JP4835123B2 - Turning table for thick plate rolling mill - Google Patents

Description

  The present invention relates to a turning table of a thick plate rolling machine that can achieve improvement in productivity of thick plates.

  The thick plate rolling process is generally performed in the following three processes. (1) Forming and rolling process to reduce the slab, which is the raw material, to the required thickness, (2) Widening rolling to reduce the thickness until the product width can be secured by expanding the width of the formed and rolled material. And (3) a finish rolling step of reducing the thickness to the thickness of the product while maintaining the width of the rolled material that has been rolled out, and for this reason, between (1) and (2), and ( Between 2) and (3), the material to be rolled needs to be turned 90 ° in the plane. This 90 ° turning operation is performed by turning tables 2 and 3 as shown in FIG.

  The turning tables 2 and 3 are composed of a plurality of turning rollers 4 composed of 4A and 4B, and these two types of rollers are arranged in a staggered manner. The turning roller 4A is a roller having a larger diameter on the OP side than the DR side, and the other turning roller 4B is a roller having a larger diameter on the DR side than the OP side. During thick plate rolling, the material to be rolled S can be rotated 90 degrees by the mutual reverse rotation of the adjacent rolling rollers 4A and 4B, and the material to be rolled S can be conveyed by rotation in the same direction.

In FIG. 1B, when the slab is subjected to a plurality of passes of reverse rolling to produce a thick plate, a 90 ° turning operation is performed after the final pass of forming rolling and after the final pass of tenter rolling. Showed that. In FIG. 1B, a indicates the slab length of the thick plate material, and b indicates the slab width. Reference numeral 6 denotes a rolling direction, and 1A denotes an axis of a work roll incorporated in the rolling mill 1.
Thus, in thick plate rolling, two 90 ° turning operations are performed for each thick plate. Therefore, various studies have been made since shortening this time leads to improvement in the productivity of thick plates.

Here, the direction in which the slab is conveyed to the rolling mill 1 is the front surface, and the direction in which the thick plate rolled to the product thickness is conveyed to the next process is the rear surface. The turning operation will be specifically described with reference to FIG.
The 90 ° turning operation is performed after the material to be rolled S metal-out from the rolling mill 1 is transported in the direction indicated by the arrow 7, reaches a predetermined position on the turning table, and is temporarily stopped. Next, centering is performed by sandwiching the material to be rolled S after the 90 ° turning operation by the movable side guide 5, and then the material to be rolled S is reversed and conveyed in the direction indicated by the arrow 8. Let Centering is an operation for matching the center position of the material S to be rolled in with the center of the rolling mill 1. FIG. 3 shows an operation flow including 90-degree turning operation and centering from metal-out to metal-in.

  Recently, in the plate rolling, when the amount of downward warping of the material to be rolled is large, it is recognized that the corner of the material to be rolled S is caught by the small diameter portion of the turning roller that should not be contacted during the 90-degree turning operation. It was. As a result, it was found that the turning time is longer than that when the downward warping amount is small, and the centering time is extended. Therefore, even when the amount of downward warping is large, it is important to smoothly perform the 90-degree turning operation in order to improve the productivity of the thick plate.

  For example, Patent Document 1 proposes a thick plate turning method that smoothly and quickly turns. As shown in FIGS. 8 and 9, the thick plate rolling method described in Patent Document 1 is a thick plate on a turning table in which rolling rollers that are in point contact with the thick plate (corresponding to the material to be rolled S) are arranged. And the rotational speed of each roller is controlled so that the angular speed of the thick plate becomes substantially constant. Alternatively, before the turn, as shown in FIG. 10, the axial position of each roller is controlled so that the contact point with the thick plate is arranged on the substantially circumference.

The turning roller 11 has a large-diameter portion profile formed in an arc shape. Reference numeral 12 denotes a contact portion between the large diameter portion and the material to be rolled.
JP-A-6-7828

However, in the turning table described in Patent Document 1, it is necessary to control the number of rotations of the roller so that the angular velocity of the thick plate is constant at each contact point for each turning roller 11, or before each turning roller, Since it is moved in the axial direction, there is a drawback that the turning time is longer than before.
Further, the turning table described in Patent Document 1 is not practical because a device for controlling the number of revolutions for each turning roller or a roller shift device for each turning roller is required, and the device cost increases.

  Therefore, in view of the above problems, the present invention can effectively prevent the corner portion of the material to be rolled from being caught by the small diameter portion of the turning roller during the 90 ° turning operation even when the amount of warpage of the material to be rolled is large. An object is to provide a turning table.

The present inventors have intensively studied, in a Turkey to diameter of the small diameter portion of the turning roller than before, the above-mentioned problems are eliminated.
In other words, the present invention is such that rolling rollers having a large diameter portion and a small diameter portion continuous in the roller axial direction are arranged in a staggered manner on the front surface and the rear surface of a thick plate rolling mill, and are covered by mutual reversal of adjacent rolling rollers. In a rolling table for rolling a rolled material by 90 degrees, a thick plate characterized in that a radial difference between a large diameter portion and a small diameter portion of the rolling roller is 30 mm or more with respect to a material to be rolled having a downward warp amount of less than 30 mm. It is a turning table of a rolling mill.

  According to the turning table according to the present invention, since the radius difference between the large diameter portion and the small diameter portion is 30 mm or more, even when the amount of downward warping of the material to be rolled is large, the turning table has a downward warping portion during the 90 ° turning operation. It is possible to effectively prevent the corner portion of the material to be rolled from being caught by the small diameter portion of the rolling roller. For this reason, according to this invention, the productivity of a thick board can be improved compared with the conventional turning table.

It will be described with reference to the drawings that the turning table according to the present invention can effectively prevent the corner portion of the material to be rolled having the downward warping portion from being caught by the small diameter portion of the turning roller during the 90-degree turning operation.
FIG. 4 is a plan view schematically showing the effect when the present invention is applied to the turning table 2 on the front side of the thick plate rolling machine of FIG. 2, and FIG. 5 is a schematic view showing the main part thereof.
In FIG. 4, even if the amount of downward warping is large, the corner P at the lower left portion of the material to be rolled S is not caught by the small diameter portion of the turning roller 4A, and the material to be rolled S is smoothly turned. Showed that. The reason why the radius difference ΔR between the large diameter portion and the small diameter portion of the rotating roller 4A shown in FIG. 5 is 30 mm or more will be described later. The present invention is characterized in that the small-diameter portion of the rolling roller 4 arranged on the front-side rolling table 2 is made smaller than the conventional one.

  On the other hand, FIGS. 6 and 7 schematically show a conventional case in which rolling rollers 4 having a radius difference ΔR between the large diameter portion and the small diameter portion of less than 30 mm are arranged. In the conventional turning table, when the downward warping amount is large, the corner portion P of the material to be rolled S is caught by the small diameter portion of the turning roller as shown in FIG. 6, and the turning is not smoothly performed. Moreover, as shown in FIG. 7, since the rotation direction 10 of the rolling roller 4A is opposite to the conveying direction speed component of the rolled material S being rotated, the contact with the rolling roller 4A is the rolled material. Acts as a brake that slows the turning of S. For this reason, in the conventional rolling table 2, since the radius difference ΔR between the large diameter portion and the small diameter portion of the rolling roller 4 is small, the corner portion P of the material to be rolled S is large when the amount of warpage of the material to be rolled S is large. Since it is caught by the small diameter part of the turning roller, it takes extra time for turning.

Furthermore, when the corner portion P of the material to be rolled S is caught by the small diameter portion of the turning roller, the deviation between the conveyance direction line passing through the center of the material to be rolled S and the center of the rolling mill 1 at the time when the 90-degree turning is finished. Therefore, the centering time is increased in the conventional front turntable 2.
6 and 7, when the amount of downward warping of the material to be rolled S is large, the corner P of the material to be rolled is caught with the small diameter portion of the turning roller 4A, but the other adjacent turning roller 4B. The phenomenon in which the small diameter portion and the corner portion of the upper material S to be rolled in FIG. 6 are caught in the following cases. It corresponds to the case of rolling in the opposite direction to the rolling direction 9 at the same position as the center of the rolled material S shown in FIG. 6 (the position of the center of gravity of the rolled material S) (rotating rollers 4A and 4B are shown in FIG. 7). Reverse to direction 10).

Here, the reason why the radius difference ΔR between the large-diameter portion and the small-diameter portion of the rolling roller 4 is set to 30 mm or more is based on the result of investigating the downward warping of the material to be rolled S by the thick plate mill 1 described below.
That is, when the slab is subjected to reverse rolling of a plurality of passes by the thick plate mill 1 to produce a thick plate, the amount of downward warping of the material to be rolled S is examined after the final pass of the forming rolling and after the final pass of the tenter rolling. As a result, when the amount of downward warp is less than 20 mm, it is 60% of the total number of rolling, and when the amount of downward warping is less than 30 mm, it is 96% of the total number of rolling, while the amount of downward warping exceeds 55 mm. The result that such a thing did not generate | occur | produce in the plate rolling mill 1 was obtained.

From this result, when the radius difference ΔR between the large diameter portion and the small diameter portion of the rolling roller 4 is set to 30 mm or more, the amount of downward warpage accounting for 96% with respect to the total number of rolling is less than 30 mm. This is because the 90-degree turning operation can be performed smoothly. Furthermore, the radius difference ΔR is increased to 40 mm or more, and more preferably 50 mm or more.
In addition, when the to-be-rolled material S metal-outs from the thick plate mill 1, the downward warpage amount was measured with the warp detector on the front turn table 2 for both ends in the transport direction of the to-be-rolled material S. The value of the amount of downward warp was determined by measuring the distance from the table surface at the end in the conveying direction and the distance from the table surface at the maximum height portion that entered the inside of the material S to be rolled. The length from the front end in the conveying direction of the material to be rolled S to the maximum height portion measured on the front turntable 2 was approximately 600 mm (corresponding to L in FIG. 5).

The turning table installed on the front side of the thick plate rolling machine 1 has been described above. However, on the rear side of the thick plate rolling machine 1, a turning roller having a radius difference ΔR between the large diameter portion and the small diameter portion of 30 mm or more is arranged. The same effect can be exhibited even if it is done.
As described above, according to the turning table according to the present invention, the radius difference between the large diameter portion and the small diameter portion of the turning roller is set to 30 mm or more. During operation, it is possible to effectively prevent the corner portion of the material to be rolled having the lower warped portion from being caught by the small diameter portion of the turning roller. For this reason, according to this invention, productivity of a thick board can be improved compared with the conventional turning table.

  The thick plate rolling method of the present invention is suitable for rolling thick steel plates having a thickness of 4 mm or more, but can also be applied to rolling metal plates other than steel.

The present invention is applied to the front and rear turn tables 2 and 3 of the rolling mill 1 shown in FIGS.
In the rolling mill 1, a slab can be reverse-rolled to produce a thick plate having a finished thickness = 4 to 300 mm, a width = 1000 to 5350 mm, and a length of 52000 mm or less. The 90 ° turning operation was performed on a steel plate having a predetermined size on the front turn table 2 after the final pass of forming rolling and after the final pass of tenter rolling.

Specifications of the front side turning table 2 Machine length = 7425 mm, machine width = 7620 mm, turning roller length = 7620 mm, pitch a between the turning rollers 4 = 675 mm
Before application of the present invention: diameter of the large diameter portion of the rotating roller = 600 mm, diameter of the small diameter portion = 550 mm
After application of the present invention: diameter of the large diameter portion of the rolling roller = 600 mm, diameter of the small diameter portion = 500 mm
In the turning table of the plate rolling machine before application of the present invention, the time from metal out to metal in (including the turn time and centering time) was 15 seconds on average, The time was reduced to 10 seconds on average.

It is explanatory drawing of thick plate rolling. It is a schematic plan view of the turntable by which this invention is implemented. It is an operation | movement flowchart between paths including the turning operation | movement by which this invention is implemented. It is a top view which shows typically the effect at the time of applying this invention to the turning table of FIG. It is a schematic diagram which shows the principal part of FIG. It is a top view which shows typically the catching state in the turning table before application of this invention. It is a schematic diagram which shows the principal part of FIG. 10 is a schematic plan view of a turning table described in Patent Document 1. FIG. It is a schematic front view which shows the principal part of FIG. It is a schematic plan view explaining the problem in the turning table of patent document 1.

Explanation of symbols

S Rolled material 1 Thick plate mill 1A Work roll axis 2, 3 Turning table 4 Turning roller (generic name for 4A, 4B)
5 Side guide 6 Rolling direction 7, 8 Conveying direction 9 Rolling direction 10 Rotating direction 11 Rolling roller 12 Contact point between large diameter portion and material to be rolled

Claims (1)

Rolling rollers having a large diameter portion and a small diameter portion continuous in the axial direction of the roller are arranged in a staggered manner on the front surface and the rear surface of the thick plate rolling mill, and the material to be rolled is rotated 90 degrees by mutual reversal of adjacent rotating rollers. A rolling table for a thick plate rolling machine, characterized in that a radial difference between a large diameter portion and a small diameter portion of the rolling roller is 30 mm or more with respect to a rolled material having a downward warp amount of less than 30 mm.

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