JP2013154396A - Method and equipment for manufacturing hot-rolled steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably manufacture a hot-rolled steel strip having a fine shape without causing passing trouble of a strip due to the camber and the wedge of a material to be rolled when rolling the material to be rolled with a hot-rolling mill.SOLUTION: In a hot-rolling mill in which side guides 10x, 10y are installed on the inlet side and the outlet side of work rolls 1a, 1b, roll gap sensors A for measuring right and left roll gaps of upper and lower work rolls 1a, 1b respectively are provided, a material to be rolled is guided by the side guides 10x, 10y. Rolling is performed by adjusting the rolling reduction of right and left supporting parts of the work rolls 1a, 1b so that the gap difference δdf of the right and left rolls is not larger than the allowable value (where, the case where the allowable value is zero is included.) on the basis of the gap difference δdf of the right and left rolls of upper and lower work rolls 1a, 1b during rolling, which are measured by the roll gap sensors A while restricting the off-center and the camber.

Description

  The present invention relates to a method and equipment for producing a hot-rolled steel strip using a hot rolling mill.

  In normal rolling, when a difference in thickness between the left and right plates (wedge) in the width direction of the material to be rolled and a bending (camber) with respect to the direction of the rolled material occur, a uniform thickness shape is maintained in the width direction and the rolling direction. In addition to incurring quality reductions such as variations in sheet thickness distribution, equipment failure occurs due to the tip of the bent rolled material striking peripheral equipment such as guides, which greatly increases repair time. Lead to a significant decline in operating rate. For this reason, rolling without wedges and cambers is very important.

  The rolled material wedge and camber are directly caused by the left-right asymmetry of the roll gap. For example, in rolling in a case where the shape of the material to be rolled before rolling is bilaterally symmetric and the rolling mill has a left-right roll gap difference, the left-right reduction amount is non-uniform, so the side with the larger reduction amount is set to the smaller side. On the other hand, since the film is stretched relatively long in the rolling direction, a curvature corresponding to the difference between the left and right elongation is generated, and this is accumulated along with the rolling distance and is manifested as a camber. Further, even when the camber is corrected by restraint by the guide and is not manifested, the included wedge often becomes an operation impediment factor.

  FIGS. 18 (a) and 18 (b) show a symmetric rolling (FIG. 18 (a)) and a left / right asymmetric rolling (FIG. 18 (c)) in rough rolling performed with the side guides on the entry side and the exit side of the rolling mill retracted. It is drawing which showed typically the plate shape in b)). For example, in the case of symmetrical rolling, a product without a wedge, a camber or the like can be manufactured as shown in FIG. 18 (a). However, when the material to be rolled meanders, the material to be rolled closes as shown in FIG. 18 (b). Since the rolling load on one side is higher than that on the other side, the roll opening is wider than on the other side. Naturally, the other side with a narrow roll gap is rolled thinner than the other side, so it is elongated longer in the rolling direction, the sheet passing speed is slower than one side, and the thickness difference between the left and right plates on the exit side of the rolling mill. Camber according to the situation occurs. For this reason, the material to be rolled is bent into a "<" shape at the rolling part. Once the material to be rolled is bent, the amount of meandering from there increases with time. Thus, as shown in FIG. 18 (a), when the center of the material to be rolled deviates from the roll center, the mill elongation in the direction in which the material to be rolled is bent (the right direction in FIG. 18 (b)) increases, and the roll By opening the gap and further promoting the deflection, a meandering amount and a camber proportional to the square of time are generated.

  The above-described factors of the asymmetry of the roll gap are roughly classified into material factors, equipment factors, and operation factors. Among these factors, the geometrical factors such as the displacement of the chock within the clearance between the housing and the chock, and the difference between the left and right mill constants due to the change in contact with the progress of the rolling liner wear (the amount of change in the rolling load / roll gap) Left and right difference). Moreover, as a material factor, there are a rolling mill entrance side wedge, a left-right temperature difference, etc., and this is the left-right asymmetry that the material to be rolled already has at the stage before rolling. Furthermore, the operating factors include human error such as poor left / right reduction balance setting by the operator, asymmetric wear of the rolling roll, and the like.

  Regarding the left and right mill constant difference, a mill constant curve obtained by a test (kiss roll test) in which the roll gap setting means is tightened in the gap reduction direction with the upper and lower work rolls in contact [= roll gap tightening amount-rolling load graph] From the viewpoint of equipment protection, the kiss roll test should be performed in a load range that is lower than the actual rolling load range. In many cases, the roll gap during rolling cannot be accurately evaluated.

  It is also necessary to deal with mild changes over time, such as changes in the left and right mill constants due to equipment deterioration, but in the case of discontinuous changes in machine factors or rolled material factors, conventional roll gap control methods However, there are many cases where wedges and cambers suddenly occur and operations are hindered. For example, it is common to replace the backup roll and work roll periodically, but if the chock width dimension of the replaced roll, the liner seating surface condition that receives the rolling load, etc. change significantly, it is stable before the roll replacement. In spite of being able to operate, rolling may become unstable suddenly. Usually, since it is difficult to control all the left-right asymmetry and feed back to the roll gap control, it has been considered difficult to avoid the variation in the left-right asymmetry.

The most direct way to solve these problems is to directly measure the camber shape and wedge amount of the material to be rolled on the exit side of the rolling mill, and to dynamically control the left and right roll gap so that it is symmetrical. It is considered to be an effective means.
Patent Document 1 discloses a method of measuring the left and right roll gap of a rolling mill, not the material to be rolled, and controlling the left and right roll gap difference to be zero. Since the difference between the left and right roll gaps of the rolling mill is considered to substantially reflect the left-right asymmetry of the material to be rolled, the method of Patent Document 1 is also considered to be an effective means. Here, the left-right roll gap difference δdf in the left-right asymmetric rolling is shown in FIG.

  On the other hand, in Patent Document 2, side guides are installed on the entry side and exit side of the rolling roll in rough rolling, and a measuring instrument for measuring the amount of wedge of the material to be rolled is arranged on the exit side of the rolling roll. While restraining the bending of the material to be rolled with the side guides on the side and the exit side, rolling is performed by adjusting the rolling amount of the support portions on the left and right sides of the roll based on the wedge amount measured by the measuring instrument, and the camber and the wedge A method of simultaneously suppressing the above has been proposed.

JP-A-6-297013 Japanese Patent No. 3690282

However, the above-described conventional technology has the following problems.
First, although the method of Patent Document 1 is based on the premise that camber is eliminated if the roll gap difference is zero, there is a case where this premise does not hold.
For example, in a hot rolling line, it is common to arrange an apparatus called a sizing press between a heating furnace and a roughing mill. This sizing press is a device for pressing the left and right end faces of the slab from both sides to reduce the width dimension of the slab. The slab width and length dimensions that can be corrected with a single press are limited due to equipment restrictions, so pinch rolls are placed before and after the press mold, and the slab is pinched until the total length of the slab reaches the desired width. In general, slab conveyance by rolls and pressing by a mold are repeated alternately.

  However, when the slab extracted from the heating furnace has a non-uniform temperature distribution in the width direction, the deformation resistance, which is a physical property value indicating the difficulty of deformation of the material, is also non-uniform in the width direction depending on the temperature. Also, the deformation behavior of the slab at the time of pressing becomes asymmetrical, and a wedge and a camber are generated on the exit side of the sizing press. Also, not only due to materials such as slab temperature, but also when there is equipment-induced left-right asymmetry, such as a difference in the installation mold level between press dies due to machine accuracy, pressure-receiving surface wear, etc. The slab deformation is asymmetrical.

The slab deformation behavior described above is often not uniform in the longitudinal direction of the slab because the slab conveyance and the press by the mold are alternately repeated in the sizing press. For example, when a local bending occurs in a portion corresponding to one press in the longitudinal direction of the slab, a wedge is not generated, but a camber is generated. Furthermore, in the rough rolling mill on the downstream side of the press, when the camber is corrected by the roll roll, the rolling mill entrance side and the exit side guide, the volume of the material to be rolled is stored before and after the correction, so that the longitudinal direction accompanying the camber correction The difference between the left and right elongations generates a wedge in the thickness direction.
In such a case, the camber may not be eliminated simply by correcting the wedge so that the left-right roll gap difference becomes zero as in the method of Patent Document 1.

Also, the method of Patent Document 2 has the following problems.
In normal hot rolling, the sheet bar thickness after the final pass of rough rolling is generally about 20 to 40 mm. For this reason, in order to measure the amount of wedges of a material to be rolled, a measuring instrument (sensor) using a highly transparent radiation source such as γ rays is required. In general, a measuring instrument using such a radiation source is expensive and requires strictly controlled legally. Moreover, since it is necessary to ensure the dimension for installing the measuring instrument, it is difficult to install it on the exit side of all the existing rolling mills where this is not assumed.

  Even if a measuring instrument can be installed on the exit side of the rolling mill, a time lag is generated according to the distance between the rolling roll and the measuring instrument and the moving speed of the material to be rolled on the exit side of the rolling mill. As shown in the example of Patent Document 2, when the fluctuation of the wedge amount during rolling is relatively stable in one sheet bar, in the reduction amount control for feeding back the wedge amount, Time lag is not a big problem, but it can't cope with the presence of discontinuous wedge changes in the seat bar.

  Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, and without rolling troubles due to the camber or wedge of the material to be rolled when rolling the material to be rolled by a hot rolling mill. An object of the present invention is to provide a method and equipment for manufacturing a hot-rolled steel strip that can stably manufacture a hot-rolled steel strip having a simple shape.

The gist of the present invention for solving the above problems is as follows.
[1] In a hot rolling mill in which side guides are installed on the entry side and the exit side of the work roll, a roll gap sensor for measuring the left and right roll gaps of the upper and lower work rolls is provided, and the material to be rolled is removed by the side guide. The left and right roll gap difference δdf is an allowable value (however, the allowable value is zero) based on the left and right roll gap difference δdf of the upper and lower work rolls measured by the roll gap sensor while constraining the off-center and camber. The method for producing a hot-rolled steel strip is characterized in that rolling is performed by adjusting the reduction amount of the left and right support portions of the work roll so as to be as follows.

[2] In the manufacturing method of [1] above, a means for detecting a load acting on the side guide by contact with the material to be rolled is provided, and the threshold is exceeded by the detecting means during the guide of the material to be rolled by the side guide. A method of manufacturing a hot-rolled steel strip, wherein a side guide is quickly opened when a load is detected.
[3] In the manufacturing method of [2] above, the threshold value is set so that the load acting on the side guide due to contact with the material to be rolled does not exceed the equipment strength of the side guide. Steel strip manufacturing method.
[4] In the manufacturing method according to [2] or [3], the hydraulic servo cylinder includes a drive unit for adjusting the opening degree of the side guide, and a detection unit that detects a load acting on the side guide through the cylinder pressure. A method of manufacturing a hot-rolled steel strip, comprising: detecting a load acting on a side guide by contact of a material to be rolled by the detecting means.

[5] In a hot-rolled steel strip manufacturing facility in which side guides are installed on the entry side and exit side of a work roll of a hot rolling mill,
A roll gap sensor for measuring the left and right roll gaps of the upper and lower work rolls of the hot rolling mill;
Based on the left and right roll gap difference δdf of the upper and lower work rolls during rolling measured by the roll gap sensor, the left and right roll gap difference δdf is less than or equal to an allowable value (including the case where the allowable value is zero). Means for respectively adjusting the amount of reduction of the left and right support parts of the work roll;
Driving means for adjusting the opening degree of the side guide;
Detecting means for detecting a load acting on the side guide by contact of the material to be rolled;
By controlling the driving means, the material to be rolled is guided by the side guide to restrain the off-center and the camber, and the side guide is rapidly opened when a load exceeding the threshold is detected by the detecting means. A facility for manufacturing a hot-rolled steel strip, characterized by comprising means.
[6] In the manufacturing equipment of [5], the drive means for adjusting the opening degree of the side guide is constituted by a hydraulic servo cylinder provided with a detection means for detecting a load acting on the side guide through the cylinder pressure. A hot-rolled steel strip manufacturing facility, wherein the detecting means detects a load acting on the side guide by contact with a material to be rolled.

  According to the manufacturing method and the manufacturing equipment of the hot-rolled steel strip according to the present invention, it is possible to stably manufacture a hot-rolled steel strip having a good shape without causing a trouble of passing a plate by a camber or a wedge of the material to be rolled. it can. For this reason, even in the production of thin hot-rolled steel strips, it is possible to ensure a good steel strip shape and achieve stable threading, and to improve line operation rate and roll unit consumption by suppressing drawing trouble. On the other hand, it is possible to stably produce an excellent quality hot-rolled steel strip.

1 shows an embodiment of a hot roughing mill provided for the implementation of the present invention, and is a front view of a rolling mill work roll and a backup roll when the roll gap is zero In the embodiment of FIG. 1, a side view of a rolling mill work roll and a backup roll when the roll gap is zero (in this figure, the roll gap sensor A should be originally represented by a broken line, but is represented by a solid line for convenience of explanation). 1 is a front view of a rolling mill work roll and a backup roll when there is a roll gap. In the embodiment of FIG. 1, a side view of a rolling mill work roll and a backup roll when there is a roll gap (in this figure, the roll gap sensor A should be originally represented by a broken line, but is represented by a solid line for convenience of explanation). Explanatory drawing for demonstrating the off-center and camber restraint method of a to-be-rolled material by a side guide Explanatory drawing which shows the apparatus structure for controlling a side guide in this invention. The rolling mill used in the Example of this invention WHEREIN: The front view which shows the rolling mill work roll and backup roll in the case of zero roll gap 7 is a side view showing the work roll and the backup roll of the rolling mill when the roll gap is zero (in this figure, the roll gap sensor A should be originally represented by a broken line, but is represented by a solid line for convenience of explanation). FIG. 7 is a front view showing a rolling mill work roll and a backup roll when there is a roll gap δ in the rolling mill of FIG. In the rolling mill of FIG. 7, a side view showing a rolling mill work roll and a backup roll when there is a roll gap δ (in this figure, the roll gap sensor A should be represented by a broken line, but is represented by a solid line for convenience of explanation) ) 7 is a side view partially showing a take-up reel mechanism and the like of a roll gap sensor in the rolling mill of FIG. Sectional drawing which follows the XII-XII line | wire of FIG. Explanatory drawing which shows arrangement | positioning of the roll gap sensor and measuring apparatus in an Example. Explanatory drawing which shows the flow of the power supply and data signal in an Example Explanatory drawing for explaining the left-right roll gap difference δdf in left-right asymmetric rolling In an Example, the chart figure which shows the generation | occurrence | production situation of the camber and wedge by an example of this invention and a prior art example A graph showing the transition of the frequency of occurrence of plate troubles in Examples Explanatory drawing schematically showing the plate shape in left-right symmetric rolling and left-right asymmetric rolling in the hot rough rolling process

1 to 4 show an embodiment of a hot roughing mill used in the practice of the present invention. FIG. 1 is a front view of a rolling mill work roll and a backup roll when the roll gap is zero. 2 is also a side view (in this figure, the roll gap sensor A is originally represented by a solid line for convenience of explanation), and FIG. 3 is a front view of a rolling mill work roll and a backup roll when there is a roll gap. 4 and 4 are side views.
In the figure, 1a is the upper work roll, 3a is the roll chock, 1b is the lower work roll, 3b is the roll chock, 2a is the upper backup roll, 4a is the roll chock, 2b is the lower backup roll, and 4b is the roll chock. S is a material to be rolled.

  Roll gap sensors A for measuring the left and right roll gaps of the upper and lower work rolls 1a and 1b are provided in the vicinity of the left and right roll ends of the upper and lower work rolls 1a and 1b, respectively. By adjusting the zero point of the roll gap sensor A in a state where there is no roll gap as shown in FIGS. 1 and 2, the roll gap measurement value δ when a roll gap is generated as shown in FIGS. Can be obtained. Further, the left-right roll gap difference δdf can be obtained by the calculation difference of the roll gap measurement value δ by the roll gap sensor A arranged on the left and right of the upper and lower work rolls 1a, 1b.

Further, side guides are provided on the entry and exit sides of the upper and lower work rolls 1a and 1b of the hot rolling mill. This side guide is a means for constraining and centering both sides of the material S to be rolled, and as shown in FIG. 5 to be described later, the opening degree (guide width) by a driving means for opening / closing the guide (for guide width expansion / contraction). Is adjustable.
In the present invention, the roll gap sensor A is used to measure the left-right roll gap difference δdf between the upper and lower work rolls 1a, 1b during rolling. The difference between the left and right roll gaps of the upper and lower work rolls 1a and 1b at the time of rolling measured by the roll gap sensor A while guiding the material S to be rolled by the entry-side and exit-side guides and restraining the off-center and the camber. Based on δdf, roll gap control is performed to adjust the rolling amount of the support portions on the left and right of the work roll so that the left and right roll gap difference δdf is equal to or less than the allowable value (including the case where the allowable value is zero). For example, when the roll gap difference δdf is +200 μm (the right side is wider) during the rolling, the roll gap control is performed by a roll gap adjusting means such as a rolling hydraulic cylinder with the target position where the roll gap difference δdf is zero. I do.

  Here, as the roll gap adjusting means, a reduction screw (electric screw) or a reduction hydraulic cylinder is generally used. In the case of a reduction screw, the screw is driven when a large load such as a rolling load is applied. The pressure-receiving surface may be burned out, and in the worst case, the stroke may become impossible. Therefore, in the present invention for performing dynamic roll gap control that feeds back the roll gap difference δdf from immediately after the tip of the material to be rolled bites into the rolling mill until the tail end of the material to be rolled exits the rolling mill. The roll gap adjusting means is preferably composed of a reduction hydraulic cylinder.

FIG. 5 is an explanatory diagram for explaining a method of restraining the off-center and the camber of the material to be rolled by the side guide.
In the figure, 10x is a side guide installed on the entrance side of the rolling mill (work rolls 1a, 1b), 10y is a side guide installed on the exit side of the rolling mill (work rolls 1a, 1b), and 11 is an opening of each side guide. It is a drive means (actuator) for adjusting the degree (guide width).
The side guides 10x and 10y need to have a rigidity capable of withstanding the restraint of the off-center and the camber while quickly changing the position setting according to the sheet width of the material to be rolled S and the position in the rolling direction. The driving means 11 for adjusting the opening degree of the side guides 10x, 10y is conventionally an electric screw, but in order to reduce the phenomenon that the side guide position fluctuates due to a load acting on the side guide during off-center and camber correction. It is preferable to set the position of the side guide (adjustment of the opening degree) using a highly responsive driving means such as a hydraulic servo cylinder. For this reason, the drive means 11 of this embodiment is also comprised by the hydraulic servo cylinder.

Here, the off-center of the material to be rolled S means that the center of the material to be rolled (center in the width direction) deviates from the roll center of the rolling mill, and is generated by meandering of the material to be rolled S. Further, as described above with reference to FIG. 18, the camber of the material to be rolled S is a phenomenon in which the material to be rolled bends into a "<" shape due to the difference between the left and right roll gaps. That is. In the present invention, the off-center and the camber of the material to be rolled S are restrained as shown in FIG. 5 using the side guides 10x and 10y.
5A shows a stage where the tip of the material to be rolled S has entered the side guide 10x on the entrance side of the rolling mill, and FIG. 5B shows a state where the tip of the material to be rolled S is a rolling roll (upper and lower work rolls 1a and 1b). FIG. 5 (c) shows a side guide in which the tip of the material to be rolled S is on the exit side of the rolling mill, in which the opening of the side guide 10x on the rolling mill entrance side is narrowed and the centering (off-center restraint) is performed. FIG. 5D shows a stage where the camber restraint is performed by narrowing the opening degree of the side guide 10y on the rolling mill exit side.

In other words, in the present invention, the tip of the material to be rolled S enters the side guide 10x on the entrance side of the rolling mill, and before the bite into the rolling roll, the opening (guide width) of the side guide 10x is narrowed to the material to be rolled. When the material S is centered (off-center constrained) by guiding (restraining) both sides of the S, and the tip of the material S enters the side guide 10y on the rolling material exit side, the side guide The camber of the material to be rolled S is restricted by narrowing the opening (guide width) of 10y and guiding (restraining) both sides of the material to be rolled S.
Here, the side guides 10x and 10y can also release the restraint of the material to be rolled S in the middle of the length direction of the material to be rolled. The opening degree (guide width) of each of the side guides 10x and 10y is narrowed at the same timing, and the state (a state in which the opening degree is reduced) is maintained until the tail end of the material S to be rolled passes. Is preferably guided (restrained) over the entire length thereof.

  In addition, after the front-end | tip of the to-be-rolled material S leaves a rolling mill until it reaches the side guide 10y on the rolling mill exit side, the tail end of the to-be-rolled material S passes through the side guide 10x on the rolling mill entry side. The material to be rolled S is not constrained by the side guides 10x and 10y until it exits the rolling mill. In this case, the local camber which exists in the tip end part of the to-be-rolled material S corresponding to the range which is not restrained cannot be corrected. In order to reduce the uncorrected range as much as possible, the side guides 10x and 10y are preferably installed as close to the rolling mill as possible without interfering with the work roll of the rolling mill.

  In addition, in the camber correction with the side guide opening closed, the camber is caused by a shape defect of the material to be rolled S such as a local camber at the tip of the material to be rolled S or a variation in the width dimension in the longitudinal direction. There is concern about side guide clogging. The clogging trouble of the material S to be rolled is accompanied by overloading the side guides 10x and 10y and the work roll drive system of the rolling mill. Therefore, in order to avoid such a side guide clogging trouble, a detecting means for detecting a load acting on the side guides 10x and 10y by contact of the material to be rolled S is provided, and the material to be rolled S by the side guides 10x and 10y is provided. It is preferable that the side guides 10x and 10y are quickly opened when a load exceeding a threshold is detected by the detection means during the guide, and means (equipment protection means) that enables this is provided. desirable. In addition, the said threshold value is set so that the load which acts on the side guides 10x and 10y by the contact of the material to be rolled S does not exceed the equipment strength of the side guides 10x and 10y.

Here, when a hydraulic servo cylinder is used as the driving means 11 of the side guides 10x and 10y as in the present embodiment, a load (a load due to a load acting on the side guides 10x and 10y) is applied to the hydraulic servo cylinder. Since it is possible to attach detection means for detecting via pressure, if such a detection means is provided, detection of the load acting on the side guides 10x and 10y without providing a new independent load detection means. Is possible.
FIG. 6 shows an apparatus configuration for controlling the side guide 10 (the side guide 10x and the side guide 10y, hereinafter the same) as described above. Reference numeral 12 denotes the side guide 10 by the contact of the material S to be rolled. Detection means for detecting the acting load, 13 is a calculation means 13 (comparator) for comparing the detection value by the detection means 12 with a threshold value, and 14 is a control for controlling the drive means 11 to operate the side guide 10. Means (control device).

In the embodiment of FIG. 6, the driving means 11 of the side guide 10 is constituted by a hydraulic servo cylinder 110, and a load (a load due to a load acting on the side guide 10) is detected in the hydraulic servo cylinder 110 via the cylinder pressure. The detection means 12 is attached.
The opening degree of the side guide 10 is adjusted by controlling the driving means 11 (hydraulic servo cylinder) by the control means 14. During the guide of the material to be rolled S by the side guide 10, the detection means 12 detects the load acting on the side guide 10 by the contact of the material to be rolled S. The detection value by the detection means 12 is sent to the calculation means 13, compared with a preset threshold value, and the result is sent to the control means 14. When the detected value exceeds the threshold value, the drive means 11 (hydraulic servo cylinder 110) is controlled by the control means 14, and the side guide 10 is rapidly opened.

  As explained earlier, in rolling with no wedge / cambered material, with wedge / no camber material, the volume of the material to be rolled is preserved before and after correction. When a wedge is generated and the latter is wedge-corrected by adjusting the roll gap, a camber is generated. That is, the camber correction and the wedge correction need to be performed independently at the same time. By performing the dynamic roll gap control so as to eliminate the left-right roll gap difference δdf while guiding the material S to be rolled by the side guides 10x and 10y as in the present invention and constraining the off-center and camber over the entire length, Regardless of the state of the camber and wedge of the material to be rolled S on the upstream side of the rolling mill, the camber and the wedge can be suppressed independently, and the wedge is stable against discontinuous wedge fluctuations in the rolling longitudinal direction. Correction is possible. This ensures uniform shape quality in the sheet width direction and the rolling direction, and causes a failure of the equipment due to the tip of the bent material being struck against peripheral equipment such as a guide. It will no longer induce a reduction in operating rate. That is, it is possible to stably manufacture a hot-rolled steel strip having a good shape without causing a trouble of passing plates due to wedges or cambers.

  The hot-rolled steel strip manufacturing facility of the present invention is a manufacturing facility in which side guides 10x and 10y are installed on the entry side and exit side of the work roll of a hot rolling mill, as shown in FIGS. The roll gap sensor A for measuring the left and right roll gaps of the upper and lower work rolls of the hot rolling mill, and means for adjusting the reduction amount of the left and right support parts of the work roll based on the measured values by the roll gap sensor A, respectively. B (not shown), drive means 11 for adjusting the opening degree of the side guides 10x and 10y, detection means 12 for detecting a load acting on the side guides 10x and 10y by contact of the material to be rolled, and the drive means The control means 14 (control apparatus) which controls 11 is provided.

  The means B is based on the left / right roll gap difference δdf of the upper and lower work rolls during rolling measured by the roll gap sensor A, and the left / right roll gap difference δdf is not more than a permissible value (including the case where the permissible value is zero). In order to achieve this, it has a function of adjusting (roll gap control) the amount of reduction of the left and right support portions of the work roll. This means B usually comprises a roll gap adjusting means such as a reduction hydraulic cylinder and a control means (control device) for controlling the roll gap. As described above, at the time of rolling, for example, the roll gap difference δdf is +200 μm. In the case where the right side is the wider side, roll gap control is performed with the target position where the roll gap difference Δdf is zero.

The control means 14 controls the driving means 11 to guide the material to be rolled by the side guides 10x and 10y to constrain its off-center and camber, and the detection means 12 exceeds the threshold value. It has a function of rapidly opening the side guide when a load is detected.
Further, in the manufacturing facility of the present invention, as shown in FIG. 6, the drive means 11 for adjusting the opening degree of the side guides, the detection means 12 for detecting the load acting on the side guides 10x and 10y via the cylinder pressure. It is preferable that the hydraulic servo cylinder 110 is provided, and the detection means 12 detects the load acting on the side guides 10x and 10y by the contact of the material to be rolled. Thereby, this invention can be implemented, avoiding troubles, such as side guide clogging, more appropriately.

  Side guides 10x and 10y as shown in FIG. 5 were installed on the entry and exit sides of the upper and lower work rolls 1a and 1b of the final stand of the hot roughing mill. In order to reduce the uncorrected range that is not constrained by the side guides 10x and 10y, the side guides 10x and 10y are installed as close as possible to the rolling mill within a range that does not interfere with the work roll of the rolling mill. Further, as shown in FIGS. 5 and 6, the drive means 11 of the side guides 10x and 10y is composed of a highly responsive hydraulic servo cylinder 110 and a load (on the side guides 10x and 10y via the cylinder pressure ( A detecting means 12 capable of detecting (load) is provided. A threshold is set at a level where the load on the side guides 10x and 10y does not exceed the equipment strength, and when the load exceeding the threshold is detected, the side guides 10x and 10y are rapidly opened by the control means 14. .

  As shown in FIGS. 7-12, the roll gap sensor A was each provided in the right-and-left roll end of the up-and-down work rolls 1a and 1b of the last stand of a hot roughing mill. 7 is a front view of a rolling mill work roll and a backup roll when the roll gap is zero, and FIG. 8 is a side view of the same (in this figure, the roll gap sensor A should be represented by a broken line, but is represented by a solid line for convenience of explanation). 9 is a front view of the rolling mill work roll and the backup roll in the case of the roll gap δ, and FIG. 10 is also a side view (in this figure, the roll gap sensor A should be originally represented by a broken line; 11 is a side view partially showing a take-up reel mechanism and the like of the roll gap sensor, and FIG. 12 is a cross-sectional view taken along line XII-XII in FIG.

  Each roll gap sensor A is provided at one end of the rope member 5 fixed to the roll chock 3b of the lower work roll 1b via the locking member 8 and the roll chock 3a of the upper work roll 1a. In order to detect the reel rotation position of the take-up reel mechanism 6, the rotary encoder 7 attached to each take-up reel mechanism 6 is provided. In this roll gap sensor A, tension is applied to the rope member 5 by the take-up reel mechanism 6, and the reel rotation position of the take-up reel mechanism 6 is determined by the take-up length of the rope member 5 according to the size of the roll gap. Since it corresponds, the roll gap amount can be obtained from the encoder output at the reel rotation position.

  The roll gap sensor A was used to measure the roll gap during rolling. FIG. 13 shows an equipment layout around the rolling mill during data measurement. In actual operation, work rolls must be reassembled between used rolls and polished new rolls every 24 to 36 hours. It is necessary to arrange so as not to stop. Therefore, the roll gap sensor A is attached in advance to a ground new roll that is waiting for roll reassembly, and is incorporated in the rolling mill together with roll recombination.

  In addition, a data signal and power supply wiring of the roll gap sensor are required. As shown in FIG. 13, a spindle for transmitting the power source from the main motor to the work roll is arranged around the work roll on the drive side. Therefore, it is difficult to access for wiring work, and when performing the above wiring work, it is necessary to install a scaffold, and it is expected that a large line stop time will occur. In order to solve these problems, the power supply of the roll gap sensor is a small battery, and the data signal is transmitted using the wireless unit, thereby eliminating the data signal and power wiring work normally required for the roll gap sensor. I was able to.

FIG. 14 is a schematic diagram showing the flow of power and data signals. A set of equipment including a roll gap sensor, a battery, and a transmitting wireless unit installed on the rolling mill side was housed in a resin sensor box in order to protect it from steam, cooling water, and ambient temperature. The signal from the transmission side radio unit is transmitted to the reception side radio unit installed on the safety path outside the line, and the A and B phase encoder signals are converted into the roll gap measurement value δ by the counter and recorded in the data logger. .
Subsequently, after confirming the output signal from the roll gap sensor A, the leveling zero tone, which is normally performed after the roll change, was performed. As shown in FIGS. 7 and 8, leveling zero adjustment was performed to adjust the left-right reduction position balance while the upper and lower work rolls were in contact with each other. Considering that the difference between the left and right roll gaps between the upper and lower work rolls was zero during this leveling zero adjustment, the left and right roll gap measurement sensor was zeroed.

  According to the method of the present invention, the left and right roll gaps of the upper and lower work rolls during rolling measured by the roll gap sensor A while guiding the material to be rolled by the side guides on the entry side and the exit side of the rolling mill and restraining the off center and camber thereof Based on the difference δdf (see FIG. 15), the rolling reduction amounts of the left and right support portions of the work roll are adjusted so that the left and right roll gap difference δdf is less than the allowable value (including the case where the allowable value is zero). And rolled. In this embodiment, dynamic roll gap control is performed by feeding back the roll gap difference δdf from immediately after the tip of the material to be rolled bites into the rolling mill until the tail end of the material to be rolled passes through the rolling mill. The roll gap adjusting means employs a reduction hydraulic cylinder.

  In this example, the suppression effect of the camber and the wedge due to the application of the present invention was investigated for the material to be rolled having an entrance side plate thickness h1 = 45 mm, an exit side plate thickness h0 = 32 mm, and a plate width b = 1300 mm. Regarding the camber amount, a virtual center line passing through the center of the plate width at the leading end was obtained by a piano wire centering method, and the displacement of the plate width center with respect to the virtual center was measured at a pitch of 0.5 m. The difference between the left and right roll gaps was obtained from the difference between the left and right roll roll sensors A.

FIG. 16 (a) shows the occurrence of camber in the method of the present invention and the conventional method, and FIG. 16 (b) shows the difference between the left and right roll gaps, that is, the occurrence of a wedge. Here, in the conventional method, the roll gap adjusting means is a reduction screw, and the balance adjustment of the left and right roll gap is adjusted so that the left and right load cell loads installed in the rolling mill are balanced in the pre-rolling kiss roll test and during rolling. The meandering behavior of the material to be rolled is monitored, and the operator adjusts the balance of the reduction screw tightening amount based on the feeling and experience from the rolling to the rolling of the next material. Further, the side guide does not positively correct the camber, and is a condition for setting the side guide opening setting of the plate width of the material to be rolled + 50 mm over the entire length direction of the material to be rolled as a centering application. According to FIG. 16, it can be seen that by applying the method of the present invention, the camber amount can be stably achieved within ± 5 mm and the wedge within ± 100 μm.
FIG. 17 shows the transition of the frequency of occurrence of plate troubles in the rough rolling mill and the finishing mill that is the downstream rolling mill group before and after applying the method of the present invention to the final stand of the hot rough rolling mill. When the average before application of the present invention was set to 1.0, it was confirmed that the plate passing trouble was reduced to 1/3 or less after the application of the present invention, which was effective for meandering control.

DESCRIPTION OF SYMBOLS 1a, 1b Work roll 2a, 2b Backup roll 3a, 3b, 4a, 4b Roll chock 5 Rope member 6 Take-up reel mechanism 7 Rotary encoder 8 Locking member 10, 10x, 10y Side guide 11 Drive means 12 Detection means 13 Calculation means 14 Control means 110 Hydraulic servo cylinder A Roll gap sensor S Rolled material

Claims (6)

  In a hot rolling mill in which side guides are installed on the entry side and the exit side of the work roll, a roll gap sensor for measuring the left and right roll gaps of the upper and lower work rolls is provided, and the material to be rolled is guided by the side guide, Based on the left and right roll gap difference δdf of the upper and lower work rolls measured by the roll gap sensor while restraining the off-center and camber, the left and right roll gap difference δdf is an allowable value (however, when the allowable value is zero) A method for producing a hot-rolled steel strip, characterized in that rolling is performed by adjusting the amount of reduction of the left and right support portions of the work roll so as to be as follows.   A means for detecting the load acting on the side guide by the contact of the material to be rolled is provided, and the side guide is quickly opened when a load exceeding the threshold is detected by the detecting means during the guide of the material to be rolled by the side guide. The method for producing a hot-rolled steel strip according to claim 1.   The method for producing a hot-rolled steel strip according to claim 2, wherein the threshold value is set so that the load acting on the side guide due to contact with the material to be rolled does not exceed the equipment strength of the side guide.   The drive means for adjusting the opening degree of the side guide is constituted by a hydraulic servo cylinder provided with a detection means for detecting a load acting on the side guide through the cylinder pressure, and the side by the contact of the material to be rolled by the detection means. The method for producing a hot-rolled steel strip according to claim 2 or 3, wherein a load acting on the guide is detected. In the production facility for hot-rolled steel strips with side guides installed on the entry side and exit side of the work roll of a hot rolling mill,
A roll gap sensor for measuring the left and right roll gaps of the upper and lower work rolls of the hot rolling mill;
Based on the left and right roll gap difference δdf of the upper and lower work rolls during rolling measured by the roll gap sensor, the left and right roll gap difference δdf is less than or equal to an allowable value (including the case where the allowable value is zero). Means for respectively adjusting the amount of reduction of the left and right support parts of the work roll;
Driving means for adjusting the opening degree of the side guide;
Detecting means for detecting a load acting on the side guide by contact of the material to be rolled;
By controlling the driving means, the material to be rolled is guided by the side guide to restrain the off-center and the camber, and the side guide is rapidly opened when a load exceeding the threshold is detected by the detecting means. A facility for manufacturing a hot-rolled steel strip, characterized by comprising means.   The drive means for adjusting the opening degree of the side guide is constituted by a hydraulic servo cylinder provided with a detection means for detecting a load acting on the side guide through the cylinder pressure, and the side by the contact of the material to be rolled by the detection means. The hot-rolled steel strip manufacturing facility according to claim 5, wherein a load acting on the guide is detected.

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