JP2009028769A - Cast slab guide device in continuous casting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cast slab guide device, which promptly widens the interval between rolls to perform re-drawing when continuous casting is stopped due to occurrence of abnormality. <P>SOLUTION: The cast slab guide device includes: a disk spring cassette 5, which is arranged between a nut 4 connected to a column 3 and a movable frame 2, and which is elastically deformed so that the movable frame 2 is separated from a fixed frame 1 when a load of a predetermined value or more is applied to between a pair of rolls 7, 8; a spacer insertion/withdrawal mechanism 21, by which a spacer 16 is inserted to or withdrawn from between the nut 4 and an elastic buffer mechanism; and a hydraulic jack 22, which compresses and deforms the disk spring cassette 5 so that the spacer 16 is withdrawn from between the nut 4 and the disk spring cassette 5. Even if disk springs 10 are almost in intimate contact with each other due to excessive reaction force generated by an abnormal cast slab, the compressive force to the disk springs 10 is removed by withdrawing the spacer 16, so that a driving mechanism is operated to widen the interval between the rolls 7, 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a slab guide device in a continuous casting facility that continuously draws and transports slabs such as slabs, blooms, and billets from a mold.

  In a continuous casting facility, a slab guide device in which a large number of rolls are arranged is provided in order to transport a slab drawn from a mold. Many rolls are arranged along curves, such as a circular arc and a parabola, so that a slab can be guided from a perpendicular direction to a horizontal direction. In consideration of the workability of roll replacement, the slab guide device is divided into roll segments provided with a plurality of pairs of rolls facing both side surfaces of the slab. On the downstream side of the slab guide device, a drawing device such as a pinch roll drive system is provided continuously to the slab guide device. A cutting device for cutting the slab by a gas torch, hydraulic cutting or the like is provided on the downstream side of the drawing device.

  When continuous operation stops due to operation / equipment abnormalities such as breakout and cutter trouble, the slab is supercooled and begins to expand (bulging) due to the effect of the molten steel static pressure. In such a case, what should be done immediately is to remove the problem that caused the stop, widen the roll interval, and quickly discharge (redraw) the remaining slab. This is because when the solidification and bulging progress while the slab is in the machine, the slab of the curved band is caught on the lower correction point and also on the roll because of the large bulging. In this case, the slab must be cut into small increments from the machine end, or the upper frame and roll can be disassembled and discharged out of the machine by the overhead crane, which takes a long time to recover. One side overheating by slab during restoration and cutting torch at the time of slab cutting causes equipment damage such as bending of the roll and flaws due to fusing on the body.

  When adjusting the opening degree of the roll, the movable frame that supports the roll is moved up and down relative to the fixed frame that supports the roll. In order to move the movable frame up and down, a drive mechanism including a worm mechanism and a screw jack is used. Here, when the drive mechanism is firmly coupled to the movable frame, when a load is applied between a pair of rolls facing each other with the slab interposed therebetween, the roll is bent and the bearing that guides the rotation of the roll is damaged. For this reason, when a certain load or more is applied between the rolls, an elastic buffer mechanism including a disc spring cassette is added so that the movable frame is slightly separated from the fixed frame (see, for example, Patent Documents 1 to 3).

  As shown in FIG. 8, in the slab guide device to which an elastic buffer mechanism is added, a nut 4 is coupled to a column 3 that connects the fixed frame 1 and the movable frame 2, and the nut 4 and the movable frame 2 are connected. Is provided with a disc spring cassette 5. The disc spring cassette 5 includes a top plate 6, a bottom plate 9, and a plurality of disc springs 10 interposed between the top plate 6 and the bottom plate 9. When a large load is applied between the pair of rolls 7 and 8, the disc spring 10 is compressed, and the movable frame 2 rises with respect to the nut 4 fixed to the column 3. By letting the movable roll 7 escape from the fixed roll 8, it is possible to prevent a large load from being applied between the rolls 7 and 8.

  As described above, when the continuous operation is stopped, the slab starts bulging from that moment, so it is necessary to widen the roll interval by the drive mechanism and quickly redraw the remaining slab. However, when the continuous operation is stopped, the disc spring is compressed and brought into a close-contact state due to an excessive reaction force of the thick slab that has been solidified and an excessive spreading force resulting from the passage of the bulged slab. When the disc spring is compressed so as to be in close contact, an excessive load is applied to the drive mechanism, and the drive mechanism is locked. When this happens, the roll interval cannot be increased.

In order to solve this problem, in Patent Document 1, as shown in FIG. 9, a cylinder device 31 is provided at the upper end portion of the column 3, and the movable frame 2 is indicated by a two-dot chain line in the figure by the cylinder device 31. A technique is disclosed in which the load applied to the movable frame 2 and thus the load applied to the drive mechanism is released by further raising the disk spring 10 and further compressing the disc spring 10. If a gap can be opened between the movable roll 7 of the movable frame 2 and the slab, the drive mechanism can be operated and the roll interval can be widened.
Utility Model Registration No. 2528184 JP-A-6-63714 Japanese Utility Model Publication 4-64451

  However, when the reaction force due to the abnormal slab is excessive and the disc spring is almost in close contact, even if the disc spring is compressed by the cylinder device, only a slight gap can be opened between the movable roll and the slab. .

  Moreover, if a clearance is opened between the movable roll and the slab, an appropriate frictional force cannot be generated between the movable roll and the slab. In order to pull out the slab, it is necessary to have an appropriate frictional force between the roll and the slab.

  More generally, one segment has four columns, and a drive mechanism is provided for each of the four columns. Even if you try to raise the movable frame evenly with the four drive mechanisms, the slab that has been pressed down at the four points will be bent asymmetrically due to unloading, or the slab will slide down, The load condition fluctuates and the load concentrates on a specific column. If the clearance between the movable roll and the slab disappears due to the concentration of the load on a specific column, the drive mechanism cannot be operated at that time.

  Accordingly, an object of the present invention is to provide a slab guide device that can quickly widen a roll interval and perform redrawing even if an abnormality occurs and continuous casting stops.

  By the way, the segment of the slab guide device is required to be able to be extracted and inserted from a very narrow gap at the time of replacement. This is because in the curved band, the segment is pulled out toward the inside of the arc. When a bulky cylinder device is arranged at the top of the column like a conventional slab guide device, a segment to be pulled out interferes with a cylinder device of an adjacent segment.

  Therefore, another object of the present invention is to provide a slab guide device in which a segment to be pulled out does not interfere with an adjacent segment when the segment of the slab guide device is pulled out during replacement.

  In order to solve the above-mentioned problem, the invention described in claim 1 is characterized in that at least one pair of guide rolls facing both side surfaces of the slab and arranged in parallel with each other, A fixed frame that rotatably supports the guide roll; a movable frame that rotatably supports the other guide roll of the at least one pair of guide rolls; a column that connects the fixed frame and the movable frame; Provided between a drive mechanism for moving the movable frame relative to the fixed frame, a nut coupled to the column, and the movable frame, so that at least a distance between the pair of guide rolls can be adjusted. When a predetermined load or more is applied between a pair of guide rolls, the movable frame is elastic so that it can be separated from the fixed frame. An elastic buffer mechanism that deforms, a spacer insertion / removal mechanism that allows a spacer to be inserted / removed between the nut and the elastic buffer mechanism of the column, and a spacer insertion / removal mechanism that moves the spacer between the nut of the column and the elastic buffer mechanism. It is a slab guide device in a continuous casting facility comprising a push-down mechanism that compresses and deforms the elastic buffer mechanism so that the elastic buffer mechanism can be removed from the slab.

  According to a second aspect of the present invention, in the slab guide device in the continuous casting facility according to the first aspect, when an abnormal slab is generated, the push-down mechanism compresses and deforms the elastic buffer mechanism, and then the spacer The insertion / removal mechanism removes the spacer from between the end portion of the column and the elastic buffer mechanism, and then the push-down mechanism releases the compressive deformation of the elastic buffer mechanism.

  According to a third aspect of the present invention, in the slab guide device in the continuous casting equipment according to the first or second aspect, the spacer has a horseshoe shape so that the spacer can be inserted into and removed from the column.

  Invention of Claim 4 is the slab guide apparatus in the continuous casting equipment in any one of Claim 1 thru | or 3, The said push-down mechanism is a core couple | bonded with the end part of the said column with a screw, Oil is supplied to a hydraulic cylinder provided around the core and slidable with respect to the core to compress and deform the elastic buffer mechanism, and a hydraulic chamber formed between the core and the movable cylinder. And a hydraulic pressure supply device.

  According to a fifth aspect of the present invention, in the slab guide device in the continuous casting equipment according to any one of the first to fourth aspects, the spacer insertion / removal mechanism includes a movable nut coupled to the spacer, and the spacer insertion / removal. A screw shaft that extends in a direction to be engaged with the movable nut, and a drive mechanism that rotationally drives the screw shaft.

  According to a sixth aspect of the present invention, in the slab guide device in the continuous casting equipment according to any one of the first to fifth aspects, in the plan view of the movable frame, the push-down mechanism and the spacer insertion / removal mechanism are the movable It is arranged on the frame so as not to jump out of the movable frame.

  According to the present invention, even if the reaction force due to the abnormal slab is excessive and the elastic buffer mechanism is almost in close contact, the compressive force applied to the elastic buffer mechanism can be unloaded by removing the spacer. Therefore, it is possible to operate the drive mechanism and widen the roll interval appropriately. As a result, an appropriate frictional force continues to work between the roll and the slab even after the spacer is removed, so that the slab can be drawn again. If the slab can be carried out by quick redrawing, the continuous casting equipment will not be stopped for a long time, and secondary damage can be prevented.

  Further, since the push-down mechanism can be placed on the segment without being bulky, when the segment of the slab guide device is pulled out, the segment to be pulled out does not interfere with the adjacent segment.

  Hereinafter, a slab guide device according to an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, in order to guide a slab drawn from a mold from a vertical direction to a horizontal direction, a slab guide device in which a large number of rolls are arranged along a curve such as an arc or a parabola is provided. In consideration of the workability of roll exchange, the slab guide device is divided into roll segments 11 each having a plurality of pairs of rolls facing both side surfaces of the slab. When the roll segment 11 is replaced, the roll segment 11 is pulled out along the guide 12 extending toward the center of the arc.

  Each roll segment 11 has a lower roll 8 and an upper roll 7 as a pair of guide rolls facing both side surfaces of the slab. In each roll segment 11, a plurality of lower rolls 8 and upper rolls 7 are provided in the direction in which the slab moves. The plurality of lower rolls 8 are rotatably supported by the lower frame 1 that is a fixed frame. The plurality of upper rolls 7 are rotatably supported by the upper frame 2 that is a movable frame via a cylinder 26 (see FIG. 8).

  The lower frame 1 and the upper frame 2 are connected by a column 3. Four columns 3 are provided at the four corners of one roll segment. The distance between the upper frame 2 and the lower frame 1 is adjusted by a worm mechanism 13 and a screw jack 14 (see FIG. 8) that are drive mechanisms. The structure of the drive mechanism is the same as that of the slab guide device shown in FIG. 8, and will be described with reference to FIG. In the column 3, a worm wheel 13 a having an internal screw is rotationally driven by a worm mechanism 13. The column 3 has a built-in screw shaft 14a. When the screw shaft 14a is moved up and down by the worm wheel 13a, it appears as a change in roll interval via the spherical bush 14b fitted to the upper frame 2. In this way, the rotation of the worm wheel 13a is converted to the raising and lowering of the upper frame 2.

  FIG. 2 shows a detailed view of the column 3 in the vicinity of the upper frame 2. A nut 4 is coupled to the upper end of the column 3. Between the nut 4 and the lower plate 2a of the upper frame 2, a disc spring cassette 5 which is an elastic buffer mechanism is provided. The disc spring cassette 5 includes a top plate 6, a bottom plate 9, and a plurality of disc springs 10 interposed between the top plate 6 and the bottom plate 9. The top plate 6 and the bottom plate 9 are connected by a tie rod 15.

  A spacer 16 and a spherical bush 17 are interposed between the lower surface of the nut 4 and the disc spring cassette 5. The spherical bush 17 allows the disc spring cassette 5 to tilt slightly with respect to the column 3. During normal use, the disc spring cassette 5 is compressed between the nut 4 of the column 3 and the lower plate 2 a of the upper frame 2. The force transmitted from the upper frame 2 to the column 3 is transmitted in the order of the upper frame 2 → the disc spring cassette 5 → the spherical bush 17 → the spacer 16 → the nut 4 → the column 3. Since the lower frame 1 is coupled to the lower end portion of the column 3, the column 3 is finally transmitted to the lower frame 1.

  The disc spring cassette 5 has a role of slightly separating the upper roll 7 from the lower roll 8 when a load greater than the set load is applied between the upper roll 7 and the lower roll 8. Specifically, a large load is applied between the upper roll 7 and the lower roll 8, and the disc spring cassette 5 is compressed and deformed when a compression load greater than the set load is applied to the disc spring cassette 5. Due to the compression deformation of the disc spring cassette 5, the upper frame 2 rises with respect to the nut 4 fixed to the column 3. Since the upper roll 7 is rotatably supported by the upper frame 2 and the lower roll 8 is rotatably supported by the column 3 via the lower frame 1, the upper roll 7 is compressed by the compression deformation of the disc spring cassette 5. Can be released from the lower roll 8. It should be noted that the disc spring cassette 5 is not compressed and deformed at a compression load less than the set load. This is to prevent the gap between the upper roll 7 and the lower roll 8 from changing due to a slight change in molten steel static pressure.

  The spacer 16 is inserted and removed between the nut 4 and the disc spring cassette 5 by the spacer insertion / extraction mechanism 21. The hydraulic jack 22 that is a push-down mechanism compresses and deforms the disc spring cassette 5. When the hydraulic jack 22 pushes down the disc spring cassette 5 and a slight clearance is opened between the nut 4 and the disc spring cassette 5 (more precisely, the spherical bush 17 fixed to the disc spring cassette 5), the spacer insertion / extraction mechanism 21 is The spacer 16 can be pulled out.

  3 and 4 are detailed views of the hydraulic jack 22 and the spacer insertion / extraction mechanism 21. FIG. The hydraulic jack 22 includes a core 23 coupled to the upper end portion of the column 3 with a screw, and a movable cylinder 24 provided around the core 23. A hydraulic chamber 25 is formed between the core 23 and the movable cylinder 24. When oil is supplied to the hydraulic chamber 25 from the hydraulic supply device, the movable cylinder 24 slides downward. The movable cylinder 24 compresses and deforms the disc spring cassette 5.

  The spacer insertion / removal mechanism 21 includes a movable nut 27 coupled to the spacer 16, a screw shaft 28 that extends in a direction in which the spacer 16 is inserted / removed and is screwed to the movable nut 27, a drive mechanism 29 that rotationally drives the screw shaft 28, Is provided. When the screw shaft 28 is driven to rotate, the movable nut 27 and the spacer 16 slide in the axial direction of the screw shaft to a position indicated by a two-dot chain line in FIG. The planar shape of the spacer 16 is formed in a horseshoe shape so that it can be inserted into and removed from the column 3.

  FIG. 5 shows a process chart when the spacer 16 is removed. First, oil is supplied to the hydraulic chamber 25, the movable cylinder 24 is slid downward, and the disc spring cassette 5 is compressed and deformed (S1). When the disc spring cassette 5 is compressed and deformed, a slight gap is opened between the nut 4 and the spacer 16. Here, the spacer insertion / extraction mechanism 21 extracts the spacer 16 from between the nut 4 and the disc spring cassette 5 (S2). When a gap is opened between the nut 4 and the spacer 16, the spacer 16 can be removed. Finally, the supply of oil to the hydraulic chamber 25 is stopped, and the hydraulic jack 22 releases the compression deformation of the disc spring cassette 5 (S3). The disc spring cassette 5 is unloaded and extends by the thickness of the spacer 16. Then, the upper surface of the disc spring cassette 5 (more precisely, the spherical bush 17) comes into contact with the lower surface of the nut 4 by the restoring force of the disc spring cassette 5.

  FIG. 6 is a graph showing an example of the relationship between the amount of compressive deformation 8 of the disc spring 10 and the load P. In the figure, the set time represents the normal operation time. During normal operation, a load of 120 Ton is applied to the disc spring 10, and the disc spring is compressed and deformed by 36.5 mm. When the pressure is reduced by 7 mm, the hydraulic jack 22 compresses the disc spring 10 by 7 mm in order to remove the spacer 16. “At the time of close contact” represents a state in which the disc spring 10 is compressed to the maximum in close contact in an emergency. At the close contact, a load of 164 Ton is applied to the disc spring 10 and the disc spring is compressed and deformed by 50 mm.

  Even if the disc spring 10 is compressed to a close contact by bulging of the slab, when the spacer 16 is pulled out, the disc spring 10 is unloaded by the thickness of the spacer 16. In this embodiment, since the spacer 16 has a thickness of about 20 mm, it can be unloaded up to a load of about the time of setting.

  Thus, even if the reaction force by the abnormal slab is excessive and the disc spring 10 is almost in close contact, the compression force applied to the disc spring 10 can be unloaded by removing the spacer 16. Therefore, a drive mechanism can be operated and a roll space | interval can be expanded.

  As shown in FIG. 1, when the roll segment 11 is replaced, the roll segment 11 is pulled out toward the inside of the arc in the curved band. It is necessary to dodge adjacent roll segments 11. When the adjacent roll segment 11 is tall, the roll segment 11 to be pulled out interferes with the adjacent roll segment 11, and when the width of the adjacent roll segment 11 is wide, the roll segment to be pulled out is adjacent to the next roll segment 11. Interfering with the roll segment 11. In adding the hydraulic jack 22 and the spacer insertion / extraction mechanism 21 to the roll segment 11, the roll segment 11 cannot be made tall and the roll segment 11 cannot be widened.

  According to the present embodiment, as shown in FIG. 2, the hydraulic jack 22 can be disposed on the roll segment 11 without being bulky by screwing the core 23 of the hydraulic jack 22 into the column 3. Further, as shown in the plan view of the upper frame 2 in FIG. 7, the hydraulic jack 22 and the spacer insertion / extraction mechanism 21 are arranged so as not to protrude from the upper frame 2. Thereby, it can prevent that the lateral width of the roll segment 11 spreads. In order to further save space, the direction in which the spacer insertion / removal mechanism 21 inserts / removes the spacer 16 is the length direction of the rolls 7 and 8 and is preferably inside the column 3. However, since it is necessary to avoid interference with incidental facilities, such as a spray nozzle, as an incidental facility, when there is interference with incidental facility, it is not restricted to the length direction of the rolls 7 and 8.

  In addition, this invention is not restricted to the said embodiment, It can change into various embodiment in the range which does not change the summary of this invention. For example, the drive mechanism that moves the movable frame relative to the fixed frame is not limited to the worm mechanism and the screw jack, and may be a hydraulic cylinder.

The side view of the slab guide apparatus in one Embodiment of this invention Detailed view of the vicinity of the upper frame of the slab guide device Top view of hydraulic jack and spacer insertion / extraction mechanism Side view of hydraulic jack and spacer insertion / extraction mechanism (including partial cross-sectional view) Process drawing when removing the spacer Graph showing an example of the relationship between the amount of compressive deformation and load of a disc spring Top view of the upper frame of the roll segment The figure which shows the conventional slab guide apparatus which added the elastic buffer mechanism The figure which shows the conventional slab guide apparatus which provided the cylinder in the upper end part of the column

Explanation of symbols

1 ... Lower frame (fixed frame)
2… Upper frame (movable frame)
3 ... Column 4 ... Nut 5 ... Belleville spring cassette 7 ... Upper roll (roll)
8 ... Lower roll (roll)
9 ... bottom plate 10 ... disc spring 11 ... roll segment 13 ... worm mechanism (drive mechanism)
14 ... Screw jack (drive mechanism)
16 ... Spacer 21 ... Spacer insertion / extraction mechanism 22 ... Hydraulic jack (push-down mechanism)
23 ... Core 24 ... Movable cylinder 25 ... Hydraulic chamber 27 ... Movable nut 28 ... Screw shaft 29 ... Drive mechanism

Claims (6)

At least a pair of guide rolls facing both side surfaces of the slab and arranged parallel to each other;
A fixed frame that rotatably supports one of the at least one pair of guide rolls;
Of the at least one pair of guide rolls, a movable frame that rotatably supports the other guide roll;
A column connecting the fixed frame and the movable frame;
A drive mechanism for moving the movable frame with respect to the fixed frame so that an interval between the at least one pair of guide rolls can be adjusted;
Provided between the nut coupled to the column and the movable frame, and elastically deformed so that the movable frame can be separated from the fixed frame when a predetermined load or more is applied between the at least one pair of guide rolls. An elastic shock absorbing mechanism,
A spacer insertion / removal mechanism capable of inserting / removing a spacer between the nut of the column and the elastic buffer mechanism;
A push-down mechanism that compressively deforms the elastic buffer mechanism so that the spacer insertion / extraction mechanism can pull out the spacer from between the nut of the column and the elastic buffer mechanism;
A slab guide device in a continuous casting facility comprising: When abnormal slabs occur,
The push-down mechanism compresses and deforms the elastic buffer mechanism, and then the spacer insertion / removal mechanism pulls out the spacer from between the end of the column and the elastic buffer mechanism, and then the push-down mechanism moves the elastic buffer mechanism. 2. The slab guide device in a continuous casting facility according to claim 1, wherein the slab is released from compressive deformation.   The slab guide device in the continuous casting equipment according to claim 1, wherein the spacer has a horseshoe shape so that the spacer can be inserted into and removed from the column. The push-down mechanism is
A core coupled by screws to the end of the column;
A movable cylinder that is provided around the core and slides relative to the core to compress and deform the elastic buffer mechanism;
A hydraulic pressure supply device that supplies oil to a hydraulic chamber formed between the core and the movable cylinder;
The slab guide device in the continuous casting equipment according to claim 1, comprising: The spacer insertion / extraction mechanism is
A movable nut coupled to the spacer;
A screw shaft extending in the direction of inserting and removing the spacer and screwed into the movable nut;
A drive mechanism for rotating the screw shaft;
The slab guide device in the continuous casting equipment according to claim 1, comprising: 6. The plan view of the movable frame, wherein the push-down mechanism and the spacer insertion / extraction mechanism are arranged on the movable frame so as not to jump out of the movable frame. Slab guide device in continuous casting equipment.

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