JPS61196160A - Spalling position detector for rolling roll - Google Patents

Abstract

PURPOSE:To locate the position of spalling generation on a rolling roll accurately, by comparing the arrival order of two elastic wave signals to an elastic wave transducer mounted at both axial ends of the roll. CONSTITUTION:An elastic wave transducer 5 is mounted at both ends of a bearing 4 of a backup roll 1 and elastic wave signals S1 and S2 generated are detected to obtain effective signal components S1a and S2a through an amplifier 6 and a filter 7. On the other hand, a revolutions detector 9 is mounted to a driving part of a work roll 2 to obtain a rotation signal C with a tachometer 10. Then, the X-axis position of the signals S1a and S2a and the Y-axis position distribution of the rotating direction are measured with a position locating circuit 8 and the results are transferred to a microcomputer 12 for data analysis. Then, when the results are larger than the location value predetermined in the location of the position of the circuit 8 in comparison, an alarm 11 is given to detect the generation of spalling on the rolls 1 and 2. Besides, the distribution of the generation position thereof is displayed in hystogram on a monitor TV 13 to locate the generation position accurately.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is directed to the occurrence (or existence) of spalling (a general term for surface scratches, surface peeling, etc.) of rolling rolls that occurs in an operating rolling mill, and its occurrence. This invention relates to a device for detecting the location of occurrence.

[Background of the invention]

Generally, a rolling mill has work rolls or backup rolls, and the rolled material is rolled between the work rolls, and the work roll is pressed against the work roll by the backup roll. The diameter of the work roll is about 1/2 that of the backup roll, and when the work roll makes one revolution, the backup roll makes about 1/2 revolution. Therefore, the load on the work roll is greater than the rolling load. In addition, roll spalling such as minute scratches and peeling occurs on the roll surface because the rolled material is hot and the material and shape are not constant. Even if this roll spalling occurs, it does not immediately render it unusable, and the mill is operated while replacing and repairing the rolling rolls as appropriate. Therefore, there is a need for a device that detects the location where roll spalling occurs in order to determine when to replace the rolling rolls.

For example, Japanese Patent Laid-Open No. 53-12 discloses a method of detecting flaws, cracks, etc. that occur in various devices and component parts to predict destruction.
As described in Publication No. 1686, elastic waves (acoustic emissions) generated due to the presence of spalling are detected, and a point where the number of elastic waves that occur rapidly in a predetermined unit time is determined as a failure prediction point. There are known methods to do this.

This method can predict failure with a simple configuration, but elastic waves occur not only at crack propagation but also at stress concentration points in the elastic region, and can be detected by increasing the distance between acoustic transducers that detect elastic waves. It is also difficult to detect noise other than the desired elastic wave, and it becomes difficult for the point of sudden increase in the detected elastic wave signal to coincide with the predicted failure point. In addition, in operating equipment, the level of elastic waves generated by the progress of destruction and other disturbing elastic wave signals is high, making it difficult to detect elastic wave signals based on destruction.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rolling roll spalling detection device that can detect the occurrence of roll spalling on a rolling roll and can accurately detect the position where roll spalling occurs.

[Summary of the invention]

In order to achieve the above object, the present invention includes an elastic wave transducer attached to each of bearings that pivotally support both axial ends of a roll, a rotation speed detector that detects the rotation speed of the roll, and a rotation speed detector that detects the rotation speed of the roll. By comparing the arrival of the two elastic wave signals to the wave transducer, the spalling occurrence position in the axial direction of the roll is determined, and the spalling occurrence position in the circumferential direction of the roll is determined from the rotation speed detection signal. The present invention is characterized in that it includes a position locating circuit that determines and locates the spalling occurrence position on the rolling roll.

The position locating circuit includes, for example, a detector that detects when two elastic wave signals arrive at the elastic wave transducer, and an an axis address counter, a Y-axis address counter that counts in synchronization with the rotational direction of the rolling roll, a writable memory that stores the count values of the X-axis address counter and the Y-axis address counter, and one of the elastic wave signals. When an elastic wave signal arrives after , the data stored in the memory can be successively read out, and after adding @1#, the data can be written again.

That is, the outline will be explained below. A feature of the present invention is that when roll spalling occurs, the positions of the elastic wave transducers that detect the elastic wave signals generated due to the roll spalling are aligned at the same position with respect to the rotational direction of the rolling rolls. Focusing on being oriented in return,
The point is that the position is determined from two elastic wave signals and a rolling roll rotation signal.

This elastic wave signal is generated when the work roll and backup roll rotate while contacting each other, and when this contact point coincides with the position of roll spalling. The positioning between the transducers at both ends of the flat bearing is determined by the distance t1 from the center of the rolling roll 1 to the source, as shown in Figure 1.
If the speed of sound propagating through the rolling roll 1 is v1 and the arrival time difference between the two elastic wave signals obtained by the elastic wave transducer is Δt, then the relationship of equation α) exists.

t=1/2・V・Δt・・・・・・・・・・・・
(1) Here, the sound speed V is a known number), and a theoretical value or an actual value can be adopted. Whether the occurrence occurs on the left or right side of the center of the rolling roll 1 can be detected by comparing and determining where the two elastic wave signals arrive and determining which elastic wave arrived first (hereinafter referred to as the first arriving wave). can. In the arrangement shown in FIG. 1, if the wave is generated from the left side of the rolling roll 1, Sl becomes the first arriving wave.

In this way, the position of the rolling roll 1 in the axial direction (hereinafter referred to as the X-axis direction) can be determined from the arrival order of the two elastic wave signals, the arrival order of the elastic wave signals, and the time difference between the arrival points of the elastic wave signals. .

On the other hand, the position of the rolling roll 1 in the rotational direction (hereinafter referred to as the Y-axis direction) can be determined by dividing the rotation period of the rolling roll 1 into several parts, finding the time of the occurrence position for each rotation, and synchronizing the position. Become.

By locating the elastic wave signals generated in combination in the X-axis direction and Y-axis direction of the rolling roll 1 in this manner, it is possible to specify the position where roll spalling occurs.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.

In FIG. 2, a rolled material 3 is rolled between work rolls 2 of a rolling mill, and a pick-up roll 1 presses down this work roll 2. Acoustic (elastic wave) transducers 5 are attached to both ends of the speed bearing 4 supporting the backup roll 1, and the acoustic transducers 5 detect each acoustic (elastic wave) signal 81 pSs generated. Since the detected acoustic signal 5158m is minute, it is amplified by the amplifier 6, and the mechanical noise and electrical noise are 100KHz to 2MH! It is a component of degree. on the other hand,
A rotation speed detector 9 is attached to the drive portion of the work roll 2, and a rotation signal C is obtained by a tachometer 10. A position locating circuit 8 which receives the acoustic signal SL from the filter 7 and the rotation signal C from the tachometer 1O calculates the position of the generated acoustic signal 81s8 in the X-axis direction and the Y-axis position distribution in the rotational direction. Measure.

The position distribution data from the position locating circuit 8 is transferred to the microcomputer 12 for various data analysis. Further, the microcomputer 12 and a monitor television 13 are connected to display a histogram of the position distribution. Position locating circuit 8°
When locating the position, if the location value is larger than a predetermined location value, the alarm 11 can sound an alarm. This alarm allows it to be determined that spalling has occurred in the backup roll or work roll. In addition,
In addition to the histogram display, the monitor TV 13 also displays the rolling α
- The position locating circuit will be explained below using a moving image of the spalling positions existing in the room together with the time chart of FIG. The acoustic signals Sem and Sem from the filter 7 are input to the arrival order detection circuit 14 .

The arrival order detection circuit 14 has a means for pulsing the acoustic signals 81a and SMS exceeding a threshold value so that they can be digitally processed, and obtains a pulse signal 5+b and F3sb. Further, the arrival order detection circuit 14
determines the arrival order of the two pulse signals 81b and 8mb, and if %81b is early, the S1 priority circuit 15 is selected, and if Ss is early, S! Activate the priority circuit 16.

When the SS priority circuit 15 is activated, the XL address counter 17 starts counting. Similarly, SS priority circuit 16
When the Xm address counter 18 is activated, the Xm address counter 18 starts counting. For example, as shown in FIG.
In a relative comparison between waveform W in 182@ and waveform X, waveform 8 arrives earlier, so the output signal fi of the XL address counter 17 is obtained. In the waveform Vm'' in the acoustic signal 81 m * 8 t a, 82 m arrives earlier, so in this case, the output signal g of the X3 address counter 18
get.

XL address counter 17 and Xm address counter 18
The output signal f9g corresponds to the next lower address of the RAM memory 23, and corresponds to each acoustic transducer on the left and right from the center of the rolling mill. This corresponds to positions (distance L) up to 5. Therefore, the maximum time of each address counter 17, 18 is L/V, and the order of arrival is determined every this time. Note that ■ is the speed of sound. The XL address counter 17 and the X-axis address counter 18 perform counting using the clock signal e of the X-axis lock signal generator 19. One clock of this clock signal e is the resolution of the X-axis positioning.Here, if one side is divided into 64 parts from the center, the resolution is about 47 tM. The resolution can be improved by further dividing the clock signal e, but since the RAM memory 23 has a large capacity, it is appropriate to divide the clock signal e into 64 parts on one side.

Further, when the rotation signal C from the tachometer 10 is input to the Y-axis lock signal generator 20, the Y-axis lock signal generator 20
A clock signal d, which always has a constant number in one cycle, is output from the circuit. This Y-axis lock signal d is a signal divided into 128 parts between the X-axes, and the resolution in the Y-axis direction is, for example, about 3.7 m if the diameter of the backup roll is 15 m.

The Y-axis lock signal d is input to the Y-axis address counter 21 to obtain a Y-axis address signal d. The Y-axis address signal repeats counting every cycle, up to a maximum of 128. The address of the RAM memory 23 is the XL address signal f or X! The address is determined by a combination of address signal g and Y address signal. This ram memory 23
The map is shown in Figure 5. It was divided into 128 sections in both the X and Y directions, giving a total capacity of 16K (16384) bytes.

Next, when the second arriving pulse occurs while the X-axis address signal 'yg is being generated, the R/W control circuit 22
Create a signal l and an X-axis address signal f.

RλM of address combining g and Y-axis address signal
Specify one memory 230 and read data 0 For example, the waveform W in the acoustic signal 81m18Ib has data 04
For waveform 2, 22 data can be read. Next, add 1 to the read data in the adder circuit 24, and write the data at the specified address in the RAM memory 23 with the write pulse of the /W signal 6. For example, the acoustic signal 81as
Waveform W in slb is written as data 05, and waveform 2 is written as data 23. Even if an X address signal is generated as shown in the waveforms x and y in the preceding arrival signal 5ea1 Bib, reading and writing of data in the RAM memory 23 will not be performed unless there is a second arrival pulse. In this way, with the second arriving pulse, the RAM
By rewriting the data in the memory 23, real-time high-speed processing is possible.

If the addition output of the addition circuit 24 is always compared with the set value by the comparator 25, the output of the comparator 25 can be directly used in the alarm 11.
You can connect with In this way, a warning can be easily output without constantly comparing all data in the RAM memory 23.

The data in the RAM memory 23 is the accumulation of positional orientations after the start of measurement, but since the amount of data is usually 1 byte, there is a risk that the amount of data will become full in a short period of time.

For this reason, the Y-axis lock signal d of the Y-axis lock signal generator 20 is counted a certain number by the rate count 26, and when the number of rotations reaches a certain multiple, the clear circuit 27 clears the data at all addresses in the RAM memory 23. . By adding this clear circuit 27, it becomes possible to monitor the rotation speed in units of fixed multiples.

For example, the data in ordinary person M memory 23 is 256 (1 byte)
If the clear circuit 27 is to be cleared every 200 rotations due to the number of rotations, and if the alarm is issued when the number of position constants during this period is 100, it can be determined that sirol spalling has occurred.

According to the above-described embodiment of the present invention, acoustic signals other than noise and roll spalling are also detected, but since the positioning of noise and the like is distributed throughout, it is easy to distinguish it from noise. Furthermore, since roll spalling can be repeatedly detected whenever the mill rolls are rotating, the progress of roll spalling can be observed.

In addition, it is large enough for roll spalling.

Regarding the influence of these differences on the detection accuracy of the present invention, there are differences in direction and depth.

The depth has almost no relation to the depth because the present invention processes in two dimensions of X-Y coordinates. However, regarding the size, spalling can be considered as a point within the resolution range mentioned above, but if it exceeds this, it cannot be considered as a point.
If the data exceeds the resolution, the data at the adjacent address becomes @1'. Since data is written according to the spread of spalling, its distribution state can also be detected, so there is no problem with accuracy. .

In addition, large impact sounds are generated when the rolled material is bitten by the rolling mill and when it falls out of the rolling mill, but the nature of these acoustic signals is that they occur only once each time, in other words, they are periodic. Therefore, it can be easily distinguished from a true acoustic signal due to spalling. This also applies to other noises. Furthermore, depending on the situation, if the spalling detection of the present invention is started after the time when the spalling has occurred, the problem of noise can be eliminated.

〔Effect of the invention〕

According to the present invention, it is possible to detect the occurrence of roll spalling in rolling mill rolls, and also to accurately locate the occurrence position, so that it is possible to accurately determine when to replace or repair the rolling mill rolls. Therefore, from a work and economic standpoint, there is great efficiency in contributing to highly efficient operation of the rolling mill.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the detection principle of the present invention, FIG. 2 is a block diagram showing the overall configuration of a roll spalling detection device for a rolling mill according to the present invention, and FIG. 3 is a block diagram of a position locating circuit.
FIG. 4 is a flowchart showing signals of each part, and FIG. 5 is an address map diagram showing examples of addresses of the M memory used in FIG. 2. 1, 6... Amplifier, 7... Filter, 8... Position locating circuit, 9... Rotation speed detector, lO... Tachometer, 11... Alarm, 12. ...Microcomputer, 13...Monitor TV, 14...Arrival order detection circuit, 23...-RAM memory, 24...Addition circuit, 26
... Rate counter, 27... Clear circuit.

Claims (1)

[Claims] 1. An elastic wave transducer attached to each of the bearings that pivotally supports both axial ends of the roll, a rotation speed detector that detects the rotation speed of the roll, and a rotation speed detector for the elastic wave transducer. The spalling occurrence position in the axial direction of the rolling roll is determined by comparing the arriving points of the two elastic wave signals, and the spalling occurrence position in the circumferential direction of the rolling roll is determined from the rotation speed detection signal. A spalling position detection device for a rolling roll, comprising: a position locating circuit for locating a spalling occurrence position on the rolling roll. 2. In the apparatus according to claim 1, the position locating circuit includes a detector for detecting where the two elastic wave signals arrive at the elastic wave transducer, and a rolling roll for the elastic wave signal that arrived first. an X-axis address counter that counts time proportional to the axial direction of the rolling roll, a Y-axis address counter that counts in synchronization with the rotational direction of the rolling roll, and a writing device that stores the count values of the X-axis address counter and Y-axis address counter. and a read/write control circuit that reads data stored in the memory when a later one of the elastic wave signals arrives, adds "1", and then writes the data again. Spalling detection device for rolling rolls.