JP5407673B2 - Online diagnosis method of tracking sensor in hot rolling line - Google Patents

Description

  The present invention relates to an on-line diagnostic method for a tracking sensor installed in a hot rolling line.

  In the hot rolling line, a tracking sensor is installed at a predetermined location in order to track the material to be rolled. As the tracking sensor, CMD (Cold Metal Detector), HMD (Hot Metal Detector), and the like are used. The CMD detects the presence of an object by shielding a laser beam, and the HMD detects an object by receiving an infrared ray normally emitted from an object at 400 ° C. or higher.

  Such a tracking sensor changes from the OFF state to the ON state when the tip of the material to be rolled passes through the installation position (starts the ON operation), thereby detecting that the tip of the material to be rolled has passed. can do. Moreover, when the tail end of the material to be rolled passes through the installation position, it changes from the on state to the off state (starts off operation), so that it is possible to detect that the tail end of the material to be rolled has passed. it can.

  However, the tracking sensor that detects the passage of the material to be rolled by the on / off operation as described above may cause malfunction due to water vapor, light amount decrease, temperature decrease, foreign matter contamination, and the like. If the tracking sensor malfunctions, it will cause a tracking error, which may cause the equipment operation or setup timing to be lost, causing the line to stop suddenly, and in the worst case, the equipment may be destroyed.

  Therefore, if an abnormal operation of the tracking sensor can be known at an early stage, it is possible to take measures such as exchanging the tracking sensor when the line is stopped, and it is possible to prevent a sudden line stop. Therefore, conventionally, an abnormality determination method (diagnostic method) has been adopted for early determination of an abnormality of the tracking sensor.

  For example, Patent Document 1 discloses that at least three or more tracking sensors (first HMD, second HMD, and third HMD) installed in a rolling line have a first moving distance (from the start of the first HMD on operation to the second HMD on). A technique for calculating whether or not there is an abnormality in the tracking sensor by calculating the time until the start of the operation × speed) and the second movement distance (the time from the start of the second HMD ON operation to the start of the third HMD ON × speed) are described. Has been.

JP 09-218085 A

  However, since the technique described in Patent Document 1 performs abnormality diagnosis with tracking sensors installed at least at three or more locations, the number of installation locations of tracking sensors is reduced to reduce costs. There is a problem that it is difficult to apply as it is.

  The present invention has been made in view of the circumstances as described above, and is capable of performing abnormality diagnosis with tracking sensors installed at two places where the number is smaller than that of the technique described in Patent Document 1. It is an object of the present invention to provide an on-line diagnostic method for a tracking sensor in a rolling line.

  In order to solve the above problems, the present invention has the following features.

[1] On-line diagnosis of the presence or absence of abnormalities in tracking sensors installed on the hot rolling line to track the material to be transported and starting on or off when the material is rolled A way to
For tracking sensors installed at two locations at a predetermined interval, the downstream tracking sensor is turned on or off based on the time when the upstream tracking sensor starts the on or off operation and the conveyance speed of the material to be rolled. Calculate the start time of the operation, compare the calculated start time of the ON or OFF operation with the time when the downstream tracking sensor actually starts the ON or OFF operation, and the time difference is within the allowable range. An on-line diagnostic method for a tracking sensor in a hot rolling line, characterized in that if it exceeds, the tracking sensor is determined to be abnormal.

  [2] In the online diagnosis method according to [1], when it is determined that the downstream tracking sensor is abnormal, the time and the time when the upstream tracking sensor starts the on operation or the off operation are detected. Calculate the time at which the downstream tracking sensor starts the ON or OFF operation from the rolling material conveyance speed, and then calculate the calculated ON operation or OFF operation start time. An on-line diagnostic method for a tracking sensor in a hot rolling line, wherein tracking is performed by considering the time when the off operation is started.

  In the present invention, it is possible to perform abnormality diagnosis using tracking sensors installed at two places where the number is smaller than that of the technique described in Patent Document 1. Therefore, even when the number of installation locations of the tracking sensor is reduced to reduce the cost, it can be sufficiently applied.

It is a side view which shows the hot rolling line to which one Embodiment of this invention is applied. It is a flowchart which shows the diagnostic procedure of the tracking sensor in one Embodiment of this invention. It is a flowchart which shows the diagnostic procedure of the tracking sensor in one Embodiment of this invention.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a hot rolling line to which an embodiment of the present invention is applied. In this hot rolling line, tracking sensors are installed at two locations at predetermined intervals in order to track the material to be rolled (slab or steel plate) 2 conveyed by the conveying roll 1. An upstream tracking sensor 4 and a downstream tracking sensor 5.

  If the upstream side tracking sensor 4 and the downstream side tracking sensor 5 are normal, when the tip of the material 2 to be rolled passes through the installation position, the upstream side tracking sensor 4 and the downstream side tracking sensor 5 change from the off state to the on state (starts the on operation). In addition, when the tail end of the material to be rolled passes through the installation position, it changes from the on state to the off state (starts off operation).

  Further, a speed detector (pulse generator) 3 is attached to the transport roll 1 in order to detect the transport speed of the material 2 to be rolled. Thereby, the conveyance speed of the to-be-rolled material 2 is always measured. In addition, as an apparatus which detects the conveyance speed of the to-be-rolled material 2, there exists a measuring roll etc. which detect the conveyance speed of the to-be-rolled material 2 by touching the to-be-rolled material 2 directly, and these may be used.

  In addition, in this embodiment, the upstream tracking sensor 4 is assumed to be normal, and the presence or absence of abnormality of the downstream tracking sensor 5 is diagnosed as follows.

  In other words, when the upstream tracking sensor 4 starts an on operation or an off operation by the tip or tail end of the material to be rolled 2 passing through the installation position of the upstream tracking sensor 4, the installation position of the upstream tracking sensor 4 is changed. The starting point starts continuous tracking of the tip or tail of the material 2 and the time when the tip or tail of the material 2 passes the installation position of the downstream tracking sensor 5 (that is, the downstream tracking sensor). 5 is the time when the on operation or the off operation starts. Then, the calculated start time is compared with the time when the downstream tracking sensor 5 actually starts the on operation or the off operation. If the time difference exceeds the allowable range, the downstream tracking sensor 5 is operated. It is determined that there is an abnormality.

  In addition, said continuous tracking is the passage position of the material 2 to be rolled (using the conveyance speed information from the conveyance speed detection device (pulse generator 3 etc.) with an arbitrary passage position and the passage time as a starting point. Arrival position) and passage time (arrival time) are calculated and continuously tracked.

  As for the diagnosis method of the downstream tracking sensor 5 in this embodiment as described above, the specific diagnosis procedure will be described based on the flowcharts shown in FIGS. FIG. 2 shows a case in which the tip of the material to be rolled 2 is diagnosed as a tracking target, and FIG. 3 shows a case in which the tail of the material to be rolled 2 is diagnosed as a tracking target.

  Here, the upstream tracking sensor 4 is referred to as sensor A, the downstream tracking sensor 5 is referred to as sensor B, and the respective installation positions are referred to as point A and point B.

  First, when diagnosing the tip of the material 2 to be tracked as a tracking target, as shown in FIG. 2, the downstream tracking sensor 5 is diagnosed in the following procedure.

  (S1) When the tip of the material 2 to be rolled passes the installation position (point A) of the sensor A, the sensor A starts an on operation.

  (S2) When the sensor A starts an ON operation, continuous tracking of the tip of the material to be rolled 2 is started with the installation position (point A) of the sensor A as a starting point.

  (S3) In the continuous tracking of (S2) above, the fact that the tip of the material to be rolled 2 reaches and passes the installation position (point B) of the sensor B is referred to as continuous tracking B on occurrence, Starting the on operation is referred to as sensor B on occurrence, and it is determined whether or not sensor B is on before the continuous tracking B on occurrence.

  (S4.1) In the above (S3), when the sensor B is on before the continuous tracking B is on, the time (time difference) from the sensor B on time to the continuous tracking B on time is counted.

  (S4.2) In the above (S3), when the sensor B is turned on after the continuous tracking B is turned on, the time (time difference) from the continuous tracking B on time to the sensor B on time is counted.

  (S5) It is determined whether or not the time difference in (S4.1) or (S4.2) is within an allowable range.

  (S6.1) If the time difference is within the allowable range in (S5), it is determined that the sensor B is normal.

  (S6.2) In (S5) above, if the time difference exceeds the allowable range, it is determined that the sensor B is abnormal.

  Moreover, when diagnosing the tail end of the material 2 to be tracked as a tracking target, as shown in FIG. 3, the downstream tracking sensor 5 is diagnosed in the following procedure.

  (P1) When the tail end of the material 2 to be rolled passes the installation position (point A) of the sensor A, the sensor A starts an off operation.

  (P2) Then, when the sensor A starts an off operation, continuous tracking of the tail end of the material to be rolled 2 is started with the installation position (point A) of the sensor A as a starting point.

  (P3) In the continuous tracking of (P2) above, the fact that the tail end of the material 2 to be rolled reaches and passes the installation position (point B) of the sensor B is referred to as continuous tracking B-off occurrence, while the sensor B Starting the off operation is referred to as sensor B off occurrence, and it is determined whether or not sensor B off occurs before the continuous tracking B off occurrence.

  (P4.1) In the above (P3), when the sensor B is turned off before the continuous tracking B is turned off, the time (time difference) from the time when the sensor B is turned off to the time when the continuous tracking B is turned off is counted.

  (P4.2) In the above (P3), when the sensor B is off after the continuous tracking B is off, the time (time difference) from the continuous tracking B off occurrence time to the sensor B off occurrence time is counted.

  (P5) It is determined whether or not the time difference in (P4.1) or (P4.2) is within an allowable range.

  (P6.1) If the time difference is within the allowable range in (P5) above, it is determined that the sensor B is normal.

  (P6.2) In (P5) above, if the time difference is within the allowable range, it is determined that the sensor B is abnormal.

  In addition, it is possible to perform either one of the above-described diagnosis in which the tip of the rolled material 2 is a tracking target and the diagnosis in which the tail end of the rolled material 2 is a tracking target, but it is preferable to perform both as much as possible. .

  Further, by narrowing the allowable range for the time difference, it is possible to perform diagnosis with higher accuracy.

  Since the operation and setup of various facilities are often performed at the on-operation start timing and off-operation start timing of the downstream tracking sensor 5 (sensor B), as a result of the above diagnosis, the downstream tracking sensor 5 (sensor If it is determined that B) is abnormal, then continuous tracking is employed instead of the downstream tracking sensor 5 (sensor B). That is, the tracking B on occurrence time is regarded as the sensor B on occurrence time, and the continuous tracking B off occurrence time is regarded as the sensor B off occurrence time. Then, at the next periodic line stop, the downstream tracking sensor 5 (sensor B) is inspected / repaired / replaced.

  On the contrary, as a result of the above diagnosis, if the downstream tracking sensor 5 (sensor B) is not judged abnormal once within a predetermined period (for example, one month in winter when steam is likely to be generated) Considering that the downstream tracking sensor 5 (sensor B) and the continuous tracking are in good agreement, it is also possible to steadily adopt continuous tracking as an alternative to the downstream tracking sensor 5 (sensor B). This eliminates the maintenance cost of the downstream tracking sensor 5 (sensor B).

  In the above, the upstream tracking sensor 4 (sensor A) is assumed to be normal, and the downstream tracking sensor 5 (sensor B) is diagnosed for abnormality. Similarly, the downstream tracking sensor It is also possible to diagnose whether the upstream tracking sensor 4 (sensor A) is abnormal, assuming that 5 (sensor B) is normal.

1 Transport roll 2 Rolled material (slab or steel plate)
3 Speed detector (pulse generator)
4 Upstream tracking sensor (Sensor A)
5 Downstream tracking sensor (Sensor B)

Claims (1)

In a hot rolling line, a tracking sensor that is installed to track the material to be transported and starts an on or off operation by passing the material to be rolled is a method of diagnosing online whether there is an abnormality. There,
For tracking sensors installed at two locations at a predetermined interval, the downstream tracking sensor is turned on or off based on the time when the upstream tracking sensor starts the on or off operation and the conveyance speed of the material to be rolled. Calculate the start time of the operation, compare the calculated start time of the ON or OFF operation with the time when the downstream tracking sensor actually starts the ON or OFF operation, and the time difference is within the allowable range. If it is exceeded, it is determined that the tracking sensor is abnormal, and if it is determined that the downstream tracking sensor is abnormal, then the time when the upstream tracking sensor starts an on operation or an off operation and Calculate the time when the downstream tracking sensor starts the ON or OFF operation from the transport speed of the material to be rolled. The start time of the ON operation or OFF operation of the calculated, and performing tracking regarded as actual time tracking sensor on the downstream side is started turned on or off operation, the tracking sensor in the hot rolling line Online diagnostic method.

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