JP7440714B2 - Slab heating equipment and continuous casting equipment - Google Patents

Description

The present disclosure relates to a slab heating device and continuous casting equipment.

Patent Document 1 discloses continuous casting equipment that continuously manufactures slabs by cooling molten metal (molten steel) in a mold and forming it into a predetermined shape. The continuous casting equipment is equipped with a high-frequency induction heating coil provided midway through the conveyance path of the slab. By applying a high frequency current to the coil and heating the slab according to the principle of induction heating, defects on the surface of the slab are suppressed. Since the strength H of the magnetic field is inversely proportional to the square of the linear distance from the coil, it is desirable to maintain an appropriate linear distance between the coil and the slab in order to effectively heat the slab with the coil.

Japanese Patent Application Publication No. 11-170019

By the way, there are various types of slabs manufactured in continuous casting equipment, such as billets, blooms, and slabs. The billet has a substantially square cross section of, for example, 200 mm x 200 mm or less. The bloom has a substantially rectangular cross section of, for example, about 350 mm x 450 mm. The slab has a substantially rectangular cross section of, for example, about 250 mm x 2000 mm.

As described above, the size (particularly the width) varies greatly depending on the type of slab. Therefore, in the continuous casting equipment of Patent Document 1, in order to maintain an appropriate distance between the coil and the slab, it is necessary to reinstall the coil with an appropriate inner diameter depending on the type of slab to be manufactured. The replacement work was complicated. In particular, when a slab is manufactured as a slab in a continuous casting facility, the size of the slab may change continuously during transportation (during manufacture) of the slab. In such cases, it may be difficult to uniformly heat the slab using the principles of induction heating using coils.

Therefore, the present disclosure describes a slab heating device and continuous casting equipment that can effectively heat various slabs without replacing the coils.

[1] A slab heating device according to one aspect of the present disclosure includes a heating coil configured to be wound around a slab by combining a plurality of coil pieces, and at least one of the plurality of coil pieces. The actuator is configured to move one coil piece while maintaining a state of contact with another adjacent coil piece.

In the slab heating device according to one aspect of the present disclosure, the heating coil is configured by a combination of a plurality of coil pieces, and the actuator moves at least one of the plurality of coil pieces. Therefore, as the one coil piece moves, its positional relationship with other coil pieces changes. That is, the inner diameter of the heating coil made up of a plurality of coil pieces changes. Therefore, by simply moving the coil piece according to the type of slab, it becomes possible to effectively heat slabs of different sizes with the heating coil without replacing the entire heating coil.

[2] In the device described in item 1 above, the plurality of coil pieces include a pair of straight rod-shaped first and second coil pieces and a straight rod-shaped pair of third and fourth coil pieces. The heating coil has a spiral shape in which a first coil piece, a third coil piece, a second coil piece, and a fourth coil piece are brought into contact with each other in this order. At least one of the four coil pieces may be moved while maintaining a state of contact with another adjacent coil piece.

[3] In the device according to item 1 above, the plurality of coil pieces includes a pair of L-shaped first and second coil pieces, and the heating coil has a pair of L-shaped first and second coil pieces. One end portions are in contact with each other to form a spiral shape, and the actuator is configured to move at least one of the first and second coil pieces while maintaining a state of contact with the other coil piece. You can leave it there.

[4] In the device according to item 1 above, the plurality of coil pieces include a pair of straight rod-shaped first and second coil pieces, a straight rod-shaped pair of third and fourth coil pieces, and a straight rod-shaped pair of third and fourth coil pieces. It has a pair of rod-shaped fifth and sixth coil pieces, the fifth and sixth coil pieces extend along the extending direction of the first and second coil pieces, and the fifth and sixth coil pieces extend along the extending direction of the first and second coil pieces. The length of the No. 6 coil piece is shorter than the length of the first and second coil pieces, and the actuator has the first coil piece, the third coil piece, the second coil piece, and the fourth coil piece. The first form contacts in this order to form a spiral shape, and the fifth coil piece, third coil piece, sixth coil piece, and fourth coil piece contact in this order to form a spiral shape. At least one of the third and fourth coil pieces may be moved between the second form and the second form. In this case, the heating coil changes between the first configuration and the second configuration by moving at least one of the third and fourth coil pieces using the actuator. Here, the lengths of the fifth and sixth coil pieces are shorter than the lengths of the first and second coil pieces, so in the second form, compared to the first form, the length of the heating coil is shorter. The inner diameter becomes smaller. Therefore, even if the size of the slab changes in the extending direction of the first, second, fifth, and sixth coil pieces, slabs of different sizes cannot be effectively heated by the heating coil. It becomes possible.

[5] The device according to any one of Items 1 to 4 above has a distance between the slab and the heating coil on the upstream side and/or downstream side of the heating coil in the extending direction of the slab. The sensor may further include a detector configured to detect the separation distance, and a control unit that controls the actuator to adjust the position of the coil piece in accordance with the separation distance detected by the detector. In this case, it is possible to automatically adjust the positions of the coil pieces so that the separation distance is approximately constant. In particular, if the detector detects the separation distance on both the upstream and downstream sides of the heating coil, even if the slab heating device is placed in the middle where the slab is continuously changing. Also, since the distance between the slab and the coil piece is kept substantially constant depending on the shape of the slab, the slab can be effectively heated by the heating coil. Note that the cross-sectional area of the slab may increase or decrease from the upstream side to the downstream side.

[6] In the device according to any one of items 1 to 5 above, the plurality of coil pieces may be solid members having conductivity. In this case, the heat of the slab heated by the heating coil is difficult to be removed by the heating coil itself. Therefore, since the heating coil can be brought closer to the slab, it becomes possible to heat the slab more effectively with the heating coil.

[7] In the device according to any one of items 1 to 5 above, the plurality of coil pieces may be hollow members through which a refrigerant can flow.

[8] Continuous casting equipment according to another aspect of the present disclosure includes a mold that forms a slab by cooling and molding molten metal into a predetermined shape, and a mold that is located downstream of the mold and maintains the slab at a predetermined temperature. the slab heating device according to any one of the above items 1 to 7, and a light rolling device that is located downstream of the slab heating device and applies a rolling force to the slab in the final stage of solidification. Be prepared. Continuous casting equipment according to another example of the present disclosure provides the same effects as the apparatus according to item 1 above. By the way, if the temperature of the slab before reaching the light reduction device changes, the solidification state of the unsolidified molten steel existing inside the slab will also change, so the unsolidified molten steel in the slab will reach the final stage of solidification. A deviation may occur between the position (final solidification point) and the position where the slab is rolled down by the light rolling down device. However, according to the continuous casting equipment described in item 8, since the slab heating device is located upstream of the light reduction device, the slab reaching the light reduction device is maintained at a predetermined temperature. Therefore, the fluctuation in the position of the final freezing point is suppressed, so that it is possible to appropriately roll down the area before and near the final freezing point using the light rolling down device. Therefore, it becomes possible to further suppress the occurrence of segregation and center segregation in the slab.

[9] Continuous casting equipment according to another aspect of the present disclosure includes a mold that forms a slab by molding the molten metal into a predetermined shape while cooling it, and a mold that is located downstream of the mold and softens the slab by heating. The slab heating device according to any one of items 1 to 7 above, and a slab rolling down device that is located downstream of the slab heating device and applies a rolling force to the slab after solidification. Be prepared. Continuous casting equipment according to another example of the present disclosure provides the same effects as the apparatus according to item 1 above. By the way, when a slab is completely solidified, a minute cavity (sometimes referred to as "center porosity") may be formed in the center of the slab, extending in the direction in which the slab extends. If a slab with such cavities still present is rolled by a rolling mill, minute cavities may remain after the rolling, resulting in a product containing defects. Therefore, the slab after solidification is rolled down using a slab rolling down device to reduce the number of cavities. However, if the size of the slab is large, the load required to reduce the cavity may be several tens of tons or more, and the reaction force also acts on the slab rolling down device, so it is necessary to There is a tendency for slab rolling down devices to become larger. Here, according to the continuous casting equipment described in item 9, the slab heating device is located upstream of the slab rolling device. Therefore, the slab that has been softened by being heated by the slab heating device is introduced into the slab rolling down device. Therefore, when the slab is rolled down by the slab rolling down device, the reaction force acting on the slab rolling down device is reduced, so it is possible to downsize the slab rolling down device.

According to the slab heating device and continuous casting equipment according to the present disclosure, it is possible to effectively heat various slabs without replacing the coil.

FIG. 1 is a side view schematically showing an example of continuous casting equipment. FIG. 2 is a perspective view showing an example of a slab heating device. FIG. 3 is a front view showing the slab heating device of FIG. 2. 4 is a side view showing the slab heating device of FIG. 2. FIG. FIG. 5 is a top view showing the slab heating device of FIG. 2. FIG. 6 is a front view for explaining the operation of the slab heating device of FIG. 2. FIG. 7 is a side view showing a slab heating device according to another example. FIG. 8 is a side view showing a slab heating device according to another example. FIG. 9 is a front view showing a slab heating device according to another example. FIG. 10 is a front view for explaining the operation of the slab heating device of FIG. 9. FIG. 11 is a front view showing a slab heating device according to another example. FIG. 12 is a top view showing a slab heating device according to another example.

Since the embodiments according to the present disclosure described below are examples for explaining the present invention, the present invention should not be limited to the following contents. In the following description, the same elements or elements having the same function will be denoted by the same reference numerals, and redundant description will be omitted.

[Configuration of continuous casting equipment]
First, the configuration of continuous casting equipment 100 will be explained with reference to FIG. 1. Continuous casting equipment 100 includes a ladle 101, a tundish 102, a mold 103, a secondary cooling zone 104, a pinch roll 105, a plurality of light reduction devices 106, a plurality of slab support rolls 107, and a cast member. It includes a piece reduction device 109, a cutting machine 110, and a slab heating device 1.

The ladle 101 is a container that stores molten metal (molten steel) M. Tundish 102 is arranged below ladle 101. The tundish 102 has a function of storing the molten metal M flowing out from the ladle 101 and removing inclusions (for example, granular solids made of alumina, etc.) present in the molten metal M.

The mold 103 is placed below the tundish 102. The mold 103 cools the molten metal flowing out from a nozzle provided on the bottom wall of the tundish 102 and forms it into a predetermined shape to form a strand St.

The secondary cooling zone 104 is located downstream of the mold 103 and further cools the slab St pulled out from the mold 103. In this cooling process, the slab St gradually solidifies from the surface side. In other words, unsolidified molten steel exists inside the slab St that has passed through the secondary cooling zone 104. The pinch rolls 105 are located on the downstream side of the secondary cooling zone 104, and pull out the slab St toward the downstream side while bending and straightening it.

Here, the slab St formed by the mold 103 is composed of a solidified part (solidified shell) whose surface part is solidified, and a molten part (unsolidified molten steel) which is molten metal in an unsolidified state inside the solidified shell. ing. As the slab St moves downstream, it is cooled in the secondary cooling zone 104 and the like, the molten part gradually solidifies, and a solidified shell grows. That is, as the solidified shell grows, the molten part shrinks and the thickness of the solidified shell increases. Before the slab St reaches the slab rolling down device 109, the slab St is completely solidified.

A plurality of light reduction devices 106 are located downstream of the secondary cooling zone 104. The light rolling down device 106 is configured to roll down the slab St in the middle of solidification from above and below using a pair of light rolling rolls. Specifically, the light reduction device 106 uses a pair of light reduction rolls to reduce the vicinity of a portion of the slab St where the molten portion is at the final stage of solidification. This suppresses the occurrence of internal cracks and center segregation in the slab St.

A plurality of slab support rolls 107 are arranged throughout the continuous casting equipment 100 on the downstream side of the mold 103. The slab support roll 107 has a function of conveying the slab St toward the downstream side while cooling it. That is, the direction in which the plurality of slab support rolls 107 are lined up is the extending direction of the slab St.

The slab rolling down device 109 is located downstream of the light rolling down device 106. The slab rolling down device 109 is configured to roll down the solidified slab St from above and below using a pair of rolling rolls. This suppresses the formation of minute cavities extending in the extending direction of the slab St in the central portion of the slab St.

The cutting machine 110 is located downstream of the slab rolling down device 109. The cutting machine 110 cuts the slab St that has arrived at the cutting machine 110 in the width direction to form a metal piece P of a predetermined length.

In this embodiment, the slab heating device 1 is located downstream of the pinch rolls 105 and upstream of the light rolling device 106, and downstream of the light rolling device 106 and upstream of the slab rolling device 109, respectively. are doing. The slab heating device 1 has a function of heating the slab St using the principle of induction heating.

[Configuration of slab heating device]
Next, the configuration of the slab heating device 1 will be explained with reference to FIGS. 2 to 5. In this embodiment, a slab heating device 1 suitable for heating a slab St having a rectangular cross section is illustrated. The slab heating device 1 includes a heating coil 10, connectors 21 to 24, actuators (drivers) 31, 32, sensors 41, 42 (detectors), a power source 50, and a controller (controller, detector). ) 60.

The heating coil 10 is configured to wind the slab St around the slab St. In this embodiment, the heating coil 10 has a spiral shape as a whole. The heating coil 10 is not in contact with the slab St, but is spaced apart by a predetermined distance. The distance between the heating coil 10 and the slab St may be, for example, about 20 mm in a straight line. The heating coil 10 is formed by combining a plurality of coil pieces 11, a plurality of coil pieces 12, a plurality of coil pieces 13, and a plurality of coil pieces 14.

In this embodiment, the coil pieces 11 to 14 are solid members having conductivity. The material for the coil pieces 11 to 14 may be any conductive material that has a melting point that does not melt when exposed to the heat of the slab St heated by the heating coil 10, such as copper, iron, alloy, graphite, etc. can be mentioned. The coil pieces 11 to 14 may be, for example, prismatic members extending linearly. The coil pieces 11 to 14 may have a square cross section of, for example, about 50 mm x 50 mm.

The plurality of coil pieces 11 (four coil pieces 11a to 11d in this embodiment) are arranged above the slab St. The coil pieces 11a to 11d are arranged in this order from the downstream side to the upstream side. The coil pieces 11a to 11d extend along the width direction of the slab St so as to be substantially parallel to each other.

The plurality of coil pieces 12 (four coil pieces 12a to 12d in this embodiment) are arranged on the left side of the slab St when viewed from the downstream side. The coil pieces 12a to 12d are arranged in this order from the downstream side to the upstream side. The coil pieces 12a to 12d extend along the height direction of the slab St so as to be substantially parallel to each other.

The plurality of coil pieces 13 (four coil pieces 13a to 13d in this embodiment) are arranged below the slab St. The coil pieces 13a to 13d are arranged in this order from the downstream side to the upstream side. The coil pieces 13a to 13d extend along the width direction of the slab St so as to be substantially parallel to each other.

The plurality of coil pieces 14 (four coil pieces 14a to 14d in this embodiment) are arranged on the right side of the slab St when viewed from the downstream side. The coil pieces 14a to 14d are arranged in this order from the downstream side to the upstream side. The coil pieces 14a to 14d extend along the height direction of the slab St so as to be substantially parallel to each other.

The coil pieces 11a, 13a, the coil pieces 11b, 13b, the coil pieces 11c, 13c, and the coil pieces 11d, 13d each form a pair in the height direction (vertical direction) of the slab St. The coil pieces 12a, 14a, the coil pieces 12b, 14b, the coil pieces 12c, 14c, and the coil pieces 12d, 14d each form a pair in the width direction (horizontal direction) of the slab St.

The lower surface of the left end side of the coil piece 11a and the upper end surface of the coil piece 12a are in contact with each other. The lower end surface of the coil piece 12a and the upper left end surface of the coil piece 13a are in contact with each other. The upper surface of the right end side of the coil piece 13a and the lower end surface of the coil piece 14a are in contact with each other. The upper end surface of the coil piece 14a and the lower surface on the right end side of the coil piece 11b are in contact with each other.

The lower surface of the left end side of the coil piece 11b and the upper end surface of the coil piece 12b are in contact with each other. The lower end surface of the coil piece 12b and the upper left end surface of the coil piece 13b are in contact with each other. The upper surface of the right end side of the coil piece 13b and the lower end surface of the coil piece 14b are in contact with each other. The upper end surface of the coil piece 14b and the lower surface on the right end side of the coil piece 11c are in contact with each other.

The lower surface of the left end side of the coil piece 11c and the upper end surface of the coil piece 12c are in contact with each other. The lower end surface of the coil piece 12c and the upper left end surface of the coil piece 13c are in contact with each other. The upper surface of the right end side of the coil piece 13c and the lower end surface of the coil piece 14c are in contact with each other. The upper end surface of the coil piece 14c and the lower surface on the right end side of the coil piece 11d are in contact with each other.

The lower surface of the left end side of the coil piece 11d and the upper end surface of the coil piece 12d are in contact with each other. The lower end surface of the coil piece 12d and the upper left end surface of the coil piece 13d are in contact with each other. The upper surface of the right end side of the coil piece 13d and the lower end surface of the coil piece 14d are in contact with each other.

The heating coil 10 is configured by the coil pieces 11a, 12a, 13a, 14a, 11b, 12b, 13b, 14b, 11c, 12c, 13c, 14c, 11d, 12d, 13d, and 14d coming into contact in this order. That is, in the extending direction of the heating coil 10, the coil pieces 11 and 12, the coil pieces 12 and 13, the coil pieces 13 and 14, and the coil pieces 14 and 11 are adjacent to each other.

The connector 21 extends in the extending direction of the slab St above the coil pieces 11a to 11d. Coil pieces 11a to 11d are each fixed to the connector 21. An insulator (not shown) is interposed between the connector 21 and the coil pieces 11a to 11d.

The connector 22 extends in the extending direction of the slab St on the left side of the coil pieces 12a to 12d when viewed from the downstream side. Coil pieces 12a to 12d are each fixed to the connector 22. An insulator (not shown) is interposed between the connector 22 and the coil pieces 12a to 12d.

The connector 23 extends in the extending direction of the slab St below the coil pieces 13a to 13d. Coil pieces 13a to 13d are each fixed to the connector 23. An insulator (not shown) is interposed between the connector 23 and the coil pieces 13a to 13d.

The connector 24 extends in the extending direction of the slab St on the right side of the coil pieces 14a to 14d when viewed from the downstream side. Coil pieces 14a to 14d are each fixed to the connector 24. An insulator (not shown) is interposed between the connector 24 and the coil pieces 14a to 14d.

Actuator 31 is connected to connector 22 . The actuator 31 is, for example, a hydraulic cylinder, and is configured to be able to drive the connecting tool 22 in the width direction of the slab St (the extending direction of the coil pieces 11 and 13). When the actuator 31 operates, the coil pieces 12a to 12d fixed to the connector 22 also move in the width direction of the slab St. When the coil pieces 12a to 12d are moved by the actuator 31, the state of contact between the coil piece 12 and the adjacent coil pieces 11 and 13 is maintained.

Actuator 32 is connected to connector 24 . The actuator 32 is, for example, a hydraulic cylinder, and is configured to be able to drive the connecting tool 24 in the width direction of the slab St (the extending direction of the coil pieces 11 and 13). When the actuator 32 operates, the coil pieces 14a to 14d fixed to the connector 24 also move in the width direction of the slab St. When the coil pieces 14a to 14d are moved by the actuator 32, the state of contact between the coil piece 14 and the adjacent coil pieces 11 and 13 is maintained.

The sensor 41 is located upstream of the heating coil 10 in this embodiment. As shown in detail in FIG. 5, the sensor 41 includes a biasing member 41a, a support member 41b, and a touch roll 41c. The biasing member 41a is attached to the connector 22 so as to extend from the connector 22 toward the slab St. The biasing member 41a biases the support member 41b toward the side surface (left side surface when viewed from the downstream side) of the slab St.

The support member 41b supports the touch roll 41c so as to be rotatable around a rotation axis extending along the vertical direction. Therefore, the urging member 41a maintains the contact state between the outer circumferential surface of the touch roll 41c and the left side surface of the slab St. The sensor 41 detects the position of the left side surface of the slab St based on the amount of expansion and contraction (the amount of deviation from the reference position) of the biasing member 41a. This detected value is also the separation distance between the coil piece 12 fixed to the connector 22 and the left side surface of the slab St.

The sensor 42 is located upstream of the heating coil 10 in this embodiment. The sensor 42 may be opposed to the sensor 41 in the width direction of the slab St. The sensor 42 includes a biasing member 42a, a support member 42b, and a touch roll 42c. The biasing member 42a is attached to the connector 24 so as to extend from the connector 24 toward the slab St. The biasing member 42a biases the support member 42b toward the side surface (the right side surface when viewed from the downstream side) of the slab St.

The support member 42b supports the touch roll 42c so as to be rotatable around a rotation axis extending in the vertical direction. Therefore, the urging member 42a maintains the contact state between the outer peripheral surface of the touch roll 42c and the right side surface of the slab St. The sensor 42 detects the position of the right side surface of the slab St based on the amount of expansion and contraction (the amount of deviation from the reference position) of the biasing member 42a. This detected value is also the separation distance between the coil piece 14 fixed to the connector 24 and the right side surface of the slab St.

As shown in FIG. 2, the power source 50 is connected to both ends of the heating coil 10, that is, the right end of the coil piece 11a and the upper end of the coil piece 14d. Power source 50 is an AC power source. When alternating current is applied to the heating coil 10 by the power source 50, an alternating magnetic field acts on the slab St located within the heating coil 10, and an induced current (eddy current) is generated in the slab St. As a result, the slab St is heated by Joule heat according to the electric resistance of the slab St.

Controller 60 controls the operation of power supply 50. Controller 60 controls the operation of actuators 31 and 32 based on signals from sensors 41 and 42. Specifically, upon receiving the positional information of each side surface of the slab St from the sensors 41 and 42, the controller 60 operates the actuators 31 and 32 until the amount of deviation of the biasing members 41a and 42a from the reference position is zero. Move the connectors 22, 24 so that they approach the . Thereby, the distance between the coil pieces 12, 14 and each side surface of the slab St is kept substantially constant.

[Effect]
By the way, in the process of manufacturing slab St by the continuous casting equipment 100, for example, the width of slab St is continuously changed from a wide state as shown in FIG. 3 to a narrow state as shown in FIG. It can change. Even in such a case, the controller 60 controls the actuators 31, 32 based on the signals from the sensors 41, 42, so that the coil pieces 12, 14 and the slab St are separated as shown in FIG. The distance from each side is automatically kept approximately constant. Therefore, it becomes possible to effectively heat slabs St of different sizes by the heating coil 10 without replacing the entire heating coil 10.

In this embodiment, the slab heating device 1 is located downstream of the mold 103 and the secondary cooling zone 104 and upstream of the light reduction device 106. Therefore, even if the slab St is cooled more than necessary, the slab St can be heated to a predetermined temperature by the slab heating device 1 before the slab St reaches the light reduction device 106. Therefore, since the fluctuation in the position of the final freezing point is suppressed, it becomes possible to appropriately roll down the area around the final freezing point by the light rolling down device 106. As a result, it becomes possible to further suppress the occurrence of segregation and center segregation in the slab St.

In this embodiment, the slab heating device 1 is located downstream of the mold 103 and the light rolling down device 106 and upstream of the slab rolling down device 109. Therefore, the slab St softened by being heated by the slab heating device 1 is introduced into the slab rolling down device 109 . Therefore, when the slab St is rolled down by the slab rolling down device 109, the reaction force acting on the slab rolling down device 109 is reduced, so it is possible to downsize the slab rolling down device 109.

[Other embodiments]
Although the embodiments according to the present disclosure have been described in detail above, various modifications may be made to the above embodiments within the scope of the gist of the present invention.

1) For example, as shown in FIG. 7, the slab heating device 1 further includes actuators 33 and 34, and the heating coil 10 further includes a plurality of coil pieces 15 and a plurality of coil pieces 16. You can stay there.

The plurality of coil pieces 15 (four coil pieces 15a to 15d in this embodiment) are arranged on the left side of the slab St when viewed from the downstream side. Each of the coil pieces 15a to 15d is located between the coil pieces 12a to 12d. That is, the coil pieces 12a, 15a, 12b, 15b, 12c, 15c, 12d, and 15d are arranged in this order from the downstream side to the upstream side. The coil pieces 12a to 12d and 15a to 15d extend along the height direction of the slab St so as to be substantially parallel to each other. The lengths of the coil pieces 15a to 15d are set shorter than the lengths of the coil pieces 12a to 12d.

The plurality of coil pieces 16 (four coil pieces 16a to 16d in this embodiment) are arranged on the right side of the slab St when viewed from the downstream side. Each of the coil pieces 16a to 16d is located between the coil pieces 14a to 14d. That is, the coil pieces 14a, 16a, 14b, 16b, 14c, 16c, 14d, and 16d are arranged in this order from the downstream side to the upstream side. The coil pieces 14a to 14d and 16a to 16d extend along the height direction of the slab St so as to be substantially parallel to each other. The lengths of the coil pieces 16a to 16d are set shorter than the lengths of the coil pieces 14a to 14d.

Actuator 33 is connected to connector 21 . The actuator 33 is, for example, a hydraulic cylinder, and is configured to be able to drive the connecting tool 21 in the height direction of the slab St (extending direction of the coil pieces 12, 14 to 16). When the actuator 33 operates, the coil pieces 11a to 11d fixed to the connector 21 also move in the height direction of the slab St.

Actuator 34 is connected to connector 23 . The actuator 34 is, for example, a hydraulic cylinder, and is configured to be able to drive the connecting tool 23 in the height direction of the slab St (extending direction of the coil pieces 12, 14 to 16). When the actuator 34 operates, the coil pieces 13a to 13d fixed to the connector 23 also move in the height direction of the slab St.

In this way, when the coil pieces 12, 14 and the coil pieces 15, 16 having different heights exist, as shown in FIG. A first form in which the coil piece 13 abuts the upper end and the lower end of the coil pieces 12, 14, and a first form in which the coil piece 11 abuts the upper end of the coil pieces 15, 16 and the coil piece 13 abuts the lower end of the coil pieces 15, 16. It changes between a second form in which it abuts the lower end. That is, the heating coil 10 changes between a first form having a relatively large inner diameter (height) and a second form having a relatively small inner diameter (height). Therefore, even if the height of the slab St changes from a tall state as shown in FIG. 4 to a low height state as shown in FIG. 7, the entire heating coil 10 must be replaced. It becomes possible to effectively heat slabs St of different sizes by the heating coil 10 without causing any problems.

2) As shown in FIG. 8, the coil pieces 12, 14 have a substantially trapezoidal shape when viewed from the side, and the ends of the coil pieces 11, 13 that come into contact with the coil pieces 12, 14 are the coil pieces 12, 14. It may be inclined corresponding to the ends of 12 and 14. Note that in FIG. 8, illustration of the coil piece 14 is omitted. In this case, the coil pieces 12 and 14 slide relative to the coil pieces 11 and 13 in the extending direction of the slab St, without preparing coil pieces with different heights as in the embodiment shown in FIG. By doing so, it becomes possible to realize the heating coil 10 whose inner diameter (height) changes between the first form and the second form.

3) As shown in FIG. 9, for example, the left ends of the connectors 21 and 23 may be connected by a link member 71, and the right ends of the connectors 21 and 23 may be connected by a link member 72. In this case, the connectors 21 and 23 and the link members 71 and 72 constitute a parallel link mechanism. Therefore, by driving only the coil piece 13 in the width direction of the slab St using one actuator 35, for example, as shown in FIG. , 13 can be changed. Therefore, it is possible to realize the heating coil 10 whose inner diameter (height) changes between the first form and the second form while reducing the number of actuators.

4) As shown in FIG. 11, a coil piece 10A in which coil pieces 11 and 12 are integrated, and a coil piece 10B in which coil pieces 13 and 14 are integrated may be used. In this case, the coil pieces 10A and 10B have an L-shape when viewed from the extending direction of the slab St. In this way, the heating coil 10 may be configured by at least one pair of coil pieces. Alternatively, in the above embodiment, the heating coil 10 is configured by combining at least one coil piece 11, at least one coil piece 12, at least one coil piece 13, and at least one coil piece 14. You can leave it there. The shape of the coil piece is not limited to a linear shape or an L-shape, but may be any shape that corresponds to the outer shape of the slab St, for example, an arc shape, a bent shape, or the like.

5) The cross-sectional shape of the slab St may have a shape other than a rectangular shape (for example, a circular shape).

6) The sensors 41 and 42 may be located downstream of the heating coil 10, or may be located both upstream and downstream of the heating coil 10, as shown in FIG. . In the embodiment shown in FIG. 12, actuators 31 are further provided on the upstream and downstream sides of the connector 22, and actuators 32 are provided on the upstream and downstream sides of the connector 24, respectively. In this case, the upstream sensors 41, 42 and the upstream actuators 31, 32 independently adjust the distance between the upstream portion of the coil pieces 12, 14 and the side surface of the slab St. The downstream sensors 41 and 42 and the downstream actuators 31 and 32 independently adjust the distance between the downstream portions of the coil pieces 12 and 14 and the side surface of the slab St. Therefore, as shown in FIG. 12, even if the cross-sectional area of the slab St gradually changes in the extending direction of the slab St, the side surface of the slab St and the coil piece 12, depending on the shape of the slab St, 14 is kept constant. Therefore, it becomes possible to effectively heat the slab St by the heating coil 10.

7) As the sensors 41 and 42, not only contact sensors but also non-contact sensors can be used.

8) The slab heating device 1 does not need to be equipped with a sensor.

9) The positions of the coil pieces 11 to 14 may be adjusted depending on the width and/or height of the mold 103.

10) The coil pieces 11 to 14 may be hollow members provided with hollow passages (cooling paths) through which a refrigerant can flow. When the coil pieces 11 to 14 are hollow members, the coil pieces 11 to 14 may be made of a low melting point material.

DESCRIPTION OF SYMBOLS 1... Slab heating device, 10... Heating coil, 11-14... Coil piece, 31-35... Actuator (drive part), 41, 42... Sensor (detector), 60... Controller (control part, detector), DESCRIPTION OF SYMBOLS 100... Continuous casting equipment, 103... Mold, 106... Light reduction device, 109... Slab rolling device, St... Slab.

Claims (9)

A heating coil configured to be wound around a slab by combining a plurality of coil pieces;
an actuator configured to move at least one coil piece among the plurality of coil pieces while maintaining a state of contact with another adjacent coil piece ;
It is equipped with a control section ,
The control unit is configured to control the actuator so that a distance between the plurality of coil pieces and each side surface of the slab is kept substantially constant . The plurality of coil pieces includes a pair of straight rod-shaped first and second coil pieces, and a straight rod-shaped pair of third and fourth coil pieces,
The heating coil has a spiral shape in which the first coil piece, the third coil piece, the second coil piece, and the fourth coil piece contact each other in this order,
The actuator according to claim 1, wherein the actuator is configured to move at least one of the first to fourth coil pieces while maintaining a state of contact with another adjacent coil piece. Device. The plurality of coil pieces includes a pair of L-shaped first and second coil pieces,
The heating coil has a spiral shape with one ends of the first and second coil pieces in contact with each other,
The device according to claim 1, wherein the actuator is configured to move at least one of the first and second coil pieces while maintaining a state of contact with the other coil piece. The plurality of coil pieces include a pair of straight rod-shaped first and second coil pieces, a straight rod-shaped pair of third and fourth coil pieces, and a pair of straight rod-shaped fifth and sixth coil pieces. and has
The fifth and sixth coil pieces extend along the extending direction of the first and second coil pieces,
The lengths of the fifth and sixth coil pieces are shorter than the lengths of the first and second coil pieces,
The actuator has a first form in which the first coil piece, the third coil piece, the second coil piece, and the fourth coil piece contact each other in this order to form a spiral shape; The coil piece No. 5, the third coil piece, the sixth coil piece, and the fourth coil piece contact each other in this order to form a spiral shape. 2. The device of claim 1, wherein the device is configured to move at least one of the four coil pieces. a detector configured to detect a separation distance between the slab and the heating coil on the upstream side and/or downstream side of the heating coil in the extending direction of the slab;
The apparatus according to any one of claims 1 to 4, further comprising a control section that controls the actuator to adjust the position of the coil piece according to the separation distance detected by the detector. The device according to any one of claims 1 to 5, wherein the plurality of coil pieces are solid members having conductivity. The apparatus according to any one of claims 1 to 5, wherein the plurality of coil pieces are hollow members through which a refrigerant can flow. A mold that cools the molten metal and forms it into a predetermined shape to form a slab;
The slab heating device according to any one of claims 1 to 7, which is located downstream of the mold and maintains the slab at a predetermined temperature.
Continuous casting equipment, comprising: a light reduction device located downstream of the slab heating device and applying a rolling force to the slab in the final stage of solidification. A mold that cools the molten metal and forms it into a predetermined shape to form a slab;
The slab heating device according to any one of claims 1 to 7, which is located downstream of the mold and softens the slab by heating;
Continuous casting equipment, comprising a slab reduction device located downstream of the slab heating device and applying a rolling force to the solidified slab.

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