[Document Type] Specification [Title of the Invention] DEVICE FOR PRODUCING COATED STEEL SHEET AND METHOD FOR PRODUCING COATED STEEL SHEET [Technical Field of the Invention] [OOO 11 t The present invention relates to a device for producing a coated steel sheet and a method for producing a coated steel sheet capable of reliably solving a problem caused by excessive coating which accumulates along a side edge of a steel sheet. [Related Art] [0002] Recently, due to the expansion of usages, a coated steel sheet has been required to have further improvements in quality and characteristics, for example, a uniform thickness of a coating film, improvements in surface glossiness and surface smoothness, stacking and compounding of coating films, and thinning and thickening of coating films. [0003] For example, in Patent Document 1, for the purpose of rectifying air current in the atmosphere, a technique of discharging gas into the atmosphere to prevent coating that falls in a curtain shape from shaking and unifonnize the film thickness of a coating film is disclosed. In Patent Document 2, a technique of discharging gas into an object to be coated so as to remove a thick coating generated immediately after starting the application of the coating and achieve a uniform thickness overall is disclosed. [0004] However, it is apparent from the technical configuration that the technique disclosed in Patent Document 1 has an effect only in a case where the falling coating has a small flow rate and a low flow velocity, or the falling coating has a low viscosity. In addition, in Patent Document 2, as described in the examples thereof, only a case where the discharge flow rate of gas is a small flow rate of about 10 m3k and a lowviscosity coating having a viscosity of 10 cP (centipoise) is used is postulated. These techniques cannot cope with the thickening of a coating film using a high-viscosity coating and the like among the above-mentioned characteristics that require fbrther improvements. [OOOS] On the other hand, in Patent Documents 3 to 9, techniques of stacking and applying coatings using a multilayer curtain coater are disclosed. The multilayer curtain coater forms a multilayer coating film without contact, and thus has characteristics in that surface defects such as roping of a coating film, which occurs in a case of using a roll coater, do not occur. [0006] However, the stacking of coating films according to a wet-on-wet method including the multilayer curtain coater and the roll coater has a problem in that coatings are mixed with each other and locally form a mixed layer and thus external appearance failure such as stripe patterns is likely to occur. That is, although the techniques in the related art cope with the stacking of coating films among the abovementioned characteristics that require further improvements, there are still problems. [Prior Art Document] [Patent Document] [0007] [Patent Document I] Japanese Unexamined Patent Application, First Publication No. 2004-1 8 145 1 [Patent Document 21 Japanese Unexamined Patent Application, First Publication No. 2002-273299 [Patent Document 31 Japanese Unexamined Patent Application, First Publication No. H07-080378 [Patent Document 41 ~ a ~ a n kUsnee xamined Patent Application, First Publication No. H07-080394 [Patent Document 51 Japanese Unexamined Patent Application, First Publication No. H07-080395 [Patent Document 61 Japanese Unexamined Patent Application, First Publication No. H07-080396 [Patent Document 71 Japanese Unexamined Patent Application, First Publication No. H08-252502 [Patent Document 81 Japanese Unexamined Patent Application, First Publication No. H08-276150 [Patent Document 91 Japanese Unexamined Patent Application, First Publication No. 2006-1 75826 [Summary of the Invention] [Problems to be Solved by the Invention] [OOOS] The present inventors have paid attention to a possibility that the above problems may be solved by using a high-viscosity coating having a viscosity of 700 mPasec (700 cP) or higher and 2000 mPa.sec (2000 cP) or lower. That is, by using the high-viscosity coating, the thickening of a coating film can be achieved to a higher degree than that of the related art, and even in a case where the coating films are stacked by the wet-on-wet method, the coatings can be prevented from being mixed with each other and thus the stacking of the coating films can be achieved. [0009] The present inventors performed various experiments by using the highviscosity coating, and as a result, it was confirmed that the above-described effects can be obtained. However, when the high-viscosity coating was used, it became apparent that there is a problem in that after applying a coating to a steel sheet, a coating film protrusion in which excessive coating accumulates is formed at side edge of the steel sheet in the sheet-width direction (which are the ends of the steel sheet in the sheetwidth direction and are parts of the steel sheet along the longitudinal direction). [OO lo] FIG. 6 is a perspective view illustrating a device for producing a coated steel sheet, which coats a steel sheet using a coating curtain, according to the related art. As illustrated in FIG. 6, a coating 3 which stays between an applicator roll 1 that rotates in an arrow A direction and a doctor roll 2 that rotates in an arrow B direction is scraped by a blade 4 and forms a coating curtain 3a. A pair of curtain guides 5 is provided so that the coating curtain 3a reaches a coating pan 6 from the blade 4 without contracted flow, and thus the curtain thickness of the coating curtain 3a in the sheet-width direction becomes uniform. The coating curtain 3a falls onto the surface of a steel sheet 8 which is supported by a support roll 7 and threads in an arrow C direction such that a coating film 9 is formed on the steel sheet 8. In addition, the coating pan 6 which is provided below the steel sheet 8 accommodates the coating 3 which is not used for coating the steel sheet 8. [OO 1 11 FIG. 7 is a longitudinal sectional view of the steel sheet 8 after the coating film 9 is formed, and is a cross-sectional view taken along the line X-X of FIG. 6. In a case where the coating 3 is a high-viscosity coating having a viscosity of 700 mPa.sec (700 cP) or higher and 2000 mPa.sec (2000 cP) or lower, as illustrated in FIG. 7, the excessive coating 3 accumulates at both side edge 8x of the steel sheet 8 in the sheet-width direction (which are ends of the steel sheet 8 in the sheet-width direction and are parts of theasteel sheet 8 along the longitudinal direction) such that coating film protrusion 9x in which the coating film 9 protrudes are formed. [OO 121 When the coating film protrusion 9x is formed on the coated steel sheet, there may be cases where the coated steel sheet cannot be cleanly coiled in a production process and thus production efficiency is reduced. In addition, when the coating film protrusion 9x is formed, there may be cases where the product shipping form of the coated steel sheet such as lot size or shape is also limited. [OO 131 In order to solve the problems, the coating film protrusion 9x needs to be removed. The present inventors examined various methods of removing the coating film protrusion 9x, and as a result, it was proved that a method of blowing off and removing the coating film protrusion 9x by spraying gas is preferable from the viewpoints of product quality, production cost, maintenance of a production device, and the like. [00 1 41 However, when the excessive coating (the coating film protrusion 9x) which accumulates on the steel sheet 8 is blown off by the blowing-off method, there is concern that the blown-off coating may scatter and adhere to the steel sheet 8 again. That is, when the blown-off coating is reflected or flows back and adheres to the steel sheet 8 again, there may be cases where external appearance failure on the coated steel sheet which is a product occurs. [00 1 51 That is, although there is a possibility that the above-described problems associated with the thickening of the coating film 9 or the stacking of the coating film 9 may be solved by using the high-viscosity coating 3, there is conce;n that the coating film protrusion 9x may be formed along the side edge 8x of the steel sheet 8. Although the blowing-off method performed by spraying gas is preferable as the method of removing the coating film protrusion 9x, there is concern that a problem in that the blown-off coating returns and adheres to the steel sheet 8 again may newly occur. In order to cope with this, using an aspirator including a fan for gas discharge may be considered. However, the suctioned excessive coating adheres to the fan and thus maintenance is necessary, resulting in a reduction in production efficiency. From this viewpoint, it is difficult to adopt this technique. For the above-described reasons, in the related art, solving the various problems due to the excessive coating (coating film protrusion 9x) that adheres to the side edge 8x of the steel sheet 8 causes another problem in turn, and thus it is difficult to collectively solve all the problems. [00 161 The present invention has been made taking the foregoing circumstances into consideration, and an object thereof is to provide a device for producing a coated steel sheet and a method for producing a coated steel sheet capable of removing excessive coating that accumulates along the side edge of a steel sheet and reliably preventing the removed excessive coating from re-adhering to the steel sheet. [Means for Solving the Problem] [OO 1 71 The gist of the present invention is as follows. [OO 181 (1) A device for producing a coated steel sheet according to an aspect of the present invention includes: a blowing-off unit which sprays a gas onto and remove an ixcessive coating that accumulates along a side edge of a steel sheet that threads along one direction; and a coating-collection unit which collects the excessive coating removed by the blowing-off unit. The blowing-off unit includes a spray nozzle which is directed in a direction from an inside to an outside in a sheet-width direction of the steel sheet and directed toward the side edge, and a gas supply member which supplies the gas to the spray nozzle. The coating-collection unit includes a duct having an inlet that receives the excessive coating and an outlet that discharges the received excessive coating, and a coating container having an opening that receives the excessive coating discharged from the outlet. In a case where the duct is seen in a plan view, the outlet is disposed to fit in and overlap an inside of the opening of the coating container, and in a case where the duct is seen in a side view, a gap is provided between the outlet and the opening of the coating container. (2) In the producing device described in (I), when an angle between an extension line of a center axis line of the spray nozzle and a projection line of the extension line on a surface of the steel sheet is defined as P, an angle between the projection line and a sheet threading direction of the steel sheet in a case where the surface is seen in a facing view is defined as a, and the distance from a tip end of the spray nozzle to a point that intersects a plane including the surface when seen along the extension line is defined as d in units of mm, all the following Expressions A, B, and C may be satisfied, and a discharge direction of the spray nozzle may be disposed to be opposite to the sheet threading direction of the steel sheet. 20°Fa5700 . . .(Expression A) 2O0_90°, that is, even in a case where the spray nozzle 11 a is arranged so that the discharge direction of the gas from the spray nozzle 1 la is along with the sheet threading direction C when seen in the plan view, the obtained effect is substantially equal. In this case, it is preferable that the angle a satisfies 110" to 160". More preferably, the angle a is 120" to 150". In addition, as described above, the angle a is the angle between the projection line 11 a2 and the sheet threading direction C of the steel sheet 8 in the case where downstream in the sheet threading direction C is the reference (an angle of 0"). [0033] Similarly, when the angle P is smaller than 20°, it is difficult to blow off the excessive coating. When the angle P exceeds 70°, it is difficult to smooth the coating film 9 after the excessive coating is blown off. Therefore, it is preferable that the angle P is 20' to 70". More preferably, the angle P is 30" to 60". [0034] When the distance d exceeds 55 mm, it is difficult to blow off the excessive coating. When the distance d is shorter than 10 mm, it is difficult to smooth the coating film 9 after the excessive coating is blown off. Therefore, it is preferable that the distance d is 10 mm to 55 mm. More preferably, the distance d is 15 mm to 40 mm. [003 51 In addition, as a result of the test, the following knowledge was obtained. When a, P, and d associated with the spray nozzle 1 1 a satisfy all the above Expressions A, B, and C and also satisfy the following Expression D, the coating film protrusion 9x which is the excessive coating formed at the side edge 8x of the steel sheet 8 are reliably blown off and thus a flat coating film 9 can be obtained, which is more preferable. 0.1IsinacosP10.9 . . .(Expression D) [003 61 The above Expression D is an expression that shows a preferable arrangement of the spray nozzle 1 la. The upper limit and the lower limit of the Expression D were set on the basis of the result of the spray-smoothing test. More preferably, 0.2<_sina.cos~50i.s8 set. Most preferably, 0.40p2 and Op1>0p2 are satisfied, the blown-off excessive coating is appropriately prevented from being reflected or flowing back and re-adhering to the steel sheet 8, and the blown-off excessive coating can be collected by the coating container 12b. [0049] In a case where the opening area of each of Op 1, Op2, and Op3 is smaller than the above range, there is a possibility that the blown-off excessive coating may be I reflected or flow back and re-adhere to the steel sheet 8 and the blown-off excessive coating may not be reliably collected. In a case where the opening area of each of Opl, Op2, and Op3 exceeds the above range, the above-described effect is saturated and there is a problem in that the size of the coating-collection unit 12 itself becomes too large. [OOSO] In addition, in the case of OpI>Op2, an air current in the duct 12a is rectified, and thus the blown-off excessive coating can be appropriately prevented from being reflected or flowing back and re-adhering to the steel sheet 8. In the case of Op3>0p2, as described above, the blown-off excessive coating can be reliably collected by the coating container 12b. That is, it is preferable that the relationship between Opl, Op2, and Op3 satisfies Op3>0p2 and Op1>0p2. COO5 I] In addition, as a result of the test, the following knowledge was obtained. It is preferable that an extension member for receiving the excessive coating that is directed to the outside of the inlet be provided in the inlet 12al of the duct 12a. FIG. 4 is a diagram illustrating a modified example in which the extension member is provided in the inlet 12al of the duct 12a of the coating-collection unit 12 and is a side view corresponding to FIG. 2. As illustrated in FIG. 4, the extension member 12d is disposed in the inlet 12al so as to be directed to the outside of the inlet 12al of the duct 12a and be concealed under the lower surface of the steel sheet 8. By providing the extension member 12d in the inlet 12al of the duct 12a, the excessive coating that is blown off the steel sheet 8 by the blowing-off unit 11 can be incorporated into the duct 12a. [0052] * In the coating collection test described above, the duct 12a and the coating container 12b in which the shape of each of the openings thereof is a circle are used. However, the shapes of the duct 12a and the coating container 12b are not limited to the above shape, and the shape of each of the openings thereof when seen in a facing view may be any of a circle, a rectangle, an ellipse, and a flat shape. [0053] In addition, in the coating collection test described above, a single duct 12a and a single coating container 12b are arranged to be provided for a single spray nozzle 1 la. However, the arrangement of the duct 12a and the coating container 12b is not. limited thereto, and in a range that satisfies the above-described conditions, for example, an arrangement in which two ducts 12a and a single coating container 12b are provided for two spray nozzles 1 la may be adopted. [0054] The device for producing a coated steel sheet of this embodiment described above will be summarized as follows. (1) The device for producing a coated steel sheet in this embodiment includes: the blowing-off unit 1 1 which sprays the gas onto and remove the coating film protrusion 9x which is excessive coating that accumulates along the side edge 8x of the steel sheet 8 that threads along the sheet threading direction C; and the coatingcollection unit 12 which collects the excessive coating removed by the blowing-off unit 1 1. The blowing-off unit 11 includes the spray nozzle 1 1 a which is directed in a direction from the inside to the outside in the sheet-width direction of the steel sheet 8 and directed toward the side edge 8x, and the gas supply member 1 lc which supplies the gas to the spray nozzle 1 la. The coating-collection unit 12 includes the duct 12a having the inlet 12al that receives the excessive coating and the outlei 12a2 that discharges the received excessive coating, and the coating container 12b having the opening 12bl that receives the excessive coating discharged from the outlet 12a2. In a case where the duct 12a is seen in the plan view, the outlet 12a2 is disposed to fit in and overlap the inside of the opening 12bl of the coating container 12b, and in a case where the duct 12a is seen in a side view, the gap 12c is provided between the outlet 12a2 and the opening 12bl of the coating container 12b. [005 51 (2) In addition, when the angle between the extension line 1 la1 of the center axis line of the spray nozzle I la and the projection line 11 a2 of the extension line 1 la1 on the surface of the steel sheet 8 is p in units of degrees O, the angle between the projection line 11 a2 and the sheet threading direction C of the steel sheet 8 in a case where the surface is seen in a facing view is a in units of degrees O, and the distance from the discharge port I la3 which is the tip end of the spray nozzle 11 a to the point that intersects the plane including the surface when seen along the extension line 1 la1 is d in units of mm, all the following Expressions A, B, and C are satisfied, and the discharge direction of the spray nozzle 11 a is disposed to be opposite to the sheet threading direction C of the steel sheet 8. 20° 60 60 .45 45 45 - SPRAY CONDITIONS OF GAS GAS TYPE AIR AIR AIR AIR AIR AIR AIR B (" > 45 45 45 30 60 45 - PRESSURE (MPa) 0.40 0.25 0.25 0.25 0.25 0.30 0.20 d (mm> 15 15 40 15 15 15 - s i n ~ ~ c o s p 0.6 1 0.6 1 0.50 0.6 1 0.35 0.7 1 - DISCHARGE FLOW RATE (rn3/~) 17.9 12.4 12.4 12.4 12.4 14.2 10.5 DISCHARGE FLOW VELOCITY 1 (m/s> 509.6 423.1 423.1 423.1 423.1 458.4 375.3 DISCHARGE FLQW VELOCITY 2 (m/s> 292.9 238.0 131.0 238.0 238.0 274.2 - [Document Type] [Claim I] CLAIMS A device for producing a coated steel sheet, comprising: a blowing-off unit which sprays a gas onto and remove an excessive coating that accumulates along a side edge of a steel sheet that threads aiong one direction; and a coating-collection unit which collects the excessive coating removed by the blowing-off unit, wherein the blowing-off unit includes a spray nozzle which is directed in a direction from an inside to an outside in a sheet-width direction of the steel sheet and directed toward the side edge, and a gas supply member which supplies the gas to the spray nozzle, the coating-collection unit includes a duct having an inlet that receives the excessive coating and an outlet that discharges the received excessive coating, and a coating container having an opening that receives the excessive coating discharged from the outlet, and in a case where the duct is seen in a plan view, the outlet is disposed to fit in and overlap an inside of the opening of the coating container, and in a case where the duct is seen in a side view, a gap is provided between the outlet and the opening of the coating container. [Claim 21 The device for producing a coated steel sheet according to Claim 1, wherein, when an angle between an extension line of a center axis line of the spray nozzle and a projection line of the extension line on a surface of the steel sheet is defined as P, an angle between the projection line and a sheet threading direction of the steel sheet in a case where the surface is seen in a facing view is defined as a, and a distance from a tip end of the spray nozzle to a point that intersects a plane including the surface when seen along the extension line is defined as d in units of rnm, all the following Expressions 1,2, and 3 are satisfied, and a discharge direction of the spray nozzle is disposed to be opposite to the sheet threading direction of the steel sheet. 20°Fa5700 . . .(Expression 1) 20°FP_<700 . . .(Expression 2) 10 mmFdi55 mm . . .(Expression 3) [Claim 31 The device for producing a coated steel sheet according to Claim 1, wherein a size of the gap in a side view is 60 mm or more and 100 mm or less. [Claim 41 The device for producing a coated steel sheet according to Claim 1, wherein a viscosity of the coating applied to the steel sheet is 700 mPa.sec or higher and 2000 mPasec or lower. [Claim 51 The device for producing a coated steel sheet according to Claim 1, wherein the blowing-off unit is adjusted so that a discharge flow rate of the gas discharged from the spray nozzle is 12 m3k or more and 20 m3k or less, a discharge flow velocity of the gas discharged from the spray nozzle at a position of 5 mm from a tip end of the spray nozzle in a discharge direction when seen along an extension line of a center axis line of the spray nozzle is 420 rnls or more and 520 m/s or less, and a discharge flow velocity of the gas discharged from the spray nozzle at a position of 5 mm from a point where the extension line intersects a plane including a surface of the steel sheet toward the spray nozzle when seen along the extension line of the center axis line of the spray nozzle is 130 rnls or more and 520 m/s or less. [Claim 61 The device for producing a coated steel sheet according to Claim 1, wherein the inlet of the duct is provided with an extension member which receives the excessive coating directed to an outside of the inlet. [Claim 71 The device for producing a coated steel sheet according to Claim 2, wherein the spray nozzle is disposed so that the discharge direction of the gas is along with the sheet threading direction when seen in the plan view. [Claim 81 The device for producing a coated steel sheet according to Claim 2, wherein the spray nozzle is disposed so as to further satisfy the following Expression 4. 0.1Isinacosfk50.9 . . .(Expression 4) [Claim 91 The device for producing a coated steel sheet according to Claim I, wherein a shape of a discharge port of the spray nozzle in a facing view is any of a rectangle, a circle, an ellipse, and a flat shape. [Claim 101 A method for producing a coated steel sheet, the method comprising: blowing off and removing an excessive coating that accumulates along a side edge of a steel sheet on which a coating is applied; and receiving and collecting the removed excessive coating by a coating container - via a duct having an inlet and an outlet, wherein an internal pressure of the duct is released from a gap between the outlet of the duct and an opening of the coating container. [Claim 1 I] The method for producing a coated steel sheet according to Claim 10, wherein a viscosity of the coating applied to the steel sheet is 700 mPa.sec or higher and 2000 mPasec or lower. Dated this 05th day of February, 2014 [SWATI PAHUJA] OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANT[S]