JPH109945A - Method for monitoring cutter of tbm and device for monitoring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for monitoring the state of the wear of the cutter of a TBM in digging operation without discontinuing the digging operation in real time. SOLUTION: A vibration detector 10 is arranged close to the rotary cutter head 2 of a TBM1 to detect the vibrations of the cutter head 2 in actual digging operation by the vibration detector 10. A processing unit 12 carries out a frequency spectrum analysis on the detected vibrations. And by comparing the information of peak distribution to be a standard with the information of peak distribution in digging operation, the state of roller bit according to each peak is monitored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting wear of a cutter in the construction of a rock tunnel using a TBM.

[0002]

2. Description of the Related Art In the construction of a rock tunnel using a TBM, wear of a cutter not only greatly reduces excavation efficiency, but in some cases, also leads to breakage of a cutter body, damage to bearings, and other expensive mechanical parts. Has to be replaced, causing a great deal of cost and time loss.

[0003] Therefore, it is extremely important to detect the wear of the cutter at an early stage and quickly replace it, not only in terms of improving the economy but also the safety of the TBM method. From such a meaning, it has been conventionally performed to visually observe the state of wear of the cutter. In order to observe visually, the excavation was stopped, the TBM was slightly retracted, a space for observation was provided on the face, and the observer entered the space directly.
The wear condition of the cutter is investigated by visual observation.

[0004]

However, in the conventional visual observation method as described above, excavation must be stopped every time the wear of the cutter is investigated, so that time and cost are lost due to a delay in the construction process. There is a problem of inviting. Also, since the observer needs to enter the narrow space between the face and the cutter, there is a danger of unpredictable sudden accidents such as collapse of the face or falling rocks, which poses a major safety problem. .

Accordingly, an object of the present invention is to provide a method and apparatus for monitoring the state of wear of a cutter of a TBM during excavation operation in real time without stopping excavation.

[0006]

According to a first aspect of the present invention, there is provided a cutter monitoring method according to the first aspect, wherein vibrations of a plurality of roller bits provided in a radial direction on a rotating cutter head of the TBM are detected by detecting the vibration provided near the cutter head. It was configured to detect with a vessel. And in the cutter monitoring method of claim 2,
The configuration is such that the vibrations of a plurality of roller bits arranged in the radial direction on the cutter head which rotates the TBM are detected by a plurality of vibration detectors respectively arranged near each roller bit.

In the cutter monitoring method according to the third aspect, a vibration detector for detecting vibration of the rotating cutter head of the TBM is provided near the cutter head, and the cutter head is in operation while all the roller bits are normal. Is detected by the vibration detector, the vibration is subjected to frequency spectrum analysis, and reference peak distribution information and corresponding information between each peak and each roller bit are obtained in advance, and the actual excavation is performed. The vibration of the cutter head in is detected by the vibration detector, and the vibration is subjected to frequency spectrum analysis to obtain peak distribution information during excavation,
The state of the roller bit corresponding to each peak is monitored by comparing the corresponding peaks in the reference peak distribution information and the peak distribution information during the excavation.

According to a fourth aspect of the present invention, there is provided a cutter monitoring device which is provided near a rotating cutter head of a TBM and detects vibration of the cutter head, and a frequency spectrum of the vibration detected by the vibration detector. And a spectrum analyzing means for analyzing.

According to a fifth aspect of the present invention, there is provided a cutter monitoring apparatus, comprising: storage means for storing predetermined reference peak distribution information, each beak and each roller bit in the reference peak distribution information, and a rotating cutter head of the TBM. A vibration detector that is disposed in the vicinity of and detects vibration of the cutter head, a frequency spectrum analysis of the vibration detected by the vibration detector, and a spectrum analysis unit that outputs peak distribution information. A means for determining the state of the roller bit corresponding to each peak by comparing the output peak distribution information with the reference peak distribution information is provided.

The principle of the above method will be described below. TBM
During excavation, the cutter head is rotated via gears by a hydraulic motor, and in this state, the cutter bit is pressed against the face by a hydraulic jack. In this state, since the cutter head is rotating, the cutter bit pressed against the rock also rotates to cut the rock.

In the course of such excavation, vibrations of various factors are generated around the cutter bit. First, there is vibration caused by the rotation of the cutter head, which changes according to the number of rotations of the cutter head.

FIG. 8 shows a state in which the rotation of the cutter head is stopped and the propulsion force of the jack is very small (about 20).
(Ton: about one-fifth of normal) is a frequency spectrum distribution measurement diagram of vibration. According to this, two large peaks are observed at a frequency of slightly lower than 10 kHz and 19 kHz. FIG.
FIG. 4 is a frequency spectrum distribution measurement diagram in a state where the thrust of the jack is zero when the cutter head is rotating 7 times per minute. According to this, the frequency is 10 kHz as in FIG.
There are two large peaks at a little less than z and 19 kHz, but there is also a peak at about 500 Hz.

The difference between the measurement conditions in FIGS. 8 and 9 is the presence or absence of the rotation of the cutter head. Therefore, it can be assumed that the peak appearing at around 500 Hz is caused by the rotation of the cutter head. Thus, it can be seen that some peaks appearing in the frequency spectrum distribution are caused by the rotation of the cutter head.

On the other hand, the vibration frequency F associated with the rotary cutting by the roller bit can be expressed by the following equation (1).

[0015]

(Equation 1)

Here, D: diameter of mounting roller bit d: diameter of roller bit α: contact angle F ₀ : motor rotation speed

As described above, since the vibration frequency F is proportional to the mounting diameter D of the roller bit (the distance from the center of rotation of the cutter head), if each roller bit is normal, the frequency spectrum shows the frequency of the roller bit. It can be seen that a peak corresponding to the mounting position appears. That is, it can be seen that a peak distribution according to the configuration of the cutter head is observed in the frequency spectrum of the vibration detected near the normally operating cutter head. And
If an abnormality occurs in any of the roller bits and the rotation of the roller bit changes, the distribution of frequency peaks will change.

In this way, by monitoring the peak of the frequency spectrum, it is possible to grasp the rotation status of the roller bit of the cutter head. When abnormalities such as uneven wear or breakage of the roller bit occur, the roller bit does not rotate normally, and such abnormalities in the rotation state include changes in the peak of the frequency spectrum,
Specifically, it appears as disappearance of a specific peak.

Then, according to the above-described equation, the mounting position of the roller bit in which the abnormality has occurred can be known from the frequency of the changed peak. Usually, the distances from the center of the cutter head to the respective roller bits are arranged so as to have a constant difference so that the trajectories of the respective roller bits draw concentric circles at equal intervals (see FIG. 2). In addition, the mounting diameter D of the roller bit in the above equation becomes a constant difference, and the distribution of peaks at the time of spectrum analysis becomes a constant frequency interval.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for monitoring a cutter of a TBM according to the present invention will be described below in detail with reference to the drawings showing an embodiment of a monitoring device used in the method. In FIG. 1 showing the configuration of a cutter monitoring device used in the cutter monitoring method of the present invention, reference numeral 1 denotes a TBM, and n roller bits B1, B2,... , A cutter head 2 rotated by a motor, and a gripper 3 pressed against a pit wall to maintain a position behind the cutter head 2, and the cutter head 2 is propelled between the cutter head 2 and the gripper 3. A jack 4 is provided.

Reference numeral 5 denotes a screw conveyor for scraping the earth and sand excavated in front of the partition wall 6 to the rear, and reference numeral 7 denotes a belt conveyor for discharging the earth and sand scraped by the screw conveyor 5 further to the rear.

Reference numeral 10 denotes a vibration detector using a piezoelectric accelerometer fixed to the partition 6, reference numeral 11 denotes an amplifier for amplifying a vibration signal detected by the vibration detector 10, and reference numeral 12 denotes a vibration amplified by the amplifier 11. This is a processing device that performs spectrum analysis on a signal by FFT operation.

Using the cutter monitoring device having the above structure, TB
When monitoring M, first, spectrum analysis is performed while excavating under normal conditions with all roller bits in a normal state in advance. As shown in FIG. 2, the n roller bits B1, B2,..., Bn have distances L, 2L, 3L,.
nL and a constant difference, the spectrum distribution has equally spaced peaks P1, P2,.
n.

Each roller bit B1, B2,... Bn
It is previously confirmed that the spectrums of the vibrations generated by the rotation correspond to the peaks P1, P2,... Pn. In this manner, the spectrum distribution of FIG. 3 is hard-copyed or the like as peak distribution information serving as a reference.

Next, actual excavation work is performed. At this time,
During excavation, spectrum analysis is performed in the same manner as described above to monitor the distribution state of peaks. When the spectrum distribution during such excavation is as shown in FIG. 4, it is observed that the seventh peak P7 is extremely low in comparison with the peak distribution of FIG.

Since the seventh peak P7 corresponds to the seventh roller bit B7, it can be determined that the seventh roller bit B7 has an abnormality such as uneven wear or chipping. Then, the operation of the TBM is stopped, the roller bit is replaced, and the operation is restarted.

As described above, there is no need to stop and inspect the TBM until a peak abnormality as shown in FIG. 4 appears, so that excavation work can be performed extremely efficiently. In addition, danger is reduced because the number of times a person enters between the face and the cutter head is reduced.

In the above, a method of making a judgment by a person while monitoring the result of the spectrum analysis has been described. However, an automatic judgment function may be provided. For this purpose, in addition to the configuration of FIG. 1, as shown in FIG. 5, a storage device that stores peak distribution information P serving as a reference and position information Q that specifies the position of each peak and the corresponding roller bit. 121, and the peak distribution information P serving as a reference is compared with the peak distribution information P ′ during excavation, and when the height of the corresponding peak changes beyond a set range, based on the position information Q, It is preferable to include a determination circuit 122 for specifying the position of the roller bit in which the abnormality has occurred.

By removing noise and correcting the difference in attenuation rate due to the difference in frequency, peak distribution information P and peak distribution information P ′ during excavation as shown in FIG. 6 can be obtained. As shown in FIG. 7, the position information Q is stored as information for specifying the position and number of the roller bit in which an abnormality has occurred, based on the number of the peak whose peak height has changed.

Further, the vibration detectors are not fixed to the partition wall, but several vibration detectors are dispersed and arranged.
The spectrum analysis may be performed by adding the signals of the respective vibration detectors. Further, the signals of the respective vibration detectors may be subjected to spectrum analysis and then added. Since the high frequency vibration is easily attenuated before reaching the vibration detector, the amplification factor of the high frequency in the amplifier may be set large.

Further, when the vibration detector is fixed in the vicinity of each roller bit, the influence of the vibration of other roller bits and the influence of noise are reduced, so that more accurate monitoring becomes possible. At this time, the vibration of each roller bit may be able to be identified without analyzing the signal of each vibration detector. If the frequency of each peak does not change, it is possible to perform processing with a plurality of filters instead of spectral analysis.

Further, a second vibration detector is fixed at a position distant from the cutter head, and the amplifier uses a second vibration detector based on a signal from the vibration detector fixed near the cutter head.
The vibration signal other than the vibration due to the rotation of the roller bit may be removed by subtracting the signal from the vibration detector.

[0033]

According to the method for monitoring the cutter of the TBM according to the first and second aspects, it is possible to monitor abnormalities such as uneven wear and breakage of the roller bit by detecting the vibration caused by the rotation of the roller bit. There is no need to stop the operation of the TBM and visually observe the roller bit, so that high work efficiency and safety can be obtained.

According to the monitoring method and the monitoring apparatus of the TBM according to the third, fourth, and fifth aspects, the frequency spectrum analysis of the vibration caused by the rotation of the roller bit can monitor the abnormalities such as uneven wear and loss of the roller bit. So many times TB
There is no need to stop the operation of M and visually observe the roller bit, so that high work efficiency and safety can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of a cutter head monitoring device according to the present invention.

FIG. 2 is a schematic front view of a cutter head.

FIG. 3 is a reference spectrum distribution diagram in the monitoring device.

FIG. 4 is a spectrum distribution diagram during excavation in the monitoring device.

FIG. 5 is a configuration diagram of a main part of a monitoring device according to claim 4;

FIG. 6 is a diagram illustrating the contents of peak distribution information.

FIG. 7 is a diagram illustrating the contents of position information.

FIG. 8 is an example of a spectrum distribution diagram obtained by the monitoring method of the present invention.

FIG. 9 is an example of a spectrum distribution diagram obtained by the monitoring method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 TBM 2 Cutter head 6 Partition wall 10 Vibration detector 12 Processing device (spectral analysis means) 121 Storage device (storage means) 122 Judgment circuit (judgment means) B1, B2, ... Bn roller bit

Claims (5)

[Claims] 1. A cutter monitor for a TBM, wherein vibrations of a plurality of roller bits arranged in a radial direction on a rotating cutter head of the TBM are detected by the vibration detector arranged near the cutter head. Method. 2. The TBM according to claim 1, wherein vibrations of a plurality of roller bits arranged in a radial direction on a rotating cutter head of the TBM are detected by a plurality of vibration detectors respectively arranged near each roller bit. Cutter monitoring method. 3. A vibration detector for detecting vibration of a rotating cutter head of the TBM is provided near the cutter head.
The vibration detector detects vibration of the cutter head while all the roller bits are normal and digging, analyzes the frequency spectrum of the vibration, and provides a reference peak distribution information and a correspondence between each peak and each roller bit. Information in advance, the vibration of the cutter head during the actual excavation is detected by the vibration detector, the vibration is subjected to a frequency spectrum analysis, and peak distribution information during the excavation is obtained, and a reference peak distribution is obtained. A method for monitoring a cutter of a TBM, comprising: comparing a state of a roller bit corresponding to each peak by comparing corresponding peaks in information and peak distribution information during excavation. 4. A vibration detector, which is disposed near a rotating cutter head of the TBM and detects vibration of the cutter head, and spectrum analysis means for analyzing a frequency spectrum of the vibration detected by the vibration detector. A cutter monitoring device for a TBM. 5. A storage means for storing predetermined reference peak distribution information, corresponding to each beak and each roller bit in the reference peak distribution information, and a cutter head disposed near the rotating cutter head of the TBM. A vibration detector for detecting the vibration of the vibration detector, a frequency spectrum analysis of the vibration detected by the vibration detector, and a spectrum analysis means for outputting peak distribution information, the peak distribution information output from the spectrum analysis means, A TBM cutter monitoring device comprising: a determination unit configured to determine a state of a roller bit corresponding to each peak by comparing with peak distribution information.