JPH0441793A - Diagnostic device of dryer failure by sound pressure - Google Patents

Abstract

PURPOSE:To simply diagnose degree of wear and position of wear by obtaining a noise level while rotating microphones against each roll group of a dryer, subtracting back ground noise from the noise level and calculating a noise source position signal. CONSTITUTION:Dryer rolls are divided into plural roll groups A, B, C, D and E, microphones 5a to 5e which are horizontally revolved by about 180 deg. and detect sound pressure are arranged at a drive side central part of each group. Noise levels at a revolution position of the microphones are obtained by a control calculating device 15 while turning the microphones, back ground noise is subtracted from the obtained noise levels, actual noise signals 19 are obtained and a noise source position signal 20 is calculated from a combination of the obtained noise signals to show a display device 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dryer failure diagnosis device using sound pressure.

[Prior art] A dryer for a paper manufacturing machine is equipped with a large number of dryer rolls for drying the product (paper) and supporting the canvas, etc., and the product or rack is rotated and moved between them. By doing this, the product is dried.

Since such dryer rolls are rotated at high speeds under adverse conditions of high temperature and humidity, it is necessary to always reliably lubricate the bearings, power transmission system, etc.

[Problem 8 to be solved by the invention] However, in the above-mentioned dryer, since it rotates under adverse conditions and at high speed, the bearings and power transmission system of the dryer roll tend to wear out over time, and furthermore, the lubrication is incomplete. In some cases, the dryer rolls are subject to significant wear and tear, and when such wear and tear occurs, problems such as vibrations of the dryer rolls adversely affect the product and generate noise. Therefore, when the above-mentioned wear occurs, it is necessary to detect the wear and the worn parts at an early stage, and to replace the worn parts and inspect and adjust the lubrication system.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dryer failure diagnosis device based on sound pressure that can detect wear and tear on a dryer with a simple device configuration.

[Means for Solving the Problems] The present invention provides a microphone installed horizontally for each group of rolls in a dryer of a paper manufacturing machine to detect the noise of each group of rolls, and a microphone for detecting the noise of each group of rolls. a scanner that selects and outputs the sound pressure signal detected by each microphone; and a scanner that inputs the sound pressure signal selected by the scanner and also issues a rotation command to the microphone that is inputting the sound pressure signal. A signal is output, a noise level signal corresponding to the rotational position of the microphone is obtained, and a background noise signal input in advance is subtracted from the noise level signal to obtain an actual noise signal. a control calculation device that calculates a noise source position signal from a rotation position of the microphone that indicates the maximum value of the sound pressure signal;
This invention relates to a dryer failure diagnosis device based on sound pressure, characterized in that it is equipped with a display device that inputs and displays a noise signal and a noise source position signal from the control arithmetic device.

[Function] While rotating the microphone for each roll group of the dryer, the control calculation device determines the noise level at the rotating position, and the actual noise signal is determined by subtracting the background noise signal from the determined noise level. , and a noise source position signal is calculated from the combination of the determined noise signals, and the noise signal and the noise source position signal are input to a display device and displayed.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing one embodiment of the present invention, showing a dryer of a paper manufacturing machine consisting of a pre-dryer 1, a size press 2, and an after-dryer 3, and each dryer roll of the pre-dryer 1 and after-dryer 3. 4 is divided into a plurality of roll groups, for example, 1st group A, 2nd group B, 3rd group C, 4th group, and 5th group E.

At the drive side central part of each of the roll groups A, B, C, D, H, each roll group A, B, C,
Microphone 5 for detecting sound pressure of each of D and E
Install a, 5b, 5c, 5d, and 5e.

The microphones 5a, 5b, 5c, 5d, 5e are 5
Taking example a, as shown in FIG. 2, the base end of the sound collecting section 6 is supported so as to be horizontally rotatable around a vertical support shaft 7, and a pinion 8 concentric with the support shaft 7 is attached to the base end. Furthermore, a rack 9 that meshes with the binion 8 and an actuator 1 such as a cylinder that pushes and pulls the rack 9 are formed.
A swing drive device 11 consisting of 0 is constructed to allow the sound collecting section 6 to freely swing within a range of approximately 180 degrees.

Sound pressure signals 12a, 12b, 12c, 12d, 12 detected by the microphones 5a, 5b, 5c, 5d, 5e
e is guided to the scanner 14 via the amplifier 13,
Sound pressure signals 12a, 1 selected by the scanner 14
2b, 12c, 12d.

12e is input to the control device 15.

Control calculation bag! 15 is a scanner which sends a selection command signal 16 instructing the control calculation device 15 to select one of the sound pressure signals 12a, 12b, 12c, 12d, I2e from the microphones 5a, 5b, 5c, 5d, 5e. 14, and is selected by the selection command signal 16.

Turn command signals 17a, 17b, 17e, 17d, and 17e are output to the actuators 10 of actuators 5b, 5c, 5d, and 5e.

The control arithmetic unit 15 includes microphones 5a, 5b, and 5c that have been obtained during normal operation of the dryer.

A background noise signal 18 corresponding to each turning position of microphones 5d and 5e is input, and the microphones 5a, 5b, 5c
, 5d.

Sound pressure signals 12a, 12b, 12c, 1 detected at 5e
Noise level signal S (obtained by frequency analysis of 2d and 12e)
The actual noise signal 19 is obtained by subtracting the background noise signal 18 from the background noise signal 18 (see FIG. 3).

Further, the control calculation device 15 controls each roll group A as described above.
, B, C, D, H detected sound pressure signals 12a, 1
A noise source position signal 20 is calculated and output from the sizes of the microphones 2b, 12c, 12d, and 12e and the turning positions of the microphones 5a, 5b, 5c, 5d, and 5e.

Furthermore, the noise signal 19 obtained by the control calculation device 15
The noise source position signal 20 is input to a display device 21 and displayed, and an abnormality alarm is issued depending on the magnitude of the noise signal 19.

In diagnosing a failure, for example, the sound pressure signal 12a from the microphone 5a provided in the roll group A is sent to the control/arithmetic unit [15] using the selection command signal 16 from the control/arithmetic unit [15
In the state where the scanner 14 is switched so as to input the rotation command signal 17a to the rotation drive device ! fil, the microphone 5a is rotated, and a noise level signal S is obtained by frequency-analyzing the sound pressure signal 12a as shown in FIG. 3 in accordance with each rotation position of the microphone 5a.

Further, from the noise level signal S, a background noise signal 18 corresponding to the rotational position of the microphone 5a, which has been input in advance to the control calculation device 15, is subtracted to obtain an actual noise signal I9 as shown in FIG. The noise signal 19 is displayed on the display device 21.

The degree of wear such as wear can be determined by the level of the noise signal 19, and the cause of wear of bearings, gears, etc. can be determined by the frequency.

Further, when the noise signal 19 exceeds a certain level at this time, an alarm may be issued or an abnormality may be displayed.

Furthermore, the same operation as described above is performed for the microphones 5b, 5c, 5d, and 5e provided in the other roll groups B, C, D, and H to obtain and display the noise signal 19.

In addition, sound pressure signals 12a from each microphone 5a, 5b, 5c, 5d, and 5e are input to the first control calculation device 15.
.

1.2b, 12c, 12cl, and 12e are, for example, when the microphone 5a is used as an example, when there is a noise source T due to wear and tear in the roll group A, the sound pressure level increases as shown in FIG. 5 due to the rotation of the microphone 5a. 12a changes to show the maximum value M when the microphone 5a faces the noise source T.

Therefore, the position of the noise source T can be calculated from the rotational position of the microphone 5a when the sound pressure signal 12a shows the maximum value M, and the noise source position signal 20 calculated in this way is output to the display device 2I. and display it. Further, by performing the operation of calculating the position of the noise source T based on the rotational position of the microphone 5a where the sound pressure signal 12a has the maximum value M for the microphones (for example, 5b) of the adjacent roll group, more accurate noise can be calculated. The source position can be calculated.

According to the above, determination of normality or abnormality based on the magnitude of the noise signal 19, determination of the cause of abnormal wear and tear based on the frequency, and determination of the position of the noise source T based on the range and noise source position signal 20 are immediately and accurately performed and displayed. Therefore, it is possible to quickly take measures against the occurrence of an abnormality.

It should be noted that the dryer failure diagnosis device using sound pressure according to the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, according to the sound pressure-based dryer failure diagnosis device of the present invention, the position of the noise source can be determined by the sound pressure signal from the microphone provided in the roll group, and from the sound pressure signal. The degree of wear and tear and the cause of the wear can be diagnosed quickly and accurately using the obtained noise signal.Diagnosis is performed using sound pressure signals from a microphone that can cover a wide range, so it is relatively easy to diagnose. Excellent effects can be achieved with a simple configuration and easy implementation.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a plan view showing an example of a microphone, Fig. 3 is a line diagram showing a noise level signal and a background noise signal, and Fig. 4 is a line diagram of the noise signal. figure,
FIG. 5 is a diagram showing an example of changes in sound pressure level with respect to the rotational position of the microphone. In the figure, 5a, 5b, 5c, 5d, and 5e are microphones,
11 is a turning disturbance device, 12a, 12b, 12c, 12d
, 12e is a sound pressure signal, 14 is a scanner, 5 is a control calculation device, 17a, 17b. 17c, 17d, 17e are turning command signals, 18 is a background noise signal, 19 is a noise signal, 20 is a noise source position signal, 21 is a display device, A, B, C, D, E are roll groups,
S represents the noise level signal, and M represents the maximum value. Figure 2

Claims (1)

[Claims] 1) A microphone installed horizontally for each group of rolls in a dryer of a paper manufacturing machine to detect the noise of each group of rolls, a rotation drive device for rotating each microphone, and a rotation drive device for each microphone. A scanner that selects and outputs a detected sound pressure signal, and a scanner that inputs the selected sound pressure signal and outputs a rotation command signal to a microphone inputting the sound pressure signal, and determines the rotation position of the microphone. find a noise level signal corresponding to the noise level signal, subtract a background noise signal input in advance from the noise level signal to obtain an actual noise signal, and perform the operation for obtaining the actual noise signal for each of the microphones; and a control calculation device that calculates a noise source position signal from the rotational position of the microphone indicating the maximum value of the sound pressure signal, and a display device that inputs and displays the noise signal and the noise source position signal from the control calculation device. A dryer failure diagnosis device using sound pressure.