JPH0826743B2 - Face collapse detector for shield machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [Field of Industrial Application] The present invention relates to a face collapsing detector for a shield machine, which detects the collapsing of a face generated during excavation by using electromagnetic waves.

[Conventional technology]

Conventionally, shield excavators for excavating tunnels and the like have a cutter head that is rotated by a drive source at the front of the shield body.The cutter head is used to excavate the face while propelling the shield body with a jack. Let's do Hori Susumu.

Also, the earth and sand excavated by the cutter head are taken into the cutter head and then carried out rearward through the shield body.However, when the geology is an aquifer gravel layer, etc. The amount of earth and sand excavated by and taken into the cutter head may increase,
As a result, the upper part of the face collapses and a cavity is formed above the cutter head, and the cavity causes problems such as subsidence of the ground and depression of the road.

For this reason, conventionally, a face collapse detection device has been developed which detects a face collapse using electromagnetic waves.

The above-mentioned conventional face collapsing detection device is provided with a transmitting antenna for emitting electromagnetic waves to the upper face of the shield body or above the shielding body and a receiving antenna for receiving reflected waves from the ground, and the reflection time of electromagnetic waves. By measuring the distance to the natural ground, the collapsed state of the face was detected.

For example, JP-A-58-181999, JP-A-60-157065 and JP-A-60-173294.

[Problems to be Solved by the Invention]

In the above-mentioned conventional face collapse detector, in order to detect face collapse, it was necessary for the operator to perform all operations such as start and end of measurement, so face collapse due to human error such as forgetting to collect data. There was a problem that could not be detected in advance.

Also, as shown in FIG. 10, the antenna part that emits radio waves toward the natural ground and receives the reflected wave from the natural ground is covered with a wind plate a made of resin,
Since the wind plate a is formed thick so as to withstand earth pressure and muddy water pressure, this wind plate a
As a result, the reflected wave is attenuated, and when the shield machine plunges into the aquifer or the like, there is a problem that the wind plate a is damaged due to a sudden pressure change and the collapse of the face cannot be detected.

Further, in the conventional face collapse detecting device, as shown in FIG. 11, since one transmitting antenna c and one receiving antenna d are provided in the direction orthogonal to the excavation direction b, the excavation direction and the There was a problem that only two-dimensional collapse information in the vertical direction was obtained.

It is an object of the present invention to provide a collapse detection device for a shield machine which eliminates the above-mentioned conventional problems.

[Means and Actions for Solving the Problems]

In order to achieve the above-mentioned object, the present invention receives a reflected wave from a natural ground of an electromagnetic wave emitted from a transmitting antenna provided in a shield machine to a natural ground by a receiving antenna and propagating the electromagnetic wave. In a face collapsing detector for a shield machine, which calculates the distance to the natural ground by time and detects collapse of the face, the rotation of the cutter head provided in the front part of the shield machine and the promotion of the shield machine The operation state of the shield machine is detected from the expansion / contraction movement and stroke length of the propulsion jack, and the operation of the face collapse detection device body is controlled based on the obtained operation state, so that no artificial operation is required when starting the excavation. Moreover, it becomes possible to measure the distance to the natural ground and detect the collapse of the face due to this.

As a result, it is possible to prevent land subsidence and road depression due to human error.

Also, by supporting the wind plate covering the antenna part provided with the transmitting and receiving antennas from the inside with columns and increasing the pressure resistance of the above-mentioned wind plate against external pressure, it is possible to use a thinner wind plate than before. become.

〔Example〕

 An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a shield machine 1 excavating in the ground. A cutter head 3 rotated by a cutter drive motor 2 is provided in the front part, and the earth and sand excavated by the cutter head 3 are muddy water. Is slurried and taken into the cutter head 3, and further discharged inside the shield machine 1 and the segment 5 by a muddy water discharge pipe (not shown).

Reference numeral 6 denotes a propulsion jack for propelling the shield machine 1 using the segment 5 as a reaction force. The propulsion jack 6 is expanded and contracted by the hydraulic pressure supplied from the hydraulic power source 7 via the electromagnetic valve 8 and the pipe line 9. Switching control is performed in synchronization with a cutter rotation command switch 11 provided between the cutter rotation motor 2 and the power supply 10.

Further, an antenna portion 15 of the face collapse detector main body 14 is installed on the upper front side of the shield machine 1.

As shown in FIGS. 2 and 3, the antenna portion 15 has a case 15a provided in a recessed portion 1b formed by opening the skin plate 1a of the shield machine 1, and the case 15a is provided in the case 15a. A support member 16 supported by a plurality of, for example, four support rods 16a is accommodated, and an antenna substrate 18 is provided on the support member 16 via a sponge-shaped radio wave absorber 17.

The antenna substrate 18 is provided with a transmitting antenna 18a and a receiving antenna 18b which are separated from each other in a direction orthogonal to the excavation direction A, and the central portion of the electromagnetic wave absorber 17 is located at the center of the upper surface of the supporting member 16. A pillar 16b is provided so as to penetrate therethrough.

The column 16b is a window plate 20 made of resin attached so as to liquid-tightly cover the upper opening of the case 15a.
Since the central part of the wind plate 20 is supported from below and the pillar 16b supports the earth pressure applied to the wind plate 20 from below, the thickness of the wind plate 20 is half that of a conventional wind plate (see FIG. 10). It can be:

On the other hand, the transmitting antenna 18a and the receiving antenna 18b are connected to a pulse generating circuit 21 and a sampling circuit 22, respectively.

The pulse generating circuit 21 and the sampling circuit 22 are connected to a trigger circuit 23, and the trigger signal sent from the trigger circuit 23 causes the pulse generating circuit 21 to send a pulse signal of a constant cycle to the transmitting antenna 18a. At the same time, the sampling circuit 22 samples the signal received by the receiving antenna 18b and sends it to the arithmetic circuit 24, and the arithmetic circuit 24 calculates the distance to the natural ground.

Further, the arithmetic circuit 24 includes a cutter rotation command switch 11
The cutter rotation detector 25 for detecting the rotation of the cutter from the on / off state of the cutter, and the propulsion jack 6 provided on the propulsion jack 6.
The stroke length detector 27 that detects the stroke length 1 of the above and the propulsion jack expansion and contraction detector 26 that detects the expansion and contraction of the propulsion jack 6 from the position of the solenoid valve 8 are respectively input, and automatic measurement is performed as follows. I am supposed to do it.

In the figure, 28 indicates a display device for displaying the measurement result as an image in real time.

Next, the operation will be described. The working state is divided into three modes, that is, preparing, excavation and rest, in advance, and these judgments are made by binary signals from the detectors 25 and 26.

That is, when the cutter rotation detector 25 and the propulsion jack extension detector 26 are turned on from the state of being prepared for work, the work shifts to the excavation process and the excavation start signal (see FIG. 5) is turned on.

At the same time, a trigger signal is sent from the trigger circuit 23 to the pulse generation circuit 21 to drive the pulse generation circuit 21, and an electromagnetic wave is emitted from the transmitting antenna 18a toward the natural ground, and the reflected wave from the natural ground is received. The signal is received by the antenna 18b and sent to the sampling circuit 22.

The sampling circuit 22 samples this, converts it into a low frequency, and outputs it to the arithmetic circuit 24.

The arithmetic circuit 24 arithmetically processes the input signal to measure the distance to the natural ground, and displays it on the display device 28 as an image in real time.

After this, the cutter rotation detector 25 and the propulsion jack expander 27
When both are turned off, the working state changes from the excavation to the resting state, and the propulsion stroke lq at that time is stored in the memory in the arithmetic circuit 24 by the signal from the stroke length detector 27.

After that, when the cutter rotation detector 25 and the propulsion jack expansion / contraction detector 26 are turned on again, the working state is in excavation and the measurement is started again. In addition, the shield excavator 1 is propelled by the length L of the segment 5 in the above operation. Repeat until

Then, when the shield machine 1 is propelled a distance L and l <lq is established during the rest, the working state is changed from the rest state to the ready state, the excavation end signal is issued together with the reduction of the propulsion jack 6, and the reduced propulsion is performed. A new segment 5 is assembled between the jack 6 and the segment 5.

As described above, the collapsing of the face can be detected by automatically measuring the distance to the natural ground in conjunction with the excavation operation of the shield machine 1.

On the other hand, FIG. 6 to FIG. 9 show another embodiment of the antenna unit 15, which is separated in the direction orthogonal to the direction A of the shield machine 1 for transmitting and receiving, and the transmitting and receiving antenna 18c and two receiving antennas 18c on both sides thereof. Antenna 18b is installed.

The transmitting / receiving antenna 18c is connected to the pulse generating circuit 21, emits the pulse signal sent from the pulse generating circuit 21 toward the natural ground, and reflects waves l, r from the natural ground. , M are received by the two receiving antennas 18b and the transmitting / receiving antennas 18c, and the sampling circuit 2
Sent to 2.

The transmission / reception antenna 18c is switched to a reception side by a transmission / reception switching circuit (not shown) after electromagnetic wave transmission, receives the reflected wave m, and sends it to the sampling circuit 22.

The sampling circuit 22 samples the input signal, converts it into a low frequency, and outputs it to the arithmetic circuit 24.

The arithmetic circuit 24 calculates the distance from each antenna 18b, 18c to the natural ground from the reflected wave data l, r, m received by each antenna 18b, 18c, and the shield machine 1 of the shield machine 1 input from the machine information input circuit 30. Display device for the status of natural grounds based on location information
Displayed as a three-dimensional image on 28 as shown in FIG.

As a result, it becomes possible to more accurately detect the collapsed state of the face as compared with the conventional two-dimensional image displayed.

In the above embodiment, one transmitting / receiving antenna 18c and two receiving antennas 18b are combined, but the combination is not limited to the above combination and the number of antennas may be increased.

〔The invention's effect〕

As described above in detail, since the present invention automatically measures the distance to the natural ground in conjunction with the excavation operation of the shield machine, it is necessary for the operator to perform operations such as starting and ending the measurement. As a result, operability is improved, and problems such as failure to detect face collapse due to forgetting to collect data are eliminated.

In addition, since the wind plate provided in the antenna part of the shield machine is supported from below by the pillars and part of the earth pressure is received by the pillars, the wall thickness of the wind plate can be made thinner than the conventional one. As a result, it is possible to reduce the attenuation of electromagnetic waves, and it is possible to eliminate problems such as damage to the wind plate due to a sudden change in pressure.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a sectional view of a shield machine, FIG. 2 is an enlarged plan view of an antenna section, and FIG.
FIG. 4 is a sectional view of the same, FIG. 4 is a block diagram of the face collapse detecting device main body, FIG. 5 is a timing chart showing operation, and FIGS. 6 to 9 are explanatory views showing other embodiments, FIG. First
FIG. 11 is a conventional explanatory view. 1 is a shield machine, 3 is a cutter head, 6 is a propulsion jack, 14 is a face collapse detector main body, 15 is an antenna part, 16
b is a pillar, 18a is a transmitting antenna, 18b is a receiving antenna, 18c is a transmitting / receiving antenna, and 20 is a wind plate.

Claims (2)

[Claims] 1. A reception antenna 18b receives a reflected wave of an electromagnetic wave emitted toward the ground from a transmission antenna 18a provided in a shield machine 1 and receives the ground wave according to the propagation time of the electromagnetic wave. In a face collapsing detector of a shield machine for calculating a distance to a mountain and detecting collapsing of a face, rotation of a cutter head 3 provided in front of the shield machine 1 and promotion of the shield machine 1 Shield machine 1 based on the expansion / contraction movement and stroke length of the propulsion jack 6.
The operation of the face collapsing detecting device main body 14 is detected according to the obtained operating state, and the face collapsing detecting device of the shield machine is controlled. 2. The ground plate side opening of the antenna portion 15 provided with the transmitting antenna 18a and the receiving antenna 18b is covered with a wind plate 20 and the wind plate 20 is also provided.
The face collapsing detection device according to claim 1, wherein an inner surface of the face is supported by a pillar 16b.