JPH0636939B2 - Down coiler-step avoidance control system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a down coiler for hot rolling equipment, and more particularly to a down coiler step avoidance control system.

[Background of the Invention]

Generally, a down coiler, which is a hot strip steel winder, is an important facility located at the end of a hot rolling facility and configured to wind a hot rolled steel sheet at 500 ° C to 800 ° C into a coil. However, the winding function greatly affects the production amount and yield improvement of the entire rolling mill.

However, the biggest problem of the down coiler is the large impact force generated when the coil stepped portion formed in the portion where the second layer overlaps the tip of the steel strip in the first layer of the coil inner diameter passes through each lapper roll. Atsuta Due to this impact force, each part of the down coiler suffered severe wear and damage, and winding failure due to excessive splashing of the lapper roll occurred.Therefore, a large maintenance cost was incurred to keep the winding performance operable. .

In order to solve this problem, in recent years, a control system has been developed in which the coil step portion is retracted immediately before passing through each rat roll, and the rat roller roll is pushed back again after passing the step portion to press the coil. Has been done.

FIG. 1 shows an example of a conventional control system. The strip 1 conveyed on the roller table from a hot strip rolling mill (not shown) is pressed around the mandrel 2 by the lapper rolls 3, 4 and 5 and wound. As shown in FIG. 2, a stepped portion 1a is formed at a position where the coil is wound from the first winding to the second winding due to the step at the tip of the wound strip, and when the stepped portion 1a passes through the lapper roll 3, the lapper roll 3 is formed. 3 is forcibly retracted by the plate thickness "t". Since this retreat time is extremely short (1/1000 second to 1/100 second), impact force is generated by the resistance due to the inertia of the lapper roll. The generation of the impact force has been basically inevitable since the inception of the down coiler, but FIG. 1 shows an impact force avoidance method that has been recently implemented to solve this difficulty.

The lapper roll 3 is supported by a bearing of a lapper frame 6 which rotates around a fulcrum 7. The lapper frame 6 is configured to rotate around a fulcrum 7 by a fluid pressure cylinder 8 to move toward and away from the mandrel 2. Further, the cylinder 8 operates by switching the servo valve 9 by the hydraulic pressure supplied from the hydraulic pressure source 10.

When the tip of the strip 1 passes through the upper and lower pinch rolls 13 and 14 and is fed to the down coiler, the acceleration detector 11 detects the acceleration generated when the pinch roll is bited, so that the arrival time of the tip of the strip 1 is determined. It is measured and transmitted to the control board 12 as a signal. In the control panel 12, a plate thickness signal which is previously inserted in the control panel 12,
The servo valve 9 is switched over in comparison with the winding speed signal to calculate the escape and pressing operation timing of the lapper roll 3.

The gap of the lapper roll 3 is set in advance to a plate thickness t or more. Strip 1 jumps into mandrel 2 and 1
A stepped portion 1a as shown in FIG. 2 is generated when the second winding is started after forming the winding. The timing signal calculated by the control board 12 immediately before the stepped portion 1a passes through the ratchet roll 3. The switching valve 9 is switched, and the operation of the cylinder 8 moves the lapper roll 3 away from the stepped portion 1a.
Immediately after the stepped portion 1a has passed, the same roll timing calculation signal causes the lapper roll 3 to be pressed by the strip 1 to perform the winding function. Since the stepped portion 1a passes through the lapper roll 3 for each winding, the same operation is repeated for each winding. As a result, the ratchet roll 3 has the stepped portion 1a.
The collision is avoided and no impact force is generated.

FIG. 3 is a diagram for explaining the above operation in a more understandable manner. The horizontal axis indicates time, and the time advances to the right. That is,
The tip of a strip 1 is a top and bottom pinch rolls 13, 1
Only t _j time from the timing that arrived to 4 after t _o time to switch the servo valve 9 in the direction of the Ratsuparoru retreat.
As a result, the lapper roll 3 jumps over the step portion 1a of the strip 1 and presses the strip 1 again. This is repeated for each volume. In FIG. 3, A shows the movement of the servo valve, and B shows the movement of the lapper roll.

The above is the principle of step avoidance control, and its expected effects (elimination of multiple scratches by avoiding impact force, extension of mechanical component life, etc.) are large, but there are still various problems for practical use, and complete system As a result, many devised peripheral technologies are required. Of these, the most important and difficult problem is the strip tip detection technique. As shown in FIG. 3, the operation of this system uses the leading edge detection timing of B as the starting point.
It is necessary to surely detect and to detect at an accurate timing.

In the case of the method in which the acceleration detector 11 detects the acceleration generated when the upper and lower pinch rolls 13 and 14 bit the tip of the strip 1 as shown in FIG. 1, between the upper and lower pinch rolls 13 and 14. The magnitude of the acceleration generated varies depending on the difference in the setting of the gap, and may be extremely small. And
If it is extremely small, it will be at the same level as the acceleration generated due to vibrations of surrounding machines, and may not be detected as a signal. The experimental results show that detection is particularly difficult in the case of a thick strip having a relatively low strip speed.
Only 0% could be detected. Further, if the tip 1b of the strip 1 has a tapered cross section as shown in FIG. 7,
The generated acceleration is small. Further, the actual sheet width direction of the distal end of the strips 1 have various shapes as shown in FIG. 5 (a) ~ (e), the center O _a of strips _1, O _c, relative to O _d,
The actual tip or filed at a position shifted a _{l a, l c, l d} . In the case of the acceleration detection method as shown in FIG. 1, when the shape is uneven as shown in FIG. 5, the tapered cross section is likely to occur, and therefore the magnitude of acceleration generation is small and it is difficult to identify it as a signal. As described above, the conventional method has low detection reliability, and therefore, a method for surely detecting the true strip tip has been desired.

[Object of the Invention]

The present invention has been made in view of the above-mentioned drawbacks of the prior art,
It is an object of the present invention to provide a down coiler step avoidance control system capable of surely detecting a true strip tip regardless of the shape of any strip tip.

[Outline of Invention]

To achieve the above object, in the present invention, between the pinch roll and the down coiler, a down coiler step avoidance control system for detecting the passage timing of the strip tip by providing a pair of laser oscillator and laser receiver, A plurality of pairs of the laser transmitter and the laser receiver are arranged side by side along the strip width direction.

Water vapor from the cooling water for cooling the coil is trapped in the vicinity of the down coiler, so that the light transmittance is extremely poor. However, in the present invention, a pair that sufficiently permeates even under such an atmosphere and detects only the strip. By providing the laser transmitter and the laser receiver, the tip of the strip can be reliably detected.

Moreover, in the present invention, a plurality of pairs of laser transmitters and laser receivers are arranged side by side along the strip width direction, so that a true strip tip can be reliably detected even for tip shapes of various strips. It is a division that can be done.

Example of Invention

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 4 is an overall configuration diagram of a down coiler step avoidance control system to which the present invention is applied. The difference from FIG. 1 is that instead of the acceleration detector 11 of FIG. 1, a laser beam emitter 15 and a photodetector 16 are provided between the upper and lower pinch rolls 13 and 14 and the mandrel 2. Is. The light shielding method is excellent as a means for detecting regardless of the taper cross section of the tip of the strip 1 and the like. But,
The area around the down coiler is filled with water vapor from the cooling water used to cool the coil, resulting in extremely poor light transmission.
In such an atmosphere, a general photoelectric detector using white light has a weak penetrating power, so that steam and strip cannot be discriminated from each other, and an erroneous detection signal is output. For this reason, in the present invention, the laser beam receivers and light emitters 16 and 15 are provided to sufficiently permeate even in such a dense atmosphere of steam and detect only the strip 1. In FIG. 4, reference numerals 3 to 5 are rapper rolls, 6 is a rapper frame, 7 is a fulcrum, 8 is a fluid pressure cylinder, 9 is a servo valve,
Reference numeral 10 is a hydraulic pressure source.

Here, the light emitter 15 and the light receiver 16 of the laser beam in the down coiler step avoidance control system shown in FIG.
The arrangement will be described.

FIG. 6 shows a plurality of a pair of laser transmitters and laser receivers arranged along the strip width direction of the strip 1.

A pair of laser transmitters and laser receivers are arranged in parallel at five locations a, b, c, d, and e, which are substantially evenly distributed along the strip width direction of the strip 1. By doing so, one of the detectors catches the true tip of the strip 1 as shown in "a" of FIG. 6 with respect to the tip shape of the strip 1 of various shapes as shown in FIG. , for example, erroneous connexion "c" (commensurate one time the length l) timing deviation due to the detecting point is not Okoshira, is "t _o" timing by connexion Figure 3 to correctly portion passes with strips stage Therefore, accurate step avoidance control can be performed.

As described above, according to the present invention, the true tip of the strip 1 is made to have the taper tip shape of the plate by the strong transmitting power of the laser beam and the arrangement of the plurality of receivers and light emitters 16 and 15 in the plate width direction. It is possible to detect reliably without fear of malfunction or omission of detection due to water vapor or the like.

The laser beam receiving and emitting devices 16 and 15 are generally easy to install after the upper and lower pinch rolls 13 and 14, but the upper and lower pinch rolls 13 and 1 are easy to install.
Even if it is installed before 4, the effect of the present invention does not change. Further, the arrangement of the receivers and light emitters 16 and 15 in the plate width direction is arranged obliquely as shown in FIG. 8 or as shown in FIG. It is also possible to arrange them alternately. In this case, the difference in installation position is "L"
Is corrected in advance by the timing calculation section of the control panel 12 ', so that the effect of the present invention is not impaired.

〔The invention's effect〕

As described above, according to the down coiler step avoidance control system of the present invention, a plurality of pairs of laser transmitters and laser receivers are arranged side by side along the strip width direction between the pinch roll and the down coiler. Since it is provided so as to detect the passage timing of the strip tip, it is possible to reliably detect the true strip tip in any strip tip shape.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a conventional down coiler step avoidance control system, FIG. 2 is a partially enlarged configuration diagram showing an enlarged part of FIG. 1, and FIG. 3 is a conventional down coiler step avoidance control system. 4 is an overall configuration diagram showing an embodiment of the down coiler step avoidance control system of the present invention, FIGS. 5 (a) to 5 (e) are explanatory diagrams showing the tip shape of the strip, and FIG. FIG. 7 is an enlarged configuration diagram of an essential part of the system of the present invention in an enlarged manner, FIG. 7 is a view showing an embodiment of a cross section of the tip of the strip, and FIGS. It is explanatory drawing of an Example. 1 …… Strip, 13 …… Upper pinch roll, 14 ……
Lower pinch roll, 15 ... Light emitter, 16 ... Light receiver.

Claims (1)

[Claims] 1. A pinch roll and a down coiler,
In a down coiler step avoidance control system for detecting a passage timing of a strip tip by providing a pair of laser transmitters and laser receivers, a plurality of the pair of laser transmitters and laser receivers are arranged along a strip width direction of the strip. A down coiler step avoidance control system characterized by being installed in parallel.