JPH0647416A - Rolling method - Google Patents

Abstract

(57) [Summary] [Purpose] The backup fulcrum can be changed to any position at high speed to control the shape, and the support roll is oscillated to prevent the roll mac from forming. [Structure] A pair of support rolls having a short body width, which are rotatable and axially slidable and are in rolling contact with a work roll, are mounted on the outer periphery of a backup shaft which is rotatably supported by a bearing in a housing of a rolling mill. In addition, a position detector and hydraulic solenoid valves for high speed and fine speed are installed on the hydraulic cylinder that moves the support roll, and the support roll is shifted to the set position at high speed to oscillate the support roll at low speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in the fields of iron and steel industry and non-ferrous industry, and is used in a rolling mill for passing a plate material such as a steel plate between rolls to perform plastic deformation to obtain a desired plate thickness. In particular, the present invention relates to a rolling method in which a support roll can be moved to a set position at high speed for shape correction and crown correction, and after the movement, a roll mark is prevented by oscillating at a very low speed.

[0002]

2. Description of the Related Art Generally, various methods have been proposed to control the shape of a material to be rolled. For example, a conventional four-high rolling mill has a pair of work rolls having a relatively small diameter and And a backup roll with a relatively large diameter, which is arranged so as to sandwich it from the outside, all of which are formed to have substantially the same cylinder length so that they roll over the entire length, and a bending cylinder is mounted between the bearings of the work roll. I am trying. The material to be rolled is passed through such a rolling mill to obtain a strip material having a desired plate thickness. The central portion of the work roll is widened as the material to be rolled passes, and the material to be rolled is rolled. Has a so-called middle-height cross-sectional shape with a thick central part and thin side edges, so that a crown is formed on the backup roll, and the bending cylinders act to drive the necks of the work rolls toward each other in the expanding direction. The work roll is adjusted so that the pressure lower surface is flat, and shape control is performed to correct the crown generated in the rolled material.

[0003]

However, in the above-described conventional rolling mill, since the work rolls are restricted by the entire surface of the backup rolls, it is difficult to give sufficient roll bending to the work rolls, and it is difficult to control the shape. In addition to lacking absolute capability, there are drawbacks such as the need to change the crown shape by changing the backup roll depending on the strip width, strength, shape, etc. of the rolled material, especially in the 4-high rolling mill. In addition, the backup roll rolling on the work roll contacts the entire surface, so the backup fulcrum cannot be changed arbitrarily and the shape cannot be controlled at an arbitrary position. In recent years, a method has been proposed in which the rolling mill has six stages and the intermediate roll is moved in the axial direction to control the shape (Japanese Patent Publication No. 52-5304), but since the upper and lower intermediate rolls have different moving directions, the plate Since it cannot be controlled symmetrically in the width direction, there are problems in product accuracy and strip characteristics. Further, there is a drawback that a sufficient space space is required on the side of the rolling mill due to the shift mechanism of the intermediate rolls.

Further, when the intermediate roll is moved inward from the strip width of the material to be rolled, the roll surface pressure at one end where the intermediate roll and the work roll do not come into contact with each other becomes maximum. When the rolling mill is used for a long time in such a state, the marks due to the stress concentration are transferred to the strip material at the maximum surface pressure part, resulting in a beautiful appearance for materials such as aluminum and stainless steel that require a particularly beautiful surface. There are problems such as damage.

Therefore, the applicant has recently developed a rolling mill in which a plurality of support rolls are moved in the axial direction of the backup roll according to the shape and strip width of the material to be rolled to control the shape in combination with roll bending. In this rolling mill, as shown in FIG. 7 (1), the upper and lower support rolls 5, 6, 7, and 8 are moved in the axial direction of the backup shafts 3 and 4 according to the plate width shape of the material 11 to be rolled. Is a type of rolling mill that performs shape control in combination with roll bending 9 and 10.

Since this rolling mill can be controlled symmetrically with respect to the strip thickness and strip width directions, it is possible to obtain markedly better product accuracy and strip passing characteristics than the conventional 6-roll rolling mill, but it is still the 6-roll rolling type. Similar to the rolling mill, the surface pressure of the work rolls 1 and 2 shown in Fig. 7 (2) in contact with both ends of the support rolls 5, 6, 7, and 8 becomes maximum, and when the rolling mill is operated for a long time, Streaky roll marks 12 are generated on the outer peripheral surface of the work roll due to stress concentration at positions corresponding to both ends and are transferred to the strip material, and the surface of the strip material has streaks. Has the drawback of decreasing

An object of the present invention is to pay attention to the above-mentioned conventional problems, to move the support roll position at a high speed according to the change of the strip width of the material to be rolled, and to move the support roll at the position after the support roll is moved. It is an object of the present invention to provide a rolling method for preventing roll marks on a strip material caused by stress concentration between a support roll and a work roll by oscillating a short stroke at a low speed.

[0008]

In order to achieve the above-mentioned object, in the rolling method according to the present invention, a material to be rolled is rolled to a pair of work rolls, and at least one work roll is rolled. A rolling mill for controlling the shape of a material to be rolled by axially moving a pair of support rolls mounted on a large-diameter backup shaft arranged parallel to the work rolls while rollingly contacting the work rolls, Using a device equipped with a position detector that detects the position of the support roll, while moving the support roll in the axial direction at high speed based on the output signal of the position detector, the support roll in the axial direction during rolling. It was made to oscillate at a slow speed and a short stroke.

[0009]

According to the above structure, the function of each backup roll that suppresses the work roll bending that directly rolls down the material to be rolled is that the pair of support rolls separated in the axial direction of the backup roll and the backup roll equipped with this support roll are separated. It is exerted by the shaft and supports the work roll rolling force. These separation support rolls can be continuously moved in the axial direction even during rolling of the material to be rolled, and the bending moment fulcrum is changed by moving the position, and the roll bending is performed by the bending means provided on the work roll neck. The amount can be adjusted. Therefore, the overall amount of bending is controlled by the position movement of the support rolls, the shape of the crown of the material to be rolled, etc. can be controlled, and the bending moment fulcrum can be arbitrarily changed. improves.

According to the structure of the rolling mill described above, since each roll rotates during rolling (when loaded), the contact between the work roll, the support roll and the backup shaft causes dynamic friction, and the roll is installed in the backup shaft bearing. The hydraulic cylinder can easily move the support roll to any position in the axial direction of the backup shaft at high speed. Also,
When not rolling (no load), the support roll can be moved at high speed in the axial direction of the backup shaft by using the gap between the support roll inner diameter and the backup shaft outer diameter.

Further, by moving the position of the support roll in the axial direction of the backup shaft during rolling of the material to be rolled, it is possible to disperse the stress concentration generated between the support roll and the work roll. Further, in order to prevent the surface pressure of the work roll from being worn and the so-called roll mark being generated by strongly pressing the support roll against the work roll, the oscillation is performed at a slow speed and a short stroke.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a rolling mill according to the present invention will be described in detail below with reference to the drawings.

1 and 2 show the overall construction of a rolling mill according to an embodiment. As shown, the gate-shaped housing 20
A pair of upper and lower work rolls 24, 26 that are parallel to each other are horizontally laid so as to be capable of rolling contact with each other, and the rolled material 23 can be passed between them. Such upper and lower work roll 2
An upper backup roll unit 28 and a lower backup roll unit 30, which are in rolling contact with each other in parallel with 4, 4 and sandwiching them from above and below, are also laid horizontally in parallel.

The upper backup roll unit 28 has a backup shaft 32 arranged in parallel with the work roll 24, which is separated into left and right sides in the roll axis direction.
A pair of support rolls 34R, 34L having a body length shorter than the plate width of the material 23 to be rolled are attached so as to be rotatable and slidably movable in the axial direction. The pair of support rolls 34R and 34L are in rolling contact with the upper work roll 24 and serve as a backup support for the work roll 24 during rolling. Similarly, the lower backup roll unit 30 is also equipped with a backup shaft 36 and support rolls 38R and
8L, and these rolls are brought into rolling contact with the lower work roll 26 to provide backup support during rolling. In addition, the support rolls 34R, 34L,
38R and 38L, as shown as a representative of the upper unit 28 in FIG.
R and 42L are arranged and mounted, and hydraulic cylinders 56R and 56 are built in the backup shaft bearing 50.
The L allows the backup shaft 32 to move in the axial direction. Reference numeral 90 is a bellows, which protects the slide portion with a scale, foreign matter, rolling oil, or the like. In addition, 8
8 is a roller bearing.

The above-mentioned neck portions of the upper and lower work rolls 24 and 26 and the upper and lower backup roll units 28 and 3
As shown in FIG. 2, bearings 46, 47, 50, and 52 are attached to the neck portions of the backup shafts 32 and 36 of No. 0, and these are attached to the housing 20 in a tandem arrangement. A lowering cylinder 54 is provided at a lower position of the housing 20, and a predetermined rolling pressure is generated between the work rolls 24 and 26 by driving the lowering cylinder 54.

In such a structure, the separation support roll 34 of the upper backup roll unit 28 described above is used.
R, 34L, and lower backup roll unit 30
The position of each of the separation support rolls 38R and 38L can be adjusted by moving in the roll axial direction. Because of this position movement, the support roll 34
R and 34L include hydraulic cylinders 56R, which serve as drive members,
56L is formed in the bearing 50 of the backup shaft 32. Furthermore, the support roll 34R,
It is set so that the support rolls 34R and 34L are not tilted when the support rolls 34R and 34L are moved by the frictional force between the work roll 24 and the work roll 24 which are in contact with each other.
The thrust bearing support 62 (62L, 62L, 62L, which is the frame of the connecting portion between the hydraulic cylinders 56R, 56L and the support roll 34 by supplying and discharging pressure oil to the R, 56L.
62R), and push and pull the support roll 34R,
34L can be moved.

In FIG. 4, a position detector 81 for moving the support rolls 34R, 34L by hydraulic cylinders 56R, 56L, a hydraulic solenoid valve 83 for high speed movement and a hydraulic solenoid valve 84 for fine speed movement are attached. The controller 82, based on the signal from the host and the signal from the position detector 81, controls the solenoid valves 83, 84.
Are in control. Reference numeral 85 is an oil pump, and 86 is an oil tank.

A work roll bending device 100 is incorporated in the housing 20, and is composed of an upper roll bending rod, a lower roll bending rod, a roll bending cylinder block and a piston (not shown). The lower end portion of the upper roll bending rod is fixed to the piston, and the upper end portion is arranged so as to be able to come into contact with and separate from the upper work roll bearing 46. On the contrary, the lower roll bending rod has its upper end fixed to the piston and its lower end freely contactable with and separable from the lower work roll bearing 47. The piston is built in the bore of the cylinder block, and a small-diameter communication hole is provided in the bore located in the middle of both pistons. When pressure oil is introduced from this pressure oil supply device, it is used for vertical roll bending. The rods are separated from each other, and the upper and lower work rolls 24,
It acts so as to press the bearings 46 and 47 of 26.

As shown in FIG. 2, the reduction cylinder 54 has a built-in head 116, and when rolling, pressure oil is introduced into the reduction cylinder 54 from a pressure oil supply device (not shown) to raise the head 116. I am trying to let you. The operation of the head 116 pushes up the backup shaft bearing 52 of the lower backup roll unit 30, and this rolling force is lower support rolls 38R, 38L, lower work roll 26, upper work roll 24, upper support rolls 34R, 34L, upper backup shaft. The desired rolling force is generated by being transmitted to the bearing 50 and the housing 20.

The operation of the rolling mill thus configured is as follows. Before rolling, the positions of the support rolls 34R, 34L and 38R, 38L are determined in advance according to the width of the material 23 to be rolled. In this case, the support rolls 34, 3
The rolling contact position of the work roll 8 to the work rolls 24 and 26 is the material to be rolled 2
It is set at a position where it overlaps with the side part of 3. In this initial setting, the position adjusting hydraulic cylinders 56R and 56L of the support rolls 34 and 38 are driven to excite the high-speed moving hydraulic solenoid valve 83 to move it to a preset position at a speed of 30 mm / sec. As a result, the distance between the pair of support rolls 34R, 34L and 38R, 38L is set to a desired distance. Then, after that, the work rolls 24 and 26 and the support rolls 34 and 38 are lightly contacted with each other by using the roll bending device 100 and a roll balancing cylinder (not shown).

After the initial setting is completed, the rolled material 23 is passed between the work rolls 24 and 26. As a result, the material 23 to be rolled is rolled to a desired plate thickness and emerges as a strip material. This shape determination is performed visually or by a contact method using a sensor roll or a non-contact method using light or magnetism. When the edge extension or the middle extension occurs due to this determination, the hydraulic cylinders 56R and 56L are operated to form a pair of support rolls 34R, 34L and 38R,
By moving 38L so as to be close to or away from each other, the amount of bending moment acting on the work rolls 24, 26 is adjusted, occurrence of abnormal shape is suppressed, and a rectangular strip material can be obtained. .

In order to prevent the generation of roll marks on the surface of the material 23 to be rolled, a hydraulic solenoid valve 84 for slow speed movement is used, and the support rolls 34R, 34L are used.
And 38R and 38L are oscillated with a stroke of about ± 50 mm at a speed of about 0.15 mm / sec. The support rolls 34R, 34L and 38
If the shape of the strip material changes when the R and 38L are moved in the axial direction of the backup shafts 32 and 36, the pressure of the roll bending device 100 is adjusted.

According to the rolling mill of this embodiment, the bending fulcrums of the work rolls 24, 26 can be freely changed, so that the roll bending effect can be sufficiently achieved without being restricted by the conventional full-contact backup roll. Can be demonstrated. Also, the upper and lower support rolls 34
Since the positions of R, 34L and 38R, 38L can be individually changed, the shape can be controlled at any position in the plate width direction. Therefore, in addition to shape defects such as medium elongation and edge elongation of the rolled material, it is possible to obtain an advantage that it is possible to control not only shape defects of composite elongation that is a composite of the two.

By oscillating the support rolls 34R, 34L and 38R, 38L,
Since it is possible to prevent the local surface pressure from being generated due to the stress concentration between the support rolls 34 and 38 and the work rolls 24 and 26, it is possible to prevent the generation of roll marks that impair the aesthetics of the strip material surface, and it is possible to maintain it beautifully.

Since the positions of the support rolls 34R, 34L and 38R, 38L can be made symmetrical vertically and horizontally, the shape control can be performed symmetrically in the plate thickness direction and the plate width direction of the material 23 to be rolled. ， It is possible to obtain strip material (rolled product) with excellent accuracy.

In addition, since the positions of the support rolls 34R, 34L and 38R, 38L can be freely adjusted by the plate width, the contact surfaces between the work rolls 24, 26 and the plate width end portions can be made smoother by using the roll bending. Therefore, the edge drop prevention effect is high. Further, since the plate thickness and the plate width direction can be controlled symmetrically, the rolled material 23 does not meander when it is threaded, and there is an effect that stable threading characteristics can be obtained.

In the above embodiment, an example of application to a four-high rolling mill with upper and lower support rolls is shown.
It can also be applied to a rolling mill in which a support roll is applied only to the upper portion as shown in (1). Further, the present invention can be applied to a cluster type rolling mill as shown in Fig. 2 (2) and further to a 6-high rolling mill as shown in Fig. 3 (3).

[0028]

As described above, the rolling method according to the present invention comprises a pair of work rolls through which a material to be rolled is threaded,
A pair of support rolls, which are rollingly contacted with at least one work roll and mounted on a large-diameter backup shaft arranged in parallel with the work rolls, are axially movable while rolling contacting with the work rolls. A rolling mill for controlling the shape of the support roll, using a device equipped with a position detector for detecting the position of the support roll, and moving the support roll in the axial direction at high speed based on the output signal of the position detector. By oscillating the support roll in the axial direction at a slow speed and a short stroke during rolling, it has a quick response to the conditions that change momentarily in high-speed rolling, and in particular, the work roll bending control amount is greatly increased. It is possible to increase the shape control ability and improve the edge drop reduction effect. Also it is possible to perform a shape control at an arbitrary position in the sheet width direction of the rolled material. In particular,
In order to prevent the stress concentration between the support roll and the work roll from occurring, by adjusting the roll bending force by moving the support roll, it is possible to control the shape of the material to be rolled and prevent the generation of roll marks. Excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a front view of a rolling mill according to an embodiment of the present invention.

FIG. 2 is a side view of the rolling mill.

FIG. 3 is an enlarged sectional view of an essential part of an upper support roll portion of the rolling mill.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is a control block diagram of the hydraulic cylinder of FIG.

FIG. 7 is a schematic view of a conventional rolling machine with support rolls.

FIG. 8 is an example of another rolling mill in which the embodiment backup roll device can be mounted.

[Explanation of symbols]

 20 Housing 23 Rolled Material 24, 26 Work Roll 28, 30 Backup Roll Unit 32, 36 Backup Shaft 34R, 34L, 38R, 38L Support Roll 42R, 42L Thrust Bearing 46, 47, 50, 52 Bearing 54 Rolling Down Cylinder 56R, 56L Hydraulic cylinder 81 Position detector 82 Controller 83 High speed moving hydraulic solenoid valve 84 Fine speed moving hydraulic solenoid valve 85 Hydraulic pump 86 Hydraulic tank 88 Roller bearing 100 Work roll bending device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B21B 29/00 C 8727-4E 31/18 B 8727-4E

Claims (1)

[Claims] 1. A pair of work rolls through which a material to be rolled is threaded, and a pair of supports mounted on a large-diameter backup shaft which is rotatively contacted with at least one work roll and arranged parallel to the work rolls. A rolling mill for controlling the shape of a material to be rolled by rolling the roll onto the work roll and axially moving the roll, using a device equipped with a position detector for detecting the position of the support roll. A rolling method in which the support roll is moved in the axial direction at a high speed based on the output signal of the detector, and the support roll is oscillated at a slight speed in the axial direction during the rolling.