JP2012223811A - Method for rolling metal plate, rolling mill, and metal plate manufactured by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling mill and a rolling method that can appropriately control a plate crown or shape (flatness or steepness) by a bending apparatus in the rolling mill requiring large roll opening.SOLUTION: Rolling is performed using the rolling mill that includes a vertical pair of working rolls and a vertical pair of reinforcing rolls, wherein hydraulic cylinders for applying increase bending force to the vertical working rolls respectively are disposed at projecting blocks that project to the inside of a rolling mill housing. In the rolling method using the rolling mill, such a bending force that the plate crown on the rolling path outlet side has a target value is computed, and the hydraulic cylinders are controlled to impart the computed bending force.

Description

  The present invention relates to a method for rolling a metal plate, a rolling mill, and a metal plate manufactured thereby.

  In the rolling operation of the metal plate material, elastic deformation such as bending occurs in the work roll due to a large rolling load, and as a result, a plate thickness difference in the width direction occurs in the rolled plate material. Such a plate thickness difference is called a plate crown. In general, a rolled plate has a thick central portion in the width direction and tends to become thinner toward the edge in the width direction. The difference between the plate thickness at the central portion and the plate thickness at the crown definition point provided at a predetermined distance from the edge portion is called a plate crown.

  Further, when the ratio of the sheet crown to the sheet thickness (hereinafter referred to as “crown ratio”) changes between the rolling pass entry side and the rolling pass exit side, between the width direction center portion and the width direction edge portion of the plate material. A difference occurs in the amount of stretching of the material, and as a result, the shape (flatness) may be disturbed. Such disturbance of the shape mainly includes the middle elongation that occurs when the elongation in the width direction central portion of the plate material is larger than the elongation in the width direction edge portion, and the elongation in the width direction edge portion of the plate material in the width direction central portion. And ear elongation that occurs when the elongation is greater than the elongation.

  In the rolling operation of a metal plate material, the plate crown and shape of the rolled plate are important quality indicators, and many techniques relating to plate crown and shape control have been disclosed.

  For example, Patent Document 1 obtains a plate crown as a target plate crown such that an expected value of the output flatness that is calculated based on the input plate crown, the target plate thickness, the target output plate crown, and the like falls within an allowable range. A rolling method is disclosed in which the setting condition of the shape control actuator, for example, the bending force of the work roll bending apparatus, is controlled so that the outlet plate crown becomes the target plate crown.

  In Patent Document 2, work roll bending is performed so that the flatness on the delivery side of the rolling mill is actually measured and the measured delivery-side flatness is increased (that is, the rolled plate is flattened). A rolling method for controlling the bending force of the apparatus is disclosed.

  In Patent Document 3, the roll bending force of the rolling mill is controlled so that the mechanical plate crown is constant based on the rolling load detected by the load cell, and the actual measurement by the shape meter provided on the exit side of the rolling mill. It is disclosed that the roll bending force of a rolling mill is controlled so that the elongation strain difference calculated from the value becomes a desired value.

  Patent Document 4 discloses that the sheet crown on the exit side of the rolling mill is measured and the bending force of the work roll bending apparatus is controlled so that the measured sheet crown becomes equal to the mechanical sheet crown.

  In Patent Document 5, the sheet crown on the entrance side of the rolling mill and the sheet crown on the exit side of the rolling mill are measured, and the change in the crown ratio accompanying the rolling is obtained based on these measured values, and the flatness calculated based on this is obtained. It is disclosed that an actuator for crown control, for example, a work roll bending apparatus, is controlled so that is within an allowable range.

JP-A-6-71319 Japanese Patent Publication No. 48-42539 JP 59-130614 A Japanese Patent Laid-Open No. 4-200121 JP-A-7-251213 JP-A-6-87011 JP-A-62-220205

Honjo, Sato, Kuchi, "IHI shape control device in sheet rolling", IHI Technical Bulletin, IHI Co., Ltd., issued in June 2008, Vol. 48, No. 2, pages 93 to 100 (particularly, FIG. 3 (page 94)) Nishioka, Mizutani, Hori, Kojima, Ogawa, "Large rolling rolling technology in a rolling pair cross mill", Nippon Steel Technical Report, Nippon Steel Corporation, November 1997, No. 365, pp. 9-17 (In particular, Fig. 7 (page 12))

  By the way, 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, at least the gap between the upper and lower work rolls (roll opening degree) is rolled. It must be possible to expand to the same thickness as the material. For this reason, as such a rolling mill, what was disclosed by FIG. 1, for example is used (for example, refer patent document 6).

  The rolling mill shown in FIG. 1 is of a type in which an upper work roll chock 3-1 is held by an arm part connected to the upper reinforcement roll chock 4-1, and an increment bending apparatus 6 of the upper work roll 1-1 is held on this arm part. 1, 6-2 are incorporated. By setting it as such a format, a big roll opening degree can be taken.

  Here, the increment bending device means a hydraulic device that applies a force to the work roll chock in the direction of decreasing the roll opening degree at the central portion of the plate width, and is a general term for devices including a hydraulic cylinder that is an actuator thereof. . 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. Further, in this specification, a force applied to the work roll by the increment bending apparatus is referred to as an increment bending force.

  In addition, in the rolling mill shown in FIG. 1, 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, but a large roll opening degree is obtained. As a rolling mill type that can be taken, there is also a conventional type in which the reinforcing roll chock 4-1 and 4-2 hold the work roll chock 3-1 and 3-2 in both the upper and lower sides.

  However, the typical thick plate rolling mill as shown in FIG. 1 has a problem that a strong roll bending force cannot be applied because it is necessary to increase the roll opening as described above. is there. This is because the arm portion connected to the upper reinforcing roll chock 4-1 whose vertical position is set and controlled by the reduction device 11 holds the upper work roll chock 3-1, so that the increase bending device 6- 1 and 6-2 need to be incorporated, but the arm portion is structurally limited in size, so that it is difficult to incorporate a large capacity hydraulic cylinder as an increment bending device.

  For example, a work roll bending apparatus having a capacity exceeding ± 150 tf / check has been put into practical use even in a hot strip mill finish rolling mill having a work roll diameter of about 800 mm. On the other hand, only a work roll bending apparatus with a work roll diameter of about ± 120 tf / check has been put to practical use in a thick plate mill with a work roll diameter of about 1000 mm.

  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, even if a roll bending apparatus capable of applying an equivalent bending force is provided, the roll bending effect of the thick plate rolling mill having a work roll diameter of 1000 mm is approximately the same as that of a hot strip mill finish rolling mill having a work roll diameter of 800 mm. 60% will be inferior.

  As a result, in the work roll bending mechanism of the conventional thick plate rolling machine, as shown in Non-Patent Document 1, the controllable mechanical plate crown has several tens of microns for narrow materials and several hundreds for wide materials. Stays in micron. It can be seen that this is insufficient compared to the required amount of mechanical plate crown control shown in Non-Patent Document 2.

  Here, in the plate crown and shape control described in Patent Documents 1 to 5, the plate crown and shape (flatness or steepness) of the rolled plate material are controlled by changing the bending force of the work roll. However, in the conventional plate rolling mill, it is necessary to change the sheet crown, etc. of the rolled sheet material by a target amount because it cannot give a strong roll bending force as described above. May not be able to act on the work roll. Therefore, the method for controlling the sheet crown and shape described in Patent Documents 1 to 5 may be used in a thin plate rolling machine such as a hot strip mill, but is not practical in a thick plate rolling machine. .

  For this reason, in order to perform plate crown and shape control in a thick plate rolling mill, generally, a rolling mill having a roll cross function and a roll shift function has been put into practical use and mainly used. However, it is difficult to quickly change the settings of the roll cloth function and the roll shift function during rolling. Therefore, since it is impossible to remove the disturbance factor during rolling, it must be said that the shape control end is incomplete.

  Moreover, since the work rolls 1-1 and 1-2 shown in FIG. 1 are more easily worn out than the reinforcing rolls by rolling operation, 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 cannot employ a servo valve for high response hydraulic control. Further, since the reinforcing roll chock 4-1 and 4-2 move relative to the rolling mill housing 9, the increment bending apparatuses 6-1 and 6-2 incorporated in the reinforcing roll chock 4-1 and 4-2, The hydraulic piping to 6-3 and 6-4 needs to be detachable piping (flexible piping or the like) having a flexible structure between the reinforcing roll chock 4-1 and 4-2 and the rolling mill housing 9. Become. However, if flexible piping is employed, the flexible structure may absorb and relieve fluctuations in hydraulic pressure, resulting in a decrease in responsiveness of the increment bending apparatus. Therefore, it is difficult to improve the responsiveness of the increment bending apparatus.

  Here, for example, in the plate crown / shape control described in Patent Documents 3 to 5, it is also proposed to change the bending force of the work roll bending apparatus during rolling of the plate material. As described above, when the bending force feedback control is performed based on some actual measurement value during the rolling of the plate material, if the response of the increment bending apparatus is low, the bending force is rapidly changed so as to follow the change in the actual measurement value. As a result, the disturbance factor during rolling cannot be removed, and the sheet crown and shape of the sheet after rolling may change in the rolling progress direction.

  In addition, as a hot strip mill finish rolling mill, for example, a rolling mill as shown in FIG. 2 is also known (for example, Patent Document 7). In this rolling mill, the increment bending apparatuses 6-1 and 6-2 are incorporated in project blocks 5-1 and 5-2 connected to the rolling mill housing 9. 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.

  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.

  Therefore, in view of the above problems, the object of the present invention is to appropriately control the plate crown or shape by a bending device in a thick plate rolling machine or a thin plate hot rolling rough rolling mill that requires a large roll opening degree. It is to provide a rolling mill and a rolling method.

In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, shifted the project block protruding inward from the housing to the lower side with respect to the pass line, and moved up and down with respect to the pass line. It has been found that the installation can be made asymmetrical to enable the following.
(A) A structure in which the rolling direction force applied to the upper work roll chock is always received by the housing. Thereby, a work roll chock can be supported stably.
(B) An upper and lower increase 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) In addition, the hydraulic piping can be fixed and the servo valve can be applied by incorporating the increment bending device into the project block. As a result, it is possible to control a highly responsive increase bending force.

Moreover, it discovered that the invention on these apparatuses enabled the following rolling mill operating methods.
(D) Even in the case of a decrease bending device with low responsiveness, it is possible to control the bending force with high response by cooperating with the incremental bending device with high responsiveness. This greatly improves product quality and rolling yield.

This invention was made | formed based on the said knowledge, and the summary is as follows.
(1) A metal plate rolling machine having a pair of upper and lower work rolls and a pair of upper and lower reinforcement rolls that respectively support them, and a hydraulic cylinder that applies a bending force to at least one of the upper and lower work rolls, Rolling direction force that is arranged on the project block protruding inside the rolling mill housing and is loaded on the lower work roll body is supported by the contact surface between the project block and the lower work roll chock, and is loaded on the upper work roll body. In the rolling method of a metal plate by a rolling mill in which a rolling direction force is supported by a contact surface between a rolling mill housing window and an upper work roll chock located above the project block, Calculate the bending force to be the target value, and the calculated bending There controlling the hydraulic cylinders to be granted, rolling method of metal plate.
(2) When calculating the bending force, the calculation is performed by substituting the measured value or estimated value of the rolling load into a model formula representing the relationship between the rolling load, the bending force, and the sheet crown on the rolling pass exit side. The method for rolling a metal plate according to (1), wherein the bending force is calculated so that a plate crown on a rolling pass exit side has a target value.
(3) The plate crown on the rolling pass exit side is measured by the plate crown measuring device, and the above model formula is corrected so that the error between the measured value and the estimated value of the plate crown on the rolling pass exit side is reduced. The rolling method of the metal plate as described in 2).

(4) The above model formula is a model formula that expresses the relationship between the rolling load, bending force, and exit side plate crown in a certain rolling pass, and the rolling pass entry side plate crown. The method for rolling a metal plate according to (2) or (3), wherein an actual measured value or an estimated value of the sheet crown on the rolling pass entry side is substituted into the model formula.
(5) When calculating the bending force, the bending force is calculated based on the difference between the measured value of the sheet crown on the rolling pass exit side and the target value, and the measured value of the sheet crown on the exit side of the rolling pass. The method for rolling a metal plate according to (1), which is calculated so as to coincide with a target value.

(6) The method for rolling a metal plate according to any one of (1) to (5), wherein a target value of the sheet crown on the rolling pass exit side is a predetermined constant value during the rolling pass.
(7) The target value of the sheet crown on the rolling pass exit side is set so that the difference between the crown ratio on the rolling pass entry side and the crown ratio on the rolling pass exit side is constant (1) to (5) The rolling method of the metal plate as described in any one of).
(8) The flatness on the rolling pass exit side is measured by the flatness measuring device, and the above model formula is set so that the difference is reduced based on the difference between the measured value of the flatness and the calculated value of flatness. The method for rolling a metal plate according to (7), which is corrected.

(9) A metal plate rolling machine 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 a hydraulic cylinder that applies a bending force to at least one of the upper and lower work rolls, Rolling direction force that is arranged on the project block protruding inside the rolling mill housing and is loaded on the lower work roll body is supported by the contact surface between the project block and the lower work roll chock, and is loaded on the upper work roll body. In the rolling method of the metal plate by the rolling mill supported by the contact surface between the rolling mill housing window located above the project block and the upper work roll chock, the flatness on the rolling pass exit side is Calculate the bending force to be the target value, and the calculated bending force is Controlling the hydraulic cylinders to be given, rolling method.
(10) The rolling method according to any one of (1) to (9), wherein the roll opening degree during rolling of the rolled sheet material is changed so that the thickness of one rolled sheet material changes in the rolling direction. .
(11) A metal plate manufactured by the rolling method according to (10), wherein the plate thickness changes in the longitudinal direction.

(12) The metal plate according to (11), wherein the crown variation is 100 μm or less over the entire length.
(13) The metal plate according to (11) or (12), wherein the steepness is within 1.0% over the entire length.
(14) In a metal plate rolling mill having a pair of upper and lower work rolls and a pair of upper and lower reinforcement rolls that respectively support the work rolls, hydraulic cylinders that respectively apply bending force to the upper and lower work rolls are provided inside the rolling mill housing. The rolling direction force provided on the project block projecting and loaded on the lower work roll body is supported by the contact surface between the project block and the lower work roll chock, and the rolling direction force loaded on the upper work roll body is An arithmetic unit for calculating a bending force that is supported by a contact surface between the rolling mill housing window located above the project block and the upper work roll chock and that has a plate crown on the rolling pass exit side as a target value; The hydraulic cylinder is controlled so that the calculated bending force is applied. Comprising a hydraulic cylinder control device for rolling mill of the metal plate.

  According to the present invention, a plate crown or shape can be appropriately controlled by a bending apparatus in a thick plate mill that requires a large roll opening.

It is a figure which shows the example of the rolling mill of a prior art. It is a figure which shows the example of the rolling mill of a prior art. 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 flowchart which shows roughly the control means of the rolling method in 1st embodiment. It is a flowchart which shows roughly the control means of the rolling method in 2nd embodiment. It is a flowchart which shows roughly the control means of the rolling method in 3rd embodiment. It is a flowchart which shows roughly the control means of the rolling method in 4th embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are assigned to similar components. First, the structure of the rolling mill according to the present invention will be described with reference to FIGS.

  FIG. 3 is a side view showing an example of the structure of the rolling mill according to the present invention. As shown in FIG. 3, the 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.

  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. Lower increase bending devices 6-3 and 6-4 are provided. These upper increment bending apparatuses 6-1 and 6-2 and the lower increase bending apparatuses 6-3 and 6-4 are provided in project blocks 5-1 and 5-2 protruding inside the rolling mill housing 9.

  This is the same as the conventional rolling mill shown in FIG. However, the rolling mill according to the present invention has undergone a fundamental review to solve 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. 2 cannot take a large roll opening. 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 decreases. 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. As shown in FIG. 3, 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. 2, the project blocks 5-1 and 5-2 are arranged so as to be vertically asymmetric with respect to the pass line. Further, the upper work roll chock 3-1 is configured not to support the rolling force by contact with the project block 3-1, but to support the rolling force by contact with the housing window.

  Thereby, in the rolling mill which concerns on this invention, rolling of offset component force etc. which act on the upper work roll 1-1 with the contact surface of the upper work roll chock 3-1 and the housing window 12 above the project block 5-2 is carried out. The directional force, that is, the rolling direction force applied to the body portion of the upper work roll 1-1 from the material to be rolled 10, the upper reinforcing roll 2-1 or the like is supported.

  With such a structure, even if the roll opening degree is increased by operating the rolling device 11 of the rolling mill, the area where the upper work roll chock 3-1 and the housing window are in contact 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.

  As shown in FIG. 2, a rolling mill in which upper and lower increase bending apparatuses are arranged in a project block is well known. However, the rolling mill according to the present invention performs 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, Since the applied rolling direction force is supported by the contact surface between the upper work roll chock 3-1 and the housing window 12 above the project block 5-2, 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 supported by the contact surface between the lower work roll chock 3-2 and the project block 5-2. For this reason, the rolling mill according to the present invention shown in FIG. 1 increases the 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.

  FIG. 4 is 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 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. 4, the upper increment bending apparatuses 6-1 and 6-2 and the lower increase bending apparatuses 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. 4, each of the lower increment bending apparatuses 6-3 and 6-4 has two hydraulic cylinders on the entry side and the exit 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. 5 is also 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. As shown in FIG. 5, the upper increment bending apparatuses 6-1 and 6-2 and the lower increase 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.

  According to the rolling mill of the present invention, since the roll opening can be increased, a thick plate mill (a metal plate having a thickness of 3 mm or more) that is required to greatly change the roll opening in one rolling mill. It is possible to perform appropriate rolling in a rolling mill), particularly a reverse rolling mill.

  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 application of strong roll bending force and improvement of responsiveness, which are other problems to be solved.

  FIG. 1 shows a rolling mill according to the prior art, and this rolling mill can take a large roll opening.

  However, this conventional rolling mill cannot give a strong roll bending force. That is, the upper increase bending apparatuses 6-1 and 6-2 are incorporated in the arm portion that protrudes downward from the upper reinforcing roll chock 4-1. However, a sufficient installation space for the upper increment bending apparatus cannot be obtained in this arm portion. For this reason, it is not possible to provide the large increment bending apparatus 6-1 and 6-2 with a large capacity and a large stroke. Therefore, the conventional rolling mill of FIG. could not.

  Moreover, in this rolling mill, when providing an upper decrease bending apparatus, for example, an upper decrease bending apparatus will be arrange | positioned in the position facing the arm part of the upper reinforcement roll chock 4-1. Therefore, the installation space for the upper decrease bending apparatus is close to the axis of the roll. For this reason, since it interferes with the bearing of the upper reinforcing roll, it is not possible to deploy the upper decrease bending apparatuses 7-1 and 7-2 having a large capacity and a large stroke. For this reason, in the conventional rolling mill of FIG. 1, a strong decrease bending force could not be applied.

  The decrease bending apparatus means a hydraulic apparatus that applies a force in the direction of increasing the roll opening degree at the central portion of the plate width to the work roll chock, and is a general term for apparatuses including a hydraulic cylinder that is an actuator thereof. However, in this specification, in order to simplify the explanation, the decrease bending device refers to a hydraulic cylinder as an actuator thereof unless otherwise specified. Moreover, in this specification, the force loaded on a work roll by a decrease bending apparatus is called a decrease bending force.

  Further, in this specification, unless otherwise specified, both the increment bending device and the decrease bending device are collectively referred to as a bending device, and the resultant force of the increment bending force and the decrease bending force is the bending force (ink The lease bending power is positive). For example, if the increase bending force is 100 tons and the decrease bending force is 20 tons, the bending force is 80 tons.

  On the other hand, as shown in FIG. 3, in the rolling mill according to the present invention, the upper increment bending apparatuses 6-1 and 6- 2 is deployed. Therefore, it is possible to secure a sufficient installation space for the upper increase bending devices 6-1 and 6-2. As the upper increase bending devices 6-1 and 6-2, a large capacity and large stroke hydraulic cylinder is used. Can be used. As a result, it is possible to apply a large decrease bending force to the upper work roll 1-1.

  Moreover, in the rolling mill which concerns on this invention, it is not necessary to arrange | position an upper decrease bending apparatus in the position facing the arm part of the upper reinforcement roll chock 4-1. For this reason, the installation space of the upper decrease bending device does not interfere with the bearing of the upper reinforcement roll, and therefore, a large capacity, large stroke hydraulic cylinder is used as the upper decrease bending device 7-1, 7-2. it can. 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 is According to the rolling mill according to the present invention configured to be supported by the contact surface between the upper work roll chock 3-1 and the housing window 12, a large roll opening degree can be obtained and a strong roll bending force can be applied. You can also.

  Moreover, in the conventional rolling mill of FIG. 1, the hydraulic piping of the increment bending apparatus must be attached and detached when the work rolls 1-1 and 1-2 are rearranged. For this reason, there is a high possibility that minute foreign matter will be mixed in the hydraulic pipe when the pipe is attached or detached. Since the servo valve capable of performing high response hydraulic control is likely to break down due to the mixing of minute foreign matter, the serve valve cannot be employed in the rolling mill of FIG.

  Further, the reinforcing roll chock 4-1 in which the increment bending apparatuses 6-1 and 6-2 are incorporated moves relative to the housing 9. For this reason, detachable piping having a flexible structure is required for the hydraulic piping between the increment bending apparatuses 6-1 and 6-2 and the reinforcing roll chock 4-1. However, if a pipe having a flexible structure such as a flexible pipe is employed, the hydraulic structure may be absorbed and relaxed due to the flexible structure, and as a result, the responsiveness of the increment bending apparatus is lowered.

  On the other hand, as shown in FIG. 3, in the rolling mill according to the present invention, the increment bending apparatuses 6-1 and 6-2 are formed integrally with the housing 9 instead of the reinforcing roll chocks 4-1 and 4-2. Provided in the project blocks 5-1 and 5-2. For this reason, it is not necessary to attach or detach the hydraulic piping of the increment bending apparatus every time the work roll is reassembled, and as a result, a servo valve for high response hydraulic control can be used. Further, it is not necessary to use a pipe having a flexible structure for the hydraulic pipe communicating with the increment bending apparatus 6-1, 6-2. Therefore, in the rolling mill according to the present invention, the responsiveness of the increment bending apparatus can be increased.

Next, a rolling method according to the present invention, particularly a method for controlling the bending apparatus will be described.
First, model equations used in this control method will be described. Generally, the change of the sheet crown before and after each rolling pass is represented by the following formula (1).

Here, H is the plate thickness (incoming plate thickness) of the rolled plate on the rolling pass entry side, h is the plate thickness (exit side plate thickness) of the rolled plate on the rolling pass exit side, and C _H is the rolling pass entry. The plate crown (entrance side plate crown) of the plate material to be rolled on the side, _Ch denotes the plate crown (outside plate crown) of the plate material to be rolled on the exit side of the rolling pass. Further, c ₁ is a correction term, and usually, 0 is often given to c ₁ . In the following description, it is assumed that the correction term c ₁ is zero, but the present invention can also be applied when the correction term c ₁ is other than zero. The entry side plate thickness H and the exit side plate thickness h can be grasped relatively accurately by actual measurement or by estimation using a gauge meter formula based on the roll opening degree, rolling load, and mill rigidity. For this reason, in the present invention, these are treated as known values.

In the above formula (1), η represents a crown ratio genetic coefficient. Here, the crown ratio genetic coefficient is a rolling pass when all other rolling conditions remain the same and only the crown ratio (entrance side plate crown ratio) C _H / H on the rolling pass entry side changes by δC _H / H. It means an influence coefficient on the crown ratio (exit-side plate crown ratio) C _h / h on the exit side. Therefore, when the change amount of the exit side plate crown generated in this case is δC _h , the following equation (2) is established.

  In this way, the exit side plate crown ratio is affected by the entrance side plate crown ratio. A change in the entrance side plate crown causes a slight difference in the distribution in the plate width direction of the drawing in the rolling pass. This can be explained by the mechanism that the distribution of the tension in the width direction changes. Here, although the crown ratio genetic coefficient takes different values for different rolling conditions, it hardly changes during the rolling pass unless the rolling conditions change significantly.

Also, C _M in the formula (1) shows the mechanical strip crown. The mechanical plate crown is a plate crown determined from the elastic deformation of the rolling mill, and the upper and lower work rolls determined from the deformation of the rolling mill when the width direction distribution of the rolling load acting between the rolled material and the work roll is uniform. The gap distribution between them, that is, the plate thickness distribution, is expressed by the difference between the plate thickness at the plate width center and the plate thickness at an arbitrary position in the width direction, that is, the plate crown. Alternatively, the mechanical plate crown can be used to calculate the gap distribution between the upper and lower work rolls determined by deformation of the rolling mill when the elongation strain acting on the rolled plate material is uniform in the plate width direction, that is, the plate thickness distribution. In some cases, a difference between the thickness and the plate thickness at an arbitrary position in the width direction, that is, a plate crown is used. For example, as disclosed in Japanese Examined Patent Publication No. 3-72364, the mechanical plate crown has rolling conditions including a roll size and a roll profile of the rolling mill, a plate width of the rolled material, an inlet / outlet plate thickness, and a rolling load. If the set value of the crown shape control device is given, it is a physical quantity that is theoretically and accurately obtained by calculating the elastic deformation of the rolling mill.

ここで、ｃ_P、ｃ_Fはそれぞれ、圧延荷重、ベンディング力がメカニカル板クラウンに及ぼす影響係数であり、ミルディメンジョンや圧延条件に依存する値であるが、圧延パス中はほぼ一定の値となる。ｃ₀はロールプロフィルの影響項であり、長期的に見ると熱膨張や摩耗によって変化するが、一本の被圧延板材を圧延している途中ではそれほど大きくは変化しないと考えられる。なお、本明細書では、メカニカル板クラウンを減少させる方向（板幅中央部の上下ロール間隙を減少させる方向）のベンディング力を正と定義して説明する。つまり、インクリースベンディング力の増加はベンディング力の増大を意味し、ディクリースベンディング力の増大はベンディング力の減少を意味する。 In general, it is known that the mechanical plate crown C _M is given by the following equation (3), where P is the rolling load and F is the roll bending force.

Here, c _P and c _F are influence coefficients that the rolling load and bending force exert on the mechanical plate crown, respectively, and are values that depend on the mill dimension and rolling conditions, but are substantially constant during the rolling pass. . c ₀ is an influence term of the roll profile, and changes due to thermal expansion and wear in the long term, but it is considered that it does not change so much in the middle of rolling a single plate. In the present specification, the bending force in the direction in which the mechanical plate crown is reduced (the direction in which the upper and lower roll gaps in the central portion of the plate width are reduced) is defined as positive. That is, an increase in the increment bending force means an increase in the bending force, and an increase in the decrease bending force means a decrease in the bending force.

ここで、ξは、形状変化係数であり、該圧延パスでのクラウン比率変化が伸びひずみ差となって表われる度合いを示すパラメータである。一般に、板厚が薄く、板幅が広くなるほど、形状変化係数は大きくなる。また、ｃ₂は補正項であり、通常、ｃ₂にはゼロを与えることが多い。以下の説明では、補正項ｃ₂はゼロであるものとして説明するが、補正項ｃ₂がゼロ以外の場合においても本発明を適用することができる。 Further, it is considered that an elongation strain difference Δε is generated due to a difference between a crown ratio at a certain rolling pass entry side and a sheet crown ratio at the rolling pass exit side, which is expressed by the following formula (4). .

Here, ξ is a shape change coefficient, and is a parameter indicating the degree to which the crown ratio change in the rolling pass appears as an elongation strain difference. In general, the thinner the plate thickness and the wider the plate width, the larger the shape change coefficient. Further, c ₂ is a correction term, and usually, 0 is often given to c ₂ . In the following description, it is assumed that the correction term c ₂ is zero. However, the present invention can be applied even when the correction term c ₂ is other than zero.

The elongation strain difference Δε is often related to the steepness λ used when quantifying the flatness of the plate by the following equation (5). In this specification, description will be made using steepness as an index representing flatness. Therefore, the “steepness” of the rolled sheet material used in the present specification also effectively represents the “flatness” of the rolled sheet material.

Next, the rolling method according to the present invention using the above model formula will be specifically described.
First, the rolling method of the first embodiment will be described. In the first embodiment, the estimated value of the side plate crown C _h out in the rolling path of interest to control the bending force to be constant target delivery side crown C _ht performed.

Here, in the above formulas (1) and (3), it is considered that the crown ratio genetic coefficient η, the entry side plate thickness H, the exit side plate thickness h, and the shape change coefficient ξ are constant during the rolling pass. Thus, delivery side crown C _h is entrance side crown C _H, rolling load P, and varies depending on the bending force F.

Note that entry side crown C _H of the rolled sheet material to be introduced into the rolling path, based on the rolling conditions in the rolling pass previous rolling pass, before actually performing the rolling in the rolling passes, for example, the formula ( 1) and the like can be estimated in advance. Here, it is known that the entrance plate crown in the first pass may be set to zero or an appropriate value. Therefore, when the estimated value C _He of the entry side plate crown is substituted into the equations (1) and (3), and the target value _Cht of the exit side plate crown is further substituted to arrange the bending force F, the exit side plate is obtained in the rolling pass. The bending force F for setting the crown to the target value _Cht is a function of the entrance plate crown _CHe and the rolling load P as shown in the following formula (6).

Therefore, in the present embodiment, the bending force F is calculated by substituting the estimated value C _He and the rolling load P of the entry side plate crown at each point in the rolling direction of the rolled material into the above formula (6), and the calculated bending force is calculated. The bending apparatus is controlled to load F. Here, as the rolling load P, an estimated value based on the rolling condition of the rolling pass may be used, or an actually measured value detected by the load cell 16 incorporated in the reduction device 11 may be used.

That, in the first embodiment, calculated by substituting the measured values or estimated values of the rolling load to a model expression representing the relationship between the side plate crown C _h out with rolling load P and the bending force F (1) and (3) estimated value of the delivery side crown C _h is calculates the bending force F such that the target value C _ht, it can be said that the calculated bending force F is controlled bending device so as to impart. More specifically, in the first embodiment, actual measurement of the rolling force model expression representing the relationship between the side plate crown C _h out with rolling load P and the bending force F and entry side crown C _H (1) and (3) calculating a bending force such that the estimated value of the delivery side crown C _h is calculated by substituting the value or estimated value becomes the target value C _ht, controls the bending device so the calculated bending force is applied It can be said that.

  FIG. 6 is a flowchart schematically showing a control procedure of the rolling method in the first embodiment. Step S11 in FIG. 6 is performed as a setup before starting rolling in the target rolling pass, and steps S12 to S17 are performed during the actual rolling process (during the rolling of one material to be rolled, or before and after the rolling of each rolled material. ) Is repeated.

  First, in step S11, the crown ratio genetic coefficient η, the entry side plate thickness H, the exit side plate thickness h, and the shape change coefficient ξ are calculated based on the rolling conditions in the relevant rolling pass.

Next, in step S12, the entry side plate crown C _{He at} the control target position of the rolled material is estimated based on the rolling record before the rolling pass, etc. (this estimated value is set as C _He ). In step S13, a target value _{Cht for the} outlet plate crown is set. In step S12 and step S13, it is also possible to calculate and set the target values _Cht of the entry side plate crown _CHe and the exit side plate crown in advance before starting rolling of the pass. In step S14, the rolling load is estimated or measured in synchronism with the timing at which the control target position of the rolled material is rolled, and in step S15, the actually measured value or estimated value of the obtained rolling load is substituted into equation (6). As a result, the bending force F is calculated. In step S16, the bending apparatus is controlled based on the bending force F calculated in step S15. Next, in step S17, it is determined whether or not the rolling process has been completed. If the rolling process has not been completed, steps S12 to S17 are repeated.

In the above embodiment, the entry-side plate crown _CH is estimated based on the rolling record in the rolling pass before the rolling pass. However, placing a measurable entrance side crown measuring device entry side crown C _H on the upstream side of the rolling passes, it may be actually measured at entrance side crown C _H This entry side crown measuring device.

Moreover, in the said embodiment, the target value _Cht of the exit side plate crown which becomes constant in the rolling pass of one to-be-rolled sheet material is set, and bending force is set so that the estimated value of the exit side plate crown becomes the target value _Cht. Is controlled. The target value _Cht of the outgoing plate crown can be set to various values. For example, the target flatness (specifically, the steepness used for quantifying the flatness of the rolled plate on the outgoing side of the rolling pass). It may be set based on a target value of degree λ.

Here, the elongation strain difference Δε is calculated by the equation (4), and the steepness λ is calculated by the equation (5) using the elongation strain difference Δε. In order to increase the flatness, it is necessary to bring the steepness λ and the elongation strain difference Δε close to zero (or a desired value), that is, the right side of the equation (4) needs to be close to zero. Therefore, the target value _Cht of the exit side plate crown may be a value calculated by the following equation (7) so that the steepness λ and the elongation strain difference Δε become substantially zero, for example. Alternatively, the target value _Cht of the outlet plate crown may be a value calculated based on the equations (4) and (5) so that the steepness λ and the elongation strain difference Δε become desired constant values. In other words, the target value C _ht of delivery side crown may be set to be constant values or desired such that the difference between the inlet side crown ratio and the exit-side crown ratio becomes substantially zero.

  In any case, from such a viewpoint, in the first embodiment, the bending force is calculated such that the estimated value of the sheet crown on the rolling pass exit side becomes the target value, and the calculated bending force is applied. Thus, it can be said that the bending apparatus is controlled.

Next, as a second embodiment, on the basis of a state in which a bending force F ₀ that can realize the target value C _ht of the exit plate crown is set with respect to the estimated value P ₀ of the rolling load acting in the rolling pass, as a reference. Consider the case where the bending force is corrected according to the estimated error of the rolling load. At this time, in the rolling pass before the rolling pass, if the exit side plate crown is controlled to coincide with a predetermined target value constant in the rolling direction, the rolling pass entrance side plate crown is constant in the rolling direction. Therefore, it is considered that the estimated value C _He of the entry side plate crown at each point in the rolling direction of the rolled material is a constant value. First, the rolling load in the rolling pass to be controlled can be predicted before starting the actual rolling based on the rolling conditions. Therefore, the predicted value of such rolling load (estimated value) and P _0, the estimated value of the side plate crown C _h out when rolling load corresponding to the predicted value P ₀ is loaded becomes the target value C _ht a such a bending force and F _0. Here, even if the rolling load P during actual rolling deviates by δP (= P−P ₀ ) with respect to the predicted value P ₀ of the rolling load, the exit side plate crown is maintained at the target value C _ht. Therefore, it is necessary to manipulate the bending force according to the rolling load deviation amount δP. Considering the above formulas (1) and (3), the operation amount δF with respect to the bending force reference value F ₀ needs to be set so that the mechanical plate crown C _M becomes constant. It is expressed as the following formula (8).

Therefore, instead of calculating the bending force F to be applied to the bending apparatus based on the equation (6) as shown in the above embodiment, the rolling load predicted value P ₀ and the corresponding bending force reference value are preliminarily calculated. F ₀ may be calculated, and the operation amount δF with respect to the bending force reference value F ₀ may be changed according to the deviation amount δP with respect to the predicted value P ₀ of the rolling load.
FIG. 7 is a flowchart schematically showing a control procedure of the rolling method in the second embodiment. Steps S21 to S24 in FIG. 7 are performed as a setup prior to the start of rolling in the target rolling pass, and steps S25 to S29 are performed during the actual rolling process (during the rolling of one material to be rolled, or for each rolling material. Repeatedly before and after rolling.

First, in step S21, a crown ratio genetic coefficient η, an entry side plate thickness H, an exit side plate thickness h, and a shape change coefficient ξ are calculated based on the rolling conditions in the rolling pass for the target rolling pass, and the rolling A rolling load prediction value P ₀ is calculated based on the rolling reduction (= (H−h) / H) in the pass. Further, in step S22, estimation of the C _H of entry side crown (and C _{the He} this estimate) is performed based on the rolling pass before rolling past records. Next, in step S23, a target value _{Cht for the} outlet plate crown is set. Furthermore, in step S24, the crown ratio genetic coefficient η calculated and set in steps S21 to S23, the entry side plate thickness H, the exit side plate thickness h, the shape change coefficient ξ, the rolling load prediction value P ₀ , and the entry side plate crown estimation. The reference value F ₀ of the bending force is calculated by substituting the value C _He and the target value C _ht of the outlet plate crown into the above equation (6).

Thus, after the calculation of the bending force reference value F ₀ is completed, rolling of the plate material to be rolled is started. At step S25 after the start of rolling, the rolling load P is detected by the load cell 16 mounted on rolling device 11, then, in step S26, the deviation amount between the predicted value P ₀ of the rolling load and the measured value P _m of the rolling force δP (= P _m −P ₀ ) is calculated. Next, in step S27, the amount of deviation δP calculated in step S26 is substituted into equation (8), thereby calculating the bending force operation amount δF with respect to the reference value F ₀ . In step S28, the bending apparatus is controlled based on the bending force operation amount δF calculated in step S27. Next, in step S29, it is determined whether or not the rolling process is finished. If the rolling process is not finished, steps S25 to S29 are repeated.

As described previously, so that the the entry side crown C _H on the upstream side of the rolling pass is arranged measurable entrance side crown measuring device, actually measuring the entry side crown C _H This entry side crown measuring device It may be. In addition, the target value _Cht of the exit side plate crown is set based on the target flatness of the plate material to be rolled on the exit side of the rolling pass (specifically, the target value of the steepness λ used when quantifying the flatness). May be. Alternatively, the target value _Cht of the outlet plate crown may be a value calculated based on the equations (4) and (5) so that the steepness λ and the elongation strain difference Δε become desired constant values.

  In any case, from this point of view, also in the second embodiment, the bending force is calculated so that the estimated value of the sheet crown on the rolling pass exit side becomes the target value, and the calculated bending force is applied. It can be said that the bending device is controlled.

Next, the rolling method of 3rd embodiment is demonstrated. In the third embodiment, actual measurement values of the measured delivery side crown C _h by the side plate crown measuring device exits the rolling path of interest Control of bending force so that the target value C _ht is performed.

Thus, if it is measurable by the side plate crown measuring device exits the delivery side crown C _h, when the measured value C _hm of delivery side crown is substantially equal to the target value C _ht is operating the bending force do not have to. On the other hand, if the measured value C _hm of delivery side crown is greater than its target value C _ht, it is necessary to increase the bending force to close the delivery side crown to the target value C _ht. Conversely, when the actual value _Chm of the exit side plate crown is smaller than the target value _Cht , it is necessary to reduce the bending force so that the exit side plate crown approaches the target value.

Further, the bending force δF required to change the outlet plate crown by δC _h can be expressed by the following equation (9) from the relationship between _Ch and F in equations (1) and (3).

Accordingly, in the present embodiment, the difference δC _h (= C _ht −C _hm ) between the actual value C _hm of the exit side plate crown measured by the exit side plate crown measuring device and the target value C _ht is calculated and calculated. The bending force is operated by δF calculated by substituting the difference δC _h into the above equation (9). In other words, in the present embodiment, the difference δC _h between the actually measured value C _hm of the outlet plate crown and the target value C _ht is calculated, and bending is performed so that the calculated difference δC _h becomes small or becomes zero. It can be said that it is manipulating force.

  FIG. 8 is a flowchart schematically showing a control procedure of the rolling method in the third embodiment. All steps S31 to S36 in FIG. 8 are repeatedly performed during the actual rolling process (during rolling of one material to be rolled, or before and after rolling of each rolled material).

First, in step S31, the target value _Cht of the exit side plate crown is set for the target rolling pass. Further, in step S32, the measurement of the side plate crown out by the side plate crown measuring device out C _h is (a C _hm the measured value) to be performed. Next, in step S33, a difference δC _h between the actual value C _hm of the outlet plate crown and the target value C _ht is calculated. Next, in step S34, by substituting the difference .delta.C _h in the equation (9), bending amount of the operation amount δF is calculated. In step S35, the bending apparatus is controlled based on the bending force operation amount δF calculated in step S34.

In the third embodiment, the bending force is controlled so that the actually measured value C _hm of the outlet plate crown becomes the target value C _ht , but the steepness λ is measured as a modification of the third embodiment. The bending force may be controlled so that the steepness λ measured by the possible steepness measuring device becomes the target value λ _t (usually zero).

  That is, it has been found that there is a relationship between the plate shape represented by the steepness and the like and the bending force such that when the bending force is increased, the plate shape changes from the tendency to stretch to the middle. Therefore, when the bending force is increased, the steepness becomes a positive value. Conversely, when the bending force is decreased, the steepness becomes a negative value.

Therefore, in this modification, when the measured value λ _m of the steepness measured by the steepness measuring device is larger than the target value λ _t , the bending force F is increased and the measured value λ _{m of the} steepness is set to the target value. When it is smaller than the value λ _t , the bending force F is reduced. In other words, in this modification, the difference between the measured value of the output steepness (output flatness) and the target value is calculated, and the bending is performed so that the calculated difference becomes smaller or almost zero. It can be said that it is manipulating force.

  Next, the rolling method of 4th embodiment is demonstrated. In the fourth embodiment, the bending force is controlled based on the rolling method of the first embodiment, the actual exit plate crown is measured, and the model is based on the difference between the actually measured value and the estimated value of the exit plate crown. An error occurring in the equation is corrected.

The rolling method of the first embodiment described above, the estimated value of the delivery side crown C _h is the control of bending force so that the target value C _ht has been performed. However, there are cases where an error occurs between the case where error is present, the actual delivery side crown and the target value C _h between the measured non actual delivery side crown C _h and the estimated value Yes.

In this case, for example, in equation (1), the actual output side crown and its estimated value (note that the estimated value is taken into account that the bending force is controlled so that the estimated value of the output side plate crown becomes the target value. an error .delta.C _h between the also conceivable) target value are approximately the same, resulting due to estimation error .delta.C _M for estimation error .delta.C _H and / or mechanical strip crown C _M for entrance side crown C _H If considered, these relationships can be expressed as the following formula (10) by transforming the formula (1).

Here, only formula (10), unknown two (i.e., estimated error .delta.C _M estimated error .delta.C _H and a mechanical strip crown C _M of the entry side crown) for the presence of these from the error .delta.C _h of delivery side crown The unknown cannot be determined uniquely. Consider, however, for example, entry side crown C _H or zero and assuming a one of the estimation error of the mechanical strip crown (for example, when the can measured the entry side crown C _h an estimation error of the entry side crown zero These can be determined uniquely by using a learning method disclosed in Japanese Patent Application Laid-Open No. 59-215205. Alternatively, by measuring the steepness λ in side out rolling pass in addition to the delivery side crown C _h, to uniquely determine both the estimation error .delta.C _M estimated error .delta.C _H and a mechanical strip crown of the entry side crown Is also possible.

Therefore, in the present embodiment, as described above, the estimated error δC _H of the incoming plate crown and the estimated error δC _M of the mechanical plate crown are calculated based on the actual measured value C _hm of the outgoing plate crown measured by the outgoing plate crown measuring device. At the same time, the equations (1) and (3) are corrected based on the calculated estimated error δC _H of the entry side plate crown and the estimated error δC _M of the mechanical plate crown. Specifically, for example, a value obtained by adding the estimated error δC _H to the entry side plate crown C _H of the equation (1) or the equation (6) is set as a new entry side plate crown (C _H = C _H + δC _H ). A value obtained by adding the mechanical plate crown estimation error δC _M to the term c ₀ in (3) or Expression (6) is defined as a new c ₀ (c ₀ = c ₀ + δC _M ). As a result, the bending force can be controlled so that the outlet plate crown accurately matches the target value.

  Therefore, in the fourth embodiment, the output side plate crown is measured by the output side plate crown measuring device, and the difference is reduced or becomes zero based on the difference between the actual value and the estimated value of the output side plate crown. It can be said that the model formula is corrected.

  FIG. 9 is a flowchart schematically showing a control procedure of the rolling method in the fourth embodiment. Steps S41 to S48 in FIG. 9 are the same as steps S21 to S28 in FIG.

At step S49, the side plate crown C _h out by delivery side crown measuring device is measured. Next, in step S50, it is determined whether or not the rolling process has been completed in the same manner as in step S29 in FIG. 7. If the rolling process has not been completed, the process proceeds to step S51. In step S51, is the difference δC _h (= C _hm −C _ht ) between the actual value C _hm of the exit side plate crown measured in step S49 and the target value (estimated value) C _ht of the exit side plate crown substantially zero? It is determined whether or not. If it is determined that the difference δC _{h is} substantially zero, the process proceeds to step S45.

On the other hand, in step S51, if the difference δC _h between the actual value C _hm of the exit side plate crown measured in step S49 and the target value (estimated value) C _ht of the exit side plate crown is a value away from zero, step S52 is performed. Proceed to In step S52, in the way described above, the estimation error .delta.C _M and the estimated error .delta.C _H of entrance side crown mechanical strip crown is calculated. Thus the estimated error .delta.C _H of the estimation error .delta.C _M and entrance side crown of the calculated mechanical strip crown and the bending using the equation (6) at the time and step S44 of the estimation of the entry side crown C _{the He} in step S42 It is used when calculating the force reference value F ₀ . Specifically, for example, in step S42, the entry side plate crown C _H is set to a value obtained by adding the estimation error δC _H to the original entry side plate crown C _H , and in step S44, the term c ₀ in the equation (6) is the value of the term c ₀ and a value obtained by adding the estimated error .delta.C _M mechanical strip crown.

In this way, the process is repeated until it is determined in step S50 that the rolling has been completed. Even if it is determined that the rolling is finished at step S50, based on the estimation error of the delivery side crown calculates an estimation error .delta.C _M mechanical strip crown, be reflected in the setting calculation or the like in the subsequent rolling pass Good.

  Next, the rolling method of 5th embodiment is demonstrated. In the fifth embodiment, the bending force F is controlled so that the steepness becomes the target value based on the rolling method of the first embodiment, and the actual steepness is measured, An error occurring in the model formula is corrected based on the difference from the target value.

  As described above, in the rolling method of the first embodiment, the bending force is controlled so that the estimated value of the steepness λ becomes the target value, but the actual steepness λ is not measured. There may be a case where an error occurs between the actual steepness and its estimated value (target value).

In this case, if it is considered that the steepness estimation error δλ is caused by, for example, the estimation error δC _H of the entrance side plate crown and the estimation error of the exit side plate crown δC _h , from the relationship of Expressions (4) and (5) The following relationships (11) and (12) can be derived.

Here, unknowns are two (i.e., estimated error .delta.C _h estimated error .delta.C _H and delivery side crown entry side crown) for the presence, it is impossible to uniquely determine these unknowns from steepness of the error [delta] [lambda]. However, for example, the assuming either one of the estimation error of the entry side crown C _H or delivery side crown C _h to zero (e.g., the estimation error of the side plate crown out by measuring the plate crown C _h out zero By using a learning method disclosed in Japanese Patent Application Laid-Open No. 59-215205 after expressing both the entrance plate crown and the exit plate crown as a function of the mechanical plate crown, these are uniquely determined. It is possible to determine. Alternatively, by measuring the entry side crown C _H in addition to the steepness λ in the rolling path exit side, it is possible to make a two relational expressions for the two unknowns, thereby be determined uniquely unknown It becomes possible.

Therefore, in the present embodiment, as described above, the input side plate crown estimation error δC _H and the output side plate crown estimation error δC _h are calculated based on the output side steepness λ _m measured by the steepness measurement device. Equations (1) and (3) are corrected based on the calculated input plate crown estimation error δC _H and output plate crown estimation error δC _h . Specifically, for example, a value obtained by adding the estimated error .delta.C _H to entry side crown C _H of the formula (4) as a new entry side crown _{(C H = C H + δC} H), also Equation (4) a value obtained by adding the estimated error .delta.C _h the delivery side crown C _h a is the new _{C h (= C h + δC} h). As a result, the bending force can be controlled with the exit side plate crown as the target value so that the steepness λ in the equation (4) is zero.

  Therefore, in the fifth embodiment, the output steepness is measured by the steepness measuring device, and the difference is reduced or becomes zero based on the difference between the actual value and the estimated value of the output steepness. In this way, the model formula is corrected.

Next, the metal plank manufactured by the rolling method as described above will be described.
According to the rolling method as described above, with respect to the thick metal plate, the exit plate crown can be matched with the target value relatively accurately by appropriate control of the bending apparatus. For this reason, for example, it becomes possible to stably manufacture a thick metal plate having a crown variation of 100 μm or less over the entire length and a steepness of 1.0% or less over the entire length of the rolled material.

  Moreover, in the rolling method mentioned above, even if a rolling load changes a lot during rolling, the exit side plate crown can be matched with a predetermined target value relatively accurately. Thus, for example, a thick plate manufactured by changing the roll opening during rolling of the rolled plate so that the thickness of one rolled plate changes in the rolling direction, that is, the plate thickness changes in the rolling direction. For thick plates such as differential thick plates and LP thick plates, it is possible to match the exit side plate crown to the target value relatively accurately over the entire length in the rolling direction.

  The present invention can be used for rolling a thick metal plate, particularly a reverse rolling mill that requires a large opening. Moreover, it can utilize also for the rolling mill in the rough process of hot rolling.

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 11 screw down device 12 housing window

Claims (14)

A metal sheet rolling machine having a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls for supporting them,
A hydraulic cylinder that applies a bending force to at least one of the upper and lower work rolls is provided in a project block that protrudes inside the rolling mill housing,
The rolling direction force applied to the lower work roll body is supported by the contact surface between the project block and the lower work roll chock,
In the rolling method of the metal plate by the rolling mill supported by the contact surface between the rolling mill housing window located above the project block and the upper working roll chock, the rolling direction force loaded on the upper working roll body portion is as follows:
A rolling method for a metal plate, wherein a bending force is calculated such that a sheet crown on a rolling pass exit side has a target value, and the hydraulic cylinder is controlled so that the calculated bending force is applied.   When calculating the bending force, the rolling pass output calculated by substituting the measured value or estimated value of the rolling load into a model formula representing the relationship between the rolling load, bending force, and the sheet crown on the rolling pass output side. The method of rolling a metal plate according to claim 1, wherein the bending force is calculated so that the side plate crown has a target value.   3. The plate crown on the rolling pass exit side is measured by the plate crown measuring device, and the model equation is corrected so that an error between the actual value and the estimated value of the sheet crown on the rolling pass exit side is reduced. The rolling method of the metal plate as described.   The model formula is a model formula that expresses the relationship between the rolling load and bending force in a certain rolling pass and the sheet crown on the rolling pass entry side in addition to the rolling crown, and when calculating the bending force, The method for rolling a metal plate according to claim 2 or 3, wherein an actual measurement value or an estimated value of the sheet crown on the rolling pass entry side is substituted into the model formula.   When calculating the bending force, the bending force is calculated based on the difference between the actual value of the sheet crown on the rolling pass exit side and the target value. The method for rolling a metal plate according to claim 1, wherein the method is calculated so as to match.   The method for rolling a metal sheet according to any one of claims 1 to 5, wherein a target value of the sheet crown on the rolling pass exit side is a predetermined constant value during the rolling pass.   The target value of the sheet crown on the rolling pass exit side is set so that the difference between the crown ratio on the rolling pass entrance side and the crown ratio on the rolling pass exit side is constant. The method for rolling a metal plate according to Item.   The flatness on the rolling pass exit side is measured by a flatness measuring device, and the above model formula is corrected so as to reduce the difference based on the difference between the measured value of the flatness and the calculated value of flatness. The method for rolling a metal plate according to claim 7. A metal sheet rolling machine having a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls for supporting them,
A hydraulic cylinder that applies a bending force to at least one of the upper and lower work rolls is provided in a project block that protrudes inside the rolling mill housing,
The rolling direction force applied to the lower work roll body is supported by the contact surface between the project block and the lower work roll chock,
In the rolling method of the metal plate by the rolling mill supported by the contact surface between the rolling mill housing window located above the project block and the upper working roll chock, the rolling direction force loaded on the upper working roll body portion is as follows:
A rolling method in which a bending force is calculated such that the flatness on the exit side of the rolling pass is the target value, and the hydraulic cylinder is controlled so that the calculated bending force is applied.   The rolling method according to any one of claims 1 to 9, wherein a roll opening degree during rolling of the rolled sheet is changed so that a thickness of one rolled sheet changes in a rolling direction.   It is a metal plate manufactured by the rolling method of Claim 10, Comprising: Plate | board thickness is changing in the longitudinal direction.   The metal plate according to claim 11, wherein the crown variation is 100 μm or less over the entire length.   The metal plate according to claim 11 or 12, wherein the steepness is 1.0% or less over the entire length. In a metal plate rolling mill having a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls that respectively support them,
A hydraulic cylinder that applies a bending force to each of the upper and lower work rolls is provided in a project block protruding inside the rolling mill housing,
The rolling direction force applied to the lower work roll body is supported by the contact surface between the project block and the lower work roll chock,
The rolling direction force loaded on the upper work roll body is supported by the contact surface between the rolling mill housing window located above the project block and the upper work roll chock,
A calculation device for calculating a bending force such that a sheet crown on the rolling pass exit side has a target value; and a hydraulic cylinder control device for controlling the hydraulic cylinder so that the calculated bending force is applied. , Metal plate rolling machine.

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