JP4155360B2 - Nozzle plate - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a nozzle plate used in a two-sheet sliding nozzle that is disposed at the bottom or side of a molten metal container such as a ladle or tundish and can control the flow rate of the molten metal.

  Patent Documents 1 to 3 introduce a two-sheet sliding nozzle. The sliding nozzle described in these documents is interposed between the upper nozzle and the lower nozzle. The two-sheet sliding nozzle includes a fixed plate that is integrally disposed on the upper nozzle and a sliding plate that is integrally disposed on the lower nozzle. These two plates are stacked in the vertical direction. Each of these two plates is provided with a nozzle hole. The two nozzle holes are arranged in series in the vertical direction. The sliding plate can slide in the horizontal direction together with the lower nozzle. When the sliding plate slides, the communication state of the two nozzle holes changes. By changing the communication state, the two-sheet sliding nozzle controls the flow rate of the molten metal flowing from the upper nozzle to the lower nozzle.

As described in these documents, in the double slide nozzle, damage to the plate due to the flow of molten metal (hereinafter referred to as “melting damage”) becomes a problem. In the case of the two-sheet sliding nozzles described in Patent Documents 1 and 2, by correcting the deviation in the pressure-bonding force between the fixed plate and the sliding plate, the entrainment of air is reduced and the erosion is suppressed. Further, in the case of the two-sheet sliding nozzle described in Patent Document 3, the erosion is suppressed by forming a region where erosion is likely to occur in the plate with a refractory mainly composed of alumina carbon. .
JP 2005-177768 A JP 2004-174582 A JP 2005-34883 A Special table 2003-526516 gazette

  However, in the case of the two-sheet sliding nozzle described in Patent Documents 1 and 2, it is necessary to change the outer peripheral shape of the plate. Here, the fixed plate is fixed to the concave portion of the fixed metal frame, and the sliding plate is fixed to the concave portion of the sliding metal frame. For this reason, when changing the outer peripheral shape of a plate, it is necessary to change even the shape of a fixed metal frame or a sliding metal frame. Therefore, according to the plates described in Patent Documents 1 and 2, the manufacturing cost of the two-plate sliding nozzle is increased. On the other hand, according to the plate of patent document 3, it is necessary to produce one plate with two types of refractories. Accordingly, also in this case, the manufacturing cost of the plate and the two-sheet sliding nozzle is increased.

  In view of these circumstances, the present inventor has found that, instead of suppressing melting damage, an allowance for allowing melting damage is set in advance in a region where melting damage is likely to occur in the plate. . By the way, Patent Document 4 introduces a three-sheet sliding nozzle instead of a two-sheet type. The three-sheet sliding nozzle described in the same document includes an upper fixed plate that is integrally disposed on the upper nozzle, a lower fixed plate that is integrally disposed on the lower nozzle, and an upper fixed plate and a lower fixed plate. And a sliding plate interposed therebetween. These three plates are stacked in the vertical direction. Each of these three plates has a nozzle hole. The three nozzle holes are arranged in series in the vertical direction. The sliding plate is slidable in the horizontal direction independently of the upper fixing plate and the lower fixing plate, in other words, independent of the upper nozzle and the lower nozzle. When the sliding plate slides, the communication state of the three nozzle holes changes. By changing the communication state, the three-sheet sliding nozzle described in the document controls the flow rate of the molten metal flowing from the upper nozzle to the lower nozzle.

  As shown in FIG. 39 of the same document, the opening of the nozzle hole of the sliding plate has a rectangular shape. That is, the opening / closing direction total length of the opening is set shorter than the vertical total length substantially perpendicular to the opening / closing direction. The reason why the shape of the opening is rectangular is to ensure the symmetry of the flow of the molten metal, as described in [0043] and [0044] of the same document.

  There is no description in the same document that suggests a two-sheet sliding nozzle as described in Patent Documents 1 to 3. In addition, it is difficult to use a plate dedicated to the three-sheet sliding nozzle described in the same document for the two-sheet sliding nozzle. The reason will be described below.

  First, the configuration differs between a three-sheet sliding nozzle and a two-sheet sliding nozzle as described in the same document. That is, the sliding plate of the three-sheet sliding nozzle is independent of the upper fixed plate and the lower fixed plate. In the fully closed state, the nozzle hole of the sliding plate is closed by the upper fixing plate and the lower fixing plate. For this reason, there exists a possibility that a molten metal may solidify in the nozzle hole of the obstruct | occluded sliding plate. In order to avoid solidification of the molten metal, the shape of the nozzle hole of the sliding plate is such that the nozzle hole of the sliding plate and the nozzle hole of the lower fixed plate communicate with each other even in the fully closed state. It is necessary to devise. For example, the opening shape of the nozzle hole needs to be a shape in which a perfect circle portion and a rectangular portion (a portion communicating with the nozzle hole of the lower fixed plate) extending in the diameter increasing direction of the perfect circle portion are connected.

  In contrast, the sliding plate of the two-sheet sliding nozzle is directly connected to the lower nozzle. For this reason, the nozzle hole of the sliding plate is not blocked in the fully closed state. Therefore, in the case of a two-sheet sliding nozzle, it is not necessary to make the opening shape of the nozzle hole other than a perfect circle. That is, in the case of a two-sheet sliding nozzle, the idea of making the opening shape of the nozzle hole a shape other than a perfect circle shape hardly occurs. Thus, the configuration differs between the three-sheet sliding nozzle and the two-sheet sliding nozzle. Further, the concept of the opening shape of the nozzle hole is different.

  Secondly, the use differs between the three-sheet sliding nozzle and the two-sheet sliding nozzle. That is, the three-sheet sliding nozzle is limited to a specific type of product. As described above, the sliding plate of the three-sheet sliding nozzle is independent of the lower nozzle. For this reason, even if the sliding plate is moved, the lower nozzle does not move. Therefore, the three-sheet sliding nozzle is limited to a product of a type that is inconvenient if the molten metal surface below the lower nozzle is disturbed.

  In contrast, the sliding plate of the two-sheet sliding nozzle is disposed integrally with the lower nozzle. For this reason, when the sliding plate is moved, the lower nozzle moves together. Therefore, the two-sliding nozzle is a product that uses an air blocking agent and equipment that matches the movement of the lower nozzle so that it does not hinder the molten metal surface below the lower nozzle. Used. Thus, the use differs between the three-sheet sliding nozzle and the two-sheet sliding nozzle.

  Third, the melted area is different between the three-sheet sliding nozzle and the two-sheet sliding nozzle. That is, the flow path shape of the molten metal in the half-open state is different between the three-sheet sliding nozzle and the two-sheet sliding nozzle. Specifically, in the case of a two-sheet sliding nozzle, the flow path is curved in an S shape. On the other hand, in the case of the three-sheet sliding nozzle, the flow path is first curved in an S shape and then curved in an inverted S shape. As described above, the flow path of the molten metal is more complicated in the three-sheet sliding nozzle than in the two-sheet sliding nozzle. For this reason, the turbulent flow is more likely to occur in the flow of the molten metal in the three-sheet sliding nozzle than in the two-sheet sliding nozzle. In addition, the two-sheet sliding nozzle and the three-sheet sliding nozzle have different turbulent flow generation locations due to the difference in the channel shape. For these reasons, the three-sliding nozzle and the two-sliding nozzle are different in the region where erosion is likely to occur.

  In addition, in the case of a three-sheet sliding nozzle, it is conceivable to devise the shape of the nozzle hole of the sliding plate in order to suppress the occurrence of turbulent flow. However, in the case of a two-sheet sliding nozzle, there is little need to suppress the occurrence of turbulent flow in the first place, so the idea of devising the shape of the nozzle hole in the sliding plate is unlikely to occur. For the reasons described above, it is difficult to use the plate described in Patent Document 4 for the two-sheet sliding nozzle described in Patent Documents 1 to 3.

  The nozzle plate of the present invention has been completed in view of the above problems. Therefore, an object of the present invention is to provide a nozzle plate that can ensure a melting allowance allowance and is inexpensive to manufacture.

(1) In order to solve the above-described problem, the nozzle plate of the present invention has nozzle holes each having a sliding side opening and a fixed side opening, and the sliding side openings are arranged so that they can be connected to each other. At least one of the two plates of the two-plate sliding nozzle that can be opened and closed by relatively sliding the two plates and changing the communication state of the sliding side openings. A nozzle plate used as one of the sliding-side opening and the fixed-side opening, wherein at least the sliding-side opening has an opening / closing direction total length shorter than a vertical total length substantially perpendicular to the opening / closing direction. Ri set profiled opening der, the opening direction end out of the opening and closing opposite ends of the foreign-shaped opening, to the virtual substantially true circle diameter the vertical direction entire length, protruding only on the inner diameter side predetermined overhanging amount The overhanging part is placed Ri, part other than the protruding portion of the foreign-shaped opening is characterized that you have substantially a perfect circle shape.
(2) Moreover, in order to solve the said subject, while the plate for nozzles of this invention has each nozzle hole with a sliding side opening and a fixed side opening, these sliding side openings are arrange | positioned so that connection is possible. Two sliding nozzles that can be opened and closed by sliding the two plates relative to each other in a circular arc shape and changing the communication state of the sliding side openings. A nozzle plate used as at least one of the plates, wherein at least the sliding side opening of the sliding side opening and the fixed side opening has a full length in the opening and closing direction and a vertical direction substantially perpendicular to the opening and closing direction. It is a deformed opening set shorter than the full length, and the both ends of the deformed opening in the opening / closing direction are projected toward the inner diameter side by a predetermined projecting amount with respect to a virtual substantially perfect circle whose diameter is the full length in the vertical direction. A pair of overhangs are placed The portions other than the pair of projecting portions in the deformed opening have a substantially perfect circle shape, and the pair of projecting portions each have a partial circle shape surrounded by a straight line and an arc. The pair of straight lines extend so that an interval between the pair of straight lines extends toward an outer diameter direction of an arc that is a sliding track of the two plates.

  In this specification, the “opening / closing direction” refers to the opening / closing direction of the nozzle, that is, the relative sliding direction of the two plates. For example, when two plates slide relative to each other in a straight line, the straight line direction is referred to. Further, when the two plates slide relative to each other in an arc shape, the arc direction is referred to. In this specification, the “full length” refers to the maximum length in a predetermined direction.

  The nozzle plate of the present invention has nozzle holes. The nozzle hole has a fixed side opening and a sliding side opening. The fixed side opening of the nozzle plate of the present invention is connected to a counterpart member such as an upper nozzle or a lower nozzle, for example. On the other hand, the sliding side opening is connected to the sliding side opening of another nozzle plate (not necessarily the nozzle plate of the present invention).

  Melting damage of the nozzle plate is likely to occur at the opening / closing direction end (at least one of the opening direction end and the closing direction end) of the lip of the sliding side opening. In view of this point, the overall opening / closing direction of the sliding side opening of the nozzle plate of the present invention is set shorter than the entire vertical direction substantially perpendicular to the opening / closing direction. That is, the allowance for melting damage is secured in advance at the opening / closing direction end of the lip of the sliding side opening by an amount corresponding to the short total length. For this reason, as compared with the prior art, the progress of the erosion can be delayed only while the flow of the molten metal erodes the erosion allowance. Therefore, the possibility that the molten metal leaks is reduced. In addition, the life of the nozzle plate is extended. That is, the replacement frequency of the nozzle plate is reduced.

  Further, according to the nozzle plate of the present invention, a special outer peripheral shape such as the plates described in Patent Documents 1 and 2 is unnecessary. For this reason, the manufacturing cost of the nozzle plate and the two-sheet sliding nozzle is low. Moreover, it is not necessary to dare to change the shape of a plate holding member that has been conventionally used (for example, a fixed metal frame or a sliding metal frame). For this reason, the plate for nozzles of the present invention can be added on to the conventionally used two-sliding nozzle relatively easily. Therefore, the nozzle plate of the present invention is highly versatile.

  Further, according to the nozzle plate of the present invention, two types of refractory materials, such as the plate described in the above-mentioned Patent Document 3, are unnecessary. For this reason, the man-hour at the time of manufacture is few and manufacturing cost is also cheap.

  Here, the “open direction end” refers to a portion that becomes the rear end when the nozzle is switched from the fully open state to the fully closed state. For example, when two plates slide relative to each other in a straight line (for example, when a plate is used for a two-sheet sliding nozzle), when the movement of the other plate is viewed with respect to one plate, the other plate This is the part that becomes the rear end of the irregularly shaped opening of the plate.

  However, when the two plates rotate relatively in an arc shape and the rotation direction does not reverse (for example, when a plate is used for a rotary nozzle), the opening direction and the closing direction of the nozzle coincide. It will be. In this case, the “open direction end” refers to a portion that becomes the rear end when the nozzle is switched from the fully open state to the fully closed state with the fully open state as a reference position (reset position).

In the configurations (1) and (2) , the overhanging portion is arranged at the opening direction end among the both ends of the opening and closing direction. The end in the opening direction corresponds to a region where melting damage is particularly likely to occur in the entire nozzle plate. If the overhanging portion is disposed at the end in the opening direction, the progress of the melting loss can be delayed only while the flow of the molten metal erodes the overhanging portion.

Moreover, according to the configuration of (1), it is easier to secure the flow rate of the molten metal than in the case where the overhanging portions are arranged at both ends in the opening and closing direction. In addition, the shape of the irregular opening is simplified, and turbulent flow is less likely to occur in the molten metal flow.

(3) Preferably, in the configuration of the above (1) or (2), the fixed side opening is connected to a counterpart nozzle hole of a counterpart member, and the center of the virtual substantially perfect circle is the counterpart nozzle hole It is better to have a configuration arranged on the hole axis. In other words, this configuration has a virtual substantially circular center on the hole axis of the mating nozzle hole of the mating member (for example, the upper nozzle communicating with the molten metal container or the lower nozzle discharging the molten metal in the next process). Is to arrange.

  According to this configuration, the hole axis of the counterpart nozzle hole and the center of the virtual substantially perfect circle are arranged coaxially. In other words, the hole axis of the counterpart nozzle hole and the center of the virtual substantially perfect circle are not offset. For this reason, compared with the case where the hole axis | shaft of the other party nozzle hole and the center of a virtual substantially perfect circle are offset (for example, the case of above-mentioned patent document 4), curving of the flow path of a molten metal is suppressed. Can do. Therefore, it becomes easy to ensure the flow rate of the molten metal. Further, turbulent flow is less likely to occur in the molten metal flow.

Moreover , according to the configuration of (1) or (2) above, the portion other than the overhanging portion in the irregular opening has a substantially perfect circle shape.

  The counterpart nozzle hole of the counterpart member connected to the two-sheet sliding nozzle often has a substantially circular shape. The reason will be described below. First, a counterpart member such as an upper nozzle and a molten metal container such as a ladle are disposed on the upstream side of the two-sheet sliding nozzle. In the fully closed state of the two-sheet sliding nozzle, the mating nozzle hole of the mating member is filled with silica sand. Silica sand overflows from the counterpart nozzle hole and fills up to the bottom of the molten metal container. A baked dome with a mixture of molten metal and silica sand is formed at the top of the quartz sand pile. The dome has a conical shape or a hemispherical shape concealed at the bottom of the molten metal container. When the two-sheet sliding nozzle is switched from the fully closed state to the fully opened state, first, silica sand flows down the two nozzle holes of the mating nozzle hole and the two-sheet sliding nozzle. Next, the dome of the fused silica mixed with the molten metal collapses due to the static pressure of the molten metal filled on the dome. Thereafter, the dome fragments flow down through the two nozzle holes of the mating nozzle hole and the two-sheet sliding nozzle. At this time, if the counterpart nozzle hole has a substantially circular shape, the broken pieces of the dome that have collapsed in the molten metal container can uniformly flow into the counterpart nozzle hole from all 360 ° directions. For this reason, the residue of the dome fragments in the molten metal container can be suppressed. In addition, if the mating nozzle hole has a substantially circular shape, the dome fragments are less likely to get caught in the mating nozzle hole. For this reason, it is possible to suppress dome fragments remaining in the counterpart nozzle hole. As described above, in order to suppress the remaining dome fragments, the counterpart nozzle hole often has a substantially perfect circle shape.

  Secondly, historically, the opening of the mating nozzle hole that appears on the bottom of the molten metal container was closed by a brick round bar called a stopper when closed. In order to prevent the molten metal from leaking from between the stopper and the opening, in other words, in order to improve the sealing performance between the stopper and the opening, the stopper tip has a hemispherical shape. In addition, the opening was substantially circular. Thus, for historical reasons, the counterpart nozzle hole often has a substantially perfect circle shape.

  Third, nozzle cleaning is performed by inserting a small-diameter metal pipe from a counterpart nozzle hole of a counterpart member (for example, a lower nozzle) disposed on the downstream side of the two-sheet sliding nozzle. Oxygen is blown into the mating nozzle hole from the insertion end of the metal pipe. Oxygen blown melts the metal fixed in the other nozzle hole or in the nozzle hole of the two-sheet sliding nozzle. In this way, nozzle cleaning is performed by melting the fixed metal. When cleaning the nozzle, if the mating nozzle hole has a substantially circular shape, the metal pipe can be easily moved in the mating nozzle hole. Therefore, nozzle cleaning is easy. Thus, for convenience of nozzle cleaning, the counterpart nozzle hole often has a substantially perfect circle shape. For the three reasons described above, the counterpart nozzle hole often has a substantially circular shape.

On the other hand, according to the configuration of the above (1) or (2), the portions other than the projecting portion of the irregular opening have a substantially perfect circle shape. That is, when the mating nozzle hole of the mating member (for example, the upper nozzle or the lower nozzle) connected to the two-sheet sliding nozzle has a substantially round shape, the projecting portion of the mating nozzle hole and the irregular opening The part other than is a similar shape (or the same shape). According to this configuration, when the counterpart nozzle hole has a substantially perfect circle shape, the step between the counterpart nozzle hole and the irregularly shaped opening is reduced (or the step is eliminated). Therefore, it becomes easy to ensure the flow rate of the molten metal. Further, turbulent flow is less likely to occur in the molten metal flow. In addition, the dome fragments are not easily caught. The nozzle cleaning is also easy.

( 4 ) Preferably, in the configuration of the above (1) or (2), the amount of overhang is preferably set to 1% or more with the diameter as 100%. Here, the reason why it is set to 1% or more is that when it is less than 1%, it is difficult to obtain a sufficient melting loss delay effect (an effect that the molten metal erodes the overhanging portion to delay the progress of the melting loss).

Preferably, in the configuration of the above (1) or (2), the overhang amount is preferably set to 40% or less with the diameter being 100%. Here, the reason why it is 40% or less is that when it exceeds 40%, it becomes difficult to secure the flow rate of the molten metal. In addition, turbulent flow is likely to occur in the molten metal flow.

( 5 ) Preferably, in the configuration of the above ( 4 ), the overhang amount is set to 20% or less. Here, the reason why it is set to 20% or less is that it becomes easier to secure the flow rate of the molten metal as compared with the case of exceeding 20%. Furthermore, it is because it becomes difficult to generate a turbulent flow in the flow of the molten metal.

( 6 ) Preferably, in the configuration of the above (1) or (2), the amount of the overhang is preferably set to 1 mm or more. Here, the reason why the thickness is 1 mm or more is that when it is less than 1 mm, it is difficult to obtain a sufficient effect of delaying the melting loss.

Preferably, in the configuration of the above (1) or (2), the protruding amount is preferably set to 5 mm or less. Here, the reason why the thickness is set to 5 mm or less is that the process management becomes complicated when it exceeds 5 mm. That is, for example, management of each process such as tundish, molding, and cooling is performed using a computer based on the calculation of the flow rate of the molten metal. When the overhang amount exceeds 5 mm, the influence of the overhang portion is remarkably expressed in the flow rate of the molten metal. That is, the flow rate of the molten metal is significantly reduced. Further, turbulent flow is likely to occur in the molten metal flow. For this reason, it becomes difficult to use an existing program (a program created under the condition that no overhanging portion is arranged). Therefore, the process management becomes complicated because the computer is difficult to use.

  In this regard, when the overhang amount is set to 5 mm or less, the influence of the overhang portion on the flow of the molten metal is reduced. For this reason, it becomes easy to divert the existing program as it is. Therefore, process management becomes simple. Also, no program change is required.

( 7 ) Preferably, in the configuration of the above (1) or (2), it is better that the fixed side opening has a substantially circular shape. If the other side nozzle hole of the mating member is substantially a perfect circle shape, according to the present configuration, the step between the fixed-side opening to a mating nozzle hole becomes smaller (or the step is eliminated). Therefore, it becomes easy to ensure the flow rate of the molten metal. Further, turbulent flow is less likely to occur in the molten metal flow.

  According to the present invention, it is possible to provide a nozzle plate that can secure an allowance for melting damage and that is inexpensive to manufacture.

  Hereinafter, embodiments of the nozzle plate of the present invention will be described.

  <First embodiment>

  First, the structure of a two-sheet sliding nozzle in which the nozzle plate of the present embodiment is used will be described. FIG. 1 shows a cross-sectional view of a two-sheet sliding nozzle as seen from the lateral direction. FIG. 1 shows a fully opened state. As shown in FIG. 1, the two-sheet sliding nozzle 1 includes a fixed plate 2, a fixed metal frame 3, a sliding plate 4, a sliding metal frame 5, and an operating rod 6. The two-sheet sliding nozzle 1 is included in the two-sheet sliding nozzle of the present invention. The fixed plate 2 and the sliding plate 4 are included in the nozzle plate of the present invention.

  The fixed plate 2 is made of a refractory material and has a plate shape. A metal band 22 is disposed on the outer peripheral side of the fixed plate 2. A convex portion 20 is formed on the upper surface of the fixed plate 2. The fixed plate 2 has a nozzle hole 21 that penetrates the fixed plate 2 in the vertical direction. The space in the nozzle hole 21 has a cylindrical shape with the same diameter except for an overhanging portion 212 described later. The nozzle hole 21 has a fixed side opening 210 and a sliding side opening 211. The fixed side opening 210 and the sliding side opening 211 are included in the modified opening of the present invention. The fixed side opening 210 is disposed on the upper surface of the convex portion 20. The sliding side opening 211 is disposed on the lower surface of the fixed plate 2. The shapes of the fixed side opening 210 and the sliding side opening 211 will be described in detail later.

  The fixed metal frame 3 is made of metal and has a plate shape. A recess 30 is formed on the lower surface of the fixed metal frame 3. Further, an upper nozzle holding hole 31 is formed between the upper surface of the concave portion 30 (corresponding to the bottom surface of the concave portion 30) and the upper surface of the fixed metal frame 3. The fixed plate 2 is accommodated in the recess 30 so that the protrusion 20 is arranged in the upper nozzle holding hole 31.

  A ladle 95 is disposed above the fixed metal frame 3. The ladle 95 has a bottomed cup shape that opens upward. An upper nozzle through hole 950 is formed in the bottom wall of the ladle 95. The upper nozzle 90 is inserted into the upper nozzle through hole 950. The upper nozzle 90 is made of a refractory material and has a cylindrical shape. The upper nozzle 90 is included in the counterpart member of the present invention. The upper nozzle 90 is formed with a nozzle hole 901 extending in the vertical direction. The nozzle hole 901 is included in the counterpart nozzle hole of the present invention. The space in the nozzle hole 901 has a cylindrical shape with the same diameter. The lower end portion of the upper nozzle 90 is inserted into the upper nozzle holding hole 31 of the fixed metal frame 3. A recess 900 is formed at the lower end portion of the upper nozzle 90. The convex portion 20 of the fixed plate 2 is inserted into the concave portion 900. In this way, the upper nozzle 90 and the fixed plate 2 are fixed. In addition, the nozzle hole 901 of the upper nozzle 90 and the fixed side opening 210 of the nozzle hole 21 of the fixed plate 2 are connected in the vertical direction.

  The sliding plate 4 is made of a refractory material and has a plate shape. The sliding plate 4 is disposed below the fixed plate 2. A metal band 42 is disposed on the outer peripheral side of the sliding plate 4. A convex portion 40 is formed on the lower surface of the sliding plate 4. The sliding plate 4 is provided with a nozzle hole 41 penetrating the sliding plate 4 in the vertical direction. The space in the nozzle hole 41 has a columnar shape with the same diameter except for a protruding portion 412 described later. The nozzle hole 41 has a fixed side opening 410 and a sliding side opening 411. The fixed side opening 410 and the sliding side opening 411 are included in the modified opening of the present invention. The fixed side opening 410 is disposed on the lower surface (top surface) of the convex portion 40. The sliding side opening 411 is disposed on the upper surface of the sliding plate 4. The sliding side opening 411 and the sliding side opening 211 of the nozzle hole 21 of the fixed plate 2 can be connected in the vertical direction. The shapes of the fixed side opening 410 and the sliding side opening 411 will be described in detail later.

  The sliding metal frame 5 is made of metal and has a plate shape. A concave portion 50 is formed on the upper surface of the sliding metal frame 5. Further, a lower nozzle holding hole 51 is formed between the lower surface of the recess 50 (corresponding to the bottom surface of the recess 50) and the lower surface of the sliding metal frame 5. The sliding plate 4 is accommodated in the concave portion 50 so that the convex portion 40 is disposed in the lower nozzle holding hole 51. The operation rod 6 is connected to the sliding metal frame 5. The sliding metal frame 5 is linearly reciprocated in the horizontal direction by the operation rod 6.

  The lower nozzle 91 is made of a refractory and has a cylindrical shape. The lower nozzle 91 is included in the counterpart member of the present invention. The lower nozzle 91 is formed with a nozzle hole 911 extending in the vertical direction. The nozzle hole 911 is included in the counterpart nozzle hole of the present invention. The space in the nozzle hole 911 has a cylindrical shape with the same diameter. The upper end portion of the lower nozzle 91 is inserted into the lower nozzle holding hole 51 of the sliding metal frame 5. A recess 910 is formed in the upper end portion of the lower nozzle 91. The convex portion 40 of the sliding plate 4 is inserted into the concave portion 910. In this way, the lower nozzle 91 and the sliding plate 4 are fixed. In addition, the nozzle hole 911 of the lower nozzle 91 and the fixed side opening 410 of the nozzle hole 41 of the sliding plate 4 are connected in the vertical direction. A joint 92 is connected below the lower nozzle 91. The joint 92 is made of a refractory material and has a cylindrical shape. The nozzle hole 920 of the joint 92 and the nozzle hole 911 of the lower nozzle 91 are connected in the vertical direction. Below the joint 92, a tundish (not shown) of a continuous casting machine is arranged.

  Thus, between the upstream ladle 95 and the downstream tundish, nozzle hole 901 (upper nozzle 90) → nozzle hole 21 (fixed plate 2) → nozzle hole 41 (sliding plate 4) → A molten steel flow path that continues from the nozzle hole 911 (lower nozzle 91) to the nozzle hole 920 (joint 92) is formed.

  The nozzle hole 901 and the nozzle hole 21 (specifically, the portion other than the overhanging portion 212 in the nozzle hole 21) are connected coaxially, in the same diameter, and integrally. In addition, the nozzle hole 41 (specifically, the portion other than the overhanging portion 412 in the nozzle hole 41), the nozzle hole 911, and the nozzle hole 920 are connected coaxially, in the same diameter, and integrally.

  Next, the shape of the nozzle hole 41 of the sliding plate 4 will be described in detail. FIG. 2 shows an enlarged top view of the vicinity of the nozzle hole of the sliding plate. As shown in the figure, the portion other than the overhanging portion 412 (shown by hatching for convenience of description) in the nozzle hole 41 (fixed side opening 410, sliding side opening 411) has a perfect circle shape centered on the point 4o. Yes. The overhanging portion 412 has a partial circle shape surrounded by a straight line and an arc. The overhanging portion 412 is arranged at the opening direction end (the right direction end in the figure) among the both ends of the nozzle hole 41 in the opening and closing direction. The opening / closing direction total length 4a of the nozzle hole 41 is set shorter than the vertical total length 4b perpendicular to the opening / closing direction by the amount of the protruding portion 412 disposed. The overhanging portion 412 protrudes toward the inner diameter side (closed side, left side in the drawing) by an overhang amount 4c with respect to a virtual perfect circle 4d (indicated by a one-dot chain line in the drawing) having a diameter in the vertical direction full length 4b. In this embodiment, the overhang amount 4c is set to 1 mm, the full length 4b in the vertical direction is set to 40 mm, and the full length 4a in the opening / closing direction is set to 39 mm (= 40 mm-1 mm).

  Next, the shape of the nozzle hole 21 of the fixed plate 2 will be described in detail. The opening / closing direction of the fixed plate 2 and the opening / closing direction of the sliding plate 4 are exactly opposite. The reason is that when the sliding plate 4 moves to the left in the figure, the fixed plate 2 moves to the right in the figure when viewed relatively. In addition, when the sliding plate 4 moves in the right direction in the figure, the fixing plate 2 moves in the left direction in the figure when viewed relatively. That is, the left direction in the figure corresponds to the closing direction of the sliding plate 4 and the opening direction of the fixed plate 2. Further, the right direction in the drawing corresponds to the opening direction of the sliding plate 4 and the closing direction of the fixed plate 2.

  FIG. 3 shows an enlarged top view of the vicinity of the nozzle hole of the fixed plate. As shown in the figure, the portion other than the overhanging portion 212 (shown by hatching for convenience of description) in the nozzle hole 21 (fixed side opening 210, sliding side opening 211) has a perfect circle shape centered on the point 2o. Yes. The overhang portion 212 has a partial circle shape surrounded by a straight line and an arc. The overhanging portion 212 is disposed at the opening direction end (left direction end in the drawing) of the both ends of the nozzle hole 21 in the opening and closing direction. The opening / closing direction total length 2a of the nozzle hole 21 is set to be shorter than the vertical total length 2b perpendicular to the opening / closing direction by the amount of the protruding portion 212 disposed. The protruding portion 212 protrudes toward the inner diameter side (closed side, right side in the drawing) by a protruding amount 2c with respect to a virtual perfect circle 2d (indicated by the alternate long and short dash line in the drawing) having the entire length 2b in the vertical direction as a diameter. In this embodiment, the overhang amount 2c is set to 1 mm, the full length 2b in the vertical direction is set to 40 mm, and the full length 2a in the opening / closing direction is set to 39 mm (= 40 mm-1 mm).

  Next, the movement when switching the two-sheet sliding nozzle from the fully open state to the fully closed state via the half open state will be described. FIG. 4 shows a top view of the fixed plate and the sliding plate of FIG. For convenience of explanation, the convex portion 20 of FIG. 1 is omitted in FIG.

  As shown in FIG. 4, in the fully opened state, the nozzle hole 21 and the nozzle hole 41 are connected so that the center 2o and the center 4o are aligned. Returning to FIG. 1, when the operating rod 6 is operated from this state, the sliding metal frame 5 slides in the left direction in the figure. For this reason, the sliding plate 4 accommodated in the sliding metal frame 5 also slides in the left direction in the figure.

  FIG. 5 shows a cross-sectional view of the two-sheet sliding nozzle viewed from the lateral direction (half-open state). FIG. 6 shows a top view of the fixed plate and the sliding plate of FIG. For convenience of explanation, the convex portion 20 of FIG. 5 is omitted in FIG. FIG. 7 is a perspective view of the fixed plate and the sliding plate shown in FIG.

  As shown in FIGS. 5 and 6, in the half-open state, the nozzle hole 41 of the sliding plate 4 is arranged to be shifted in the left direction in the drawing with respect to the nozzle hole 21 of the fixed plate 2. For this reason, a part of the upper surface of the sliding plate 4 (indicated by the hatching with the right rising in FIGS. 6 and 7) and a part of the lower surface of the fixing plate 2 (indicated by the hatching with the rising left in the FIGS. 6 and 7). Appears in the flow path of the molten steel. These hatched portions correspond to regions where melting damage is likely to occur. The overhanging portion 212 and the overhanging portion 412 are arranged including an area where the melting damage is likely to occur. When the operating rod 6 is operated from this state, the sliding metal frame 5 slides in the left direction in the figure. For this reason, the sliding plate 4 accommodated in the sliding metal frame 5 also slides in the left direction in the figure.

  FIG. 8 shows a cross-sectional view of the two-sheet sliding nozzle viewed from the lateral direction (fully closed state). FIG. 9 shows a top view of the fixed plate and the sliding plate of FIG. For convenience of explanation, the convex portion 20 of FIG. 8 is omitted in FIG.

  As shown in FIGS. 8 and 9, in the fully closed state, the sliding side opening 411 of the nozzle hole 41 of the sliding plate 4 is closed by the lower surface of the fixed plate 2. Similarly, the sliding side opening 211 of the nozzle hole 21 of the fixed plate 2 is closed by the upper surface of the sliding plate 4. For this reason, the nozzle hole 21 and the nozzle hole 41 are blocked.

  In this way, the double sliding nozzle 1 is switched from the fully open state to the half open state to the fully closed state. When switching from the fully closed state to the fully open state, the sliding metal frame 5 is slid in the direction opposite to the above direction (that is, the right direction in the figure) by the operating rod 6.

  Next, the effect of the nozzle plate (fixed plate 2 and sliding plate 4) of this embodiment will be described. According to the nozzle plate 2 of this embodiment (4 to hereafter, the reference sign on the fixed plate 2 side is indicated outside the parentheses, and the reference sign on the sliding plate 4 side is indicated in the parentheses), the sliding side opening 211 (411). The fixed opening 210 (410) has a full length 2a (4a) in the opening / closing direction corresponding to a protruding amount 2c (4c) of the protruding portion 212 (412) with respect to a full length 2b (4b) in the vertical direction perpendicular to the opening / closing direction. It is set short. The overhang portion 212 (412) acts as an allowance for melting damage. For this reason, as compared with the conventional case, the progress of the erosion can be delayed only while the flow of the molten steel erodes the erosion allowance. Therefore, the possibility that the molten steel leaks is reduced. Further, the life of the nozzle plate 2 (4) is prolonged. That is, the replacement frequency of the nozzle plate 2 (4) is reduced.

  Further, according to the nozzle plate 2 (4) of the present embodiment, a special outer peripheral shape like the plates described in the aforementioned Patent Documents 1 and 2 is not necessary. For this reason, the manufacturing cost of the nozzle plate 2 (4) and the two-sheet sliding nozzle 1 is low.

  Moreover, it is not necessary to dare to change the shapes of the fixed metal frame 3 and the sliding metal frame 5 that are conventionally used. For this reason, the nozzle plate 2 (4) of the present embodiment can be added on to the two-slide sliding nozzle 1 conventionally used in a relatively simple manner. Therefore, the nozzle plate 2 (4) of this embodiment is highly versatile.

  In addition, according to the nozzle plate 2 (4) of the present embodiment, two types of refractory materials such as the plate described in the above-mentioned Patent Document 3 are unnecessary. For this reason, the man-hour at the time of manufacture is few and manufacturing cost is also cheap.

  Further, according to the nozzle plate 2 (4) of the present embodiment, the overhanging portion 212 (412) is arranged at the opening direction end among the both ends of the opening and closing direction. The end in the opening direction also corresponds to a region where melting damage is particularly likely to occur in the entire nozzle plate 2 (4). If the overhanging portion 212 (412) is disposed at the end in the opening direction, the progress of the melting damage can be delayed only while the flow of molten steel erodes the overhanging portion 212 (412).

  Moreover, compared with the case where the overhang | projection part 212 (412) is arrange | positioned at the opening-and-closing direction both ends, it becomes easy to ensure the flow volume of molten steel. Further, the shapes of the sliding side opening 211 (411) and the fixed side opening 210 (410) are simplified, and turbulence is less likely to occur in the flow of molten steel.

  Further, according to the nozzle plate 2 of the present embodiment, the hole axis of the nozzle hole 901 of the upper nozzle 90 and the center 2o of the virtual perfect circle 2d are arranged coaxially. In addition, according to the nozzle plate 4 of the present embodiment, the hole axis of the nozzle hole 911 of the lower nozzle 91 and the center 4o of the virtual perfect circle 4d are arranged coaxially. In other words, the hole axis of the nozzle hole 901 (911) and the center 2o (4o) of the virtual perfect circle 2d (4d) are not offset. For this reason, compared with the case where both are offset, the curvature of the flow path of molten steel can be suppressed. Therefore, it becomes easy to ensure the flow rate of molten steel. Moreover, it becomes difficult to generate turbulent flow in the flow of molten steel.

  Further, according to the nozzle plate 2 (4) of the present embodiment, the portions other than the overhanging portion 212 (412) in the sliding side opening 211 (411) and the fixed side opening 210 (410) have a perfect circle shape. Yes. On the other hand, the nozzle hole 901 of the upper nozzle 90 and the nozzle hole 911 of the lower nozzle 91 also have a perfect circle shape. In addition, the nozzle hole 901 of the upper nozzle 90 and the nozzle hole 21 of the nozzle plate 2 are coaxial and have the same diameter. In addition, the nozzle hole 911 of the lower nozzle 91 and the nozzle hole 41 of the nozzle plate 4 are coaxial and have the same diameter. For this reason, it becomes easy to ensure the flow rate of molten steel. Moreover, it becomes difficult to generate turbulent flow in the flow of molten steel.

  Further, according to the nozzle plate 2 (4) of the present embodiment, the amount 2c (4c) of the overhanging portion 212 (412) is 100% of the total length 2b (4b) in the vertical direction of the nozzle hole 21 (41). It is set to 2.5% (= 1 mm / 40 mm × 100%). That is, the overhang amount 2c (4c) is set within a range of 1% to 20%. For this reason, sufficient melting damage delay effect can be obtained. In addition, it becomes easy to secure the flow rate of the molten steel. Moreover, it becomes difficult to generate turbulent flow in the flow of molten steel.

  The overhang amount 2c (4c) is set to 1 mm. That is, the overhang amount 2c (4c) is set within a range of 1 mm to 5 mm. For this reason, sufficient melting damage delay effect can be obtained. In addition, it becomes easy to secure the flow rate of the molten steel. Moreover, it becomes difficult to generate turbulent flow in the flow of molten steel.

  In addition, management of each process such as tundish, mold, and cooling in continuous casting is performed using a computer based on calculation of the flow rate of molten steel. When the overhang amount 2c (4c) exceeds 5 mm, the flow rate of the molten steel is significantly reduced due to the influence of the overhang portion 212 (412). Moreover, it becomes easy to generate | occur | produce a turbulent flow in the flow of molten steel. This makes it difficult to use existing programs. Therefore, the process management becomes complicated because the computer cannot be used.

  In this regard, as in the present embodiment, when the overhang amount 2c (4c) is set to 5 mm or less, the influence of the overhang portion 212 (412) on the flow of molten steel is reduced. For this reason, it becomes easy to divert the existing program as it is. Therefore, process management becomes simple. In addition, it is not necessary to rewrite the program.

  In addition, existing programs often include a precondition that the shape of the nozzle hole 21 (41) is a perfect circle. In this regard, the nozzle hole 21 (41) of the present embodiment has a perfect circle shape except for the overhang portion 212 (412). For this reason, in combination with the overhang amount 2c (4c) being 5 mm or less, the existing program can be easily used as it is. Also, when the dome collapses, the dome fragments are not easily caught. In addition, the nozzle cleaning is easy.

  According to the present embodiment, the fixed plate 2 and the sliding plate 4 have the same shape. For this reason, the same nozzle plate can be used as the fixed plate 2 or the sliding plate 4. Thus, the nozzle plate of the present embodiment is highly versatile.

  <Second embodiment>

  The difference between this embodiment and the first embodiment is only the shape of the nozzle holes of the nozzle plate. Therefore, only the differences will be described here. FIG. 10 shows a cross-sectional view of the fixed plate and the sliding plate of this embodiment as viewed from the lateral direction. FIG. 10 shows a half-open state. Moreover, about the site | part corresponding to FIG. 1, it shows with the same code | symbol.

  As shown in FIG. 10, the fixed-side opening 210 of the fixed plate 2 has a perfect circle shape that is coaxial with the nozzle hole (not shown) of the upper nozzle and has the same diameter. On the other hand, an overhanging portion 212 is disposed at the opening direction end (left direction end) of the sliding side opening 211. The overhang portion 212 has a partial circle shape surrounded by a straight line and an arc (see FIG. 3 above). That is, the nozzle hole 21 has a taper shape in which the opening direction end gradually protrudes from the upper side to the lower side with respect to the straight tubular nozzle hole (indicated by a one-dot chain line in the drawing).

  Similarly, the fixed side opening 410 of the sliding plate 4 has a perfect circle shape that is coaxial with the nozzle hole (not shown) of the lower nozzle and has the same diameter. On the other hand, an overhanging portion 412 is disposed at the opening direction end (right direction end) of the sliding side opening 411. The overhanging portion 412 has a partial circle shape surrounded by a straight line and an arc (see FIG. 2 above). That is, the nozzle hole 41 has a tapered shape in which the opening direction end gradually protrudes from the bottom toward the inner diameter side with respect to the straight tubular nozzle hole (indicated by a one-dot chain line in the drawing).

  The nozzle plate 2 (4) of this embodiment has the same effects as the nozzle plate of the first embodiment. Further, according to the nozzle plate 2 (4) of the present embodiment, the fixed side opening 210 (410) has a perfect circle shape that is coaxial with the nozzle hole of the upper nozzle (nozzle hole of the lower nozzle) and has the same diameter. Yes. For this reason, there is no step between the fixed side opening 210 (410) and the nozzle hole of the upper nozzle (nozzle hole of the lower nozzle). Therefore, it becomes easy to ensure the flow rate of molten steel. Moreover, it becomes difficult to generate turbulent flow in the flow of molten steel. In addition, the shape of the nozzle hole 21 (41) changes gently in the vertical direction. Also in this point, it becomes easy to ensure the flow rate of molten steel. Moreover, it becomes difficult to generate turbulent flow in the flow of molten steel.

  <Third embodiment>

  First, the configuration of a rotary nozzle in which the nozzle plate of the present embodiment is used will be described. FIG. 11 shows a cross-sectional view of the rotary nozzle as viewed from the lateral direction. FIG. 11 shows a fully opened state. Moreover, about the site | part corresponding to FIG. 1, it shows with the same code | symbol.

  As shown in FIG. 11, the rotary nozzle 7 includes a fixed plate 2, a fixed metal frame 3, a sliding plate 4, a sliding metal frame 5, and a gear 8. The rotary nozzle 7 is included in the two-sheet sliding nozzle of the present invention. The fixed plate 2 and the sliding plate 4 are included in the nozzle plate of the present invention.

  The fixed plate 2 is made of a refractory material and has a plate shape. A metal band 22 is disposed on the outer peripheral side of the fixed plate 2. The fixed plate 2 has a nozzle hole 21 that penetrates the fixed plate 2 in the vertical direction. The space in the nozzle hole 21 has a columnar shape with the same diameter, excluding an overhang portion described later. The nozzle hole 21 has a fixed side opening 210 and a sliding side opening 211. The fixed side opening 210 and the sliding side opening 211 are included in the modified opening of the present invention. The fixed side opening 210 is arranged on the upper surface of the fixed plate 2. The sliding side opening 211 is disposed on the lower surface of the fixed plate 2. The shapes of the fixed side opening 210 and the sliding side opening 211 will be described in detail later.

  The fixed metal frame 3 is made of metal and has a plate shape. A recess 30 is formed on the lower surface of the fixed metal frame 3. Further, an upper nozzle holding hole 31 is formed between the upper surface of the concave portion 30 (corresponding to the bottom surface of the concave portion 30) and the upper surface of the fixed metal frame 3. The fixed plate 2 is accommodated in the recess 30.

  A ladle 95 is disposed above the fixed metal frame 3. The ladle 95 has a bottomed cup shape that opens upward. An upper nozzle through hole 950 is formed in the bottom wall of the ladle 95. The upper nozzle 90 is inserted into the upper nozzle through hole 950. The upper nozzle 90 is made of a refractory material and has a cylindrical shape. The upper nozzle 90 is included in the counterpart member of the present invention. The upper nozzle 90 is formed with a nozzle hole 901 extending in the vertical direction. The nozzle hole 901 is included in the counterpart nozzle hole of the present invention. The space in the nozzle hole 901 has a cylindrical shape with the same diameter. The lower end portion of the upper nozzle 90 is inserted into the upper nozzle holding hole 31 of the fixed metal frame 3. The upper nozzle 90 and the fixed plate 2 are fixed. In addition, the nozzle hole 901 of the upper nozzle 90 and the fixed side opening 210 of the nozzle hole 21 of the fixed plate 2 are connected in the vertical direction.

  The sliding plate 4 is made of a refractory material and has a plate shape. The sliding plate 4 is disposed below the fixed plate 2. A metal band 42 is disposed on the outer peripheral side of the sliding plate 4. The sliding plate 4 is provided with nozzle holes 41a and 41b penetrating the sliding plate 4 in the vertical direction. The nozzle holes 41a and 41b are arranged 180 degrees apart from the center of rotation of the sliding plate 4 described later.

  The space in the nozzle hole 41a (41b to the following, the code on the nozzle hole 41a side outside the parenthesis, and the code on the nozzle hole 41b side inside the parenthesis, respectively) is a cylindrical column with the same diameter except for the overhanging portion described later. Presents. The nozzle hole 41a (41b) has a fixed side opening 410a (410b) and a sliding side opening 411a (411b). The fixed side opening 410a (410b) and the sliding side opening 411a (411b) are included in the modified opening of the present invention. The fixed side opening 410a (410b) is disposed on the lower surface of the sliding plate 4. The sliding side opening 411a (411b) is arranged on the upper surface of the sliding plate 4. The sliding side opening 411a (411b) and the sliding side opening 211 of the nozzle hole 21 of the fixed plate 2 can be connected in the vertical direction. The shapes of the fixed side opening 410a (410b) and the sliding side opening 411a (411b) will be described in detail later.

  The sliding metal frame 5 is made of metal and has a stepped cylindrical shape. On the inner peripheral surface of the sliding metal frame 5, a stepped portion 52 is formed that decreases in diameter from the upper side to the lower side. A recess 50 is formed above the stepped portion 52. On the other hand, a lower nozzle holding hole 51 is formed below the stepped portion 52. The sliding plate 4 is accommodated in the recess 50. The gear 8 is mounted on the upper end portion of the outer peripheral surface of the sliding metal frame 5. The gear 8 meshes with a gear (not shown) of the drive device. The driving force in the horizontal rotation direction is transmitted to the sliding metal frame 5 by the meshing of the gears.

  The lower nozzle 91a (91b) is made of a refractory material and has a cylindrical shape. The lower nozzle 91a (91b) is included in the counterpart member of the present invention. The lower nozzle 91a (91b) has a nozzle hole 911a (911b) extending in the vertical direction. The nozzle hole 911a (911b) is included in the counterpart nozzle hole of the present invention. The space in the nozzle hole 911a (911b) has a cylindrical shape with the same diameter. The lower nozzle 91 a (91 b) is accommodated in the lower nozzle holding hole 51 of the sliding metal frame 5. The lower nozzle 91a (91b) and the sliding plate 4 are fixed. In addition, the nozzle hole 911a (911b) of the lower nozzle 91a (91b) and the fixed side opening 410a (410b) of the nozzle hole 41a (41b) of the sliding plate 4 are connected in the vertical direction. A tundish (not shown) of the continuous casting machine is disposed below the lower nozzle 91a (91b).

  Thus, between the upstream ladle 95 and the downstream tundish, nozzle hole 901 (upper nozzle 90) → nozzle hole 21 (fixed plate 2) → nozzle hole 41a or nozzle hole 41b (sliding) Plate 4) → A molten steel flow path that is continuous with the nozzle hole 911a (lower nozzle 91a) or the nozzle hole 911b (lower nozzle 91b) is formed.

  The nozzle hole 901 and the nozzle hole 21 (specifically, the portion other than the overhanging portion in the nozzle hole 21) are connected coaxially and in the same diameter and integrally. The nozzle hole 41a (specifically, the portion other than the protruding portion in the nozzle hole 41a) and the nozzle hole 911a, and the nozzle hole 41b (specifically, the portion other than the protruding portion in the nozzle hole 41b) and the nozzle hole 911b are coaxial and the same. It is connected to the diameter and integrally.

  Next, the shape of the nozzle hole 41a of the sliding plate 4 will be described in detail. The shape of the nozzle hole 41b is the same as the shape of the nozzle hole 41a. Therefore, explanation is omitted here.

  FIG. 12 shows an enlarged top view of the vicinity of the nozzle hole of the sliding plate. As shown in the figure, the portion other than the overhanging portion 412a (shown by hatching for convenience of description) in the nozzle hole 41a (fixed side opening 410a, sliding side opening 411a) has a perfect circle shape centered on the point 4ao. Yes. The overhanging portion 412a is disposed at the opening direction end (clockwise direction end in the figure) among the arc-shaped opening / closing direction ends of the nozzle hole 41a. The opening / closing direction total length 4aa of the nozzle hole 41a is set shorter than the vertical total length 4ab perpendicular to the opening / closing direction by the amount of the protruding portion 412a. The overhanging portion 412a protrudes toward the inner diameter side (closed side, counterclockwise in the drawing) by an overhang amount 4ac with respect to a virtual perfect circle 4ad (indicated by a one-dot chain line in the drawing) having a vertical length 4ab as a diameter. Yes. In this embodiment, the overhang amount 4ac is set to 1 mm, the vertical length 4ab is set to 40 mm, and the opening / closing direction length 4aa is set to about 39 mm (= about 40 mm-1 mm).

  Next, the shape of the nozzle hole 21 of the fixed plate 2 will be described in detail. The rotation direction of the fixed plate 2 and the rotation direction of the sliding plate 4 are just opposite. The reason is that when the sliding plate 4 moves counterclockwise in the figure, the fixed plate 2 moves clockwise in the figure when viewed relatively.

  FIG. 13 shows an enlarged top view in the vicinity of the nozzle holes of the fixed plate. As shown in the figure, the portion other than the overhanging portion 212 (shown by hatching for convenience of description) in the nozzle hole 21 (fixed side opening 210, sliding side opening 211) has a perfect circle shape centered on the point 2o. Yes. The overhanging portion 212 is disposed at an opening direction end (counterclockwise direction end in the drawing) of both ends of the nozzle hole 21 in the opening and closing direction. The opening / closing direction total length 2a of the nozzle hole 21 is set to be shorter than the vertical total length 2b perpendicular to the opening / closing direction by the amount of the protruding portion 212 disposed. The overhanging portion 212 protrudes toward the inner diameter side (closed side, counterclockwise in the drawing) by a protruding amount 2c with respect to a virtual perfect circle 2d (indicated by the alternate long and short dash line in the figure) having a vertical length 2b as a diameter. Yes. In this embodiment, the overhang amount 2c is set to 1 mm, the full length 2b in the vertical direction is set to 40 mm, and the full length 2a in the opening / closing direction is set to about 39 mm (= about 40 mm-1 mm).

  Next, the movement when the rotary nozzle is switched from the fully open state to the fully closed state via the half-open state will be described. FIG. 14 shows a top view of the fixed plate and the sliding plate of FIG. As shown in FIG. 14, in the fully open state, the nozzle hole 21 and the nozzle hole 41a are connected so that the center 2o and the center 4ao are aligned. Returning to FIG. 11, when the driving force is transmitted to the gear 8 from this state, the sliding metal frame 5 rotates in the counterclockwise direction in the drawing around the rotation center 7o in FIG. For this reason, the sliding plate 4 accommodated in the sliding metal frame 5 also rotates counterclockwise in the figure around the rotation center 7o.

  FIG. 15 shows a top view of the fixed plate and the sliding plate in the half-open state. FIG. 16 is a perspective view of the fixed plate and the sliding plate shown in FIG. As shown in FIGS. 15 and 16, in the half-open state, the nozzle hole 41 a of the sliding plate 4 is arranged to be shifted in the counterclockwise direction in the drawing with respect to the nozzle hole 21 of the fixed plate 2. For this reason, a part of the upper surface of the sliding plate 4 (shown by hatching hatched in the left direction in FIGS. 15 and 16) and a part of the lower surface of the fixed plate 2 (shown by hatching hatching in the right direction in FIGS. 15 and 16). Appears in the flow path of the molten steel. These hatched portions correspond to regions where melting damage is likely to occur. The overhanging portion 212 and the overhanging portion 412a are arranged including a region where the melting damage is likely to occur. When a driving force is applied to the gear (not shown) from this state, the sliding metal frame (not shown) rotates around the rotation center 7o in the counterclockwise direction in the figure. For this reason, the sliding plate 4 accommodated in the sliding metal frame also rotates counterclockwise in the figure.

  FIG. 17 shows a top view of the fixed plate and the sliding plate in the fully closed state. As shown in FIG. 17, in the fully closed state, the nozzle hole 41 a of the sliding plate 4 is closed by the lower surface of the fixed plate 2. Similarly, the nozzle hole 21 of the fixed plate 2 is closed by the upper surface of the sliding plate 4. For this reason, the nozzle hole 21 and the nozzle hole 41a are blocked. In this way, the rotary nozzle 7 is switched from the fully open state to the half open state to the fully closed state.

  When switching from the fully closed state to the fully open state, the driving force is transmitted to the gear (not shown), and the sliding metal frame (not shown) is rotated about the rotation center 7o and further counterclockwise in the figure. Let That is, the sliding plate 4 is further rotated counterclockwise in the drawing. Then, not the nozzle hole 41 a but the nozzle hole 41 b is connected to the nozzle hole 21.

  Thus, in the case of the rotary nozzle 7, the sliding plate 4 rotates only in the counterclockwise direction. For this reason, the opening / closing direction of the nozzle hole 41a is defined based on the fully opened state (the state in which the nozzle hole 41a and the nozzle hole 21 are connected with the maximum flow path cross-sectional area) shown in FIG. Similarly, the opening / closing direction of the nozzle hole 41b is defined based on the fully opened state (the state in which the nozzle hole 41b and the nozzle hole 21 are connected with the maximum flow path cross-sectional area). Specifically, the counterclockwise direction is defined as the closing direction and the clockwise direction is defined as the opening direction based on each fully opened state. The nozzle plate of the present embodiment has the same effects as the nozzle plate of the first embodiment.

  <Fourth embodiment>

  The only difference between this embodiment and the first embodiment is the shape of the nozzle holes of the fixed plate and the nozzle holes of the sliding plate. Therefore, only the differences will be described here. FIG. 18 shows an enlarged top view of the vicinity of the nozzle holes of the sliding plate of the present embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol.

  As shown in the figure, the portion other than the overhanging portion 412 (shown by hatching for convenience of description) in the nozzle hole 41 (fixed side opening 410, sliding side opening 411) has a perfect circle shape centered on the point 4o. Yes. The overhanging portion 412 has a crescent shape surrounded by a perfect circle partial arc and an elliptical partial arc. The overhanging portion 412 is disposed at the opening direction end (right end in the drawing) of the nozzle hole 41.

  In the present embodiment, the overhang amount 4c is set to 3 mm, the vertical length 4b is set to 40 mm, and the opening / closing direction length 4a is set to 37 mm (= 40 mm-3 mm). The shape of the nozzle hole of the fixed plate is the same as the shape of the nozzle hole 41 of the sliding plate 4. Therefore, explanation is omitted here. The nozzle plate of the present embodiment has the same effects as the nozzle plate of the first embodiment.

  <Fifth embodiment>

  The only difference between this embodiment and the first embodiment is the shape of the nozzle holes of the fixed plate and the nozzle holes of the sliding plate. Therefore, only the differences will be described here. FIG. 19 shows an enlarged top view of the vicinity of the nozzle hole of the sliding plate of the present embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol.

  As shown in the figure, the portion other than the overhanging portion 412 (shown by hatching for convenience of description) in the nozzle hole 41 (fixed side opening 410, sliding side opening 411) has a perfect circle shape centered on the point 4o. Yes. The projecting portion 412 has a shape surrounded by a partial arc of a perfect circle and a partial arc of a perfect circle that is reverse R with respect to the partial arc of the perfect circle. The overhanging portion 412 is disposed at the opening direction end (right end in the drawing) of the nozzle hole 41.

  In the present embodiment, the overhang amount 4c is set to 5 mm, the vertical length 4b is set to 40 mm, and the opening / closing direction length 4a is set to 35 mm (= 40 mm-5 mm). The shape of the nozzle hole of the fixed plate is the same as the shape of the nozzle hole 41 of the sliding plate 4. Therefore, explanation is omitted here. The nozzle plate of the present embodiment has the same effects as the nozzle plate of the first embodiment.

< First Reference Form>

The only difference between this reference embodiment and the first embodiment is the shape of the nozzle holes of the fixed plate and the nozzle holes of the sliding plate. Therefore, only the differences will be described here. Figure 20 shows an enlarged top view of the vicinity of the nozzle hole of the sliding plate of the present reference embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol.

  As shown in the figure, the portions other than the overhanging portions 412c and 412d (shown by hatching for convenience of description) in the nozzle hole 41 (fixed side opening 410, sliding side opening 411) have a perfect circle shape centered on the point 4o. Presents. The overhanging portion 412 c is disposed at the opening direction end (right end in the drawing) of the nozzle hole 41. The overhanging portion 412d is disposed at the end of the nozzle hole 41 in the closing direction (left end in the figure).

In this reference embodiment, the amount of projection 4e of the projecting portion 412c to 1 mm, the amount of projection 4f of the projecting portion 412d to 1 mm, to 40mm vertical full length 4b, and the opening and closing direction entire length 4a 38mm (= 40mm-1mm- 1mm) Respectively. The shape of the nozzle hole of the fixed plate is the same as the shape of the nozzle hole 41 of the sliding plate 4. Therefore, explanation is omitted here.

< Second reference form>

The only difference between this reference embodiment and the first embodiment is the shape of the nozzle holes of the fixed plate and the nozzle holes of the sliding plate. Therefore, only the differences will be described here. Figure 21 shows an enlarged top view of the vicinity of the nozzle hole of the sliding plate of the present reference embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol.

As shown in the figure, the nozzle hole 41 (fixed side opening 410, sliding side opening 411) has a rectangular shape. In this reference embodiment, the vertical overall length 4b to 40 mm, the opening and closing direction entire length 4a to 25 mm, are set, respectively. The shape of the nozzle hole of the fixed plate is the same as the shape of the nozzle hole 41 of the sliding plate 4. Therefore, explanation is omitted here.

< Third Reference Form>

The only difference between this reference embodiment and the first embodiment is the shape of the nozzle holes of the fixed plate and the nozzle holes of the sliding plate. Therefore, only the differences will be described here. Figure 22 shows an enlarged top view of the vicinity of the nozzle hole of the sliding plate of the present reference embodiment. In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol.

As shown in the figure, the nozzle hole 41 (fixed side opening 410, sliding side opening 411) has a regular hexagonal shape. In this reference embodiment, the vertical overall length 4b to 40 mm, approximately 34.6mm closing direction entire length 4a, are set, respectively. The shape of the nozzle hole of the fixed plate is the same as the shape of the nozzle hole 41 of the sliding plate 4. Therefore, explanation is omitted here.

  <Others>

  The embodiment of the nozzle plate of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, the shape and dimensions of the nozzle hole 21 and the nozzle holes 41, 41a, 41b are not particularly limited. Moreover, the shape of the nozzle hole 21 and the nozzle holes 41, 41a, 41b may not be the same. For example, the protruding portion may be arranged only in one of the nozzle holes. Further, when switching from the fully closed state to the fully open state, the two nozzle plates 2 and 4 may move together.

  Moreover, in this embodiment, although molten steel was used as a molten metal, the kind of molten metal is not specifically limited. In the present embodiment, the nozzle plates 2 and 4 of the present invention are arranged on the two-sheet sliding nozzles 1 and 7 on the downstream side of the ladle 95. For example, the two-sheet sliding nozzle on the downstream side of the tundish For example, the nozzle plates 2 and 4 of the present invention may be arranged in a two-sheet sliding nozzle arranged in another section.

It is sectional drawing seen from the horizontal direction of the two-piece sliding nozzle in which the plate for nozzles of 1st embodiment is used (fully opened state). It is an enlarged top view near the nozzle hole of the sliding plate of the same embodiment. It is an enlarged top view near the nozzle hole of the fixed plate of the same embodiment. It is a top view of the fixed plate and sliding plate of FIG. It is sectional drawing seen from the horizontal direction of the two-sheet type sliding nozzle of the embodiment (semi-open state). FIG. 6 is a top view of the fixed plate and the sliding plate of FIG. 5. FIG. 6 is a perspective view of the fixed plate and the sliding plate of FIG. 5. It is sectional drawing seen from the horizontal direction of the two-sheet sliding nozzle of the embodiment (fully closed state). FIG. 9 is a top view of the fixed plate and the sliding plate of FIG. 8. It is sectional drawing seen from the horizontal direction of the stationary plate and sliding plate of 2nd embodiment (half-open state). It is sectional drawing seen from the horizontal direction of the rotary nozzle in which the plate for nozzles of 3rd embodiment is used (fully opened state). It is an enlarged top view near the nozzle hole of the sliding plate of the same embodiment. It is an enlarged top view near the nozzle hole of the fixed plate of the same embodiment. FIG. 12 is a top view of the fixed plate and the sliding plate of FIG. 11. It is a top view of the fixed plate and sliding plate of the same embodiment (half open state). FIG. 16 is a perspective view of the fixed plate and the sliding plate of FIG. 15. It is a top view of the fixed plate and sliding plate of the same embodiment (fully closed state). It is an enlarged top view near the nozzle hole of the sliding plate of 4th embodiment. It is an enlarged top view near the nozzle hole of the sliding plate of 5th embodiment. It is an enlarged top view near the nozzle hole of the sliding plate of the first reference embodiment. It is an enlarged top view near the nozzle hole of the sliding plate of the second reference form. It is an enlarged top view near the nozzle hole of the sliding plate of the third reference form.

Explanation of symbols

  1: two-sheet sliding nozzle (two-sheet sliding nozzle), 2: fixed plate (nozzle plate), 2a: full length in the open / close direction, 2b: full length in the vertical direction, 2c: overhang amount, 2d: virtual perfect circle, 2o : Center, 20: Projection, 21: Nozzle hole, 210: Fixed side opening (irregular opening), 211: Sliding side opening (irregular opening), 212: Overhang, 22: Band, 3: Fixed metal frame, 30 : Concave portion, 31: upper nozzle holding hole, 4: sliding plate (nozzle plate), 4a: full length in opening / closing direction, 4aa: full length in opening / closing direction, 4ab: full length in vertical direction, 4ac: overhang amount, 4ad: virtual perfect circle, 4ao: center, 4b: full length in the vertical direction, 4c: overhang amount, 4d: virtual perfect circle, 4e: overhang amount, 4f: overhang amount, 4o: center, 40: convex portion, 41: nozzle hole, 41a: nozzle hole, 41b: Nozzle 410: Fixed side opening (irregular opening), 410a: Fixed side opening (irregular opening), 410b: Fixed side opening (irregular opening), 411: Sliding side opening (irregular opening), 411a: Sliding side opening (irregular shape) 411b: sliding portion 412a: overhanging portion 412b: overhanging portion 412c: overhanging portion 412d: overhanging portion 42: band 5: sliding metal frame, 50: recessed portion, 51: lower nozzle holding hole, 52: stepped portion, 6: operating rod, 7: rotary nozzle (two-sheet sliding nozzle), 7o: center of rotation, 8: gear, 90: upper nozzle (partner side) Member), 900: recess, 901: nozzle hole (mating nozzle hole), 91: lower nozzle (mating member), 91a: lower nozzle (mating member), 91b: lower nozzle (mating member), 910: Recess, 911: Slur hole (mating nozzle hole), 911a: nozzle hole (mating nozzle hole), 911b: nozzle hole (mating nozzle hole), 92: joint, 920: nozzle hole, 95: ladle, 950: upper nozzle penetration Hole.

Claims (7)

Each has a nozzle hole having a sliding side opening and a fixed side opening, and includes two plates arranged such that the sliding side openings can be connected to each other, and the two plates are relatively slid. A nozzle plate used as at least one of the two plates of the two-sheet sliding nozzle that can be opened and closed by changing the communication state between the sliding side openings,
At least the sliding side opening of the sliding-side opening and the stationary opening, the opening and closing direction overall length, than a substantially perpendicular direction perpendicular entire length to the closing direction, Ri profiled opening der which is shorter,
A projecting portion projecting toward the inner diameter side by a predetermined projecting amount with respect to a virtual substantially perfect circle having a diameter of the entire length in the vertical direction is arranged at the opening direction end of the both ends of the opening and closing direction of the deformed opening,
Sites other than the protruding portion of the foreign-shaped opening is approximately nozzle plate, wherein that you have exhibited a circular shape.   Each has a nozzle hole having a sliding side opening and a fixed side opening, and includes two plates arranged so that the sliding side openings can be connected to each other, and the two plates are relatively arc-shaped. A nozzle plate used as at least one of the two plates of the two-sheet sliding nozzle that can be opened and closed by sliding and changing the communication state between the sliding side openings,
  At least the sliding side opening of the sliding side opening and the fixed side opening is a modified opening whose opening / closing direction overall length is set shorter than the vertical direction overall length substantially perpendicular to the opening / closing direction,
  A pair of projecting portions projecting toward the inner diameter side by a predetermined projecting amount with respect to a virtual substantially perfect circle whose diameter is the entire length in the vertical direction are arranged at both ends in the opening and closing direction of the deformed opening,
Sites other than the pair of overhanging portions in the deformed opening have a substantially circular shape,
  Each of the pair of projecting portions has a partial circle shape surrounded by a straight line and an arc,
  The pair of straight lines extend so that an interval between the pair of straight lines extends toward an outer diameter direction of an arc that is a sliding track of the two plates. . The stationary opening is connected to the mating nozzle hole of the mating member, the center of the virtual substantially perfect circle, according to claim 1 or claim 2 is disposed on the hole axis of the mating-side nozzle hole Nozzle plate.   3. The nozzle plate according to claim 1, wherein the overhang amount is set to 1% or more and 40% or less, with the diameter being 100%. 4.   The nozzle plate according to claim 4, wherein the overhang amount is set to 20% or less.   The nozzle plate according to claim 1 or 2, wherein the overhang amount is set to 1 mm or more and 5 mm or less.   The nozzle plate according to claim 1, wherein the fixed side opening has a substantially perfect circle shape.

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