JP2012200758A - Rolling mill and method of rolling metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling mill in which stability of upper and lower work roll chocks and the opening degree of the upper and lower work rolls are made compatible, responsiveness is high and sheet crown/shape control range is large to disturbance during rolling.SOLUTION: A hydraulic cylinder for loading bending force to the upper and the lower work rolls is disposed on a projecting block which is projected to the inside of a rolling mill housing; rolling-direction force to be loaded on a lower work roll body is supported by the contact surface of a lower projecting block disposed on a lower crosshead with the lower work roll chock; the rolling-direction force to be loaded on an upper work roll body is supported by the contact surface of an upper crosshead disposed on the rolling mill housing with the upper work roll chock which are positioned above the projecting block; and a pair crossing means with which the upper and the lower work rolls are relatively crossed within a parallel plane to the metal plate to be rolled is disposed.

Description

  The present invention can take a large maximum opening between the upper and lower work rolls, which is suitable as a rough rolling mill for thick plate rolling or thin plate hot rolling, and has high responsiveness and strong roll bending force. The present invention relates to a rolling mill that can be applied.

  In particular, the present invention is a metal capable of performing a wide range of plate crown and shape control of a metal plate by crossing the upper work roll and the lower work roll relatively in a plane parallel to the metal plate to be rolled. The present invention relates to a plate mill. The present invention also relates to a rolling method using the rolling mill.

  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 thick product by multi-pass reverse rolling, such as a thick plate rolling mill or a thin plate hot rolling rough rolling mill, the gap between the upper and lower work rolls (roll opening) It must be larger than the thickness of the rolled material. For this reason, restrictions on the rolling mill equipment design are imposed on the plate crown / shape control device.

  For example, in Patent Document 1, in thick plate rolling in which a plurality of passes are rolled to a predetermined plate thickness, a work roll bending device is used as a shape control device, and the roll bending force is controlled based on the result of rolling in the previous pass. A rolling method is disclosed.

  The rolling mill type disclosed in Patent Document 1 is a four-high rolling mill, and the rolling mill type has a structure shown in FIG. The rolling mill shown in FIG. 10 is obtained by arranging a decrease bending apparatus in the rolling mill of FIG. Both rolling mills have basically the same structure. In other words, the upper work roll chock 3-1 is held by the arm portion that connects the upper reinforcement roll chock 4-1. Increase bending apparatuses 6-1 and 6-2 of the upper work roll 1-1 are incorporated in this arm portion. By setting it as such a format, a big roll opening degree can be taken.

  In the rolling mills of FIGS. 10 and 14, the increment bending apparatuses 6-3 and 6-4 of the lower work roll 1-2 are incorporated in a project block connected to the rolling mill housing 9. In addition to this, as a rolling mill type capable of taking a large roll opening degree, as shown in FIG. 11, the rolling roll chocks 4-1 and 4-2 hold the work roll chock 3-1 and 3-2 on both the upper and lower sides. There is also a machine.

  The increment bending apparatus means a hydraulic apparatus that applies a force in the direction of increasing the roll opening degree to the work roll chock. The increment bending apparatus is a general term for apparatuses including a hydraulic cylinder as an actuator. However, in the present invention, in order to simplify the description, the increment bending apparatus refers to a hydraulic cylinder that is an actuator thereof unless otherwise specified. A force applied to the work roll by the increase bending apparatus is referred to as an increase bending force.

  On the other hand, a hydraulic device that applies a force in the direction of decreasing the roll opening degree to the work roll chock is referred to as a decrease bending device, and a force applied to the work roll by this is referred to as a decrease bending force. The decrease bending apparatus is a general term for apparatuses including a hydraulic cylinder as an actuator. However, in the present invention, in order to simplify the description, the decrease bending apparatus refers to a hydraulic cylinder that is an actuator thereof unless otherwise specified.

  Patent Document 2 discloses, for example, a rolling mill in which the work roll increase bending apparatuses 6-1 and 6-2 are incorporated in the work roll chock 3-1 and 3-2 as shown in FIG. .

  Patent Document 3 discloses a roll cloth type rolling mill. Also in this rolling mill, for example, as shown in FIG. 12, the increment bending apparatuses 6-1 and 6-2 are incorporated in the work roll chock 3-1 and 3-2.

  For example, Patent Document 4 discloses a rolling mill having a work roll shift function as shown in FIG. In this rolling mill, the increment bending apparatuses 6-1 and 6-2 are incorporated in project blocks 5-1 and 5-2 integrated with the rolling mill housing. In the rolling mill disclosed in Patent Document 4, a plurality of hydraulic cylinders of the increment bending apparatus are arranged in the roll axis direction, and are devised so that an uneven load is not applied when the work roll is shifted.

  In general, a thick steel plate rolling machine does not have a decrease bending apparatus as shown in FIG. (For example, refer to Patent Document 1)

  However, the rolling mill according to the present invention is premised on having a decrease bending apparatus in order to make the rolling mill compatible with a wide range of thickness steel plates. Therefore, FIG. 10, FIG. 11, FIG. 12, and FIG. 13 show cases where a decrease bending apparatus is provided.

  Patent Document 5 includes a rolling mill and a rolling method that include a roll-bending device, and that have a pair cross function that relatively intersects an upper work roll and a lower work roll in a plane parallel to a metal sheet to be rolled. It is disclosed.

JP-A-6-87011 JP-A-62-220205 JP-A-6-198307 Japanese Patent Laid-Open No. 4-52014 Japanese Patent No. 2607013

  A typical thick plate rolling mill as disclosed in Patent Document 1 (the rolling mill shown in FIGS. 10 and 11) is designed with the highest priority given to a large roll opening. That is, the rolling mill disclosed in Patent Document 1 has a structure in which the arm portion connected to the upper reinforcing roll chock 4-1 whose vertical position is set and controlled by the rolling device 11 holds the upper work roll chock 3-1. . And since the rolling mill disclosed by patent document 1 incorporates the increment bending apparatuses 6-1 and 6-2 in the said arm part with a restriction | limiting on a structure size, it is difficult to incorporate a high capacity | capacitance hydraulic cylinder. That's why. For this reason, a strong roll bending force cannot be imparted.

  For example, in a hot strip mill finish rolling mill having a work roll diameter of about 800 mm, a work roll bending apparatus having a capacity exceeding 2MN / chock (200 tf / chock) has been put into practical use. On the other hand, only a work roll bending apparatus of about 2MN / chock (200 tf / chock) has been put to practical use even with a thick plate mill having a work roll diameter of about 1000 mm. From the contrast of the roll diameter, it is clear that a higher capacity roll bending force is required.

  Here, the roll deflection, which is an index of the roll bending effect, is inversely proportional to the roll secondary moment when the applied bending moment is the same. Therefore, the roll bending effect of the thick plate mill with a work roll diameter of 1000 mm is inferior by about 60% compared to the hot strip mill finish rolling mill with a work roll diameter of 800 mm.

  For this reason, a roll bending device is also used as a plate crown / shape control device of a thick plate mill, but the effect is not great, and a pair cross function and a roll shift function have been put into practical use and mainly used.

  However, the pair cross function and the roll shift function are not only difficult to change the condition setting during rolling, but also may not be able to secure the time for changing the condition setting between passes during multi-pass rolling, and are not suitable as shape control means. I must say it is perfect.

  On the other hand, in the case where the increment bending apparatuses 6-1 and 6-2 are incorporated in the work roll chock 3-1 and 3-2 as shown in the rolling mills disclosed in Patent Documents 2 and 3 (FIG. 12) The hydraulic cylinder stroke can be taken longer. Thereby, a large roll opening degree can be realized. In addition, since it is possible to incorporate a large capacity hydraulic cylinder, a practical work roll bending effect can be expected even with a thick plate mill.

  On the other hand, the work rolls 1-1 and 1-2 are more easily worn out than the reinforcing rolls due to rolling operation, and therefore it is necessary to periodically change the rolls. For this reason, it is necessary to attach and detach the hydraulic piping of the increment bending apparatus every time the reassembly work is performed. This not only lengthens the roll reassembly time, but also increases the possibility of minute foreign matter entering the hydraulic piping when the piping is attached or detached.

  For this reason, this rolling mill (FIG. 12) cannot employ a servo valve for high response hydraulic pressure control. In addition, in order to facilitate the attachment / detachment of the pipe, it must be connected to each hydraulic control valve via a flexible and detachable hydraulic pipe (flexible pipe or the like). In addition, when flexible piping is employed, fluctuations in hydraulic pressure may be absorbed and relaxed due to the flexible structure. Therefore, it becomes difficult to obtain a roll bending apparatus with high responsiveness.

  On the other hand, the rolling mills disclosed in Patent Documents 2 and 4 (FIG. 13) are incorporated in project blocks 5-1 and 5-2 in which the increment bending apparatuses 6-1 and 6-2 are connected to the rolling mill housing 9. Yes. For this reason, it is not necessary to attach or detach the hydraulic piping of the increment bending apparatus every time the roll is reassembled. Therefore, this rolling mill can be a roll responsive apparatus with high responsiveness. Therefore, it is frequently used in hot strip mill finish rolling mills.

  However, in this rolling mill, it is the contact surface between the work roll chock 3-1 and the project block 5-2 that supports the rolling direction force such as offset component force acting on the upper work roll 1-1. Therefore, when the roll opening degree is increased by operating the reduction device 11, the rotation center of the work roll becomes outside the contact surface, and the posture of the work roll chock 3-1 becomes unstable. As a result, a large roll opening cannot be taken. For this reason, this rolling mill is rarely adopted in a thick plate rolling mill that requires a large roll opening.

  Moreover, control of the rolling mill which has a pair cross mechanism which sets the bending force to a pair of upper and lower work rolls according to the angle at which the upper work roll and the lower work roll are relatively intersected, disclosed in Patent Documents 3 and 5 The method has the following problems.

  During rolling, it is not possible to perform a pair cross in which the upper work roll and the lower work roll are relatively crossed in a plane parallel to the metal sheet to be rolled. Therefore, if the rolling state changes during rolling at the set cross angle (pair cross amount), roll bending force is additionally applied to the work roll with the roll bending device, and the plate crown and shape are Adjust the control.

  However, as described above, the work roll bending apparatus of the conventional rolling mill can only add a roll bending force of about 2 MN / chock at the maximum, and is sufficient as an adjustment range of the sheet crown / shape control effect during rolling. It wasn't.

  In particular, when the pair cross is performed, the effect of the plate crown / shape control is very large. Therefore, the narrowness of the plate crown / shape control effect in the work roll bending apparatus becomes more obvious as a relative problem.

  For example, in the pair cloth, a plate crown / shape control effect equivalent to 16MN / chock can be obtained relatively easily in terms of the roll bending force applied to the work roll.

  When the plate crown and shape control effect equivalent to 16MN / chock is obtained by pair crossing, even if the rolling state changes during rolling and an attempt is made to additionally load the work roll with 3MN roll bending force, as described above, The maximum roll bending force that can be applied by a conventional roll bending apparatus is about 2 MN / chock.

  Therefore, in a conventional rolling mill, adjustment cannot be performed by additionally loading a plate crown / shape control exceeding 2MN during rolling. Therefore, in a conventional rolling mill, the pair cross is a plate crown / shape control method that is difficult to apply in an actual operation with a large disturbance.

  Accordingly, there has been a demand for a rolling mill capable of additionally applying a strong roll bending force comparable to the plate crown / shape control effect obtained by pair crossing during rolling while performing pair crossing.

  In other words, the problem to be solved by the present invention is that the opening between the upper and lower work rolls can be increased while maintaining the stability of the upper and lower work roll chock that supports the upper and lower work rolls. The present invention is to provide a rolling machine having a high responsiveness due to a bending force load and having a wide plate crown and shape control range against disturbances varying during rolling, and a rolling method using the rolling machine.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, shifted the project block projecting inward from the housing to the lower side with respect to the pass line, and vertically with respect to the pass line. By installing a pair of cross means for making the upper work roll and the lower work roll relatively intersect in a plane parallel to the metal sheet to be rolled, the following can be achieved. I found out.

  (A) A structure in which the rolling direction force applied to the upper work roll chock is always received by the entrance side crosshead or the exit side crosshead provided in the housing. Thereby, a work roll chock can be supported stably.

  (B) A structure in which the rolling direction force applied to the lower work roll chock is always received by the entry-side crosshead or the exit-side crosshead provided in the project block. Thereby, a work roll chock can be supported stably.

  (C) The hydraulic piping can be fixed and the servo valve can be applied by incorporating the increment bending device into the project block. This makes it possible to control the incremental bending force with high response.

  (D) In addition, an upper and lower increase bending apparatus can be incorporated into the project block. Thereby, a powerful bending device having a large capacity and a large stroke can be provided.

  (E) With this powerful bending device, roll bending that is comparable to the plate crown and shape control effect obtained by paired crossing even when the rolling state changes greatly during rolling while performing paired crossing It is possible to add an additional force to the work roll. In other words, with conventional rolling mills, the roll bending force is small, so it is impossible to adjust the crown and shape control over a wide range during rolling just to meet the effect of the strong crown and shape control obtained by pair crossing. This is possible with the rolling mill according to the present invention.

  Moreover, it discovered that the invention on these apparatuses enabled the following rolling mill operating methods.

  (F) Even with a decrease-bending device with low responsiveness, it is possible to control bending force with high response by cooperating with an incremental bending device with quick responsiveness. This greatly improves product quality and rolling yield.

  (G) In the manufacture of a differential thickness steel plate (LP steel plate) that changes the longitudinal plate thickness of the metal plate material, a significant change in rolling load occurs due to a change in the plate thickness during rolling, and at the same time changes in roll deflection occur. Arise. In response to this problem, the rolling mill according to the present invention can increase the control range of roll deflection during rolling. Therefore, the rolling mill according to the present invention can produce a differential thickness steel plate (LP steel plate) in which the thickness difference in the longitudinal direction of the metal plate material cannot be obtained by a conventional rolling mill.

  The present invention has been made based on these findings, and the gist thereof is as follows.

(1) A rolling machine for a metal plate having a pair of upper and lower work rolls composed of an upper work roll and a lower work roll, and a pair of upper and lower reinforcing rolls that respectively support these,
A hydraulic cylinder that applies an incremental bending force to each of the upper and lower work rolls is provided in a project block that protrudes inside the rolling mill housing,
A pair cross means is provided for crossing each of the upper and lower work rolls relatively in a plane parallel to the metal sheet to be rolled,
The pair cross means includes an upper drive crosshead, an upper cross reducer, a lower drive crosshead, a lower cross reducer, an upper driven crosshead, an upper cross driven hydraulic cylinder, a lower driven crosshead, and a lower cross driven hydraulic cylinder. And
A rolling direction force applied to the lower work roll body is supported by a contact surface between the project block and the lower work roll chock disposed on the lower drive crosshead and the lower driven crosshead,
The rolling direction force applied to the upper work roll body is supported by the upper drive crosshead and the contact surface between the upper driven crosshead and the upper work roll chock disposed in the rolling mill housing located above the project block. A rolling machine for a metal plate material.

(2) A rolling machine for a metal plate having a pair of upper and lower work rolls composed of an upper work roll and a lower work roll, and a pair of upper and lower reinforcing rolls that respectively support these rolls,
A hydraulic cylinder that applies an incremental bending force to each of the upper and lower work rolls is provided in a project block that protrudes inside the rolling mill housing,
A pair cross means is provided for crossing each of the upper and lower work rolls relatively in a plane parallel to the metal sheet to be rolled,
The pair cross means includes an upper drive crosshead, an upper cross reducer, a lower drive crosshead, a lower cross reducer, an upper cross driven hydraulic cylinder, and a lower cross driven hydraulic cylinder,
The rolling direction force applied to the lower work roll body is supported by the contact surface of the project block and the lower cross driven hydraulic cylinder and the lower work roll chock arranged in the lower drive crosshead,
The rolling direction force applied to the upper work roll body is supported by the contact surfaces of the upper drive crosshead and the cross driven hydraulic cylinder provided in the rolling mill housing located above the project block. A metal plate rolling machine characterized by

(3) A hydraulic cylinder that applies an increase bending force to the upper work roll and a hydraulic cylinder that applies an increase bending force to the lower work roll are arranged at different positions on the plan view in the project block. A rolling mill for a metal sheet according to (1) or (2) above, wherein

(4) The hydraulic cylinder for applying a decrease bending force to the upper work roll is provided in the upper reinforcement roll chock of the upper reinforcement roll, according to any one of (1) to (3), Metal plate material rolling machine.

(5) The hydraulic cylinder that applies a decrease bending force to the lower work roll is disposed in the lower reinforcement roll chock of the lower reinforcement roll or the second project block installed below the project block. The metal sheet material rolling mill according to any one of (1) to (4) above.

(6) A method for rolling a metal sheet, which is performed using the rolling machine for a metal sheet according to any one of (1) to (5) above,
Before starting rolling, the upper work roll and the lower work roll are relatively crossed in a plane parallel to the metal sheet to be rolled, and the sheet crown and shape control are performed,
The metal crown is characterized in that the adjustment of the sheet crown and shape control due to the change of the rolling state during rolling is performed by a hydraulic cylinder that applies at least one of an increment bending force and a decrease bending force to each of the upper and lower work rolls. A method for rolling plate materials.

(7) A method for rolling a metal sheet material using the metal sheet material rolling machine according to (4) or (5) above,
Before starting rolling, both the increase bending force and the decrease bending force are applied, and the roll bending force corresponding to the roll balance force is applied to the work roll chock as a resultant force.
After that, at the start of rolling, the increase bending force is changed to the work roll chock as a resultant force while changing the increase bending force while continuing the control of maintaining the decrease bending force during the predetermined rolling. Put it into action,
During rolling, performing the rolling so as to maintain the work roll bending force during the predetermined rolling,
After that, at the end of rolling, the increase bending force is changed, and the roll bending force corresponding to the roll balance force is applied to the work roll chock as a resultant force with the decrease bending force, and the rolling of the metal plate material is finished in this state. A method for rolling a metal sheet.

(8) Measure the hydraulic pressure in the hydraulic cylinder that generates the decrease bending force or in the hydraulic piping connected to the hydraulic cylinder, and based on the measured value, the roll bending force acting on the work roll chock as a resultant force becomes a predetermined value. The said bending bending force is controlled so that it may become, The rolling method of the metal plate material as described in said (7) characterized by the above-mentioned.

  As shown in FIG. 1, the rolling mill according to the present invention applies the rolling direction force applied to the body of the upper work roll 1-1 to the housing 9 above the upper work roll chock 3-1 and the project block 5-2. Is supported by a contact surface with the upper cross heads 21-1, 21-2 or the upper cross driven hydraulic cylinder 23-1. In addition, the rolling mill according to the present invention provides the upper bending machine 6-1 and 6-2 for applying the increase bending force to the upper work roll 1-1, and the increase bending force to the lower work roll 1-2. The lower increase bending apparatuses 6-3 and 6-4 to be loaded are arranged in the project blocks 5-1 and 5-2 protruding inside the housing 9. Therefore, a large roll opening degree can be obtained and a strong roll bending force can be obtained. Further, the roll can be stably supported also in the horizontal direction.

  In addition, this powerful roll bending force is equivalent to the range of plate crown and shape control obtained by paired crosses in which the upper work roll and the lower work roll intersect relatively in a plane parallel to the metal plate material to be rolled. In a wider range than that, it is possible to adjust the sheet crown and shape control during rolling.

  Therefore, it is possible to build a good plate crown and shape even when there are large disturbances that occur during rolling, such as the thickness of the rolled material entering side and the temperature of the rolled material, which greatly improves product quality and yield. can do.

  And it is not necessary to attach or detach the hydraulic piping of the increment bending apparatus every time the work roll is reassembled. For this purpose, it is possible to connect to each hydraulic control valve via fixed hydraulic piping to the incremental bending device, and it is possible to adopt a servo valve for high response hydraulic control, highly responsive incremental bending It can be a device.

  Further, the rolling method using the rolling mill according to the present invention compensates for this by a highly responsive incremental bending apparatus even when a declining bending apparatus having low responsiveness must be provided. Highly responsive and powerful plate crown / shape control function can be provided.

  And since the rolling method using the rolling mill according to the present invention can control the crown and shape of the plate with a pair cross and increase the distance between a pair of upper and lower work rolls during rolling using an increment bending apparatus. For example, it is possible to manufacture a differential thickness steel plate having a thickness difference in the longitudinal direction of the metal plate that cannot be obtained by a conventional rolling mill.

It is a side view which shows an example of the structure of the rolling mill which concerns on this invention. It is a perspective top view which shows the example of arrangement | positioning of an upper and lower increase bending apparatus. It is a perspective top view which shows the example of arrangement | positioning of an upper and lower increase bending apparatus. It is a side view which shows another example of the structure of the rolling mill which concerns on this invention. It is a figure which shows an example of the operation flow of the rolling method which concerns on this invention. It is a figure which shows time-sequential changes, such as roll bending force accompanying the operation flow of FIG. It is a figure which shows time-sequential changes, such as roll bending force, when the responsiveness of a decrease bending apparatus is low. It is a figure which shows another example of the operation flow of the rolling method which concerns on this invention. It is a figure which shows time-sequential changes, such as roll bending force accompanying the operation flow of FIG. It is a side view which shows the structure of the rolling mill which concerns on a prior art. It is a side view which shows the structure of the rolling mill which concerns on a prior art. It is a side view which shows the structure of the rolling mill which concerns on a prior art. It is a side view which shows the structure of the rolling mill which concerns on a prior art. It is a side view which shows the structure of the rolling mill which concerns on a prior art. It is a figure which shows the plate crown control range at the time of wide-width steel plate rolling. It is a figure which shows the plate crown control range at the time of narrow-width steel plate rolling. In the rolling mill which concerns on this invention, it is a side view which shows an example of embodiment which abbreviate | omitted the upper driven crosshead and the lower driven crosshead.

  Hereinafter, with reference to FIGS. 1-17, the rolling mill which concerns on this invention, and the rolling method using this rolling mill are demonstrated.

  FIG. 1 is a side view showing an example of the structure of a rolling mill according to the present invention. As shown in the figure, a 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 them. It is.

  The rolling mill according to the present invention provides the upper bending machine 6-1 and 6-2 that applies the increase bending force to the upper work roll 1-1, and the increase bending force to the lower work roll 1-2. This is a rolling mill in which lower incremental bending apparatuses 6-3 and 6-4 to be loaded are arranged in project blocks 5-1 and 5-2 protruding inside the housing 9.

  This is the same as the conventional rolling mill shown in FIG. However, the rolling mill according to the present invention performs a fundamental review and solves the problems of the conventional rolling mill shown in FIG. That is, the position of the project blocks 5-1 and 5-2 and the shape of the upper work roll chock 3-1 were changed from the viewpoint of structural design of the rolling mill, particularly from the viewpoint of increasing the roll opening.

  The conventional rolling mill shown in FIG. 13 cannot take a large roll opening. Therefore, the conventional rolling mill shown in FIG. 13 is used as a rolling mill for thin plates. In this rolling mill, the project blocks 5-1 and 5-2 are arranged so as to be almost vertically symmetrical with respect to a position (pass line) through which the material to be rolled 10 passes. For this reason, the rolling direction force such as offset component force acting on the upper work roll 1-1 by the contact surface where the upper work roll chock 3-1 and the project block 5-2 are in contact, that is, the material to be rolled 10 and the upper reinforcement. This is because the structure supports the rolling direction force applied to the body of the upper work roll 1-1 from the roll 2-1 or the like.

  In this structure, as the roll opening is increased, the rotation center position (the point of action of the rolling direction force) of the upper work roll 1-1 and the upper work roll chock 3-1 move upward to support the rolling direction force. The contact area with the project block 5-2 is reduced. Therefore, the posture of the upper work roll chock 3-1 becomes unstable as the roll opening degree is increased, and a large roll opening degree cannot be taken.

  The rolling mill according to the present invention solves the above problems. FIG. 1 is a side view showing an example of the structure of a rolling mill according to the present invention. Above the line AA in FIG. 1 is a view seen from the operator side, and below the line AA is a view seen from the drive side. As shown in FIG. 1, the rolling mill according to the present invention arranges project blocks 5-1 and 5-2 projecting inward from the housing 9 at positions shifted downward with respect to the pass line. That is, unlike the conventional rolling mill shown in FIG. 13, the project blocks 5-1 and 5-2 are arranged so as to be vertically asymmetric with respect to the pass line. The entry-side project block 5-1 is arranged and integrated with the entry-side lower driven crosshead 22-1. Similarly, the output side project block 5-2 is disposed and integrated with the output side lower drive crosshead 22-2. Further, the upper upper driven crosshead 21-1 and the upper upper drive crosshead 21-2 are arranged in the housing 9. The upper work roll chock 3-1 is not in contact with the exit side project block 5-2 and supports the rolling direction force, but the upper work roll chock 3-1 is provided on the entrance side upper crosshead provided in the housing 9. 21-1 and the upper crosshead 21-2 on the exit side were contacted to support the rolling direction force.

  Thus, in the rolling mill according to the present invention, the upper work roll chock 3-1 and the incoming upper driven crosshead arranged in the housing 9 above the incoming project block 5-1 and the outgoing project block 5-2. 21-1 and a rolling contact force such as an offset component force acting on the upper work roll 1-1 by the contact surface with the upper drive crosshead 21-2 on the exit side, that is, the material to be rolled 10 and the upper reinforcement roll 2- The rolling direction force loaded from 1 etc. to the trunk | drum of the upper work roll 1-1 is supported.

  With such a structure, even if the rolling device 11 of the rolling mill is operated to increase the roll opening degree, the upper work roll chock 3-1 and the upper driven follower crosshead 21- installed in the housing 9 are used. 1 and the area where the upper drive crosshead 21-2 comes into contact with each other do 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.

  As shown in FIG. 13, a rolling mill in which upper and lower increase bending apparatuses are arranged in a project block is well known. However, as shown in FIG. 1, the rolling mill according to the present invention performs a fundamental review on the positions of the project blocks 5-1 and 5-2 and the shape of the upper work roll chock 3-1, and the upper work roll 1. -1 is applied to the upper work roll chock 3-1 and the upper driven crosshead 21-1 and the outgoing side crosshead 21-1 disposed above the project block 5-2 of the housing 9. Since the structure is supported by the contact surface with the upper drive crosshead 21-2, a large roll opening can be obtained.

  Furthermore, in the rolling mill according to the present invention, the upper bending apparatus 6-1 and 6-2 for applying the increase bending force to the upper work roll 1-1, and the increase bending force to the lower work roll 1-2. The lower increase bending apparatuses 6-3 and 6-4 to be loaded are arranged in the project blocks 5-1 and 5-2 protruding inside the housing 9. Therefore, it is not necessary to attach or detach the hydraulic piping of the increment bending apparatus every time the work rolls are reassembled, and an increase bending responsive apparatus can be obtained. This is because each hydraulic control valve can be connected via a fixed hydraulic pipe, and a servo valve for high response hydraulic control can be employed.

  In the rolling mill according to the present invention, the rolling direction force applied to the body portion of the lower work roll 1-2 is arranged in the lower work roll chock 3-2 and the lower drive crosshead 22-2 on the exit side. It is supported by the contact surface between the exit-side project block 5-2 and the entrance-side project block 5-1 provided in the entrance-side lower driven crosshead 22-1. For this reason, the rolling mill according to the present invention shown in FIG. 1 increases the height of the portion sandwiched between the entry project block 5-1 and the exit project block 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.

  FIG. 2 is a sectional plan view showing an arrangement example of the upper and lower increase bending apparatuses. That is, it is a cross-sectional view of the pass line height of the project blocks 5-1 and 5-2. In FIG. 2, the pair cross means is omitted for the sake of simplicity.

  In the rolling mill according to the present invention, it is desirable that the upper and lower increase bending apparatuses are shifted from each other on the sectional plan view of the project block. For example, as shown in FIG. 2, the upper increment bending devices 6-1 and 6-2 and the lower increment bending devices 6-3 and 6-4 are shifted in the axial direction of the work roll 1-2. It is desirable to deploy in a relationship. In this way, the upper and lower increase bending apparatuses do not interfere with each other. It is possible to increase the stroke of the upper increment bending devices 6-1 and 6-2, and to take a larger roll opening.

  In FIG. 2, each of the lower increase bending apparatuses 6-3 and 6-4 has two hydraulic cylinders on the input side and the output side. However, the same effect can be obtained by arranging one hydraulic cylinder at different positions in the axial direction of the work roll 1-2 so as not to interfere with the upper increment bending apparatuses 6-1 and 6-2.

  FIG. 3 is also a cross-sectional plan view showing an arrangement example of the upper and lower increase bending apparatuses. That is, it is a cross-sectional view of the pass line height of the project blocks 5-1 and 5-2. In FIG. 3, as in FIG. 2, the pair cross means is omitted.

  As shown in FIG. 3, the upper increment bending apparatuses 6-1 and 6-2 and the lower increment bending apparatuses 6-3 and 6-4 may be in a positional relationship shifted in the rolling direction. Even in such an arrangement, the upper and lower increase bending apparatuses do not interfere with each other. It is possible to increase the stroke of the upper increment bending devices 6-1 and 6-2, and to take a larger roll opening.

  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, the application of a strong roll bending force, which is another problem to be solved, can be easily achieved.

  10 and 11 are both rolling mills according to the prior art, and any rolling mill can take a large roll opening.

  However, these conventional rolling mills cannot provide a strong roll bending force. This is a structure in which the upper increase bending devices 6-1 and 6-2 are incorporated in the arm portion that protrudes downward from the upper reinforcing roll chock 4-1, so that the upper increase bending device 6- has a large capacity and a large stroke. This is because 1, 6-2 cannot be deployed. Moreover, since these rolling mills take out an arm part from an upper reinforcement roll chock, the installation space of an upper discrete bending apparatus will approach the axial center of a roll. Therefore, since it interferes with the bearing of the upper reinforcing roll, it is impossible to deploy the upper capacity bending apparatuses 7-1 and 7-2 having a large capacity and a large stroke.

  On the other hand, as shown in FIG. 1, in the rolling mill according to the present invention, a large-capacity / large-stroke upper increment bending apparatus is provided on project blocks 5-1 and 5-2 projecting inward from the housing 9 of the rolling mill. 6-1, 6-2 can be deployed.

  Further, in the rolling mill according to the present invention, the upper reinforcing roll chock 4-1 does not include an arm portion like the rolling mill shown in FIGS. For this reason, large capacity and large stroke upper decrease bending apparatuses 7-1 and 7-2 can be provided at positions that do not interfere with the bearings of the upper reinforcing roll of the upper reinforcing roll chock 4-1. As a result, it is possible to apply a large decrease bending force to the upper work roll 1-1.

  That is, a fundamental review of the positions of the project blocks 5-1 and 5-2 and the shape of the upper work roll chock 3-1 is performed, and the rolling direction force applied to the trunk of the upper work roll 1-1 In the rolling mill according to the present invention, the upper work roll chock 3-1 is supported by a contact surface between the upper crosshead 21-1 on the entrance side or the upper crosshead 21-2 on the exit side provided in the housing 9. According to this, a large roll opening degree can be taken and a strong roll bending force can be given.

  Moreover, the rolling mill which concerns on this invention was arrange | positioned by the rolling direction force loaded to the trunk | drum of the lower work roll 1-2 to the lower work roll chock 3-2 and the outgoing side lower drive crosshead 22-2. By adopting a structure that supports by the contact surface with the entry side project block 5-1 arranged in the exit side project block 5-2 and the entry side lower driven crosshead 22-1, a larger roll opening is taken. Can do. In addition, a stronger roll bending force can be imparted.

  And it is not necessary to attach or detach the hydraulic piping of the increment bending apparatus every time the work roll is reassembled. For this reason, each increment bending apparatus 6-1 to 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 responsiveness.

  As described above, the rolling mill according to the present invention includes the pair cross means for causing the upper work roll and the lower work roll to cross relatively in a plane parallel to the metal sheet to be rolled. The structure of the pair cross means will be described in more detail with reference to FIG.

  In FIG. 1, although it shows about one edge part of each of the upper work roll 1-1, the lower work roll 1-2, the upper reinforcement roll 2-1, and the lower reinforcement roll 2-2, the other end part Has the same structure.

  The pair cross means 20 includes an incoming upper driven crosshead 21-1, an outgoing upper drive crosshead 21-2, an incoming lower driven crosshead 22-2, an outgoing lower drive crosshead 22-1, and an upper. Cross driven hydraulic cylinder 23-1, lower cross driven hydraulic cylinder 23-2, upper cross reducer 24-2, lower cross reducer 24-1, upper cross drive motor 25-1, lower cross drive motor 25-2 Have

  The inlet-side upper driven crosshead 21-1 and the outlet-side upper drive crosshead 21-2 are arranged in the housing 9. In general, the input lower driven crosshead 22-1 includes an input project block 5-1, and the output lower drive crosshead 22-2 includes an output project block 5-2.

  The upper work roll chock 3-1 and the upper reinforcement roll chock 4-1 are supported by contact with the incoming upper driven crosshead 21-1 and the outgoing upper drive crosshead 21-2. The incoming upper driven cross head 21-1 is connected to the upper cross driven cylinder 23-1. The exit-side upper drive crosshead 21-2 is connected to the upper cross reducer 24-1.

  Similarly, the lower work roll chock 3-2 and the lower reinforcing roll chock 4-2 are connected to the lower driven cross head 22-1, the lower cross driven hydraulic cylinder 23-2. The outgoing side lower drive crosshead 22-2 is coupled to the lower cross reducer 24-2.

  That is, as shown in FIG. 1, the upper cross driven hydraulic cylinder 23-1 and the lower cross driven hydraulic cylinder 23-2 are arranged on the entry side, and the upper cross reducer 24-1 and the lower cross reducer 24-2 are arranged. Is arranged on the exit side.

  An upper cross drive motor 25-1 is connected to the upper cross reducer 24-1 through an upper cross drive shaft 26-1. A lower cross drive motor 25-2 is coupled to the lower cross reducer 24-2 via a lower cross drive shaft 26-2. Note that FIG. 1 is a view as seen from the operator side above the line AA and from the drive side below the line AA, so that the upper cross drive shaft 26-1 and the lower cross are shown in FIG. The drive shaft 26-2 is shown overlapping. The same applies to the upper cross drive motor 25-1 and the lower cross drive motor 25-2.

  Then, the upper cross drive motor 25-1 and the lower cross drive motor 25-2 are operated, and the metal plate material to be rolled from now on by the outgoing upper drive crosshead 21-2 and the outgoing lower drive crosshead 22-2. Relative to each other in a plane parallel to.

  At this time, the upper cross driven hydraulic cylinder 23-1 follows the operation of the outgoing upper drive cross head 21-2, and the upper cross driven hydraulic cylinder 23-1 passes through the upper driven cross head 21-1. And the upper reinforcing roll chock 4-1 is pressed. Then, the upper work roll chock 3-1 comes into contact with the outgoing upper drive crosshead 21-2 provided in the housing 9, and supports the rolling direction force. At the time of reverse rolling, the upper work roll chock 3-1 is in contact with the incoming upper driven crosshead 21-1 provided in the housing 9, and supports the rolling direction force.

  Similarly, following the operation of the output lower drive crosshead 22-2, the lower cross driven hydraulic cylinder 23-2 passes through the input lower drive crosshead 22-1, and the lower work roll chock 3-2. And the lower reinforcing roll chock 4-2 is pressed. Then, the lower work roll chock 3-2 comes into contact with the entry-side project block 5-1 provided in the entry-side lower driven crosshead 22-1, and supports the rolling direction force. Similarly, the lower reinforcing roll chock 4-2 contacts the lower driven crosshead 22-1, and supports the rolling direction force. At the time of reverse rolling, the lower work roll chock 3-2 contacts the outgoing project block 5-2 provided in the outgoing lower drive crosshead 22-2 and supports the rolling direction force. Similarly, at the time of reverse rolling, the lower work roll chock 3-2 contacts the incoming project block 5-1 provided in the incoming lower drive crosshead 22-1, and supports the rolling direction force.

  As shown in FIG. 17, of the upper side driven crosshead 21-1 on the entry side and the upper drive crosshead 21-2 on the outgoing side, the entry side on which the upper cross driven hydraulic cylinder 23-1 is disposed. For the upper driven cross head 21-1, the upper driven driven cross head 21-1 is omitted, and the upper cross driven hydraulic cylinder 23-1 is directly connected to the upper work roll chock 3-1 and the upper reinforcing roll chock 4-1. 1 may be pressed. In this case, the upper work roll chock 3-1 contacts the upper cross driven hydraulic cylinder 23-1, and supports the rolling direction force.

  Similarly, as shown in FIG. 17, the lower cross driven hydraulic cylinder 23-2 of the input side lower driven crosshead 22-1 and the output side lower drive crosshead 22-2 is provided. As for the entry-side lower driven cross head 22-1, the entry-side lower driven cross head 22-1 is omitted, and the lower cross driven hydraulic cylinder 23-2 is directly connected to the lower work roll chock 3-2 and the lower work cross chock 3-2. The reinforcing roll chock 4-2 may be pressed. In this case, the lower work roll chock 3-2 contacts the lower cross driven hydraulic cylinder 23-2 and supports the rolling direction force.

  Moreover, in FIG. 1, the upper work roll 1-1, the upper reinforcement roll 2-1, the lower work roll 1-2, and the lower reinforcement roll 2-2 are horizontal on either the drive side or the work side of the rolling mill. An embodiment of a so-called single-cross rolling machine that moves inside is shown. For example, a single-cross rolling mill that moves only the upper work roll 1-1 and the upper reinforcement roll 2-1 on the work side and moves only the lower work roll 1-2 and the lower reinforcement roll 2-2 on the drive side. However, it is not limited to a single cross rolling mill, and may be a double cross rolling mill.

  Thereby, the upper work roll 1-1 and the lower work roll 1-2 are relatively crossed in a plane parallel to the metal plate material to be rolled, and paired crossing can be performed. In the plate crown / shape control by pair cross, the control amount is determined by setting the crossing angle of the upper work roll 1-1 and the lower work roll 1-2. Since the crossing angle cannot be set during rolling, it is performed before starting rolling.

  The bending of the plate can be corrected by the output values of the upper work roll horizontal force detection load cell 27-1 and the lower work roll horizontal force detection load cell 27-2. The upper work roll horizontal force detection load cell 27-2 is incorporated in the upper crosshead 21-2 on the outgoing side while being in contact with the outgoing side surface of the upper work roll chock 3-1. The lower work roll horizontal force detection load cell 27-2 is incorporated in the lower drive crosshead 22-2 on the outgoing side while being in contact with the outgoing side surface of the lower work roll chock 3-2. When the rolling direction forces on the working side and the driving side are different, these load cells 27-1 and 27-2 detect the bending of the plate. Therefore, based on the detection values of these load cells, for example, the bending of the plate can be corrected by correcting the reduction amount on the working side and the driving side.

  FIG. 4 is a side view showing another example of a rolling mill according to the present invention. The above-described pair cross means shown in FIG. 1 is similarly provided in the rolling mill shown in FIG. Although the pair cross means is shown in FIG. 4, the explanation about the pair cross means is the same as that of the rolling mill shown in FIG. 4 is a view as seen from the operator side above the line AA in FIG. 4, and is a view as seen from the drive side below the line AA.

  In the rolling mill shown in FIG. 4, the upper roll system has the same configuration as that of FIG. 1, but the lower roll system has a different configuration. In the rolling mill shown in FIG. 1, lower decrease bending apparatuses 7-3 and 7-4 that apply a decrease bending force to the lower work roll are provided in the lower reinforcing roll chock 4-2. On the other hand, in the rolling mill shown in FIG. 4, the lower decrease bending apparatuses 7-3 and 7-4 are arranged in dedicated project blocks 5-3 and 5-4 located below the project blocks 5-1 and 5-2. Has been deployed.

  By the way, when the lower decrease bending apparatuses 7-3 and 7-4 are arranged in the lower reinforcing roll chock 4-2 as in the rolling mill shown in FIG. 1, when the lower reinforcing roll 2-2 is reassembled, the decrease bending apparatus Hydraulic piping must be attached and detached. In other words, there is a high possibility that minute foreign matter will be mixed in the hydraulic piping during attachment / detachment.

  For this reason, it is generally difficult to employ a servo valve for high response hydraulic pressure control, and flexible piping may have to be partially employed. Therefore, the responsiveness of the roll bending apparatus is inevitably lowered as compared with the case where fixed piping and servo valves are employed.

  On the other hand, according to the rolling mill shown in FIG. 4, the said problem which arises when the lower reinforcement roll 2-2 is rearranged can be solved. This is because a servo valve for high-response hydraulic control can be used for the hydraulic piping of the lower decrease bending device deployed in the dedicated project block, and it is not necessary to use flexible piping. For this reason, it is possible to easily change the lower reinforcing roll 2-2 and to provide a roll responsive apparatus with high responsiveness.

  Next, the rolling method according to the present invention will be described. As shown in FIGS. 1 and 4, when the upper decrease bending devices 7-1 and 7-2 are arranged in the upper reinforcement roll chock 4-1, when the upper reinforcement roll 2-1 is reassembled, the hydraulic pressure of the decrease bending device is changed. The pipe must be attached and detached, and there is a high possibility that minute foreign matter will be mixed in the hydraulic pipe when attaching and detaching.

  For this reason, it is generally difficult to employ a servo valve for high response hydraulic control. In addition, in order to facilitate the attachment / detachment of the pipe, it is necessary to connect to each hydraulic control valve via a flexible and detachable hydraulic pipe such as a flexible pipe. In the case of adopting a flexible and detachable hydraulic pipe such as a flexible pipe, the fluctuation of the hydraulic pressure may be absorbed or alleviated because of the flexible structure.

  Therefore, when the upper decrease bending devices 7-1 and 7-2 are provided in the upper reinforcing roll chock 4-1, the response of the roll bending device is less than when the fixed piping and the servo valve are used. It must be lowered.

  By the way, the decrease bending force cannot be applied during idling when no rolling load is applied. Therefore, when applying the decrease bending force, it is necessary to quickly set the decrease bending force from the idle state in which the roll balance is achieved to the start of rolling, and to quickly return to the roll balance state at the end of rolling.

  Therefore, when the roll bending force is changed by the control of the decrease bending device having poor responsiveness, there is a possibility that the predetermined defect bending force is not applied to the leading end of the rolled material and the defective shape portion becomes long. .

  The rolling method according to the present invention solves the above problems. That is, it is a rolling method using the rolling mill according to the present invention in which the upper decrease bending apparatuses 7-1 and 7-2 are arranged in the upper reinforcing roll chock 4-1, and solves the above-described problems that may occur in the rolling mill. It is a rolling method.

  As described above, in the rolling mill in which the upper decrease bending apparatuses 7-1 and 7-2 are arranged in the upper reinforcing roll chock 4-1, the response of the decrease bending apparatus may be deteriorated.

  However, in the rolling mill according to the present invention, the upper increment bending apparatuses 6-1 and 6-2 are arranged in the project blocks 5-1 and 5-2 protruding in the inner direction from the housing 9, Large increase and large stroke upper increment bending apparatuses 6-1 and 6-2 can be used.

  In addition, since it is not necessary to attach and detach the hydraulic piping of the increment bending apparatus every time the rolls are changed, it is possible to employ a fixed hydraulic piping or a servo valve, which makes it possible to obtain an increase bending responsive apparatus. .

  In the rolling method according to the present invention, when a decrease bending force is applied to a work roll for the purpose of plate crown and shape control, a change in roll bending force at the start of rolling and at the end of rolling is performed with a highly responsive increase. This is performed by using a bending apparatus and compensates for the response of the decrease bending apparatus.

  FIG. 5 is a diagram showing an example of an operation flow of the rolling method according to the present invention. That is, it is a diagram showing an operation flow of an increase bending apparatus having a high response and a decrease bending apparatus having a slightly lower response than the above.

  FIG. 6 shows time-series changes such as roll bending force for one rolled material in this rolling method. FIG. 6 shows the rolling load, the output of the increment bending apparatus, the output of the decrease bending apparatus, and the time series change of the work roll bending force, which is the resultant force, from the top. Hereinafter, a description will be given with reference to FIGS.

First start rolling before, then rolled settings F _R of the rolling work roll bending force corresponding to operation and output to the rolling. Here F _R is a negative value, that is, those which are calculated as decrease-bending force. In the present invention, the increase bending force (the force in the increase direction (the direction in which the roll is opened)) is a positive value, and the decrease bending force (the force in the decrease direction (the direction in which the roll is pressed)) is a negative value. To do.

Prior to the start of rolling, both the increase bending force and the decrease bending force are applied, and the roll bending force on the increase side corresponding to the roll balance force (F _B ) is applied to the work roll chock as a resultant force.

That is, at idle before rolling, the increment bending device output is I _B (> 0), the decrease bending device output is D _B (<0), and I _B + D _B is the roll balance force F _B (> 0). Works.

Roll balancing force F _B is rolls as a work roll and a driven which are driven by an electric motor in the idling state is determined as a force that does not slip. This time D _B may be set at a level of minimum hydraulic actuator decrease-bending device is not Shimawa away from the work roll chock.

And in certain timing before the start of rolling (a point on the time axis), a sufficient predetermined rolling in decrease-bending device output D _S to exert the work roll bending force F _R during rolling D _{S =} F _R - computing the I _R. As the roll balancing force _{(F B)} is constant, at the same time outputs the _{D S} and _{I S.} Here, I _R is-bending device output during rolling, determined in advance a value close to minimum controllable value such that the absolute value of D _S does not become excessive. I _S is the output of the increment bending apparatus where I _S + D _S = F _B. Therefore, in the setting timing, the work roll bending force of the resultant force is substantially unchanged remains F _B.

Then, immediately after the start of rolling, while decrease-bending force holds a constant value, reduce the increase-bending force, the work in a given rolling roll bending force F _R is to act on the work roll chock as resultant force. This is because if the increase bending force is reduced before the metal sheet to be rolled bites into the rolling mill, the roll gap is closed and the metal sheet cannot be bitten.

That is, when the start of rolling (b point on the time axis), is changed to I _R ink bending device output from the I _S. While such decrease-lease low response by the bending device output D _S, the control of the quick-bending apparatus responsive, the work roll bending force of the resultant force from the roll balancing force F _{B (>} 0) It is possible to quickly switch to the work roll bending force F _R (<0) during rolling.

  In addition, the rolling start time (b) refers to the time point when the rolling is started, and the detection thereof, for example, the load detected by the load cell for measuring the rolling load of the rolling mill exceeds 30% of the predicted rolling load. You can decide by the method of time.

Then, the rolling end just before, for returning the roll bending force to the state before the start of rolling, the roll bending force corresponding to the roll balancing force (F _B) by acting on the work roll chock as resultant force, ends the rolling. This is because if the operation of the increment bending apparatus is delayed, the upper and lower work rolls collide when the end portion of the metal sheet of the rolling mill comes out of the rolling mill.

That is, when completion of rolling (c point on the time axis), decrease-bending device output varies the fast-bending device output response from the I _R in I _S remain D _S. By doing in this way, the work roll bending force as a resultant force can be quickly switched from the work roll bending force during rolling (F _R (<0)) to the roll balance force (F _B (> 0)).

  The end of rolling (c) refers to the end of rolling. For example, the load detected by the load cell for measuring the rolling load of the rolling mill is less than 60% of the actual rolling load average value. What is necessary is just to decide by the method of timing. Preferably, it may be determined by a method of setting the timing below 50%.

Then from the time the end of rolling (c), for example, a time has elapsed 1-3 seconds and work completion timing (d points on the time axis), at this timing, the increase-bending device output I _B, decrease-bending device to change the output to the _{D B.} Even with this change, the work roll bending force as the resultant force is substantially maintained at the roll balance force (F _B ).

  As shown in FIGS. 5 and 6, in the rolling method according to the present invention, the roll bending force is changed at the start of rolling and at the end of rolling by using an increase bending responsive apparatus. For this reason, even if it is necessary to deploy a decrease bending device having a relatively low response, a highly responsive increase bending device compensates for this. A shape control function can be provided.

  In addition, even when the rolling direction force changes due to various factors (disturbances) during rolling, a highly responsive incremental bending device can be quickly controlled to maintain the optimum work roll bending force. Is possible.

  In addition, as described above, the rolling mill according to the present invention can perform powerful control of the sheet crown and shape by pair crossing. It can be done with a responsive and powerful increase bending machine.

  That is, according to the rolling method according to the present invention, powerful plate crown and shape control can be performed by setting the pair cross set before the start of each pass. In addition to this, even after the start of rolling, a wide range of work roll bending forces are additionally loaded with a powerful incremental bending device against disturbances that change during rolling, such as the thickness of the rolled material entry side and the temperature of the rolled material. be able to. This additional load makes it possible to compensate for the crown and shape control over a wide range. As a result, it is possible to build a good plate crown and shape, which can greatly improve product quality and yield.

  FIG. 7 is a diagram showing time-series changes in roll bending force and the like when the response of the decrease bending apparatus is low (particularly, when the reaction force is reduced and the pressure drops when the reaction force is released). Similar to FIG. 6, changes in time series such as a roll bending force accompanying a rolling operation on a single rolled material are shown in accordance with the operation flow of the increment bending apparatus and the decrease bending apparatus shown in FIG. 5. That is, an example in which the response speed of the decrease bending apparatus is slower than in the case of FIGS.

At timings b and c, the output of the increase bending apparatus with high responsiveness changes abruptly, so that the output of the decrease bending apparatus with poor responsiveness fluctuates. As a result, the work roll bending force of the resultant force, is delayed to reach F _R at timing b, it will be delayed possible to reach F _B at the timing c. The rolling method shown in FIG. 8 solves this problem.

  FIG. 8 is a diagram showing an operation flow in the case of having an increase bending device with high responsiveness and a decrease bending device with low responsiveness. Hereinafter, a description will be given based on the drawing.

In the rolling method shown in FIG. 8, the decrease bending force or the hydraulic pressure in the hydraulic piping connected to the apparatus is constantly measured by a load cell installed in the decrease bending apparatus, and the incremental bending apparatus is controlled based on the measured value. To do. That is, as the work roll bending force before and after rolling is rolled balancing force F _B, during rolling as the work roll bending force is F _R, the output of the increase-bending device, decrease-bending force Mahata It is controlled according to the hydraulic pressure of the decrease bending device. The other control is the same as the rolling method shown in FIG.

  By rolling with the rolling method shown in FIG. 8, as shown in FIG. 9, the increase bending device compensates for fluctuations in the output of the decrease bending device, and the work roll bending force is optimized to achieve high-response control. Can be realized.

  In addition, it is possible to predict the fluctuation of the output of the decrease bending apparatus in advance and set the output of the increment bending apparatus to compensate for it without the need for measuring the bending bending force during rolling or feedback control by measuring the hydraulic pressure. In this way, the same effect can be obtained.

  Next, the present invention will be further described with reference to examples. Conditions in the examples are one example of conditions adopted to confirm the feasibility and effects of the present invention, and the present invention is examples of these one condition. It is not limited to. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

Example 1
A steel plate having a plate width of 3800 mm and a plate thickness of 20 mm was rolled to a plate thickness of 16 mm with the rolling mill according to the present invention shown in FIG. In this case, the control range of the plate crown was investigated. The roll width of this rolling mill is 4700 mm.

The rolling conditions are as follows.
・ Rolling load: 44.5MN (4540tf)
・ Work roll bending force: ± 3.4MN (± 350tf / chock)
・ Pair cross angle: 0.7 °

  The result of investigating the control range of the plate crown is shown in FIG. For comparison, FIG. 15 shows a control range of the plate crown when a work roll bending force of 1.2 to 2.0 MN (120 to 200 tf / chock) is applied in the conventional rolling mill shown in FIG. The results of the survey were added. The rolling conditions in the conventional rolling mill are the same as the rolling conditions in the rolling mill according to the present invention except for the magnitude of the work roll bending force. Moreover, the pair rolling is not performed in the conventional rolling mill.

  The control range of the plate crown was investigated separately for work roll bending effect and pair cross effect.

  In the work roll bending effect of the rolling mill according to the present invention shown in FIG. 15, the solid portion indicates the increment bending effect, and the hatched portion indicates the decrease bending effect.

  In addition, the investigation result of the control range of the sheet crown when the rolling load is changed in the range of ± 9.8 MN is also added. During rolling, the rolling load can vary in the range of ± 9.8 MN. Therefore, when evaluating the work roll bending effect, it is one of the criteria for determining whether the work roll bending effect exceeds the control range of the plate crown when the rolling load is changed within a range of ± 9.8 MN. It is. Moreover, if the sheet crown can be controlled even if the rolling load changes within the range of ± 9.8 MN, a difference thickness steel sheet is produced in which the difference in sheet thickness in the longitudinal direction of the metal sheet cannot be obtained with a conventional rolling mill. Because it can be done.

  As is clear from FIG. 15, it was confirmed that the work roll bending effect of the rolling mill according to the present invention is comparable to the pair cross effect. It was confirmed that the work bending effect according to the present invention exceeded the control range of the plate crown when the rolling load was changed in the range of ± 9.8 MN. On the other hand, it was confirmed that the work roll bending effect of the conventional rolling mill was about 1/9 compared with the present invention.

  In the rolling conditions of Example 1, the rolling mill according to the present invention can obtain a wide range of sheet crown control of about 950 μm by the pair cross effect. In addition, a wide range of sheet crown control with a work roll bending effect equivalent to the pair cross effect of about 800 μm can be added during rolling. Therefore, it has been confirmed that the rolling mill according to the present invention can easily cope with various disturbances during rolling just enough to meet the sheet crown and shape control by the pair cross effect.

  That is, the rolling mill according to the present invention can compensate a wide range of the sheet crown by an additional load of the work roll bending force even in a rolling environment with many disturbances. Therefore, it was confirmed that it was easy to improve the quality related to the plate crown and shape of the rolled metal sheet material even when pair crossing was performed.

  On the other hand, the fact that the sheet crown control range by the work roll bending effect is as narrow as about 80 μm as in the conventional rolling mill means that it is difficult to cope with disturbances during rolling. Therefore, in a rolling environment with many disturbances, it is difficult for a conventional rolling mill to perform pair cross. As a result, it is difficult for conventional rolling mills to improve the quality related to the sheet crown and shape of the rolled metal sheet.

  Further, as is apparent from FIG. 15, it was confirmed that the rolling mill according to the present invention has a large decrease bending effect.

(Example 2)
A steel plate having a plate width of 2200 mm and a plate thickness of 20 mm was rolled to a plate thickness of 16 mm with the rolling mill according to the present invention shown in FIG. In this case, the control range of the plate crown was investigated. The roll width of this rolling mill is 4700 mm.

The rolling conditions are as follows.
Rolling load: 25.7MN (2630tf)
・ Work roll bending force: ± 3.4MN / chock (± 350tf / chock)
・ Pair cross angle: 0.7 °

  The result of investigating the control range of the plate crown is shown in FIG. For comparison, FIG. 16 shows a control range of the plate crown when a work roll bending force of 1.2 to 2.0 MN (120 to 200 tf / chock) is applied to the conventional rolling mill shown in FIG. The results of the survey were added. The rolling conditions in the conventional rolling mill are the same as the rolling conditions in the rolling mill according to the present invention except for the magnitude of the work roll bending force. Moreover, the pair rolling is not performed in the conventional rolling mill.

  In addition, the investigation results of the control range of the plate crown when the rolling load is changed in the range of ± 7.8 MN are also added. During rolling, the rolling load can vary in the range of ± 7.8 MN. Therefore, when evaluating the work roll bending effect, it is one of the criteria for determining whether the work roll bending effect exceeds the control range of the plate crown when the rolling load is changed within a range of ± 7.8 MN. It is. Moreover, if the sheet crown can be controlled even if the rolling load changes within the range of ± 7.8 MN, a difference thickness steel sheet in which the sheet thickness difference in the longitudinal direction of the metal sheet cannot be obtained by a conventional rolling mill is manufactured. Because it can be done.

  As apparent from FIG. 16, the work roll bending effect of the rolling mill according to the present invention is higher than the pair cross effect. This is because in Example 2, the plate width is smaller than the roll width as compared to Example 1, and thus the pair cross effect is reduced. It was confirmed that the work bending effect according to the present invention exceeded the control range of the plate crown when the rolling load was changed in the range of ± 7.8 MN. On the other hand, it was confirmed that the work roll bending effect of the conventional rolling mill was significantly smaller than the work roll bending effect of the rolling mill according to the present invention.

  Further, in the rolling mill according to the present invention, when the plate width is small with respect to the roll width as in Example 2, the decrease bending effect shown by the hatched portion in FIG. 15 is relatively large. I was able to confirm.

  The present invention can be used for rolling a steel sheet, particularly a reverse rolling mill that requires a large opening.

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 Chock 4-2 Lower Reinforcement Roll Chock 5- 1 Incoming Project Block 5-2 Outgoing Project Block 5-3 Incoming Lower Project Block 5-4 Outgoing Lower 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 Incoming Upper Decrease Bending Device 7-2 Outgoing Upper Decrease Bending Device 7-3 Incoming Lower Decrease Bending Device 7- 4 Outgoing Lower Decrease Bending Device 8-1 Entry Side Reinforcement Row Balancing device 8-2 exit side rolls balancing device 9 housing 10 the material to be rolled (metal plate)
DESCRIPTION OF SYMBOLS 11 Reduction device 12 Housing window 20 Pair cross means 21-1 Incoming upper driven crosshead 21-2 Outgoing upper driving crosshead 22-1 Incoming lower driven crosshead 22-2 Outgoing lower driving crosshead 23 -1 Upper cross driven hydraulic cylinder 23-2 Lower cross driven hydraulic cylinder 24-1 Upper cross reducer 24-2 Lower cross reducer 25-1 Upper cross drive motor 25-2 Upper cross drive motor 26-1 Upper cross Drive shaft 26-2 Lower cross drive shaft 27-1 Upper work roll horizontal force detection load cell 27-2 Lower work roll horizontal force detection load cell

Claims (8)

It is a rolling machine of a metal plate material having a pair of upper and lower work rolls composed of an upper work roll and a lower work roll, and a pair of upper and lower reinforcement rolls that respectively support these,
A hydraulic cylinder that applies an incremental bending force to each of the upper and lower work rolls is provided in a project block that protrudes inside the rolling mill housing,
A pair cross means is provided for crossing each of the upper and lower work rolls relatively in a plane parallel to the metal sheet to be rolled,
The pair cross means includes an upper drive crosshead, an upper cross reducer, a lower drive crosshead, a lower cross reducer, an upper driven crosshead, an upper cross driven hydraulic cylinder, a lower driven crosshead, and a lower cross driven hydraulic cylinder. And
A rolling direction force applied to the lower work roll body is supported by a contact surface between the project block and the lower work roll chock disposed on the lower drive crosshead and the lower driven crosshead,
The rolling direction force applied to the upper work roll body is supported by the upper drive crosshead and the contact surface between the upper driven crosshead and the upper work roll chock disposed in the rolling mill housing located above the project block. A rolling machine for a metal plate material. It is a rolling machine of a metal plate material having a pair of upper and lower work rolls composed of an upper work roll and a lower work roll, and a pair of upper and lower reinforcement rolls that respectively support these,
A hydraulic cylinder that applies an incremental bending force to each of the upper and lower work rolls is provided in a project block that protrudes inside the rolling mill housing,
A pair cross means is provided for crossing each of the upper and lower work rolls relatively in a plane parallel to the metal sheet to be rolled,
The pair cross means includes an upper drive crosshead, an upper cross reducer, a lower drive crosshead, a lower cross reducer, an upper cross driven hydraulic cylinder, and a lower cross driven hydraulic cylinder,
The rolling direction force applied to the lower work roll body is supported by the contact surface of the project block and the lower cross driven hydraulic cylinder and the lower work roll chock arranged in the lower drive crosshead,
The rolling direction force applied to the upper work roll body is supported by the contact surfaces of the upper drive crosshead and the cross driven hydraulic cylinder provided in the rolling mill housing located above the project block. A metal plate rolling machine characterized by   The hydraulic cylinder that applies an increase bending force to the upper work roll and the hydraulic cylinder that applies an increase bending force to the lower work roll are disposed in different positions on the plan view in the project block. The metal sheet material rolling mill according to claim 1 or 2.   4. The metal plate material according to claim 1, wherein a hydraulic cylinder that applies a decrease bending force to the upper work roll is provided in an upper reinforcement roll chock of the upper reinforcement roll. 5. Rolling mill.   The hydraulic cylinder for applying a decrease bending force to the lower work roll is provided in a lower reinforcement roll chock of the lower reinforcement roll or a second project block installed below the project block. The metal plate material rolling mill according to any one of 1 to 4. A rolling method for a metal plate material using the metal plate material rolling machine according to any one of claims 1 to 5,
Before starting rolling, the upper work roll and the lower work roll are relatively crossed in a plane parallel to the metal sheet to be rolled, and the sheet crown and shape control are performed,
The metal crown is characterized in that the adjustment of the sheet crown and shape control due to the change of the rolling state during rolling is performed by a hydraulic cylinder that applies at least one of an increment bending force and a decrease bending force to each of the upper and lower work rolls. A method for rolling plate materials. A method for rolling a metal sheet using the rolling machine for a metal sheet according to claim 4 or 5,
Before starting rolling, both the increase bending force and the decrease bending force are applied, and the roll bending force corresponding to the roll balance force is applied to the work roll chock as a resultant force.
After that, at the start of rolling, the increase bending force is changed to the work roll chock as a resultant force while changing the increase bending force while continuing the control of maintaining the decrease bending force during the predetermined rolling. Put it into action,
During rolling, performing the rolling so as to maintain the work roll bending force during the predetermined rolling,
After that, at the end of rolling, the increase bending force is changed, and the roll bending force corresponding to the roll balance force is applied to the work roll chock as a resultant force with the decrease bending force, and the rolling of the metal plate material is finished in this state. A method for rolling a metal sheet.   Measure the hydraulic pressure in the hydraulic cylinder that generates the decrease bending force or in the hydraulic piping connected to the hydraulic cylinder so that the roll bending force acting on the work roll chock as a resultant force becomes a predetermined value based on the measured value. The method for rolling a metal sheet according to claim 7, wherein the increase bending force is controlled.

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