JPS63280192A - Shield excavator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shield excavator equipped with a ground exploration function that detects soil changes in the ground in front of the excavator prior to excavation.

[Conventional technology]

There are various types of shield excavators depending on the construction conditions, such as a mud pressure type, a mud pressure type, and a mud type, but in the following explanation, the mud press type shield excavation machine will be mainly described.

A pressurized mud shield excavator uses a cutter wheel to excavate a face, fills the stirring chamber behind the cutter wheel with the excavated earth, uses the propulsive force of the shield excavator to pressurize the earth and sand in the stirring chamber, and uses the upper pressure to pressurize the earth and sand in the stirring chamber. Preventing the collapse of the face, while
The mechanism is such that the earth and sand that fills the stirring chamber is excavated while being removed by a screw conveyor.

FIG. 2 is a side sectional view of a conventional mud pressurized shield excavator. In the figure, 1 is a shield main body of a shield tunneling machine, and has a hood part 1a formed at the front and a girder part 1b formed at the rear.

2 is the food section! This is a bulk heel that separates the girder part 1b from the girder part 1b. 3 is a cutter wheel rotatably installed in the hood part la, and this cutter wheel 3 is
A boss 3a at the center, a plurality of spokes 3b attached radially to the boss 3a, stirring blades 3C% attached to the spokes 3b, a setter bit 3d attached to the face side of the boss 3a, and a setter bit 3d attached to the spokes 3b. It is comprised of a large number of bits 3e, and an injection port 3f that is provided on the boss 3a and that injects a mud preparation material such as bentonite solution toward the ground. A center shaft 4 is attached to the boss 3a and extends rearward. 5a, 5b, and 5c are bearings for rotating the cutter wheel 3, 5a is a slide bearing supported by the bulkhead 2, 5b is a slide bearing supported by a bearing case 6b, and 5C is a slide bearing supported by the bearing case 6b. It is a radial hair ring. 6 is a swing gear attached to the center shaft 4, 6a is a gear case attached to the bulkhead 2 and surrounds the swing gear 6, and 6b is a bearing case integrally formed on the rear surface of the gear case 6a. 7 is a drive device such as a hydraulic motor that is attached to the gear case 6a and drives the cutter wheel 3; 7a is a pinion that is attached to the output shaft of the drive device 7; the pinion 7a meshes with the swing gear 6 within the gear case 6a; There is. Reference numeral 8 denotes a stirring chamber formed in a cylindrical shape behind the cutter wheel 2. As is clear from the figure, the face side of the stirring chamber 8 is open, and the side opposite to the face is sealed by the bulkhead 2. 9 is a slide bearing 5 that removes soil and sand in the stirring chamber 8.
10 is a screw conveyor whose intake port is the opening on the closed side of the stirring chamber 8; 11 is an earth pressure gauge attached to the bulkhead 2 and measures the pressure of the excavated earth and sand in the stirring chamber 8; 12 is a shield jack that provides propulsion force to the shield body 1.

The shield excavator configured in this manner transmits the driving force of the drive device 7 to the cutter wheel 3 via the swing gear 6 to rotate the cutter wheel 3 so as to rotate the cutter wheel 3.

Excavate the face with 3e. On the other hand, mud material is injected from the injection port 3f toward the face side and mixed into the excavated earth and sand. The excavated soil mixed with the mud-making material enters the stirring chamber 8, where both are sufficiently stirred by the stirring blades 3C and converted into mud with improved fluidity and impermeability. As a result, the excavated earth and sand reaches the intake port of the screw conveyor 10 without much resistance, and is conveyed to the outside of the machine by the screw conveyor 10.

In this case, the pressure of the excavated soil filling the hood portion 1a and the stirring chamber 8 is detected by the earth pressure gauge 11, and the earth pressure is maintained at an appropriate earth pressure based on the detected value. (Management of Tonosho).

[Problem that the invention seeks to solve]

Now, in the mud pressurized shield excavator as described above, a good mud condition must always be maintained in the stirring chamber 8 during excavation. This mud condition is determined by the properties of the injected mud material and excavated soil. If the excavated soil is clayey soil and the amount of mud material is too small, the mud condition at that time will become excessively plastic and fluidity will deteriorate, making it difficult to discharge the soil from the screw conveyor 10. (In short, this is what happens if the soil is such that it sticks). In addition, if the excavated soil is sandy soil, if the concentration of the mud material is too dilute, it will have poor plasticity and fluidity, which will increase the stirring torque and may even make it impossible to operate. .in this way,
In order to maintain good mud conditions, it is necessary to delicately control the concentration and flow rate of the mud material, as well as the propulsion speed of the excavation machine, depending on the properties of the excavated soil. However, it is not always easy to maintain such good muddy conditions.

In other words, if the soil quality of the ground in front of the excavator changes from a sandy silt layer ■ to a waterlogged gravel layer ■, as shown in Figure 3, the concentration and flow rate of the sludge material should be adjusted accordingly. If this change is not made, a situation will occur in which water and sand will be ejected from the screw conveyor section.

Once the mud is destroyed, it takes a considerable amount of time, effort, and skill to restore it.

In this way, the concentration of mud material,
It is important to control the flow rate, but in the conventional shield tunneling machine shown in Fig. 2, the screw conveyor 10
Since the condition of the mud discharged from the mixing chamber 8 is observed and the properties of the excavated soil in the stirring chamber 8 and the properties of the ground in front are estimated, it may be too late to respond to the changes in soil quality as described above. was.

This results in the eruption of water and sand as described above.

The above was about the mud pressurized shield excavator, but
In a mud pressure type shield excavator, excavated earth fills the chamber at the front of the excavator and the screw conveyor to generate earth pressure in the chamber that counters the face earth pressure and face water pressure, and applies lubricant depending on the soil quality. In a muddy type shield excavator, muddy water of a predetermined specific gravity and viscosity is pumped and pressurized into the mud chamber at the front of the excavator to improve the earth pressure at the face. A method is adopted in which excavated earth and sand are mixed with muddy water and flowed to the ground against water pressure. Therefore, in these methods as well, it is necessary to change the concentration and flow rate of the lubricant and mud water to be injected in response to changes in the soil quality of the ground, as in the case of the mud pressurization method described above. As described above, it is generally necessary for a shield excavator to excavate while predicting changes in the soil quality of the ground in front of the excavator, but no effective method for this has been realized so far.

SUMMARY OF THE INVENTION In view of the problems of the prior art described above, an object of the present invention is to provide a shield excavator having a function of detecting changes in the soil quality of the ground in front of the excavator before the excavator enters.

[Means for solving problems]

The above purpose is to provide an exploration rod that protrudes from the front part of the excavator and penetrates into the ground in front of it, and that the exploration rod has a built-in vibration sensor that converts the vibrations generated when penetrating the rondo into electrical signals. This is achieved by including a processing device that processes sensor output signals and outputs soil information on the ground.

[Effect]

To explore the ground, a penetrating device such as a hydraulic cylinder attached to the excavator causes an exploration rod, which is always stored inside the excavator, to protrude from the front of the excavator and penetrate into the ground in front of it. Alternatively, using the propulsion of the excavator itself provided by the shield jack, the exploration rod, which is constantly protruding from the front of the excavator, is used to penetrate the ground in front of the excavator. The vibration sensor built into the exploration rod converts the vibrations generated when the exploration rod penetrates into the ground into electrical signals, and the processing device processes this sensor output signal to obtain soil information about the ground. Output.

Next, the principle of this soil quality determination will be explained.

When a rod-shaped object is inserted into the soil, a kind of frictional sound can be heard as the rod breaks through the soil layer. This sound is caused by the soil being crushed at the tip of the rod,
The vibration caused by friction with the rod is transmitted through the rod and is the sound that propagates into the air above the ground. This sound varies depending on the soil type, and in the case of clay, it is usually so weak that it is almost inaudible, but in the case of compacted sand and gravel, it is quite loud, and the sound has characteristics such as rasping, rasping, crunching, and shaky. In many cases, it can be written separately.

Focusing on this point, the inventors manufactured an exploration rod having a shape approximately shown in FIG. 4, which had a built-in microphone in its tip cone, and attempted experiments in which the rod was penetrated into soil of various soil types. As for the soil type, (11) clay, (2) river sand 70
%10 clay 30%, (3) river sand 80% 10 clay 20%, (4
) 90% river sand, 10% clay, (5) river sand, (6) river sand 7
0% + glass beads (gravel model) 30%, (7) river sand 50
% + glass beads 50%, (8) choose 8 types of glass beads,
The sound collected by the microphone during each penetration was frequency-analyzed. In Figure 5, the frequency (k Ilz ) is plotted on the horizontal axis,
The frequency analysis results are illustrated with the sound pressure level plotted on the vertical axis. According to Figure 5, when clay is the main component, the sound pressure level is low and there is almost no sound, but as the sand content increases, the sound level increases, and when the sand content is 90% In case of soil quality (4), it is clearly different from case (1). Furthermore, it can be seen that the sound pressure level becomes even louder when the inspection is mixed with sand.

From this result, it was found that soil quality can be estimated by examining the loudness of the sound when the rod penetrates, the range of its fluctuations, and the frequency of fluctuations.

In the above experiments, when the exploration rod penetrates the soil, vibrations generated by the crushing of external soil particles or friction between soil particles and vibrations caused by the friction between the rod tip cone and the soil are transmitted to the tip cone surface. The force propagates through the metal that makes up the cone and reaches the metal surface of the microphone's sensing surface, and the vibrations on the metal surface become pressure waves (longitudinal waves) that propagate through the air and are then sensed by the microphone. It is an indirect method for detecting vibrations. Therefore, by attaching an acceleration sensor or an AE (acoustic emission) sensor to the metal surface of the tip cone, directly detecting the vibration propagating through the metal, and analyzing the sensor output signal, it is possible to use a microphone. It is possible to determine soil quality in the same way as detecting sound. In this specification, devices that detect vibrations generated when an exploration rod penetrates, whether directly or indirectly, and convert them into electrical signals are collectively referred to as vibration sensors.

Moreover, the soil quality information outputted from the processing device means information corresponding to the soil quality (or soil particle size), such as the magnitude, fluctuation range, and frequency of the detected sound (vibration).

〔Example〕

FIG. 1 shows an embodiment of the present invention. In the figure, components with the same functions and names as those in FIG. 2 are given the same reference numerals, and their explanations will be omitted.

13 is an exploration rod operated by a hydraulic cylinder type penetration device. This exploration rod 13 is provided inside the center shaft 4, and there are hydraulic pipes 15a and 15b in the cylinder chamber 14 before and after the rod large diameter portion 13a that constitutes the piston of the hydraulic cylinder, and the center shaft 4 connected to them. By supplying and discharging pressure oil through the hydraulic paths 16a and 16b, the slider slides to the left or right in the figure. In this embodiment, the exploration rod 13 is provided inside the rotating center shaft 4, so in order to prevent damage to the signal line of the vibration sensor, which will be described later, the exploration rod 13 is installed, although not shown in the drawings. 13 is prevented from rotating. A tip cone portion 17 containing a built-in vibration sensor is provided at the tip of the exploration rod 13 on the face side.

In order to show a specific example of the configuration of the vibration sensor, a detailed view of the vicinity of the tip of the exploration rod 13 is shown in FIG. 4. A tip cone portion 17, which has a conical shape to facilitate penetration and prevent soil from adhering, is attached to the main body portion of the exploration rod 13 with a bolt 18. A microphone 19 is attached to the inside of the tip cone portion 17 with a screw 20, and is shown as an example of a vibration sensor. The microphone 19 has a sensitive surface facing the metal surface of the tip cone portion 17 with a space in between, and detects sound transmitted from the outer surface of the tip cone portion 17 to the internal space when the exploration rod 13 penetrates into the soil. Collect sound. Reference numeral 21 denotes a signal line that passes through the inside of the exploration rod 1-3 to the rear driver's cab, and transmits the electric signal output from the microphone 19. In the driver's seat section, there is a processing device 22 that processes the output signal from the microphone 19 and presents information on the soil quality of the ground in front of the excavator to the driver.
is installed.

The configuration of the processing device 22 includes, for example, a microphone 19.
After amplifying the output signal with a preamplifier, the amplified signal is logarithmically compressed with a log amplifier and displayed on a sound pressure display as sound pressure, that is, the loudness of the sound.

Furthermore, if necessary, a part of the signal amplified by the preamplifier is converted to a voltage proportional to the vibration frequency only for sounds exceeding the footstep sound pressure level using a pulse counter, and a pulse indicator shows the voltage per unit time. It may also be displayed as the number of pulses. In this way, both the sound pressure and the number of pulses output from the processing device increase as the particle size of the soil increases, and it is possible to determine the soil quality based on this.

Next, the operation of this embodiment will be explained.

In Figure 1, it is assumed that the entire shield excavator is underground. In the shield construction method using a shield excavator, every time the tunnel excavates a predetermined distance (for example, In), the excavation is interrupted in order to add a member called a segment that will become a part of the tunnel. For ease of explanation, it is assumed that the following operations are performed during this excavation interruption.

During segment construction, when pressure oil is supplied from the hydraulic pipe 15b, this pressure oil acts on the right side of the large diameter portion 13a of the exploration rod 13 in the figure through the hydraulic passage 16b, and its propulsive force causes the exploration rod 13 to move forward in the figure. Move to the center left. That is, the tip cone portion 17 protrudes from the front face of the excavator and penetrates into the ground that has not yet been excavated. The penetration pad generated at this time is detected by the microphone 19 in the tip cone portion 17, and is sent as an electrical signal to the processing device 22 via the signal line 21.

As explained in the basic principle above, this intrusion platform corresponds to the soil quality of the ground ahead, so the driver can check the output of this processing device 22, such as the size of the intrusion platform, the range of fluctuation, and the Depending on the frequency, etc., it is possible to know the soil quality of the ground that the excavator will enter from now on before entering, and if a change in soil quality is predicted, the flow of water from the mud-making material supply pipe 23 to the injection port 3f will be adjusted accordingly. It becomes possible to prepare in advance the concentration and flow rate of the sludge material to be supplied to the tank.

FIG. 6 shows a state in which the exploration rod 13 has completed its penetration.

When the exploration rod 13 moves forward a predetermined distance (in this embodiment, the stroke of the large diameter portion 13a constituting the piston), the pressure oil in the hydraulic pipe 15b is released. Then, wait for the completion of the segment construction work before starting excavation. As the excavation progresses, the exploration rod 13 is again pushed into the center shaft 4 by the excavation force and returns to the state shown in FIG. 1, that is, the retracted state.

In the above description of the operation, it has been explained that the exploration rod 13 is penetrated while the excavation machine is stopped, but the penetration operation is not limited to the time when excavation is stopped (it can also be performed at any time during excavation).

A long stroke of the exploration rod 13 is best from the point of view of predicting the soil quality of the ground ahead, but considering the possibility of mechanical damage, a stroke of 1 to 2 segments is appropriate. Dew. In addition, the digging speed of the excavator is several ell.
Considering the slow speed of /mil, there is no need to explore the soil that far ahead, and the above level is considered to be sufficient.

In the above embodiment, the exploration rod 13 slides within the center shaft 4 and is configured to be able to explore the soil quality of the ground in front as needed. According to this, the exploration rod is not constantly exposed to the soil, so it has the advantage of being less likely to be damaged. In addition, since exploration can be performed while excavation is stopped, there is an advantage that only pure intrusion platforms can be detected without being affected by vibrations caused by excavation of earth and sand during excavation, that is, without noise from external vibrations being mixed in.

However, the gist of the present invention is not limited to the form of such a retractable exploration rod, but as shown in FIG.
With the exploration rod 13 always protruding from the front part of the excavator, the exploration rod 13 is penetrated into the ground by the propulsion force when the shield body 1 moves forward by the operation of the shield jack 12, and the penetration platform is Detection is also included within the technical scope of the present invention (in FIG. 7, 24 is a fixing bolt for the exploration rod 13).

Further, in the embodiment shown in FIG. 1, the exploration rod 13 is placed inside the center shaft 4, but if the exploration is limited to exploration while excavation is stopped, the exploration rod 13 can be moved from the bulkhead 2 to the spoke 3b of the cutter wheel 3. , the hood part 1 may be configured to protrude forward through the space between the agitating blades 3c, and the hood part 1 does not interfere with the rotation of the cutter wheel 3.
It is also possible to arrange the exploration rod 13 on the outer periphery of a.

In FIG. 8, 25 is a hydraulic cylinder for penetration attached to the outer periphery of the hood part 1a, 26 is a protective cover, 27 is an exploration rod with a built-in vibration sensor such as a microphone at its tip, and 28 is inserted into the protective cover 26. This is a seal that prevents the intrusion of earth, sand, and water, and when it is desired to explore the soil quality of the ground ahead, whether the excavation is stopped or during excavation, the exploration rod 27 is protruded from the front end of the hood part 1a by the hydraulic cylinder 25. and penetrate into the ground in front.

FIG. 9 shows an example in which only the exploration rod 27 is fixed to the outer periphery of the hood part 1a. to penetrate.

By making the exploration rod 27 protrude from the outer periphery of the hood portion 1a as shown in FIGS. 8 and 9, the cutter wheel 3 does not become an obstruction or is restricted to being able to penetrate only when digging is stopped. Further, there is no need to increase the diameter of the shaft unlike when the exploration rod is provided in the center shaft 4, and the exploration rod can be installed without significantly changing the structure of other parts of the excavator. It is also possible to arrange multiple sets of hydraulic cylinders 25, exploration condos 25, etc. on the outer circumference of the hood part. For example, if four sets are installed on the top, bottom, left and right sides, the ground changes as shown in Figure 3. In such cases, the device installed at the bottom detects changes in the ground faster, and then detects from the left and right, and then the top. By doing so, it is possible to detect the direction of changes in the strata, allowing for more precise mud management.

In the above embodiment, an example was explained in which the penetration table is detected by a microphone, but in FIG. 1
The vibration propagating through the metal 7 may be directly detected.

In addition, vibration sensors such as microphones, acceleration sensors, and AE sensors can be combined with one or more other sensors such as load cells that detect penetration resistance and pressure sensors that detect the water pressure of pore water in the soil. By incorporating these signals into a system and processing those signals, it is possible to provide more information about the properties of the ground.

〔Effect of the invention〕

According to the present invention, it is possible to detect changes in the soil quality of the ground in front of the excavator before digging, and by making preparations to change the concentration and flow rate of the mud-making material accordingly, the mud pressurized shield This has the effect that the mud condition inside the stirring chamber of the excavator can always be maintained in a good condition. The present invention also provides a mud pressure type shield propulsion machine that plastically fluidizes the filled earth by injecting a slipping material into the excavated earth filled in the chamber at the front of the excavation machine according to the soil quality, and a mud water chamber at the front of the excavation machine. The present invention can be similarly applied to a muddy shield excavator that pumps and pressurizes muddy water of a predetermined specific gravity and viscosity and transports it together with excavated soil, and the same effects as those described above can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of one embodiment of the present invention, showing a state in which the exploration rod is retracted. Figure 2 is a side sectional view of a conventional shield tunneling machine, Figure 3 is an explanatory diagram of changes in the ground during excavation by the shield tunneling machine, and Figure 4 is an enlarged view of the tip of the exploration rod in Figure 1. 5 is an explanatory diagram of the principle of the present invention, FIG. 6 is a state diagram of the exploration rod of the embodiment shown in FIG. 1 after it has penetrated, and FIGS. 7, 8, and 9 are FIG. 7 is a side sectional view of another embodiment of the present invention in which the exploration rod has a different form. 1... Shield body, 1a... Hood part, 2...
Bulkhead, 3... Cutter wheel, 4... Center shaft, 8... Stirring chamber, 13... Rod for exploration, 14... Cylinder chamber for penetration, 15a, 15b
...Hydraulic piping, 17...Tip cone part, 19...
Microphone (vibration sensor), 21... signal line, 22
... Processing device, 25 ... Hydraulic cylinder for penetration, 27
...Exploration rod. Agent Patent attorney Masami Akimoto (1 other person) Figure 1 1 --- Shield body 1o-11 Screw competition? 17-List corridor height 2--High head 13--4, warehouse entrance, door 19-11 Micro wood 3--a, Terre I/I/14--
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-&W! 16a, 16b---aFL! To M' 2 'Teaching' Figure 3? 1 purchase silt layer 13--One rod J1 opening, de 19...-Microphone 17--L'4 cone f 20...-fiL' old--
- +) 21-Signal Forest Fig. 5 Fig. 6 Fig. 7 ■ 1-, -, Red body 17-...', jI Kono egg 12... Shield -7 Ki 19...-7 p Hong 13... [tl! I Road 24・-Ro、D Pentateuch J4) Figure 8

Claims (1)

[Claims] 1. An exploration rod that protrudes from the front of the excavator and penetrates the ground in front, and the exploration rod has a built-in vibration sensor that converts vibrations generated when the rod penetrates into electrical signals. A shield excavator characterized in that it is equipped with a processing device that processes the sensor output signal and outputs soil quality information of the ground. 2. The shield excavator according to claim 1, wherein the exploration rod is configured to be able to protrude in front of the excavator at any time by a penetration device attached to the excavator. 3. The shield excavator according to claim 1 or 2, wherein the exploration rod is arranged on the outer periphery of the hood portion of the shield body.