JPH0262355A - Vibration restraint and position controller for steel sheet - Google Patents

Abstract

PURPOSE:To check the vibration of a steel sheet and control its position as well as to make it stable travel on a traveling line at all times by performing a signal process of proportion, integration, differentiation or the like by a controller on the basis of a detection signal out of a steel sheet position detector, and adjusting the attraction of an electromagnet on the basis of this signal process. CONSTITUTION:When a steel sheet 5 moves at rapid speed toward an arrow 23 with its own force, output of a differentiating circuit 14 comes to a larger negative signal than a positive signal being outputted by a proportional circuit 13. In consequence, each output of both add circuits 15 and 17 comes to negativeness, and attraction of an electromagnet 7 is annihilated by action of a half- wave rectifying circuit 19, and attraction of an electromagnet 8 is generated instead by each action of a reverse circuit 18 and a half-wave rectifying circuit 20. The attraction of this electromagnet 8 brakes a movement of the steel sheet 5 against such force as making the steel sheet 5 move in direction of the arrow 23, so that vibration in the steel sheet 5 is thus damped and checked.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vibration suppression and position control device for a traveling strip-shaped steel plate, and more specifically, to a vibration suppression device and a position control device provided on either side of a steel plate surface. The position of the steel plate is detected by a detector, and based on the detection signal, the attraction force of two electromagnets arranged in a pair between the steel plate is automatically controlled, thereby suppressing vibrations and positioning the steel plate. This invention relates to a device for controlling.

[Prior Art] For example, in a molten galvanizing line, pressurized air or pressurized gas is ejected from a nozzle having a slit-shaped ejection port, and the ejected flow is directed onto the surface of a steel plate to be plated as it passes through a molten zinc tank and is pulled up. Excess molten zinc is blown off by spraying.

It is common practice to set the plating thickness to the required thickness.

In such cases, the steel plate often vibrates or deviates from the road surface on which it is intended to run, which causes the distance between the nozzle and the steel plate surface to fluctuate, resulting in In many cases, the jetting force fluctuates, resulting in uneven plating thickness and quality deterioration.

This is the reason why the steel plate does not run stably on the running surface.

The main causes include distortion of the steel plate and center runout of the conveyor roll, but it is extremely difficult to completely eliminate these causes, and there are limits. Supporting the plated surface is inappropriate because it deteriorates the finished state of the plated surface.

It was devised in view of these points, and is one of the conventional technologies that uses the attractive force of an electromagnet to control the position of a steel plate.
JP 52-111 filed on March 18, 1975
There is No. 838.

In this technology, a magnet with variable suction force is installed inside the nozzle, and the position of the steel strip to be plated is controlled by adjusting the suction force of this magnet.The method of control is to detect warpage, etc. It is said that manual operation by nine workers is sufficient even without automatic control. In this technique, when the copper strip is farther away from one magnet than the running surface on which it is to be run.

It is controlled by turning on that magnet and turning off other magnets facing it.

However, such a control method is
As mentioned in the issue, even if the purpose can be achieved if the steel strip does not vibrate in the direction of the plate surface, in reality the copper strip runs while vibrating, so if the WA strip approaches the magnet due to vibration, Furthermore, the steel strip tends to be attracted to the magnet, which increases the vibration of the copper strip, and in extreme cases, the steel strip may collide with the magnet, causing not only damage but also an extremely dangerous situation. have.

Another example of the prior art is Japanese Patent Publication No. 60-21238, which was filed later.

This technology is understood to utilize the separation reaction force of the actuator, including the application of electromagnetic force.1 Although it is not directly related to the present invention, it is possible to use electromagnetic force to create a gap between the plated steel plate and the plated steel plate. In practice, it is difficult to generate a repulsion force of sufficient magnitude.

Furthermore, even if this technology replaces the repulsive force of electromagnetic force with attractive force,
This is the same technology as No. 8 and has the same drawbacks.

Further, the above-mentioned Japanese Patent Publication No. 12144/1986 is a technique for preventing lateral deflection and C warping of a steel strip by pulling the steel strip in the width direction using the attractive force of a magnet.

Although this is not directly related to the present invention, in this technology, when the steel strip is thin, the suction surface decreases and the suction force becomes weak.9On the other hand, when the steel strip is thick, its rigidity becomes strong and the steel strip is sufficiently thin. It is not possible to flatten the strip, and there is a limit to how accurately the center of the strip can match the target running surface, and furthermore, due to the size of the magnetic pole and the spread of magnetic flux, it is difficult to flatten both edges of the steel strip. It has the disadvantage that it cannot precisely match the target running surface.

[Problem to be solved by the invention]

The reason why vibration suppression and position control of a traveling steel strip cannot be stably performed in the technique disclosed in Japanese Patent Application Laid-Open No. 52-111838 will be explained in detail with reference to FIG.

FIG. 5 is a side view of a steel plate running vertically from bottom to top, with the steel plate 1 running at a position that deviates from the normal running surface 2 on which it should run. shows. Reference numerals 3 and 4 indicate a pair of electromagnets disposed facing each other with the running surface 2 in between.

In this state, in order to align the steel plate 1 with the running surface 2, an attractive force is generated in the electromagnet 3 disposed beyond the running surface 2 from the steel plate 1, and an electromagnet 3 disposed on the opposite side. Assume that an operation is performed to eliminate the attractive force of the electromagnet 4.

In this case, if the steel plate 1 is trying to maintain its own position away from the running road surface 2 as shown in the figure.

That is, if it is stably stationary in this state and does not attempt to return to the running track surface 2, the steel plate 1 can be moved to the running track surface 2 by generating an appropriate attractive force in the electromagnet 3.

However, in actual cases, the steel plate 1 does not necessarily remain stable at the position shown in the figure because the plate 1 runs while vibrating or has unusual deformation. The vehicle may try to move from this position toward the normal running surface 2 or in the opposite direction.

However, when the steel plate 1 has the force to return from this position towards the normal running track surface 2, it is difficult to pull it back just because the steel plate 1 is off to the other side of the running track surface 2. When the electromagnet 3 generates an attractive force, the attractive force of the electromagnet 3 will add to the return movement of the steel plate 1 itself, and as a result, the steel plate 1 will pass the running surface 2 and go too far to the opposite side. The vibration of the steel plate 1 is amplified, resulting in the opposite of the desired result.

In other words, it is not always possible to suppress vibrations or control the position of the steel plate by suctioning it with an electromagnet placed on the side opposite to the side where the steel plate is misaligned. There is even a risk of colliding with electromagnets.

Moreover, in the state shown in FIG. 5, if the tension, rigidity, etc. of the steel plate 1 change, the electromagnet 4 may generate an attractive force corresponding only to the amount of deviation of the steel plate l from the running surface 2. The steel plate 1 can only move to a position where its own positional holding force and the attractive force of the electromagnet 3 are balanced, and this cannot be perfectly aligned with the position of the running road surface 2.

In order to eliminate these inconveniences, when the steel plate is off the track surface, an electromagnet placed on the opposite side of the track surface to the side where the steel plate is located always generates an attractive force. A new control method is needed to replace a simple control method that attempts to pull the vehicle back onto the road surface only by a suction force proportional to the distance off the road surface.

The present invention was devised in view of these problems, and its technical objective is to provide a device that can achieve stable running of a steel plate along a running line without vibration.

[Means for solving problems] Therefore, at least one pair of electromagnets 7,8.

It consists of a steel plate position detector 9 and a controller 10.

The electromagnets 7 and 8 are arranged facing each other at a required distance from the plane of symmetry on which the strip-shaped steel plate is to run. The steel plate position detector 9 is of a non-contact type and is provided near one of the electromagnets of each pair with a required distance from the surface on which the steel plate 5 is to be run. Then, the controller 10 performs signal processing such as proportionality, integration, and differentiation based on the detection signal from the steel plate position detector 9, and operates the electromagnets 7.8 while mutually switching the attraction forces of each pair of electromagnets 7.8. It has functions for

[Function and Examples]

The operation of the present invention will be explained with reference to examples.

1 to 4 are views showing an embodiment of the present invention apparatus, in which FIG. 1 is a side sectional view, FIG. 2 is a front view taken along line A-A in FIG. 1, and FIG. The figure is a block diagram of the controller 10, and FIG. 4 is a side sectional view showing the operating situation.

In FIG. 1, reference numeral 5 indicates a strip-shaped steel plate being moved while being tensioned in the vertical direction, and 6 indicates a vibration suppression and position control device for a steel plate according to the present invention.

This steel plate vibration suppression and position control device 6 is as follows.

A pair of electromagnets 7 and 8. Steel plate position detector 9 Controller 1
It consists of main parts such as 0.

The electromagnets 7 and 8 are arranged at positions facing each other with a normal running road surface 11 on which the steel plate 5 is to be moved and a required distance from the running track painter 1. It is necessary for these electromagnets 7 and 8 to improve the responsiveness of the attractive force, and for this purpose, the number of coil turns is minimized, the applied current is increased, the inductance is reduced, and laminated electromagnetic steel sheets are used to reduce loss. Consideration has been taken to reduce the number of

The steel plate position detector 9 is located near the electromagnet 7 and on the running road surface 1.
1 at a required interval. The steel plate position detector 9 may be of a non-contact type, such as an eddy current type, an infrared light type, a laser type, or an ultrasonic type, depending on the properties of the steel plate 5.

The controller 10 has an input terminal connected to the steel plate position detector 9, and an output terminal connected to the electromagnets 7 and 8, respectively. As shown in the block diagram of FIG. 3, this controller 10 includes a reference position setting circuit 12. Proportional circuit 13.
Differential circuit 14. Addition circuit 15. Integrating circuit 16. Addition circuit 171 Inversion circuit 1st, Half wave rectification circuit 19. Half-wave rectifier circuit 20. Power amplifier circuit 21. It is composed of main parts such as a power amplifier circuit 22.

The reference position setting circuit 12 compares the signal value corresponding to the position of the steel plate 5 inputted from the steel plate position detector 9 with the signal value corresponding to the position where the steel plate 5 should travel, that is, the set value, and calculates the difference between them. Output the signal value.

The proportional circuit 13 is a circuit for receiving the output of the previous stage reference position setting circuit 12 and proportionally amplifying it, and adjusts the gain of the control loop.

The differentiation circuit 14 is for differentiating the output of the proportional circuit 13 and obtaining a signal value corresponding to the rate of increase or decrease in the output, and is used to differentiate the output of the proportional circuit 13 and obtain a signal value corresponding to the rate of increase or decrease in the output. When this is the case, a positive polarity signal is output, and when the opposite is true, a negative polarity signal is output as a signal with a magnitude proportional to the moving speed of the steel plate 5.

The adding circuit 15 adds the output of the proportional circuit 13 and the output of the differentiating circuit 14, and the output of this adds the output of the running surface 1 of the steel plate 5.
The signal value is proportional to the amount of displacement from 1 and the displacement speed of the steel plate 5.

The integrating circuit 16 integrates the output of the adding circuit 15 and outputs the input value as a signal value proportional to time. Even if the input value from the adder circuit 15 is very small in the offset state, it is increased over time and output, thereby working to move the steel plate 5 until it completely matches the running road surface.

The adding circuit 17 is for adding the two outputs of the integrating circuit 16 and the adding circuit 15, and the signal output from this is sent to the proportional circuit 13. Differential circuit 14. All of the signals processed by the integrating circuit 16 and the like are combined.

The inversion circuit 18 inverts the output signal of the addition circuit 17 so that it has the opposite polarity, and performs preprocessing to separate the signal into positive and negative polarity signals at the primary stage.

The half-wave rectifier circuits 19 and 20 extract only the positive polarity portion from the AC signal.
Only its negative polarity portion is output to a20.

Inverting circuit 18. Half-wave rectifier circuit 19 and half-wave rectifier circuit 2
0, etc., functions to switch so that only either the electromagnet 7 or the electromagnet 8 is activated depending on the polarity of the output signal of the adder circuit 17.

Power amplification circuits 21 and 22 are for matching the output signals of half-wave rectification circuits 19 and 20, respectively, to amplify the power necessary to drive electromagnets 7 and 8.

The operation of the device of the present invention will be based on this embodiment.

This will be explained below mainly using FIG.

Now, suppose that the rope plate 5 has shifted to the left of the normal running surface 11 and the distance between it and the steel plate position detector 9 has become Lx, then at
The board position detector 9 outputs a signal (2)8 corresponding to the distance Lx. This signal 8 is compared in the reference position setting circuit 12 with a setting signal V corresponding to the distance between the running road surface 11 and the steel plate position detection circuit 9, and (vxvs) is subtracted. The signal of (■ Addition circuit 17. Half-wave rectifier circuit 19. The power is applied to the electromagnet 7 through the power amplification circuit 21. As a result, the electromagnet 7 generates an attractive force proportional to the value of (V, -VS) and moves the steel plate 5 l
Make a movement to pull it towards the l side.

However, if the steel plate 5 itself is to be held at a position shown in FIG. The steel plate 5 can only be pulled back to an intermediate position where the suction force, which is proportional to the value of , ), is balanced.

In other words, even if (VX V!1) = O, the steel plate 5
The steel plate 5 can stop at an intermediate position, resulting in an offset state, and the steel plate 5 cannot be perfectly aligned with the running surface 11.

In this controller 10, the integrating circuit 16 plays an effective role in dealing with such inconveniences.

The integrating circuit I6 functions to increase the signal value of (Vx Vs) in proportion to the elapsed time. Therefore, the analogy (V
)l −VS )<<1, the output signal value of the integrating circuit 16 increases as time passes. This output signal is combined by the adding circuit 17 with the proportional operation signal from the proportional circuit 13 sent through the adding circuit 15, and this combined signal causes the electromagnet 7 to move until (VX Vs)=0, that is, the steel plate The suction operation is performed indefinitely until 5 matches the runway painter 1.

In this way, when the steel plate 5 is trying to maintain its position away from the running track surface 11, the steel plate 5 can be made to match the running track surface 11 by proportional action and integral action, but in reality, the shape of the steel plate 5 is Due to non-uniformity and vibration, the steel plate 5 itself does not always try to maintain a specific position, and as shown by the arrow 23 in FIG. There are many cases in which the object tries to move toward the road surface 11, or is moving, and cannot be controlled using only proportional and integral actions.

In other words, if the electromagnet 7 attracts the steel plate 5 even though it is located further away from the running surface 11, the attraction force will add to the movement toward the running surface 11 due to the restoring force of the steel plate 5. As a result, the steel plate 5 crosses the running surface 11 to the opposite side (excessively, which increases the vibration of the steel plate 5, or in extreme cases, the steel plate 5 collides with the electromagnet 7).

It may get out of control.

In the controller 10 according to the present invention, the above-mentioned disadvantages are eliminated by providing the differentiating circuit 14.

When the steel plate 5 moves away from the steel plate position detector 9, that is, when the signal value of the steel plate position detector 9 increases, the differential circuit 14 generates a positive polarity whose magnitude corresponds to the increasing rate. When a signal is output and the steel plate 5 approaches the steel plate position detector 9.

That is, when the signal value of the steel plate position detector 9 decreases, a negative polarity signal of a magnitude corresponding to the rate of decrease is output.

Therefore, as shown in FIG. 4, when the steel plate 5 is moving at a high speed in the direction of the arrow 23 due to its own force, the output of the differentiator circuit 14 has a negative polarity larger than the positive polarity signal output from the proportional circuit 3. As a result, the outputs of the adder circuit 15 and the adder circuit 17 become negative, and the attractive force of the electromagnet 7 disappears due to the action of the half-wave rectifier circuit 19, and in its place, the output of the inverter circuit 18 and the half-wave rectifier circuit 2
0 generates an attractive force in the electromagnet 8. The attractive force of the electromagnet 8 resists the force that causes the steel plate 5 to move in the direction of the arrow 23 and brakes the movement of the steel plate 5.
vibrations are damped and suppressed.

Further, when the steel plate 5 is moving in the opposite direction to the direction indicated by the arrow 23 due to its own force, the output signal of the differentiating circuit 14 has a positive polarity, and is added to the positive polarity signal of the proportional circuit 13.
The attraction force of the electromagnet 7 is increased to control the movement of the steel plate 5, and the vibration of the steel plate 5 is attenuated and suppressed.

In the explanation so far, the case where the steel plate 5 is on the left side of the running road surface 11 has been described, but even if the steel plate 5 is on the right side of the running road surface 11, it is added from the output of the reference position setting circuit 12. and that the polarity of all signals up to the output of circuit 17 is reversed.

It goes without saying that the actions of the electromagnets 7 and 8 can be similarly explained by their opposite actions.

As is clear from the above description, in this controller IO, the position of the steel plate 5 must be matched with the running surface 11.

and vibration of the steel plate 5 can be simultaneously and accurately suppressed.

Note that in this controller 10, the proportional circuit 13. The constants of the differential circuit 14, the integral circuit 16, etc. are selected in accordance with the tension, thickness, support spacing, etc. of the steel plate 5 so that the steel plate 5 can be positioned on the track surface 11 most quickly and stably.

The device of the present invention, which performs these functions, is used in a wide range of areas and exhibits excellent effects. Examples are listed below.

The results of actually using the steel plate vibration suppression and position control device according to the present invention in a hot-dip galvanizing line.

Conventionally, the maximum amplitude including vibration and positional deviation of the steel plate was 1.
0, but this has been reduced to less than 2 mm, which is less than a fraction of that.As a result, the variation in plating thickness has been greatly improved to less than a fraction of that.

This steel plate vibration suppression and position control device has the function of holding the steel plate in a required constant position, so when it is used in a hot-dip galvanizing line, it uses pressurized gas injection to control the plating thickness. Even if the force is applied asymmetrically on the front and back surfaces, the steel plate to be plated will not be pushed to the side where the jetting force is lower and move, making it possible to easily obtain a differentially plated steel plate with different plating thicknesses on the front and back sides. .

In addition, by arranging three or more of these steel plate vibration suppression and position control devices at a required distance from each other in the width direction of the steel plate, warping in the width direction can be eliminated and the amount of warping can be freely controlled. Is possible.

Furthermore, this steel plate vibration suppression and position control device is used in the gas wiping device section of chemical treatment lines.

It can also be used to great effect in areas that are adversely affected by warping or vibration, such as a part of the coater on a painting line.

〔Effect of the invention〕

In this way, the device of the present invention performs proportional and integral calculations by the controller based on the detection signal of the steel plate position detector.

Since the attraction force of the electromagnet is adjusted based on signal processing such as differentiation, the vibration of the steel plate is suppressed and its position is controlled, so that the steel plate can always run stably on the running line.

The device of the present invention, which exhibits such stable functions, exhibits excellent effects in a wide range of applications such as double plating lines and chemical conversion treatment lines. The benefits obtained by using the apparatus of the present invention are large, and its industrial value is extremely high.

[Brief explanation of the drawing]

1 to 4 are views showing one embodiment of the device of the present invention, in which FIG. 1 is a side sectional view, FIG. 2 is a tightening surface view taken along line AA in FIG. 1, and FIG. FIG. 4 is a block diagram of the controller 10, and FIG. 4 is a side sectional view showing the operating status. FIG. 5 is a side sectional view showing the prior art. Explanation of symbols 1: Steel plate, 2: Running surface, 3: Electromagnet. 4: Electromagnet, 5: Steel plate, 6: Vibration suppression and position control device, 7: Electromagnet, 8: Electromagnet. 9: Position detector, 10: Controller, 11: Running surface. 12: Reference position setting circuit, 13: Proportional circuit. 14: Differentiating circuit, 15: Adding circuit, 16: Integrating circuit. 17: adder circuit, 18: inverter circuit, 19: half-wave rectifier circuit, 20: half-wave rectifier circuit, 21: power amplifier circuit. 22: Power amplifier circuit. " ++-@A bu27ω

Claims (1)

[Claims] A pair or multiple pairs of electromagnets arranged facing each other at a required distance from the plane of symmetry on which the strip-shaped steel plate is to run, and an electromagnet on one side of each pair. A non-contact steel plate position detector is installed near the surface with a required spacing between it and the surface on which the steel plate is to be run, and proportional, integral, and differential calculations are performed based on the detection signal of the steel plate position detector. A vibration suppression and position control device for a steel plate, comprising a controller having a function of performing signal processing such as the above, and operating the electromagnets forming each pair while mutually switching the attraction forces.