JPH07217372A - Clearance measuring device of shield excavator and attitude controller thereof - Google Patents

Abstract

PURPOSE:To provide a clearance measuring device of a shield excavator capable of automatically measuring a tail clearance accurately and easily. CONSTITUTION:Magnetic sensors 8a, 8b, 8c and 8d are scattered in the circumferential direction and are equally arranged to the circumferential surface of the rear tail plate 1a of a shield excavator main body in the shield excavator. A tail clearance as the distance between the circumferential surface of the tail plate 1a and the peripheral surface of a segment 4 can be automatically measured on the basis of output signals of the magnetic sensors 8a-8d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tail clearance measuring device for a shield excavator and an attitude control device for a shield excavator, and is particularly useful when controlling the attitude during tunnel excavation by the shield excavator. .

[0002]

2. Description of the Related Art FIG. 11 is an explanatory view conceptually showing an entire shield excavator used for excavating a tunnel. As shown in the figure, a cutter 2 for excavation is provided on the front surface of the cylindrical shield machine body 1, and a cutter 2 is provided inside the shield machine body 1.
A screw conveyor 3 is provided to carry out the earth and sand excavated in step 1 to the rear.

A rear portion of the shield machine body 1 is a tail plate 1a which faces the outer peripheral surface of the segment 4 assembled in the already excavated portion. In the vicinity of the tail plate 1a inside the shield machine main body 1, a large number of shield jacks 5 dispersed at equal intervals in the circumferential direction of the segment 4 are provided.
Is disposed so as to face the front end surface of the. Thus, by extending the piston rod 5a of the shield jack 5 and bringing its tip into contact with the tip surface of the segment 4 to receive a reaction force, the shield machine body 1 moves forward (to the left in the figure).
It is configured so that it can be moved to.

The segment 4 is transported to a predetermined position by the erector device 6 arranged inside the tail plate 1a, and is assembled by being coupled with the already assembled segment 4.

Construction of a tunnel using such a shield excavator is generally performed by repeating the work of assembling the segment 4 along the inner wall of the tunnel behind the shield machine main body 1 after the shield excavator has advanced a predetermined distance. .

In such a work, during the excavation by the shield excavator, it is detected whether the gap between the outer peripheral surface of the assembled segment 4 and the inner peripheral surface of the tail plate 1a is within a predetermined distance. There is a need to. This is to measure whether or not the shield excavator is traveling straight by detecting whether or not the gap is within a predetermined dimension when the shield excavator is traveling along a straight path.

Incidentally, the fact that the shield excavator does not go straight ahead means that the shield excavator does not go straight.
Therefore, in such a case, the shield jack 5
It is necessary to correct the posture of the shield machine main body 1 to correct the gap by changing the expansion and contraction amount of the piston rod 5a and changing the shield jack 5 to be selected. The correction of the posture of the shield machine body 1 is also necessary so as not to hinder the subsequent assembly of the segment 4.

Conventionally, the measurement of the gap between the inner peripheral surface of the tail plate 1a and the outer peripheral surface of the segment 4 has often relied on the manual work of an operator. That is, the tail plate 1a
And a segment 4 was applied between them to measure.

[0009]

However, in the manual measurement of the operator as described above, not only is the work time-consuming, but also accurate measurement is difficult.

Further, it also becomes a hindrance in automating a series of operations such as automatic excavation and automatic direction control of the shield excavator.

When measuring the tail clearance using a measuring device, it is possible to use an ultrasonic sensor, a laser sensor, or the like. In this case, however, the sensor itself is too large to be installed in the tail clearance.
There is a problem that it is not suitable for the measurement of minute gaps (50 mm or less), it is weak against water, and the usage environment is limited.

Further, it is considered to use a proximity switch as a measuring sensor. In this case, since the output is only ON / OFF, the measuring range is narrow, and the sensitivity of the measuring range is widened. There are problems that it is necessary to install a plurality of different proximity switches, and it is difficult to utilize as data for automatic direction control because the output is not analog.

In view of the above-mentioned prior art, the present invention can accurately and easily automatically measure the tail clearance, which is the gap between the tail plate and the segment of the shield excavator, and also the attitude of the shield excavator during excavation. It is an object of the present invention to provide a tail clearance measuring device for a shield excavator and an attitude control device for the shield excavator, which can automatically hold the above as specified.

[0014]

[Means for Solving the Problems] First to achieve the above object
The configuration of the invention of the above, on the inner peripheral surface of the tubular tail plate which is the rear part of the shield machine body of the shield excavator, of the tubular segment dispersed in the circumferential direction and assembled inside the tail plate. A plurality of magnetic sensors arranged so as to face the outer peripheral surface, and information processing means for processing the output signals of each magnetic sensor to detect the tail clearance, which is the distance between the inner peripheral surface of the tail plate and the outer peripheral surface of the segment. And having.

According to the second aspect of the invention, the shield machine is abutted against the front end face of the cylindrically assembled segment inside the cylindrical tail plate which is the rear part of the shield machine body, and this segment is used as a reaction force receiver. A posture control device for a shield excavator having a plurality of shield jacks arranged inwardly of a tail plate so as to advance a main body, the inner peripheral surface of the tail plate being dispersed in the circumferential direction,
Further, a plurality of magnetic sensors arranged so as to face the outer peripheral surface of the cylindrical segment assembled inside the tail plate, and the output signals of the magnetic sensors are processed to process the inner peripheral surface of the tail plate and the segment. It is characterized by having a control means for detecting a tail clearance which is a distance from the outer peripheral surface and controlling each shield jack so that each distance becomes equal.

[0016]

According to the first aspect of the present invention, the distance to the outer peripheral surface of the segment, that is, the tail clearance is detected by processing the output signal of the magnetic sensor.

According to the second aspect of the invention, the amount of expansion and contraction of the piston rod of the shield jack is adjusted based on the tail clearance detected by the first aspect of the invention so that the tail clearances are the same, and the shield machine main body and the segment are separated from each other. Hold the concentric state of.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. The same parts as those of the conventional technique are designated by the same reference numerals, and a duplicate description will be omitted.

FIG. 1 is a vertical sectional view showing the portion A of FIG. 11 in an extracted and enlarged manner. As shown in the figure, a tail packing 7 is provided at the rear part of the tail plate 1a. The tail packing 7 is for contacting the outer peripheral surface of the existing segment 4 to prevent dirt and sand from entering the tail plate 1a, and is made of a brush or rubber.

In the tail clearance measuring device according to the present embodiment, the outer peripheral surface of the segment 4 is opposed to the concave portion 1b formed in the inner peripheral surface near the rear end of the tail plate 1a, and the front end surface is the inner peripheral surface. It has a magnetic sensor 8 arranged so as to slightly project from it. The magnetic sensor 8 detects the steel segment 4 and
The output signal of the level according to the distance to is transmitted.

The magnetic sensor 8, as shown in FIG. 2 which is a view taken along the line BB of FIG.
Is sent to the outside along the groove 1c which is continuously formed in the recess 1b on the inner peripheral surface of the tail plate 1a and is surrounded by the molding material 10 which is a non-magnetic material. It is isolated from the plate 1a and its influence is removed.

Further, in the present embodiment, the magnetic sensors 8 are arranged at a total of four locations on the inner peripheral surface of the tail plate 1a, that is, the top portion, the ground portion, the left portion and the right portion, as shown in FIG. There is. These are sequentially assigned the reference numerals 8a, 8b, 8c and 8d.

In this embodiment, the four magnets are
Since it has the air sensors 8a to 8d, as shown in FIG.
The tail plate 1a and the center of the segment 4 are the same,
In the case of concentricity, the magnetic sensors 8a to 8d
Distance output represented by output signal l _a, L_b, L_c, L_dIs equal
It becomes a new value.

On the other hand, as shown in FIG. 5, when the centers of the tail plate 1a and the segment 4 are deviated and the clearance of the ground portion is narrowed, the distance outputs l _c and l _d of the left and right magnetic sensors 8c and 8d are Although equal, the distance output l _{a at the top} is large and the distance output l _{b at the} ground is small.

As described above, the tail plate 1a is generated by the output signals of the magnetic sensors 8a to 8d provided on the left and right sides.
An attitude control device as another embodiment controls the shield jack 5 by calculating the deviation between the center of the circle and the center of the segment 4. That is, in this attitude control device, as shown in FIG. 6, the output signals of the magnetic sensors 8a to 8d are supplied to the controller 11. Controller 1
1, the output signals of the magnetic sensors 8a to 8d are processed, and the center O ₁ of the tail plate 1a and the center O _{2 of the} segment 4 are processed.
The shift amount and the direction thereof are detected, and the expansion / contraction amount of the piston rod 5a of each shield jack 5 is selectively controlled via the shield jack hydraulic circuit 12 so that the centers O ₁ and O ₂ coincide with each other.

7 and 8 are principle diagrams showing the principle of a preferred embodiment of the magnetic sensor 8. FIG. 7 shows a high-frequency transmission type which detects a change in the impedance of the detection coil 8e when a detection object, that is, the steel segment 4 approaches, and outputs it. FIG. 8 shows a differential coil type, which similarly detects and outputs the magnetic flux due to the eddy current generated in the detection object by the approach of the detection object, that is, the steel segment 4, by the difference between the detection coil 8f and the comparison coil 8g.

In any case, the detection output P increases as the detection object, that is, the steel segment 4 approaches, so that the distance 1 and the detection output P are in inverse proportion to each other.

FIG. 9 shows the arrangement of magnetic sensors according to another embodiment. In the present embodiment, a plurality of magnetic sensors 8a to 8d arranged in the circumferential direction in the above embodiment and another set of magnetic sensors 8a to 8d at positions axially separated from the shield machine body 1 are provided. The corresponding magnetic sensor 13 is added.

That is, according to this embodiment, since the tail clearances at two locations arranged with a span in the axial direction can be detected, the central axis L of the tail plate 1a in the axial direction can be detected based on both detected values. The tilt angle θ between ₁ and the central axis L ₂ of the segment 4 in the same direction can be detected, and the three-dimensional relative positional relationship between the tail plate 1a and the segment 4 together with the planar tail clearance data obtained by the magnetic sensors 8a to 8d. Becomes clear. Therefore, by using this data, the data processing is further facilitated, and the predetermined attitude control can be easily performed accordingly.

[0030]

As described above in detail with the embodiments, according to the present embodiment, the direct value of the gap dimension between the tail plate and the segment can be detected in real time, and the relative value between the tail plate and the segment can be detected. The relative position is clear, and automation of attitude control of the shield excavator can be easily realized.

Further, since the magnetic sensor can perform a predetermined measurement without any problem even if it is immersed in water, the initial explanation can be satisfactorily exhibited even in a bad environment where the shield excavator is applied.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a view taken along the line BB of FIG.

FIG. 3 is an explanatory view conceptually showing the mounting position of the magnetic sensor in the above-described embodiment.

FIG. 4 is an explanatory view conceptually showing a mode at the time of measuring tail clearance.

FIG. 5 is an explanatory view conceptually showing another aspect at the time of measuring the tail clearance.

FIG. 6 is a block diagram showing an attitude control device according to an embodiment of the present invention.

FIG. 7 is a principle diagram showing a magnetic sensor used in an embodiment of the present invention.

FIG. 8 is a principle view showing another magnetic sensor used in the embodiment of the present invention.

FIG. 9 is an explanatory view showing another arrangement mode of the magnetic sensor.

FIG. 10 is an explanatory view showing a mode of deviation of the central axes of the tail plate and the segment in the case of FIG.

FIG. 11 is an explanatory view conceptually showing the entire shield excavator.

[Explanation of symbols]

 1 shield machine main body 1a tail plate 4 segment 5 shield jack 5a piston rod 8, 8a, 8b, 8c, 8d, 13 magnetic sensor 11 controller

Claims (2)

[Claims] 1. An outer periphery of a tubular segment, which is dispersed in the circumferential direction and is assembled inside the tail plate, on an inner circumferential surface of a tubular tail plate which is a rear portion of a shield machine body of a shield excavator. A plurality of magnetic sensors arranged so as to face each other, and information processing means for processing an output signal of each magnetic sensor to detect a tail clearance which is a distance between an inner peripheral surface of the tail plate and an outer peripheral surface of the segment. A tail clearance measuring device for a shield excavator, comprising: 2. A tail for contacting a front end face of a cylindrically assembled segment inside a cylindrical tail plate which is a rear portion of the shield machine body, and advancing the shield machine body by using this segment as a reaction force receiver. A posture control device for a shield excavator having a plurality of shield jacks arranged inward of a plate in a circumferential direction. A plurality of magnetic sensors are arranged so as to face the outer peripheral surface of the cylindrical segment assembled in the above, and the output signal of each magnetic sensor is processed to determine the distance between the inner peripheral surface of the tail plate and the outer peripheral surface of the segment. A shield excavator characterized by having control means for detecting a certain tail clearance and controlling each shield jack so that each distance becomes equal. The control device.