0001]The present invention, after the finish rolling of the hot rolling step, a cooling device for cooling the lower surface of the hot-rolled steel sheet conveyed on the conveying rolls, and to a cooling method using the cooling device.
BACKGROUND
[0002]With the weight of recent automobiles, among hot-rolled steel sheet has been increasing demand for high-tensile steel plate, it has been increasing more the quality required for the hot-rolled steel sheet. Particularly in recent years, not only high strength, fall within excellent processability and tensile strength and workability predetermined range over the entire region of the steel sheet the variation in the mechanical properties such as such as press formability and hole expandability It has been determined also to such things.
[0003]
　However, the finishing time of cooling after rolling, there are cases where uneven temperature distribution is generated in the plate width direction of the hot rolled steel sheet to various factors. As a specific example, streaky nonuniform temperature distribution extending in the rolling direction of the hot-rolled steel sheet and the like can occur in the plate width direction. Factors There are several, before entering the cooling after finish rolling, by finish rolling and finishing by scale remaining in descaling performed before rolling, is sprayed during the finish rolling remaining plate width direction distribution of lubricant things, by non-uniformity of the finishing mill coolant spray provided between stands, and the like due to the heating furnace due. Also, since the beginning of cooling after finish rolling, and the like occurrence of uneven temperature distribution due to the maintenance of the cooling system failure.
[0004]
　Incidentally, in the manufacturing process of the hot rolled steel sheet, as one of the factors that greatly affect the properties of the final product as described above, there is a coiling temperature. Therefore, in order to improve the quality of the steel sheet, it is important to improve the uniformity of the winding temperature over the entire area of ​​the steel sheet. Here, the coiling temperature is the temperature of the steel sheet in the winding device immediately before the time of the steel sheet after finish rolling after the cooling step is wound.
[0005]
　Generally, in the cooling step for injecting cooling water to the hot steel finish 800 ° C. ~ 900 ° C. after rolling, while the steel sheet temperature is above approximately 600 ° C., steam stably steel sheet surface generated by film boiling the cover. Therefore, the cooling capacity is itself reduced by the cooling water, it becomes relatively easy to uniformly cool the steel plate over the entire surface.
However, from around, particularly steel sheet temperature is below 550 ° C., the amount of steam generated with decreasing temperature of the steel strip is reduced. Then, begin to disintegrate vapor film covering the steel surface, the transition boiling zone distribution of the steam film is changed temporally and spatially. As a result, non-uniformity is increased in cooling, nonuniformity of temperature distribution in the plate width direction and the rolling direction of the steel sheet tends to rapidly expand. Therefore, it becomes difficult to control the temperature of the steel strip, it becomes difficult to finish cooling the entire steel sheet in the winding temperature as intended.
[0006]
　Meanwhile, in order to produce a product having excellent characteristics having both the strength and workability, it is effective to reduce the winding temperature to a low temperature region below 500 ℃. Therefore, the non-uniformity of the coiling temperature throughout the steel plate including the distribution in the plate width direction and the longitudinal direction, it is very important to fall within a predetermined range with respect to temperature of a target. From this point of view, the invention for controlling the coiling temperature have been many heretofore.
[0007]
　Many things in these invention relates to countermeasures, and means for non-uniform cooling that occurs due to the cooling device itself. Especially in hot-rolled steel sheet, since the uneven cooling in the plate width direction caused by cooling water injected into the upper surface side of the steel sheet is retained on the steel sheet becomes a big problem, various countermeasures have been made. Further, other than this, other than the cooling device factors, before cooling particularly uneven temperature distribution in the plate width direction and the longitudinal direction, or the steel sheet surface roughness and surface texture, such as the scale thickness of the non-uniform cooling caused by uneven those that reduce the challenges seen many. In other words, especially when the coiling temperature is a low temperature range, the uneven temperature distribution before cooling, since the previously vapor film is rapidly cooled enters the transition boiling zone and collapsed in a low temperature portion, after cooling problems temperature deviation will be larger than the temperature difference of the incoming side of the cooling device occurs. Similarly, the influence of the surface property unevenness, the surface roughness is large portion, or scale selectively vapor film is collapsed earlier in the thick portion, until again several times in the entrance side of the cooling apparatus after cooling temperature a problem that deviation will to expand occurs.
[0008]
　Most preferably as measures of heterogeneous cooling unevenness of the temperature of the pre-cooling and surface properties are caused, it is to apply some means so that these irregularities are small enough prior to cooling. In fact, the invention has been made many on such measures. However, in mass production facilities, such as a production line of hot-rolled steel sheet, it is also important productivity and cost. Even measures even improving the non-uniformity of temperature before cooling and surface texture were present, in achieving the overall cost balance, until the non-uniformity improvement measures before cooling problems after cooling completely eliminated it is very difficult in practice to be thoroughly implemented. Further, the cause of occurrence of non-uniformity of the surface texture is often part not been elucidated mechanistically, some drastic measures are not found cases.
[0009]
　Therefore, as another means to deal with non-uniformity of pre-cooling, based on the temperature distribution information of the course before cooling or cooling to limit the selective cooling amount to the low-temperature unit, or for high temperature portion by increasing the amount of cooling, it is considered that a uniform temperature profile after cooling. It is also contemplated to be able to equalize the temperature distribution after cooling in the following manner. That is, unevenness of surface properties such as scale can not be regarded necessarily cooled before the temperature distribution information. However, the temperature distribution of the middle cooling is often the effect appears. Therefore, an appropriate timing, i.e., by the collapse of the vapor film is a temperature distribution measured at timing before a catastrophic uneven temperature distribution occurs progressing earnest, controls the amount of cooling based on the information, It is considered to be uniform temperature distribution after cooling.
Therefore, as shown in the following invention has been made so far.
[0010]
　For example, Patent Document 1, in a spray header having an array of injection nozzles with a built-in opening and closing valve for opening and closing the pilot pressure, on-off valve of the respective injection nozzle, a control cylinder which supplies the pilot pressure to be turned off is provided, this in the steel plate cooling method by spraying width controller for controlling the ejection of the cooling water injection nozzle by controlling the internal pressure in the control cylinder at the position of the piston rod moving on rotated screw at a variable motor, a spray header among the plurality of injection nozzles provided, edge mask by adjusting the operating pilot pressure to the on-off valve of the particular injection Nozuruhe set in advance, or, and forming a front and tail mask cooling method of steel plate is disclosed.
[0011]
　Patent Document 2, tubs for receiving an injection device for changing the direction does not strike the flow of the cooling water by injecting fluid into the steel pipe to a cooling water ejected toward the steel pipe, cooling water is changed the flow direction by the injection device steel pipes of the cooling apparatus having the door is disclosed.
[0012]
　Patent Document 3, a circular tube header having a slit blown up the plate-shaped water flow, recesses progressively blocking the water flow toward the widthwise center of the width direction end portion of the water stream blown up is formed, the header concentric a width adjusting member rotatable, a cooling device of hot-rolled with a disclosed.
[0013]
　Patent Document 4, in the cooling device, a nozzle for adding coolant to the hot-rolled steel sheet has a plurality of installed in the width direction on both sides of the upper and lower surfaces of the hot-rolled steel sheet, these nozzles, particularly that a high temperature is controlled in a manner that the cooling agent is added to the position which is detectable is disclosed. The cooling device is further installed a plurality of temperature sensors in the width direction, these temperature sensors detect the temperature distribution in the width direction of the hot-rolled steel sheet, depending on the basis of a signal of the temperature sensor, nozzle It is capable of controlling the coolant amount from.
[0014]
　Patent Document 5, in the cooling device, the upper cooling water header hot-rolled steel sheets which are arranged in a straight line a plurality of cooling water supply nozzle group, and are a plurality arranged in a width direction, the temperature in the plate width direction distribution on the basis of the temperature distribution measured by the temperature distribution sensor for detecting the, it is disclosed that controls the flow rate of the cooling water. Specifically, on-off control valve is provided in these cooling water header, the cooling water is controlled by on-off control valve.
CITATION
Patent Document
[0015]
Patent Document 1: JP-A-7-314028 JP
Patent Document 2: Japanese Utility Model 58-81010 JP
Patent Document 3: JP-B 62-25049 Patent Publication
Patent Document 4: JP-T 2010-527797 Patent Publication
Patent Document 5: JP No. 6-71328 JP
Summary of the Invention
Problems that the Invention is to Solve
[0016]
　Hot-rolled steel sheet, the conveying speed of the steel sheet (≒ winding speed) is very fast and the number m / s ~ than twenty m / s. Therefore, depending on the nonuniformity temperature distribution in the rolling direction of the cooling before and during cooling of the steel sheet described above, in order to switch the start and stop of the cooling water jetting from the cooling water nozzles, as short as possible a response time of the switching , it is necessary to control at high speed.
[0017]
　Further, in order to solve the uneven temperature distribution in the plate width direction of the cooling before and during cooling of the steel sheet, the switching of the starting and stopping of the injection of cooling water from the cooling water nozzles aligned along the plate width direction, It had to be performed individually fast individually or a plurality units. However, the response time of the conventional and has a cooling device used in the cooling step of hot-rolled steel sheet is about 1 to 3 seconds. Therefore, it would be hot-rolled steel sheet also has ten m ~ several tens m conveyed between the response time. Therefore, particularly for uneven temperature distribution of the steel sheet varies from about 10m below the pitch in the rolling direction, it is impossible to sufficiently suppress the non-uniform temperature distribution expansion after cooling.
[0018]
　In the technique disclosed in Patent Document 1, it arranged a nozzle incorporating a closing valve for opening and closing the pilot pressure in the plate width direction. Then, the range supplies the pilot pressure required to OFF of the cooling water injected can be selected in the pre-installed range of the plate width direction, and can be stopped selectively cooling water jetting. Thus, in response to a low temperature portion of the edges and front and rear ends of the steel sheet, it is made possible to ON / OFF control of the cooling water jetting.
However, the response time of the ON / OFF of the coolant injection is dependent on the speed of movement of the piston rod. Technique disclosed in Patent Document 1, less the movement amount for moving by rotation of the screw, it is difficult to about 3 times or more ON / OFF control per second. Thus, corresponding to the non-uniform temperature distribution of the fine pitch (e.g., 10m or less) is limited.
[0019]
　Further, in the technique disclosed in Patent Document 2, although possible to realize a state in which no cooling by changing the direction of flow of the cooling water for cooling the steel pipe is disclosed, only the switching technique in the plate width direction of the steel sheet It could not be temperature controlled at an arbitrary position.
In the technique disclosed in Patent Document 3, although the shielding plate is rotated so that is not exposed to the cooling water flow to the end of the steel plate, it was not possible to control the temperature of the arbitrary position in the plate width direction of the steel sheet .
[0020]
　Also, if the cooling device described in Patent Document 4, to control the coolant amount from the nozzle in the plate width direction has been disclosed, for controlling the coolant quantity in specific any way disclosure is not. That is, FIG. 9 of Patent Document 4, although the nozzles is shown to have been arranged in the plate width direction, the upstream side of the pipe connected to the nozzle is controlled so that the cooling agent which or it has not been disclosed. For example, in the case of state coolant piping is not satisfied that is connected to the nozzle, simply controlling the cooling agent amount, response is poor at the time of addition of coolant from the nozzle. Conveying speed of the steel sheet, since very a few m / s ~ than twenty m / s faster, depending on the nonuniformity temperature distribution in the longitudinal direction before cooling and during cooling of the steel sheet described above, part of the cooling water nozzles to control the amount of cooling water impinging on the steel sheet by switching the stop initiation and ejection of the cooling water jetting from the switching from the state where the injection cooling water to stop injection, and the cooling water injection the time required for switching from a state that is stopped to start the injection, i.e. the response time as short as possible, it is necessary to be controlled at high speed.
[0021]
　Further, Patent Document 4, although the control of the coolant quantity in the plate width direction is disclosed, there is no disclosure about control of the rolling direction of the coolant. In such a case, it is difficult to suppress the streaky nonuniform temperature distribution extending in the rolling direction of the hot-rolled steel sheet. In addition, on the upper surface there is a plate clean water, can not adequately control the plate width direction temperature the hot-rolled steel sheet. In view of the above, in the cooling device described in Patent Document 4, a sufficient homogenization of the plate width direction temperature hot rolled steel sheet not Hakare, there is room for improvement.
[0022]
　In the cooling device described in Patent Document 5, the same problem as Patent Document 4 described above. That is, the on-off control valve and the cooling water is controlled, also in the same manner as described above, response is poor in a state where the cooling water is not always met in a pipe that is connected to, for example, a nozzle. The cooling water header is in the plate width direction are provided in a plurality, in the rolling direction it is only provided one, can not control the temperature of the rolling direction relative to the hot-rolled steel sheet, streaky it is difficult to suppress the uneven temperature distribution.
[0023]
　In addition, in the cooling device of Patent Document 5, but is intended to cool by spraying cooling water on the upper surface of the hot-rolled steel sheet, the plate clean water present in the upper surface, the plate width direction temperature hot rolled steel sheet It can not be sufficiently controlled. Furthermore unless properly draining the plate clean water, it is impossible to accurately measure the temperature due to the temperature distribution sensor, there is room for improvement in temperature control.
[0024]
　In view of the above, in the conventional cooling apparatus and cooling method, uniformity of the rolling direction and the sheet width direction temperature hot rolled steel sheet was difficult.
[0025]
　The material properties of high-tensile steel plate is largely affected by the cooling. High-tensile steel plate, because the influence of the coiling temperature on the properties of the final product is greater than the conventional material, uneven temperature distribution of the degree that did not bother the conventional material, greatly affects the strength of the high-tensile steel plate to. Therefore, when manufacturing a high-tensile steel sheets, it can perform highly accurate cooling control than during the manufacture of conventional materials sought. Have been proposed, the technique attempts to control the cooling temperature of the steel sheet by the cooling water supplied from the upper surface side of the steel plate, for example, there are following problems.
(1) cooling water supplied from the upper surface side of the steel sheet, after impacting on the upper surface of the steel sheet, retained on the upper surface of the steel sheet, comprising a plate clean water. When supplying cooling water from the upper surface side, in the temperature range, particularly steel sheet temperature is below 550 ° C., in addition to the portion where collides with the cooling water, by the plate clean water, the steel sheet is cooled. The high-tensile steel plate, this effect because particularly large, uneven temperature distribution than conventional materials is increased.
(2) cooling water supplied from the upper surface side of the steel sheet, after impacting on the upper surface of the steel plate, it flows in part into the plate width direction of the steel sheet. Water flows into the plate width direction, it interferes with the cooling water supplied from the upper surface side of the steel plate. Therefore, the cooling water supplied from the upper surface side, it is difficult to control the plate width direction temperature of the steel sheet with high accuracy.
(3) In order to perform the high cooling temperature control precision by cooling water supplied from the upper surface side of the steel plate, it is necessary to remove the plate clean water using a draining facility. To help improve the measurement accuracy of the temperature, thermometer draining facilities affected hardly locations, i.e., it is placed at a position away in the rolling direction from the cooling water nozzles for injecting cooling water. As a result, the temperature becomes long time from the measured until the water collides, because the temperature change in this time becomes larger, control precision of the cooling temperature decreases.
As described above, in the prior art to try to control the plate width direction cooling temperature of the steel sheet by the cooling water supplied from the upper surface side of the steel sheet, high plate width direction temperature-level of precision required in manufacturing the high-tensile steel plate to perform the control was difficult.
[0026]
　The present invention has been made in view of the foregoing, by appropriately cooling the lower surface of the hot rolled steel sheet after finish rolling in the hot rolling step, the temperature in the rolling direction and the plate width direction of the hot-rolled steel sheet It aims to improve uniformity.
Means for Solving the Problems
[0027]
　A first aspect of the present invention, after the finish rolling of the hot rolling process, a cooling device for cooling the lower surface of the hot-rolled steel sheet conveyed on the conveying roll, the plate width direction of the lower surface of the steel plate conveyance region total the cooling region defined by the predetermined length of the region and the rolling direction and the entire cooling area, the width divided cooling zone is a cooling zone of each obtained by dividing into a plurality in the total cooling area the plate width direction, the width divided cooling and dividing the cooling surface is a cooling region obtained by dividing into a plurality in the rolling band direction, and at least one cooling water nozzle for injecting cooling water on the lower surface of each of the divided cooling surface, the cooling ejected from the cooling water nozzles water, a switching device for switching the collision and non-collision of the divided cooling surface, the width direction thermometer for measuring the temperature distribution in the plate width direction based on the measurement results of the width direction thermometers, control the operation of the switching device wherein a control device for, that is provided To a cooling device hot-rolled steel sheet.
Among the "cooling water sprayed from the cooling water nozzles, collision and non-collision with the split cooling surface", and the "collision of the divided cooling surface", there is a lower surface of the hot-rolled steel sheet divided cooling surface coolant means injection of the cooling water so as to impinge on the lower surface of the hot-rolled steel sheet in the case of. On the other hand, "non-collision of the divided cooling surface", the cooling water when the lower surface of the hot-rolled steel sheet divided cooling surface is present refers to a state that does not collide with the lower surface of the hot-rolled steel sheet.
[0028]
　In the cooling device for a hot-rolled steel sheet of the first aspect, the cooling water nozzles, the cooling water nozzle corresponding to each divided cooling surface may be disposed one or more.
[0029]
　In divided cooling surface adjacent to the cooling device for a hot-rolled steel sheet of the first aspect, the number of the cooling water nozzles are arranged may be different from each other in the rolling direction.
[0030]
　In the cooling device for a hot-rolled steel sheet of the first aspect, the divided cooling surface each rolling direction length included in the width divided cooling zone may be different from each other in the rolling direction.
[0031]
　In the cooling device for a hot-rolled steel sheet of the first aspect, the rolling direction length of the divided cooling surface may be a multiple of between transport roll length.
[0032]
　In the cooling device for a hot-rolled steel sheet of the first aspect, the arrangement of the plurality of coolant nozzles in the plate width direction are arranged so that the center distance of the cooling water nozzle adjacent the plate width direction is all equidistant it may be.
[0033]
　Above cooling device for a hot-rolled steel sheet of the first aspect, a plurality of cooling water nozzle for cooling the same division cooling surface is arranged, the switching device of the plurality to the same division cooling surface of the cooling water nozzles, switching the impingement of the cooling water and the non-collision of the same division cooling surface integrated switching control system can be controlled at the same time.
[0034]
　In the cooling device for a hot-rolled steel sheet of the first aspect, the switching device is provided in a pipe through which cooling water flows to be supplied to the cooling water nozzles, draining the water supply header, the cooling water supplying cooling water a drainage header or drainage area can be configured to comprise a valve for switching the flow of cooling water between the water supply header and the drainage header or waste area.
In this case, the valve may be a three-way valve, the transport roll way valve is provided in an the side of the plate width direction, it may be arranged at the same height as the tip of the cooling water nozzles.
[0035]
　The cooling device for a hot-rolled steel sheet of the first aspect, the switching device is provided in a pipe that is supplied cooling water flows into the cooling water nozzles, draining the water supply header, the cooling water supplying cooling water drainage area and, comprising means for changing the injection direction of the cooling water that is injected from the cooling water nozzles, and means for shielding such that the cooling water does not collide with the divided cooling surface during injection direction change, the injection direction of the cooling water the cooling water by means for changing, may be switched collision and non-collision of the lower surface of the divided cooling surface.
[0036]
　Above cooling device for a hot-rolled steel sheet of the first aspect, the width direction thermometer, provided on at least one of the rolling direction upstream and rolling direction downstream side of the total cooling area, and providing for each width divided cooling zone can. At this time, it may be arranged in the width direction thermometer on the lower surface side of the steel plate conveyance area.
[0037]
　A second aspect of the present invention, after the finish rolling of the hot rolling process, a cooling process for cooling the lower surface of the hot-rolled steel sheet conveyed on the conveying roll, the plate width direction of the lower surface of the steel plate conveyance region total the cooling region defined by the predetermined length of the region and the rolling direction and the entire cooling area, each of the cooling areas obtained by dividing the total cooling area into a plurality in the plate width direction and the width divided cooling zone, the width divided cooling zone the cooling areas obtained by dividing into a plurality in the rolling direction and divided cooling surface, measuring the temperature distribution in the plate width direction of the hot rolled steel sheet, according to the cooling water nozzles for each of the divided cooling surface on the basis of the measurement results of the temperature distribution characterized in that the collision and non-collision of the cooling water to the hot-rolled steel sheet is controlled in each of the plate width direction and the rolling direction, a method of cooling hot rolled steel sheet.
[0038]
　In the second embodiment, the same provided with a plurality coolant nozzles for injecting cooling water on the divided cooling surface, the cooling water to the hot-rolled steel sheet resides in the same divided cooling surface by the plurality of coolant nozzles collision and non-collision, it may be controlled simultaneously by integrating a plurality of cooling water nozzles.
[0039]
　In the second embodiment, the cooling water supplied to the cooling water nozzles are provided in the pipe flow, drainage and water supply header for supplying the cooling water, and drainage header or drainage area draining the cooling water, a water supply header and a valve for switching the flow of cooling water between the header or drainage area, based on the measurement of temperature distribution in the plate width direction of the hot-rolled steel sheet, cooling for each divided cooling surface by controlling the opening and closing of the valve collision and non-collision of the cooling water to the hot-rolled steel sheet by water nozzles may be controlled in each of the plate width direction and the rolling direction.
[0040]
　Here, the valve is a three-way valve for feed water header without cooling the lower surface of the hot rolled steel sheet by the cooling water from the cooling water nozzles, impingement cooling water from the cooling water nozzles on the lower surface of the hot-rolled steel sheet It may control the opening degree of the three-way valve to keep out so as not to, with respect to the feed water header by the cooling water from the cooling water nozzles for cooling the lower surface of the hot-rolled steel sheet, the cooling water from the cooling water nozzles it may control the degree of opening of the three-way valve so as to impinge on the lower surface of the hot-rolled steel sheet.
The invention's effect
[0041]
　According to the present invention, by adequately cool the lower surface of the hot rolled steel sheet after finish rolling in the hot rolling process, in the rolling direction and the plate width direction of the hot-rolled steel sheet and can improve the uniformity of temperature Become.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042]
It is an explanatory view schematically showing a configuration of FIG. 1 hot rolling mill 10.
FIG. 2 is a perspective view schematically showing the structure of the lower side width controlled cooling device 17 according to the first embodiment.
3 is a side view showing a schematic configuration of a lower width controlled cooling device 17 according to the first embodiment.
4 is a plan view showing a schematic configuration of a lower width controlled cooling device 17 according to the first embodiment.
5 is a diagram illustrating the division cooling surface A3 of one example.
Is an explanatory diagram focusing on FIG. 6 width divided cooling zone A2.
7 is a diagram illustrating a split cooling surface A3 of the other examples.
8 is a diagram illustrating a split cooling surface A3 of the other examples.
[9] divided cooling surface A3 of the lower width direction controlled cooling device 17 according to the first embodiment, and illustrates the arrangement of cooling water arrangement of the nozzles 20, and the temperature measuring device 30, 31.
It is an example of the arrangement of FIG. 10 divided cooling surface A3 and the cooling water nozzles 20.
It is an example of the arrangement of FIG. 11 divided cooling surface A3 and the cooling water nozzles 20.
It is an example of the arrangement of FIG. 12 divided cooling surface A3 and the cooling water nozzles 20.
It is an example of the arrangement of FIG. 13 divided cooling surface A3 and the cooling water nozzles 20.
14 is a diagram illustrating an embodiment of a temperature measuring device 30.
15 is a diagram illustrating an embodiment of a coolant nozzle 20.
Is a diagram illustrating the configuration of FIG. 16 lower width of the example without the intermediate header 21 Direction control cooling device 17.
17 is a diagram for explaining the structure of the cooling water traveling direction changing apparatus 126.
FIG. 18 is another diagram for explaining the structure of the cooling water traveling direction changing apparatus 126.
19 is a diagram for explaining the structure of the cooling water traveling direction changing apparatus 226.
FIG. 20 is another diagram for explaining the structure of the cooling water traveling direction changing apparatus 226.
21 is a diagram for explaining the structure of the cooling water traveling direction changing apparatus 326.
FIG. 22 is another diagram for explaining the structure of the cooling water traveling direction changing apparatus 326.
23 is a diagram showing a part of the steel plate top surface temperature distribution in the case of Comparative Example 1.
FIG. 24 is a diagram showing a part of the steel plate top surface temperature distribution in the case of Example 1.
DESCRIPTION OF THE INVENTION
[0043]
　It will be described below with reference to the drawings, embodiments of the present invention. In the specification and drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0044]
　First Embodiment
FIG 1 is apparatus for manufacturing a hot-rolled steel sheet with a cooling device in the first embodiment (hereinafter, "hot rolling mill" and referred.) Is an explanatory view schematically showing a 10 configuration.
[0045]
　In hot rolling mill 10, the slab 1 is heated continuously rolled across the upper and lower roll, and thinned to the thickness of about a minimum 1mm wound this as hot-rolled steel sheet 2. Hot rolling mill 10 includes a heating furnace 11 for heating the slab 1, and the width direction rolling mill 12 for rolling the slab 1 that has been heated in the heating furnace 11 in the plate width direction, it is rolled in the sheet width direction and the slab 1 and roughing mill 13 to rolling the crude bar from the vertical direction, the finish rolling mill 14 the crude bar further to a predetermined thickness by continuous hot finish rolling, heat by the finish rolling mill 14 a cooling device 15, 16, 17 between the finish rolled hot-rolled steel sheet 2 is cooled by cooling water, a winding device 19 for winding the hot-rolled steel sheet 2, which is cooled by the cooling device 15, 16, 17 in a coil form It is equipped with a. Of the cooling apparatus 15, 16, 17, the upper cooling device 15 is disposed above the steel plate conveyance region, the lower the cooling device 16, the lower width controlled cooling apparatus 17 is disposed below the steel plate conveyance region.
[0046]
　In the heating furnace 11, the process of heating the slab 1 which has been carried in from outside through the spout to a predetermined temperature is performed. When the heating treatment in the heating furnace 11 is completed, the slab 1 is conveyed into the heating furnace 11 outside, after a widthwise rolling mill 12, the process proceeds to the rolling step by rough rolling mill 13.
[0047]
　Slab 1 that has been conveyed by the roughing mill 13 is rolled in rough bar to a thickness of about 30 mm ~ 60 mm (sheet bar), and is conveyed to the finish rolling mill 14.
[0048]
　In finishing mill 14, a hot-rolled steel sheet 2 was rolled coarse bar which has been conveyed to a thickness of about several mm. Rolled hot-rolled steel sheet 2 is fed is conveyed by the conveyor rolls 18 (see FIGS. 2-4.) The upper cooling device 15, the lower cooling device 16, to the lower side width controlled cooling device 17.
[0049]
　Hot-rolled steel sheet 2, the upper cooling unit 15 is cooled by the lower cooling device 16 and the lower width controlled cooling device 17, and wound in a coil shape by winding device 19.
[0050]
　Configuration of the upper cooling device 15 can be applied the known cooling device without being particularly limited. For example the upper cooling device 15 has a plurality of cooling water nozzle for injecting cooling water vertically downwardly from above the steel plate conveyance region on the upper surface of the steel plate conveyance region. As the cooling water nozzles, for example, slit laminar nozzle or pipe laminar nozzles are used. Preferably upper cooling unit 15 provided in view of ensuring the cooling capacity, but are not necessarily disposed when not become insufficient cooling, normally it is required.
Lower cooling device 16 is cooled to cool the lower side of the steel plate conveyance region conveyed on the conveying rolls 18 of the run-out table, the steel plate conveyance region by injecting cooling water vertically upward toward the lower surface of the steel plate conveyance region a device, the configuration can be applied to known cooling devices without being particularly limited.
[0051]
　Next, the configuration of the lower widthwise controlled cooling device 17. Perspective view schematically showing the configuration of a portion of the lower width controlled cooling device 17 in FIG. 2 schematically illustrates the configuration of a portion of the lower width controlled cooling device 17 in FIG. 3, the plate width direction side view from (Y-direction), shows a plan view of a part of the configuration shown schematically, as seen from the vertical direction (Z direction) above the lower widthwise controlled cooling device 17 in Figure 4.
Lower widthwise controlled cooling apparatus 17 in this embodiment includes a cooling water nozzle 20, the intermediate header 21, the pipe 23, the water supply header 25, the switching device and a temperature measuring device 30 having a three-way valve 24 and drainage header 26, 31, is schematically constituted by a control unit 27.
[0052]
　Lower widthwise controlled cooling device 17 is a device for controlling the cooling of the divided cooling surface A3 of the total cooling area A1 which is a lower surface of the steel plate conveyance region to be described later formed by dividing. Shown Figure for their description in FIGS. 5-8. 5 to 8 are views for explaining a division cooling surface A3. 5 to 8, the hot rolling mill 10 is a diagram viewed from the Z direction, which shows the relationship between the position of the transport roll 18 and the total cooling area A1 will be described later. Note that in FIG. 5 through 8 for convenience of explanation, there is shown a transport roll 18 by a dotted line.
[0053]
　In this embodiment, a region that may be present in the hot-rolled steel sheet 2 can be produced by hot-rolling equipment 10 is transported on the run-out table to "steel plate conveyance region". The "steel plate conveyance region" That is partitioned with a maximum thickness × maximum strip width of manufacturable hot-rolled steel sheet, a three-dimensional region extending in the rolling direction. Therefore, "the steel sheet conveyance region" in the rolling direction, occupy space before the winder from the output end of the rolling mill finish on the run out table.
[0054]
　Of the lower surface of the "steel plate conveyance region", a region where the lower widthwise controlled cooling device 17 to cool the target, the area defined by the predetermined length of the entire area and the rolling direction of the plate width direction "total cooling the area A1 ".
[0055]
　The "total area of ​​the sheet width direction" indicates a region in which the hot-rolled steel sheet 2 may exist on the transport roll 18. The "predetermined length in the rolling direction" a rolling direction between rolls 1 pitch length at least transport roll 18. The "length of one pitch between the rolling direction rolls" means the distance between the axes of the conveying rolls adjacent to each other in the rolling direction. But are not particularly limited length of the "predetermined length in the rolling direction", preferably lower than about 20m from the viewpoint of equipment cost. Specific length may be suitably determined and the cooling capacity of the lower widthwise controlled cooling apparatus 17, the manner to be expected of the uneven temperature distribution of the hot-rolled steel sheet 2.
[0056]
　The total cooling area A1, the respective cooling areas obtained by dividing into a plurality of plate width direction and the "width divided cooling zone A2". 6 shows an example of the steel plate conveyance region A1 is divided into six width divided cooling zone A2. In the example shown in FIG. 6, for easy understanding of the technology, but the width divided cooling zone A2 are six sequences in the plate width direction, the number of divisions is not limited thereto. The number of width divided cooling zone A2 in the plate width direction (i.e., the number of divisions) is particularly are not limited to, at least one cooling water nozzle 20 is divided so as to correspond to each of the width divided cooling zone A2 there.
[0057]
　Plate width direction length of the width divided cooling zone A2 is a length that the plate width direction length of the steel plate conveyance region A1 is divided by the division number. The length of the plate width direction of the width divided cooling zone A2 is not particularly limited, such as 50mm and 100 mm, it may be appropriately set.
[0058]
　Each of the cooling regions obtained by dividing the width divided cooling zone A2 in a plurality in the rolling direction and "split cooling surface A3". Plate width direction length of the divided cooling surface A3 is the same as the sheet width direction length of the width divided cooling zone A2, the rolling direction length of the divided cooling surface A3 is a rolling direction length of the width divided cooling zone A2, divided is the length divided by the number.
The length of the rolling direction of the divided cooling surface A3 is not to be particularly limited, it can be appropriately set. The length of the rolling direction of the divided cooling surface A3 shown in FIG. 5 is set to the same length as the one pitch rolling direction rolls of the transporting roll 18. Further, in FIG. 7 shows an example which is set to the length of two pitches rolling direction rolls of the transporting roll 18. Thus dividing the length of the rolling direction of the cooling surface A3 may be any length of integral multiple of the pitch between the rolling direction rolls of the transporting roll 18.
Incidentally, the rolling direction length of the plurality of divided cooling surface A3 which is arranged adjacent to the rolling direction need not be the same, may be different from each other. For example, as shown in FIG. 8, the rolling direction length of the divided cooling surface A3 from the upstream side to the downstream side, one pitch rolling direction rolls of the conveyor roll 18, two pitches, four pitches, 8 pitches , 16 pitch, it is also possible to sequentially long and so on ....
[0059]
　In the following description, as shown in FIG. 9, the rolling direction length explaining divided cooling surface A3 is four times the length of the pitch between the rolling direction rolls of the transporting roll 18 as an example. In this embodiment, as shown in FIG. 9, and the divided cooling surface A3 having four times the rolling direction length of the pitch between the rolling direction rolls of the transporting roll 18. However, as described above, also divided cooling surface A3 of the other forms may be used.
[0060]
　Cooling water nozzle 20, from below the steel plate conveyance area of ​​the run-out table, a cooling water nozzle for injecting cooling water vertically upward toward the lower surface of the steel sheet conveyance region, a plurality of cooling water nozzle 20 is disposed. The cooling water nozzle 20 may be used various known types of nozzles, this can be mentioned pipe laminar nozzles, for example. The cooling range of the plate width direction of the cooling water nozzle 20, as hereinafter plate width direction length of the cooling divided surfaces A3, so that the collision range of the cooling water to the cooling dividing plane A3 does not enter the other cooling dividing plane A3 to.
[0061]
　9 shows, in this embodiment, expressed together also disposed in the cooling water nozzle 20 for dividing the cooling surface A3. 9 represents a cooling water nozzle 20 by "●". Cooling water nozzle 20, toward each of the divided cooling surface A3 is at least one by one arranged.
Cooling water nozzle 20 in this embodiment, in a plan view seen from above the steel plate conveyance region, on one divided cooling surface A3 four cooling water nozzles 20 are arranged to belong. Four of the cooling water nozzles 20 in the present embodiment in a plan view, are disposed respectively between the conveying adjacent rolls 18 are arranged in the rolling direction. The number and arrangement of the cooling water nozzles 20 which belong to one divided cooling surface A3 is not particularly limited, it may be one or may be plural. The number and arrangement of the cooling water nozzles 20 in the divided cooling surface A3 adjacent to each other may be different.
Incidentally, the amount of water and flow rate discharged from the cooling water nozzle 20 the plate width direction, and the same in the rolling direction of the coolant nozzle 20, who is the cooling capacity and the same control is easy. The number of the cooling water nozzles 20 installed arranged in the plate width direction in the same position in the rolling direction in each cooling divided surface A3, the discharge water amount and the discharge flow rate and the same, each of the divided cooling surface arranged in the plate width direction A3 control is better to the same cooling capacity in is easy.
Incidentally, the discharge water amount and the discharge flow rate are the same cooling water nozzle 20, the distance between the centers of the cooling water nozzles 20 thereof arranged adjacent to the plate width direction are all equal distance belongs to the divided cooling surface A3 arranged in the sheet width direction it is preferably arranged so as to. Thus it is possible to perform uniform cooling in the plate width direction with higher accuracy.
Incidentally, the discharge water amount and based on the discharge flow rate cooling capacity plate width direction of the cooling water nozzle 20, be different in the rolling direction, it is possible to control by the controller 27.
[0062]
　In this embodiment, such a split cooling surface A3 are two in the rolling direction (X direction), they are arranged six side by side in the plate width direction (Y-direction). Discharge water and the discharge flow rate are the same cooling water nozzle 20 is also arranged in each of the rolling direction, and the sheet width direction.
[0063]
　9 shows, divided cooling surface A3 in this embodiment, and expressed the arrangement of the cooling water nozzles 20 belonging to herein, is not limited thereto, it can be applied in various combinations. Exemplarily recited in FIGS. 10 to 13. Here the cooling water nozzles at the discharge water Flow rate is set to cooling capacity in the same the same.
Example shown in FIG. 10, the rolling direction length of the divided cooling surface A3 is one pitch rolling direction rolls of the conveyor roll 18, to the divided cooling surface A3 1 one cooling water nozzle 20 belongs.
Example shown in FIG. 11, the rolling direction length of the divided cooling surface A3 is one pitch rolling direction rolls of the conveyor roll 18, to the divided cooling surface A3 2 one cooling water nozzle 20 is disposed. The two cooling water nozzle 20 may be arranged in the rolling direction, it may be arranged in the plate width direction. Further, it may be arranged to be shifted in either the rolling direction and the sheet width direction as shown in FIG. 11.
Example shown in FIG. 12 is a two pitches rolling direction rolls in the rolling direction length transport roll 18 of the divided cooling surface A3, 4 one cooling water nozzle 20 is disposed in each of the divided cooling surface A3 .
Example shown in FIG. 13, the rolling direction length of the divided cooling surface A3 is, one pitch rolling direction rolls of the conveyor from the upstream roller 18, two pitches, four pitches, changes 8 pitches ... and the number of the cooling water nozzles 20 in divided cooling surface A3 adjacent to the rolling direction belonging to each of the divided cooling surface A3 are different examples.
[0064]
　Intermediate header 21 serves as a part of the switching device in the present embodiment, a header for supplying cooling water to the cooling water nozzles 20. As in the present embodiment seen from FIGS. 2 to 4, the intermediate header 21 is a tubular member extending in the rolling direction, a plurality of cooling water nozzle 20 is provided in the rolling direction. Therefore, it is possible to simultaneously control one of the cooling water from the cooling water nozzles 20 arranged in the intermediate header 21 injection and stop. In the illustrated example, the cooling water nozzle 20 are arranged four in the rolling direction with respect to one intermediate header 21, the number of cooling water nozzle 20 is not limited thereto.
The intermediate header 21 is positioned to be one to one divided cooling surface A3. Thus, it is possible to perform switching control of stopping the injection of cooling water for each divided cooling surface A3.
[0065]
　For dividing cooling surface A3 in this embodiment is provided two in the rolling direction, the intermediate header 21 is also only two in the rolling direction, the number of intermediate header 21 suitably changed according to the number of the divided cooling surface A3 do it.
[0066]
　The three-way valve 24 is a member that functions as a part of the switching device in the present embodiment. That is, the three-way valve 24 is a main member of the switching device for switching the cooling water sprayed from the cooling water nozzles 20, the collision and non-collision of the lower surface of the steel sheet conveyance region.
Three-way valve 24 of the present embodiment is a shunt type, the water from the water supply header 25, the intermediate header 21 leading to pipe 23, or more to the water supply to the cooling water nozzle 20, a valve for switching between the leads to the drainage header 26 is there. Although the present embodiment exemplifies the drainage header 26 as the site for drainage, the embodiments are not limited in particular.
Instead the two valves of the three-way valve 24 of the present embodiment (valve for stopping the flow of fluid in a broad sense, sometimes referred to as ON / OFF valves.) To perform the installation to similarly controlled three-way valve also possible it is.
[0067]
　Three-way valve 24 in this embodiment, one provided on one intermediate header 21, is disposed between the drainage header 26 for discharging the water supply header 25 and the cooling water supplying cooling water. However it not limited thereto, and may be in the form of placing a plurality of intermediate header 21 for one-way valve 24. According to this, it is possible to simultaneously control to integrate a plurality of intermediate header 21.
[0068]
　In the example shown, the water supply header 25 and the water discharge header 26 are provided two each, these numbers of the water supply header 25 and the water discharge header 26 is not limited to this, for example, a one, respectively it may be.
[0069]
　Internal piping 23, the three-way valve 24 is always adapted to the cooling water is filled. Thus, the collision with the cooling water on the lower surface of the steel sheet conveyance area (divided cooling surface A3), that is, upon cooling the lower surface of the hot-rolled steel sheet 2, since the instruction is issued to open the three-way valve 24, the cooling water nozzle can be cooling water from 20 to shorten the time until the injection, it is possible to enhance the response. Incidentally, the responsiveness of the opening and closing of the three-way valve 24 is preferably within 0.5 seconds. The solenoid valve is used for example in the three-way valve 24.
[0070]
　Further, the three-way valve 24 is preferably disposed at the same height as the tip of the cooling water nozzles 20. More specifically, of the three-way valve 24, it is preferable that the connection portion of the pipe 23 is the same height as the tip of the cooling water nozzles 20. Thus, the tip of the cooling water nozzles 20 and the leading end of the pipe 23 is the same height, the inside of the pipe 23 is always the coolant is satisfied. For example, even if the seal of the three-way valve 24 leaks little cooling water not complete, the inside of the pipe 23 can be filled with cooling water, it is possible to further improve the responsiveness.
[0071]
　The three-way valve 24 is preferably provided on the side of the plate width direction with respect to the transport roll 18. For example a three-way valve 24 it is conceivable to provide below the transport roll 18, which is limited space under the transport roll 18, it is difficult to provide a plurality of three-way valve 24. Further, it is difficult to carry out the maintenance of the three-way valve 24 below the transport roll 18. In this respect, if the three-way valve 24 as in the present embodiment is provided on the side of the plate width direction with respect to the transport roll 18, a high degree of freedom in installation of the three-way valve 24, it is easily performed maintenance it can.
[0072]
　Upstream temperature measuring device 30 is arranged at a position where the lower surface side of the steel plate conveyance area functions as the width direction thermometer to measure the temperature of the hot-rolled steel sheet 2 in the rolling direction upstream side of the total cooling area A1.
Upstream temperature measuring device 30 is preferably arranged corresponding to the respective width divided cooling zone A2, therefore in the illustrated example, the upstream temperature measuring device 30, on the upstream side of the width divided cooling zone A2 temperature arranged six in sheet width direction so as to measure (i.e. temperature before being cooled) is provided. Thereby measured over the temperature of the plate width direction of the hot-rolled steel sheet 2 on the upstream side of the lower lateral direction controlled cooling device 17 to full width.
[0073]
　Downstream temperature measuring device 31 is disposed at a position where the lower surface side of the steel plate conveyance area functions as the width direction thermometer to measure the temperature of the hot-rolled steel sheet 2 in the rolling direction downstream side of the total cooling area A1.
Downstream temperature measuring device 31 is preferably arranged corresponding to the width divided cooling zone A2, in the illustrated example, downstream temperature measuring device 31, measures the temperature of each width divided cooling zone A2 after cooling They are provided side by side six in sheet width direction as possible. Thus it can be measured over the entire width of the temperature in the plate width direction of the hot-rolled steel sheet 2 in the rolling direction downstream side than the lower width controlled cooling device 17.
[0074]
　The control device 27, the measurement result of the upstream temperature measuring device 30, one of the measurement result of the downstream-side temperature measuring device 31, or based on both the result is a device that controls the operation of the switching device. Thus the control unit 27 is provided with an electronic circuit or computer for calculation on the basis of a predetermined program, which on the upstream side temperature measuring device 30, the downstream side temperature measuring device 31 and the switching device are electrically connected .
[0075]
　Specifically, to measure the temperature of the hot-rolled steel sheet 2 conveyed a run out table after finish rolling at the upstream side temperature measuring device 30. The measurement result is sent to the control unit 27 calculates the amount of cooling required to equalize the temperature of hot-rolled steel sheet 2 for each of the divided cooling surface A3.
Then, based on the calculation result, control apparatus 27, feed forward control the opening and closing of the three-way valve 24. That is, the control device 27, in order to achieve a cooling amount for equalizing the temperature of the hot-rolled steel sheet 2 for each of the divided cooling surface A3, controls the opening and closing of the three-way valve 24, the cooling water for each divided cooling surface A3 cooling water sprayed from the nozzle 20, controls the collision and non-collision of the lower surface of the hot-rolled steel sheet 2.
[0076]
　The divided cooling surface A3 is because it is arranged in each of the plate width direction and the rolling direction, the control device 27 can be any of the plate width direction and the rolling direction to temperature control, uniformity of temperature of the hot-rolled steel sheet 2 it can be performed at a high accuracy.
[0077]
　Further, in order to suppress the streaky nonuniform temperature distribution extending in the rolling direction of the hot-rolled steel sheet 2, the feedforward control is useful, the heat by the feed-forward control using the upstream temperature measuring device 30 from this point of view it can be further homogenize the plate width direction temperature-rolled steel sheet 2.
[0078]
　However, not only the feed-forward control, based on a measurement result of the downstream-side temperature measuring device 31 may feedback control the opening and closing of the three-way valve 24. That is, performs the computation in the controller 27 using the measurement result of the downstream-side temperature measuring device 31, the calculation for each cooling dividing plane A3 based on the result, controls the opening and closing speed of the three-way valve 24. Thus, for each divided cooling surface A3, it is possible to control the impingement of the cooling water and the non-collision to the lower surface of the steel plate conveyance region.
[0079]
　In the lower widthwise controlled cooling device 17, selectively and feedforward control of the measurement result by the three-way valve 24 on the upstream side temperature measuring device 30, and a feedback control of the three-way valve 24 according to the measurement result of the downstream-side temperature measuring device 31 It can be carried out.
It is also possible to apply such a feedback control as correction control of the feed forward control results. Thus, the lower width controlled cooling device 17, a feed forward control of the measurement result by the three-way valve 24 on the upstream side temperature measuring device 30, a feedback control of the three-way valve 24 according to the measurement result of the downstream-side temperature measuring device 31 It can also be carried out by integrated.
In the case of performing only one feed-forward control or feedback control may be omitted either the upstream temperature measuring device 30 or the downstream temperature measuring device 31.
[0080]
　Further, the lower width controlled cooling device 17, the three-way valve 24 to the intermediate header 21 is provided, since the further three-way valve 24 is disposed at the same height as the tip of the cooling water nozzle 20, the interior of the pipe 23 it can always be filled with coolant. Therefore, when controlling the opening and closing of the three-way valve 24 based on the upstream temperature measuring device 30 and / or the downstream temperature measuring device 31 temperature measurement result of controlling the cooling water sprayed from the cooling water nozzles 20, the response it can be very well sex.
[0081]
　Incidentally, to meet more reliably cooling water inside of the pipe 23, may be constantly cooled water continues out from the cooling water nozzles 20. That is, for the intermediate header 21 not to collide with the cooling water from the cooling water nozzles 20 in the divided cooling surface A3, the three-way so that the cooling water from the cooling water nozzle 20 continues out to the extent that does not collide with divided cooling surface A3 It controls the opening of the valve 24. On the other hand, with respect to the intermediate header 21 impinging cooling water from the cooling water nozzles 20 in the divided cooling surface A3, opening the three-way valve 24 so that the cooling water from the cooling water nozzle 20 collides with the split cooling surface A3 to control the degree. In this case, since the inside of the pipe 23 is reliably filled with cooling water, it is possible to ensure the responsiveness.
[0082]
　In the lower width controlled cooling device 17 of the above embodiment, the upstream temperature measuring device 30, the configuration of the downstream side temperature measuring device 31 is intended to be particularly limited as long as it measures the temperature of the hot-rolled steel sheet 2 no but is preferably for example to use a temperature measurement device which is described, for example, in Japanese Patent No. 3818501. Figure 14 is an explanatory view schematically showing a configuration of the upstream side temperature measuring device 30.
[0083]
　Upstream temperature measuring device 30, a radiation thermometer 32 for measuring the temperature of the hot-rolled steel sheet 2, is disposed distal to the position facing the steel plate conveyance region (hot-rolled steel sheet 2), the rear end is a radiation thermometer 32 a connected optical fiber 33, to form a water column between the tip of the steel plate conveyance region and the optical fiber 33, to inject water toward the underside of the steel plate conveyance region, the nozzle 34 of the water column forming portion, the nozzle and a water tank 35 for supplying water to 34. Upstream temperature measuring device 30, by receiving the emitted light from the lower surface of the steel sheet conveyance region through the water column (hot rolled steel sheet 2) with a radiation thermometer 32 to measure the lower surface temperature of the hot-rolled steel sheet 2.
[0084]
　Here, the lower surface of the generally steel transport region for such cooling water from the cooling water nozzles 20 are present, when an ordinary thermometer, measurement error due to the cooling water occurs. Therefore, in order to install a thermometer, draining the cooling water, the section is not present cooling water in the rolling direction (for example, several meters) is needed.
[0085]
　In contrast, in the upstream-side temperature measuring device 30, since the light receiving radiation through the water column from the nozzle 34 at a radiation thermometer 32, and suppress the influence of the cooling water by the water column, due to the cooling water measured it is possible to reduce the error. Therefore, it is not necessary to provide an interval in which the cooling water does not exist, it is possible to the upstream side temperature measuring device 30 is close to the cooling water nozzles 20 of the most upstream side. Therefore, it is possible to further improve the responsiveness. In order to ensure sufficient responsiveness, the distance between the cooling water nozzle 20 of the upstream-side temperature measuring device 30 the most upstream side is preferably within 5 m, more preferably within 1 m.
[0086]
　Further, since the hot-rolled steel sheet 2 is on the run out table meanders, the upstream temperature measuring device 30 when the distance of the cooling water nozzle 20 of the most upstream side is long, the temperature measurement position in the sheet width direction of the hot-rolled steel sheet 2 cooling position and there is a different possibility. In such a case, there is a possibility that the particular cooling near the plate width direction end portion of the hot-rolled steel sheet 2 is not performed.
[0087]
　Against this, since in this embodiment it is possible to close the upstream side temperature measuring device 30 to the coolant nozzle 20 on the most upstream side, to ensure the temperature measurement position and the cooling position in the plate width direction of the hot-rolled steel sheet 2 can be matched, the hot-rolled steel sheet 2 can be cooled appropriately.
[0088]
　The configuration of the downstream side temperature measuring device 31 is also similar to the configuration of the upstream side temperature measuring device 30, can enjoy the same effect as the upstream side temperature measuring device 30 described above.
[0089]
　The intermediate header 21 and three-way valve 24 is provided, towards the number of the cooling water nozzles 20 in the intermediate header 21 is small, control of the cooling water that is injected into the hot-rolled steel sheet 2 is improved. On the other hand, when reducing the number of the cooling water nozzle 20 correspondingly increases the number of required three-way valve 24, equipment cost and running cost becomes high. Therefore, it is possible to consider these balance, sets the number of the cooling water nozzles 20.
[0090]
　Upon impinging cooling water to split cooling surface A3, the case of using a small amount of coolant, the rolling direction length of the entire cooling area A1 becomes longer. Thus, for example, 1 m 3 / m 2 is preferred to inject / cooling water min or more large water density from the cooling water nozzles 20.
[0091]
　In the lower width controlled cooling device 17, the tip of the cooling water nozzle 20, as shown in FIG. 15, the injection hole 40 for injecting cooling water may be provided in plurality. A plurality of injection holes 40 are provided at regular intervals in the projection surface in the plate width direction (Y-direction). For example, when a single injection hole of the cooling water nozzle 20 to inject cooling water at a high flow rate, the cooling water in the plate width direction of the hot-rolled steel sheet 2 collides at one place, streaky nonuniform temperature distribution occurs Cheap. In contrast, by providing a plurality of injection holes 40, it is possible to reduce the collision pressure of the cooling water to the divided cooling surface A3. Therefore, it is possible to more reliably suppress the stripe-like uneven temperature distribution, it is possible to further homogenize the plate width direction temperature of the hot-rolled steel sheet 2.
[0092]
　In the above embodiment, the intermediate headers 21 are provided, it is also possible to have no form an intermediate header 21 is not limited to this embodiment. The plan view illustrating a schematic configuration of a lower width controlled cooling device 17 according to this embodiment is shown in FIG. 16. Figure 16 is a view corresponding to FIG. 4, for although one each three-way valve 24 of the coolant nozzle 20 is to be connected to facilitate understanding, in FIG. 16, the three-way valve 24, a water supply header 25 , and, thus omitting the drainage header 26.
[0093]
　In the embodiment shown in FIG. 16, each coolant nozzle 20, a pipe (not shown) is connected, the three-way valve is provided in the pipe. The three-way valve is provided between the drainage header for discharging a water supply header and the cooling water supplying cooling water to the pipe. Such, be in a form one three-way valve for one of the cooling water nozzles 20 are provided, it is possible to achieve the same effect as the effect obtained by the above-described embodiment. Concept of the divided cooling surface A3 Even in this case is the same as the lower width controlled cooling device 17.
[0094]
　Lower widthwise controlled cooling device 17 in the example shown in Figure 1 are arranged at the upstream side of the lower cooling device 16, arrangement position of the lower width controlled cooling device 17 is not limited to this example.
[0095]
　By arranging the lower width controlled cooling apparatus 17 on the upstream side of the lower cooling device 16 as in the example shown in FIG. 1, to remove the non-uniform temperature distribution caused in the hot-rolled steel sheet 2 to the initial cooling step be able to.
In contrast, by arranging the lower width controlled cooling device 17 in the middle of the lower cooling device 16, as the upper cooling device 15, the cooling by the lower cooling device 16 was heterogeneous, not by it it is possible to remove the uniform temperature distribution.
Further, it is possible to be installed below the transverse direction controlled cooling apparatus 17 on the downstream side of the lower cooling device 16, to reduce the uneven temperature distribution of the coiling temperature.
[0096]
　Since the different their effects depending on the position to place the lower width controlled cooling device 17 relative to the lower cooling device 16 may be determined as appropriate placement in terms of steel type and equipment cost of manufacturing. Incidentally, from the viewpoint of suppressing as much as possible uneven temperature distribution, upstream of the lower cooling device 16, the middle, to be disposed in each of the downstream preferable.
[0097]
　Second Embodiment
In the second embodiment, the lower width controlled cooling device 117 is arranged in place of the lower widthwise controlled cooling device 17 of the hot rolling mill 10, the three-way valve of the switching device of the first embodiment 24 cooled water traveling direction change device 126, 226, 326 and the guide plate 125 is arranged in place of, albeit drainage area, in which the drainage header has run out. Since the other configurations can be applied the same configuration as the first embodiment, its description is omitted with the same reference numerals as in the first embodiment.
[0098]
　17, FIG. 18 is a diagram illustrating an example of a switching device including a cooling water traveling direction changing apparatus 126 of the switching device of the second embodiment, the one cooling water nozzle 20 disposed between the transport roll 18 it is a diagram showing attention to the surrounding area.
[0099]
　Switching device in this embodiment is provided with a guide plate 125 and the cooling water traveling direction changing apparatus 126,.
[0100]
　The guide plate 125 is a plate-like member disposed between the intermediate headers 21 and divided cooling surface A3. Guide plate 125 is also the tip of the heat-rolled steel sheet 2 during the sheet passing the hot rolled steel sheet 2 collides, it is designed with strength well tolerated. The guide plate 125 is disposed respectively between the conveying rolls 18 mutually at least adjacent. This prevents in particular the most advanced hot-rolled steel sheet 2 is cooling water nozzle 20 at the time of passing plate, an intermediate header 21, from being caught in the conveying rolls 18.
[0101]
　Further, the guide plate 125, when the cooling water traveling direction changing apparatus 126 does not inject the gas injection opening 125a for passing the cooling water injected from the cooling water nozzles 20 are provided. Thus, the cooling water injected from the cooling water nozzles 20 collides with the split cooling surface A3 through the guide plate 125, it is possible to adequate cooling. Further, it may be provided with drain holes for passing the waste water to the guide plate 125.
Top distance divided cooling surface A3 of the guide plate 125 is not particularly limited, and may be, for example, 20mm approximately.
[0102]
　The guide plate 125 has a piece 125b formed parallel to the rolling direction and having an injection port 125a, water-shielding plate 125c provided depending from the lower surface of the strip 125b downward, and 125d. Water-shielding plate 125c is provided in the injection port 125a side of the water-shielding plate 125d.
[0103]
　Water-shielding plate 125c, 125d, when you are injecting gas from the cooling water traveling direction change device 126, to avoid splashing the injection port 125a side after cooling water injected from the cooling water nozzles 20 collides with piece 125b . Further water-shielding plate 125c, 125d refrains from collide in divided cooling surface A3 is blown on the steel sheet conveyance region side cooling water from the injection port 125a by the flow of the injected gas.
Also, water-shielding plate 125d, when you are injecting gas from the cooling water traveling direction changing apparatus 126, after the cooling water injected from the cooling water nozzles 20 collides with piece 125b, that splashing cooling water nozzles 20 side avoiding also has action to prevent interfering with the injected cooling water jets from the cooling water nozzles 20. Water-shielding plate 125d is installed so as not to interfere with the flow of injected gas from the cooling water nozzle 20 coolant jets and the cooling water traveling direction changing apparatus 126 ejected from.
[0104]
　Here, the length of the water-shielding plate 125c is too long, the amount of cooling water jets will be blown from the injection port 125a to direct collision coolant steel transfer region side is increased, the degree or 30mm less 10mm it is desirable to.
On the other hand, the length of the water-shielding plate 125d, the length can be sufficiently prevented the interference it is sufficient secured, it is desirable that the degree than 150mm below 50 mm.
[0105]
　Cooling water traveling direction change device 126, the gas is jetted against the cooling water injected from the cooling water nozzle 20, a device for changing the traveling direction of the cooling water. Cooling water traveling direction change device 126, the gas header 127, the gas branch pipe 128, valve 129, and is configured to have a gas nozzle 130.
[0106]
　Gas jetted from the gas nozzle 130, by changing the traveling direction of the cooling water injected from the cooling water nozzles 20, to control the collision and non-collision of the divided cooling surface A3 of the cooling water.
[0107]
　More specifically, the gas nozzles 130 each is connected to the gas header 127 through the gas branch pipe 128, gas of a predetermined pressure from the gas header 127 (e.g., air) is supplied. Further and valve 129 is mounted in the middle of the gas branch pipe 128.
The valve 129 controls the start and stop of gas injection from the gas nozzle 130 based on a signal from the controller 27. Examples of such valves can be mentioned solenoid valve. Also with respect to the cooling water nozzles 20 which belong to one divided cooling surface A3, by placing the gas nozzle 130 in accordance with the number of the cooling water nozzle 20, the cooling water to the lower surface of the steel sheet conveyance region for each divided cooling surface A3 it is possible to control the collision and non-collision.
[0108]
　Gas nozzles 130, FIG. 17, as can be seen from Figure 18, is installed in the vicinity of the cooling water nozzles 20. From the gas nozzle 130, by injecting gas tilted degree 15 degrees 30 degrees with respect to the vertical direction, it is possible to change the traveling direction of the effective coolant jets with relatively small gas flow.
[0109]
　The gas nozzle 130, it is desirable to use a flat air nozzles that relatively collision force even away the distance from the nozzle to form a jet of a fan shape underdamped. At this time, since the attenuation is large collision force when the spread angle of the fan-shaped jets injected from the gas nozzle 130 collides with the cooling water jets too large, injected fan-shaped jets across the width direction of the cooling water jets it is desirable to adjust exactly can be covered.
[0110]
　As shown in FIG. 17, the valve 129 is closed, when the gas from the gas nozzle 130 is not injected, the cooling water injected from the cooling water nozzle 20 through the injection port 125a, collides with the split cooling surface A3 , it can be cooled hot rolled steel sheet 2. Incidentally, in FIG. 17 indicates the flow direction of the cooling water injected from the cooling water nozzles 20 at arrow designated black triangle in the solid line of the tip.
[0111]
　On the other hand, FIG. 18, in the same perspective as FIG. 17 is a schematic diagram showing a scene that injects gas from the gas nozzle 130. It indicates the flow direction of the gas injected from the gas nozzle 130 at arrow designated black triangle at the tip of the dotted lines in FIG. 18.
[0112]
　In a specific embodiment to operate the valve 129 so as to prevent the cooling water collides with the split cooling surface A3, so that the cooling water jets that are ejected from the cooling water nozzles 20 do not collide with the divided cooling surface A3, cooling It includes changing the traveling direction of the water jet.
By the valve 129 is actuated in response to a signal from the control device 27, ejects gas from the gas nozzle 130 toward the coolant jet is injected from the cooling water nozzles 20. Thus, the direction is changed coolant jets that are ejected from the cooling water nozzles 20 is pushed by the flow of gas. As a result, the impinging cooling water to the lower surface of the guide plate 125, the cooling water can no longer pass through the injection port 125a. Thus it is possible to prevent the cooling water collides with the split cooling surface A3, the cooling hot rolled steel sheet 2 is stopped.
[0113]
　The control of the switching device by the control device 27 can be carried out in the same manner following the first embodiment of the lower widthwise controlled cooling apparatus 17 described above.
[0114]
　According to this embodiment, the cooling water impinging on the divided cooling surface A3 by the switching device is prevented, since it is prevented that strikes the divided cooling surface A3, the collision of the split cooling surface A3 was prevented cooling It does not require such as a tub to collect the water. Thus, the switching device of the second embodiment also easy to install in a narrow space, such as between transport roll 18 is adjacent.
[0115]
　The switching device of the second embodiment, instead of ON / OFF control of the cooling water jetting from the cooling water nozzle 20, while injecting a predetermined amount of cooling water from the cooling water nozzle 20, from the cooling water nozzles 20 controlling the collision and non-collision of the hot-rolled steel sheet 2 of the cooling water jets after being injected. Further, as means for controlling the collision and non-collision of the cooling water jets, rather than operating like mechanical shutter, for ON / OFF controlling the injection of gas from the gas nozzle 130 by the cooling water traveling direction changing apparatus 126 by controls the collision and non-collision of the divided cooling surface A3 of the cooling water.
[0116]
　19, FIG. 20 is a diagram showing a part of a lower width controlled cooling device 117 according to a modification of the second embodiment schematically. Figure 19 is a view corresponding to FIG. 17, FIG. 20 is a view corresponding to FIG. 18.
[0117]
　Lower widthwise controlled cooling apparatus 117 illustrated in FIGS. 19 and 20, instead of the cooling water traveling direction changing apparatus 126 of the switching device, the switching device is applied to the cooling water traveling direction changing apparatus 226 is used . Here therefore be described coolant traveling direction changing apparatus 226.
[0118]
　Cooling water traveling direction change device 226 has a nozzle adapter 227 and the air cylinder 228. Nozzle adapter 227 is attached to the cooling water nozzles 20. The nozzle adapter 227 is rotatably mounted about a fixed shaft 229. The fixed shaft 229 is fixed so as not to shift position by support members (not shown). In addition, the nozzle adapter 227, a piston rod 231 of air cylinder 228 is connected so as to be rotatable in the rod end shaft 230 through the rod end shaft 230.
Therefore, by moving the air cylinder 228, it is possible to tilt the cooling water nozzle 20. That is, in the posture of the coolant nozzle 20 shown in FIG. 19, it is possible to inject cooling water upward in the vertical direction, the cooling water nozzle 20, as shown in FIG. 20 by moving the air cylinder 228 in the vertical direction it can be inclined at a predetermined angle against.
[0119]
　Nozzle adapter 227 is attached to each cooling water nozzle 20, the air cylinder 228 is attached to each nozzle adapter 227. Actuation of the air cylinder 228 can be performed by an electromagnetic valve (not shown). By the solenoid valve opens and closes in response to a signal from the controller 27, the cooling water nozzle 20 through the air cylinder 228 direction of any direction oblique to the vertical direction or the vertical direction as described above to control the attitude.
[0120]
　As shown in FIG. 19, when controlling the cooling water nozzle 20 in the vertical direction, the cooling water jets impinging on the divided cooling surface A3 through the injection port 125a provided in the guide plate 125. On the other hand, as shown in FIG. 20, when controlling the cooling water nozzle 20 to the inclined position with respect to the vertical direction, the partial cooling water nozzle 20 is inclined, the jet direction is changed guide plate of the cooling water jets It collides with the lower surface 125, cooling water divided cooling surface A3 will not collide.
[0121]
　Thus, by operating in response to a signal from the solenoid valve control device 27, by changing the posture of the cooling water nozzle 20, changing the direction of the cooling water that is injected from the cooling water nozzles 20, cooling water it is possible to switch between position does not interfere with the orientation that prevents hitting the divided cooling surface A3.
[0122]
　Incidentally, the tube having flexibility (for example, a rubber tube) by connecting the intermediate header 21 and the nozzle adapter 227 by 232, even if the cooling water nozzle 20 as described above inclined tubes having flexibility 232 There by deforming, can be absorbed the relative positional shift therebetween.
[0123]
　Angle for tilting the coolant nozzle 20, it is necessary to substantially all of the cooling water jet is adjusted so as to impinge on the lower surface of the guide plate 125. On the other hand, it is better to reduce the response time with a reduced angle to possible tilting of the cooling water nozzles 20. From these viewpoints, substantially all of the cooling water jets when the cooling water nozzle 20 is tilted degree 5 degrees or more than 10 degrees with respect to the vertical direction is preferably designed to impinge on the lower surface of the guide plate 125.
[0124]
　Figure 21, Figure 22 is a diagram showing a part of a lower width controlled cooling device 117 according to another modification of the second embodiment schematically. Figure 21 is a view corresponding to FIG. 17, FIG. 22 is a view corresponding to FIG. 18.
[0125]
　It illustrated switching device 21 and 22, instead of the cooling water traveling direction changing apparatus 126, the cooling water traveling direction changing apparatus 326 is used. Here therefore be described coolant traveling direction changing apparatus 326.
[0126]
　Cooling water traveling direction changing apparatus 326, a nozzle adapter 327 is provided with an air cylinder 328 and jet deflector plate 329. Nozzle adapter 327 is attached to the cooling water nozzles 20. In addition, the nozzle adapter 327, the jet deflector plate 329 is mounted to be rotatable about a rotation axis 330. Furthermore, the jet deflection plate 329, the piston rod 332 of air cylinder 328 is connected so as to be rotatable in the rod end shaft 331 through the rod end shaft 331.
Therefore, by moving the air cylinder 328, it is possible to tilt the jet deflector plate 329. That is, in the orientation of the jet deflector 329 shown in FIG. 21, there is the jet deflector plate 329 in a position not exposed to the cooling water injected from the cooling water nozzles 20, by moving the air cylinder 328, shown in FIG. 22 as such, to strike the cooling water injected from the cooling water nozzles 20 may be inclined at a predetermined angle to the jet deflection plate 329 with respect to the vertical direction.
[0127]
　Nozzle adapter 327 is attached to each cooling water nozzle 20, the air cylinder 328 is attached to each nozzle adapter 327. Actuation of the air cylinder 328 can be performed by an electromagnetic valve (not shown). By the solenoid valve opens and closes in response to a signal from the controller 27, the jet deflection plate 329 via the air cylinder 328 direction of any direction oblique to the vertical direction or the vertical direction as described above it is possible to control the attitude.
[0128]
　As shown in FIG. 21, the case of controlling the jet deflection plate 329 in the vertical direction, the cooling water jets impinging on the divided cooling surface A3 through the injection port 125a provided in the guide plate 125. On the other hand, as shown in FIG. 22, the case of controlling the jet deflection plate 329 to the inclined position with respect to the vertical direction, the cooling water that is injected from the cooling water nozzles 20 are bent by the jet deflector 329, cooling jet direction of the water jet is changed collides with the lower surface of the guide plate 125, the cooling water does not collide with the divided cooling surface A3.
[0129]
　Thus, by operating in response to a signal from the solenoid valve control device 27, by changing the orientation of the jet deflection plate 329, changing the direction of the cooling water that is injected from the cooling water nozzles 20, cooling water it is possible to switch between position does not interfere with the orientation that prevents a collision to divide the cooling surface A3.
[0130]
　Angle to tilt the jet deflector 329, it is necessary to substantially all of the cooling water jet is adjusted so as to impinge on the lower surface of the guide plate 125. On the other hand, it is better to reduce the response time with a reduced angle to possible tilting of the jet deflector 329. From these viewpoints, the direction as substantially all of the cooling water jet impinging on the lower surface of the guide plate 125 by the jet deflector plate 329 when tilted lower than about 10 degrees 5 degrees or more jet deflector plate 329 with respect to the vertical direction it is desirable to design so that can be changed.
[0131]
　It has been illustrated and described three forms as the cooling water traveling direction changing apparatus so far. If by injecting gas Among these changing the direction of cooling water jets, it does not require such movable portion and the air cylinder. Thus, although of course as compared with the conventional method, even in comparison with the method of tilting the method and the cooling water nozzle used jet deflector plate described above, it is possible to miniaturize the device, also placed in a narrow space It becomes easier. Further, by not requiring such movable portion and the air cylinder, which is advantageous in terms of durability. On the other hand, the gas if consumption (air) is disadvantageous in cost increases also conceivable, but the direction of the coolant jets than in the case of changing completely block or the direction increasing the conventional coolant jets as it is possible to slightly the angle to be changed, the amount of required gas (air) is significantly reduced compared to the conventional, so that the installation cost and the running cost of such a compressor can be reduced.
[0132]
　Even when using the jet flow deflectors described above, it is only slightly changing the direction of the cooling water jets, as compared with the case of changing completely block or direction larger conventional coolant jets as, applied to the jet deflection plate force is 10% to about 20% (× sinθ times, theta: the change angle of the direction of the cooling water jets). Therefore, it is possible to greatly reduce the impact load applied repeatedly, it is possible to reduce the required strength of the device the movable part. This enables the significant weight reduction, it is possible to reduce the cylinder diameter must thrust of the air cylinder is reduced. In addition, the running cost is reduced because it also reduced air consumption. In addition, to reduce the impact load applied at the time of reciprocating motion of the air cylinder can be significantly improved durability as compared with the conventional method.
[0133]
　In the above description of the second embodiment, by changing the direction of the cooling water jets after being ejected from the cooling water nozzle 20, illustrated in the form of controlling the collision and non-collision of the divided cooling surface A3 of the cooling water jets. However, the second embodiment is not limited to this embodiment, for example, by moving the guide plate into the rolling direction, or a changing the direction of the cooling water jets after being ejected from the cooling water nozzles, guide plates by combining the moving to the rolling direction, it may control the collision and non-collision of the divided cooling surface of the cooling water jets.
[0134]
　The first embodiment, in the above description of the second embodiment, using the control device, the number and the switching device operates to impinging cooling water to the divided cooling surface, the cooling impinging divided cooling surface for the second embodiment a mode of controlling the number of cooling water nozzle for injecting water exemplified. The present invention is not limited to this embodiment, for example, in addition to the control of the number and the number of the cooling water nozzle of the switching device, it is also possible to form for controlling the flow rate of the cooling water sprayed from the cooling water nozzles . Flow rate of the cooling water can be controlled using a flow control valve. In this case, flow control valve may be provided between the intermediate headers and the switching device.
[0135]
　When using a spray nozzle as cooling water nozzles may be configured to be changed the distance between the tip and the steel plate of the spray nozzle. Thereby, it becomes possible to control the impact pressure of the cooling water jet impinging on the steel sheet becomes easier to perform the control of cooling temperature.
Example
[0136]
　Hereinafter, effects of the present invention will be described based on examples and comparative examples. However, the present invention is not limited to this embodiment.
[0137]
　
In the verification of the effect, as a cooling apparatus of Example 1, utilizing a lower width controlled cooling device 17 shown in FIG. As the cooling device of Comparative Example 1 was applied to a conventional lower cooling device 16 without using the lower width controlled cooling device 17.
[0138]
　Conditions in this verification are as follows. Operating conditions of Example 1, the steel sheet width: 1300 mm, thickness: 3.2 mm, the steel plate conveyance speed: 600Mpm, before cooling temperature: 900 ° C., the target coiling temperature: was 550 ° C.. Lower widthwise controlled cooling apparatus, was used a switching device of the first embodiment. However, by way of FIG. 4 has two intermediate headers in the rolling direction, although each of the intermediate headers four cooling water nozzles are arranged, in the first embodiment, there are four intermediate header to the rolling direction, respectively It was placed two cooling water nozzle of the intermediate header. The cooling length in the rolling direction is set to 4 and the same carrier rolls between eight minute, response speed, including a three-way valve and piping system was 0.2 seconds. Further, the water density of the cooling water jetting 2m 3 / m 2 was / min. Installation position of the lower width controlled cooling device was set to the side closer to the winding device (downstream side of the lower cooling device).
On the other hand, operating conditions of Comparative Example 1 is not cooling control function in the plate width direction, water density of the cooling water injected 0.7 m 3 / m 2 was / min.
[0139]
　Figure 23 shows an example in which removed portions of the steel plate top surface temperature distribution in Comparative Example 1. For ease of Figure 23 the temperature distribution display is displaying particular from mark temperatures distributed only on the low temperature side by shading (also Fig. 24 showing a later same.). Usuzumi moiety -30 ° C. or higher -15 ° C. or less of the portion relative to the temperature of the aim, dark black portion is lower than -30 ° C. portion with respect to the temperature of the aim. As it can be seen from Figure 23, a relatively wide temperature portion p has occurred in the sheet width direction central portion in Comparative Example 1. Moreover, streaks of low-temperature portion q1 extending in the rolling direction, q2 also have occurred.
　The standard temperature deviation according to Comparative Example 1 was 23.9 ° C.. Standard temperature deviation, the result of measurement by the infrared temperature image measuring apparatus, the tip and tail each 10m of the steel sheet was further determined from all the measurement points of the temperature of the steel strip excluding the both ends each 50 mm.
[0140]
　Showed an example in which removed portions of the steel plate top surface temperature distribution in the embodiment 1 in FIG. 24. As can be seen from FIG. 24, any of the embodiments Example 1 cold section p, q1, q2 it can be seen that is smaller than that of the Comparative Example 1.
The standard temperature deviation according to Example 1 was 8.8 ° C.. Therefore, according to the present invention, it was found to be uniform the plate width direction temperature the hot-rolled steel sheet.
[0141]
　
operating conditions in the same manner as in Example 1, the same cooling length in the rolling direction of the lower widthwise controlled cooling apparatus as in Example 1, were the length of eight minutes between transport rolls. Lower widthwise controlled cooling apparatus, the cooling water traveling direction changing apparatus in switching device of the second embodiment using cooling water traveling direction changing apparatus 126, as shown in FIG. 10, one switch to one divided cooling surface A3 It was installed equipment. Response rate was 0.18 seconds. Also, water flow rate of the cooling water injected 2m 3 / m 2 was / min. Installation position of the lower width controlled cooling device was set to the side closer to the winding device (downstream side of the lower cooling device).
[0142]
　According to the second embodiment, the temperature distribution of the steel sheet over the entire surface of the hot-rolled steel sheet after cooling can be obtained the same results as in FIG. 24, the standard temperature deviation was 8.6 ° C..
DESCRIPTION OF SYMBOLS
[0143]
　1 slab
　2 hot rolled steel sheet
　10 hot rolling mill
　11 heating furnace
　12 widthwise rolling mill
　13 rough rolling mill
　14 finishing mill
　15 the upper cooling device
　16 below the cooling unit
　17 under the widthwise controlled cooling apparatus
　18 carrying roll
　19 winding device
　20 the cooling water nozzle
　21 intermediate header
　23 pipe
　24 three-way valve
　25 water supply header
　26 drainage header
　27 control device
　30 upstream temperature measuring device
　31 downstream temperature measuring device
　32 the radiation thermometer
　33 optical fiber
　34 nozzles
　35 water reservoir
　40 injection holes
　117 lower widthwise controlled cooling device
　125 guide plates
　125a injection port
　125c, 125d water-shielding plate
　126, 226, 326 cooling water traveling direction changing apparatus
　127 gas header
　128 gas branch pipe
　129 valve
　130 gas nozzles
　227,327 nozzle adapter
　228,328 air cylinder
　229 fixed shaft
　230,331 rod end shaft
　231,332 piston rod
　232 tube
　329 jet flow deflection plate
　330 rotating shaft

WE CLAIM

After finish rolling of hot rolling process, a cooling device for cooling the lower surface of the hot-rolled steel sheet conveyed on the conveying roll,
　a predetermined length of the entire area and the rolling direction of the plate width direction of the lower surface of the steel plate conveyance region the cooling area defined as the total cooling area, the width divided cooling zone is the total cooling area cooling region of each obtained by dividing into a plurality in the plate width direction,
　the width divided cooling zone in the rolling direction and dividing the cooling surface is a cooling region obtained by dividing into a plurality,
　and at least one cooling water nozzle for injecting cooling water on the lower surface of each of the divided cooling surface,
　the cooling water sprayed from the cooling water nozzles, a switching device for switching the collision and non-collision to the divided cooling surface,
　the width direction thermometer for measuring the temperature distribution of the plate width direction,
　based on a measurement result of the width direction thermometer, an operation of the switching device and a control device to control,
but Bei Characterized in that it is, the cooling device of hot-rolled steel sheet.
[Requested item 2]
　The cooling water nozzle, characterized in that the cooling water nozzles corresponding to each of the divided cooling surface is arranged one or more cooling device for a hot-rolled steel sheet according to claim 1.
[Requested item 3]
　In the divided cooling surface adjacent to, the number of cooling water nozzles being different from each other in the rolling direction, the cooling device for a hot-rolled steel sheet according to claim 1 or 2 arranged.
[Requested item 4]
　The divided cooling surface each rolling direction length included in the width divided cooling zone, characterized in that are different from each other in the rolling direction, the cooling device for a hot-rolled steel sheet according to any one of claims 1 to 3 .
[Requested item 5]
　The rolling direction length of the divided cooling surface, characterized in that said a multiple between transport roll length, the cooling device for a hot-rolled steel sheet according to any one of claims 1 to 4.
[Requested item 6]
　Arrangement of a plurality of the cooling water nozzles in the plate width direction, characterized in that the distance between the centers of the cooling water nozzle adjacent the plate width direction are arranged so that all equal distance, claim 1 or cooling device for a hot-rolled steel sheet according to any one of 5.
[Requested item 7]
　Same plurality of the cooling water nozzles for cooling the divided cooling surface is arranged,
　the switching device is
the same of the plurality of the cooling water nozzles for the divisional cooling surface, the cooling of the same of the divided cooling surface and switches the collision and non-collision of water by integrating the switching control system for controlling simultaneous cooling device for a hot-rolled steel sheet according to any one of claims 1 to 6.
[Requested item 8]
　Wherein the switching device,
the cooling water supplied to the cooling water nozzles are provided in the pipe flow, a water supply header for supplying the cooling water,
and drainage header or drainage area for draining the cooling water,
and the water supply header and a valve for switching the flow of the cooling water between the water discharge header or the drainage area, cooling device for a hot-rolled steel sheet according to any one of claims 1 to 7.
[Requested item 9]
　Said valve is a three-way valve, the transport roll is provided in an the side of the plate width direction, characterized in that it is arranged at the same height as the tip of the coolant nozzle of claim 8 cooling apparatus of hot-rolled steel sheet.
[Requested item 10]
　Wherein the switching device,
the cooling water supplied to the cooling water nozzles are provided in the pipe flow, a water supply header for supplying the cooling water,
and waste water area for draining the cooling water,
it is sprayed from the cooling water nozzles and means for changing the injection direction of the cooling water are,
at the time of jetting direction changing comprises means for blocking such that the cooling water does not impinge on the divided cooling surface, and
cooling water by means of changing the injection direction of the cooling water , the divided collision and non-collision of the lower surface of the cooling surfaces are able to be switched, the cooling device for a hot-rolled steel sheet according to any one of claims 1 to 7.
[Requested item 11]
　The width direction thermometer, said provided at least one of the rolling direction upstream and rolling direction downstream side of the total cooling area, and, of claims 1 to 10, characterized in that provided in each of the width divided cooling zone cooling device for a hot-rolled steel sheet according to any one.
[Requested item 12]
　The width direction thermometer, characterized in that it is arranged on the lower surface side of the steel plate conveyance region, a cooling device for a hot-rolled steel sheet according to claim 11.
[Requested item 13]
　After finish rolling of hot rolling process, a cooling process for cooling the lower surface of the hot-rolled steel sheet conveyed on the conveying roll,
　a predetermined length of the entire area and the rolling direction of the plate width direction of the lower surface of the steel plate conveyance region the cooling area defined as the total cooling area,
　the entire cooling area to the respective cooling areas obtained by dividing a plurality width divided cooling zone in the plate width direction,
　a plurality of the width divided cooling zone in the rolling direction the cooling region obtained by dividing the a divided cooling surface,
　the temperature distribution of the plate width direction of the hot-rolled steel sheet was measured,
　the by cooling water nozzle for each of the divided cooling surface based on a measurement result of the temperature distribution characterized in that the collision and non-collision of the cooling water to the hot-rolled steel sheet is controlled in each of the plate width direction and the rolling direction,
the cooling method of hot rolled steel sheet.
[Requested item 14]
　The cooling water nozzle for injecting said cooling water to the same of the divided cooling surface is provided with a plurality, wherein the cooling water impingement to the hot-rolled steel sheet resides in the same division cooling surface by the plurality of coolant nozzles and non-collision, and controlling at the same time by integrating a plurality of coolant nozzles, the cooling method of hot rolled steel sheet according to claim 13.
[Requested item 15]
　The cooling water supplied to the cooling water nozzles are provided in the pipe flow, a water supply header for supplying the cooling water,
and drainage header or drainage area for draining the cooling water,
the water supply header and the drainage header or the and a valve for switching the flow of the cooling water between the water discharge area,
　based on the measurement of temperature distribution in the plate width direction of the hot-rolled steel sheet, the divided cooling surface by controlling the opening and closing of the valve the collision of the cooling water and non-collision by the cooling water nozzle to the hot-rolled steel sheet is controlled in each of the plate width direction and the rolling direction, the cooling method of hot rolled steel sheet according to claim 13 or 14 for each.
[Requested item 16]
　It said valve is a three-way valve,
　with respect to the said water supply header without cooling the lower surface of the hot-rolled steel sheet by the cooling water from the cooling water nozzles, the cooling water from the cooling water nozzles on the lower surface of the hot-rolled steel sheet the opening of the three-way valve is controlled so ever get enough not to collide,
　against the water supply header for cooling the bottom surface of the hot-rolled steel sheet by the cooling water from the cooling water nozzles, from the cooling water nozzles cooling water and controlling the degree of opening of the three-way valve so as to impinge on the lower surface of the hot-rolled steel sheet, the cooling method of hot rolled steel sheet according to claim 15.