JPH0539527A - 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 downstream side steering unit 17 having one pair of second steering rolls 17a, 17b as carriable to the strip 2, is arranged and driven to right and left sides with a hydraulic cylinder 18. The meandering information detected at upstream side of the strip 2 is inputted to correct value setting part 22a in a control device 22, and by using offset quantity and correct quantity in an upstream side steering unit, the predicted offset quantity in the downstream side steering unit 17 is calculated. Control signal is outputted to a cylinder driving part 22c from a steering control part 22b so as to cancel the predicted offset quantity, and by driving the hydraulic cylinder 18, the downstream side steering unit 17 is driven. Based on the strip meandering information in the upstream side, a feedforward control is executed, and the suitable correcting control can be executed without using gain adjustment.

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 steering roll has, for example, a support roll which is swingable in the left-right direction with respect to the center line of the transport direction of the strip, and which is similar to other strip support rolls. It is adapted to be appropriately driven by a hydraulic cylinder. Further, for example, a detection sensor capable of detecting the displacement in the width direction of the portion of the strip passing through the vicinity of the steering unit is provided, and the control for driving the steering roll in the direction of correcting the meandering is performed based on the detection value. Proportional control or integral control is performed to correct the meandering of the strip with a gain according to each place where the steering roll is arranged.

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, there is a problem that the gain adjustment of the correction operation speed of the steering roll becomes complicated.

[0005]

In view of the problems of the prior art, the main object of the present invention is to optimize the correction operation of the steering roll for correcting the meandering of the strip,
An object of the present invention is to provide an improved control method for preventing meandering of a strip heat treatment furnace, which is capable of preventing the occurrence of flaws in the strip due to an abrupt operation and the rollout due to an operation delay when the strip is abruptly meandering.

[0006]

According to the present invention, such an object is provided in a furnace for heat-treating a strip at predetermined intervals in the conveying direction of the strip, and to the left and right. The upstream and downstream steering rolls that are swingably provided, a detection sensor for detecting an offset amount due to the meandering of the strip in the upstream steering roll, and the steering rolls in the swinging direction. When the upstream side offset amount is detected by the detection sensor, the upstream side steering roll is adjusted based on the detected offset amount so as to correct the meandering of the strip. The predicted offset amount is calculated when the target portion that is driven and the detected offset amount of the strip has reached the downstream side steering roll, and the predicted offset amount is calculated. It is achieved by providing a meandering preventing method of controlling strip heat treatment furnace, characterized by driving the downstream steering roller to cancel the set amount.

[0007]

With this configuration, when the offset amount due to the meandering of the strip in the upstream steering roll is detected, the predicted offset amount in the downstream steering roll is calculated and the predicted offset amount is canceled. By controlling the downstream side steering roll in this manner, the meandering prevention control can be performed by the feedforward control.

[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 upstream side steering rolls, which may have the same shape as the strip plate support rolls 15, are provided in a communication passage provided in the lower part of the furnace so as to connect the heating furnace 6 and the soaking furnace 7. Is provided with a downstream steering unit 16 including rolls 16a and 16b and a pedestal that supports the rolls 16a and 16b, and a communication passage provided in the upper part of the furnace so as to connect the soaking furnace 7 and the primary cooling furnace 8 to each other. As a downstream side steering roll, a pair of rolls 17a and 17b are similarly provided.
The downstream side steering unit 17 having the above is provided.

Each of the above steering units 16 and 17
2 has the same structure, and the downstream steering unit 17 will be described below with reference to FIG. 2 which is a schematic plan view thereof. The pedestal of the downstream side steering unit 17 is provided with side plates 17c provided on the left and right in the axial direction of the pair of steering rolls 17a and 17b so as to support the pair of steering rolls 17a and 17b in parallel with each other, and above the left and right side plates 17c on the upstream side in the transport direction. Connection plate 1 bridged integrally between the two
7d. The center of the connecting plate 17d is swingable around an axis (A in FIG. 2) which is on the tangent to the strip 2 conveyed from below the steering roll 17a on the upstream side and which passes through the center of the roll width. Thus, for example, it is pivotally attached to the furnace wall. Further, the free end of the piston rod of the hydraulic cylinder 18, for example, is connected to one of the side plates 17c in order to displace both the rolls 17a and 17b in the swinging direction.

The strip plate 2 passes over the rolls 17a and 17b, and as shown in FIG.
Is transported to the entrance of. In the vicinity of the lower side of the downstream side steering unit 17, a light emitting / receiving type detection sensor is arranged so as to face each other so as to sandwich the portion immediately after passing the band plate supporting roll 17b. The floodlight 19a has a light source in a box made of, for example, a heat insulating material, and the strip 2
Light is radiated through a window that is open toward the front and is wider than the width of the strip 2. In addition, the light receiver 19
Similarly, b has a light receiving sensor in a box made of a heat insulating material, and is adapted to receive the light that has passed through the band plate 2 without being blocked by the light emitted from the light projector 19a. The displacement of the boundary line of the light receiving portion when the plate 2 meanders can detect the offset amount with respect to the transport center line passing through the center of the roll width, for example.

The above-mentioned upstream side steering unit 16 provided on the upstream side of the downstream side steering unit 17.
Is also configured in the same manner, and the offset amount due to the meandering of the strip 2 passing therethrough is set to the corresponding projector 21a and receiver 21.
It is detected by b as in the above. Both receivers 19a
As shown in FIG.
Is input to, depending on the detected offset amount,
From the control device 22, from the steering units 16 and 17
A control signal for displacing a predetermined amount in a direction for correcting the meandering of the strip 2 is output.

A correction value setting section 22a is provided in the control device 22.
A steering control unit 22b and a cylinder drive unit 22c are provided. The correction value setting unit 22a has an offset amount δ detected in the upstream steering unit 16.
1, the correction operation amount by the upstream steering unit 16 for correcting the meandering based on the offset amount δ1, and the signal of the detection timing thereof are input as the meandering information of the strip. The steering control unit 22b receives the output signal from the correction value setting unit 22a and the detection signal from the light receiver 19b in the downstream side steering unit 17. A control signal from the steering control unit 22b is input to the cylinder drive unit 22c, and the hydraulic cylinder 18 is supplied from the cylinder drive unit 22c according to the control signal.
The drive signal is output to.

Next, referring to the flow chart of FIG. 3, the operation procedure in this embodiment will be described below. First, in step ST1 of FIG. 3, a detection offset amount δ1 of the strip 2 in the upstream steering unit 16 and a detection timing thereof, and a correction operation of the upstream steering unit 16 based on the detection offset amount δ1 are performed. The strip meandering information based on the correction operation amount is read into the correction value setting unit 22a. In the next step ST2, the correction value setting unit 22a changes the detection target portion of the offset amount δ1 of the strip 2 to
The predicted offset amount when passing through the downstream steering unit 17 is calculated based on the following formula. (Predicted offset amount) = δ1- (correction operation amount) In step ST3, the downstream steering unit 17
The correction offset amount δ2 in (1) is determined by indexing based on the predicted offset amount of the above formula using, for example, a data table stored in advance in the correction value setting unit 22a. In the next step ST4, the correction offset amount δ2 is compared with the allowable value, and if it is larger than the allowable value and the correction is necessary, the process proceeds to step ST5. Ends this one cycle.

In step ST5, the correction operation timing for operating the downstream side steering unit 17 is calculated based on the following equation. (Correction operation timing) = T- (δ2-δ1) / V

Here, T is both units 16 of the strip 2
17 is the time to be transported between 17 and V is the hydraulic cylinder 1
8 operating speed. In the above equation, the time required to operate the hydraulic cylinder 18 for correction is subtracted from the time T until the target portion to be corrected reaches the downstream steering unit 17.

In step ST6, the hydraulic cylinder 18
Is started by the timer circuit (not shown) in the controller 22 using the correction operation timing obtained by the equation in step ST5, and the start time, that is, the correction target portion is the downstream side steering unit 17
Before reaching, the steering control unit 22b outputs a control signal to the cylinder drive unit 22c. According to the control signal, in step ST7, by outputting a drive signal from the cylinder drive unit 22c to the hydraulic cylinder 18,
The correction operation for canceling the predicted offset amount can be performed by the feedforward control at the timing when the target portion to be corrected reaches the downstream side steering unit 17.

Therefore, even if the gain of the hydraulic cylinder 18 is not increased by the initial adjustment, the correction operation for the large meandering of the strip 2 can be sufficiently coped with, and the occurrence of the slip flaw due to the excessive increase of the gain can be preferably prevented. When the upstream steering unit 16 detects a sudden meandering of the strip 2, the downstream steering unit 17 can perform a correction operation before the generation portion reaches the downstream steering unit 17. In the same manner as described above, it is possible to prevent the rollout by responding appropriately.

In the present embodiment, an example in which one downstream side steering unit 17 as a steering roll for carrying out the feedforward control is provided is shown, but an appropriate interval is set according to the length of the conveying path. , A plurality of steering units and detection sensors having the same configuration may be arranged,
For example, in the continuous heat treatment apparatus shown in the embodiment, it may be provided at about 10 places.

[0021]

As described above, according to the present invention, the amount of offset due to the meandering of the strip is detected by the detection sensor provided on the upstream side, and the correction operation amount by the upstream side steering roll based on the offset amount is taken into consideration. Then, calculate the predicted offset amount on the downstream side steering roll,
Since the correction operation is performed by the downstream side steering roll so as to cancel the predicted offset amount, it is possible to perform suitable meandering correction control by the feedforward control. Therefore, when the device is provided with a plurality of steering rolls, it is possible to prevent the occurrence of slip flaws and rollout due to meandering without requiring complicated gain adjustment work such as adjusting the gain for each installation location. Suitable meandering prevention control can be performed.

[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 flowchart according to the present invention.

[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 reel 15 Band support roll 16 Upstream side steering unit 16a ・ 16b Roll 17 Downstream side steering unit 17a ・ 17b Roll 17c Side plate 17d Connecting plate 18 Hydraulic cylinder 19a Light projector 19b Light receiver 21a Light projector 21b Light receiver 22 Control device 22a Correction value Setting unit 22b Steering control unit 22c Cylinder drive unit

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

Claims (1)

[Claims] 1. An upstream side steering roller and a downstream side steering roll, which are arranged in a furnace for heat treating a strip plate at predetermined intervals in a conveying direction of the strip plate and are swingably provided to the left and right, The upstream side steering roll has a detection sensor for detecting an offset amount due to the meandering of the strip, and a drive unit for driving each of the steering rolls in the swing direction, the upstream side When the offset amount is detected by the detection sensor, the upstream side steering roll is driven based on the detected offset amount to correct the meandering of the strip plate, and the detected offset amount of the strip plate is detected. The downstream steering wheel is configured to calculate a predicted offset amount when a portion reaches the downstream steering roll and cancel the predicted offset amount. Meandering preventing method of controlling strip heat treatment furnace, characterized in that to drive the Lumpur.