JP3675576B2 - Ground judgment device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an apparatus for investigating and determining the ground condition in front of a face in a shield method.
[0002]
[Prior art]
In order to excavate while stabilizing the face in the shield method, it is necessary to know the ground condition in front of the face and manage the machine so that it is in an optimal operating state.
In particular, in order to safely replace a worn bit, it is necessary to stop the shield machine and perform the bit replacement work when the ground of the face is stable.
[0003]
As described above, it is important to grasp the ground in front of the face, but the ground in front of the cutter head cannot be directly observed, and thus the ground state of the face cannot be known. Therefore, the ground condition can be estimated by observing the excavated earth and sand, or in the case of a muddy water shield, observing the lump and sediment discharged together with the muddy water, or examining the results of the boring survey from the ground before tunnel construction.・ Judgment was made.
[0004]
Instead of such an indirect observation method, as a more direct observation method, a technique for determining the ground condition in front of the face by analyzing the sound pressure / frequency analysis of the frictional sound between the bit and the ground at the face is disclosed. -22839.
Alternatively, a method of measuring the sound or vibration when a detection rod attached to a bit or a cutter head comes into contact with the face of the face and determining the ground state of the face from its size and frequency characteristics has been proposed.
[0005]
[Problems to be solved by the invention]
However, in the technique of the above-mentioned Japanese Utility Model No. 62-22839, when bit wear progresses, the characteristics of sound pressure and frequency distribution change even on the same ground, so as bit wear progresses. There is a problem that it is difficult to make a highly reliable determination.
Further, the method using the detection rod has the same problem as described above when the detection rod is worn.
[0006]
Therefore, the present invention has been made for the purpose of providing an apparatus capable of determining the ground with high reliability regardless of the degree of bit wear.
[0007]
[Means for Solving the Problems]
According to claim 1 of the present invention, in a ground determination device used in a shield machine for excavating the ground with a blade attached to a rotating cutter head, a cutting vibration generated in the blade is detected by a vibration sensor, and the frequency of the cutting vibration is detected. Vibration measuring means for measuring distribution, wear amount measuring means for measuring the amount of blade wear by detecting the state of the blade with a blade state sensor, and the ground according to the wear amount of the excavated blade prepared in advance. A reference table that represents the relationship between the type of cutting vibration and the frequency distribution of cutting vibration, and a determination means that determines the type of ground by referring to the reference table based on the frequency distribution of cutting vibration and the amount of wear of the blade I took the steps.
[0008]
According to a second aspect of the present invention, the blade body includes a vibration sensor and a blade state sensor.
[0009]
According to a third aspect of the present invention, in a ground determination device used in a shield machine for excavating the ground with a blade attached to a rotating cutter head, a cutting vibration generated in the blade is detected by a vibration sensor and a frequency distribution of the cutting vibration is obtained. Vibration measuring means for measuring the amplitude and amplitude, wear amount measuring means for measuring the amount of wear of the blade body by detecting the state of the blade body with a blade state sensor, and depending on the wear amount of the excavation blade body prepared in advance The reference table that shows the relationship between the ground type and the frequency distribution and amplitude of the cutting vibration, and the ground type is determined by referring to the reference table based on the frequency distribution and amplitude of the cutting vibration and the amount of blade wear. And means for providing a determination means.
[0010]
According to a fourth aspect of the present invention, the rotation angle measuring means for outputting the rotation angle signal of the rotating cutter head, and the ground type determined by the determining means are taken in for each rotation angle of the cutter body by taking each rotation angle of the cutter head. A means of adding a distribution measuring means for outputting the distribution of the type of ground on the trajectory is taken.
In the fifth aspect, the vibration measuring means for measuring the cutting vibration of a plurality of blades arranged at different radii around the axis of the cutter head and the wear amount measuring means for measuring the wear amount of the blade body are provided. The distribution measuring means outputs the distribution of the ground type in the face section.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, a ground determination device according to the present invention will be described in detail based on the drawings showing embodiments thereof.
[0012]
In FIGS. 1 and 2, reference numeral 1 denotes a rotating cutter head, 2 denotes a shaft of the cutter head 1, 3 denotes a partition wall, and 4 denotes a drive motor that rotates the cutter head 1 via a gear 41. 11, 12... Are excavation bits attached to the cutter head 1, and are attached at different distances from the shaft 2 so that the rotation trajectory draws a concentric circle.
[0013]
In FIG. 4 showing the details, reference numeral 5 denotes a vibration sensor using an accelerometer or a piezoelectric element attached to the bit 11. An ultrasonic sensor 6 as a blade state sensor is attached to the bit 11. A signal cable between the vibration sensor 5 and the ultrasonic sensor 6 passes through the shaft 2 and is taken out via the slip ring 7 and input to the analyzer 8.
[0014]
As shown in FIG. 3A, the analyzer 8 includes a vibration signal amplification unit 81, a vibration signal analysis unit 82, an ultrasonic oscillation unit 83, an ultrasonic reception unit 84, a wear analysis unit 85, and a ground determination unit 86. I have.
The vibration signal amplification unit 81 and the vibration signal analysis unit 82 correspond to the vibration measurement means in the claims, and the ultrasonic oscillation unit 83, the ultrasonic reception unit 84, and the wear analysis unit 85 correspond to the wear amount measurement means. The ground discriminating unit 86 corresponds to the judging means.
[0015]
The signal from the vibration sensor 5 is amplified by the vibration signal amplification unit 81, a predetermined frequency component set in advance is extracted by the vibration signal analysis unit 82, and the amplitude thereof is measured. The frequency component set in advance in the vibration signal analysis unit 82 is set to a frequency generated by friction between the bit and the ground, and in a state where the ground is not pressed while the cutter head is rotated. This is a frequency having a certain bandwidth determined by comparing the vibration and the vibration in the pressed state.
[0016]
In addition, since the frequency of the generated vibration is characterized by the type of ground in the ground in front of the face, the vibration signal analyzing unit 82 has a plurality of types of ground G1, G2, G3 as shown in FIG. ,..., Gn are set to frequencies f1, f2, f3,..., Fn, and filters F1, F2, F3,. .
[0017]
The ultrasonic oscillating unit 83 intermittently generates a drive signal for a predetermined ultrasonic region, drives the ultrasonic sensor 6 with the drive signal to generate a predetermined ultrasonic wave, and generates an ultrasonic wave toward the tip of the bit. Oscillates vibration. The ultrasonic receiving unit 84 is in a receiving state between intermittent ultrasonic vibrations, and the ultrasonic wave reflected by the tip of the bit is detected by the ultrasonic sensor 6 and received by the ultrasonic receiving unit 84 and worn. The analyzer 85 measures the change in the distance to the tip of the bit, that is, wear of the bit by means such as measuring the delay time of the received timing from the oscillated timing, and outputs a wear amount signal.
[0018]
However, the measurement of the amount of wear is sufficient with a frequency of about once per rotation of the cutter head 1.
[0019]
The ground determination unit 86 measures the amplitude of each frequency component output from each filter F1, F2, F3,... Fn, and determines the ground determination table (reference table) 87 based on the amplitude distribution of each frequency component. To determine the ground in front of the face.
For example, if the amplitude of the frequency f1 is excellent, it is determined as the ground G1 with reference to the ground determination table 87 shown in FIG. 3C, and if the amplitude of the frequency f2 is excellent, it is determined as the ground G2. It is.
[0020]
In this way, the ground can be determined by the frequency distribution, but when the bit is worn, the amplitude and frequency of vibration generated by friction with the natural ground change.
Accordingly, by referring to the ground determination table while correcting or switching based on the wear amount signal output from the wear analysis unit 85, it is possible to accurately determine the ground even if the bit is worn. It is.
[0021]
The effect of bit wear on ground determination will be described below.
First, basically, when the strength of a natural ground is large, excavation similar to that of a natural ground with low strength cannot be performed unless the force for pressing the bit is increased. Accordingly, when the ground strength is high, the pressing force of the bit is increased, so that the amplitude of vibration generated in the bit inevitably increases. Therefore, as shown in FIG. 5, the magnitude of the strength of the natural ground can be determined based on the magnitude of the amplitude of the vibration generated in the bit.
[0022]
In addition, the bit tip becomes dull due to wear of the bit, and if the pressing force remains the same, the amount of biting into the ground will decrease and the excavation speed will decrease, but in order to prevent a decrease in the excavation speed normally Since the pressing force is increased, the frictional force between the bit and the ground is increased, and the amplitude of the generated vibration is increased as shown in FIG. The relationship between bit wear, ground strength and amplitude is shown in FIG.
[0023]
Further, since the contact area with the natural ground increases when the bit is worn, the apparent particle size of the particles is different, and the frequency of the generated vibration changes as shown in FIG.
[0024]
FIG. 9 is an example of a ground determination table in which the influence on the amplitude and frequency due to wear is corrected.
In FIG. 9, the X axis represents the frequency, the Y axis represents the wear amount, and the Z axis represents the amplitude. The plane P1 is a determination table when the wear amount is small, and the plane P2 is a determination table when the wear amount is medium. P3 indicates a determination table when the wear amount is large. The conversion table in FIG. 9 switches the plane to be referenced by switching or correcting the conversion table according to the wear amount.
[0025]
The area A1 of each plane shows the clay in the ground, the area A2 shows the silty in the ground, the area A3 shows the sand in the ground, and the area A4 shows the gravel in the ground.
For example, when the wear amount signal output from the wear analysis unit 85 is “small”, when the dominant frequency is f3 and the amplitude is large, the ground belongs to the area A3 in the plane P1, so the ground is hard sandy. It can be determined that there is.
[0026]
In addition, when the wear amount signal is “large”, when the dominant frequency is f4 and the amplitude is a medium level, the ground belongs to the region A4 in the plane P3, and therefore the ground is a gravel with a medium hardness. Can be determined.
Thus, since the ground is determined in consideration of the influence of the amplitude and frequency due to the wear of the bit, the ground can be determined with high reliability.
[0027]
FIG. 4 shows a side cross-sectional view of the bit portion in the case where both the vibration sensor 51 and the ultrasonic sensor 61 are provided in one bit.
[0028]
Next, as shown in FIG. 10, when different types of ground exist in the cross section of the face, an embodiment of the ground determination device capable of grasping the distribution state of those grounds is shown in FIG. 11 will be described.
In FIG. 11, the vibration sensor 5, the ultrasonic sensor 6, the vibration signal amplifying unit 81, the vibration signal analyzing unit 82, the ultrasonic oscillating unit 83, the ultrasonic receiving unit 84, the wear analyzing unit 85, and the ground discriminating unit 86 are shown in FIG. Since the circuit configuration is the same as that of FIG.
[0029]
Reference numeral 9 denotes a rotation angle measuring unit. Based on the output signal of the tachometer 91 such as a rotary encoder to which the shaft 2 of the cutter head 1 is attached and the output signal of the tachometer 91, for example, 1 of the cutter head 1 And a conversion circuit 92 that outputs a rotation angle signal obtained by dividing the rotation into 360 equal parts, for example.
Reference numeral 10 denotes a ground distribution analysis unit. Based on the rotation angle signal from the rotation angle measurement unit 9, every time the bit 11 provided with the vibration sensor 5 rotates 10 degrees, the state of the ground at that position is analyzed. The ground determination result is taken in and output to output means such as a CRT screen. For example, “x” is output for silty, “Δ” for sand, and “◯” for gravel.
[0030]
Therefore, when the bit 11 provided with the vibration sensor 5 rotates 360 degrees, the distribution of the ground of the cross section of the face can be grasped as a distribution on the circumference as shown in FIG.
In addition, a vibration sensor and an ultrasonic sensor are provided for each bit, and a vibration signal amplification unit, a vibration signal analysis unit, an ultrasonic oscillation unit, an ultrasonic reception unit, and an abrasion unit that process the signals of the respective vibration sensors and the ultrasonic sensor. By providing the analyzing unit and the ground discriminating unit, the distribution on the circumference of each concentric circle is output as shown in FIG. 12B, so that the ground distribution of the cross section of the face shown in FIG. It can be grasped as a ground distribution.
[0031]
Note that the vibration sensor may not be directly incorporated in the bit but may be disposed in the vicinity. Further, the blade sensor may be one using other means such as high frequency or radiation instead of the ultrasonic sensor, and may be any one that can detect bit wear. Further, the vibration signal analysis unit may use other means such as a DSP (digital signal processing) technique, an FFT processing technique, or a tracking filter instead of the plurality of filter groups. Further, the reference table may be expressed as a function according to the wear amount signal or may be a further subdivided table, and a transmission method such as a rotary transformer or optical communication can be used instead of the slip ring.
[0032]
【The invention's effect】
According to the first aspect of the present invention, the ground type is determined by referring to a reference table that represents the relationship between the ground type and the frequency distribution of the cutting vibration in accordance with the amount of wear of the excavating blade prepared in advance. The ground type can be accurately determined regardless of the amount of wear.
[0033]
According to claim 2, since the vibration sensor and the blade state sensor are incorporated in the blade body, vibration and wear of the blade body can be measured more accurately.
[0034]
According to the third aspect, since the ground type is determined in consideration of not only the frequency distribution of the cutting vibration but also the amplitude of the cutting vibration, a more accurate determination can be made.
According to the fourth aspect of the present invention, since the rotation angle measuring means for outputting the rotation angle signal of the rotating cutter head is provided, it is possible to obtain the ground type distribution on the trajectory for one rotation of the blade body.
[0035]
According to the fifth aspect of the present invention, the vibration measuring means for measuring the cutting vibration of the plurality of blades and the wear amount measuring means for measuring the amount of wear of the blades are provided. Can be obtained.
[Brief description of the drawings]
1 is a side configuration diagram of an embodiment of a ground determination device according to claims 1 and 3 of the present invention;
FIG. 2 is a front configuration diagram of the ground determination device.
FIG. 3 is a block diagram of the ground determination device.
4 is a cross-sectional view showing an embodiment of a blade body according to claim 2. FIG.
FIG. 5 is a diagram showing the relationship between the strength of natural ground and the amplitude of vibration.
FIG. 6 is a diagram showing the relationship between the amount of wear of the blade and the amplitude of vibration.
FIG. 7 is a diagram showing the relationship between the strength of a natural ground, the blade body and the amplitude.
FIG. 8 is a diagram showing a change in frequency of vibration due to wear.
FIG. 9 is a diagram showing a ground determination table according to claims 1 and 3;
FIG. 10 is a diagram showing an example of a ground distribution state;
FIG. 11 is a block diagram of a ground determination device according to claims 4 and 5;
FIG. 12 is a diagram showing a distribution obtained by the ground determination device.
[Explanation of symbols]
1 Cutter head
11, 12 ... Bit (blade)
5 Vibration sensor 6 Ultrasonic sensor (blade body sensor)
8 Analyzer
81 Vibration signal amplifier (vibration measuring means)
82 Vibration signal analyzer (vibration measuring means)
83 Ultrasonic oscillator (Abrasion amount measuring means)
84 Ultrasonic wave receiver (Abrasion amount measuring means)
85 Wear analysis part (Wear amount measuring means)
86 Ground discrimination part (judgment means)

Claims (5)

In a ground determination device used in a shield machine that excavates the ground with a blade attached to a rotating cutter head, vibration measuring means for detecting a cutting vibration generated in the blade with a vibration sensor and measuring a frequency distribution of the cutting vibration; , A wear amount measuring means for measuring the amount of wear of the blade body by detecting the state of the blade body with a blade state sensor, and the type of ground and the frequency distribution of the cutting vibration according to the wear amount of the excavated blade body prepared in advance. And a reference table for determining the type of ground by referring to the reference table based on the frequency distribution of the cutting vibration and the wear amount of the blade body apparatus. The ground determination device according to claim 1, wherein the blade body includes a vibration sensor and a blade state sensor. In a ground judgment device used in a shield machine that excavates the ground with a blade attached to a rotating cutter head, vibration that detects the cutting vibration generated in the blade with a vibration sensor and measures the frequency distribution and amplitude of the cutting vibration Measuring means, wear amount measuring means for measuring the amount of wear of the blade body by detecting the state of the blade body with a blade state sensor, and the type of ground and cutting vibration according to the wear amount of the excavated blade body prepared in advance this with the a reference table showing a relationship between a frequency distribution and amplitude, and determining means for determining the type of ground with reference to the reference table based on the amount of wear of the frequency distribution and amplitude and blade body of the cutting vibrations A ground determination device characterized by the above. In the ground determination device of any one of claims 1 and 3,
A rotation angle measuring means for outputting a rotation angle signal of the rotating cutter head;
A distribution measuring means for adding the ground type determined by the determining means for each rotation angle of the cutter head and outputting the distribution of the ground type on the trajectory for one rotation of the blade body is added. Ground judgment device. A vibration measuring means for measuring cutting vibrations of a plurality of blades arranged at different radii around the axis of the cutter head, and a wear amount measuring means for measuring the wear amount of the blade,
5. The ground determination device according to claim 4, wherein the distribution measuring means is configured to output a distribution of ground types in the face section.

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