JPH09110252A - Rotational abnormality detecting method of non-driven roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably and continuously detect rotational abnormality, particularly, a nonrotating condition in a nondriven roller by detecting rotational abnormality of the roller on the basis of a vibration signal of a roller support part. SOLUTION: It is arranged in a housing of a support roller in a plating line pot, and detects vibrational acceleration in a feed plate. A detected signal is amplified by a vibration amplifier 4, and is outputted to an active band-pass filter 5. On the other hand, operation is performed on a roller rotating frequency from a line speed signal and a roller diameter inputted from an external part by an operation circuit 6, and a central frequency of the active band-pass filter is determined. The active band-pass filter 5 varies a filtering band by this central frequency, and extracts only the roller rotating frequency. A signal level is monitored by a judging circuit 7, and when it exceeds a threshold value, an alarm is outputted by an alarm device 8. Therefore, an alarm is outputted at a high detecting rate, and an unrotating condition is detected in its early stages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a rotation state of a non-driving roll of a metal plate threading line, particularly the roll in a hot dip plating bath, and detects abnormal rotation (for example, reduction in rotation speed, non-rotation).
The present invention relates to a method for preventing an obstacle caused by the above, that is, a flaw in a product, a trouble of passing a plate, and the like.

[0002]

2. Description of the Related Art In general, a roll is marked with a light-reflective sensor or a eddy current pulse sensor to monitor the number of revolutions.
There is known a means for mechanically transmitting roll rotation using a chain or the like to mark the transmitted rotating body and detecting the number of rotations with a light reflection sensor or an eddy current type pulse sensor.

[0003]

However, these methods have the following drawbacks. In the above-mentioned method, it is necessary to mark or mechanically transmit rotation to the roll, but for example, in a roll in a plating pot bath, marking is impossible due to high temperature and adhesion of plating, and the detection sensor Installation is also impossible. Further, even in the method of mechanically extracting the rotation, the adhesion of the plating becomes a problem and continuous detection is impossible. The present invention solves the above-mentioned drawbacks of the prior art, and reliably and continuously detects abnormal rotation, especially non-rotation state, in a non-driving roll (for example, a roll in a plating bath).

[0004]

[Means for Solving the Problems]

(1) When detecting a rotation abnormality of a non-driving roll in a metal plate threading line, a rotation abnormality detection method of the non-driving roll is characterized by detecting the rotation abnormality of the roll based on a vibration signal of the roll supporting portion. . (2) When detecting the abnormal rotation of the roll based on the vibration signal of the roll supporting portion, the theoretical rotation of the roll and the actual rotation speed of the roll are extracted using a bandpass filter. The method for detecting the abnormal rotation of the non-driving roll is as described above.

[0005]

In the present invention, the number of rotations of the roll is detected based on the vibration signal of the roll supporting portion by, for example, a vibration sensor installed in a housing supporting the roll. The rotation state of the roll can also be detected reliably and continuously. There are various kinds of vibrations transmitted to the roll housing, but the rotational speed of the roll, which targets the strip speed, is calculated using an arithmetic circuit, and the center frequency of the active bandpass filter is set from this theoretical rotational speed. Since the rotation frequency of the roll is preferentially extracted, the disturbance noise included in the vibration sensor signal can be removed and only the rotation of the roll can be detected. Therefore, abnormal rotation of the roll, for example, a non-rotation state can be reliably detected.
Moreover, there is no risk of sensor damage because the sensor can be installed at a location that is not close to the roll.

[0006] The applicable non-driving roll may be a roll in a plating bath, a roll in a liquid such as alkaline water, a pass line roll, or a tension roll. . The roll supporting portion may be a roll bearing, a roll mount, or the like other than the roll housing. In order to obtain the vibration signal of the roll supporting portion, a method such as a strain gauge method may be used as long as it is possible to reliably and continuously detect vibration other than providing a vibration sensor on the roll housing.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention is shown in FIG. The vibration sensor 1 is shown in FIG. It is installed in the housing 2 of the support roll in the plating line pot, and the vibration acceleration of the through plate 3 is detected. The detected signal is amplified by the vibration amplifier 4 and output to the active bandpass filter 5. On the other hand, in the arithmetic circuit 6, the roll rotation frequency is calculated from the line velocity signal input from the outside and the roll diameter to determine the center frequency of the active bandpass filter 5. The active band pass filter 5 varies the filtering band at this center frequency and extracts only the roll rotation frequency. The determination circuit 7 monitors the signal level, outputs an alarm when the threshold value is exceeded, and an alarm device 8 generates an alarm. The present invention is carried out by using, for example, the above-mentioned device, but the specific configuration of the device can be arbitrarily changed within the range in which the object of the present invention can be achieved.

FIG. 3 is a diagram showing a vibration waveform during passage, (A) is a raw vibration waveform without filtering, and (B) is a waveform.
Is a vibration waveform with filtering, (C) is a vibration waveform when a non-rolling state occurs without filtering, and (D) is a vibration waveform when a non-rolling state with filtering occurs. These are data with the same speed. (C),
When there is no filtering as shown in (D), it is impossible to detect the non-conversion state because there are many noise components. On the other hand, when there is filtering, only the rotation frequency of the roll is output, so it is not affected by noise and the non-conversion It can be seen that State 9 can be detected.

[0009]

As a result of detecting the non-conversion state by the above-mentioned device using the present invention, an alarm is output at a high detection rate and the non-conversion state can be detected early. As a result, it is possible to minimize the flawing of the metal plate by the roll and intermesh operations.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the overall configuration of an apparatus using the present invention,

FIG. 2 is a diagram showing the installation situation of the vibration sensor of the present invention,

FIG. 3 is a diagram showing a vibration waveform during passage of a plate.

[Explanation of symbols] 1 Vibration sensor 2 Support roll housing in plating line pot 3 Metal plate 4 Vibration amplifier 5 Active bandpass filter 6 Calculation circuit 7 Judgment circuit 8 Alarm device 9 Roll non-rotation state occurrence point

Claims (2)

[Claims] 1. An abnormal rotation of a non-driving roll is detected on the basis of a vibration signal of a roll supporting portion when detecting an abnormal rotation of a non-driven roll of a metal plate threading line. Detection method. 2. The actual rotation speed of the roll is extracted by using a theoretical rotation of the roll and a bandpass filter when detecting the rotation abnormality of the roll based on the vibration signal of the roll supporting portion. A method for detecting abnormal rotation of a non-driving roll as described above.