JP2017087269A - Method for slab feeding abnormality detection in hot-rolling width press and hot-rolling width press facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for slab feeding abnormality detection which is reliable and is high responsive.SOLUTION: A method for detecting slab feeding abnormality when hot-rolling width press is performed by use of a width press facility comprising: width rolling equipment which has a metal mold, a drive motor and a crank shaft for connecting the metal mold and the drive motor to each other and which reciprocates the metal mold by a crank mechanism and rolls a slab by hammering the slab in a width direction; and transportation equipment which holds the slab from a vertical direction by a pinch roll and feeds the slab by rotating the pinch roll. The method comprises: a step at which during slab width rolling, the number of times of hammering required for rolling a slab total length from a length of an object slab by a target width rolling amount only is predicted; a step at which from increase and decrease in a crank rotation angle and a width press load, counting for the number of the slab actually hammered times is predicted; and a step at which a ration between the number of the slab actually hammered times and the predicted number of the hammering times is determined, and whether the ratio exceeds a specified threshold or not is monitored during width press execution.SELECTED DRAWING: Figure 3

Description

  The present invention is a hot-rolling width press facility that performs slab width reduction in a hot rolling line, which causes deviation from the slab target width after width pressing, equipment failure, and increased die wear. The present invention relates to a detection method and a hot-rolled width press facility capable of detecting such a feed abnormality.

  In the equipment of the width press (hot rolling width press, sizing press) in the hot rolling line, the slab enters between the dies installed on both sides in the traveling direction, and the dies are continuously reciprocated by the crank mechanism. In particular, it hits the side of the slab and the width is reduced. Between the width reductions, a pinch roll sandwiching the slab in the thickness direction rotates, and the width reduction is performed over the entire length of the slab by intermittently sending the slab a fixed length in the longitudinal direction.

  At this time, when the slab is hit with a mold due to uneven heat of the slab or deviation of the striking position in the thickness direction, the slab buckles, and the contact area between the slab and the pinch roll decreases and the pinch roll slips. Sometimes. In this case, the slab cannot be sent and the same position in the longitudinal direction continues to be reduced, resulting in poor quality on the side surface of the slab, failure to achieve the target product width due to subsequent hot rolling, and generation of unstruck parts. As such, the process proceeds to the next process, causing problems such as inducing line troubles.

  In response to the above problem, Patent Document 1 proposes a method of monitoring the slab feed by attaching an operating speed detection device to a movable body of a sizing press facility and measuring the operating speed. Further, Patent Document 2 describes a method in which a side surface of a slab after sizing press is photographed with a camera, and a hit position deviation is monitored from a change in luminance in the thickness direction.

JP-A-3-77704 JP 2006-181618 A

  However, in Patent Document 1, only the operation time of the equipment is monitored rather than the speed of the slab itself. For example, the inversion of the pinch roll can be detected, but it cannot be detected whether the slab and the pinch roll slip. . This is because, when slipping, even if the slab is stopped, the pinch roll itself is running idle. Further, in Patent Document 2, since the position where the camera can be attached is on the sizing press delivery side, the slab during the sizing press cannot be monitored in real time, and the displacement of the tapping position cannot be found until the sizing press is completed. There is a problem that discovery is delayed.

  Accordingly, the present invention is capable of detecting slippage between a slab and a pinch roll and detecting a slab feed abnormality in real time, and a slab feed abnormality detection method with high reliability and responsiveness. It is an object of the present invention to provide a hot-rolled width press facility capable of detecting an abnormality.

  In order to solve the above problems, the present invention provides the following means (1) and (2).

(1) It has a mold, a drive motor, and a crankshaft that connects them, and by reciprocating the mold by the crank mechanism, hammering down the slab in the width direction and rolling down by a pinch roll A method for detecting abnormalities in slab feeding when performing hot-rolling width press using a width press facility equipped with a transport facility that feeds a slab by rotating a pinch roll by sandwiching the slab from a direction,
During slab width reduction,
Predicting the number of hammering times required to reduce the total length of the slab by the target width reduction amount from the length of the target slab;
From the increase and decrease of the crank rotation angle and width press load, counting the number of times the slab is actually hammered,
Determining the ratio of the number of times the slab was actually hammered and the hammering reference number that is the predicted number of hammering, and monitoring during the width press whether the ratio exceeds a predetermined threshold; and
A method for detecting abnormal slab feeding in a hot-rolled width press.

(2) A width reduction facility that has a mold, a drive motor, and a crankshaft connecting them, and reciprocates the mold by a crank mechanism to hammer down the slab in the width direction and reduce it.
Conveying equipment that sandwiches the slab from above and below with a pinch roll and sends the slab by rotating the pinch roll, and
A hot-rolling width press facility equipped with a slab feed abnormality detection device for detecting a slab feed abnormality,
The slab feed abnormality detection device
During slab width reduction,
A hammering frequency predicting unit that predicts the number of hammering times required to reduce the total length of the slab from the length of the target slab by the target width reduction amount;
From the increase / decrease of the crank rotation angle and width press load, the hammering frequency measurement unit that counts the number of times the slab is actually hammered,
The ratio of the actual number of hammering times of the slab and the estimated number of hammering times is obtained, and the number of hammering times is monitored during the width press execution to determine whether the ratio exceeds a predetermined threshold. And
A hot-rolling press facility characterized by comprising:

  In the present invention, the slab feed amount that is difficult to measure directly is converted into the hammering reference number using the slab feed amount for each hammering, and the number of times that the slab can be actually measured and hammered. Is a method of monitoring.

  According to the present invention, since the movement of the slab can be directly monitored, it is possible to find a slab feeding abnormality due to a pinch roll slip. In addition, since the number of hammering slabs is monitored in real time, it is possible to detect slab feed abnormalities online in real time. Thereby, when a slab feed abnormality occurs, the rolling of the slab can be quickly stopped and the slab can be returned to the outside of the hot rolling line, and the efficiency loss can be minimized.

It is the schematic which shows an example of the manufacturing line which can implement the slab feed abnormality detection method of this invention. It is a block diagram which shows an example of a slab feed abnormality detection apparatus. It is a flowchart which shows the abnormality detection flow in a slab feed abnormality detection apparatus. It is a figure which shows the result of the Example of this invention.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view showing an example of a production line capable of implementing the slab feed abnormality detection method of the present invention.

  This production line includes a heating furnace 1 and a width press facility 10. The slab 2 heated to a predetermined temperature in the heating furnace 1 is conveyed to the width press facility 10 by the table roller 9 and is reduced in width by the width press facility 10 until the target width after the width press is set according to the product width. Is done.

  The width press facility 10 includes a width reduction facility 11 and a transport facility 12. The width reduction equipment 11 includes two dies 3 disposed opposite to both sides in the slab traveling direction, a drive motor 4 provided corresponding to each of the dies 3, and a crankshaft 5 connecting them. Have. The drive motor 4 and the crankshaft 5 constitute a crank mechanism. Reference numeral 8 denotes a drive shaft of the drive motor 4. Moreover, the conveyance equipment 12 has the pinch roll 6 (only upper part is shown in figure) installed up and down, the drive device 7 which rotates and raises / lowers it, and the slab feed abnormality detection apparatus 20 which detects the slab feed abnormality.

  The interval (referred to as opening) of the mold 3 is determined according to the target width after the width press, and is set up before the slab enters the width press facility 10. After entering the slab, the die 3 that reciprocates by the crank mechanism hits the side surface of the slab 2 (hammering), and the slab 2 is reduced in width. At this time, in one hammering, the slab 2 can be reduced only from the upper and lower sides during the continuous hammering because it can be reduced only by the die length shorter than the slab length in the entire length in the longitudinal direction of the slab. The pinch roll 6 sandwiched is rotated so that the slab 2 is intermittently sent by a certain length.

  As shown in the block diagram of FIG. 2, the slab feed abnormality detection device 20 is configured in a host computer 30 and a width press PLC (Programmable Logic Controller) 40, and includes a hammering frequency prediction unit 21, a hammer. A ring frequency measurement unit 22 and a hammering frequency monitoring unit 23 are provided. The hammering frequency predicting unit 21 is incorporated in the host computer 30, and the hammering frequency measuring unit 22 and the hammering frequency monitoring unit 23 are incorporated in the width press PLC.

Next, an example of an embodiment of the slab feed abnormality detection method of the present invention will be described.
FIG. 3 is a flowchart showing an abnormality detection flow in the slab feed abnormality detection device (slab feed abnormality detection system).

  In the abnormality detection flow, first, the hammering frequency prediction unit 21 of the host computer 30 reduces the total length of the slab under the width of the slab from the length L of the target slab and the slab feed amount a for each hammering. The number of hammering times (hammering reference number) necessary for this is predicted (predicted hammering number (x)) (step 1), and the predicted hammering number (x) at that time is input to the PLC for width press.

  Next, the number of times of actual hammering of the slab 2 from the crank rotational angle θ and the width press load P around the drive shaft 8 during the width reduction of the target slab by the hammering frequency measuring section 22 of the PLC 40 for width press ( Count the actual number of hammering times y). Here, the crank angle is defined as 0 ° when the mold is farthest from the slab and 180 ° when it is closest, and can be measured by a PLG (Pulse Generator) of the drive motor. On the other hand, the width press load can be measured by a load cell attached to the mold. When the tip of the slab enters the width press, the actually measured number of hammering y is cleared to zero (step 2). Thereafter, the width press load is a predetermined threshold value P ′ when the crank angle is 180 ° until the width reduction is completed. If it exceeds the value, it is determined that the mold has hit the slab, and the actual number of hammering times y is increased by 1 (step 3).

  Then, in the hammering frequency monitoring unit 23 of the PLC 40 for width press, the ratio of the actual number of hammering times (y) and the predicted number of hammering times (x) based on the predicted number of hammering times (x), r = y / x is obtained (step 4), and when it exceeds a predetermined threshold value r ', it is detected as an abnormal feeding (step 5). In order to allow some slip, it is desirable to set r ′> 1.

  Thus, in this flow, the actual hammering frequency (y) that can be measured is monitored by converting the predicted hammering frequency (x) using the slab feed amount a for each hammering. As a result, the movement of the slab 2 can be directly monitored, and it is possible to detect an abnormal feeding of the slab 2 due to the slip of the pinch roll 6. In addition, since the number of hammering operations of the slab 2 is monitored in real time, it is possible to detect an abnormal feeding of the slab 2 online in real time. Thereby, when an abnormality occurs, the rolling of the slab can be quickly stopped and the slab can be returned to the outside of the hot rolling line, and the efficiency loss can be minimized.

Next, examples of the present invention will be described.
FIG. 4 is a diagram showing the results of the embodiment of the present invention, and shows a time chart of the predicted number of hammering times x and the actual number of hammering times y with time on the horizontal axis. Note that the threshold value r ′ = y / x = 1.1.

  The upper part (a) is an example in which no feeding abnormality occurs and it is determined to be normal. The estimated number of hammering times x is set, and the actual number of hammering times y is gradually counted up after starting the width reduction, but the width reduction is completed with y / x <1.1.

  On the other hand, the lower part (b) is a chart when an abnormality occurs. During the width reduction, y / x> 1.1, and feed abnormality detection is detected, and the width of the slab after width pressing deviates from the target value. Was.

  Thus, according to the present invention, it has been confirmed that the slab movement abnormality detection method can be realized by directly monitoring the slab movement in real time through the measurable number of actually measured hammerings.

DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Slab 3 Mold 4 Drive motor 5 Crankshaft 6 Pinch roll 7 Pinch roll drive device 8 Drive shaft 10 Width press equipment 11 Width reduction equipment 12 Conveyance equipment 20 Slab feed abnormality detection device 21 Hammering frequency prediction part 22 Hammer Ring number measurement unit 23 Hammering number monitoring unit 30 Host computer 40 PLC for width press

Claims (2)

It has a mold, a drive motor, and a crankshaft that connects them, and by reciprocating the mold by a crank mechanism, hammering down the slab in the width direction and rolling down the slab, and a slab from the top and bottom with a pinch roll Is a method of detecting abnormalities in slab feeding when performing hot-rolling width pressing using a width press facility equipped with a transport facility that feeds a slab by rotating a pinch roll,
During slab width reduction,
Predicting the number of hammering times required to reduce the total length of the slab by the target width reduction amount from the length of the target slab;
From the increase and decrease of the crank rotation angle and width press load, counting the number of times the slab is actually hammered,
Determining the ratio of the number of times the slab was actually hammered and the hammering reference number that is the predicted number of hammering, and monitoring during the width press whether the ratio exceeds a predetermined threshold; and
A method for detecting abnormal slab feeding in a hot-rolled width press. A width reduction facility that has a mold, a drive motor, and a crankshaft connecting them, and reciprocates the mold by a crank mechanism to hammer down the slab in the width direction,
Conveying equipment that sandwiches the slab from above and below with a pinch roll and sends the slab by rotating the pinch roll, and
A hot-rolling width press facility equipped with a slab feed abnormality detection device for detecting a slab feed abnormality,
The slab feed abnormality detection device
During slab width reduction,
A hammering frequency predicting unit that predicts the number of hammering times required to reduce the total length of the slab from the length of the target slab by the target width reduction amount;
From the increase / decrease of the crank rotation angle and width press load, the hammering frequency measurement unit that counts the number of times the slab is actually hammered,
The ratio of the actual number of hammering times of the slab and the estimated number of hammering times is obtained, and the number of hammering times is monitored during the width press execution to determine whether the ratio exceeds a predetermined threshold. And
A hot-rolling press facility characterized by comprising:

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