JPH0377702A - Multistage rolling mill for high load of variable work roll diameter - Google Patents

Abstract

PURPOSE:To equalize the life of each backup roll even if changing the work roll diameter, by setting the ratio of the roll diameters of a work roll, intermediate roll, center backup roll and both ends backup roll at the specified value. CONSTITUTION:The life of each back-up roll can be equalized by making the maximum diameter of a work roll 2 in the changeable roll diameters about the same diameter as of the intermediate rolls 3, 4 and also setting the ratio of the roll diameters of minimum diameter of the work roll 2, a center back-up roll 5 simultaneously supporting intermediate rolls 3, 4 and a both end backup rolls 6, 7 supporting one intermediate roll 3 or 4, within the range surrounded by (1:4:5.2), (1:4.5:5.2), (1:4.5:5.75), (1:4.22:6) and (1:4:6).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a high-load multi-high rolling mill in which the diameter of work rolls can be changed.

(Prior art) In a 12-high rolling mill in which one upper and lower work roll for rolling a material to be rolled is supported by three backup rolls via two intermediate rolls, each backup roll is supported by three backup rolls. If they were made to have the same diameter, there would be a problem in that the load would be uneven and the life of the bearing would be shortened.

Therefore, in order to solve this problem, it has been proposed to make the durability performance of the bearings of the backup rolls uniform by varying the roll diameter of the backup rolls according to the respective rolling loads ( Japanese Unexamined Patent Publication No. 57-
(See Publication No. 206507).

In this conventional rolling mill that uses work rolls with a single diameter, the roll diameter ratio of the central backup roll and both end backup rolls is set to 0.3 to 0.7, preferably 0.4 to 0.6. It was to be set.

In other words, the life of the roll bearing is determined by variously changing the roll diameter ratio of the center backup roll and both end backup rolls, and the roll diameter ratio when the life of the center and both end backup rolls are approximately equal is determined as the appropriate roll diameter ratio. This was what I was looking for.

(Problems to be Solved by the Invention) Some multi-high rolling mills are capable of changing at least two types of roll diameters of work rolls. In such a high-load multi-high rolling mill with variable work roll diameter, the above conventional technology cannot be applied as is to determine an appropriate backup roll diameter ratio in order to make the life of each backup roll approximately equal. Ta.

That is, in the conventional technology, the roll diameter ratio of each backup roll is determined for a work roll of a single diameter, but if the roll diameter of the work roll changes, the load of each bank up roll changes. This is because the appropriate roll diameter ratio also changes.

Further, the purpose of making the diameter of the work roll variable is to improve productivity and improve the shape of the rolling mill.

That is, when a large diameter roll is used, high speed rolling is possible, a good shape can be obtained, and stable rolling is possible.

This is because the large-diameter roll has a large heat capacity, and the rise in temperature of the roll due to heat generated by friction, etc. is small, and as a result, the influence of the heat generated on the rolled material on the shape is small.

Furthermore, when a small diameter roll is used, a high rolling reduction ratio can be obtained, the number of baths can be reduced, and productivity can be improved.

This is because the force required for rolling applied to the material to be rolled can be relatively small, so that the amount of rolling reduction per bus can be increased.

Therefore, for example, when a multi-stage rolling mill with variable work roll diameter is used as a reverse rolling mill and a product is rolled in 6 passes,
The first 1 to 4 passes are rolled using small diameter work rolls at a high rolling reduction rate, and the final 5 to 6 passes are rolled using large diameter work rolls to obtain a good shape.

That is, in a multistage pressure machine with variable work roll diameters, not only the diameters of the work rolls are different, but also the frequencies of use of the large diameter work rolls and the small diameter work rolls are different.

Therefore, when determining the roll diameter ratio of the backup roll, it is not appropriate to simply determine the roll diameter ratio of the backup roll for a roll between the large diameter work roll and the small diameter work roll. I couldn't say it.

Therefore, the present invention provides that the diameter of the work roll changes, and
Taking into account that different types of work rolls are used at different frequencies, we created a high-load multi-high rolling mill with a variable work roll diameter that has approximately the same bearing life for the backup rolls and has a long lifespan for the backup rolls as a whole. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the present invention takes the following measures.

That is, the feature of the high-load 12-high rolling mill with variable work roll diameter of the present invention is that each of the upper and lower work rolls 2 for rolling the material 1 to be rolled is replaced by two intermediate rolls 3 of the same diameter. ．．
In a high-load 12-high rolling mill, the roll diameter of the upper and lower work rolls 2 can be changed in at least two types, in addition to being supported by three buffer rolls 5 and 6.7 through the work rolls 4. Among the roll diameters of the work rolls 2, the roll diameter of the work roll 2 having the maximum diameter is approximately the same as the roll diameter of the intermediate roll 3.4, and the roll diameter of the work roll 2 having the minimum diameter. and the ratio of the roll diameter of the central backup roll 5 that supports two intermediate rolls 3 and 4 at the same time to the roll diameter of both end backup rolls 6.7 of the same diameter that support one intermediate roll 3 or 4 is , (1:4:5.2) ,(1:4.5
:5.2'), (1:4.5 :5.75), (1
:4.22:6) and (1:4:6).

Further, the feature of the high load 20-high rolling mill with variable work roll diameter of the present invention is that the upper and lower rolling mills for rolling the material 1 to be rolled are
The book work rolls 10 are each divided into two first intermediate rolls 11.12 and three second intermediate rolls 13.14.1 of the same diameter.
5 and 4 backup rolls through 16.17.1
8.20 for high loads, which is supported by 19 and allows at least two types of roll diameter changes for the upper and lower work rolls IO.
In the corrugating rolling mill, the roll diameter of the work roll 10 having the largest diameter among the roll diameters of the work rolls 10 that can be changed is approximately the same as the roll diameter of the first intermediate roll 11.12; , the roll diameter of the work roll lO with the smallest diameter and the two second intermediate rolls 13°14 or 14.15
A central backup roll 17. of the same diameter that simultaneously supports the
18 roll diameter and one second intermediate roll 13 or 15
The ratio of the roll diameter of the backup roll 16.19 at both ends of the same diameter supporting the is (l:4:5.5), (1:5:
5.5), (1:5:5.8)1:4.6:
6.5) and (1:4:6.5).

(for production) The rolling mill of the present invention is used as a reverse type.

For example, when a finished product is obtained in 6 passes, the first 1 to 4 passes are rolled using small diameter work rolls, and the final 5 to 6 passes are rolled using large diameter work rolls. The purpose of using small diameter rolls is to obtain a high rolling reduction, and the purpose of using large diameter rolls is to obtain a good shape and high speed rolling.

Further, when used for rolling soft materials such as pure copper, copper alloys such as brass, and 42 nickel alloys, large diameter rolls are used relatively frequently.

Accordingly, when the frequency of use of large diameter rolls and small diameter rolls was statistically investigated, the frequency of use of large diameter rolls was 20 to 30%, and the frequency of use of small diameter rolls was 80 to 70%.

Therefore, in the present invention, the roll ratio is set based on the frequency of use.

In the present invention, the roll diameter of the large-diameter work roll is made approximately equal to the roll diameter of the intermediate roll for the following reason. In other words, in order to obtain a good shape and high-speed rolling, which is the purpose of using large-diameter work rolls, it is better to make the diameter as large as possible, but if the diameter is larger than the intermediate roll, the stability of the roll seating will be affected. The limit is to make it approximately the same diameter as the intermediate roll.

The roll diameter of the small-diameter work roll is not particularly limited, but if the angle between the axes of the backup rolls at both ends, the intermediate roll, and the small-diameter work roll is 180° or less, the intermediate roll will pop out. By considering the roll arrangement, the ratio with other roll diameters is automatically determined. Since this ratio is a well-known value, it is not particularly limited. In the present invention, the diameter of the large diameter roll is set to be approximately 2 (1.8 to 2.0) times that of the small diameter roll.

In determining the backup roll diameter ratio, the small diameter work roll diameter is used as the standard for the following reason.

In other words, the diameter of the backup roll can be arbitrarily selected only by the ratio of the diameter of the backup roll at the center and at both ends.
Since it is not possible to specify the roll arrangement of the entire rolling mill, the backup roll diameter ratio is determined based on the work roll.

Further, it is for convenience that the reference work roll is a small-diameter work roll, and the meaning is the same even if a large-diameter roll is used as a reference.

The diameter ratio of the center backup roll and both end backup rolls is determined by balancing the bearing life of both backup rolls, assuming the use of both small-diameter work rolls and large-diameter work rolls.

Among these, it is advantageous if the usage ratio of small diameter rolls is higher as the ratio approaches the diameter ratio of 11:6, and 1:4.5.
:5.2, it is advantageous when the usage ratio of large-diameter rolls increases as the ratio approaches the diameter ratio of 5.2.

That is, if the diameter ratio of both backup rolls is 0.67
(1:4:6) or less, the life of the central backup roll will be shorter than the life of the backup rolls at both ends, and the life of the backup roll as a whole will be shortened.

Also, if the diameter ratio of both backup rolls is 0.87 (1
:4.5 F5.2) or less, the life of the backup rolls at both ends will be shorter than that of the center backup roll, and the life of the backup roll as a whole will be shortened.

Further, the ratio of the diameter of both backup rolls to the diameter of the work roll is determined from the limitation of the diameter of the intermediate roll and from the stability of the roll arrangement such as roll pop-out.

That is, if the ratio of the diameter of the central backup roll to the diameter of the work roll is less than (1:4), the diameter of the backup roll will become too small and high load rolling will not be possible.
(1:4.5) or more, the stability of roll arrangement deteriorates.

Furthermore, when the roll diameter ratio exceeds (1:4.5:5.75) and (1:4.22:6), the center backup roll and both end backup rolls interfere with each other,
This range is excluded because it will no longer be possible to place a role.

The above is an explanation of the operation of the 12-high rolling mill of the present invention, but the operation is the same for the 20-high rolling mill.

(Example) Embodiments of the present invention will be described below based on the drawings.

The one shown in Figure 1 is a high-load type 1 with variable work roll diameter.
It is a roll arrangement diagram of a two-high rolling mill. In addition, in the figure, different usage conditions are shown for the upper side and the lower side of the rolled material. That is, the upper side shows the roll arrangement when the work roll with the smallest diameter is used as the work roll, and the lower side shows the roll arrangement when the work roll with the largest diameter is used. Of course, in actual use, except in special cases,
The roll diameters of the upper and lower work rolls are the same.

The rolling mill has one upper and lower work roll 2 for rolling a material 1 to be rolled. Each work roll 2 is supported by two upper and lower intermediate rolls 3.4. The roll diameters of these two intermediate rolls 3 and 4 are the same. Each intermediate roll 3.4 is supported by three upper and three back-up rolls 5.6.7.

Among the three backup rolls 5.6.7, the central backup roll 5 is similar to the two intermediate rolls 3,
4. support at the same time. The two backup rolls 6.7 at both ends support one intermediate roll 3 or 4. The roll diameters 0□ of the backup rolls 6.7 at both ends are the same diameter. Further, the roll diameter of the central backup roll 5 and the roll diameters of the both end rolls are different in diameter.

As shown in a longitudinal section of the rolling mill in FIG. 2, the backup rolls 5, 6.7 are bearing-type rolls divided into a plurality of rolls in the axial direction, and the roll bearings are mounted on saddles attached to stands. It is pivoted by 8.

The work rolls 2 can be reassembled steplessly from the largest diameter to the smallest diameter.

The maximum diameter of the work roll 2 is approximately the same diameter as the intermediate roll 3.4. The minimum diameter of the work roll 2 is approximately % of the maximum diameter.

As shown in FIG. 3, the ratio of the minimum diameter of the work roll 2, the roll diameter of the central backup roll 5, and the roll diameter of both end backup rolls 6.7 is (1:4).
:5.2 ), (1:4.5 :5.2), (
1:4.5:5.75), (1:4.22:6), and (1:4:6).

FIG. 4 shows a backup roll life diagram for determining the roll diameter ratio. The roll life Lh of the backup roll was determined using the following formula and the conditions shown in Tables 1 and 2.

However, N; rotation speed C of backup roll; load capacity P of backup roll; average load of work roll Table 1 Table 2 In Figure 4, dotted lines a and a' indicate that work roll 2 is 4
Backup rolls at the center and both ends at 0m 5.5.
7 roll life, - dot-dashed lines and b'' are for work roll 2.
is the roll life of the center and both end backup rolls 5.6.7 when is 80++n++.

The method of determining the optimum roll diameter ratio from the dotted lines a, a', and b'' is a conventional method disclosed in Japanese Patent Application Laid-Open No. 57-206507.

In the present invention, instead of using these dotted line diagrams, solid lines C and C" shown in FIG. 4 are used.

That is, the solid lines C and Co are obtained by calculating the average load P of the work roll by averaging the load when the work roll 2 is 40 an and the load when it is 80 -, and taking into account the frequency of use of both rolls. Calculated backup rolls in the center and both ends 5.
6.7, respectively.

At the point where the solid lines C and Co intersect, the roll lives of the backup rolls 5, 6.7 at the center and both ends become equal. Therefore, as an appropriate range centered on this point, (
The roll diameter ratio of center)/(both ends) was determined to be 0.67 to 0.87.

If this range is expressed using the minimum work roll diameter as a reference, it will be a rectangular range surrounded by points A, B, and C1D in FIG. 3. However, the range surrounded by the triangle DEF is excluded because the center backup roll 5 and the end backup rolls 6.7 interfere with each other, making it a range that cannot be actually used.

The one shown in Figure 5 is a high-load type 2 with variable work roll diameter.
It is a roll arrangement diagram of a 0-high rolling mill.

This 20-high rolling mill has one upper and lower work roll 10 for rolling a rolled material 1. Each work roll 10 is supported by two first intermediate rolls 11.12.

The roll diameters of these two first intermediate rolls 11 and 12 are the same. The two first intermediate rolls 11.12 are supported by three second intermediate rolls 13.14.15. These three second intermediate rolls 13.14.15
Among them, the central roll 14 is the roll 13.1 on both sides.
5, and the rolls 13.15 on both sides have the same diameter. Said three second intermediate rolls 13.14.15
is 4 backup rolls 16.17°18, 19
Supported by 4 backup rolls 1
6.17.18.19, the center two are of the same diameter,
Moreover, the two on both the left and right ends have the same diameter.

The roll diameter of the work roll 10 is freely changeable, and its maximum diameter is set to be equal to the roll diameter of the first intermediate roll 11, 12 and time. Other conditions were the same as those of the 12-high rolling mill.

The ratio of the minimum roll diameter of the work roll 10, the roll diameter of the central backup roll 17.18, and the roll diameter of both end backup rolls 16.19 is (1:4
:5.5), (175:5.5), (1:5:5.8
), (1:4.6:6.5 > and (1:4:
6.5).

That is, this range is the range surrounded by the pentagon GHIJK shown in FIG. The method for determining this range is the same as in the case of the 12-high rolling mill. Table 3 shows an example of the roll diameter of this 20-high rolling mill.

Table 3 Note that the present invention is not limited to the above embodiments.

(Effects of the Invention) According to the present invention, the roll life of each backup roll can be made equal even though the roll diameter of the work roll is changed.

[Brief explanation of drawings]

Figure 1 shows a work roll diameter-variable high-load type 1 according to the present invention.
Roll arrangement diagram of a two-high rolling mill, Figure 2 is a longitudinal sectional view of the same, Figure 3 is a longitudinal sectional view of the same.
The figure is a graph showing the range of roll diameter ratio, Figure 4 is a roll life diagram, Figure 5 is a roll arrangement diagram of a high load 20-high rolling mill with variable work roll diameter according to the present invention, and Figure 6 is a roll diagram. It is a graph showing the range of diameter ratio. ■... Rolled material, 2... Work roll, 3, 4...
- Intermediate C)-) Lt, 5... Central backup roll, 6.7... Both end backup rolls, 10... Work roll, 11.12... First intermediate roll, 13,
14.15...Second intermediate roll, 17, 18...Central backup roll, 16.19...Both end back unroll.

Claims (2)

[Claims] (1) One upper and lower work roll (2) for rolling the material to be rolled (1) is connected to two intermediate rolls (3) and (4) each having the same diameter.
) through three backup rolls (5) (6) (7
) and in which the roll diameters of the upper and lower work rolls (2) can be changed in at least two types, the maximum of the roll diameters of the work rolls (2) that can be changed. The roll diameter of the work roll (2) having a diameter of is approximately the same as the roll diameter of the intermediate rolls (3) and (4), and the roll diameter of the work roll (2) having the smallest diameter; The roll diameter of the central backup roll (5) that simultaneously supports the book intermediate rolls (3) and (4), and the both end backup rolls (6) (with the same diameter that support one intermediate roll (3) or (4)) ( 7) to the roll diameter is (
1:4:5.2), (1:4.5:5.2), (1:4
．． 5:5.75), (1:4.22:6) and (1:4
:6) A high-load 12-high rolling mill with variable work roll diameter. (2) One upper and lower work roll (10) for rolling the material to be rolled (1) is connected to two first intermediate rolls (10) each having the same diameter.
1) (12) and three second intermediate rolls (13) (14)
(15) and four backup rolls (16) through
(17) In a high-load 20-high rolling mill in which the roll diameters of the upper and lower work rolls (10) can be changed in at least two types while being supported by (18) and (19), the work rolls ( The work roll (10) having the largest diameter among the roll diameters in step 10) is approximately the same as the roll diameter of the first intermediate rolls (11) and (12), and has the smallest diameter. The roll diameter of the roll (10) and the two second intermediate rolls (13
) (14) or (14) and (15) at the same time, and the roll diameter of the central backup rolls (17) and (18) that support one second intermediate roll (13) or (15) at the same time. The ratio of the diameter to the roll diameter of the backup rolls (16) and (19) at both ends is (1:4:5.5) and (1:5:5).
．． 5), (1:5:5.8), (1:4.6:6.5)
A 20-high high-load rolling mill with variable work roll diameter, characterized in that the work roll diameter falls within a range surrounded by (1:4:6.5).