KR101707807B1 - Brush roll controlling method - Google Patents

Abstract

The present invention relates to a brush roll control method, comprising: a load current measuring step (S1) of measuring a load current of a motor which drives a brush roll during rotation of the brush roll; a first determining step (S2) of determining whether the measured load current of the motor falls within a predetermined current fluctuation width for a predetermined time; and a second determination step (S3) of determining whether the measured load current of the motor falls within a predetermined target load current range when transitioning from the first determination step to a subsequent step.

Description

Brush roll controlling method [0002]

The present invention relates to a brush roll control method and, more particularly, to a brush roll control method and a brush roll control method which can appropriately control the operating conditions of the variable means for varying the position of the brush roll, The present invention relates to a brush roll control method and a brush roll control method that can extend the service life of a variable means and enable a stable brushing operation with a brush roll.

There are many cases where a surface treatment, particularly a surface cleaning, is required in the course of manufacturing an article. For example, the steelmaking process requires surface cleaning to remove residues such as rolling oil that remain on the surface of the strip during the rolling process. The following is an example of this based on steel production.

During the steel production process, the cold-rolled strip passes through a heat treatment process such as annealing or plating. At this time, rolling oil supplied during cold rolling, scale powder generated during cold rolling, iron powder and the like remain on the surface of the strip, and they must be cleaned before heat treatment, and a cleaning process for removing them is required.

In the cleaning process, there is a process of mechanically cleaning the surface of the strip using a brush roll.

Typically, the brush roll contacts the surface of the strip and rotates at a different direction and / or speed than the advancing direction of the strip to perform the cleaning operation. At this time, in order to control the amount of contact of the brush roll on the surface of the strip, that is, the amount of pressure applied to the surface of the strip by the brush roll, a current control method is conventionally used.

In the current control method, the load current of the motor for driving the brush roll rotating in contact with the strip is measured to monitor the degree of load on the motor, while varying the brush roll so that the predetermined load current So as to be within the target load current range. That is, when the measured load current is excessively increased beyond a predetermined target load current range, the brush roll is spaced from the surface of the strip to reduce the load of the motor that drives the brush roll (hereinafter referred to as 'open' , And conversely if the measured load current is excessively reduced beyond a predetermined target load current range, the brush roll is brought into contact with the surface of the strip to increase the load of the motor that drives the brush roll (hereinafter referred to as & 'shout). By controlling the load of the motor that drives the brush roll by repeating the opening / closing as described above and controlling the amount of depression on the surface of the strip, the variable for varying the brush roll for the open / close operation of the brush roll Means is used.

Such a conventional current control method should repeatedly control the variable means so as to follow a predetermined predetermined target load current range, i.e., to cause the value of the measured load current to be measured to be kept within a predetermined predetermined target load current range This process is called hunting. The term 'hunting', also referred to as controlled oscillation, refers to the phenomenon that the controlled variable is constantly oscillating above and below the setpoint, and as an automatic control or servo mechanism, It happens when you can not. This hunting can cause the variable means to be subjected to excessive stress, resulting in problems of malfunctions and / or side effects due to early breakage or wear of the variable means, and repeated and continuous hunting of the variable means can be prevented by the variable means And unnecessary consumption of energy for operation can be caused.

However, when this control vibration (hunting) is not performed, it is impossible to control an appropriate amount of reduction of the brush roll on the surface of the strip, and when the state of too large a reduction amount continues, The life of the motor may be shortened or failure may occur. On the contrary, if the state of too small a reduction amount is maintained, the cleaning of the surface of the strip by the brush roll may be inadequately performed.

Korean Unexamined Patent Publication No. 1999-0052667 (July 15, 1999) Korean Patent Publication No. 10-2014-0082121 (July 2, 2014)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is an object of the present invention to appropriately control the operating conditions of the variable means for varying the position of the brush roll, The present invention also provides a method of controlling a brush roll, which is capable of avoiding harsh operating conditions due to frequent operation of the variable means, thereby extending the service life of the variable means and simultaneously enabling a stable brushing operation. .

According to an aspect of the present invention, there is provided a method of driving a brush roll, comprising: a load current measuring step (S1) of measuring a load current of a motor that drives a brush roll during rotation of the brush roll; A first determining step (S2) of determining whether the measured load current of the motor belongs to a predetermined current fluctuation width for a predetermined time; And a secondary determination step (S3) of determining whether the measured load current of the motor falls within a predetermined target load current range when the transition from the primary determination step to the subsequent step is carried out.

If the load current of the motor measured in the primary determining step S2 does not fall within the predetermined current fluctuation width for a predetermined time, the flow returns to the load current measuring step S1, It may be shifted to the next step.

When the load current of the motor measured in the secondary determination step (S3) is within the target load current range, the process proceeds to a fixing step (S4) of fixing the position of the brush roll to the load state at the time of the load current measurement, If the load current of the motor exceeds the target load current range, the process proceeds to an open step (S5) for opening the brush roll. If the measured load current of the motor is less than the target load current range, The process may be shifted to the closing step S6.

The open step S5 or the closing step S6 may be performed by varying the brush roll.

The opening step (S5) or the closing step (S6) may be performed by operation of a variable means for variably fixing the brush roll.

The brush roll is brought into contact with the surface of the strip conveyed at a predetermined speed before the load current measuring step (S1), and the brush roll is moved in the same direction as the advancing direction of the strip or in the other direction at the same speed as the advancing speed of the strip, And a pre-driving step of presetting the roll to rotate and rotating the brush roll in the preset state.

After the fixing step S4, the open step S5 or the closing step S6, the load current measurement step S1 may be performed.

According to the brush roll control method of the present invention, the operation condition of the variable means for varying the position of the brush roll and pressing the brush roll to an appropriate pressure is appropriately controlled to optimally adjust the amount of reduction applied to the brush roll, It is possible to avoid a severe operating condition due to frequent operation, thereby prolonging the service life of the variable means, and at the same time, it is possible to provide an effect of enabling a stable brushing operation by the brush roll.

FIG. 1 is a side view schematically showing a strip cleaning apparatus as one embodiment in which the brush roll control method according to the present invention can be applied.
2 is a flow chart for implementing one embodiment of the brush roll control method according to the present invention.
3 is a control conceptual diagram showing the brush roll control method of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a strip cleaning apparatus including a brush roll as an apparatus to which the brush roll control method according to one aspect of the present invention can be preferably applied.

The strip cleaner comprises a brush roll 11 contacting the surface of the strip S for variable cleaning and in contact with the strip S in a variable manner and a brush roll 11 for contacting the brush S on the surface of the strip S, A backup roll 12 for supporting the pressure against the strip S of the brush roll 11 and a backup roll 12 for supporting the pressure of the brush roll 11, which is rotatably fixed by the bearing block 16, (14) for rotating the brush roll (11) and a second motor (14) for rotating the brush roll (11) Wherein the brush roll (11), the first motor (14), the backup roll (12), and the second motor (15) May be connected by a coaxial 18, preferably a universal axis. As the variable means 17, for example, a screw jack can be used, but it should be understood that the present invention is not intended to be limited thereto.

The brush roll control method according to one aspect of the present invention is applied to an apparatus including a brush roll 11 which is fixed so as to be variable like a strip cleaning apparatus having the above-described structure, so that the brush roll is moved relative to the strip S The surface of the strip is cleaned in a constantly pressurized state. In particular, the brush roll 11 is constantly controlled by measuring the load current caused by the load applied to the brush roll 11, It is possible to prevent the malfunction or malfunction of the variable means and to improve the life of the variable means while preventing an excessive load from being applied to the motor for rotating the brush roll to prevent the device from failing and to improve the durability, It is characterized by the fact that it is heightened.

That is, one embodiment of a brush roll control method according to one aspect of the present invention is shown in the flowchart in Fig. 2, which includes a load current measuring step S1); A first determining step (S2) of determining whether the measured load current of the motor belongs to a predetermined current fluctuation width for a predetermined time; And a secondary determination step (S3) of determining whether the measured load current of the motor falls within a predetermined target load current range when transitioning from the first determination step to the subsequent step.

If the load current of the motor measured in the primary determining step S2 does not fall within the predetermined current fluctuation width for a predetermined time, the flow returns to the load current measuring step S1, It may be shifted to the next step.

When the load current of the motor measured in the secondary determination step (S3) is within the target load current range, the process proceeds to a fixing step (S4) of fixing the position of the brush roll to the load state at the time of the load current measurement, If the load current of the motor exceeds the target load current range, the process proceeds to an open step (S5) for opening the brush roll. If the measured load current of the motor is less than the target load current range, The process may be shifted to the closing step S6.

The load current measurement step S1 may be performed by measuring the load current of the motor that drives the brush roll during the rotation of the brush roll. Load current refers to the current flowing when a load is applied to the motor in the case of a motor (motor), and when the load becomes large, the current also becomes large. In the case of the present invention, a brush roll is connected to the motor, and when the brush roll is driven by the strip, And is rotated in a state of being in contact with the rotating shaft. This load current is directly proportional to the load applied to the motor, and if a high load current is sustained, it means that the motor is overloaded, which means that it may lead to failure or life span of the motor. On the contrary, when the low load current is continued, it means that almost no load is applied to the motor. This means that no load is applied to the brush roll driven by the motor, and therefore, It means that the operation of the target bar is not normally performed. It can be understood that the measurement of the load current can be performed by using a conventional ammeter.

The primary determining step S2 may include determining whether the load current of the motor measured in the load current measuring step S1 falls within a predetermined current fluctuation width for a predetermined time, to be. If the load current of the motor measured in this step does not fall within a predetermined current fluctuation width for a predetermined time, it may be returned to the load current measuring step (S1). That is, when the load current of the motor fluctuates significantly during a short period of time, it is not a normally sustainable operation state such as a contact state of the brush roll and the strip or a supply of the current supplied to the motor for driving the brush roll is not stable In this state, the load current can be measured again without driving the variable means for varying the brush roll. Therefore, it is possible to prevent the frequent operation of the variable means and prevent the so-called " hunting " phenomenon, thereby making it possible to extend the service life of the variable means and / or prevent malfunction or malfunction. Alternatively, if the measured load current of the motor falls within a predetermined current fluctuation range for a predetermined time, it may be shifted to a subsequent stage, where the subsequent stage may be a secondary determination step S3 described later.

The 'predetermined time' and the 'predetermined current fluctuation width' as criteria for the determination may vary according to the specifications of the apparatus to which the brush roll control method according to the present invention is applied, the operating conditions, etc. In particular, As a criterion of judgment that can be arbitrarily determined to carry out the operating conditions of the device of FIG.

The 'predetermined time' may be, for example, 0.5 to 5 seconds, preferably 0.5 to 4 seconds, more preferably 1 to 3 seconds, and most preferably 1.5 to 2.5 seconds. This predetermined time may be determined in accordance with the durability or life expectancy of the variable means and the motor connected to the above-described brush roll, etc. When the predetermined time is set too short, for example, There may be a problem that it is difficult to achieve the object of the present invention intended to reduce the unnecessary frequent operation of the variable means. On the other hand, when the predetermined time is set too long, for example, The motor for driving the brush roll must be continuously operated in a high load state, which may result in a problem that the service life of the motor is lowered.

Here, the 'predetermined current fluctuation width' means an allowable fluctuation range of the load current measured during the predetermined time, and when the current fluctuates during or over the predetermined time within the fluctuation range, It can be judged that the current is stabilized. The predetermined current swing width may be, for example, 15.1 to 25A, preferably 16 to 24A, more preferably 17 to 23A, and most preferably 18 to 22A. The predetermined current fluctuation width can be determined in accordance with the durability or life expectancy of the variable means and the motor connected to the aforementioned brush roll, and when the predetermined current fluctuation width is set too small, for example, less than 15.1 A The range of the predetermined current fluctuation width becomes too large, and the distinction from the no-load state (idling) becomes unclear, which may cause a problem that the function of the brush roll, in particular, the cleaning function of the surface of the strip is insufficient, On the contrary, when the current exceeds 25 A, the range of the predetermined current fluctuation width becomes too large, and the overload state continues, which may cause problems such as malfunction, failure and shortened life of the motor for driving the brush roll. The no-load state means that only the motor is driven in a state in which the brush roll is not connected to the motor for driving the brush roll (no-load state), and the current value of the motor in the no-load state is measured by the motor manufacturer Or a value measured when the motor is driven in the no-load state after it is installed in the field by the user and may vary depending on the type of the motor, the installation position of the motor, the electric power supplied to the motor, For example, in the case of a motor for driving a brush roll, which is exemplarily described in the present invention, it can be regarded as no-load if it is 15A or less, for example, 13 to 15A.

The secondary determination step S3 is a step of determining whether the transition from the first determination step S2 to the subsequent step is determined, that is, when the load current of the motor measured in the load current measurement step in the primary determination step is a predetermined time (S4) in which the position of the brush roll is fixed to be the load state at the time of the load current measurement, for example, for 0.5 to 5 seconds when it falls within a predetermined current fluctuation range, for example, 15.1 to 25A do. If the measured load current of the motor exceeds the target load current range, the process proceeds to the open step (S5) for opening the brush roll. If the measured load current of the motor is less than the target load current range, It may be shifted to the closing step S6 for closing the brush roll. The term "target load current" as used herein refers to a state in which the motor for driving the brush roll is in a loaded state, that is, the brush roll is connected, and the brush roll contacts the surface of the strip, It is understood that the driving current of the motor at the target load current is such that the motor is not overloaded and the motor can be operated continuously and stably and statically. Such a target load current may be a recommended value for the operating condition of the motor under the load condition provided by the motor manufacturer, or it may be a preset value for the normal operating condition of the motor after it is installed in the field by the user.

The target load current may be a current value outside the range of the predetermined current fluctuation width, but may be a current value within the predetermined range of the current fluctuation width. That is, when the current value of the target load current is 20A, the upper limit of the predetermined current fluctuation width can be set to 25A and the lower limit of the predetermined current fluctuation width can be set to 15.1A. The load current value is set to the predetermined current fluctuation range, for example, 0.5 to 5 seconds, preferably 0.5 to 4 seconds, more preferably 1 to 3 seconds, and most preferably 1.5 to 2.5 seconds, For example, within a range of 15.1 to 25 A, preferably 16 to 24 A, more preferably 17 to 23 A, and most preferably 18 to 22 A, the position of the brush roll is fixed or variable, When the load current value is within the target load current range, the process proceeds to a fixing step (S4) of fixing the load current at the time of measurement of the load current.

Otherwise, when the measured load current of the motor exceeds the target load current range, it is possible to proceed to the open step (S5) for opening the brush roll. The open step is a step of reducing the load of the motor driving the brush roll by separating the brush roll from the surface of the strip when the load current of the measured motor is excessively increased beyond a predetermined target load current range, "He says. In order to open the brush roll, a screw jack open step S5 'is performed in which the screw jack is operated to open the screw jack.

Otherwise, when the measured load current of the motor is less than the target load current range, it may be shifted to the closing step S6 for closing the brush roll. The closing step is a step of increasing the load of the motor that drives the brush roll by bringing the brush roll into contact with the surface of the strip when the load current of the measured motor is excessively reduced beyond a predetermined target load current range, "He says. In order to close the brush roll, a screw jack closing step (S6 ') is performed in which the screw jack is operated to close the screw jack.

By repeating the opening / closing as described above, the load of the motor for driving the brush roll is controlled to control the amount of reduction on the surface of the strip. The open / close operation of the brush roll is performed by varying the brush roll And the opening step or the closing step may be performed by operation of a variable means for variably fixing the brush roll.

At this time, in the opening step, the brush roll is spaced from the surface of the strip, and in the closing step, the brush roll is brought into contact with the surface of the strip, and the degree of variation of the brush roll by the variable means is preferably, The amount of displacement of the brush roll may be within the range of 1 to 3 times, preferably 1.5 to 2 times the amount of displacement of the brush roll in the closing step. It is advantageous to increase the amount of displacement so as to depart from the overload state as quickly as possible, and the closing step is to return from the no-load state to the load state again, As shown in Fig. The specifications of the motor and / or brush roll, in particular the radius, the position at which they are installed, the dimensions (in particular thickness) of the strip to be worked and the feed rate, may vary depending on the operating conditions, For example, the amount of displacement of the brush roll in the opening step is within a range of 1 to 2 mm, for example, 1.2 mm, and the amount of displacement of the brush roll in the closing step is within a range of 0.1 to 1.0 mm, .

According to another aspect of the present invention, a brush roll is brought into contact with a surface of a strip conveyed at a predetermined speed before the load current measurement step, and the brush roll is moved in the same direction as the advancing direction of the strip, And a pre-driving step of presetting the brush roll to rotate at a speed or another speed, and rotating the brush roll in the preset state. The pre-drive step is particularly suitable for the initial operation of a device in which the brush roll control method according to the invention is implemented, for example a surface cleaning device for removing residues such as rolling oil remaining on the surface of the strip during the rolling process in a steelmaking process, The brush roll control method according to the present invention can be implemented even when there is no actual measured value of the load current of the brush roll applied during restart after the operation of the surface cleaning apparatus is stopped. The position of the roll can be controlled to be pre-positioned at a predetermined position. It is to be understood that such presets may be suitably implemented by the user and / or driver operating the surface cleaning apparatus as described above.

Further, in the secondary determination step, it is possible to proceed to the load current measurement step after performing the fixing step, the open step or the closing step, and the brush roll control method according to the present invention can be continuously performed And / or may be implemented as needed at any time during normal operation of the device.

In the case of the conventional current control method, the load current of the motor is measured and it is judged whether or not it belongs to the target range. If it is normal, the brush roll is fixed in this state to continue the operation, The opening and / or closing of the brush roll is controlled by a variable means such as a screw jack so that the motor driving the brush roll is operated in a proper load state, and this process is performed by feedback of the measured load current Lt; / RTI > As shown in Fig. 2, there is a step of fixing the screw for fixing, opening or closing the brush roll, measuring the load of the motor for rotating the brush roll again after the screw is opened or after the screw is closed S7) is performed so as to repeatedly measure the motor load, thereby continuously and appropriately controlling the opening and / or closing operation of the brush roll, thereby maintaining a stable operation state in which the motor for rotating the brush roll is not overloaded .

However, in the case of such a conventional current control method, as described in the background of the present invention, a predetermined predetermined target load current range is followed, i.e., the value of the measured load current is within a predetermined target load current range When the load current is set to 18 A and the target load current range is set to 1 A, the variable means must be repetitively controlled repeatedly in order to keep the load current within the range of 17 to 19 A. The hunting phenomenon is inevitable. The hunting can cause the variable means to be subjected to excessive stress and cause malfunctions and / or side effects due to premature breakage or wear of the variable means, and repeated and continuous hunting of the variable means can cause unnecessary Energy consumption and the like can be caused.

FIG. 3 shows a control concept of the brush roll control method of the present invention.

As shown in FIG. 3, according to the present invention, the number of times of operation of the variable means can be remarkably reduced as compared with the current control method which is a conventional control method. As a result of application to a strip surface cleaning apparatus in an actual field, For example, the additional current hunting phenomenon is reduced by the constant open / closed driving of the screw jack, the cleaning effect of the surface of the strip is increased by the stable operation of the brush roll, and the number of breakage of the variable means is remarkably reduced, In the case of the control method, the number of breaks on the average of 4 times per quarter (3 months) was remarkably reduced by about 1 time per quarter according to the present invention, and the operation rate of the brush roll was also decreased from 80% %, And the whiteness of the washed strip surface (the degree of whiteness The higher value indicates the washing effect is high) could also determine the improvement in average 90% of the present invention from the prior average of 80%.

11: Brush roll 12: Backup roll
13: Throttling cylinder 14: First motor
15: second motor 16: bearing block
17: variable means 18:
S: Strip

Claims (7)

A load current measuring step of measuring a load current of a motor which drives the brush roll during rotation of the brush roll;
A first determining step of determining whether the measured load current of the motor belongs to a predetermined current fluctuation width for a predetermined time;
A regeneration step of returning to a load current measurement step without driving a variable means for varying the position of the brush roll when the load current of the motor measured in the primary determination step does not fall within a predetermined current fluctuation width for a predetermined time; And
If the load current of the motor measured in the primary determination step falls within a predetermined current fluctuation width for a predetermined time, it is determined whether the measured load current of the motor falls within a predetermined target load current range A second determination step,
When the load current of the motor measured in the secondary determination step is within the target load current range, the controller moves to a fixing step of fixing the position of the brush roll to the load state at the time of the load current measurement, When the target load current range is exceeded, the procedure moves to an open step of opening the brush roll, and when the measured load current of the motor is less than the target load current range, the brush roll is closed. Brush roll control method. delete delete The method according to claim 1,
Wherein the opening step or the closing step is performed by varying the position of the brush roll. The method according to claim 1 or 4,
Wherein the opening step or the closing step is performed by operation of a variable means for variably fixing the position of the brush roll. The method according to claim 1,
Contacting the brush roll to the surface of the strip conveyed at a predetermined speed before the load current measurement step and rotating the brush roll at the same speed as the advancing speed of the strip in the same direction as the advancing direction of the strip or in the other direction, A pre-driving step of pre-setting the brush roll in the preset state and rotating the brush roll;
Wherein the brush roll control method comprises: The method according to claim 1,
And after the completion of the fixing step, the opening step, or the closing step, the load current measurement step is performed.

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