JPS6096307A - Deflection self-compensating type roll - Google Patents

Abstract

PURPOSE:To absorb the deflection change of a work roll and to reduce the sheet crown of a rolling material by forming an air gap of prescribed shape at the boundary part between an arbor and a sleeve of sleeve coll in shrinkage fitting the sleeve to the arbor and forming taper parts at both ends of the sleeve. CONSTITUTION:In a main roll 1 consisting of an arbor 2 and a sleeve 3 fitted to the outside of the arbor 2, the boundary part between the arbor 2 and the sleeve 3 is constituted of a roll central part and shrinkage fitting parts 7, 8 at its both ends. Air gaps 5 having each an approximately triangular cross section are formed at the sides of arbor 2 between the parts 7 and 8. Both end-parts of the surface of sleeve 3 are formed into taper or curved shapes which are tapered toward outsides so that a part of the formed part at each side-end overlaps on the gap 5. By this construction, the surface of roll 1 is hardly bent and is deflected approximately uniformly in a shape of straight line even when a rolling load and the sheet width of a rolling material are changed. When this self-compensating type roll is used instead of an ordinary backup roll, etc., the bending curvature of work roll is made small and the sheet crown produced in the material is restricted to the minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deflection self-compensating roll used as a backup roll or an intermediate roll in a multi-high rolling mill for rolling thin plates.

Conventionally, as this type of rolling mill, for example, the most common four-film rolling mill has a pair of work rolls arranged one above the other at appropriate intervals across the pass line of the rolled material 11, as shown in Fig. 1.
12.13 and backup rolls 14,15 that support the back of these.

When thin plate rolling is performed using this rolling mill, the second
As shown in the figure, since each roll is in a state of oil, the rolled product has a plate crown in which the cross section is bulged, for example, at the center.

In general, it is desirable for this sheet crown to be small in order to improve dimensional accuracy and yield, but it is affected by roll deflection, thermal crown, wear, etc. Among them, roll deflection changes depending on rolling load and sheet width. . That is, the plate crown changes depending on these rolling conditions and is not constant.

In view of this point, various rolling mills or rolls have recently been developed and put into practical use in order to improve the plate crown. Among these, the typical ones are 6-stage (-HC) mill,
There are rolls that inflate the sleeve using internal pressure, and each has excellent characteristics depending on the application.

However, each has its own drawbacks, such as, for example, 6-high (-HC) mills are expensive and difficult to maintain, and rolls whose sleeves are expanded by internal pressure have an upper limit on rolling load, limiting the range of application. ing.

The present invention has been made in view of the above-mentioned conventional drawbacks, and the present invention has been made by firing a part of the boundary between the arbor and the sleeve in the vicinity of the center plane and both ends so as to be symmetrical with respect to the center plane of the roll barrel of the sleeve roll. A gap of a predetermined shape is provided between the two fired parts, and a tapered or curved shape is formed at both ends of the sleeve surface so as to partially overlap with the gap through the body of the sleeve. By doing so, the present invention aims to provide a deflection self-compensating roll that can absorb changes in deflection of the work roll as much as possible even when the rolling load and strip width change, thereby making it possible to improve the strip crown.

Next, the present invention will be explained with reference to the drawings, which are one embodiment.

Fig. 3 shows a deflection self-compensating roll (hereinafter referred to as the main roll) 1 according to the present invention, which is used in place of the backup roll 1.4.15 shown in Fig. 1, for example. The number of this roll is shown in parentheses.

This roll 1 is a sleeve roll consisting of an arbor 2 forming a narrow part and a sleeve 3 fitted onto the arbor 2. A gap 5 is provided at the boundary between the sleeve 2 and the sleeve 3, and a tapered taper 6 is provided at both ends of the surface of the sleeve 3.

That is, in the above boundary part, the center part of the roll and both ends are the fired part 7.8, and the part 7 between the two fired parts 7.8 is
- A void 5 is formed on the bar 2 side, and has a substantially triangular cross-section with the top shifted toward the roll end.

In addition, the taper 6 sandwiches the sleeve 3 and the gap 5
The length of the overlapping portion is shown in FIG.

3- Next, the state t during rolling by the main roll 1 having the above configuration will be explained.

As shown in FIG. 2, in the case of a normal cylindrical roll, during rolling, the roll barrel is curved so that the center plane becomes the maximum.

However, in the present roll 1, the central part where the deflection is greatest is the fired part 7, and the back surface of the sleeve 3 is more firmly supported than the arbor 2, making the roll surface difficult to deflect.

In the case of a normal roll, the deflection decreases toward the end of the roll, but in this roll 1, voids 5 are provided on both sides of the fired part 7, and the shape is as described above. The sleeve 3 has a generally triangular cross section with the top shifted toward the roll end, and a toothpick is formed on the inner surface of the sleeve 3 so that a gap smoothly increases from the firing part 7 toward the roll end to the vicinity of the firing part 8. . That is, similar to the central portion, the portion that normally tends to deflect a lot is made difficult to deflect, while the portion that deflects small is made relatively easy to deflect. Furthermore, as the middle part of the sleeve 3 bends, the surface end of the sleeve 3 protrudes conversely, and the contact pressure between the gap part 5 and the work roll 12.13 is increased at a position corresponding to the reroll end side. In order to prevent the sleeve 3 from becoming high and having an adverse effect on the deflection of the work roll 12.13, a taper 6 or a curved shape is formed through the body of the sleeve 3 so as to partially overlap the cavity 5.

Therefore, when looking at the entire length of the sleeve 3, even if it bends during rolling, the tendency is opposite to the tendency to bend.) It is supported by the arbor 2, and the taper 6 eliminates protrusion at the end of the roll. , the sleeve surface is deformed substantially linearly. As a result, by pressing and supporting the work roll 12.13 with the main roll 1, the curvature of the work roll 12.13 is reduced, and the plate crown of the rolled material 11 is also reduced.

Next, the results of experiments conducted on this roll 1 will be explained.

As shown in Fig. 1, this roll 1 is applied as a backup roll for a four-film rolling mill, and the plate width B of the rolled material 11 is 19.
00mm and rolling load Q=1500t.

FIG. 4 shows the measurement results of the surface profile of the roll 1 when loaded with n and 3000 tons. In addition, in the figure, the curve (■) shows the surface shape of the arbor 2, and the curve 11 shows the surface shape of the sleeve 3.

According to this result, when Q = 1500 tons, the sleeve 3 and the arbor 2 contact up to about 500 mm from the center of the roll barrel, and the crown amount of the main roll 1 during this period (portion p C1 in the figure) is 0.35 mm/ In contrast, in the case of Q"3000 tons, the contact area increases and the crown amount (PC2 part in the figure) is also 0.6 m.
m/radius.

That is, the roll crown increases as the rolling load Q increases. Therefore, in a normal roll, the roll deflection increases as the load increases, but in the present roll 1, as described above, the roll crown increases with the load, thereby preventing an increase in the deflection of the work roll.

Next, the plate width B2 was 1000 mm using the above four-high rolling mill.
FIG. 5 shows the measurement results regarding the influence of the rolling load P on the plate crown when rolling a 1900mm plate.

With normal rolls, the plate crown increases significantly with the load, and also changes greatly depending on the plate width B. However, with this roll 1, the influence of the load on the plate crown is significantly reduced, and the plate crown increases significantly with the load. It can be seen that the influence of width is also small.

In addition, in the above embodiment, the cavity 5 was provided on the side of the developer 2, but the present invention is not limited to this.
In addition, a gap 5a may be provided on the sleeve 3a side, for example, as in a deflection self-compensating roll 1a consisting of an arbor 2a and a sleeve 3a shown in FIG.

Further, the circular shape of the void portions 5, 5a is a parabola, c.

In addition to a 5ine curve or a circular arc, it may be formed by a straight line.

Furthermore, in order to deal with changes in the crown of the rolled material, thermal crown changes in the rolls, roll wear, etc., it is effective to combine the method with control means such as 7-roll bending and work roll shafts.

In addition, the present invention is not limited to the backup roll of the above-mentioned four-high rolling mill, but can be widely applied to backup rolls and intermediate rolls of multi-high rolling mills.

As is clear from the above description, according to the present invention, the boundary between the 7-bar of the sleeve roll and the sleeve is made symmetrical with respect to the center plane of the roll barrel, and the vicinity of the upper center plane and both ends of the boundary between the brackets are burnt. As a fitting part, a gap having the predetermined shape is provided between both fired parts, and a tapered or curved shape is provided at both ends of the sleeve surface so as to partially overlap the gap through the body of the sleeve. It forms the shape.

Therefore, even if the rolling load or the width of the rolled material changes, the surface of this roll hardly curves, and deflects almost uniformly in a straight line.As a result, the curvature of the work roll becomes small, and the rolling It is possible to minimize the plate crown that occurs on the material.

Since this roll has a simple structure, it has advantages such as low cost and easy maintenance.

[Brief explanation of the drawing]

FIG. 1 is a roll arrangement diagram of a four-high rolling mill, FIG. 2 is an explanatory diagram showing the upper half of FIG. 1 and shows the state during rolling with conventional rolls, and FIG. 4 is a cross-sectional view of the compensation type roll, FIG. 4 is a diagram showing the measurement results of the surface profile during rolling of the roll shown in FIG. 3, and FIG. FIG. 6 is a cross-sectional view showing another embodiment of the present invention, which shows the measurement results of the resulting plate crown. 1.1a...Deflection self-compensating roll, 2,2a...
- Arbor, 3, 3a...Sleeve, 4...Roll barrel center surface, 5, 5a...Gap portion, 6...Taper, 7°...Shrink fitting part. Patent applicant Kobe Steel, Ltd.

Claims (1)

[Claims] (1) A sleeve roll consisting of an arbor forming an axial center and a sleeve fitted onto the arbor so that the boundary between the two and the sleeve surface are symmetrical with respect to the roll barrel center plane perpendicular to the axial center. , the center part and both ends of the roll at the boundary part are used as fired parts, and a gap with a generally triangular cross section with the top shifted toward the shaft end is provided between the fired parts, while this A deflection self-compensating roll characterized in that a tapered or curved shape is formed through the body of the sleeve so as to overlap the above-mentioned gap.