JP5527238B2 - Thick plate rolling machine for metal sheet - Google Patents

Description

  The present invention relates to a rolling mill for metal sheets, and in particular, it is suitable for thick plate rolling, can take a large maximum opening between upper and lower work rolls, and can exert a strong roll bending force, as a result. Further, the present invention relates to a thick plate rolling machine capable of providing a highly responsive and powerful sheet crown / shape control function.

In the rolling operation of a metal plate material, the crown and shape of the rolled plate are important quality indicators, and many techniques related to plate crown and shape control have been disclosed.
However, for example, in a rolling mill that manufactures a product with a large thickness by multi-pass reverse rolling, such as a thick plate rolling mill, the gap between the upper and lower work rolls, that is, the roll opening is larger than the thickness of the rolled material. Under this premise, the plate crown and shape control device that can be used imposes restrictions on the design of rolling mill equipment.

For example, Patent Document 1 relates to a work roll shift type rolling mill. As shown in FIG. 5, the work roll increase bending apparatuses 6-1 to 6-4 include work roll chocks 3-1, 3-2. Discloses a rolling mill.
Patent Document 2 relates to a roll-cross type rolling mill. As shown in FIG. 6, an increment bending apparatus 6-3 and 6-4 includes a work roll chock 3-1 and 3-3. 2 is incorporated.
Patent Document 3 also discloses a rolling mill having a work roll shift function. In this rolling mill, as shown in FIG. 7, the increment bending apparatuses 6-1 to 6-4 are connected to the rolling mill housing. It is incorporated in the integrated project blocks 5-1, 5-2. In the rolling mill disclosed in Patent Document 3, a plurality of hydraulic cylinders of the increment bending apparatus are arranged in the roll axis direction, and are devised so that uneven load is not applied during work roll shift.

In general, a rolling machine for producing a thick steel plate is not provided with a decrease bending apparatus as shown in FIGS. 5 to 7 (see Patent Documents 1 to 3).
This is because work rolls with relatively large diameters are used compared to sheet rolling, so that the change in roll crown shape is small even when the same bending force is applied, and furthermore, compared to sheet rolling mills. Even if a small decrease bending device is installed in a narrow area around a relatively large diameter work roll chock, the control range is narrow and the mechanical structure is complicated, which is disadvantageous in terms of cost performance. To do.
However, in order to make the rolling mill according to the present invention a thick plate rolling machine that can handle a wide range of thickness steel plates ranging from a very thick plate to a hot rolled thin plate, the same reduction as the thin plate rolling mill as shown in FIG. It is assumed that bending devices 7-1 to 7-4 are provided.

JP-A-62-220205 JP-A-6-198307 Japanese Patent Laid-Open No. 4-52014

  As disclosed in Patent Documents 1 and 2, that is, as shown in FIGS. 5 and 6, the increment bending apparatuses 6-1 to 6-4 are incorporated in the work roll chock 3-1, 3-2. In the rolling mill, a large opening can be realized by taking a longer stroke of the hydraulic cylinder, and it is also possible to incorporate a large-capacity hydraulic cylinder. A roll bending effect can be expected.

  However, since the work rolls 1-1 and 1-2 are severely worn by the rolling work, in general, the rolls are frequently required to be replaced, and the hydraulic piping of the increment bending apparatus must be attached and detached for each replacement work. As a result, the roll replacement time becomes longer, and the possibility of minute foreign matter entering the hydraulic piping at the time of attachment / detachment increases.

  On the other hand, as shown in FIG. 7, that is, as shown in FIG. 7, the increment bending apparatuses 6-1 to 6-4 are incorporated in the project blocks 5-1 and 5-2 connected to the rolling mill housing. In the type of rolling mill, the disadvantages of the type of rolling mill shown in FIGS. 5 and 6 can be eliminated. This is because, in this format, since the increment bending apparatus is incorporated in the project block, it is not necessary to attach or detach the hydraulic piping of the increment bending apparatus every time the roll is changed. Therefore, this type is frequently used in hot strip mill finish rolling mills.

  However, in this type, the rolling direction force such as offset component force acting on the upper work roll 1-1 is supported by the contact surface between the work roll chock 3-1 and the project block 5-2. When the roll opening degree is increased by operating, the rotation center of the work roll becomes outside the contact surface, and the posture of the work roll chock 3-1 becomes unstable. I can't. For this reason, this type is rarely adopted in a plate rolling mill that requires a large roll opening.

As described above, there is no conventional rolling mill type that can incorporate a powerful roll bending apparatus in a thick plate rolling machine capable of increasing the roll opening degree.
The problem to be solved by the present invention is to provide a thick plate mill that can increase the maximum opening between the upper and lower work rolls and can impart a strong roll bending force.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have a form in which the arm portion extending from the upper reinforcing roll chock holds the upper work roll chock and has an increase bending force on the upper work roll. A hydraulic cylinder that loads the upper reinforcing roll chock is disposed on the arm portion that extends from the upper reinforcing roll chock, and a hydraulic cylinder that loads the incremental bending force on the lower work roll is disposed on the project block protruding inside the rolling mill housing, It has been found that the following can be achieved by installing a hydraulic cylinder in the upper reinforcement roll chock, which applies a decrease bending force to the upper work roll.

(A) A structure in which the rolling direction force applied to the lower work roll chock is always received by the housing. Thereby, the lower work roll chock can be stably supported.

(B) The lower increment bending apparatus can be incorporated in the project block. Thereby, it is possible to provide a powerful bending device with a large capacity and a large stroke.

(C) Further, the hydraulic piping can be fixed by incorporating the increase bending apparatus for the lower work roll into the project block.

(F) By adopting a method in which the upper work roll chock is held in the arm portion extending from the upper reinforcing roll chock, a large-opening roll gap can be easily obtained during the partial roll rolling and the thick plate rolling.

The present invention has been made based on these findings, and the gist thereof is as follows.
(1) A thick plate rolling machine capable of rolling a metal plate having a plate width of 2500 mm or more having a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls that respectively support them, and extends from an upper reinforcing roll chock. The arm part is a type that holds the upper work roll chock, and a hydraulic cylinder that loads the upper work roll with an increase bending force is provided on the arm part that extends from the upper reinforcement roll chock, and the lower work roll has an increase bending force. A hydraulic cylinder that is loaded on the project block that protrudes inside the rolling mill housing, and a hydraulic cylinder that loads a lower bending force on the upper work roll is placed in the upper reinforcing roll chock. Rolling mill.

(2) The hydraulic cylinder that applies the incremental bending force to the lower work roll is stronger and has a larger capacity than the hydraulic cylinder that applies the incremental bending force to the upper work roll. Plate rolling machine.

(3) The metal plate thick plate rolling machine according to (1) or (2), further comprising a hydraulic cylinder that applies a decrease bending force to the lower work roll on the lower reinforcing roll chock.

(4) In the thick plate rolling machine described in any one of (1) to (3), an initial body crown (convex shape) is provided to the work roll or the reinforcing roll, and the control range by roll bending is set to ink. Thick plate rolling machine for metal sheets characterized by shifting to the lease bending side.

  The present invention is a thick rolling mill in which the sheet width of the material to be rolled may exceed 2500 mm, and can take a large roll opening and can also obtain a strong roll bending force, resulting in a low responsiveness. Even if it is necessary to deploy a bending device, a highly responsive incremental bending device compensates for this and has a highly responsive and powerful plate crown and shape control function. Providing a plate rolling machine that can build a good plate crown and shape against disturbances that vary during rolling, such as thickness and rolling stock temperature, and can greatly improve product quality and yield can do.

It is a side view which shows an example of the structure of the plate rolling machine which concerns on this invention. The surface pressure distribution state between the rolled material and the work roll when the increase bending force is applied in a thin plate rolling machine for hot rolling with a short roll length and a thick plate rolling machine with a long roll length. It is a conceptual diagram which shows the comparison with the surface pressure distribution state between a roll and a reinforcement roll. The surface pressure distribution between the rolled material and the work roll when the decrease bending bending force is applied to the thin plate rolling machine for hot rolling with a short roll length and the thick plate rolling machine with a long roll length. It is a conceptual diagram which shows the comparison with the surface pressure distribution state between a roll and a reinforcement roll. The comparison figure of the crown control capability of the thick plate rolling machine which concerns on this invention, and the rolling mill which concerns on a prior art is shown. It is a side view which shows the structure of the rolling mill for thick plate rolling which concerns on a prior art. It is a side view which shows the structure of the rolling mill for thick plate rolling which concerns on a prior art. It is a side view which shows the structure of the rolling mill for thick plate rolling which concerns on a prior art. It is a side view which shows the structure of the rolling mill for sheet rolling which concerns on a prior art.

Hereinafter, the thick plate mill according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view showing an example of the structure of a thick plate rolling machine according to the present invention. As shown in the drawing, the thick plate rolling mill according to the present invention includes a pair of upper and lower work rolls 1-1 and 1-2 and a pair of upper and lower reinforcing rolls 2-1 and 2-2 for supporting these. Plate mill.

  The thick plate rolling machine according to the present invention is a project block 5 in which the lower increment bending apparatuses 6-3 and 6-4 that apply an increase bending force to the lower work roll 1-2 are protruded inside the housing 9. 1 and 5-2, and further, a hydraulic cylinder for applying a decrease bending force to the upper work roll 1-1 is provided in the upper reinforcing roll chock 4-1, and the upper work roll decrease bending apparatus 7-1 is provided. , 7-2.

  In the project blocks 5-1 and 5-2, the up-and-down work roll increment bending devices 6-1 to 6-4 are provided, and the up-and-down reinforcing roll chock 4-1 and 4-2 are provided with the up and down work rolls 1-1 and 1-2. The installation of the decrease bending apparatus is often used in a sheet rolling mill for hot rolling finish rolling shown in FIG. 8. In this type, the upstream side surface of the output side project block 5-2 and the upper work roll chock 3 are used. Since the rolling direction force at the time of rolling operation is supported by the contact surface with -1, the center position of the rotational moment of the upper work roll chock 3-1 is upward from the contact surface as the roll opening degree is increased. And the area of the contact surface that supports the rolling direction force decreases.

  Therefore, even if the height of the convex portion sandwiched between the project blocks 5-1 and 5-2 is increased, the posture of the upper work roll chock 3-1 becomes unstable as the roll opening degree is increased, and the large roll opening is performed. Cannot take the degree.

On the other hand, in this invention, as shown in FIG. 1, the form which the upper reinforcement roll chock 4-1 equips with the arm which holds the upper work roll chock 3-1 is employ | adopted.
In this type of rolling mill, since the upper reinforcing roll chock 4-1 holds the upper working roll chock 3-1, the upper working roll 1-1 is lifted as the upper reinforcing roll 2-1 is pulled up, and a large roll The opening can be taken.

Further, the force in the rolling direction acting on the upper work roll 1-1 is the same as the force received at the contact surface on the downstream side of the upper work roll chock 4-1 and the upper work roll chock 3-1, in the upper work roll chock 4-1. -1 in the rolling direction downstream arm and the contact surface formed by the contact surface between the housing window and the inner side of the housing window, it is finally received. With this structure, the rolling device 11 of the rolling mill is operated. Even if the roll opening degree is increased, the area of the surface where the upper work roll chock 3-1 contacts the housing window via the arm portion of the upper reinforcement roll chock does not change at all. Therefore, the posture of the upper work roll chock 3-1 is always stably maintained regardless of the roll opening degree.

  Furthermore, in the thick plate rolling machine according to the present invention, the lower increment bending apparatuses 6-3 and 6-4 for applying the increment bending force to the lower work roll 1-2 are projected in the project block 5- 1, 5-2. For this reason, it is not necessary to attach or detach the hydraulic piping of the increase bending device of the lower work roll every time the work roll is recombined, and by using a fixed pipe, the response is high and the capacity is high using a precise servo valve. -It can be a large stroke increment bending device.

  Further, since the decrease bending devices 7-1 and 7-2 of the upper work roll 1-1 are composed of hydraulic cylinders installed on the upper reinforcing roll chock 4-1, the sheet crown, such as rolling with a sheet thickness of about 100 mm or less, is used. When control is required, a strong decrease bending force can be applied. From rolling a rolled material with a thickness of more than 800 mm, to precise plate crown and shape control in rolling to a thickness of 100 mm or less. It is possible to cope with rolling with a single rolling mill.

  In the thick plate rolling machine according to the present invention, the rolling direction force applied to the body of the lower work roll 1-2 is supported by the contact surface between the lower work roll chock 3-2 and the project block 5-2. The For this reason, the plate rolling machine according to the present invention shown in FIG. 1 has a large height of the portion sandwiched between the project blocks 5-1 and 5-2 of the lower work roll chock 3-2.

  Moreover, since the roll opening is adjusted mainly by moving the upper work roll chock up and down, the amount of movement of the lower work roll chock up and down is small. Therefore, the posture of the lower work roll does not become unstable as the roll opening degree increases.

Up to this point, the structure of the rolling mill according to the present invention has been described mainly from the viewpoint of obtaining a large roll opening, which is one of the problems to be solved.
Next, it will be described that according to this structure, it is possible to easily achieve the application of a strong roll bending force, which is another problem to be solved.

  As shown in FIG. 1, in the thick plate rolling mill according to the present invention, a large-capacity, large-stroke lower-increase projecting from a housing 9 of the rolling mill to project blocks 5-1 and 5-2 projecting inward. Bending devices 6-3 and 6-4 can be provided.

  That is, according to the rolling mill according to the present invention in which the rolling direction force applied to the body of the lower work roll 1-2 is supported by the contact surface between the lower work roll chock 3-2 and the project block 5-2. For example, a large roll opening degree can be obtained and a strong roll bending force can be applied.

  Further, it is not necessary to attach or detach the hydraulic piping of the lower increase bending apparatus every time the work roll is recombined. For this reason, each of the bending bending apparatuses 6-3 and 6-4 can be connected to each hydraulic control valve via a fixed hydraulic pipe, and employs a servo valve for high response hydraulic control. be able to. Therefore, it is possible to provide an incremental bending apparatus with high response.

  Utilizing the characteristics of the lower increase bending apparatus, an appropriate convex initial body crown is imparted to the work roll and / or the reinforcing roll, and the characteristics of the rolling mill are shaken in advance toward the increase bending side. Therefore, even a thick plate rolling mill with the same length as the roll can be loaded with a strong bending force while avoiding the occurrence of edge marks on the roll. Can be enlarged.

When rolling using the rolling mill according to the present invention, for the purpose of plate crown and shape control, when the bending force is applied to the work roll, or when changing the roll bending force at the start of rolling and at the end of rolling, By using an increase bending device with high responsiveness, the total bending force control can be made highly responsive by guaranteeing a decrease bending device that has a slight problem with responsiveness.
As shown in the conceptual diagram in FIG. 2, the sheet width of the material to be rolled may exceed 2500 mm for a thin rolling mill for hot rolling or the like mainly intended for a material having a sheet width of 2500 mm or less. A certain thick plate mill has a relatively long roll body length, and gives a surface pressure Pwm distribution between the same work roll and the rolled material in order to give the same crown control amount to the rolled material of the same width. Thus, when the increase bending force is applied, a larger roll deflection is required as compared with a hot rolling thin plate rolling machine having a relatively short roll body length, and the surface pressure Pwb between the work roll and the reinforcing roll (work) The resistance against roll bending becomes large, which is disadvantageous in controlling the plate crown and shape due to the increase bending force.

  In the present invention, as shown in a conceptual diagram in FIG. 3, by applying a decrease bending force to a work roll by a decrease bending apparatus provided in a reinforcing roll chock, compared with a thin sheet rolling mill for hot rolling or the like. The surface pressure Pwb (resistance to work roll bending) distribution between the work roll and the reinforcing roll is kept at a small value by utilizing the characteristics of the plate mill with a relatively long body length, that is, the moment arm Lm. The plate crown and shape control ability per unit decrease bending force is increased. At this time, for example, by assigning an appropriate convex initial body crown with a quadratic curve of about 1 to 2 mm at a diameter reduction value at the end of the roll to the work roll, the characteristics of the rolling mill are preliminarily set. By swinging toward the increase bending side, the effect of the decrease bending force can be further increased.

  Table 1 shows a case in which a wide and narrow rolled material is rolled from a thickness of 20 mm to 16 mm at a reduction ratio of 20% by a rolling mill according to the present invention provided with a decrease bending apparatus in addition to an increment bending apparatus. FIG. 4 shows the plate crown control range based on the increment bending force and the decrease bending force.

表１及び図４から明らかなように、従来のインクリースベンダーのみを備えた圧延機と比較して、ディクリースベンダーをも具備した本発明に係る圧延機においては、板クラウン制御範囲が格段に広がっており、特に同図の（２）に示されるように、幅広ロールを用いて、幅の狭い被圧延材を圧延した場合においては、ディクリースベンディング力による板クラウン制御範囲が非常に大となっているので、前述したように、圧延機のイニシャルロールクラウンを予めインクリース側に振っておくこと、換言すれば、ベンディング力無負荷状態で、圧延機のロールがインクリースベンディング力をやや掛けた状態となるようなイニシャルロールクラウンとすることで、ディクリースベンディング力の広い負荷範囲を有効に活用することが可能となり、フラット近傍を中立点として非常に広範囲にわたって板クラウンを制御することが可能となる。
その結果、板クラウン・形状制御が問題となる熱延薄板の圧延においても、作業ロールと補強ロール間のエッジマークの発生等を抑制しながら、良好な板クラウン・形状制御能力を獲得している。

As apparent from Table 1 and FIG. 4, in the rolling mill according to the present invention having the decrease bender as compared with the rolling mill having only the conventional increase bender, the plate crown control range is remarkably increased. In particular, as shown in (2) of the figure, when rolling a narrow material using a wide roll, the sheet crown control range by the decrease bending force is very large. Therefore, as described above, the initial roll crown of the rolling mill should be shaken in advance toward the ink lease side, in other words, the rolling mill roll slightly applies the ink bending bending force in a state where no bending force is applied. It is possible to effectively utilize a wide load range of decrease bending force by using an initial roll crown that will be Ri, it is possible to control the strip crown over a very wide range of flat near the neutral point.
As a result, even in the rolling of hot-rolled thin plates where plate crown and shape control is a problem, excellent sheet crown and shape control capability has been obtained while suppressing the generation of edge marks between the work roll and the reinforcing roll. .

  The present invention relates to rolling of steel sheets, particularly as a reverse rolling mill that requires a large opening, and as a rolling mill that requires strong sheet crown and shape control, rolling mills ranging from extremely thick plate materials to thin plates. Can be provided.

1-1 Upper work roll 1-2 Lower work roll 2-1 Upper reinforcement roll 2-2 Lower reinforcement roll 3-1 Upper work roll chock 3-2 Lower work roll chock 4-1 Upper reinforcement roll 4-2 Lower reinforcement roll 5- 1 Incoming Project Block 5-2 Outgoing Project Block 6-1 Incoming Upper Increase Bending Device 6-2 Outgoing Upper Increase Bending Device 6-3 Incoming Lower Increase Bending Device 6-4 Outgoing Lower Increase Bending device 7-1 Entry-side upper decrease bending device 7-2 Entry-side upper decrease bending device 7-3 Entry-side lower decrease bending device 7-4 Exit-side lower decrease bending device 8-1 Entry-side reinforcing roll balance Device 8-2 Delivery side reinforcing roll balance device 9 Housing 10 Material to be rolled 11 Reduction Location 12 housing window

Claims (4)

  A thick plate rolling machine capable of rolling a metal plate material having a plate width of 2500 mm or more having a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls that respectively support the work rolls, and an arm portion extending from an upper reinforcing roll chock The upper work roll chock is a type that holds a hydraulic cylinder that applies an increase bending force to the upper work roll on the arm portion that extends from the upper reinforcement roll chock, and loads the lower work roll to the increase bending force. A thick plate rolling machine characterized in that a hydraulic cylinder is arranged in a project block protruding inside the rolling mill housing, and a hydraulic cylinder that loads a lower bending force on the upper work roll is arranged in the upper reinforcing roll chock.   2. The thick plate according to claim 1, wherein the hydraulic cylinder that applies an increase bending force to the lower work roll is stronger and has a larger capacity than the hydraulic cylinder that applies an increase bending force to the upper work roll. Rolling mill.   The metal plate material thick plate rolling machine according to claim 1 or 2, further comprising a hydraulic cylinder that applies a decrease bending force to the lower work roll on the lower reinforcing roll chock.   The thick plate rolling machine according to any one of claims 1 to 3, wherein an initial body crown (convex shape) is imparted to the work roll or the reinforcing roll, and the control range by roll bending is set to the increase bending side. Thick plate rolling machine for metal sheets characterized by shifting.

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