JPS6036321B2 - rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling mill, and more particularly, to a rolling mill that improves the crown control and shape control functions of rolled material.

Conventionally, a roll bender has been used as the simplest crown control and shape control means for rolled materials.

However, the control by the roll bender is difficult to extend to the center of the rolled material in the width direction, and the control effect is also limited by the ability of the roll bender. The capabilities of the roll bender are limited by the chock structure. Therefore, new control methods such as variable crown roll rolling and skew rolling were developed. The rolling mill to which the present invention is directed consists of at least a work roll and a backup roll, the roll arrangement is triple or more (mainly quadruple), and the roll arrangement is single stand or tandem stand.
It is suitable for both hot rolling and cold rolling.

Here, the work roll refers to a roll that directly contacts the material to be rolled, and the backup roll refers to a roll that directly or indirectly supports the work roll. The variable crown roll is configured such that the amount of crown of the roll is controlled by pressurizing fluid or viscous material into a predetermined space formed between the arbor and the sleeve.

Conventionally, such variable crown rolls have been used in double rolling mills, but there have been no examples of their use in triple or higher rolling mills.

In a double rolling mill using variable crown rolls, the work rolls cannot withstand high rolling loads;
It is difficult to manufacture a high-hardness sleeve for the roll, and because the roll requires a high surface hardness, the graininess value of the sleeve decreases, and the strip may suffer from shape defects near the pressure-receiving end of the roll. It had drawbacks such as being easy to use. Therefore, such a rolling mill is suitable for light-load rolling such as dry rolling, but is not suitable for heavy-load rolling such as cold rolling or hot rolling. Then, the reason why variable crown rolls were not used in multiple rolling mills (especially backup rolls) was because of the following concerns.

[1} Usually, the workpiece has a diameter of 500 to 60 mm.
Since the material is rolled by squeezing the rolls, the backup roll is called a variable crown roll (hereinafter simply referred to as V).
Even if you try using it as a C-roll, you can't expect much of an effect.

■ It is doubtful whether it can be rolled with pipe-shaped rolls such as VC rolls.

{3' Even if you try to inflate the VC roll, it may become indented due to the high load and may not be effective.

[4] I suspect that the sleeve gripping force is insufficient and roll bending is likely to occur.

'5} Isn't VC roll dangerous from the perspective of fatigue safety factor?

Regarding these concerns, the present invention and others consider the following based on many years of experience and support from theory and experiment.

○) Even if the work roll is rolled, the bulge effect of the backup roll is transmitted and the amount of bulge is 1'2 to 1/
Changes in cormness appear in the material.

Even with this amount of change, crown control and shape control can be achieved sufficiently. '2} Since the VC roll has a slight gap only in the pressure receiving part, the mill rigidity is substantially the same as that of a solid roll.

[3' It is possible to make the bulge of the VC roll larger than the dent caused by high loads.

(4) If the backup role is a VC role,
Since the pressure-receiving length of the backup roll does not need to be larger than the material width, the VC roll gripping force can be increased.

Generally, since a rolling mill is driven by work rolls, the torque applied to the backup roll is smaller than the torque applied to the work roll. {5} Fatigue safety factor is 1.
It is possible to design 5 to 3.

Therefore, the present invention is confident that it is fully possible to utilize VC rolls in multiple rolling mills.

However, the VC roll naturally has its limits, and excessive crown control cannot be expected.

In order to increase the crown control function, the wall thickness of the sleeve must be made thinner and the pressure receiving length must be made longer. This poses a problem in terms of roll strength and worsens roll consumption. On the other hand, as another method for crown control, skew rolling has been carried out from the secondary. This skew rolling is a rolling process in which the work roll axis or the backup roll axis is inclined with respect to a straight line perpendicular to the pass line. In skew rolling, the crown control amount of the rolled material increases in proportion to the square of the oblique angle Q (the angle between the axis of the roll and a straight line perpendicular to the pass line). As the mirror inclination angle Q increases, the thrust force increases, so mechanically it is not possible to make the inclination angle Q too large. Furthermore, since it is difficult to change the oblique angle Q at high speed, it is difficult to perform crown control during high speed rolling. In this way, V.C.

Rolling with a roll and skew rolling have advantages and disadvantages.
However, if these two types of rolling are combined and only their strengths are utilized, it is possible that dramatic effects that have not been seen before can be expected. Therefore, an object of the present invention is to use a variable crown roll in a multiple rolling mill and further explore skew rolling to enable a wide variety of rolling operations.

The basic idea of the present invention is to make at least one roll a VC roll in a multi-roll mill (mainly a 4-roll mill) consisting of a work roll and a backup roll, and to make the work roll a VC roll. The axial line of at least one of the roll and the backup roll is tilted with respect to a straight line perpendicular to the pass line (hereinafter simply referred to as tilt).

Based on this configuration, the present invention contemplates the following embodiments.

B. In a quadruple rolling mill, at least one of a pair of backup rolls is a VC roll, and the work rolls are tilted.

(b) In a four-layer rolling mill, a pair of backup rows
Make at least one of the files into the VC role and use the backup
To make the roll oblique.

C. In a quadruple rolling mill, at least one of the pair of work rolls is a VC roll, and the work roll is tilted. D. In a four-layer rolling mill, at least one of a pair of work rolls is a VC roll, and the backup roll is mirror-slanted.

Next, specific embodiments of the present invention will be described with reference to the drawings.

First, before entering into the explanation, the structure and function of the variable crown roll used in the present invention will be briefly described with reference to FIG. As shown in FIG. 1, the basic structure of the variable crown roll is that an annular gap 3 is provided between the arbor and the sleeve 2, and a conduit 11 provided from the medium pressurizing unit 4 to the arbor 1 is passed through. A high-pressure medium (for example, water, oil, grease, etc.) is supplied to the gap 3, and the pressure of the medium is adjusted by the unit 4 to adjust the crown amount of the roll (
It is configured to control the amount of bulge in the diametrical direction of the outer diameter of the roll.

Although FIG. 1 shows a VC roll having one pressure receiving chamber, a VC roll having two or more pressure receiving chambers may be used if necessary. The types of rolling mills targeted by the present invention are, for example, those shown in FIGS. 2 to 4.

First of all, regarding the roll arrangement, as shown in Figure 2, in principle, the roll arrangement is of the multiple type, and among these, mainly the three-layer type A to the six-layer type F, and the four-layer type C is especially applicable. Optimal. Therefore, the following explanation will be made using a quadruple rolling mill as an example. However, with regard to the arrangement of the multiple rolling mills, this explanation may be applied to a single stand A or a tandem stand B, as shown in FIG. For convenience of explanation, the basic configuration of the rolling mill of the present invention is as shown in FIG. 4 taking a triple rolling mill as an example. VC role (
(hatched in the drawing).

Therefore, for example, in the case of a triple rolling mill,
The combination shown in G is obtained. The effects obtained by such a configuration will become clear from the description that follows. First, as shown in FIG. 5, at least one of the backup rolls of the quadruple rolling mill is a VC roll (shaded in the drawing).

In this example, we first vary the amount of crown on the backup roll, and the effect of that variation is applied to the work roll, causing the entire axis of the work roll to curve, thereby creating a substantially constant force on the work roll. Produces a crown change in amount.

Next, as shown in Fig. 6, the workpiece of the 4-layer rolling mill is
At least one of the rolls is a VC roll (hatched in the drawing).

In this embodiment, the amount of crown of the work roll is directly changed, and this change is reinforced by the reaction of the backup roll.

Furthermore, as shown in FIG. 7, one of the backup roll and the work roll is made into a VC roll (shaded in the drawing). In this embodiment, a combination of the effects shown in FIGS. 5 and 6 described above can be obtained. In the present invention, skew rolling is performed in addition to the VC roll rolling described above. What is skew rolling?
As shown in FIG.
,,Q2 (hereinafter simply referred to as inclination angle). The inclination angles Q, , Q2 are usually the same, but may be different. In the skew rolling of the present invention, at least one of the work roll and the backup roll is tilted.

For example, in a four-layer rolling mill (Fig. 2C), only the work rolls are inclined (Fig. 9), only the backup rolls are inclined (Fig. 10), or the work rolls and Tilt both backup rolls (Figure 11). When tilting the work roll and the backup roll at the same time, it is preferable to tilt them in opposite directions from the viewpoint of rolling effects.

However, since roll wear becomes severe, so-called bare skew, in which the work roll and backup roll are skewed in the same direction and at the same angle, is desirable from the point of view of roll consumption. Furthermore, in addition to VC roll rolling and skew rolling, more effective crown control and shape control can be obtained by combining roll bending.

Next, examples of the present invention will be described.

In a single-stand four-layer rolling mill with a work roll diameter of 70 ribs, a backup roll diameter of 150 ribs, and a roll body length of 200 ribs, a VC roll was incorporated into the backup roll on one side (Fig. 5A). Or B) Change the VC roll internal pressure PI in the range of 0 to 500k9/ground, and change the relative inclination angle Q,2 (however, Q=Q, 10Q2) of the upper and lower work rolls in the range of 0 to 20. (Fig. 9), an aluminum plate with a thickness of 1 rim and a width of 120 rims (
The dotted line in FIG. 12 shows the amount of crown change when a corresponding sample of hot-worked steel strip is rolled. By changing the VC roll internal pressure PI within the range of 0 to 5000 k9/m, it is possible to obtain a crown change of approximately 15 peaks, but when skew rolling is added to this, Q,2=
At 0.50, the amount of crown change is approximately 6.0 peaks, Q,2 = 1.
00 is about 24 French, Q,2=1.50 is about 54r, Q. 2
= 2.00, a superimposition effect of about 96 Buddhas can be obtained.

Therefore, the effect of skew rolling is expressed by the relative inclination angle, 2 of 2.
Corresponds to the power. Incorporate VC rolls into the upper and lower backup rolls of the rolling mill (Fig. 2 C) (Fig. 5 C),
While changing the internal pressure PI within the range of 0 to 5000k9/2, the relative inclination angle of the upper and lower work rolls Q, 2 (
However, when Q=Q, 10Q2) and Q,=Q2 are changed within the range of 0 to 2o, the amount of crown change when rolling an aluminum plate with a thickness of 10 legs x width of 120 mm is shown in Figure 12. Indicated by solid line.

When the VC roll is incorporated into the upper and lower backup oars, the amount of crown change is doubled (approximately 30) compared to the one-sided case.

The above-mentioned skew rolling effect is superimposed on this. Backup roll diameter 300 side, intermediate roll diameter 15 side, work roll diameter 10 side (upper side) and 12 side
In a single-stand 5-layer hot rolling mill (Figure 2D) with a roll body length of 46 mm (lower side), an aluminum plate with a thickness of 4 yam and a width of 20 yam was rolled.

When a VC roll was incorporated into the upper backup roll and the internal pressure PI was varied within the range of 0 to 5000 kg/ground, a crown change of 14 degrees and an edge drop of 3 degrees were obtained.

When the internal pressure of the VC roll PI = 0 and the inclination angle of only the upper work roll is set to Q = 10, the amount of crown change is 1.
2 mountains... I got the effect of 3 Buddhas with Edge Drop.
Combining the two, the amount of crown change is 3 Buddhas, edge
The effect of 7 Buddhas was obtained with the drop. In a similar five-layer hot rolling mill (Fig. 2D), a VC roll was incorporated into the intermediate roll, and the upper and lower work rolls were tilted to roll an aluminum plate of similar size. With VC roll alone, the crown change amount was 10 French, and the edge drop had a 2 mountain effect.

In the case of only skew rolling, an effect of Q.2 of 10, a crown change of 15, and an edge drop of 5 were obtained. When you combine both, the amount of crown change is 32w
, an effect of 9r was obtained with edge drop. Next, an example of skew rolling using backup rolls will be described.

In a single-stand four-layer hot rolling mill with a work roll diameter of 700 mm, a backup roll diameter of 150 mm, and a roll body length of 200 mm, a VC roll is incorporated into the backup roll on one side (the fifth Figure A or B), VC
While changing the roll internal pressure PI in the range of 0 to 5000 kg/kilogram, the relative inclination angle Q8 (however, Q:Q, 10Q2) of the upper and lower backup rolls was changed in the range of 0 to 2o (Fig. 10). ), the amount of crown change when rolling an aluminum plate (test sample corresponding to a hot-worked steel strip) with a thickness of 10 skins and a width of 1200 ribs is shown by a dotted line in FIG. VC
By changing the roll internal pressure PI within the range of 0 to 5000 k9/ground, a crown change of about 15 degrees can be obtained, but if skew rolling is added to this, Q,2 = 0.50 The amount of crown change is approximately 3.54, Q
,2=1.00, about 13 French, Q,2=1.50, about 29
When Buddha,Q,2=2.00, a superimposition effect of about 52 Buddhas can be obtained.

Therefore, the effect of skew rolling is 2 of the relative inclination angle Q,2.
Corresponds to the power. Incorporate VC rolls into the upper and lower backup rolls of the rolling mill (Fig. 2 C) (Fig. 5 C),
While changing the internal pressure PI within the range of 0 to 500 kg/, the relative inclination angle Q of the upper and lower backup rolls,
2 (however, Q=Q, 10 is 2, Q,=Q2) from 0 to 2o
The solid line in FIG. 13 shows the amount of crown change when an aluminum plate with a thickness of 1 rib and a width of 120 ribs is rolled by changing the crown value within the range of .

When the VC roll is incorporated into the upper and lower backup rolls, the amount of crown change is doubled (approximately 30r) compared to the one-sided case.

The above-mentioned skew rolling effect is superimposed on this. Backup roll diameter 150 ratio, intermediate roll diameter 75
The diameter of the work roll is 59 (upper side) and 7.
Single stand 5 with a roll length of 200 m and a roll length of 200 m.
An aluminum plate having a thickness of 1 mm x width of 120 mm was rolled in a heavy hot rolling mill (FIG. 2D).

When a VC roll is incorporated into the upper backup roll and the internal pressure PI is changed within the range of 0 to 500k9/ground, the amount of crown change is 13y and the edge drop is 4r.
The effect was obtained.

When the internal pressure PI of the VC roll is 0, the lower backup
When only the roll tilt angle was set to Q = 10, the amount of crown change was 10 degrees, and an effect of 3 mm was obtained in edge drop. By combining the two, an effect of 30 French in crown change and 10 French in edge drop was obtained. In a similar five-layer hot rolling mill (FIG. 2D), a VC roll was incorporated into the intermediate roll, and an aluminum plate of similar size was rolled by tilting the intermediate roll. With VC roll alone, an effect of 12 mm was obtained for crown change and 4 mm for edge drop.

In the case of only skew rolling, when Q,2=10, an effect of 12 peaks in crown variation and 4 peaks in edge drop was obtained. When you combine both, the amount of crown change is 32
Buddha, the effect of 12 Buddhas was obtained with Edge Drop. A 6-stand quadruple rolling mill (the dimensions of each roll are the same as those of the aforementioned quadruple rolling mill.

), a downstream two-stand VC roll was installed and rolling was performed in combination with skew rolling. No. 5 stand 'This is a VC roll for the upper and lower backup rolls, N
o. 6 stand 'This is a V in the backup roll on one side.
Each incorporates C-roll. No. The 5th stand was adjusted so that the work roll and backup roll could be tilted at the same time. Finished dimension is thickness 3. Vengeance×
Table 1 shows the results of rolling strips with a width of 1224 mm under various conditions. No. The internal pressure PI of the 6-stand VC roll was selected under each condition so that the final shape of the strip on the exit side would be good.

As can be seen from Table 1, the crow control effect and edge drop reduction effect were confirmed. It can be seen that when VC roll rolling and skew rolling are combined, a superimposed effect can be obtained more clearly than when they are used alone. It is clear that even greater effects can be obtained if the present invention is applied to upstream stands.

Table 1 C5o: Amount of crown of the rolled material at a position 5 meters from the edge of the rolled material E5o-, o: 50 Yanagi and 1 from the edge of the rolled material
4-layer rolling mill with 6 stands (dimensions of each roll are the same as those of the above-mentioned 4-layer hot rolling mill).

), a VC roll is installed in the 2 downstream stands,
Rolling was performed in combination with skew rolling using backup rolls. No. 5 stand' This is a VC roll for the upper and lower backup rolls, No. Each of the 6 stands has a VC roll built into the backup roll on one side. N
o. In the 5th stand, only the backup roll was adjusted so that it could be tilted. Finished dimensions are thickness 3.2 ribs x width 1
Table 2 shows the results of rolling a strip of 32 ribs under various conditions. No. The conditions for the internal pressure PI of the 6-stand VC roll were selected so that the final shape of the strip on the exit side would be good.

As can be seen from Table 2, the crown control effect, edge
Drop reduction effect was confirmed. It can be seen that when VC roll rolling and skew rolling are combined, a superimposed effect can be obtained more clearly than when they are used alone. Table 2

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram of a variable crown roll used in the rolling mill of the present invention. FIG. 2 is a roll layout diagram showing a typical example of a rolling mill to which the present invention is applied. FIG. 3 is a roll arrangement diagram of a rolling mill to which the present invention is applied. FIG. 4 to FIG. 7 are explanatory diagrams showing examples of use of the variable crown roll. FIG. 8 is an explanatory diagram showing the skew angle of the roll. FIG. 9 is an explanatory diagram of an embodiment in which the axis of the work roll is inclined with respect to a straight line perpendicular to the bus line. 1st
Figure 0 is an explanatory diagram of an embodiment in which the wisteria line of the backup roll is inclined with respect to a straight line perpendicular to the pass line. FIG. 11 is an explanatory diagram of an embodiment in which the work roll and backup roll are inclined in a straight line perpendicular to the pass line. FIG. 12 and FIG. 13 are graphs showing the crown control effect of the present invention. R,, R2: roll, L, L: axis line, P: pass line, Q,, Q2: oblique angle, V: straight line. Figure 1 Figure 2 Figure 5 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13

Claims (1)

[Claims] 1 In a multiple rolling mill, at least one roll is made into a variable crown roll, and at least one axis of the work roll and the back-up roll is made into a pass roll.
A rolling mill characterized in that the line is inclined and intersected with respect to a straight line perpendicular to the line.