JPH0539528A - Method for controlling and preventing meandering in strip heat treatment furnace - Google Patents

Abstract

PURPOSE:To prevent the development of slip flaw, etc., due to meandering of a strip in a heat treatment furnace. CONSTITUTION:In the heat treatment furnace, a steering unit 17 having one pair of steering rolls 17a, 17b as carriable to the strip 2, is arranged and driven to right and oleft sides with a hydraulic cylinder 18. At least one among passing velocity of the strip 2, strip thickness, strip width, tension, strip temp., presence or absence of welding part, kinds of materials and detecting standard as parameter is inputted to a data setting part 22b, and by multiplying this parameter by a factor corresponding to the data setting part 22b, driving gain is decided. Based on this driving gain, a control signal is outputted to a cylinder driving part 22d from a steering control part 22c, and by driving a hydraulic cylinder 18, the steering unit 17 is driven. The gain corresponding to variation of the operational condition for the strip can suitably be used and the suitable meandering correcting control to the various kinds of strips can be executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a meandering prevention control method for a strip heat treatment furnace, and more particularly to a strip that is continuously conveyed while being supported by a plurality of strip plate support rolls provided in the furnace for heat treatment. The present invention relates to a meandering prevention control method for a strip heat treatment furnace suitable for an apparatus having a steering roll for correcting the meandering of a plate.

[0002]

2. Description of the Related Art For example, in a continuous annealing apparatus for heat-treating a strip in a predetermined heat cycle, a plurality of strip supporting rolls are arranged above and below in a heat treatment furnace, and the strip is placed above and below the strip. There is one in which the furnace is continuously passed through by alternately turning them in different directions. In such a device, the strip to be transported may meander for some reason,
A steering roll for correcting the meandering is arranged in a proper place.

The above-mentioned steering roll has, for example, a roll which conveys a strip and which is swingable in the left-right direction with respect to the conveying direction like other strip-supporting rolls, and is appropriately driven in the left-right direction. It is adapted to be driven by a hydraulic cylinder as means. Then, a detection sensor that can detect the displacement in the width direction of the portion of the strip that passes near the steering roll is provided as an offset amount, and proportional control or integral control is performed according to the offset amount, and each steering roll is arranged. I tried to correct the meandering of the strip with the gain according to the place.

However, since the correction control is so-called feedback control, if the gain is increased to increase the operation speed of the steering roll, for example, when the strip temperature is high and the tension is low, the strip and the steering roll are There is a problem that a minute slip occurs between the strips and the strip plate is flawed. On the other hand, if the gain is lowered to slow down the operation speed of the steering roll, the response of the steering roll is delayed and the strip rolls out, for example, when the strip is meandering rapidly. Therefore, strip passing speed, strip thickness, strip width, tension, strip temperature,
The problem that the adjustment that optimizes the drive gain of the correction operation of the steering roll is complicated so that it can respond to all cases where the operating conditions including the presence / absence of welds, materials, and inspection standards change. was there.

[0005]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the main object of the present invention is a driving means for performing a meandering prevention operation of a steering roll for preventing meandering of a strip. It is an object of the present invention to provide a meandering prevention control method for a strip heat treatment furnace which is improved so that the gain can be optimized.

[0006]

According to the present invention, such a purpose is to convey a strip plate into a furnace for heat-treating the strip plate and to swing the steering roll in the left-right direction. And driving means for driving the steering roll in the left-right direction, and a sensor for detecting the meandering of the strip, so as to prevent the meandering of the strip according to the meandering information from the detecting sensor. A method for controlling meandering prevention of a strip heat treatment furnace for controlling the output of a drive signal to the drive means, wherein the strip passage speed, strip thickness, strip width, tension,
Provided is a meandering prevention control method for a strip heat treatment furnace, wherein the drive gain of the drive means is variably adjusted using at least one of the strip temperature, the presence / absence of a welded part, a material, and an inspection standard as parameters. It is achieved by

[0007]

As described above, the drive gain of the drive means for performing the meandering correction operation is changed in accordance with the operating conditions such as the strip running speed, strip thickness, strip width, etc. of the strip to be heat-treated, and the steering roll Since the control is performed, it is possible to automatically respond to the change in the operating condition of the strip, and it is possible to perform the meandering correction control with an appropriate gain.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described in detail below with reference to specific embodiments shown in the accompanying drawings.

FIG. 1 shows a schematic structure of a continuous heat treatment facility to which the present invention is applied. The strip 2 is continuously supplied from the pay-off reel 1 installed at the line entrance, and the leading end of the latter strip is connected to the end of the former strip by the welding connection device 3 and then cleaned. After being cleaned by the device 4, the amount of supply is adjusted by the entrance looper device 5, and then fed into the furnace for heat treatment. Then, the strip 2 which is heat-treated according to a predetermined heat cycle through the heating furnace 6, the soaking furnace 7, the primary cooling furnace 8, the overaging furnace 9, and the secondary cooling furnace 10 has a delivery amount by the delivery side looper device 11. It is adjusted and sent to the skin pass mill 12. After being temper-rolled by this skin pass mill 12, the inspection and conditioning device 1
The defective portion is removed or divided at 3, and the processed strip 2 is wound around the tension reel 14.
Further, in each furnace, the strip plate 2 is applied with an appropriate tension.
A plurality of strip plate support rolls 15 including a hearth roll for continuously running the sheet are arranged vertically and alternately at appropriate places from the entrance to the exit.

A pair of steering rolls 17a.1 having the same shape as the strip plate supporting roll 15 is provided in a communication passage provided at the upper part of the furnace so as to connect the soaking furnace 7 and the primary cooling furnace 8 to each other.
A second steering unit 17 having 7b is provided. As shown in the schematic plan view of FIG. 2, the pedestal of the steering unit 17 includes side plates 17c provided on the left and right in the axial direction for supporting the pair of steering rolls 17a and 17b in parallel with each other, and the left and right side plates 17c. It is composed of a connecting plate 17d integrally bridged between the side plates 17c on the upstream side in the transport direction. The center of the connecting plate 17d oscillates around the axis (A in FIG. 2) which is on the tangent to the strip 2 conveyed from below the upstream side strip supporting roll 17a and which passes through the center of the roll width. It is rotatably mounted, for example, on the furnace wall. Also, both rolls 17
In order to displace the a and 17b in the swinging direction, the side plate 17
For example, the free end of the piston rod of the hydraulic cylinder 18 is connected to one side of c.

The strip 2 passes over the rolls 17a and 17b, and as shown in FIG. 1, the lower primary cooling furnace 8 is provided.
Is transported to the entrance of. Steering unit 17
A light emitting and receiving sensor is arranged near the lower part of the so as to face each other so as to sandwich the portion immediately after passing through the steering roll 17b. The floodlight 19a has a light source in a box made of, for example, a heat insulating material, and emits light through a window that is open toward the strip 2 and is wider than the width of the strip 2. Is becoming Also, the light receiver 19b is
Similarly, a light receiving sensor is provided in a box made of a heat insulating material, and it receives light that has passed through the strip plate 2 without being blocked by the strip plate 2 among the irradiation light from the projector 19a. By the displacement of the boundary line of the light receiving portion when meandering, for example, the offset amount with respect to the transport center line passing through the center of the roll width can be detected.

As shown in FIG. 2, the control device 22 includes an operating condition data section 22a, a gain setting section 22b, a steering control section 22c, and a cylinder drive section 22d. In the operating condition data section 22a, various data such as the running speed, the plate thickness, the plate width, the tension, the temperature, the presence / absence of the welded portion, the material, and the inspection standard as the operating conditions of the strip 2 are input by, for example, a key or the like. Alternatively, it is rewritten at any time by a signal from a sensor not shown, and the operating condition data section 22
The above data are output from a to the gain setting unit 22b. The inspection standard in the above operating conditions may be for the surface finishing accuracy or the like.

The gain setting unit 22b determines a coefficient Kn for each digitized value Dn of the above data, and calculates the operation gain G of the hydraulic cylinder 18 based on the following equation. G = K1 ・ D1 + K2 ・ D2 + ... + Kn ・ Dn

The gain G obtained by the above equation is input from the gain setting section 22b to the steering control section 22c. Further, an offset amount detection signal for the strip 2 is input to the steering control unit 22c from the above-mentioned light receiver 21b. In the steering control unit 22c, for example, if the strip 2 is conveyed to the left or right with an offset equal to or greater than the allowable value, control is performed to drive the hydraulic cylinder 18 in the correction direction according to the offset amount and using the gain G. The signal is output to the cylinder drive unit 22d. In response to the control signal, a drive signal is output from the cylinder drive unit 22d to the hydraulic cylinder 18 to correct the meandering of the strip 2 with an appropriate gain G.
7 is driven.

As described above, since the drive gain G of the hydraulic cylinder 18 is determined by using each data of the operating conditions, even if each data of the strip 2 changes, it is calculated based on the changed data appropriately. Control using gain. Therefore, it is possible to perform an appropriate corrective action immediately corresponding to a change in operating conditions.

Each of the above-mentioned coefficients Kn can be set in advance based on the experimental values shown in FIGS. 3 to 5, which show, for example, the threading speed, temperature, and tension of the strip 2 as parameters. In each figure, the case where slip flaws occur is indicated by x, and the case where slip flaws do not occur is indicated by o. Therefore, in each figure, the corresponding coefficient Kn may be set so that the gain changes within the range of the imaginary line with respect to the change of each parameter. The same can be obtained for other conditions, and using the coefficient Kn thus obtained,
The gain G adapted to the operating condition can be obtained from the above equation.

[0017]

As described above, according to the present invention, since the steering roll is drive-controlled using the gain calculated corresponding to each operating condition to correct the meandering of the strip, it is always optimum. It is possible to control by using the gain, and it is possible to prevent the occurrence of a slip defect due to a sudden operation speed due to an inappropriate gain for a certain operating condition and a roll-out due to an operation delay. Therefore, it is possible to carry out optimal transportation for various strip operating conditions, and it is possible to perform favorable heat treatment.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a strip continuous annealing equipment to which the present invention is applied.

FIG. 2 is a schematic plan view of a steering unit and a block diagram of a control device according to the present invention.

FIG. 3 is a diagram showing how a slip flaw is generated due to a change in gain with respect to a strip passing speed of a strip plate.

FIG. 4 is a diagram showing how a slip flaw is generated due to a change in gain with respect to a temperature of a strip plate.

FIG. 5 is a diagram showing how slip flaws are generated due to a change in gain with respect to tension of a strip plate.

[Explanation of symbols]

 1 Payoff reel 2 Strip plate 3 Welding connection device 4 Cleaning device 5 Entry side looper device 6 Heating furnace 7 Soaking furnace 8 Primary cooling furnace 9 Overaging passage 10 Secondary cooling furnace 11 Exit side looper device 12 Skin pass mill 13 Inspection and refining device 14 Tension Reels 15 Strip Support Rolls 17 Steering Units 17a and 17b Steering Rolls 17c Side Plates 17d Connecting Plates 18 Hydraulic Cylinders 19a Emitters 19b Light Receivers 22 Control Devices 22a Operating Condition Data Parts 22b Gain Setting Parts 22c Steering Control Parts 22d Cylinder Drive Parts

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hirohisa Kawamura, 1 Kimitsu, Kimitsu City Nippon Steel Corporation Kimitsu Steel Works

Claims (1)

[Claims] 1. A steering roll that conveys the strip and is swingable in the left-right direction into a furnace for heat-treating the strip, and drive means for driving the steering roll in the left-right direction. And a sensor for detecting the meandering of the strip, and heat-treating the strip for controlling to output a drive signal to the driving means so as to prevent the meandering of the strip according to the meandering information from the detection sensor. A method for controlling the meandering of a furnace, wherein the strip plate speed, strip thickness, strip width, tension, strip temperature, presence / absence of a weld, material, and inspection standard are used as parameters. A meandering prevention control method for a strip heat treatment furnace, characterized in that a drive gain of a drive means is variably adjusted.