JPH02176590A - Method and device for detecting working face breakage of shield type drilling machine - Google Patents

Abstract

PURPOSE:To speed up detection and to detect even a working face breakage state at an optional position in a circumferential direction by detecting the working face, breakage state from the angle of rotation of a cutter face and a measured voltage detected by a voltage measuring electrode. CONSTITUTION:Four electrodes 23a and 23b, and 24a and 24b are arranged on the side 21 of a skin plate at electrode intervals a1, and four electrodes 25a and 25b, and 26a and 26b are arranged at electrode intervals a2 which are wider than the intervals a1. On the front surface side of a cutter face side 22, four electrodes 27a and 27b, and 28a and 28b are arranged at electrode intervals a3 and four electrodes 29a and 29b, and 30a and 30b are arranged at intervals a4 respectively. Two outside electrodes of each group correspond to electric feeding electrodes and two inside electrodes of the group correspond to voltage measuring electrodes. Then the electric double layer consisting of drilling mud and earth is fed with electricity from the feeding electrodes and in which direction and how deep and wide the working face breakage is can be detected from the current angle of rotation of the cutter face and the measured voltage detected by the voltage measuring electrodes.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and an apparatus for detecting a state of face collapse that occurs when excavation work is performed using a shield excavator, and particularly relates to The present invention relates to a face collapse detection method and a detection device for a shield type excavator, which detects the face collapse state in more detail using a four-electrode method.

[Conventional technology]

Conventional shield type excavators include closed type shield type excavators such as slurry type, Tonosho type, and mud water pressure type.
These machines are shielded by a skin plate on the outside, making it impossible to detect the state of the face when digging inside. As a result, as shown in Figure 8, even if a cavity 1 is created due to the collapse of the face, the shield type excavator excavates by leaving the cavity 1 as it is, so that the cavity 1 may cause the ground to collapse later. It was possible. 2 in the figure is the ground surface,
3 is the ground, and 4 is a segment formed after the face.

Therefore, in order to prevent the ground from collapsing as described above, the inventors of the present invention developed a four-layer structure consisting of a pair of current-carrying electrodes and a voltage-measuring electrode on the surface of the skin plate, as described in Japanese Patent Laid-Open No. 61-38092. The electrodes are attached, and the electrical double layer consisting of the muddy water and the ground is energized by the current-carrying electrode, and the potential distribution generated in the electrical double layer due to the difference in resistivity between the muddy water and the ground is adjusted to the voltage 1fpI constant electrode that forms the pair. From this current and ap+p+ pressure, the apparent resistivity of the electrical double layer surrounding the muddy water side is determined, and from the change in resistivity, the existence of a cavity due to face collapse is detected as a change in the thickness of the muddy water. We have proposed a collapse detection method and a detection device. FIG. 10 and FIG. 11 are a configuration diagram and a schematic diagram of a detection device using the upper 24-electrode method. In these figures, 5 is muddy water, 6 is a cutter face, 7 is a motor for rotationally driving the cutter face 6, 8 is a skin plate, and 9 is an insulating plate which is attached by cutting out the skin plate 8. Also, are 10a and 1ob a pair of contacts? [very,
lla and llb are a pair of voltage measuring electrodes, and these electrodes are arranged at an equal distance Ma from each other. 12
is a signal processing device, which applies a predetermined constant current to the current-carrying electrodes 10a and 10b to energize the electrical double layer consisting of the muddy water 5 and the ground 3, as shown in FIG. The muddy water thickness d is detected from the measurement voltage determined by the Al 11 through the measurement electrodes 11a and 11b and the relationship shown in FIG.

In the figure, ρ1 indicates the specific resistance of muddy water, and ρ2 indicates the specific resistance of the ground (for example, clay).

However, with the above device, if the shape of the collapse formed by the excavator is, for example, an inverted V-shape, the measurement voltage changes due to the change in the width of the collapse, and therefore the collapse can be detected, but the collapse shape cannot be accurately detected. There was a problem that was not asked for.

Therefore, in order to solve the above problem, the present inventors proposed a detection device based on the configuration of the detection device described above, but with an improved electrode configuration as shown in FIG. Public bulletin). This detection device has a set of four electrodes consisting of energizing electrodes 13a, 13b and voltage measuring electrodes 14a, 14b, which are narrowly spaced, on an insulating plate 9 attached to a skin plate 8 in the same way as shown in FIG. A set of four electrodes is made up of energizing electrodes 15'a, 15b and voltage measuring electrodes 16a, 16b, and each set is selected to energize the electrical double layer consisting of muddy water 5 and rock 3, and measure its potential. By knowing the collapse width and collapse depth from the change in the number of minutes (11), the collapse shape can be detected with high accuracy.

[Problem to be solved by the invention]

However, both of the above two devices have electrode groups (10a, 10b, lla) only on the skin plate.

11b, 13a, 13b to 16a, 16b), the following points were pointed out.

■One is that the shield excavator moves forward while collapsing the ground 3 with the cutter face 6, and the shape of the collapse is detected only when the collapsed part approaches the electrode group on the skin plate. Therefore, there is a considerable time delay between the time when the collapse occurs and the time when the collapse is detected.As a result, it is not possible to obtain valid data for subsequent excavation conditions, and backfilling work such as repairing the collapsed part is delayed, causing the collapsed part to be damaged. There is a problem that countermeasures for the collapsed parts cannot be implemented quickly, such as increasing the amount of damage.

(2) The other method is that the electrode group is fixed to the insulating plate 9 on the skin plate 8, so that the shield tunneling machine can only detect the circumferential ground collapse situation in the direction in which the fixed electrodes are arranged. As a result, there is a possibility that ground collapse occurring in a direction other than the direction in which the fixed electrodes are arranged cannot be detected. It may be possible to arrange a large number of electrodes in the circumferential direction on the skin plate in order to detect ground failure in the circumferential direction in detail, but in this case, the mechanical strength of the skin plate 8 would be reduced. Not desirable.

The present invention has been made in view of the above circumstances, and provides a method for detecting face collapse of a shield type excavator, which can quickly detect the state of face collapse and can also detect the face collapse state at any location in the circumferential direction. The U-purpose is to provide.

Another object of the present invention is to provide a face collapse detection device for a vine shield type excavator that can quickly and reliably detect the state of face collapse with a simple configuration without reducing the strength of the skin plate. [ ] Target.

Another object of the present invention is to provide a face collapse detection device for a shield type excavator that can reliably notify an operator when the collapse state is severe.

[Means and effects for solving the problems] In order to solve the above problems, the method for detecting face collapse of a shield type excavator according to the present invention includes providing a current-carrying electrode and a voltage-measuring electrode on the cutter face. A predetermined current is supplied to the current-carrying electrode while rotating, and the state of face collapse in the circumferential direction is detected from the rotation angle of the cutter face and the measurement voltage detected by the voltage measurement pole. be.

Further, in the method of the present invention, the skin plate and the cutter face are respectively insulated, and two sets of four electrodes each consisting of a current-carrying electrode and a voltage measuring electrode are provided with different electrode intervals, and the cutter face and the skin are insulated. Each set of electrodes on the plate is selected in a predetermined order, and electricity is applied from the current-carrying electrode to the electrical double layer consisting of muddy water and rock, and the rotation angle of the cutter face at that time and the voltage measurement electrode are detected. Based on the measured voltage, it is possible to reliably detect in which direction and at what depth and width the face collapse is occurring.

Further, in the apparatus of the present invention, an electrode arrangement means is provided in which two sets of four electrodes each consisting of a current-carrying electrode and a voltage-measuring electrode are arranged on the skin plate and the cutter face, respectively, with different electrode intervals; a rotation angle detection means for detecting the rotation angle of the face; a switching section for switching and selecting each set of electrodes arranged on the skin plate and the cutter face in a predetermined order; and a switch for energizing the set selected by the switching section. measurement voltage detection means for applying a predetermined current to the electrodes and detecting the measurement voltage with the voltage 1tPI constant electrodes of the group; and 791 constant voltage of each group fixed by the measurement voltage detection means. Among them, the collapse depth and collapse width in the rotation angle direction by the rotation angle detection means are determined from the measured voltage when the set on the cutter face side is selected, and from the measured voltage when the set on the skin plate side is selected. This configuration includes calculation control means for determining the collapse depth and collapse width in the electrode arrangement direction.

Therefore, by purchasing the above-mentioned means, the device of the present invention can switch and select each set of electrodes on the cutter face side and each set of electrodes on the skin plate side sequentially in a predetermined order in the switching section, while energizing. By energizing the electrical double layer made of muddy water and the ground from the electrode and detecting the measured voltage from the voltage measurement electrode selected at that time, the strength of the cutter face side can be increased without reducing the strength of the skin plate. When selecting electrodes, it is possible to grasp the state of face collapse in all circumferential directions based on the rotation angle data from the rotation angle detection means, and this allows prompt countermeasures to be taken. It is possible to reliably know the state of face collapse in the arrangement direction and changes in face collapse.

Furthermore, the apparatus of another invention is configured to compare at least the calculated collapse depth obtained by the calculation control means with a preset set collapse depth, and when the calculated collapse depth exceeds the set collapse depth, the cutter A face collapse detection means is newly added that outputs both rotation angle direction data and data to that effect when the face side is selected, and only outputs data to that effect when the skin plate side is selected.

Therefore, this device further compares the depth of face collapse with the set depth, and if the depth of face collapse is greater than the set depth, it reliably determines the condition and outputs it, allowing the operator to quickly necessary countermeasures can be taken.

〔Example〕

Embodiments of the method of the present invention will be described below with reference to FIGS. 1 to 4. That is, the method of the present invention is the same as the conventional method in that it employs a four-electrode method that electrically measures the thickness of muddy water by focusing on the difference in resistivity between muddy water and the ground, but the main differences are shown in Figure 1. Two sets of four electrodes are arranged on both the skin plate side 21 and the cutter face side 22, and on the cutter face side 22, a constant current is applied every time the cutter face rotates at a predetermined angle, for example, 30', and the potential distribution is measured. There is a particular thing. Specifically, a set of four electrodes 23a, 23b, 24a are provided on the skin plate side 21 with a narrow electrode interval a1.
, 24b are arranged, of which the outer two electrodes 23a, 2
3b corresponds to the current-carrying electrode, and the two inner electrodes 24a, 24b
corresponds to the voltage 71111 constant. Furthermore, the above 4
Electrode 23a.

Another set of four electrodes 25a, 25b, 26a with a wider electrode spacing a2 than those of 23b, 24a, 24b.

26b are arranged, and similarly two outer electrodes 25a.

25b corresponds to a current-carrying electrode, and two inner electrodes 26a.

26b corresponds to the voltage Al11 constant electrode.

On the other hand, on the cutter face side 21, a set of four electrodes 27a are provided on the front side, side surface side, or both sides of the cutter face with a narrow electrode interval a3.

27b, 28a, 28b are arranged, of which the outer two
The electrodes 27a and 27b correspond to current-carrying electrodes, and the two inner electrodes 28a and 28b correspond to voltage measurement electrodes. Furthermore, the four electrodes 27a and 27b.

Another set of 4 with electrode spacing a4 wider than 28a and 28b.
Electrodes 29a, 29b, 30a, and 30b are arranged, and similarly, the two outer electrodes 29a, 29b correspond to current-carrying electrodes, and the two inner electrodes 30a, 30b correspond to voltage measuring electrodes.

In addition, although the said space|interval a1a3 is set to 70nu+, for example, mutually different space|interval may be sufficient. Also, the interval a2
Although a4 is set to 100 fiIn+, for example, it may be a different interval as described above.

Also, since the cutter face is rotated by a motor,
Two sets of four electrodes 27a, 27b on the cutter face side 22
The signal lines from ~30a and 30b are taken into the skin plate as an outer body via a rotary connector (not shown), and connected to two sets of four electrodes 23a on the skin plate side 21.
Along with the signal lines 23b to 26a and 26b, the energizing side switch circuits 31a and 31b and the detection side switch 3 are connected in a predetermined order.
The distribution is connected to the fixed contact 2a; 32b.

After configuring the electrode arrangement as described above, the thickness of muddy water due to face collapse is determined by 211. In this case, a constant current source is connected to the widely spaced outer electrodes 29a and 29b on the cutter face side 22. A predetermined constant current is supplied to energize the electrical double layer made of muddy water and the earth, and the change in potential distribution at that time is determined as a voltage by the inner electrodes 30a and 30b.

Hereinafter, each switch circuit 31a, 31b, 32a.

32b are sequentially switched in a predetermined order and energized in the same manner to sequentially determine the potential distribution as a voltage.

Furthermore, the above operation is repeated every time the cutter face rotates a predetermined amount.

Therefore, while performing the Δ)l constant as described above, the collapse depth and collapse width are determined from the n1 constant voltage obtained by changing the potential distribution separately for the skin plate side 21 and cutter face side 22. For convenience, 1, for example, 2 sets of 4 electrodes 23a, 23b on the skin plate side 21.
~26a, 26b, for example, 4 electrodes 2 with a narrow interval a1
3a, 23b.

The case where 24a and 24b are used will be explained with reference to FIG. In the figure, 41 is muddy water, 42 is earth, 43.44
indicates a constant current source, and 45.46 indicates an n1 constant voltage.

Now, the specific resistance of the muddy water 41 is ρ1, and the specific resistance of the earth 42 is ρ2.
And if the apparent resistivity seen from the electrodes 23a, 23b is ρ, then the current from the constant current source 43 to the electrodes 23a, 2
When a predetermined constant current T is applied to electrodes 24a, 2
From between 4b, V-(I p-) / (2πal)
--(11 measurement voltage ■ is obtained. And,
can be obtained from this equation (1). However, al is the electrode spacing, and d is the muddy water thickness.

As is clear from Fig. 3, which shows the relationship between the resistivity ρ above and the muddy water thickness and electrode spacing ratio d/at, the above apparent appearance is due to the fact that the electrode spacing a1 is compared to the muddy water thickness d. When the resistivity ρ is small, the resistivity ρ hardly changes. Therefore, by using four electrodes 23a, 23b, 24a, and 24b with narrow electrode spacing a1, for example, the collapse width A of the face collapse shape shown in FIG.
-B can be detected, but there is no sensitivity in the depth direction. In the figure, 47 indicates a skin plate.

Therefore, the depth of the collapse shape is determined by using four electrodes 25a, 25b, 26a, 26b with a wide electrode spacing a2, and from the obtained measurement voltage V, for example, based on the above-mentioned FIG. , and obtain the collapsed shape.

Note that on the cutter face side 22, the collapsed shape can also be detected in the same manner as described above using two sets of four electrodes 27a, 27b to 30a, 30b.

Therefore, according to the face collapse detection method of the embodiment described above, four electrodes with narrow electrode spacing and 478 electrodes with wide electrode spacing are provided, and by switching each set of these four electrodes to obtain a measurement voltage, The collapse shape can be determined with high accuracy. Furthermore, since four electrodes were provided only on the cutter face and the measurement voltage was obtained while rotating the cutter face, the collapsed shape in the circumferential direction could be determined with high accuracy.

In addition, four electrodes with narrow electrode spacing and four electrodes with wide electrode spacing are provided on the skin plate side 21 and the cutter face side 22 located at the tip of the excavator, and they are switched sequentially in a predetermined order including the skin plate side 21. Since the al constant voltage is obtained, the shape of collapse can be detected early at the position of the cutter face at the tip of the shield excavator, which makes it possible to quickly take measures such as changing excavation conditions. By similarly obtaining the collapsed shape on the skin plate side 21, it is possible to grasp changes in the collapsed shape, and obtain data that is useful for determining subsequent excavation conditions. It also greatly contributes to the control of quantity, etc. Furthermore, by obtaining the measured voltage while rotating the cutter face, it is possible to grasp the ground failure and its shape in the entire circumferential direction, which is also effective in determining excavation conditions and increasing the efficiency of backfilling work. Data can be obtained.

Next, an embodiment of the apparatus of the present invention will be described with reference to the drawings. That is, as shown in FIG. 5, this device is provided with a cutter face 51 on the front side, and on the back side of this cutter face 51 is an annular outer body having the same diameter as the cutter face r stripe 1. A functional skin plate 47 is provided. This cutter face 51 is configured to be rotated continuously or by a predetermined angle by a motor 52 fixed inside the skin plate 47.

One side of the skin plate 47 is cut out, and an insulating plate 53 having a surface substantially flush with the surface of the skin plate 47 is fitted into this portion. This insulating plate 53 has a first
As shown in the figure, the narrow electrode spacing al on the skin plate side 21
Four collapse width detection electrodes 23a, 23 with
In addition to b ~ 24 a and 24 b, there are four collapse depth detection electrodes 25 a, 25 b, and 26 a having a wide electrode interval a2 on the outside of these electrodes.

26b is embedded. Among these electrodes, the outer electrodes 23a, 23b, 25a, 25b correspond to current-carrying electrodes, and the inner electrodes 24a, 24b correspond to current-carrying electrodes.

26a and 26b correspond to voltage/JPj constant electrodes.

On the other hand, on one side of the cutter face 51 or on the front side (not shown) or on both sides, there are four electrodes 27a having narrow electrode spacing a3 as shown on the cutter face side 22 shown in FIG. 1, similar to the skin plate 47; 27b, 28
a, 28b and four electrodes 29a with a wide electrode spacing a4
, 29b.

30a and 30b are insulated and embedded.

Particularly in the case of the cutter face 51, if it is difficult to provide an insulating plate due to the excavation function of the ground, each electrode may be insulated and buried directly in the cutter face body.

Each electrode 2 attached to the cutter face 51 side
The signal lines from 7 a , 27 b to 30 a , 30 b pass through a hollow portion formed in the rotating shaft of the motor 52 , and are further introduced into the signal processing device 55 via the rotary connector 54 . In addition, skin plate 47
Each electrode 23a23b to 26a, 26b attached to the side
Each signal line is directly introduced into the signal processing device 55. 56 is an angle meter for detecting the rotation angle of the cutter face 51; 57 is a jack for moving the excavator; the tip of the jack 57 hits the jack receiving member 58 to transmit hydraulic pressure or other driving force transmission means; Advance the excavator at . 59 is a jack stroke meter that outputs a signal of the distance traveled by the jack 57 of the excavator.

As shown in FIG. 6, the signal processing device 55 includes an arithmetic control means 61 that outputs a command at a predetermined timing and obtains collapse depth, collapse width, etc.
a constant current source 62 which supplies a predetermined constant current to the energized electrodes in response to a command from the controller, and a switch circuit 31a shown in FIG. , 31b, 32a, and 32b, a detection voltage signal processing means 64 that amplifies and digitally converts the measurement voltage sent through each voltage dp1 constant electrode electrode switching section 63, and outputs the same. An angle signal processing means 65 and a distance signal processing means 66 having amplification and digital conversion functions are provided. 6
Reference numeral 7 denotes a memory 68 in which data necessary for calculating the collapse depth and collapse width, data obtained by each processing means 64 to 66, data of calculation results by the calculation control means 61, and other necessary data are stored. outputs the collapse depth and collapse width data obtained by the calculation control means 61, and compares the calculated collapse depth with a predetermined set collapse depth, and when the calculated collapse depth exceeds the set collapse depth, The face collapse detection means outputs a signal to that effect, and 69 is a data output device such as a recorder or a display unit.

Next, the operation of the apparatus configured as above will be explained.

When the arithmetic control means 61 sends a switching control signal to the switching section 63 based on a predetermined sequence program and also gives an operation command to the constant current source 62, the switching section 6B receives the switching control signal and performs the operation as shown in FIG. When the connection relationship shown in is set, from the constant current source 62 to the cutter face side 22
A constant current is supplied to the current-carrying electrodes 29a and 29b with a wide electrode spacing a4. As a result, these two electrodes 29a.

From 29b, electricity is applied to the electrical double layer made of muddy water and the ground to form a potential distribution, and at that time, a narrow electrode spacing a
Voltage measuring electrode 30a with 3.

Since a measured voltage according to the potential distribution can be obtained between 3('') and b, this measured voltage is acquired by the detected voltage signal processing means 64 via the rotary connector 54 and the switching section 63, and is amplified and amplified here. It is digitally converted and introduced into the arithmetic control means 61.

When this calculation control means 61 receives the measured voltage V, it obtains the collapse depth d from the data corresponding to FIG. 11 previously stored in the memory 67. Further, this arithmetic control means 61 takes in the respective angle data and distance data acquired by the angle signal processing means 65 and the distance signal processing means 66 at the time of constant current supply to the current-carrying electrodes 29a, 29b or voltage measurement, and the collapse The collapse depth data is stored in the memory 67 together with the depth data, and the collapse depth data is also stored in the face collapse detection means 68.
Send to.

Subsequently, when the arithmetic control means 61 sends a switching control signal to the switching section 63, the switching section 63 sets the current-carrying electrodes 27a and 27b with the narrow electrode spacing a3, and the current-carrying electrodes 28a and 28.
b is selected as the voltage measurement electrode, and similarly, the n1 constant voltage obtained between the electrodes 28a28b on the cutter face 51 side is sent to the calculation control means 61 via the detection voltage signal processing means 64.

After the collapse width is determined by the arithmetic control means 61 based on the equation (2), it is stored in the area of the memory 67 corresponding to the angle data and distance data. on the other hand,
The face collapse detection means 68 compares the calculated collapse depth data sent from the calculation control means 61 with the set collapse depth data, and when the calculated collapse depth exceeds the set collapse depth, it detects data to that effect. is output to the data output device 69 along with the angle and distance data to notify the operator, and if necessary, the collapse depth data and collapse width data are retrieved from the memory 67 to obtain the collapse shape, and similarly, the data output device 69
It can also be output to .

Furthermore, the electrode 23a on the skin plate 47 side.

Similar operations and processing are performed for 23b to 26a and 26b to obtain the collapse depth and collapse width and store them in the memory 67, and the face collapse detection means 68 makes a determination.
The determination result is output to the data output device 69. however,
In this case, angle data is not necessary.

Thereafter, when the cutter face 51 is rotated by a predetermined angle based on the angle signal sent from the angle 1156, the calculation control means 61 repeats the same operations and processing as described above.

FIG. 7 is a diagram showing the measurement results of the collapse depth during actual excavation by an excavator. In other words, this figure shows that when the electrode of the cutter face 51 is located exactly above (0°C), the electrode of the cutter face 51 allows a distance of 1200a+m to 1200a+m.
A ground collapse with a depth of about 1001 mm has been detected at around 1800 mm. Furthermore, about 100011I
When the excavation was carried out, a ground collapse at a depth of approximately 13011I+1 was detected by the electrodes of the skin plate 47.
From this, it can be determined that the depth of the ground failure became slightly deeper due to excavation. Furthermore, in the same figure (b), the distance is 160
The measurement results of the circumferential rock collapse distribution at a point of 0 mra are shown, and it can be seen from these results that the rock collapse exists only near directly above the shield excavator.

Therefore, according to the configuration of the embodiment as described above, not only the skin plate 47 but also the cutter face 51 are provided with four electrodes with a narrow electrode interval and a wide electrode interval, so that the δp1 constant voltage is sequentially obtained. The collapsed state of the collapsed part of the face can be detected before it reaches the skin plate 47, and the measurement voltage can be obtained by rotating the cutter face 51 without providing a large number of electrodes in the circumferential direction of the skin plate 47. The state of collapse can be accurately grasped in all circumferential directions without reducing the mechanical strength of 47. In addition, cutter face 51 and skin plate 47
By incorporating the 4-electrode method in each case, it is possible to accurately detect changes in the collapsed extraction condition, obtain data that is effective for determining subsequent excavation conditions, and further improve the effectiveness of backfilling work to repair collapsed areas. Management can be performed efficiently.

In addition, the extent of the collapse depth can be determined from the actual collapse depth and the predetermined collapse depth, and if the collapse depth is greater than the predetermined collapse depth, the operator can be immediately notified, so that necessary appropriate measures can be taken.

〔Effect of the invention〕

As explained above, according to the present invention, the following various effects can be achieved.

First, in claims 1 and 2, it is possible to provide a face collapse detection method for a shield type excavator that can quickly detect a face collapse state at any location in the circumferential direction.

Next, in claim 3, the collapsed state can be quickly determined with a simple configuration, and the collapsed state in the circumferential direction can be reliably determined without reducing the strength of the skin plate.

Furthermore, in claim 4, while determining the degree of face collapse, if the degree is severe, the operator is notified, so that appropriate measures can be taken quickly.

[Brief explanation of the drawing]

Figures 1 to 4 are shown to explain the method of the present invention. Figure 1 is a diagram showing the electrode arrangement configuration and the switching selection state of the electrodes, and Figure 2 is a diagram showing the electrode arrangement configuration and the switching selection state of the electrodes. Schematic diagram, Figure 3 is a diagram explaining the change in apparent resistivity with respect to the ratio of mud thickness to electrode spacing, Figure 4 is a schematic diagram of the collapsed shape, and Figure 5 is a configuration diagram of the device of the present invention. , FIG. 6 is a block diagram showing a specific example of the signal processing device shown in FIG. 5, and FIG. 7 (
a) is a data diagram of the calculation results obtained by the device of the present invention, FIG. Fig. 8 is a cross-sectional view of the ground formed by excavation with an excavator, Fig. 9 is a configuration diagram of a conventional device, and Fig. 10 is a diagram showing the collapse shape using the four-electrode method. A schematic diagram explaining the measurement conditions, Figure 11 is a diagram of the relationship between muddy water thickness and measurement voltage, and Figure 12 is a schematic diagram explaining the conditions in which the collapse shape is measured using the four-electrode method, which is a further improvement of Figure 10. It is a diagram. 23a, 23b, ~26a, 26b-- electrodes on the skin plate side, 27a, 27b ~30a. 30b... Electrode on the cutter face side, 41... Mud water, 42... Earth, 43, 44.62... Constant current source,
47... Skin plate, 51... Cutter face, 52... Motor, 53... Insulating plate, 54... Rotary connector, 55... Signal processing device, 56...
Angle meter, 57... Jacket, 59... Jacket stroke meter, 61... Arithmetic control means, 63... Switching section, 67... Memory, 68... Face collapse detection means, 6
9...Data processing device. 0.1 Muddy water! #/Electrode gap Figure 3 Applicant's agent Patent attorney Takehiko Suzue Figure 4 tg! String distance IE (mm) (a) (b) Figure Foil Figure Figure 10

Claims (4)

[Claims] (1) In a shield type excavator in which a cutter face is provided on the front side of a skin plate, a current-carrying electrode and a voltage-measuring electrode are provided on the cutter face, and while rotating the cutter face, a predetermined voltage is applied to the current-carrying electrode. A method for detecting face collapse of a shield type excavator, comprising: supplying a current, and detecting a state of face collapse based on the rotation angle of the cutter face and the measured voltage detected by the voltage measuring electrode. (2) In a shield type excavator in which a cutter face is provided on the front side of a skin plate, a set of four electrodes each consisting of an energizing electrode and a voltage measuring electrode are arranged on the skin plate and the cutter face, respectively, and the electrode spacing is varied. Two sets are provided, and the electrodes of each set of the cutter face and skin plate are selected in a predetermined order, and electricity is applied from the current-carrying electrode to the electric double layer consisting of muddy water and the ground, and the cutter face at that time is A method for detecting face collapse of a shield type excavator, characterized in that a state of face collapse is detected from a rotation angle and a measured voltage detected by the voltage measuring electrode. (3) A cutter face is provided on the front side of the skin plate to collapse the rock face, and the electric double layer consisting of muddy water and the rock is energized, and the face collapses from the measured voltage obtained from the potential distribution. In a face collapse detection device for a shield-type excavator that detects the state of electrode arrangement means, and rotation angle detection means for detecting the rotation angle of the cutter face;
A switching section switches and selects each set of electrodes arranged on the skin plate and the cutter face in a predetermined order, and a predetermined current is applied to the current-carrying electrodes of the set selected by the switching section. measurement voltage detection means for detecting the measurement voltage with the voltage measurement electrode; and the measurement voltage when the set on the cutter face side is selected from among each set of measurement voltages measured by the measurement voltage detection means. calculation control means for determining the collapse depth and collapse width in the rotation angle direction by the rotation angle detection means from the above, and determining the collapse depth and collapse width in the electrode arrangement direction from the measured voltage when the skin plate side set is selected; A face collapse detection device for a shield type excavator, characterized by comprising: (4) Compare at least the calculated collapse depth obtained by the calculation control means with a preset set collapse depth, and when the calculated collapse depth exceeds the set collapse depth, when the cutter face side is selected, rotation angle direction data 4. The face collapse detection device for a shield type excavator according to claim 3, further comprising a face collapse detection means that outputs data to that effect in both cases, and outputs only data to that effect when the skin plate side is selected.