JP3806182B2 - Method for diagnosing wear of cutter face of tunnel excavator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for diagnosing the soundness of a cutter face for excavating the ground in tunnel excavation work by a tunnel excavation machine such as a shield machine or a tunnel boring machine (TBM).
[0002]
[Prior art]
In tunnel excavation work using the shield method, the cutter face (disk cutter) that rotates at the front of the shield machine and excavates the ground is worn and damaged over time as the ground is cut, so the cutter face is worn to some extent. If you do, you need to replace it. However, exchanging the cutter face in the ground involves complicated and large-scale construction, so exchanging it more frequently than necessary will increase the number of interruptions of excavation work, increase the construction period, increase costs, and If the replacement frequency is too low, the excavation speed and excavation efficiency will be significantly reduced due to the cutter face being worn beyond the allowable range.Therefore, the soundness of the cutter face is constantly diagnosed on the ground and the replacement time is determined. It needs to be determined accurately.
[0003]
As a method for diagnosing the soundness of such a cutter face, conventionally, based on the assumption that the degree of wear of the cutter face is approximately proportional to the amount of sliding with the ground, the circumference of the cutter face that accompanies excavation is measured. The method to do is adopted. According to this method, it is diagnosed that the harder the ground, the longer the cutting distance of the cutter face at a certain excavation distance, and the more the wear proceeds.
[0004]
[Problems to be solved by the invention]
However, since the wear of the cutter face is actually controlled by the operating conditions of the tunnel excavating machine and the hardness of the ground to be excavated, the data of only the cutter face sliding distance obtained from the rotational speed is used. It is difficult to accurately diagnose the progress of wear and tear and accurately estimate the replacement time.
[0005]
The present invention has been made under the circumstances as described above, and the technical problem is that the machine amount data of the tunnel excavating machine and the data of the hardness of the ground to be excavated are cut by the cutter face. By adopting it as a characteristic parameter for diagnosing wear and tear, it is to improve the accuracy of diagnosis.
[0006]
[Means for Solving the Problems]
The ground excavation sound due to the cutter face of the tunnel excavation machine changes in response to the change in the excavation situation due to the hardness of the excavation ground, for example, the sound is soft in the soft viscous soil layer, such as the gravel layer, the rock layer, Since the excavation sound becomes louder as the ground becomes harder, it is possible to know the hardness of the excavation ground using such loudness, and the amplitude of the excavation sound uses the amplitude value of the signal waveform. Can be expressed. Therefore, in the method for diagnosing wear of a cutter face of a tunnel excavating machine according to the present invention, unnecessary frequency components are included in an acoustic detection signal from a sound wave sensor that detects ground excavation sound including noise such as noise caused by driving of the machine. The average amplitude value V of the excavation sound for each fixed excavation distance obtained by cutting off and processing the waveform is used as a characteristic parameter representing the hardness of the excavated ground.
[0007]
On the other hand, the total thrust P of the tunnel excavating machine, the propulsion speed J, and the rotation speed R of the cutter face are all information representing the ground excavation status by the cutter face. Therefore, in the method for diagnosing wear of the cutter face of the tunnel excavating machine according to the present invention, the total thrust P, the propulsion speed J and the rotational speed R are measured, and the ground excavation status is used as a parameter of the machine amount from these measured values. Is defined by the following equation (1).
k = P / (J / R) ........................... 1
[0008]
This excavation factor k is an index representing the degree of excavation resistance depending on the change of the geometric condition of the cutter face, that is, the excavation force change due to the wear of the cutter face and the mechanical properties of the ground to be excavated. It is.
[0009]
That is, it can be considered that the average amplitude value V and the excavation coefficient k described above all shorten the cutter face life as the numerical value increases. Therefore, the soundness of the cutter face estimated from the combination of the average amplitude value V and the excavation coefficient k described above is previously patterned, and several diagnostic patterns are set. The wear state of the cutter face can be diagnosed by comparing the average amplitude value V and the excavation coefficient k for each excavation distance with the diagnosis pattern.
[0010]
In this case, for example, the following four cases can be considered as the diagnostic pattern.
[Case 1] When V and k are both smaller than a predetermined reference value;
It shows that the ground is soft and the ground cutting condition is good, the amount of wear of the cutter face is small, and the excavation distance per rotation of the cutter face is estimated to be large, so excavation until replacement is necessary The distance is extended.
[Case 2] When V is smaller than the reference value and k is larger than the reference value;
Although the ground is soft, it shows that the cutting resistance is large, and the amount of wear per rotation of the cutter face is small, but the excavation distance per rotation of the cutter face is estimated to be short, so it is necessary to replace it The digging distance to become does not increase or decrease so much.
[Case 3] When V is larger than the reference value and k is smaller than the reference value;
The ground is hard, but the ground cutting condition is good. The wear amount per rotation of the cutter face is large, but the excavation distance per rotation of the cutter face is estimated to be long. The distance until is required does not increase or decrease so much.
[Case 4] When V and k are both larger than the reference value;
This indicates that the ground is hard and the cutting resistance is large, the cutter face is significantly worn out, and the digging distance per one rotation of the cutter face is estimated to be short, so the distance until the replacement is necessary is shortened Is done.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a preferred embodiment of a cutter face wear diagnosis method for a tunnel excavation machine according to the present invention. Reference numeral 10 denotes a shield machine used for tunnel excavation work by a shield method. This shield machine 10 has a disk-shaped cutter face (disc cutter) 12 provided with a number of cutter bits 12 a at the front end in the direction of drilling of a substantially cylindrical shield frame 11 around the axial center of the shield frame 11. The ground G is rotated to be excavated, and the excavated soil (slip) G ′ generated thereby is introduced into a sealed chamber 13 formed on the back surface thereof through a slit (not shown) formed in the cutter face 12. Then, the agitation is performed as the cutter face 12 is rotated, and the mixture is continuously conveyed to the earth discharging gate 15 through the screw conveyor 14 extending rearward from the sealed chamber 13 and further from there to the ground via appropriate conveying means. To be discharged.
[0012]
In addition, at the rear end of the shield frame 11 in the excavation direction, a plurality of segments 20 are annularly assembled on the excavated pit inner wall by an unillustrated erector, and a primary lining is applied to withstand earth pressure. When the segment 20 is assembled by one ring, the propulsion hydraulic jack 16 is applied to the front end of the segment 20 and pressed, thereby causing the shield machine 10 to have the axial width W of the one ring by the reaction force. After digging for a certain distance, the cycle of the process of assembling the next 20 segments for one ring is repeated.
[0013]
An acceleration sensor 1 serving as a sound wave sensor is attached to the rear surface of the partition wall 17 forming the sealed chamber 13, and an acoustic monitor 3, an oscilloscope 4, a tape recorder 5, and a waveform processing device are provided in a control room on the ground. 6, a computer 7 and the like are installed.
[0014]
The acceleration sensor 1 generates an electrical signal proportional to the vibration acceleration due to the piezoelectric effect of the PZT ceramic element, that is, the excavation sound of the ground G by the cutter face 12, the stirring flow sound of the shear G 'in the sealed chamber 13, An acoustic detection signal corresponding to the acoustic vibration of the partition wall 17 due to the driving sound of the machine or the like is output. The acoustic detection signal output from the acceleration sensor 1 is first amplified by the preamplifier 2 and supplied to the acoustic monitor 3 in the control room on the ground. The acoustic monitor 3 includes an amplifier 31, a cut-off frequency variable band-pass filter 32, and an acoustic conversion unit 33 including headphones or speakers.
[0015]
The acoustic detection signal supplied from the acceleration sensor 1 includes noise due to noise generated by the machine itself, such as the drive device of the cutter face 12 in the shield machine 10 and the drive device of the screw conveyor 14. This noise can be effectively removed by adjusting the cutoff frequency of the bandpass filter 32. For this reason, in the acoustic conversion unit 33, an acoustic detection signal corresponding to the excavation sound of the ground G mainly by the cutter face 12 is converted as acoustic information. As will be described later, the magnitude and tone of the excavation sound correspond to the properties of the ground to be excavated, and therefore the operator in the control room can output the sound (pitch of sound) output from the acoustic conversion unit 33 such as a speaker. By distinguishing changes in sound volume, tone size, tone color, etc., it is possible to audibly determine the soil properties of the ground G at the face and the excavation status at the cutter face 12.
[0016]
The acoustic detection signal that has passed through the bandpass filter 32 is supplied to the oscilloscope 4, the tape recorder 5, and the waveform processing device 6. The oscilloscope 4 outputs and displays the waveform of the acoustic detection signal, and can visually determine changes in the waveform pattern and amplitude level. FIG. 2 shows an example of an actual signal waveform. (A) is a clay soil layer, (B) is a gravel layer, (C) is a soft rock layer, and (D) is a hard rock layer excavated by a cutter face 12. It is a signal waveform at the time. That is, the waveform pattern and amplitude level of the acoustic detection signal have a clear correspondence with the hardness of the ground to be excavated. For example, in a uniform soft ground such as a viscous soil layer, the excavation sound is Small, hard rock formations generate loud excavation noise as shown in (D), and in the ground where many hard gravel and rock fragments are scattered, as shown in (B), it responds to interference with gravel and rock fragments. The amplitude changes randomly. For this reason, by observing the waveform with the oscilloscope 4, it is possible to visually determine the situation such as the hardness of the ground G being excavated. If the sound detection signal is recorded on the tape recorder 5, the recorded signal can be analyzed.
[0017]
The waveform processing device 6 includes a rectification circuit 61, an envelope detection circuit 62, and an A / D conversion circuit 63. The rectifier circuit 61 performs full-wave rectification of the acoustic detection signal having the waveform shown in FIG. 3A filtered by the bandpass filter 32 into the absolute value display waveform shown in FIG. The circuit 62 envelopes the amplitude peak in the absolute value display waveform and integrates and outputs it as an envelope detection waveform as shown in FIG. 3C. The A / D conversion circuit 63 detects the envelope. An analog signal is sampled at a constant sampling period ΔT (for example, 20 msec), and as shown in FIG. 3D, the amplitude level is quantized at each sampling time, and binarized amplitude value data V as shown in FIG. ₀ is output.
[0018]
A rotational speed sensor 8 such as a rotary encoder is attached to a motor (not shown) for rotating the cutter face 12 or a central axis of the cutter face 12 in order to measure the rotational speed R thereof. A jack sensor 9 is attached to measure the total thrust P and the propulsion speed J of the shield machine 10 by the hydraulic jack 16. The jack sensor 9 includes, for example, a pressure sensor that measures the hydraulic pressure supplied to the hydraulic jack 16 as the total thrust P, a speed sensor that measures the stroke speed of the output shaft of the hydraulic jack 16 as the propulsion speed J, and the like. .
[0019]
The amplitude value data V ₀ output from the waveform processing device 6, the detection data of the rotation speed R output from the rotation speed sensor 8, and the detection data of the total thrust P and the propulsion speed J output from the jack sensor 9 are Or the like to the computer 7. The computer 7 accumulates the amplitude value data V ₀ for each digging progress corresponding to each ring of the segment 20, for example, calculates the average amplitude value V for each digging progress, and the calculation result is used as chart data. Output to a display unit 7a such as a display of the computer 7 or a printer (not shown), and from the measurement data of the rotational speed R, total thrust P, and propulsion speed J, the excavation coefficient k according to the above-described equation (1). Is calculated for each of the excavation progresses, and the calculation result is output to the display unit 7a or the printer as chart data.
[0020]
As described above, the average amplitude value V of the excavation sound clearly corresponds to the hardness of the ground G to be excavated, and the excavation coefficient k is an index representing the degree of excavation resistance. However, it can be considered that the greater the value, the shorter the excavable distance of the cutter face. Accordingly, the size of the cutter face 12 is determined by comparing with a reference value set in advance for each, and the soundness of the cutter face 12 is diagnosed by comparing with the diagnosis patterns of [Case 1] to [Case 4] described above. The replacement time can be estimated.
[0021]
【Example】
FIG. 4 shows, as a specific example of the present invention, an image corresponding to the segment ring number 1000 to 1800 calculated from the starting position of the shield machine was output as chart data on the display unit 7a of the computer 7. The change of the average amplitude value V for each ring (digging progress) and the change of the excavation coefficient k for each ring are illustrated. In this example, for example, the average amplitude value V and the excavation factor k both show extremely small values at positions near 1000 to 1150 rings, and thereafter the average amplitude value V and the excavation factor k increase from around 1150 rings. Although there is a tendency, the distance (life) until the cutter face needs to be replaced becomes longer because it shows the diagnosis pattern of [Case 1]. As a result, when excavating to a position corresponding to 1304 ring The cutter face was replaced.
[0022]
After that, since the average amplitude value V is large but the excavation coefficient k is small, there is a section showing the diagnosis pattern of [Case 3]. That is, in this section, the wear amount of the cutter face is small, but the ground is hard. Since it is estimated that the digging distance per rotation of the cutter face will be shortened, the average amplitude value V and the excavation coefficient k both increase from around 1400 rings, although it does not affect the increase or decrease of the cutter face life. That is, since the diagnostic pattern of [Case 4] is shown, it was estimated that the life of the cutter face was remarkably shortened. As a result, the cutter face that was exchanged at the previous 1304 ring position was excavated a distance of only 141 rings, that is, it was exchanged again at the 1445 ring position.
[0023]
In addition, this invention is not limitedly interpreted by embodiment of illustration. For example, the average amplitude value V and the excavation coefficient k can be calculated with higher accuracy by considering the magnitude of deviation from the reference value. Moreover, although the above-mentioned embodiment demonstrated the shield machine, it can implement also in other tunnel excavation machines, such as TBM.
[0024]
【The invention's effect】
According to the method for diagnosing wear of a cutter face of a tunnel excavating machine according to the present invention, the total thrust measured during operation of the tunnel excavating machine using the amplitude value data of the ground excavating sound as a characteristic parameter representing the hardness of the excavating ground By using the excavation factor calculated from the propulsion speed and the rotation speed of the cutter face as a machine quantity parameter that represents the degree of excavation resistance depending on the excavation force of the cutter face and the mechanical properties of the excavation ground, It is possible to accurately diagnose the wear situation of the cutter face and accurately estimate the replacement time.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory diagram showing an embodiment of a cutter face wear diagnosis method for a tunnel excavating machine according to the present invention.
FIG. 2 is an explanatory diagram showing a signal waveform of an acoustic detection signal for detecting excavation sound generated when excavating a clay soil layer, a gravel layer, a soft rock layer, and a hard rock layer.
FIG. 3 is an explanatory diagram showing waveform processing by the waveform processing device in the embodiment.
FIG. 4 is an explanatory diagram showing changes in average amplitude value V and excavation coefficient k for each ring actually measured for an excavation section corresponding to 1000 to 1800 rings as the number of segment rings, as an example according to the present invention. is there.
[Explanation of symbols]
1 Acceleration sensor (sonic wave sensor)
3 Acoustic monitor 6 Waveform processing device 7 Computer 8 Speed sensor 9 Jack sensor 10 Shield machine (tunnel excavator)
12 Cutter Face G Ground

Claims (2)

The average amplitude value of the excavation sound for each fixed excavation distance obtained by cutting off the unnecessary frequency component from the acoustic detection signal from the acoustic wave sensor that detects the ground excavation sound by the cutter face of the tunnel excavation machine and processing the waveform. V,
The total thrust P, the propulsion speed J and the rotation speed R of the cutter face of the tunnel excavating machine are measured, and the excavation coefficient k for each constant excavation distance calculated from these values by the following equation:
k = P / (J / R)
By correlating the correlation between the soundness of the cutter face and the soundness of the cutter face in advance, and comparing the average amplitude value V and the excavation coefficient k obtained sequentially by the operation of the tunnel excavating machine with the pattern, the wear state of the cutter face is determined. A method for diagnosing wear of a cutter face of a tunnel excavation machine, characterized by estimating. In the description of claim 1,
Tunnel excavation characterized in that when the average amplitude value V and the excavation factor k are smaller than a predetermined reference value, the cutter face replacement time is extended, and when the average amplitude value V and the excavation factor k are larger than the reference value, the cutter face replacement time is shortened. A method for diagnosing wear on the cutter face of a machine.

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