Method for measuring meandering, traction device, and method for adjusting the conveying unit of a walking beam type heating furnace

Abstract

This system allows for easy position adjustment of the transported object used for meandering measurement, and enables measurement of the meandering state while also considering dimensional changes of the transport unit that transports the object. [Solution] A heating furnace 1 in which a material to be heated is heated while being transported by a walking beam type transport unit 11, and a meandering measurement method for measuring the meandering state of the material to be heated inside the heating furnace 1, wherein a transport body lighter than the material to be heated is transported by the transport unit 11, and the meandering state of the material to be heated is measured from the meandering state of the transport body caused by the transport, the transport body has an internal cavity 70E, and at least one surface of the transport body facing forward or backward with respect to the transport direction is provided with a mark 80 for detecting the behavior of the transport body.

Description

Technical Field

[0005] , , ,

[0001] The present invention relates to a technique for measuring the behavior of a heated object during conveyance in a walking beam type heating furnace. The present invention also relates to a technique for adjusting a conveyance unit of a walking beam type heating furnace based on the measurement of the behavior.

Background Art

[0002] As a heating furnace for heating a continuously cast metal slab (hereinafter also referred to as a heated material), a walking beam type heating furnace is widely used. The heated material heated in the heating furnace is conveyed to a hot rolling line and rolled.

[0003] A walking beam type heating furnace is a heating furnace that heats a heated material while conveying it from an inlet to an outlet by a walking beam type conveyance unit. The walking beam conveyance unit moves the movable beam intermittently up and down and back and forth to move the heated material along the fixed beam. Here, the movable beam and the fixed beam are arranged in a plurality of rows along the furnace width direction. Also, the plurality of rows of movable beams are integrally supported and configured to move up and down by a lifting mechanism such as a cam mechanism using eccentric wheels that are paired left and right, for example.

[0004] As described above, the conveyance unit uses the movable beam to lift the heated material from the fixed beam or lower it onto the fixed beam. When this conveyance is performed, if the virtual surface defined by the upper surfaces of a group of movable beams arranged in the furnace width direction inclines in the furnace width direction, the heated material being conveyed may meander in the furnace. And if the meandering of the heated material increases, there is a risk that the heated material will come into contact with the furnace wall. Therefore, it is necessary to periodically or as needed inspect the meandering state of the heated material conveyed by the conveyance unit. As a method for measuring the meandering state of the heated material, for example, there are the methods described in Patent Document 1 and Patent Document 2.

[0005] In the method described in Patent Document 1, firebricks are placed on top of the material to be heated for the purpose of measuring meandering, and the material to be heated is then transported. Patent Document 1 describes how the amount of meandering of the material to be heated that occurs during transport is determined based on the change in position of the firebricks during transport. Furthermore, Patent Document 2 discloses a method for measuring the behavior of left and right eccentric wheels that move a movable beam up and down using a laser rangefinder. Malfunctions in the behavior of the left and right eccentric wheels can cause the heated material to meander. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 4635922 [Patent Document 2] Japanese Patent Publication No. 2018-31052 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In the method described in Patent Document 1, it is necessary to place refractory bricks for measurement on top of the material to be heated and then transport the material to be heated, which makes handling the refractory bricks and the material to be heated while transporting them inside the furnace cumbersome. Furthermore, the increased weight of the material to be heated while transporting it inside the furnace also makes handling the refractory bricks and the material to be heated cumbersome. In addition, because the material to be heated is heavy, if the material to be heated meanders and comes into contact with the furnace wall or adjacent slab during measurement, correcting the position of the material to be heated is time-consuming.

[0008] In the method described in Patent Document 2, it is necessary to provide a separate laser receiver and laser transmitter near each eccentric wheel for measurement. Furthermore, the method described in Patent Document 2 does not directly measure the behavior of the material being heated while being transported by the transport unit. Therefore, it cannot measure the meandering of the material being heated caused by means other than the lift-up mechanism that moves the movable beam up and down. In other words, the method described in Patent Document 2 can measure the behavior of the movable beam caused by the left and right eccentric wheels that move the movable beam up and down. However, the method described in Patent Document 2 does not take into account dimensional errors during the manufacturing of the movable beam itself, which constitutes the structure of the transport unit, or dimensional changes due to wear of the various parts constituting the transport unit due to the use of the transport unit. And the meandering state can also change due to such dimensional errors and dimensional changes. However, the method described in Patent Document 2 has the problem that it cannot measure the meandering state of the material being heated while taking into account the effects of such dimensional changes.

[0009] This invention was made in view of the points mentioned above. One of the objectives of this invention is to enable easy position adjustment of a conveyed object for meandering measurement, and to enable measurement of the meandering state while taking into account changes in the dimensions of the conveying unit that conveys the object. [Means for solving the problem]

[0010] To solve the problem, one aspect of the present invention relates to a heating furnace in which a material to be heated is heated while being transported by a walking beam type transport unit, and provides a meandering measurement method for measuring the meandering state of the material to be heated inside the heating furnace, wherein a transport body lighter than the material to be heated is transported by the transport unit, and the meandering state of the material to be heated is measured from the meandering state of the transport body caused by the transport, the transport body is hollow inside, and the transport body is provided with a mark on at least one surface of the surface facing forward or backward with respect to the transport direction for detecting the behavior of the transport body. [Effects of the Invention]

[0011] In an embodiment of the present invention, a conveyor lighter than the material to be heated is used to measure the meandering state of the material to be heated. Therefore, adjusting the position of the conveyor, which is transported by the conveyor unit of the heating furnace, is easier than adjusting the position of the material to be heated. Adjusting the position of the conveyor refers to actions such as returning the conveyor to the entrance side of the heating furnace for another meandering measurement. Alternatively, adjusting the position of the conveyor refers to changing the position of the conveyor within the furnace.

[0012] Furthermore, in this embodiment of the present invention, since the meandering state is measured on the conveyed object actually being conveyed by the conveying unit, it becomes possible to take into account the dimensional changes of the conveying unit during measurement. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram illustrating the configuration of a heating furnace according to an embodiment of the present invention. [Figure 2] This diagram illustrates an example of the configuration of a transport unit. (a) is a schematic diagram viewed from the side illustrating the configuration in the furnace length direction. (b) is a schematic diagram viewed from the furnace length direction. [Figure 3] This diagram illustrates the movement of the transport unit. [Figure 4] This diagram illustrates the mechanism by which meandering occurs due to eccentric wheels on the left and right sides. [Figure 5] This figure shows the relationship between the rotation angle θ of the eccentric wheel and the lift amount h for the left and right eccentric wheels. [Figure 6] This figure shows an example of a dummy slab (conveyor). [Figure 7] This figure illustrates a method for measuring meandering according to an embodiment of the present invention. [Figure 8] This diagram illustrates an example of detecting a mark's offset due to meandering. [Figure 9] This figure shows an example of a mark meandering along the furnace length. [Figure 10] This is a diagram illustrating an example of a traction device that constitutes an example of a traction means. [Modes for carrying out the invention]

[0014] Next, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a slab is exemplified as the heated object. And in this embodiment, a walking beam type heating furnace for heating the slab is targeted. In the following description, the walking beam type heating furnace is also simply referred to as a heating furnace.

[0015] FIG. 1 is a schematic diagram for explaining the configuration of the heating furnace 1. As shown in FIG. 1, the heating furnace 1 includes a burner 4 and a conveying unit 11 in a furnace body 2. In FIG. 1, the conveying unit 11 is illustrated in a simplified manner, and only a part of its configuration is shown.

[0016] <Furnace body 2> As shown in FIG. 1, the heating furnace 1 of this embodiment has a plurality of combustion zones 2A to 2C arranged along the conveying direction (pass line) of the slab 10 to be heated. Further, the furnace body 2 is provided with a charging door 5 for charging the slab 10 and an extraction door 6 for extracting the heated slab 10. In this embodiment, as the plurality of combustion zones 2A to 2C, three types of combustion zones 2A to 2C, namely a preheating zone 2A, a heating zone 2B, and a soaking zone 2C, are exemplified from the charging port 2a side (upstream side) toward the extraction port 2b side (downstream side). In FIG. 1, the case where there is one heating zone 2B and one soaking zone 2C respectively is exemplified, but the heating zone 2B and the soaking zone 2C may each be provided with two or more. Note that the reference numeral 3 represents a flue.

[0017] <Burner 4> In addition, a plurality of burners 4 are provided in each of the combustion zones 2A to 2C. In the example of FIG. 1, in each of the combustion zones 2A to 2C, the burners 4 are arranged at upper positions above and lower positions below the conveying position of the slab 10, respectively.

[0018] <Conveying unit 11> The conveying unit 11 of this embodiment is a walking beam type conveying unit. As shown in Figure 2, the transport unit 11 of this embodiment includes multiple rows of fixed beams 21 and multiple rows of movable beams 31.

[0019] As shown in Figure 2(b), the multiple rows of fixed beams 21 are arranged in parallel in the furnace width direction, and each fixed beam 21 extends in the furnace length direction. The upper surfaces of these multiple rows of fixed beams 21 define the transport position (pass line) of the slab 10 within the heating furnace 1. The upper surfaces of the multiple rows of fixed beams 21 also define the support surface that supports the slab 10. This support surface is adjusted to be a horizontal plane. Each fixed beam 21 is supported by the hearth 2d via fixed posts 22.

[0020] Furthermore, as shown in Figure 2(b), the multiple rows of movable beams 31 are arranged in parallel in the furnace width direction, and each movable beam 31 extends in the furnace length direction. The upper surfaces of the multiple rows of movable beams 31 define the support surfaces that support the slab 10. These support surfaces are adjusted to be horizontal. The multiple rows of movable beams 31 are driven to lift the slab 10 from the fixed beam 21 by a predetermined amount by moving up and down and back and forth, displace the lifted slab 10 in the transport direction, and then lower it back onto the fixed beam 21. The transport unit 11 intermittently moves the multiple rows of movable beams 31 up and down and back and forth to move the slab 10 along the extending direction of the fixed beam 21.

[0021] Multiple rows of movable beams 31 are each provided at the upper end of a movable post 32. The lower ends of all of these movable posts 32 are fixed to a walking beam frame 33. This allows the multiple rows of movable beams 31 to move together vertically and horizontally. The walking beam frame 33 extends in the direction of the furnace length. Reference numeral 34 denotes a travel rail provided on the walking beam frame 33.

[0022] The transport unit 11 includes a lift-up mechanism and a forward / backward movement mechanism. The lift-up mechanism is a mechanism that moves the movable beam 31 up and down via the walking beam frame 33. The lift-up mechanism of this embodiment is equipped with a cam mechanism using eccentric wheels 50. The cam mechanism uses a pair of left and right eccentric wheels 50 that are arranged in the furnace width direction. The left and right eccentric wheels 50 each abut against the lower part of the travel rail 34. The rotation axis of each eccentric wheel 50 is connected to a motor (not shown) via a motor transmission shaft 60, so that the multiple eccentric wheels 50 are rotated synchronously.

[0023] Furthermore, the forward and backward movement mechanism is a mechanism that moves the walking beam frame 33 back and forth. The forward and backward movement mechanism is composed of, for example, a cylinder device 40.

[0024] The movable beam 31 is then driven to move up and down and back and forth in the cycle shown in Figure 3. That is, as shown in Figure 3(a), at the bottom dead center of the eccentric wheel 50, the movable beam 31 is positioned below the fixed beam 21. At this time, the slab 10 is resting on the fixed beam 21. Next, as shown in Figure 3(b), when the eccentric wheel 50 rotates to the top dead center position, the movable beam 31 rises via the walking beam frame 33, and the slab 10 rests on the movable beam 31. In this state, as shown in Figure 3(c), the cylinder device 40 is driven, causing the movable beam 31 to move forward in the transport direction. Subsequently, as shown in Figure 3(d), the eccentric wheel 50 rotates to the bottom dead center position, causing the movable beam 31 to descend. As a result, the slab 10 on the movable beam 31 moves onto the fixed beam 21. As a result, the slab 10 moves along the fixed beam 21 for a predetermined distance. Furthermore, when the eccentric wheel 50 is in the bottom dead center position, the cylinder device 40 is driven, causing the movable beam 31 to retract and return to the state shown in Figure 3(a). By repeating the above cycle, the slab 10 intermittently moves along the fixed beam 21 from the inlet 2a side to the outlet 2b side.

[0025] Here, the eccentric wheel 50, walking beam frame 33, travel rail 34, cylinder device 40, etc., constitute the mechanism for driving the movable beam 31. The mechanism for driving the movable beam 31 is housed in a space formed below the hearth 2d. When the hearth 2d is set at ground level, the line connecting the charging port 2a and the extraction port 2b coincides with the ground, and the upper ends of the movable beam 31 and the fixed beam 21 are installed so that they can move up and down close to the ground. With this arrangement, the slab 10 can move almost horizontally close to the ground from the charging port 2a to the extraction port 2b.

[0026] On the other hand, there is a large gap between the installation position of the eccentric wheels 50 and the transport height of the slab 10 by the movable beam 31. This gap varies depending on the size of the heating furnace 1, but in steelmaking facilities, it is generally about 5m to 6m. This is one of the reasons why it becomes difficult to adjust the phase of the pair of eccentric wheels 50 on the left and right sides if the actual slab 10 has a large meander.

[0027] Furthermore, multiple pairs of eccentric wheels 50, each forming a pair on the left and right, are arranged along the furnace length. The synchronized rotation of these multiple pairs of eccentric wheels 50 causes the rows of movable beams 31, which are aligned in the furnace width direction, to move up and down.

[0028] Furthermore, if there is a phase difference in the rotation of the pair of eccentric wheels 50 in the furnace width direction, a shift occurs in the vertical position (lift amount of the slab 10) of each of the multiple rows of movable beams 31 arranged along the furnace width direction, causing the slab 10 to meander within the heating furnace 1.

[0029] Figure 4 shows the specific behavior of the slab 10 when there is a phase difference in the rotation of the left and right eccentric wheels 50. Figure 4(b) shows a state where there is a phase difference in the rotation of the pair of eccentric wheels 50 on the left and right sides. In this example, it shows a state where there is a difference (lift amount difference) in the vertical position (lift amount of the slab 10) between the leftmost movable beam 31 and the rightmost movable beam 31.

[0030] Figure 5 is a superimposed diagram showing the relationship between the rotation angles θ of the left and right eccentric wheels 50 and the corresponding vertical position (lift amount) h of the movable beam 31. The solid line in Figure 5 shows an example of the left eccentric wheel 50 and the leftmost movable beam 31. The dotted line in Figure 5 shows an example of the right eccentric wheel 50 and the rightmost movable beam 31. In this example, a phase difference Δθ occurs between the two eccentric wheels 50, resulting in a lift amount difference Δh between the two movable beams 31.

[0031] When the left and right eccentric wheels 50, which have such a phase difference, are rotated synchronously, as shown in Figure 4(b), the left movable beam 31 rises ahead of the right movable beam 31 when rising. Also, as shown in Figure 4(c), the left movable beam 31 descends ahead of the right movable beam 31 when descending. As a result, as shown in Figure 4(d), the slab 10 moves by ΔL in the furnace width direction toward the side of the eccentric wheel 50 that rises and descends ahead (the left side in the example shown). In this way, the position of the slab 10 shifts in the furnace width direction during the vertical movement of the movable beams 31, causing the slab 10 to meander as it is transported within the furnace. From this idea, it can be seen that the meandering can be suppressed by adjusting the phase difference between the left and right eccentric wheels 50 in accordance with the meandering.

[0032] Furthermore, if the meandering of slab 10 exceeds the permissible limit, there is a risk that slab 10 may come into contact with the inner wall of the furnace. If such contact occurs, it could lead to damage to slab 10, and in the worst case, it could result in a serious problem such as the shutdown of the line. In order to prevent the slab 10 from meandering within the heating furnace 1, it is necessary to periodically monitor the presence or absence of a phase difference between the left and right eccentric rings 50, which are paired in the furnace width direction, and adjust them so that no phase difference occurs.

[0033] In addition to the meandering caused by the phase difference between the left and right eccentric wheels 50, wear and tear on the various parts constituting the transport unit 11 can also cause differences in lift amounts between multiple rows of movable beams 31 aligned in the furnace width direction, potentially leading to meandering in the slab 10.

[0034] (Method for measuring meandering in slab 10) In this embodiment, the meandering state of the slab 10 being transported inside the furnace is measured as follows. In this embodiment, a conveyor lighter than the actual slab is conveyed by the conveyor unit 11 instead of the slab 10, and the meandering state of the slab 10 is measured from the meandering state of the conveyor. In this example, slab 10 is used as the material to be heated; therefore, in the following explanation, the conveying body will also be referred to as dummy slab 70.

[0035] <Regarding Dummy Slab 70 (Conveyor Body)> The dummy slab 70 in this embodiment has an external shape that mimics the external shape of the slab 10 to be heated in the target heating furnace 1. Since the slab 10 is usually rectangular, the external shape of the dummy slab 70 is also rectangular or approximates a rectangular parallelepiped. The rectangular parallelepiped shape is box-like. However, the external shape of the dummy slab 70 is not limited to this. It may have other shapes as long as it has a bottom surface portion 70C (see Figure 6(b)) having a bottom surface of a size that can be transported by the transport unit 11, and side walls that are erected from the bottom surface portion 70C and arranged endlessly in a plan view. The bottom surface portion 70C having a bottom surface of a size that can be transported by the transport unit 11 means, for example, that the bottom surface is flat and has a size that can be supported by all the fixed beams 21 in the furnace width direction. Here, the support surface defined by the multiple rows of fixed beams 21 and the support surface defined by the multiple rows of movable beams 31 are flat surfaces. Therefore, if the bottom surface is flat, it can be stably supported by the multiple rows of fixed beams 21 and the multiple rows of movable beams 31.

[0036] The dummy slab 70 may be smaller or larger than the actual slab. Furthermore, the dummy slab 70 and the slabs 10 do not need to be identical in shape, as each slab 10 heated in the target heating furnace 1 also has a predetermined width. However, the bottom surface of the dummy slab 70 should be shaped to be supported by the fixed beam 21 and movable beam 31 of the transport unit 11.

[0037] Furthermore, the actual slab being heated is heavy and cannot be moved by hand. When moving heavy slabs in steelmaking facilities, overhead cranes are typically used. However, in this example, the slab needs to be moved inside the furnace, making it difficult to use a crane to move it. This makes handling the heated slab 10 difficult. For this reason, in this embodiment, the dummy slab 70, which is moved inside the furnace for meandering measurement, is made to be lighter than the actual slab (material being heated).

[0038] In this example, the walking beam type heating furnace 1 is the object of measurement. As described above, the walking beam type transport unit 11 intermittently performs the operation of lifting the dummy slab 70 from the fixed beam 21 with the movable beam 31 and lowering the lifted dummy slab 70 onto the fixed beam 21. This moves the dummy slab 70 along the fixed beam 21. Therefore, even if the weight of the dummy slab 70 is lighter than that of the slab 10, the behavior during transport will be the same for the lighter dummy slab 70 and the slab 10. Normally, the slab 10 supported by the fixed beam 21 and the movable beam 31 will not slide on the fixed beam 21 and the movable beam 31.

[0039] Therefore, by transporting a lightweight dummy slab 70 in place of the slab 10, the meandering state of the slab 10 can be easily measured.

[0040] The actual slab weighs approximately 13 tons. A dummy slab 70 was prepared, made of aluminum and shaped as shown in Figure 6. The dummy slab 70 weighed 30 kg. The bottom surface of the actual slab and the bottom surface of the dummy slab 70 were made to have similar shapes. When the actual slab and the dummy slab 70 were transported, it was confirmed that they behaved the same way during transport. The lighter the dummy slab 70, the better. Ideally, the weight of the dummy slab 70 should be less than or equal to the weight obtained by multiplying the number of people carrying it by the maximum weight that one person can continuously carry, which is 20 kg. In the steel industry, a weight of 20 kg or less is considered the maximum weight that one person can continuously carry.

[0041] The material of the dummy slab 70 is not limited as long as it does not deform in shape during transport and can withstand the furnace temperature. Examples of materials for the dummy slab 70 include aluminum and steel. Here, it is not necessary to heat the dummy slab 70 during measurement. Therefore, if the furnace temperature during measurement is, for example, near the ambient temperature, the dummy slab 70 may be made of resin or cardboard. However, this is conditional on the bottom surface not deforming during transport.

[0042] Furthermore, the dummy slab 70 of this embodiment is made lighter by having a hollow interior 70E. Even though the interior is hollow 70E, it is not necessary for the hollow 70E to be sealed. The dummy slab 70 of this embodiment is shown in Figure 6. The dummy slab 70 of this embodiment shows a state in which the hollow 70E is open upwards by omitting the top surface. That is, the dummy slab 70 of this embodiment consists of a bottom surface 70C and four side surfaces that constitute an endlessly arranged side wall. Because the dummy slab 70 is lightweight, its rigidity can be lower than that of an actual slab. However, it is necessary to prevent the bottom surface 70C of the dummy slab 70 from bending during transport. For this reason, in this example, the endlessly arranged side walls rising from the bottom surface 70C act as ribs to suppress the bending of the bottom surface 70C during transport. In a plan view, it is preferable to form the side walls as close as possible to the outer edge of the bottom surface 70C. To further prevent bending of the bottom surface 70C, additional ribs may be provided inside the cavity 70E. The bottom surface 70C and the side surfaces may be a single unit or joined by welding or other means. Also, if the rigidity of the bottom surface 70C can be ensured, some of the four side surfaces of the dummy slab 70 may be omitted. Furthermore, it is not necessary to set the end face of the bottom surface 70C and the outer surface of the side surfaces flush.

[0043] Furthermore, the side section 70A should have a certain thickness (height) to prevent it from bending during the transport of the dummy slab 70.

[0044] By using the dummy slab 70 described above, the weight of the conveyor is significantly reduced. Therefore, the position of the dummy slab 70 located inside the furnace can be easily adjusted using manual labor or machinery. Furthermore, since the dummy slab 70 of this embodiment can be placed on the transport unit 11 (fixed beam 21 and movable beam 31), it is possible to measure the amount of meandering that reflects changes in the dimensions of the transport unit 11. In addition, because the size and placement position do not change from those of the actual slab, it becomes possible to more accurately simulate the amount of meandering during actual movement.

[0045] <mark> The dummy slab 70 is provided with marks 80 on at least one of its surfaces 70A and 70B, which face forward or backward with respect to the transport direction, for detecting the behavior of the dummy slab 70 inside the furnace. In this embodiment, as shown in Figure 6, the marks 80 are provided on the outer surface of the side portion 70B that faces forward in the transport direction, i.e., towards the extraction port 2b. In Figure 6, dot-shaped marks 80 are shown as an example, but the marks 80 may be composed of a scale with markings. In the case of a scale, the amount of displacement can be determined using the markings on the scale. The markings are oriented in the direction of the furnace width.

[0046] In the case of the heating furnace 1 used in the pre-process of hot rolling, the displacement of one set of eccentric wheels 50 over a furnace length of several tens of meters may be only a few millimeters. Therefore, it is necessary to accurately measure the displacement in the furnace width direction.

[0047] The position of the mark 80 in the furnace width direction is not particularly limited, as long as it is in a position that can be observed from outside the furnace. However, as described later, it is preferable to set the mark 80 to be located above a predetermined fixed beam 21. In this case, the positioning of the dummy slab 70 relative to the multiple rows of fixed beams 21 can be easily determined using the mark 80 as a reference. In addition, the mark 80 can be observed with reference to the stationary fixed beams 21.

[0048] (Method for measuring meandering condition) In this embodiment, the meandering state of the dummy slab 70 during transport is measured by transporting the dummy slab 70, which is made of an object lighter than the slab 10, using the transport unit 11.

[0049] In this embodiment, a mark 80 is provided on the dummy slab 70 to measure the meandering state of the dummy slab 70. By measuring the displacement of the mark 80 in the furnace width direction during transport, based on the behavior of the mark 80 during transport, the meandering state of the dummy slab 70 during transport can be measured. A known method can be used to measure the meandering state using the mark 80.

[0050] Next, an example of a method for measuring the meandering state in this embodiment will be described. In this example, as shown in Figure 6, the mark 80 was set so that its position is above the fixed beam 21 near the right-hand furnace wall. The reference position is set based on the fixed beam as described later.

[0051] Then, as shown in Figure 7, the dummy slab 70 is installed so that mark 80 is positioned above the corresponding fixed beam 21. In Figure 7, for clarity, only the beams on the furnace wall side are shown as the fixed beam 21 and movable beam 31. In this example, the dummy slab 70 is placed on the fixed beam 21 so that the mark 80 on the dummy slab 70 is positioned on the rightmost fixed beam 21 in Figure 7. The dummy slab 70 is then transported by the transport unit 11. By setting the position so that the fixed beam 21 and the mark 80 on the dummy slab 70 are aligned, it becomes easy to position the dummy slab 70 on the fixed beam 21. In addition, as the dummy slab 70 is transported, the mark 80 moves along the direction of extension of the fixed beam 21, making it easier to observe the mark 80.

[0052] In this embodiment, a camera 90 is provided for observing the mark 80. The camera 90 is positioned outside the furnace on the extraction port 2b side, and as shown in Figure 7, the shooting axis S is set on the fixed beam 21 in a plan view. That is, by setting the shooting axis S of the camera 90 along the extending direction of the fixed beam 21, the setup work of the camera 90 for measurement becomes easier.

[0053] As described above, once the preparations for measurement are complete, the transport unit 11 inside the furnace is operated under the same conditions as actual operation, and the dummy slab 70 is transported by the transport unit 11. Simultaneously with the transport, the camera 90 is activated, and images are taken with the camera 90 continuously at a preset sampling period (shooting period).

[0054] In this embodiment, the mark 80 is imaged once with the camera 90 before transport, and the position of the mark 80 in the furnace width direction relative to the fixed beam 21 is set as the reference position 81 (see Figure 8). Then, as shown in Figure 8, the amount of deviation (offset) d in the furnace width direction between the position of mark 80 in the image captured during transport and the reference position 81 set with respect to the fixed beam 21 is used as measurement information to determine the meandering state. This deviation amount d is calculated for each image captured consecutively. This process is performed by the image processing unit 91. If a scale is set with mark 80 as the origin and oriented in the furnace width direction, the deviation amount d can be measured depending on which scale position the reference position 81 is at.

[0055] Figure 9 shows an example of plotting the amount of displacement, which was continuously determined along the conveying process, along the furnace length. In Figure 9, the amount of displacement is shown with a negative value for displacement to the left of the reference point (initial position) and a positive value for displacement to the right. In the example shown in Figure 9, there are four pairs of eccentric rings 50, numbered #1 to #4. The distance between pairs of eccentric rings 50 in the furnace length direction is, for example, 40m or more.

[0056] The meandering of the dummy slab 70 occurs in the set of eccentric wheels 50 near the transport position of the dummy slab 70. Therefore, in this embodiment, the meandering state is measured using the set of eccentric wheels 50 that are measured in the furnace length direction as a reference. Specifically, the offset amount D of the mark 80 in the furnace width direction is determined in the range from just before the support position of the target set of eccentric wheels 50 to the position past the support position of that set of eccentric wheels 50. This offset amount D is then taken as the amount of information D regarding the meandering state of that set of eccentric wheels 50. The amount of information D regarding the meandering state is an index value of the meandering state.

[0057] For example, for the eccentric wheel #3 50 in Figure 9, the amount of information D regarding the meandering state of the dummy slab 70 supported by the eccentric wheel #3 50 is calculated by subtracting the amount of displacement between #3 and #4 from the amount of displacement between #2 and #3 in the furnace length direction. The larger the amount of information D regarding the meandering state, the greater the amount of meandering is determined to be. It should also be assumed that the amount of information D regarding the meandering state includes information in the offset direction. Note that in Figure 9, the position between #2 and #3 is set to the center position between #2 and #3, but it is not limited to the center position; it may also be a position closer to #3. The same applies to the position between #3 and #4.

[0058] In this manner, the information D regarding the meandering state is obtained for each set of eccentric wheels 50.

[0059] (Regarding serpentine course adjustment) Based on the information D of the meandering state obtained as described above for each set of eccentric wheels 50, the phases of the left and right eccentric wheels 50 constituting the set are adjusted in a direction that reduces the meandering for each set of eccentric wheels 50 with a large amount of meandering state information D. Once the adjustment is complete, the dummy slab 70 is transported through the furnace again for measurement, and the meandering condition information D is obtained again. Based on the obtained information D, the meandering is adjusted if necessary.

[0060] In this manner, the above meandering adjustment and the above meandering state measurement (acquisition of meandering state information D) are repeated until the meandering state information D for each set of eccentric wheels 50, obtained by measuring the meandering state, falls within a predetermined threshold range. To achieve this, it is necessary to move the dummy slab 70, which has been moved to the extraction port 2b side, back to the charging port 2a side, so it is preferable that the dummy slab 70 be lightweight.

[0061] (Method for adjusting the set of eccentric rings 50) The amount of meandering of the dummy slab 70 that occurs at and near the position supported by the pair of left and right eccentric wheels 50 is a value proportional to the obtained meandering state information D, and the direction of the meandering can be determined by its offset direction.

[0062] Here, the meandering described above is caused by the difference in lift amounts between the left and right eccentric wheels 50 and the wear of the movable beam 31 and other components that make up the body of the transport unit 11. In this embodiment, it is assumed that the cause of this meandering is entirely due to the difference in lift amounts between the left and right eccentric wheels 50. Then, the meandering is reduced by adjusting the phase difference between the left and right eccentric wheels 50.

[0063] In this case, assuming that the absolute value of the meandering state information D is proportional to the difference in lift amounts between the left and right eccentric wheels 50, the phase difference between the left and right eccentric wheels 50 should be adjusted in a direction that reduces this difference in lift amounts. This adjusts the meandering to be reduced at the position supported by the target eccentric wheel 50 and in its vicinity. The adjustment of the phase difference between the left and right eccentric wheels 50 can be performed by known means.

[0064] (Towing means and towing devices) The method for measuring the meandering state in this embodiment includes the step of changing the position of the dummy slab 70 (i.e., the conveyor) along the furnace length direction toward the charging port 2a side of the heating furnace. This step can be performed, for example, using a traction means. The traction means is a means for moving the dummy slab 70, which has been transported to the outside of the furnace on the extraction port 2b side of the heating furnace 1, or the dummy slab 70 which is located inside the furnace, in the direction opposite to the transport direction.

[0065] Using this traction mechanism, the dummy slab 70, which has been transported through the furnace and moved to the extraction port 2b side for measurement, can be moved back to the charging port 2a for further measurement. Furthermore, the traction mechanism can be used to move the dummy slab 70 along the furnace length direction to the starting position of a specific area within the furnace, for example, in order to focus on measuring only that area.

[0066] The towing means of this embodiment is implemented, for example, by a towing device described below. As shown in Figure 10, the towing device of this embodiment includes a towing wire 100, a towing platform 101, and a winch 103. In Figure 10, for clarity, the movable beam 31 of the transport unit 11 is omitted from the illustration, and only the two fixed beams 21 closest to the furnace wall are shown.

[0067] <Towing wire 100> As shown in Figure 6, one end of the towing wire 100 is attached to the side surface 70A of the dummy slab 70 on the rear side (inlet 2a side) in the transport direction. The side surface 70A is provided with hook portions 71 on both sides in the width direction for hooking the towing wire 100. One end of the towing wire 100 is branched into two, and the ends of the branched wires are attached to the respective hook portions 71 as shown in Figure 6. The reason for branching one end of the towing wire 100 into two and attaching it to the dummy slab 70 is to prevent the dummy slab 70 from being rotated or displaced by the towing of the towing wire 100.

[0068] As shown in Figure 10, the traction wire 100 extends from one end to the other end along the furnace length towards the loading port 2a. Here, the towing wire 100 can be made of any material as long as it has sufficient tensile strength to withstand pulling an object with a mass of 50 kg or less. Commercially available towing wires can be used.

[0069] <Tow stand 101> The towing platform 101 is installed outside the furnace on the loading entrance 2a side. Here, on the outside of the furnace on the loading entrance 2a side, there are mounting rails 104 that form a pair on the left and right sides of the fixed beam 21 outside the furnace. The towing platform 101 is supported by mounting rails 104 that form a pair on the left and right sides. The towing platform 101 has a base portion 101A, a guide portion 101B, and a support column portion 101C.

[0070] The base section 101A is installed between the left and right mounting rails 104 and is detachably fixed to the left and right mounting rails 104. Fixation can be any known means of fixing, as long as it can fix the entire traction device so that it does not move when the dummy slab 70 is towed. For example, this can be achieved by connecting with clamps or by fastening with bolts to holes formed in the mounting rails 104.

[0071] The guide portion 101B is a member that extends in the direction of the furnace from the base portion 101A. The guide portion 101B extends in the direction of the furnace at the center in the furnace width direction. A pulley 102 is provided at the top of the guide section 101B, with its axis oriented in the direction of the furnace width. This pulley 102 makes it possible to change the direction of extension of the traction wire 100 upwards. Furthermore, the lower end of the support column 101C is fixed to the base portion 101A so that it rises upward from the base portion 101A.

[0072] <Winch 103> The winch 103 is installed on the upper part of the base 101A, and the other end of the towing wire 100, which has been redirected upward by the pulley 102, is wound up on it. The dummy slab 70 is then retracted towards the entrance 2a side by winding up the towing wire 100 with the winch 103. The winch 103 may be a manual or electric type.

[0073] Furthermore, the winch 103 is set so that when it moves from the loading port 2a side to the extraction port 2b side of the dummy slab 70, the towing wire 100 is automatically rewound and fed out as it moves. In other words, the rewinding is left free. However, it is preferable to adjust the towing wire 100 so that a predetermined tension is applied to it so that it does not bend too much.

[0074] Here, although the dummy slab 70 is light, it can be heavy and large in size to transport by hand. Therefore, transporting it outside the furnace from the extraction port 2b side to the loading port 2a side is troublesome. In contrast, in this embodiment, the traction device is used to pull the traction wire 100, causing it to slide along the fixed beam 21 that extends in the furnace length direction.

[0075] Furthermore, if the dummy slab 70 meanders excessively within the furnace during transport and interferes with or comes into contact with the furnace wall, it is necessary to temporarily suspend the measurement and move the dummy slab 70 out of the furnace. Even in such cases, the traction device can be used to easily move the dummy slab 70 backward towards the loading entrance 2a.

[0076] By using this traction device, it becomes unnecessary for people to enter the furnace, and the measurement of the meandering amount can be safely performed even when the heating furnace 1 is ignited.

[0077] Furthermore, when performing meandering measurements after extinguishing the heating furnace 1, conventionally, transporting the dummy slab 70 to the loading entrance 2a required crossing a high place on the fixed beam 21, which was a dangerous operation. In contrast, in this embodiment, by using a traction device, it is no longer necessary to enter a high place on the fixed beam 21, allowing for safe operation.

[0078] (modified version) The above description explains a lift-up mechanism using an eccentric wheel 50. The lift-up mechanism may also be composed of a pair of cylinder devices on the left and right sides. Alternatively, the mark 80 of the dummy slab 70 may be provided on the surface 70A facing the entrance 2a side. Furthermore, the dummy slab 70 may have a top surface, and the cavity 70E may not be open upwards. Although the total weight will be heavier, it will be stronger against deformation and bending. Alternatively, the traction device may be configured to pull the dummy slab 70 toward the extraction port 2b.

[0079] (Operation and other functions) In this embodiment, the meandering state of the slab 10 is measured using a dummy slab 70 (conveyor body) that is lighter than the slab 10. Therefore, adjusting the position of the dummy slab 70 conveyed by the conveyor unit 11 of the heating furnace 1 is easier than adjusting the position of the slab 10. Furthermore, in this embodiment, the meandering state is measured using the dummy slab 70 that is actually transported by the transport unit 11, making it possible to take into account dimensional changes of the transport unit 11 as well.

[0080] Furthermore, by forming a cavity 70E in the dummy slab 70, the dummy slab 70 is made lighter in a simple way. Therefore, it is easy to lighten the dummy slab 70. At this time, by providing four side parts that rise from the bottom part 70C to form an endless side wall, the rigidity of the bottom part 70C of the dummy slab 70 is improved, and the bottom part 70C of the dummy slab 70 is less likely to deform when it is transported by the transport unit 11.

[0081] Furthermore, when performing meandering measurements multiple times, the dummy slab 70 can be easily moved backward towards the loading port 2a side using the traction device, thus further improving the operability of the dummy slab 70.

[0082] In this embodiment, a walking beam type heating furnace is the subject of evaluation. The walking beam type transport unit 11 intermittently performs the operation of lifting the dummy slab 70 from the fixed beam 21 with the movable beam 31 and then lowering the lifted dummy slab 70 back onto the fixed beam 21. This operation moves the dummy slab 70 along the fixed beam 21. Therefore, even if the weight of the dummy slab 70 is lighter than the material to be heated, there is no difference in the behavior during transport between the dummy slab 70 and the material to be heated in this embodiment.

[0083] Furthermore, in this embodiment, the weight of the dummy slab 70 can be reduced by a simple method of making the inside of the dummy slab 70 hollow. Also, by using a dummy slab 70 solely for measurement purposes instead of the material to be heated, marks for meandering evaluation can be easily made on the dummy slab 70.

[0084] (others) This disclosure may also take the following form: (1) Disclosure 1 relates to a heating furnace in which a material to be heated is heated while being transported by a walking beam type transport unit, and is a method for measuring the meandering state of the material to be heated inside the heating furnace, A transporter lighter than the material to be heated is transported by the transport unit, and the meandering state of the material to be heated is measured from the meandering state of the transporter during transport. The aforementioned transporter has a hollow interior. The conveying body is provided with a mark on at least one of its surfaces facing forward or backward with respect to the conveying direction for detecting the behavior of the conveying body. Method for measuring meandering. (2) Disclosure 2 is that the bottom surface of the conveying body is flat and of a size that can be conveyed by the conveying unit, The conveying body comprises a bottom portion that constitutes the bottom surface, and an endless side wall portion that is erected from the bottom portion and is in an endless shape when viewed from above. The cavity is formed in the space enclosed by the upper surface of the bottom portion and the inner surface of the side wall portion. The meandering measurement method described in Disclosure 1. (3) Disclosure 3 states that the transport body is a rectangular parallelepiped or a shape that approximates a rectangular parallelepiped. The meandering measurement method described in Disclosure 1 or Disclosure 2. (4) Disclosure 4 measures the meandering state of the material to be heated based on the amount of deviation of the mark in the furnace width direction with respect to a preset reference position in the furnace width direction, The transport unit includes a fixed beam that extends in the direction of the furnace length and is capable of supporting the material to be heated, and the reference position is set based on the fixed beam. A method for measuring meandering as described in any of Disclosures 1 to 3. (5) Disclosure 5 describes a method for changing the position of a conveyor along the furnace length direction by using a towing and retrieval means to move the conveyor, which has been transported to the outside of the furnace on the extraction port side of the heating furnace, or the conveyor which is inside the furnace, to the charging port or extraction port of the heating furnace. A method for measuring meandering described in any one of the disclosures 1 to 4. Herein, as a variation of disclosure 5 above, the traction means may also include a traction wire with one end attached to the conveyor and extending toward the charging port side of the heating furnace, and the function of moving the conveyor by pulling the traction wire. (6) Disclosure 6 is a traction device for moving the conveyor along the furnace length direction, used in the meandering measurement method described in any of Disclosures 1 to 5, A traction wire, one end of which is attached to the conveying body and which extends out of the furnace along the furnace length, The towing platform installed outside the furnace, A winch capable of winding up the towing wire is provided on the aforementioned towing platform, A towing device equipped with a towing device. (7) Disclosure 7 is a method for adjusting a transport unit in a walking beam type heating furnace, The transport unit is equipped with a mechanism that allows a movable beam to move up and down using a cam mechanism with an eccentric wheel. The amount of meandering during the transport of the heated material is estimated by the meandering measurement method described in any of Disclosures 1 to 5. The state of the eccentric wheel is adjusted so that the estimated amount of meandering is reduced. A method for adjusting the transport unit of a walking beam type heating furnace. [Explanation of Symbols]

[0085] 1 Furnace 2a charging port 2b Extraction port 10 Slab (material to be heated) 11 Conveyor Unit 21 Fixed beam 31 Movable Beam 33 Walking Beam Frame 34 Travel Rails 40 Cylinder device 50 Eccentric Wheel 70 Dummy Slab 70A Side part (side wall part) 70C bottom part 70E hollow 71 Hook part 80 marks 81 Reference position 90 Camera 91 Image Processing Unit 100 Towing wires 101 Traction platform 101A Base 101B Information Department 101C Support section 102 Pulley 103 Winch D. Information content of meandering S Shooting axis d. Amount of deviation (offset amount)

Claims

1. A method for measuring meandering behavior in a heating furnace in which a material to be heated is heated while being transported by a walking beam type transport unit, wherein the meandering behavior of the material to be heated is measured within the heating furnace. A transporter lighter than the material to be heated is transported by the transport unit, and the meandering state of the material to be heated is measured from the meandering state of the transporter during transport. The aforementioned transporter has a hollow interior. The conveying body is provided with a mark on at least one of its surfaces facing forward or backward with respect to the conveying direction for detecting the behavior of the conveying body. Method for measuring meandering.

2. The bottom surface of the conveying body is flat and of a size that can be conveyed by the conveying unit. The conveying body comprises a bottom portion that constitutes the bottom surface, and an endless side wall portion that is erected from the bottom portion and is in an endless shape when viewed from above. The cavity is formed in the space enclosed by the upper surface of the bottom portion and the inner surface of the side wall portion. The meandering measurement method described in claim 1.

3. The transporter has a rectangular parallelepiped shape or a shape that approximates a rectangular parallelepiped shape. The meandering measurement method described in claim 1.

4. Based on the amount of deviation of the mark in the furnace width direction from a pre-set reference position in the furnace width direction, the meandering state of the material to be heated is measured. The transport unit includes a fixed beam that extends in the direction of the furnace length and is capable of supporting the material to be heated, and the reference position is set based on the fixed beam. The meandering measurement method described in claim 1.

5. The transporter, which has been transported to the outside of the furnace on the extraction port side of the heating furnace, or the transporter which is inside the furnace, is moved to the charging port or extraction port of the heating furnace by a traction means, thereby changing the position of the transporter along the furnace length direction. A method for measuring meandering according to any one of claims 1 to 4.

6. A traction device for moving the conveying body along the furnace length direction, used in the meandering measurement method described in any one of claims 1 to 4, A traction wire, one end of which is attached to the conveying body and which extends out of the furnace along the furnace length, The towing platform installed outside the furnace, A winch capable of winding up the towing wire is provided on the aforementioned towing platform, A towing device equipped with a towing device.

7. A method for adjusting a transport unit in a walking beam type heating furnace, The transport unit is equipped with a mechanism that allows a movable beam to move up and down using a cam mechanism with an eccentric wheel. The amount of meandering during the transport of the heated material is estimated by the meandering measurement method described in any one of claims 1 to 4. The state of the eccentric wheel is adjusted so that the estimated amount of meandering is reduced. A method for adjusting the transport unit of a walking beam type heating furnace.

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