KR101792094B1

KR101792094B1 - Continuous casting device and method for using same

Info

Publication number: KR101792094B1
Application number: KR1020157035699A
Authority: KR
Inventors: 다카시 아사리
Original assignee: 스틸플랜테크가부시키가이샤
Priority date: 2013-06-20
Filing date: 2013-06-20
Publication date: 2017-11-01
Also published as: EP3012042A4; CN105307797A; KR20160009673A; WO2014203375A1; TR201807472T4; EP3012042B1; CN105307797B; JPWO2014203375A1; EP3012042A1; JP6047657B2

Abstract

The continuous casting machine includes a mold, a dummy bar inserted into the mold and receiving molten steel at the start of casting, a dummy bar curved in the longitudinal direction at a predetermined curvature, a dummy bar drawn from the mold, A feed roll for feeding the slab separated from the dummy bar at a lower end of the circular path in a tangential direction of the circular path; and a guide roll for guiding the dummy bar separated from the slab And a guide mechanism that moves along the circular path and inserts the mold from above into the mold.

Description

Continuous casting machine and method of using same

The present invention relates to a continuous casting machine having a casting path curved at a constant radius of curvature and a method of using the continuous casting machine, wherein the dummy bar is also curved at a constant radius of curvature and a method of using the continuous casting machine.

In continuous casting equipment of steel, molten steel conveyed from a converter by ladle is injected into the tundish from the bottom of the ladle and once transferred to the tundish, and is constituted of four surfaces or a cylinder from the tundish Lt; / RTI > A dummy bar is inserted in the mold from below. Molten steel injected into the mold is cooled by contacting the inner surface of the dummy bar and the mold. The periphery is coagulated by the inner surface of the mold, and the dummy bar is pulled downward with the non-solidified portion inside, whereby the main strip is pulled downward from the mold. This cast slab is guided by a pinch roll group disposed below the casting mold, and a curved path formed by the pinch roll group is pulled downward, and the casting is completely solidified on the way. The preceding dummy bars are separated from the casting at the lowermost end of the curved movement trajectory, and the casts are horizontally corrected and horizontally bent from the curved shape, and then cut into a predetermined dimension and conveyed to a post-process.

Figs. 7 (a) and 7 (b) are views showing the operation of the conventional continuous casting machine disclosed in Patent Document 1. Fig. A dummy bar 1 having a constant radius of curvature is inserted into the mold 8 from below the mold 8 and molten steel is injected into the mold from a tundish (not shown) to cover the rear end of the dummy bar 1 with molten steel, The bar 2 is pulled downward from the bottom of the mold 8 by pulling the bar 1 downward so that the portion of the casting 8 in contact with the casting 8 solidifies. The dummy bars 1 are arranged at the lower ends of the moving regions of the dummy bars 1 and the casting 2 so that the dummy bars 1 are moved upward by moving the calibrating rolls 4, 7) and moves upward along the locus of the same arc as it is. The casting roll 2 is lowered and the leading end of the casting 2 is pulled downward so that the leading end of the casting 2 is separated from the rear end of the dummy bar 1. [ The cast steel 2 is pressed downward by the calibrating rolls 3 and 4 to be calibrated from a curved state to a horizontal straight material state and cut to an appropriate dimension and discharged from the continuous casting equipment.

The dummy bars 1 are evacuated upward as shown in Fig. 7 (b). When the injection of molten steel into the tundish from the ladle is completed and the injection of molten steel into the casting 8 from the tundish is finished and the last part of the casting 2 passes through the calibrating rolls 3 and 4, 1) is inserted into the mold 8 from the bottom of the mold 8, with the trailing end of the arc facing the trajectory. Then, the casting process of the next step is started. Also, Patent Documents 2 to 4 disclose similar continuous casting machines.

Patent Document 5 discloses a continuous casting machine of the type in which the curvature of the cast strip pulling process is not constant but is corrected so that the radius of curvature is gradually increased in the process of pulling the cast strip from the casting mold by the pinch roll. In this continuous casting machine, a dummy bar is constituted by connecting a plurality of units in a chain shape, and the relative angle between the units is gradually changed while the radius of curvature is gradually increased to move downward between the pinch rollers. This dummy bar is then detached from the end of the casting and then inserted into the casting mold from the top of the casting mold and provided in the casting process of the next step. In the continuous casting machine disclosed in Patent Document 5, the dummy bar lifting winch lifts the dummy bar separated from the casting to the casting floor at the casting separation position at the lower end of the continuous casting machine. Then, a dummy bar is placed on a carriage frame running on a guide rail provided on the casting floor, and the carriage is transported to the vicinity of the casting mold, and the carriage frame is tilted and moved in the vicinity of the casting mold, and the dummy bar is slid Move it into the mold.

Patent Document 1: JP-A-7-328751 Patent Document 2: JP-A-9-108792 Patent Document 3: USP 5,131,453 Patent Document 4: USP 4,043,383 Patent Document 5: JP-A-2003-53495

However, in the above-described conventional continuous casting machine, after the molten steel is injected from the tundish into the mold 8, after the pinch roll group (not shown) is removed from the rear end of the cast piece 2, And the dummy bar 1 is inserted into the mold 8 from the bottom of the mold 8, the preparation of the next step of the casting process is completed. Therefore, there is a problem that the operating rate of the continuous casting machine is low because the waiting time until the next casting process can be started after the completion of the previous casting process is long and the waiting time is long.

Patent Document 5 discloses a continuous casting machine in which a dummy bar is inserted into a mold from the top of the mold. In order to insert the dummy bar from the upper end of the mold into the mold, a plurality of units are connected in a chain- It is necessary that the entire shape is bent at the unit connecting portion so that the entire shape can be deformed. There is also a need for a baler transporting device in which a hoisting winch for lifting a dummy bar is provided on a casting floor, and the dummy bar is transported from the lifting position to the vicinity of the casting mold. For this reason, the casting equipment becomes too large. In addition, it is necessary to install such a hoist winch and a truck transporting device on the casting floor. As described in Patent Literature 5, since casting command chambers and the like are provided on the casting floor, these obstacles are avoided, A large installation space is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a continuous casting machine capable of improving the productivity by shortening the standby time between the previous casting process and the next casting process without causing complication and enlargement of facilities, And a method thereof.

In the continuous casting machine according to the present invention,

The mold,

A dummy bar which is inserted into the mold to receive molten steel at the start of casting and curved in the longitudinal direction at a constant curvature,

A guide roll group for drawing the dummy bar and the cast strip drawn from the casting mold downward along a circular path having the curvature radius through the inside of the casting mold,

A feeding part for feeding the piece separated from the dummy bar at a lower end of the circular path in a tangential direction of the circular path;

And a guiding mechanism for moving the dummy bar separated from the cast slab along the circular path and inserting the dummy bar from above into the casting mold.

In this continuous casting machine,

The guide mechanism includes:

A first pinch roll portion including at least two pairs of pinch rolls disposed on the circular path and applying a pulling force to the dummy bar and the cast piece;

And a second pinch roll portion that includes at least two pairs of pinch rolls and that is disposed on the circular path and applies a driving force for moving the dummy bar along the circular path.

Further, in this continuous casting machine,

Wherein the first pinch roll portion is provided in the delivery portion,

The second pinch roll portion may be disposed at two or more positions in the circular path.

Further, in this continuous casting machine,

Wherein the second pinch roll portion comprises:

Wherein the circular path is disposed at two or more positions including the positions on both sides of the upper end of the circular path,

The guide mechanism includes:

And a support roll which is disposed above the second pinch roll portion and rolls on and supports the inner side in the radial direction of the circular path in the dummy bar.

Further, in this continuous casting machine,

The guide mechanism includes:

A bottom roll which rolls on a radially outer surface of the circular path in the dummy bar and supports the bottom roll,

And a side roll for rolling and supporting the side of the dummy bar.

The method for using the continuous casting machine according to the present invention is characterized in that,

A step of inserting the dummy bar from above in the mold and arranging the dummy bar on the bottom of the mold to prepare for casting;

A step of injecting molten steel from a tundish disposed above the casting mold and starting a drawing of the dummy bar after forming a solidified shell in the casting mold and drawing the cast steel connected to the dummy bar;

Continuing the injection of molten steel into the mold from the tundish, drawing out the dummy bar and the casting,

The leading end of the casting reaches the arrangement position of the delivery portion and separates the cast piece and the dummy bar, and then the dummy bar is guided and driven by the guide mechanism to move along the circular path, To a next process by a second process,

After the completion of the casting of molten steel into the casting mold from the tundish, the tundish is removed from above the casting mold, and before the casting piece formed by the molten steel supplied from the tundish reaches the casting section, And a step of preparing the casting in the next step by inserting it into the mold from above the casting mold.

According to the present invention, the dummy bars are rotated and moved in one direction along the circular path to arrange the dummy bars in the casting molds and perform casting, so that before the molten steel is injected from the tundish into the casting molds, It is possible to start the casting of the molten steel in the next procedure as quickly as possible, that is, substantially without waiting time. Therefore, the continuous casting machine of the present invention has a high operation rate and high productivity. Further, since the present invention can be implemented simply by newly installing a guide mechanism of a dummy bar of a simple structure and a second pinch roll portion for a dummy bar, it is possible to provide a large- There is no work.

1 is a front view showing a continuous casting machine of an embodiment of the present invention.
2 is a front view showing a part of a continuous casting machine of an embodiment of the present invention.
3 is a view showing a part of the dummy bar DB, wherein (a) is a front view and (b) is a right side view.
4 is a front view showing a dummy bar guide and a second pinch roll portion 21 for separating the dummy bar DB from the cast steel and returning it to the casting mold in the casting drawing process by the casting machine of Fig.
5 is a side view thereof in the same manner.
6 is an enlarged front view of the second pinch roll portion 21. FIG.
Figs. 7 (a) and 7 (b) are views showing the operation of the conventional continuous casting machine disclosed in Patent Document 1. Fig.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a front view showing a continuous casting machine of the present embodiment, and Fig. 2 is a front view showing a part of the same. The movement locus 20 (actually, the locus of movement of the outer surface of the dummy bar DB) of the dummy bar DB is an arc. That is, the dummy bar DB is curved to have a constant radius of curvature D, and moves on a circular path along the movement locus 20. It is preferable that the dummy bar (DB) has a length of at least 1/3 of the circumferential length of the circular path. A mold 10 is disposed at an approximately middle position in the vertical direction of the movement locus 20. The mold 10 is also curved along the movement trajectory 20 with a radius of curvature D. A guide roll group 11 for guiding the dummy bar DB and the cast piece C downward along the curved locus is disposed under the mold 10. An end portion (lower end portion) of the guide roll group 11 For example, five pairs of pinch rolls 12 (first pinch roll portion) are disposed. The second pinch roll portions 21 and 22 are provided at two positions above the movement locus 20 for rolling and sending out the dummy bar DB while sandwiching the dummy bar DB. At the upper end of the movement locus 20, there is provided a support roll 23 for supporting the lower surface of the dummy bar DB (inner surface of the arc) from below. These molds 10, the guide roll group 11, the first pinch roll portion 12, the second pinch roll portion 21, the support roll 23 and the second pinch roll portion 22 are moved along the movement locus of the dummy bar DB (20). In the present embodiment, the second pinch roll portions 21 and 22 are provided at two positions on the movement locus 20 of the arc, and each of the second pinch roll portions 21 and 22 is formed by two pairs of rolls Consists of.

The dummy bar DB and the cast steel C are separated from each other in the delivery portion 30 provided with the first pinch roll portion 12 and the cast steel C is separated from the movement locus 20 and the first pinch roll portion 12 in the horizontal direction by the first pinch roll portion 12 after being calibrated from the curved state to the horizontal state. The cast piece C is fed onto a conveying roll 17, cut to a predetermined length by a cutting device 13, and then sent out in a subsequent process. The upper limit of the length of the dummy bars DB is set such that the front end in the moving direction of the dummy bars DB does not reach the mold 10 at the time when the rear end of the dummy bars DB has passed the feeder 30 Length. However, it is preferable that the length of the dummy bars DB is sufficiently shorter than the upper limit and slightly longer than 1/3 of the circumferential length. In the present embodiment, the dummy bar DB has a length that is always fitted to at least two pairs of rolls of the pair of pinch rolls included in the first pinch roll portion 12 and the second pinch roll portion 21, 22.

A tundish 14 is disposed above the mold 10 and a ladle 16 is disposed above the tundish 14. The tundish 14 is disposed above the tundish 14, The tundish 14 is mounted on a tundish carriage (not shown) moving on a work floor and is movable between an upper position of the mold 10 and a position deviated from the upper side of the mold 10. [ The ladle 16 receives the molten steel from the converter (not shown), which has been refined, and is conveyed onto the orbiting device 15 by an appropriate crane device. The ladle 16 is then swiveled by the swivel device 15 and installed above the tundish 14 above the casting mold 10. After the molten steel in the ladle 16 is injected into the tundish 14 and once received in the tundish 14, the molten steel is injected into the mold 10 from the tundish 14. The molten steel in the ladle 16 is supplied into the casting mold 10 through the tundish 14 and solidified in the casting mold 10 and the trailing end of the casting is pulled out from the casting mold 10, Thereafter, the tundish 14 is moved from the top of the mold 10 to the retracted position by the tundish carriage, and is subjected to restoration of the refractory of the refractory at this retracted position.

As shown in Fig. 2, the molten steel injected into the mold 10 is cooled in the mold 10, the peripheral portion in contact with the mold 10 solidifies to form a solidification angle, and an un- The cast steel C is pulled downward. At this time, a dummy bar (DB) is connected to the leading end of the cast piece (C). The dummy bars DB and the cast steel C are moved downward by the guide roll group 11 while maintaining the same radius of curvature. The rear end portion of the dummy bar DB is separated from the cast piece C by the upward stress by the first pinch roll portion 12 disposed at the lower end of the movement locus 20 and the front end portion of the cast piece C And is calibrated in a horizontal state. A nozzle (not shown) for spraying cooling water is disposed between each roll of the guide roll group 11 to cool the cast steel C by ejecting cooling water to the cast steel C. [ The mold 10 and the guide roll group 11 are curved at the same radius of curvature as the predetermined curvature radius D of the dummy bar movement locus 20. [ Therefore, the dummy bars DB curved at a constant radius of curvature D can smoothly move the mold 10 and the guide roll group 11.

3 is a view showing a part of the dummy bar DB, wherein (a) is a front view and (b) is a right side view. As shown in Fig. 3, the dummy bar DB is configured by connecting a plurality of units DB1, DB2, DB3, DB4, .... The respective units DB1 and the like are connected to each other by a connection shaft 19 so as to be able to adjust relative angles relative to each other, and are connected to each other in a fixed state after adjusting relative angles. The relative angles of these units DB1 and the like are set so that the curvature radius D of the dummy bars DB constituted by the connection of the units DB1 and the like coincides with the radius of curvature of the movement locus 20 of the continuous casting machine .

Fig. 4 is a front view showing a part of a guide mechanism for separating the dummy bar DB from the cast steel and returning it to the casting mold, and Fig. 5 is a side view of the casting machine by the continuous casting machine of Fig. 6 is an enlarged front view of the second pinch roll portion 21. FIG. The upper roll of the rear end roll 12b moves upward in the two pairs of rolls 12a and 12b on the next process side of the first pinch roll portion 12 and the dummy bar DB having a constant radius of curvature moves in the guide roll group 11) and advances upward as it is. When the front end of the cast piece C connected to the rear end of the dummy bar DB reaches the position of the rear end roll 12b of the first pinch roll part 12, The cast piece C is pressed downward to separate the rear end of the upwardly directed dummy bar DB and the front end of the cast piece C. [ Thereafter, the cast steel C is sandwiched between the lowered upper roll 12b and the lower lower roll 12b, sandwiched between the adjacent rolls 12a, and held vertically, thereby being horizontally calibrated And is transported forward by the rotation of the first pinch roll portion 12 and transported onto the transport roll 17.

The dummy bars DB are supported while being restrained by a guide mechanism provided on stands 31 and 35 erected on the floor to move upward while maintaining the radius of curvature D. [ A horizontal base frame 32 is provided at the upper end of the base frame 31 and a base frame 33 vertically extending therefrom is erected upwardly. The guide mechanism includes a side roll 25 and a bottom roll 24 provided on the base 35 in the vicinity of the first pinch roll portion 12 and a base band Side rolls 25, outer surface rolls 42, and side rolls 44 provided on the outer surface rollers 31 to 33. The side rolls 25 roll on the side of the dummy bar DB and regulate the position of the dummy bar in the horizontal direction so that the dummy bar DB does not deviate from the predetermined movement locus 20. [ On the other hand, the bottom roll 24 rolls on the underside of the dummy bar DB and supports the weight of the dummy bar DB while the dummy bar DB is moved outward from the arc of the predetermined movement locus 20 The position of the dummy bar (DB) is regulated so as not to deviate. The outer surface roll 42 rolls on the outer surface of the dummy bar DB so that the dummy bar DB does not deviate from the arc of the predetermined movement locus 20 in the outer direction (horizontal direction) . A side roll 44 which rolls on the side of the dummy bar DB is disposed in the vicinity of the outer roll 42. The dummy bar DB is moved in the horizontal direction from the movement locus 20, Thereby regulating the lateral position of the bar (DB).

The second pinch roll portion 21 is provided on a horizontal base 32 and on a base 33 erected on the base 32. The second pinch roll portion 21 is constituted by two pairs of rolls of a pinch roll 21a made of rolls 41a and 42a and a pinch roll 21b made up of rolls 41b and 42b, The rolls 41a and 41b roll on the inner surface of the dummy bar DB and the rolls 42a and 42b roll on the outer surface of the dummy bar DB. The rolls 42a and 42b are provided on the table 33 and follow the outer surface of the dummy bar DB to support the lateral stress by the dummy bar DB. On the other hand, the rolls 41a and 41b are driven by the motor 43 to press the inner surface of the dummy bar DB while sandwiching the dummy bar DB between the opposed rolls 42a and 42b, 43 to move the dummy bar DB along the movement locus 20 of the arc. The rolls 41a and 41b and the motor 43 are provided on the base 32 so as to swing around the horizontal rotation shaft 45 as a whole. The second pinch roll portion 22 also has the same structure as the second pinch roll portion 21. Thus, in the present embodiment, the second pinch roll portions 21 and 22 are provided at two positions along the movement locus 20 of the dummy bar DB. The second pinch roll portion 21 has two pairs of rolls 21a and 21b and is sandwiched between rolls 41a and 41a and rolls 41b and 42b of each pair of rolls 21a and 21b, (DB) moves. The same applies to the second pinch roll portion 22. However, in the present invention, it is not necessary to provide two pairs of rolls for each of the second pinch roll portions 21 and 22, and each of the second pinch roll portions 21 and 22 may be constituted by a pair of rolls.

1, a second pinch roll portion 22 having a structure similar to that of the second pinch roll portion 21 is provided at a position opposite to the second pinch roll portion 21 on the upper part of the movement locus 20 of the circular arc, . In the second pinch roll portion 22, the dummy bar DB is pulled out by the pair of rolls and moved forward along the predetermined movement locus 20.

Next, the operation of the continuous casting machine of the present embodiment configured as described above will be described. As described above, the dummy bar DB is curved so that its radius of curvature D becomes equal to the radius of curvature of the predetermined movement locus 20, and is in a rigid state as a whole. The radius of curvature of the dummy bars DB can be adjusted by appropriately adjusting the relative angular relations of the units DB1 and DB as described above. The length of the dummy bars DB is longer than the circumferential length from the mold 10 to the first pinch roll portion 12. The length of the dummy bars DB is determined by the circumferential length between the first pinch roll portion 12 and the second pinch roll portion 21 and the circumferential length between the second pinch roll portion 21 and the second pinch roll portion 22 It is also necessary to be over the length.

The ladle 16 is pivoted to the casting position by the swivel device 15 and the tundish 14 on the tundish bogie is moved to the standby position to evacuate the mold 10 from above. The roll portion 21 and the second pinch roll portion 22 are driven to advance the dummy bar DB in the direction of the arrow in Figure 1 and insert the dummy bar DB into the mold 10 from the top of the mold 10 . At this time, the dummy bar (DB) enters the mold (10) from the front end thereof, passes down the mold (10) and the rear end of the dummy bar (DB) stops at the bottom of the mold ). Thereby, a casting space is formed as a space formed by the side surface of the mold 10 and the upper surface of the dummy bar DB. At this time, the dummy bar DB is forwardly fed by the rolling motion of the second pinch roll portion 22 in a state sandwiched by the second pinch roll portion 22, The front end of the dummy bar DB is already sandwiched between the rolls of the first pinch roll portion 12 when the rear end of the dummy bar DB is positioned in the mold 10, (DB) is drawn and driven by the first pinch roll portion (12).

Thereafter, the tundish carriage is driven to place the completed tundish 14 above the mold 10. [ The ladle 16 which has carried the molten steel from the converter is then driven to position the tundish 15 above the tundish 14 and the molten steel is injected into the tundish 14 from the ladle 16 , Molten steel is injected into the mold 10 from the tundish nozzle. Then, the molten steel is cooled by contact with the mold 10, the peripheral portion and the bottom portion are solidified to form a solidification angle, and a cast steel C in a state in which the non-solidified molten steel remains therein is formed. Thereafter, the dice bar DB is pulled out by the first pinch roll part 12 to draw the cast piece C connected to the dummy bar DB downward from the mold 10, And then draws the cast steel C downward. Thereby, the cast steel C is guided by the guide roll group 11 on the lower side of the mold 10 and is cooled down by the cooling water ejected from the spray nozzle while moving downward, and is completely solidified to the inside.

Since the front end of the dummy bar DB passes through the pair of rolls 12a and 12b of the first pinch roll portion 12 and the dummy bar DB is a rigid body, The outer surface side is supported by the outer surface roll 42 and moves upward. At this time, since the side surface of the dummy bar (DB) is also supported by the side roll (25), the dummy bar (DB) does not deviate from the predetermined movement locus (20). Thereafter, when the rear end of the dummy bar DB reaches the position of the roll 12b of the first pinch roll portion 12, immediately after the rear end of the dummy bar DB passes the upper roll 12b, The upper roll 12b moves downward and presses the cast piece C connected to the rear end of the dummy bar DB downward to drop the cast piece C from the dummy bar DB. The cast steel C is sandwiched between the lowered upper roll 12b and the lower roll 12b and also held between the pair of adjacent rolls 12a, Is horizontally calibrated by the pair of rolls of the roll portion 12 and is conveyed onto the conveying roll 17 and is cut to a predetermined dimension by the cutting device 13 in the middle.

The dummy bars DB are further fed out by the first pinch roll portion 12 and the front portions of the dummy bars DB are guided by the guide mechanism and moved upward to move the rolls 21a and 21b of the second pinch roll portion 21 ). Then, the dummy bar DB is driven by the second pinch roll portion 21 and then fed out.

1, the dummy bar DB is moved away from the first pinch roll portion 12 and driven only by the second pinch roll portion 21 to move along the movement locus 20 to the second pinch roll portion 22 . The dummy bar (DB) is supported by the support roll (23) on the way. The front end portion of the dummy bar DB is inserted into the second pinch roll portion 22 and driven by the second pinch roll portion 21, Thereafter, the rear end of the dummy bar DB is separated from the second pinch roll 21, and the dummy bar DB is driven only by the second pinch roll 22. Then, the front end of the dummy bar DB is latched in the second pinch roll portion 22 and waits until the casting process is completed.

The first pinch roll portion 12 continues to dispatch the cast piece C onto the conveying roll 17 so that the molten steel in the ladle 16 disappears and molten steel in the tundish 14 is substantially discharged from the entire mold 10 The molten steel bath surface in the mold 10 is lowered so that the rear end of the cast steel C escapes from the mold 10.

Thereafter, the used tundish 14 is moved from above the mold 10 to the retracted position by the tundish carriage. Thereafter, the second pinch roll portion 22 drives the dummy bar DB and feeds the dummy bar DB into the mold 10. The first pinch roll portion 12 temporarily stops driving the dummy bar DB in a state where the rear end of the dummy bar DB is positioned at the bottom of the mold 10. [ Thereafter, the new tundish 14, which has been repaired, is moved above the mold 10 by the tundish carriage. Next, the ladle 16 carries the refined molten steel from the converter. The ladle 16 is placed on the pivoting device 15 and pivoted by the pivoting device 15 to position the ladle 16 on the tundish 14. [ Then, the casting process of the next step is started.

Thus, in the present embodiment, the dummy bar DB moves in one direction along the movement locus 20, which is an arc having a constant radius of curvature D. Since the dummy bars DB are arranged and cast in the mold by the movement along the movement locus 20 of the dummy bar DB after the molten steel is injected from the tundish 14 into the mold 10 It is possible to commence the molten steel casting in the next procedure in a state in which the tundish 14 is replaced with a new one as quickly as possible, that is, substantially without waiting time. For this reason, the continuous casting machine of the present embodiment has a high operation rate and high productivity.

The continuous casting machine according to the present embodiment is characterized in that the dummy bars DB separated from the casting in the casting section are moved along the circular path passing through the mold simply as compared with the continuous casting machine described in the conventional patent documents 1 to 4, It is sufficient to newly install a guide mechanism which is configured to be insertable upward from the inside of the mold, and such a guide mechanism does not require a complicated structure as in the prior art. Therefore, as described in Patent Document 5, it is possible to improve the operating rate of the casting without causing a large size and complication of the apparatus and without requiring a large space.

As described above, the present invention requires that the dummy bars move on the arc phase. In a continuous casting machine for casting steel, particularly a continuous casting machine for casting a rectangular or circular small-section casting such as a bloom or a billet, or a continuous casting machine for casting a beam blank having an H-shaped section such as an H-shaped section, The guide roll group is curved with a constant radius of curvature. This is for smoothly drawing the billet by keeping the billet with the peripheral portion solidified in the billet as it is and maintaining the radius of curvature at the end of the guide roll group. Therefore, the dummy bars are also curved to have a constant radius of curvature as in the case of the mold and the guide roll group, and are guided by the guide roll group and are not deformed while moving, and the guide roll group is moved while maintaining this curved shape.

When the length of the dummy bar is long, it is basically sufficient to provide the second pinch roll portion dedicated to the dummy bar at one position on the opposite side (the upper end of the movement locus) of the first pinch roll portion for casting. However, when the length of the dummy bars DB is not so long, it is necessary to arrange two or more of the second pinch roll portions at two or more positions. However, in order to increase the cost reduction effect with a simpler structure, it is preferable that the second pinch roll portion is disposed at only two portions. The guide mechanism may be provided with a bottom roll supporting the load of the dummy bar and a side roll supporting the dummy bar so as to prevent the dummy bar from deviating in the lateral direction. However, the means for moving the dummy bar along the arc- none. In the above-described embodiment, the second pinch roll portions 21 and 22 are each provided with two pairs of rolls. Thereby, each of the second pinch roll portions 21, 22 can reliably support the dummy bar DB. However, by providing sufficient support of the dummy bars by the guide mechanisms (side rolls and bottom rolls), it is also possible to form pairs of rolls of each second pinch roll section.

The first pinch roll portion 12 and the second pinch roll portion 21 and 22 move the dummy bar DB in only one direction along the movement locus of the arc so as to move the dummy bar DB into the mold 10 To be inserted into the mold. However, it is also possible to insert the dummy bar DB into the mold from below the mold 10 by using the continuous casting machine of the present embodiment.

INDUSTRIAL APPLICABILITY The present invention contributes greatly to the improvement of the operating rate and the productivity of the continuous casting machine, thereby contributing to the reduction of the manufacturing cost.

10: Mold
11: Guide roll group
12: first pinch roll portion
13: Cutting device
14: Tundish
15: Swing device
16: ladle
17:
20: Movement locus
21, 22: second pinch roll portion

Claims

The mold,
A dummy bar which is inserted into the mold to receive molten steel at the start of casting and curved in the longitudinal direction at a constant radius of curvature,
A guide roll group for drawing the dummy bar and the cast strip pulled out from the casting mold downward along a circular path having the constant radius of curvature through the inside of the casting mold,
A feeding part for feeding the piece separated from the dummy bar at a lower end of the circular path in a tangential direction of the circular path;
And a guide mechanism for moving the dummy bar separated from the cast slab along the circular path and inserting the dummy bar from above into the cast slab,
The guide mechanism includes:
A first pinch roll portion including at least two pairs of pinch rolls disposed on the circular path and applying a pulling force to the dummy bar and the cast piece;
And a second pinch roll portion including at least one pair of pinch rolls and disposed on the circular path to apply a driving force for moving the dummy bar along the circular path.

The method according to claim 1,
And the second pinch roll portion includes at least two pairs of pinch rolls.

The method according to claim 1 or 2,
Wherein the first pinch roll portion is provided in the delivery portion,
And the second pinch roll portion is disposed at two or more positions in the circular path.

The method according to claim 1 or 2,
Wherein the second pinch roll portion comprises:
Wherein the circular path is disposed at two or more positions including the positions on both sides of the upper end of the circular path,
The guide mechanism includes:
And a support roll which is disposed above the second pinch roll portion and rolls on and supports the inner side in the radial direction of the circular path in the dummy bar.

The method according to claim 1 or 2,
The guide mechanism includes:
A bottom roll which rolls on a radially outer surface of the circular path in the dummy bar and supports the bottom roll,
And a side roll which rolls on and supports the side of the dummy bar.

The method of using the continuous casting machine according to claim 1 or 2,
A step of inserting the dummy bar from above in the mold and arranging the dummy bar on the bottom of the mold to prepare for casting;
A step of injecting molten steel from a tundish disposed above the casting mold and starting a drawing of the dummy bar after forming a solidified shell in the casting mold and drawing the cast steel connected to the dummy bar;
Continuing the injection of molten steel into the mold from the tundish, drawing out the dummy bar and the casting,
The leading end of the casting reaches the arrangement position of the delivery portion and separates the cast piece and the dummy bar, and then the dummy bar is guided and driven by the guide mechanism to move along the circular path, To a next process by a second process,
After the completion of the injection of molten steel into the mold from the tundish, the tundish is removed from above the mold, and before the main piece formed by the molten steel supplied from the tundish reaches the delivery portion, And inserting the casting mold into the casting mold from above the casting mold to prepare for casting in the following order.

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