JP2833154B2 - Tail clearance measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a tail clearance measuring device to be mounted inside a shield machine for excavating a tunnel by a shield method.

<Prior Art> Excavation by a shield machine was generally performed by a mechanism as shown in FIG. FIG. 4 is a sectional view showing the configuration of an example of a shield machine. In the figure, 1 is a shield excavator main body having a cylindrical shape, which advances while excavating the earth and sand portion 10. Reference numeral 2 denotes a cutter head for excavating a disc-shaped earth and sand portion, 3 denotes a tail portion serving as a cylindrical portion of the shield machine 1, and 4 denotes a sediment discharging device, and a screw conveyor 41 in which the excavated earth and sand is disposed. And is taken into the shield machine 1 and transported by a conveyor in the machine not shown. 5 is a propulsion jack for propelling the cutter head 2 in the excavation direction, and 6 is a segment assembled cylindrically along the inner wall of the excavated tunnel. A plurality of propulsion jacks 5 are provided on the end surface of the segment 61 assembled at the end portion of the inner wall of the tunnel, and the thrust is obtained by pushing the segment 6. Numeral 7 is a milk hardening material that solidifies between each segment and the earth wall 11 each time the segment 6 is assembled.

Here, the operation of this conventional shield machine will be described. The excavation path of this shield excavator 1 will advance along a path programmed in advance from a management computer, but the direction and level are analyzed with a gyro compass and a jabbel (not shown), and errors with the target line are corrected as needed. Dig in. First, the earth and sand portion 10 is excavated by the cutter head 2, and the excavated earth and sand is taken into the shield machine 1 through the screw conveyor 41 in the earth and sand discharging device 4, and is conveyed to the outside by a conveyor (not shown). As the excavator 1 excavates, the segments 6 are assembled in a cylindrical shape, and the propulsion jack 5 pushes the segments 6 in the direction of arrow A, thereby obtaining the propulsive force of the shield excavator 1. A plurality of the propulsion jacks 5 are provided on the circumference formed by the segments. The path of the shield machine 1 can be changed by selectively increasing or decreasing the pushing force of the propulsion jacks 5. After assembling the segments 6 continuously to some extent, holes are made near the center of all the segments on the same ring, milk powder is poured, and the segments 6 and the earth wall 11 are fixed. At this time, if the milk material is injected immediately after assembling the segments, the milk material may adhere to the tail portion 3. Therefore, a sufficient distance is required between the segment into which the milk material is injected and the tail portion. .

This operation is repeated as described above, and digging is performed while making corrections in a predetermined direction as needed.

Here, when the course of the shield machine 1 is bent, the clearance (tail clearance) between the inner wall of the tail portion 3 and the outer wall of the segment 6 increases or decreases, thereby reducing the position of the segment or the amount of milk solid material. I have to change. Therefore, measuring tail clearance is a very important factor.

Next, an example of a conventional clearance measuring device will be described. Fifth
FIG. 1 is a sectional view showing the configuration of an example of a conventional clearance measuring device. Note that the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. The same applies to the following figures.
Reference numeral 8 denotes a tail clearance sensor for measuring the distance between the outer wall of the segment and the earth wall 11 based on the amount of deflection of the blade. Reference numeral 9 denotes a clearance measuring device that detects the amount of deflection of the tail clearance sensor 8 of the beam with a strain gauge and converts the amount into a clearance amount. Here, the clearance measuring device measures the distance between the outer wall of the segment and the earth wall 11 and calculates La from the measured value L and the thickness a of the tail portion 3 of the shield machine 1 by calculating La. The distance between the outer wall of the segment and the inner wall of the tail part 3 could be known. The measured value of the tail clearance determined the amount of milk solid material flowing between the segment 6 and the earth wall 11.

<Problems to be Solved by the Invention> Generally, the tail clearance can also be used as reference data for the amount of milk solidified material. It prevents the club from hitting. However, in the above-mentioned conventional tail clearance measuring device, since the measurement is performed at the time of assembling the segments after excavation, there is a problem that the distance at the time of excavation cannot be measured. Therefore, if the digging is performed after assembling the segment, the tail portion may collide with the segment and be damaged.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a tail clearance measuring device capable of measuring a tail clearance during excavation.

<Means for Solving the Problems> The present invention is a tail clearance measuring device having the following configuration.

In a tail clearance measuring device that measures a tail clearance formed between an outer wall of a segment assembled along an inner wall of a tunnel excavated by a shield machine and an inner wall of a tail portion of the shield machine, A wedge-shaped member installed so that the hypotenuse contacts the segment, a position sensor arranged on the hypotenuse of the wedge-shaped member, and a signal from the position sensor is input to contact the segment And a calculating means for calculating a tail clearance for performing a predetermined calculation while identifying a position to perform.

Further, the calculation means calculates the tail clearance TL by performing the following calculation.

TL = K−p cos α−b, where K: length of a side perpendicular to the tail of the wedge-shaped member p: distance from the vertex not in contact with the tail of the wedge-shaped member to the contact point of the segment α: of the wedge-shaped member Angle formed between the side perpendicular to the tail and the oblique side b: Height from the contact point between the wedge-shaped member and the segment to the outer wall of the segment.

<Operation> In the present invention, a wedge-shaped member provided with a position sensor on the oblique side opposite to the excavation direction is attached to the tip of the jack for pushing the existing segment, and the wedge-shaped member is pressed against the segment. The tail clearance is geometrically calculated by identifying the pressed position sensor.

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a configuration of an embodiment of a tail clearance measuring device according to the present invention. Since this shows the tail clearance measuring device inside the shield machine, the explanation of the operation of the shield machine is omitted, and the shield machine itself performs the same operation as the shield machine of FIG. I do. In the figure, reference numeral 12 denotes a wedge-shaped member attached to the tip of the propulsion jack 5, and a position sensor 120 is attached to the oblique side opposite to the digging direction. Only the sensor at the contact point with the segment 6 functions as the position sensor 120. The tail clearance is calculated by the clearance measuring device 9 as a calculating means based on the position signal, and a computer (not shown) calculates the tail clearance according to the calculated value. Perform predetermined processing and control.

FIG. 2 shows a specific configuration example of the position sensor. FIG. 2 is a diagram showing an example of a position sensor arranged on a wedge-shaped member. In the figure, reference numeral 121 denotes a segment contact surface that comes into contact with the segment and is formed of conductive rubber. Reference numeral 122 denotes a printed circuit board on which conductors 123 serving as sensors are arranged in the oblique direction. Reference numeral 124 denotes a signal line. When a segment applies pressure in the direction of arrow B in the figure, a conductor located below the pressure point emits a position signal, which is sent to the clearance measuring device 9 via this signal line 124 to perform calculation. Is done.

Next, the operation of the present invention will be described with reference to FIGS. FIG. 3 is a diagram showing a main part of the wedge-shaped member. First,
The propulsion jack 5 is turned on to bring the wedge-shaped member 12 into contact with the existing segment 6. At this time, pressure is applied to one point of the segment contact surface shown in FIG. 3, and a sensor located thereunder reacts and outputs a signal, which is sent from the signal line 124 to the clearance measuring device 9. At this time, p is detected by the position sensor in FIG.
Since the length of one side perpendicular to the tail of the wedge-shaped member 12 is K, and the angle between the oblique side and this side is α, the calculation unit of the clearance measuring device 9 calculates The length is calculated as x = K−p cosα. Further, assuming that the thickness of the tail portion 3 is a and the height from the contact point of the segment 6 to the outer wall of the segment is b (these values are known values), the tail clearance TL is TL = x−b = K−p cos α −b. The distance L between the outer wall of the segment 6 and the earth wall 11 is as follows: L = x + ab = K-p cos α + ab Thereafter, the calculated value is sent to a management computer (not shown), and predetermined processing and control are performed.

In this manner, the tail clearance can be easily measured geometrically using the position sensor.

In addition to the case where the wedge-shaped member and the propulsion jack are simply brought into contact with each other, the wedge-shaped member may be movable by using a flexible joint at a joint between the propulsion jack and the wedge-shaped member.

<Effect of the Invention> As described in detail above, in the present invention, the tail clearance can be easily obtained by using the wedge-shaped member attached to the tip of the jack and having the position sensor disposed on the contact surface with the segment. Can be calculated, so that the tail clearance can be measured at any time while excavating. In addition, since the measurement can be performed online by connecting to a computer, the clearance width at the time of excavation of a straight line or a curve can be measured, and the measurement is not required to be stopped at the time of excavation, so that an optimal segment can be assembled. Furthermore, unlike the case of using a conventional spring, the measurement can be performed without contacting the earth wall, so it is inexpensive and it should be measured without affecting even when submerged by rolling of the excavator. Can be. In addition, depending on the measured distance of the tail clearance or the distance between the segment and the earth wall, the operation of the shield excavator can be suppressed and the milk material can be adjusted. Prevention of excessive injection of material can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of a tail clearance measuring device according to the present invention, FIG. 2 is a diagram showing a configuration example of a position sensor, FIG. FIG. 4 is a sectional view showing an example of a conventional shield machine, and FIG.
FIG. 1 is a sectional view showing the configuration of an example of a conventional clearance measuring device. 1 ... shield excavator, 3 ... tail 5 ... propulsion jack, 6 ... segment 9 ... clearance measuring instrument 11 ... earth wall 12 ... wedge-shaped member 120 ... position sensor, 121 ... segment contact Surface 122 Printed circuit board 123 Conductor 124 Signal line

Claims (2)

(57) [Claims] 1. A tail clearance measuring device for measuring a tail clearance formed between an outer wall of a segment assembled along an inner wall of a tunnel excavated by a shield machine and an inner wall of a tail portion of the shield machine. A wedge-shaped member installed such that one side is in contact with the tail and the hypotenuse is in contact with the segment; a position sensor arranged on the hypotenuse of the wedge-shaped member; and a signal from the position sensor is input. And a calculating means for calculating a tail clearance for performing a predetermined calculation while identifying a position where the segment is in contact with the segment. 2. The tail clearance measuring device according to claim 1, wherein said calculating means calculates the tail clearance TL by performing the following equation. TL = K−p cos α−b, where K: length of a side perpendicular to the tail of the wedge-shaped member p: distance from the vertex not in contact with the tail of the wedge-shaped member to the contact point of the segment α: of the wedge-shaped member Angle between the side perpendicular to the tail and the hypotenuse b: Height from the point of contact between the wedge-shaped member and the segment to the outer wall of the segment