 26, and a pair of deflector rolls 32 are provided above the strip 53.
A work roll 33 is provided on the lower side facing a pair of deflector rolls 32. The work roll 33 includes the work roll 25,
Intermesh adjusting means is provided for correcting the warp by applying a correcting force to the strip 53 which has become warped due to being bent at 26. That is, a fixed shaft 17 and an eccentric shaft 43 are provided below the work roll 33, and by rotating the eccentric shaft 43, the work roll 33 and the back-up roll 38 are rotated.
moves up and down. Here, work rolls 25, 26,
The roll groups including 33 are respectively referred to as a first unit 54, a second unit 55, and an anticambering unit 58. Other deflector rolls 24, 2
7 is provided to keep the pass line of the strip 53 from changing even if the work rolls 25, 33 move up and down. Note that 44 and 46 are deflector rolls for roll replacement.

In such a scale breaker, work roll 2
5 and 26, the strip 53 is elongated by forward bending and reverse bending, and the strip 53, which has been repeatedly bent in this way and has warped in the width direction and longitudinal direction, is straightened by the work roll 33. . By using this scale breaker, the pickling time was shortened by 2 to 3 times as compared to the case where the scale breaker shown in FIG.

However, in the case of special steel that is thick and has a high yield strength (yield point), there is a drawback that it is not possible to generate enough cracks in the scale of the strip.
Despite the increasing need for such special steel, we are unable to meet it.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a scale breaker that can sufficiently generate cracks in the scale even in a strip having a large plate thickness and high yield strength.

The structure of the present invention that achieves this object includes a first work roll having a work roll and intermeshed adjustment means for the work roll, which are disposed opposite to each other on both sides of the strip conveyed under tension. a second unit having a unit and a work roll; a pair of deflector rolls provided on one side of the strip on the conveying direction side of the first and second units;
A scale breaker comprising a work roll located between and facing the deflector rolls, and an anticambering unit having an interface adjustment means for the work rolls,
A third unit having a work roll and intermeshed adjusting means for the work roll, which is disposed facing each other on both sides with the strip between the first and second unit pairs, the deflector roll and the anti-cambering unit; It is characterized in that at least one fourth unit pair having work rolls is provided.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. Since the present invention is a partial improvement of the conventional scale breaker shown in FIG. 2, the same parts as those of the conventional scale breaker are given the same reference numerals, and only the different parts will be explained.

The present invention is a scale breaker shown in FIG. 2, which is provided with two sets of work rolls on the side opposite to the conveyance direction with respect to the pair of deflector rolls 32. That is, a third unit 56, which is the same as the first unit 54, is provided between the first unit 54 and the anticambering unit 58, and a third unit 56, which is the same as the first unit 54, is provided between the first unit 54 and the anticambering unit 58.
A fourth unit 57, which is the same as the second unit 55, is provided between the deflector roll 5 and the pair of deflector rolls 32. By adding the third unit 56 and fourth unit 57 in this way, the strip 53
Deflector rolls 28 and 31 are added to prevent fluctuations in the pass line, and a deflector roll 45 for roll replacement is also added.

The function of such a scale breaker will be explained. The strip 53 moves from left to right in the figure while being tensioned by the entry bridle 21 and the exit bridle 51. Eccentric shaft 41 is fixed shaft 1
When the back-up roll 34 and work roll 25 are raised by rotating the strip 53 around the work rolls 25 and 26
As a result, the work roll 25 enters between the deflector roll 24 and the work roll 26, resulting in a so-called mesh state. next,
Similarly to the first unit 54, the eccentric shaft 42 is rotated around the fixed shaft 16 to raise the backup roll 36 and the work roll 29, so that the work roll 29 is connected to the deflector roll 28 and the work roll 3.
0. Similarly, in the anticambering unit 58, the work roll 33 is raised to bring the strip 53 into contact with the pair of deflector rolls 32 and the work roll 33.

The tensioned strip 53 is forward and reverse bent and elongated by work rolls 25 and 26. Thereafter, the strip 53 is stretched again by the work rolls 29 and 30. Finally, the strip 53 is stretched by the work roll 33 of the anticambering unit 58. This anticambering unit 58 has the function of elongating the strip 53 like the first to fourth units, but it also corrects warping in the width direction and longitudinal direction due to residual stress in the strip 53 that has been repeatedly bent in the previous process. It also has functions. In actual operation, the first unit 54
The interface between the third unit 56 and the fourth unit 57 is made smaller to increase the surface strain and elongation of the strip 53, causing many cracks in the scale, and the interface between the third unit 56 and the fourth unit 57 is made smaller. If the scale breaker is operated in a manner that reduces elongation and primarily performs shape correction, good results will be obtained in terms of scale removal and shape correction.

Conventional scale breakers have a set of work rolls for elongation, so they can only process strips with a small thickness and low yield strength (σ<40Kg/mm ² ), whereas strips with a thickness of 4.5 mm or more have high yield strength. (σ＞40Kg/
mm ² ) Not applicable for high-strength materials. On the other hand, since the scale breaker according to the present invention has two sets of work rolls for elongation, the first unit 5
4 and the second unit 55 can be compensated for by the third unit 56 and the fourth unit 57, which improves the ability to create cracks in the scale and the ability to correct the strip shape. Even if the thickness is large, it can be used satisfactorily.

In addition, since the tension leveler 23 is divided into two parts as shown in FIG. 3, it is convenient to replace the rolls. With conventional scale breakers, the tension leveler cannot be used at all when changing rolls, but with the scale breaker according to the present invention, when changing rolls, the third unit 56 and fourth unit 57 can be pulled out of the line. The first unit 54 and the second unit 55 can also be used. Conversely, when the first unit 54 and the second unit 55 are pulled out of the line and the rolls are replaced, the third unit 56 and the fourth unit 57 are removed.
and can be used.

Although the present embodiment shows a case in which two sets of work rolls are provided on the opposite side of the conveyance side with respect to a pair of deflector rolls, the present invention is not limited to this, and three or more sets may be provided.

As described above with reference to the embodiments and drawings, the scale breaker according to the present invention is equipped with two or more sets of work rolls for elongation, so even if the plate thickness is large or the strip has high yield strength, cracks will not occur in the scale. It is possible to cause

[Brief explanation of drawings]

1 and 2 are structural diagrams of a conventional scale breaker, respectively, and FIG. 3 is a structural diagram of a scale breaker according to the present invention. In the drawing, 15, 16, 17 are fixed shafts, 21 is an entrance bridle, 25, 26, 29, 30, 33 are work rolls, 32 is a deflector roll, 41,
42, 43 are eccentric shafts, 51 is an exit bridle, 5
3 is a strip.

Claims (1)

[Claims] 1. A first unit having a work roll and an interface adjustment means for the work roll, and a second unit having a work roll, which are disposed opposite to each other on both sides of the strip to sandwich the strip being conveyed under tension; The first of these,
A pair of deflector rolls provided on one side of the strip on the conveying direction side of the second unit, a work roll located between and facing the deflector rolls, and intermeshed adjustment between the work rolls. a scale breaker comprising an anti-cambering unit having a strip, the work rolls being disposed facing each other on both sides with a strip between the first and second pair of units and the deflector roll and the anti-cambering unit; 1. A scale breaker comprising: a third unit having a work roll interface adjustment means; and a fourth unit having a work roll.