JPH06145818A - Method for controlling prevention of meandering in strip heat treatment equipment - Google Patents

Abstract

PURPOSE:To prevent the generation of slipping flaw caused by the meandering of a strip in a heat treatment furnace. CONSTITUTION:Steering units for controlling carrying direction of the strip 2 are arranged in plural positions just at front of the inlet of a heat treatment furnace and in the heat treatment furnace. Then, based on offset quantity of the strip 2 detected just before carrying into furnace and correcting quantity in the steering unit 16 at the furnace inlet side, a predicting offset quantity in each of steering units 17, 18 in the furnace is calculated, and each steering unit in the furnace is driven so as to cancel this predicting offset. By this method, as the feedforward control is executed based on the informations of the strip meandering just before carrying into the furnace and at the first steering unit in the upstream side, the correction control of the meandering can further suitably 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 heat treatment equipment for strips, and more particularly to a meandering prevention method for strips which are continuously conveyed while being supported by a plurality of rolls provided in a heat treatment furnace for strips. The present invention relates to a meandering prevention control method suitable for an apparatus having a steering unit for correction.

[0002]

2. Description of the Related Art In continuous annealing equipment for heat-treating a strip in a predetermined heat cycle, a plurality of strip-supporting rolls are arranged at upper and lower positions in a heat treatment furnace, and the strips are staggered in the vertical direction. It is known that the inside of the furnace is continuously threaded by being drawn around. In such an apparatus, the belt strip to be conveyed may meander for some reason, and therefore a steering unit for correcting the meander may be provided in a proper place.

As this steering unit, for example, a support roll similar to other strip support rolls is constructed so as to be swingable in the left-right direction with respect to the center line of the strip transport direction, and the support roll is A hydraulic cylinder is known that can be appropriately driven in the left-right direction.
Further, for example, by providing a detection sensor capable of detecting the displacement (offset amount) in the width direction of the strip portion passing near the steering unit, and performing the proportional control or the integral control based on the detected value, the steering unit is It is known that the drive control of the steering unit is performed with a gain according to each place where the steering unit is arranged.

[0004]

However, since the above-mentioned conventional correction control is so-called feedback control, if the gain is increased to increase the operating speed of the steering unit, for example, the strip temperature is high and the tension is low. In this case, there is a problem that a minute slip occurs between the strip and the support roll of the steering unit, and the strip has a flaw. On the contrary, if the gain is lowered to lower the operation speed of the steering unit, the steering unit cannot follow the rapid meandering of the strip due to, for example, a camber, and the strip rolls out.
Therefore, there is a problem that the gain adjustment of the correction operation speed of the steering roll becomes complicated.

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 unit for correcting the meandering of the strip so that the flaw of the strip due to the abrupt movement is generated. Another object of the present invention is to provide a meandering prevention control method for a strip heat treatment equipment which is improved so as to prevent rollout due to a response delay when the strip is meandering rapidly.

[0006]

According to the present invention, such an object is provided in the heat treatment line of the strip before the furnace inlet and at a plurality of positions in the furnace in the conveying direction of the strip. A meandering correction steering unit arranged along a predetermined distance along the width direction, a detection sensor for detecting the widthwise offset amount of the strip at each steering unit position, and an offset from the detection sensor. Offset amount before flowing into the furnace detected by the detection sensor of the steering unit before the entrance of the furnace, and driving means for driving each steering unit based on the quantity data to correct the meandering of the strip. The offset amount detection point on the upstream side is determined based on the data and the detected offset amount data on the steering unit on the upstream side between adjacent steering units. Calculate the predicted offset amount when reaching the steering unit on the flow side, and perform a meandering correction operation on each steering unit so as to cancel the predicted offset amount at the timing when the offset detection point passes through each steering unit in the furnace. The present invention is achieved by providing a meandering prevention control method for a strip heat treatment equipment, which is characterized by being performed.

[0007]

In this way, the offset amount due to the meandering of the strip in a certain steering unit in the line is detected, and the offset amount in the steering unit one downstream side is predicted based on this detected value. A control signal can be given to the steering roll on the downstream side so as to cancel the predicted offset amount. In addition, since the meandering information of the original plate before flowing into the furnace is reflected in the offset amount predicted value, more accurate feedforward control can be realized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure 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 payoff 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 has been 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 is delivered by the delivery side looper device 11. Is adjusted and then sent to the skin pass mill 12. After being temper-rolled by the skin pass mill 12, defective portions are removed or divided by the inspection and conditioning device 13, and the processed strip 2 is wound on the tension reel 14. Further, in each furnace, a plurality of strip plate supporting rolls 15 including a hearth roll for applying an appropriate tension to the strip plate 2 to continuously run the strip plate 2 are provided between the inlet and the outlet. Are arranged in a staggered manner up and down in appropriate places.

The strip plate supporting roll 15 is basically arranged so that the strip plate 2 is centered and passed through the furnace at a portion just before the furnace inlet between the entrance looper device 5 and the furnace. There is provided an inlet side steering unit 16 including a pair of rolls 16a and 16b which may have the same shape as the above and a mount for supporting them. Then, the heating furnace 6 and the soaking furnace 7
An in-reactor upstream steering unit 17 similar to the above steering unit 16 is provided in the passage connecting the lower part of the furnace to the upper part of the furnace between the soaking furnace 7 and the primary cooling furnace 8. Inside the connecting passage, a steering unit 18 on the downstream side in the furnace similar to the steering units 16 and 17 is provided.

Each of the steering units 16 and 17
Reference numeral 18 has substantially the same structure, and is shown in FIG. 2 as a representative of the in-reactor upstream steering unit 17. The pedestal of the 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 on the upstream side in the transport direction of the left and right side plates 17c. And a connecting plate 17d integrally bridged between the two. The center of the connecting plate 17d oscillates on the horizontal plane around the axis (A in FIG. 2) passing through the center of the roll width on the tangent line to the strip 2 conveyed through the steering unit 16 on the inlet side. It is rotatably attached, for example, to the furnace wall. Further, in order to swing and drive both rolls 17a and 17b, for example, the free end of the piston rod of the hydraulic cylinder 19 is connected to one side plate 17c.

The strip 2 passes under both rolls 17a and 17b and is conveyed toward the inlet of the soaking pit 7 as shown in FIG. In the vicinity of the upper part of the steering unit 17 on the upstream side in the furnace, there is disposed a light emitting / receiving type detection sensor 20 facing each other so as to sandwich the portion immediately after passing through the belt plate supporting roll 17b. Its floodlight 2
0a has a light source in a box made of, for example, a heat insulating material, and is adapted to emit light through a window which is opened toward the strip 2 and wider than the width of the strip 2. There is. Also,
Similarly, the light receiver 20b has a light receiving sensor in a box made of a heat insulating material, and is adapted to receive, of the irradiation light from the light projector 20a, light that has passed through the band plate 2 without being blocked. By displacing the boundary line of the light receiving portion when the strip 2 meanders, for example, the offset amount with respect to the transport center line passing through the center of the roll width can be detected.

The inlet side steering unit 16 and the in-furnace downstream side steering unit 18, which are provided in front of and behind the in-furnace upstream steering unit 17, are also constructed in the same manner. By 22b, the offset amount due to the meandering of the passing strip 2 can be detected in the same manner as described above. The detection signals of each of the light receivers 20b, 21b, 22b are input to the control device 23, and a control signal for displacing each of the steering units 16, 17, 18 in a direction for correcting the meandering of the strip 2 is provided. , Is output from the control device 23 in accordance with the detected offset amount data.

A correction value setting section 23 is provided in the control device 23.
a, steering control unit 23b, and cylinder drive unit 2
3c is provided. Of these, the correction value setting unit 23
In a, offset amount data δ1, δ2, δ3 detected by the light receivers 20b, 21b, 22b at the respective steering units 16, 17, 18 positions, and the strip 2 based on these offset amount data δ1, δ2, δ3. Correction amount of each steering unit 16, 17, 18 for correcting the meandering of the vehicle and each offset amount data δ1, δ2, δ
The signal of the detection time of 3 is input as the meandering information of the strip 2. Further, the steering controller 23b receives the output signal from the correction value setting unit 23a and the offset amount data from each steering unit. The cylinder drive unit 23c includes a steering control unit 23b.
From the cylinder drive unit 23c, and a drive signal is output from the cylinder drive unit 23c to the hydraulic cylinder 19 in accordance with the control signal.

Next, the operating procedure in this embodiment will be described with reference to FIG. First, the detected offset amount data δ of the strip 2 when passing through the position of the entrance side steering unit 16
1 and its detection time and its detection offset amount data δ
The inlet side steering unit 16 including the correction operation amount given to the inlet side steering unit 16 based on 1.
The strip meandering information at the position is read into the correction value setting unit 23a (step ST1).

Next, the portion on the strip where the offset amount data δ1 is detected is the in-core upstream steering unit 17
The estimated offset amount when passing through the correction value setting unit 23
It is calculated from the following equation at a (step ST2). (Predicted offset amount) = δ1− (correction operation amount of the entrance side steering unit)

Next, for example, a data table stored in advance in the correction value setting section 23a is searched based on the predicted offset amount obtained by the above formula, and the correction offset amount δC1 for the in-reactor upstream steering unit 17 is determined. Yes (step ST3). And the corrected offset amount δC
1 is compared with a predetermined allowable value to determine the necessity of correction (step ST4). If the correction value is larger than the allowable value and correction is necessary, the process proceeds to step ST5. Will end this one cycle.

In step ST5, the correction operation timing for operating the in-furnace steering unit 17 is calculated from the following equation. (Correction operation timing) = (conveyance time between both steering units of the strip 2) − (δC1-δ1) / (operating speed of the hydraulic cylinder 19)

In the above equation, the time required for the hydraulic cylinder 19 to perform the correction operation is subtracted from the time required for the target portion to be corrected to reach the upstream steering unit 17.

Next, the timing for starting the operation of the hydraulic cylinder 19 is determined by the timer circuit in the controller 23 based on the correction operation timing obtained in step ST5.
The start timing, that is, the upstream steering unit 1 in the furnace
The steering control unit 23 before the correction target portion reaches 7
A control signal is output from b to the cylinder drive unit 23c (step ST6).

The cylinder drive unit 23 is responsive to this control signal.
By outputting a drive signal from c to the hydraulic cylinder 19, a correction operation for canceling the predicted offset amount in accordance with the timing at which the target portion to be corrected reaches the in-core upstream steering unit 17 is executed by the feedforward control ( Step ST7).

The upstream steering unit 17 in the furnace
After execution of the correction operation of No. 3, the detected offset amount data δ2 of the strip 2 in the in-furnace upstream steering unit 17 and the detection time, and the detected offset amount data δ2 are given to the in-reactor upstream steering unit 17. The strip meandering information at the position of the steering unit upstream of the furnace, which is composed of the correction operation amount, is read into the correction value setting section 23a (step ST8).

Next, the steering unit 1 on the upstream side in the furnace
7, the predicted offset amount when the portion of the strip 2 in which the offset amount data δ2 is detected passes through the in-core downstream steering unit 18 is calculated by the correction value setting unit 23a from the following equation (step ST9). ). (Predicted offset amount) = δ1-δ2- (correction operation amount)

Next, the steering unit 1 on the downstream side of the furnace
The correction offset amount δC2 in step 8 is set to step ST3.
Similar to the process of step 1, the data table is searched and determined based on the predicted offset amount obtained by the above equation (step ST
10). Then, the corrected offset amount δC2 is compared with a predetermined allowable value (step ST11), and if it is larger than the allowable value and needs to be corrected, the process proceeds to step ST12. Of 1
End the cycle.

In step ST12, the correction operation timing for operating the steering unit 18 on the downstream side in the furnace is calculated from the following equation in the same manner as in step ST5. (Correction operation timing) = (conveyance time between both steering units of the strip 2) − (δC2-δ2) / (operating speed of the hydraulic cylinder 19)

The controller 23 determines the timing of starting the operation of the hydraulic cylinder 19 based on the corrected operation timing.
The control signal is output from the steering control section 23b to the cylinder drive section 23c before the correction target portion reaches the downstream side steering unit 18 by the internal timer circuit (step ST13).

The cylinder drive unit 23 is responsive to this control signal.
By outputting a drive signal from the hydraulic pressure cylinder 19 to the hydraulic cylinder 19, a correction operation for canceling the predicted offset amount in accordance with the timing when the target portion to be corrected reaches the downstream steering unit 18 is executed by the feedforward control (step ST14). ).

If there is a steering unit on the further downstream side, steps ST8 to ST14 are similarly repeated. As a result, even if the meandering due to the influence of the original plate shape (camber etc.) immediately before flowing into the furnace occurs even when the result is corrected by one steering unit on the upstream side and when the shape is collapsed in the furnace. Feedforward control considering the offset amount can be performed for each steering unit appropriately disposed in the furnace.

In this way, even if the gain of the hydraulic cylinder 19 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 slip defect due to the excessive increase of the gain is preferable. Can be prevented. Also,
When the entrance side steering unit 16 detects a sudden meandering of the strip 2, the correction operation by the corresponding steering unit 17 is performed before the generation portion reaches the steering unit 17 on the downstream side. In addition, the correction operation can be similarly performed on the steering unit on the downstream side, and the rollout can be prevented in the same manner as described above.

In this embodiment, two in-core steering units to be fed forward controlled are provided, but the steerings having the same structure are arranged at appropriate intervals according to the length of the conveying path. A large number of units and detection sensors may be arranged. For example, in the continuous heat treatment equipment shown in the embodiment, it may be arranged at about 10 places.

[0031]

As described above, according to the present invention, the offset amount of the strip before flowing into the furnace is detected at the steering unit position provided before the entrance of the furnace, and the offset amount and each steering unit in the furnace are detected. The predicted offset amount in the steering unit on the downstream side is calculated in consideration of the corrected motion amount due to, and the correction operation is executed to the corresponding steering unit so as to cancel the predicted offset amount in accordance with the flow of the strip. Therefore, the appropriate meandering correction control can be performed by the feedforward control. Therefore, even when a plurality of steering units are provided in the heat treatment furnace, slip defects and rollout due to meandering can be prevented without performing complicated gain adjustment work such as adjusting the gain for each installation location of each steering unit. Occurrence can be suitably prevented.

[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 of control 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 path Mill 13 Inspection and refining device 14 Tension reel 15 Strip support roller 16 ・ 17 ・ 18 Steering unit 17a ・ 17b Roll 17c Side plate 17d Connection plate 19 Hydraulic cylinder 20a ・ 21a ・ 22a Light projector 20b ・ 21b ・ 22b Light receiver 23 Control device 23a Modification Value setting unit 23b Steering control unit 23c Cylinder drive unit

Claims (1)

[Claims] 1. A meandering correction device provided at a plurality of positions in a furnace before a furnace entrance in a heat treatment line for a strip and at a plurality of positions along a conveyance direction of the strip at predetermined intervals. A steering unit, a detection sensor for detecting a widthwise offset amount of the strip at each steering unit position, and each steering unit is driven based on offset amount data from the detection sensor. Drive means for correcting the meandering of the strip, offset amount data before flowing into the furnace detected by the detection sensor of the steering unit before the furnace inlet, and the upstream side between adjacent steering units. The offset amount detection point on the upstream side reaches the steering unit on the downstream side based on the detected offset amount data of the steering unit of When calculating the predicted offset amount, the offset amount detection point to cause each steering unit to perform a meandering correction operation so as to cancel the predicted offset amount in accordance with the timing of passing each steering unit in the furnace. A characteristic method for controlling meandering prevention of strip heat treatment equipment.