Center-bending small-diameter earth pressure shield tunneling machine

Abstract

To provide a center-bending type small-diameter mud pressure shield tunneling machine capable of crushing rock blocks and efficiently discharging them together with mud, and capable of working on sharp curved sections with a simple configuration. [Solution] A crushing device 40 for crushing rock blocks taken in is attached to the screw conveyor 11 and is coaxially joined to the rear end portion 12c of the cylindrical body 12. An earth discharge hose 14 is attached and connected to an earth discharge opening 41a formed in the lower part of the cylindrical outer body 41 of the crushing device 40. The cylindrical body 12 of the screw conveyor 11 has a tip portion 12a joined to a lower end opening 34a of a partition wall 34 via a first spherical seat 15a so as to be swingable, and an axial middle portion 12b is supported by a slide support portion 24 so as to be slidable, and the earth discharge hose 14 is rotatably connected to the earth discharge opening 41a of the crushing device 40 via a rotation mechanism 16.

Description

[Technical Field]

[0001] The present invention relates to a center-bending type small-diameter mud pressure shield tunneling machine, and in particular to a center-bending type small-diameter mud pressure shield tunneling machine equipped with a skin plate consisting of a front body section and a rear body section, with a screw conveyor provided inside the skin plate. [Background technology]

[0002] An earth pressure shield machine (earth pressure shield machine) is a shield machine with a known structure in which excavated soil and sand excavated by a cutter plate (rotary cutter) at the front end is taken into an earth pressure chamber at the rear and filled, the earth pressure of the filled excavated soil and sand is used to stabilize the tunnel face, and the excavated soil and sand are discharged from the earth pressure chamber via a screw conveyor as the tunnel is excavated. In an earth pressure shield machine, the excavated soil and sand taken into the earth pressure chamber and filled is preferably mixed with a mud-adding material or the like to fluidize it as mud, and in this state it is continuously discharged from the earth pressure chamber via the screw conveyor while pressing down on the tunnel face in a balanced manner.

[0003] Furthermore, when using a small-diameter earth pressure shield machine, for example one with an outer diameter of the skin plate of around 3000 mm or less, to excavate gravelly ground containing boulders, there is a risk that the screw conveyor will become clogged if the boulders are taken into the earth pressure chamber. Therefore, the basic construction method is to first crush the rock into small pieces using a bit attached to the cutter plate, and then take the crushed rock into the earth pressure chamber together with the excavated soil through a narrow intake opening, and then discharge it via the screw conveyor mixed with the mud from the excavated soil.

[0004] On the other hand, when excavating gravelly ground containing boulders over long distances, for example, the bits may need to be replaced due to wear, or the excavation speed may slow down. Therefore, in order to reduce the burden of crushing boulders with the rotary cutter bits, small-diameter earth pressure shield tunneling machines have been developed that take in rock blocks, including those with relatively large boulder diameters, from the earth pressure chamber onto a screw conveyor, and then crush the rock blocks using a crushing device installed at the rear end of the screw conveyor, so that the crushed rock blocks can be discharged together with the mud (see, for example, Patent Document 1).

[0005] In the shield tunneling machine of Patent Document 1, the debris discharge device is connected to the rear end of the screw conveyor via an opening and closing gate, and the jaw crusher is composed of a fixed blade and an oscillating blade provided inside the outer shell. The jaw crusher crushes gravel by pinching it between the oscillating blade and the fixed blade, which is oscillated by a hydraulic cylinder, and the crushed gravel is discharged rearward together with slurry mud through a slurry pipe connected in a straight line to the rear of the jaw crusher. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 60-162196 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-150698 Summary of the Invention [Problem to be solved by the invention]

[0007] However, with the small-diameter shield tunneling machine of Patent Document 1, for example, when constructing a shield tunnel with a sharp curve, if the rear section bends in the middle relative to the front section, the rear end of the screw conveyor and the positions of the jaw crusher and slurry pipe, which are crushing devices connected to it, will shift to the left or right from the center of the rear section, and there is a risk that an unbalanced load will occur, particularly at the connection between the crushing device and the slurry pipe, which will hinder the excavation work.

[0008] In response to this, for example, Patent Document 2 discloses a position control mechanism for preventing the rear end of a screw conveyor, which is installed with its tip opening open in an earth pressure chamber provided in the front barrel, from shifting position in the rear barrel when the shaft is bent, in a center-bending type mud pressure shield tunneling machine having a front barrel and a rear barrel. In the position control mechanism described in Patent Document 2, the screw conveyor has a tip end that is supported in a state where it is rotatably joined to the lower end of the partition wall that forms the earth pressure chamber, and a middle portion that is supported by a slide support portion so that it can slide back and forth and left and right, and a portion rearward of the slide support portion is fixed to a work deck provided in the rear barrel and is positioned so that it can be swingably held in the lateral center of the rear barrel by a pair of pressure fittings arranged on both sides of the screw conveyor.

[0009] On the other hand, the position control mechanism described in Patent Document 2 is applicable to medium- to large-diameter earth pressure shield machines, which have a considerable working space inside the skin plate, and is difficult to adopt for small-diameter earth pressure shield machines, for example, those with an outer diameter of the skin plate of around 3000 mm or less, for reasons such as the inability to install a working deck in the narrow working space inside the rear body.In particular, for small-diameter earth pressure shield machines with narrow working space, it is desirable to be able to handle sharp curves with a simpler configuration that does not take up working space.

[0010] The object of the present invention is to provide a center-bending small-diameter mud pressure shield tunneling machine that can crush rock blocks taken in at the rear end of a screw conveyor and efficiently discharge the rock blocks together with fluidized excavated soil and mud, and that has a simpler configuration and can handle the construction of sharp curved sections. [Means for solving the problem]

[0011] The present invention achieves the above-mentioned object by providing a bending-type small-diameter mud pressure shield tunneling machine which has a skin plate consisting of a front barrel section and a rear barrel section, and a screw conveyor having screw blades with a blade diameter of at least 19% of the outer diameter of the skin plate, which is installed inside the skin plate, wherein a crushing device for crushing taken-in rock blocks is attached to the screw conveyor and is coaxially connected to the rear end portion of the cylindrical body, and an earth discharge hose is attached and connected to an earth discharge opening formed at the bottom of the crushing device, and the front end portion of the cylindrical body of the screw conveyor is swingably connected to the lower end opening of a partition wall installed in the front barrel section via a first spherical seat, and the axial middle portion is supported in a slidable state by a slide support section installed upright from the rear barrel section, and the earth discharge hose is rotatably connected to the earth discharge opening of the crushing device via a pivot mechanism.

[0012] Furthermore, in the articulated small-diameter mud pressure shield tunneling machine of the present invention, it is preferable that the crushing device is connected to the rear end portion of the cylindrical body of the screw conveyor via a second spherical seat so that it can swing left and right.

[0013] In addition, it is preferable that the center-bending type small-diameter mud pressure shield tunneling machine of the present invention is such that the screw conveyor is a ribbon-type screw conveyor in which band-shaped helical blades are arranged as screw blades along the inner surface of the cylindrical body.

[0014] Furthermore, it is preferable that the center-bending small-diameter mud pressure shield tunneling machine of the present invention is configured so that the crushing device includes a cylindrical outer casing arranged coaxially with the cylindrical body of the screw conveyor, an outer cone protrusion extending circumferentially along the inner surface of the cylindrical outer casing at the axial middle part of the cylindrical outer casing and protruding radially inward, the outer cone protrusion having an inclined clamping surface that slopes radially inward toward the rear end in the axial direction, and an inner cone rod portion rotatably supported and attached to the cylindrical outer casing, with a tip portion equipped with a clamping and crushing means positioned in the inner region surrounded by the outer cone protrusion. [Effects of the Invention]

[0015] The articulated small-diameter earth pressure shield tunneling machine of the present invention can crush rock blocks taken in at the rear end of the screw conveyor and efficiently discharge the rock blocks together with the fluidized excavated soil and mud, and its simpler configuration makes it possible to construct sharp curves. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic vertical cross-sectional view illustrating a center-bent type small-diameter mud pressure shield tunneling machine according to a preferred embodiment of the present invention. [Figure 2] FIG. 10 is a longitudinal cross-sectional view of a main portion illustrating the tip portion of a screw conveyor that is swingably joined to the lower end opening of a partition wall provided in the front body section via a first spherical seat. [Figure 3] 2 is a cross-sectional view of a main part taken along the line AA in FIG. 1, illustrating an axially intermediate portion of the screw conveyor that is slidably supported by a slide support portion erected from the rear body portion. [Figure 4] FIG. 4 is a longitudinal sectional view of a main part illustrating a crushing device that is swingably joined to the rear end portion of the cylindrical body of the screw conveyor via a second spherical seat. DETAILED DESCRIPTION OF THE INVENTION

[0017] As shown in Figure 1, the articulated small-diameter earth pressure shield tunneling machine 10 according to a preferred embodiment of the present invention is a small-diameter articulated earth pressure shield tunneling machine equipped with a skin plate 20 consisting of a front barrel section 21 and a rear barrel section 22, with the skin plate 20 preferably having an outer diameter of approximately 3000 mm or less. As is well known, the earth pressure shield tunneling machine 10 excavates a tunnel by taking in and filling the excavated earth and sand excavated by the rotary cutter 32 at the tip with an earth pressure chamber 33 behind the rotary cutter 32, stabilizing the face with the earth pressure of the filled excavated earth and sand, and discharging the excavated earth and sand from the earth pressure chamber 33 via the screw conveyor 11 as it excavates the tunnel. The excavated soil and sand taken into the earth pressure chamber 33 is preferably mixed with mud-adding materials and fluidized as mud, which makes it possible to press down on the tunnel face in a balanced manner, and it can also be easily discharged continuously from the earth pressure chamber 33 via the screw conveyor 11.

[0018] As is well known, the articulating type mud pressure shield tunneling machine 10 has a skin plate 20 with a well-known structure that can be bent in the center, consisting of a front body section 21 and a rear body section 22.The front body section 21 and the rear body section 22 are arranged between them, and by extending a selected jack from a plurality of articulating jacks 23 that are spaced apart circumferentially, the front body section 21 can be bent relative to the rear body section 22, allowing the shield tunneling machine 10 to excavate in a curved line in a predetermined direction.

[0019] In this embodiment, the mud pressure shield tunneling machine 10 is a so-called small-diameter, center-bending type mud pressure shield tunneling machine, with the outer diameter of the skin plate 20 being, for example, around 3000 mm or less, and is designed to minimize the installation of equipment such as a work deck, particularly in the narrow working space inside the rear section 22. By reducing the amount of equipment inside the rear section 22, the mud pressure shield tunneling machine 10 of this embodiment can avoid collisions between the rear end of the screw conveyor 11 and this equipment, and by ensuring a considerable swing range at the rear end of the screw conveyor 11, it can more easily handle the construction of sharp curves. In addition, by making it possible to crush rock blocks at the rear end of the screw conveyor 11, it is possible to take in excavated soil containing rock blocks with relatively large diameters into the earth pressure chamber 33 and the screw conveyor 11.This reduces the burden of crushing rock blocks with the bits of the rotary cutter 32, even when excavating gravelly ground containing large boulders over long distances, thereby eliminating the need for bit replacement due to wear and preventing the excavation speed from slowing down.

[0020] The articulated small-diameter mud pressure shield tunneling machine 10 of this embodiment is equipped with a skin plate 20 consisting of a front body section 21 and a rear body section 22, and is a articulated small-diameter mud pressure shield tunneling machine in which a screw conveyor 11 having screw blades 13 with a blade diameter d (see Figure 2) that is 19% or more of the outer diameter of the skin plate 20 is provided inside the skin plate 20.As shown in Figures 2 to 4, the screw conveyor 11 is equipped with a crushing device 40 that is coaxially joined to the rear end portion 12c of the cylindrical body 12 and crushes the rock blocks that have been taken in, and an earth discharge hose 14 is attached and connected to an earth discharge opening 41a formed at the bottom of the cylindrical outer body 41 of the crushing device 40. The cylindrical body 12 of the screw conveyor 11 has a tip portion 12a that is swingably joined to the lower end opening 34a of the partition wall 34 provided in the front body portion 21 via a first spherical seat 15a, and an axial middle portion 12b that is supported in a slidable state by a slide support portion 24 that stands upright from the rear body portion 22, and the soil discharge hose 14 is rotatably connected to the soil discharge opening 41a of the crushing device 40 via a rotating mechanism 16.

[0021] In this embodiment, the crushing device 40 is preferably joined to the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 via the second spherical seat 15b so as to be swingable in the left-right direction.

[0022] Furthermore, in this embodiment, the screw conveyor 11 is preferably a ribbon-type screw conveyor in which a band-shaped helical blade 13 is arranged as a screw blade along the inner peripheral surface of the cylindrical body 12.

[0023] In this embodiment, the earth pressure shield tunneling machine 10 is a small-diameter earth pressure shield tunneling machine with a known articulated structure, as described above, and the earth intake port of the rotary cutter 32 is not made particularly narrow, so that when excavating gravelly ground containing boulders, for example, rock blocks of a considerable size that can pass through the earth intake port are taken into the earth pressure chamber 33 along with the excavated earth. The excavated earth taken into the earth pressure chamber 33 through the earth intake port together with the rock blocks is preferably mixed with a mud-adding agent or the like to fluidize it as mud, and in this state it presses down on the tunnel face in a balanced manner. The excavated soil, including rock blocks 50 fluidized as mud, is further taken into the screw conveyor 11 and transported rearward via the screw conveyor 11. The rock blocks 50 are crushed by a crushing device 40 attached to the rear end of the screw conveyor 11, and then easily discharged continuously together with the crushed rock blocks via a soil discharge hose 14 connected to a soil discharge opening 41a at the bottom of the crushing device 40.

[0024] In this embodiment, the articulating earth pressure shield machine 10 has a known structure that can be articulated, including a skin plate 20 with an outer diameter of, for example, about 2330 mm, and is made up of a forward section 21 and a rear section 22, as shown in Figure 1. By extending a selected, predetermined jack from a plurality of articulating jacks 23 that are interposed between the forward section 21 and the rear section 22 and spaced apart in the circumferential direction, the forward section 21 can be bent relative to the rear section 22, allowing the shield machine 10 to excavate in a curved line in a predetermined direction.

[0025] A rotary cutter 32 is provided on the front barrel 21 of the skin plate 20 that constitutes the articulated earth pressure shield tunneling machine 10, covering the open surface at the tip. Behind the rotary cutter 32, an earth pressure chamber 33 is formed, separated by a partition wall 34. The rotation center shaft 32a of the rotary cutter 32, a rotation drive unit 32b, and other components are attached to and supported by the partition wall 34. The rear barrel 22 is flexibly connected to the rear of the front barrel 21 via an overlapping sliding part 35 that has a known configuration.

[0026] Additionally, a plurality of shield jacks 37 are attached to the rear body section 22 of the skin plate 20 at predetermined intervals in the circumferential direction, supported by an annular support ring section 36. The shield jacks 37 extend their piston sections rearward to bring their rear-end pressing sections 37a into contact with the leading end surfaces of the segment lining bodies 39 assembled in advance, and by further extending the piston sections, they obtain an excavation reaction force from the segment lining bodies 39, which pushes the shield machine 10 forward as the rotary cutter 32 cuts the face, thereby enabling the shield machine 10 to excavate. Also attached, supported by the annular support ring section 36, is an erector device 38 having a known configuration for assembling the segment lining bodies 39.

[0027] In this embodiment, the screw conveyor 11 constituting the earth pressure shield tunneling machine 10 is preferably a ribbon-type screw conveyor, as described above, in which strip-shaped helical blades 13 are arranged as screw blades along the inner circumferential surface of the cylindrical body 12. The cylindrical body 12 is formed of a steel pipe with an inner diameter of, for example, about 500 mm, and extends from the partition wall 34 provided in the forward section 21 to the rear of the rear section 22. A known helical blade 13 with a blade diameter of, for example, about 450 mm is rotatably inserted and arranged inside the cylindrical body 12 as a screw blade, thereby forming the ribbon-type screw conveyor 11. As a result, the screw conveyor 11 is a ribbon-type screw conveyor with a screw blade 13 whose blade diameter d (see FIG. 3) is 19% or more of the outer diameter of the skin plate 20, for example, about 2330 mm. The screw conveyor 11 is a ribbon-type screw conveyor with a conveying space that penetrates the center in a straight line, which makes it possible to transport rock blocks 50 of a considerable size rearward more smoothly than in the case of a screw conveyor with a central shaft. In this embodiment, the screw conveyor 11 is configured so that the tip portion 12a of the cylindrical body 12 is swingably supported on the lower end opening 34a of the partition wall 34 of the forward section 21 via the first spherical seat 15a, and the axial intermediate portion 12b is slidably supported by the slide support portion 24 that stands upright from the rear section 22.

[0028] As shown enlarged in Figure 2, the first spherical seat 15a is formed by a seat member with a convex and arcuate cross-sectional shape attached in a continuous annular manner along the outer circumferential surface of the tip of the cylindrical body 12 of the screw conveyor 11. When the tip of the cylindrical body 12 of the screw conveyor 11 is joined to the lower end opening 34a of the partition wall 34, the first spherical seat 15a is slidably disposed so as to overlap a seat portion with a concave and arcuate cross-sectional shape formed in a continuous annular manner along the inner circumferential surface of the support ring portion 34b, which is integrally fixed to the periphery of the lower end opening 34a and protrudes rearward at an obliquely upward angle. This allows the tip portion 12a of the cylindrical body 12 of the screw conveyor 11 to be stably and swingably supported by the lower end opening 34a of the partition wall 34.

[0029] 1 and 3, the slide support section 24 that supports the axially intermediate section 12b of the cylindrical body 12 of the screw conveyor 11 is configured to include a base section 25 disposed at the bottom of the rear body section 22 and having a slidable plate 25a on its upper surface, and a mounting slide section 26 that has a movable slide plate 26a on its lower surface and supports the axially intermediate section 12b of the cylindrical body 12 from below by placing it thereon. The movable slide plate 26a is slidable in all directions along the slidable plate 25a.

[0030] The base 25 constituting the slide support section 24 is fixed by welding or the like to the bottom of the annular support ring 36, which is integrally attached to the front end of the rear section 22. The base 25 includes a slide plate 25a and a pair of support legs 25b that support the slide plate 25a from below so that it is positioned horizontally or approximately horizontally. The slide plate 25a is formed using, for example, a steel plate member and preferably has a rectangular planar shape. The slide plate 25a has an upper surface coated with, for example, a sleeve plate to facilitate sliding of the moving slide plate 26a of the mounting slide section 26.

[0031] The mounting slide portion 26, which constitutes the slide support portion 24 together with the base portion 25, is formed by assembling, for example, steel plate members by welding or the like. The mounting slide portion 26 includes a movable slide plate 26a that is slidably stacked on the slidable plate 25a of the base portion 25, and an upright support portion 26b that stands upright from the movable slide plate 26a and is provided as an integral part. The movable slide plate 26a is smaller than the slidable plate 25a and preferably has a rectangular planar shape. The movable slide plate 26a is placed on top of the slidable plate 25a in a state where it can slide back and forth and left and right along the upper surface of the slidable plate 25a.

[0032] The upright support portion 26b is formed by arranging a pair of upright plates (see FIG. 1) with trapezoidal side faces, each with an upper edge cut at an angle similar to that of the screw conveyor 11, spaced apart in the width direction of the rear body portion 22 (see FIG. 3). The upright support portion 26b is attached by fastening the lower edge of each upright plate to the upper surface of the movable slide plate 26a by welding or the like. The axially intermediate portion 12b of the cylindrical body 12 of the screw conveyor 11 rests on the upper edges of the pair of upright plates, straddling the upper edges of the pair of upright plates. This allows the intermediate portion of the screw conveyor 11, which extends at an incline at a predetermined angle, to be stably supported from below.

[0033] 1 and 4, a known rotation drive device 27 for rotating the ribbon-type spiral blade 13 is attached to the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11. Behind the rotation drive device 27, an openable and closable first gate mechanism 28 can be provided between the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 and the cylindrical outer shell 41 of the crushing device 40 to block the inflow of mud from the screw conveyor 11 to the crushing device 40 as needed. The crushing device 40 is coaxially joined and attached to the rear end of the cylindrical body 12 further behind the first gate mechanism 28.

[0034] The crushing device 40 is a device that crushes rock blocks 50 that have been taken into the screw conveyor 11 and transported together with excavated earth and sand to the rear end portion 12c of the cylindrical body 12 by the rotational drive of the spiral blades 13 into small pieces before being sent to the soil discharge hose 14. In this embodiment, the crushing device 40 preferably includes a cylindrical outer shell 41 arranged coaxially with the cylindrical body 12 of the screw conveyor 11, an outer cone protrusion 42 that extends circumferentially along the inner peripheral surface of the cylindrical outer shell 41 at an axially intermediate portion of the cylindrical outer shell 41 and protrudes radially inward, and has an inclined clamping surface 42a that slopes radially inward toward the axial rear end, and an inner cone rod portion 43 that is rotatably supported and attached to the cylindrical outer shell 41, with a tip portion equipped with a clamping and crushing means 43a located in an inner region surrounded by the outer cone protrusion 42.

[0035] In addition, in this embodiment, the inner cone rod portion 43 of the crushing device 40 is preferably connected to a rotary drive device 45 attached to a rear end blocking member 44 that blocks the rear end opening of the cylindrical outer body 41, and is thereby rotatably supported by the cylindrical outer body 41.

[0036] Furthermore, in this embodiment, the clamping and crushing means 43a is preferably a crushing blade having an inclined tip edge portion 43b that is arranged opposite the inclined clamping surface 42a of the outer cone protrusion 42 and that extends radially outward from the tip portion of the inner cone rod portion 43.

[0037] The rock blocks 50 transported to the rear end portion 12c of the cylindrical body 12 via the screw conveyor 11 are efficiently crushed by being clamped between the inclined clamping surface 42a of the outer cone protrusion 42 and the crushing blade 43a of the inner cone rod portion 43 as the inner cone rod portion 43 is rotated by the rotary drive device 45, and are then discharged via the soil discharge hose 14 from the soil discharge opening 41a formed at the bottom of the cylindrical outer body 41 together with the mud sent rearward by the spiral blades 13 of the screw conveyor 11.

[0038] In this embodiment, as shown in Figure 4, a cylindrical earth discharge port member 46 is joined and attached as a single unit, protruding downward from the opening periphery of the earth discharge opening 41a formed at the bottom of the cylindrical outer casing 41, and the earth discharge hose 14 is rotatably connected to the earth discharge opening 41a at the lower end of the earth discharge port member 46 via a rotation mechanism 16 made of a rotation joining jig, which will be described later.

[0039] In addition, in this embodiment, the soil discharge port member 46 can be provided with an openable and closable second gate mechanism 29 that is interposed between the soil discharge opening 41a and the rotating mechanism 16 using a rotating connecting jig to which the soil discharge hose 14 is connected, and that blocks the flow of mud from the crushing device 40 into the soil discharge hose 14 as necessary.

[0040] The rotating jig, which serves as the rotation mechanism 16 for rotatably connecting the soil discharge hose 14 to the soil discharge opening 41a, includes a plurality of inverted L-shaped fall prevention hardware 16a, preferably spaced circumferentially around the annular flange 46a, which is engaged with the annular flange 46a extending outward from the lower end of the cylindrical soil discharge opening member 46. The fall prevention hardware 16a is attached to the fall prevention hardware 16a, for example, by bolting, and is supported by the annular flange 46a. The rotating ring 16b, which includes a bearing mechanism and the like, is attached to the annular flange 46a. The soil discharge hopper 17 is integrally joined to the lower end of the rotating ring 16b, and the soil discharge hose 14 is connected to the discharge opening 17a of the soil discharge hopper 17 via a joint hardware 17b. As a result, the soil discharge hose 14 is rotatably connected to the soil discharge opening 41a of the crushing device 40 via the rotation mechanism 16, preferably the rotating jig.

[0041] In this embodiment, as described above, the crushing device 40 is preferably joined to the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 via the second spherical seat 15b so as to be swingable in the left-right direction. That is, the second spherical seat 15b is formed by a seat member attached continuously in an annular shape in the circumferential direction along the outer circumferential surface of the rear end portion of the cylindrical body 12 of the screw conveyor 11, and the outer circumferential surface has a convex and arcuate cross-sectional shape. When the rear end portion of the cylindrical body 12 of the screw conveyor 11 is joined to the front end opening 41b of the cylindrical outer shell 41 of the crushing device 40, the second spherical seat 15b is slidably arranged so as to overlap, over the entire circumference, with a seat member having a concave and arcuate cross-sectional shape formed continuously in an annular shape in the circumferential direction on the inner circumferential surface of the joining ring metal fitting 47, which is fixed integrally to the periphery of the front end opening 41b. This allows the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 to be supported stably and swingably on the front end opening 41b of the cylindrical outer shell 41 of the crushing device 40.

[0042] In this embodiment, a crusher support bracket 48 is attached so as to straddle the upper part of the rear end of the cylindrical body 12 of the screw conveyor 11 and the upper part of the front end of the cylindrical outer shell 41 of the crusher 40. This prevents the cylindrical outer shell 41 of the crusher 40 from bending downward relative to the cylindrical body 12 of the screw conveyor 11 at the second spherical seat 15b. This also allows the crusher 40 and the soil discharge hose 14 connected thereto to be connected to the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 via the second spherical seat 15b, preferably in a state in which they can swing only in the left-right direction.

[0043] Furthermore, with the center-bending small-diameter mud pressure shield tunneling machine 10 of this embodiment, which has the above-mentioned configuration, it is possible to crush the rock blocks 50 taken in at the rear end of the screw conveyor 11 and efficiently discharge the rock blocks 50 together with the mud of the fluidized excavated soil and sand, and with a simpler configuration it is possible to handle the construction of sharp curved sections.

[0044] In other words, according to the mud pressure shield tunneling machine 10 of this embodiment, a crushing device 40 is attached which is coaxially joined to the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 and crushes the rock blocks 50 that are taken in. Therefore, the rock blocks 50 taken in by this crushing device 40 can be crushed and the crushed rock blocks 50 can be efficiently discharged together with the fluidized mud through the earth discharge hose 14. In addition, without providing a work deck, construction of sharp curved sections can be handled with a simple configuration in which the tip portion 12a of the cylindrical body 12 of the screw conveyor 11 is joined to the lower end opening 34a of the partition wall 34 via the first spherical seat 15a, the axial middle portion 12b is supported so as to be slidable by the slide support portion 24, and the earth discharge hose 14 is rotatably connected to the earth discharge opening 41a of the crushing device 40 via the rotation mechanism 16.

[0045] In addition, in this embodiment, the crushing device 40 is connected to the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 via the second spherical seat 15b so that it can swing left and right, which makes it possible to further improve the workability when excavating sharp curved sections.

[0046] The present invention is not limited to the above-described embodiment and various modifications are possible. For example, the screw conveyor does not necessarily have to be a ribbon-type screw conveyor, but may be a screw conveyor with screw blades having a central shaft. The crushing device does not necessarily have to be a cone crusher including an outer cone protrusion and an inner cone rod, but may be various other crushing devices such as a jaw crusher.

[0047] 10. Center-bending small-diameter earth pressure shield tunneling machine 11 Screw conveyor 12 Cylinder 12a Tip part 12b Axial middle part 12c rear end part 13 Spiral blade (screw blade) 14 Soil discharge hose 15a 1st sphere 15b Second sphere 16 Rotating joining jig (rotating mechanism) 16a Fall prevention hardware 16b Rotating ring part 17 Soil discharge hopper 17a Discharge port 17b Joint hardware 20 Skin Plate 21 Front body 22 Rear fuselage 23 Center-bending jack 24 Slide support 25 Base 25a Sliding plate 25b Support leg 26 Mounting slide part 26a Moving slide plate 26b Standing support part 27 Rotational drive unit 28 First Gate Mechanism 29 Second Gate Mechanism 32 Rotary cutter 32a Rotational axis 32b Rotational drive unit 33 Earth pressure chamber 34 Bulkhead 34a Bottom opening 34b Support ring part 35 Overlap sliding part 36 Annular support ring 37 Shield Jack 37a Rear end pressing part 38 Erector device 39 Segment lining 40 Crushing equipment 41 Cylindrical outer shell 41a Soil removal opening 41b Tip opening 42 Outer cone protrusion 42a Inclined clamping surface 43 Inner cone rod part 43a Crushing blade (clamping crushing means) 43b Sloped tip edge 44 Rear end blocking member 45 Rotational drive unit 46 Earth removal port member 46a Annular flange 47 Joint Ring Hardware 48 Crushing device support hardware 50 Rock mass d Blade diameter

Claims

1. A center-bending small-diameter earth pressure shield tunneling machine is provided with a skin plate consisting of a front body portion and a rear body portion, and a screw conveyor having screw blades with a blade diameter of 19% or more of the outer diameter of the skin plate is provided inside the skin plate, A crushing device is attached to the screw conveyor, coaxially connected to the rear end of the cylindrical body, for crushing the rock blocks that have been taken in, and an earth discharge hose is attached to the crushing device, connected to an earth discharge opening formed at the bottom of the crushing device, The cylindrical body of the screw conveyor has a tip portion that is swingably connected to the lower end opening of the partition provided in the front body portion via a first spherical seat, and an axial middle portion that is supported in a slidable state by a slide support portion that stands upright from the rear body portion, and the earth discharge hose is a center-bend type small-diameter mud pressure shield tunneling machine that is rotatably connected to the earth discharge opening of the crushing device via a pivot mechanism.

2. 2. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 1, wherein the crushing device is connected to the rear end portion of the cylindrical body of the screw conveyor via a second spherical seat so as to be swingable in the left-right direction.

3. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 1 or 2, wherein the screw conveyor is a ribbon-type screw conveyor in which band-shaped spiral blades are arranged as screw blades along the inner surface of the cylindrical body.

4. The crushing device is a center-bending small-diameter mud pressure shield tunneling machine as described in claim 1 or 2, which is composed of a cylindrical outer casing arranged coaxially with the cylindrical body of the screw conveyor, an outer cone protrusion extending circumferentially along the inner surface of the cylindrical outer casing at the axial middle portion of the cylindrical outer casing and protruding radially inward, and having an inclined clamping surface that slopes radially inward toward the axial rear end, and an inner cone rod portion that is rotatably supported and attached to the cylindrical outer casing, with its tip portion equipped with a clamping and crushing means positioned in the inner region surrounded by the outer cone protrusion.

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