JPH01273616A - Method of diagnosing timing for replacing work roll of tension leveler - Google Patents

Abstract

PURPOSE:To prevent the failure and jump out of the work rolls of the tension leveler by deciding the point of the time when the bending of the work rolls or the difference between the circumferential speed of the work rolls and the traveling speed of a strip exceeds a prescribed value as the timing for replacing the work rolls. CONSTITUTION:The work rolls 42 disposed to work roll units 5, 8, 9 are pressed onto the traveling strip 3 from above and below to correct the shape of the strip 3 in the traveling state. The bending of the work rolls 42 is measured by bend measuring sensors and the circumferential speed of the work rolls 42 is obtd. from rotating speed sensors. The traveling speed of the strip 3 is detected by a traveling speed sensor. The point of the time when the bend of the work rolls or the difference between the circumferential speed of the work rolls 42 and the traveling speed of the strip 3 exceeds the prescribed value is decided as the timing for replacing the work rolls 42. The failure and jump out of the work rolls of the tension leveler are thereby prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used in a tension leveler that corrects the shape of a strip by pressing a plurality of upper roll units and lower roll units against a traveling strip. The present invention relates to a method of diagnosing when to replace work rolls.

[Conventional technology]

Tension levelers are used for the purpose of correcting shape defects such as warping or partial elongation such as edge elongation and belly elongation that occur during the rolling process in a cold rolled steel plate or the like rolled by a rolling mill.

As a conventional tension leveler, there is one described in Japanese Unexamined Patent Publication No. 72431/1988, which was previously proposed by the applicant of the present invention.

This conventional example has a fixedly arranged upper roll unit,
A lower roll unit that faces the upper part roll unit with a strip in between and is moved up and down by an intermesh device, and strip joint detection devices that are respectively disposed on the upstream and downstream sides in the traveling direction of the strip. It has a configuration that includes an elevating device that moves the lower roll unit up and down independently of the ink mesh device, and a locking device that fixes the lower roll unit with respect to the traveling direction of the band plate.

When the joint of the strip approaches the upstream side of the tension leveler, the joint of the strip is detected by the strip joint detection device on the upstream side, and the detection signal is sent to the lower roll unit independently of the ink mesh device. The material is then supplied to a lifting device that moves it up and down, and the lower roll unit is lowered to thread the strip joint. By doing so, it is possible to prevent the small-diameter work roll of the work roll unit from being damaged by being subjected to a large impact force due to the difference in level between the joints of the strips passing at a high speed of 1000 m/min.

After that, when the strip joint passes through the tension leveler, a joint detection signal from the downstream strip joint detecting device is supplied to the lifting device to raise and return the lower roll unit to continue normal straightening work. .

However, the work roll of the tension leveler is non-driven, and once the work roll leaves the strip, the rotation speed of the work roll decreases, and the work roll tries to contact the strip again by passing through the joint of the strip. At this time, the circumferential speed of the work roll is smaller than the running speed of the strip. If the difference between the circumferential speed of the work roll and the running speed of the strip is large,
When the work roll comes into contact with the strip, the work roll is dragged by the strip in the running direction of the strip rather than being rotated, which may cause the work roll to fly out or even break at the center of the work roll. Ta.

Therefore, in the conventional tension leveler, when the lower roll unit returns to the upper position, the work roll included in the lower roll unit and rolling into contact with the strip plate is moved by the geared motor via the intermediate roll, backup roll, and distribution gear.
It was driven to rotate so that its circumferential speed was approximately equal to the traveling speed of the strip.

[Problem to be solved by the invention]

However, in the above-mentioned conventional tension leveler, the work roll included in the lower roll unit and in rolling contact with the strip is controlled by a geared motor when the lower roll unit is lowered so that its circumferential speed is almost equal to the traveling speed of the strip. Since it is rotationally driven, when the lower roll unit is raised and returned to start straightening work, the circumferential speed of the work roll and the traveling speed of the strip can be matched to prevent breakage of the work roll. However, since the power transmission between the backup roll and the work roll is friction transmission, if the work roll deteriorates, normal transmission will not occur due to the reasons shown in the following It was difficult to accurately match the circumferential speed of the roll with the traveling speed of the strip.

■ 6000 to 100 tonnage passing through work rolls
00), the work roll bends,
When this bending increases, the work roll dances on the intermediate roll, causing slippage between the intermediate roll and the work roll, resulting in rotation transmission loss.

(2) When the work roll bends as shown in (2), an uneven load is applied to the bearing that supports the backup roll, causing deterioration of the bearing, and as a result, the rotation of the work roll is restricted.

However, even if the work roll reaches this state,
Conventionally, it was difficult to detect this in advance, so when the lower roll unit was returned to its original position and the strip straightening work was started, it was not possible to reliably prevent the work roll from flying out or breaking. There was an unresolved problem of frequent breakage of work rolls.

Therefore, it is an object of the present invention to provide a method for diagnosing work roll replacement timing for a tension leveler, which can determine the work roll replacement time in advance in order to reliably prevent the work roll from breaking or popping out. The purpose is

[Means to solve the problem]

In order to achieve the above object, the present invention brings a work roll disposed in a non-driving state in a roll unit into pressing contact with a running band plate from above and below, and causes the work roll to be rotated by being dragged by the running of the band plate. When the shape of the strip is corrected by repeated bending while the strip is in motion, at least one of the bends of the work roll or the difference between the circumferential speed of the work roll and the running speed of the strip detect one,
The present invention is characterized in that the point in time when this detected value exceeds a predetermined value is determined to be the time to replace the work roll.

[Effect]

According to the present invention configured as described above, it is possible to detect bending that occurs in the work roll or a decrease in the rotational circumferential speed of the work roll due to deterioration of the work roll, and to compare these with a predetermined value. As a result, the degree of deterioration of the work roll can be determined and the time to replace the work roll can be determined in advance, thereby ensuring that the work roll does not break or pop out, which may occur if the deteriorated work roll is used as is. It can be prevented.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of a tension leveler showing a first embodiment of the present invention.

In the figure, a predetermined tension is applied to the inlet prydle roll 1 and the outlet prydle roll 2, and in this state, a tension leveler 4 equipped with a large number of small diameter rolls applies a pending force to elongate the strip plate 3. to correct the shape. The tension leveler 4 includes a lower roll unit RL consisting of work roll units 5 and 9 facing the strip plate 3 from below and a deflector roll unit 7 disposed between these, and each work roll unit 5.9. Band plate 3
The upper roll unit Ru is comprised of deflector roll units 6 and 10 facing each other with a strip 3 in between, and a work roll unit 8 facing the deflector roll unit 7 with a strip 3 in between.

Each roll unit 6 of the upper roll unit Ru.

8 and 10 are fixed to an upper frame 11, and this upper frame 11 is detachably held at the upper part of the housing 12 by a cylinder 13. - On the other hand, each roll unit 5, 7.9 of the lower roll unit RL is fixed to an independent support frame 5a, 7a, 9a, respectively,
It is supported so as to be movable up and down within the guide groove 15a of the lower frame 15 by ink mesh adjustment devices 16, 17, and 18 having motor-driven jacks attached to the bottom of the lower frame 15. The lower frame 15 is supported by a cylinder 19 at the lower part of the housing 12 so as to be movable up and down within the housing 12, and further includes an upper frame 11 and a lower frame 1.
It is detachably held on the upper frame 11 via support members 20a and 20b protruding from the surface facing the upper frame 11.

At the jack supporting center position of the ink mesh adjustment devices 16, 17, and 18, as shown in FIG. 2, there is a piston rod 30a with a small stroke t of, for example, about 20 mm, which expands and contracts in the vertical direction independently of the vertical movement of the jack. A hydraulically actuated quick opening/closing cylinder 30 is embedded therein.

Each backup roll 33 of each work roll unit 5.8.9 also has a drive shaft 36 rotatably supported by bearings 34, 35, and a drive shaft 36, as shown in FIG.
Oil seal 37 for 6.

The roll shell 39 is rotatably mounted with a constant resistance through a roll shell 38, and each work roll unit 5, 8.9 has three rolls. The bank up rolls 33 can be simultaneously driven by a geared motor 41 via a distribution gear 40. Each work roll 42 is rotationally driven via an intermediate roll 43 by forcibly driving a backup roll 33.

Then, the rapid opening/closing cylinder 30 and the guard motor 41
is rotationally driven by the control device 50.

As shown in FIG. 4, the control device 50 receives detection signals from position sensors 51 and 52, such as known non-contact types, that detect welding points at the entrance and exit sides of the tension leveler 4, and the running speed of the strip 3. A detection signal Sl of a known traveling speed sensor 53 that detects
and the detection signal S2 of the rotational speed sensor 54 which detects the rotational speed of the work roll disposed close to the outer periphery of the work roll 42 and the detection signal S2 of the work roll disposed close to the outer periphery of the work roll 42 as shown in FIG. The detection signal S3 of the bend measurement sensor 55 that detects bending is inputted, for example, and is configured with a direct digital controller, and the rapid opening/closing cylinder 30 is configured based on the detection signal of the position sensor 51.
is controlled to drive the lower roll unit RL downward, and the geared motor 41 is controlled based on the detection signal of the running speed sensor 53 to synchronize the running speed of the strip 3 and the circumferential speed of the work roll 42. The rapid opening/closing cylinder 30 is controlled based on the detection signal of the sensor 52, the traveling speed sensor 53, and the rotational speed sensor 54 to drive the lower roll unit RL upward.

The control device 50 also includes a recorder 56 and an alarm 57.
are connected, and the detection signal S of the traveling speed sensor 53,
Based on the detection signal of the rotation speed sensor 54, the difference between the circumferential speed of the work roll 42 and the speed of the strip 3 is constantly calculated, and further, the bending value of the work roll 42 is calculated based on the detection signal S3 of the bending measurement sensor 55. Calculated. Control device 5
0 displays this calculation result on the recorder 56, and
If the above calculation result exceeds a limit value that is set in advance in the control device 50 and will be described later, an alarm signal S4 of logical value "l" for generating an alarm sound is output to the alarm device 57, and the work roll This is to encourage the replacement of 42.

Here, as shown in FIG. 4, a rotation speed sensor 54 that detects the rotation speed of the work roll 42
It is composed of a reflective tape 60 attached to one end of the work roll 2 and a reflective photoelectric converter 61 facing the reflective tape 60, and outputs a pulse signal according to the rotational speed of the work roll 42.

Further, as the bend measurement sensor 55 for detecting the bend of the work roll 42, for example, a distance sensor can be used, and as this distance sensor, a known ultrasonic sensor and a capacitance sensor can be used.
An electric signal corresponding to the distance between the bend measurement sensor 55 and the bend measurement sensor 55 is amplified by the amplifier 80 and output.

Next, a description will be given of the operation of the tension leveler to perform the strip straightening work.

Now, assuming that the part of the strip 3 that is not the welding point is passing through the tension leveler 4, in this state, the detection signals of the position sensors 51 and 52 are, for example, a logical value "O'°,
Logic value ``0'' that holds the quick opening/closing cylinder 30 in the raised position
Since the control signal C8I is output to the cylinder drive circuit 30b, the lower roll unit) RL is controlled to the raised position, and works in cooperation with the upper roll unit Ru to move the work roll units 5, 8.9 and the deflector roll unit. 6
．． 7.10, a pending force is applied to the strip plate 3 to perform a predetermined straightening operation. In this state, the rotation speed command value for the motor drive circuit 41a of the guard motor 41 is zero, the guard motor 41 maintains a forced rotation stop state, and the work roll 42 is rotated by rolling contact with the strip plate 3.

In this state, when the welding point of the strip 3 is detected by the position sensor 51, the rotation speed of the work roll 42 corresponding to the traveling speed of the strip 3 is calculated, and this is sent to the motor drive circuit 41a as a rotation speed command value. Since the geared motor 41 is outputted, the geared motor 41 is rotationally driven, and the rotational force is transmitted to the work roll 42 via the backup roll 33 and the intermediate roll 43, and the work roll 42 is rotationally driven in synchronization with the running speed of the strip plate 3. Ru.

After that, when the welding point of the strip plate 3 reaches the tension leveler 4 position, the cylinder drive circuit 30 of the quick opening/closing cylinder 30
A control signal CS with a logic value of "1" is applied to b.

is output, the piston rod 30a of each rapid opening/closing cylinder 30 rapidly contracts and the lower roll unit RL
is lowered to release the work roll unit 5.8.9 from straightening the strip and to prevent the work roll 42 from being subjected to impact forces due to the welding points of the strip 3.

After that, when the welding point of the strip plate 3 passes through the tension leveler 4 and reaches the position of the position sensor 52, the logical value "1" is reached.
A detection signal of "-" is obtained, and a control signal CS with a logical value of "0" is output to the cylinder drive circuit 30b of the rapid opening/closing cylinder 30, and the piston rod 30a of the rapid opening/closing cylinder 30 is
, thereby raising the lower roll unit RL and restoring the straightening operation, and gradually reducing the motor drive current to stop the forced drive of the guard motor 41.

Next, an embodiment of the method for diagnosing the time to replace a work roll having the above configuration will be described based on the flowchart of FIG. 6 showing the processing procedure of the control device 50.

First, in step (3) in FIG. 6, the control device 50 reads the value of the signal C8, which is output to the cylinder drive circuit 30b, and the value of C8, is a logical value "0" that maintains the rapid opening/closing cylinder 30 in the raised position. °” is determined.

This step (2) is for determining whether the quick opening/closing cylinder 30 is held in the raised position and the lower roll unit) 5.7°9 is in the process of straightening the strip in contact with the traveling strip 3. It is.

In step (3), if C8 is the logical value "1pa" that holds the rapid opening/closing cylinder 30 at the convergence position, then C8,
The judgment in step (2) is repeated until the value becomes 0''.

If C8 is determined to be 1° in step (2), the control device 50 moves to step (2) and reads the detection signal S of the traveling speed sensor 53, The traveling speed (T, ) of is calculated. Next, the process moves to step (3), and the detection signal S! of the rotational speed sensor 54 is detected. is read and the circumferential speed (W, ) of the work roll is calculated based on the pulse count value.

Next, the process moves to step ①, where the strip traveling speed (T, )−
Calculate the work roll circumferential speed (W, ). Control device 50
outputs a signal for displaying the values of T and -W on the recorder 56.

Next, the process moves to step (2), and it is determined whether T, -W, is larger than a predetermined limit value set in advance through an operational test or the like.

That is, the bearing 42a due to bending of the work roll 42
Due to deterioration, the circumferential speed W of the work roll.

is a small value compared to the traveling speed T of the strip, so
By determining T and -W, the degree of deterioration of the work roll 42 can be predicted, and the time to replace the work roll can be determined.

In this embodiment, 150 m/min is selected as the above limit value based on the results of various operational tests. This limit value can be changed as appropriate depending on differences in operating conditions.

In the above step (■), T, -W, ≧150m/
If it is determined that it is min, the process moves to step (2). In this step (3), the control device 50 controls the alarm 57
Outputs an alarm signal S4 with a logical value of "1°" to the alarm 5.
7 generates an alarm sound to warn that the work roll 42 may be broken or the work roll may fly out.

In the above step (■), T, -w, <150m/
If it is determined to be min, the process moves to step (2). In step (2), the control device 50 reads the detection signal S from the bending measurement sensor 55, and calculates the bending value (W,) of the work roll converted to the center position of the work roll. In this embodiment, this bending of the work roll is taken as a variation value of the distance between the bend measurement sensor 55 and the work roll 42. This curve value is displayed and recorded in the recorder 56 as in step (2) above.

Next, the process moves to step (2), where this curve (Wl) is compared with a preset limit value. That is, in this embodiment, it is determined whether W,≧0.1 or W,<O,t. W,
If it is determined that ≧0.1, the process moves to step (2), and an alarm sound is generated as in step (2). W, <0.1
If it is determined that the work roll 42 has not deteriorated yet, and that there is no roll breakage or popping out, the process moves to step (2), and it is determined whether or not to end the control. If the control is not ended, step (2) is performed. If the control is to be returned to and terminated, the process is terminated.

As described above, according to the above embodiment, since the time when the work roll needs to be replaced can be determined in advance, breakage or popping out of the work roll can be reliably prevented.

In the above embodiment, in order to determine when to replace the work roll, it is determined whether the difference between the circumferential speed of the work roll and the traveling speed of the strip is larger than a predetermined setting value, and the bending value of the work roll is determined. Although it has been determined whether or not it is larger than a predetermined setting value, it is also possible to determine the time to replace the work roll by determining either of the two.

Next, we will discuss the second case when this invention is applied to a continuous annealing line.
An embodiment will be described with reference to FIG.

In this embodiment, the tension leveler is composed of three units, including elongated roll units (71 and 72) and a straightening roll unit 73 disposed on the subsequent stage, and each roll unit 71 to 73 includes a work roll 42 and an intermediate roll. 43 and a backup roll 33, and the elongation roll units 71 and 72 are equipped with
First, the diameter of the work roll 42 of the straightening roll unit 73 is selected to be 35 mm. Although not shown, the extension roll units 71 and 72 are provided with a quick opening/closing cylinder 30 and a guard motor 41, similar to the tensile leveler 4 in the first embodiment, and these are controlled by the control device 50 in the first embodiment. Just as in the example, the circumferential speed of the work roll 42 is synchronized with the running speed of the strip 3 by driving the geared motor 41 before the welding point or surface defect of the strip 3 reaches the elongated roll unit 71, 72. When the welding point or surface defect reaches the elongation roll unit 71, 72, the lower roll unit Rt is lowered, and the welding point or surface defect reaches the elongation roll unit! -71, 72, when the circumferential speed of the work roll 42 and the running speed of the strip plate 3 match, the lower roll unit RL is returned to the upward position, and then the geared motor 41
The drive current for the motor drive circuit 41a is gradually reduced to zero.

Further, although not shown in the drawings, the extension roll units 71 and 72 are provided with a rotation speed sensor 61 and a bend measurement sensor 55, similar to the tension leveler in the first embodiment, and the control device 50 reads the signals of these sensors. The speed difference between the strip plate 3 and the work roll 42 is calculated, the bending of the work roll 42 (median value conversion) is calculated, and the calculation results are printed out on the recorder 56, and the calculation results are set in advance. When the value exceeds a certain value, an alarm signal can be output to the alarm device 57 to prompt replacement of the work roll.

Also in this embodiment, as in the first embodiment, the work roll replacement timing can be determined in advance, so that the same effects as in the first embodiment can be obtained.

In each of the above embodiments, the case where the reflective tape 60 and the photoelectric converter 61 were applied as the work roll 420 rotation speed sensor 54 was explained, but the invention is not limited to this, and a rotation sensor such as an encoder etc. It goes without saying that any rotation sensor such as a pulse generator or the like can be applied.

Further, in each of the above embodiments, a case has been described in which the detection signals of the position sensors 51 and 52, the running speed sensor 53 and the rotational speed sensor 54, and the bending sensor 55 are input to the control device 50, but the present invention is not limited to this. When the running state of the plate 3 is monitored by a host computer, the running speed command value, work roll straightening drive command, lifting command for the lower roll unit RL, etc. are input from the host computer to the III control device 50. , the control device 50 may perform necessary processing in accordance with these.

Further, the control device 50 is not limited to a direct digital controller, and may be configured by combining other electronic circuits.

〔Effect of the invention〕

As explained above, according to the present invention, the work roll can be replaced in advance by detecting work roll bending and work roll rotation failure caused by work roll deterioration. As a result, it is possible to reliably prevent the work roll from breaking or popping out, which would otherwise occur if a deteriorated work roll is used as is.

In addition, in order to prevent accidents such as work rolls flying out or damage to work rolls, replacing work rolls early on the safety side will increase maintenance costs.On the other hand, if you postpone the work roll replacement period to reduce maintenance costs, However, according to the present invention, it is possible to decide in advance when to replace the work rolls, which has the effect of meeting both cost and safety requirements at a high level.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view taken in the direction of the arrow ■ in Fig. 1, and Fig. 3 is an enlarged cross-sectional view showing the backup roll forced drive mechanism of the work roll unit. , FIG. 4 is a block diagram showing an example of a control device, and FIG. 5 is a block diagram showing an example of a control device.
FIG. 6 is a block diagram showing an example of a bend measurement sensor, FIG. 6 is a flowchart showing an example of a processing procedure of a control device, and FIG. 7 is a configuration diagram showing an example of the case where the present invention is applied to a continuous annealing line. In the figure, 1 is the entry side priddle roll, 2 is the exit side priddle roll, 3 is the strip plate, 4 is the tension leveler, 5, 8.9
6, 7° 10 is a deflector roll, RL is a lower roll unit, Ru is an upper roll unit, 30 is a quick opening/closing cylinder, 30b is a cylinder drive circuit, 33 is a backup roll, 41 is a guard motor, 41a is a a motor drive circuit, 50 a control device, 51
52 is a position sensor, 53 is a running speed sensor, 54 is a rotational speed sensor, 55 is a bending measurement sensor, 71.72 is a stretching roll unit, and 73 is a straightening roll unit. Patent applicant: Kawasaki Steel Corporation Representative Patent attorney: Tetsuya Mori

Claims (1)

[Claims] (1) A work roll placed in a non-driven state in a roll unit is brought into pressing contact with a running strip from above and below, and repeated bending is performed while the work roll is rotated by being dragged by the running of the strip. When processing and correcting the shape of the strip, at least one of the bending of the work roll or the difference between the circumferential speed of the work roll and the running speed of the strip is detected, and this detected value is A method for diagnosing replacement time for a tension leveler work roll, characterized in that the time point when a predetermined value is exceeded is determined as the time to replace the work roll.