JPH0455009A - Inter-stand tension control method for continuous rolling mill - Google Patents

Abstract

PURPOSE:To stabilize the plate passing state of a strip between stands with respect to the strip which is allowed to pass through by dividing a contact load to the strip into at least two or more in the plate width direction and correcting it. CONSTITUTION:The plate width direction of a strip l which is passing through is divided into 13 pieces, and at every section thereof, a contact load to the strip of a looper roll 12 is detected, and a one-side elongation state of the strip which is allowed to pass through can be detected. That is, the one-side elongation state related to whether a worker side OP of the strip l which is allowed to pass through is elongated, or its driving side Dr is elongated can be decided. Also, in the worker side OP or the driving side Dr, by further expanding and correcting a cylinder 16 of the side in which it is judged that the strip l is elongated, the strip l can be allowed to pass through stably even in the case the one-side elongation state is generated in the strip 1.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for controlling tension between stands of a continuous rolling mill using at least one looper roll disposed between the stands of a continuous rolling mill, and particularly to improving the stability of a strip being threaded.

[Conventional technology]

Conventionally, looper rolls have been placed between the stands of continuous rolling mills! Thus, tension control between the stands of a continuous rolling mill is performed. The strip tension between the stands of a continuous rolling mill is the exit tension during rolling in the front stand between the stands, and the entry tension during rolling in the rear stand. Therefore, the strip tension between this stand is
This has a great influence on the rolling control of these front stands and rear stands. Therefore, by controlling the tension between the stands of the continuous rolling mill using such a looper roll, it is possible to suppress such fluctuations in the plate thickness and width of the continuous rolling mill. FIG. 5 is a layout diagram of the looper 12 in a continuous rolling mill. In FIG. 5, the machine lip 1 consisting of the right side is rolled while passing through two rolling stands 30 in order. By controlling the tension, rear tension, etc. as needed, a strip 1 having a desired thickness and width can be obtained. A louver 11 is arranged between these two rolling stands 30 in order to control the tension between the stands. This louver 11 includes a looper roll 12 that contacts the threaded strip 1 with a desired contact load, a cylinder 16 that controls the contact load, and a rod 14 that connects the looper roll 12 and the piston of the cylinder 16. , plate 24. This plate 24 includes the cylinder 16 therein, and therefore holds the looper roll 12 and the rod 14. Further, a load cell 10 is attached to the lower part of the cylinder 6 inside this plate 24, and this load cell 10 detects the contact load of the looper roll 12 to the strip l via the cylinder 16, the rod 14, and the looper roll 12. ing. In such a louver 11, the inter-stand tension between the rolling stands 30 is determined from the contact load detected by the load cell IO, and the stand 1gJ force of the threaded strip 1 is controlled accordingly. . Furthermore, in JP-A-52-142649, in the louver 11 that controls the tension between the stands, one end of the louver arm is attached to the lower end of a hydraulic cylinder that is provided to be expandable and retractable in the vertical direction. By controlling the tension of the strip 1 through the looper roll 12, these louver arms and the looper roll 12
A technique has been disclosed for improving control responsiveness of inter-stand tension control and reducing failures of this fluid pressure cylinder and the load detector attached to this fluid pressure cylinder due to cooling water and scale. Furthermore, in JP-A-52-150762, in a louver that controls strip tension via a looper roll 12 by arc motion of a louver arm relative to a rotation axis, a fluid pressure cylinder is provided on the rotation axis to rotate the rotation axis. A technique is disclosed in which a suitable connection is made, ie, the cooling water applied to the strip 1 during the rolling operation does not come into contact with the drive device for rotating the rotary shaft. Further, in JP-A-52-152853, a bracket having a load detector and a looper roll 12 is provided on a louver arm pivotally connected to a stand of a rolling mill, and control is provided for vertically rotating the arm in the vicinity of the load detector. A technique is disclosed in which a hydraulic cylinder is provided for responsive control of the louver arm and control of the strip tension between the stands. Further, in JP-A-55-73415, a first load cell is provided on a first arm extending from the center of rotation and receives a force applied to the looper roll 12, and a load cell is provided on a second arm extending from the center of rotation. and a second port for receiving the force applied to the loaded weight, and determining the strip tension from the outputs of the first and second load cells.
A technique is disclosed in which the influence of acceleration due to looper operation is removed from a load cell attached between a louver arm and a louver roll 12, and the tension of the strip 1 is detected with high accuracy without using an accelerometer.

[What the invention aims to accomplish! ! ! ]

However, in the strip 1 that is passed through a continuous rolling mill, irregularities in the shape of the strip 1, such as so-called one-sided elongation, may occur due to deformation due to wear of the rolling rolls used. When such a disturbance in the shape of the strip 1 occurs, the contact between the looper roll 12 and the passed strip 1 becomes uneven in the width direction of the strip. Therefore, in such a case, the tension between the stands of the strip 1 to be threaded becomes uneven between the operator side and the drive side (in the width direction of the strip), making the threading condition unstable, and this looper roll 1
2, there is a problem in that the rolling state in the rolling stands before and after the stand where the tension between the stands is controlled becomes unstable. Conventionally, problems in tension control between stands of such a continuous rolling mill have been discussed, for example, in the above-mentioned Japanese Patent Application Laid-Open No. 52-142.
649, JP-A-52-150762, JP-A-52-15
No. 2853, JP-A No. 55-73415, etc. do not disclose any technology. That is, these conventional techniques disclose techniques for improving the responsiveness of tension control between stands of a continuous rolling mill using the louver rolls 12 and for improving the detection accuracy of strip tension. Therefore, even with these techniques, if a disturbance in the shape of the strip 1, such as one-sided elongation, occurs, the threading of the strip 1 becomes unstable, causing so-called waving, vertical movement, and tension fluctuations. Also, if the tension between the stands becomes unstable like this, the rolling shape of the rolling stands before and after the place where the tension between the stands has become unstable! fs also became unstable,
A problem arises in that the thickness and width of the strip 1 also vary. The present invention has been made in view of such conventional problems, and even if the strip 1 to be sold by mail has irregularities in shape such as elongation on one side, it is possible to prevent waving or the like when passing the strip 1 between the stands. This improves stability without vertical movement or tension fluctuations, and also stabilizes the rolling condition in the front and rear stands where inter-stand tension control is performed, suppressing fluctuations in plate thickness and width. The purpose of the present invention is to provide a method for controlling tension between stands of a continuous rolling mill.

[Means to achieve the task]

The present invention provides tension control based on the contact load of at least one louver roll 12 placed between stands of a continuous rolling mill on the strip 1 being passed, by at least two louver rolls 12 in the width direction of the strip 1. The contact load of the louver roll 12 on the strip 1 is detected for each of the above sections, and the louver roll 1 is divided for each section according to the detected contact load.
By performing string force control according to 2, the above! This achieved IN.

[Effect]

The present invention detects the occurrence of irregularities in the shape of the strip 1, such as one-sided elongation, of the strip 1 sold by mail order to a continuous rolling mill, and according to this, the contact load of the louver roll 12 to the strip 1 is divided into at least two or more parts in the width direction of the strip. By dividing and correcting, even if the strip 1 to be threaded has a shape irregularity such as elongation on one side, the state of threading the strip 1 between the stands is stabilized. In addition, in the present invention, the strip 1 being passed is divided into at least two sections in the width direction, and the contact 'R weight between the louver roll 12 and the strip 1 is detected for each section, so that the JIi Detecting disturbances in the shape of strip 1. FIG. 4 shows the contact load of the louver roll 12 and the strip 1.
This is a graph showing the relationship between one-sided elongation (the operator side OP is elongated compared to the drive side D'). In the graph of Fig. 4, the solid line is the
It shows the change in contact load f between the strip 1 and the louver roll 12 between the stands during sheet threading with respect to time t. In addition, in the graph of Fig. 4, the broken line indicates the operator side O.
P shows the change in contact load f between the strip 1 and the louver roll 12 between the stands during threading with respect to time t. The period T between the solid line and the broken line in the graph of FIG.
When comparing the
is shorter than the period T of change in contact load. Further, the amplitude @F of the change in the contact load of the strip 1 on the operator side OP is larger than the amplitude F@ of the change in the contact 'FT weight of the strip 1 on the drive side Dr. (The strip 1 to be measured in FIG. 4 is a strip 1 in a state where the operator's side OP is stretched on one side.)
Strip 1 at each part in the width direction of strip 1
From the results of many tests regarding changes in the dark contact load f between the looper roll 12 and the looper roll 12 over time t, we have found the following method for detecting disturbances in the shape of the strip 1. (1) In each part of the strip 1 in the plate width direction, the shorter the cycle T of the change in the contact load f as described above is, the more the strip 1 in that part is elongated. (2) At each part of the strip 1 in the plate width direction, the larger the amplitude @F of the change in the contact load f as described above is, the more the strip 1 in that part is elongated. Therefore, the disturbance in the shape of the strip 1 being threaded can be detected from at least one of the period T and fi@F of the change in the contact load f as described above at each part of the strip 1 in the width direction. I can do it. At this time, the period T and the magnitude of the amplitude @F at each part of the strip 1 in the width direction are determined by predetermined values for each section of the strip 1 in the width direction, for example. The evaluation may be made by comparing each section of the strip 1 in the board width direction. By such evaluation under the period T and 1i#jA, it is possible to detect the disturbance in the shape of the strip 1 between the stands during sheet threading, and also detect the amount of elongation of each section of the strip 1 in the sheet width direction. be able to. Furthermore, even if a shape disorder occurs in the strip 1 being passed, the strip of the looper roll 12 in each section of the strip 1 in the width direction is adjusted according to the detected elongation amount in each section of the strip 1 in the width direction. By controlling the contact load on the strip 1, the strip 1 can be stably threaded.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1(A) is a side view of a looper of a first embodiment to which the present invention is applied. In this 11th J(A), a cylinder 16 is provided in the plate 24. This cylinder 16 is connected to the looper roll 12 (as described later using FIG. 1(B)).
The rod 14 to which the looper roll outer ring 12a and the louver roll core 12b is attached is expanded and contracted, thereby modifying the contact load of the looper roll 12 on the strip 1 being threaded. FIG. 1(B) is a front view of the first embodiment. In this FIG. 1(B), the code 14.16.24 is
These are the same as those with the same reference numerals in FIG. 1(A) described above. In this FIG. 1(B), this looper roll 12 is
It is composed of one louver roll core 12b and a plurality (13 pieces) of louver roll outer rings 12a. Further, both ends of the louver roll core 12b are attached to the rod 14 by chocks 22. Both ends of this louver roll core 12b can be expanded and contracted independently by respective independent cylinders 16. Therefore, the contact load f of the looper roll 12 on the strip 1 being threaded by the operator (11op) and the drive side D'
Contact cargo i! Lf can be modified independently. Moreover, between the plurality (13 ([1)) looper roll outer rings 12a and the louver roll core 12b, a plurality (13) load cells 108 are installed for each looper roll outer ring 12a.
~1011 are attached one by one. Therefore, each section of the strip 1 in the width direction (the looper roll outer ring 12a
looperol 12 to the strip l in the tin group of
The contact loads f can be detected independently. Therefore, according to the first embodiment of the present invention shown in No. 11M(A) and (B), the strip 1 during threading is
The strip width direction is divided into 13 sections, and the contact load of the looper roll 12 on the strip 1 can be detected for each section, and the state of one-sided elongation of the strip 1 being threaded can be detected. In other words, it is possible to determine whether the strip 1 being threaded is stretched on one side, whether the operator's side OP is stretched or the drive side D' is stretched. By correcting the elongation of the cylinder 16 on the side where it is determined that the strip 1 is elongated, the strip 1 can be threaded stably even if one-sided elongation occurs in the threaded strip 1. Fig. 2(A) is a side view of a louver of a second embodiment to which the present invention is applied.In Fig. 2(A), reference numerals 12.12b, 14.
16.24 are the same as those with the same reference numerals in FIG. 1(A) described above. However, the louver roll outer ring 12 in FIG. 2(A) (and FIGS. 2(B) and (C) described later)
A is different from the looper roll outer ring 12a shown in FIGS. 1(A) and 1(B) described above. That is, each of the looper roll outer rings 12a shown in FIGS. 1(A) and 1(B) described above has a relatively narrow width, and has a structure in which a plurality of looper roll outer rings 12a are attached to the louver roll core 12b. However, this figure 2 (A) (and the second
The looper roll outer ring 12a in FIGS. (B) and (C)) is longer than the width of the strip 1 to be threaded, as will be described later with reference to FIG.
One looper roll outer ring 12a is attached to b. FIG. 2(B) is a structural diagram of the looper roll core 12b used in the second embodiment of the present invention as seen from the load cell mounting surface. In FIG. 2(B), a total of 13 load cells 10a to 101 are linearly attached to the looper roll core 12b at equal intervals. Therefore, with these 13 load cells 108 to 10+e, it is possible to detect the load acting between the looper roll outer ring 12a and the looper roll core 12b in each section of the strip 1 in the width direction, and thereby the strip 1 It is possible to detect the contact load lf of the louver roll 12 on the strip 1 being passed in each section in the strip width direction. FIG. 2(C) is a front view of the second embodiment of the invention described above. In this Figure 2 (C), the code 14.16.22.2
4 are the same as those with the same reference numerals in FIGS. 1(A) and 1(B) described above. However, the structure of the louver roll 12 shown in FIG. 2(C) is different from that of the louver roll 12 shown in FIGS. 1(A) and 1(B) described above. That is, this second
In Figure (C), the looper roll outer ring 12a is composed of only one looper roll outer ring 12a. Therefore, 13a attached to the looper roll core 12b
The load cells 10a to 1oll can detect disturbances in the shape of the strip 1 being stretched on one side (i.e., the louver roll 12 of this second embodiment
According to the second embodiment of the present invention, it is possible to detect only a one-sided extension state in which either the operator (11op or the drive yAD is extended more than the other). Person 1
N! By correcting the two cylinders 16 attached to both ends of the plate 24 according to the amount of one-sided elongation of either loP or drive side D, even if the strip 1 being threaded has an irregular shape, , the strip 1 can be stably passed through. Fig. 3 is a block diagram of a third embodiment to which the present invention is applied. In Fig. 3, two rolling stands 3 (not shown) are installed.
Two louvers lla and 1ltl are arranged between the louvers 11a and 1ltl, and the strip 1 is passed through the louvers 11a and 1ltl in this order.These louvers 11a and 11b each have a louver roll 12, and the strip 1 is passed over these two louver rolls 12. Similar to the first embodiment of the present invention shown in FIG.
A total of 13 load cells 10a to 1011 are attached to 2b. On the other hand, the louver itb is a conventionally used looper that uses one wide looper roll outer ring 12a and has a load cell 10 attached between a cylinder 16 and a grate 24. When the strip 1 is passed through the looper la, the disturbance in the shape of the passed strip 1 is caused by a plurality of load cells (not shown) attached to the looper roll core 12b as in the first embodiment described above. Detected. In this third embodiment, as in the first embodiment and the first embodiment described above, even if the strip 1 to be sold by mail is irregularly stretched, the strip 1 can be stably
can be passed through. Furthermore, in this third embodiment, two loopers l
a, llb, the strip 1 can be stably sold by mail even if the shape of the strip 1 is distorted in the stretched state. That is, when a disturbance occurs in the shape of the strip 1 in the state of elongation, this state of elongation is detected and the inclination corrections of the respective looper rolls 12 of these two loopers la and iTo are reversed. We can respond. In this manner, according to the first, second, and third embodiments of the present invention, the mail-order strip 1 and the louver roll 12 are divided in the width direction of the mail-order strip 1 and the louver roll 12 for each division. By detecting the contact load f with the strip 1, detecting the disturbance in the shape of the strip 1 being passed and the amount of elongation of each section, it is possible to control the tension of the looper for each section. Therefore,
The stability of the strip 1 being passed through can be improved. Incidentally, in order to relatively easily deal with only the one-sided state of the strip 1 sold by mail order, the cylinder 16 and the looper 12b used in the third embodiment of the present invention shown in FIG. A looper with a load cell 10 provided between it and the plate 24 may be used. In this case, by processing the signals from the left and right load cells 10 independently, the contact load of the louver roll 12 on the strip 1 can be reduced. 2 on the left and right
It can be determined separately. As a result, the state of one-sided extension is detected as described above with reference to FIG. 3, and the left and right cylinders 16 are corrected independently.

【Effect of the invention】

As explained above, according to the present invention, even if a shape disorder such as one-sided elongation occurs in the strip to be threaded, the threading of the strip between the stands can be performed without causing waving, vertical movement, or tension fluctuation. The excellent effect of stably passing the strip, and furthermore, stabilizing the rolling condition in the front and rear stands where the tension between the stands is controlled and suppressing fluctuations in plate thickness and width. be able to.

[Brief explanation of drawings]

FIG. 1(A) is a side view of the looper of the first embodiment to which the present invention is applied; FIG. 1(B) is a front view of the first embodiment of the present invention; FIG. > is a side view of the looper of the second embodiment to which the present invention is applied, Figure 2 (B) is a structural diagram of the looper roll core used in the second embodiment of the present invention, Figure 2 (C ) is a front view of the second embodiment of the present invention, FIG. 3 is a configuration diagram of the third embodiment to which the present invention is applied, and FIG. 4 is a diagram showing the contact load of the louver roll and the one-sided elongation of the strip. A graph showing the relationship, FIG. 5 is a layout diagram of the looper in a continuous rolling mill. 1... Strip, 1O... Load cell, 11.1la-11b... Looper, 12... Louver roll, 12a... Looper roll outer ring, 12b... Looper roll core, 14... Rod-16... Cylinder, 22... Chock, 24... Plate, 30... Rolling stand.

Claims (1)

[Claims] (1) When tension control is performed by the contact load of at least one looper roll placed between the stands of a continuous rolling mill on the strip being passed, the strip is divided into at least two parts in the width direction. , a continuous rolling mill characterized in that a contact load of the looper roll on the strip is detected for each of the sections, and tension control by the looper roll is performed for each section according to the detected contact load of each of the sections. Inter-stand tension control method.