JP5877167B2 - Continuous casting method of slab and mold for continuous casting - Google Patents

Description

The present invention detects the short side reaction force from the short side of the slab applied to the short side foot roll disposed immediately below the short side of the continuous casting mold during casting, and the value of the short side reaction force The pressing force of the short side foot roll against the short side of the slab is adjusted by controlling the position of the short side foot roll contacting the short side of the slab according to The long side foot roll that detects the long side reaction force from the long side of the slab applied to the long side foot roll that has been placed and contacts the long side of the slab according to the value of the long side reaction force The present invention relates to a continuous casting method of a slab that suppresses bulging by adjusting the pressing force of a long side foot roll with respect to the long side of the slab by controlling the position of the slab, and a continuous casting mold thereof.

Immediately below the continuous casting mold, the solidified shell thickness of the slab is thin, and the slab tends to be bulged by the hydrostatic pressure inside the slab. Therefore, for the purpose of preventing breakout or uniform cooling of the slab, the casting is brought into contact with the long side and the short side of the slab coming out of the continuous casting mold, respectively, immediately below the continuous casting mold. A long side foot roll and a short side foot roll for guiding the movement of the piece are provided.
For example, Patent Document 1 discloses that in continuous casting of stainless steel, the long side of the slab is a flat type for the purpose of making the long side of the slab as flat as possible and slightly denting the short side. It has been proposed that a foot roll is used, and the short side of the slab is a foot roll with a crown. In addition, using a foot roll with a crown increases the risk of breakout due to excessive pressing of the slab into the center of the short side, and a foot roll with a crown is less expensive to manufacture than a flat foot roll. For example, in Patent Document 2, a foot roll that abuts on the short side of the slab, a single center roll that abuts on the short side center of the slab, and a casting It has been proposed to be constituted by two end rolls that respectively contact the both ends of the short side of the piece.

JP-A-3-291130 JP 2005-270981 A

Here, since the foot roll with a crown of patent document 1 is supported by the foot roll frame provided in the lower end part of the short side phrase which attached the short side copper plate of the mold for continuous casting, The position is fixed. For this reason, if the solidification shrinkage amount of a slab changes by changing the steel type and casting speed of molten steel, the pushing force with respect to the short side of the slab by the foot roll also changes during casting. For example, when the indentation force on the short side of the slab by the foot roll is reduced, large bulging deformation is likely to occur on the short side of the slab in a steel type having a low high-temperature strength (such as extremely low carbon steel or SUS430). Thus, the bulging deformation start portion has a problem that slab cracking is likely to occur.

On the other hand, in Patent Document 2, the center roll constituting the foot roll and the roll shafts of the two end rolls arranged on both sides of the central roll are provided at the bottom of the mold frame holding the mold short-side copper plate. The roll shaft is supported by a swing frame suspended from the shaft, and the lower end of the swing frame and the lower end of the fixed frame extending downward from the bottom of the mold frame are connected by a disc spring type elasticity applying means. The foot roll (the center roll and the two end rolls) is pressed against the short side of the slab with an appropriate force. For this reason, when the solidification shrinkage of the slab changes due to the change in the steel type or casting speed of the molten steel, the swing frame rotates, so that the pressing force of the foot roll by the elastic force applying means during casting also changes. For example, when the solidification shrinkage of the slab increases, the short side of the slab discharged from the continuous casting mold tends to separate from the foot roll, so the foot roll moves following the short side of the slab. However, as the elastic recovery force of the disc spring decreases, the pushing force of the foot roll against the short side of the slab decreases. As a result, in steel types with low high-temperature strength (such as ultra-low carbon steel and SUS430), large bulging deformation is likely to occur on the short side of the slab, and slab cracking is likely to occur at the bulging deformation start portion. Problems arise.

The present invention has been made in view of such circumstances, and detects the reaction force on the short side from the short side of the slab that is applied to the short side foot roll disposed immediately below the short side of the continuous casting mold during casting. And, by controlling the position of the short side foot roll that abuts the short side of the slab according to the value of the short side reaction force, the short side foot roll with respect to the short side of the slab (in some cases, The long side reaction force from the long side of the slab applied to the long side foot roll arranged immediately below the long side is detected, and abuts on the long side of the slab according to the value of the long side reaction force Continuous casting method of slab capable of controlling bulging by adjusting the pressing force of the long side foot roll against the long side of the slab by controlling the position of the long side foot roll and its continuous casting An object is to provide a casting mold.

The continuous casting method of a slab according to the first invention that meets the above-mentioned object is a continuous casting mold having a long side and a short side that are opposed to each other, and having a short-side foot roll directly under each short side. In the continuous casting method of slabs using
A bearing member that supports a roll shaft on which the short side foot roll is mounted is provided on a short side frame provided by projecting downward from a lower end portion of the short side. It is provided so as to be able to advance and retreat with respect to the side, and during the casting of the slab, the short side reaction force applied to the short side foot roll is measured by a reaction force measuring means, and based on the short side reaction force, By operating the advancing / retreating drive means, the bearing member is advanced / retreated with respect to the short side of the slab to adjust the pressing force on the short side of the slab by the short side foot roll , and the short side reaction Control the force within a certain range .

The continuous casting method of a slab according to the second invention that meets the above object is a continuous casting mold having a long side and a short side facing each other, and having a long side foot roll immediately below each long side. In the continuous casting method of slabs using
Long-side advance / retreat drive means is provided on a long-side frame provided with a long-side bearing member that supports a long-side roll shaft on which the long-side foot roll is mounted protruding downward from the lower end of the long side. The long side reaction force applied to the long side foot roll during casting of the slab is measured by the long side reaction force measuring means during the casting of the slab. Then, the long side advance / retreat driving means is operated based on the long side reaction force to advance and retract the long side bearing member with respect to the long side of the slab, and the casting by the long side foot roll is performed. The pressing force on the long side of the piece is adjusted to control the long side reaction force within a certain range .

The continuous casting mold according to the third aspect of the present invention, which has the above object, has a long side and a short side that are arranged to face each other, and is for continuous casting of a slab provided with a short side foot roll immediately below each short side. In the mold,
The short-side foot roll is provided on a short-side frame provided so as to protrude downward from the lower end of the short side so as to be capable of advancing and retreating with respect to the short side of the slab via an advancing / retreating driving means. Mounted on a roll shaft supported by a bearing member ;
When the bearing member is moved back and forth with respect to the short side of the slab and the short side of the slab is pressed by the short side foot roll, the short side reaction force acting on the short side foot roll is applied. a reaction force measuring means for measuring, that having a drive control means for operating said advancing drive means based on the short side reaction force.

The advancing / retreating drive means can include an advancing / retreating drive source, a drive transmission member that connects the advancing / retreating drive source and the bearing member, and a cross-sectional area of an intermediate portion is reduced. The force measuring means may be configured to have a strain gauge embedded in an intermediate portion of the drive transmission member.

The continuous casting mold according to the fourth aspect of the present invention, which has the above-mentioned object, has a long side and a short side that are arranged to face each other, and is used for continuous casting of a slab provided with a long-side foot roll directly under each long side. In the mold,
The long side foot roll is capable of advancing and retreating with respect to the long side of the slab via a long side advance / retreat driving means on a long side frame provided to protrude downward from the lower end of the long side. It is attached to the long side roll shaft supported by the provided long side side bearing member ,
The long side acting on the long side foot roll when the long side bearing member is advanced and retracted with respect to the long side of the slab and the long side foot roll presses the long side of the slab. a long side reaction force measuring means for measuring a lateral reaction force, that have a long side-side drive control means for operating the long side advancing drive means based on the long side side reaction force.
Here, the long side bearing member provided so as to be able to advance and retract with respect to the long side of the slab refers to providing the long side bearing member so as to be horizontally movable toward the inside of the mold.

The long side advancing / retreating drive means includes a long side advancing / retreating drive source, the long side advancing / retreating drive source and the long side bearing member connected to each other, and the cross section of the intermediate part is reduced. The long side reaction force measuring means may have a strain gauge embedded in an intermediate portion of the long side drive transmission member.

In the continuous casting method of a slab according to the first invention, during the casting of the slab, the pressing force against the short side of the slab by the short side foot roll is adjusted, so that the steel type that is easy to bulge (for example, low It is possible to effectively suppress bulging on the short side of the slab of carbon steel, SUS430, etc., and to reduce the frequency of cracking of the slab.

In slab continuous casting method according to the first invention, the short side reaction force applied to the short side foot rolls was measured by operating the advancing drive means based on the short side reaction force, short side and controls the reaction force within a predetermined range, it is possible to control the pressing force when pressing the short side of the slab at the short side foot rolls in a proper range, the effect of bulging of the short side of the slab It is possible to prevent the slab from being deformed and cracking of the slab accompanying the deformation.
Moreover, since the pressing force at the time of pressing the short side of a slab with a short side foot roll is adjusted, it becomes possible to form the hollow of desired depth in the short side of a slab. For this reason, when pinching the short side which the slab opposes with a suspender, it becomes easy to hook the tip side of a suspender on the short side of a slab.

In the slab continuous casting method according to the second invention, during the casting of the slab, the pressing force on the long side of the slab by the long side foot roll is adjusted. It is possible to effectively suppress bulging on the long side and reduce the frequency of occurrence of cracks in the slab.

In slab continuous casting method according to the second aspect of the present invention to measure the long side reaction force applied to the long side foot rolls, by operating the long side advancing drive means based on the long side reaction force, and controls the long side reaction force within a certain range, it is possible to control the pressing force when pressing the long sides of the slab at the long side foot rolls in a proper range, the long side of the slab It is possible to effectively suppress bulging and to prevent deformation of the slab and cracking of the slab accompanying the deformation.

In the continuous casting mold according to the third aspect of the invention, the short side foot roll can be moved back and forth with respect to the short side of the slab by operating the advance / retreat driving means. It is possible to adjust the pressing force on the short side of the slab by the side foot roll. As a result, it is possible to effectively suppress bulging on the short side of the slab of a steel type that is easily bulged (for example, low carbon steel, SUS430, etc.), and to reduce the frequency of cracking of the slab.

The third in the continuous casting mold according to the present invention, the short side side foot rolls upon pressing the short side of the strip cast by advancing and retracting the bearing members against the short side of the slab at the short side foot rolls a reaction force measuring means for measuring the short side reaction force acting on, because it has a drive control means for operating the reciprocating drive means based on the short side reaction force, the short side foot a short side of the slab The pressing force when pressing with a roll can be controlled within an appropriate range, effectively suppressing bulging on the slab and the short side, and preventing the slab from cracking due to deformation and deformation of the slab. Is possible.

In the continuous casting mold according to the fourth aspect of the invention, since the long side foot roll can be moved back and forth with respect to the long side of the slab by operating the long side advance / retreat driving means, In addition, it is possible to adjust the pressing force on the long side of the slab by the long side foot roll. As a result, it is possible to effectively suppress bulging on the long side of the slab of a steel type that is easily bulged, and to reduce the frequency of occurrence of cracks in the slab.

4 In continuous casting mold according to the invention, long side when the pressing the long sides of the long side foot roll cast strip by advancing and retracting the long side bearing member with respect to the long side of the slab a long side reaction force measuring means for measuring the long side reaction force acting on the side foot roll, because it has a long side drive control means for operating the long side advancing drive means based on the long side reaction force The pressing force when pressing the long side of the slab with the long side foot roll can be controlled within an appropriate range, effectively suppressing bulging on the slab and the long side, and deformation of the slab And it becomes possible to prevent the crack of the cast piece accompanying a deformation | transformation.

It is a partial sectional side view by the side of the short side of the casting_mold | template for continuous casting which concerns on one embodiment of this invention. It is a rear view by the side of the short side of the same casting mold. It is AA arrow sectional drawing of FIG. It is explanatory drawing of the drive control means and long side drive control means which operate advancing / retreating drive means and a long side advance / retreat driving means, respectively. It is a partial sectional side view by the side of the long side of the casting mold for continuous casting which concerns on one embodiment of this invention. It is a top view of the long side foot roll of the same casting mold. It is explanatory drawing which shows the relationship between the casting speed in Example 1, and a short side reaction force. It is explanatory drawing which shows the relationship between the casting speed and long side reaction force in Example 1. FIG. It is explanatory drawing which shows the relationship between the casting speed in Example 2, and a short side reaction force. It is explanatory drawing which shows the relationship between the casting speed and long side reaction force in Example 2. FIG. It is explanatory drawing which shows the relationship between the casting speed in Example 3, and a short side reaction force. It is explanatory drawing which shows the relationship between the casting speed and long side reaction force in Example 3.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 and 2, a continuous casting mold 10 according to an embodiment of the present invention is disposed so as to face each other between a pair of long sides 11 opposed to each other and the long sides 11. A short side foot roll 13 is provided immediately below each short side 12. The short side foot roll 13 can be moved back and forth with respect to the short side 17 of the slab 16 via an advancing / retracting drive means 15 on a short side frame 14 provided to protrude downward from the lower end of the short side 12 ( It is mounted on a roll shaft 19 supported by a bearing member 18 provided in a horizontally movable manner (directly moving directly under a mold space constituted by a long side 11 and a short side 12 which are opposed to each other). Details will be described below.

As shown in FIG. 3, the bearing member 18 is arranged in parallel with a gap, and roll support portions 22 and 23 in which insertion holes 20 and 21 into which both end sides of the roll shaft 19 are respectively inserted are formed on the front side, and a roll It has the connection part 24 which connects the base end side of the support parts 22 and 23. As shown in FIG. Moreover, as shown in FIGS. 1 to 3, the short-side frame 14 extends downward on both sides in the width direction (width direction of the short side 12) of the lower end portion of the short-side back plate 25 fixed to the short side 12. Projecting portions 26, 27 provided to project respectively, side plate portions 28, 29 projecting downward in parallel to the lower ends of the projecting portions 26, 27, and connection portions for connecting the side plate portions 28, 29. 30.
In addition, the short side foot roll 13 is attached via a bush 31 (an example of a slide bearing) that is externally mounted on the roll shaft 19. As a result, the short side foot roll 13 is rotatable around the roll shaft 19.

Here, the space | interval of the side-plate parts 28 and 29 arrange | positioned in parallel is adjusted to the distance in which the roll support parts 22 and 23 of the state connected with the connection part 24 can be inserted. With this configuration, the roll support portions 22 and 23 of the bearing member 18 can be inserted between the side plate portions 28 and 29 of the short side frame 14, and the outer surfaces of the roll support portions 22 and 23 Can be slid on the inner surface of the side plate portions 28 and 29. As a result, the movement of the bearing member 18 can be guided by the side plate portions 28 and 29 of the short side frame 14, and the side plate portions 28 and 29 of the short side frame 14 can be guided by the surface of the short side 17 of the slab 16. When the bearing member 18 is arranged so as to be orthogonal to the surface (parallel to the surface of the long side 80 (see FIG. 5) of the slab 16), the bearing member 18 is advanced and retracted along the direction orthogonal to the short side 17 of the slab 16. Can do.

As shown in FIGS. 1 and 2, the advancing / retreating drive means 15 is erected downward at the base of a mounting member 32 that is horizontally arranged with the front side fixed to the protrusions 26, 27 of the short side frame 14. The screw jack 34 which is an example of the advancing / retreating drive source held by the supporting member 33 is provided. Here, the screw jack 34 is held by the support member 33 so that the tip of the output screw shaft 35 of the screw jack 34 is disposed horizontally toward the connecting portion 24 of the bearing member 18.
Further, the advancing / retreating drive means 15 is screwed into the output screw shaft 35 of the screw jack 34, and the base side is connected to a traveling nut 36 that moves in the axial direction of the output screw shaft 35 as the output screw shaft 35 rotates. It has a bolt member 37 which is an example of a drive transmission member whose front side is fixed to the connecting portion 24 of the bearing member 18 and whose cross-sectional area of the intermediate portion is reduced. Reference numeral 38 denotes an electric motor (for example, a servo motor) that is connected to an input shaft (not shown) of the screw jack 34 and applies a rotational driving force to the output screw shaft 35.

Here, the bolt member 37 is inserted in the width direction of the connecting portion 24 (in the state where the roll support portions 22 and 23 connected by the connecting portion 24 are inserted between the side plate portions 28 and 29 connected by the connecting portion 30). The through hole 39 formed in the center part of the roll shaft 19 and the through hole 40 formed in the center part of the connecting part 30 in the width direction (width direction of the short side back plate 25) are connected to the connecting part 24 side. The front side of the bolt member 37 protrudes from the through hole 40 of the connection portion 30 toward the tip end portion of the output screw shaft 35. Then, the nuts 41 and 42 are screwed into the male screw portion formed on the head side from the intermediate portion of the bolt member 37, whereby the connecting portion 24 is fastened by the head 43 and the nut 41 of the bolt member 37 from both sides in the thickness direction. ing. Note that the nut 41 can be prevented from loosening by pressing the nut 41 with the nut 42.

Further, a nut member 46 in which a fitting hole 45 into which a projection 44 formed at the tip of the output screw shaft 35 can be fitted is formed on the front side of the bolt member 37 protruding from the through hole 40 of the connecting portion 30. It is attached. Then, with the projection 44 of the output screw shaft 35 fitted in the fitting hole 45 of the nut member 46, the traveling nut 36 and the nut member 46 are brought into contact with each other, and a bolt 47 and a nut 48, which are examples of fastening members, are attached. In use, the traveling nut 36 and the nut member 46 are connected.

With this configuration, the output screw shaft 35 of the screw jack 34 can be rotated, and the traveling nut 36 can be moved in the axial direction of the output screw shaft 35, and the traveling nut 36 can be connected via the nut member 46. In conjunction with this movement, the bolt member 37 can be advanced and retracted in the axial direction of the bolt member 37. Thus, the roll shaft 19 is moved in the axial direction of the output screw shaft 35 via the bearing member 18 to which the bolt member 37 is connected, that is, along the direction orthogonal to the short side 17 of the slab 16. Can be advanced and retracted.

Further, as shown in FIG. 4, the continuous casting mold 10 advances and retracts the bearing member 18 with respect to the short side 17 of the slab 16 and the short side foot roll 13 moves the short side 17 of the slab 16. When pressed, reaction force measuring means 49 for measuring the short side reaction force acting on the short side foot roll 13 and the operation of the screw jack 34 based on the short side reaction force, that is, traveling of the screw jack 34 Drive control means 50 for controlling the position of the nut 36.

Here, the reaction force measuring means 49 has a strain gauge 51 embedded in an intermediate portion of the bolt member 37. Here, the strain gauge 51 is inserted on the bottom side of the mounting hole portion drilled from the tip end side to the intermediate position of the bolt member 37, and the lead wire 52 connected to the strain gauge 51 is taken out from the hole portion to the outside. It is. Then, a resin (for example, epoxy resin) is filled in the hole portion in which the strain gauge 51 is inserted and solidified. With such a configuration, when the intermediate portion of the bolt member 37 is distorted, the resin filled in the hole portion is also distorted at the same time. By measuring the strain of the resin with the strain gauge 51, the intermediate portion of the bolt member 37 is distorted. Can be detected.

Further, the reaction force measuring means 49 is connected to the strain gauge 51 via the lead wire 52, and the bridge box 53 that measures a change in electrical resistance accompanying the strain of the strain gauge 51 and the electrical resistance output from the bridge box 53. A strain measuring unit 54 provided with a short side strain measuring device that determines the strain generated in the intermediate portion of the bolt member 37 from the signal, and the short side applied to the short side foot roll 13 from the strain signal obtained by the strain measuring unit 54 And a calculation unit 55 having a short side reaction force measuring device for calculating the reaction force.
The short side reaction force measuring device includes a storage unit that stores the elastic modulus of the material forming the bolt member 37, a program for calculating the strain amount of the intermediate portion of the bolt member 37 from the strain signal, For example, a personal computer equipped with a program for calculating stress from the elastic modulus and strain amount of the intermediate portion of the member 37 and calculating the reaction force on the short side from the slab 16 applied to the roll shaft 19 can be configured. .

The drive control means 50 for operating the screw jack 34 based on the short side reaction force obtained by the short side reaction force measuring device of the computing unit 55 has an input function for setting the short side reaction force and a preset value. A short side reaction panel and a short side input from the short side reaction force measuring device of the computing unit 55 and a short side operation panel 56 having a function of displaying the position of the short side foot roll 13 with respect to the reference position. By using the short side reaction force setting signal output from the side operation panel 56, the short side reaction force signal from the short side reaction force measuring device becomes the short side reaction force setting signal. And a control unit 57 on which a program for creating a position control signal for determining the position of the roll 13 is mounted. Further, the drive control means 50 is a signal for supplying power to the electric motor 38 of the screw jack 34 via the signal cable 58 and electric power via the power cable 59 based on the position control signal output from the control unit 57. A power output unit 60 is provided.

1 and 2, the continuous casting mold 10 is a cylinder provided with pistons 63 and 64 respectively connected to connecting pins 61 and 62 provided on both upper and lower sides of the short side back plate 25. 65 and 66 and a fixed frame 70 to which cylinders 65 and 66 are attached. With such a configuration, the taper of the short side 12 can be adjusted by moving the short side back plate 25 by moving the pistons 63 and 64 of the cylinders 65 and 66 forward and backward.

Further, as shown in FIGS. 5 and 6, the continuous casting mold 10 is provided with a long side foot roll 77 immediately below each long side 11, and the long side foot roll 77 is a lower end of the long side 11. Can be moved forward and backward with respect to the long side 80 of the slab 16 via a long side advance / retreat driving means 79 (longer side 11 and short side 12 facing each other). Is mounted on a long-side roll shaft 82 supported by a long-side bearing member 81 provided so as to be horizontally movable toward a position directly below the mold space.

The long side bearing member 81 is arranged in parallel with a gap, and long side roll support portions 83 and 84 in which insertion holes (not shown) into which both end sides of the long side roll shaft 82 are respectively inserted are formed on the front side. And a long side connecting portion 85 that connects the base end sides of the long side roll support portions 83 and 84. Further, the long side frame 78 is provided on the both sides in the width direction (width direction of the long side 11) of the lower end portion of the long side back plate 86 fixed to the long side 11 so as to protrude downward. Long side side plate portions 88 and 89 that are protruded downward and arranged in parallel at the lower ends of the protruding portion 87 and the long side side protruding portions 87, and the base sides of the long side side plate portions 88 and 89 ( And a long side connecting portion 90 that connects to the back side of the back of the long side back plate 86.
The long side foot roll 77 is attached via a bush 91 (an example of a sliding bearing) that is externally mounted on the long side roll shaft 82. As a result, the long side foot roll 77 can rotate around the long side roll shaft 82.

Here, the gap between the side plates 88 and 89 on the long side arranged in parallel is adjusted to a distance in which the long side roll support portions 83 and 84 in the state of being connected by the long side connecting portion 85 can be inserted. Yes. With this configuration, the long-side roll support portions 83 and 84 of the long-side bearing member 81 can be inserted between the long-side side plate portions 88 and 89 of the long-side frame 78. The outer surfaces of the long side roll support portions 83 and 84 can be slid on the inner surfaces of the side plates 88 and 89 on the long side. As a result, the movement of the long side bearing member 81 can be guided by the side plates 88 and 89 on the long side of the long side frame 78, and the side plates 88 and 89 on the long side of the long side frame 78. Is arranged so as to be orthogonal to the surface of the long side 80 of the slab 16, the long side bearing member 81 can be advanced and retracted along the direction orthogonal to the long side 80 of the slab 16.

The long side advance / retreat driving means 79 is erected downward at the base of a mounting member 92 that is horizontally arranged with the front side fixed to one side of the long side protrusion 87 that forms a pair with the long side frame 78. The screw jack 94 which is an example of the long side advance / retreat drive source held by the support member 93 and the other side of the long side projecting portion 87 which is a pair of the long side frame 78 are fixed horizontally and the front side is fixed. And a screw jack 97 as an example of a long side advance / retreat drive source held by a support member 96 erected downward at the base of the mounting member 95. Here, the screw jacks 94, 97 are horizontally arranged so that the tips of the output screw shafts 98, 99 of the screw jacks 94, 97 are directed toward the long side connection portion 85 of the long side bearing member 81. The supporting members 93 and 96 are held respectively.
Further, the long side advance / retreat driving means 79 is screwed into the output screw shafts 98 and 99 of the screw jacks 94 and 97, respectively, and the axial direction of the output screw shafts 98 and 99 is accompanied by the rotation of the output screw shafts 98 and 99. The long side drive transmission member whose base side is connected to the traveling nuts 100 and 101 that move to the long side, the front side is fixed to the long side connecting portion 85 of the long side bearing member 81, and the cross-sectional area of the intermediate portion is reduced. Bolt members 102 and 103, which are examples of the above. Reference numerals 104 and 105 denote electric motors (for example, servo motors) that are connected to an input shaft (not shown) of the screw jacks 94 and 97 and give a rotational driving force to the output screw shafts 98 and 99.

Here, the bolt members 102 and 103 include long side roll support portions 83 and 84 connected by the long side side connecting portion 85, and long side side plate portions 88 and 89 connected by the long side side connecting portion 90. The through-hole 106 formed in both sides in the width direction of the long side connecting portion 85 (axial direction of the long side roll shaft 82) and the long side side connecting portion 90 in the width direction (long side back) The plate 86 is inserted into the through holes 107 formed on both sides from the long side connecting portion 85 side, and the front sides of the bolt members 102 and 103 are output from the through holes 107 of the long side connecting portion 90. Projecting toward the tip of the screw shafts 98 and 99. The nuts 108 and 109 are screwed into male screw portions formed on the head side with respect to the intermediate portions of the bolt members 102 and 103, whereby the long side connecting portion 85 is connected to the head portions of the bolt members 102 and 103 from both sides in the thickness direction. 110 and nut 108 are fastened. Note that the nut 108 can be prevented from loosening by pressing the nut 108 with the nut 109.

In addition, on the front side of the bolt members 102 and 103 protruding from the through hole 107 of the long side connection portion 90, a fitting hole 112 into which the protruding portion 111 formed on the tip portion of the output screw shafts 98 and 99 can be fitted. The formed nut member 113 is attached. Then, the traveling nuts 100 and 101 and the nut member 113 are brought into contact with each other in a state in which the protruding portions 111 of the output screw shafts 98 and 99 are fitted into the fitting holes 112 of the nut member 113, and a bolt 114 which is an example of a fastening member. The nuts 113 are connected to the traveling nuts 100 and 101 using the nut 115.

With such a configuration, by rotating the output screw shafts 98 and 99 of the screw jacks 94 and 97, the traveling nuts 100 and 101 can be moved in the axial direction of the output screw shafts 98 and 99. The bolt members 102 and 103 can be moved back and forth in the axial direction of the bolt members 102 and 103 in conjunction with the movement of the traveling nuts 100 and 101 via the nut member 113. Thereby, the long side roll shaft 82 is moved in the axial direction of the output screw shafts 98 and 99 via the long side bearing member 81 to which the bolt members 102 and 103 are connected, that is, the long side of the slab 16. It can be advanced and retracted along a direction orthogonal to 80.

Further, as shown in FIGS. 4 and 5, the continuous casting mold 10 has the long side bearing member 81 moved forward and backward with respect to the long side 80 of the slab 16, and the slab 16 by the long side foot roll 77. A long side reaction force measuring means 116 for measuring a long side reaction force acting on the long side foot roll 77 when the long side side 80 is pressed, and a screw jack 94 based on the long side reaction force, 97 has a long side drive control means 117 which operates in synchronization with 97, that is, controls the position of the traveling nuts 100, 101 of the screw jacks 94, 97.

Here, the long side reaction force measuring means 116 has a strain gauge 118 embedded in an intermediate portion of the bolt members 102 and 103. Here, the strain gauge 118 is inserted into the bottom side of the mounting hole portion drilled from the tip side to the intermediate position of the bolt members 102 and 103, and the lead wire 119 connected to the strain gauge 118 is externally connected from the hole portion. Has been taken out. Then, a resin (for example, epoxy resin) is filled in the hole portion in which the strain gauge 118 is inserted and solidified. With such a configuration, when the intermediate portion of the bolt members 102 and 103 is distorted, the resin filled in the hole portion is also distorted at the same time, and by measuring the strain of the resin with the strain gauge 118, the bolt member 102, The distortion of the middle part 103 can be detected.

Further, the long side reaction force measuring means 116 is connected to a lead wire 119 connected to the strain gauge 118 and measures a change in electric resistance due to strain of the strain gauge 118, and is output from the bridge box. A strain measuring unit 54 having a long side strain measuring device for determining the strain generated in the intermediate portion of the bolt members 102 and 103 from the electrical resistance signal, and the long side from the strain signal determined by the strain measuring unit 54 And a calculator 55 having a long side reaction force measuring device for calculating a long side reaction force applied to the foot roll 77.
The long side reaction force measuring device includes a storage unit that stores the elastic modulus of the material forming the bolt members 102 and 103, and calculates the strain amount of the intermediate portion of the bolt members 102 and 103 from the strain signal. The program and a program for calculating the long-side reaction force from the slab 16 applied to the long-side roll shaft 82 by calculating the stress from the elastic modulus and strain amount of the intermediate part of the bolt members 102 and 103 are mounted. For example, it can be configured using a personal computer.

The long side drive control means 117 for operating the screw jacks 94 and 97 based on the long side reaction force obtained by the long side reaction force measuring device of the computing unit 55 is an input function for setting the long side reaction force. A long side operation panel 120 having a function of displaying the position of the long side foot roll 77 with respect to a preset reference position, and a long side side reaction input from the long side reaction force measuring instrument of the computing unit 55 Using the force signal and the long side reaction force setting signal output from the long side operation panel 120, the long side reaction force signal from the long side reaction force measuring device becomes the long side reaction force setting signal. And a control unit 121 on which a program for creating a position control signal for determining the position of the long side foot roll 77 is mounted.

Further, the long side drive control means 117 is connected to the motors 104 and 105 of the screw jacks 94 and 97 via the signal cable 122 and the drive signal and the power cable 123 based on the position control signal output from the control unit 121. And a signal power output unit 124 for supplying power respectively. Since the same drive signal is input from the control unit 121 to each of the motors 104 and 105, each of the motors 104 and 105 is driven in synchronization. Therefore, the long side foot roll 77 moves forward and backward while holding the axial direction of the long side foot roll 77 parallel to the surface of the long side 80 of the slab 16. The deformation of the slab 16 by the roll 77 can be prevented.

Then, the continuous casting method of the slab 16 using the casting mold 10 for continuous casting which concerns on one embodiment of this invention is demonstrated.
In the continuous casting method of the slab 16 using the continuous casting mold 10 which has the long side 11 and the short side 12 which are respectively opposed to each other and includes the short side foot roll 13 immediately below each short side 12, the short side A cast piece 16 is provided on a short side frame 14 provided with a bearing member 18 that supports a roll shaft 19 on which the side foot roll 13 is mounted protruding downward from a lower end portion of the short side 12 via an advancing / retracting drive means 15. It is provided so as to be able to advance and retreat with respect to the short side 17. Then, during casting of the slab 16, the short side reaction force applied to the short side foot roll 13 is measured, and the advancing / retreating drive means 15 is operated based on the short side reaction force to cast the bearing member 18. The pressing force of the short side foot roll 13 against the short side 17 of the cast piece 16 is adjusted by moving the short side 17 of the piece 16 forward and backward.
For this reason, the pressing force at the time of pressing the short side 17 of the slab 16 with the short side foot roll 13 can be controlled within an appropriate range, and the bulging of the short side 17 of the slab 16 is effectively suppressed. In addition, it is possible to prevent the slab 16 from being deformed and cracking of the slab 16 due to the deformation.

Moreover, since the pressing force at the time of pressing the short side 17 of the slab 16 with the short side foot roll 13 can be adjusted, a recess having a desired depth can be formed on the short side 17 of the slab 16. become. For this reason, when pinching the short side 17 which the slab 16 opposes with the hanger which is not shown in figure, it becomes easy to latch the front side of a hanger to the short side 17 of the slab 16. As a result, the slab 16 can be easily handled.

In the continuous casting method of the slab 16 using the continuous casting mold 10 of the present invention, a long side roll shaft is provided with a long side foot roll 77 provided immediately below each long side 11, and the long side foot roll 77 is mounted. A long-side advance / retreat driving means 79 is provided on a long-side frame 78 provided by projecting the long-side bearing member 81 supporting the 82 downward from the lower end of the long-side back plate 86 attached to the long side 11. It is provided so as to be able to advance and retreat with respect to the long side 80 of the slab 16. Then, during the casting of the slab 16, the long side reaction force applied to the long side foot roll 77 is measured, and the long side advance / retreat driving means 79 is operated based on the long side reaction force. The side bearing member 81 is moved back and forth with respect to the long side 80 of the slab 16 to adjust the pressing force of the long side foot roll 77 against the long side 80 of the slab 16.
For this reason, the pressing force at the time of pressing the long side 80 of the slab 16 with the long side foot roll 77 can be controlled within an appropriate range, and the bulging of the long side 80 of the slab 16 can be effectively suppressed. At the same time, it becomes possible to prevent deformation of the slab 16 and cracking of the slab accompanying the deformation.

Example 1
A square-shaped mold space composed of short sides opposed to each other between long sides opposed to each other, and a long side foot roll and a short side foot roll just below the long side and short side, respectively. Using the continuous casting mold, slabs were cast from the molten steel A poured into the mold space at various casting speeds. At that time, each of the short side foot rolls on the short side and long side of the slab discharged from the lower end of the mold space portion of the continuous casting mold by operating the forward / backward driving means and the long side forward / backward driving means, respectively. And while measuring the movement of the slab by contacting the long side foot roll, the short side reaction force applied to the short side foot roll is measured with a strain gauge embedded in the bolt member of the advancing / retreating drive means. Thus, the long-side reaction force applied to the long-side foot roll was obtained by measuring the strain with a strain gauge embedded in the bolt member of the long-side advance / retreat driving means. The measurement result of the short side reaction force is shown in FIG. 7, and the measurement result of the long side reaction force is shown in FIG.
The inner dimension of the lower end of the mold space is such that the distance on the long side is, for example, 200 mm, the distance on the short side is, for example, 1200 mm, and the length of the mold space is, for example, 700 mm. The taper rate formed was 1.21% / m.

As shown in FIGS. 7 and 8, when casting was started and the casting speed became a constant value, it was confirmed that the short side reaction force and the long side reaction force fluctuate within a certain range. Moreover, the short side reaction force was larger than the long side reaction force, and it was confirmed that the slab was easily bulged to the short side.
Further, as the casting speed increased, both the short side reaction force and the long side reaction force tended to increase. The increase in the reaction force on the short side and the reaction force on the long side respectively decreases the function of cooling the slab when the casting speed increases (the shrinkage rate of the slab decreases) and is discharged from the mold space. It is understood that this corresponds to an increase in the size of the slab.

(Example 2)
Using the continuous casting mold having the same configuration as in Example 1, the slab is cast from the molten steel A at various casting speeds, and the short side reaction is applied to the short side foot roll and the long side foot roll during casting. The force and the long side reaction force were obtained. The measurement result of the short side reaction force is shown in FIG. 9, and the measurement result of the long side reaction force is shown in FIG. The inner dimension of the lower end of the mold space is such that the distance on the long side is, for example, 200 mm, the distance on the short side is, for example, 1200 mm, and the length of the mold space is, for example, 700 mm. The taper rate formed was 1.25% / m.
As shown in FIGS. 9 and 10, when casting was started and the casting speed became a constant value, it was confirmed that the short-side reaction force and the long-side reaction force fluctuate within a certain range. Moreover, it has confirmed that the long side reaction force became larger than the short side reaction force, and the tendency for a slab to bulge to the short side became small. This is considered to be because the short side taper rate of 1.25% / m promotes cooling on the short side of the slab and increases the thickness on the short side of the solidified shell.

(Example 3)
Using the casting mold for continuous casting having the same configuration as in Example 1, the slab is cast from the molten steel B at various casting speeds and applied to the short side foot roll and the long side foot roll during casting. The force and the long side reaction force were obtained. The measurement result of the short side reaction force is shown in FIG. 11, and the measurement result of the long side reaction force is shown in FIG. The inner dimension of the lower end of the mold space is such that the distance on the long side is, for example, 200 mm, the distance on the short side is, for example, 1200 mm, and the length of the mold space is, for example, 700 mm. The taper rate formed was 1.45% / m.
As shown in FIGS. 11 and 12, when casting was started and the casting speed became a constant value, it was confirmed that the short side reaction force and the long side reaction force fluctuate within a certain range. Moreover, it has confirmed that the long side reaction force became larger than the short side reaction force, and the tendency for a slab to bulge to the short side became small. This is understood because the pressing force on the short side is optimized.

As described above, in the continuous casting method and continuous casting mold of the slab according to the present invention, the long side reaction force and the short side from the slab applied to the long side foot roll and the short side foot roll during casting are shortened. It can be confirmed that the side reaction force can be accurately measured, and the short side and the long side foot roll are adjusted based on the short side reaction force and the long side reaction force to adjust the position of the short side. It was confirmed that the movement of the slab can be guided while the slab is supported with the optimum pressing force by the foot roll and the long side foot roll.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
Further, the present invention also includes a combination of components included in the present embodiment and other embodiments and modifications.
For example, the short-side foot roll and the long-side foot roll can each be provided with only one step in the vertical direction, or two or more steps.
Also, multiple short-side foot rolls and long-side foot rolls are provided, and short-side reaction force measuring means and long-side reaction force measuring means are installed on the short-side foot rolls and long-side foot rolls, respectively. However, the short side reaction force measurement unit and the long side reaction force measurement unit may be provided in at least one of the short side foot roll and the long side side foot roll.
Furthermore, in this embodiment, the short side foot roll is provided on the short side of the continuous casting mold, and the long side foot roll is provided on the long side, but the short side foot roll is provided only on the short side, or the long side. It is also possible to provide a long side foot roll only on the side.

10: continuous casting mold, 11: long side, 12: short side, 13: short side foot roll, 14: short side frame, 15: forward / backward drive means, 16: cast slab, 17: short side, 18: Bearing member, 19: Roll shaft, 20, 21: Insertion hole, 22, 23: Roll support part, 24: Connection part, 25: Short side back plate, 26, 27: Projection part, 28, 29: Side plate part, 30 : Connection part, 31: bush, 32: attachment member, 33: support member, 34: screw jack, 35: output screw shaft, 36: traveling nut, 37: bolt member, 38: electric motor, 39, 40: through hole, 41, 42: nut, 43: head, 44: protrusion, 45: insertion hole, 46: nut member, 47: bolt, 48: nut, 49: reaction force measuring means, 50: drive control means, 51: distortion Gauge, 52: Lead wire, 5 : Bridge box, 54: Strain measuring unit, 55: Calculation unit, 56: Short side operation panel, 57: Control unit, 58: Signal cable, 59: Power cable, 60: Signal power output unit, 61, 62: Connection Pin, 63, 64: Piston, 65, 66: Cylinder, 70: Fixed frame, 77: Long side foot roll, 78: Long side frame, 79: Long side advance / retreat driving means, 80: Long side, 81 : Long-side bearing member, 82: Long-side roll shaft, 83, 84: Long-side roll support, 85: Long-side coupling, 86: Long-side back plate, 87: Long-side protrusion, 88, 89: Long side side plate part, 90: Long side side connection part, 91: Bush, 92: Attachment member, 93: Support member, 94: Screw jack, 95: Attachment member, 96: Support member, 97: Screw jack , 98, 99 Output screw shaft, 100, 101: Traveling nut, 102, 103: Bolt member, 104, 105: Electric motor, 106, 107: Through hole, 108, 109: Nut, 110: Head, 111: Projection, 112: Insertion Hole: 113: Nut member, 114: Bolt, 115: Nut, 116: Long side reaction force measuring means, 117: Long side drive control means, 118: Strain gauge, 119: Lead wire, 120: Long side operation Panel, 121: Control unit, 122: Signal cable, 123: Power cable, 124: Signal power output unit

Claims (4)

In the continuous casting method of a slab using a continuous casting mold having a long side and a short side, which are respectively arranged to face each other, and having a short side foot roll immediately below each short side,
A bearing member that supports a roll shaft on which the short side foot roll is mounted is provided on a short side frame provided by projecting downward from a lower end portion of the short side. It is provided so as to be able to advance and retreat with respect to the side, and during the casting of the slab, the short side reaction force applied to the short side foot roll is measured by a reaction force measuring means, and based on the short side reaction force, By operating the advancing / retreating drive means, the bearing member is advanced / retreated with respect to the short side of the slab to adjust the pressing force on the short side of the slab by the short side foot roll , and the short side reaction A method for continuously casting a slab, wherein the force is controlled within a certain range . In the continuous casting method of a slab using a continuous casting mold that has a long side and a short side that are respectively arranged to face each other and has a long side foot roll immediately below each long side,
Long-side advance / retreat drive means is provided on a long-side frame provided with a long-side bearing member that supports a long-side roll shaft on which the long-side foot roll is mounted protruding downward from the lower end of the long side. The long side reaction force applied to the long side foot roll during casting of the slab is measured by the long side reaction force measuring means during the casting of the slab. Then, the long side advance / retreat driving means is operated based on the long side reaction force to advance and retract the long side bearing member with respect to the long side of the slab, and the casting by the long side foot roll is performed. A continuous casting method for a slab , wherein the pressing force on the long side of the piece is adjusted to control the long side reaction force within a certain range . In a continuous casting mold of a slab having a long side and a short side that are arranged to face each other and having a short side foot roll immediately below each short side,
The short-side foot roll is provided on a short-side frame provided so as to protrude downward from the lower end of the short side so as to be capable of advancing and retreating with respect to the short side of the slab via an advancing / retreating driving means. Mounted on a roll shaft supported by a bearing member ;
When the bearing member is moved back and forth with respect to the short side of the slab and the short side of the slab is pressed by the short side foot roll, the short side reaction force acting on the short side foot roll is applied. a reaction force measuring means for measuring a continuous casting mold, characterized in Rukoto that having a drive control means for operating said advancing drive means based on the short side reaction force. In a continuous casting mold of a slab having a long side and a short side, which are respectively arranged to face each other, and having a long side foot roll immediately below each long side,
The long side foot roll is capable of advancing and retreating with respect to the long side of the slab via a long side advance / retreat driving means on a long side frame provided to protrude downward from the lower end of the long side. It is attached to the long side roll shaft supported by the provided long side side bearing member ,
The long side acting on the long side foot roll when the long side bearing member is advanced and retracted with respect to the long side of the slab and the long side foot roll presses the long side of the slab. to the long sides reaction force measuring means for measuring a lateral reaction force, characterized Rukoto which have a long side-side drive control means for operating the long side advancing drive means based on the long side side reaction force Continuous casting mold.

Images