JPH05113096A - Position detector of underground excavator - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to directly measure the relative position instead of the calculation method from the absolute position measurement using a transit etc. which has been used to calculate the relative position of the underground excavator until now. To [Structure] A plurality of metal detectors 8a, 8b, 8c are provided in a radial direction at the tip of the underground excavator 1, and the underground excavator 1 is provided at a reference position facing the underground excavator. A small-diameter boring device 6 is provided which is projected toward the metal detectors so as to approach the metal detectors, and the metal detectors 8a, 8b, 8c are attached to the tip of the boring device 6.
Is provided with a magnetic mass such as a metal mass or a permanent magnet that can be detected by the metal detectors 8a, 8b, 8c,
It is configured to include a calculation device that calculates the relative position of the underground excavator 1 with respect to the reference position based on the detected value of ... And the length of excavation of the boring device 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device for an underground excavator capable of obtaining the position of the underground excavator during underground excavation as a relative position with respect to a reference position.

[0002]

2. Description of the Related Art Conventionally, for example, surveying for operating an underground excavator in a shield construction method using an underground excavator has been carried out in addition to on-site survey by a transit etc. An optical transmitter that generates coherent light, such as a laser, is installed, a tunnel planning line is radiated from this device, and the excursion of the underground excavator is read by reading the light spot on the target attached to the shield excavator. ,
Seeking the declination. Alternatively, there is also known a method of obtaining a relative position from a reference position by combining an azimuth gyro, a pressure squat gauge, an inclinometer, and an odometer based on a segment length. It was common to use these measuring devices to calculate the current position, calculate the deviation from the tunnel planning line, and correct the direction toward the target while excavating. The above method always uses the first excavation position of the underground excavator as a reference point, sets the next reference point at a distance that can be transmitted by transit from that reference point, and further sets the next reference point from that reference point. Since the procedure is repeated, the error accumulates. For this reason, the error tends to increase in the case of tunnels with many curves and for long distances. On the other hand, when building tunnels under the seabed or in a dense area of buildings, many vertical shafts cannot be installed, so it is necessary to start underground excavators facing each other and join tunnels in the ground. It is necessary to measure the relative positions of the two underground excavators and bring the first underground excavator closer to the second underground excavator. Conventionally, in this case as well, the relative position of two underground excavators has been divided by a method of tracing a plurality of reference points from the initial excavation positions of both underground excavators. However, with this method, the error increases as the two underground excavators approach each other.
Originally, it is desirable to measure the relative position of two underground excavators regardless of the first reference point, and it is desirable that the error becomes smaller as the two approach, so that the central axes of the two underground excavators match. It is desirable to be able to join while guiding, but there was no effective means to achieve this.

[0003]

The conventional underground excavator using the position measuring means has the following problems. (1) Underground surveying by transit etc. cannot be performed in real time because it is necessary to have many measurement points when the tunnel is bent and excavated, especially for the guidance of joining two units or joining to the reaching shaft. Is not practical. (2) In the method using laser light, if the tunnel planning line is bent, the laser light from the vertical shaft may not be able to irradiate the target, and the optical transmission device must be moved to an appropriate position. Moreover, since it is not possible to directly irradiate the entire length of the planned route with the laser light, the positional relationship between the target, the optical surveying device, and the tunnel planning line is measured with respect to each other's angle and distance, and after calculating the planned route from the results, The excursion and declination of the underground excavator will be calculated. For this reason, there is a problem in that the relocation of the optical surveying device, the measurement and the calculation require manpower, and the efficiency of the excavation work is reduced. (3) The method using a gyro has a problem of accumulated error and is not suitable for long-distance excavation, and is also unsuitable for sharp curves and continuous curves. And like underground joint 2
This error is further increased when measuring the excavator excavator excursion.

The present invention has been conceived in light of the above.
For the relative position of two underground excavators facing each other, which are required for the underground connection of the shield type underground excavator, and the reference position provided in the shaft of the underground excavator that advances toward the shaft. The relative position can be measured and the distance between them is 0
It is an object of the present invention to provide an underground excavator that can guide the user to the target site at all times. In the surveys so far, the absolute position of the underground excavator was first known, and then the relative position of the two was calculated, but in the present invention, the absolute position does not matter, and attention is paid only to the relative position of each other. .. Therefore, the cumulative error of the absolute position up to the present time does not matter. Further, since it is guidance, it is sufficient that the error becomes smaller as the separation distance becomes smaller, and the efficiency of the work for improving the measurement accuracy does not decrease. The relative position can be observed at all times without waiting for the survey when the excavation is stopped, so it is quick to respond to the correction of the excavation direction.

[0005]

To achieve the above object, a position detecting device for an underground excavator according to the present invention comprises a plurality of metal detectors 8a, 8b, 8c at the tip of the underground excavator.
Is provided in the radial direction, and at the reference position facing the underground excavator 1, the tip is protruded toward the underground excavator 1 to bring the tip end toward the metal detectors 8a, 8b, 8c. A small-diameter boring device 6 is provided, and the metal detectors 8a, 8b, 8 are attached to the tip of the boring device 6.
c is provided with a metal mass or a magnetic body such as a permanent magnet, and metal detectors 8a, 8b, 8c for the magnetic body,
It is configured to include a calculation device that calculates the relative position of the underground excavator 1 with respect to the reference position based on the detected value of ... And the length of excavation of the boring device 6.

[0006]

[Operation] While excavating the underground excavator 1, the boring device 6 is excavated toward the front surface of the underground excavator 1,
The tip of this is brought close. This enables the underground excavator 1
The magnetic detector provided at the tip of the boring device 6 is detected by the metal detectors 8a, 8b, 8c, and points on the front surface of the boring device 6, and the detected value of the magnetic substance and the excavation length of the boring device 6 are used for the underground excavator with respect to the reference position. The relative position of 1 is calculated by the calculation device.

[0007]

Embodiment An embodiment of the present invention will be described with reference to the drawings. A small-diameter boring device 6 is excavated from the reference position 5 of the front surface portion 4 of the second underground excavator 3 toward the front surface portion 2 of the first underground excavator 1 that is excavating underground. The tip portion 7 of the boring device 6 is brought close to a plurality of metal detectors 8a, 8b, 8c and points provided on the front surface portion 2 of the first underground excavator 1. At this time, when the first underground excavator knows the distance from the reference position 5 to the first underground excavator 1 from the length of excavation of the boring device 6, the metal detectors 8a, 8b, 8c, ... It reacts with the part 7 (magnetic metal) and outputs a detection signal. Of the plurality of metal detectors, as shown in FIG. 4, the metal detector closest to the tip 7 of the boring device (8 in this embodiment).
The strongest reaction is obtained from c). Further, according to the rotation of the front surface portion 2 of the first underground excavator 1, a metal detector (for example, 8
In c), the strongest reaction is obtained at a certain rotation angle θ ₁ . That is, the excavation length L of the boring device 6 and the plurality of metal detectors 8a, 8b, 8c, ... Arranged in a line in the radial direction.
From the three information of the distance M from the central axis in the radial direction obtained from the information indicating which one of the above has reacted most strongly, and the angle θ obtained from the information indicating at which rotation angle the most reacted, 2 Calculate the relative position of the ground excavator on the platform.

Now, in FIG. 3, the reference position 5 of the front surface portion 4 of the second underground excavator 3 is radially M from the central axis 10.
2. It is assumed that the angle is θ2 clockwise from the apex. First
7 of the boring device 6 observed by the underground excavator 1
Is M1 in the radial direction from the central axis 9 and θ1 counterclockwise from the apex, the central axis 9 of the first underground excavator 1 and the central axis 10 of the second underground excavator 3 are It can be seen that is only N. Therefore, if M and θ observed by the first underground excavator 1 are advanced in directions such that they approach M2 and θ2, respectively, the central axis 9 of the first underground excavator 1
And the N of the central axis 10 of the second underground excavator 3 becomes smaller. That is, the two underground excavators are guided so that their central axes coincide with each other. At this time, if the boring device 6 is pulled back by the digging distance of the first underground excavator 1, the boring device 6 can be guided in real time. In this example,
Although the tip portion 6 of the boring device is made of magnetic metal,
A permanent magnet may be installed at this position. The metal detector is commercially available, for example, under the trade name of "metal checker", and may be a method of observing the amount of distortion of the magnetic field produced by the electromagnet by the metal with the induction coil. The second underground excavator may be a reaching shaft.

[0009]

According to the present invention, the relative position of the direct underground excavator is replaced with a method of calculating the relative position of the underground excavator, which has been used up to now, instead of the calculation method from the absolute position measurement using a transit or the like. Can be measured. Due to this, 1. The labor of absolute position measurement can be reduced. 2. The error can be reduced. 3. It can be guided in real time. Such an effect can be expected. And the like.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a main part.

FIG. 3 is an explanatory diagram for explaining the operation of the present invention.

FIG. 4 is a diagram showing a change of a magnetic field with respect to a rotation angle.

[Explanation of symbols]

1,3 ... Underground excavator, 2,4 ... Front part, 5 ... Reference position,
6 ... Boring device, 7 ... Tip, 8a, 8b, 8c,
...... Metal detector, 9, 10 ... Central axis.

Claims (1)

[Claims] 1. An underground excavator 1 is provided with a plurality of metal detectors 8a, 8b, 8c in the radial direction, and the excavator 1 is located at a reference position facing the underground excavator 1. 1 is protruded toward the end of the metal detector 8a,
8b, 8c is provided with a small diameter boring device 6, and the tip of the boring device 6 is provided with a metal mass detectable by the metal detectors 8a, 8b, 8c or a magnetic body such as a permanent magnet, The detection values of the metal detectors 8a, 8b, 8c, ... For this magnetic substance, and the boring device 6
2. A position detecting device for an underground excavator, comprising a calculation device for calculating a relative position of the underground excavator 1 with respect to the reference position based on the length of excavation.