JP3972529B2 - Steel plate damping device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a steel plate damping device for damping vibrations of a strip-like steel plate that travels on a road surface in a rolling line, a surface treatment line, and the like of an iron manufacturing facility.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a vibration damping device that suppresses vibration of a traveling steel sheet and stably travels the steel sheet along a running surface, as disclosed in Japanese Patent Application Laid-Open No. 5-245523. A schematic configuration of this vibration damping device is shown in FIG. The vibration damping device includes a pair of electromagnets 112 and 113 that are symmetrically arranged at a predetermined distance from the road surface 111 on both sides of the road surface 111 on which the strip-shaped steel plate 110 is to travel, and one electromagnet. 112, a non-contact type position detector 114 incorporated in the interior of the circuit 112, and signal processing such as proportionality, integration, and differentiation based on a signal output from the position detector 114, and the attractive force of each electromagnet 112, 113. And a controller 119 for controlling.
[0003]
According to this vibration damping device, the displacement of the strip-shaped steel plate 110 traveling on the road surface 111 is detected by the position detector 114, and based on the signal, the controller 119 performs signal processing such as proportional, integral, and differential. The attraction force of each of the electromagnets 112 and 113 is controlled to control the vibration of the steel plate 110.
[0004]
[Problems to be solved by the invention]
In such a vibration damping device, when the steel plate is out of the detection range of the position detector (sensor), control becomes impossible, so that the distance between the opposing electromagnets is limited within the detection distance of the sensor. There is.
Conversely, when trying to widen the gap between the electromagnets, a sensor with a large detection range is required. However, since such a sensor generally has a large sensor head diameter, the electromagnet also becomes larger and attracts the electromagnet. The force acts on a wide range of steel plates. Here, this steel plate is often a thin and very flexible steel plate, and when the attractive force of the electromagnet acts on a large area as described above, deformation is likely to occur in the plane. Then, there is a problem in that the control tends to become unstable because the distance to the steel plate detected by the sensor and the control force of the electromagnet act to cause a difference between the distance at the deformed position.
[0005]
Further, an eddy current displacement sensor is often used as the sensor because it is resistant to high temperatures and dust. In this eddy current displacement sensor, the offset voltage changes due to the magnetic flux generated from the electromagnet, and the gain changes depending on the temperature. On the other hand, a sensor having a function of correcting these changes is expensive. Therefore, when a normal inexpensive sensor is used, there is a problem that the position signal output from the sensor must be corrected each time the sensor is used.
[0006]
The present invention has been made to solve the above-described problem, and uses a cheap and small sensor, and without increasing the size of the electromagnets, the steel plates can be made even if the sensors or the intervals between the electromagnets are widened. A steel plate damping device capable of controlling the vibration and the traveling position of the steel plate, and having a small change in the characteristics of the damping device with respect to a change in magnetic flux and temperature due to an electromagnet and capable of stable damping control. Is.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is an electromagnet that applies a magnetic force in a direction intersecting with the steel plate in order to perform vibration suppression of the traveling steel plate, a sensor for detecting a distance between the electromagnet and the steel plate, And a control device for controlling the excitation current flowing through the electromagnet based on the distance detected by the sensor, and the sensors are arranged in pairs at positions facing each other across the steel plate. The distance obtained by subtracting the plate thickness from the distance between the opposing sensors is equal to or less than the sum of the maximum detectable distances of the opposing sensors, and the control device calculates the difference between the output voltages of the pair of sensors arranged in pairs. The steel plate vibration damping device is characterized in that an excitation current flowing through the electromagnet is controlled based on a difference output by the difference detection means.
[0008]
The invention according to claim 2 is characterized in that the electromagnets are arranged in pairs at positions facing each other across the steel plate, and the sensor is arranged in the center of the electromagnet. The steel plate damping device according to claim 1.
[0009]
The invention according to claim 3 is characterized in that the non-linearity of the difference between the output voltages of the pair of sensors is linearized by an analog circuit or digital processing . It is a vibration control device.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
First, the configuration of the first embodiment of the present invention will be described with reference to FIG. The steel plate 1 travels from the bottom to the top of the figure. That is, the figure which looked at the steel plate 1 from the side surface is shown by this figure. An electromagnet 2A is provided on the front surface side of the traveling steel plate 1, and an electromagnet 2B is provided on the back surface side. The electromagnets 2A and 2B are provided at positions facing each other with the steel plate 1 interposed therebetween. A sensor 3A for detecting the distance to the steel plate 1 is provided in the electromagnet 2A, and a sensor 3B for detecting the distance to the steel plate 1 is also provided in the electromagnet 2B. The detection surface of the sensor 3A is flush with the magnetic pole surface of the electromagnet 2A, and the detection surface of the sensor 3B is flush with the magnetic pole surface of the electromagnet 2B. That is, the sensors 3A and 3B are also provided at positions facing each other with the steel plate 1 interposed therebetween.
[0011]
The outputs of the sensors 3A and 3B are input to the controller 4. The output of the controller 4 is input to the power amplifiers 5A and 5B, the output of the power amplifier 5A is input to the electromagnet 2A, and the output of the power amplifier 5B is input to the electromagnet 2B.
[0012]
FIG. 2 is a detailed configuration diagram in the controller 5. A sensor signal indicating the position of the steel plate 1 detected by the sensors 3A and 3B is input to the first difference detection means 6a, and the difference between these inputs is taken. The output of the first difference detection means 6a is input to the second difference detection means 6b in the next stage. The second difference detection means 6b is further inputted with a position command value output from the position command means 7, and the difference between this position command value and the output of the first difference detection means is taken.
[0013]
The output of the second difference detection means 6b is input to the vibration control controller 8, and the output of the vibration control controller 8 is input to the current control means 9A and 9B. The power command A output from the current control unit 9A is input to the power amplifier 5A, and the power command B output from the current control unit 9B is input to the power amplifier 5B.
[0014]
Next, the operation of this embodiment will be described. The sensor 3 </ b> A detects the distance dA between the detection surface of the sensor 3 </ b> A and the surface of the steel plate 1 and transmits the detection result to the controller 4. Similarly, the sensor 3 </ b> B detects a distance dB between the detection surface of the sensor 3 </ b> B and the back surface of the steel plate 1 and transmits the detection result to the controller 4.
[0015]
The controller 4 takes the difference between the detection result of the distance dA and the detection result of the distance dB, that is, the sensor difference value by the first difference detection means 6a built in the controller 4. Further, a difference between the sensor difference value and the position command value output from the position command means 7 is taken by the second difference detection means 6b. This position command value is, for example, 0 if the target position of the steel plate 1 is exactly between the sensors 3A and 3B.
[0016]
The difference between the sensor difference value and the position command value, that is, the output of the second difference detection means, is input to the vibration controller 8, and the vibration controller 8 is configured so that the input difference becomes zero, that is, the sensor. The current control means 9A and 9B are controlled so that the difference value matches the position command value.
[0017]
Current control means 9A and 9B control power amplifiers 5A and 5B according to power commands A and B, and power amplifiers 5A and 5B increase or decrease excitation currents IA and IB supplied to electromagnets 2A and 2B. For example, if dA <dB, IA <IB, and if dA> dB, IA> IB. By the above operation, the steel plate 1 is always pulled back to the target position and vibration suppression is performed.
[0018]
Next, the operation of the sensors 3A and 3B will be described in detail with reference to FIG. FIG. 3A shows the operation of the sensor 3A alone. The horizontal axis of this figure is the distance between the detection surface of the sensor 3A and the surface of the steel plate 1 facing this detection surface, and the vertical axis is the output voltage of the sensor 3A. The distance and the output voltage are proportional while the distance is short, but when the distance exceeds the maximum detection distance ls, the output voltage is saturated and a constant value is output. The operation of the sensor 3B alone is the same.
[0019]
FIG. 3B is a combination of the operations of the sensors 3A and 3B. The horizontal axis represents the distance between the sensor 3A and the steel plate 1, and the vertical axis represents the sensor difference value, that is, the difference between the output voltages of the sensors 3A and 3B. Here, when the distance obtained by subtracting the plate thickness from the distance between the sensors 3A and 3B is 2l, it is assumed that l ≦ ls ≦ 2l.
[0020]
In this way, the position of the steel plate 1 can be detected regardless of the position of the steel plate 1 between the sensors 3A and 3B. At this time, even if the distance 21 between the sensors 3A and 3B is larger than the maximum detection distance ls of the sensor, the position of the steel plate 1 can be detected.
Further, the non-linearity of the detection sensitivity as shown in FIG. 3B caused by the overlap of the detection processes of the sensors 3A and 3B can be linearized by an analog circuit or a digital process.
[0021]
Next, the relationship between the magnetic flux generated by the electromagnet and the output voltage of the sensor will be described. FIG. 4 shows the positional relationship between the electromagnets 2A and 2B and the sensors 3A and 3B in the present embodiment. That is, the sensors 3A and 3B are arranged inside the electromagnets 2A and 2B. In such an arrangement, when the excitation current flowing through the electromagnets 2A and 2B is changed, the magnetic flux generated by the electromagnets 2A and 2B changes, and the position of the steel sheet 1 changes due to the change in the magnetic flux. Despite the absence, the output voltages of the sensors 3A and 3B change as shown in FIG.
[0022]
At this time, if the difference between the output voltages of the sensors 3A and 3B is taken, the influence of the magnetic flux generated by the electromagnets 2A and 2B is canceled, and the difference between the output voltages becomes a substantially constant value.
[0023]
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the electromagnet 2 </ b> A is provided only on one side of the steel plate 1. Accordingly, only one power amplifier 5A for driving the electromagnet 2A is provided. Other configurations are the same as those in the first embodiment. For example, the sensors 3A and 3B are provided opposite to both sides of the steel plate 1 as in the first embodiment. Even when only one electromagnet is used as in the second embodiment, the present invention can be applied.
[0024]
【The invention's effect】
According to the present invention, the sensors are arranged in pairs facing each other across the steel plate, and the distance between the sensor and the steel plate is set to be equal to or less than the maximum detectable distance of the sensor. Can do. Further, even if the distance between the sensors is wide, the detection range is wide and it is not necessary to use a large sensor. Therefore, even if the sensor is arranged at the center of the electromagnet, the electromagnet is not enlarged.
In addition, when the electromagnets are arranged in pairs at positions facing each other with the steel plate in between, the distance between the facing electromagnets can be widened.
In addition, since a difference detection means that takes the difference between the distances detected by the sensors arranged in pairs is provided, even if an inexpensive sensor is used, it can be used against changes in magnetic flux and temperature due to electromagnets. Thus, the change in the characteristics of the vibration damping device can be reduced, and stable vibration damping control is possible.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a steel plate damping device according to a first embodiment of the present invention.
FIG. 2 is an internal configuration diagram of a controller 4;
FIG. 3 is a graph showing the relationship between the sensor-steel plate distance and the output voltage of the sensor.
FIG. 4 is a diagram showing a positional relationship between an electromagnet and a sensor.
FIG. 5 is a graph showing the relationship between the magnetic flux density generated by the electromagnet and the output voltage of the sensor.
FIG. 6 is a schematic configuration diagram of a steel plate damping device according to a second embodiment of the present invention.
FIG. 7 is a schematic configuration diagram of a conventional steel plate vibration damping device.
[Explanation of symbols]
1 Steel plate 2A, 2B Electromagnet 3A, 3B Sensor 4 Controller (control device)
5A, 5B Power amplifier 6a First difference detecting means (difference detecting means)
6b Second difference detection means 7 Position command means 8 Vibration control controller 9A, 9B Current control means 110 Steel plate 111 Running road surface 112, 113 Electromagnet 114 Position detector 119 Controller

Claims (3)

An electromagnet that exerts a magnetic force in the direction intersecting with the steel plate in order to control the traveling steel plate;
A sensor for detecting the distance between the electromagnet and the steel plate;
Based on the distance detected by this sensor, a control device for controlling the excitation current flowing through the electromagnet,
Have
The sensors are arranged in pairs at opposite positions across the steel plate, and at this time, the distance obtained by subtracting the plate thickness from the distance between the opposed sensors is equal to or less than the sum of the maximum detectable distances of the opposed sensors. ,
The control device includes a difference detection unit that takes a difference between output voltages of the pair of sensors arranged in a pair, and controls an excitation current flowing through the electromagnet based on a difference output from the difference detection unit. A steel plate damping device characterized by that. The electromagnets are arranged in pairs at opposite positions across the steel plate,
The steel plate vibration damping device according to claim 1, wherein the sensor is disposed at a center of the electromagnet. The steel plate vibration damping device according to claim 1 or 2, wherein the nonlinearity of the difference between the output voltages of the pair of sensors is linearized by an analog circuit or digital processing .

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