JPH04182028A - Method for controlling position of tail end of steel strip - Google Patents

Abstract

PURPOSE:To align center-lines of the preceding and succeeding steel strips and to prevent them from dogleg welding by obtaining the deviation of the central position of preceding steel strip, changing the position of the carrying reel and correcting the central position of the tail end of preceding steel strip to the central position of the steel strip carrying line. CONSTITUTION:After the passage of prescribed time from the position detecting at the time when the remainder length of strip coil of the pay-off reel 11 is become shorter than the prescribed length, the CPC device 15 controls the reel 11 for centering based on the position detecting signal of the sensor 34 further. When the tail end of the preceding strip 2a approaches to the welder 32, the carrying speed is made down, and stopped at the time when the tail end is positioned at the feasible position for the welder 32. The top end of succeeding strip 2b is butted to the tail end of preceding strip 2a by feeding to the welder 32 while centering-controlling the succeeding strip 2b from the 2nd pay-off reel 21. The butted welding part is flash butt welded while the draft force is applied to the longitudinal direction of the strips 2a, 2b after clamping.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the position of a tail end of a steel plate in continuous steel plate processing equipment.

[Conventional technology] In a thin plate manufacturing line, when the coil of the payoff reel is finished unwinding, the starting end (tip) of the next steel plate is welded to the terminal end (tail end) of the steel plate, and the steel plate is continuously transferred to a rolling mill, etc. to be sent.

For example, as shown in FIG.
Centering is controlled by the C device 12. That is,
On the downstream side of the welding machine 31, a position sensor 53 detects the center position of the running steel plate 2a, and based on this position information, the positional deviation (deviation) of the running steel plate 2a from the center position of the feeding line is detected.
The CPC device 52 determines the roll 5 according to the deviation.
1 and performs centering control so that the center of the steel plate 2a travels in the center of the feed line. Furthermore, on the upstream side of the welding machine 31, a position sensor 13 detects the center position of the running steel plate 2a, and based on this position information, the deviation of the running steel plate 2a from the center position of the feeding line is grasped, and the C
The payoff reel 11 is moved by the PC device 12, and centering control is performed so that the center of the steel plate 2a runs in the center of the feed line.

On the other hand, the trailing steel plate 2b is a C for another payoff reel 21.
Centering is controlled by the PC device 1F22. That is, the position sensor 23 detects the center position of the tip of the trailing steel plate 2b, and based on this position information, the deviation of the steel plate 2b from the center position of the feeding line is determined, and the CPC is adjusted according to the deviation.
The payoff reel 21 is moved by the device 22, and the steel plate 2
Centering control is performed so that the center of b runs in the center of the feeding line.

In the welding machine 31, the tail end of the leading steel plate 2a and the leading end of the trailing steel plate 2b are aligned and welded together in accordance with the following steps (1) to (2).

(2) The position sensor 34 on the exit side of the welding machine detects the center position of the tail end of the preceding steel plate 2a.

(2) The position sensor 35 on the inlet side of the welding machine detects the center position of the tip of the trailing steel plate 2b.

(2) Calculate the deviation between the center of the tail end of the leading steel plate 2a and the center of the tip of the trailing steel plate 2b.

■ Shift the tip of the trailing steel plate 2b by the amount of deviation, align the center of the tip of the trailing steel plate 2b with the center of the tail end of the leading steel plate 2a,
Weld this.

The relationship between the leading steel plate and the trailing steel plate is that of the payoff reels 11 and 21, the position sensors 13 and 23, and the CPC device 1.
2 and 22 are used alternately.

[Problems to be Solved by the Invention] However, in the conventional position control method, when the leading ends of the trailing steel plates 2b are shifted so that the centers of the end faces of the plates coincide with each other and welded, as shown in FIG. Wire 3 is steel plate 2
A so-called "dog-shaped weld" occurs obliquely to the center line of a and 2b. This is done at the position of the welding machine 31 by the preceding steel plate 2a.
does not necessarily pass through the center of the feeding line, the deviation between the center of the tail end of the leading steel plate 2a and the center of the leading end of the trailing steel plate 2b becomes large, and the center line of the leading steel plate 2a and the center of the trailing steel plate 2b become large.
This is due to the fact that the center lines of When "dog-shaped welding" occurs, the steel plate cannot be passed through the center of the feed line correctly, resulting in various inconveniences. Moreover, it has a serious effect on the subsequent surface treatment process, leading to a decline in the quality of the steel sheet.

This invention was made in view of the above circumstances, and involves aligning the center line of the leading steel plate and the center line of the following steel plate to be in a straight line, thereby preventing the occurrence of "dog-legged welding". The purpose of the present invention is to provide a method for controlling the position of the tail end of a steel plate.

[Means and effects for solving the problem] The method for controlling the tail end position of a steel plate according to the present invention is to weld the tail end of a preceding steel plate to the tail end of a preceding steel plate. In a steel plate tail end position control method for aligning with the tip of a steel plate, when the remaining length of the preceding steel plate becomes less than a predetermined length, the passing position of the preceding steel plate is detected on the exit side of the welding machine,
Based on this detected position information, the deviation of the center position of the preceding steel plate from the center position of the steel plate feeding line is ascertained, and the position of the feed reel that feeds the preceding steel plate to the welding machine is changed according to this deviation. , the center position of the tail end of the preceding steel plate in the welding machine is corrected to the center position of the steel plate feeding line.

Until the tail end of the leading steel plate leaves the feed reel, the center position of the leading steel plate on the exit side of the welding machine is repeatedly detected, and the position of the feed reel is changed each time according to the deviation to improve position accuracy. It is preferable to increase the

Furthermore, when the remaining length of the preceding steel plate reaches a predetermined length, it is desirable to change the gain of the CPC device downstream of the welding machine in order to prevent the feed reel from interfering with the CPC device. In this case, the gain of the CPC device for the feed reel is changed according to the plate thickness, line speed, or shift amount of the CPC device for the feed reel,
By correspondingly changing the gain of the downstream CPC device, better control can be achieved.

[Embodiments] Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a thin plate production line in which a steel plate tail end position control method according to an embodiment of the present invention is used. The strip 2a is fed from the first payoff reel 11 toward downstream equipment at a speed of about 200 m/min. On the downstream side of the reel 11, a welding unit 30, a priddle roll 40, a conveyance roll 51, etc. are arranged.

A desired tension is applied to the running strip 2a by the priddle roll 40. It should be noted that another strip coil is attached to the second payoff reel 21, and is on standby to be sent to downstream equipment as the trailing strip 2b.

First payoff reel 11, second payoff reel 21
, and a power source for a cylinder (not shown) connected to each drive shaft of the transport roll 51.
The output section of is connected.

Each cylinder has the role of shifting the reel 11.21 or roll 51 in the axial direction.

The light receiving section of the position sensor 1B, 23.53 is connected to the input section of each CPCPCl5, 25.52, respectively. Each position sensor 13, 23.53 is an optical sensor having a light projecting part and a light receiving part, and has the role of detecting the passing position of the strips 2a, 2b by detecting transmission or blocking of irradiation light.

The welding unit 30 is equipped with a flash butt welder 32 having a plurality of clamp electrodes. This welding machine 32 has a built-in control section, and an outlet side sensor 34 and an inlet side sensor 35 are connected to the control section.
The operation of the clamp electrode of the welding machine 32 is controlled based on the position detection signal from the welding machine 5. Each sensor 34
, 35 is a position sensor in which a light emitting/receiving section is integrated.

The control section of the welding machine 32 is connected to the input sections of the first and second CPC devices 15.25, and the signal transmission circuit within the control section is configured to be switchable. That is,
The position detection signals from the sensors 34 and 35 are switched by the welding machine control section and sent to each CPCilf 15 and 25.

In such a thin plate production line, in a steady state, the first CPC device 15 shifts the payoff reel 11, and the downstream CPC device 52 further shifts the conveyance roll 51, thereby controlling the centering of the preceding strip 2a. .

Next, the trailing strip 2b is attached to the tail end of the leading strip 2a.
The case of welding the tip of will be explained.

The remaining length of the strip coil of the payoff reel 11 is detected, and when the remaining length becomes shorter than a predetermined setting value, the transmission circuit of the welding machine control section is switched, the position detection signal from the sensor 34 is sent to the CPC device 15, and the welding is started. The deviation between the center of the preceding strip 2a and the center of the line on the machine exit side is determined. The CPC device 15 stops automatic control until the remaining coil amount becomes shorter than a predetermined value, and if the deviation exceeds the predetermined value, the CPC device 15 controls the cylinder of the payoff reel 11 according to the deviation. Proportional operation is performed to shift the reel 11 and control the centering of the leading strip 2a. The proportional movement of the cylinders is determined by the gain of the CPC device 15 and is typically 1:1 or less to avoid overshooting the strip 2a. At this time,
In order to prevent interference with the CPC device 52 on the downstream side, the CP
Change the gain of the C device 15. The gain is determined by three factors: strip thickness, feeding speed, and reel shift amount. The gain of the downstream CPC device 52 is changed corresponding to the gain of the CPC device 15.

After a predetermined time has elapsed since the first position detection when the coil remaining length is shorter than the predetermined length, the payoff reel 11 is further moved by the CPC device 15 based on the position detection signal of the sensor 34.
Control the centering.

Such centering control operation is repeated until the deviation between the welding machine outlet side strip and the line becomes less than a predetermined value.

When the tail end of the leading strip 2a leaves the payoff reel 11 and approaches the welding machine 32, the feeding speed of the strip 2a is reduced and the feeding of the strip 2a is stopped when the tail end is located at the appropriate position of the welding machine 32. . The tail end of the leading strip 2a is gripped by one clamp electrode. Then, from the second payoff reel 21, the trailing strip 2
b is fed to the welding machine 32 while controlling the centering, and the leading end surface of the trailing strip 2b is butted against the tail end surface of the leading strip 2a. The leading end of the trailing strip 2b is gripped by the other clamp electrode.

After the clamps are fixed, each electrode is energized while applying a reduction blade in the longitudinal direction of the strips 2a and 2b, and the butt joints are flash butt welded. After the clamp is released, the bridal roll 40 and payoff reel 21 are rotated to feed the strip toward the downstream side.

According to the above embodiment, it is possible to position the center of the tail end of the leading strip 2a substantially at the center of the line, so that the amount of shift of the trailing strip 2b is significantly reduced.
It is possible to prevent the butt welding part 3 from forming a "dog-shaped" shape or a "bend", and as shown in FIG. 2, the center lines of the leading strip 2a and the trailing strip 2b are aligned in a straight line.

[Effects of the Invention] According to the present invention, the welded portion of the leading steel plate and the trailing steel plate is
It is possible to effectively prevent the occurrence of doglegs or bends.
Since the center lines of the leading steel plate and the following steel plate are aligned, line threading performance is improved, and by correctly threading the steel plate in the center of the line, it greatly contributes to improving the workability of the subsequent process. can.

In addition, the quality of steel sheets can be significantly improved on lines that include a surface treatment process.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an outline of a steel plate production line in which a steel plate tail end position control method according to an embodiment of the present invention is used;
The figure is a plan view showing a leading steel plate and a following steel plate that have been welded together, Figure 3 is a schematic diagram showing an overview of a steel plate production line using a conventional steel plate tail end position control method, and Figure 4 is a diagram showing a conventional welding process. It is a top view which shows the leading steel plate and trailing steel plate which were joined. 2a, 2b; steel plate, 11, 21; feeding reel, 15.2
5,52. CPC device, 13.2B. 34.35,53; sensor, 32; welding machine, 40°51
;roll

Claims (1)

[Claims] In order to weld the tip of the trailing steel plate to the tail end of the leading steel plate, the tail end position control method of the steel plate aligns the tail end of the leading steel plate with the tip of the trailing steel plate. When the length is below a predetermined length, the passing position of the preceding steel plate is detected on the exit side of the welding machine, and based on this detected position information, the deviation of the center position of the preceding steel plate from the center position of the steel plate feeding line is determined. , changing the position of a feed reel that feeds the preceding steel plate to the welding machine according to this deviation, and correcting the center position of the tail end of the preceding steel plate in the welding machine to the center position of the steel plate feeding line. A method for controlling the position of a tail end of a steel plate.