Title of the invention: Cooling device for hot-rolled steel sheet and cooling method for hot-rolled steel sheet
Technical field
[0001]
　The present invention relates to a cooling device that cools the upper surface of a hot-rolled steel sheet that is transported on a transport roll after hot rolling, and a cooling method that uses the cooling device.
Background technology
[0002]
　With the recent weight reduction of automobiles, the demand for high-strength steel sheets among hot-rolled steel sheets is increasing, and the quality required for hot-rolled steel sheets is further increasing. Especially in recent years, not only high strength but also excellent workability such as press formability and hole expansion, and variation in mechanical properties such as tensile strength and workability are kept within a predetermined range over the entire area of ​​the steel sheet. That is also required.
[0003]
　In the manufacturing process of hot-rolled steel sheet, winding temperature is one of the factors that greatly affect the characteristics of the final product as described above. Here, the take-up temperature is the temperature of the steel sheet immediately before the take-up device when the steel sheet is taken up after the cooling step after finish rolling.
[0004]
　Generally, in the cooling process of injecting cooling water onto a hot-rolled steel sheet having a high temperature of 800 ° C. to 900 ° C. after finish rolling, the steam generated by boiling the film is stable while the steel sheet temperature is approximately 600 ° C. or higher. Cover the surface of the steel plate. Therefore, although the cooling capacity itself by the cooling water is reduced, it becomes relatively easy to uniformly cool the steel sheet over the entire surface.
　However, especially when the temperature of the steel sheet falls below 600 ° C., the amount of steam generated decreases as the temperature of the steel sheet decreases. Then, the vapor film covering the surface of the steel sheet begins to collapse, and the distribution of the vapor film becomes a transition boiling region where the distribution changes temporally and spatially. As a result, the non-uniformity of cooling increases, and the non-uniformity of the temperature distribution of the steel sheet tends to rapidly increase. For this reason, it becomes difficult to control the temperature of the steel sheet, and it becomes difficult to finish cooling the entire steel sheet at the desired winding temperature.
[0005]
　On the other hand, in order to produce a product having excellent characteristics in which both strength and workability are compatible, it is effective to lower the winding temperature to a low temperature range of 500 ° C. or lower. Therefore, it is important to keep the non-uniformity of the winding temperature over the entire steel sheet within a predetermined range with respect to the target temperature. From this point of view, many inventions have been made for uniform winding temperature, particularly uniform winding temperature in the plate width direction.
[0006]
　In Patent Document 1, a plurality of nozzles for adding a coolant to a hot-rolled steel sheet are installed in the width direction on both the upper side and the lower side of the hot-rolled steel sheet in the cooling device, and these nozzles are particularly high. It is disclosed that the temperature is controlled in a manner in which a coolant is added where it can be detected. In this cooling device, a plurality of temperature sensors are further installed in the width direction, and these temperature sensors detect the temperature distribution in the width direction of the hot-rolled steel plate and cool from the nozzle based on the signal of the temperature sensor. It is configured so that the dosage can be controlled.
[0007]
　In Patent Document 2, in the cooling device, a plurality of cooling water headers in which a plurality of cooling water supply nozzles are linearly arranged are arranged above the hot-rolled steel plate and in the width direction, and the temperature in the plate width direction is provided. It is disclosed that the flow rate of the cooling water is controlled based on the temperature distribution measured by the temperature distribution sensor that detects the distribution. Specifically, these cooling water headers are provided with an on / off control valve, and the cooling water is controlled by the on / off control valve.
[0008]
　The cooling device disclosed in Patent Document 3 is a spray nozzle that injects cooling water in the width direction of the steel sheet transport region with respect to the steel sheet transport region when the region occupied by the hot-rolled steel sheet on the transport roll is the steel plate transport region. Are arranged in pairs on both sides of the steel sheet transport region on the side in the width direction, and a plurality of spray nozzle pairs are arranged side by side in the transport direction of the hot-rolled steel sheet. In this cooling device, in the collision region of the cooling water injected from the spray nozzle in the steel sheet transport region, the far end in the injection direction is located at the end of the transport region, and the near end is the steel plate transport region. It is located on the inside, and the near ends of the two collision regions of the spray nozzle pair form an association in the width direction. Further, in Patent Document 3, the meeting portions are arranged in a staggered pattern in a meeting zone defined in the center in the width direction of the steel sheet transport region, so that the meeting portions are dispersed in the width direction and supercooled. It is disclosed that the portion to be used is minimized and the hot-rolled steel sheet is uniformly cooled in the width direction.
[0009]
　In Patent Document 4, in a cooling facility installed in a hot-rolled steel sheet production line and supplying cooling water to the upper and lower surfaces of a steel sheet after finish rolling, a header that supplies cooling water to the upper surface of the steel sheet after finish rolling is provided. , It is disclosed that it consists of a normal cooling header and a strong cooling header. Normally, the cooling header is directly above the steel plate and supplies cooling water at a flow density of 0.5 to 2.0 m 3 / m 2 · min. The strong cooling header is located above the outside in the width direction of the steel sheet , and supplies rod-shaped cooling water toward the inside and bottom in the width direction at a flow density of 2.0 to 10.0 m 3 / m 2 · min and lands on the steel sheet. The subsequent cooling water is prevented from staying on the steel plate.
Prior art literature
Patent documents
[0010]
Patent Document 1: Japanese
Patent Application Laid-Open No. 2010-527977 Patent Document 2: Japanese Patent Application Laid-Open No. 6-71328
Patent Document 3: International Publication No. 2018/073973
Patent Document 4: Japanese Patent Application Laid-Open No. 2011-51002
Outline of the invention
Problems to be solved by the invention
[0011]
　However, Patent Documents 1 and 2 do not disclose the cooling control of the hot-rolled steel sheet in the steel sheet transport direction, and the cooling devices of Patent Documents 1 and 2 suppress the non-uniform temperature distribution of the hot-rolled steel sheet in the steel sheet transport direction. It's difficult to do.
　Further, in the cooling device of Patent Document 1, as described above, since the nozzle for adding the cooling agent to the hot-rolled steel sheet is installed on the upper side of the hot-rolled steel sheet, when cooling water is used as the cooling agent, Since the water on the plate is present on the upper surface of the hot-rolled steel sheet for a long time, the temperature in the width direction of the hot-rolled steel sheet cannot be sufficiently controlled. The cooling device of Patent Document 2, that is, the cooling device in which the cooling water header in which the cooling water supply nozzles are linearly arranged as described above is arranged above the hot-rolled steel plate is the same as the cooling device of Patent Document 1. Is.
[0012]
　In the cooling device disclosed in Patent Document 3, the spray nozzle injects cooling water in the width direction of the steel sheet transport region to cool the hot-rolled steel sheet while discharging the water on the sheet, and two spray nozzle pairs. The near ends of the collision area coincide with each other in the width direction to form a meeting part, and this meeting part is arranged in a staggered pattern in order to suppress supercooling, but the meeting part is arranged in a steel plate. It is in the meeting zone partitioned in the center of the transport area in the width direction, not the entire width direction. Therefore, the cooling device disclosed in Patent Document 3 has room for improvement in terms of uniform cooling over the entire width in the width direction. Further, Patent Document 3 does not disclose the cooling control of the hot-rolled steel sheet in the steel sheet transport direction.
[0013]
　Further, the strong cooling header disclosed in Patent Document 4 supplies rod-shaped cooling water inward and downward in the width direction so that the cooling water after landing on the steel plate does not stay on the steel plate, but the rod-shaped cooling is performed. Since water is used, the collision region of the cooling water from the nozzle of the header on the steel plate has a gap between the collision region and the other collision regions adjacent in the width direction. Since the steel sheet is insufficiently cooled at the position corresponding to this gap, the cooling device disclosed in Patent Document 4 cannot perform uniform cooling in the width direction. Further, Patent Document 4 does not disclose the cooling control of the hot-rolled steel sheet in the steel sheet transport direction.
[0014]
　The present invention has been made in view of the above circumstances, and by appropriately cooling the upper surface of the hot-rolled steel sheet after hot rolling, the temperature uniformity is improved in the steel sheet transport direction and the width direction of the hot-rolled steel sheet. The purpose is to make it.
Means to solve problems
[0015]
　The present invention that solves the above problems is a cooling device for a hot-rolled steel plate that cools the upper surface of a hot-rolled steel plate that is conveyed on a transport roll after hot rolling, and has a cooling machine length on the upper surface of a region to be cooled. The region defined by the total width in the width direction or the region excluding the non-cooling region in the central portion in the width direction is defined as the total cooling region, and the region obtained by dividing the total cooling region into 3 or more in the width direction is divided into widths. When a cooling zone is used and a region obtained by dividing the width-divided cooling zone into a plurality of parts in the machine length direction is used as a divided cooling surface, cooling water is sprayed on each of the divided cooling surfaces and the cooling water collides with the upper surface of the cooling target area. Each of the divided cooling surfaces is provided with at least one cooling water nozzle forming a region and a switching device for switching between collision and non-collision of the cooling water ejected from the cooling water nozzle with the divided cooling surface. Further, based on the temperature detection device for measuring the width direction temperature distribution of the cooling target region and the width direction temperature distribution measurement result by the temperature detection device, for each of the width division cooling zones, in the width division cooling zone. A control device that controls the cooling of the entire length of the width-divided cooling zone by controlling the operation of the switching device with respect to each of the plurality of included divided cooling surfaces, and controls the cooling of the entire cooling region in combination with these. , And one said cooling water collision region forms a group of cooling water collision regions connected in the width direction while overlapping with the other cooling water collision regions adjacent in the width direction in the entire cooling region. , Each of the cooling water collision area groups does not overlap with the other cooling water collision area groups, and the total width of the entire cooling area in the width direction is one pair of the cooling water collision area groups or a pair adjacent to each other in the machine length direction. The cooling water nozzle, which is covered by the cooling water collision region group and forms one cooling water collision region group, has an injection shaft inclined with respect to a perpendicular line on the upper surface of the cooling target region in the direction of the machine length. The direction in which the injection shaft is tilted is not the opposite in the direction of the captain.
[0016]
　The uncooled region may not be present.
[0017]
　The width in the width direction of the region where the cooling water collision region overlaps with the other cooling water collision region adjacent in the width direction may be 5% or more of the width in the width direction of one cooling water collision region.
[0018]
　The inclination angle of the injection shaft of the cooling water nozzle may be 10 ° to 45 °.
[0019]
　The injection shaft of the cooling water nozzle does not have to be inclined in the machine length direction.
[0020]
　The cooling water collision region may overlap with the central axis of the transport roll in a plan view.
[0021]
　The cooling water nozzle may be provided so that the center of the cooling water collision region is located on the central axis of the transport roll in a plan view.
[0022]
　The cooling water nozzle may be provided above or to the side of the cooling target area in the direction of the captain.
[0023]
　The cooling water collision region group formed by the cooling water nozzle that injects toward one side in the width direction is designated as the first cooling water collision region group, and the cooling water nozzle that injects toward the other side in the width direction serves as the first cooling water collision region group. When the cooling water collision region to be formed is a second cooling water collision region group, the cooling water nozzle has both the first cooling water collision region group and the second cooling water collision region group. Even if it is formed and the boundary in the width direction between the first cooling water collision region group and the second cooling water collision region group is provided so as to be located at the center in the width direction of the cooling target region. Good.
[0024]
　On the upper surface of the cooling water collision region group, for each region on the downstream side in the captain direction of each of the cooling water collision region groups, or on the downstream side in the captain direction from the region group on the most downstream side in the captain direction of the cooling water collision region group. The region may be provided with a drain nozzle that injects drain water to form a drain water collision region.
[0025]
　According to the present invention from another viewpoint, it is a method of cooling a hot-rolled steel plate using a cooling device that cools the upper surface of the hot-rolled steel plate transported on a transport roll after hot rolling, and is a method of cooling the hot-rolled steel plate on the upper surface of a cooling target region. The entire cooling region is defined as the region defined by the cooler length and the full width in the width direction or the region excluding the non-cooling region in the central portion in the width direction, and the total cooling region is divided into 3 or more in the width direction. When the region to be divided is a width-divided cooling zone and the region obtained by dividing the width-divided cooling zone into a plurality of parts in the machine length direction is a divided cooling surface, the cooling device performs the divided cooling for each of the divided cooling surfaces. At least one cooling water nozzle for injecting cooling water onto the surface to form a cooling water collision region on the upper surface of the cooling target region is provided, and one cooling water collision region is provided in the width direction in the entire cooling region. While overlapping with the other adjacent cooling water collision regions, a cooling water collision region group connected in the width direction is formed, and each of the cooling water collision region groups does not overlap with the other cooling water collision region group, and the cooling water collision region group is not overlapped with the cooling water collision region group. The entire width in the width direction of the entire cooling region is covered by one cooling water collision region group or a pair of cooling water collision region groups adjacent to each other in the machine length direction, and the cooling forming one cooling water collision region group. The water nozzle has an injection shaft that is tilted with respect to the vertical line on the upper surface of the cooling target region in the machine length direction, and the direction in which the injection shaft is tilted is not opposite in the machine length direction, and the cooling method is the cooling target. The width direction temperature distribution of the region is measured, and based on the measurement result of the width direction temperature distribution of the cooling target region, the cooling water by the cooling water nozzle to the plurality of the divided cooling surfaces included in the width division cooling zone. By controlling the collision and non-collision with the divided cooling surface for each of the width-divided cooling zones, the cooling of the width-divided cooling zone over the entire length in the machine length direction is controlled, and the cooling of the entire cooling region is controlled. The cooling water ejected from the cooling water nozzle is directed to the opposite side in the width direction from the cooling water nozzle and discharged.
[0026]
　On the upper surface of the cooling water collision region group, for each region on the downstream side in the captain direction of each of the cooling water collision region groups, or on the downstream side in the captain direction from the region group on the most downstream side in the captain direction of the cooling water collision region group. The drainage water may be sprayed into the region to form a drainage water collision region.
Effect of the invention
[0027]
　According to the present invention, by appropriately cooling the upper surface of the hot-rolled steel sheet after hot rolling, it is possible to improve the temperature uniformity in the steel sheet transport direction and the width direction of the hot-rolled steel sheet.
A brief description of the drawing
[0028]
FIG. 1 is an explanatory diagram showing an outline of a configuration of a hot rolling apparatus 10 according to a first embodiment of the present invention.
FIG. 2 is a side view showing an outline of the configuration of the upper width direction control cooling device 16 according to the first embodiment of the present invention.
FIG. 3 is a bottom view showing an outline of the configuration of the upper width direction control cooling device 16 according to the first embodiment of the present invention.
FIG. 4 is a diagram illustrating a divided cooling surface A3 of one example.
FIG. 5 is an explanatory diagram focusing on the width-divided cooling zone A2.
FIG. 6 is a diagram illustrating another example of the divided cooling surface A3.
FIG. 7 is a diagram illustrating another example of the divided cooling surface A3.
FIG. 8 is a diagram illustrating the positional relationship between the divided cooling surfaces A3 and the temperature measuring devices 28 and 29 in the upper width direction control cooling device 16 according to the first embodiment of the present invention.
FIG. 9 is a diagram illustrating a cooling water nozzle 23 and a cooling water collision region R formed on the upper surface of the cooling width region by the cooling water nozzle 23.
FIG. 10 shows the inclination angle θ of the injection shaft P of the cooling water nozzle 23, which is a full cone spray nozzle, and the direction opposite to the cooling water injection direction after colliding with the hot-rolled steel plate 2 of the cooling water from the cooling water nozzle 23. It is a figure which shows the relationship with the ratio of the return cooling water.
FIG. 11 is a diagram showing the relationship between the inclination angle θ of the injection shaft P of the cooling water nozzle 23, which is a full cone spray nozzle, and the collision pressure index.
FIG. 12 is a diagram illustrating another example of a cooling water collision region R formed on the cooling water nozzle 23 and the upper surface of the cooling width region by the cooling water nozzle 23.
FIG. 13 is a diagram illustrating another example of a cooling water collision region R formed on the cooling water nozzle 23 and the upper surface of the cooling width region by the cooling water nozzle 23.
FIG. 14 is a diagram illustrating another example of a cooling water collision region R formed on the cooling water nozzle 23 and the upper surface of the cooling width region by the cooling water nozzle 23.
15 is a diagram showing a part of an XX cross section and a YY cross section of FIG. 14. FIG.
FIG. 16 is a diagram illustrating an upper width direction control cooling device 16 according to a second embodiment.
FIG. 17 is a diagram illustrating another example of the draining nozzle 40.
FIG. 18 is a diagram for explaining the influence when the cooling water nozzle 23 is used as a slit laminar nozzle.
FIG. 19 is a diagram illustrating a total cooling region A1 of another example.
FIG. 20 is a diagram illustrating a cooling water collision region R formed in the case of the total cooling region A1 in the example of FIG.
FIG. 21 is a diagram illustrating another example of a cooling water collision region R formed in the case of the total cooling region A1 of the example of FIG.
FIG. 22 is a diagram illustrating a switching device of another example.
[Fig. 23] Fig. 23 is a diagram showing a part of the temperature distribution of steel sheets in Comparative Examples and Examples.
Mode for carrying out the invention
[0029]
　The present inventors have made extensive studies and found the following. That is, when the cooling water nozzle is provided above the hot-rolled steel plate, the injection axis of the cooling water nozzle is tilted, and after the cooling water from the cooling water nozzle collides with the hot-rolled steel plate, the cooling water nozzle and the width direction ( Hereinafter, the width direction may be referred to as the plate width direction or the machine width direction, but they have the same meaning.) By allowing the hot-rolled steel plate to flow down toward the opposite side, the cooling water is directly cooled by the cooling water from the cooling water nozzle. It was found that the heat transfer coefficient of the former region is about four times or more that of the latter region between the region and the region cooled by the water on the plate after the collision with the hot-rolled steel plate until it flows down. Based on the results of this study, the injection shaft is used for each of the divided cooling surfaces in which the upper surface of the cooling target area is divided into the width direction and the steel plate transport direction (hereinafter, the steel plate transport direction may be referred to as the machine length direction, but has the same meaning). By providing a cooling water nozzle tilted and switching between collision and non-collision with the divided cooling surface injected from the cooling water nozzle based on the temperature distribution measurement result in the width direction, in the transport direction and width direction of the hot-rolled steel sheet. It was found that it is possible to improve the uniformity of temperature.
[0030]
　Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.
[0031]
(First Embodiment)
　FIG. 1 is an explanatory view showing an outline of the configuration of a hot-rolled steel sheet manufacturing apparatus (hereinafter, referred to as “hot rolling equipment”) 10 provided with a cooling apparatus according to the first embodiment of the present invention. Is.
[0032]
　As shown in FIG. 1, in the hot rolling equipment 10, the heated slab 1 is sandwiched between rolls up and down and continuously rolled, thinned to a minimum plate thickness of about 1 mm, and wound as a hot-rolled steel plate 2. .. The hot rolling equipment 10 includes a heating furnace 11 for heating the slab 1, a width rolling mill 12 for rolling the slab 1 heated in the heating furnace 11 in the plate width direction, and rolling in the plate width direction. A rough rolling mill 13 that rolls the slab 1 from the vertical direction to make a rough bar, a finishing rolling mill 14 that continuously hot-rolls the rough bar to a predetermined thickness, and a finishing rolling mill 14 that is hot. It is provided with cooling devices 15, 16 and 17 for cooling the rolled hot-rolled steel sheet 2 with cooling water, and a winding device 18 for winding the hot-rolled steel sheet 2 cooled by the cooling devices 15 and 16 and 17 in a coil shape. ing.
[0033]
　In the heating furnace 11, a process of heating the slab 1 carried in from the outside through the inlet to a predetermined temperature is performed. When the heat treatment in the heating furnace 11 is completed, the slab 1 is extracted to the outside of the heating furnace 11 and transferred to the rolling process by the rough rolling mill 13 via the width direction rolling mill 12.
[0034]
　In the rough rolling step, the slab 1 is rolled by the rough rolling mill 13 into a rough bar (sheet bar) having a thickness of, for example, about 30 mm to 60 mm, and is conveyed to the finishing rolling mill 14.
[0035]
　In the finish rolling mill 14, the conveyed rough bar is rolled to a plate thickness of about several mm (for example, 1 to 15 mm) to obtain a hot-rolled steel sheet 2. The rolled hot-rolled steel sheet 2 is conveyed by a transfer roll 19 (see FIGS. 2 and 3), first sent to a cooling zone including a main cooling device 15, and further, an upper width direction control cooling device (see FIG. 3). Hereinafter, it is referred to as an “upper cooling device”), and is sent to a cooling zone composed of 16 and further sent to a cooling zone composed of an adjustment cooling device 17.
[0036]
　The hot-rolled steel sheet 2 is cooled by the main cooling device 15, the upper cooling device 16, and the adjusting cooling device 17, and is wound into a coil by the winding device 18. Of the cooling devices 15, 16 and 17, the main cooling device 15 mainly cools the hot-rolled hot-rolled steel plate 2, and the upper cooling device 16 mainly cools the hot-rolled steel plate 2 cooled by the main cooling device 15. The hot-rolled steel plate 2 is cooled from the upper surface side so as to eliminate the temperature non-uniformity in the width direction, and the adjusting cooling device 17 cools the hot-rolled steel plate 2 cooled by the upper cooling device 16 to a target temperature. .. The main cooling device 15 and the adjusting cooling device 17 are arranged so as to sandwich the hot-rolled steel plate 2 to which the runout table is conveyed, and the upper cooling device 16 is arranged above the hot-rolled steel plate 2. Further, the adjusting cooling device 17 cools the hot-rolled steel sheet 2 so that the temperature is lowered by, for example, about 50 ° C.
[0037]
　The configuration of the main cooling device 15 is not particularly limited, and a known cooling device can be applied. For example, the main cooling device 15 includes a cooling water nozzle that injects cooling water vertically downward from above the hot-rolled steel plate 2 conveyed on the transport roll 19 of the runout table toward the upper surface of the hot-rolled steel plate 2, and hot-rolling. Each of the plurality of cooling water nozzles for injecting cooling water vertically upward from below the steel plate 2 toward the lower surface of the hot-rolled steel plate 2 is provided. As the cooling water nozzle, for example, a slit laminar nozzle, a pipe laminar nozzle, or the like is used.
[0038]
　In the example of the figure, the lower surface cooling device for cooling the hot-rolled steel sheet 2 from the lower surface side is not provided at the position facing the upper cooling device 16, but the lower surface cooling device may be provided. The configuration of the bottom surface cooling device is not particularly limited, and a known cooling device can be applied. For example, as the bottom surface cooling device, the cooling device of International Publication No. 2018/179449 can be installed.
[0039]
　Further, the configuration of the adjusting cooling device 17 is not particularly limited, and a known cooling device can be applied. It is not always arranged if the cooling to the upper cooling device 16 does not cause insufficient cooling, but it is usually required.
[0040]
　Next, the configuration of the upper cooling device 16 will be described. FIG. 2 schematically shows a part of the configuration of the upper cooling device 16, a side view seen from the width direction (± Y direction), and FIG. 3 schematically shows a part of the configuration of the upper cooling device 16. , The bottom view seen from below in the vertical direction (± Z direction) is shown. In FIG. 2, among the cooling water nozzles 23, those belonging to the first nozzle group G1 are shown by virtual lines. Further, in FIG. 3, for convenience of explaining the horizontal positional relationship, the hot-rolled steel plate 2, the transport roll 19, the upstream temperature measuring device 28, and the downstream temperature measuring device 29 are shown by dotted lines.
　The upper cooling device 16 in the present embodiment includes a cooling water nozzle 23, a switching device including an intermediate header 24, a pipe 25, and a three-way valve 27, a water supply header 26, and a water supply header 26, as schematically shown in FIGS. It is roughly configured with a drainage header (not shown), temperature measuring devices 28 and 29, and a control device 30. Although partly omitted in the drawing, a three-way valve 27 is arranged for each intermediate header 24.
[0041]
　The upper cooling device 16 is a device that controls cooling for each of the divided cooling surfaces A3 formed by dividing the entire cooling region A1 formed on the upper surface of the cooling width region described later in the runout table. 4 to 7 are plan views of the cooling width region on the runout table at the place where the upper cooling device 16 is arranged, as viewed from above in the vertical direction (± Z direction), and the total cooling region A1 and the width. The relationship between the split cooling zone A2 and the split cooling surface A3 and the position of the transport roll 19 is shown. In FIGS. 4 and 5, the transport roll 19 is shown by a dotted line for convenience of explanation. The lower surface of the cooling width region is also a plane in contact with the apex of the runout table.
[0042]
　In the present embodiment, the region that can exist when the hot-rolled steel sheet 2 that can be manufactured by the hot rolling equipment 10 is conveyed on the runout table is referred to as a “cooling width region”. The "cooling width region" is a three-dimensional region that is originally partitioned by the maximum plate thickness x (maximum plate width + maximum meandering width) of the hot-rolled steel sheet that can be manufactured and extends in the steel sheet transport direction. Therefore, the "cooling width region" occupies the region from the exit side end of the finish rolling mill on the runout table to the front of the winding device in the steel sheet transport direction. This cooling width region is the “cooling target region” in the present embodiment. In practice, the part related to the maximum plate thickness can be ignored, so the cooling width region, that is, the cooling target region, is divided by (maximum plate width + maximum meandering width) on the plane in contact with the apex of the runout table. In other words, it may be regarded as a flat surface.
[0043]
　Of the upper surface of the cooling width region, the region to be cooled by the upper cooling device 16 and defined by the total width in the machine width direction and the length of the cooler is referred to as “total cooling region A1”. FIG. 4 shows an example of the total cooling region A1. The "machine width" has the same meaning as the length of the upper cooling device 16 in the machine width direction (hereinafter, the length in the machine width direction may be referred to as the length in the width direction or the width in the width direction). ), And the "total width in the width direction" is the length in the width direction of the region where the hot-rolled steel plate 2 can exist on the transport roll 19. The “cooler length” is the length of the region cooled by the upper cooling device 16 in the steel plate transport direction, and is at least a length of 1 pitch or more (for example, 1 m or more) between the rolls in the steel plate transport direction of the transport roll 19. The “length of one pitch between the rolls in the steel plate transport direction” means the distance between the axes of the adjacent transport rolls 19 in the steel plate transport direction. The "cooler length" is not particularly limited, but is preferably about 20 m or less from the viewpoint of equipment cost. The specific length may be appropriately determined from the cooling capacity of the upper cooling device 16 and the predicted mode of the non-uniform temperature distribution of the hot-rolled steel sheet 2.
[0044]
　Each cooling region obtained by dividing the entire cooling region A1 into three or more in the machine width direction, that is, in the width direction is referred to as a "width division cooling zone A2". FIG. 5 shows an example in which the entire cooling region A1 is divided into 10 width-divided cooling zones. The number of divisions of the entire cooling region A1 in the width direction (that is, the number of width division cooling zones A2 in the width direction) is not limited to this. In order to make the temperature distribution in the width direction uniform, it is better that the number of divisions is large. For example, the lower limit of the number of divisions may be 4, 6, 8, 10 or 12. However, since the equipment cost increases as the number of divisions increases, the upper limit of the number of divisions may be 30, 20, 16 or 14.
[0045]
　Further, each cooling region obtained by dividing the width-divided cooling zone A2 into a plurality of parts in the machine length direction, that is, in the steel plate transport direction is referred to as a "divided cooling surface A3". The individual width direction lengths of the divided cooling surfaces A3 are the same as the width direction lengths of the width divided cooling zone A2. The length of the divided cooling surface A3 in the steel plate transport direction is, for example, the length obtained by evenly dividing the length of the width divided cooling zone A2 in the steel plate transport direction by the number of divisions.
　The length of the divided cooling surface A3 in the steel plate transport direction is not particularly limited and can be set as appropriate. The length of the divided cooling surface A3 shown in FIG. 4 in the steel plate transport direction is set to be four times one pitch of the transport roll 19. Further, in the example of FIG. 6, the length of the divided cooling surface in the steel plate transport direction is set to one pitch of the transport roll 19. As described above, the length of the divided cooling surface A3 in the steel plate transport direction is preferably an integral multiple of the pitch between the rolls in the steel plate transport direction of the transport roll 19.
　The lengths of the plurality of divided cooling surfaces A3 arranged adjacent to each other in the steel plate transport direction do not have to be the same, and may be different from each other. In other words, the width-divided cooling zone A2 may be a combination of the divided cooling surfaces A3 having different lengths in the steel plate transport direction. For example, as shown in FIG. 7, the length of the divided cooling surface A3 in the steel plate transport direction is changed from the upstream side to the downstream side by 1 pitch, 2 pitches, 4 pitches, 8 between the rolls in the steel plate transport direction of the transport roll 19. It may be lengthened in sequence, such as by the pitch.
[0046]
　In the following description, as shown in FIG. 4, it is assumed that the length of the divided cooling surface A3 in the steel plate transport direction is 4 pitches between the rolls in the steel plate transport direction of the transport roll 19.
[0047]
　At least one cooling water nozzle 23 is provided for each of the divided cooling surfaces A3 as described above. The cooling water nozzle 23 injects cooling water from above the cooling width region toward the upper surface of the cooling width region. Various known types of nozzles can be used for the cooling water nozzle 23, and for example, a full cone spray nozzle to which a back pressure of about 0.3 MPa is applied (hereinafter, abbreviated as "full cone nozzle"). There is.). Further, the cooling water nozzle 23 preferably has a small diameter in order to prevent the cooling water from falling out of the cooling water nozzle 23 in the standby state.
[0048]
　The cooling range in the width direction of the cooling water nozzle 23 is preferably set to a part of the divided cooling surfaces A3 adjacent to both sides in the width direction in addition to the length in the width direction of the corresponding divided cooling surface A3. .. If the cooling range in the width direction of the cooling water nozzle 23 is limited to the width in the width direction of the single divided cooling surface A3, the cooling capacity on the boundary line with other divided cooling surfaces A3 adjacent in the width direction may be insufficient. I am concerned. In order to eliminate such a cooling shortage, the width in the width direction in which the cooling water collision region R described later of the nozzle 23 overlaps with another cooling water collision region R adjacent in the width direction is the width direction of the cooling water collision region. It is preferable to set it so that it is 5% or more of the width. The width in the width direction overlapping with the other cooling water collision region R is more preferably 7% or more or 8% or more of the width in the width direction of the cooling water collision region. The width in the width direction overlapping with the other cooling water collision region R is more preferably 15% or less of the width in the width direction of the cooling water collision region. The width in the width direction overlapping with the other cooling water collision region R is more preferably 13% or less or 11% or less of the width in the width direction of the cooling water collision region.
[0049]
　FIG. 8 shows a width-divided cooling zone A2 in which the entire cooling region A1 on the upper surface of the cooling width region in the upper cooling device 16 is divided in the width direction, and a divided cooling zone A2 in which the width-divided cooling zone A2 is divided in the steel plate transport direction. The surface A3 is shown in a plan view seen from above in the vertical direction (± Z direction), and the cooling water from the cooling water nozzle 23 provided for each of the divided cooling surfaces A3 is a cooling width region corresponding to the divided cooling surface A3. It is a figure which also shows the region (cooling water collision region) R formed by colliding with the upper surface. The cooling water nozzle 23 is arranged so that at least one cooling water collision region R is formed on each of the divided cooling surfaces A3. The width of one cooling water collision region R is larger than the width of the divided cooling surface A3 to which the cooling water collision region R belongs.
　In this embodiment, the cooling water nozzle 23 is arranged so that four cooling water collision regions R are formed on one divided cooling surface A3. The four cooling water nozzles 23 and the cooling water collision region R are arranged with respect to each of the transport rolls 19 in a plan view, and are arranged in the steel plate transport direction. The number of cooling water nozzles 23 corresponding to one divided cooling surface A3 is not particularly limited, and the entire width in the width direction of each of the divided cooling surfaces A3 is provided for the divided cooling surface A3. As long as it is covered with the cooling water collision region R by the above, it may be one or a plurality.
[0050]
　It is easier to control if the amount of water discharged from the cooling water nozzle 23 and the flow velocity are the same for each of the cooling water nozzles 23 in the width direction and the steel plate transport direction, and the cooling capacity of each is the same. In addition, the type, number, discharge water amount, and discharge flow velocity of the cooling water nozzles 23 installed for each of the plurality of divided cooling surfaces A3 arranged in the width direction at the same position in the steel plate transport direction are the same, and each division arranged in the width direction. Control is easier if the cooling capacity on the cooling surface A3 is the same.
　Further, in the cooling water nozzles 23 belonging to the divided cooling surfaces A3 arranged in the width direction and having the same discharge water amount and discharge flow rate, the distance between the centers of the cooling water nozzles 23 adjacent to each other in the width direction and / or the cooling water nozzles 23 are It is preferable that the cooling water collision regions R to be formed are arranged so that the distances between the centers are all equal. As a result, uniform cooling in the width direction can be performed with higher accuracy.
　Even if the cooling capacity based on the discharge water amount and the discharge flow velocity of the cooling water nozzle 23 is different in the width direction and the steel plate transport direction, it can be controlled by the control device 30.
[0051]
　FIG. 9 is a diagram illustrating the cooling water nozzle 23. FIG. 9A is a front view of the cooling water nozzle 23 as viewed from the steel plate transport direction, and FIG. 9B is a cooling water nozzle 23 colliding with the cooling width region, that is, the upper surface of the hot-rolled steel plate 2. It is a top view of the region (cooling water collision region) R viewed from above in the vertical direction (± Z direction). In FIG. 9B, the position of the cooling water discharge port of the cooling water nozzle 23 is indicated by a small “●”.
[0052]
　As shown in FIG. 9, the cooling water nozzle 23 has an injection shaft P inclined with respect to the vertical line P 0 on the upper surface of the hot-rolled steel plate 2 in the steel plate transport direction view, and the cooling water jetted from the cooling water nozzle 23 After the water collides with the cooling water collision region R, the water heads toward the opposite side of the cooling water nozzle 23 in the width direction. In the present embodiment, the cooling water nozzle 23 constitutes either the first nozzle group G1 or the second nozzle group G2. The cooling water nozzle 23 of the first nozzle group G1 drains water from one end side in the width direction by tilting the injection shaft P so that the cooling water is injected toward one side in the width direction. The cooling water nozzle 23 of the second nozzle group G2 is tilted in the direction opposite to that of the cooling water nozzle 23 of the first nozzle group G1 so that the cooling water is injected toward the other side in the width direction. Therefore, the water is drained from the other end side in the width direction.
[0053]
　The cooling water collision region R by the cooling water nozzle 23 constituting the first nozzle group G1 is connected to another cooling water collision region R adjacent in the width direction, and is connected to the first cooling water collision region group RG1 in the width direction. (Hereinafter, it may be abbreviated as the first region group RG1). Further, the cooling water collision region R formed by the cooling water nozzles 23 constituting the second nozzle group G2 is connected to another cooling water collision region R adjacent in the width direction, and is connected to the second cooling water collision region R in the width direction. A group RG2 (hereinafter, may be abbreviated as a second region group RG2) is formed.
　The cooling water nozzle 23 of the first nozzle group G1 forming the first region group RG1 and the cooling water nozzle 23 of the second nozzle group G2 forming the second region group RG2 are in the steel plate transport direction view. It is tilted so that it is symmetrical with each other. The cooling water nozzles 23 constituting the first nozzle group G1 forming the first region group RG1 have the same direction in which the injection shaft P is tilted with respect to the perpendicular line P 0 in the direction of the captain. That is, among the cooling water nozzles 23 constituting the first nozzle group G1 forming the first region group RG1, the direction in which the injection shaft P is tilted with respect to the perpendicular line P 0 is not opposite, and the width is wide. Cooling water is sprayed toward one side in the direction. Further, the cooling water nozzle 23 of the second nozzle group G2 forming the second region group RG2 also has the same direction in which the injection shaft P is tilted with respect to the perpendicular line P 0 in the direction of the captain. That is, among the cooling water nozzles 23 constituting the second nozzle group G2 forming the second region group RG2, the direction in which the injection shaft P is tilted with respect to the perpendicular line P 0 is not the opposite direction, and the width is wide. Cooling water is sprayed toward the other side.
[0054]
　It is preferable that each cooling water nozzle 23 is provided so that the angle of the injection shaft P with respect to the perpendicular line P 0 , that is, the inclination angle θ, is larger than half of the injection spreading angle of the cooling water from the cooling water nozzle 23. The inclination angle θ of the cooling water nozzle 23 is, for example, 10 ° to 45 °. The injection spread angle of the cooling water from the cooling water nozzle 23 is, for example, about 12 °, and the cooling water collision region R is formed so that the diameter is, for example, 200 mm.
[0055]
　Further, as can be seen from the positional relationship between the position of the cooling water discharge port of the cooling water nozzle 23 shown by “●” in the figure and the positional relationship of the cooling water collision region R, the injection shaft P of the cooling water nozzle 23 is in the steel plate transport direction. It is not inclined to, specifically, is not inclined to the downstream side in the steel plate transport direction, and is substantially parallel to the width direction in a plan view. It is not necessary to exclude that the injection shaft P of the cooling water nozzle 23 is inclined in the steel plate transport direction. It is not necessary to incline the injection shaft P, and it is preferable not to incline it.
[0056]
　Further, cooling water nozzles 23 of both the first nozzle group G1 and the second nozzle group G2 are provided for one transfer roll 19 position. Then, in each cooling water nozzle 23, if the cooling water collision region group does not overlap with the other cooling water collision region group (that is, the first region group RG1 overlaps with each other and the second region group RG2 overlaps with each other). Instead, the first region group RG1 and the second region group RG2 are provided so as not to overlap each other). Further, cooling water is provided so that the first region group RG1, the first region group RG1 and the second region group RG2 adjacent to the steel plate transport direction cover the cooling width region, that is, the entire width in the width direction of the hot-rolled steel plate 2. A nozzle 23 is provided. As described above, since each cooling water nozzle 23 is provided so that each of the cooling water collision region groups does not overlap with the other cooling water collision region groups, the first region group RG1 and the second region group RG2 are provided. Even if the cooling width region, that is, the entire width in the width direction of the hot-rolled steel plate 2 is covered, the jet of cooling water from the first nozzle group G1 and the jet of cooling water from the second nozzle group G2 interfere with each other. Never. As a method for preventing each of the cooling water collision region groups from overlapping with the other cooling water collision region groups, the position of the cooling water nozzle 23 forming one cooling water collision region group is set to another cooling water. There is a method of shifting the position of the cooling water nozzle 23 forming the collision region in the steel plate transport direction. Further, by shifting the position of the cooling water nozzle 23 forming the first region group RG1 and the position of the cooling water nozzle 23 forming the second region group RG2 back and forth in the steel plate transport direction, the first region group RG1 Even when the cooling water nozzle 23 forming the cooling water nozzle 23 forming the second region group RG2 and the cooling water nozzle 23 forming the second region group RG2 overlap in the steel plate transport direction view, the two cooling collision region groups do not overlap each other on the upper surface of the cooling width region. can do. As a result, it is possible to prevent the cooling waters from the cooling water nozzles 23 from interfering with each other. As described above, the width of one cooling water collision region R is larger than the width of the divided cooling surface A3 to which the cooling water collision region R belongs. Therefore, one cooling water collision region R belongs to the same width-divided cooling zone A2.
[0057]
　Further, as described above, since the cooling water nozzle 23 is provided so that each of the cooling water collision region groups does not overlap with the other cooling water collision region groups, cooling that forms one of the cooling water collision region groups. The drainage of the cooling water injected from the water nozzle 23 and colliding with the hot-rolled steel plate 2 may be hindered by the cooling water injected from the cooling water nozzle 23 forming another cooling water collision region group and colliding with the hot-rolled steel plate 2. Absent.
[0058]
　In this embodiment, the first region group RG1 and the second region group RG2 are staggered in a plan view based on the arrangement position of the transport roll 19. Specifically, one each of the first region group RG1 and the second region group RG2 is set for one transport roll 19, and the first region group RG1 for one transport roll 19 is set. And the second region group RG2 are alternately arranged along the steel plate conveying direction. For example, the first region group RG1 is set so that the center of the cooling water collision region R is located on the downstream side in the steel plate transport direction from the central axis S of the transport roll 19, and the second region group RG2 is the cooling water collision region. The center of R is set to be located upstream of the central axis S of the transport roll 19 in the steel plate transport direction.
[0059]
　The cooling water collision region R by each cooling water nozzle 23 has a length in the width direction so as not to cause non-uniform cooling such as insufficient cooling capacity in the intermediate portion between the cooling water collision region R and the adjacent cooling water collision region R in the width direction. And the lap width (the length in the width direction of the region overlapping between the cooling water collision regions R adjacent to each other in the width direction) is set. In the example of FIG. 9, the first region group RG1 and the second region group RG2 overlap at the center Q in the width direction of the cooling width region in the steel plate transport direction view, and the width direction of the overlapping region The length is set in the same manner as the lap width described above.
[0060]
　Further, in the example of FIG. 9, the boundary between the first region group RG1 and the second region group RG2 coincides with the center Q in the width direction of the cooling width region. By the way, the number of cooling water nozzles 23 constituting each nozzle group may be different between the first nozzle group G1 and the second nozzle group G2, and in this case, the first region by the first nozzle group G1. The boundary between the group RG1 and the second region group RG2 by the second nozzle group G2 does not coincide with the widthwise center Q of the cooling width region. However, the closer the boundary is to the center Q in the width direction, the smoother the drainage from each of the one end side and the other end side in the width direction. Therefore, the boundary coincides with the center Q in the width direction as in the example of FIG. It is preferable to set it.
[0061]
　Further, the cooling water nozzle 23 is preferably provided so that the cooling water collision region R overlaps with the central axis S of the transport roll 19 in a plan view in order to ensure the plate-passability. From the viewpoint of ensuring plate-passability, the center of the cooling water collision region R is within a range in which the jet of cooling water from the first nozzle group G1 and the jet of cooling water from the second nozzle group G2 do not interfere with each other. It is preferable that the position is set close to directly above the central axis S of the transport roll 19 in a plan view.
[0062]
　Returning to the description of the upper cooling device 16.
　The intermediate header 24 is a header that functions as a part of the switching device in the present embodiment and supplies cooling water to the cooling water nozzle 23. In this embodiment, as can be seen from FIGS. 2 and 3, the intermediate header 24 is a tubular member extending in the steel plate transport direction, and a plurality of cooling water nozzles 23 are provided along the steel plate transport direction. Therefore, the injection and stop of the cooling water from the cooling water nozzle 23 arranged in one intermediate header 24 can be controlled at the same time. In the illustrated example, four cooling water nozzles 23 are arranged in the steel plate transport direction with respect to one intermediate header 24, but the number of cooling water nozzles 23 is not limited to this.
　The intermediate header 24 is arranged so as to be one on one divided cooling surface A3. This enables switching control between injection and stop of cooling water for each of the divided cooling surfaces A3.
[0063]
　The three-way valve 27 is a member that functions as a part of the switching device in this embodiment. That is, the three-way valve 27 is a main member of the switching device for switching between collision and non-collision of the cooling water injected from the cooling water nozzle 23 with the upper surface of the cooling width region. The switching device is provided for each of the above-mentioned divided cooling surfaces A3.
　The three-way valve 27 of this embodiment is a diversion type, and whether the pressurized water from the water supply header 26 is guided to the pipe 25 to be supplied to the intermediate header 24 and further to the cooling water nozzle 23 or to the drainage header (not shown). It is a valve that switches between. In this embodiment, the drainage header is illustrated as a part for drainage, but the mode is not particularly limited.
　Instead of the three-way valve 27 of this embodiment, two stop valves (a valve for stopping the flow of fluid in a broad sense, sometimes called an ON / OFF valve) may be installed to perform control in the same manner as the three-way valve. It is possible. By using the three-way valve 27, the fluctuation of water pressure at the time of switching can be reduced.
[0064]
　In this embodiment, one three-way valve 27 is provided for each of the intermediate headers 24, and is arranged between the water supply header 26 for supplying the cooling water and the drainage header for discharging the cooling water.
[0065]
　The upstream temperature measuring device (hereinafter, referred to as “first measuring device”) 28 functions as the temperature detecting device in the present embodiment.
　The first measuring device 28 is arranged at a position on the lower surface side of the cooling width region, and measures the temperature of the hot-rolled steel plate 2 on the upstream side in the steel plate transport direction of the total cooling region A1 as shown in FIG.
　The first measuring device 28 is provided so as to be arranged in the width direction corresponding to each of the width-divided cooling zones A2 so that the temperature can be measured on the upstream side of the width-divided cooling zone A2. Thereby, the temperature in the width direction of the hot-rolled steel sheet 2 on the upstream side of the upper cooling device 16 can be measured over the entire width, that is, the temperature distribution in the width direction of the hot-rolled steel sheet 2 on the upstream side of the upper cooling device 16 is measured. be able to.
[0066]
　The downstream temperature measuring device (hereinafter, referred to as “second measuring device”) 29 also functions as the temperature detecting device in this embodiment.
　The second measuring device 29 is arranged at a position on the lower surface side of the cooling width region, and measures the temperature of the hot-rolled steel plate 2 on the downstream side in the steel plate transport direction of the total cooling region A1.
　The second measuring device 29 is provided so as to be arranged in the width direction corresponding to each of the width-divided cooling zones A2 so that the temperature of each of the width-divided cooling zones A2 after cooling can be measured. Thereby, the temperature in the width direction of the hot-rolled steel sheet 2 on the downstream side of the upper cooling device 16 can be measured over the entire width, that is, the temperature distribution in the width direction of the hot-rolled steel sheet 2 on the downstream side of the upper cooling device 16 is acquired. be able to.
[0067]
　The configuration of the first measuring device 28 and the second measuring device 29 is not particularly limited as long as it measures the temperature of the hot-rolled steel plate 2, but for example, the thermometer described in Japanese Patent No. 3818501. Is preferably used.
[0068]
　The control device 30 is a device that controls the operation of the switching device based on the measurement result of the first measuring device 28, the measurement result of the second measuring device 29, or both of them. Specifically, the control device 30 divides the width of each of the width-divided cooling zones A2 based on the measurement result of the first measuring device 28, the measurement result of the second measuring device 29, or both of them. By controlling the operation of the switching device for each of the plurality of divided cooling surfaces A3 included in the cooling zone A2, the cooling over the entire length of the width divided cooling zone A2 is controlled, and these are combined to cool the entire cooling region A1. Control. The control device 30 includes an electronic circuit or a computer that performs calculations based on a predetermined program, to which the first measuring device 28, the second measuring device 29, and the switching device are electrically connected.
[0069]
　For example, the temperature of the hot-rolled steel sheet 2 transported after rolling the run-out table having the transport roll 19 and after cooling by the main cooling device 15 is measured by the first measuring device 28. This measurement result is sent to the control device 30, and the amount of cooling required to make the temperature of the hot-rolled steel sheet 2 uniform for each of the divided cooling surfaces A3 is calculated.
　Then, based on the calculation result, the control device 30 feedforward-controls the opening and closing of the three-way valve 27. That is, the control device 30 controls the opening and closing of the three-way valve 27 and injects cooling water from the cooling water nozzle 23 for each of the divided cooling surfaces A3 in order to realize uniform temperature in the width direction of the hot-rolled steel sheet 2. The collision with the upper surface of the hot-rolled steel sheet 2 and the non-collision are controlled.
[0070]
　According to this embodiment, the following effects can be obtained.
　In this embodiment, as described above, the divided cooling surface A3 is based on the measurement result of the first measuring device 28 that measures the temperature in the width direction of the hot-rolled steel plate 2 after being cooled by the main cooling device 15 over the entire width. Each time, the collision and non-collision of the cooling water injected from the cooling water nozzle 23 with the upper surface of the hot-rolled steel plate 2 is controlled. Since three or more divided cooling surfaces A3 are arranged in the width direction and a plurality of the divided cooling surfaces A3 are arranged in the rolling direction, the temperature of the hot-rolled steel sheet 2 applied to both the width direction and the rolling direction can be made uniform with high accuracy. it can.
[0071]
　Further, according to this embodiment, the injection shaft P of the cooling water nozzle 23 is tilted with respect to the perpendicular line P 0 on the upper surface of the cooling width region, and the cooling water injected from the cooling water nozzle 23 and collides with the cooling water collision region R. Is discharged from one end or the other end of the hot-rolled steel plate 2 in the width direction toward the side opposite to the cooling water nozzle 23 in the width direction. Therefore, the cooling water injected from the cooling water nozzle 23 and colliding with the cooling water collision region R does not affect the cooling of the hot-rolled steel sheet 2 as the plate water.
[0072]
　Here, the main cooling device 15 and the adjusting cooling device 17 are already installed, and cooling is performed based on the temperature of the central portion in the width direction of the hot-rolled steel plate 2, and the winding temperature of the central portion in the width direction becomes the target value. When the cooling is performed, the upper cooling device 16 is incorporated between the main cooling device 15 and the adjusting cooling device 17. Even in this case, according to the present embodiment, the winding temperature of the central portion in the width direction of the hot-rolled steel sheet 2 is cooled to the target value without changing the main cooling device 15 and the adjusting cooling device 17. be able to.
[0073]
　It should be noted that, as in the present embodiment, when the hot-rolled steel plate 2 is further cooled after being cooled by the main cooling device 15 based on the measurement result of the temperature over the entire width of the hot-rolled steel plate 2, it is different from the present embodiment. It is conceivable that the cooling water nozzle is provided below the cooling width region in the vertical direction (that is, the lower surface), and the cooling water is sprayed from the lower surface side of the cooling width region. However, in this case, maintenance may be difficult because the transport roll 19 and the like are present around the cooling water nozzle. On the other hand, in the present embodiment, since the cooling water nozzle 23 is provided above the cooling width region, the maintainability is high. When only the lower configuration of the main cooling device 15 is extended to the downstream side and a cooling water nozzle is provided at a position facing the upper cooling device 16, the cooling water nozzle is referred to as the main cooling device 15. Since it is not necessary to control it independently, the configuration is simple and maintainability is not required.
[0074]
　Further, in the present embodiment, the inclination angle θ of the injection shaft P of the cooling water nozzle 23 is 10 ° to 45 °.
[0075]
　FIG. 10 shows the tilt angle θ of the injection shaft P of the cooling water nozzle 23, which is a full cone nozzle, and the cooling water from the cooling water nozzle 23, which returns to the direction opposite to the cooling water injection direction after colliding with the hot-rolled steel plate 2. It is a figure which shows the relationship with the ratio of cooling water (hereinafter, referred to as "return ratio of cooling water from a cooling water nozzle 23").
　As shown in the figure, by setting the inclination angle θ of the injection shaft P of the cooling water nozzle 23 to 10 ° or more, the return ratio of the cooling water from the cooling water nozzle 23 can be suppressed to 20% or less, and the plate can be used. The amount of water can be reduced.
[0076]
　FIG. 11 is a diagram showing the relationship between the inclination angle θ of the injection shaft P of the cooling water nozzle 23, which is a full cone nozzle, and the collision pressure index. The collision pressure index is an index relating to the pressure when the cooling water injected from the cooling water nozzle 23 collides with the hot-rolled steel plate 2, and is an index that becomes 1 when the inclination angle θ is 0 °. The higher the collision pressure index, the higher the cooling capacity, which is desirable. However, when the inclination angle θ is 45 ° or less, the collision pressure index can be 0.7 or more.
[0077]
　Further, according to this embodiment, the injection shaft P of the cooling water nozzle 23 is not inclined in the steel plate transport direction and is substantially parallel to the width direction in the plan view. Unlike this embodiment, when the injection shaft P of the cooling water nozzle 23 is inclined in the steel plate transport direction and is not parallel to the width direction in a plan view, the return ratio of the cooling water from the cooling water nozzle 23 described above increases. .. Therefore, when the injection shaft P of the cooling water nozzle 23 is substantially parallel to the width direction in the plan view as in the present embodiment, the return ratio can be suppressed and a high cooling capacity can be obtained. Further, when the injection shaft P of the cooling water nozzle 23 is not parallel to the width direction in the plan view, the cooling water return ratio increases and the collision force index decreases with respect to the inclination angle θ of the same injection shaft, but the injection shaft P. When is parallel to the width direction in a plan view and the angle with respect to the width direction is 0 °, such a problem does not occur. The angle of the injection shaft P of the cooling water nozzle 23 with respect to the plate width direction in a plan view is not limited to 0 °. The angle may be an angle or less at which the return ratio of the cooling water from the cooling water nozzle 23 is 20% or less and an angle at which the collision pressure index is 0.7 or more.
[0078]
　Further, according to the present embodiment, the cooling water collision region R of the cooling water nozzle 23 overlaps with the central axis S of the transport roll 19 in a plan view. Therefore, the cooling water from the cooling water nozzle 23 does not impair the plate-passability of the hot-rolled steel plate 2.
[0079]
　The intermediate header 24 is provided with a three-way valve 27, and the smaller the number of cooling water nozzles 23 in the intermediate header 24, the better the controllability of the cooling water injected onto the hot-rolled steel plate 2. On the other hand, if the number of the cooling water nozzles 23 is reduced, the number of required three-way valves 27 is increased by that amount, and the equipment cost and the running cost are increased. Therefore, the number of cooling water nozzles 23 can be set in consideration of these balances.
[0080]
　When a small amount of cooling water is used to collide the cooling water with the divided cooling surface A3, the length of the entire cooling region A1 in the steel plate transport direction becomes long. Therefore, for example , it is preferable to inject cooling water having a large water density of 1.0 m 3 / m 2 / min or more from the cooling water nozzle 23.
[0081]
　In the above description, the first measuring device 28 and the second measuring device 29 are arranged at positions on the lower surface side of the cooling width region, but are arranged on the upper surface side of the cooling width region and heat-spread from the upper surface side. It may be configured to measure the temperature of the steel plate 2. However, in the case of a configuration in which the temperature of the hot-rolled steel plate 2 is measured from the upper surface side of the cooling width region, it is necessary to provide a drainage device on the upstream side of the temperature measuring device, and at least the area required for temperature measurement by this drainage device. The length of the upper cooling device in the steel plate transport direction increases, and the cooling rate per unit length of the upper cooling device in the steel plate transport direction, that is, the cooling capacity decreases. Therefore, it is necessary to provide a drainage device for temperature measurement in a configuration in which the temperature of the hot-rolled steel plate 2 is measured from the lower surface side of the cooling width region like the first measuring device 28 and the second measuring device 29 described above. It is preferable because it has a high cooling capacity.
[0082]
　Further, in the above description, the opening and closing of the three-way valve 27 is controlled by feedforward based on the measurement result of the first measuring device 28, but feedback control is performed based on the measurement result of the second measuring device 29. May be good. That is, a calculation is performed by the control device 30 using the measurement results of the second measuring device 29, and based on the calculation results, the number of open / closed three-way valves 27 is controlled for each of the divided cooling surfaces A3 having different positions in the steel plate transport direction. You may. Thereby, it is possible to control the collision and non-collision of the cooling water with the upper surface of the cooling width region for each of the divided cooling surfaces A3.
[0083]
　In the upper cooling device 16, the feedforward control of the three-way valve 27 based on the measurement result of the first measuring device 28 and the feedback control of the three-way valve 27 based on the measurement result of the second measuring device 29 can be selectively performed.
　Further, such feedback control can be applied as correction control of the feedforward control result. As described above, in the upper cooling device 16, the feedforward control of the three-way valve 27 based on the measurement result of the first measuring device 28 and the feedback control of the three-way valve 27 based on the measurement result of the second measuring device 29 are integrated. You can also.
　When only one of the feedforward control and the feedback control is performed, either the first measuring device 28 or the second measuring device 29 may be omitted.
[0084]
(Other Example 1
　of Cooling Water Nozzle 23 ) FIG. 12 is a diagram illustrating another example of the cooling water nozzle 23.
　As shown in FIG. 9A, it may not be possible to dispose the cooling water nozzle 23 directly above the hot-rolled steel sheet 2 (that is, directly above the cooling width region) because there is already another cooling device. is there. In this case, as shown in FIG. 12A, the cooling water nozzle 23 may be provided as a side spray on the outside of the hot-rolled steel sheet 2 (that is, outside the cooling width region) in the steel sheet transport direction view.
[0085]
　Also in this case, as shown in FIG. 12B, as in the above example, the first region group RG1 and the second region group RG2 are viewed in a plan view with reference to the arrangement position of the transport roll 19. It is staggered. Therefore, the jet of the cooling water from the first nozzle group G1 and the jet of the cooling water from the second nozzle group G2 do not interfere with each other until they collide with the hot-rolled steel sheet 2. Further, as described above, the drainage of the cooling water injected from the cooling water nozzle 23 and colliding with the hot-rolled steel sheet 2 is not hindered by the cooling water injected from the other cooling water nozzle 23 and colliding with the hot-rolled steel sheet 2. ..
[0086]
　In the case of this example, the distance from the cooling water nozzle 23 to the upper surface of the cooling width region differs for each nozzle. Therefore, it is preferable that the injection angle and the injection pressure of the cooling water of each of the cooling water nozzles 23 are set so that the size of the cooling water collision region R and the flow rate of the cooling water colliding with the cooling water collision region R are equal. ..
[0087]
(Other Example 2
　of Cooling Water Nozzle 23 ) FIG. 13 is a diagram illustrating another example of the cooling water nozzle 23.
　As shown in FIG. 13A, the cooling water nozzle 23 of this example is arranged directly above the hot-rolled steel plate 2 as in the example of FIG.
　Further, as shown in FIG. 13B, in the cooling water nozzle 23 of this example, the first region group RG1 and the second region group RG2 are viewed in a plan view with reference to the arrangement position of the transport roll 19. It is staggered in. However, in this example, unlike the previous example, one of the first region group RG1 and the second region group RG2 is set for one transport roll 19, and the first region group RG2 is set. The region group RG1 and the second region group RG2 are alternately arranged along the steel plate conveying direction. The first region group RG1 and the second region group RG2 are set so that the center of the cooling water collision region R is located on the central axis S of the transport roll 19 in a plan view.
[0088]
　According to the cooling water nozzle 23 of this example, the center of the cooling water collision region R is provided so as to be located on the central axis S of the transport roll 19 in a plan view. Therefore, the plate-passability of the hot-rolled steel sheet 2 can be maintained higher.
　When the cooling water collision region R is provided as in this example, the cooling water nozzle 23 is placed outside the hot-rolled steel plate 2 (that is, outside the cooling width region) in the steel plate transport direction as in FIG. ) May be provided as a side spray.
[0089]
(Other Example 3 of Cooling Water Nozzle 23)
　FIGS. 14 and 15 are diagrams for explaining another example of the cooling water nozzle 23. 15 (A) shows a part of the XX cross section of FIG. 14, and FIG. 15 (B) shows a part of the YY cross section of FIG.
　In this example, each first nozzle group G1 is provided so that one first cooling water collision region group RG1 covers the entire width direction of the cooling width region, and each second nozzle group. G2 is also provided so that the entire width in the width direction of the cooling width region is covered by one second cooling water collision region group RG2.
[0090]
　In the case of such a nozzle group configuration, the cooling water nozzle 23 is provided so that the center of the cooling water collision region R is located on the central axis S of the transport roll 19 in a plan view. Therefore, the plate-through property of the hot-rolled steel sheet 2 can be maintained high. As in this example, when both the first cooling water collision region group RG1 and the second cooling water collision region group RG2 are provided so as to cover the entire width direction of the cooling width region, the influence of the water on the plate is affected. In order to reduce the number, the cooling water nozzle 23 has a cooling water nozzle 23 as compared with the case where the first cooling water collision region group RG1 and the second cooling water collision region group RG2 are provided so as to cover each side in the width direction of the cooling width region. It is preferable to increase the tilt angle θ.
[0091]
　Further, when the cooling water collision region R is provided as in this example, the first nozzle group G1 and the second nozzle group G2 do not have to be arranged alternately along the steel plate transport direction. There may be a portion where the first nozzle group G1 or the second nozzle group G2 is continuous along the steel sheet conveying direction, or only from one of the first nozzle group G1 and the second nozzle group G2. It may be configured.
[0092]
(Second Embodiment)
　FIG. 16 is a diagram schematically showing a part of the configuration of the upper cooling device 16 according to the second embodiment.
　The upper cooling device 16 according to the present embodiment has a drain nozzle 40 as shown in addition to the configuration of the upper cooling device 16 according to the first embodiment.
[0093]
　One drain nozzle 40 is provided for each of a region on one side and a region on the other side in the width direction of the cooling width region. Further, the draining nozzle 40 is provided on the outer side in the width direction of the cooling width region, and the draining nozzle 40 for the region on one side in the width direction is provided on the outer side on the other side in the width direction to drain water on the other side in the width direction. The nozzle 40 is provided on the outer side on one side in the width direction.
[0094]
　These draining nozzles 40 inject draining water into a region downstream of the steel plate transport direction from the cooling water collision region group on the most downstream side in the steel plate transport direction to form a drain water collision region T on the downstream side in the transport direction.
[0095]
　Water on the plate may remain in the region downstream of the cooling region by the cooling water nozzle 23, but by providing the drain nozzle 40 as in this embodiment, the remaining water on the plate can be immediately drained and heat spread. The steel plate 2 can be cooled appropriately.
[0096]
(Other Examples
　of Draining Nozzle 40 ) FIG. 17 is a diagram illustrating another example of the draining nozzle 40.
　In the example of FIG. 16, the draining nozzle 40 is provided only in the region on the downstream side in the steel plate transport direction from the cooling water collision region group on the most downstream side in the steel plate transport direction. On the other hand, in the example of FIG. 17, a drain nozzle 40 is provided for each region on the downstream side in the transport direction from each cooling water collision region group.
[0097]
　Also in this example, the plate water remaining in the region downstream of the cooling region by the cooling water nozzle 23 can be immediately drained, and the hot-rolled steel plate 2 can be appropriately cooled.
[0098]
(Modified Examples of First and Second Embodiments) In the
　above description, the cooling water nozzle 23 is a full cone spray nozzle, but if it is a spray nozzle to which a back pressure of about 0.3 MPa is applied, cooling water The collision region R is not limited to the circular full cone spray nozzle, and the cooling water collision region R may be another nozzle such as an elliptical flat spray nozzle.
[0099]
　It is not preferable to use a laminar nozzle that supplies cooling water by a bulk flow (that is, a laminar flow) such as a rod-shaped jet as the cooling water nozzle 23, unlike the dispersed flow from the spray nozzle. This is because the return ratio of the cooling water from the cooling water nozzle 23 is larger and a large amount of water on the plate is more likely to remain when the laminar nozzle is used than when the spray nozzle is used. is there. Further, even when a laminar nozzle is used, the amount of water on the plate can be reduced by increasing the inclination angle θ of the injection shaft P, but if the inclination angle θ is increased, the cooling that collides with the hot-rolled steel plate 2 is performed. The momentum of the vertical component of water weakens and the cooling capacity weakens. Further, if the inclination angle θ is increased, the flow velocity of the water on the plate increases, so that the cooling capacity of the water on the plate increases, and the portion that should not be cooled is cooled by the water on the plate. That is, if the inclination angle θ is increased, the difference in cooling capacity between the collision region and the non-collision region of the cooling water cannot be sufficiently obtained. Therefore, when the inclination angle θ is increased by using the laminar nozzle, the temperature of the hot-rolled steel sheet 2 is increased by switching the cooling control as in the above-described embodiment, that is, the collision and non-collision of the cooling water for each of the divided cooling surfaces A3. The control of cooling so as to be uniform cannot be realized. Moreover, even if it can be realized, the length of the cooling machine will be long. The above points are the same for the pipe laminar nozzle and the slit laminar nozzle as long as it is a laminar nozzle.
[0100]
　FIG. 18 is a diagram showing the relationship between the inclination angle θ of the injection shaft P of the cooling water nozzle 23 and the return ratio of the cooling water from the cooling water nozzle 23 when the slit laminar nozzle is used.
　When a full cone nozzle is used, as shown in FIG. 10, by setting the inclination angle θ of the injection shaft P of the cooling water nozzle 23 to 10 ° or more, the return ratio of the cooling water from the cooling water nozzle 23 can be increased. It can be suppressed to 20% or less. On the other hand, when the slit laminar nozzle is used, as shown in FIG. 18, the return ratio of the cooling water from the cooling water nozzle 23 cannot be suppressed to 20% or less unless the inclination angle θ is 37 ° or more. ..
[0101]
　Further, the pipe laminar nozzle and the slit laminar nozzle are used as the cooling water nozzle 23 because it is necessary to provide a gap between the cooling water collision regions adjacent to each other in the width direction in order to prevent the cooling water as the laminar flow from interfering with each other. Is not preferable.
[0102]
　In the above example, the region defined by the length of the cooler and the total width of the cooling width region in the width direction is defined as the total cooling region. Instead of this, in a specific case, as shown in FIG. 19, the entire region excluding the non-cooling region A4 in the central portion in the width direction from the region defined by the cooler length and the total width in the width direction of the cooling width region is the entire region. It may be the cooling region A1. In a specific case, for example, in order to prevent the tip of the hot-rolled steel plate 2 from falling between the transport rolls 19, a hot-roll plate guide is provided at the center in the width direction between the adjacent transport rolls 19 in the steel plate transport direction. This is the case. When the hot-rolled plate guide is provided in the central portion in the width direction in this way, the temperature of the central portion in the width direction of the hot-rolled steel sheet becomes lower than that of other parts in the width direction due to the cooling water for protecting the guide. In some cases. In order to prevent such a situation, the central portion in the width direction of the cooling width region may be set as a non-cooling region, and the temperature distribution in the width direction of the hot-rolled steel sheet 2 may be made uniform.
[0103]
　When the total cooling region A1 excludes the non-cooling region A4, as shown in FIG. 20, the first region group RG1 and the second region group RG2 are formed in the total cooling region A1 and are not cooled. It is not formed in region A4. However, also in this case, the entire width in the width direction of the entire cooling region A1 is covered by the first region group RG1, the first region group RG1, and the second region group RG2 adjacent to the steel plate transport direction.
[0104]
　Further, even when the total cooling region A1 excludes the non-cooling region A4, as shown in FIG. 20, the first region group RG1 and the second region group RG2 are as in the example of FIG. , The cooling water collision region R, which is staggered in a plan view and constitutes each region group, may overlap with the central axis S of the transport roll 19 in a plan view based on the arrangement position of the transport roll 19.
[0105]
　Not limited to this example, for example, as shown in FIG. 21, both the first region group RG1 and the second region group RG2 are set for one transport roll 19, and each region is set in a plan view. The center of the cooling water collision region R forming the group may be located on the central axis S of the transport roll 19. In this example, "a pair of regions adjacent to each other in the captain direction" means "a pair of regions whose positions in the captain direction coincide with each other".
　Further, when the total cooling region A1 excludes the non-cooling region A4 and the center of the cooling water collision region R is positioned on the central axis S of the transport roll 19, one is used as in the example of FIG. Either one of the first region group RG1 and the second region group RG2 may be set for the transport roll 19.
[0106]
　Even when the total cooling region A1 excludes the non-cooling region A4, the cooling water nozzle 23 may be provided directly above the hot-rolled steel plate 2, or may be provided as a side spray on the outside of the hot-rolled steel plate 2. May be good. Further, a drain nozzle may be provided.
[0107]
　In the above example, the intermediate header 24 is provided, but it is also possible to configure the structure without the intermediate header 24. FIG. 20 shows a plan view showing an outline of the configuration of the upper cooling device 16 according to this configuration. FIG. 22 is a diagram corresponding to FIG. 3, and a three-way valve 27 is connected to each cooling water nozzle 23. However, in order to facilitate understanding, FIG. 22 shows the three-way valve 27 and the water supply header. 26, the illustration of the drainage header is omitted.
　In the example of FIG. 22, a pipe (not shown) is connected to each cooling water nozzle 23, and a three-way valve is provided in this pipe. The three-way valve is provided between the water absorption header that supplies cooling water to the pipe and the drainage header that discharges the cooling water. Even with such a configuration in which the intermediate header 24 is omitted, it is possible to obtain the same effect as the configuration having the intermediate header 24 described above.
[0108]
　Further, in order to improve the plate-passability, a disc roll that supports the hot-rolled steel plate 2 from below may be provided between the transport rolls 19 adjacent to each other in the steel plate transport direction.
[0109]
　Further, although the upper cooling device 16 is arranged on the downstream side of the main cooling device 15, the arrangement location of the upper cooling device 16 is not limited to this example.
[0110]
　Further, in the above description, a mode in which the opening and closing of the three-way valve 27 is controlled to switch between collision and non-collision of the cooling water with the divided cooling surface is illustrated. The present invention is not limited to this embodiment. For example, a flow rate adjusting valve is provided between the intermediate header 24 and the three-way valve 27 to control the injection flow rate of cooling water from the flow rate adjusting valve to cool the divided cooling surface. It is also possible to switch between water collision and non-collision. However, from the viewpoint of responsiveness and the like, a form in which the opening and closing of the three-way valve 27 is controlled is preferable.
[0111]
　Although the embodiments of the present invention have been described above, the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical idea described in the claims, and of course, the technical scope of the present invention also includes them. It is understood that it belongs to.
Example
[0112]
　Hereinafter, the effects of the present invention will be described based on Examples and Comparative Examples. However, the present invention is not limited to this embodiment.
[0113]
　 In
　the verification of the effect, in Example 1, cooling was performed using a cooling device including the main cooling device 15 of FIG. 1, the upper cooling device 16, and the adjusting cooling device 17. Further, in Comparative Example 1, cooling was performed using a cooling device including a main cooling device 15 and an adjustment cooling device 17 without the upper cooling device 16. In Example 1 and Comparative Example 1, the cooling in the main cooling device 15 is performed by feedback control based on the measurement result by a temperature sensor (not shown) provided on the downstream side of the main cooling device 15, and the cooling device for adjustment is used. Similarly, the cooling at 17 was performed by feedback control based on the measurement results by a temperature sensor (not shown) provided on the downstream side of the adjusting cooling device 17.
[0114]
　Further, in Example 1 and Comparative Example 1, the steel plate width: 1600 mm, the plate thickness: 2.0 mm, the steel plate transport speed: 600 mpm, the temperature before cooling: 900 ° C., and the target take-up temperature: 550 ° C.
[0115]
　The structure of the upper cooling device 16 according to the first embodiment was the same as that of FIG. Further, the total cooling region A1 does not include the non-cooling region A4 of FIG. 19 as shown in FIG. 5 and the like. The number of width-divided cooling zones A2 was set to eight. That is, the length of the divided cooling surface A3 in the width direction is the length obtained by dividing the entire cooling region A1 into eight equal parts in the width direction. Further, among the divided cooling surfaces A3, the first nozzle group G1 injects cooling water on four on one side in the width direction, and the second nozzle group G2 injects cooling water on four on the other side in the width direction. It was supposed to be sprayed. The length of the divided cooling surface A3 in the steel plate transport direction was set to 4 pitches between the rolls in the steel plate transport direction. Further, the number of the divided cooling surfaces A3 in the steel plate transport direction was set to 3. That is, 24 divided cooling surfaces A3 are provided, 8 (number in the width direction) × 3 (number in the steel plate transport direction), in other words, 8 (number in the width direction) cooling units having the cooling water nozzle 23. ) X 3 (number in the steel plate transport direction) 24 units are provided. The height of the cooling water nozzle 23, specifically, the height from the upper surface of the hot-rolled steel plate 2 to the tip of the cooling water nozzle 23 was 1.1 m, and the inclination angle θ of the cooling water nozzle 23 was 15 °. Further, in order to avoid interference of the cooling water between the cooling water nozzle 23 of the first nozzle group G1 and the cooling water nozzle 23 of the second nozzle group G2, the center of the cooling water collision region R from the cooling water nozzle 23 As shown in FIG. 9 and the like, the position of is slightly shifted to the upstream side or the downstream side from directly above the central axis S of the transport roll 19. As the cooling water nozzle 23, a full cone nozzle having a cooling water amount of 186 liters per minute was used. The pitch of the cooling water nozzle 23 and the pitch of the cooling water collision region R in the width direction were set to 200 mm. The temperature drop per unit of the above-mentioned cooling units provided on each of the divided cooling surfaces A3 is about 15 ° C. In addition, in Example 1 and Comparative Example 1, the lower surface cooling device was not installed at the position facing the upper cooling device 16 or the position corresponding to the position.
[0116]
　FIG. 23 is a diagram showing a part of the temperature distribution of the winding temperature of the hot-rolled steel sheet 2 in Example 1 and Comparative Example 1, and FIGS. 23 (A) and 23 (B) are Comparative Example 1 and FIG. 23 (B), respectively. The temperature distribution in Example 1 is shown. In the figure, the distribution in which the absolute value of the temperature difference with respect to the target temperature is within 20 ° C. is shown in white, the portion larger than 20 ° C. and within 40 ° C. is shown in light gray, and the portion larger than 40 ° C. is shown in dark gray.
[0117]
　As shown in FIG. 23 (A), in Comparative Example 1, streaky temperature variation occurs due to temperature deviation caused by equipment such as poor maintenance, and there is a portion higher than the target temperature. Further, in Comparative Example 1, the standard temperature deviation was 25.7 ° C. The standard temperature deviation of Comparative Example 1 is the total temperature of the steel sheet excluding the tip and the tail end of the steel sheet of 100 m each (to exclude the free tension part) and 50 mm at both ends in the width direction from the results measured by the infrared temperature image measuring device. Obtained from the measurement point.
　On the other hand, as shown in FIG. 23 (B), in Example 1, the portion higher than the target temperature is much smaller than that in Comparative Example 1. When the hot-rolled steel sheet shown in the figure was cooled, the standard temperature deviation in the examples was as small as 16.5 ° C. The standard temperature deviation of Example 1 was obtained from the temperature of the steel sheet excluding the tip and tail ends of the steel sheet of 100 m each and the ends of each of 50 mm.
　Therefore, according to the present invention, it has been found that the temperature of the hot-rolled steel sheet 2 in the width direction can be made uniform.
[0118]

[0119]
[table 1]

[0120]
　In Examples 2 to 4, as in Example 1, cooling was performed using a cooling device including the main cooling device 15 in FIG. 1, the upper cooling device 16, and the adjusting cooling device 17. The height of the cooling water nozzle 23 was set to 1.1 m. The pitch of the cooling water nozzle 23 and the pitch of the cooling water collision region R in the width direction were set to 200 mm. Further, the width in the width direction (hereinafter, referred to as "lap length of the cooling water collision region R") of the region where the cooling water collision regions R adjacent to each other in the width direction overlap each other forming each cooling water collision region group is defined. It was set to 20 mm. In Examples 2, 3 and 4, as shown in Table 1, a full cone nozzle is used as the cooling water nozzle 23, and the inclination angles θ of the injection shaft P of the cooling water nozzle 23 are 15 °, 30 ° and 60 °, respectively. And said. Other conditions of Examples 2 to 4 are the same as those of Example 1.
[0121]
　On the other hand, in Comparative Example 2, a full cone nozzle was used as the cooling water nozzle 23, and the inclination angle θ of the injection shaft P was set to 0 °. Other conditions of Comparative Example 2 are the same as those of Example 2.
　Further, in Comparative Example 3, as the cooling water nozzle 23, a pipe laminar nozzle for supplying cooling water by a rod-shaped jet (jet jet) having a high flow rate density was used, and the inclination angle θ of the injection shaft P was set to 50 °.
　In Comparative Example 4, a pipe laminar nozzle that supplies cooling water by a free fall flow was used as the cooling water nozzle 23. Since it is a free fall flow, the inclination angle θ of the injection shaft P is 0 °. Further, also in Comparative Examples 3 and 4, the lower surface cooling device was not installed at a position facing the upper cooling device 16.
　In Comparative Example 3, the pitch of the cooling water nozzle 23 in the width direction was 60 mm, and the nozzle diameter was 7 mm. In Comparative Example 4, the pitch of the cooling water nozzle 23 in the width direction was 60 mm, and the nozzle diameter was 15 mm. In Comparative Example 3 and Comparative Example 4, the cooling water collision region R formed by the cooling water nozzle 23 does not overlap with other cooling water collision regions R adjacent in the width direction. This is because the cooling water as the laminar flow interferes with each other when they overlap. Further, in Comparative Example 3 and Comparative Example 4, the amount of cooling water per cooling water nozzle 23 was 73 L / min. , 67 L / min. Is. In Comparative Example 3 and Comparative Example 4 in which the pipe laminar nozzle is used, the amount of cooling water per cooling water nozzle 23 is larger than that of Examples 2 to 4 and Comparative Example 2, but the pitch of the cooling water nozzle 23 is large. The total amount of cooling water is smaller than that of Examples 2 to 4 and Comparative Example 2 in which the spray nozzles are used because the number of the cooling waters is small and the number of the cooling waters is large.
[0122]
　As shown in Table 1, in Comparative Example 2 in which the full cone nozzle was used as the cooling water nozzle 23 and the inclination angle θ of the injection shaft P was 0 ° and was not tilted, the standard temperature deviation was as high as 22.2 ° C. .. On the other hand, in Examples 2 to 4 in which the full cone nozzle is used as the cooling water nozzle 23 and the inclination angle θ of the injection shaft P exceeds 0 °, the standard temperature deviation is 15.6 ° C to 16.5 ° C. It was very small. In particular, in Examples 2 and 3 in which the inclination angle θ of the injection shaft P of the cooling water nozzle 23 falls within the range of 10 ° to 45 °, the collision pressure index was 0.7 or more and the cooling capacity was high.
　Further, in Comparative Examples 3 and 4 in which the pipe laminar nozzle was used as the cooling water nozzle 23, the standard temperature deviation was as large as 20 ° C. or more. In particular, as in Comparative Example 3, the density of the cooling water from the cooling water nozzle 23 is high, and the inclination angle θ of the injection shaft P is as large as 50 ° so that no water on the plate remains. Even in this case, the standard temperature deviation was 20 ° C. or higher.
[0123]

[0124]
[Table 2]

[0125]
　In Example 2, as described above, the lap length of the cooling water collision region R was set to 20 mm. On the other hand, in Examples 5 and 6, the lap lengths were set to 10 mm and 0 mm, respectively. Further, in Comparative Examples 5 and 6, the lap lengths of the cooling water collision region R were set to −10 mm and −20 mm, respectively. That is, in Comparative Examples 5 and 6, a gap was provided between the cooling water collision regions R adjacent to each other in the width direction to form each cooling water collision region group. Other conditions of Examples 5 and 6 and Comparative Examples 5 and 6 are the same as those of Example 2.
[0126]
　As shown in Table 2, the standard temperature deviations were as large as 20.3 ° C and 23.6 ° C in Comparative Examples 5 and 6, whereas they were as low as 18.2 ° C in Example 6 and in Examples 2 and 5. It was even lower at 16.5 ° C and 16.7 ° C. From this, it is necessary to overlap the cooling water collision regions R adjacent to each other in the width direction forming each cooling water collision region group, and if the lap length of the cooling water collision region is at least 10 mm or more, heat is generated. It can be seen that the temperature of the rolled steel plate 2 can be made more uniform, and that the larger the lap length of the cooling water collision region R, the more uniform the temperature of the hot rolled steel plate 2 can be. The lap length of 10 mm of the cooling water collision region R corresponds to 5% of the width in the width direction of one cooling water collision region R.
[0127]

[0128]
[Table 3]

[0129]
　As described above, in the second embodiment, the cooling water nozzle 23 is provided at the position shown in FIG. On the other hand, in the seventh embodiment, the cooling water nozzle 23 is provided at the position shown in FIG. 12, and the inclination angle θ of the injection shaft P is set to 45. Further, in the eighth embodiment, the cooling water nozzle 23 was provided at a position as shown in FIG. 13, and in the ninth embodiment, the cooling water nozzle 23 was provided at a position as shown in FIGS. 14 and 15. In Example 10, as shown in FIG. 16, the cooling water nozzle 23 and the draining nozzle 40 were provided. Other conditions of Examples 6 to 10 are the same as those of Example 2.
　Further, the eleventh embodiment is different from the second embodiment only in that the lower surface cooling device is installed at a position facing the upper cooling device 16. In the lower surface cooling device used in the eleventh embodiment, a pipe laminar nozzle as a cooling water nozzle is provided between the transport rolls so as to face the lower surface of the hot rolled steel sheet 2 over the entire width of the hot rolled steel sheet 2. They were arranged in the width direction, and the amount of cooling water of the nozzle was kept constant regardless of the temperature distribution in the width direction of the hot-rolled steel sheet 2.
[0130]
　As shown in Table 3, the standard temperature deviation was as low as 17.8 ° C. in Example 7 as well. That is, with the cooling water nozzle 23 having the configuration shown in FIG. 9, the temperature of the hot-rolled steel plate 2 can be made uniform while increasing the degree of freedom in arranging the cooling water nozzle 23.
　Further, in Examples 8 and 9, the standard temperature deviation was as low as 17.2 ° C. and 18.9 ° C. That is, with the cooling water nozzle 23 having the configuration shown in FIG. 13 and the cooling water nozzle 23 having the configuration shown in FIG. 14, the temperature of the hot-rolled steel plate 2 can be made uniform while ensuring the plate-passability.
　Further, in Example 10, that is, even in the configuration provided with the drain nozzle 40 as shown in FIG. 16, the standard temperature deviation was as low as 16.8 ° C. This standard temperature deviation is higher than that of Example 2 in which the drain nozzle 40 is not provided, but is a very low value. Further, the configuration in which the drain nozzle 40 is provided as shown in FIG. 16 has a merit that the drainage property downstream of the cooling device is good and a measuring device such as a thermometer can be installed in the immediate vicinity of the downstream side. That is, by providing the draining nozzle 40, the temperature of the hot-rolled steel sheet 2 can be made uniform while enjoying the above-mentioned merits.
　Furthermore, even in the eleventh embodiment, that is, in the configuration in which the lower surface cooling device is provided at the position facing the upper cooling device 16, the standard temperature deviation is the case where the lower surface cooling device is not provided at the position facing the upper cooling device 16. Was similar to. That is, if the upper cooling device 16 is used, the temperature in the width direction of the hot-rolled steel sheet 2 can be made uniform regardless of whether or not the lower surface cooling device is provided at a position facing the upper cooling device 16.
Industrial applicability
[0131]
　The present invention is useful in a cooling technique for hot-rolled steel sheets.
Code description
[0132]
1 Slab
2 Hot-rolled steel plate
10 Hot rolling equipment
11 Heating furnace
12 Width rolling machine
13 Rough rolling machine
14 Finishing rolling mill
15 Main cooling device
16 Upper width direction control cooling device
17 Adjustment cooling device
18 Winding device
19 Conveyance roll
23 Cooling water nozzle
24 Intermediate header
25 Piping
26 Water supply header
27 Three-way valve
28 Upstream side temperature measuring device
29 Downstream side temperature measuring device
30 Control device
40 Drain nozzle
A1 Full cooling area
A2 Width split cooling zone
A3 Split cooling surface
A4 Non-cooling area
G1 1st nozzle group
G2 2nd nozzle group
P 0　　Vertical line on the upper surface of the cooling width region
P1 Injection shaft
Q Width direction center
R Cooling water collision region
RG1 First cooling water collision region group
RG2 Second cooling water collision region group
S Central axis of transport roll
T Drainage water collision region
The scope of the claims
[Claim 1]
　A cooling device for a hot-rolled steel plate that cools the upper surface of the hot-rolled steel plate that is transported on a transport roll after hot rolling, and
　is a region defined by the cooler length and the full width in the width direction on the upper surface of the region to be cooled. The region excluding the non-cooling region in the central portion in the width direction is defined as the total cooling region, and the region obtained by dividing the entire cooling region into three or more in the width direction is defined as the width division cooling zone. At
　least one cooling water that injects cooling water to each of the divided cooling surfaces to form a cooling water collision region on the upper surface of the cooling target region when the region obtained by dividing the above into a plurality of parts in the machine length direction is used as the divided cooling surface. Each of the divided cooling surfaces is provided with a nozzle and a switching device for switching between collision and non-collision of the cooling water injected from the cooling water nozzle with the divided cooling surface, and
　further, in the width direction of the cooling target region. Based on the temperature detection device that measures the temperature distribution and
　the width direction temperature distribution measurement result of the temperature detection device, each of the plurality of divided cooling surfaces included in the width-divided cooling zone for each width-divided cooling zone. A control device for controlling the cooling of the entire length of the width-divided cooling zone by controlling the operation of the switching device with respect to the cooling zone and controlling the cooling of the entire cooling region in combination with the control device
is provided
　. the cooling water impact area, in the total cooling area, while overlapping with the other of said cooling water impingement region adjacent in the width direction, forming a cooling water impingement region group continuous in the width direction,
　wherein each cooling water impact area group , The
　entire width in the width direction of the entire cooling region is covered by one cooling water collision region group or a pair of cooling water collision region groups adjacent to each other in the captain direction without overlapping with the other cooling water collision region group. I,
　The cooling water nozzle forming one cooling water collision region group has an injection shaft inclined with respect to a perpendicular line on the upper surface of the cooling target region in the machine length direction, and the direction in which the injection shaft is tilted is in the machine length direction. A cooling device for hot-rolled steel sheets, which is characterized in that it is not oriented in the opposite direction.
[Claim 2]
　The cooling device for a hot-rolled steel sheet according to claim 1, wherein the non-cooling region is not provided.
[Claim 3]
　The width in the width direction of the region where the cooling water collision region overlaps with the other cooling water collision region adjacent in the width direction is 5% or more of the width in the width direction of one cooling water collision region. , The cooling device for a hot-rolled steel plate according to claim 1 or 2.
[Claim 4]
　The cooling device for a hot-rolled steel sheet according to any one of claims 1 to 3, wherein the inclination angle of the injection shaft of the cooling water nozzle is 10 ° to 45 °.
[Claim 5]
　The cooling device for a hot-rolled steel sheet according to any one of claims 1 to 4, wherein the injection shaft of the cooling water nozzle is not inclined in the machine length direction.
[Claim 6]
　The cooling device for a hot-rolled steel sheet according to any one of claims 1 to 5, wherein the cooling water collision region overlaps with the central axis of the transport roll in a plan view.
[Claim 7]
　The cooling water nozzle according to claim 6, wherein the cooling water nozzle is provided so that the center of the cooling water collision region is located on the central axis of the transport roll in a plan view. apparatus.
[Claim 8]
　The cooling device for a hot-rolled steel sheet according to any one of claims 1 to 7, wherein the cooling water nozzle is provided above or to the side of the cooling target region in the direction of the captain.
[Claim 9]
　The cooling water collision region group formed by the cooling water nozzle that injects toward one side in the width direction is designated as the first cooling water collision region group, and the
　cooling water nozzle that injects toward the other side in the width direction serves as the first cooling water collision region group. When the cooling water collision region to be formed is a second cooling water collision region group, the
　cooling water nozzle has both the first cooling water collision region group and the second cooling water collision region group. It is formed, and the boundary in the width direction between the first cooling water collision region group and the second cooling water collision region group is provided so as to be located at the center in the width direction of the cooling target region. The hot-rolled steel plate cooling device according to any one of claims 1 to 8, wherein the hot-rolled steel plate is cooled.
[Claim 10]
　On the upper surface of the cooling water collision region group, for each region on the downstream side in the captain direction of each of the cooling water collision region groups, or on the downstream side in the captain direction from the region group on the most downstream side in the captain direction of the cooling water collision region group. The cooling device for a hot-rolled steel plate according to any one of claims 1 to 9, wherein the region is provided with a drain nozzle that injects drain water to form a drain water collision region.
[Claim 11]
　After hot rolling, a hot-rolled sheet cooling method using a cooling device for cooling the upper surface of the hot-rolled steel sheet conveyed on the conveying roll,
　the upper surface of the cooling target region defined by the cooling captain and widthwise entire width The region to be cooled or the region excluding the non-cooling region in the central portion in the width direction is defined as a total cooling region, and the region obtained by dividing the total cooling region into three or more in the width direction is defined as a width division cooling zone. When the area obtained by dividing the width-divided cooling zone into a plurality of parts in the
　machine length direction is used as the divided cooling surface, the cooling device
　injects cooling water onto the divided cooling surface for each divided cooling surface to cool the target area. At least one cooling water nozzle forming a cooling water collision region is provided on the upper surface of the cooling water,
　and one said cooling water collision region is connected to another cooling water collision region adjacent in the width direction in the entire cooling region. While overlapping, a cooling water collision region group connected in the width direction is formed, and
　each of the cooling water collision region groups does not overlap with the other cooling water collision region group, and
　the total width of the total cooling region in the width direction is The
　cooling water nozzle, which is covered by one cooling water collision region group or a pair of cooling water collision region groups adjacent to each other in the machine length direction and forms one cooling water collision region group, is cooled in the machine length direction. It has an injection shaft that is tilted with respect to the vertical line on the upper surface of the target region, and the direction in which the injection shaft is tilted is not opposite in the direction of the
　machine
　length.
　Based on the measurement result of the temperature distribution in the width direction of the cooling target region, the cooling water by the cooling water nozzle collides with the divided cooling surface and does not collide with the plurality of divided cooling surfaces included in the width divided cooling zone. By controlling the collision for each of the width-divided cooling zones, the cooling of the width-divided cooling zone over the entire length in the machine length direction is controlled, the cooling of the entire cooling region is controlled, and the
　cooling injected from the cooling water nozzle is controlled. A method for cooling a hot-rolled steel plate, which comprises directing water toward the side opposite to the cooling water nozzle in the width direction and discharging the water.
[Claim 12]
　The method for cooling a hot-rolled steel sheet according to claim 11, wherein there is no uncooled region.
[Claim 13]
　The width in the width direction of the region where the cooling water collision region overlaps with the other cooling water collision region adjacent in the width direction is 5% or more of the width in the width direction of one cooling water collision region. The method for cooling a hot-rolled steel plate according to claim 11 or 12.
[Claim 14]
　The method for cooling a hot-rolled steel sheet according to any one of claims 11 to 13, wherein the inclination angle of the injection shaft of the cooling water nozzle is 10 ° to 45 °.
[Claim 15]
　The method for cooling a hot-rolled steel sheet according to any one of claims 11 to 14, wherein the injection shaft of the cooling water nozzle is not inclined in the machine length direction.
[Claim 16]
　One of claims 11 to 15, wherein the cooling water nozzle is provided so that the cooling water collision region is formed in a region overlapping the central axis of the transport roll in a plan view. The method for cooling a hot-rolled steel sheet according to.
[Claim 17]
　The cooling water nozzle according to claim 16, wherein the cooling water nozzle is provided so that the center of the cooling water collision region is located on the central axis of the transport roll in a plan view. Method.
[Claim 18]
　The method for cooling a hot-rolled steel sheet according to any one of claims 11 to 17, wherein the cooling water nozzle is provided above or to the side of the cooling target region in the direction of the captain.
[Claim 19]
　The cooling water collision region group formed by the cooling water nozzle that injects toward one side in the width direction is designated as the first cooling water collision region group, and the
　cooling water nozzle that injects toward the other side in the width direction serves as the first cooling water collision region group. When the formed cooling water collision region is set as the second cooling water collision region group, the
　cooling water nozzle has both the first cooling water collision region group and the second cooling water collision region group. It is formed, and the boundary in the width direction between the first cooling water collision region group and the second cooling water collision region group is provided so as to be located at the center in the width direction of the cooling target region. The method for cooling a hot-rolled steel plate according to any one of claims 11 to 18, wherein the hot-rolled steel plate is cooled.
[Claim 20]
　On the upper surface of the cooling water collision region group, for each region on the downstream side in the captain direction of each of the cooling water collision region groups, or on the downstream side in the captain direction from the region group on the most downstream side in the captain direction of the cooling water collision region group. The method for cooling a hot-rolled steel plate according to any one of claims 11 to 19, wherein a drainage water collision region is formed by injecting drainage water into the region.