JPH073419A - Plating deposition controller for hot dip metal coating line of metallic wire - Google Patents

Abstract

PURPOSE:To minimize the fluctuation in plating deposition in operation to be carried out over a long period of time by executing feed back control of the plating deposition during a plating stage. CONSTITUTION:The wire diameter D1 of the unplated wire delivered from a delivery section and the wire diameter D2 of the plated wire taken up on a take-up section are measured. The plating deposition N is calculated from the wire diameter data obtd. in such a manner. Whether the plating deposition N is within a permissible range of the preset objective deposition or not is decided. The traveling speed of the wire is controlled to vary in a direction where the plating deposition N is kept within the permissible range when the plating deposition is decided to be deviated from this range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating amount control device for a metal wire hot dip coating line.

[0002]

2. Description of the Related Art A general metal wire hot-dip galvanizing line is
After the metal wire sent out from the sending part at a constant speed, after undergoing pretreatment steps such as pickling, washing with water, and flux treatment,
Plating is performed by immersing in a molten plating solution in a plating bath.
Then, the plated metal wire is cooled by a cooling device and then wound by a winding unit. These steps are performed as continuous operations.

Conventionally, the control of the coating amount of a metal wire produced by such a hot dip coating line is performed by cutting a test piece of an appropriate length from the metal wire after being wound by a winding section at a plurality of points. Then, the amount of plating adhered on these test pieces is measured. The traveling speed of the metal wire in the hot dip galvanizing line is controlled based on the measurement result.

[0004]

However, in such a conventional method, since the coating amount of the test piece is merely measured, the coating amount over the entire length of the metal wire is not controlled and the total length of the metal wire is not controlled. I could not get a reliable quality guarantee.

Further, when the measured value of the test piece is clarified, the plating process of the metal wire from which the test piece has been sampled has already been completed. It was impossible to control the coating weight based on the measurement results. For this reason, the running speed of the metal wire has to be controlled to a constant speed at which it is estimated that the optimum amount of deposited metal is always obtained when one work is started.

However, the amount of coating adhered largely depends on the state when the metal wire is pulled up from the molten plating liquid surface of the plating bath, and remains the same for a long time even if the running speed of the metal wire is controlled to be constant. It was difficult to maintain the conditions, and it was not possible to prevent large changes in the coating weight due to long-term work.

The present invention has been made under such circumstances, and an object of the present invention is to make it possible to feedback-control the amount of plating adhered during the plating process.
As a result, it is possible to minimize fluctuations in the coating weight of the work over a long period of time, and reliable quality assurance can be obtained over the entire length of the metal wire. It is intended to provide a control device.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a traveling speed control means for constantly controlling the traveling speed of a metal wire in a hot dip galvanizing line to a reference speed, and a wire diameter of a metal wire sent from a sending part before plating. The untreated portion wire diameter measuring means for measuring, the treated portion wire diameter measuring means for measuring the wire diameter of the metal wire after the plating treatment before being wound in the winding portion, and these both measuring means. A plating adhesion amount calculation means for calculating the plating adhesion amount of the metal wire from the wire diameter data of the metal wire before the plating treatment and the wire diameter data after the plating treatment, and the plating adhesion amount calculated by this calculation means are set in advance. The deposit amount determining means for determining whether or not the target deposit amount is within the allowable range, and when this determining means determines that the deposit amount is out of the allowable range, the plating deposit amount is in the allowable range. Traveling speed system The reference speed in section is obtained by a speed varying means for variably setting.

[0009]

According to the present invention having such a structure, the traveling speed of the metal wire in the hot dip galvanizing line is controlled by the traveling speed control means to be the reference speed. In this state, the wire diameter of the metal wire that has been sent out from the sending portion and has not been subjected to the plating treatment is measured by the untreated portion wire diameter measuring means. Further, the wire diameter of the metal wire after the plating treatment before being wound up by the winding portion is measured by the processing portion wire diameter measuring means. Then, the plating adhesion amount of the metal wire is calculated from the wire diameter data of the metal wire before the plating treatment and the wire diameter data after the plating treatment, and the plating adhesion amount is within an allowable range with respect to the preset target adhesion amount. It is determined whether it is inside. As a result of this determination, when it is determined that the amount of coating adherence deviates from the allowable range, the reference speed is variably set in the direction in which the plating adhesion amount is within the allowable range. As a result, the running speed of the metal wire in the hot dip coating line changes, and fluctuations in the coating weight are suppressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the coating weight control device of the present invention is applied to a hot dip galvanizing line will be described below with reference to the drawings. FIG. 1 shows the overall configuration of this embodiment. The hot dip galvanizing line is a feeding section 2 for feeding a wire (metal wire) 1a before plating treatment, and a winding section 3 for winding the wire 1b after plating treatment. Between the pickling bath, the pickling bath 5, the washing bath 5, the flux bath 6, the plating bath 7,
The cooling device 8 is arranged and configured.

Then, the untreated wire 1a pulled out from the feeding portion 2 by driving the winding portion 3 is subjected to pickling, water washing and flux treatment as a pretreatment step,
It is immersed in the hot dip galvanizing solution 9 in the plating bath 7. After that, the treated wire 1b pulled up from the liquid surface of the plating bath 7 is cooled by the cooling device 8 and then wound up by the winding section 3 to form a traveling path of the wire by a large number of guide rollers and the like.

The take-up unit 3 has a drive motor 31 whose rotation speed is controlled by a plating amount control unit 10 which will be described later, a drive roller 32 which is rotated by the drive motor 31, and the drive roller 32 which is opposite in the drawing. A winding mechanism 33 for winding the processed wire 1b fed into the winding portion 3 by rotating in the clockwise direction is provided.

Non-contact type wire diameter measuring instruments 11 and 12 are arranged between the feeding portion 2 and the pickling tank 4 and between the cooling device 8 and the winding portion 3 in the wire traveling path, respectively. There is. The measurement signals of the wire diameter measuring instruments 11 and 12 are input to the plating amount control unit 10, respectively.

Here, one wire diameter measuring device 11 constitutes an untreated part wire diameter measuring means for measuring the wire diameter of the wire 1a before the plating process sent from the sending part 2, and the other wire diameter measuring device. Reference numeral 12 constitutes a processing portion wire diameter measuring means for measuring the wire diameter of the wire 1b after the plating treatment before being wound up by the winding portion 3.

In addition, in the vicinity of the winding portion introducing port in the wire traveling path, the wire 1a,
A traveling speed detector 13 for detecting the traveling speed of 1b is attached. The detection signal of the speed detector 13 is also input to the plating adhesion amount control unit 10.

FIG. 2 is a block diagram showing the structure of the essential parts of the plating adhesion amount control unit 10. This control unit 10
Has a motor control unit 14 that constitutes a traveling speed control unit that constantly controls the traveling speed of the wires 1a and 1b in the hot dip coating line to a reference speed.

The motor control section 14 includes a signal input circuit 1
The motor drive circuit 16 so that the detection output of the traveling speed detector 13 taken in via 5 always coincides with the reference speed.
The rotational speed of the drive motor 31 is sequence-controlled via the.

Further, the control unit 10 includes the wire diameter data of the wire 1a before the plating processing and the wire 1b after the plating processing which are measured by the untreated wire diameter measuring instrument 11 and the treated wire diameter measuring instrument 12. Plating adhesion amount calculation means for calculating the plating adhesion amount from the wire diameter data, and the adhesion amount for determining whether the plating adhesion amount calculated by this calculation means is within the allowable range with respect to the preset target adhesion amount The determining means and the speed varying means for variably setting the reference speed in the motor control unit 14 in a direction in which the amount of deposited plating falls within the allowable range when it is determined that the allowable range is deviated by the determining means It has an arithmetic processing unit 17.

The motor control unit 14 and the arithmetic processing unit 17 are connected so that data can be exchanged. The arithmetic processing unit 1
As shown in FIG. 3, 7 is a wire traveling speed V, a plating target adhesion amount M, an adhesion amount allowable range ± A, and a plating untreated portion wire diameter D.
1, a storage unit 18 for storing each data such as the plating processing portion wire diameter D2 and the plating adhesion amount N.

Further, the arithmetic processing section 17 inputs the signal from the unprocessed portion wire diameter measuring instrument 11 through the signal input circuit 19 and inputs the signal from the processing portion wire diameter measuring instrument 12 into the signal input circuit 20. Enter through.

Further, the arithmetic processing unit 17 includes a wire traveling speed V, a plating target adhesion amount M, and an allowable adhesion amount range ± A.
A keyboard 21 for inputting setting data such as data is connected via a keyboard circuit 22, and a display 23 for displaying key input data and the like is provided in the display control circuit 2.
4 are connected.

Therefore, when the line is activated, the arithmetic processing unit 17
Supplies the wire traveling speed data V (m / min) preset in the storage unit 18 to the motor control unit 14 as a reference speed. Then, the motor control unit 14 commands the start of operation of the drive motor 31, rotates the drive roller 32, and starts winding the wire pulled out from the feeding unit 2. Then, the motor control unit 14 constantly monitors the detection output of the traveling speed detector 13, and controls the drive motor 31 to accelerate until it matches the wire traveling speed data V (m / min).

Thus, the wire travels at a traveling speed V (m / min).
When the vehicle travel control is performed, the arithmetic processing unit 17 is configured to execute the processing shown in the flowchart of FIG. 4 at a constant cycle.

That is, first, as ST (step) 1, a signal from the untreated portion wire diameter measuring device 11 is input through the signal input circuit 19 to obtain untreated portion wire diameter data D1 (m) and the storage portion 18 is obtained. To store. Here, as shown in FIG. 5A, the signal from the untreated portion wire diameter measuring device 11 is the diameter dx0 in the X direction of the wire 1a before the plating treatment and the Y of the wire 1a.
The unprocessed part wire diameter data D1 are two kinds of signals respectively corresponding to the direction diameter dy0 and are obtained by the following equation (1).

D1 = (dx0 + dy0) / 2 (1) Next, as ST2, the signal from the processing portion wire diameter measuring device 12 is input via the signal input circuit 20, and the processing portion wire diameter data D
2 is obtained and stored in the storage unit 18. Here, as shown in FIG. 5B, the signal from the processing portion wire diameter measuring device 12 is the same as the diameter dx1 of the wire 1b after plating and the wire 1b in the X direction.
There are two kinds of signals corresponding to the Y direction diameter dy1 of b, and the processing portion wire diameter data D2 is obtained by the following equation (2).

D2 = (dx1 + dy1) / 2 (2) Next, at ST3, the uncoated portion wire diameter data D1 and the treated portion wire diameter data D2 are used to determine the plating adhesion amount N per unit area 1 (m ² ). (G / m ² ) is calculated by the following equation (3) (plating adhesion amount calculating means).

N = [(D2 / 2)-(D1 / 2)] × K (3) (K is zinc Zn density: 7.13 (g / m ³ )) That is, Perimeter [2π (D1 /
2)] and the outer circumference of the wire after plating [2π (D2 /
2)] and the average value [(2π (D2 / 2) + 2π (D1 /
2)) / 2] is multiplied by a predetermined wire length L to be a unit area 1 (m ² ), and the zinc plating is uniformly applied to the thickness [(D2 / 2)-(D1 / 2) )], The amount N (g / m ² ) of the plating deposit is determined.

Thereafter, the arithmetic processing unit 17 determines ST4 and S
The difference B between the plating target adhesion amount M preset in the storage unit 18 as T5 and the plating adhesion amount N calculated in ST3 is calculated, and this difference B is the preset allowable deposit amount in the storage unit 18. It is determined whether it is within the range ± A (adhesion amount determination means).

When the difference B is a negative value larger than the lower limit value -A of the allowable range, the process proceeds to YES in ST4, and the wire traveling speed data V (m / min) is decreased by 1 (m / min). At the same time, a motor deceleration command is given to the motor control unit 14. As a result, the motor control unit 14 decelerates the drive motor 31 to match the wire traveling speed with the wire traveling speed data V (m / min).

On the other hand, when the difference B is a positive value larger than the upper limit value A of the allowable range, the process proceeds to YES in ST5, and the wire traveling speed data V (m / min) is increased by 1 (m / min). At the same time, a motor acceleration command is given to the motor control unit 14. As a result, the motor control unit 14 accelerates the drive motor 31 to match the wire traveling speed with the wire traveling speed data V (m / min) (speed varying means).

On the other hand, the difference B is within the allowable range (-A≤B≤
In the case of A), the current state is maintained. In the present embodiment configured as described above, the traveling speed of the wire in the hot dip galvanizing line is controlled to be the wire traveling speed data V (m / min) set in the storage unit 18. In this state, the wire diameter data D1 of the wire 1a before the plating process, which is sent from the sending part 2, is measured by the unprocessed part wire diameter measuring device 11. Also, the winding unit 3
The wire diameter data D2 of the wire 1b after the plating treatment before being wound up at is measured by the processing portion wire diameter measuring device 12.

Then, the plating adhesion amount N of the wire is calculated from the wire diameter data D1 and D2, and the plating adhesion amount N is within the allowable range ± A with respect to the target adhesion amount M preset in the storage unit 19. It is determined whether or not.

As a result of this judgment, when the plating adhesion amount N is smaller than the target adhesion amount M and is less than the allowable range, the wire traveling speed data V (m / min) is 1 (m / min).
And an acceleration command for the drive motor 31 is generated. As a result, the traveling speed of the wire in the hot dip coating line is accelerated by 1 (m / min). Then, since the wire pulling speed from the plating bath 7 is accelerated, the plating adhesion amount N increases.

On the other hand, when the plating adhesion amount N is larger than the target adhesion amount M and exceeds the allowable range, the wire traveling speed data V (m / min) is decreased by 1 (m / min). A deceleration command for the drive motor 31 is generated. As a result, the running speed of the wire in the hot dip coating line is 1
It is decelerated by (m / min). Then, since the wire pulling speed from the plating bath 7 is reduced, the plating adhesion amount N
Is reduced.

On the other hand, if the plating adhesion amount N is within the allowable range with respect to the target adhesion amount M, the current state is maintained. Thereafter, such wire traveling speed control is periodically performed at regular intervals. By doing so, feedback control is performed in the direction in which the plating adhesion amount N matches the target adhesion amount M during the plating process, so that fluctuations in the plating adhesion amount can be minimized even during long-term work. As a result, a reliable quality guarantee can be obtained over the entire length of the wire.

Now, according to this embodiment, the unplated wire 1a having a diameter of 3 mm is plated with a reference speed V of 40 (m / min) and a plating target adhesion amount M of 325 g / m ² . At this time, if the plating adhesion amount N exceeds the target adhesion amount M by more than +8 g / m ² , the reference speed V is 1 (m / min).
Deceleration control is performed only, and conversely, when the velocity is less than -8 g / m ² , the reference speed V is accelerated by 1 (m / min).
FIG. 6 shows the change over time in the amount of deposited plating in this case.

On the other hand, FIG. 7 shows the change over time in the amount of plating adhered when the unplated wire 1a having a diameter of 3 mm was plated at a constant speed V = 40 (m / min) as in the conventional case. Figure 6
As is clear from a comparison between FIG. 7 and FIG. 7, in the case of the present embodiment in which the feedback control of the wire traveling speed is performed, the variation of the plating adhesion amount is the target adhesion amount M =
It is suppressed within the range of 325 g / m ² to at most ± 25 g / m ² , but in the case of constant control, the plating adhesion tends to gradually decrease, and after a long time the target adhesion M = 325
g / m ² becomes a -25g / m ² or less than the decrease in quality is concerned.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, every time the plating adhesion amount N is calculated from the wire diameter data D1 of the wire before the plating treatment and the wire diameter data D2 of the wire after the plating treatment, a comparison with the target adhesion amount M is made. Although the wire running speed was controlled by performing the above, since there is some variation in the amount of coating adhered in hot dip plating, the calculated data of the amount of adhered plating N is statistically processed by a predetermined number, and the statistical processing result and the adhesion are obtained. The wire traveling speed may be controlled based on the comparison with the target amount M.

Further, in the above-mentioned embodiment, the reference speed is changed by 1 (m / min) when the allowable range is deviated regardless of the difference B between the plating deposition amount N and the target deposition amount M.
The amount of change in the reference speed may be varied depending on the magnitude of the difference B. In addition to this, it goes without saying that various modifications such as a method for measuring the wire diameter and a method for calculating the plating adhesion amount N can be implemented without departing from the scope of the present invention.

[0040]

As described above in detail, according to the present invention, the wire diameter of the metal wire before being plated, which is sent out from the sending portion, and the metal wire after being plated, before being wound up by the winding portion. The wire diameter of the metal wire is measured, and the plating amount of the metal wire is calculated from these wire diameter data, and it is determined whether or not the plating amount is within an allowable range with respect to a preset target adhesion amount, When it is judged that the deviation is found, the running speed of the metal wire is variably controlled in the direction in which the plating adhesion amount falls within the allowable range, so the plating adhesion amount can be feedback-controlled during the plating process. It is possible to minimize fluctuations in the coating weight due to work over a long period of time, and to obtain reliable quality assurance over the entire length of the metal wire. Can be provided.

[Brief description of drawings]

FIG. 1 is a system diagram showing the overall configuration of a coating weight control device in a hot dip galvanizing line that is an embodiment of the present invention.

FIG. 2 is a block diagram showing a main configuration of a plating adhesion amount control unit shown in FIG.

FIG. 3 is a conceptual diagram showing a specific configuration of a storage unit shown in FIG.

FIG. 4 is a flowchart showing a main processing procedure of an arithmetic processing section shown in FIG.

FIG. 5 is a cross-sectional view of an unplated wire and a plated wire.

FIG. 6 is a characteristic diagram showing a change over time in the amount of deposited plating in the example.

FIG. 7 is a characteristic diagram showing a change over time in the amount of plating deposited in a conventional example.

[Explanation of symbols]

 1a ... Unplated wire 1b ... Plated wire 2 ... Sending part 3 ... Winding part 7 ... Plating bath 10 ... Plating adhesion amount control unit 11 ... Untreated part linear measuring device 12 ... Processing part linear measuring device 13 ... Running Speed detector 14 ... Motor control unit 17 ... Arithmetic processing unit 31 ... Drive motor

Claims (1)

[Claims] 1. A plating adhesion amount control device in a hot-dip galvanizing line for a metal wire, which is fed from a feeding section, is dipped in a hot dip plating solution and plated, and then is wound in a winding section. In the traveling speed control means for constant control of the traveling speed of the metal wire to a reference speed, an untreated portion wire diameter measuring means for measuring the wire diameter of the metal wire before the plating process sent from the sending part, and the winding. Treatment part wire diameter measuring means for measuring the wire diameter of the metal wire after the plating treatment before being wound in the take-up part, and wire diameter data and plating before the plating treatment of the metal wire measured by the both measuring means A plating adhesion amount calculation means for calculating the plating adhesion amount of the metal wire from the treated wire diameter data, and a plating adhesion amount calculated by this calculation means to a preset target adhesion amount. And determining adhesion amount determining means for determining whether or not within the allowable range by,
When it is determined by the determination means that the amount of plating adhered falls outside the allowable range, the speed change means for variably setting the reference speed in the traveling speed control means in the direction in which the amount of deposited plating falls within the allowable range is provided. An apparatus for controlling the amount of plating applied in a hot-dip galvanizing line for metal wires.