JPS6010802B2 - rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling mill, and particularly to a rolling mill that is capable of high reduction rolling and is configured to have four rolling points at the same time.

The applicant proposed the TriStar roll rolling mill disclosed in Tokusekki Showaichi No. 134058 as a unique rolling mill having a roll arrangement different from that of conventional rolling mills.

FIG. 1 shows the basic roll arrangement of this Tristar roll. Three driving outer peripheral work rolls 2a, 2b, 2c are arranged around the outer periphery of the non-driving center work roll 1 of the small flea. The three center lines of the outer peripheral work rolls 2-a, 2b, and 2c have an angle of approximately 120 degrees, and the rolled strip 3 is wound around approximately two-thirds of the outer circumference of the center work roll 1, and the center and 3 at the same time between outer work rolls
It is constructed to have three rolling points 4a, 4b, and 4c. The TriStar roll rolling mill has three rolling points at the same time in one pass, so high reduction rolling is possible, and as shown in the second figure, the rolling load is about 1/1 compared to the conventional 4-high rolling mill. It has been confirmed through experiments by the present inventors that the rolling energy can be reduced to 9.9 and that the rolling energy can be reduced by about 15% as shown in FIG. 3 (both in the case of ordinary steel).

Therefore, in principle, the Tristar roll rolling mill has two different diameter and different circumferential speed rolling mills (the first outer work roll and the center work roll, and the third outer work roll and the center work roll). , it can be regarded as a type of rolling mill in which one different circumferential speed rolling mill (a second outer circumferential work roll and a central work roll) is sandwiched, and exhibits characteristics of different circumferential speed rolling as a whole.

In other words, the different speed ratios of the first outer circumferential work roll and the third outer circumferential work roll (the circumferential speed v of the first outer circumferential work roll, the third outer circumferential work. - skin circumferential speed V3) - the difference in speed (%) ) gives the area in which the cold rolling rate is determined. The range including the flat portion of each different speed rate x shown in FIG. 4 can be said to be a stable rolling region exhibiting high rolling reduction characteristics. Furthermore, when considering the cold rolling rate and the difference between the exit tension and the entry tension in tri-star roll rolling, stable rolling is possible above the line connected by the ○ marks in FIG. 5.

This relationship can be easily estimated since the difference between the exit tension and the entry tension (tr-tb) is theoretically related to the cold rolling rate in the known PV rolling and different circumference rolling, as shown in Figure 5. can. However, in the case of the Tristar roll mill, there are two rolling points and there is a subsequent effect, so the level is lower than that of the PV mill. As mentioned above, the TriStar roll rolling mill has the unique property of having high rolling reduction characteristics and being able to determine the rolling ratio based on the different speed ratios, but its exit tension level is 4. Because it is higher than the 10-20k9/Iso of the corrugated rolling mill,
This is disadvantageous against rolled strip breakage.

In addition, in the Tristar roll rolling mill, due to the special roll arrangement, the center work roll side is responsible for three rolling operations, so there is a difference in lubrication conditions from the outer work roll side.
As a result, there is also a quality characteristic in that there is a slight difference in the degree of surface organization of the strip after rolling. The present invention not only improves the quality characteristics found in such Tristar roll mills, but also increases the exit tension level to the usual 4.
To provide a rolling mill that can reduce the surface roughness of a strip rolled by the center work roll side of a Tristar roll rolling mill to the level of a strip rolling mill, and adjust the surface roughness of the strip rolled by the peripheral work roll side to the same level as that of a corrugated rolling mill. The purpose is to

A feature of the rolling mill of the present invention for achieving the above object is that in the Tristar roll rolling mill, the rolling mill has a rolling mill on the extension of the center line connecting the center work roll and the third outer work roll forming the third rolling point. , a fourth rolling point to constitute a fourth rolling point where the strip passing through the third rolling point is further rolled.
The work rolls are arranged so that there are four rolling points at the same time.

In the present invention, a tri-star roll rolling mill having three rolling points is further provided with one work roll on the circumferential work roll side of the strip exit area to form a fourth rolling point.

At this fourth pressure point, almost no rolling action is performed, and the role is mainly to adjust the exit tension and the surface roughness. The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 6 shows the roll arrangement of the rolling mill of the present invention, and the basic roll arrangement of the center work roll 1 and the outer work rolls 2a, 2b, 2c is the same as that of the Tristar roll rolling mill shown in FIG. direction has changed slightly).

Similarly, the strip 3 is rolled at three rolling points 4a, 4b, 4c formed by a central working roll and a peripheral working roll. In the present invention, in such a roll arrangement, the fourth outer circumferential work is performed at a position whose center is on a line connecting the centers of the center work roll 1 and the third outer circumferential work roll 2c forming the third rolling point 4c. Place rule 6,
The strip that has passed through the third rolling point 4c wraps around 1/2 circumference of the third outer working roll 2c, and a fourth rolling down point 4d is formed between the third outer working roll 2c and the fourth outer working roll 6. The board will be passed through the board. 5a, 5b, and 5c are the first, second, and fourth outer peripheral work rolls 2a, 2b, and 6, respectively.
This is a backup roll that presses down.

The center work roll 1 is not driven, and the first to fourth outer work rolls 2a, 2b, 2c, and 6 are of an independently driven type, and all the outer work rolls 2a, 2b, and 2c have approximately the same diameter. , 6 have a slightly larger diameter than 2a, 2b, and 2c.

FIG. 7 shows an example of a driving device for a rolling mill according to the present invention, in which the central work roll 1 is set in the rolling mill with a movable support 7 for pushing the central work roll in contact with the strip to be rolled 3. It is the same machine as the conventional Tristar roll rolling mill.

Four work rolls 2a, 2b other than the center work roll 1,
2c, 6 are independent drive motors 8a, 8b,
It is controlled and driven to a specific speed by 8c and 8d. Furthermore, a desired tension is applied to the strip 3 by an inlet tensioning device (beo reel) 9a and an outlet tensioning device (take-up roll) 9b, and the deflector roll 1
0a, 1ob allow the strip 3 to enter and leave the rolling mill in parallel. As described above, the present invention is a roll arrangement in which the fourth work roll 6 is arranged on the center line of the center work roll 1 and the third peripheral work roll 2c to form the fourth rolling point 4d. The same rolling load as at the third rolling point 4c is applied.

At this fourth rolling point 4d, almost no rolling is performed by increasing the diameter of the fourth work roll 6, and the tension of the portion wound around the outer peripheral work roll 2c (third rolling point 4d)
This has the effect of exhibiting a green cutting effect between the output side tension of c) and the tension of the output side strip 3 by the output side tension applying device 9b. That is, if the friction coefficient of the contact portion between the strip and the roll at the fourth rolling point 4d is assumed to be the friction coefficient of the contact portion between the strip and the roll at the fourth rolling point 4d, the maximum tension is . The tension can be flattened by the fourth work roll drive motor 8d. Therefore, the tension on the exit side of the strip can be lowered by 1 (ton) at the maximum, and the capacity of the tension applying device 9b on the exit side can be increased. can be kept low.

As a result, no excessive tension is applied to the output strip, so troubles such as breakage do not occur. On the other hand, the fourth rolling point 4d
The strip surface in contact with the fourth work roll 6 is the surface on the center work roll side, so by adjusting the surface roughness of the fourth work roll 6, the strip rolled three times on the center work roll 1 side. It is easily possible to make the surface texture close to the strip surface roughness of the surface rolled by the third outer peripheral work roll 2c, considering the knowledge of transfer of the conventional roll surface texture to the strip.

As a result, the difference in surface roughness between both sides of the strip, which was observed in the conventional TriStar roll rolling mill, is almost eliminated, and a finished product strip of good quality can be obtained. As explained above, according to the rolling mill of the present invention, the rolling mill is based on the ordinary Tristar roll rolling mill, utilizes its unique advantages, and uses the fourth work roll arrangement to achieve the fourth lower point. It became possible to effectively solve the characteristics of exit tension and strip surface assembly that were observed in the machine. Therefore, it can be said that the present invention makes a significant technical and industrial contribution to the practical application of Tristar roll rolling mills.

[Brief explanation of the drawings] Figure 1 is an explanatory diagram showing the basic roll arrangement of the Tristar roll rolling mill, and Figure 2 is the cold rolling rate and rolling force in the Tristar roll rolling mill and a normal 4-high rolling mill. Figure 3 is a diagram comparing the rolling energy of two types of rolling mills as in Figure 2, and Figure 4 is a diagram showing the rolling characteristics of the Tristar rotor rolling mill at different speed ratios. Figure 5 shows the TriStar roll rolling mill and P
A chart showing the relationship between the cold rolling rate and the tension difference between the exit side and the entry side in a V-rolling mill, Fig. 6 is an explanatory diagram showing an example of the basic roll arrangement of the rolling mill of the present invention, and Fig. 7 is a diagram showing the relationship between the cold rolling rate and the tension difference on the exit side and inlet side in a V rolling mill. FIG. 2 is a schematic diagram for explaining a drive section of the machine. 1... Center work roll, 2a, 2b, 2c...
...Outer circumferential work roll, 3... Strip,
4a, 4b, 4c, 4d... Rolling point, 5a, 5
b, 5c...Backup roll, 6...Fourth work roll, E7...Movable support for pushing the center work roll, 8a, 8b, 8c, 8d...Drive motor Evening, 9a... Entrance side tension adding device, 9b...
- Output side tension adding device, 10a, 10b...deflector roll. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. Three work rolls are arranged around the outer periphery of the non-driven center work roll, and the three center lines of the center work roll and the outer peripheral work roll form an angle of approximately 120 degrees, and the center line of the center work roll is In a rolling mill in which a strip to be rolled is wound around approximately 2/3 of the outer circumference to simultaneously form three rolling points between the four work rolls, a third rolling point is formed with the central work roll. A fourth work roll is placed on the extension of the center line connecting the third peripheral work roll to form a fourth rolling point where the strip that has passed through the third rolling point is further rolled. A rolling mill characterized in that the rolling machine has dots.