JP2005111532A - Method for tracking weld zone and side trimming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for tracking a weld zone, which correctly locates the position of a weld zone of a metal strip subjected to a plurality of processing steps so as to minimize a wasteful cut length, and to provide a side trimming method, which can prevent poor side trimming due to clogging with shaved selvages. <P>SOLUTION: In the method for tracking the weld zone of the metal strip (sheet) 1 subjected to a plurality of processing steps, a specific point 3 for tracking the weld zone 2 is set and detected. A positional relation between the specific point when detected and the weld zone is calculated from the positional relation between the specific point when set and the weld zone, the number of the processing steps to which the strip was subjected from the time of setting to the time of detection and the rate of change in strip length between the time of setting and the time of detection. In the side trimming method, notches are made into the strip edges on the basis of the positional relation calculated in the above tracking method and cutting is initiated from the notches. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a welded part tracking method and a side trimming method of a metal band, and more specifically, formed by welding a leading material tail end and a trailing material tip of a metal band (also referred to as a plate) passing through a plurality of processing steps. The present invention relates to a welded part tracking method for tracking the position of a welded part that is a connected joint, and a side trimming (continuous cutting off of surplus portions (ears) at both ends in the width direction) using the tracking method.

  As a conventional technique related to a method for tracking a welded portion of a metal strip, a step for forming a weld detection hole in the vicinity of a welded portion of a strip (metal strip), and a laser beam is irradiated on the strip and the strip is driven by the reflected light. There is known a method including a step of detecting a speed and a step of detecting, as a welding point, a portion where reflected light disappears by the weld detection hole (Patent Document 1). According to this, by using a laser reflection type velocimeter (laser Doppler velocimeter), the ambient humidity is high (for example, 60 ° C. or higher) such as between tandem rolling mill stands, and oil fume, water vapor, etc. The weld can be detected even under a large amount of environmental conditions.

  A device such as a punch for drilling a weld detection hole is usually attached to a welding machine that performs welding, and the weld detection hole is forward (downstream) in the metal band traveling direction of the weld during welding. ) That is, it is drilled on the leading material tail end side.

  Further, as a conventional technique related to the side trimming method, there is a method in which the position of the trimmer blade is shifted from the fixed position in the plate width direction to the center side at the start of cutting, and returned to the fixed position after a few seconds from the start of cutting. Known (Patent Document 2). According to this, the width of the tip portion of the trimmed ear dust is larger than the width of the succeeding portion, and no spiral rounding occurs at the tip portion, so that clogging of the scrap guide can be prevented.

In addition, there is a possibility that a step is likely to occur in the plate width at the position of the welded portion, and this step may interfere with the conveying member. Therefore, in general, both ends of the plate width at the position of the welded portion are notched in a round shape to reduce the step. To be done. This notch has a size that can also be used as a margin space for placing the trimmer blade at an initial position within the plate width.
JP-A-7-116716 JP 2002-273671 A

    In Patent Document 1, a strip weld detection hole is detected between the stands of a tandem rolling mill, and the thickness change rate due to the rolling of the plate is determined at the distance between the weld detection hole and the weld on the entry side of the tandem rolling mill. Is used to calculate the distance between the welded part detection hole and the welded part between the stands, and based on the calculated distance, the accuracy of the roll opening adjustment when the welded part is caught in the next stand is improved. .

  On the other hand, a metal strip passing through a plurality of processing steps (or equipment lines for executing the processing steps), such as a pickling line, a cold rolling line, or a cleaning line, to a hot dip galvanizing line or a continuous annealing line. In the steel strip to be carried in, a weld detection hole detected at the entry side of the hot dip galvanizing line or continuous annealing line is drilled at the entry side of the pickling line in some cases, and in some cases It is drilled on the entry side of the cold rolling line. Further, the metal strip passing through the plurality of processing steps is wound in a coil shape on the exit side of each processing step, conveyed to the next step, and processed while being rewound in the processing step of the transfer destination. In these cases, for example, in the case of the above-described steel strip, the number of winding / rewinding operations that the steel strip has passed differs, so that the front and back of the weld detection hole and the weld are on the entry side of the hot dip galvanizing line or continuous annealing line. In some cases, the positional relationship is reversed from the initial setting. In addition, the welding machines on the entry side of each line are not necessarily the same model, and the initial distance between the welded part and the welded part detection hole is generally different if the model is different.

  However, there is no document that discloses a method for correctly tracking a weld in consideration of such a situation. In Patent Document 1, the distance between the welded portion detection hole and the welded portion between the stands is set to the distance between the welded portion detection hole and the welded portion on the entry side of the tandem rolling mill. However, what happens when the distance between the weld detection hole on the entry side of the tandem rolling mill and the weld varies, and the front-rear positional relationship on the entry side also varies? It has not been described.

Thus, since there is no conventional method for correctly tracking a welded portion of a metal strip that passes through a plurality of processing steps, for example, when the metal strip is a steel strip, the following problems have occurred.
(1) When cutting the welded part and the welded part detection hole on the exit side of the continuous annealing line, it is unclear which line in the previous process the welded part and the welded part detection hole were formed. Since the positional relationship and distance are unclear, the cutting plate length range has been set so that the welded portion detection hole can be cut off regardless of the line formed. However, such a prescription has an excessive safety factor, and thus has a problem that hinders yield improvement.
(2) When performing side trimming on the entry side of the hot dip galvanizing line, it is desirable to set the initial position of the trimmer blade to the position of the welded portion, but since the position of the welded portion is unclear, instead, As shown in FIG. 1, both end portions in the plate width direction at the detected position of the weld detection hole 3 are set as initial positions of the trimmer blade, and the notch 4 is provided as a margin space for placing the trimmer blade in this portion. However, as shown in FIG. 1, the weld zone 2 and the notch 6 formed on, for example, the entrance side of the pickling line in the previous step of the hot dip galvanizing line are the steel strip (plate, metal strip) 1 in the pickling line. When arriving at the entry side of the hot dip galvanizing line via the cold rolling line, it comes after the weld detection hole 3, that is, at the upstream side in the sheet passing direction 5. In such a case, when the side trimming is performed by the method of Patent Document 2, the locus 7 of the trimmer blade temporarily goes outside the plate 1 at the point A and enters the inside of the plate 1 again at the point B. That is, even though the tip of the ear dust was widened by the method of Patent Document 2 to prevent spiral rounding, this ear dust was interrupted at point A, and the ear dust generated again at point B was Since the tip is pointed, there is a problem that spiral rounding occurs and scrap guide clogging occurs.

  In order to solve these problems, the present invention correctly grasps the position of the welded portion of the metal band that has undergone a plurality of processing steps to reduce the waste of the cutting length, and also causes side trimming failure due to clogging of ear dust An object of the present invention is to provide a welding portion tracking method and a side trimming method capable of preventing the occurrence of the above.

  The welded part tracking method of the present invention is a method for tracking a welded part of a metal band that passes through a plurality of processing steps, sets a singular point for tracking a welded part, detects the singular point, The positional relationship between the singular point and the welded portion at the time of detection, the positional relationship between the singular point and the welded portion at the time of setting, the number of processing steps in which the metal band has passed between the time of setting and the time of detection, and between them It is calculated from the metal band length change rate. Here, as the singular point, the above-described hole for detecting a welded portion can be preferably used.

  Further, the side trimming method of the present invention is a method in which a notch is made at the metal band width end portion based on the positional relationship between the singular point and the welded portion obtained by using the welded portion tracking method of the present invention, and the metal from the notched portion to the metal The cutting of the band side edge is started.

  According to the welding portion tracking method of the present invention, the positional relationship between the singular point and the welded portion when the singular point set for tracking the welded portion of the metal band is detected, and the position between the singular point and the welded portion at the time of setting. Since the calculation is based on the relationship, the number of processing steps that the metal band has passed between the setting time and the detection time, and the change rate of the metal band length between them, the welded part is on either side before or after the singular point. Since the distance from the singular point can be correctly grasped, when cutting off the singular point and the welded portion, the cutting length can be minimized as much as possible, and the yield is improved.

  Further, according to the side trimming method of the present invention, a notch is made in the end portion of the metal strip based on the positional relationship between the weld and the singular point that has been correctly grasped as described above, and the metal strip side from the notch portion. Since the cutting of the edge is started, this notch can be placed at the position where it overlaps with the notch of the previous process or at an upstream position thereof. The side trimming failure due to scrap guide clogging or the like can be effectively prevented.

  In the present invention, when the singular point is set at a position overlapping with the welded portion, the position of the detected singular point becomes the position of the welded portion as it is, and the above problems (1) and (2) do not occur. Such a case is practically rare, and even if so, it does not hinder the implementation of the present invention, so this case is also included in the present invention for convenience. Here, the singular point means a marking point such as a hole or notch set for tracking a welded portion.

  As the singular point, it is easy to use one having a weld detection hole formed in the vicinity of the weld, and the weld detection hole may be formed at the time of welding. In this case, the positional relationship between the singular point and the welded part at the time of setting is determined by the equipment specifications of the welding machine and the drilling machine (punch, etc.), and is not particularly limited in the present invention, but the drilling position is downstream from the welded part. It is preferable to be within a range of about 100 to 300 mm on the side (preceding material side). Moreover, the hole diameter of the welding part detection hole is not particularly limited, but for example, about 5 to 30 mm is preferable.

  The processing step for setting the singularity may be any processing step that is performed before the processing step for detecting the singularity among the plurality of processing steps through which the metal band passes. On the other hand, the processing step for detecting a singular point is a processing step performed after the step for setting the singular point, and requires weld tracking information for a processing operation within the processing step. Any kind of processing step may be used, and the same singularity may be detected before the start of processing / operation that requires tracking information in the processing step. The detector for detecting a singular point is not particularly limited in the present invention, and an appropriate detector may be used according to the type of the singular point set. A photodetector of the type, the above-described laser reflection type velocimeter, or the like can be preferably used.

  In the welded part tracking method of the present invention, the positional relationship between the singular point and the welded part at the time of detection, the positional relationship between the singular point and the welded part at the time of setting, the metal band (plate) between the time of setting and the time of detection. It is characteristic that it is calculated from the number of processing steps passed through and the rate of change in the metal band (plate) length between them. This calculation method will be described below.

  As described above, the positional relationship between the singular point and the welded portion at the time of setting is determined by the model and relative positional relationship between the singular point setting device and the welding machine. The singular point is set at a position separated from the welded portion by a distance X0 (a positive number; in the case of the upstream side, a negative number). The number of processing steps that the plate has passed from the time of setting the singular point to the time of detection is n, and the plate length change rate during that time is regarded as the plate volume and width being constant, the plate thickness h0 when setting the singular point. And the ratio h0 / h1 of the plate thickness h1 at the time of detecting the singular point. At this time, the position of the welded portion represented by the distance with the upstream side as a positive number and the downstream side as a negative number starting from the singular point at the time of detection is calculated as follows.

  When n is an odd number, it is calculated by the formula: X0 × h0 / h1 × (−1). When X0 is positive (singular point is downstream of the weld), the value of the equation is negative (the weld is downstream of the singular point = the singular point is upstream of the weld).

  When n is an even number, it is calculated by the formula: X0 × h0 / h1. When X0 is positive (singular point is downstream of the weld), the value of the equation is positive (the weld is upstream of the singular point = the singular point is downstream of the weld).

Alternatively, these are collectively calculated by the formula: X0 × h0 / h1 × (−1) ⁿ .

  Since the plate has been wound and unwound n times from the time of setting the singular point to the time of detection, the positional relationship between the singular point and the welded portion at the time of detection is the same as that at the time of setting when n is an odd number. On the other hand, when n is an even number, it is the same as when setting. Since the above calculation method reflects this faithfully, the positional relationship between the singular point and the welded portion at the time of detection can be obtained correctly.

  It should be noted that the above calculation is preferably performed by a process computer of a processing step for detecting a singular point, and data (X0, n, h0, h1) necessary for this calculation is used for overall management of a plurality of processing steps. Since it is owned by the host computer, it is better to transmit it from there to the process computer. The correspondence between the name code of the processing step for setting the singular point and X0 is stored in the process computer, and the name code of the processing step for which the singular point is set instead of X0 is stored in the process computer from the upper computer. X0 corresponding to the name code may be transmitted and the process computer may extract the stored correspondence.

  In the side trimming method of the present invention, a notch is made in the plate width end portion based on the positional relationship between the singular point at the time of detection obtained as described above and the welded portion, and side trimming is started from there. For example, as shown in FIG. 2, the place where 4 is inserted is preferably a place that overlaps the upstream portion of the old notch 6 formed in the plate width end portion of the welded portion in the previously performed processing step. By newly making the notch 4 at such a location, the trimming blade locus 7 does not interfere with the old notch 6, and the side trimming defect due to the breakage of the ear dust does not occur. In addition, when the radius (curvature radius) of the corner part of the new notch 4 exceeds 350 mm, the tip of the ear dust becomes a pointed shape, and it is caught on the surrounding guide member or jumped out from the same member. Since it tends to occur, the radius is preferably 350 mm or less. If the radius is too small, the notch 4 may have to be reinserted several times. Therefore, it is practically preferable that the radius is about 200 mm or more.

  The present invention was applied to the step of separating and winding the steel strip processed through the pickling line, the cold rolling line, and the continuous annealing line in the coil unit on the exit side of the continuous annealing line, and was taken as Example 1. . Conventionally, it was unclear whether the weld detection hole as a singular point was drilled on the entry side of the above-described line, so there is no uncut portion of the weld and the weld detection hole. As described above, the plate length with the weld detection hole detected by the light projecting / receiving method as the center position = α × 2 + β (where α is the upper limit of the feasible distance range between the weld and the weld detection hole Value, β: cutting margin) was rounded down. On the other hand, in the first embodiment, the detected position of the welded portion and the position of the welded portion detected hole are calculated by the calculation method described in the previous section and sandwiched between the welded portions where the position is correctly grasped. The plate length range obtained by adding β to the area was cut off. As a result, the cut-off portion can be minimized as much as possible, and as shown in FIG. 3, the outgoing cut-off length of the continuous annealing line can be reduced from 4.3 m to about 3.1 m. did it.

  After annealing and rolling, the present invention was applied to a side trimming line for side trimming a steel strip that was pickled in a pickling line and cold-rolled in a cold rolling line. The steel strip to be passed through the side trimming line is subjected to 0 or 1 or more treatment steps between the pickling line and the cold rolling line and / or between the cold rolling line and the side trimming line. . Therefore, the case where n is an odd number or even number may occur. Moreover, a welding part detection hole is used as a singular point, and the welding part detection hole is formed on the entry side of the pickling line or the entry side of the cold rolling line. A line in which a weld detection hole is formed on the line entry side is referred to as a wrap-around welding line. When the entrainment welding line is the pickling line, X0 = 250 mm, and when it is the rolling line, X0 = 150 mm. In addition, the hole diameter at the time of drilling is 10-20 mm. Further, since the entrainment welding line is a line before the cold rolling line, h0 = hot rolled sheet thickness and h1 = cold rolled sheet thickness.

  This side trimming equipment is equipment arranged on the entry side of the hot dip galvanizing line, and its outline is shown in FIG. This equipment uses the first and second payoff reels 11 and 12 alternately to deploy the coil to the steel strip 1 and welds the leading end and the trailing end of the developed strip 1 with a welding machine 13. In addition, the steel strip is configured to be side-trimmed by a side trimmer 16 after being cut by a notch 14 at a width-width end portion of the welded portion, and then passed through a bridle roll group 15 that performs tension control. . The bridle roll group 15 is provided with a tachometer 17 for measuring the number of times of each roll in the roll group, and a rotation speed measurement value 17A of the tachometer 17 is input to the tracking calculation device 18.

  When the trimming by the side trimmer 16 is to be started from the position of the own line welded portion, the own line welded portion is formed by stopping the line and welding with the welding machine 13. Starting from the time when this welding is completed, the tracking calculation unit 18 integrates the rotational speed measurement value 17A, and this integration result matches the equipment distance between the welding machine 13 and the notch 14 as the first target distance. The rotation index 19B is sent to the motor 19 that drives each roll rotation of the bridle roll group 15, and the rotation speed of the motor 19 is controlled. As a result, the self-line welded portion moves to the position of the notch 14 and stops, and the notch for punching out the trimmer blade of the side trimmer 16 is punched out at the plate width end of the self-line welded portion. The corner radius of this notch is 300 mm. When trimming is to be started from the position of the own line welded portion, the singular point is not detected, and the present invention is not applied.

  On the other hand, this side trimming equipment is unique to any line in the previous process on the inlet side of the welder 13 so that it can also be used for starting trimming by the side trimmer 16 from the position of the weld area in the previous process. A hole detector 20 for detecting a weld detection hole formed as a point is provided. When the hole detector 20 detects the weld detection hole, it transmits a hole detection signal 20A to the tracking arithmetic unit 18. The present invention is applied to the case where trimming is to be started from the position of the pre-process weld.

  In this case, conventionally, the tracking calculation device 18 integrates the rotation speed measurement value 17A starting from the reception time of the hole detection signal 20A, and the integration result is the second target distance. The rotation command 19B is sent to the motor 19 that drives the rotation of each roll of the bridle roll group 15 so that the rotation distance of the motor 19 is controlled so as to match the equipment distance (L). As a result, when the welded portion detection hole stops at the position of the notch 14 and the displacement between the welded portion detection hole and the welded portion is large, the problem as shown in FIG. 1 has occurred.

  On the other hand, in the second embodiment, before the hole detector 20 detects the weld detection hole, the process computer 21 performs detection according to the flowchart shown in FIG. The same applies hereinafter)), the position Δx of the welded portion expressed by a distance (a positive number on the upstream side of the hole and a negative number on the downstream side of the hole) is obtained, and the second target distance is defined as (L + Δx). A target distance change command 21B of Seyo is transmitted to the tracking calculation device 18, and the second target distance is changed to (L + Δx). Thereafter, when the hole detector 20 detects the hole and transmits the hole detection signal 20A to the tracking calculation unit 18, the tracking calculation unit 18 integrates the rotation speed measurement value 17A from the reception time of the hole detection signal 20A, A rotation command 19B is sent to the motor 19 that drives the rotation of each roll of the bridle roll group 15 to control the number of rotations of the motor 19 so that the integration result matches the changed second target distance (L + Δx). To do. As a result, the hole stops at a position shifted by Δx from the notch 14 (when Δx> 0, | Δx | forwards (downstream), and when Δx <0, stops behind (upstream) by | Δx |. At the position of 14, if Δx> 0, the position behind the hole by | Δx | (upstream side), that is, the welded portion stops, and if Δx <0, | Δx | Therefore, the welded part stops at the position of the notch 14, and the notch 4 can be made at the end of the plate width of the welded part 2 as shown in FIG.

  As a result, as shown in FIG. 6, the trimming defect rate could be reduced to about 1/5. In addition, after implementation of Example 2, the trimming trouble in the case of starting side trimming from a pre-process welding part has not generate | occur | produced.

  The present invention can be used in any industry that processes a metal strip across a plurality of processes.

It is explanatory drawing which shows that a side trimming defect arises in a prior art. It is explanatory drawing which shows an example of the side trimming method by this invention. It is a graph which shows the reduction effect of the outgoing side cut-off length of the continuous annealing line by Example 1. It is an equipment layout diagram showing an outline of the side trimming equipment used in Example 2. It is a flowchart which calculates | requires the positional relationship of the singular point at the time of the detection used in Example 2, and a welding part. 6 is a graph showing an effect of reducing a side trimming defect rate according to Example 2.

Explanation of symbols

1 Plate (steel strip, metal strip)
2 Welded part 3 Welded part detection hole (singular point)
4 Notch (Notch provided at the time of detecting singularity (eg on the entry side of the hot dip galvanizing line))
5 Threading direction 6 Notch (Notch provided at the time of setting a singular point (eg on the entry side of the pickling line)
7 Trace of trim blade
11 First payoff reel
12 Second payoff reel
13 Welding machine
14 Notcher
15 Bridle rolls
16 Side trimmer
17 Tachometer
17A Rotational speed measurement
18 Tracking arithmetic unit
19 Motor
19B Rotation command
20 hole detector
20A Hole detection signal
21 Process computer
21B Target distance change command

Claims (2)

  A method for tracking a welded portion of a metal strip that passes through a plurality of processing steps, wherein a singular point for tracking the welded portion is set, the singular point is detected, and the singular point and the welded portion at the time of detection are detected. Is calculated from the positional relationship between the singular point and the weld at the time of setting, the number of processing steps that the metal band has passed between the setting time and the detection time, and the rate of change of the metal band length between them. A method of tracking a welded portion.   A notch is made in the metal band width end portion based on the positional relationship between the singular point and the welded portion obtained by using the welding portion tracking method according to claim 1, and cutting of the metal band side edge portion from the notch portion is started. A side trimming method characterized by the above.

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