KR19990077316A - Continuous casting mold and sealing member for continuous casting mold - Google Patents

Abstract

A sealing member made of a flexible material for sealing the annular gap between the vibrating mold tube 10 and the stationary housing element 22 of the continuous casting mold is introduced. The sealing member includes a circumferential bulge 40, and the convex shape of the circumferential bulge is located at the pressure surface when the sealing members 36, 38, 80, 100, 102, 104 and 106 are installed. It also introduces a continuous casting mold having at least one flexible sealing member for sealing the vibrating mold tube 10, the fixed housing 22 and the annular pressure chamber for the coolant between the vibrating casting tube and the fixed housing. The flexible sealing members 36, 38, 100, 102, 104, 106 are of the type described above, wherein the convex shape of the outer bulge 40 thereof faces the annular pressure chamber.

Description

Continuous casting mold and sealing member for continuous casting mold

When continuously casting the steel billet, the mold vibrates in the casting direction to prevent the billet from sticking to the cooling inner wall of the casting pipe. The vibration of the mold can for example exhibit a frequency of several hertz and an amplitude of 10 mm or more, with the vibration mass reaching several tons. Thus, vibration of the mold requires a lot of work. For this reason, it is desirable to keep the vibration mass as low as possible.

The traditional vibrator encompasses a vibration table, on which the continuous casting mold is arranged as an entity. International patent application WO 95/03904, however, describes a mold having a fixed housing with a combination vibration lever. The casting tube is supported by the vibration lever in the mold, and is connected to the external fixed housing by two elastically deformable ringtype seal membranes, so that the casting tube can vibrate along the casting shaft in the housing. Here, the annular sealing membrane seals the annular pressure chamber for the coolant around the casting tube. In the mold, the mass of the vibrating parts and thus the work consumption are significantly reduced.

Patent application WO 95/03904 proposes not only metallic but also rubber-elastic cyclic membranes. The annular membrane is subjected to very complex mechanical stresses. The annular membrane must first withstand a cooling water pressure of at least 5 bar which is already an intrinsic tensile stress in the annular membrane. The annular membrane is likewise exposed to a vibrational stress having a frequency of several hundred times per minute, wherein the vertical stroke of the cast tube causes a maximum of tensile stress in the annular membrane. The billet can also exert a horizontal tensile force on the cast tube that can stress the annular membrane. Under such complex stresses, the fatigue of the annular membrane is certainly expected relatively quickly.

The present invention relates to a sealing member for sealing an annular gab between a vibrating casting tube and a fixed housing element of a continuous casting mold. The present invention also relates to a continuous casting mold having at least one sealing member as described above.

1 is a schematic view of a longitudinal section of a mold having two sealing members according to the present invention;

2 is a schematic view of a longitudinal section of a mold having four sealing members according to the present invention;

Figure 3 is a cross-sectional view of the sealing member and the guide member according to the present invention in an enlarged one surface of FIG.

4 to 6 show possible embodiments of the fixing part of the sealing member according to the invention.

7 to 9 show possible embodiments of the hinge for the guide member.

10 is a front view of an alternative form of the guide member.

It is an object of the present invention to create an improved sealing member made of a flexible material for sealing an annular gap between a vibrating casting tube and a fixed housing element of a continuous casting mold.

The object is achieved by the sealing member forming a peripheral bulge and the convex shape of the peripheral bulge being located at the pressure surface upon installation of the sealing member.

The sealing member according to the present invention is structurally and essentially much more suitable than the conventional flat sealing membranes for accommodating very complex mechanical stresses in a continuous casting mold. The sealing member exhibits fatigue less quickly, which leads to a relatively longer service life. The technical achievements as described above may be described in detail as follows. The sealing member is deformed when the casting tube moves axially relative to the stationary housing element, and the deformation is to substantially flatten the bulge. The sealing member according to the invention thus extends less than the previously disclosed flat annular membrane, so that the tensile stress is relatively small. In addition, since pressure acts on the convex shape of the outer bulge of the sealing member, it causes substantially compressive stress in the sealing member but no tensile stress.

The sealing member according to the invention is preferably formed as an annular membrane which is inserted horizontally into the continuous casting mold. Because of the bulge according to the invention, the material of the annular membrane does not extend substantially in either the centrifugal or circumferential direction when the cast tube is moved axially. The sealing member according to the present invention may likewise be formed as a pipe socket inserted into the continuous casting mold with the casting shaft coaxial. However, in the embodiment as a pipe socket, the sealing member extends slightly in the circumferential direction in the region of the bulge.

The sealing member according to the invention is preferably made of a rubber-elastic material such as, for example, elastomer or rubber. The sealing member preferably encompasses a reinforcement insert, for example a textile insert. In an embodiment as a pipe socket such a fabric insert should have a stop in the circumferential direction in consideration of expansion in the conical direction.

The invention likewise relates to a continuous casting mold having at least one flexible sealing member for sealing a vibration casting tube, a fixed housing and an annular pressure chamber for a coolant between the vibration casting tube and the fixed housing. The flexible sealing member forms a circumferential bulge, as described above, with the convex shape of the circumferential bulge facing the annular pressure chamber.

Such a mold preferably encompasses the vibrator and the stationary support structure, wherein the support structure supports the vibrator and the vibrator supports the casting tube. The weight of the casting tube is thereby received by the vibrator, and the sealing members are no longer stressed due to the weight of the casting tube. No additional support members need to be arranged between the housing and the casting tube. The small vibration device is formed with a vibration lever mounted in the support structure by a hinge and connected to the casting pipe by a hinge. The vibration device preferably encompasses a hydraulic cylinder as a driver. Alternatively, the casting tube may be elastically suspended in the housing even by using a spring member, so that the vibrator does not need to perform a supporting function, but merely transmit vibrational energy to the casting tube.

The present invention proposes various solutions such that the sealing members according to the present invention are preferably arranged in the continuous casting mold.

In the first embodiment the mold has a lower and an upper sealing member according to the invention which delimit the annular pressure chamber for the coolant around the entire casting tube. The annular pressure chamber is preferably divided into lower and upper annular accumulators which are connected to the inlet or outlet conduits for the coolant by an internal seal with a rubber-elastic annular membrane. A water pipe casing is preferably arranged around the casting pipe so that the water pipe casing forms an annular gap along the casting pipe, one side of which goes into the lower accumulator and the other into the upper accumulator. .

In a second embodiment the mold has a lower and an upper flexible annular accumulator, the accumulator encompasses a lower end or an upper end of the cast tube, wherein the flexible annular accumulators are each two. Comprising sealing members according to the invention located directly opposite the dog, the sealing members are arranged such that the accumulators delimit an annular pressure chamber for the coolant therebetween. Compared with the first embodiment, the cooling water amount of the mold is reduced in the second embodiment. An electromagnetic stirrer may also be arranged between the lower and upper flexible annular accumulators.

In the second embodiment of the mold, the water pipe casing may be arranged around the casting pipe so that the water pipe casing forms an annular gap along the casting pipe, and one side of the annular gap is into the lower flexible annular accumulator. The other side leads into the upper flexible annular accumulator. The water pipe casing is formed as a pressure casing between annular accumulators.

In all molds, at least one guide member may be arranged between the vibrating casting tube and the fixed housing to accommodate the horizontal force acting on the casting tube, so that the guide member has at least one side turn of the casting tube. Restrict in the first direction of. The guide member is preferably connected to the vibrating casting tube or the fixed housing by at least one hinge. The hinge may have a horizontal clearance, for example, to prevent tensile stress in the induction member. The horizontal clearance allows horizontal displacement of the induction member in a second direction opposite to the first direction. Alternatively the guide member may also be mounted in a resiliently sleeve that is at least one hinge or may be telescopically formed. Leaf springs which are installed substantially horizontally and fixedly inserted on one side are likewise possible solutions as guide members.

Embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 shows a first embodiment of a mold for continuous casting equipment. The mold has a casting tube 10 which forms a casting channel 12 for molten steel. The casting tube 10 has an integrated copper tube 12 made of, for example, copper or copper alloy, which has a lower flange 16 at the lower end and an upper flange 18 at the upper end. Vertical bracings 20 connect the lower flange 16 and the upper flange 18 to impart additional rigidity to the casting tube. It can be seen that the casting tube 10 may of course encompass individual forming plates instead of the integrated copper tube 12. The forming plates are connected by a frame structure to form the casting pipe. The mold can of course also be formed for casting other products, such as, for example, billets, beam blanks, slabs, thin slabs and the like.

The casting tube 10 is surrounded by an external cooler 22 having a lower frame 24 and an upper frame 26. The cooler 22 is fixed by a fixed support structure, for example indicated by beam 28 in FIG. The casting tube 10 is here fixed by an oscillating lever 30 which is connected to a fixed cooling box 24 by a cylindrical hinge 32. The second cylinder-type hinge 34 connects the casting tube 10 and the free end of the vibration lever 30. The other free end of the vibration lever 30 is connected to a hydraulic cylinder for generating a vibration having, for example, some millimeter stroke and some Hertz vibration. The vibration is transmitted to the casting pipe 10 by the lever 30.

The lower flange 16 of the casting tube 10 is connected to the lower frame 24 of the cooler 22 by using the flexible first sealing member 36 according to the present invention. The upper flange 18 of the casting tube 10 is connected to the lower frame 24 of the cooler 22 using the second flexible sealing member 38 according to the present invention. Thus, the annular pressure chamber is sealed in the axial direction by two sealing members 36 and 38 according to the present invention around the casting tube 10, wherein the casting tube 10 is freely along the casting shaft in the cooling box 22. Can vibrate.

The two sealing members 36, 38 according to the invention consist of a flexible material, preferably a woven insert, of rubber elastic material. Each sealing member 36, 38 forms an annular membrane, the outer side of the membrane is inserted into the upper or lower frame 26, 24 of the cooling box 22, the inner side of the membrane is the upper or It is inserted into the lower flanges 18 and 16.

3, the lower membrane 36 will be described on behalf of all other membranes. The membrane 36 forms a circumferential bulge 40 and the convex shape of the circumferential bulge faces the annular pressure chamber. Substantially flat annular bodies 42, 44 are continuously connected to both sides of the circumferential bulge 40. The wall thickness and reinforcement insert of the membrane are designed such that the outer bulge 40 remains convex in the direction of the pressure chamber even after pressure is applied to the annular pressure chamber. When the cast tube 10 is moved down by the value + y (actually the cast tube is approximately 5 to 10 mm in most cases) (see arrow), the membrane 36 has the shape indicated by the dotted line. Deformation of the membrane substantially means that the bulge 40 is flattened, ie the radius of curvature is deformed. It can be seen that the material of the membrane 36 does not extend substantially in either the centrifugal or circumferential direction when the casting tube 10 moves in the axial direction, so that no substantial tensile stress occurs in the membrane due to the stroke movement. The initial stress of the sealing member 36 acts positively in relation to the vibration stress of the sealing member. This is because the initial stress interferes with the remaining tensile stress occurring during the vibration process, thereby reducing the maximum value of the tensile stress in the material of the sealing member.

3 and 5 it can be seen that the membrane 36 shows annular swelling portions 24, 44 having a rounded cross section not only on the inner side but also on the outer side. The annular swelling portions 24, 44 are inserted into the annular groove of the flange 16 of the cast pipe or the annular groove of the frame 24 of the cooling box 22 by using the fixing flange 16 'or 24'. In Fig. 4, the annular swelling portion 44 'has a rectangular cross section with substantially two concave outer circumferential indentations, into which the swelling portions of the frame 24 or the fixing flange 24' are engaged, respectively. Reference numeral 48 denotes a clearance hole for the bolt in the swelling portion 44 '. If the annular swelling portion 44 'is formed relatively flat in Fig. 4, the height of the annular swelling portion 44 "in Fig. 6 is larger than the width.

As shown in FIG. 3, the membrane 36 preferably spans at least one guide member 50. The guide member 50 transmits a horizontal force acting on the casting tube 10 by a rod from the casting tube 10 to the support frame 28 (see FIG. 1) through the lower frame 24. In Fig. 3, the guide member 50 is connected to the flange 16 or the frame 24 using a hinge 51 or 52 formed in a cylindrical or spherical shape. As can be seen in FIG. 7, the hinge 52 allows the guide member 50 not only to rotate by the hinge axis "O", but also to allow the guide member 50 to be displaced to the right by a value "x". :

x ≥ L-(L ² -ymax ² ) 0.5,

L = length of guide member 50,

ymax = maximum stroke (positive or negative)

As a result, the guide member 50 does not substantially resist the stroke of the casting tube 10. In other words, the stroke of the casting tube 10 does not cause bending stress as well as tensile stress in the induction member 50. When the horizontal force of the casting tube is transmitted to the frame 24, the guide member 50 operates only in the direction of arrow 44, and receives a compressive stress. Accordingly, the guide member 50 prevents the casting pipe 10 from moving in the direction of the arrow 54 in FIG. The second guide member 56 (see FIG. 1) arranged on the surface opposite to the casting tube 10 prevents the casting tube 10 from moving in a direction opposite to the arrow 54. The additional guide members may for example be arranged in the longitudinal plane in the figure.

The hinge embodiment of FIG. 8 corresponds to the hinge embodiment of FIG. 7, wherein only the guide sleeve 58 for the cylindrical pivot 60 of the guide member 50 is formed. 9 relates to an alternative embodiment of the hinge of the guide member 50. In this embodiment, the two side bearing journals 60 are each provided with elastically compressible sleeves 62, for example rubber, which are each inserted into a fixed link 64. The elastically compressible sleeve 62 prevents the guide member 50 'from substantially resisting the longitudinal stroke of the casting tube 10. Induction member 50 ′ of FIG. 9 may transmit not only compressive stress but also tensile stress in contrast to guide members 50 of FIGS. 7 and 8. The guide member 50 may be formed as a spring member (for example a leaf spring). In this case, the end of the spring member may be fixedly inserted, and the second end may be mounted in the hinge corresponding to FIG. 7, 8, or 9. In this embodiment, the stroke movement in the spring member of the casting tube 10 causes bending stress but no tensile stress. The guiding member 50 may be formed as a telescopic rod, wherein the inhibitor limits the axial overlap of the telescopic rod. By means of the lever 30 it is possible to arrange the guide members between the upper flange 18 and the upper frame 26, although it is well guided at the upper end of the mold.

10 shows a further form of the guide member. The guide member 50 "is formed as a spring-elastic metal annular membrane with centrifugal wedge openings 150. In other words, the guide member 50" has an inner annular flange 152 and an inner ring connected by an elastic web 156. It has an annular flange 154. The outer annular flange 152 is inserted into the frame 24. The inner annular flange 154 is inserted into the flange 16 of the casting tube 10.

In FIG. 1, reference numeral 70 designates an annular chamber between the casting tube 10 and the cooling chamber 22 in the state where the casting tube 10 is freed to move axially in the cooling chamber 22. The sealing apparatus divided into 74 is shown. The sealing device 70 preferably comprises an inner annular plate 76 on the cast tube 10 and an outer annular plate 78 on the cooler 22 which are connected using a flexible annular sealing membrane 80. The flexible annular sealing membrane 80 preferably has a circumferential bulge in which the convex shape of the circumferential bulge is directed toward the accumulator with the highest pressure (lower accumulator 74 in FIG. 1). The lower accumulator 74 is supplied with cooling water through the inlet conduit 82. The coolant flows through the annular inlet slot 84 into the annular gap 86 formed by the water pipe casing 88 surrounding the pipe 14. The coolant flows into the upper accumulator 46 by the annular outlet slot 90 and exits the mold through the outlet conduit 92.

The annular conduits 116, 118 with spray nozzles below or above the annular membranes 36, 38 are arranged externally. The spray nozzles spray coolant onto the surface facing the pressure chambers of the annular membranes 36, 38. The inner surface as well as the outer surface of the cyclic membranes 36, 38, which are relatively thick and undesirable, are thereby cooled relatively uniformly, which prevents premature aging of the cyclic membrane.

Figure 2 shows an embodiment of a mold for a continuous casting plant having four annular membranes 100, 102. 104. 106 in accordance with the present invention. The embodiment is essentially different from the embodiment of FIG. 1 except that the upper and lower accumulators 72 and 74 of FIG. 1 are flexible annular accumulators 72 'and 74', each having two annular membranes 100, positioned up and down. It is formed by 102 or 104, 106. The annular membranes 100, 102 or 104, 106 are formed and fixed as described above.

Therefore, in the mold according to Fig. 2, the original cooler 22 is omitted. The casting tube 10 is surrounded only by the support structure 108, the casting tube 10 is suspended in the support structure to form two pairs of ring plate 110 for the connection of the annular membranes 100, 102 and 104, 106, 112 and 114, 116. The annular plates of each pair 110, 112 and 114, 116 are connected to each other by an external pressure casing 111 or 115, respectively. The pair of annular plates 110, 112 and the pressure casing 111 form an outer fixed boundary of the lower annular accumulator 74 '. Paired annular plates 114, 116 and pressure casing 115 form an external fixed boundary of the upper annular accumulator 72 '. The struts 118 connect the outer fixed boundary of the upper annular accumulator 72 'and the outer fixed boundary of the lower annular accumulator 72' and between the annular accumulators 72 ', 74' for the electromagnetic stirrer 200 in the axial direction. Make a seat It can be seen that the water pipe casing 88 'is of course implemented as a pressure casing between the annular accumulators 72' and 74 '. This is because the water pipe casing must bear the cooling water pressure here. The annular conduits 120, 122, 124 and 126 with spray nozzles are also arranged above and below the annular membranes 100, 102, 104 and 106, as shown in FIG. It is.

Claims (21)

In the sealing member made of a flexible material for sealing the annular gap between the vibrating casting tube 10 and the stationary housing element 22 of the continuous casting mold, A sealing member characterized by a convex outer circumference bulge (40) located on the pressure surface when the sealing member (36, 38, 80, 100, 102, 104, 106) is installed. The sealing member according to claim 1, wherein the sealing member is formed as an annular membrane. The sealing member according to claim 1, wherein the sealing member is formed as a pipe socket. 4. The sealing member according to any one of claims 1 to 3, wherein the sealing member is made of a rubber elastic material. In the continuous casting mold having the vibration casting tube 10, the fixed housing 22 and at least one flexible sealing member for sealing the annular pressure chamber for the coolant between the vibration casting tube and the fixed housing, The flexible sealing members 36, 38, 80, 100, 102, 104 and 106 correspond to any one of claims 1 to 4, wherein the convex shape of the outer bulge 40 faces the annular pressure chamber. Continuous casting molds. 6. The continuous casting mold according to claim 5, characterized in that the vibrator supporting the casting pipe and the support structure (22) supporting the casting tube. The continuous casting mold according to claim 6, wherein the vibration device includes a vibration lever (30) mounted in the support structure (22) by a hinge and connected to the casting pipe (10) by a hinge. . The lower end and the upper end of the casting tube are connected to the fixed housing 22 by the flexible sealing members 36 and 38 according to any one of claims 1 to 4. Therefore, the continuous casting mold, characterized in that the boundary of the annular pressure chamber (72, 74) for the coolant is drawn around the casting tube (10). 9. The annular chamber according to claim 8, wherein the annular chamber is divided into lower and upper annular accumulators (72 and 74) by an inner sealer (70), and the lower and upper annular accumulators (72 and 74) are for cooling liquid. Continuous casting mold, characterized in that connected to the inlet conduit 82 or outlet conduit (92). 10. The continuous casting mold according to claim 9, wherein the inner sealing device (70) comprises an elastic annular membrane (80). The water pipe casing 88 is formed around the casting pipe 10, wherein the water pipe casing forms an annular gap along the casting pipe, and one side of the annular gap is lower. Continuous casting mold, characterized in that through the accumulator, the other side into the upper accumulator. The flexible according to any one of claims 5 to 7, wherein the accumulators are arranged directly opposite each other, arranged to delineate the annular pressure chamber for cooling therebetween. Characterized by lower and upper flexible annular accumulators 72 'and 74' surrounding the lower or upper end of the casting tube 10, respectively covering the sealing members 100, 102 and 104 and 106, respectively. Continuous casting molds. 13. The water pipe casing 88 'is arranged around the casting pipe to form an annular gap 86' along the casting pipe 10, wherein one side of the annular gap is a lower flexible ring. Inside the accumulator 74 ', the other side into the upper flexible annular accumulator 72', where the water pipe casing 88 'is a pressure casing outside the annular accumulators 72' and 74 '. Continuous casting mold, characterized in that formed. 13. The continuous casting mold according to claim 12, wherein an electromagnetic stirrer (200) is arranged between the lower and upper flexible annular accumulators (72 ', 74'). 14. The cooling water spraying device according to any one of claims 5 to 13, wherein the cooling water spraying device is arranged on a surface of the at least one flexible sealing member that faces the pressure chamber so that the cooling water can be sprayed on the surface of the flexible sealing member. Continuous casting molds. 15. The method according to any one of claims 5 to 14, characterized in that it is arranged between the vibrating casting tube and the fixed housing to at least one guide member which limits the side turning of the casting tube in at least one first direction. Continuous casting molds. 16. The continuous casting mold according to claim 15, wherein the induction member is connected to the vibration casting tube or the fixed housing by at least one hinge. 17. The continuous casting mold according to claim 16, wherein the at least one guide member in the hinge has a horizontal clearance, and the horizontal clearance permits horizontal displacement of the guide member in a second direction opposite to the first direction. . 17. The continuous casting mold as claimed in claim 16, wherein the guide member in the at least one hinge is mounted in an elastically compressible sleeve. The continuous casting mold according to claim 15 or 16, wherein the induction member is formed telescopic. 18. The continuous casting mold according to claim 15, 16, or 17, wherein the guide member is formed as a leaf spring that is mounted substantially horizontally.