JPH055561B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) 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 back-up rolls via two intermediate rolls, each back-up When the rolls were made to have the same diameter, there was a problem 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 that the roll diameter of the back-up rolls is made different depending on the rolling load of each back-up roll, thereby making the durability performance of the back-up roll bearings uniform. (Refer to Japanese Patent Application Laid-Open No. 57-206507). This conventional method uses a multi-stage rolling mill that uses work rolls with a single diameter, with a roll diameter ratio of the center back-up roll and both end back-up rolls.
It was set to 0.3 to 0.7, preferably 0.4 to 0.6. In other words, the life of the roll bearing is determined by variously changing the roll diameter ratio of the center back-up roll and the back-up rolls at both ends, and the appropriate roll diameter ratio is determined when the life of the back-up rolls at the center and both ends are approximately equal. It was determined as a roll diameter ratio. (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-mentioned conventional technology can be applied as is to determine an appropriate back-up roll diameter ratio in order to make the life of each back-up roll approximately equal. I couldn't do it. That is, in the conventional technology, the roll diameter ratio of each back-up 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 back-up roll changes. This is because the appropriate roll diameter ratio changes as well. In addition, the purpose of making the diameter of the work roll variable is
This is to improve productivity and shape with one 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. Further, when a small diameter roll is used, a high rolling reduction ratio can be obtained, and the number of passes can be reduced, thereby improving productivity. This is because the force required for rolling applied to the material to be rolled can be relatively small, so the amount of rolling reduction per pass can be increased. Therefore, for example, when a multi-high rolling mill with variable work roll diameter is used as a reverse rolling mill to roll a product in 6 passes, the first 1 to 4 passes are rolled at a high reduction rate using small diameter work rolls, and the final A large diameter work roll is used for 5 to 6 passes 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, in order to find the roll diameter ratio of the back-up roll, it is not enough to simply determine the roll diameter ratio of the back-up roll for a roll between the large-diameter work roll and the small-diameter work roll.
It was not an appropriate way to define it. Therefore, the present invention takes into account the fact that the work roll diameter changes and the frequency of use of different types of work rolls is different, and makes the bearing life of the back-up roll approximately uniform, so that the back-up roll as a whole The purpose of the present invention is to provide a high-load multi-stage rolling mill with variable work roll diameter and a long service life. (Means for Solving the Problems) In order to achieve the above object, the present invention takes the following measures. That is, the work roll diameter variable work roll diameter for high load use 12 of the present invention
The feature of the corrugated rolling mill is that the work rolls 2, one each for upper and lower sides, which roll the material 1 to be rolled, are connected to three back-up rolls 5, 2 via two intermediate rolls 3, 4 of the same diameter, respectively. In a high-load 12-high rolling mill in which the roll diameters of the upper and lower work rolls 2 can be changed in at least two types, the maximum diameter of the changeable roll diameters of the work rolls 2 is supported by the work rolls 6 and 7. The roll diameter of the work roll 2 having a diameter 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 and the two intermediate rolls 3 and 4 are simultaneously The ratio of the roll diameter of the central back-up roll 5 supporting one intermediate roll 3 or 4 to the roll diameter of both end back-up rolls 6 and 7 having the same diameter and supporting 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)
It is at a certain point within the range surrounded by . In addition, the present invention has a variable work roll diameter for high load use.
The feature of the 20-high rolling mill is that the work rolls 10, which roll the material to be rolled 1, are one each on the upper and lower sides, two first intermediate rolls 11, 12 each having the same diameter, and three second intermediate rolls. 13, 14, 15, supported by four back-up rolls 16, 17, 18, 19, and in which the roll diameter of each upper and lower work roll 10 can be changed in at least two types. In this case, 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 rolls 11 and 12, and the smallest roll diameter. The roll diameter of the work roll 10 having a diameter, the roll diameter of the central back-up rolls 17, 18 having the same diameter that simultaneously support two second intermediate rolls 13, 14 or 14, 15, and one second intermediate roll Roll 13 or 15
A back-up roll 16 at both ends of the same diameter supporting the
The ratio of roll diameter of 19 is (1:4:5.5), (1:
5:5.5), (1:5:5.8), (1:4.6:6.5), and (1:4:6.5). (Function) The rolling mill of the present invention is used as a reverse type. For example, when obtaining a finished product in 6 passes, the first 1 to 4 passes use small diameter work rolls, and the final 5 to 4 passes use small diameter work rolls.
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. Furthermore, 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. Therefore, when we statistically investigated the frequency of use of large-diameter rolls and small-diameter rolls, we found that large-diameter rolls used 20% to 30% of the time,
Small diameter rolls accounted for 80-70%. 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 because
Due to the following reasons. 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 the angle formed by the axes of the back-up rolls at both ends, the intermediate roll, and the small-diameter work roll is 180°.
If it is not less than this, the intermediate roll will pop out, so the ratio with the other roll diameters is automatically determined by considering the roll arrangement. Since this ratio is a well-known value, it is not particularly limited. In the present invention, the large diameter roll is approximately 2 times larger than the small diameter roll.
(1.8 to 2.0) times. In determining the back-up roll diameter ratio, the small work roll diameter is used as the standard for the following reason. In other words, the back-up roll diameter can be arbitrarily selected based only on the ratio of the back-up roll diameters at the center and both ends, and the roll arrangement of the entire rolling mill cannot be specified. The roll diameter ratio is determined. 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 between the center back-up roll and both end back-up rolls is based on the assumption that both small-diameter work rolls and large-diameter work rolls are used.
It is determined by balancing the bearing life of both backup rolls. Among these, it is advantageous if the usage ratio of small diameter rolls increases as the ratio approaches the diameter ratio of 1:4:6, and the usage ratio of large diameter rolls increases as the ratio approaches the diameter ratio of 1:4.5:5.2. This is advantageous when the In other words, if the diameter ratio of both back-up rolls is
If it is less than 0.67 (1:4:6), the life of the center back up roll will be shorter than the life of both end back up rolls, and the life of the back up roll as a whole will be shortened. Also, if the diameter ratio of both backup rolls is 0.87
(1:4.5:5.2) or less, the life of the back-up rolls at both ends will be shorter than that of the center back-up roll, and the life of the back-up roll as a whole will be shortened. Further, the ratio of the diameter of both back-up 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 protrusion. That is, if the ratio of the diameter of the central back-up roll to the diameter of the work roll is less than (1:4), the diameter of the back-up roll becomes too small and high-load rolling cannot be performed, and if it is more than (1:4.5), This is because 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 back-up roll and both end back-up rolls interfere with each other, making it impossible to arrange the rolls. This range is excluded. 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) Hereinafter, an example of the present invention will be described based on the drawings. What is shown in FIG. 1 is a roll arrangement diagram of a high-load 12-high rolling mill with variable work roll diameter. 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, the roll diameters of the upper and lower work rolls are the same, except in special cases. The rolling mill has upper and lower parts 1 each for rolling the material 1 to be rolled.
It has a work roll of books 2. Each work roll 2 is supported by two upper and lower intermediate rolls 3 and 4, respectively. The roll diameters of these two intermediate rolls 3 and 4 are the same. These intermediate rolls 3 and 4 each have three upper and lower back-up rolls 5,
6 and 7. Among the three backup rolls 5, 6, and 7, the central backup roll 5 supports the two intermediate rolls 3 and 4 at the same time. And the two back-up rolls 6 and 7 at both ends are
One intermediate roll 3 or 4 is supported. The roll diameters D ₂ of the back-up rolls 6 and 7 at both ends are the same. Further, the roll diameter D ₁ of the central back-up roll 5 and the roll diameter D ₂ at both ends are different. As shown in the longitudinal section of the rolling mill in FIG. 2, the backup rolls 5, 6, and 7 are bearing-type rolls that are divided into a plurality of pieces in the axial direction, and the roll bearings are mounted on stands. It is pivotally supported by a saddle 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 as that of the intermediate rolls 3 and 4. Work roll 2
The minimum diameter is approximately 1/2 of the maximum diameter. As shown in FIG. 3, the ratio of the minimum roll diameter of the work roll 2, the roll diameter of the central back-up roll 5, and the roll diameter of the back-up rolls 6 and 7 at both ends is (1:4:5.2). (1:4.5:5.2), (1:
4.5:5.75), (1:4.22:6) and (1:4:6)
It is set within the range enclosed by . FIG. 4 shows a back-up roll life diagram for determining the roll diameter ratio. The roll life L _h of back-up roll is calculated by the following formula and Table 1,
It was determined under the conditions shown in Table 2. L _h = 3×0 ^-6 /60×N×(C/P) ^10/3 However, N: Number of rotations of the back-up roll C: Load capacity of the back-up roll P: Average load of the work roll

【table】

[Table] In Fig. 4, dotted lines a and a' indicate the roll life of the backup rolls 5, 6, and 7 at the center and both ends when the work roll 2 is 40 mm, and dashed-dotted lines b and b' indicate the roll life of the back-up rolls 5, 6, and 7 when the work roll 2 is 80 mm. This is the roll life of the backup rolls 5, 6, and 7 at the center and both ends. The method of determining the optimum roll diameter ratio from the dotted line diagrams a, a' and b, b' is a conventional method disclosed in the above-mentioned Japanese Patent Laid-Open No. 57-206507. In the present invention, instead of using these dotted lines, solid lines c and c' shown in FIG. 4 are used. That is, solid lines c and c' indicate that the work roll 2 is 40 mm
Average the load at , and the load at 80mm, and
The roll lives of the backup rolls 5, 6, and 7 at the center and both ends are calculated by calculating the average load P of the work rolls, taking into account the frequency of use of both rolls. At the point where the solid lines c and c' intersect, the roll lives of the backup rolls 5, 6, and 7 at the center and both ends become equal. Therefore, the roll diameter ratio (center)/(both ends) was determined to be 0.67 to 0.87 as an appropriate range centered on this point. If this range is expressed based on the minimum work roll diameter, points A, B, C in Fig. 3,
This is the rectangular range surrounded by D. However, the range surrounded by the triangle DEF is excluded because the center back up roll 5 and the end back up rolls 6 and 7 interfere with each other, making it a range that cannot be actually used. What is shown in FIG. 5 is a roll arrangement diagram of a high-load 20-high rolling mill with variable work roll diameter. 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 and 12. These two first intermediate rolls 1
The diameters of rolls 1 and 12 are the same. Said 2
The first intermediate rolls 11, 12 of the book are supported by three second intermediate rolls 13, 14, 15. These three second intermediate rolls 13, 14, 15
Among them, the center roll 14 is the roll 1 on both sides.
The diameter is smaller than 3,15, and the rolls 13,1 on both sides
5 has the same diameter. The three second intermediate rolls 13, 14, 15 are supported by four backup rolls 16, 17, 18, 19. 4 back up rolls 16, 17, 1
Of 8 and 19, the two central ones have the same diameter, and
The two on both the left and right ends are also of the same diameter. The roll diameter of the work roll 10 is freely changeable, and its maximum diameter is the same as that of the first intermediate roll 1.
The diameter of the rolls 1 and 12 is approximately the same. Other conditions were the same as those of the 12-high rolling mill. And, the minimum roll diameter of the work roll 10,
The ratio of the roll diameter of the central back-up rolls 17, 18 and the roll diameter of the end back-up rolls 16, 19 is (1:4:5.5), (1:5:5.5),
(1:5:5.8), (1:4.6:6.5) and (1:4:
6.5). That is, this range is the pentagon shown in Figure 6.
This is the range surrounded by GHIJK. The method for determining this range is the same as in the case of the 12-high rolling mill. this
Table 3 shows an example of the roll diameter of a 20-high rolling mill.

【table】

[Table] Note that the present invention is not limited to the above-mentioned examples. (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 the drawing]

Fig. 1 is a roll arrangement diagram of a high-load 12-high rolling mill with variable work roll diameter according to the present invention, Fig. 2 is a longitudinal sectional view thereof, Fig. 3 is a graph showing the range of roll diameter ratio, and Fig. 4 5 is a roll life diagram, FIG. 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 FIG. 6 is a graph showing a range of roll diameter ratios. 1... Rolled material, 2... Work roll, 3, 4
...Middle roll, 5...Central back up roll, 6,7...Both end back up roll, 10...
... Work roll, 11, 12 ... First intermediate roll, 13, 14, 15 ... Second intermediate roll, 1
7,18...Central Backup Prowl, 16,1
9...Both ends back up.

Claims (1)

[Scope of Claims] 1. One upper and lower work roll 2 for rolling a material to be rolled 1 is transferred to three back-up rolls 5, 6, 7 via two intermediate rolls 3, 4 each having the same diameter. In a high-load 12-high rolling mill in which the roll diameters of the upper and lower work rolls 2 can be changed in at least two types, the workpiece has the largest diameter among the changeable roll diameters of the work rolls 2. The roll diameter of the roll 2 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 and a center that simultaneously supports the two intermediate rolls 3 and 4. The ratio of the roll diameter of the back-up roll 5 to the roll diameter of the back-up rolls 6 and 7 at both ends 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)
A high-load 12-high rolling mill with variable work roll diameter, which is within the range surrounded by . 2 One upper and lower work roll 10 for rolling the material 1 to be rolled is replaced with two first intermediate rolls 1 each having the same diameter.
1, 12 and three second intermediate rolls 13, 14, 1
5 and 4 back up rolls 16,1
7, 18, and 19, and in which the roll diameters of the upper and lower work rolls 10 can be changed in at least two types, the maximum of the roll diameters of the work rolls 10 that can be changed. The roll diameter of the work roll 10 having a diameter of is approximately the same as the roll diameter of the first intermediate rolls 11 and 12, and the roll diameter of the work roll 10 having the smallest diameter and the two second intermediate rolls The roll diameter of the central back-up rolls 17, 18 having the same diameter that simultaneously support the rolls 13, 14 or 14, 15, and one second intermediate roll 13 or 15.
A back-up roll 16 at both ends of the same diameter supporting the
The ratio of roll diameter of 19 is (1:4:5.5), (1:
5:5.5), (1:5:5.8), (1:4.6:6.5), and (1:4:6.5) 20 stages for high load with variable work roll diameter. rolling machine.