JP4342967B2 - Immersion nozzle for continuous casting - Google Patents

Description

  The present invention relates to an immersion nozzle for continuous casting, and more particularly to an immersion nozzle for continuous casting that is optimal for use in a continuous casting facility equipped with an immersion nozzle changing device that allows the immersion nozzle to be replaced during casting.

  In the continuous casting facility, as shown in a sectional view of an example in FIG. 9, a slide valve 2 is provided at the bottom of a tundish 1 as a typical example of a molten metal container for receiving molten metal. The opening and closing movement causes the molten metal to flow out from the immersion nozzle 4 through the chute nozzle 3 (lower nozzle) immediately below.

  That is, as shown in FIG. 9, the configuration of the housing of the slide valve 2 via the bottom plate support fitting 5 fixed to the bottom surface of the tundish 1 is illustrated as an example in which the three-layer slide valve 2 is used. 6, and an insert nozzle 8 is inserted from below into a nozzle receiving brick 7 fitted in the bottom of the tundish 1, and a bottom plate 9, a slide plate 10, and a seal plate set in the housing 6. 11, and the nozzle holes 8 a, 9 a, 10 a, 3 a, and 4 a of the chute nozzle 3 and the submerged nozzle 4 are arranged so as to be on the same axis.

  A piston rod 12a of a hydraulic cylinder 12 supported by the housing 6 is connected to the slide plate 10, and the slide plate 10 is slidable in the left-right direction in FIG. The flow rate of the molten metal in the tundish 1 is controlled by making the axis of the nozzle hole 10a of the slide plate 10 coincide or disagree with the axis of each nozzle hole.

  In the continuous casting equipment as described above, since the immersion nozzle 4 immersed in the molten metal melts earlier than other nozzles, it is necessary to replace it with a new immersion nozzle in a timely manner.

  Since this exchange is performed during the operation of continuous casting, it is necessary to perform the exchange operation quickly. Therefore, the cross-section L shape that hangs the neck lower part of the immersion nozzle 4 on the molten metal outflow part below the chute nozzle 3 A pair of parallel guide rails 13 and 13 are installed, and the immersion nozzle 4 is supplied from one end of the guide rails 13 and 13 by the immersion nozzle supply means, and the lower part of the neck is passed between the guide rails 13 and 13 and suspended. Then, the automatic changer is employed in which the immersion nozzle 4 is pushed to a position directly below the chute nozzle 3 and the immersion nozzle 4 used so far is pushed out and discharged from the opposite ends of the guide rails 13 and 13. It is like that.

  In FIG. 9, reference numeral 14 denotes a cylinder for pulling up the guide rails 13, 13 to press the upper end surface of the immersion nozzle 4 against the lower surface of the chute nozzle 3.

  On the other hand, in the immersion nozzle 4, the lower end of the nozzle hole 4a is bifurcated into two paths symmetrically on the diameter line to form two outflow holes 4b and 4b, and molten metal (molten steel) is supplied from the outflow holes 4b and 4b to a predetermined amount. It is necessary to determine and set the outflow direction in order to make it flow out in the direction.

  Therefore, when using the immersion nozzle automatic changer as described above, when the immersion nozzle 4 is transferred to the guide rails 13 and 13, the guide rails 13 and 13 are set in the correct direction so that the outflow holes 4b and 4b are directed in a predetermined direction. Must be suspended.

  Therefore, conventionally, for example, as seen in Patent Document 1, the length of two opposite sides of the plate portion 4c in a plan view square shape at the upper end of the immersion nozzle 4 is different from the length of the other two opposite sides. In order to prevent the wrong setting of the immersion nozzle 4 or to provide projections on two opposite sides, the distance between the tips of these projections can be set to the guide rail 13, The distance between the guide rails 13 and 13 cannot be inserted between the guide rails 13 and 13 so as to prevent setting errors.

  However, although the purpose can be achieved by adopting the above-mentioned means in terms of preventing the orientation of the outflow holes 4b and 4b from being mistaken, the function of aligning the nozzle holes 4a cannot be achieved as an actual problem. .

That is, in continuous casting, from the viewpoint of workability of replacing the immersion nozzle during casting, it is usual that the clearance with respect to the guide rails 13 and 13 at the portion inserted between the guide rails 13 and 13 is set to be slightly larger. Therefore, the nozzle holes 4a of the immersion nozzle 4 and the nozzle holes 3a of the chute nozzle 3 are likely to be joined in a state where they do not coincide with each other, and thus the nozzle holes 3a, 4a are not exactly coincident with each other. If it is set to, it will cause "steel bar", leakage steel, abnormal melting of the joint part between the joining surfaces of the chute nozzle 3 and the immersion nozzle 4, or cause deterioration of steel quality due to molten steel drift, etc. There was a problem.
Japanese Patent No. 2760899

  In the present invention, when setting an immersion nozzle, the direction of the outflow hole can be set without making a mistake, and at the same time, the nozzle hole is automatically centered, and a metal insert between the nozzles, leakage steel, melting damage, etc. The issue is to eliminate the occurrence of any problems.

  As a means for solving the above-mentioned problems, the present invention is such that a lower neck portion is suspended between a pair of parallel guide rails arranged in a molten metal outflow portion of a molten metal container in a continuous casting facility and joined to the outflow portion. In the immersion nozzle, an elastic member is arranged at a position facing the opposite surface of the guide rail of the immersion nozzle, and these elastic members are pressed against each of the guide rails on both sides of the immersion nozzle so that the guide rails are in contact with each other. This is because the axis of the nozzle hole is positioned at the center position.

  The installation position of the elastic member is the lower neck portion of the uppermost plate portion of the immersion nozzle or the side surface of the top plate.

  The elastic member can be constituted by a leaf spring (Claim 4). In that case, a linear flat portion that extends over substantially the entire length of the plate portion in the moving direction of the immersion nozzle on the leaf spring and makes surface contact with the guide rail is provided. It is preferable to provide (Claim 5).

  Then, if both ends of the flat portion are folded at an acute angle and an attachment portion is provided at the tip thereof, and the folded leg side portion is provided with a spring function, good spring properties can be given with a simple configuration. If both ends of the flat portion are inclined surfaces that incline in a direction retreating from the side edges of the plate portion (Claim 6), this becomes a guide surface when setting between the guide rails, and the setting work is easy. This is preferable.

  According to the present invention, the elastic member is provided at a position facing the guide rail of the immersion nozzle, and the elastic member is uniformly pressed against the guide rails on both sides of the immersion nozzle so that the immersion nozzle is positioned at the center position between the guide rails. As a result, the presence of this elastic member serves as an index for knowing the direction in which the immersion nozzle is inserted between the guide rails and does not cause a setting error due to a wrong direction, and at the same time, the immersion nozzle can be aligned at once. it can.

  In addition, since the immersion nozzle is in contact with the guide rail via an elastic member, the axis of the nozzle hole can be set correctly even when the clearance between the guide rails is large, It is possible to prevent the occurrence of defects such as quality deterioration due to leakage steel, abnormal melting loss, and molten steel drift.

  Further, since the clearance can be increased, workability at the time of replacing the immersion nozzle during casting can be further improved.

  1 is a cross-sectional view of an embodiment of the immersion nozzle 20 according to the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a cross-sectional view corresponding to the arrow AA in FIG.

  The immersion nozzle 20 has a main body portion made of a refractory material, an outer periphery thereof surrounded by a metal case 21, and has a plate portion 22 having a square shape in plan view at the upper end. A straight portion 20a having a required length range from the lower neck portion, a tapered portion 20b having a constriction extending to the straight portion 20a, and a straight portion 20c having a small diameter extending from the lower end of the tapered portion 20b to the lower end of the immersion nozzle 20 are provided. In addition, a refractory 23 having higher heat resistance is fitted in the axially intermediate portion exposed to the molten steel of the straight portion 20c. Reference numeral 31 denotes a sealing material provided on the upper surface of the plate portion 22.

  A nozzle hole 24 whose upper end is opened from the upper end to the vicinity of the lower end is formed in the axial center portion of the immersion nozzle 20, and the lower end portion of the nozzle hole 24 is branched into two paths on the left and right sides and opens to the side surface. Outflow holes 24a and 24a are provided.

  Elastic members 25, 25 are provided symmetrically on the outer periphery of the position directly below the plate portion 22 (under the neck).

  In the illustrated embodiment, the elastic members 25 and 25 are configured by leaf springs formed by bending as shown in FIGS.

  That is, the elastic member 25 is parallel to the side edge 22a at a position slightly retracted from the opposite side edges 22a, 22a of the plate portion 22 and has a length over a substantially entire length region in the moving direction of the immersion nozzle. A flat portion 26 that is linear in a plan view, leg side portions 27 and 27 at which both ends of the flat portion 26 are folded at an acute angle, and a tip portion of the leg side portions 27 and 27 at the tip of the neck portion of the immersion nozzle 20. It consists of attachment parts 28 and 28 that are in stable contact with the outer peripheral surface and are fixed by welding or the like, and both ends of the flat part 26 are slightly inclined in a direction retreating from the side edge 22a of the plate part 22. The inclined surfaces 29 and 29 function as guide surfaces for facilitating fitting when the inclined surfaces are inserted between the guide rails 30 and 30.

  The distance L1 (shown in FIG. 3) between the flat portions 26 and 26 when the left and right elastic members 25 and 25 are unloaded is the inner end surface of the plate portion support surface 30a (step surface) of the pair of parallel guide rails 30 and 30. The elastic members 25 and 25 are formed to be slightly larger than the distance L2 (shown in FIG. 6) between 30b and 30b, and the side edges 22a and 22a of the plate portion 22 are inserted between the guide rails 30 and 30 from the end portions thereof. Smoothly enters between the inner end surfaces 30c, 30c of the guide rails 30, 30 using the inclined surfaces 29, 29 as a guide, and the flat portions 26, 26 are relatively pressed by the inner end surfaces 30c, 30c, and the leg sides 27, 27, the flat portions 26, 26 of the left and right elastic members 25, 25 are evenly pressed against the inner end faces 30b, 30b of the guide rails 30, 30, and the axial center of the nozzle hole 24 is It is naturally positioned at the center between the drains 30 and 30 and coincides with the axial center of the nozzle hole 3a of the chute nozzle 3, and in this state, the upper surface of the plate portion 22 is pressed against the lower surface of the chute nozzle 3 by the operation of the cylinder 14. .

  The means for bringing the immersion nozzle 20 into pressure contact with the chute nozzle 3 (which may be other than the chute nozzle depending on the configuration of the molten metal outflow portion) is not limited to the cylinder 14 shown in FIG. A spring mechanism or the like may be used.

  As described above, the nozzle holes 3a and 24 are reliably aligned and joined, so that no metal insert or leakage steel occurs on the joining surface, and the steel quality is deteriorated due to abnormal melting of the joining portion or drift of molten steel. Can be prevented.

  Therefore, even if the clearance between the guide rails 30 and 30 and the plate portion 22 is increased to such an extent that the immersion nozzle 20 can be easily inserted, the relationship between the immersion nozzle 20 and the guide rails 30 and 30 is determined by the elastic members 25 and 25. Therefore, the axial center of the nozzle hole 24 is not displaced, and both satisfactory workability when setting the immersion nozzle 20 and the realization of the accuracy of the setting position of the immersion nozzle 20 can be satisfied at the same time. it can.

  FIG. 8 shows an embodiment in which the installation positions of the elastic members 25, 25 are the opposite side surfaces of the plate portion 22, and the configuration of the elastic member 25 itself used is substantially the same as that of the above embodiment. The attachment portions 28 are fixed to the side surface of the plate portion 22 by welding or the like. Since the detailed configuration is the same as that of the above-described embodiment, the same reference numerals are given to portions corresponding thereto.

  Also in this embodiment, the flat portions 26, 26 of the elastic members 25, 25 are in pressure contact with the inner side surfaces 30c, 30c (shown in FIG. 6) of the guide rails 30, 30, so that the nozzle holes 24 of the immersion nozzle 20 are formed. It can be located in the center between the guide rails 30 and 30.

  The elastic member 25 is not limited to the one formed by bending a leaf spring, and it is needless to say that a plurality of parts may be combined to elastically support a member corresponding to the flat portion 26. is there.

1 is a cross-sectional view of an embodiment of an immersion nozzle according to the present invention. FIG. Sectional drawing equivalent to the AA arrow of FIG. The perspective view which takes out and shows one of the elastic members. The fragmentary perspective view of the upper part of the immersion nozzle of FIG. The top view of the state which set the immersion nozzle to the guide rail. FIG. The top view which shows the modification of the installation position of the elastic member in this invention. Sectional drawing of the principal part which shows an example of a continuous casting installation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dundish as an example of molten metal container 2 Slide valve 3 Chute nozzle 20 Immersion nozzle 22 according to the present invention Plate part 24 Nozzle hole 25 Elastic member 26 Flat part 27 Leg side part 28 Attachment part 29 Inclined surface 32 Guide rail

Claims (7)

In a submerged nozzle in which a lower neck portion is suspended between a pair of parallel guide rails arranged in a molten metal outflow portion of a molten metal container in a continuous casting facility and joined to the outflow portion, the guide rail of the submerged nozzle The elastic members are arranged at positions facing the opposite surfaces, and these elastic members are pressed against each of the guide rails on both sides of the immersion nozzle evenly so that the axis of the nozzle hole is positioned at the center position between the guide rails. An immersion nozzle for continuous casting, characterized in that it is configured as described above.   The immersion nozzle for continuous casting according to claim 1, wherein the installation position of the elastic member is the lower neck portion of the lowermost plate portion of the immersion nozzle.   The immersion nozzle for continuous casting according to claim 1, wherein the installation position of the elastic member is a side surface of the uppermost plate portion of the immersion nozzle.   The immersion nozzle for continuous casting according to any one of claims 1 to 3, wherein the elastic member is constituted by a leaf spring.   5. The continuous casting immersion nozzle according to claim 4, wherein the plate spring of the elastic member has a linear flat portion that extends over substantially the entire length of the plate portion in the moving direction of the immersion nozzle and is in surface contact with the guide rail. The plate spring of the elastic member includes a flat portion that is parallel to the side edge of the plate portion, a leg side portion that functions as a spring by folding both ends of the flat portion at an acute angle, and a tip of the leg side portion. And an attachment portion for attachment to the immersion nozzle, and both end portions of the flat portion are inclined surfaces that are inclined in a direction of retreating from the flat portion and serve as guide surfaces when set on the guide rail. Item 5. A continuous casting immersion nozzle according to Item 4. The elastic member is composed of a leaf spring, a flat portion that is located slightly behind the side edge of the plate portion and is parallel to the side edge, and both ends of the flat portion are folded back at an acute angle, and the spring A leg side portion that functions as an attachment portion and an attachment portion that is provided at the tip of the leg side portion and is attached to the immersion nozzle, and both end portions of the flat portion are inclined in a direction of retreating from the side edge of the plate portion. The continuous casting immersion nozzle according to claim 2, wherein the nozzle is an inclined surface that serves as a guide surface when set on the guide rail.

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