JP2017170481A - Ring diameter control method of wire rod and manufacturing device of wire rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ring diameter control method of a wire rod capable of promoting uniformization of a ring diameter.SOLUTION: A ring diameter control method of a wire rod on the present invention is the ring diameter control method of the wire rod for winding the wire rod in a coil shape by a plurality of rolling rolls, a pair of pinch rolls, and a laying head, and comprises a process of measuring an average ring diameter rin a state of supporting the wire rod by both of a pair of final rolling rolls and the pair of pinch rolls positioned on the most downstream side among the plurality of rolling rolls and a maximum ring diameter rafter the tail end of the wire rod passes through the pair of final rolling rolls, a process of calculating a change rate Δr=(r-r)/rof a ring diameter from an average ring diameter rand a maximum ring diameter rmeasured by the measurement process and a process of adjusting a rotation speed of the pair of final rolling rolls and the pair of pinch rolls when winding a next material on the basis of the change rate Δr calculated by the calculation process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wire ring diameter control method and a wire manufacturing apparatus.

  2. Description of the Related Art A wire manufacturing apparatus that manufactures a wire rod by continuously rolling a slab such as a billet is known. In this wire manufacturing apparatus, a plurality of rolling rolls, a pair of pinch rolls, and a laying head are arranged in this order from upstream to downstream, and after continuous rolling by the plurality of rolling rolls, the pair of pinch rolls to the laying head. The wire is guided, and the laying head is configured to be able to wind the wire in a coil shape. The wire wound up in a coil shape by the wire manufacturing apparatus is bundled and shipped. Since the quality of the wire wound in the coil shape is evaluated by the uniformity of the ring diameter, it is desired that the ring diameter is strictly controlled.

  However, such a wire manufacturing apparatus has a problem that the ring diameter on the tail end side of the wire becomes extremely large due to poor control of the tension. In view of such a problem, the present applicant determines the winding speed of the winding machine (laying head) based on the rolling speed of the finishing mill before the wire rod comes out of the finishing mill (a pair of final rolling rolls). A winding method was devised to control the winding speed of the winder based on the measured value of the wire speed of the wire after the wire rod passed through the finish rolling mill (see JP 2009-45640 A).

  In this winding method, the winding speed of the winding machine is controlled based on the measured value of the wire speed of the wire after the wire has passed through the finish rolling mill. Uniformity with the ring diameter can be achieved. That is, after the wire rod passes through the finish rolling mill, the tail end of the wire rod cannot be constrained by the finish rolling mill, so the wire speed of the wire rod cannot be controlled based on the rolling speed of this finish rolling mill, The ring diameter on the tail end side of the wire can be controlled by controlling the winding speed of the winder based on the measured value of the wire speed of the wire, and the ring diameter can be made uniform.

JP 2009-45640 A

  However, as a result of intensive studies by the present inventors, it has been found that the wire speed may not be stably measured due to run-out of the rolling mill or the like when the wire diameter is small according to the above-described winding method. . As a result, it has been found that the winding method described above has a problem that the ring diameter may not be appropriately controlled depending on the diameter of the wire.

  The present invention has been made based on such circumstances, and an object of the present invention is to provide a wire diameter control method and a wire manufacturing apparatus that can promote uniform ring diameter.

The ring diameter control method of the wire rod according to the present invention made to solve the above problems is a ring diameter control method of a wire rod that winds the wire rod in a coil shape by a plurality of rolling rolls, a pair of pinch rolls, and a laying head. The average ring diameter r _ave in a state where the wire is supported by both the pair of final rolling rolls located at the most downstream of the plurality of rolling rolls and the pair of pinch rolls, and the tail ends of the wires are the pair of final rolls. The step of measuring the maximum ring diameter r _max after passing through the rolling roll, and the average ring diameter r _ave and the maximum ring diameter r _max measured in the measurement step, and the ring diameter change rate Δr = (r _max −r _ave ) / R _ave and a pair of final rolling rolls and a pair of pins at the time of winding the next material based on the change rate Δr calculated in the above calculation step And a step of adjusting the rotation speed of the tyrol.

The method of controlling the ring diameter of the wire includes an average ring diameter r _ave in a state where the wire is supported by both the pair of final rolling rolls located at the most downstream of the plurality of rolling rolls and the pair of pinch rolls, and A ring diameter change rate Δr = (r _max −r _ave ) / r _ave is calculated from the maximum ring diameter r _max after the tail end passes through the pair of final rolling rolls, and the next material is calculated based on the change rate Δr. Since the number of rotations of the pair of final rolling rolls and the pair of pinch rolls at the time of winding is adjusted, it is possible to promote the equalization of the ring diameter on the tail end side of the wire rod and the ring diameter of other portions. In other words, the wire speed after passing through the pair of final rolling rolls may not be stably measured due to run-out of the rolling rolls, but the ring diameter after being wound by the laying head In order to be stably maintained in the state, by measuring the ring diameter and adjusting the rotation speed of the pair of final rolling rolls and the pair of pinch rolls when winding the next material based on the ring diameter, for example, a small diameter Even with a wire rod, it is possible to ensure uniform ring diameter.

In the state in which the adjusting step is such that the wire rod is supported by both the pair of final rolling rolls and the pair of pinch rolls, the ratio X of the rotational speed VP of the pair of pinch rolls to the rotational speed VR of the pair of final rolling rolls X = (VP / VR) may be adjusted by the following formula (1).
X = X0−a × Δr (1)
However, X0 is the ratio of the rotational speed VP of the pair of pinch rolls to the rotational speed VR of the pair of final rolling rolls before the rotational speed ratio is adjusted by the adjustment process, and a is preset based on the improvement results of the ring diameter Coefficient.

  Thus, in the state in which the adjusting step is performed in such a state that the wire is supported by both the pair of final rolling rolls and the pair of pinch rolls, the rotational speed VP of the pair of pinch rolls with respect to the rotational speed VR of the pair of final rolling rolls. By adjusting the ratio (VP / VR) by the above formula (1), the ring diameter of the wire after the tail end passes through the pair of final rolling rolls can be controlled easily and reliably.

  In the method for controlling the ring diameter of the wire, the adjustment step may be performed when the rate of change Δr exceeds a predetermined threshold. Thus, the uniformity of the ring diameter of the wire can be sufficiently maintained by performing the adjustment step when the rate of change Δr exceeds a predetermined threshold.

In addition, the wire rod manufacturing apparatus according to the present invention made to solve the above-described problems includes a plurality of rolling rolls, a pair of pinch rolls, and a laying head arranged in this order from upstream to downstream, and the plurality of rolling rolls An apparatus for manufacturing a wire rod that winds a wire rod in a coil shape by a pair of pinch rolls and a laying head, wherein the wire rod is located at the most downstream of a plurality of rolling rolls, and a pair of final rolling rolls and the pair of pinch rolls Based on the average ring diameter r _ave in a state where both are supported and the maximum ring diameter r _max after the tail end of the wire passes through the pair of final rolling rolls, and the measurement result of the measurement apparatus And a control device that adjusts the number of rotations of the pair of final rolling rolls and the pair of pinch rolls. Mean a ring diameter _{r ave} and the maximum rate of change of the ring diameter from the ring diameter _{r max Δr = (r max -r} ave) / r ave control element for calculating a was boss, on the basis of the change rate [Delta] r, the following material winding And a control element for adjusting the rotational speed of the pair of final rolling rolls and the pair of pinch rolls.

In the wire manufacturing apparatus, the measuring device measures the average ring diameter r _ave and the maximum ring diameter r _max of the wire, and the control device calculates the ring calculated from the average ring diameter r _ave and the maximum ring diameter r _max. Since the rotation speed of the pair of final rolling rolls and the pair of pinch rolls at the time of winding the next material is adjusted based on the rate of change Δr = (r _max −r _ave ) / r _ave of the diameter, Uniformity between the ring diameter of the end side and the ring diameter of other portions can be promoted.

  As explained above, the ring diameter control method and the wire manufacturing apparatus of the present invention can promote uniform ring diameter.

It is a schematic diagram which shows the manufacturing apparatus of the wire which concerns on one Embodiment of this invention. It is a schematic diagram for demonstrating the measuring method of the ring diameter in the manufacturing apparatus of the wire of FIG. It is a flowchart which shows the procedure which adjusts the ring diameter of the wire by the manufacturing apparatus of the wire of FIG. It is a graph which shows the measurement result of the ring diameter of the wire in a comparative example. It is a graph which shows the measurement result of the ring diameter of the wire in an Example.

  Hereinafter, embodiments of the present invention will be described in detail.

[Wire production equipment]
The wire rod manufacturing apparatus (hereinafter also simply referred to as “the manufacturing apparatus”) in FIG. 1 includes a plurality of rolling rolls 1, a pair of pinch rolls 2, a laying head 3, a measuring device 4, and a control device 5. Is mainly provided. Further, the manufacturing apparatus further includes a heating furnace (not shown) for heating a slab such as a billet and a conveyor 6 for conveying the wire X wound up by the laying head 3. In the manufacturing apparatus, the heating furnace, a plurality of rolling rolls 1, a pair of pinch rolls 2, a laying head 3, and a conveyor 6 are arranged in this order from upstream to downstream. The manufacturing apparatus heats the slab in the heating furnace, processes the slab into a wire X with a plurality of rolling rolls 1, and further converts the wire X into a coil shape with a pair of pinch rolls 2 and a laying head 3. It is configured to be wound up. The manufacturing apparatus may further include a cooling unit that cools the wire X sent from the plurality of rolling rolls 1 to the laying head 3. About the said heating furnace and a cooling means, since it can be set as a well-known structure, detailed description is abbreviate | omitted.

(Rolling roll)
The manufacturing apparatus includes a rough rolling roll, an intermediate rolling roll, and a finishing rolling roll as the plurality of rolling rolls 1. These rough rolling rolls, intermediate rolling rolls, and finish rolling rolls are arranged in this order from upstream to downstream. The manufacturing apparatus includes one or more pairs of a rough rolling roll, an intermediate rolling roll, and a finishing rolling roll, and a pair of rolling rolls positioned at the most downstream side of the finishing rolling roll is configured as a pair of final rolling rolls 1a. ing. The manufacturing apparatus is capable of processing the slab into a wire X having a predetermined cross-sectional shape and diameter by sequentially conveying the slab heated by the heating furnace to a rough rolling roll, an intermediate rolling roll, and a finishing rolling roll. It is configured.

  The average diameter of the wire X processed by the plurality of rolling rolls 1 is not particularly limited. In addition, when the average diameter of the wire X is small, the linear velocity after a tail end passes a pair of final rolling roll 1a tends to become unstable. Therefore, it is difficult for the conventional manufacturing apparatus that adjusts the rotation speeds of the pair of final rolling rolls and the pair of pinch rolls based on the actual measurement value of the linear velocity to adjust the ring diameter of such a thin wire rod. In this respect, the manufacturing apparatus can achieve a uniform ring diameter even with such a thin wire rod. Therefore, as an upper limit of the average diameter of the wire X manufactured with the said manufacturing apparatus, for example, 9 mm may be sufficient and 7 mm may be sufficient. On the other hand, the lower limit of the average diameter of the wire X can be set to 5 mm, for example. The “average diameter” means an average value of diameters when converted to a perfect circle of equal area.

(Pinch roll)
The pair of pinch rolls 2 is disposed with a certain distance from the pair of final rolling rolls 1a. The pair of pinch rolls 2 presses the wire X conveyed from the pair of final rolling rolls 1 a with a constant pressure, and guides the wire X to the laying head 3.

(Laying head)
The laying head 3 has a rotating body having a rotating shaft and a helical laying pipe attached to the rotating body. The laying head 3 is configured such that the rotational axis and the central axis of the laying pipe coincide with each other, and the wire X guided from the pair of pinch rolls 2 is passed through the laying pipe while rotating the rotating body. It is configured to be coilable.

(Conveyor)
The conveyor 6 conveys the wire X wound in a coil shape by the laying head 3 (hereinafter, the wire wound in a coil shape is also referred to as “coiled wire X”) to the downstream side. The conveyor 6 includes a first transport unit 6a that is inclined upward toward the downstream side with respect to a horizontal plane, and a second transport unit 6b that is continuous from the first transport unit 6a and extends in the horizontal direction. In addition, the said manufacturing apparatus has a stacking apparatus (illustration omitted) in the downstream of the conveyor 6, and the coil-shaped wire X conveyed by the conveyor 6 is mounted in this stacking apparatus.

(measuring device)
The measuring device 4 includes an image sensor such as a CCD camera. The measuring device 4 images the coiled wire X transported on the first transport unit 6 a, and the pair of final rolling rolls 1 a and the pair of pinch rolls 2 in which the wire X is located on the most downstream side of the plurality of rolling rolls 1. The average ring diameter r _ave in a state supported by both of them and the maximum ring diameter r _max after the tail end of the wire X passes through the pair of final rolling rolls 1a are measured.

Referring to FIG. 2, illustrating a method of measuring the average ring diameter r _ave and the maximum ring diameter r _max by the measuring device 4. First, the measuring device 4 images the vicinity of the placement position of the coiled wire X in the first transport unit 6a. At this time, the measuring device 4 may take an image of the vicinity of the mounting position of the coiled wire X from above vertically on the upper surface of the first transport unit 6a. However, as shown in FIG. It is preferable to image the vicinity of the placement position of the coiled wire X from the front side in the transport direction. The measuring device 4 is positioned above the upper surface of the first transport unit 6a, sets the measurement line Y at a position parallel to the upper surface and lower than the stacking height of the coiled wire X, and the measurement line Y Measure the brightness. The measuring device 4 differentiates the brightness of the image in the ring diameter direction in the measurement line Y, recognizes the position where the differential value exceeds a certain threshold as the ring edge position, and determines the number of pixels between the left and right edge positions as the actual ring. It converts into a diameter and, thereby, the ring diameter of the coil-shaped wire X is measured. In the manufacturing apparatus, since the coiled wire X placed on the first transport unit 6a is red-hot, the measuring device 4 can stably measure the ring diameter. In addition, although it does not specifically limit as vertical direction distance from the upper surface of the 1st conveyance part 6a to the measurement line Y, For example, they can be 100 mm or more and 500 mm or less.

The measuring device 4 continuously performs the above measurement at a constant interval in a state where the wire X is supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2, and an average ring diameter is obtained by averaging these measured values. The r _ave may be obtained, or the ring diameter after a certain time has elapsed after the winding start by the laying head 3 may be obtained as the average ring diameter r _ave . However, since there is some variation in the ring diameter of the wire X supported by both the pair of final rolling rolls 1 a and the pair of pinch rolls 2, the measuring device 4 continuously performs the above measurement and measures It is preferable to obtain the average ring diameter r _ave by averaging the values. When the measurement device 4 performs the above-described measurement continuously, the measurement frequency by the measurement device 4 can be set within a range of 2 times / second or more and 200 times / second or less, and 5 times / second or more and 60 times / second. It is more preferable to set within the following range. If the measurement frequency is less than the lower limit, the average value of the ring diameters of the wire rods X supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2 may not be accurately measured. On the other hand, even if the measurement frequency exceeds the upper limit, the measurement accuracy of the average value of the ring diameter may not be improved so much.

Moreover, after the tail end of the wire X passes the pair of final rolling rolls 1a, the measuring device 4 continuously performs the above-described measurement at regular intervals, and obtains the maximum ring diameter r _max based on these measured values. at best, may be obtained ring diameter after the tail end of the wire X is a predetermined time through the pair of final rolling rolls 1a has passed a maximum ring size r _max. However, in order to easily and reliably measure the maximum ring diameter r _max, after the tail end of the wire X passes through the pair of final rolling rolls 1a, the above measurement is continuously performed at regular intervals, and the maximum ring diameter is measured. It is preferable to measure as _rmax . When the measurement device 4 performs the above-described measurement continuously, the measurement frequency by the measurement device 4 can be set within a range of 2 times / second or more and 200 times / second or less, and 5 times / second or more and 60 times / second. It is more preferable to set within the following range. If the measurement frequency is less than the lower limit, there is a possibility that the maximum diameter of the wire X after the tail end of the wire X has passed through the pair of final rolling rolls 1a cannot be measured accurately. On the other hand, even if the measurement frequency exceeds the upper limit, the measurement accuracy of the maximum value of the ring diameter may not be improved much.

(Control device)
The control device 5 adjusts the rotational speeds of the pair of final rolling rolls 1 a and the pair of pinch rolls 2 based on the measurement result of the measuring device 4. The control device 5 can be configured by, for example, a personal computer or a programmable controller. That is, the measuring device 4 can control the rotation speeds of the pair of final rolling rolls 1a and the pair of pinch rolls 2 according to a control program.

The control device 5 has a control element that calculates a ring diameter change rate Δr = (r _max −r _rave ) / r _ave from the average ring diameter r _ave and the maximum ring diameter r _max measured by the measuring device 4.

  Further, the control device 5 has a control element for determining whether or not the change rate Δr exceeds a predetermined threshold value.

Further, when the change rate Δr exceeds the threshold value, the control device 5 adjusts the rotation speeds of the pair of final rolling rolls 1a and the pair of pinch rolls 2 when winding the next material based on the change rate Δr. Control elements. As an example, when the change rate Δr exceeds a predetermined threshold value, the control device 5 sets the rotational speed VP of the pair of pinch rolls 2 relative to the rotational speed VR of the pair of final rolling rolls 1a at the time of manufacturing the next material. The ratio X = (VP / VR) is adjusted by the following formula (1).
X = X0−a × Δr (1)
However, X0 is the rotational speed ratio before adjusting the rotational speed ratio at the time of manufacturing the next material (that is, the rotational speed VP of the pair of pinch rolls 2 relative to the rotational speed VR of the pair of final rolling rolls 1a at the time of calculating the change rate Δr). A) is a value set in advance based on the improvement of the ring diameter.

  The control device 5 adjusts the rotation speed ratio (VP / VR) in a state where the wire X is supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2 when the next material is manufactured. In the state where the wire rod X is supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2, the manufacturing apparatus adjusts the rotational speed ratio (VP / VR) by the above formula (1). The ring diameter of the wire X after the tail end passes through the pair of final rolling rolls 1a can be easily and reliably controlled. In addition, the manufacturing apparatus can sufficiently maintain the uniformity of the ring diameter of the wire X by adjusting the rotation speed ratio (VP / VR) when the rate of change Δr exceeds a predetermined threshold value. it can. The coefficient a may be determined based on the average diameter of the wire X and the steel type.

<Ring diameter control method for wire>
Next, a method for controlling the ring diameter of the wire using the manufacturing apparatus (hereinafter also simply referred to as “the ring diameter control method”) will be described. The ring diameter control method is a wire diameter control method for winding a wire X in a coil shape by a plurality of rolling rolls 1, a pair of pinch rolls 2 and a laying head 3. As shown in FIG. 3, the ring diameter control method is an average in a state in which the wire X is supported by both the pair of final rolling rolls 1 a and the pair of pinch rolls 2 located on the most downstream side among the plurality of rolling rolls 1. maximum measuring the ring diameter r _max and (measuring step), the average ring diameter r _ave and the maximum measured in the measuring step in after the tail end of the ring diameter r _ave and the wire X passes through the pair of final rolling rolls 1a A step (calculation step) of calculating the ring diameter change rate Δr = (r _max −r _ave ) / r _ave from the ring diameter r _max, and the ring diameter change rate Δr calculated in the calculation step is set to a predetermined threshold value. A pair of steps for winding the next material based on the rate of change Δr calculated in the calculation step when it is determined that the threshold is exceeded in the determination step (determination step) And a step (adjusting step) for adjusting the rotational speed of the final work roll 1a and a pair of pinch rolls 2.

(Measurement process)
The measurement step (S01) is performed by the measurement device 4. In the measurement step, the measurement line Y is set at a position that is above the upper surface of the first transport unit 6a, is parallel to the upper surface, and is lower than the stacking height of the coiled wire X, and the brightness of the measurement line Y Measure. In the measurement process, in the measurement line Y, the brightness of the image is differentiated in the ring radial direction, and the position where the differential value exceeds a certain threshold is recognized as the ring edge position, and the number of pixels between the left and right edge positions is determined as the actual ring. It converts into a diameter and, thereby, the ring diameter of the coil-shaped wire X is measured.

In the above measurement step, the ring diameter after a certain time has elapsed after the start of winding by the laying head 3 may be obtained as the average ring diameter r _ave , but the wire X is a pair of final rolling rolls 1a and a pair of pinch rolls. It is preferable to perform the above-mentioned measurement continuously at a constant interval in a state where both are supported by 2 and obtain the average ring diameter r _ave by the average of these measured values.

Moreover, in the said measurement process, although the tail end of the wire X passes a pair of final rolling roll 1a, you may obtain _| require the ring diameter after fixed time passed as the maximum ring diameter rmax, There after passing through the pair of final rolling rolls 1a, performed continuously measured above at regular intervals, it is preferable to determine the maximum ring diameter r _max.

(Calculation process)
The calculation step (S02) is performed by the control device 5. In the calculation step, a ring diameter change rate Δr = (r _max −r _rave ) / r _ave is calculated from the average ring diameter r _ave and the maximum ring diameter r _max measured in the measurement step as described above.

(Judgment process)
The determination step (S03) is performed by the control device 5. In the determination step, it is determined whether or not the ring diameter change rate Δr measured in the calculation step exceeds a predetermined threshold value. When it is determined in the determination step that the ring diameter change rate Δr is equal to or less than the threshold value, the adjustment step described later is not performed when the next material is manufactured. On the other hand, when it is determined in the determination step that the ring diameter change rate Δr exceeds the threshold value, the adjustment step is performed when the next material is manufactured. That is, the ring diameter control method performs the adjustment process when the change rate Δr exceeds a predetermined threshold value. The threshold value may be determined according to the management range of the ring diameter. For example, any number between 0.03 and 0.10 can be adopted, and 0.05 is preferable.

(Adjustment process)
The adjustment step (S04) is performed by the control device 5. In the adjustment step, when it is determined in the determination step that the ring diameter change rate Δr exceeds a threshold value, the rotation speed ratio X = (VP / VR) is adjusted by, for example, the following equation (1) at the time of manufacturing the next material To do.
X = X0−a × Δr (1)
However, X0 is the rotational speed ratio before adjusting the rotational speed ratio at the time of manufacturing the next material (that is, the rotational speed VP of the pair of pinch rolls 2 relative to the rotational speed VR of the pair of final rolling rolls 1a at the time of calculating the change rate Δr). A) is a value set in advance based on the improvement of the ring diameter.

  The adjustment step is performed in a state where the rotation speed ratio (VP / VR) is supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2 when the next material is manufactured. In the ring diameter control method, in the state in which the adjusting step is such that the wire rod X is supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2, the rotational speed ratio (VP / VR) is expressed by the above formula (1 ), The ring diameter of the wire X after the tail end has passed through the pair of final rolling rolls 1a can be controlled easily and reliably. Moreover, the said ring diameter control method can aim at equalization of the ring diameter of the wire X more exactly by performing the said adjustment process, when the said change rate (DELTA) r exceeds the predetermined threshold value. The coefficient a may be determined based on the average diameter of the wire X and the steel type.

<Advantages>
In the ring diameter control method, the average ring diameter r _{ave and the} wire X in a state where the wire X is supported by both the pair of final rolling rolls 1 a and the pair of pinch rolls 2 located at the most downstream of the plurality of rolling rolls 1. The ring diameter change rate Δr = (r _max −r _ave ) / r _ave is calculated from the maximum ring diameter r _max after the tail end of each passes through the pair of final rolling rolls 1a. Since the rotation speeds of the pair of final rolling rolls and the pair of pinch rolls at the time of winding the material are adjusted, it is possible to promote the equalization of the ring diameter on the tail end side of the wire X and the ring diameters of other portions. That is, the wire speed of the wire X after passing through the pair of final rolling rolls 1a may not be stably measured due to rolling roll deflection or the like, but the ring diameter after being wound by the laying head 3 Is stably maintained in the winding state, so that this ring diameter is measured and the number of rotations of the pair of final rolling rolls 1a and the pair of pinch rolls 2 when winding the next material is adjusted based on the ring diameter. Thus, for example, even with a small-diameter wire X, the ring diameter can be made uniform. Further, since the ring diameter control method is to actually measure the ring diameter after winding by the laying head 3, it is possible to confirm the actual ring diameter adjustment and to easily grasp the ring diameter fluctuation. Can do.

In the manufacturing apparatus, the measuring device 4 measures the average ring diameter r _ave and the maximum ring diameter r _max of the wire X, and the control device 5 calculates the ring diameter calculated from the average ring diameter r _ave and the maximum ring diameter r _max. Since the rotation speed of the pair of final rolling rolls 1a and the pair of pinch rolls 2 at the time of winding the next material is adjusted based on the rate of change Δr = (r _max −r _ave ) / r _ave , the wire X Uniformity between the ring diameter on the tail end side and the ring diameter of other parts can be promoted. Further, since the manufacturing apparatus can actually measure the ring diameter after winding by the laying head 3, it is possible to confirm the adjustment of the actual ring diameter and to easily grasp the ring diameter fluctuation. .

[Other Embodiments]
In addition, the ring diameter control method and wire manufacturing apparatus according to the present invention can be implemented in variously modified and modified modes in addition to the above-described modes. For example, the ring diameter control method and the manufacturing apparatus may adjust the rotational speed of the laying head in addition to the ratio (VP / VR) of the rotational speed VP of the pair of pinch rolls to the rotational speed VR of the pair of final rolling rolls. Good. Moreover, the said manufacturing apparatus does not limit the number of rolling rolls.

  The ring diameter control method and the manufacturing apparatus preferably adjust the rotation speed ratio (VP / VR) with the wire supported on both the pair of final rolling rolls and the pair of pinch rolls. The rotational speed ratio (VP / VR) may be adjusted before the start of manufacturing. The ring diameter control method and the manufacturing apparatus need not adjust the rotation speed ratio (VP / VR) when the ring diameter change rate Δr exceeds a predetermined threshold. The ring diameter control method and the manufacturing apparatus may adjust the rotation speed ratio (VP / VR) at a constant cycle, for example, or may adjust the rotation speed ratio (VP / VR) at every manufacturing.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

[Comparative example]
Using the above-described wire rod manufacturing apparatus, the ratio of the rotation speed VP of the pair of pinch rolls 2 to the rotation speed VR of the pair of final rolling rolls 1a (VP / VR) is set to 1.0, and the average diameter is 5.5 mm. The wire X was wound into a coil. Further, the ring diameter of the wire X wound in a coil shape is continuously imaged by the measuring device 4, and the ring diameter in a state where the wire X is supported by both the pair of final rolling rolls 1 a and the pair of pinch rolls 2. The average ring diameter r _ave was obtained by averaging the measured values, and the maximum value of the ring diameter after the tail end of the wire X passed through the pair of final rolling rolls 1a was obtained as the maximum ring diameter r _max . The steel type of the wire X was SCR420 defined by JIS-G4104: 1979, and the wire speed of the wire X was 95 m / s. The average ring diameter r _ave according to the comparative example was 1243 mm, the maximum ring diameter r _max was 1358 mm, and the change rate Δr of the ring diameter obtained from the average ring diameter r _ave and the maximum ring diameter r _max was 0.092. FIG. 4 shows the result of measurement by the measuring device 4 in this comparative example.

[Example]
After the production of the wire X according to the comparative example, the wire X was produced under the same conditions as in the comparative example. However, in the example, in a state where the wire X is supported by both the pair of final rolling rolls 1a and the pair of pinch rolls 2, the rotational speed ratio (VP) is based on the ring diameter change rate Δr measured in the comparative example. / VR) was adjusted. Specifically, the rotation speed ratio (VP / VR) was adjusted by the following formula (2).
VP / VR = 1.0−0.08 × 0.092 (2)
In the above formula (2), “1.0” is the rotation speed ratio before changing the rotation speed ratio, “0.08” is a coefficient set in advance based on the improvement results of the ring diameter, “0.092” is the ring diameter change rate Δr measured in the comparative example.

The average ring diameter r _ave according to this example is 1267 mm, the maximum ring diameter r _max is 1305 mm, and the change rate Δr of the ring diameter obtained from the average ring diameter r _ave and the maximum ring diameter r _max is 0.03. . FIG. 5 shows the result of measurement by the measuring device 4 in this example.

<Evaluation results>
As described above, in the example in which the rotation speed ratio (VP / VR) is adjusted based on the ring diameter change rate Δr, the ring diameter change rate Δr is 0.062 smaller than that of the comparative example. It can be seen that the uniform ring diameter was promoted. From this, for example, when the ring diameter change rate Δr exceeds a certain threshold value, the rotation speed ratio (VP / VR) is adjusted based on the ring diameter change rate Δr, so that the ring diameter of the wire X can be reduced. It can be seen that homogenization can be promoted.

  As described above, the ring diameter control method and the wire manufacturing apparatus of the present invention are suitable for manufacturing a high-quality wire because the ring diameter can be made uniform.

DESCRIPTION OF SYMBOLS 1 Roll 1a Final rolling roll 2 Pinch roll 3 Laying head 4 Measuring apparatus 5 Control apparatus 6 Conveyor 6a 1st conveyance part 6b 2nd conveyance part X Wire rod Y Measurement line

Claims (4)

It is a ring diameter control method of a wire rod that winds the wire rod into a coil shape with a plurality of rolling rolls, a pair of pinch rolls and a laying head,
The average ring diameter r _ave in a state where the wire is supported by both the pair of final rolling rolls and the pair of pinch rolls located in the most downstream of the plurality of rolling rolls, and the tail ends of the wires are the pair of final rollings. Measuring the maximum ring diameter r _max after passing through the roll;
Calculating the ring diameter change rate Δr = (r _max −r _ave ) / r _ave from the average ring diameter r _ave and the maximum ring diameter r _max measured in the measurement step;
Adjusting the rotation speed of the pair of final rolling rolls and the pair of pinch rolls at the time of winding the next material based on the change rate Δr calculated in the calculation step. In the state in which the adjusting step is such that the wire rod is supported by both the pair of final rolling rolls and the pair of pinch rolls, the ratio X of the rotational speed VP of the pair of pinch rolls to the rotational speed VR of the pair of final rolling rolls X = The ring diameter control method for a wire rod according to claim 1, wherein (VP / VR) is adjusted by the following formula (1).
X = X0−a × Δr (1)
However, X0 is the ratio of the rotational speed VP of the pair of pinch rolls to the rotational speed VR of the pair of final rolling rolls before the rotational speed ratio is adjusted by the adjustment process, and a is preset based on the improvement results of the ring diameter Coefficient.   The ring diameter control method for a wire rod according to claim 1 or 2, wherein the adjustment step is performed when the rate of change Δr exceeds a predetermined threshold value. A wire rod manufacturing apparatus in which a plurality of rolling rolls, a pair of pinch rolls and a laying head are arranged in this order from upstream to downstream, and the wire rod is wound in a coil shape by the plurality of rolling rolls, the pair of pinch rolls and the laying head. There,
The average ring diameter r _ave in a state where the wire is supported by both the pair of final rolling rolls and the pair of pinch rolls located in the most downstream of the plurality of rolling rolls, and the tail ends of the wires are the pair of final rollings. A measuring device for measuring the maximum ring diameter r _max after passing through the roll;
A control device for adjusting the number of rotations of the pair of final rolling rolls and the pair of pinch rolls based on the measurement result of the measuring device,
The control device is
A control element for calculating a ring diameter change rate Δr = (r _max −r _ave ) / r _ave from the average ring diameter r _ave and the maximum ring diameter r _max measured by the measuring device;
And a control element that adjusts the number of rotations of the pair of final rolling rolls and the pair of pinch rolls at the time of winding the next material based on the change rate Δr.

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