JPS5930487B2 - Composite roll for rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables the rigidity of a rolling composite roll to be changed in the longitudinal direction of the roll body, thereby reducing the edge lop of the rolled material and increasing the ability to control the shape during rolling. The purpose is to measure.

As is well known, the quadruple rolling mill used for rolling processing is
As shown in the figure, it is composed of small-diameter work rolls 1, 1 that directly roll a rolled material 3, and a pair of back unrolls 2, 2 that are pressed behind the small-diameter work rolls 1, 1.

However, when rolled by this rolling mill, the rolled material 3
Due to the deformation resistance, the work rolls 1, 1 and the bank unrolls 2, 2 are bent and deformed as shown in Fig. 2a. However, it is difficult to control the rolling surface to be flat, and for this reason, as shown in Figure 2, the rolled material 3 has an edge elongation 3 due to the deformation of the rolls 1, 1 and 2, 2.
The problem of frequent shape defects such as a was observed.

Therefore, today, as shown in Figures 1a and 3a, a hydraulic device or the like is used to apply a pengu load P to the spindles of rolls 1, 1 and 2.2 to forcefully correct the deformation. death,
As a result, a so-called roll bending method is adopted in which the thickness and shape of the rolled material 3 are appropriately controlled as shown in FIG.

However, by adopting this bending method, the following new issues and problems arise.

In other words, the structure of a composite roll generally used for rolling is as follows:
As shown in FIG. 8, the thickness H of the outer shell layer 4 is constant over the longitudinal direction of the roll body, and the stiffness of the roll is constant in the longitudinal direction of the body. The material of the outer shell layer 4 and its core material 5. stiffer than the material (Young's modulus)
If a roll with a high The following problems occur at the end contact area A between the work roll 1 and the rolled material 3, and at the end contact area B between the work roll 1 and the rolled material 3, which are shown in enlarged views in FIGS. 6 and 7.

(The contact pressure between the rehack unroll and the work roll increases at the end where the roll deformation (bending) is large.

(11) A work roll bender is used to control the shape of the rolled material, but since the rigidity of the roll is the same at the center and both ends, its straightening action is inefficient.

(iii) The niche drop of rolled material is large.

Therefore, if we further consider the causes of such problems, it goes without saying that the use of the bender load P as shown in Fig. 3a is because the work roll 1 is strongly pressed against the bank up roll 2. The purpose is to control the shape of the rolled material 3 by both bending and flattening as described in 1. In this case, a large load will be applied to the end contact portion A of the rolled material 3.

-3 However, if the thickness of the outer shell layer 4 is constant as in conventional composite rolls, the Young's modulus of the inner shell layer (core material)
In the case of the Young's modulus of the outer shell layer, the thicker the outer shell layer 4, the greater the rigidity of the entire roll, and the resistance to deformation is evenly strengthened, so that undesirable contact pressure at the end contact area A is reduced. This results in an increase.

In other words, with conventional composite rolls, a large bender load is required in order to control the desired shape, resulting in poor bender performance), and as a result, when the bender load is increased, the end contact area This results in the generation of an increasingly large contact pressure on A.

In addition, in the case of the work roll 1 and the rolled material 3, similarly, when the end part rigidity of the work roll 1 is large, the contact pressure increases, and the rolling load is concentrated on the end contact part B. As a result, a large edge drop 3b (h2-h, ) is generated in the rolled material 3 as shown in FIG.

In view of the above-mentioned technical considerations, the present invention provides a composite roll for rolling used in the O-ru pending method, in which the rigidity of both ends of the roll body is made lower than the rigidity of the central part. The purpose of the present invention is to increase the bending and flattening deformability of the roll to achieve the desired purpose. That is, the thickness of the outer shell layer is partially changed.

FIG. 9 shows the Young's modulus of the core material <
One embodiment of the present invention is shown for a composite roll in which the Young's modulus of the outer shell layer is the same.

That is, in this case, the thickness H2 of the outer shell layer is set at the center of the body (II-n), while the thickness H2 of the outer shell layer is set at the center of the body (II-n), while at both ends of the body (I-n).
1) The thickness Hl of the outer shell layer is reduced in the vicinity, and the thickness of the outer shell layer 4 is symmetrical in the axial direction with the center of the body as the axis of symmetry, and changes continuously and smoothly. It is formed to have a concave cross section.

If a composite roll with the outer shell layer 4 having a different thickness is used, as shown in FIG. The thickness of the outer shell layer is thin, so the rigidity in this part can be lowered better than in the center part of the mouth.

For this reason, in this composite roll, compared to a conventional composite roll with a uniform outer shell layer thickness, bending deformation and flattening at the end of the roll body are promoted, and the contact pressure at the end contact area A is reduced. The ability of the pentane to control the shape of the roll is improved and the required bender load is reduced.

In addition, regarding the end contact portion B between the work roll 1 and the rolled material 3, the roll 1 is similarly bent and flattened, so that
Since the concentration of rolling load in this part can be reduced and the rolling load can be evenly applied to the rolled material 3, the edge drop 3b' of the rolled material 3 can also be reduced as shown in Fig. 7. This makes it possible to reduce the

Fig. 11 shows a modification of Fig. 9, and the outer shell layer thickness is changed in stages (■■2>...Hi......
.
Of course, it is preferable to change the outer shell layer 4 continuously in the longitudinal direction as shown in the figure, but considering the convenience of the manufacturing process, it is preferable to change the outer shell layer 4 in stages as shown in Fig. 11. It is easy to use.

In other words, this type of roll can be easily manufactured by cutting the inner surface into a stepwise shape after casting the outer shell layer, and then casting the molten core material in the normal manufacturing method of composite rolls using centrifugal force casting. You can get it.

In a structure in which the thickness of the outer shell layer 4 is changed stepwise in this way, if the steps are made as small as possible and as many as possible, almost the same performance as that in FIG. 9 can be achieved. It becomes something that can be demonstrated.

The above is an example of the Young's modulus of the core material <Young's modulus of the outer shell layer, but the present invention is of course also applicable to a composite roll in which the Young's modulus of the core material>Young's modulus of the outer shell layer.

In this case, since the material of the outer shell layer is less rigid than the material of the core material, in order to achieve the intended technical purpose,
Contrary to the case of the previous example, the outer shell layer thickness H2 at the center of the body must be smaller than the outer shell layer thickness Hl at both ends of the body.

FIG. 10 shows an embodiment in this case, and FIG. 12 shows a modification thereof.

Next, specific application examples of the typical embodiments of the present invention shown in FIGS. 9 and 10 will be listed below.

As explained in detail above, the present invention relates to a composite roll for rolling, in which the thickness of the outer shell layer is changed in the longitudinal direction of the body depending on the type of roll, and the unevenness of the thickness of the outer shell layer is adjusted. Based on this, the roll stiffness at both ends is made smaller than that at the center, thereby promoting roll bending and flattening, and reducing the end contact pressure between the backup roll and the work roll, and It has also succeeded in reducing the concentration of load at the end of the work roll on the rolled material.

Therefore, when the composite roll of the present invention is subjected to rolling processing, the ability of the bender to control the shape of the rolled material can be greatly improved, and the bender load required to control the predetermined shape can also be reduced, and at the same time, the edge of the rolled material can be This will also help reduce drops, and the improvement of this roll will significantly contribute to the technical field of rolling processing.

The present invention is applicable not only to rolling work rolls but also to rolling backup rolls, and can be used in the general technical field of rolling rolls, regardless of hot rolling or cold rolling. It is something that can be done.

[Brief explanation of the drawing]

FIGS. 1a and 1b are side and front schematic views for explaining a quadruple rolling mill. FIG. 2a is an explanatory side view showing the rolling state when no bender is used, and FIG. 2 is a perspective view showing the rolled material in that case. FIG. 3a is an explanatory side view showing the rolling state when a bender is used, and FIG. 3 is a perspective view showing the rolled material in that case. FIG. 4 shows the end contact portion between the backup roll and the work roll when a conventional composite roll is used, and FIG. 5 shows the same end contact portion when the composite roll of the present invention is used. . Figure 6a shows the contact area between the conventional composite roll and the rolled material,
Figure 6 shows the shape of the rolled material in that case. Fig. γ a shows the contact portion between the composite roll of the present invention and the rolled material, and Fig. 7 shows the shape of the rolled material in that case. FIG. 8 is a half-sectional view showing a conventional composite roll. FIG. 9a is a half sectional view showing one embodiment of the present invention,
FIG. 9 is a sectional view taken along line I--I, and FIG. 9C is a sectional view taken along line--n. FIG. 10 is a sectional view showing another embodiment of the present invention. FIG. 11 is a tenth cross-sectional view showing a modification of FIG. 9;
FIG. 12 is a cross-sectional upper half view showing a modification of FIG. 10. 1... Work roll, 2... Bank up roll, 3... Rolled material, 4... Outer shell layer, 5... Core Material.

Claims (1)

[Scope of Claims] 1. A composite roll for rolling comprising an outer shell layer and a core material welded together, characterized in that the thickness of the outer shell layer in the roll body is not constant over the longitudinal direction. roll. 2. The composite roll for rolling according to claim 1, wherein the thickness of the outer shell layer varies continuously in the longitudinal direction. 3. The rolling composite roll according to claim 1, wherein the thickness of the outer shell layer changes stepwise in the longitudinal direction. 4. Claims 1 and 2, in which the thickness of the outer shell layer changes symmetrically from the center of the roll body to both ends.
Composite roll for rolling according to item 1 or 3.