JPS6064709A - Rolling mill - Google Patents

Abstract

PURPOSE:To eliminate perfectly the mark transferred to a rolling material from the end parts of segmental backup rolls by using a high wear-resistant material for constructing backup rolls which are in direct contact with work rolls among backup rolls. CONSTITUTION:A six-high mill is used for rolling, which consists of a pair of upper and lower work rolls 1, intermediate rolls 2 which are in contact with these work rolls 1 respectively, and backup rolls 3 which are in contact with the rolls 2 and support a rolling load. Backup rolls 4 which support the small diametral work rolls 1 while being in direct contact with them are arranged at both sides of the rolls 1 respectively. A roll constituted of sintered silicon carbide body excellent in wear-resistant property is used for the roll 4. In this way, a mark at the end part of segmental roll is never transferred to a rolling material 10 through the roll 4, because the lubricity between the roll 4 and a bearing 5 is excellent and the hardness of roll 4 is large as compared with that of the bearing 5.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a multi-high rolling mill having a support device that supports work rolls from the rolling direction, and in particular aims to prevent marks from rolling onto the work rolls by the support device. Regarding rolling mills.

[Background of the invention]

In recent years, particularly in multi-high rolling mills, there has been a trend to reduce the diameter of the work rolls in contact with the rolled material in order to reduce the rolling load, achieve strong reduction rolling, rolling of high hardness materials, rolling of ultra-thin materials, etc. As work rolls become smaller in diameter, due to constraints on the roll drive system, the strength of the rolls, and the torsional vibration of the drive system,
It becomes difficult to drive the work roll, and it is necessary to drive a roll that circumscribes the work roll, for example (a reinforcing roll in a 4-high rolling mill, an intermediate roll or a reinforcing roll in a 6-high rolling mill).

By the way, when a roll other than the work roll is driven, the work roll is displaced in the anti-contact direction due to the tangential force F generated by the driving torque, as shown in FIG.
(See double-dashed line).

Note that the tangential force is expressed by the following formula.

T F = 1 (Rn" drive ° - ' radius T "drive tri) Due to this displacement of the work roll, the gap ε per radius in the vertical direction of the work roll becomes as follows, and the thickness of the material to be rolled in the width direction The problem arises that the distribution changes and the shape also deteriorates.

Therefore, in order to solve the problems mentioned above, for example, Figures 2 and 3
The rolling mill shown in the figure is being considered. That is, the rolled material lO
Small-diameter upper and lower work rolls are arranged, and reinforcing rolls 3 are arranged in contact with each work roll.
The center is shifted toward the exit side of the rolling machine with respect to the rolling line connecting the centers of the upper and lower reinforcing rolls 3. As a result, the upper and lower work rolls are in a so-called offset state. The upper and lower confectionery rolls 1 are reinforced by upper and lower insert rolls 4' and upper and lower reinforcing rolls 11 from the rolling machine exit direction. Note that the upper and lower insertion rolls 4' and the upper and lower reinforcing rolls 11 are integrally pivotally connected by a bracket (not shown).

Incidentally, the upper and lower reinforcing rolls 11 are divided into a plurality of parts in the axial direction, and are supported throughout the axial direction by a large number of bearings to prevent deflection. In this device, by displacing the individual upper and lower reinforcing rolls 11 in the lateral direction, lateral displacement is applied to the upper and lower work rolls 1 via the upper and lower inserting rolls 4, and this lateral displacement causes the upper and lower work rolls 1 to be vertically moved. This is used to control the shape of the rolled material by changing the direction.

However, since the reinforcing roll 11 has a divided structure in the axial direction, there is a problem in that the marks from the roll ends are reflected on the upper and lower work rolls l via the presser roll 4, and are also transferred onto the rolled material 10.

This also applies to a 5-high or 6-high rolling mill similar to the above-mentioned rolling mill, as shown in FIG.

As shown in Fig. 5, the center of the upper and lower work rolls 1 is aligned with the rolling line formed by connecting the centers of the upper and lower reinforcing roll groups 2 and 3 (no offset), and the center of the upper and lower work rolls 1 is A rolling mill in which the rolling mill is supported by a group of support rolls from both sides of the exit side has also been proposed. In this rolling mill, the lateral force acting on the upper and lower work rolls 1 is only the tangential force generated by the torque from the drive roll, and the lateral force of the rolled load 1 generated by the offset of the work rolls is taken into account. Since there is no need for this, plate thickness control, shape control, etc. can be simplified. However, the configuration of the support roll group consists of a support roll 4 in contact with the upper and lower work rolls 1 and two reinforcing rolls 12 (divided rolls), which has the same drawbacks as described above.

[Purpose of the invention]

The present invention' has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a rolling mill that can reliably prevent marks from reinforcing rolls from being completely transferred to the rolling mill.

[Summary of the invention]

The rolling mill according to the present invention has upper and lower small-diameter forming rolls and one or more support rolls that are in contact with each of the work rolls, and at least the surface portion of the support roll that is in direct contact with the work rolls. The material is made of a highly wear-resistant material, such as a roll material or a ceramic material. This is intended to prevent the reinforcing roll mark from being transferred to the rolled material.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 6 to 8. For ease of explanation, parts that are the same or correspond to those of the conventional rolling mill are designated by the same or corresponding symbols as in FIGS. 1 to 4.

The rolling mill according to the present embodiment includes a pair of upper and lower work rolls 1, intermediate rolls 2 respectively following the work rolls 1, and reinforcing rolls 3 that are in contact with each of the intermediate rolls 2 and carry the rolling load.
A 6-high rolling mill consisting of Small diameter work roll I
Support rolls 4 that are in direct contact with and support the work roll 1 are disposed on both sides of the work roll 1. A bearing 5 that receives the supporting roll 4 in surface contact, and a bracket 6 that can be attached to the tip end thereof are installed 9 to suppress and control the lateral displacement of the small diameter work roll l. The support roll 4 is made of a material with good abrasion resistance, and is replaced much less frequently than the work roll I.

As the support roll 4, a roll made of sintered silicon carbide is used. The Vickers hardness of this support roll 4 is approximately 3300.
kg f/rR1n2. The sintered body contains boron carbide IN and 4% by weight of carbon, and has a theoretical density of 98%.
The sintered body using a material having a density of The raw material powder used had a particle size of about 0.7 μm.

Moreover, as the material of the support roll 4 other than the above, a roll made of silicon nitride sintered body may be used.

In this case, the Pinkers hardness is approximately 3000 kgf, /
'+rrm2. The sintered body contains 2% by weight of ittria as a sintering aid and 1% by weight of aluminum chips.The sintered body is made by hot pressing and has a theoretical density of about 99%.
% density. The particle size of the raw material powder is approximately 1 μm.

In addition, as the support roll 4, the Pinkers hardness is approximately 1.3.
A roll made of a sintered body made of only alumina of 00 kg f/wn and having a density close to the theoretical density may be used. This sintered body was produced by isostatic press molding and then firing. The particle size is 3 μm, and the density is 98.5 cm, which is the theoretical density.

The bearing 5 is also made of a bearing material with good wear resistance (for example, synthetic resin or LBC) to reduce the frequency of replacement like the support roll 4, and the contact surface between the support roll 4 and the bearing 5 is made of a material used during rolling. The same liquid as the coolant liquid of the work roll 1 to be used, or a liquid that does not cause problems even when mixed with the coolant liquid (a liquid that can be reused in the mixing case or separated from the coolant liquid) is supplied via the bracket 6 ( Arrow direction A).

Further, the bracket 6 is movable in the direction of the arrow XX, and even if the support roll 4 or the bearing 5 is worn out, the position of the upper and lower work rolls l can always be set to the initial setting position, or the position of the upper and lower work rolls l can be actively set. The structure allows for control of lateral displacement. 2. The bracket 6 is attached to a fixed member, such as a nozzle/gua.

If only the lateral displacement of the upper and lower work rolls 1 is to be suppressed,
The bearing 5 can be fitted in one piece (as shown in FIG. 7 in this example) or in a plurality of parts.If the lateral displacement is to be utilized for shape control, the bearing 5 can be fitted in a plurality of parts in the axial direction. It is sufficient that the bearings are individually arranged and each bearing can be individually controlled in the direction of the arrow XX. An example thereof is shown in FIG. In this case, it is desirable that the bracket 6 be provided with a hydraulic cylinder 8 for movement in the direction of the arrow X-X, and that the cylinder 8 be attached to a fixing member 9. As the moving means, in addition to a hydraulic cylinder, manual or motorized means can be used.

According to the above configuration, the end marks of the split rolls are formed by the support roll 24 due to the good lubricity between the support roll 4 and the bearing 5, and because the hardness of the support roll 4 is greater than that of the bearing 5. It is not transferred to the rolled material IO via the .

2. In the above embodiment, the support rolls 4 are arranged on both sides of the upper and lower work rolls l, but the rolling mill, as shown in FIG. Of course, it can also be applied to a case where the support roll is provided only on one side (in the case where the rolled material 10 flows from left to right in Fig. 6, the support roll 4 is provided only on the left side). ).

Further, in the above embodiment, the rolling line of the reinforcing roll 3 and the center of the upper and lower work rolls 1 are aligned, but the invention is not limited to this. For example, as shown in FIG. 9, the center of the upper and lower work rolls 1 is rolled down. Shift it to the exit side with respect to the line to generate a lateral component force due to the rolling load (rightward in the figure, on the other hand,
It is also possible to arrange a support roll 4 on the exit side and control the lateral displacement of the upper and lower work rolls l.

Furthermore, although a six-high rolling mill was shown in the above embodiment, the present invention is of course applicable not only to this but also to multi-high rolling mills as shown in FIGS. 10 to 12.

In the present invention, the support roll 4 is basically integrated, but the bearings 5 may be integrated or a plurality of bearings may be arranged in the axial direction.

〔Effect of the invention〕

As described above, according to the present invention, since the reinforcing rolls, especially the supporting rolls, are made of a highly wear-resistant material, it is possible to eliminate any marks transferred to the rolled material by the ends of the split reinforcing rolls, and to improve the shape of the rolled material. Excellent effects are achieved in improving the quality of the product.

[Brief explanation of the drawing]

Figures 1 to 5 show the prior art, and Figure 1 is a schematic front view showing the order status of lateral displacement of a small diameter work roll;
Fig. 2 is a schematic front view showing another conventional technique, and Fig. 3 is a schematic front view showing another conventional technique.
4 and 5 are schematic front views showing other slightly different conventional techniques, and FIGS. 6 and 7 show an embodiment of the present invention, and FIG. is a schematic front view, FIG. 7 is a partial side view of FIG. 6, FIG. 8 is a side view showing a modification of FIG. 7, and FIGS. 9 to 12 show other embodiments of the present invention, respectively. It is a schematic front view. l...Work roll, 3...Reinforcement roll, 4'...
High n1it *$1 Figure 2nd Port %30 Figure 4 1 $f Eye No. 60 80th' Mouth 1O Figure 1 Figure 120

Claims (1)

[Claims] 1. A rolling mill having a pair of upper and lower work rolls reinforced with reinforcing rolls from above and below, and one or more stages of support rolls that roll and support at least one of the work rolls from the lateral direction. A rolling mill characterized in that, among the support rolls, the support roll in direct contact with the work roll has a roll shape in which at least a surface portion thereof is made of a highly wear-resistant material and has a continuous surface in the axial direction. 2. The rolling mill according to claim 1, wherein the highly wear-resistant material constituting the support roll is ceramic. 3. The rolling mill according to claim 2, wherein the support roll is entirely made of a ceramic material or has a surface coated with a ceramic material.