JPS642442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling method using a rolling mill for controlling the shape of a rolled material.

In recent years, various methods of bending work rolls in four-high rolling mills have been developed and implemented in order to control the thickness profile of rolled materials in the width direction.
Conventional roll bending methods have had limitations in their ability to control the shape of rolled materials.

That is, in order to obtain a rolled product with a good shape and little change in thickness, especially in the width direction, it is necessary to minimize the deformation of the work rolls due to rolling loads, etc., and to increase the correction ability by roll bending. This is very important.

Conventional four-high rolling mills only have a vertical roll bending device, so the amount of crown correction of the roll is small and only a simple parabolic shape is corrected. The shape of the inside was able to be corrected. In addition, the effect was small on narrow plates of less than 1/2 of the roll axis length, and a good shape correction effect could not be obtained.

The present invention was made in view of the above-mentioned circumstances, and one of the upper and lower work rolls is a small-diameter work roll, and the other is a large-diameter work roll, and the small-diameter work roll is larger than the large-diameter work roll. Of the upper and lower work rolls, at least the work roll with a small diameter is appropriately shifted toward the downstream side of the rolling line with respect to the upper and lower back-up rolls so that the work roll with the small diameter is located on the downstream side of the rolling line. An intermediate roll is disposed between the roll and the back-up roll on the side of the small-diameter work roll, and on the downstream side of the rolling line of the small-diameter work roll, the intermediate roll contacts the outer peripheral surface of the small-diameter work roll and rolls the small-diameter work roll. A presser roll that can adjust the horizontal deflection of the work roll is provided, and a divided reinforcing roll or a divided static pressure pad that is divided into a plurality of parts in the longitudinal direction of the presser roll is arranged downstream of the presser roll in the rolling line. In a five-high rolling mill in which the outer peripheral surface of the presser roll on the downstream side of the rolling line is supported by the split reinforcing roll or the split static pressure pad, the small-diameter work roll is driven at low speed, and the large-diameter work roll is driven at low speed. The present invention relates to a rolling method characterized by driving rolls at high speed to perform rolling at different speeds.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Figure 1, upper and lower work rolls 1 and 2
, upper and lower back-up rolls 3 and 4 that support the upper and lower work rolls 1 and 2, and an intermediate roll 5 disposed between the upper work roll 1 and the upper back-up roll 3. In the rolling mill, the upper work roll 1 is formed to have a small diameter within an allowable range in terms of strength, and the upper work roll 1 is disposed at a position appropriately shifted in the downstream direction of the rolling line. When the rolled material 8 is subjected to reduction rolling in this state, the upper work roll 1 is bent so as to escape to the downstream side of the rolling line.

In order to perform shape control using this deflection, the outer peripheral surface of the upper work roll 1 on the downstream side of the rolling line is
A presser roll 6 having approximately the same length as the upper work roll 1 is provided, and is pressed against the upper work roll 1 to adjust the horizontal deflection of the upper work roll 1. A reinforcing roll 7 suitably divided into a plurality of parts in the longitudinal direction is provided on the downstream side of the rolling line to support the presser roll 6. Each reinforcing roll 7 is supported by a suitable support 9, and the support 9 moves the upper work roll 1 and the presser roll 6 by a screw rod type (or cylinder type, etc.) moving device 10 provided in a housing 11. It is configured to be movable in a straight line. Note that two reinforcing rolls 7 may be arranged at positions sandwiching a straight line connecting the presser roll 6 and the upper work roll 1 (see imaginary lines in FIG. 1).

Furthermore, double chocks are provided at both ends of the shafts of the upper and lower work rolls 1 and 2 and the intermediate roll 5, and cylinders are provided at the upper and lower portions of each chock.
A bending device (not shown above) is provided for applying vertical curvature to the lower work rolls 1, 2 and the intermediate roll 5.

In the five-high rolling mill configured as described above, the small-diameter upper work roll 1 is driven at low speed, and the large-diameter lower work roll 2 is driven at high speed. To control the shape of the rolled material 8, the pressing force applied to the presser roll 6 via the reinforcing roll 7 is adjusted individually by the operation of the moving device 10, and the displacement of the pressing force is defined as a vertical displacement.
The deflection of the upper work roll 1 is freely adjusted at each part in the length direction. At this time, the reinforcing roll 7
When pressed strongly against the presser roll 6, the top of the
When the gap between the lower work rolls 1 and 2 is reduced, the thickness of the rolled material 8 in that area is reduced, and conversely, when the pressing force of the reinforcing rolls 7 is weakened, the thickness of the rolled material 8 is increased in that area. Further, by operating the moving device 10, each of the reinforcing rolls 7 provided in a plurality in the width direction can be adjusted to move simultaneously in a direction in which they are pressed toward the presser roll 6 side or moved away from the presser roll 6 side. In this way, since the upper work roll 1 having a small diameter is controlled from the horizontal direction, it is possible to reduce the rolling force and the rolling power, and the deflection of the upper work roll 1 can be freely adjusted at multiple locations. , the shape of the rolled material 8 can be controlled arbitrarily.

Furthermore, by combining the above operation with the operation of the bending devices provided on the intermediate roll 5 and the upper and lower work rolls 1 and 2, the shape of the rolled material 8 can be controlled with high accuracy and over a wide range. .

Furthermore, by driving the small-diameter upper work roll 1 at low speed and driving the lower work roll 2 at high speed, the effect of different speed rolling is added to the small-diameter roll effect, which can be further improved by reducing the rolling load.

The reason why the diameter of the work roll driven at low speed can be reduced will be explained with reference to FIGS. 2A and 2B.

Figure 2 A shows the difference between the low-speed driven work roll and the high-speed driven work roll when rolling is performed with one work roll driven at low speed and the other work roll driven at high speed. It shows how much torque is applied. Note that the portion where the different speed ratio is 1 is uniform speed rolling. From this Figure 2 A, the low-speed drive work roll torque decreases as the different speed ratio increases, and if the different speed ratio becomes larger than a certain value, it becomes negative (acts as a brake), and the absolute value of the torque is small. I understand. Therefore, it can be understood that the work roll driven at low speed can be made smaller in diameter.

Figure 2B is similar to the case of Figure 2A, in which one work roll is set at a low speed and the other work roll is set at a high speed, and the rolling reduction ratio is varied while maintaining the different speed ratio at a certain value. This shows the amount of torque that acts on the low-speed driven work roll and the high-speed driven work roll when rolling is performed. As shown in Fig. 2B, the absolute value of the torque of the low-speed driven work roll decreases as the rolling reduction rate increases, and therefore, in the case of a large rolling reduction, it is possible to reduce the diameter of the low-speed driven work roll more significantly. It is shown that.

In the above embodiment, a structure that can move parallel to the upper work roll 1 may be added to the devices 6 and 7 groups, and furthermore, only the presser roll 6 can be moved relative to the reinforcing roll 7, or the reinforcing roll may be moved relative to the reinforcing roll 6. A structure that allows only the upper work roll 1 to move horizontally may be added to the upper work roll 7.

Furthermore, as a method of rolling the upper work roll 1 and the lower work roll 2 at different speeds, methods such as those shown in FIGS. 3 to 6 can be used. In other words, pinion stand method (different speed ratio depends on roll diameter)
(Fig. 3), a step gear system (Fig. 4), a twin drive system (Fig. 5) using the planetary gear device 12, a twin drive system (Fig. 6), etc. can be used. M in FIGS. 3 to 6 is a motor.

FIG. 7 shows still another embodiment of the present invention, in which the upper work roll 1 and the upper back up roll 3 are connected in a straight line and the upper work roll 1 and the lower back up roll 4 are connected on the downstream side of the rolling line. The intermediate roll 5 and the lower work roll 2 are eccentrically arranged on a straight line connecting the two, and in this method, a horizontal component force between the intermediate roll 5 and the lower work roll 2 is not generated.

In the above embodiments, the present invention is exemplified by reducing the diameter of the upper work roll and shifting the upper work roll to the downstream side of the rolling line with respect to the lower work roll. The structure may be such that it is shifted to the downstream side of the rolling line from the upper work roll;
It goes without saying that a divided static pressure pad may be used in place of the divided reinforcing roll that presses and supports the presser roll, and that various other changes may be made without departing from the gist of the present invention.

As described above, according to the present invention, the small-diameter work roll is shifted downstream of the rolling line from the large-diameter work roll, and the horizontal deflection of the small-diameter work roll is transferred to the downstream side of the rolling line of the small-diameter work roll. A presser roll that can be adjusted is disposed, and a divided reinforcing roll or a divided static pressure pad that can support the presser roll is disposed downstream of the presser roll in the rolling line, and the small diameter Since the work roll is driven at low speed and the large diameter work roll is driven at high speed, the rolling load can be reduced and the position of the work roll can be controlled from the horizontal direction, thus achieving high precision and wide range control. This has the excellent effect of making it possible.

[Brief explanation of drawings]

Fig. 1 is a side view showing a rolling mill for implementing the method of the present invention, Fig. 2A is a graph showing the relationship between roll torque and different speed ratio, and Fig. 2B is a graph showing the relationship between roll torque and rolling reduction. Graphs showing relationships, Figures 3 to 6
The figures are explanatory diagrams showing different speed operation systems of the rolling mill according to the present invention, and FIG. 7 is a side view showing a modification of the rolling mill in FIG. 1. 1...Upper work roll, 2...Lower work roll, 3
... Upper back up roll, 4... Lower back up roll, 5... Intermediate roll, 8... Rolled material, M... Motor.

Claims (1)

[Claims] 1. One of the upper and lower work rolls is a small-diameter work roll, and the other is a large-diameter work roll, and the small-diameter work roll is located downstream of the large-diameter work roll in the rolling line,
Out of the upper and lower work rolls, at least the small diameter work roll is appropriately shifted to the downstream side of the rolling line with respect to the upper and lower back up rolls, and the small diameter work roll and the small diameter work roll on the side of the small diameter work roll are provided. An intermediate roll may be disposed between the back-up roll and the small-diameter work roll on the downstream side of the rolling line and abut against the outer circumferential surface of the small-diameter work roll to adjust the horizontal deflection of the small-diameter work roll. A presser roll having the above structure is disposed, and a divided reinforcing roll or a divided static pressure pad divided into a plurality of parts in the longitudinal direction of the presser roll is disposed downstream of the presser roll in the rolling line. In a five-high rolling mill in which the side outer peripheral surface is supported by the divided reinforcing rolls or the divided static pressure pads, the small-diameter work roll is driven at low speed, and the large-diameter work roll is driven at high speed to perform different speed rolling. A rolling method characterized by: