JP2020023841A - Shield machine, method for constructing tunnel, and screw conveyor - Google Patents

Abstract

To provide a screw conveyor capable of easily coping with a change and having a simple configuration, even when the configuration of a stratum changing according to an excavation of a shield machine.SOLUTION: A screw conveyor for a shield machine includes a cylindrical casing having a sediment intake at one end and a sediment discharge at the other end, a screw 22 rotatably provided in a casing and including a spiral rotating blade 28, a first space portion 51 formed in the casing adjacent to the rotating blade 28 and extending in the longitudinal direction of the casing, and a projecting member 55 provided on the rotating blade 28 and able to project into the first space portion 51.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a shield machine, a tunnel construction method using the shield machine, and a screw conveyor for the shield machine.

Shield tunnels used as pipes for water supply and sewerage, common ditches, roads, railways, etc. are constructed by a shield method.
In the shield method, a shield machine is used. The shield machine is formed, for example, between a cylindrical head, a cutter head disposed at the front end of the body, a partition disposed in the body behind the cutter head, and a cutter head and the partition. A chamber for storing the earth and sand excavated by the cutter head, and a soil discharging device for discharging the earth and sand stored in the chamber from the earth and sand discharge port opened to the partition wall to the rear of the partition wall. It may include a conveyor.

  In the shield method, for example, a starting shaft and a reaching shaft are built in the ground, and while excavating the ground with a shield machine from the starting shaft to the reaching shaft, the inside of the rear part (tail part) of the trunk is The segments are assembled one after another to form a cylindrical lining. In this method, the shield machine presses the existing segment backward with the propulsion jack, and moves forward while excavating the ground by the thrust generated as a reaction force.

  When a shield excavator excavates a stratum with a mixture of gravel and boulders, a ribbon-type screw conveyor can be employed as the above-mentioned earth removal device. The ribbon-type screw conveyor includes, for example, a cylindrical casing having a sediment inlet at a front end and a sediment discharge port at a rear end, and a helical rotary blade rotatably provided in the casing. And a sediment inlet of the casing is connected to a sediment discharge port of a partition wall of the shield machine.

  In this regard, Patent Document 1 discloses that a shaft member is detachably attached along a central axis of a ribbon screw (screw auger) in a screw conveyor for a shield machine. In Patent Literature 1, when the configuration of the stratum (characteristics of the soil to be excavated) changes with the excavation of the shield machine, the shaft member is removed from the ribbon screw or attached to the ribbon screw according to the change. Specifically, for example, when the stratum is large-size gravel, the shaft member is removed from the ribbon screw to carry out the earth and sand, and when the stratum is fine-grained soil, the shaft member is moved along the central axis of the ribbon screw. To carry out the earth and sand (see paragraphs 0010 and 0020 of Patent Document 1).

JP-A-07-011891

  In Patent Document 1, when attaching a shaft member along the center axis of the ribbon screw, the shaft member is inserted into the central space of the ribbon screw from behind the screw conveyor (see FIG. 1 of Patent Document 1). Therefore, in the technique disclosed in Patent Literature 1, it is necessary to secure a wide space that can cover the length of the shaft member immediately after the screw conveyor.

  However, in actual tunnel construction, for example, a lining body (segment), a trailing bogie, and the like are arranged immediately after the screw conveyor. Therefore, in practice, it is very difficult to secure a wide space that can cover the length of the shaft member immediately after the above-mentioned screw conveyor. In addition, there was a concern that excavation efficiency would be reduced or excavation would not be possible due to the obstruction of earth and sand due to narrowing of the discharge path for gravel and boulders.

  The present invention has been made in view of the above circumstances, and provides a screw conveyor having a simple configuration that can easily cope with a change in the configuration of a stratum due to the excavation of a shield excavator and that has a simple configuration. With the goal.

  Therefore, in a first aspect of the present invention, a shield machine includes a cylindrical trunk, a cutter head disposed at a front end of the trunk, a partition disposed in the trunk behind the cutter head, and a cutter head. And a chamber formed between the and the partition wall for storing the earth and sand excavated by the cutter head, and a soil discharging device for discharging the earth and sand stored in the chamber from the earth and sand discharge port opened to the partition wall to the rear of the partition wall. It is comprised including. The discharging device includes a screw conveyor. The screw conveyor has a cylindrical casing having a sediment inlet at the front end and a sediment discharge port at the rear end, a screw rotatably provided in the casing and including spiral rotating blades, and a casing. And a space formed adjacent to the rotating blade and extending in the longitudinal direction of the casing, and a projecting member provided on the rotating blade and capable of projecting into the space. The sediment intake of the casing is connected to the sediment discharge of the bulkhead.

  A second aspect of the present invention is a method for constructing a tunnel using the shield machine according to the first aspect. The construction method of this tunnel is to stop the excavation of the shield excavator, to rotate the screw with the excavation of the shield excavator stopped, and to discharge the soil inside the casing from the sediment discharge port of the casing to the outside of the casing Changing the protruding amount of the protruding member into the space, and restarting the excavation of the shield excavator.

  In a third aspect of the present invention, a screw conveyor for a shield machine is provided with a cylindrical casing having a sediment intake port at one end and a sediment discharge port at the other end, and rotatably provided in the casing. A screw including a spiral rotating blade that is provided, a space formed in the casing adjacent to the rotating blade and extending in the longitudinal direction of the casing, a projecting member provided on the rotating blade and capable of projecting into the space, Is provided.

  In the present invention, the “spiral” is known as a kind of three-dimensional curve, and is referred to as a “helix” or a “helix”.

  According to the present invention, the screw conveyor includes a projecting member that can project into the space in the casing. Therefore, even if the configuration of the stratum changes with the excavation of the shield machine, the above-mentioned projecting member can be used instead of the shaft member described in Patent Document 1 in accordance with the change, so that a simple configuration can be used. Thus, it is possible to easily cope with the above-mentioned change in the configuration of the stratum.

Schematic configuration diagram of a shield machine in a first embodiment of the present invention FIG. 3 is a perspective view showing a retracted state of a protruding member provided on the rotary blade in the first embodiment. View from arrow A in FIG. The arrow B view of the area P of FIG. FIG. 4 is a perspective view showing a state in which a protruding member provided on the rotary blade according to the first embodiment is pushed out. View from arrow C in FIG. 5 is a view of an area P in FIG. FIG. 4 is a diagram illustrating an example of a protrusion amount changing mechanism according to the first embodiment. The figure which shows the 1st modification of the screw conveyor in the said 1st Embodiment. The figure which shows the 2nd modification of the screw conveyor in the said 1st Embodiment. The figure which shows the installation method to the rotating blade of the protruding member in 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of a shield machine according to a first embodiment of the present invention. In this embodiment, for the sake of convenience, the forward and backward directions are defined as the tunnel digging direction.

  A mud pressure shield excavator 1 used for constructing a tunnel has a main body (excavator main body) 2 including a cylindrical body 3. Here, the skin plate 4 constituting the outer peripheral surface of the trunk 3 forms an outer shell of the machine 2.

  The body 3 has a cutter head 5 for excavation and a bulkhead (bulk head) 6. The cutter head 5 is disposed at the front end of the body 3 and is rotatable. The partition wall 6 is disposed in the body 3 behind the cutter head 5 and spaced apart therefrom. The cutter head 5 is rotatably supported by the partition wall 6, and excavates the ground while rotating using a driving motor 7 provided on the rear surface of the partition wall 6 as a driving source.

  A chamber (cutter chamber) 8 is defined between the cutter head 5 and the partition wall 6 and the body 3. The chamber 8 stores the earth and sand excavated by the cutter head 5. In other words, the excavated earth and sand generated by the excavation by the cutter head 5 stays in the chamber 8. An additive (mud material) can be supplied into the chamber 8 via an additive injection tube (not shown). An earth and sand discharge port 6 a is formed at the lower end of the partition wall 6 so as to face the bottom of the chamber 8.

  The shield machine 1 includes an erector 9 in the body 3. The erector 9 has a grip 9a. The erector 9 can appropriately move the segment 10 in the tunnel axial direction, the radial direction, and the circumferential direction while holding the segment 10 having an arc-shaped cross section with the holding portion 9a inside the body 3. The erector 9 assembles the segments 10 to form a cylindrical lining 11.

  A plurality of propulsion jacks 12 are arranged on the periphery of the body 3 of the shield machine 1 at intervals in the circumferential direction of the body 3. The propulsion jack 12 is a hydraulic jack composed of a cylinder 12a and a rod 12b. The front end of the cylinder 12a is fixed to the body 3, and the rod 12b can advance and retreat at the rear end. By extending the propulsion jack 12 with the rear end of the rod 12b of the propulsion jack 12 in contact with the existing segment 10, the shield machine 1 can obtain a propulsion force. In this manner, the propulsion jack 12 takes the reaction force from the existing segment 10 to propel the shield machine 1 forward.

  The shield machine 1 includes an earth discharging device 15 that discharges the earth and sand stored in the chamber 8 from the earth and sand discharge port 6 a of the partition 6 to the rear of the partition 6. The soil discharging device 15 is configured to include a plurality of screw conveyors 20 and 30 (in this embodiment, two stages before and after). The number of screw conveyors constituting the discharging apparatus 15 is not limited to two, but may be only one, or may be three or more.

  The former (first-stage) screw conveyor 20 is a so-called ribbon-type screw conveyor. The screw conveyor 20 includes a cylindrical casing 21, a screw (ribbon screw) 22 rotatably provided in the casing 21, and a driving device 23 that drives the screw 22 to rotate.

  The casing 21 has a sediment intake 21a at a front end (one end) and a sediment discharge port 21b at a rear end (the other end). The earth and sand intake 21 a of the casing 21 is connected to the earth and sand discharge port 6 a of the partition wall 6. The casing 21 extends obliquely upward from the earth and sand discharge port 6 a of the partition wall 6 to the rear of the partition wall 6.

  An opening 25 is formed in the peripheral wall of the casing 21. The screw conveyor 20 includes a lid 26 that can open and close the opening 25. The number of the openings 25 formed in the casing 21 is not limited to one, and may be two or more. When the number of the openings 25 formed in the casing 21 is two or more, it is preferable that these openings 25 are formed in the peripheral wall of the casing 21 at intervals in the longitudinal direction of the casing 21. In this case, a lid 26 is provided in each opening 25.

  A pressure gauge 27 that measures and displays the pressure in the casing 21 (specifically, the pressure of earth and sand flowing through the casing 21) is provided near the opening 25 in the casing 21. In the present embodiment, the pressure gauges 27 are provided near the opening 25 in the casing 21 and on the front side (upstream side) and the rear side (downstream side) of the opening 25, respectively. In addition, it goes without saying that the pressure gauge 27 may be provided on one of the front side (upstream side) and the rear side (downstream side) of the opening 25.

  The drive device 23 is configured by, for example, a hydraulic motor or an electric motor, and is provided at a rear end of the casing 21. A pinion gear (not shown) is fixed to a rotation shaft (output shaft) of the drive device 23, and a ring gear (not shown) is engaged with the pinion gear. The ring gear is integrally fixed to the screw 22 on the inner peripheral surface. Therefore, the rotational force of the driving device 23 can be transmitted to the screw 22 via the pinion gear and the ring gear. As a method for driving the screw 22 to rotate by the driving device 23, a method disclosed in Patent Document 1, a method disclosed in Japanese Patent No. 5848669, or the like can be adopted.

  The latter (second stage) screw conveyor 30 is also a so-called ribbon-type screw conveyor, and has the same configuration as the screw conveyor 20 described above. The screw conveyor 30 includes a cylindrical casing 31, a screw (ribbon screw) (not shown) rotatably provided in the casing 31, and a driving device 33 that rotationally drives the screw.

  The casing 31 has a sediment intake 31a at a front end (one end) and a sediment discharge port 31b at a rear end (the other end). The earth and sand intake port 31 a of the casing 31 is connected to the earth and sand discharge port 21 b of the casing 21 via the elbow pipe 17. The casing 31 extends rearward from the rear end of the elbow pipe 17 obliquely upward. Here, the inclination gradient of the casing 31 is smaller than the inclination gradient of the casing 21. The earth and sand discharge port 31b of the casing 31 faces downward, and for example, a belt conveyor (not shown) constituting the soil discharging device 15 may be disposed below the earth and sand discharge port 31b.

  Two openings 35 are formed in the peripheral wall of the casing 31. The screw conveyor 30 includes a lid 36 that can open and close each opening 35. These openings 35 are formed in the peripheral wall of the casing 31 at intervals in the longitudinal direction of the casing 31. The number of the openings 35 formed in the casing 31 is not limited to two, but may be only one, or may be three or more.

  In the vicinity of the opening 35 in the casing 31, a pressure gauge 37 for measuring and displaying the pressure in the casing 31 (specifically, the pressure of the earth and sand flowing in the casing 31) is provided. In the present embodiment, the pressure gauges 37 are provided near the opening 35 in the casing 31 and at the front side (upstream side) and the rear side (downstream side) of the opening 35, respectively. In addition, it goes without saying that the pressure gauge 37 may be provided on one of the front side (upstream side) and the rear side (downstream side) of the opening 35.

  The driving device 33 has the same configuration as the driving device 23 described above, and similarly to the driving device 23, the rotational force of the driving device 33 can be transmitted to the screw of the screw conveyor 30 via the pinion gear and the ring gear.

  In the present embodiment, three openings (one opening 25 and one opening 25) are formed on the peripheral wall of the cylindrical casing (the casings 21, 31 and the elbow tube 17) of the screw conveyor unit 40 including the screw conveyors 20, 30 and the elbow tube 17. Two openings 35) are formed at an interval in the longitudinal direction (extending direction) of the screw conveyor unit 40, and lids 26 and 36 are provided in each of these openings. The screw conveyor unit 40 is bent or curved at 17 places of the elbow pipe. The screw conveyor unit 40 constitutes the discharging device 15.

The screw 22 constituting the screw conveyor 20 includes a spiral rotating blade (conveying blade) 28.
As for the screw conveyor 20, as shown in FIGS. 2 to 4 described later, the internal space of the casing 21 has a cylindrical first space portion 51 and a spiral second space portion located radially outward thereof. 52. That is, the screw conveyor 20 includes the first space 51 and the second space 52.

  The first space portion 51 is formed adjacent to the rotary blade 28 in the casing 21 and extends in the longitudinal direction of the casing 21. Here, the first space 51 corresponds to the “space” of the present invention. The first space 51 is formed along the central axis (virtual line) CL of the casing 21 and the screw 22. As viewed in a cross section orthogonal to the longitudinal direction of the casing 21 (for example, the center axis line CL), the first space 51 is located radially inward of the rotary blade 28 (see FIGS. 3 and 4).

  The second space 52 is spirally defined by the inner peripheral surface of the casing 21 and the spiral rotating blade 28.

  FIG. 2 is a perspective view illustrating a retracted state of the protruding member 55 provided on the rotary blade 28. FIG. 3 is a view on arrow A in FIG. FIG. 4 is a view of the region P in FIG. FIG. 5 is a perspective view showing a state in which the protruding member 55 provided on the rotary blade 28 is pushed out. FIG. 6 is a view taken in the direction of arrow C in FIG. FIG. 7 is a view of the region P in FIG. Here, FIGS. 2 and 5 show a part of the rotating blade 28 (for three pitches in a spiral shape). The region P shown in FIGS. 2 and 5 is a region of the rotary blade 28 that can face the opening 25.

  A plurality (six in the present embodiment) of projecting members 55 are provided on the surface of the rotary blade 28 on the side of the earth and sand discharge port 21b in the region P. Therefore, the screw conveyor 20 includes the projecting member 55. The protruding member 55 can protrude into the first space 51. The protruding member 55 is an isosceles trapezoidal plate-shaped member that tapers inward in the radial direction of the rotary blade 28. These projecting members 55 are arranged side by side in the circumferential direction of the rotary blade 28 (see FIGS. 3 and 4).

  In the present embodiment, the plurality of protruding members 55 are provided on the surface on the side of the earth and sand discharge port 21b in the region P of the rotary blade 28, but instead of or in addition to this, the region of the rotary blade 28 A plurality of projecting members 55 may be provided on the surface of P on the side of the earth and sand intake 21a.

  In the present embodiment, in the region P of the rotating blade 28, the six projecting members 55 are provided on the rotating blade 28 at intervals of 60 ° in the circumferential direction of the rotating blade 28. Interval) is not limited to this. That is, in the region P of the rotating blade 28, one or more arbitrary number of the protruding members 55 can be provided on the rotating blade 28. In the case where a plurality of projecting members 55 are provided on the rotating blade 28 in the region P of the rotating blade 28, the projecting members 55 may be arranged at any intervals in the circumferential direction of the rotating blade 28 (for example, at 15 ° intervals, 30 °). °, 45 °, 60 °, 90 °, 120 °, and 180 ° intervals).

  In the present embodiment, a region P of the rotating blade 28 that can face the opening 25 corresponds to one spiral pitch of the rotating blade 28. That is, the length of the opening 25 in the longitudinal direction of the screw conveyor 20 corresponds to the length of one spiral pitch of the rotating blade 28. However, it is needless to say that the length of the opening 25 in the longitudinal direction of the screw conveyor 20 is not limited to the length of one pitch in the spiral shape of the rotating blade 28. For example, the length of the opening 25 in the longitudinal direction of the screw conveyor 20 may correspond to the length of two or three pitches in the spiral shape of the rotating blade 28.

  The screw conveyor 20 includes a protrusion amount changing mechanism 60 that changes the protrusion amount of the protrusion member 55 into the first space 51. The protrusion amount changing mechanism 60 is not shown in FIGS. 2 to 7. The schematic configuration of an example of the protrusion amount changing mechanism 60 will be described later with reference to FIG.

  2 to 4 show the retracted state of the projecting member 55 in which the projecting member 55 is located at the most retracted position. FIGS. 5 to 7 show the pushed-out state of the projecting member 55 when the projecting member 55 is located at the most advanced position. By using the protrusion amount changing mechanism 60, the protrusion member 55 is slidable in the radial direction of the rotary blade 28 between the most retreated position and the most advanced position, and the most retreated position and the most advanced position. Can be held at a desired position in between.

  In the retracted state of the protruding member 55 shown in FIGS. 2 to 4, when the first space 51 is viewed from the earth and sand discharge port 21b side, the protruding member 55 projects very slightly into the first space 51, Or, it does not protrude at all. In this state, the projecting member 55 does not obstruct the passage of the gravel or the like in the first space 51.

On the other hand, in the pushed-out state of the protruding member 55 shown in FIGS. Therefore, a part of the flow path composed of the cylindrical first space portion 51 is narrowed by the projecting member 55. In this state, when the first space portion 51 is viewed from the side of the earth and sand discharge port 21b, the protruding members 55 that are adjacent to each other in the circumferential direction of the rotary blade 28 partially overlap each other. The degree of overlap between the projecting members 55 in this state can be set arbitrarily.
In this state, the first space 51 may be closed by the protrusion 55 when the first space 51 is viewed from the earth and sand discharge port 21 b side.

  Here, the configuration of the stratum changes with the excavation of the shield excavator 1, and the sediment and groundwater pass from the chamber 8 through the first space 51 of the screw conveyors 20, 30, and the earth and sand discharge port 31b of the screw conveyor 30. For example, when there is a possibility that the protruding member 55 will erupt, the pushing state of the protruding member 55 shown in FIGS. 5 to 7 can be adopted.

  Therefore, with respect to the flow path composed of the cylindrical first space portion 51, a throttle portion having a reduced cross-sectional area can be formed by the plurality of projecting members 55. The cross-sectional area (aperture ratio) of the throttle unit can be changed by the protrusion amount changing mechanism 60.

  FIG. 8 shows an example of the protrusion amount changing mechanism 60 in the present embodiment. Here, FIG. 8A shows a retracted state of the protruding member 55 in which the protruding member 55 is located at the most retracted position. FIG. 8B shows the pushed-out state of the projecting member 55 in which the projecting member 55 is located at the most advanced position. Here, only one of the plurality of projecting members 55 provided in the region P of the rotary blade 28 will be described, but the same applies to the remaining members.

  In this example, the protrusion amount changing mechanism 60 includes a pair of bolts 61, a pair of female screw portions (not shown) formed on the rotary blade 28, each of which is screwed with a male screw portion of the bolt 61, and a protrusion member 55. It is formed by a pair of elongated holes 62 which are formed and into which the male screw portions of the bolts 61 are inserted, and which extend in the radial direction of the rotary blade 28.

  In the retracted state of the protruding member 55 shown in FIG. 8A, the bolt 61 is loosened and the protruding member 55 is pressed inward in the radial direction of the rotary blade 28, so that the protruding member 55 is elongated. And while being guided by the bolt 61, the rotary blade 28 slides inward in the radial direction of the rotary blade 28. By changing the slide amount, the protrusion amount of the protruding member 55 into the first space 51 can be changed. After the change of the protrusion amount is completed, the bolt 61 is tightened.

  In the pushed-out state of the protruding member 55 shown in FIG. 8B, the bolt 61 is loosened and the protruding member 55 is pulled outward in the radial direction of the rotary blade 28 so that the protruding member 55 is While being guided by the bolt 61, the rotating blade 28 slides radially outward. By changing the slide amount, the protrusion amount of the protruding member 55 into the first space 51 can be changed. After the change of the protrusion amount is completed, the bolt 61 is tightened.

  In the present embodiment, by using the protrusion amount changing mechanism 60, the protrusion member 55 is moved between the retracted state of the protrusion member 55 shown in FIG. 8A and the pushed state of the protrusion member 55 shown in FIG. The amount of protrusion of 55 into first space 51 can be changed arbitrarily. Here, increasing the amount of protrusion of the protruding member 55 into the first space portion 51 can substantially correspond to increasing the surface area (exposed area) of the rotary blade 28, Can lead to an increase in pressure loss (friction loss) against the earth and sand flowing through.

  The screws constituting the screw conveyor 30 also include spiral rotating blades (transport wings) similarly to the screw 22 described above. Therefore, the screw conveyor 30 also includes the first space 51 and the second space 52. The rotating blades of the screw conveyor 30 are also provided with a projecting member 55 and a projecting amount changing mechanism 60, similarly to the rotating blades 28 of the screw conveyor 20 described above. Here, the protruding member 55 and the protruding amount changing mechanism 60 may be provided in a region of the rotating blade of the screw conveyor 30 which can face the opening 35.

Next, a method for constructing a tunnel according to the present embodiment will be described.
In the present embodiment, when the configuration of the stratum changes along with the excavation of the shield machine 1, one of the following first operation example and second operation example can be performed according to the change. .

[First working example]
The first working example includes the following steps (A) to (F).

(A) The excavation of the shield excavator 1 is stopped.
(B) The earth and sand intake 21a of the casing 21 is closed.
(C) With the excavation of the shield excavator 1 stopped, the screws of the screw conveyors 20 and 30 are rotated to discharge the earth and sand in the casings 21 and 31 from the earth and sand discharge port 31 b of the casing 31 to the outside.

(D) When the discharge of the earth and sand from the casings 21 and 31 is completed, the rotation of the screws of the screw conveyors 20 and 30 is stopped. Thereafter, the worker opens the lids 26 and 36, and the worker changes the amount of protrusion of the protruding member 55 into the first space 51 via the openings 25 and 35.
(E) The worker closes the lids 26 and 36 to release the blockage of the sediment intake 21 a of the casing 21.
(F) The excavation of the shield excavator 1 is restarted.

  When closing the sediment intake 21a of the casing 21, for example, the sediment intake 21a is closed by a gate member (not shown) provided on the casing 21 and capable of opening and closing the sediment intake 21a. You may. Alternatively, the earth and sand intake 21a may be closed by freezing the earth and sand located in the vicinity of the earth and sand intake 21a in the chamber 8 and / or the casing 21.

[Second working example]
The second working example includes the following steps (G) to (L).

(G) The excavation of the shield excavator 1 is stopped.
(H) The earth and sand intake 31a of the casing 31 is closed.
(I) With the excavation of the shield excavator 1 stopped, the screw of the screw conveyor 30 is rotated to discharge the earth and sand in the casing 31 from the earth and sand discharge port 31b of the casing 31 to the outside.

(J) When the discharge of the earth and sand from the casing 31 is completed, the rotation of the screw of the screw conveyor 30 is stopped. Thereafter, the worker opens the lid 36 and changes the amount of protrusion of the protruding member 55 into the first space 51 via the opening 35.
(K) The worker closes the lid 36 and releases the blockage of the sediment intake 31a of the casing 31.
(L) The excavation of the shield excavator 1 is restarted.

  When closing the sediment intake 31a of the casing 31, for example, the sediment intake 31a is closed by a gate member (not shown) provided on the casing 31 and capable of opening and closing the sediment intake 31a. You may. Alternatively, of the earth and sand in the elbow pipe 17 and / or the casing 31 located near the earth and sand intake 31a, the earth and sand intake 31a may be closed by freezing.

  Also, without closing the earth and sand intake port 31a of the casing 31, a water stopping chemical (for example, CPS method) is added to the casing 21 located in front of the plurality of casings 21 connected in series. By stopping the rotation of the screw 22 and rotating the screw in the casing 31 located on the rear side, the earth and sand in the casing 21 exerts the same function as closing the earth and sand intake port 31a. By rotating the screw inside, the discharge of the earth and sand in the casing 31 can be completed.

At the time of tunnel construction, for example, the following points (A) to (C) are used so that the pressure in the casings 21 and 31 gradually decreases from the upstream side to the downstream side based on the monitoring results of the pressure gauges 27 and 37 by the worker. (C) can be determined.
(A) Which of the first working example and the second working example is performed?
(A) Of the one opening 25 and the two openings 35, which opening should the projecting member 55 adjacent to change the amount of projection into the first space 51?
(C) How much the projecting amount of the projecting member 55 into the first space 51 is changed.

  According to the present embodiment, the shield machine 1 is arranged in the trunk 3, the cutter head 5 disposed at the front end of the trunk 3, and the rear of the cutter head 5 in the trunk 3. A partition wall 6, a chamber 8 formed between the cutter head 5 and the partition wall 6 for storing the earth and sand excavated by the cutter head 5, and a sediment discharge port 6 a for opening the earth and sand stored in the chamber 8 to the partition wall 6. And an earth discharging device 15 that discharges water from the rear of the partition wall 6. The discharging device 15 includes a screw conveyor 20. The screw conveyor 20 includes a cylindrical casing 21 having a sediment inlet 21a at a front end and a sediment discharge port 21b at a rear end, and a spiral rotating blade 28 rotatably provided in the casing 21. , A first space 51 (space) formed in the casing 21 adjacent to the rotating blade 28 and extending in the longitudinal direction of the casing 21, and a first space 51 provided in the rotating blade 28 And a projecting member 55 that can project inside. The earth and sand intake 21 a of the casing 21 is connected to the earth and sand discharge port 6 a of the partition 6. Therefore, even if the configuration of the stratum changes with the excavation of the shield machine 1, the projecting member 55 can be used instead of the shaft member described in Patent Document 1 in accordance with the change. Therefore, it is possible to easily cope with the above-mentioned change in the configuration of the stratum.

  According to the present embodiment, the screw conveyor 20 further includes a protrusion amount changing mechanism 60 that changes the protrusion amount of the protrusion member 55 into the first space 51 (space). Thus, the degree of restriction (cross-sectional area and aperture ratio) of a part of the flow path composed of the cylindrical first space 51 can be arbitrarily adjusted using the protrusion amount changing mechanism 60.

  Further, according to the present embodiment, the first space 51 (space) is located radially inward of the rotary blade 28 when viewed in a cross section orthogonal to the longitudinal direction of the casing 21, and the plurality of projecting members 55 Are arranged side by side in the circumferential direction of the rotary blade 28. Accordingly, the plurality of projecting members 55 can be arranged in a well-balanced manner in the circumferential direction of the rotating blade 28, so that the rotating blade 28 can be prevented from vibrating during rotation due to the installation of the projecting member 55.

  Further, according to the present embodiment, the screw conveyor 20 further includes the lid 26 that can open and close the opening 25 formed in the peripheral wall of the casing 21. A projecting member 55 is provided in a region P of the rotary blade 28 that can face the opening 25. Thus, the worker can easily change the amount of protrusion of the protruding member 55 into the first space 51 via the opening 25 by opening the lid 26.

  According to this embodiment, a plurality of openings 25 and 35 are formed in the peripheral wall of casings 21 and 31 at intervals in the longitudinal direction of casings 21 and 31. A body 26, 36 is provided. This makes it possible to easily change the amount of protrusion of the protruding member 55 into the first space 51 via the openings 25 and 35 at a plurality of locations in the longitudinal direction of the casings 21 and 31.

  Further, according to the present embodiment, the tunnel construction method using the shield excavator 1 includes stopping the excavation of the shield excavator 1, and stopping the excavation of the shield excavator 1 with the screw of the screw conveyor 20, 30. Is rotated to discharge the earth and sand in the casings 21 and 31 from the earth and sand discharge port 31b of the casing 31 to the outside of the casing 31, and to change the amount of protrusion of the projecting member 55 into the first space 51 (space). , And restarting the excavation of the shield excavator 1. Therefore, even if the configuration of the stratum changes as the shield machine 1 excavates, the amount of protrusion of the protruding member 55 into the first space 51 can be easily changed according to the change.

  Further, according to the present embodiment, the tunnel construction method using the shield machine 1 is configured such that the soil of the casing 21 is rotated before the screws of the screw conveyors 20 and 30 are rotated with the shield machine 1 stopped excavating. The method further includes closing the intake port 21a. Accordingly, the operation of changing the amount of protrusion of the protruding member 55 can be performed safely in a state where the inflow of earth and sand from the inside of the chamber 8 into the casing 21 is prevented.

  According to the present embodiment, the screw conveyors 20 and 30 are screw conveyors for the shield machine 1. The screw conveyor 20 has a cylindrical casing 21 having a sediment intake 21a at a front end (one end) and a sediment discharge port 21b at a rear end (the other end), and is rotatable in the casing 21. A screw 22 provided and including a spiral rotary blade 28; a first space 51 (space) formed in the casing 21 adjacent to the rotary blade 28 and extending in the longitudinal direction of the casing 21; And a protruding member 55 that is provided in the first space portion 51 and can protrude into the first space portion 51. The screw conveyor 30 has a similar configuration. Therefore, even if the screw conveyors 20 and 30 are connected in series via the elbow pipe 17, the amount of protrusion of the projecting member 55 into the first space 51 can be easily changed in each of the screw conveyors 20 and 30. be able to.

  FIG. 9 is a diagram illustrating a first modified example of the screw conveyor 20 in the present embodiment. Here, FIG. 9A shows a retracted state of the protruding member 55 in which the protruding member 55 is located at the most retracted position. FIG. 9B shows the pushed-out state of the projecting member 55 in which the projecting member 55 is located at the most advanced position.

  In this modified example, in the region P of the rotating blade 28 that can face the opening 25, three protruding members 55 are provided on the rotating blade 28 at 120 ° intervals in the circumferential direction of the rotating blade 28. It goes without saying that the screw conveyor 30 may have a similar configuration.

  FIG. 10 is a diagram illustrating a second modified example of the screw conveyor 20 in the present embodiment. Here, FIG. 10A shows a retracted state of the protruding member 55 in which the protruding member 55 is located at the most retracted position. FIG. 10B shows the pushed-out state of the projecting member 55 in which the projecting member 55 is located at the most advanced position.

  In this modified example, the screw 22 is different from the first modified example in that the screw 22 is connected to the shaft portion 24a extending along the central axis (virtual line) CL, and the shaft portion 24a and the rotary blade 28 so as to be connected to each other. And a connecting member 24b extending radially from the rotating blade 28 in the radial direction. It goes without saying that the screw conveyor 30 may have a similar configuration.

FIG. 11 is a diagram illustrating a method of installing the protruding member 55 on the rotary blade 28 according to the second embodiment of the present invention. Here, FIG. 11A shows a state in which the projecting member 55 has been removed from the rotating blade 28, and FIG. 11B shows a state in which the projecting member 55 has been attached to the rotating blade 28. Here, only one of the plurality of projecting members 55 provided in the region P of the rotary blade 28 will be described, but the same applies to the remaining members.
The differences from the first embodiment will be described.

  In the present embodiment, a pair of female threads 65 are formed on the rotating blade 28, and a male thread of a bolt 66 can be screwed into each female thread 65. The projecting member 55 has a pair of through holes (not shown) into which the male screw portions of the bolts 66 are inserted. Therefore, in the present embodiment, the protruding member 55 is fixed to the rotary blade 28 via the bolt 66, and the protruding member 55 can be removed from the rotary blade 28 by loosening and removing the bolt 66.

  In particular, according to the present embodiment, the protruding member 55 is provided on the rotating blade 28 so as to be detachable from the rotating blade 28. Thus, by attaching or detaching the protruding member 55 to or from the rotary blade 28, it is possible to easily switch the presence or absence of the constricted portion in the flow path including the cylindrical first space 51.

  Needless to say, the method of installing the projecting member 55 on the rotary blade 28 in the present embodiment may be applied to the screw conveyor 30.

  Further, in the present embodiment, in the step (D) of the above-described first working example, changing the amount of protrusion of the projecting member 55 into the first space portion 51 can be achieved by changing the projecting member 55 to the screw conveyors 20 and 30. It can correspond to attaching to the rotating blade and removing the projecting member 55 from the rotating blades of the screw conveyors 20 and 30.

  Further, in the present embodiment, in the step (J) of the above-described second working example, the amount of protrusion of the projecting member 55 into the first space portion 51 can be changed by changing the projecting member 55 to the rotating blades of the screw conveyor 30. And removing the projecting member 55 from the rotating blades of the screw conveyor 30.

  In the first and second embodiments described above, the projecting member 55 has a plate shape, but the shape of the projecting member 55 is not limited to the plate shape. The protruding member 55 may have, for example, a rod shape.

  In the first and second embodiments described above, the screws constituting the screw conveyors 20, 30 are ribbon screws, but the screws constituting the screw conveyors 20, 30 are not limited to ribbon screws. For example, it may be a standard screw or a cut screw.

  In the above-described first and second embodiments, a mud pressure type shield excavator has been described as an example of the "shield excavator" of the present invention. In addition, a mud type shield excavator may be used. Needless to say.

  The illustrated embodiments are merely illustrative of the present invention, and the present invention covers various improvements and modifications made by those skilled in the art within the scope of the claims, in addition to those directly shown by the described embodiments. It goes without saying that it includes.

  DESCRIPTION OF SYMBOLS 1 ... Shield excavator, 2 ... excavator main body, 3 ... trunk | drum, 4 ... skin plate, 5 ... cutter head, 6 ... partition, 6a ... earth and sand discharge port, 7 ... drive motor, 8 ... chamber, 9 ... erector , 9a ... gripping part, 10 ... segment, 11 ... lining body, 12 ... propulsion jack, 12a ... cylinder, 12b ... rod, 15 ... earth removal device, 17 ... elbow pipe, 20 ... screw conveyor, 21 ... casing, 21a ... Sand intake, 21b ... Sand discharge, 22 ... Screw, 23 ... Driver, 24a ... Shaft, 24b ... Connecting member, 25 ... Opening, 26 ... Lid, 27 ... Pressure gauge, 28 ... Rotating blade , 30: screw conveyor, 31: casing, 31a: earth and sand intake, 31b: earth and sand discharge, 33: drive unit, 35: opening, 36: lid, 37: pressure gauge, 40: screw conveyor unit G, 51: first space portion, 52: second space portion, 55: projecting member, 60: protrusion amount changing mechanism, 61: bolt, 62: elongated hole, 65: female screw portion, 66: bolt, CL: center axis , P ... area

Claims (9)

A cylindrical body,
A cutter head arranged at the front end of the trunk,
A partition wall disposed in the body portion behind the cutter head,
A chamber formed between the cutter head and the partition wall for storing earth and sand excavated by the cutter head;
An earth discharging device for discharging earth and sand stored in the chamber from the earth and sand discharge port opened to the partition to the rear of the partition,
Is composed of
The dumping device includes a screw conveyor,
The screw conveyor,
A cylindrical casing having a sediment intake at the front end and a sediment discharge at the rear end;
A screw rotatably provided in the casing and including a spiral rotating blade,
A space formed in the casing adjacent to the rotating blade and extending in a longitudinal direction of the casing;
A projecting member provided on the rotating blade and capable of projecting into the space,
With
A shield excavator, wherein a sediment intake of the casing is connected to a sediment discharge of the bulkhead.   2. The shield machine according to claim 1, wherein the screw conveyor further includes a protrusion amount changing mechanism that changes a protrusion amount of the protrusion member into the space. 3.   The shield machine according to claim 1, wherein the protruding member is provided on the rotary blade so as to be detachable from the rotary blade. Seen in a cross section orthogonal to the longitudinal direction of the casing, the space is located radially inward of the rotating blades,
The shield machine according to any one of claims 1 to 3, wherein the plurality of projecting members are arranged side by side in the circumferential direction of the rotary blade. The screw conveyor further includes a lid that can open and close an opening formed in a peripheral wall of the casing,
The shield machine according to any one of claims 1 to 4, wherein the protruding member is provided in a region of the rotary blade that can face the opening.   The shield machine according to claim 5, wherein the plurality of openings are formed in the peripheral wall at intervals in a longitudinal direction of the casing, and the lid is provided in each of the openings. A tunnel construction method using the shield machine according to any one of claims 1 to 6,
Stopping the excavation of the shield excavator;
By rotating the screw in a state where the excavation of the shield machine is stopped, the soil in the casing is discharged from the sediment discharge port of the casing to the outside of the casing,
Changing the amount of protrusion of the protruding member into the space, and
Resuming the excavation of the shield machine,
, Including tunnel construction methods.   The tunnel construction method according to claim 7, further comprising closing a sediment intake of the casing before rotating the screw while the excavation of the shield excavator is stopped. A screw conveyor for a shield machine,
A cylindrical casing having a sediment intake at one end and a sediment discharge at the other end;
A screw rotatably provided in the casing and including a spiral rotating blade,
A space formed in the casing adjacent to the rotating blade and extending in a longitudinal direction of the casing;
A projecting member provided on the rotating blade and capable of projecting into the space,
A screw conveyor.