JP5533754B2 - Tandem rolling equipment and hot rolling method for metal sheet - Google Patents

Description

  The present invention relates to a rolling mill for metal sheets, and relates to a rolling mill having high responsiveness and capable of imparting a strong roll bending force. In particular, a tandem rolling facility that can achieve a large maximum opening between the upper and lower work rolls, which is suitable for a thick plate mill or a thin plate hot rolling rough mill, and can easily achieve a strong roll bending force. And a rolling method using the same.

  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 (hereinafter referred to as “roll opening degree”). ")" Is required to be larger than the thickness of the rolled material, which imposes restrictions on the design of the rolling mill equipment in 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 disclosed in Patent Document 1 is a four-high rolling mill, and the rolling mill format is, for example, a structure shown in FIG. The rolling mill shown in FIG. 11 is provided with 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. The arm portion incorporates the upper entry bending device 6-1 on the upper work roll 1-1 and the upper increase bending device 6-2 on the outgoing side. By setting it as such a format, a big roll opening degree can be taken.

  In the rolling mill shown in FIGS. 7 and 11, the entry-side lower increment bending apparatus 6-3 and the exit-side lower increase bending apparatus 6-4 of the lower work roll 1-2 are incorporated in a project block connected to the rolling mill housing 9. It is. In addition to this, as shown in FIG. 8, the upper reinforcing roll chock 4-1 and the lower reinforcing roll chock 4-2 are respectively formed as upper rolling roll chock 3- 1 and a rolling mill that holds the lower work roll chock 3-2 exists.

  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.

  In Patent Document 2, for example, as shown in FIG. 9, a work roll entry upper increment bending apparatus 6-1 and an exit upper increment bending apparatus 6-2 are respectively provided with an upper work roll chock 3-1. A rolling mill for rolling a thin plate incorporated in the lower work roll chock 3-2 is disclosed.

  Patent Document 3 discloses a roll-cross type rolling mill. For example, as shown in FIG. 9, the rolling mill includes an upper work roll chock 3-1 and a lower work, respectively. It is incorporated in the roll chock 3-2.

  Patent Document 4 discloses, for example, a rolling mill for thin plate rolling having a work roll shift function as shown in FIG. In this rolling mill, the entry-side upper bending unit 6-1 and the delivery-side upper bending unit 6-2 are integrated with the rolling mill housing 9, and an entry-side project block 5-1 and an exit-side project block 5- 2 is incorporated.

  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 FIGS. 7 and 8 (see, for example, Patent Document 1). This is because the roll opening is large, so that even if a decrease bending device is installed, the control range is narrow and the mechanical structure is only complicated.

  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 the crown control of a wide range of thickness steel plates. 9 to 11 show a rolling mill having a decrease bending apparatus.

JP-A-6-87011 JP-A-62-220205 JP-A-6-198307 Japanese Patent Laid-Open No. 4-52014 International Publication WO 2004/082860 Specification International publication WO2009 / 057820 specification

  One way to increase the productivity of rolling is to use a tandem rolling mill. In finish rolling of hot rolling, tandem rolling equipment is often used.

  In finish rolling, since the plate thickness of the material to be rolled is thin, the rigidity of the material to be rolled is low. For this reason, the material to be rolled that has passed through the first rolling mill is easy to pass through according to the guidance of the guide or table, and is equipped with a sufficient plate crown / shape control device, so it is bitten by the second rolling mill. It is possible to roll with a second rolling mill.

Thick plate rolling and hot rolling rough rolling (hereinafter referred to as “hot rolling rough rolling”) are usually single-stand reverse rolling. When these rollings are made into tandem, loss at the time of reversing the material to be rolled can be reduced, so that productivity can be improved. However, since the material to be rolled is thick at the beginning of rolling, its rigidity is high, so it is difficult to correct with a guide or the like if a trouble with passing plates such as meandering, camber or warpage occurs. I can't. Further, in addition to the above, in a region where the plate thickness is thin, when the crown ratio obtained by dividing the plate crown by the plate thickness is not constant before and after rolling, that is, when the plate crown and shape control is not sufficient, the effect is reduced after rolling. Appears as a defective plate shape. When such a shape defect occurs, a so-called squeezing trouble is caused, in which the material to be rolled is rolled while being bitten in the second rolling mill.
Advantages of tandem rolling equipment include improved productivity by reducing the number of reverses and reduced load on the front and rear processes by expanding the rolling range (rolling from thick to thin). In conventional thick plate rolling and hot rolling rough rolling, it was difficult to realize tandem rolling mills because the control capability against the troubles due to shape defects, meandering / cambering and warping as described above was not sufficient. .

  A typical thick plate rolling mill (FIG. 7) as disclosed in Patent Document 1 is designed with the highest priority given to a large roll opening. That is, the arm portion connected to the upper reinforcing roll chock 4-1 whose vertical position is set and controlled by the reduction device 11 is configured to hold the upper work roll chock 3-1. In addition, it is difficult to incorporate a large-capacity hydraulic cylinder in order to incorporate the entry-side upper increase bending device 6-1 and the exit-side upper increase bending device 6-2 into the arm portion that is structurally limited in size. That's why. For this reason, a strong roll bending force cannot be imparted.

  For example, a work roll bending apparatus having a capacity exceeding 200 tf / chock 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 having a work roll diameter of about 200 tf / chock has been put to practical use in 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 cross function and a roll shift function have been put into practical use and utilized as a plate crown / shape control device of a thick plate rolling mill. Work roll bending devices are rarely used. However, it is difficult to quickly change the settings of the roll cloth function and the roll shift function during rolling. Therefore, it is impossible to remove disturbance factors during rolling, and it must be said that shape control for performing tandem rolling is incomplete.

  On the other hand, like the rolling mills disclosed in Patent Documents 2 and 3, the entry-side upper increment bending apparatus 6-1 and the exit-side upper increase bending apparatus 6-2 are respectively When incorporated in the upper work roll chock 3-1 and the lower work roll chock 3-2, the stroke of the hydraulic cylinder can be increased. Thereby, a large roll opening degree can be realized. Furthermore, 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, since the upper work roll 1-1 and the lower work roll 1-2 are severely worn by the rolling operation, it is necessary to periodically change the rolls. Then, the hydraulic piping of the increment bending apparatus must be attached and detached for each reassembly work. This not only increases 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, in this rolling mill (FIG. 9), a servo valve for high response hydraulic pressure control cannot be employed. In addition, in order to facilitate the attachment and detachment of the pipes, they must be connected to the respective hydraulic control valves via hydraulic pipes such as flexible pipes that are flexible and detachable. 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 provide a roll bending apparatus with sufficient response for performing tandem rolling.

  On the other hand, in the rolling mill as disclosed in Patent Document 4 (FIG. 10), the upper entrance increment bending device 6-1 and the exit upper increment bending device 6-2 are respectively provided in the rolling mill housing 9. Are incorporated in the input project block 5-1 and the output project block 5-2. 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 form, it is the contact surface between the upper work roll chock 3-1 and the outgoing project block 5-2 that supports the rolling direction force such as offset component force acting on the upper work roll 1-1. Therefore, if 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 upper 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 employed in a thick plate rolling mill that requires a large roll opening.

  As described above, in rolling mills that can take a large roll opening, there is a rolling mill that can incorporate a work roll bending device that is responsive and powerful, and that has sufficient sheet crown and shape control. do not do.

  Therefore, simply arranging two rolling mills cannot be a tandem rolling facility, and a tandem rolling facility that can handle thick plate rolling and hot rolling rough rolling cannot be realized.

  In view of the above circumstances, the present invention is to provide a tandem rolling facility capable of handling thick plate rolling and hot rolling rough rolling by sufficiently controlling the plate crown and shape by applying a strong roll bending force. And Furthermore, it is an object to provide a tandem rolling facility that suppresses the occurrence of meandering, camber, and warpage.

  As a result of intensive studies to solve the above-mentioned problems, the inventors shifted the project block protruding inward from the rolling mill housing to the lower side with respect to the pass line, and It has been found that the following can be achieved by installing it so as to be asymmetrical.

  (A) A structure in which the rolling direction force applied to the upper work roll chock is always received by the rolling mill 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.

  (E) As a result of these, in slab rolling and hot rolling rough rolling, as a tandem rolling facility in which two or more rolling mills are arranged, the occurrence of biting troubles such as drawing due to shape defects can be suppressed, Sufficient shape control is possible. As a result, even as a tandem rolling facility with two or more rolling mills, the occurrence of troubles such as occlusion defects can be suppressed, and tandem rolling can also be applied to thick plate rolling and hot rolling rough rolling, which could not be applied conventionally. To be like that.

(F) Furthermore, the rolling direction force acting on the upper roll chock is firmly supported by the housing window and the rolling direction force acting on the lower roll chock is firmly supported by the project block, and it is easy to deploy the load cell. It is easy to perform camber control based on the difference in directional force, and when this control is used, the camber on the stand-out side can be suppressed, so that it is possible to prevent occlusion defects due to the camber.
(G) In addition to the above, warpage can be prevented from occurring by providing a warpage control function in which one is the rotational speed control and the other is the rolling torque control. Therefore, it is possible to prevent biting defects due to warping.

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

(1) In a tandem rolling facility in which two or more metal sheet rolling mills are continuously arranged,
The rolling mill has a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls that respectively support them,
Hydraulic cylinders that apply an incremental bending force to the upper and lower work rolls are arranged in the project block protruding inside the rolling mill housing,
The rolling direction force applied to the body of the lower work roll is supported by the contact surface between the project block and the lower work roll chock,
Tandem rolling equipment for a metal plate material, wherein a rolling direction force applied to the body of the upper work roll is supported by a contact surface between a rolling mill housing window located above the project block and the upper work roll chock .

(2) On either the entry side or the exit side in the rolling direction of the work roll chock,
An apparatus for pressing the work roll chock against the contact surface with the housing window or project block of the rolling mill in the rolling direction;
A load detection device for measuring the force in the rolling direction acting on the work roll chock, both on the work side of the work roll and on the roll direction entry side and the exit side of the drive side roll chock;
An arithmetic device that calculates the difference between the working side and the driving side of the rolling direction force acting on the work roll chock based on the measurement value by the load detection device,
An arithmetic device that calculates a left-right asymmetric component control amount of the roll opening of the rolling mill based on a calculated value of the difference between the working side and the driving side of the rolling direction force;
The metal plate tandem rolling equipment according to (1), further comprising a control device that controls the roll opening degree of the rolling mill based on a calculated value of a left-right asymmetric component control amount of the roll opening degree.

(3) having a pair of electric motors that independently drive the pair of work rolls;
One motor controls the roll rotation speed as a control target value,
The other electric motor is provided with a control means for controlling the driving torque as a control amount with a control target that the rolling torque applied to the material to be rolled from the work roll driven by the electric motor becomes substantially constant. (1) or (2) metal plate tandem rolling equipment.

  (4) 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 arranged at different positions on the plan view in the project block. A tandem rolling facility for a metal plate material according to any one of (1) to (3) above.

  (5) The metal plate material according to any one of (1) to (4), wherein a hydraulic cylinder that applies a decrease bending force to the upper work roll is provided in the upper reinforcement roll chock of the upper reinforcement roll. Tandem rolling equipment.

  (6) 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. (5) The tandem rolling equipment of the metal plate material.

  (7) A hot rolling method, wherein reverse rolling is performed using the tandem rolling equipment according to any one of (1) to (6).

  As shown in FIG. 4, the rolling mill used in the tandem rolling facility according to the present invention applies the rolling direction force applied to the body portion of the upper work roll 1-1 to the upper work roll chock 3-1 and the outgoing project block 5. -2 is a structure supported by a contact surface with the rolling mill housing window 12 above -2. Therefore, a large roll opening degree can be obtained and a strong roll bending force can be obtained.

  And the structure which the hydraulic cylinder which loads an increase bending force to each of the upper work roll 1-1 and the lower work roll 1-2 was respectively provided in the exit side project block 5-2 which protruded inside the rolling mill housing. It is. Therefore, 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 a fixed hydraulic pipe to the incremental bending apparatus, and it is possible to employ a servo valve for high response hydraulic control, which is a highly responsive incremental lease. It can be a bending device.

  Therefore, it is possible to build a good sheet crown and shape against disturbances that vary during rolling, such as the entry side thickness of the material to be rolled and the temperature of the material to be rolled. Even in the case where they are arranged, a biting defect does not occur in the second and subsequent units, and a tandem rolling facility compatible with thick plate rolling and hot rolling rough rolling can be obtained.

  Furthermore, since the work roll chock is sufficiently supported, it is easy to provide a load cell that acts in the rolling direction, and a meandering and camber control function based on the left-right difference in the rolling direction can be provided.

It is a figure which shows the structure of the tandem rolling installation which concerns on this invention. It is a figure which shows the other example of the structure of the tandem rolling installation which concerns on this invention. It is a figure which shows the other example of the structure of the tandem rolling installation which concerns on this invention. It is a figure which shows the structure of the rolling mill used for the tandem rolling installation 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 figure which shows the structure of the rolling mill for thick plate rolling which concerns on a prior art. It is a figure which shows the structure of the rolling mill for thick plate rolling which concerns on a prior art. It is a figure which shows the structure of the rolling mill for sheet rolling which concerns on a prior art. It is a figure which shows the structure of the rolling mill for sheet rolling which concerns on a prior art. It is a figure which shows the structure of the rolling mill for sheet rolling which concerns on a prior art. It is a figure which shows the other example of the structure of the rolling mill used for the tandem rolling installation which concerns on this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 1 is a diagram showing the structure of a tandem rolling facility according to the present invention. FIG. 4 is a diagram showing the structure of a rolling mill used in this tandem rolling facility. The rolling mill according to the present invention includes an entry-side upper increment bending apparatus 6-1 and an exit-side upper increase bending apparatus 6 that apply an increase bending force to the upper work roll 1-1 via the upper work roll chock 3-1. -2 and the entry-side lower increase bending apparatus 6-3 and the output-side lower increase bending apparatus 6-4 that apply the increase bending force to the lower work roll 1-2 via the lower work roll chock 3-2. Are arranged in the entry side project block 5-1 and the exit side project block 5-2 that protrude inside the rolling mill housing 9.

  In the rolling mill according to the present invention, from the viewpoint of the structural design of the rolling mill, in particular, from the viewpoint of increasing the roll opening, the positions of the entry side project block 5-1 and the exit side project block 5-2, and above The shape of the work roll chock 3-1 and the like are fundamentally reviewed, and as described below, the problems of the conventional rolling mill shown in FIG. 10 are solved.

  That is, in the conventional type shown in FIG. 10, a large roll opening cannot be taken in an area where plate crown / shape control is required. In this rolling mill, the entry-side project block 5-1 and the exit-side project block 5-2 are substantially vertically symmetrical with respect to a position (hereinafter also referred to as “pass line”) through which the material to be rolled 10 passes. Is arranged. For this reason, rolling direction force such as offset component force acting on the upper work roll 1-1 by the contact surface between the upper work roll chock 3-1 and the exit side project block 5-2, that is, the material to be rolled 10 and the upper reinforcement This is because the roll 2-1 and the like support the rolling direction force applied to the body of the upper work roll 1-1.

  In this structure, as the roll opening is increased, the rotational center position of the upper work roll 1-1, that is, the point of action of the rolling direction force and the upper work roll chock 3-1 move upward, and the rolling direction force is increased. The contact area with the supporting outgoing project block 5-2 is reduced. Therefore, since the posture of the upper work roll chock 3-1 becomes unstable as the roll opening degree is increased, a large roll opening degree cannot be obtained.

  The rolling mill according to the present invention solves the above problems. As shown in FIG. 4, the rolling mill according to the present invention lowers the incoming project block 5-1 and the outgoing project block 5-2 that protrude inward from the rolling mill housing 9 with respect to the pass line. Place it at a position shifted to the side. That is, unlike the conventional rolling mill shown in FIG. 10, the entry project block 5-1 and the exit project block 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 not in contact with the exit project block 5-2 to support the rolling force, but is in contact with the rolling mill housing window 12 to support the rolling force.

  Thereby, in the rolling mill which concerns on this invention, the offset part which acts on the upper work roll 1-1 by the contact surface of the upper work roll chock 3-1 and the rolling mill housing window 12 above the exit side project block 5-2. A rolling direction force such as a force, that is, a rolling direction force applied to the body 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 rolling device 11 on the upper side of the rolling mill is operated to increase the roll opening, the area where the upper work roll chock 3-1 and the rolling mill housing window 12 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 value of the roll opening degree.

  As shown in FIG. 10, 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 shown in FIG. 4 performs a fundamental review of the positions of the entry side project block 5-1 and the exit side project block 5-2 and the shape of the upper work roll chock 3-1. The rolling direction force applied to the body of the upper work roll 1-1 is supported by the contact surface where the upper work roll chock 3-1 and the rolling mill housing window 12 above the projecting project block 5-2 are in contact with each other. Since the structure is adopted, a large roll opening degree can be obtained in a region where plate crown / shape control is required.

  Further, in the rolling mill according to the present invention, the entry-side upper increment bending apparatus 6-1 that loads the upper work roll 1-1 with an increase bending force, the exit-side upper increment bending apparatus 6-2, and the lower work An entry-side project block 5-5 in which an entry-side lower increase bending apparatus 6-3 and an exit-side lower increase bending apparatus 6-4 that apply an increase bending force to the roll 1-2 are protruded inside the rolling mill housing 9. 1 and the outgoing project block 5-2.

  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 the incremental bending device can be connected to the respective hydraulic control valves via the hydraulic piping fixed to the inlet side project block 5-1 and the outlet side project block 5-2. This is because a servo valve for the above can be employed.

  When the sheet thickness of the material to be rolled is approximately 100 mm or less, the sheet crown / shape control is required. In this case, roll balance is achieved by using the entry-side upper increment bending apparatus 6-1 and the exit-side upper increment bending apparatus 6-2 that apply an increase bending force to the upper work roll 1-1.

  In addition, in the rolling mill which concerns on this invention, about the rolling direction force loaded on the trunk | drum of the lower work roll 1-2, it is supported by the contact surface of the lower work roll chock 3-2 and the exit side project block 5-2. . For this reason, in the rolling mill shown in FIG. 4, the height of the part pinched | interposed into the entrance side project block 5-1 of the lower work roll chock 3-2 and the exit side project block 5-2 is enlarged.

  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. 5 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 entry-side project block 5-1 and the exit-side project block 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. 5, the entry-side upper increment bending apparatus 6-1, the exit-side upper increment bending apparatus 6-2, the entry-side lower increment bending apparatus 6-3, and the exit-side lower increment bending apparatus Are preferably arranged so as to have a positional relationship shifted in the axial direction of the lower work roll 1-2.

  In this way, the upper and lower increase bending apparatuses do not interfere with each other. As a result, the strokes of the entry-side upper increment bending device 6-1 and the exit-side upper increase bending device 6-2 are increased to take a larger roll opening in an area where plate crown / shape control is required. Can do.

  In FIG. 5, the entry-side lower increment bending apparatus 6-3 and the exit-side lower increment bending apparatus 6-4 each have two hydraulic cylinders on the entry side and the exit side. The same effect can be obtained by arranging the lower work roll 1-2 at different positions in the axial direction so as not to interfere with the upper increase bending apparatus 6-1 and the outgoing upper increase bending apparatus 6-2. .

  FIG. 6 is also a perspective 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 entry-side project block 5-1 and the exit-side project block 5-2. As shown in FIG. 5, the entry-side upper increment bending apparatus 6-1 and the exit-side upper increment bending apparatus 6-2, the entry-side lower increment bending apparatus 6-3, and the exit-side lower increment bending are performed. The positional relationship may be shifted in the rolling direction. Even in such an arrangement, the upper and lower increase bending apparatuses do not interfere with each other. As a result, the strokes of the entry-side upper increment bending device 6-1 and the exit-side upper increment bending device 6-2 can be increased to obtain 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.

  7 and 8 are side views showing the structure of a rolling mill for thick plate rolling according to the prior art, both of which are rolling mills that can take a large roll opening. These conventional rolling mills cannot provide a strong roll bending force.

  This is a structure in which the entrance-side upper increment bending device 6-1 and the exit-side upper increment bending device 6-2 are incorporated in the arm portion protruding downward from the upper reinforcing roll chock 4-1, so that the large capacity and This is because the large-stroke entry-side upper bending unit 6-1 and the outgoing-side upper increase bending apparatus 6-2 cannot be provided.

  Moreover, since these rolling mills take out an arm part from an upper reinforcement roll chock, the installation space of an upper decrease bending apparatus closes to the axial center of a roll. Therefore, since it interferes with the bearing of the upper reinforcing roll chock 4-1, the large-capacity and large-stroke inlet side upper bending device 7-1 and the outgoing upper deck bending device 7-2 cannot be provided.

  On the other hand, as shown in FIG. 4, in the rolling mill according to the present invention, a large capacity and a large stroke are provided to the entry side project block 5-1 and the exit side project block 5-2 that project inward from the rolling mill housing 9. The entry-side upper increment bending apparatus 6-1 and the exit-side upper increase bending apparatus 6-2 can be provided.

  In the rolling mill according to the present invention, the upper reinforcing roll chock 4-1 does not include an arm portion as shown in FIGS. For this reason, the large-capacity and large-stroke inlet side upper bending device 7-1 and the outgoing upper deck bending device 7-2 can be arranged at positions that do not interfere with the bearings of the upper reinforcing roll chock 4-1. 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 drastic review is performed on the positions of the entry project block 5-1 and the exit project block 5-2 and the shape of the upper work roll chock 3-1, and the load is applied to the trunk of the upper work roll 1-1. According to the rolling mill according to the present invention in which the rolling direction force is supported by the contact surface between the upper work roll chock 3-1 and the exit project block 5-2, a large roll opening degree can be obtained. At the same time, powerful roll bending power can be applied.

  Further, 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 can be connected to each hydraulic control valve via a fixed hydraulic pipe, and a servo valve for high response hydraulic control can be employed. Therefore, it is possible to provide an incremental bending apparatus with high responsiveness.

  By the way, like the rolling mill shown in FIG. 11, when the entry-side lower decrease bending device 7-3 and the exit-side lower decrease bending device 7-4 are arranged in the lower reinforcement roll chock 4-2, the lower reinforcement roll 2. When reassembling -2, the hydraulic piping of the decrease bending device must be attached and detached.

  For this reason, it is difficult to employ a servo valve for high response hydraulic control, and in some cases, flexible piping must be employed in order to facilitate attachment / detachment of the hydraulic piping.

  Therefore, the responsiveness of the roll bending apparatus is inevitably lowered as compared with the case where fixed piping and servo valves are employed. Furthermore, when attaching and detaching, there is a high possibility that minute foreign matters will be mixed in the hydraulic piping.

  On the other hand, according to the rolling mill shown in FIG. 12, 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.

  If the rolling mill described above is used, sufficient shape control is possible even in thick plate rolling and hot rolling rough rolling. Therefore, even if it is a tandem rolling facility in which two or more rolling mills are arranged, the problem due to the occlusion failure in the second and subsequent units does not occur.

  The tandem rolling equipment of the present invention firmly supports the rolling direction force acting on the upper roll chock with the housing window and the rolling direction force acting on the lower roll chock with the project block, respectively. A configuration for suppressing with high accuracy can also be provided.

  In general, the cause of the occurrence of camber due to the rolling of a plate material includes a roll gap setting failure, a left-right difference in the entry side plate thickness of the material to be rolled, or a left-right difference in deformation resistance. Regardless of the cause, the difference between left and right in the elongation strain in the rolling direction caused by rolling eventually changes the advance rate and reverse rate in the plate width direction, and the exit side speed and input rate of the material to be rolled. A lateral difference occurs in the side speed, resulting in camber.

  At this time, for example, at the time of rolling of the rolled material tip that is likely to cause camber, the length of the rolled material on the exit side that has already been rolled is short, so there is a left-right difference in the exit speed in a relatively free state. In order to produce a left-right difference in the entry side speed, it is necessary that the entire material to be rolled existing on the entry side rotates rigidly in a horizontal plane. However, since the long unrolled material generally remains on the entry side during the tip rolling, a moment against the rigid body rotation is generated by the weight of the material to be rolled and the friction between the table roller. Since this moment is transmitted as a reaction force to the work roll of the rolling mill, the moment in the rolling direction acting on the work roll chock part is left and right, and is finally supported.

  As a configuration for suppressing the meandering and camber of the material to be rolled, for example, the work roll chock is rolled on either the entry side or the exit side in the rolling direction of the work roll chock to the contact surface with the rolling mill housing window or the project block. A device for pressing in the direction can be provided.

  FIG. 2 shows an upper work roll pressing device 14 as a device for pressing the work roll chock on either the entry side or the exit side of the work roll chock in the rolling direction against the contact surface with the rolling mill housing window or the project block. -1 and the example of a tandem rolling equipment provided with the lower work roll pressing apparatus 14-2 are shown.

  When rolling with the work roll chock pressed in the rolling direction, even if a moment acts on the work roll from the material to be rolled due to the difference between the left and right elongation strains as described above, the force that presses the work roll chock acts on the work roll chock. Attenuated by power. That is, the position of the work roll chock in the rolling direction can be stabilized. As a result, it is possible to realize substantially no camber generation or extremely light camber rolling.

  In the apparatus configuration of the rolling mill provided with the work roll pressing device of FIG. 2, the upper work roll pressing device 14-1 presses the upper work roll chock 3-1 against the contact surface with the housing block, and the upper work roll chock 3-1. There is no gap between the rolling mill housing window 12 and the rolling mill housing window 12. The same applies to the lower work roll.

  Moreover, even if the roll opening degree is increased, the contact surface between the work roll pressing device and the work roll is sufficiently secured. Therefore, the problem that rattling occurs between the work roll chock and the housing window when the material to be rolled passes through the work roll and the problem that the posture of the upper work roll chock 3-1 becomes unstable are solved, and more stable plate passing Is brought about. As a result, it is possible to realize substantially no camber generation or extremely light camber rolling.

  For example, a hydraulic device can be used as an apparatus for pressing the work roll chock against the contact surface with the rolling mill housing window or the project block in the rolling direction.

  Furthermore, an apparatus for pressing the work roll chock in the rolling direction may be provided on the side opposite to the side where the work roll is offset with respect to the reinforcing roll among the entry side and the exit side of the work roll chock in the rolling direction.

  The rolling mill used in the present invention can also include load detection devices on both the work side of the work roll and the entry side and the exit side of the roll chock on the drive side. Rolling that acts on the roll chocks on the work side and the drive side regardless of the direction of force on either the input or output side by calculating the resultant force in consideration of the directionality of the load measurement values on both the input and output sides Directional force can be obtained accurately.

  In the example shown in FIG. 2, an upper load cell 13-1 and a lower load cell 13-2 are provided as load detection devices.

  In addition, by providing a calculation device that calculates the difference between the working side and the driving side of the rolling direction force acting on the work roll chock, work is performed from the material to be rolled due to the left-right difference in elongation strain in the rolling direction that causes camber. The moment acting on the roll can be detected.

  This moment is generated only when a left-right difference in elongation strain that causes the occurrence of camber occurs, and a moment is also generated almost simultaneously with the occurrence of the difference in elongation strain. Therefore, it is possible to prevent the occurrence of camber by manipulating the left-right asymmetric component of the roll opening degree of the rolling mill, that is, the reduction leveling, in the direction of reducing the left-right difference in the rolling direction force.

  In addition, an arithmetic unit that calculates a left-right asymmetric component control amount of the roll opening degree of the rolling mill for equalizing the elongation strain on the left and right sides based on the left-right difference in the rolling direction force acting on the work roll chock, By deploying a control device that controls the roll opening of the rolling mill based on the calculated value of the asymmetric component control amount, it is possible to prevent the occurrence of left-right difference in elongation strain, and there is no camber or a very light camber metal. The plate material can be rolled.

  This principle is the same when rolling the tail end of the material to be rolled, in which camber is likely to occur next after rolling the tip of the material to be rolled. When rolling at the tail end, the length of the rolled material on the exit side, which has already been rolled, is long. Is generated and transmitted to the work roll as a reaction force. Therefore, in this case as well, it is possible to detect the occurrence of the left-right difference in elongation strain by measuring and calculating the left-right difference in the rolling direction force acting on the work roll chock. At this time, it is possible to prevent the occurrence of camber at the tail end by manipulating the left-right asymmetric component of the roll opening degree of the rolling mill, that is, the reduction leveling, in a direction to reduce the difference in rolling direction force.

  The detection device and the calculation device for the rolling direction force acting on the lower work roll chock may be omitted. In general, the moment that acts on the work roll from the material to be rolled due to the left-right difference in elongation strain does not necessarily act equally on the upper and lower work rolls. However, with respect to the time-series change behavior, the trend does not reverse between the upper and lower work rolls. Therefore, by setting an appropriate control gain in the control device that controls the roll opening, it is possible to realize good camber control based on the left-right difference in the rolling direction force acting on one of the upper and lower work rolls.

  Moreover, although the asymmetrical component of the roll opening degree is a direct control parameter, in the case of extremely light rolling under temper rolling, the rolling operation can be executed with the rolling load as a target value. In such a case, the left-right difference of the rolling load may be calculated and given as the control target value. That is, based on the left-right difference of the rolling direction force acting on the work roll chock, the control amount of the left-right difference of the rolling load is calculated in the direction to eliminate this, and the rolling load control is carried out with this as the target value. The left-right asymmetric component of the roll opening is controlled.

  When rolling with the work roll chock pressed in the rolling direction, when a moment acts on the work roll from the material to be rolled due to the difference in elongation and strain, it can be immediately detected as a left-right difference in rolling direction force acting on the work roll chock. As a result, a camber control system with further excellent responsiveness and accuracy can be obtained.

  A device for pressing the work roll chock against the contact surface with the rolling mill housing window 12 or the project block in the rolling direction may be provided with a function as a load detection device. Thereby, the responsiveness and precision of the measurement of the rolling direction force acting on the upper work roll chock 3-1 are increased.

  The work roll pressing device may be provided on the entrance side or the exit side of the rolling mill.

  The rolling mill used in the present invention further measures a camber measuring device for measuring a camber of a material to be rolled, and an operation for learning a control target value of the difference between the working side and the driving side of the rolling direction force based on the camber measurement value. And a device.

  As a result, even when the difference in rolling direction force acting on the work roll chock is shifted due to roll wear or the like, the shifted amount can be corrected by learning based on the actual camber value, and an appropriate control target value can be calculated. it can.

  Further, an arithmetic unit for calculating a left-right asymmetric component control amount of the roll opening of the rolling mill for equalizing the elongation strain on the left and right based on the difference in rolling direction force acting on the work roll chock and the control target value, and the roll By deploying a control device that controls the roll opening of the rolling mill based on the calculated value of the left / right asymmetrical component control amount of the opening, it is possible to prevent the occurrence of a left / right difference in elongation strain, and no camber or extremely Minor rolling can be performed.

  For example, the method disclosed in Patent Document 5 can be used as the calculation method in the calculation device that learns the control target value of the difference between the working side and the drive side of the rolling direction force.

  The detection device and the calculation device for the rolling direction force acting on the lower work roll chock can be omitted. In general, the moment that acts on the work roll from the material to be rolled due to the left-right difference in elongation strain does not necessarily act equally on the upper and lower work rolls. However, with respect to the time-series change behavior, the trend does not reverse between the upper and lower work rolls, and the zero point of the rolling direction force left-right difference may shift.

  Also in this case, by measuring the camber of the material to be rolled during or after rolling, the learned control target value is set to the pass, the next pass, or the rolling of the next material, based on the actual camber value. The deviation of the directional force left-right difference can be corrected. As a result, it is possible to realize good camber control based on the left-right difference in the rolling direction force acting on either the upper or lower work roll.

  Further, since the occurrence of camber can be suppressed even in the first stand, it is possible to prevent occlusion defects due to the occurrence of camber.

  The rolling mill used in the present invention can further include a configuration for suppressing warpage of the material to be rolled and poor flatness due to the wave shape penetrating in the sheet width direction.

  Specifically, the upper work roll 1-1 and the lower work roll 1-2 can be driven by independent drive motors. Hereinafter, a description will be given with reference to FIG.

  The upper drive motor 21 is controlled by being given an upper drive torque control amount V3 calculated so that the upper drive torque measurement value V2 becomes a predetermined upper drive torque target value V1, and the upper work roll 1-1 is controlled. To drive.

  The lower drive motor 22 is controlled by being given a lower work roll rotational speed control amount V6 calculated so that the lower work roll rotational speed measurement value V5 becomes a predetermined lower work roll rotational speed target value V4. The work roll 1-2 is driven.

  That is, the electric motor that drives one work roll controls only the roll rotation speed and does not control the driving torque. The electric motor that drives the other work roll controls only the driving torque and does not control the roll rotation speed.

  Even when such a control is performed, the rolling mill used in the present invention can exhibit the same performance as the conventional control in which the upper work roll and the work roll are both controlled to control the rotation speed of the roll, and the upper and lower work rolls. It is also possible to prevent the rolling torque balance from changing.

  This is because normal rolling is performed in a state where the rolling reduction is almost constant, so the total torque of the upper and lower work rolls is almost constant, so if the rolling torque of one work roll is controlled, the other rolling This is because the torque can also be controlled and changes in the rolling torque balance of the upper and lower work rolls can be prevented.

  That is, the rolling torque of the other work roll that controls only the roll rotation speed is also substantially constant, and the position of the neutral point at which the slip between the work roll and the material to be rolled becomes zero is also kept substantially constant. As a result, the speed of the material to be rolled is also kept substantially constant.

  Therefore, according to this control method, a rapid change in the rolling torque balance of the upper and lower work rolls can be suppressed, and the material to be rolled is warped, swelled, or penetrated in the plate width direction called full wave, small wave, etc. Waveform generation can be suppressed.

  An example of this control method is shown in Patent Document 6.

  As described above, the rolling mill used in the tandem rolling mill of the present invention can take a large roll opening and can obtain a strong roll bending force, and has a high response and high speed plate crown / shape control function. Have

  As a result, it has been difficult to realize the problem of biting failure in the two rolling mills due to the disorder of the steel plate shape in the first rolling mill. It enables tandem rolling in the rough rolling.

  In addition, meandering and camber of the material to be rolled can be suppressed, and further, generation of a wave shape penetrating in the plate width direction called a full wave, a small wave, or the like can be suppressed.

  Furthermore, since the occurrence of warping, undulation, front wave, small wave, etc. can be suppressed even with the first stand, the bite at the second stand due to the occurrence of warp, undulation, front wave, small wave, etc. Indentation defects can be prevented.

  Since the rolling equipment of the present invention has a high-response and high-speed sheet crown / shape control function, it can also be used for reverse rolling.

  Furthermore, since the rolling equipment of the present invention can cope with a wide range of plate thicknesses, it is possible to perform from the hot rolling rough rolling to the finish rolling with one tandem rolling equipment of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the rolling of a steel plate can provide the tandem rolling equipment which can respond to a wide plate | board thickness. Therefore, it can be widely applied to the production of steel sheets in the steel industry, and industrial applicability is great.

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 6-1 Incoming Upper Increase Bending Device 6-2 Outgoing Upper Increase Bending Device 6-3 Incoming Lower Increase Bending Device 6-4 Outgoing Lower Increase Bending device 7-1 Entry-side upper decrease bending device 7-2 Entry-side upper decrease bending device 7-3 Entry-side lower decrease bending device 7-4 Exit-side lower decrease bending device 8-1 Entry-side reinforcing roll balance Equipment 8-2 Outlet reinforcement roll balance equipment 9 Rolling mill housing DESCRIPTION OF SYMBOLS 0 Rolled material 11 Reduction device 12 Rolling mill housing window 13-1 Upper load cell 13-2 Lower load cell 14-1 Upper work roll pressing device 14-2 Lower work roll pressing device 21 Upper drive motor 22 Lower drive motor V1 Upper Drive torque target value V2 Upper drive torque measurement value V3 Upper drive torque control amount V4 Lower work roll rotation speed target value V5 Lower work roll rotation speed measurement value V6 Lower work roll rotation speed control amount

Claims (7)

In a tandem rolling facility where two or more metal sheet rolling mills are continuously arranged,
The rolling mill has a pair of upper and lower work rolls and a pair of upper and lower reinforcing rolls that respectively support them,
Hydraulic cylinders that apply an incremental bending force to the upper and lower work rolls are arranged in the project block protruding inside the rolling mill housing,
The rolling direction force applied to the body of the lower work roll is supported by the contact surface between the project block and the lower work roll chock,
Tandem rolling equipment for a metal plate material, wherein a rolling direction force applied to the body of the upper work roll is supported by a contact surface between a rolling mill housing window located above the project block and the upper work roll chock . Either on the entry side or the exit side of the work roll chock in the rolling direction,
An apparatus for pressing the work roll chock against the contact surface with the housing window or project block of the rolling mill in the rolling direction;
A load detection device for measuring the force in the rolling direction acting on the work roll chock, both on the work side of the work roll and on the roll direction entry side and the exit side of the drive side roll chock;
An arithmetic device that calculates the difference between the working side and the driving side of the rolling direction force acting on the work roll chock based on the measurement value by the load detection device,
An arithmetic device that calculates a left-right asymmetric component control amount of the roll opening of the rolling mill based on a calculated value of the difference between the working side and the driving side of the rolling direction force;
2. The tandem rolling equipment for a metal sheet according to claim 1, further comprising a control device that controls a roll opening degree of the rolling mill based on a calculated value of a left-right asymmetric component control amount of the roll opening degree. A pair of electric motors for independently driving the pair of work rolls;
One motor controls the roll rotation speed as a control target value,
The other electric motor is provided with control means for controlling the driving torque as a control amount with a control target that the rolling torque applied to the material to be rolled from the work roll driven by the electric motor becomes substantially constant. Item 3. A tandem rolling facility for metal sheet according to item 1 or 2.   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 tandem rolling equipment for a metal sheet according to any one of claims 1 to 3.   5. 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. Tandem rolling equipment.   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. 5. A tandem rolling facility for a metal sheet according to 5.   Reverse rolling using the tandem rolling facility according to any one of claims 1 to 6, wherein the hot rolling method.

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