JP5421892B2 - Steel plate cooling device, hot-rolled steel plate manufacturing apparatus and manufacturing method - Google Patents

Description

  The present invention relates to a steel plate cooling device, a hot rolled steel plate manufacturing device and a manufacturing method, and more particularly to a steel plate cooling device, a hot rolled steel plate manufacturing device and a manufacturing method which are excellent in drainage of cooling water.

  Steel materials used for automobiles and structural materials are required to have excellent mechanical properties such as strength, workability, and toughness. To improve these mechanical properties comprehensively, the structure of the steel material is refined. It is effective. Therefore, many manufacturing methods for obtaining a steel material having a fine structure have been sought. Moreover, according to refinement | miniaturization of a structure, even if it reduces the addition amount of an alloy element, it becomes possible to manufacture the high intensity | strength hot-rolled steel plate provided with the outstanding mechanical property.

  As a method of refining the structure, particularly in the latter stage of hot finish rolling, a method of reducing the austenite grains by rolling under high pressure and accumulating rolling strain in the steel sheet to refine the ferrite grains obtained after rolling. It has been known. Further, it is effective to cool the steel plate to 600 ° C. to 700 ° C. within the shortest possible time after rolling from the viewpoint of suppressing the recrystallization and recovery of austenite to promote the ferrite transformation. As a method for this, following the hot finish rolling, a cooling device capable of cooling faster than before can be installed, and the steel sheet after rolling can be rapidly cooled. And in order to quench the steel plate after rolling in this way, in order to increase the cooling capacity, it is effective to increase the amount of cooling water per unit area injected onto the steel plate, that is, the flow density.

  However, when the amount of cooling water and the flow density are increased in this way, the water (residual water) that accumulates on the upper surface of the steel sheet increases on the upper surface of the steel sheet due to the relationship between water supply and drainage, and the lower surface guide and The stagnant water between the steel plates may increase. Such stagnant water is water that has been used for cooling the steel sheet, and it is desired to discharge it as soon as possible and provide the water supplied from the nozzle to the steel sheet to ensure the cooling capacity. In addition, since the accumulated water is a layer of water, if it is thick, it becomes a resistance and the water from the nozzle may not reach the steel plate effectively. Further, the stagnant water flows from the central portion of the steel plate toward the end, and the flow velocity increases as it approaches the end of the steel plate. Therefore, when the amount of stagnant water increases, the uneven cooling in the plate width direction of the steel plate increases.

  Here, paying attention to the lower surface side of the steel sheet, a transport roll is disposed on the lower surface side, and a lower surface guide is formed between the transport rolls to prevent the front end of the steel sheet from entering. This tends to cause stagnant water between the lower surface guide and the lower surface of the steel plate.

Several techniques for suppressing such stagnant water on the lower surface side of the steel sheet, that is, improving drainage are disclosed.
For example, in Patent Document 1, a slit is provided between the slit jet provided between the transport rolls and the width of the cover covering the entire lower surface of the steel plate between the transport rolls to the extent that water can be supplied and drained. Aspects are disclosed.
Patent Document 2 discloses a mode in which a header for supplying a columnar jet is integrated with a steel plate lower surface guide, and a nozzle is provided in the steel plate lower surface guide.
Patent Document 3 discloses a mode in which a full cone nozzle is used as a cooling means and a narrow guide is provided only at the center of a hot-rolled steel sheet.
In Patent Document 4, cooling water supplied by a columnar jet is formed by arranging narrow protection plates as lower surface guides at appropriate intervals, or using a plate with holes, or using a plate with holes. A mode in which drainage is secured is disclosed.
Patent Documents 5 and 6 disclose a guide that smoothes drainage by providing a hole for supplying cooling water and a hole for draining.
Moreover, in patent document 6, the aspect which inserts the front-end | tip of a nozzle directly in the hole for supplying cooling water is disclosed.
Patent Document 7 describes a technology in which a lower surface guide is provided with a water supply / drainage passage forming member and the water supply side and the water discharge side are separated to facilitate drainage.

JP 58-86922 A Japanese Patent Publication No. 5-86298 Japanese Patent No. 3300594 Japanese Patent No. 3642031 Japanese Patent No. 4029871 JP 2010-42445 A Japanese Patent Application No. 2009-156024

However, in the lower surface cover described in Patent Document 1, even if a gap for water supply / drainage is ensured, there is a possibility that the tip of the steel sheet is caught in the gap.
In the lower surface guide described in Patent Document 2, there is a possibility that the drainage may not catch up due to an increase in cooling water and a higher density, and an improvement in drainage is required.
In the lower surface guide described in Patent Document 3, the drainage can be ensured greatly, but the cooling of the guide portion is lowered, and there is a risk of causing uneven cooling.
In the lower surface guide described in Patent Document 4, there is a concern that the jet flow from the nozzle collides with a part of the guide and the jet flow is disturbed to affect the cooling ability. In addition, there is a risk that the water supply and the waste water interfere with each other to reduce the cooling capacity.
In the lower surface guide described in Patent Document 5, sufficient drainage cannot be ensured particularly when the gap between the jet holes in the width direction of the steel plate is narrow. Even if the gap between the jet holes in the width direction of the steel plate is sufficiently wide and the drainage property can be ensured, there is no mention of how water is supplied and drained through the holes in the lower surface guide.
In the lower surface guides described in Patent Literature 6 and Patent Literature 7, the water supply channel and the drainage channel are separated, and the drainage capacity is improved.
However, the lower surface guide described in Patent Document 6 is a mode in which the tip of the nozzle is inserted into the guide plate itself, and is susceptible to the influence of heat from the steel plate, so there is a concern about the deterioration of the cooling nozzle. On the other hand, if the distance between the cooling nozzle and the steel plate is increased in order to avoid the influence of the heat, there is a possibility that the jet flow is not jetted to an appropriate position of the steel plate, and there is a problem that the cooling capacity is greatly attenuated.
Further, in the lower surface guide described in Patent Document 7, a part of the injected cooling water cannot pass through the water supply holes provided in the lower surface guide and does not contribute to the cooling of the steel plate, and thus a part of the cooling water is wasted. There is a fear.

  Therefore, in the hot rolled steel sheet production line, the present invention is excellent in drainage by adding improvements to the water supply channel forming member of the cooling water jet supplied from the lower surface without hindering the movement of the steel sheet (through plate). It is another object of the present invention to provide a steel plate cooling device, a hot-rolled steel plate manufacturing apparatus, and a manufacturing method that can reduce the waste of cooling water.

  The present invention will be described below. Here, for ease of understanding, reference numerals in the drawings are appended in parentheses, but the present invention is not limited to this.

  Invention of Claim 1 is arrange | positioned in the lower process side of the last stand (11g) of a hot finish rolling mill row | line | column (11), and can cool the steel plate (1) conveyed on a conveyance roll (12). A steel plate cooling device (20) provided with a plurality of cooling nozzles (21c, 22c), wherein the cooling nozzle is provided on the upper surface side and the lower surface side of the portion through which the steel plate passes and the portion through which the steel plate passes. The lower surface guide (40) is provided on the lower surface side, and the lower surface guide has an inflow hole (42) through which the cooling water ejected from the lower surface side cooling nozzle passes, And an outflow hole (43) through which cooling water should fall and pass through in a dischargeable manner. The inflow hole is arranged in parallel in the steel plate conveyance direction, and the outflow hole is arranged in parallel in the steel plate conveyance direction. Of the inflow holes and outflow holes At least one has a water supply / drainage passage forming member (45) that forms a water passage leading to the inflow hole and a drainage passage leading from the outflow hole, and the water passage leading to the inflow hole formed by the water supply / drainage passage forming member is: It is formed so as to surround the jet jetted from the cooling nozzle, and at least a part of the wall of the water passage is provided with a communication means through the inside and outside of the water passage, and the jet of cooling water from the cooling nozzle flows in The steel sheet cooling apparatus is performed in a water passage leading to a hole.

  The invention according to claim 2 is the steel plate cooling device (20) according to claim 1, wherein one end side of the water supply / drainage passage forming member (45) is connected to the edge of the inflow hole (42). And

  A third aspect of the present invention is the steel sheet cooling device (20) according to the first or second aspect, wherein the water supply / drainage passage forming member is provided at an inflow hole or an outflow hole provided at both ends in the width direction of the steel sheet. The end portion water supply / drainage passage forming member is characterized in that the inner and outer sides of the endmost water supply / drainage passage formation member communicate with each other without surrounding the jet flow by lacking the wall on the side in the width direction of the steel plate.

  Invention of Claim 4 is the cooling device (20) of the steel plate as described in any one of Claims 1-3. By the communication means of a water supply / drainage passage formation member (45), the inside and outside of a water flow path, The pressure difference is reduced as compared with the case where the communication means is not provided.

Invention of Claim 5 is arrange | positioned at the lower process side of the last stand (11g) of a hot finish rolling mill row | line | column (11), and can cool the steel plate (1) conveyed on a conveyance roll (12). A steel plate cooling device (20) provided with a plurality of cooling nozzles (21c, 22c), wherein the cooling nozzle is provided on the upper surface side and the lower surface side of the portion through which the steel plate passes and the portion through which the steel plate passes. The lower surface guide (40) is provided on the lower surface side, and the lower surface guide has an inflow hole (42) through which the cooling water ejected from the lower surface side cooling nozzle passes, And an outflow hole (43) through which cooling water should fall and pass through in a dischargeable manner. The inflow hole is arranged in parallel in the steel plate conveyance direction, and the outflow hole is arranged in parallel in the steel plate conveyance direction. Of the inflow holes and outflow holes At least one has a water supply / drainage passage forming member (45 ″) that forms a water passage leading to the inflow hole and a water passage leading from the outflow hole, and the water passage leading to the inflow hole formed by the water supply / drainage passage forming member. Is formed so as to surround the jet flow ejected from the cooling nozzle, and the position where the flow rate is 50% with respect to the flow rate at the center of the jet flow is the jet end portion, and the jet thickness X between the jet end portions is with a _1, and a distance between the wall and the jet end of the water passage was X _2, at least in the water passage outlet,
X ₂ / X ₁ ≦ 1/4
And the cooling water jet from the cooling nozzle is carried out in the water passage leading to the inflow hole.

  The invention according to claim 6 is the steel sheet cooling device (20) according to any one of claims 1 to 5, wherein one inflow hole (42) is provided for one cooling nozzle (22c). It is characterized by being.

  The invention according to claim 7 is the steel sheet cooling device (20) according to any one of claims 1 to 6, wherein the drainage channel leading from the outflow hole (43) has a lower channel cross-section at the top. It is characterized by being formed wider than the channel cross-sectional area.

  The invention according to claim 8 is the steel plate cooling device (20) according to any one of claims 1 to 7, wherein the cooling nozzle (22c) is a flat spray nozzle.

  The invention according to claim 9 is a steel plate comprising: a final stand (11g) in the hot finish rolling mill row (11); and the steel sheet cooling device (20) according to any one of claims 1 to 8. It is a manufacturing apparatus (10) of a hot-rolled steel sheet characterized by providing in order in the conveyance direction of (1).

  The invention according to claim 10 is the final stand (11g) in the hot finish rolling mill (11), the steel sheet cooling device (20) according to any one of claims 1 to 8, and cooling water. It is a manufacturing apparatus (10) of a hot-rolled steel sheet characterized by comprising a water draining means (13) for draining water in order in the steel sheet transport direction.

  Invention of Claim 11 is the uppermost process among the cooling nozzles (21c, 22c) with which the steel plate cooling device (20) is provided in the hot rolled steel plate manufacturing apparatus (10) of Claim 9 or 10. The cooling nozzle arranged on the side is arranged inside the housing (11gh) of the final stand (11g).

  Invention of Claim 12 is a manufacturing apparatus (10) of the hot-rolled steel sheet as described in any one of Claims 9-11, Among the cooling nozzles (21c) with which the cooling device (20) of a steel plate is equipped, The cooling water injection port of the cooling nozzle closest to the final stand (11g) is directed to the steel plate to be positioned at the work roll outlet of the final stand.

  Invention of Claim 13 uses the manufacturing apparatus (10) of a hot-rolled steel sheet as described in any one of Claims 9-12, and is the last stand (11g) in a hot finish rolling mill row (11). It is a manufacturing method of the hot-rolled steel plate characterized by including the process of processing the steel plate rolled by this.

  According to the present invention, in a production line for hot-rolled steel sheets, it is possible to guide the steel sheets to be passed, and to appropriately drain water while supplying a high flow density and a large amount of cooling water with high efficiency and high accuracy. A steel plate cooling device, a hot rolled steel plate manufacturing device, and a manufacturing method can be provided. As a result, as described above, rapid cooling after rolling can be further promoted, and a steel plate with good mechanical properties can be produced.

It is the figure which showed typically a part of manufacturing apparatus of the hot rolled sheet steel which concerns on one embodiment. It is the figure expanded paying attention to the part in which the cooling device is arrange | positioned among FIG. It is a figure explaining arrangement | positioning of the cooling nozzle in this embodiment, and its injection form. It is a figure explaining an upper surface guide. It is a figure explaining the example whose outflow hole of an upper surface guide is trapezoid. It is an example explaining the other example of the outflow hole of an upper surface guide. It is a figure explaining the flow of the cooling water by an upper surface guide. It is the figure which showed the other example of the upper surface guide. It is the figure which showed other example of another form of the upper surface guide. It is a figure explaining a lower surface guide. It is a figure explaining the example whose outflow hole of a lower surface guide is trapezoid. It is an example explaining the other example of the outflow hole of a lower surface guide. It is a figure explaining the water flow path by the water supply / drainage passage formation member. It is a figure explaining the flow of the cooling water by a lower surface guide. It is a figure explaining the other example of the water supply / drainage passage formation member. It is a figure explaining the other example of the water supply / drainage passage formation member. It is a figure explaining the water supply / drain passage formation member of other forms.

  The above-mentioned operation and gain of the present invention will be clarified from the following embodiments for carrying out the invention. Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 shows a part of a steel sheet cooling device 20 according to one embodiment (hereinafter, simply referred to as “cooling device 20”) and a hot-rolled steel sheet manufacturing device 10 provided with the cooling device 20. FIG. In FIG. 1, the steel sheet 1 is conveyed from the left side (upstream side, upper process side) to the right side (downstream side, lower process side) of the paper surface, and the vertical direction of the paper surface is the vertical direction. The upstream side (upper process side) / downstream side (lower process side) direction may be described as the passing plate direction, and the direction of the plate width of the steel plate to be passed is the direction perpendicular to this direction. May be described. In the following drawings, repeated reference numerals may be omitted for easy viewing.

  As shown in FIG. 1, a hot-rolled steel plate manufacturing apparatus 10 includes a hot finish rolling mill row 11, a cooling device 20, transport rolls 12, 12,. Although illustration and explanation are omitted, a heating furnace, a rough rolling mill row, and the like are arranged upstream from the hot finish rolling mill row 11 to adjust the conditions of the steel sheet for entering the hot finish rolling mill row 11. ing. On the other hand, on the downstream side of the pinch roll 13, other cooling devices, winders and the like are provided, and various facilities for shipping as steel plate coils are arranged.

  A hot-rolled steel sheet is generally manufactured as follows. That is, the rough bar extracted from the heating furnace and rolled to a predetermined thickness by the rough rolling mill is continuously rolled to a predetermined thickness by the hot finish rolling mill row 11 while the temperature is controlled. Thereafter, it is rapidly cooled in the cooling device 20. Here, the cooling device 20 is installed in the final stand 11g of the hot finish rolling mill row 11 so as to be as close as possible to the rolling roll from the inside of the housing 11gh that supports the rolling roll. And it passes through the pinch roll 13, is cooled to a predetermined winding temperature by another cooling device, and is wound up in a coil shape by a winder.

  The hot-rolled steel sheet manufacturing apparatus 10 (hereinafter sometimes simply referred to as “manufacturing apparatus 10”) includes the hot finish rolling mill row 11 as described above. In this embodiment, seven rolling mills (11a, 11b, 11c,..., 11g) are arranged in parallel along the sheet passing direction. Each of the rolling mills 11a, 11b,..., 11g is a rolling mill that constitutes a so-called stand, and can satisfy conditions such as thickness, mechanical properties, and surface quality required for the final product. Thus, the rolling reduction is set.

  Next, the cooling device 20 will be described. FIG. 2 is an enlarged view of a portion of FIG. 1 where the cooling device 20 is provided. FIG. 2A is an enlarged view so that the entire cooling device 20 appears, and FIG. 2B is a view paying attention to the vicinity of the final stand 11g. The cooling device 20 includes upper surface water supply means 21, 21, ..., lower surface water supply means 22, 22, ..., upper surface guides 30, 30, ..., lower surface guides 40, 40, ....

The upper surface water supply means 21, 21,... Are means for supplying cooling water to the upper surface side of the steel plate 1, and are provided in a plurality of rows in the cooling headers 21 a, 21 a,. , And cooling nozzles 21c, 21c,... Attached to the tips of the conduits 21b, 21b,.
In the present embodiment, the cooling header 21a is a pipe extending in the width direction of the steel plate, that is, in the rear / front direction of FIG. 2, and such cooling headers 21a, 21a,. .
The conduits 21b, 21b,... Are a plurality of thin pipes branched from the cooling header 21a, and the open ends thereof are directed to the upper surface side of the steel plate. A plurality of conduits 21b, 21b,... Are provided in a comb-teeth shape along the tube length direction of the cooling header 21a, that is, in the steel plate width direction.

A cooling nozzle 21c, 21c,... Is attached to the tip of each conduit 21b, 21b,. The cooling nozzles 21c, 21c,... Of the present embodiment are flat type spray nozzles capable of forming a fan-shaped cooling water jet (for example, a thickness of about 5 mm to 30 mm). FIG. 3 schematically shows a collision mode of the cooling water jet formed on the steel plate surface by the cooling nozzles 21c, 21c,. In FIG. 3, the white circles represent the positions immediately below the cooling nozzles 21c, 21c,. Moreover, the collision position and shape of a cooling water jet are typically represented by a thick line. FIG. 3 shows both the sheet passing direction and the steel plate width direction.
As can be seen from FIG. 3, in this embodiment, the adjacent nozzle rows are arranged so as to shift the position in the steel plate width direction, and so-called so that the adjacent nozzle row and the steel plate width direction position are the same. It has a staggered arrangement. As a result, the collision region of the jet flow in the steel plate width direction of the steel plate conveyed is made uniform every time it passes through the nozzle row, and cooling unevenness in the steel plate width direction can be reduced.

In the present embodiment, the cooling nozzle is arranged so that the cooling water jet can pass at least twice over all positions in the steel plate width direction on the steel plate surface. That is, the point D with the steel plate to be passed moves along the straight arrow in FIG. At that time, the nozzle row A (A1, A2) twice, the nozzle row B twice (B1, B2), the nozzle row C twice (C1, C2), and so on. The jet from the nozzle belonging to the row collides twice. Therefore, between the cooling nozzle interval P _W , the cooling water jet collision width L, and the torsion angle β,
L = 2P _W / cos β
The cooling nozzle was arranged so that Here, the passage is made twice, but the present invention is not limited to this, and the passage may be made three times or more.
In addition, from the viewpoint of achieving uniform cooling ability in the steel plate width direction, the cooling nozzles were twisted in directions opposite to each other in the nozzle rows adjacent in the sheet passing direction.

Here, in the present embodiment, in the adjacent nozzle rows as described above, the cooling nozzles are twisted in opposite directions. However, the present invention is not necessarily limited to this, and all of them are in the same direction. It may be in a twisted form. Further, the twist angle (β above) is not particularly limited, and can be appropriately determined from the viewpoint of required cooling capacity, accommodation of equipment arrangement, and the like.
In the present embodiment, the nozzle rows adjacent in the sheet passing direction are arranged in a staggered pattern from the viewpoint of the advantages described above, but the present invention is not limited to this, and the cooling nozzles are linear in the sheet passing direction. It may be in a parallel form.

  The position where the upper surface water supply means 21 is provided, in particular, the position where the cooling nozzles 21c, 21c,... Should be arranged is not particularly limited, but immediately after the final stand 11g in the hot finish rolling mill row 11, the final It is preferable that the stand 11g be arranged as close as possible to the work roll 11gw of the final stand 11g from the inside of the housing 11gh. By arranging in this way, the steel plate 1 immediately after rolling by the hot finish rolling mill row 11 can be rapidly cooled, and the tip of the steel plate 1 can be stably guided to the cooling device 20. In this embodiment, the cooling nozzle 21c close | similar to the work roll 11gw is arrange | positioned close to the steel plate 1 as a low position in a perpendicular direction so that FIG. 2 may show.

  Further, the injection direction of the cooling water injected from the cooling water injection ports of the respective cooling nozzles 21c, 21c,... Is basically the vertical direction, while the injection of the cooling water from the cooling nozzle closest to the work roll 11gw of the final stand 11g. Is preferably inclined in the direction of the work roll 11gw rather than vertical. As a result, it is possible to further shorten the time from when the steel sheet 1 is crushed by the final stand 11g to when the cooling is started, and to make the time for recovering the rolling strain accumulated by rolling almost zero. Therefore, a steel sheet having a finer structure can be produced.

  Returning to FIG. 2, the lower surface water supply means 22, 22,. The lower surface water supply means 22, 22,... Are means for supplying cooling water to the lower surface side of the steel plate 1, and are provided in a plurality of rows in the cooling headers 22 a, 22 a,. , And cooling nozzles 22c, 22c,... Attached to the tips of the conduits 22b, 22b,. The lower surface water supply means 22, 22,... Are provided so as to face the upper surface water supply means 21, 21,..., And are substantially the same as the upper surface water supply means 21, 21,. Therefore, explanation is omitted here.

  Next, the upper surface guide 30 will be described. FIG. 4 conceptually shows the upper surface guide 30. FIG. 4A is a view as seen from above the cooling device 20 and is partially cut away. FIG. 4B is a view from the side. 4 also shows the positions of the cooling nozzles 21c, 21c,..., The position of the steel plate 1, and the direction shown in FIG.

  The upper surface guide 30 includes a plate-shaped guide plate 31 and drainage passage forming portions 35, 35,... Disposed on the upper surface side of the guide plate 31.

The guide plate 31 is a plate-like member and is provided with inflow holes 32, 32,... And outflow holes 33, 33,.
The inflow holes 32, 32, ... are provided at positions corresponding to the cooling nozzles 21c, 21c, ..., and the shape thereof also corresponds to the shape of the jet. Therefore, the inflow holes 32, 32,... Are arranged in parallel in the steel plate width direction to form an inflow hole array 32A, and the inflow hole arrays 32A, 32A,. Here, the shape of the inflow hole is not particularly limited, and it may be formed so that the jet flow from the cooling nozzle does not hit the guide plate as much as possible. Specifically, depending on the characteristics of the jet of the cooling nozzle used, 10% or more of the amount of cooling water ejected from one cooling nozzle 21c per unit time does not collide with the guide plate 31 of the upper surface guide 30. It is preferable that the shape passes. Further, from the viewpoint of efficiently providing the inflow holes 32, 32,... In a limited space, the opening shape of the inflow holes is substantially similar to the transverse cross-sectional shape of the cooling water jet (cross section perpendicular to the ejection direction axis). Is preferred.

On the other hand, the outflow holes 33, 33,... Are rectangular holes, and a plurality of the holes are juxtaposed in the steel plate width direction to form an outflow hole array 33A. , The part of the guide plate 31 remains between the outflow holes 33, 33,... Prevents the steel sheet conveyed from entering the outflow holes 33, 33,. It becomes. The outflow hole arrays 33A, 33A,... Are arranged between the inflow hole arrays 32A, 32A,.
That is, in the guide plate 31, the inflow hole rows 32A and the outflow hole rows 33A are alternately arranged along the plate passing direction.

  Here, the parallel rectangles as described above have been described as a preferable opening shape of the outflow holes 33, 33,. Thereby, a large opening area can be obtained efficiently in a limited space. However, the present invention is not limited to this, and it is only necessary that an appropriate amount of drainage can be secured and the steel plate can be prevented from being caught. That is, the opening shape of the outflow hole is not limited to the above-described rectangle, and examples thereof include a circle and a trapezoid. And a steel plate penetration | invasion prevention means becomes a shape corresponding to the said opening shape. For example, as shown in FIG. 5, when the outflow holes 33 ″, 33 ″,... Are formed in a trapezoidal shape having upper and lower bottoms in the through plate direction, the steel plate intrusion prevention means 33s ″, 33s ″,. Can also be a parallelogram shape inclined from the plate passing direction. As a result, the outflow hole array 33A '' is formed.

  Moreover, in this embodiment, although the inflow hole row | line | column 32A and the outflow hole row | line | column 33A are arrange | positioned alternately, it is not limited to this. For example, two or more outflow hole arrays may be arranged between the inflow hole arrays 32A and 32A.

  FIG. 6 shows a modified example of the outflow hole. In the upper surface guide 30 ′ of the modified example of FIG. 6, since only the outflow hole 33 ′ is different and the other parts are the same as the upper surface guide 30, the same reference numerals are used for the same parts and the description is omitted. . One inflow hole 33 ′ of the upper surface guide 30 ′ is one long hole 33 </ b> A ′ in the width direction, and a net member 33 </ b> B ′ is stretched here. In this way, an outflow hole can be formed. The so-called fineness of the mesh 33B ′ is preferably a mesh of 5 mm × 5 mm or more from the viewpoint that the influence of the flow of cooling water is small and foreign substances such as dust are hardly clogged.

Returning to FIG. 4, the description of the upper surface guide 30 will be continued. Of the edges of the outflow holes 33, 33,..., Backflow prevention pieces 33p, 33p,. These backflow prevention pieces 33p, 33p,... Are provided to prevent water that has entered the outflow holes 33, 33,... From flowing back from the outflow holes 33, 33,. By providing the backflow prevention pieces 33p, 33p,..., A larger amount of drainage can be secured, and drainage performance can be improved.
In this embodiment, the backflow prevention pieces 33p and 33p are erected substantially in parallel, but the backflow prevention pieces 33p and 33p may be erected so that the upper end side is narrower than the lower end side. Thereby, the flow-path cross-sectional area between the backflow prevention piece and the piece (35a, 35c) by which the drainage passage formation part mentioned later is erected can be ensured widely.

As shown in FIG. 4B, the drainage passage forming portions 35, 35,... Are members that have a concave cross section surrounded by the pieces 35a, 35b, 35c and extend in the steel plate width direction. The drainage passage forming portion 35 is disposed so as to cover the concave opening from the upper surface side of the guide plate 31 toward the guide plate 31. At this time, it covers so that a part of upper surface of the guide plate 31 and the outflow hole row | line | column 33A may be included between opening part, ie, piece 35a and piece 35c. Further, there is a predetermined interval between the adjacent drainage passage forming portions 35, 35,..., And the inflow hole rows 32A, 32A,... And the cooling nozzles 21c, 21c,.
Further, among the pieces 35b facing the outflow hole row 33A, a rectifying piece 36 is provided on the surface on the outflow hole row 33A side at a position directly above the outflow hole row 33A. The shape of the rectifying piece 36 is preferably a shape that can be rectified so as to separate the drainage impinging on the piece 35b toward the bottom surface of the drainage passage provided with the backflow prevention pieces 33p, 33p as described later. For example, an inverted triangle, a trapezoid, a wedge shape, and other protruding shapes can be mentioned.

  Here, the heights of the drainage passage forming portions 35, 35,... Are not particularly limited, but when the inner diameter of the conduits 21b, 21b,. It is preferable that it is the range of these. This is because if the conduits 21b, 21b,... Are longer than 20d, the pressure loss is undesirably increased, and if it is shorter than 5d, the injection from the cooling nozzle may be unstable.

  The upper surface guide 30 as described above is arranged as shown in FIG. In this embodiment, three upper surface guides 30, 30, and 30 are used, and these are arranged in parallel in the plate passing direction. All of the upper surface guides 30, 30, 30 are arranged so as to correspond to the height direction positions of the cooling nozzles 21c, 21c,. That is, in the present embodiment, the upper surface guide 30 close to the final stand 11g is disposed so as to be inclined so that the end on the final stand 11g side is low and the other end side is high. The other two upper surface guides 30, 30 are arranged substantially parallel to the passage plate surface at a predetermined interval from the passage plate surface.

By such an upper surface guide 30, it is possible to eliminate a problem that the front end portion is caught by a cooling nozzle or the like when the steel plate front end portion is passed, which is a basic function of the upper surface guide 30.
Furthermore, according to the upper surface guide 30, it becomes possible to appropriately discharge a large amount of cooling water supplied to the upper surface side of the steel plate. First, the cooling water supplied by the upper surface water supply means 21, 21,... Cools the steel plate, and then a part of the cooling water flows in the plate width direction and falls downward to be drained. However, if the amount and density of the supplied cooling water are large, the drainage does not catch up and the accumulated water is formed thick. On the other hand, the upper surface guide 30 can keep the accumulated water thin by providing a further drainage passage. Details are as follows.

FIG. 7 shows a diagram for explanation. Although some symbols are omitted in FIG. 7 for the sake of clarity, the corresponding symbols can be referred to the symbols in FIG. When the cooling water supply density and the cooling water supply amount are so high that the drainage from the width direction of the steel plate cannot catch up, the water flow from the cooling nozzles 21c, 21c,. In such a case, the cooling water sprayed on the upper surface of the steel plate 1 also moves forward and backward and collides as shown by the arrow R in FIG. When such a collision occurs, the cooling water changes its direction, moves upward as indicated by an arrow S, passes through the outflow holes 33, 33,..., And collides with the piece 35b of the drainage passage forming portion 35. At this time, the piece 35b is provided with the wedge-shaped rectifying piece 36 as described above, and the direction of the cooling water is changed as indicated by the arrow T. And the resistance of the said direction change is restrained low by the rectification piece 36, and direction change is performed reliably and efficiently.
As a result, the cooling water that has reached the upper surface side of the guide plate 31 moves in the back / front direction of FIG. At this time, since the backflow prevention pieces 33p and 33p are provided at the edge of the outflow hole 33, the cooling water is prevented from returning from the outflow hole 33 again.

In this way, by providing further drainage means, it is possible to suppress stagnant water even when a large amount of cooling water supplied to the upper surface side has a high flow density. In addition, the holes for supplying the cooling water are separated from the holes for discharging, and the cooling water used for cooling due to the structure as described above collides with the cooling water that has started moving because of drainage. It can be suppressed. Thereby, water supply / drainage is performed smoothly, the accumulated water can be thinned, and the cooling efficiency can be increased.
Thus, it becomes possible to suppress the uneven cooling in the width direction of the steel sheet to be small by suppressing smooth drainage and staying water. Thereby, the steel plate which has uniform quality can be obtained. As for the cooling unevenness, the temperature unevenness in the width direction of the cooling water is preferably within ± 30 ° C.

  In this embodiment, the outflow holes 33, 33,... Included in one outflow hole row 33A are arranged over the entire width direction of the steel plate of the upper surface guide 30, but the present invention is not limited to this. For example, such an outflow hole may be provided only in the vicinity of the central portion in the width direction of the steel plate, where the accumulated water tends to be thick.

In draining the cooling water that has reached the upper surface of the guide plate 31 from both ends in the width direction of the guide plate 31, a configuration for further improving the drainage may be added. For example, the following can be mentioned.
In the upper surface side of the guide plate 31, the central portion in the width direction of the steel plate may be formed high, and the inclination may be provided so as to become lower toward both ends in the width direction. According to this, the cooling water can easily move to both ends of the guide plate 31 due to the height difference, and further smooth drainage can be promoted.
In addition, the drainage may be improved by installing a pump or the like to forcibly drain water, or by making the inside of the drainage passage forming portion have a negative pressure so that the cooling water can be easily introduced into the drainage passage forming portion.
In addition, the upper surface guide itself is formed so as to be movable in the vertical direction, and the upper surface guide 30 is moved downward within a range that does not affect the plate so as to be pressed against the accumulated water and forcibly guided into the drainage passage forming portion. Also good.

  Further, in the inflow holes 33, 33,... Provided in the guide plate 31 and both ends in the width direction, chamfering or rounding may be performed on the edge portion (edge) (the edge is formed in an arc shape). . Thereby, the catch of the steel plate passed can be reduced, and the smooth flow of cooling water can also be promoted.

  The material of the guide plate 31 can be a general material having strength and heat resistance required as a guide, and is not particularly limited. However, for the purpose of reducing scratches and the like on the steel plate when the steel plate to be passed through contacts with the guide plate 31, a material such as a resin that is softer than the steel plate is used in a portion where the problem of strength and heat resistance does not occur. May be.

FIG. 8 shows a view corresponding to FIG. 4B among the upper surface guides 130 and 130 ′ of another form. FIG. 8A shows the upper surface guide 130 and FIG. 8B shows the upper surface guide 130 ′. Here, members common to the upper surface guide 30 are denoted by the same reference numerals, and description thereof is also omitted.
In the upper surface guide 130, drainage passage forming portions 135, 135,... Are formed separately from the guide plate 31. Therefore, in the drainage passage forming portions 135, 135, ..., the pieces 35a, 35a, ... and the backflow prevention pieces 33p, 33p, ... are connected by the bottom plates 135d, 135d, ..., and backflow with the pieces 35c, 35c, ... The prevention pieces 33p, 33p,... Are connected to each other by bottom plates 135e, 135e,. The separated upper surface guide 130 may be used.
The upper surface guide 130 ′ shown in FIG. 8B is a form in which the backflow prevention pieces 133 p ′, 133 p ′,... Extend to the upper surface side of the guide plate 31.

FIG. 9 shows a view corresponding to FIG. 4B among the other top surface guides 230 and 230 ′. FIG. 9A shows the upper surface guide 230, and FIG. 9B shows the upper surface guide 230 ′. Here, members common to the upper surface guides 30 and 130 are denoted by the same reference numerals, and description thereof is also omitted.
Also on the upper surface guide 230, drainage passage forming portions 235, 235,... Are formed separately from the guide plate 31. Therefore, in the drainage passage forming portions 235, 235, ..., the pieces 35a, 35a, ... and the backflow prevention pieces 233p, 233p, ... are connected by the bottom plates 235d, 235d, ..., and the pieces 35c, 35c, ... The prevention pieces 233p, 233p,... Are connected by the bottom plates 235e, 235e,. Further, the backflow prevention pieces 233p, 233p,... Extend on the upper surface side of the guide plate 31. In the upper surface guide 230, in addition to the cooling nozzles 21c, 21c,... Between the guide plate 31 and the drainage passage forming portions 235, 235,..., Headers 21a, 21a,. Yes. Such an upper surface guide 230 may be used.

  In the upper surface guide 230 ′ shown in FIG. 9B, the drainage passage forming portions 235 and 235 adjacent to the upper surface guide 230 are made one drainage passage forming portion 235 ′. This also ensures the drainage path indicated by T ′ in FIG. According to this, it becomes possible to increase the flow path cross-sectional area of the drainage channel (T ′).

  Next, the lower surface guide 40 will be described. FIG. 10 conceptually shows the lower surface guide 40. FIG. 10A shows a view from above of the cooling device 20. FIG.10 (b) is the figure seen from the side surface side. 10A and 10B also show the positions of the cooling nozzles 22c, 22c,... And the position of the steel plate 1. FIG.

  The lower surface guide 40 includes a plate-shaped guide plate 41 and a water supply / drainage passage forming member 45 disposed on the lower surface side of the guide plate 41.

The guide plate 41 is a plate-like member and has inflow holes 42, 42,... And outflow holes 43, 43,.
The inflow holes 42, 42,... Are provided at positions corresponding to the cooling nozzles 22c, 22c,. Therefore, the inflow holes 42, 42,... Are arranged in parallel in the steel plate width direction to form an inflow hole array 42A, and the inflow hole arrays 42A, 42A,. It is preferable that one corresponding inflow hole 42 is provided for one cooling nozzle 22c. As a result, the water supply and drainage can be appropriately separated to enable smooth drainage.
Although the opening shape of the inflow holes 42, 42,... Is not particularly limited, in order for the cooling water to efficiently pass through here, the jet flow from the cooling nozzles 22c, 22c,. It is preferably formed so as not to exist. Specifically, depending on the characteristics of the jet of the cooling nozzle used, 10% or more of the amount of cooling water ejected from one cooling nozzle 22c per unit time does not collide with the guide plate 41 of the lower surface guide 40. It is preferable that the shape passes.
Further, from the viewpoint of efficiently providing the inflow holes 42, 42,... In a limited space, the opening shape of the inflow holes is substantially similar to the transverse cross-sectional shape of the cooling water jet (cross-sectional shape orthogonal to the jet direction axis). Preferably there is.

On the other hand, the outflow holes 43, 43,... Are rectangular holes, and a plurality of the holes are juxtaposed in the steel plate width direction to form an outflow hole array 43A. When the guide plate 41 is partially left between the outflow holes 43, 43,..., The leading end of the steel sheet to be conveyed is prevented from entering the outflow holes 43, 43,. It becomes. The outflow hole arrays 43A, 43A,... Are arranged between the inflow hole arrays 42A, 42A,.
That is, in the guide plate 41, the inflow hole rows 42A and the outflow hole rows 43A are alternately arranged along the plate passing direction.

The passage direction size Lg (m) of the outflow holes 43, 43,... Is not particularly limited as long as appropriate drainage is possible. For example, it is formed so as to satisfy the following formula (1). You can also.
α · W · H ≦ (Lg · W−N · Lg · Wg) / 2 (1)
Here, W is the size (m) of the plate width method of the lower surface guide 40, H is the distance (m) between the upper surface of the lower surface guide 40 and the lower surface of the steel plate 1 to be passed, and Wg is the steel sheet intrusion prevention means 43s. The size (m) and N in the plate width direction respectively represent the number of the steel plate intrusion prevention means 43s arranged in the plate width direction. α is a coefficient, and is preferably about α = 0.5.
According to this, the right side of the equation (1) represents the total opening area of the outflow holes 43, 43,..., And the left side is the cooling water while reaching the outflow holes 43, 43,. The flow path cross-sectional area of the moving passage (between the upper surface of the lower surface guide 40 and the lower surface of the steel plate 1) is represented. And the drainage resistance can be kept small by making the total opening area of the outflow holes 43, 43,... On the right side equal to or larger than the area determined from the channel cross-sectional area on the left side.

  The material of the guide plate 41 can be a general material having strength and heat resistance required as a guide, and is not particularly limited. However, for the purpose of reducing scratches and the like on the steel plate when the steel plate to be passed through contacts with the guide plate 41, a material such as a resin that is softer than the steel plate is used in a portion where the problem of strength and heat resistance does not occur. May be.

  In the inflow holes 42, 42,..., And the outflow holes 43, 43,... Provided in the guide plate 41, chamfering or rounding is performed on the edge portions (edges). May be. Thereby, the catch of the steel plate passed can be reduced, and the smooth flow of cooling water can also be promoted.

  Here, as a preferable opening shape of the outflow holes 43, 43,. Thereby, a large opening area can be obtained efficiently in a limited space. However, the present invention is not limited to this, and it is only necessary that an appropriate amount of drainage can be secured and the steel plate can be prevented from being caught. That is, the opening shape of the outflow hole is not limited to the above-described rectangle, and examples thereof include a circle and a trapezoid. And a steel plate penetration | invasion prevention means becomes a shape corresponding to the said opening shape. For example, as shown in FIG. 11, when the outflow holes 43 ″, 43 ″,... Are formed in a trapezoidal shape having upper and lower bases in the plate passing direction, the steel plate intrusion preventing means 43s ″, 43s ″, ... can also be a parallelogram shape inclined from the sheet passing direction. As a result, the outflow hole row 43A ″ is formed.

  Moreover, in this embodiment, although the inflow hole row | line | column 42A and the outflow hole row | line | column 43A are arrange | positioned alternately, it is not limited to this. For example, two or more outflow hole arrays may be arranged between the inflow hole arrays 42A and 42A.

  FIG. 12 shows a modified example of the outflow hole. In the lower surface guide 40 ′ of the modified example of FIG. 12, since only the outflow hole 43 ′ is different and the other parts are the same as the above-described lower surface guide 40, the same reference numerals are used for the same parts, and the description is omitted. . One inflow hole 43 ′ of the lower surface guide 40 ′ is one long hole 43 </ b> A ′ in the width direction, and a net member 43 </ b> B ′ is stretched here. In this way, an outflow hole can be formed. The so-called fineness of the mesh 43B 'is preferably a mesh of 5 mm x 5 mm or more from the viewpoint that the influence of the flow of the cooling water is small and foreign substances such as dust are hardly clogged.

Returning to FIG. 10, the water supply / drainage passage forming member 45 will be described. Moreover, in FIG. 13, the figure which looked at the water supply / drainage channel | path formation member 45 and the jet which passes here from the upper diagonal was shown.
The water supply / drainage passage forming member 45 hangs down from the lower surface side of the guide plate 41 in the boundary portion between the inflow hole row 42A and the outflow hole rows 43A and 43A adjacent thereto, and is juxtaposed in the through plate direction and the steel plate width direction. This is a member formed by combining plate-like members. By combining such plate-like members, a plurality of cylindrical spaces arranged in parallel in the plate passing direction and the steel plate width direction are formed. That is, when the cooling water jet passes through the cylindrical inner space and the drainage passes through the outer space, the water supply channel and the drainage channel can be separated. Further details are as follows. Here, the member which forms one cylindrical space is demonstrated.

  As can be seen from FIG. 13, the water supply / drainage passage forming member 45 includes plate-like members 45a, 45b, 45c and 45d, which are combined to form a cylindrical flow passage. An inflow hole 42 is arranged in the cylindrical upper end opening. Outflow holes 43 and 43 and steel plate intrusion prevention means 43s and 43s are arranged at the upper end between the water supply and drainage passage forming members 45 and 45 adjacent to each other in the plate passing direction.

  In this embodiment, as can be seen from FIG. 10B, the steel plate intrusion prevention means 43s, 43s,... Of the guide plate 41 are formed slightly thicker downward. And the upper end part of plate-shaped member 45a, 45b is attached to the lower surface of the guide plate 41 and the side surface formed thickly of the said steel plate penetration | invasion prevention means 43s, 43s by welding. On the other hand, the plate members 45c and 45d are fixed to the plate members 45a and 45b by welding. Accordingly, the upper end portion of the water supply / drainage passage forming member 45 is connected to the guide plate 41 along the edge of the inflow hole 43.

  In the present embodiment, the form attached by welding has been described, but it may be a fixing means such as a screw or fixing by an adhesive, and is not particularly limited. In addition, the guide plate 41 and the water supply / drainage passage forming member 45 are integrated here, but need not be integrated. However, since the water supply / drainage passage forming member is a member that forms the water supply channel and the drainage channel, it is preferable that there is no gap that communicates the water supply channel and the drainage channel as much as possible. Explained what was integrated.

  Further, as can be seen from FIG. 13, so-called punching metal is applied to the plate-like members 45c and 45d facing the wider surface of the jet so as to communicate the inside and outside of the tube. ing. The reason for this will be described in detail later.

  The water supply / drainage passage forming member 45 is formed with a narrower gap on the lower end (tubular lower end opening) side, and the cooling nozzle 22c is disposed here. Along with this, between the adjacent water supply / drainage passage forming members 45, 45, as shown by V in FIG. Such a shape is preferably formed to match the shape of the jet water from the cooling nozzles 22c, 22c,.

  The lower surface guide 40 as described above is arranged as shown in FIG. In this embodiment, four lower surface guides 40, 40,... Are used and arranged between the transport rolls 12, 12, 12. All of the lower surface guides 40, 40,... Are arranged at a height that does not become too low with respect to the upper ends of the transport rolls 12, 12,.

Such a lower surface guide 40 can eliminate a problem that the steel plate tip is caught between the transport rolls 12 and 12, which is a basic function of the lower surface guide 40.
Furthermore, according to the lower surface guide 40, it becomes possible to appropriately discharge a large amount of cooling water supplied to the lower surface side of the steel plate. Details are as follows.

FIG. 14 shows an explanatory diagram. In FIG. 14, a part of the reference numerals are omitted for easy viewing of the drawing, but the corresponding reference numerals in FIG. 10 can be referred to.
The cooling water sprayed from the cooling nozzle 22c passes through the cylindrical inner side surrounded by the plate-like members 45a, 45b, 45c, 45d, reaches the lower surface of the steel plate 1 from the inflow hole 42, and cools the steel plate 1 (FIG. 14 (b)). Thereafter, the cooling water moves on the upper surface of the guide plate 41 in the direction indicated by the straight arrow in FIG. 14A and falls downward from the outflow holes 43 and 43 as indicated by the straight arrow in FIG. Drained.

Thus, not only the hole for water supply and the hole for drainage are separated, but also the water passage for water supply and the drainage channel for drainage are separated, so that the cooling water used for cooling Collisions with the drainage can be prevented. Thereby, water supply / drainage is performed smoothly, stagnant water can be suppressed, and cooling efficiency can be increased. In particular, since the cooling nozzles 22c, 22c,... Are located directly below the water supply / drainage passage forming member 45, the passage for drainage extends to the vicinity of the right and left of the cooling nozzles 22c, 22c,. The influence on… can be suppressed.
In the lower surface guide, 80% or more of the cooling water supplied by the lower surface water supply means is preferably drained from the outflow hole. Thereby, very high cooling efficiency is securable.
In addition, it is possible to suppress the cooling unevenness in the width direction of the steel sheet to be small by suppressing the smooth drainage and the staying water. Thereby, the steel plate which has uniform quality can be obtained. The cooling unevenness is preferably such that the temperature unevenness in the width direction of the steel sheet in the cooling water is within ± 30 ° C.

  In the steel plate width direction, the plate-like members 45c and 45d (see FIG. 13) are smoothly connected to the inflow hole 42, so that the jet flow is guided by the guide plate as compared with the case where the plate-like members 45c and 45d are not provided. The jet can be guided to the inflow hole 42 without waste without being collided with and scattered on the lower surface of the steel 41 and supplied to the steel plate 1. As a result, the utilization efficiency of the cooling water can be increased.

Next, the reason why holes are provided in the plate-like members 45 c and 45 d of the water supply / drainage passage forming member 45 as shown in FIG. 13 will be described.
If a plate material that is a simple plate-like member is arranged here instead of the plate-like members 45c and 45d, the pressure (atmospheric pressure) between the jet flow and the plate material decreases, and the jet flow is attracted to the plate material. If the jet accurately passes through the center between the plate members, the force of drawing the jet toward the plate members becomes equal, so the jet goes straight. However, in practice, due to manufacturing tolerances, apparatus vibrations, and the like, the jet cannot continue to accurately pass through the center between the plates, and always approaches one of the plates. Once one plate material is approached, the pressure between the jet and the plate wall surface further decreases, and the jet further moves to that plate material. And finally, it will be drawn near to the wall surface side of a board | plate material, and a bend will arise in a jet flow. This effect is known as the Coanda effect. When the jet flow is bent due to the Coanda effect, the position of the jet to be jetted with respect to the steel sheet is different from the position where the jet is actually jetted, which may cause large cooling unevenness.
On the other hand, according to the water supply / drainage passage forming member 45 of the present embodiment, the inside and outside of the water passage for water supply sandwich the plate-like members 45c, 45d by the holes provided in the plate-like members 45c, 45d. The atmospheric pressure can be made substantially equal, and a decrease in the atmospheric pressure in the water passage can be prevented. That is, it is possible to fundamentally eliminate the cause of the Coanda effect. This makes it possible to suppress the bending of the jet.
Therefore, according to this embodiment, even if the position of a cooling nozzle and a steel plate is separated, cooling water can be injected to the appropriate position of a steel plate. Thereby, it is possible to protect the cooling nozzle from deterioration caused by heat or the like. Further, in the case of a spray form in which the jet flow spreads, cooling of a wide range is possible by separating the nozzle and the steel plate to some extent, so that the effect of the present embodiment becomes more remarkable.

  Therefore, the plate-like member only needs to be provided with such communication means. In addition to the circular hole as in the embodiment, the plate-like member may be a hole such as a rectangle, a triangle, or a polygon, and may be a vertical or horizontal slit. Also good.

FIG. 15 shows a water supply / drainage passage forming member 45 ′ according to a modification. In the water supply / drainage passage forming member 45 ′, plate-like members 45 c ′ and 45 d ′ facing the wide surface of the jet are provided only on the downstream side of the jet. Thereby, a jet can be appropriately guide | induced to an outflow hole. In the present modification, the Coanda effect causes a slight attraction to the plate-like members 45c ′ and 45d ′. However, since the plate-like members 45c ′ and 45d ′ are limited to only the upper part, a large bend in the jet does not occur.
Further, the plate-like members 45c ′ and 45d ′ can be provided with communication means similar to the plate-like members 45c and 45d to suppress the bending of the jet flow.

FIG. 16 shows a water supply / drainage passage forming member 45 ″ according to still another modification. The water supply / drainage passage forming member 45 ″ is arranged so that the plate-like members 45a, 45b, 45c ″, 45d ″ form a cylindrical shape as described above. Further, in the water supply / drainage passage forming member 45 ″, the plate-like members 45c ″ and 45d ″ facing the wide surface of the jet flow are not provided with any communication means. However, plumbing passage forming member 45 '' in, as shown by X ₃ in FIG. 16, the plate-like member 45c in the feed water of the water passage 'to narrow the gap between the plate-shaped member 45d''and' in FIG. 16 is the degree approximately the same as the jet thickness indicated by X _1. Specifically, the position at which flow relative to the flow rate at the center of the jet is 50% and the jet end, as well as between the end and the jet thickness X _1, plate-shaped member 45c '', 45d '' when the distance between the jet end was X ₂ and preferably satisfies the following formula (2).
X ₂ / X ₁ ≦ 1/4 (2)
Here, it is not necessary to satisfy the formula (2) over the entire length of the water passage in the water passage direction, and it is sufficient that this is satisfied at least at the outlet of the water passage. However, it is preferable that the shape of the water channel be as close to the shape of the jet as possible. As a result, an unnecessary space is prevented from being generated between the jet and the plate-like member, and the bending of the jet due to the Coanda effect can be more efficiently prevented.
That is, according to the water supply / drainage passage forming member 45 ″, even if the jet flow is attracted to the plate-like members 45c ″ and 45d ″ due to the Coanda effect, the bending of the jet flow can be suppressed to be small, and the target position of the steel plate The jet can be guided to
Moreover, it is more preferable to satisfy | fill following Formula (3) from a viewpoint of suppressing the contact and friction with a jet and a plate-shaped member.
X ₂ / X ₁ <1/4 (3)

In the above-described embodiment, an example in which one cylindrical body of the water supply / drainage passage forming member is assigned to one cooling nozzle is described. However, the present invention is not limited to this, and a plurality of cylindrical bodies are provided in one cylindrical body. The cylindrical body may be formed so that the cooling nozzles are allocated. In this case, the amount of water of the jet that collides with and scatters on the lower surface of the guide plate 41 is increased as compared with the above-described embodiment in which one cylindrical body of the water supply / drainage passage forming member is assigned to one cooling nozzle. However, compared with the case where the water supply / drainage passage forming member is not provided, the amount of water of the jet flow that collides and scatters can be reduced, and the use efficiency of the cooling water can be increased.
In addition, for the cooling nozzles arranged at both ends in the steel plate width direction, among the plate members 45c and 45d of the water supply / drainage passage forming member, the plate member 45c arranged on the outer side in the steel plate width direction, or the plate 45-shaped member 45d may be provided with an endmost water supply / drainage passage forming member having an open form without being provided. This is because the cooling nozzles provided at both ends in the width direction of the steel plate do not necessarily require the water passages that surround the four circumferences because the cooling nozzles are not disposed outside the cooling nozzles.

  In the embodiment described above, the interval between the lower ends of the cylindrical bodies surrounded by the plate-like members 45a, 45b, 45c, and 45d forming the water supply passage is formed narrow, and accordingly the plate forming the drainage passage. The lower end portion between the shaped members 45a and 45b is formed with a wide interval. Thereby, the drainage channel is expanded, and the drainage is performed more smoothly. However, the plate-like member of the water supply / drainage passage forming member is not necessarily inclined in this manner, and may be suspended vertically downward. FIG. 17 shows a lower surface guide 140 of the example. FIG. 17 is a view corresponding to FIG. 10, and is the same as the lower surface guide 40 except for the water supply / drainage passage forming member 145 in which the plate members 145 a and 145 b extend vertically downward. Such a lower surface guide may be used.

  In the above description, it has been described that the water supply / drainage passage forming members are provided for all of the plurality of inflow holes and outflow holes. However, the present invention is not necessarily limited thereto. Should just be provided. Although the most remarkable effect is achieved by providing the water supply / drainage passage forming members for all the inflow holes and outflow holes as in the above embodiment, compared to the case where the water supply / drainage passage formation members are not provided even if the number is small. The effects described above are achieved. This is because the water supply / drainage passage forming member may not be provided for some of the inflow holes and outflow holes due to the arrangement relationship with other facilities.

  Returning to FIG. 2, the description of the hot-rolled steel sheet manufacturing apparatus 10 will be continued. The conveying rolls 12, 12,... Are rolls that convey the steel plate 1 in the plate direction while being a table of the steel plate 1. As described above, the lower surface guides 40, 40,... Are arranged between the transport rolls 12, 12,.

  The pinch roll 13 also serves as a drainer and is provided on the downstream side of the cooling device 20. Thereby, it becomes possible to prevent the cooling water sprayed in the cooling device 20 from flowing out to the downstream side of the steel plate 1. Furthermore, the waviness of the steel plate 1 in the cooling device 20 can be suppressed, and in particular, the plate-passability of the steel plate 1 can be improved at the time before the tip of the steel plate 1 bites into the winder. Here, among the rolls of the pinch roll 13, the upper roll 13a is movable up and down as shown in FIG.

  As described above, in a hot-rolled steel sheet production line, a cooling device and hot-rolled steel sheet manufacturing apparatus that are excellent in drainage even when a high flow density and a large amount of cooling water are supplied without hindering movement (passing) of the steel sheet. Can be provided. And it becomes possible to manufacture the hot rolled steel plate excellent in the mechanical characteristic by this.

In the drainage of the cooling water by the upper surface guide and the lower surface guide as described above, the specific drainage performance is appropriately determined depending on the required amount of cooling heat of the steel sheet and is not particularly limited. However, as described above, from the viewpoint of refinement of the steel sheet structure, rapid cooling immediately after rolling is effective, and therefore, it is preferable to supply cooling water having a high supply density. Therefore, the drainage in the upper surface guide and the lower surface guide is only required to ensure drainage performance corresponding to the supply amount and flow density of the cooling water. From the viewpoint of the refinement of the steel sheet, the flow rate density of the supplied cooling water can be 10 to 25 m ³ / (m ² · min). Larger flow density may be used.

  In the present embodiment, the cooling device and the manufacturing apparatus including both the upper surface guide and the lower surface guide have been described as preferable modes. However, the present invention is not limited to this, and the lower surface guide is applied and the upper surface guide is conventionally used. May be used.

A steel plate is manufactured as follows, for example, with the above-described hot-rolled steel plate manufacturing apparatus. That is, the injection of the cooling water in the cooling device 20 is stopped during the non-rolling time until the steel plate is taken up by the winder and rolling of the next steel plate 1 is started. Then, the pinch roll 13 on the downstream side of the cooling device 20 moves the upper roll 13a to a position higher than the upper surface guide 30 of the cooling device 20 during the non-rolling time, and thereafter, rolling of the next steel plate is started. The
A few seconds before the leading end of the next steel plate bites into the final stand 11g of the hot finish rolling mill row 11, the injection of cooling water from the cooling device 20 is started, and the cooling immediately after the leading end of the steel plate passes through the cooling device 20. The water injection pressure is controlled to be substantially a predetermined value. Moreover, immediately after the front-end | tip of the steel plate 1 passes the pinch roll 13, the upper side roll 13a is dropped and the pinch of the steel plate 1 is started.

By starting the injection of the cooling water before the front end of the steel plate 1 is conveyed into the cooling device 20, the length of the unsteady cooling part at the front end of the steel plate can be shortened, and the injected cooling is performed. Water can stabilize the plate-passability of the steel plate 1. That is, when the steel plate 1 floats and approaches the upper surface guide 30, the collision force that the steel plate 1 receives from the cooling water jets injected from the cooling nozzles 21 c, 21 c,. Force acts. Therefore, even when the steel plate 1 collides with the upper surface guide 30, the impact force is mitigated by the collision force received from the cooling water jet, and the frictional heat between the steel plate 1 and the upper surface guide 30 is reduced. It becomes possible to reduce the scratches generated on the steel sheet surface.
Therefore, if a hot-rolled steel sheet is manufactured by a hot-rolled steel sheet manufacturing apparatus provided with the cooling device 20 operated in this way on the downstream side of the hot finish rolling mill row 11, high-density, large-volume cooling water is used. It becomes possible to cool. That is, by manufacturing a hot-rolled steel sheet by such a manufacturing method, it becomes possible to manufacture a hot-rolled steel sheet having a refined structure.

  Further, the plate passing speed in the hot finish rolling mill row may be constant except for the plate start portion. Thereby, the steel plate with which mechanical strength was raised over the steel plate full length can be manufactured.

  Although the present invention has been described in connection with embodiments that are presently practical and preferred, the present invention is not limited to the embodiments disclosed herein, but is claimed. The steel sheet cooling apparatus, hot-rolled steel sheet manufacturing apparatus, and manufacturing method can also be changed as appropriate without departing from the scope and spirit of the invention that can be read from the entire specification and the specification. It should be understood as encompassed by the scope.

DESCRIPTION OF SYMBOLS 1 Steel plate 10 Manufacturing apparatus 11 Rolling machine row 11g Final stand 12 Transport roll 13 Pinch roll 20 Cooling device 21 Upper surface water supply means 21a Cooling header 21b Conduit 21c Cooling nozzle 22 Lower surface water supply means 22a Cooling header 22b Conduit 22c Cooling nozzle 30 Upper surface guide 31 Guide Plate 32 Inflow hole 32A Inflow hole row 33 Outflow hole 33A Outflow hole row 33p Backflow prevention piece 35 Drainage passage forming part 36 Rectification piece 40 Lower surface guide 41 Guide plate 42 Inflow hole 42A Inflow hole row 43 Outflow hole 43A Outflow hole row 45 Water supply / drainage passage Forming member 45a Plate member 45b Plate member 45c Plate member 45d Plate member

Claims (13)

A steel sheet cooling apparatus including a plurality of cooling nozzles arranged on the lower process side of the final stand of the hot finish rolling mill row and provided to be able to cool the steel sheet transported on the transport roll,
The cooling nozzle is provided on the upper surface side and the lower surface side of the portion through which the steel plate passes, and is capable of injecting cooling water toward the portion through which the steel plate passes,
A lower surface guide is provided on the lower surface side,
The lower surface guide has an inflow hole through which the cooling water sprayed from the cooling nozzle on the lower surface side should pass, and an outflow hole through which the cooling water should pass through so as to fall and be discharged.
The inflow hole is arranged in parallel in the steel plate conveyance direction, and the outflow hole is arranged between the adjacent inflow holes arranged in parallel in the steel plate conveyance direction,
At least one of the inflow hole and the outflow hole has a water supply / drainage passage forming member that forms a water passage that leads to the inflow hole and a drainage passage that leads from the outflow hole,
The water passage leading to the inflow hole formed by the water supply / drainage passage forming member is formed so as to surround a jet flow ejected from the cooling nozzle, and at least part of the wall of the water passage is provided with the passage. It has a means of communication through inside and outside the waterway,
The steel sheet cooling apparatus according to claim 1, wherein the cooling water is sprayed from the cooling nozzle into a water passage leading to the inflow hole.   The steel sheet cooling device according to claim 1, wherein one end side of the water supply / drainage passage forming member is connected to an edge of the inflow hole.   The outermost end water supply / drainage passage forming member, which is the water supply / drainage passage forming member provided in the inflow hole or the outflow hole provided at both ends of the steel plate width direction, has the jet flow by lacking the wall on the end side of the steel plate width direction. The steel plate cooling device according to claim 1, wherein the innermost and outermost water supply / drainage passage forming members communicate with each other without surrounding the outermost portion.   The pressure difference between the inner side and the outer side of the water passage is reduced by the communication means of the water supply / drainage passage forming member as compared with the case where the communication means is not provided. The steel sheet cooling device according to claim 1. A steel sheet cooling apparatus including a plurality of cooling nozzles arranged on the lower process side of the final stand of the hot finish rolling mill row and provided to be able to cool the steel sheet transported on the transport roll,
The cooling nozzle is provided on the upper surface side and the lower surface side of the portion through which the steel plate passes, and is capable of injecting cooling water toward the portion through which the steel plate passes,
A lower surface guide is provided on the lower surface side,
The lower surface guide has an inflow hole through which the cooling water sprayed from the cooling nozzle on the lower surface side should pass, and an outflow hole through which the cooling water should pass through so as to fall and be discharged.
The inflow hole is arranged in parallel in the steel plate conveyance direction, and the outflow hole is arranged between the adjacent inflow holes arranged in parallel in the steel plate conveyance direction,
At least one of the inflow hole and the outflow hole has a water supply / drainage passage forming member that forms a water passage that leads to the inflow hole and a drainage passage that leads from the outflow hole,
The water flow path leading to the inflow hole formed by the water supply / drainage passage forming member is formed so as to surround the jet flow ejected from the cooling nozzle, and has a flow rate of 50% with respect to the flow rate at the center of the jet flow. the a position and jet end, between該噴flow end with a jet thickness X _1, when the distance between the wall and the jet end of the water conduit and the X _2, at least the water passage outlet ,
X ₂ / X ₁ ≦ 1/4
The filling,
The steel sheet cooling apparatus according to claim 1, wherein the cooling water is sprayed from the cooling nozzle into a water passage leading to the inflow hole.   The steel plate cooling device according to any one of claims 1 to 5, wherein one inflow hole is provided for one cooling nozzle.   The steel plate cooling device according to any one of claims 1 to 6, wherein the drainage channel leading from the outflow hole has a lower channel cross-section formed wider than an upper channel cross-sectional area.   The said cooling nozzle is a flat spray nozzle, The cooling device of the steel plate as described in any one of Claims 1-7 characterized by the above-mentioned.   An apparatus for producing a hot-rolled steel sheet, comprising: a final stand in a hot finish rolling mill row; and the steel sheet cooling device according to any one of claims 1 to 8 in order in a steel sheet conveyance direction.   A final stand in a hot finish rolling mill row, a steel sheet cooling device according to any one of claims 1 to 8, and a draining means for draining cooling water are provided in order in the steel sheet conveying direction. An apparatus for manufacturing a hot-rolled steel sheet.   The apparatus for producing a hot-rolled steel sheet according to claim 9 or 10, wherein a cooling nozzle disposed on an uppermost process side among cooling nozzles provided in the cooling apparatus for the steel sheet is disposed inside a housing of the final stand.   Among the cooling nozzles provided in the steel sheet cooling device, at least a cooling water injection port of the cooling nozzle closest to the final stand is directed to a steel plate to be positioned at a work roll outlet of the final stand. The apparatus for manufacturing a hot-rolled steel sheet according to any one of claims 9 to 11.   Using the hot rolled steel sheet manufacturing apparatus according to any one of claims 9 to 12, the hot rolled steel sheet includes a step of processing a steel sheet rolled at a final stand in a hot finish rolling mill row. A method of manufacturing a steel sheet.

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