JP7703404B2 - Tunnel Boring Machine - Google Patents

Description

This specification discloses a tunnel boring machine.

One of the tunnel excavation methods using tunnel boring machines such as shield machines is the earth pressure method. In this earth pressure method, the pressure in the cutter chamber between the partition wall and the cutter head that excavates the ground is maintained at an appropriate high pressure. This prevents ground subsidence and upheaval caused by excavating the ground.

The soil generated by excavating the ground is discharged from the cutter chamber by a screw conveyor. Because the cutter chamber is held at high pressure, soil may be ejected from the screw conveyor. To prevent this, it has been proposed to provide a rotary feeder at the screw conveyor's discharge port. Furthermore, to prevent the rotary feeder from becoming clogged with viscous soil, it has been proposed to make the blades that define the soil holding space of the rotary feeder removable. Such a shield tunneling machine is disclosed in Patent Document 1.

Japanese Patent Application Publication No. 6-200694

In the shield tunneling machine of Patent Document 1, the blades of the rotary feeder are attached and detached in response to changes in the soil quality of the soil. Attaching and detaching the blades requires the shield tunneling machine to be stopped. Attaching and detaching the blades reduces the excavation efficiency of the shield tunneling machine.

The applicant's intention is to provide a tunnel boring machine that can excavate without having to stop due to changes in the soil quality.

A preferred tunnel boring machine includes a cutter head for excavating the natural ground, a partition wall forming a cutter chamber between the cutter head and the cutter head, a screw conveyor for discharging the soil generated by the excavation from the cutter chamber, and a discharge device including a pair of conveyor belts for trapping the soil discharged from the screw conveyor, wrapping a portion of the soil, and forming and discharging divided soil.

This tunnel boring machine confines the soil discharged from the screw conveyor with a pair of conveyor belts, and then forms and discharges divided soil. This prevents soil from erupting. Because this tunnel boring machine confines the soil with a pair of conveyor belts and discharges divided soil, it can discharge both gravelly and clayey soil. This tunnel boring machine can continue excavating without stopping even if the soil quality changes.

FIG. 1 is a cross-sectional view of a tunnel boring machine according to one embodiment. FIG. 2 is an enlarged partial view of the discharge device of the tunnel boring machine of FIG. 3A is a cross-sectional view taken along line IIIA-IIIA in FIG. 2, FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 2, and FIG. 3C is a cross-sectional view taken along line IIIC-IIIC in FIG. 4(A) is a cross-sectional view taken along line IVA-IVA in FIG. 2, FIG. 4(B) is a cross-sectional view taken along line IVB-IVB in FIG. 2, and FIG. 4(C) is a cross-sectional view taken along line IVC-IVC in FIG. 2. FIG. 5(A) is a cross-sectional view taken along line VA-VA in FIG. 2, showing a pair of conveyor belts in close contact with each other when in use, and FIG. 5(B) is a cross-sectional view showing a space formed between the pair of conveyor belts in use, through which soil and sand can flow. Figure 6 (A) is an explanatory diagram showing the state of use in which soil and sand have flowed between a pair of conveyor belts of the discharge device of Figure 2, Figure 6 (B) is an explanatory diagram showing the state of use in which the pair of conveyor belts of the discharge device have wrapped around a portion of the soil and formed divided soil, and Figure 6 (C) is an explanatory diagram showing the state of use in which the pair of conveyor belts of the discharge device have begun to discharge the divided soil. Figure 7 (A) is an explanatory diagram showing the usage state in which a pair of conveyor belts of the discharge device in Figure 2 are discharging divided soil, Figure 7 (B) is an explanatory diagram showing the usage state before the pair of conveyor belts of the discharge device have finished discharging the divided soil, and Figure 7 (C) is an explanatory diagram showing the usage state after the pair of conveyor belts of the discharge device have finished discharging the divided soil.

A preferred embodiment will be described in detail below, with reference to the drawings as appropriate.

Figure 1 shows a tunnel boring machine 1 according to one embodiment. This tunnel boring machine 1 is a shield machine that assembles segments 2 inside. This tunnel boring machine 1 is an example, and can be applied to boring machines other than shield machines. For ease of explanation, the traveling direction of the tunnel boring machine 1 will be explained as the forward direction, and the opposite direction to the traveling direction will be explained as the rearward direction.

This tunnel boring machine 1 is equipped with an excavator body 3, a cutter head 4 that excavates the natural ground, and a cutter drum 5 that rotates together with the cutter head 4. This cutter drum 5 is rotatably supported on the excavator body 3.

Although not shown, the tunnel boring machine 1 is equipped with a number of shield jacks that push against the segments 2 to move the tunnel boring machine 1 forward. These shield jacks press the jack spreaders against the segments 2. This reaction force allows the tunnel boring machine 1 to move forward while excavating the ground.

The tunnel boring machine 1's boring machine body 3 comprises a cylindrical body 6 and a partition wall 7 disposed in front of the body 6. The cross-sectional shape of the body 6 is, for example, circular. This body 6 is merely an example, and the cross-sectional shape may be rectangular or polygonal. The partition wall 7 closes the front opening of the body 6.

The cutter head 4 is disposed in front of the partition wall 7. Although not shown, the cutter head 4 is equipped with a number of cutter bits, roller cutters, and other blades.

The cutter drum 5 is annular in shape. This cutter drum 5 is connected to the cutter head 4 by a number of supports 9. The cutter drum 5 is rotatably supported by a partition wall 7. In this tunnel boring machine 1, the cutter drum 5 is rotated by a drive device, thereby rotating the cutter head 4. Note that the tunnel boring machine 1 does not necessarily have to include the cutter drum 5, and it is sufficient if it includes a rotating shaft that drives the cutter head 4.

The partition 7 is divided by the cutter drum 5 into a ring-shaped outer partition 7A and a disk-shaped inner partition 7B. Although not shown, the outer partition 7A has a peripheral wall that extends from its inner periphery to face the outer periphery of the cutter drum 5. The space between this peripheral wall and the outer periphery of the cutter drum 5 is sealed with multiple soil seals. Similarly, although not shown, the inner partition 7B has a peripheral wall that extends from its outer periphery to face the inner periphery of the cutter drum 5. The space between this peripheral wall and the inner periphery of the cutter drum 5 is sealed with multiple soil seals.

In this tunnel boring machine 1, the center of the inner bulkhead 7B and the center of the cutterhead 4 are connected by a rotary joint 10. This rotary joint 10 connects hydraulic piping and electrical wires between the rotating cutterhead 4 and the bulkhead 7.

In this tunnel boring machine 1, a cutter chamber 8 is formed between the cutter head 4 and the partition wall 7. The soil and sand generated when the cutter head 4 excavates the ground flows into this cutter chamber 8.

The tunnel boring machine 1 further includes a screw conveyor 11 for discharging soil from the cutter chamber 8, a connecting pipe 12, and a discharge device 13.

The screw conveyor 11 is disposed inside the excavator body 3. The screw conveyor 11 comprises a casing 11A and a screw 11B that rotates within the casing 11A. The front of the casing 11A opens to the cutter chamber 8. The screw conveyor 11 can transport soil and sand from within the casing 11A to the rear as the screw 11B rotates.

The connecting pipe 12 is connected to the rear opening of the screw conveyor 11. The discharge device 13 is connected to the rear opening of this connecting pipe 12. A gate 14 is attached to this connecting pipe 12 to enable the opening to be opened and closed. Note that the gate 14 does not have to be attached to the connecting pipe 12.

The tunnel boring machine 1 is further equipped with a discharge volume measuring device 64 that measures the amount of soil and sand discharged from the screw conveyor 11.

Figure 2 shows the rear part of the connecting pipe 12 and the discharge device 13. Figure 2 also shows the sensor 15 equipped to the tunnel boring machine 1. The sensor 15 is connected to a discharged soil amount measuring device 64. The connecting pipe 12 is equipped with a guide pipe 16. The discharge device 13 is connected to the rear of the guide pipe 16. The space between the guide pipe 16 and the discharge device 13 is sealed with a soil seal 17.

The discharge device 13 includes a conveyor belt 18 located below, a number of rollers 19, a conveyor belt 20 located above, and a number of rollers 21. The conveyor belt 18 is stretched over the number of rollers 19. The conveyor belt 18 can rotate while being guided by the number of rollers 19. These rollers 19 are driven rollers that rotate as the conveyor belt 18 rotates. The conveyor belt 20 is stretched over the number of rollers 21. The conveyor belt 20 can rotate while being guided by the number of rollers 21. These rollers 21 are driven rollers that rotate as the conveyor belt 20 rotates. Although not shown, the discharge device 13 includes a drive roller that rotates the conveyor belt 18 and another drive roller that rotates the conveyor belt 20. Note that the discharge device 13 does not necessarily have to include a drive roller.

Figure 3 (A) shows a cross section of the guide pipe 16 taken along line IIIA-IIIA in Figure 2. The cross section has a circular shape similar to that of the front part of the connecting pipe 12.

Figure 3(B) shows a cross section of the guide tube 16 taken along line IIIB-IIIB in Figure 2. The cross section in Figure 3(B) is elliptical. The height of the opening cross section of the guide tube 16 in Figure 3(B) is smaller than that in Figure 3(A). The width of the opening cross section of the guide tube 16 in Figure 3(B) is larger than that in Figure 3(A).

Figure 3(C) shows a cross section of the guide tube 16 taken along line IIIC-IIIC in Figure 2. The cross section in Figure 3(C) is elliptical. The height of the opening cross section of the guide tube 16 in Figure 3(C) is smaller than that in Figure 3(B). The width of the opening cross section of the guide tube 16 in Figure 3(C) is larger than that in Figure 3(B).

The opening shape of this guide tube 16 is changed from a circle in FIG. 3(A) to an ellipse in FIG. 3(C). In the guide tube 16, the height of the opening cross section gradually decreases toward the rear, and the width of the opening cross section gradually increases toward the rear. Here, the opening cross section shapes of the guide tube 16 in FIG. 3(A) to FIG. 3(C) are circular and elliptical, but the present invention is not limited to this. The opening cross section shape of the guide tube 16 may be rectangular or polygonal.

Figure 3(C) shows a cross section of the discharge device 13 taken along line IIIC-IIIC in Figure 2, together with a cross section of the guide tube 16. Figure 3(C) shows, of the rollers 19, a plurality of first guide rollers 22 arranged along the opening cross section of the guide tube 16, and a pair of pressure rollers 23 for pressing the end of the conveyor belt 18 against the conveyor belt 20. Similarly, of the rollers 21, a plurality of first guide rollers 24 arranged along the opening cross section of the guide tube 16, and a pair of pressure rollers 25 for pressing the end of the conveyor belt 20 against the conveyor belt 18 are shown. Although not shown, packing is attached to the respective ends of the conveyor belt 18 and the conveyor belt 20 along the longitudinal direction as a soil seal.

Soil and sand flow from the guide tube 16 into the space 26 formed by the conveyor belts 18 and 20. The ends of the conveyor belts 18 and 20 are sealed. The flowing soil and sand causes the conveyor belt 18 to deform along the arrangement of the first guide rollers 22. Similarly, the conveyor belt 20 deforms along the arrangement of the first guide rollers 24. Figure 3 (C) shows the space 26 formed by the conveyor belts 18 and 20 that have been deformed in this way.

Figure 4 (A) shows a cross section of the discharge device 13 taken along line segment IVA-IVA in Figure 2. Figure 4 (A) shows, among the rollers 19, a plurality of second guide rollers 28 arranged to align the conveyor belt 18 to a predetermined elliptical shape, and a pair of pressure rollers 29 that press the end of the conveyor belt 18 against the conveyor belt 20. Similarly, among the rollers 21, a plurality of second guide rollers 30 arranged to align the conveyor belt 20 to a predetermined elliptical shape, and a pair of pressure rollers 31 that press the end of the conveyor belt 20 against the conveyor belt 18 are shown.

In FIG. 4(A), the cross-sectional shape of space 26 formed by conveyor belts 18 and 20 is elliptical. The cross-sectional height of space 26 in FIG. 4(A) is smaller than that in FIG. 3(C). The cross-sectional width of space 26 in FIG. 4(A) is larger than that in FIG. 3(C).

Figure 4(B) shows a cross section of the discharge device 13 taken along line IVB-IVB in Figure 2. Figure 4(B) shows, among the rollers 19, a plurality of third guide rollers 32 arranged to align the conveyor belt 18 with another specified elliptical shape, and a pair of pressure rollers 33 that press the end of the conveyor belt 18 against the conveyor belt 20. Similarly, among the rollers 21, a plurality of third guide rollers 34 arranged to align the conveyor belt 20 with another specified elliptical shape, and a pair of pressure rollers 35 that press the end of the conveyor belt 20 against the conveyor belt 18 are shown.

In FIG. 4(B), the cross-sectional shape of space 26 formed by conveyor belts 18 and 20 is elliptical. The cross-sectional height of space 26 in FIG. 4(B) is smaller than that in FIG. 4(A). The cross-sectional width of space 26 in FIG. 4(B) is larger than that in FIG. 4(A).

Figure 4(C) shows a cross section of the discharge device 13 taken along line segment IVC-IVC in Figure 2. Figure 4(C) shows, among the rollers 19, a fourth guide roller 36 that supports the conveyor belt 18, and a pair of pressure rollers 37 that press the end of the conveyor belt 18 against the conveyor belt 20. Similarly, among the rollers 21, a fourth guide roller 38 that supports the conveyor belt 20, and a pair of pressure rollers 39 that press the end of the conveyor belt 20 against the conveyor belt 18 are shown.

The cross-sectional height of space 26 in FIG. 4(C) is smaller than that in FIG. 4(B). The cross-sectional width of space 26 in FIG. 4(C) is larger than that in FIG. 4(B).

The height of the space 26 formed by the conveyor belts 18 and 20 gradually decreases rearward from FIG. 3(C) to FIG. 4(C). The width of this space 26 gradually increases rearward from FIG. 3(C) to FIG. 4(C). The cross-sectional shapes of the space 26 shown in FIG. 3(C) to FIG. 4(C) are examples and are not limited thereto. The cross-sectional shape of the space 26 may be rectangular or polygonal.

Figure 5 (A) shows a cross section of the discharge device 13 taken along the line VA-VA in Figure 2. Figure 5 (A) shows, among the multiple rollers 19, a first movable roller 40 that supports the conveyor belt 18, and a pair of pressure rollers 41 that press the end of the conveyor belt 18 against the conveyor belt 20. Similarly, among the multiple rollers 21, a first movable roller 42 that supports the conveyor belt 20, and a pair of pressure rollers 43 that press the end of the conveyor belt 20 against the conveyor belt 18 are shown.

In FIG. 5(A), the first movable roller 40 presses the conveyor belt 18 against the conveyor belt 20. Similarly, the first movable roller 42 presses the conveyor belt 20 against the conveyor belt 18. This brings the conveyor belts 18 and 20 into close contact with each other.

Figure 5(B) shows a different state of use of the discharge device 13 from that shown in Figure 5(A). In Figure 5(B), the first movable roller 40 is positioned lower than in the position shown in Figure 5(A). Similarly, the first movable roller 42 is positioned higher than in the position shown in Figure 5(A). This forms a space 26 between the conveyor belt 18 and the conveyor belt 20 into which soil and sand can flow. The first movable rollers 40 and 42 are movable between the closed position shown in Figure 5(A) and the open position shown in Figure 5(B).

Figure 2 further shows, of the multiple rollers 19, the second movable roller 44, the third movable roller 48, the fourth movable roller 52, the fifth movable roller 56, and the tension roller 60, which support the conveyor belt 18. The second movable roller 44, the third movable roller 48, the fourth movable roller 52, and the fifth movable roller 56, like the first movable roller 40, are movable between a closed position and an open position. The tension roller 60 adjusts the tension of the conveyor belt 18.

Similarly, of the multiple rollers 21, the second movable roller 46, the third movable roller 50, the fourth movable roller 54, the fifth movable roller 58, and the tension roller 62 that support the conveyor belt 20 are shown. The second movable roller 46, the third movable roller 50, the fourth movable roller 54, and the fifth movable roller 58 are movable between a closed position and an open position, similar to the first movable roller 42. The tension roller 62 adjusts the tension of the conveyor belt 20.

Although not shown, the discharge device 13 includes a roller moving device. The roller moving device includes an actuator that moves each of the first movable roller 40, the first movable roller 42, the second movable roller 44, the second movable roller 46, the third movable roller 48, the third movable roller 50, the fourth movable roller 52, the fourth movable roller 54, the fifth movable roller 56, and the fifth movable roller 58 independently between a closed position and an open position. The actuator is not particularly limited, but is, for example, a hydraulic cylinder.

Figure 6 (A) shows the discharge device 13 in use. The first movable rollers 40 and 42, the second movable rollers 44 and 46, and the third movable rollers 48 and 50 are in the open position. The fourth movable rollers 52 and 54, and the fifth movable rollers 56 and 58 are in the closed position. Soil that has flowed between the conveyor belt 18 and the conveyor belt 20 is blocked by the fourth movable rollers 52 and 54. Although not shown, the widthwise ends of the conveyor belt 18 and the widthwise ends of the conveyor belt 20 are pressed by pressure rollers and sealed by packing. In this tunnel boring machine 1, the soil is trapped in the conveyor belt 18 and the conveyor belt 20 while maintaining pressure.

From the usage state of FIG. 6(A), soil and sand further flow in between conveyor belt 18 and conveyor belt 20. The flowing in soil and sand moves conveyor belt 18 and conveyor belt 20. The first movable rollers 40 and 42 move to the closed position while guiding conveyor belt 18 and conveyor belt 20. The fourth movable rollers 52 and 54 move to the open position while guiding conveyor belt 18 and conveyor belt 20. In this way, the discharge device 13 is changed from the usage state of FIG. 6(A) to the usage state of FIG. 6(B).

In the usage state of FIG. 6(B), the first movable rollers 40 and 42 are in the closed position, and the fourth movable rollers 52 and 54 are in the open position. The position of the other rollers 19 supporting the conveyor belt 18 and the position of the other rollers 21 supporting the conveyor belt 20 are the same as in the usage state of FIG. 6(A). In this usage state of FIG. 6(B), the conveyor belts 18 and 20 separate a portion of the soil, form soil fragments from the soil, and trap the soil fragments.

From the use state of FIG. 6(B), the second movable rollers 44 and 46 move to the closed position while guiding the conveyor belts 18 and 20. The fifth movable rollers 56 and 58 move to the open position while guiding the conveyor belts 18 and 20. In this way, the discharge device 13 is changed from the use state of FIG. 6(B) to the use state of FIG. 6(C).

In the usage state of FIG. 6(C), the second movable rollers 44 and 46 are in the closed position, and the fifth movable rollers 56 and 58 are in the open position. The positions of the other rollers 19 and 21 are the same as in the usage state of FIG. 6(B). In this usage state of FIG. 6(C), the conveyor belts 18 and 20 trap the soil and sand. The separated soil and sand are discharged outside the discharge device 13 from between the conveyor belts 18 and 20.

From the use state of FIG. 6(C), the first movable rollers 40 and 42 move to the open position while guiding the conveyor belts 18 and 20. Soil and sand flow into the gap between the first movable rollers 40 and 42. The third movable rollers 48 and 50 move to the closed position while guiding the conveyor belts 18 and 20. In this way, the discharge device 13 is changed from the use state of FIG. 6(C) to the use state of FIG. 7(A).

In the usage state shown in FIG. 7(A), the first movable rollers 40 and 42 are in the open position, and the third movable rollers 48 and 50 are in the closed position. In this usage state shown in FIG. 7(A), the conveyor belts 18 and 20 trap the soil and sand. The separated soil and sand are further discharged from between the conveyor belts 18 and 20 to the outside of the discharge device 13.

From the use state of FIG. 7(A), the second movable rollers 44 and 46 move to the open position while guiding the conveyor belts 18 and 20. Soil flows into the gap between the second movable rollers 44 and 46. The fourth movable rollers 52 and 54 move to the closed position while guiding the conveyor belts 18 and 20. In this way, the discharge device 13 is changed from the use state of FIG. 7(A) to the use state of FIG. 7(B).

In the usage state shown in FIG. 7(B), the second movable rollers 44 and 46 are in the open position, and the fourth movable rollers 52 and 54 are in the closed position. In this usage state shown in FIG. 7(B), the conveyor belts 18 and 20 trap the soil and sand. The separated soil and sand are further discharged from between the conveyor belts 18 and 20 to the outside of the discharge device 13.

From the use state of FIG. 7(B), the third movable rollers 48 and 50 move to the open position while guiding the conveyor belts 18 and 20. Soil and sand flow into the gap between the third movable rollers 48 and 50. The fifth movable rollers 56 and 58 move to the closed position while guiding the conveyor belts 18 and 20. In this way, the discharge device 13 is changed from the use state of FIG. 7(B) to the use state of FIG. 7(C).

In the use state shown in FIG. 7(C), the third movable rollers 48 and 50 are in the open position, and the fifth movable rollers 56 and 58 are in the closed position. In this use state shown in FIG. 7(C), the conveyor belts 18 and 20 trap the soil. All of the divided soil has been discharged.

The usage state in FIG. 7(C) is a return to the usage state in FIG. 6(A). In this way, the discharge device 13 changes its usage state from FIG. 6(A) to FIG. 7(B), and by repeating this change in usage state, it is possible to repeatedly form and discharge divided soil from the soil.

As shown in the usage states of Figures 6(A) to 7(C), the sensor 15 is disposed at a position where it can detect the height and width of the divided soil. This sensor 15 is not particularly limited, but is, for example, a laser sensor. The soil discharge volume measuring device 64 receives a detection signal of the divided soil from the sensor 15.

This tunnel boring machine 1 confines the soil discharged from the screw conveyor 11 with a pair of conveyor belts 18, 20, enveloping a portion of the soil to form separate soil segments before discharging it. This prevents the soil from erupting.

This tunnel excavator 1 prevents soil from being ejected from the discharge outlet of the screw conveyor 11. Conventionally, in order to prevent soil from being ejected, the overall length of the screw conveyor 11 was lengthened to reduce the pressure of the soil. With this tunnel excavator 1, the ejection of soil is prevented, so the overall length of the screw conveyor 11 can be made shorter than in the past.

This tunnel boring machine 1 confines the soil with a pair of conveyor belts 18, 20, so it can discharge the soil even if the soil quality changes. This tunnel boring machine 1 can continue excavating without stopping even if the soil quality changes. This tunnel boring machine 1 has excellent excavation efficiency.

As described above, the tunnel boring machine 1 is preferably equipped with a guide pipe 16 that guides soil from the discharge side of the screw conveyor 11 to the pair of conveyor belts 18, 20. The height of the opening cross section of this guide pipe 16 gradually decreases toward the rear, and the width of the opening cross section gradually increases toward the rear.

The guide pipe 16 reduces the height and widens the cross-sectional shape of the soil, making it easier for the soil to be trapped by the pair of conveyor belts 18, 20.

As described above, the tunnel boring machine 1 preferably includes a plurality of first guide rollers 22 and 24, a plurality of second guide rollers 28 and 30, and a plurality of third guide rollers 32 and 34 that guide the pair of conveyor belts 18, 20. The plurality of first guide rollers 22 and 24, the plurality of second guide rollers 28 and 30, and the plurality of third guide rollers 32 and 34 are arranged so that the height of the space 26 formed by the pair of conveyor belts 18, 20 gradually decreases toward the rear, and the width of this space 26 gradually increases toward the rear.

This makes the cross-sectional shape of the soil trapped by the pair of conveyor belts 18, 20 even lower in height and wider in width. This makes it easier to separate the divided soil from the soil. In addition, by changing the cross-sectional shape of the soil using the conveyor belts 18, 20 that move together with the soil, it is easy to change the cross-sectional shape of the soil even if the soil quality of the soil changes.

Here, the first guide rollers 22 and 24, the second guide rollers 28 and 30, and the third guide rollers 32 and 34 are arranged in the feed direction of the conveyor belts 18 and 20, but this is not limited to the above. A larger number of rollers 19 may be arranged in the feed direction of the conveyor belts 18 and 20, and the height and width of the space 26 may be changed.

This tunnel boring machine 1 is equipped with a guide tube 16 along with a plurality of first guide rollers 22, 24, a plurality of second guide rollers 28, 30, and a plurality of third guide rollers 32 and 34, but the guide tube 16 may not be included. Also, while this tunnel boring machine 1 is equipped with a guide tube 16, it may not be equipped with a plurality of first guide rollers 22, 24, a plurality of second guide rollers 28, 30, and a plurality of third guide rollers 32 and 34. This tunnel boring machine 1 may use the guide tube 16 to deform the cross section of the soil to a cross-sectional height that allows the divided soil to be separated.

In this tunnel boring machine 1, the divided soil is formed by the first movable rollers 40, 42, the second movable rollers 44, 46, the third movable rollers 48, 50, the fourth movable rollers 52, 54, and the fifth movable rollers 56 and 58, but this is not limited to this. The number of movable rollers arranged in the feed direction of the conveyor belts 18 and 20 may be more or less than this.

This tunnel excavator 1 uses first movable rollers 40, 42, second movable rollers 44, 46, third movable rollers 48, 50, fourth movable rollers 52, 54, and fifth movable rollers 56 and 58 to form divided soil with a predetermined height, width, and length. This forms divided soil with a predetermined volume. By discharging the soil as divided soil with this predetermined volume, the tunnel excavator 1 can measure the amount of soil discharged with higher accuracy than conventional accuracy.

The tunnel boring machine 1 is preferably equipped with a sensor 15 capable of detecting the divided soil. The tunnel boring machine 1 can detect the height and width of the divided soil using the sensor 15. This allows the tunnel boring machine 1 to measure the volume of the divided soil with higher accuracy.

The tunnel boring machine 1 is preferably equipped with a discharged soil amount measuring device 64 shown in FIG. 1. The discharged soil amount measuring device 64 receives a detection signal of the divided soil from the sensor 15. The discharged soil amount measuring device 64 calculates the volume of the divided soil and the amount of soil discharged by the screw conveyor 11 from the signal from the sensor 15 and the speed of the conveyor belts 18 and 20. This allows the tunnel boring machine 1 to measure the amount of soil discharged with high accuracy.

The discharged soil volume measuring device 64 may obtain the volume of the divided soil and the speed of the conveyor belts 18 and 20 from the discharge device 13 without using the sensor 15. Specifically, the volume of the divided soil can be obtained from the position information of the first movable rollers 40, 42, the second movable rollers 44, 46, the third movable rollers 48, 50, the fourth movable rollers 52, 54, and the fifth movable rollers 56 and 58.

The discharge device 13 and the sensor 15 are attached near the screw conveyor 11. This allows the tunnel boring machine 1 to measure the amount of soil discharged without a large time lag. Based on this amount of soil discharged, the pressure in the cutter chamber 8 can be quickly adjusted. From this perspective, it is preferable that the discharge device 13 is attached to the discharge outlet of the screw conveyor 11 or to the discharge outlet of the screw conveyor 11 via a guide pipe 16.

[Disclosure items]
Each of the following sections is a disclosure of a preferred embodiment.

[Item 1]
a cutter head 4 for excavating the natural ground; a partition wall 7 for forming a cutter chamber 8 between the cutter head 4; a screw conveyor 11 for discharging soil generated by excavation from the cutter chamber 8;
The tunnel boring machine 1 is provided with a discharge device 13 including a pair of conveyor belts 18, 20 that traps soil discharged from a screw conveyor 11, wraps up a portion of the soil, and forms divided soil for discharge.

[Item 2]
A plurality of movable rollers 40, 42 for guiding the pair of conveyor belts 18, 20 are provided.
The tunnel boring machine 1 described in item 1, wherein each movable roller 40, 42 is movable between an open position in which the pair of conveyor belts 18, 20 are separated from each other to form a space, and a closed position in which the pair of conveyor belts 18, 20 are brought into close contact with each other.

[Item 3]
3. The tunnel boring machine 1 according to claim 2, wherein the pair of conveyor belts 18, 20 envelop a portion of the soil to form a soil split as the movable rollers 40, 42 move from the open position to the closed position.

[Item 4]
A guide pipe 16 is provided to guide the soil and sand from the discharge port side of the screw conveyor 11 to a pair of conveyor belts 18, 20.
4. The tunnel boring machine 1 according to any one of items 1 to 3, wherein the height of the opening cross section of the guide pipe 16 gradually decreases toward the rear, and the width of the opening cross section gradually increases toward the rear.

[Item 5]
A tunnel boring machine 1 according to any one of items 1 to 4, comprising a plurality of guide rollers 22, 24, 28, 30 for guiding the pair of conveyor belts 18, 20, arranged so that the height of the space formed by the pair of conveyor belts 18, 20 gradually decreases toward the rear and the width of the space gradually increases toward the rear.

[Item 6]
Separating a predetermined volume of sediment from the sediment;
6. A tunnel boring machine according to any one of items 1 to 5, comprising a discharged soil amount measuring device 64 that calculates a discharged soil amount from a volume of the divided soil and the speed of the conveyor belts 18, 20.

1 ... Tunnel boring machine 4 ... Cutter head 7 ... Partition wall 8 ... Cutter chamber 11 ... Screw conveyor 13 ... Discharge device 16 ... Guide tube 18, 20 ... Conveyor belt 22, 24, 28, 30, 32, 34, 36, 38 ... Guide roller 40, 42, 44, 46, 48, 50, 52, 54, 56, 58 ... Movable roller 64 ... Discharge amount measuring device

Claims (5)

A cutter head for excavating natural ground, a partition wall for forming a cutter chamber between the cutter head and the partition wall, and a screw conveyor for discharging soil and sand generated by excavation from the cutter chamber.
a discharge device including a pair of conveyor belts that confines the soil discharged from the screw conveyor, wraps a portion of the soil, and forms divided soil and discharges the divided soil ;
The conveyor system further includes a plurality of movable rollers for guiding the pair of conveyor belts,
A tunnel boring machine , wherein each movable roller is movable between an open position in which the pair of conveyor belts are separated from each other to form a space, and a closed position in which the pair of conveyor belts are brought into close contact with each other . The tunnel boring machine of claim 1 , wherein the pair of conveyor belts encase a portion of the soil to form a soil divider as the movable rollers move from the open position to the closed position. a guide pipe for guiding the soil and sand from a discharge port side of the screw conveyor to the pair of conveyor belts;
3. The tunnel boring machine according to claim 1 , wherein the height of an opening cross section of the guide pipe gradually decreases rearward, and the width of the opening cross section gradually increases rearward. 4. A tunnel boring machine as described in any one of claims 1 to 3, comprising a plurality of guide rollers for guiding the pair of conveyor belts, the guide rollers being arranged so that the height of the space formed by the pair of conveyor belts gradually decreases toward the rear and the width of the space gradually increases toward the rear. Separating a predetermined volume of the divided soil from the soil;
5. The tunnel boring machine according to claim 1, further comprising a discharged soil amount measuring device for calculating a discharged soil amount from a volume of the divided soil and a speed of the conveyor belt.

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