JPS61126903A - Method and device for rolling plate material - Google Patents

Abstract

PURPOSE:To provide substantial control capacity for a profile and shape and to execute high draft rolling by setting the taper start points of upper and lower work rolls and the taper start points of upper and lower intermediate rolls near the side ends of a plate material. CONSTITUTION:The start points 40A, 41A of the tapered parts 40, 41 on one side of the upper and lower work rolls 11, 12 are set near the side ends of the plate material 44 to be rolled according to the width thereof by moving axially said work rolls. The taper start points 40A, 41A are set on the side inner than the side ends of the material 44 for the purpose of controlling the edge drop at the side ends of the material 44. On the other hand, the taper start points 42A, 43A of the tapered parts 42, 43 of the intermediate rolls 16, 17 are also set near the side ends of the material 44 by moving axially said rolls.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for rolling plate materials and a rolling mill.

[Prior Art] In recent years, there has been a trend in the rolling of full-bending strip materials to require stricter requirements for the uniformity of the thickness distribution (profile) in the width direction and the flatness (shape) of the product strip. For this reason, a rolling mill with excellent profile and shape adjustment ability is required, and rolling mills of various types have been proposed. In addition, from the viewpoint of energy saving and high production efficiency, the thickness of the mother plate is increasing, and therefore there is a tendency for a rolling mill with strong rolling capacity to be required. In addition, in order to improve the productivity of thin plates (e.g., steel plates of around 0.1 mm) and difficult-to-roll materials (e.g., high carbon steel, silicon steel, stainless steel), tandem rolling is becoming more popular. There is also a need for the aircraft to be capable of strong pressure reduction.

As a rolling mill that satisfies the above requirements, it is preferable to use a rolling mill that has a work roll diameter smaller than that of a conventional four-high rolling mill and that has excellent profile and shape adjustment ability.As a rolling mill that can be applied to such applications, For example, there is a Sendzimir rolling mill (20-high rolling R). However, this Sendzimir rolling mill has insufficient shape control ability, and it is difficult to make full use of its strong rolling ability.Also, since it has a multi-roll structure, it is difficult to cool the rolls, making it unsuitable for high-speed rolling. Not yet.

On the other hand, in the Special Publication No. 51-7635, it has a six-roll configuration,
In order to make the work roll relatively small and to adjust the shape, rolling mills have been proposed that are equipped with a work roll bender, a work roll shift, and an intermediate roll shift. In this rolling mill, the end of the intermediate roll is set near the side edge of the plate material by shifting the intermediate roll, and by forming a state in which one end of the work roll does not contact the intermediate roll, the bending effect of the work roll bender is improved. In addition to increasing the rolling force, it also minimizes changes in roll deflection due to rolling load fluctuations, making it possible to obtain a relatively large shape control ability.

[Problems to be Solved by the Invention] However, the biggest drawback of the rolling mill having the above-mentioned six-roll configuration is that the first-round contact pressure, so-called Hertzian contact pressure, between the rolls is high. In particular, the pressure is highest where the end of the intermediate roll contacts the work roll.

(a) The end surface of the intermediate roll becomes rough, which roughens the work roll surface, and this is transferred to the plate surface, causing poor surface appearance; and (b) The end of the intermediate roll suffers fatigue failure, causing There is also the risk of parts missing and spalling, causing a major accident. Therefore, if such a rolling mill performs strong rolling, the life of the rolls will be shortened, the roll unit consumption will be high, and the number of roll changes will also increase, reducing productivity. That is, it is unsuitable for heavy reduction rolling.

Further, in the rolling mill having the six-roll configuration described above, when the diameter of the work roll becomes small, there is a disadvantage that the effect of the work roll bender is limited to the vicinity of the end of the roll and is difficult to extend to the center of the sheet width.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for rolling a plate material and a rolling mill that enable sufficient profile and shape control and strong reduction rolling.

[Means for Solving the Problems] The first aspect of the present invention is to provide a plate material that moves a pair of upper and lower work rolls in the vertical and axial directions, and also moves an intermediate roll in contact with each of the work rolls in the downward and axial directions. In the rolling method, each work roll is provided with a tapered portion at one body end, and both work rolls are arranged so that the tapered portions of both work rolls are located on opposite sides of the rolling center, and each intermediate A tapered part is provided at one body end of the roll, and each intermediate roll is arranged so that the tapered part of each intermediate roll is located on the opposite side of the rolling center with respect to the tapered part of the work roll in contact with each other. .

The taper start points of the upper and lower work rolls and the taper start points of the upper and lower intermediate rolls are set near the side ends of the plate material.

In addition, the second aspect of the present invention includes a pair of upper and lower work rolls that are supported to be movable in the vertical and axial directions, and is movable in the vertical and axial directions in contact with each of the work rolls, and is capable of roll bending. In a plate rolling mill comprising a pair of supported intermediate rolls, each work roll is provided with a tapered part at one body end, and the tapered parts of both work rolls are located on opposite sides of the rolling center. In addition to arranging both work rolls as shown in FIG. The intermediate rolls are arranged so as to be located on opposite sides.

[Function] According to the rolling method according to the first aspect of the present invention, the contact widths of the work roll and the intermediate roll on the left and right sides with respect to the rolling center of the plate material are the same, and the width direction pressure distribution at the contact portion of the work roll and the intermediate roll is As a result, the contact pressure generated at the taper starting point of the intermediate roll is significantly reduced, making it possible to perform strong reduction rolling.

In addition, the work roll and intermediate roll support the rolling load with approximately the same width as the sheet width, which reduces bending of the work roll and minimizes changes in profile and shape due to fluctuations in rolling load. , it becomes possible to perform sufficient profile and shape control.

Further, according to the rolling mill according to the second aspect of the present invention, by setting the taper start points of the upper and lower work rolls and the taper start points of the upper and lower intermediate rolls near the side edges of the plate material, The contact width between the work roll and the intermediate roll becomes the same, and the pressure distribution in the width direction at the contact area between the work roll and the intermediate roll becomes almost uniform, which significantly reduces the contact pressure that occurs at the taper starting point of the intermediate roll, and reduces the pressure under strong pressure. Rolling becomes possible. In addition, the work roll and intermediate roll support the rolling load with approximately the same width as the sheet width, making it possible to minimize bending of the work roll and minimize changes in profile and shape due to fluctuations in rolling load. At the same time, the combination of the axial shift of the intermediate roll and the bending of the intermediate roll makes it possible to apply the bending of the roll to the center of the sheet width, making it possible to provide sufficient profile and shape control ability.

[Example] FIG. 1 is a front view showing the roll configuration of a six-high rolling mill 10 according to an example of the present invention, and FIG. 2 is a side view showing the six-high rolling mill 10.

A pair of upper and lower work rolls 11' and 12 are supported by metal links 13 and 14, and are incorporated into a housing 15. Further, a pair of intermediate rolls 16.17 in contact with the upper and lower work rolls 11.12, respectively, are supported by metal chocks 18.19, the lower intermediate roll 17 is incorporated into the housing 15, and the upper intermediate roll 16 is attached to the chock 2.
It is incorporated into 3. In addition, the upper and lower intermediate rolls 16.1
A pair of upper and lower backup rolls 2 touching each of 7
1.2z is supported by chocks 23.24 and incorporated into the housing 15.

The work rolls 11.12 are movable vertically and axially. The intermediate rolls 16, 17 are also supported to be movable vertically and axially.

A reduction adjustment device 25 is provided between the housing 15 and the tick 23 of the upper backup roll 21. This rolling down adjustment device 25 may be a rolling screw or a rolling hydraulic cylinder device, and the rolling load is as follows:
Measurement is possible with a load cell 27 provided between the lower surface of the chock 24 of the lower back up roll 22 and the liner 26 placed on the housing 15. The weight of the old backup roll 21 and chock 23 and the upper intermediate roll 16 and chock 18 is the same as the project block 28.29 fixed to the housing 15.
It is supported by a hydraulic ram 30, 31 built into the upper part of the cylinder, and is pushed upward with constant pressure. The upper intermediate roll 16 and the tip 18 are connected to the upper backup roll 21.
is supported in the chock 23 by hydraulic rams 32,33. Further, the upper intermediate roll 16 is connected to a hydraulic ram 32.
．． An upward bending moment is applied by 33 (increase bending), and a downward bending moment is applied by hydraulic rams 34 and 35 (decrease bending). Similarly, the lower intermediate roll 17 also has a hydraulic ram 36.
．． Increase bending was added by 37,
Decrease bending is applied by hydraulic rams 38,39.

Here, a tapered portion 40.41 is provided at one body end of each work roll 11.12, and both work rolls 11.12 are provided with a tapered portion 40.41.
Both work rolls 11.12 are arranged such that the twelve tapered portions 40.41 are located on opposite sides of the rolling center. Further, a tapered portion 42.43 is provided at one body end portion of each intermediate roll 16.17, and a tapered portion of the work roll 11.12 where the tapered portion 42.43 of each intermediate roll 16.17 contacts mutually. 40. Each intermediate roll 16.
17 are arranged.

Therefore, when rolling the plate material 44 using the rolling mill 10, as shown in FIG. 1, upper and lower work rolls 11.
The taper start points of No. 12 and the taper start points of the upper and lower intermediate rolls 16 and 17 are set near the side ends of the plate material 44.

That is, by moving the upper and lower work rolls 11.12 (roll diameter approximately 300 m+) in the axial direction, the starting points 4OA and 4LA of the tapered portion 40.41 on one side thereof are adjusted according to the width of the plate material 44 to be rolled. Set near the side edge.

The distance between the side edge of the plate 44 and the taper start point is EL, and when the taper start point is inside the side edge of the plate 44, it is negative. Distance @EL is upper and lower work roll 11.12
Set so that they have the same value. Note that the value of the distance #EL is set to an appropriate value that is predetermined in accordance with the profile and shape control of the plate material 44, the dispersion of wear of the work rolls 11, 12, etc. In the example of FIG. 1, the plate material 44
In order to control the edge drop at the side edge of the plate material 44, the taper start points 40A and 4LA are set inside the side edge of the plate material 44 (for example, E L = -50+sm, taper 1/4
00) I, there.

On the other hand, the intermediate rolls 16,17 are also moved in the axial direction, and the taper starting points 42A, 43A of their tapered portions 42,43 are defined near the side ends of the plate material 44. The horizontal distance between the side edge of the plate material 44 and the taper start points 42A, 43A is defined as δ, and the case where the taper start point is inside the side edge of the plate material is defined as negative.

As mentioned above, depending on the width of the plate material 44, the work roll 1
1.12 taper starting points 4OA and 41A are set near the side ends of the plate material 44, and the middle fin call 16.1
By setting the taper start points 42A and 43A of the work rolls 11.
12 and the intermediate roll 16.17 has a contact width of 3 of the plate material 44.
Since the contact width is approximately the same as the width and the contact width is approximately the same on the left and right sides with respect to the center of the plate width, the contact pressure generated between the two becomes approximately uniform. Therefore, compared to a conventional rolling mill in which the work rolls are fixed without moving in the axial direction and only the intermediate rolls are moved in the axial direction according to the sheet width, the taper start point of the intermediate rolls 16 and 17 is The contact pressure will be significantly reduced.

FIG. 3 shows an example of the contact pressure distribution. In the case of only intermediate roll shift represented by A1 in FIG. 3, the contact line load P at the taper starting point of the intermediate roll is /Plate width B), whereas according to the present invention, when the intermediate roll and work roll represented by A2 in Fig. 3 are shifted simultaneously, the contact line load P becomes the average line load. It is about 1.1 times that of PO, and the contact line load distribution is almost compensated.

By the way, the rolling capacity of a rolling mill is generally determined by the fatigue strength of the backup roll bearing and the fatigue strength of the rolls. (
This is considered within the range in which the roll and material do not slip, but the rolling reduction at the slip limit is usually large), and both of these are directly related to the rolling load. In the case of the present invention, compared to the case of only intermediate roll shift, the roll fatigue strength PH
When L (represented by the allowable Hertzian surface pressure, Hertzian surface pressure is proportional to the square root of the linear load) is equal, the rolling load corresponding to AI in Figure 3 is FO5 The rolling load corresponding to A2 in Figure 3 is If F, PHL=C,4・FO/B=Cm・FB...(1
) F/F O= 1.4/1.1 = 1.27
...(2), and it becomes possible to apply a rolling load of 1.27 times. Therefore, if the strength of the backup roll bearings is the same and the roll diameter R is the same, the rolling reduction amount corresponding to A1 in FIG. 3 is Δho, and A in FIG.
Let the rolling reduction amount corresponding to 2 be Δh.

FO=COR-Ah-(3)F=
COFrτ "・(4) Δh/Δh O= (F/F 0)2= 1.62
... (5) is established, and it is recognized that in the case of the present invention, the rolling reduction amount can be set to 1°62 times as much as in the case of only the conventional intermediate roll shift.

Therefore, for example, when cold rolling 3% silicon steel, the plate thickness is 2.
When rolling down 0+++++a, the reduction rate is 30 in the conventional method.
%, so the reduction amount is 2. OXo,3 =0.8
The rolling reduction limit is 1 mm, but in the present invention, the rolling reduction amount is 0.8 mm.
X 1.62 = 0.972 mm, L, so the rolling reduction rate can be reduced to 51.4% in one pass.

(Forged steel roll Roll diameter 35hm, Hertz surface pressure limit 20
0 Kg/as).

According to the present invention, it is possible to set such a large rolling reduction rate in one pass. For example, for a 3% silicon steel plate with a thickness of 2.0 ma+, the conventional method requires 5 passes of rolling, but this method can According to the invention, rolling can be performed in three passes, and the rolling efficiency can be increased to about 1.7 times. Furthermore, even if such a large rolling reduction is not taken, the fatigue strength at the taper starting point of the intermediate roll will increase, and if used at the same rolling load, the roll life will be reduced to 1.
It becomes possible to extend the length three times, and surface flaws such as roll flaws are less likely to occur.

Furthermore, in the above-mentioned rolling ALO, compared to the conventional method in which only the intermediate roll is shifted and the taper starting point is set near the side edge of the plate, the work roll and the intermediate roll are rolled with approximately the same width as the plate width. This supports the load, making it possible to minimize bending of the work roll and minimize changes in profile and shape due to fluctuations in rolling load. Also,
The combination of shifting the intermediate roll in the axial direction and bending the intermediate roll makes it possible to extend the bending of the roll to the center of the sheet width, making it possible to sufficiently correct edge elongation and mid-elongation.

Although the above embodiment describes the case where the present invention is applied to a six-high rolling mill, the present invention is applicable to a so-called cluster-type rolling mill in which two intermediate rolls are arranged on each of the upper and lower sides in contact with a pair of work rolls. It is also applicable to

Further, the rolling method according to the present invention can also be used in a rolling mill that is not equipped with an intermediate roll bender.

[Effects of the Invention] As described above, the first aspect of the present invention is to move a pair of upper and lower work rolls in the vertical and axial directions, and to move an intermediate roll in contact with each of the work rolls in the vertical and axial directions. In the rolling method, each work roll is provided with a tapered portion at one body end, and both work rolls are arranged so that the tapered portions of both work rolls are located on opposite sides of the rolling center, and each intermediate roll is A tapered part is provided at one body end of the intermediate roll, and each intermediate roll is arranged so that the tapered part of each intermediate roll is located on the opposite side of the rolling center to the tapered part of the work roll that touches each other, and the upper and lower workpieces are The taper start point of the roll and the taper start point of the upper and lower intermediate rolls are set near the side ends of the plate material.

Further, the second aspect of the present invention includes a pair of upper and lower work rolls supported movably in the vertical and axial directions, and
In the plate rolling mill, which is equipped with a pair of intermediate rolls that are movable vertically and axially in contact with each of the work rolls and are supported for roll bending, a tapered part is provided at one body end of each work roll. The work rolls are arranged so that the tapered portions of both work rolls are located on opposite sides of the rolling center, and a tapered portion is provided at one body end of each intermediate roll. Each intermediate roll is arranged so that its tapered portion is located on the opposite side of the rolling center with respect to the tapered portion of the work rolls in contact with each other.

In addition, according to the present invention, it is possible to provide sufficient profile and shape control ability and to perform heavy reduction rolling.

[Brief explanation of drawings]

FIG. 1 is a front view showing a roll configuration of a rolling mill according to an embodiment of the present invention, FIG. 2 is a side view showing a rolling mill according to an embodiment of the present invention, and FIG. 3 shows the effects of the present invention. FIG. 10...Rolling mill, 11.12...Work roll, 1
6.17...Intermediate roll. 40.41.42.43...Tapered part, 4OA, 4L
A, 42A, 43A...Taper starting point. Agent Patent Attorney Osamu Shiokawa Figure 1 Figure 2 Figure 3 Clearance

Claims (2)

[Claims] (1) In a plate rolling method in which a pair of upper and lower work rolls are moved vertically and axially, and an intermediate roll in contact with each of the work rolls is moved vertically and axially, one body end of each work roll is A tapered part is provided,
Both work rolls are arranged so that the tapered parts of both work rolls are located on opposite sides of the rolling center, and a tapered part is provided at one body end of each intermediate roll, and the tapered part of each intermediate roll is The intermediate rolls are arranged so that the taper parts of the work rolls that touch each other are located on the opposite side of the rolling center, and the taper start points of the upper and lower work rolls and the taper start points of the upper and lower intermediate rolls are located at the side edges of the plate material. A method for rolling plate material characterized by rolling the material in the vicinity. (2) A pair of upper and lower work rolls supported to be movable in the vertical and axial directions, and an intermediate roll in contact with each of the work rolls and supported to be movable in the vertical and axial directions and capable of roll bending. In a rolling mill for plate materials made of , a tapered part is provided at one body end of each intermediate roll, and each intermediate roll is arranged so that the tapered part of each intermediate roll is located on the opposite side of the rolling center with respect to the tapered part of the work rolls that are in contact with each other. A plate rolling mill characterized by: