JP2018178146A - Gas wiping nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce equipment cost of a gas wiping nozzle.SOLUTION: A gas wiping nozzle is provided, which blows gas onto a steel strip pulled upward from a molten metal plating bath to adjust a coating thickness of molten metal film adhered onto a surface of the steel strip. The gas wiping nozzle includes: a first lip part and a second lip part which are provided opposing to each other and form therein a nozzle chamber into which the gas is introduced; and a slit formed, as a jetting port for the gas jetted out from the nozzle chamber, at an inner side of a steel strip-side end of the first lip part and a steel strip-side end of the second lip part. Between the first lip part and the second lip part, an abutting member is provided which abuts with the steel strip-side end of one of the first lip part and the second lip part, in a longitudinal direction of the end, and further, the abutting member defines the slit in a width direction.SELECTED DRAWING: Figure 7

Description

  The present invention relates to gas wiping nozzles.

  A continuous molten metal plating apparatus is an apparatus for plating a metal band represented by a steel band with a molten metal such as zinc. This continuous molten metal plating apparatus includes, as rolls disposed in a plating tank storing molten metal, a sink roll that changes the transport direction of the metal band, and a pair of support rolls that flatly correct the shape of the metal band. . The metal strip introduced obliquely in the plating bath is pulled up out of the plating bath while passing between a pair of support rolls while passing the transport direction vertically upward by the sink roll. . Thereafter, a gas is blown from the gas wiping nozzles disposed on both sides of the metal band to the surface of the metal band to adhere to the surface of the metal band and scrape off the extra molten metal pulled up, whereby the adhesion amount of molten metal (Hereinafter, also referred to as “area weight”) is adjusted.

  A slit extending in the width direction of the metal band is formed as an injection port of a gas jetted from the inside of the gas wiping nozzle at a tip end portion which is an end portion on the metal band side of the gas wiping nozzle. The gas wiping nozzle sprays a gas through the slit and sprays the gas against the surface of the metal band pulled up from the plating bath, thereby removing the excess molten metal adhering to the surface of the metal band. Scrape. The slits may be defined in the width direction, for example, by the tips of a pair of lip portions provided to face each other in the vertical direction.

  For example, in Patent Document 1, in order to inject a uniform amount of gas (pressure) in the width direction of the steel strip, the split slit members divided into upper and lower halves are fastened at the rear end through a shim and the slit of the gas nozzle assembled There is disclosed a technique in which a damper provided with a large number of nozzle holes between a flat gas injection port and a nozzle rear end is disposed, and a predetermined arrangement is adopted as the arrangement of the nozzle holes. In the gas nozzle, a slit-like gas injection port is formed by fastening the upper member and the lower member between opposing surfaces except for the center of the tip through a shim. Therefore, the gas injection port is defined in the width direction by the tips of the upper and lower members corresponding to the pair of lip portions.

Japanese Utility Model Application Publication No. 6-025355

  By the way, in recent years, for the purpose of improvement of productivity in molten metal plating of metal bands such as steel bands, speeding up of transport speed of metal bands is required. When the transport speed of the metal strip is increased, the amount of molten metal attached to the metal strip and lifted up increases, so that the melting is scraped off by gas wiping in order to control the coating weight to a desired value. A need may arise to increase the amount of metal. An increase in the amount of molten metal scraped off by gas wiping is achieved, in particular, by increasing the collision pressure of the gas against the metal band.

  For example, it is conceivable to bring the gas wiping nozzle close to the metal band in order to increase the collision pressure of the gas against the metal band. However, when the gas wiping nozzle is brought close to the metal band, the gas wiping nozzle may come in contact with the metal band. It is also conceivable to increase the pressure of the gas supplied to the gas wiping nozzle in order to increase the pressure of impact of the gas against the metal band. However, when the gas pressure supplied to the gas wiping nozzle is increased, the operation cost may increase due to the increase in the amount of gas used.

  Further, it is conceivable to narrow the width of the slit (hereinafter also referred to as a slit gap) in order to increase the amount of gas collision pressure against the metal band while avoiding the above problems. However, in the case where the slit gap is substantially constant from the rear end to the front end, by narrowing the slit gap, the increase in flow path resistance and the pressure at the outlet side of the slit become higher than atmospheric pressure. The pressure loss tends to increase due to the occurrence of Thereby, it may be difficult to increase the collision pressure of the gas against the metal band.

  Therefore, by setting the shape of the slit as the slit gap is expanded toward the outlet on the outlet side (hereinafter, also referred to as a Laval shape), it is possible to suppress the increase in the flow path resistance and the occurrence of underexpansion. Thereby, the collision pressure of the gas on the metal band can be effectively increased. Therefore, the amount of molten metal scraped off by gas wiping can be effectively increased.

  Here, the collision pressure of the gas against the metal band depends on the detailed shape of the slit. Also, the basis weight depends on the collision pressure of the gas against the metal band. Therefore, it may be necessary to optimize the shape of the slit in order to bring the coating weight close to the desired value. Specifically, in the case where the shape of the slit is a rabble shape, it may be necessary to optimize the shape of the portion expanded toward the outlet in the slit in order to make the weight per unit area close to a desired value. Here, when the slits formed in the gas wiping nozzle are defined in the width direction by the tips of the pair of lip portions, the respective lip portions are different from the respective lip portions in order to optimally adjust the shape of the slits. It may be necessary to replace the other lip with the shape, ie to replace the nozzle itself. Usually, multiple nozzle replacements are required to reach the optimal slit shape. Thereby, the equipment cost of the gas wiping nozzle can be increased. In addition, since the part which forms a slit in a lip | rip part is a part which can be mirror-finished, when adjusting the shape of a slit by adding the said part, it may become difficult to ensure dimensional accuracy. .

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved gas wiping nozzle capable of reducing the equipment cost of the gas wiping nozzle. It is to do.

  In order to solve the above problems, according to one aspect of the present invention, a film of a molten metal film attached to the surface of the steel strip is sprayed with a gas against the steel strip pulled upward from the molten metal plating bath. A gas wiping nozzle for adjusting the thickness, which is provided opposite to each other and which is provided with a first lip portion and a second lip portion which form a nozzle chamber to which the gas is introduced inside, and is jetted from the nozzle chamber A slit formed inside the steel strip side end of the first lip portion and the steel strip side end of the second lip portion as the gas discharge port; Between the first lip portion and the second lip portion, an end portion on one of the first lip portion and the second lip portion on the steel strip side and a longitudinal direction of the end portion An abutting member for abutting along the side of the Defining a slit in the width direction, the gas wiping nozzle is provided.

  The steel strip side of the portion defining the slit of the contact member may be provided with an inclined portion which inclines inward from the steel strip side toward the nozzle chamber.

  The contact member includes a first contact member and a second contact member, and the first contact member is an end portion of the first lip portion on the steel strip side and the end portion The second contact member may abut along a longitudinal direction, and an end of the second lip on the steel strip side may abut along a longitudinal direction of the end.

  The shapes of the inclined portions provided on the first contact member and the second contact member may be different from each other.

  As described above, according to the present invention, it is possible to reduce the equipment cost of the gas wiping nozzle.

It is a schematic diagram which shows an example of schematic structure of the continuous molten metal plating apparatus which concerns on embodiment of this invention. It is a perspective view showing an example of a gas wiping nozzle concerning a reference example. It is a disassembled perspective view which shows an example of the gas wiping nozzle which concerns on a reference example. It is sectional drawing which shows an example of the gas wiping nozzle which concerns on a reference example. It is a perspective view showing an example of the gas wiping nozzle concerning the embodiment of the present invention. It is a disassembled perspective view which shows an example of the gas wiping nozzle which concerns on the embodiment. It is a sectional view showing an example of the gas wiping nozzle concerning the embodiment. It is sectional drawing which shows an example of the gas wiping nozzle which concerns on a 1st modification. It is sectional drawing which shows an example of the gas wiping nozzle which concerns on a 2nd modification. It is sectional drawing which shows an example of the gas wiping nozzle which concerns on a 3rd modification. It is sectional drawing which shows an example of the gas wiping nozzle which concerns on a 4th modification.

  The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. In the present specification and the drawings, components having substantially the same functional configuration will be assigned the same reference numerals and redundant description will be omitted.

<1. Configuration of continuous molten metal plating apparatus>
First, the configuration of a continuous molten metal plating apparatus 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1: is a schematic diagram which shows an example of schematic structure of the continuous molten metal metal-plating apparatus 1 which concerns on this embodiment.

  As shown in FIG. 1, the continuous molten metal plating apparatus 1 continuously deposits molten metal on the surface of the steel strip 2 by immersing the steel strip 2 in the plating bath 3 filled with the molten metal. An apparatus for making the molten metal have a predetermined coating weight. The continuous molten metal plating apparatus 1 includes a plating tank 4, a snout 5, a sink roll 6, a pair of upper and lower support rolls 7 and 8, and a gas wiping nozzle 10.

  The steel strip 2 is an example of a metal strip to be subjected to a plating process with molten metal. Moreover, as a molten metal which comprises the plating bath 3, the single-piece | unit of Zn, Al, Sn, and Pb, or these alloys are illustrated, for example. Alternatively, the molten metal includes, in addition to these metals or alloys, non-metal elements such as Si and P, typical metal elements such as Ca, Mg and Sr, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, etc. Also, those containing a transition metal element of In the following description, molten zinc is used as the molten metal forming the plating bath 3, and the example in which the galvanized steel sheet is manufactured by adhering the molten zinc to the surface of the steel strip 2 will be described.

  The plating tank 4 stores a plating bath 3 made of molten metal. The upper end of the snout 5 is connected to, for example, the outlet side of the annealing furnace, and the lower end is immersed in the plating bath 3 and inclined. The sink roll 6 is disposed below the plating bath 3. The sink roll 6 has a larger diameter than the support rolls 7, 8. The sink roll 6 rotates clockwise as shown in the figure as the steel strip 2 is conveyed, and the conveying direction of the steel strip 2 introduced obliquely downward into the plating bath 3 through the snout 5 is the vertically upward direction. Change to

  The support rolls 7 and 8 are disposed above the sink roll 6 in the plating bath 3, are turned by the sink roll 6, and sandwich the steel strip 2 which is pulled upward in the vertical direction from both left and right sides. The support rolls 7 and 8 suppress the vibration of the steel strip 2 to be pulled up. Only one support roll 7 or 8 may be provided without pairing, or three or more support rolls may be provided. Alternatively, the arrangement of the support rolls 7 and 8 may be omitted. The top roll 9 is disposed above the plating bath 3 and above the sink roll 6. The top roll 9 is pulled up from the plating bath 3 in the vertical direction, and changes the transport direction of the steel strip 2 in which the basis weight of the molten metal is adjusted, to the unloading direction.

  The gas wiping nozzle 10 jets a gas such as air sprayed on the surface of the steel strip 2 in order to adjust the area weight of the molten metal relative to the steel strip 2. A gas compressed by a compressor (not shown) or the like is introduced into the gas wiping nozzle 10. The gas wiping nozzles 10 are disposed on both sides in the thickness direction of the steel strip 2 and are disposed above the support rolls 7 and 8 at a predetermined height from the bath surface of the plating bath 3. The gas jetted from the gas wiping nozzle 10 is sprayed on both sides of the steel strip 2 pulled up from the plating bath 3 in the vertical direction, and excess molten metal is scraped off. Thereby, the coating weight of the molten metal with respect to the surface of the steel strip 2 is adjusted to an appropriate amount, and the film thickness of the molten metal film is adjusted.

  Specifically, a nozzle chamber into which gas is introduced is formed in each of the gas wiping nozzles 10, and a steel strip is provided at the tip end of each of the gas wiping nozzles 10 on the steel strip 2 side. A slit extending in the width direction of 2 is formed. The gas introduced into the nozzle chamber is sprayed from the slit and sprayed to the steel strip 2. Thus, the slit functions as an injection port of the gas injected from the nozzle chamber.

  In the gas wiping nozzle 10 according to the present embodiment, an end portion of the one lip portion on the steel strip 2 side and a longitudinal direction of the end portion are provided between a pair of lip portions provided to face each other in the vertical direction. An abutting member that abuts is provided, and the slit is defined in the width direction by the abutting member. Thereby, the equipment cost of the gas wiping nozzle 10 can be reduced. Details of such a gas wiping nozzle 10 will be described later.

  The operation of the continuous molten metal plating apparatus 1 configured as described above will be described. In the continuous molten metal plating apparatus 1, the steel strip 2 is moved by a drive source (not shown), and the components in the apparatus are passed. The steel strip 2 is introduced obliquely downward into the plating bath 3 through the snout 5, and travels around the sink roll 6 so that the transport direction is changed to the upper side in the vertical direction. Then, the steel strip 2 passes through between the support rolls 7 and 8 and is lifted out of the plating bath 3. Thereafter, the excess molten metal adhering to the steel strip 2 is scraped off by the pressure of the gas blown from the gas wiping nozzle 10, and the adhesion amount of the molten metal on the surface of the steel strip 2 is adjusted to a predetermined coating weight Be done. As described above, the continuous molten metal plating apparatus 1 manufactures a molten metal plated steel plate of a predetermined coating weight by continuously immersing the steel strip 2 in the plating bath 3 and plating the molten metal. .

<2. Gas wiping nozzle according to reference example>
Subsequently, prior to the detailed description of the gas wiping nozzle 10 according to the present embodiment, the gas wiping nozzle 90 according to the reference example will be described with reference to FIGS. 2 to 4.

  FIG. 2 is a perspective view showing an example of a gas wiping nozzle 90 according to a reference example. FIG. 3 is an exploded perspective view showing an example of a gas wiping nozzle 90 according to a reference example. FIG. 4 is a cross-sectional view showing an example of a gas wiping nozzle 90 according to a reference example. Specifically, FIG. 4 is a cross-sectional view of the AA cross section shown in FIG. The A-A cross section is a cross section orthogonal to the longitudinal direction of the slit 960 of the gas wiping nozzle 90. Although the gas wiping nozzles 90 are disposed in a pair on both sides in the thickness direction of the steel strip 2 in the same manner as the gas wiping nozzle 10 according to the present embodiment, one of them is illustrated in FIGS. The illustration of the other is omitted. Moreover, in FIG.2 and FIG.3, illustration of the bolts 981, 982 mentioned later and the nuts 985, 986 is abbreviate | omitted. Moreover, below, the steel strip 2 side is demonstrated as a front end side.

  For example, as shown in FIGS. 2 to 4, the gas wiping nozzle 90 according to the reference example includes an upper lip 910 and a lower lip 920 provided to face each other in the vertical direction, and the upper lip 910 and the lower. A shim 930 sandwiched between the lip portion 920 and a tip end portion 911 which is an end portion of the upper lip portion 910 on the steel strip 2 side and an inner side of a tip portion 921 which is an end portion of the lower lip portion 920 on the steel strip 2 side And a slit 960 formed in

  The upper lip portion 910 and the lower lip portion 920 are provided to face each other as shown in FIG. 4 and form a nozzle chamber 991 and a gas header chamber 992 inside. The nozzle chamber 991 and the gas header chamber 992 are formed by the upper lip portion 910 and the lower lip portion 920 respectively on the front end side and the rear end side of the gas wiping nozzle 90, and provided on the upper lip portion 910 and the lower lip portion 920, respectively. The communication holes 913 and 923 communicate with each other. A gas is introduced into the gas header chamber 992 from the outside, and the gas is introduced into the nozzle chamber 991 through the communication holes 913 and 923.

  In addition, the upper lip portion 910 and the lower lip portion 920 are fixed in a state in which the shim 930 is sandwiched in the vertical direction. The upper lip portion 910, the lower lip portion 920, and the shim 930 are fixed to each other, for example, by screw fastening with bolts 981 and 982 and nuts 985 and 986 in the vertical direction. Specifically, the upper lip portion 910, the lower lip portion 920, and the shim 930 are fixed in the vertical direction by a bolt 982 and a nut 986 at a position on the rear end side of the gas header chamber 992 in the gas wiping nozzle 90. Further, the upper lip 910, the lower lip 920, and the shim 930 are fixed at positions in the gas wiping nozzle 90 between the nozzle chamber 991 and the gas header chamber 992 by bolts 981 and nuts 985 in the vertical direction.

  The shims 930 abut on portions of the respective lip portions except for the center side of the tip. Specifically, the shim 930 abuts on a portion of the upper lip portion 910 excluding the central side of the tip end portion 911 and abuts on a portion of the lower lip portion 920 excluding the central side of the tip end portion 921. Thus, a gap corresponding to the thickness of the shim 930 can be provided between the tip portion 911 of the upper lip portion 910 and the tip portion 921 of the lower lip portion 920. Therefore, as shown in FIGS. 2 and 4, a slit 960 is formed inside the tip portion 911 of the upper lip portion 910 and the tip portion 921 of the lower lip portion 920 as a jet port of gas jetted from the nozzle chamber 991. Ru. Specifically, the slits 960 extend in the width direction of the steel strip 2.

  The slit 960 according to the reference example is defined in the width direction by a tip end 911 of the upper lip portion 910 and a tip end 921 of the lower lip portion 920 as shown in FIG. Further, as shown in FIG. 3, the shim 930 has a pair of side extending portions 933 extending from the rear end side to the front end side on both end sides in the width direction of the steel strip 2. Thereby, the slit 960 is longitudinally defined by the tip of the pair of side extending portions 933.

  Specifically, the slit 960 has a Laval shape in which the slit gap is expanded toward the outlet on the tip side which is the outlet side in order to effectively increase the collision pressure of the gas to the steel strip 2. For example, on the distal end side of the portion defining the slits 960 of each lip portion, an inclined portion which inclines inward from the distal end side toward the nozzle chamber 991 is provided. Specifically, as shown in FIG. 4, on the lower end of the lower end portion 911 which is a portion defining the slit 960 of the upper lip portion 910, the lower lip is inclined downward from the front end toward the nozzle chamber 991. An inclined portion 915 is provided. In addition, on the tip end side of the upper portion of the tip end portion 921 which is a portion that defines the slit 960 of the lower lip portion 920, a sloped portion 925 that inclines upward from the tip end toward the nozzle chamber 991 is provided. Thus, the shape of the slit 960 can be a Laval shape.

  The shapes of the tip portion 911 of the upper lip portion 910 and the tip portion 921 of the lower lip portion 920 are, for example, vertically symmetrical with each other. In that case, the shape of the portion which spreads toward the outlet in the slit 960 is vertically symmetrical.

  Specifically, the shape of the rear end side, which is the inlet side of the slit 960, is basically a linear shape in which the slit gap is substantially constant. More specifically, the rear end side of the lower end portion 911 of the upper lip portion 910 and the rear end side of the upper portion of the front end portion 921 of the lower lip portion 920 are basically substantially parallel to each other. By making the shape of the slit 960 into a Laval shape, the slit gap W2 at the outlet can be enlarged compared to the slit gap W1 at the inlet. The shape of the portion expanding toward the outlet in the slit 960 is defined, for example, by the slit gap W2 at the outlet, the slit gap W1 at the inlet, and the length L1 of each inclined portion in the direction from the tip side to the nozzle chamber 991 side. Be done. The direction from the tip side toward the nozzle chamber 991 is a direction orthogonal to the width direction of the slit 960.

  Here, as described above, it may be necessary to optimize the shape of the slit 960 in order to bring the basis weight close to a desired value. Specifically, there may be a need to optimize the shape of the portion that expands in the slit 960 towards the outlet. In the gas wiping nozzle 90 according to the reference example, the slit 960 is defined in the width direction by the tip 911 of the upper lip 910 and the tip 921 of the lower lip 920. Therefore, in order to adjust the shape of the slits 960, it may be necessary to replace each lip with another lip having a shape different from that of each lip.

  Specifically, by replacing the lip portion, each of the slit gap W2 at the outlet, the slit gap W1 at the inlet, and the length L1 of each inclined portion in the direction from the tip side toward the nozzle chamber 991 is adjusted As a result, the shape of the slit 960 is adjusted. Thus, in the reference example, since it may be necessary to replace the lip to optimize the shape of the slit 960, the equipment cost of the gas wiping nozzle 90 may be increased.

<3. Gas wiping nozzle according to the present embodiment>
Subsequently, the gas wiping nozzle 10 according to the present embodiment will be described with reference to FIGS. 5 to 7.

  FIG. 5 is a perspective view showing an example of the gas wiping nozzle 10 according to the present embodiment. FIG. 6 is an exploded perspective view showing an example of the gas wiping nozzle 10 according to the present embodiment. FIG. 7 is a cross-sectional view showing an example of the gas wiping nozzle 10 according to the present embodiment. Specifically, FIG. 7 is a cross-sectional view of the cross section B-B shown in FIG. The B-B cross section is a cross section orthogonal to the longitudinal direction of the slit 160 of the gas wiping nozzle 10. In addition, although the gas wiping nozzle 10 is arranged in a pair on both sides in the thickness direction of the steel strip 2 as described above, one of them is illustrated in FIGS. 5 to 7 and the illustration of the other is omitted. ing. Further, in FIG. 5 and FIG. 6, illustration of bolts 181 and 182 and nuts 185 and 186, which will be described later, is omitted.

  For example, as shown in FIGS. 5 to 7, the gas wiping nozzle 10 according to the present embodiment includes an upper lip portion 110 and a lower lip portion 120 which are provided to face each other in the vertical direction, the upper lip portion 110, and the like. The upper shim 140, the inner shim 130, and the lower shim 150 which are sandwiched between the lower lip portion 120 and the steel strip 2 of the tip portion 111 and the lower lip portion 120 which are ends of the upper lip portion 110 on the steel strip 2 side. And Slit 160 formed inside tip part 121 which is a side end.

  As shown in FIG. 7, the upper lip portion 110 and the lower lip portion 120 are provided to face each other, and form a nozzle chamber 191 and a gas header chamber 192 inside. The upper lip portion 110 and the lower lip portion 120 correspond to a first lip portion and a second lip portion according to the present invention, which are provided to face each other and form a nozzle chamber 191 into which gas is introduced.

  The nozzle chamber 191 and the gas header chamber 192 are respectively formed on the front end side and the rear end side of the gas wiping nozzle 10 by the upper lip portion 110 and the lower lip portion 120. Specifically, on the front end side and the rear end side of the lower portion of the upper lip portion 110, concave portions respectively forming the upper portion of the nozzle chamber 191 and the upper portion of the gas header chamber 192 are formed. On the other hand, on the front end side and the rear end side of the upper portion of the lower lip portion 120, concave portions respectively forming the lower portion of the nozzle chamber 191 and the lower portion of the gas header chamber 192 are formed. The nozzle chamber 191 and the gas header chamber 192 are formed by the upper lip portion 110 and the lower lip portion 120 being fixed via the upper shim 140, the inner shim 130, and the lower shim 150 so that the corresponding recesses are joined. Be done.

  The upper lip portion 110 and the lower lip portion 120 are substantially parallel to each other on the rear end side of the gas wiping nozzle 10, for example, as shown in FIG. Therefore, the dimension in the vertical direction of the gas header chamber 192 is substantially constant from the rear end side to the front end side. On the other hand, on the tip side of the gas wiping nozzle 10, the upper lip portion 110 and the lower lip portion 120 approach each other as they go to the tip side. Therefore, the dimension in the vertical direction of the nozzle chamber 191 becomes shorter toward the tip side.

  A communication hole 113 and a communication hole 123 penetrating from the rear end side to the front end side are provided in portions of the upper lip portion 110 and the lower lip portion 120 between the nozzle chamber 191 and the gas header chamber 192, respectively. Thus, the nozzle chamber 191 and the gas header chamber 192 are communicated with each other by the communication holes 113 and 123. Specifically, a plurality of communication holes 113 and communication holes 123 are provided along the width direction of the steel strip 2.

  At the rear end side of the gas wiping nozzle 10, a gas header chamber 192 is communicated with the outside, and an introduction hole (not shown) for introducing a gas into the gas header chamber 192 is provided. For example, at the rear end side of the upper lip portion 110, a conduction hole is vertically penetrated. The gas introduced into the gas header chamber 192 is introduced into the nozzle chamber 191 via the communication holes 113 and 123. Specifically, the gas header chamber 192 functions as a gas header, and the gas introduced into the gas header chamber 192 is rectified by passing through the communication holes 113 and 123 and is introduced into the nozzle chamber 191. Further, the nozzle chamber 191 functions as a pressure equalizing chamber, and the gas introduced into the nozzle chamber 191 is sprayed at a uniform pressure over the entire longitudinal direction of the slit 160 described later.

  Further, the upper lip portion 110 and the lower lip portion 120 are fixed in a state of sandwiching the upper shim 140, the inner shim 130, and the lower shim 150 in the vertical direction. Specifically, the upper shim 140 is below and adjacent to the upper lip 110, the lower shim 150 is above and adjacent to the lower lip 120, and the middle shim 130 is between the upper shim 140 and the lower shim 150. Intervened in between. The upper lip portion 110, the lower lip portion 120, and the shims are fixed to each other, for example, by screwing with bolts 181 and 182 and nuts 185 and 186 in the vertical direction. Specifically, the upper lip portion 110, the lower lip portion 120, and the shims are fixed in the vertical direction by the bolt 182 and the nut 186 at a position on the rear end side of the gas header chamber 192 in the gas wiping nozzle 10. Further, the upper lip portion 110, the lower lip portion 120, and the shims are fixed at positions in the gas wiping nozzle 10 between the nozzle chamber 191 and the gas header chamber 192 in the vertical direction by bolts 181 and nuts 185.

  The upper shim 140 is provided between the upper lip portion 110 and the lower lip portion 120 and abuts on the upper lip portion 110. Specifically, the upper shim 140 abuts on the distal end portion 111 of the upper lip portion 110 and the longitudinal direction of the distal end portion 111. For example, as shown in FIG. 6, the upper shim 140 has a pair of side extension parts 143 extending from the rear end side to the front end side on both end sides in the width direction of the steel strip 2. Further, on the tip end side of the upper shim 140, the tip end portions of the pair of side extension portions 143 are connected, and a tip extension portion 141 extending along the width direction of the steel strip 2 is provided. The distal end extension portion 141 of the upper shim 140 abuts on the distal end portion 111 of the upper lip portion 110 and the longitudinal direction of the distal end portion 111.

  The lower shim 150 is provided between the upper lip portion 110 and the lower lip portion 120 and abuts on the lower lip portion 120. Specifically, the lower shim 150 abuts on the distal end portion 121 of the lower lip portion 120 and the longitudinal direction of the distal end portion 121. For example, as shown in FIG. 6, the lower shim 150 has a pair of side extension portions 153 extending from the rear end side to the front end side on both end sides of the steel strip 2 in the width direction. Further, on the tip end side of the lower shim 150, tip end extending portions 151 are provided which connect the tip end portions of the pair of side extension portions 153 and extend along the width direction of the steel strip 2. The distal end extension portion 151 of the lower shim 150 abuts on the distal end portion 121 of the lower lip portion 120 and the longitudinal direction of the distal end portion 121.

  Thus, the upper shim 140 and the lower shim 150 are provided between the upper lip portion 110 and the lower lip portion 120, and one end of the upper lip portion 110 and the lower lip portion 120 on the steel strip 2 side is And a contact member according to the present invention, which contacts along the longitudinal direction of the tip end. Specifically, the upper shim 140 is provided between the upper lip portion 110 and the lower lip portion 120, and a tip end portion 111 which is an end portion on the steel strip 2 side of the upper lip portion 110 and a length of the tip end portion 111 It corresponds to a first contact member that is a contact member that contacts along a direction. Further, the lower shim 150 is provided between the upper lip portion 110 and the lower lip portion 120, and extends in the longitudinal direction of a tip end portion 121 which is an end portion of the lower lip portion 120 on the steel strip 2 side and the tip end portion 121. It corresponds to the 2nd contact member which is the contact member which contacts. As described above, the contact member is the first contact member and the lower lip portion 120 that contact the tip portion 111 that is the end portion on the steel strip 2 side of the upper lip portion 110 and the tip portion 111 in the longitudinal direction. And a second abutting member that abuts along the longitudinal direction of the distal end portion 121. The distal end portion 121 is an end portion on the steel strip 2 side.

  The inner shim 130 abuts on a portion of the upper shim 140 and the lower shim 150 excluding the respective tip extension portions. Specifically, the inner shim 130 contacts the portion of the upper shim 140 excluding the tip extension 141 and contacts the portion of the lower shim 150 excluding the tip extension 151. Thus, a gap corresponding to the thickness of the inner shim 130 can be provided between the tip extension 141 of the upper shim 140 and the tip extension 151 of the lower shim 150. Therefore, as shown in FIGS. 5 and 7, a slit 160 is formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 as a jet of gas injected from the nozzle chamber 191. Ru. Specifically, the slits 160 extend in the width direction of the steel strip 2.

  In the gas wiping nozzle 10 according to the present embodiment, as described above, one end of the upper lip portion 110 and the lower lip portion 120 on the side of the steel strip 2 is disposed between the upper lip portion 110 and the lower lip portion 120. An upper shim 140 and a lower shim 150 are provided as an abutting member that abuts in the longitudinal direction of the distal end portion that is a portion and the distal end portion. Thereby, the slit 160 is defined in the width direction by the upper shim 140 and the lower shim 150 which are abutment members. Specifically, as shown in FIG. 7, the slit 160 according to the present embodiment is defined in the width direction by the tip extension 141 of the upper shim 140 and the tip extension 151 of the lower shim 150. Further, as shown in FIG. 6, the inner shim 130 has a pair of side extending portions 133 extending from the rear end side to the front end side on both end sides in the width direction of the steel strip 2. Thereby, the slit 160 is defined in the longitudinal direction by the tip of the pair of side extending portions 133.

  Specifically, in order to effectively increase the collision pressure of the gas to the steel strip 2, the slit 160 has a Laval shape in which the slit gap is expanded toward the outlet on the tip side which is the outlet side. For example, on the tip end side of the portion defining the slits 160 of each of the upper shim 140 and the lower shim 150 which are the abutting members, a sloped portion is provided which inclines inward from the tip side toward the nozzle chamber 191 side. Specifically, as shown in FIG. 7, at the lower end of the lower end extension 141 that is the portion defining the slit 160 of the upper shim 140, the lower end is directed from the tip toward the nozzle chamber 191. An inclined slope 145 is provided. Further, on the tip end side of the upper portion of the tip extension portion 151 which is a portion that defines the slit 160 of the lower shim 150, an inclined portion 155 which inclines upward from the tip end toward the nozzle chamber 191 is provided. Thereby, the shape of the slit 160 can be made to be a Laval shape. The inclined portion 145 and the inclined portion 155 may be flat or curved. In other words, the cross-sectional shape of the inclined portion 145 and the inclined portion 155 in the B-B cross section may be a straight line or a curved line.

  The shape of the upper shim 140 and the shape of the lower shim 150 are, for example, vertically symmetrical with each other. Specifically, the shape of the tip end extension portion 141 of the upper shim 140 and the shape of the tip end extension portion 151 of the lower shim 150 are vertically symmetrical with each other. In this case, the shape of the portion of the slit 160 which is expanded toward the outlet is vertically symmetrical.

  Specifically, the shape of the rear end side, which is the inlet side of the slit 160, is basically a linear shape in which the slit gap is substantially constant. More specifically, the rear end side in the lower part of the tip extension part 141 of the upper shim 140 and the rear end side in the upper part of the tip extension part 151 of the lower shim 150 are basically substantially parallel to each other. By making the shape of the slit 160 be a Laval shape, the slit gap W2 at the outlet can be enlarged compared to the slit gap W1 at the inlet. The shape of the portion expanded toward the outlet in the slit 160 is defined, for example, by the slit gap W2 at the outlet, the slit gap W1 at the inlet, and the length L1 of each inclined portion in the direction from the tip side to the nozzle chamber 191 side. Be done. The direction from the tip end toward the nozzle chamber 191 is a direction orthogonal to the width direction of the slit 160.

  The values of the slit gap W1 at the inlet, the slit gap W2 at the outlet, and the length L1 are not particularly limited. For example, the slit gap W1 at the inlet may be set to about 1 mm to 2 mm. The difference between the slit gap W2 at the outlet and the slit gap W1 at the inlet may be set to about 1 mm to 3 mm. The length L1 may be set to about 3 mm to 10 mm.

  As described above, in the present embodiment, the front end portion which is the end portion on one steel strip 2 side of the upper lip portion 110 and the lower lip portion 120 between the upper lip portion 110 and the lower lip portion 120. An upper shim 140 and a lower shim 150 are provided as abutment members abutting along the longitudinal direction of the tip. Thereby, the slits 160 formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 are defined in the width direction by the upper shim 140 and the lower shim 150 which are abutment members. . Therefore, the shape of the slit 160 can be adjusted by replacing each shim of the upper shim 140 and the lower shim 150 with a shim having a shape different from that of each shim. In addition, since each shim of the upper shim 140 and the lower shim 150 has a small and simple shape as compared with each lip portion, the shape of the slit 160 is formed by additionally processing the portion defining the slit 160 of each shim. Is relatively easy to ensure dimensional accuracy. Therefore, the shape of the slits 160 can also be adjusted by additionally processing the portion defining the slits 160 of each shim.

  More specifically, the slit gap W2 at the outlet, the slit gap W1 at the inlet, and each inclined portion in the direction from the tip side toward the nozzle chamber 191 can be changed by replacing each shim or performing additional processing on each shim. Each of the lengths L1 can be adjusted. Thereby, the shape of the slit 160 can be adjusted. As described above, according to the present embodiment, since the shape of the slit 160 can be adjusted without replacing the lip portion, the shape of the slit 160 can be optimized relatively inexpensively. Therefore, the equipment cost of the gas wiping nozzle 10 can be reduced.

  In addition, in the plating process step by the continuous molten metal plating apparatus 1, plating may adhere to the inner circumferential surface of the slit 160. In such a case, it may be necessary to remove the deposited plating by subjecting the inner circumferential surface of the slit 160 to processing such as cutting, polishing, grinding or the like. In other words, it may be necessary to apply processing such as cutting, grinding, grinding or the like to the portion defining the slit 160 in the gas wiping nozzle 10. According to the present embodiment, as described above, in the case where the portion defining the slits 160 of each shim is additionally machined, dimensional accuracy can be relatively easily secured. Therefore, the process for removing the plating adhering to the inner circumferential surface of the slit 160 can be easily performed.

<4. Modified example>
Subsequently, a gas wiping nozzle according to each modification will be described with reference to FIGS. 8 to 11.

[4-1. First Modified Example]
First, a gas wiping nozzle 20 according to a first modified example will be described with reference to FIG. In the gas wiping nozzle 20 according to the first modification, unlike the gas wiping nozzle 10 described above, the shape of the upper shim 240 and the shape of the lower shim 250 are vertically asymmetric to each other.

  FIG. 8 is a cross-sectional view showing an example of a gas wiping nozzle 20 according to a first modification. Specifically, FIG. 8 is a cross-sectional view of a cross section corresponding to the B-B cross section shown in FIG. 5, which is orthogonal to the longitudinal direction of the slit 260 of the gas wiping nozzle 20. Although the gas wiping nozzles 20 are disposed in a pair on both sides in the thickness direction of the steel strip 2 in the same manner as the gas wiping nozzles 10 described above, one of them is illustrated in FIG. It is omitted.

  For example, as shown in FIG. 8, the gas wiping nozzle 20 according to the first modification includes an upper lip portion 110 and a lower lip portion 120 which are provided to face each other in the vertical direction, and the upper lip portion 110 and the lower portion. An upper shim 240, a middle shim 130, and a lower shim 250 which are sandwiched between the lip 120 and a slit 260 formed inside the tip 111 of the upper lip 110 and the tip 121 of the lower lip 120; It is comprised including.

  The upper lip portion 110 and the lower lip portion 120 are fixed in a state of sandwiching the upper shim 240, the inner shim 130, and the lower shim 250 in the vertical direction, as shown in FIG.

  The upper shim 240 has a pair of side extension parts extending from the rear end side to the front end side on both end sides of the steel strip 2 in the width direction. Further, on the tip side of the upper shim 240, a tip extension portion 241 is provided which connects the tip portions of the pair of side extension portions and extends along the width direction of the steel strip 2. The distal end extension portion 241 of the upper shim 240 abuts on the distal end portion 111 of the upper lip portion 110 and the longitudinal direction of the distal end portion 111.

  The lower shim 250 also has a pair of side extension parts extending from the rear end side to the front end side on both end sides of the steel strip 2 in the width direction. In addition, on the tip side of the lower shim 250, a tip extension portion 251 that extends along the width direction of the steel strip 2 is provided to connect the tip portions of the pair of side extension portions. The distal end extension portion 251 of the lower shim 250 abuts on the distal end portion 121 of the lower lip portion 120 and the longitudinal direction of the distal end portion 121.

  As described above, in the first modification, the upper shim 240 is provided as a first contact member between the upper lip portion 110 and the lower lip portion 120, and the lower shim 250 is provided as a second contact member. Is provided.

  In addition, the slits 260 are formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120, and as shown in FIG. It is defined in the width direction by the tip extension 251. At the tip end side of the lower portion of the tip extension portion 241 which is a portion that defines the slit 260 of the upper shim 240, an inclined portion 245 that inclines downward from the tip end toward the nozzle chamber 191 is provided. Further, on the tip end side of the upper portion of the tip extension portion 251 which is a portion defining the slit 260 of the lower shim 250, an inclined portion 255 is provided which inclines upward from the tip end toward the nozzle chamber 191 side. Therefore, the slit 260 has a Laval shape.

  According to the gas wiping nozzle 20 according to the first modification, the slit 260 is defined in the width direction by the upper shim 240 and the lower shim 250 which are abutment members, so the gas wiping nozzle according to the embodiment described above An effect similar to 10 can be achieved.

  Here, in the gas wiping nozzle 20 according to the first modification, as described above, the shape of the upper shim 240 and the shape of the lower shim 250 are vertically asymmetric with each other. Specifically, in the first modification, the shapes of the slopes provided on the upper shim 240 and the lower shim 250 are different from each other. More specifically, the shape of the sloped portion 245 provided in the tip end extension portion 241 of the upper shim 240 and the shape of the sloped portion 255 provided in the tip end extension portion 251 of the lower shim 250 are different from each other.

  For example, as shown in FIG. 8, the nozzle chamber 191 from the tip end side of each of the inclined portion 245 provided in the tip extension portion 241 of the upper shim 240 and the slope portion 255 provided in the tip extension portion 251 of the lower shim 250. The inclination angle θ1 and the inclination angle θ2 with respect to the direction toward the side may be different from each other. The thicknesses of the upper shim 240 and the lower shim 250 may be different from each other, and the lengths L1 of the respective inclined portions in the direction from the tip side toward the nozzle chamber 191 may be substantially the same.

  In the plating treatment with molten metal, as described above, the excess molten metal is scraped off by spraying the gas sprayed from the gas wiping nozzle 20 against the steel strip 2 pulled up vertically upward from the plating bath 3 Be Therefore, while excess molten metal adheres to the part below the location to which gas is sprayed in the steel strip 2, the excess molten metal does not adhere to the upper part from the said location. As described above, in the vicinity of the portion of the steel strip 2 to which the gas is blown, the adhesion amount of the molten metal has an uneven distribution in the vertical direction. Here, according to the first modification, since the shapes of the inclined portions respectively provided to the upper shim 240 and the lower shim 250 are different from each other, the shape of the portion expanded in the slit 260 toward the outlet is vertically asymmetric. Can. Thereby, the flow of the gas injected from the gas wiping nozzle 20 can be appropriately adjusted according to the distribution of the adhesion amount of the molten metal in the vertical direction.

[4-2. Second Modified Example]
Next, a gas wiping nozzle 30 according to a second modification will be described with reference to FIG. Unlike the gas wiping nozzle 10 described with reference to FIGS. 5 to 7, in the gas wiping nozzle 30 according to the second modified example, the inner shim is not provided.

  FIG. 9 is a cross-sectional view showing an example of a gas wiping nozzle 30 according to a second modification. Specifically, FIG. 9 is a cross-sectional view of a cross section corresponding to the B-B cross section shown in FIG. 5, which is orthogonal to the longitudinal direction of the slit 360 of the gas wiping nozzle 30. In addition, although the gas wiping nozzle 30 is arranged in a pair on both sides in the thickness direction of the steel strip 2 as in the gas wiping nozzle 10 described above, one of them is illustrated in FIG. It is omitted.

  For example, as shown in FIG. 9, a gas wiping nozzle 30 according to a second modification includes an upper lip portion 110 and a lower lip portion 120 provided opposite to each other in the vertical direction, the upper lip portion 110 and the lower portion. The upper shim 140 and the lower shim 350 which are sandwiched between the lip 120 and the slit 360 formed inside the tip 111 of the upper lip 110 and the tip 121 of the lower lip 120 Ru.

  The upper lip portion 110 and the lower lip portion 120 are fixed in a state of sandwiching the upper shim 140 and the lower shim 350 in the vertical direction, as shown in FIG. In the second modification, specifically, the upper shim 140 is adjacent to the upper lip 110 at the lower side, and the lower shim 350 is adjacent to the lower lip 120 at the upper side. 350 are adjacent to each other.

  Similar to the gas wiping nozzle 10 described above, the upper shim 140 has a pair of side extension parts 143 extending from the rear end side to the front end side on both end sides in the width direction of the steel strip 2. Further, on the tip end side of the upper shim 140, the tip end portions of the pair of side extension portions 143 are connected, and a tip extension portion 141 extending along the width direction of the steel strip 2 is provided. The distal end extension portion 141 of the upper shim 140 abuts on the distal end portion 111 of the upper lip portion 110 and the longitudinal direction of the distal end portion 111.

  Lower shim 350 has a pair of side extension parts which extend from the rear end side to the front end side on both end sides in the width direction of steel strip 2. Further, on the tip end side of the lower shim 350, a tip extension portion 351 is provided which connects the tip end portions of the pair of side extension portions and extends along the width direction of the steel strip 2. The distal end extension portion 351 of the lower shim 350 abuts on the distal end portion 121 of the lower lip portion 120 and the longitudinal direction of the distal end portion 121.

  As described above, in the second modification, the upper shim 140 is provided as a first contact member between the upper lip portion 110 and the lower lip portion 120, and the lower shim 350 is provided as a second contact member. Is provided.

  In the second modification, the upper portion 357 of the lower shim 350 abuts on a portion of the upper shim 140 excluding the tip extension portion 141. For example, the lower shim 350 is obtained by integrating the lower shim 150 and the inner shim 130 in the gas wiping nozzle 10 described above. In that case, the upper portion 357 of the lower shim 350 corresponds to the middle shim 130, and the portion of the lower shim 350 excluding the upper portion 357 corresponds to the lower shim 150. The lower portion between the tip extension 141 of the upper shim 140 and the tip extension 351 of the lower shim 350 is brought about by the abutment of the upper portion 357 of the lower shim 350 with the portion of the upper shim 140 excluding the tip extension 141. A gap can be provided according to the thickness of the upper portion 357 of the shim 350. Therefore, as shown in FIG. 9, a slit 360 is formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 as a jet port of gas jetted from the nozzle chamber 191.

  Further, as shown in FIG. 9, the slit 360 is defined in the width direction by the tip extension 141 of the upper shim 140 and the tip extension 351 of the lower shim 350. Further, on the tip end side of the upper portion of the tip extension portion 351 which is a portion that defines the slit 360 of the lower shim 350, an inclined portion 355 that inclines upward from the tip end toward the nozzle chamber 191 is provided. Thus, the slit 360 has a Laval shape. The shape of the tip extension portion 141 of the upper shim 140 and the shape of the tip extension portion 351 of the lower shim 350 may be vertically symmetrical with each other.

  According to the gas wiping nozzle 30 according to the second modification, the slit 360 is defined in the width direction by the upper shim 140 and the lower shim 350 which are abutment members, so the gas wiping nozzle according to the embodiment described above An effect similar to 10 can be achieved.

  As described above, the gas wiping nozzle 30 according to the second modification corresponds to an example in which the lower shim 150 and the inner shim 130 are integrally formed in the gas wiping nozzle 10 described above. Specifically, in the second modification, the lower shim 350 has a gap between the tip extensions of the upper shim 140 and the lower shim 150, which is a function of the inner shim 130 in the gas wiping nozzle 10 described above. It has a function to provide. Thereby, the number of parts constituting the gas wiping nozzle can be reduced.

  The upper shim 140 and the inner shim 130 may be integrally configured in the gas wiping nozzle 10 described above, and the upper shim 140 may have the above-described function of the inner shim 130 in the gas wiping nozzle 10 described above. In that case, a member obtained by integrating the upper shim 140 and the middle shim 130 corresponds to a first contact member. Also in such a case, the same effect as that of the second modification described above can be obtained.

[4-3. Third Modified Example]
Next, with reference to FIG. 10, a gas wiping nozzle 40 according to a third modification will be described. Unlike the gas wiping nozzle 10 described with reference to FIGS. 5 to 7, the upper shim is not provided in the gas wiping nozzle 40 according to the third modification.

  FIG. 10 is a cross-sectional view showing an example of a gas wiping nozzle 40 according to a third modification. Specifically, FIG. 10 is a cross-sectional view of a cross section corresponding to the B-B cross section shown in FIG. 5 which is orthogonal to the longitudinal direction of the slit 460 of the gas wiping nozzle 40. Although the gas wiping nozzles 40 are disposed in a pair on both sides in the thickness direction of the steel strip 2 in the same manner as the gas wiping nozzles 10 described above, one of them is illustrated in FIG. It is omitted.

  For example, as shown in FIG. 10, a gas wiping nozzle 40 according to a third modification includes an upper lip portion 110 and a lower lip portion 120 which are provided to face each other in the vertical direction, and the upper lip portion 110 and the lower portion. Inner shim 130 and lower shim 150 sandwiched between lip 120 and slit 460 formed inside tip 111 of upper lip 110 and tip 121 of lower lip 120; Ru.

  The upper lip portion 110 and the lower lip portion 120 are fixed in a state in which the middle shim 130 and the lower shim 150 are sandwiched in the vertical direction, as shown in FIG. In the third modification, specifically, the middle shim 130 is adjacent to the upper lip 110 at the lower side, and the lower shim 150 is upper to the lower lip 120, and the inner shim 130 and the lower shim 150 are adjacent to each other.

  The lower shim 150 has a pair of side extension parts 153 extending from the rear end side to the front end side on both end sides in the width direction of the steel strip 2 similarly to the gas wiping nozzle 10 described above. Further, on the tip end side of the lower shim 150, the tip end portions of the pair of side extension portions 153 are connected, and a tip extension portion 151 extending along the width direction of the steel strip 2 is provided. The distal end extension portion 151 of the lower shim 150 abuts on the distal end portion 121 of the lower lip portion 120 and the longitudinal direction of the distal end portion 121.

  Thus, in the third modification, the lower shim 150 is provided between the upper lip portion 110 and the lower lip portion 120 as a second contact member.

  In the third modification, the inner shim 130 abuts on a portion of the upper lip portion 110 excluding the center side of the tip end portion 111 and abuts on a portion of the lower shim 150 excluding the tip extension portion 151. Thus, a gap corresponding to the thickness of the inner shim 130 can be provided between the tip end portion 111 of the upper lip portion 110 and the tip extension portion 151 of the lower shim 150. Therefore, as shown in FIG. 10, a slit 460 is formed on the inside of the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 as a jet port of gas jetted from the nozzle chamber 191.

  Further, as shown in FIG. 10, the slit 460 is defined in the width direction by the tip end portion 111 of the upper lip portion 110 and the tip extension portion 151 of the lower shim 150. Here, on the tip end side of the upper portion of the tip extension portion 151 which is a portion defining the slit 460 of the lower shim 150, as described above, the inclined portion which inclines upward from the tip end toward the nozzle chamber 191 side 155 are provided. Hence, the slits 460 have a Laval shape.

  As described above, the gas wiping nozzle 40 according to the third modification corresponds to an example in which the upper shim 140 is omitted from the configuration of the gas wiping nozzle 10 described above. Further, in the third modified example, as described above, the slit 460 formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 is the tip portion 111 of the upper lip portion 110 and It is defined in the width direction by the lower shim 150 which is an abutting member. Therefore, the shape of the slit 460 can be adjusted by replacing the lower shim 150 or performing additional processing on the lower shim 150. Thus, according to the gas wiping nozzle 40 according to the third modification, as in the gas wiping nozzle 10 according to the embodiment described above, the shape of the slit 460 can be adjusted without replacing the lip portion. As such, the shape of the slit 460 can be optimized relatively inexpensively. Therefore, the equipment cost of the gas wiping nozzle can be reduced.

  Thus, between the upper lip portion 110 and the lower lip portion 120, the tip portion which is the end portion on the side of the steel strip 2 of one of the upper lip portion 110 and the lower lip portion 120 and the length of the tip portion At least one of the upper shim and the lower shim may be provided as an abutment member abutting along the direction. For example, the lower shim 150 may be omitted from the configuration of the gas wiping nozzle 10 described above. In that case, the slits formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 are specifically the tip ends of the tip extension portion 141 of the upper shim 140 and the lower lip portion 120 The portion 121 is defined in the width direction. Even in such a case, the same effect as the gas wiping nozzle 10 according to the above-described embodiment can be obtained.

[4-4. Fourth Modified Example]
Next, a gas wiping nozzle 50 according to a fourth modification will be described with reference to FIG. Unlike the gas wiping nozzle 30 according to the second modification described with reference to FIG. 9, the upper shim is not provided in the gas wiping nozzle 50 according to the fourth modification.

  FIG. 11 is a cross-sectional view showing an example of a gas wiping nozzle 50 according to a fourth modification. Specifically, FIG. 11 is a cross-sectional view of a cross section corresponding to the B-B cross section shown in FIG. 5 which is orthogonal to the longitudinal direction of the slit 560 of the gas wiping nozzle 50. In addition, although the gas wiping nozzle 50 is arranged in a pair on both sides in the thickness direction of the steel strip 2 as in the gas wiping nozzle 10 described above, one of them is illustrated in FIG. 11 and the other is illustrated It is omitted.

  For example, as shown in FIG. 11, a gas wiping nozzle 50 according to a fourth modification includes an upper lip portion 110 and a lower lip portion 120 provided to face each other in the vertical direction, and the upper lip portion 110 and the lower portion. The lower shim 350 is sandwiched between the lip 120 and the slit 560 formed inside the tip 111 of the upper lip 110 and the tip 121 of the lower lip 120.

  The upper lip portion 110 and the lower lip portion 120 are fixed in a state of sandwiching the lower shim 350 in the vertical direction as shown in FIG. In the fourth modification, specifically, the lower shim 350 is adjacent to the upper lip portion 110 in the lower direction and is adjacent to the lower lip portion 120 in the upper direction.

  The lower shim 350 has a pair of side extension parts extending from the rear end side to the front end side on both end sides in the width direction of the steel strip 2 similarly to the gas wiping nozzle 30 described above. Further, on the tip end side of the lower shim 350, a tip extension portion 351 is provided which connects the tip end portions of the pair of side extension portions and extends along the width direction of the steel strip 2. The distal end extension portion 351 of the lower shim 350 abuts on the distal end portion 121 of the lower lip portion 120 and the longitudinal direction of the distal end portion 121.

  Thus, in the fourth modification, the lower shim 350 is provided between the upper lip portion 110 and the lower lip portion 120 as a second contact member.

  In the fourth modification, the upper portion 357 of the lower shim 350 abuts on a portion of the upper lip portion 110 excluding the center side of the tip end portion 111. Thereby, a gap corresponding to the thickness of the upper portion 357 of the lower shim 350 can be provided between the distal end portion 111 of the upper lip portion 110 and the distal end extension portion 351 of the lower shim 350. Therefore, as shown in FIG. 11, a slit 560 is formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 as a jet port of gas jetted from the nozzle chamber 191.

  Further, as shown in FIG. 11, the slit 560 is defined in the width direction by the tip end portion 111 of the upper lip portion 110 and the tip extension portion 351 of the lower shim 350. Here, on the tip end side of the upper portion of the tip extension portion 351 which is a portion that defines the slits 560 of the lower shim 350, as described above, the sloped portion that inclines upward from the tip end toward the nozzle chamber 191 side. 355 are provided. Therefore, the slit 560 has a Laval shape.

  As described above, in the gas wiping nozzle 50 according to the fourth modification, the upper shim 140 is omitted from the configuration of the gas wiping nozzle 10 described above, and the lower shim 150 and the inner shim 130 are integrally configured. Equivalent to. Therefore, by providing the lower shim 150 with the above-mentioned function of the middle shim 130 in the gas wiping nozzle 10 described above, the number of parts constituting the gas wiping nozzle can be reduced. In the fourth modification, as described above, the slit 560 formed inside the tip end portion 111 of the upper lip portion 110 and the tip end portion 121 of the lower lip portion 120 corresponds to the tip end portion 111 of the upper lip portion 110 and It is defined in the width direction by the lower shim 350 which is an abutting member. Therefore, the shape of the slit 560 can be adjusted by replacing the lower shim 350 or performing additional processing on the lower shim 350. Thus, according to the gas wiping nozzle 50 according to the fourth modification, as in the gas wiping nozzle 10 according to the above-described embodiment, the shape of the slits 560 can be adjusted without replacing the lip portion. Since it is possible, the shape of the slit 560 can be optimized relatively inexpensively. Therefore, the equipment cost of the gas wiping nozzle can be reduced.

  The lower shim 150 may be omitted from the configuration of the gas wiping nozzle 10 described above, and the upper shim 140 and the inner shim 130 may be integrated. In that case, a member obtained by integrating the upper shim 140 and the middle shim 130 corresponds to a first contact member. Also in such a case, the same effect as that of the above-described fourth modification can be obtained.

<5. Summary>
As described above, according to the embodiment of the present invention, an end portion on one steel strip 2 side of the upper lip portion 110 and the lower lip portion 120 between the upper lip portion 110 and the lower lip portion 120 And an abutting member that abuts along the longitudinal direction of the end. Thereby, the slit 160 formed inside the end of the upper lip portion 110 on the side of the steel strip 2 and the end of the lower lip portion 120 on the side of the steel strip 2 is defined in the width direction by the abutting member. Therefore, the shape of the slit 160 can be adjusted by replacing the contact member with a contact member having a shape different from that of the contact member. In addition, since the contact member has a small and simple shape as compared to each lip portion, the dimension of the slit 160 can be adjusted by additionally processing the portion defining the slit 160 of the contact member. Accuracy is relatively easy to ensure. Therefore, the shape of the slit 160 can be adjusted also by additionally processing the portion defining the slit 160 of the contact member. As described above, according to the present embodiment, since the shape of the slit 160 can be adjusted without replacing the lip portion, the shape of the slit 160 can be optimized relatively inexpensively. Therefore, the equipment cost of the gas wiping nozzle 10 can be reduced.

  In the above description, the nozzle chamber 191 and the gas header chamber 192 have been described as being formed on the tip and rear end sides of the gas wiping nozzle 10, but the gas header chamber 192 is omitted from the configuration of the gas wiping nozzle 10. It is also good. In this case, the communication hole 113 and the communication hole 123 for communicating the nozzle chamber 191 and the gas header chamber 192 are omitted from the configuration of the upper lip portion 110 and the lower lip portion 120.

  Moreover, although the example which the upper lip part 110 and the lower lip part 120 mutually fix by screw fastening was demonstrated above, the upper lip part 110 and the lower lip part 120 may be mutually fixed by another method. Preferably, the upper lip portion 110 and the lower lip portion 120 are detachably fixed to each other.

  Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that those skilled in the art to which the present invention belongs can conceive of various modifications or applications within the scope of the technical idea described in the claims. Of course, it is understood that these also fall within the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Continuous molten metal plating apparatus 2 Steel strip 3 Plating bath 4 Plating tank 5 Snout 6 Sink roll 7, 8 Support roll 9 Top roll 10, 20, 30, 40, 50 Gas wiping nozzle 110 Upper lip part 111 Tip part 113 Communication hole 120 lower lip portion 121 tip portion 123 communicating hole 130 middle shim 133 side extension portion 140, 240 upper shim 141, 241 tip extension portion 143 side extension portion 145, 245 slope portion 150, 250, 350 lower shim 151 , 251, 351 tip extension portion 153 side extension portion 155, 255, 355 slope portion 160, 260, 360, 460, 560 slit 181, 182 bolt 185, 186 nut 191 nozzle chamber 192 gas header chamber

Claims (4)

A gas wiping nozzle for blowing a gas onto a steel strip pulled upward from a molten metal plating bath to adjust the thickness of a molten metal film deposited on the surface of the steel strip,
A first lip and a second lip which are provided opposite to each other and which form an inner nozzle chamber into which the gas is introduced;
Slit formed inside the steel strip side end of the first lip and the steel strip side end of the second lip as the gas jetted jetted from the nozzle chamber When,
Equipped with
Between the first lip portion and the second lip portion, an end portion on one of the first lip portion and the second lip portion on the steel strip side and a length of the end portion An abutment member abutting along the direction,
The contact member defines the slit in the width direction.
Gas wiping nozzle.   The gas wiping according to claim 1, wherein an inclined portion which is inclined inward from the steel strip side to the nozzle chamber side is provided on the steel strip side in a portion defining the slit of the contact member. nozzle. The contact member includes a first contact member and a second contact member,
The first abutment member abuts along an end of the first lip on the steel strip side and a longitudinal direction of the end,
The second contact member is in contact with an end of the second lip on the steel strip side and a longitudinal direction of the end.
The gas wiping nozzle according to claim 2.   The gas wiping nozzle according to claim 3, wherein the shapes of the inclined portions respectively provided to the first contact member and the second contact member are different from each other.

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