JPH0618644B2 - Multi-stage rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a multi-stage rolling mill in which a plurality of divided reinforcing rolls are improved, and is intended to increase the rolling force.

<Prior art> In recent years, in the rolling field, from the viewpoint of productivity improvement and energy saving, a high pressure rolling mill capable of significantly reducing the plate thickness in one rolling process has been demanded. The requirements for accuracy and shape are becoming more and more stringent.

Therefore, as a rolling mill satisfying such requirements, a multi-stage cluster rolling mill has been developed in which a reinforcing roll for pressing a work roll is divided into a plurality of parts in the axial direction. This multi-stage cluster rolling mill is shown in FIG. In the figure, reference numeral 1 is a material to be rolled which advances in the direction of an arrow and is rolled, 2 is a work roll used for rolling the rolled material 1, and 3 is a work roll 2 which contacts the work roll 2.
Book intermediate rolls, 4 is a large-diameter reinforcing roll that reinforces the work roll 2 through the intermediate roll 3, 5 is a small-diameter reinforcing roll, and 6 is a frame, which constitutes a rolling machine having high horizontal and vertical rigidity. There is. A plurality of the reinforcing rolls 4 (five in the illustrated example) along a direction parallel to the axial direction thereof.
Are divided into reinforcing rolls 4a, 4b, 4c, 4d, 4e, and each of the reinforcing rolls 4a to 4e can move in a direction perpendicular to the axial direction via an eccentric sleeve (not shown) in order to cope with a change in shape of the rolled material 1. Has become. The same rolling bearing is used for each of the reinforcing rolls 4a to 4e in order to emphasize the compatibility thereof.

In this multi-stage cluster rolling mill, the diameter of the work roll 2 can be reduced, so that there is an advantage that the rolling load is small and high pressure is possible. Further, when the work roll 2 is bent and deformed, there is an advantage that the bending of the work roll 2 can be offset by eccentricizing the reinforcing rolls 4 a to 4 e.

Now, let us consider the load applied to the reinforcing rolls 4a to 4e during rolling. Figure 3 shows the linear pressure (load) acting on each reinforcing roll in the case of a rolled material with a relatively wide strip.
The outline of is shown. Assuming that the rolling pressure between the rolling material 1 and the work roll 2 is evenly distributed, if the rolling pressure acts on the reinforcing rolls 4a to 4e through the intermediate roll 3, as shown in FIG. 3 (b). In addition, the load is applied most to the reinforcing rolls 4c at the center, then to the reinforcing rolls 4b and 4d on both sides thereof, and to the reinforcing rolls 4a and 4e at both ends. This inevitably occurs due to the relationship of bending rigidity of the frames of the reinforcing rolls 4a to 4e, and this tendency becomes more remarkable as the plate thickness of the rolled material 1 becomes smaller. Further, as described above, the same rolling bearing is usually used for the reinforcing rolls 4a to 4e.

<Problems to be Solved by the Invention> In the above-described multi-stage cluster rolling mill, the bearings supporting the reinforcing rolls 4a to 4e are the same, even though the largest load is applied to the central reinforcing roll 4c. Therefore, the bearing life of the reinforcing roll 4c is the shortest. Therefore, the maximum rolling load of the multi-stage cluster rolling mill is set to be relatively small because it is set with the central reinforcing roll 4c as a reference.

The present invention has been made to effectively solve this drawback, and provides a multi-stage rolling mill in which the roll width of a plurality of reinforcing rolls is changed according to the load at the time of rolling. The purpose is to improve the maximum rolling load of a multi-high rolling mill without changing the rolling stock.

<Means and Actions for Solving Problems> The gist of the present invention for achieving the above object is to provide a pair of upper and lower work rolls and a plurality of work rolls arranged along the axial direction and a plurality of work rolls arranged above and below. In a multi-stage rolling mill having a reinforcing roll that presses the work roll via an intermediate roll, the roll width of each of the reinforcing rolls is widened according to the magnitude of the load the roll receives during rolling. The feature is that the bearing strength of the reinforcing roll at the position where the maximum load is applied is increased.

<Example> FIG. 1 (a) is a layout view of a split roll according to an example of the present invention, and FIG. 1 (b) is a partial cross-sectional view of a reinforcing roll.

In the figure, 11 is a work roll, 12 is an intermediate roll that contacts the work roll 11, and 13a, 13b, 13c are reinforcing rolls that reinforce the work roll 11 via the intermediate roll 12. The roll width of the reinforcing rolls 13a to 13c is
Corresponding to the linear rolling distribution shown in FIG. 4 (b), the central reinforcing roll 13a with the largest load has the widest, the reinforcing rolls 13c at both ends have the narrowest, and the reinforcing roll 13b has an intermediate width. There is. Further, the reinforcing rolls 13a to 13c are supported by a bearing having rollers 16 and 16a provided between the inner ring 14 and the outer ring 15 in a double row.

Generally, the basic dynamic load rating C of rolling bearing is C = fe (i
・ Leff ・_cos α) ^7/9 × Z ^3/4 × Da ^29/27 , which is C∝leff ^7/9 when considered in the usual radial roller bearing.
Becomes (Leff: Effective Roller Length) Now, let us consider the load acting on the bearing of the reinforcing roll 13a in comparison with the reinforcing roll 4c shown in FIG. 3 (a). When the roll width of the reinforcing roll 4c is B and the distance between the reinforcing roll 4c and the reinforcing roll 4d is A, the load applied to the reinforcing roll 4c is substantially proportional to the corresponding width E (E = A + B). Reinforcing roll 1
When the roll width of 3a is B, the load increase rate for the reinforcing roll 4c is And the roll width increase ΔB = B′−B, Becomes On the other hand, the increase in the basic dynamic load rating of the bearing is due to the fact that the roller length l becomes l'and the effective roller length leff is also lef.
to increase with f ′ Becomes this Is relatively small, However, even though the index is 7/9, the basic dynamic load rating C of the bearing of the reinforcing roll 13a can be significantly increased. Further, if the roll width of the reinforcing roll 13a is increased, the number of rollers (Z) or the roller diameter (Da) of the bearing can be increased, so that the bearing width can be increased, which is advantageous in terms of fatigue of the outer ring. But basic dynamic load rating C
Can be increased.

In the above embodiment, the reinforcing roll 13 is divided into five parts, but the reinforcing roll is not limited to five as long as the reinforcing roll is divided into a plurality of parts. In addition, the roll width is not necessarily the widest in the center reinforcement roll,
It is determined appropriately according to the load that the reinforcing roll receives during rolling. Further, the above-mentioned one embodiment is applied to the multi-stage cluster rolling mill, but it can be applied to various multi-rolling mills as long as the reinforcing rolls that apply the pressing force to the work roll 11 are divided into a plurality of rolls. is there.

<Effect of the Invention> In the present invention, from the distribution of loads acting on the entire divided reinforcing rolls, the roll width of the reinforcing rolls is widened in response to a large load, so that the rigidity of the reinforcing rolls at the position receiving a large load is increased. . Therefore, the maximum rolling load can be improved without changing the housing and the check size.

[Brief description of drawings]

FIG. 1 relates to an embodiment of the present invention. FIG. 1 (a) is a layout view of a split roll, FIG. 1 (b) is a partial cross-sectional view of a reinforcing roll,
FIG. 2 shows an outline of a conventional multi-stage cluster type rolling mill,
FIG. 2 (a) is its side view, FIG. 2 (b) is its front view, and FIG.
FIG. 3A is a diagram showing the outline of the linear pressure acting on the reinforcing roll, and FIG. 3B is a distribution diagram of the linear pressure acting on the reinforcing roll. In the drawing, 11 is a work roll, 12 is an intermediate roll, 13a, 13b and 13c are reinforcing rolls, and B'is a roll width of the reinforcing roll.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Ikariishi 1 Kawasaki-cho, Chiba City, Chiba Prefecture Inside the Kawasaki Steel Co., Ltd. (72) Inventor Makoto Suzuki 1 Kawasaki-cho, Chiba City Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Inside the steel mill

Claims (1)

[Claims] 1. A multi-stage rolling mill comprising: a pair of upper and lower work rolls; and a plurality of reinforcing rolls which are divided into a plurality of work rolls in the axial direction and which are respectively arranged above and below to press the work rolls via intermediate rolls. In the multi-stage rolling mill, the roll width of each of the reinforcing rolls is widened according to the magnitude of the load that the roll receives during rolling.