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 efficiently crushing rock blocks contained in fed mud in a stable state at the rear of a screw conveyor. [Solution] The crushing device 40 is composed of a cylindrical outer shell 41 arranged coaxially with the cylinder 12 of the screw conveyor 11, an outer cone protrusion 42 extending circumferentially along the inner surface of the cylindrical outer shell 41 in the axial middle part of the cylindrical outer shell 41 and protruding radially inward, the outer cone protrusion 42 having an inclined clamping surface 42a that slopes radially inward toward the axial rear end, and an inner cone rod portion 43 rotatably supported and attached to the cylindrical outer shell 41, with its tip portion equipped with a clamping crushing means 43a positioned in the inner region surrounded by the outer cone protrusion 42.

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 is taken in and filled into an earth pressure chamber at the rear by a cutter plate (rotary cutter) at the front, the earth pressure of the filled excavated soil is used to stabilize the tunnel face, and the excavated soil is discharged from the earth pressure chamber via a screw conveyor as the tunnel is excavated. In an earth pressure shield machine, the excavated soil taken in and filled into the earth pressure chamber is preferably mixed with a mud-adding material or the like to be fluidized 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 excavated soil, including boulders with relatively large diameters, from the earth pressure chamber into 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 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the small-diameter shield tunneling machine of Patent Document 1, the entire jaw crusher is installed buried inside the outer body filled with slurry mud fed in via a screw conveyor.Therefore, it is difficult to properly control the drive of the hydraulic cylinder and oscillating blade buried in the slurry mud and oscillating the oscillating blade to sandwich the gravel blocks between the fixed blade and the oscillating blade, and it cannot be said that the gravel blocks taken inside the outer body can necessarily be crushed efficiently in a stable manner.Therefore, there is a need for the development of technology that enables rock blocks contained in slurry mud fed in via a screw conveyor in small-diameter shield tunneling machines to be crushed efficiently in a stable manner at the rear of the screw conveyor.

[0008] The object of the present invention is to provide a center-bending type small-diameter mud pressure shield tunneling machine that can crush rock blocks contained in slurry mud fed via a screw conveyor more stably and efficiently at the rear of the screw conveyor. [Means for solving the problem]

[0009] The present invention relates to a center-bending small-diameter earth pressure shield tunneling machine that is equipped with a skin plate consisting of a front body and a rear body, and that has a screw conveyor with screw blades having a blade diameter of 19% or more of the outer diameter of the skin plate installed inside the skin plate. The screw conveyor is equipped with a crushing device that is coaxially joined to the rear end portion of a cylindrical body and crushes the rock blocks that have been taken in, and an earth discharge hose is attached to the crushing device and is connected to an earth discharge opening formed at the bottom of the crushing device. The crushing device is an outer cylindrical body that is arranged coaxially with the cylindrical body of the screw conveyor. The above object has been achieved by providing a center-bending small-diameter mud pressure shield tunneling machine comprising: a casing; an outer cone protrusion extending circumferentially along the inner surface of the cylindrical outer casing at the axially middle portion of the cylindrical outer casing and protruding radially inward, the outer cone protrusion having an inclined clamping surface that slopes radially inward toward the axial rear end; 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.

[0010] Furthermore, it is preferable that the center-bending small-diameter mud pressure shield tunneling machine of the present invention is rotatably supported by the cylindrical outer body by having the inner cone rod portion connected to a rotary drive device attached to a rear end closing portion that closes the rear end opening of the cylindrical outer body.

[0011] In addition, it is preferable that the center-bending small-diameter mud pressure shield tunneling machine of the present invention has a crushing blade in which the clamping and crushing means is provided extending radially outward from the tip portion of the inner cone rod portion and has an inclined tip edge portion arranged opposite the inclined clamping surface of the outer cone protrusion.

[0012] Furthermore, in the articulated small-diameter mud pressure shield tunneling machine of the present invention, it is preferable that the inner cone rod portion is rotatably supported by the cylindrical outer body while being movable back and forth in the axial direction.

[0013] Furthermore, in the articulated small-diameter mud pressure shield tunneling machine of the present invention, it is preferable that the outer cone protrusion is extended circumferentially with multiple spacing portions interposed between the multiple cone protrusions, so that the multiple cone protrusions are connected together in a circumferentially intermittent manner.

[0014] 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. [Effects of the Invention]

[0015] According to the articulated small-diameter earth pressure shield tunneling machine of the present invention, rock blocks contained in the slurry-like mud fed through the screw conveyor can be crushed more stably and efficiently at the rear of the screw conveyor. [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] 1A is a longitudinal cross-sectional view of the main part of the crushing device when the inner cone rod part is advanced, and FIG. 1B is a longitudinal cross-sectional view of the main part of the crushing device when the inner cone rod part is retracted. [Figure 5] FIG. 4(b) is a cross-sectional view taken along line BB in FIG. 4(a). [Figure 6] FIG. 4(b) is a cross-sectional view taken along CC in FIG. 4(a). 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 etc. to fluidize it into a slurry-like mud, which allows it to press down on the tunnel face in a balanced manner, and 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 earth pressure shield tunneling machine 10 is a so-called small-diameter, center-bending type earth pressure shield tunneling machine, with the outer diameter of the skin plate 20 being, for example, approximately 3000 mm or less, and is designed to minimize the installation of facilities such as a work deck, particularly in the narrow working space inside the rear body 22. The earth pressure shield tunneling machine 10 of this embodiment is also equipped with a function that enables rock blocks to be crushed at the rear end of the screw conveyor 11, allowing excavated soil containing relatively large rock blocks to be taken into the earth pressure chamber 33 and the screw conveyor 11. This reduces the burden of crushing rock blocks with the bit of the rotary cutter 32, even when excavating gravelly ground containing boulders over long distances, thereby eliminating the need for bit replacement due to wear and preventing a slowdown in the excavation speed. It also has a function that enables rock blocks 50 contained in the slurry mud sent via the screw conveyor 11 to be crushed more stably and efficiently at the rear of the screw conveyor 11.

[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 21 and a rear body, and a screw conveyor 11 having screw blades 13 with a blade diameter of 19% or more of the outer diameter of the skin plate is provided inside the skin plate 20.In this articulated small-diameter mud pressure shield tunneling machine, a crushing device 40 is attached to the screw conveyor 11, which is coaxially joined to the rear end portion of the cylindrical body 12 and crushes the rock blocks 50 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 crushing device 40. The crushing device 40 is composed of a cylindrical outer shell 41 arranged coaxially with the cylinder 12 of the screw conveyor 11, an outer cone protrusion 42 extending circumferentially along the inner surface of the cylindrical outer shell 41 in the axial middle part of the cylindrical outer shell 41 and protruding radially inward, and having 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 its tip portion equipped with a clamping and crushing means 43a positioned in the inner region surrounded by the outer cone protrusion 42.

[0021] In addition, in this embodiment, the inner cone rod portion 43 of the crushing device 40 is rotatably supported by the cylindrical outer body 41 by being connected to a rotary drive device 45, which is preferably attached to a rear end closing portion 44 that closes the rear end opening of the cylindrical outer body 41, as shown in Figures 4(a) and (b).

[0022] Furthermore, in this embodiment, the inner cone rod portion 43 is rotatably supported by the cylindrical outer shell 41, preferably in a state in which it can advance and retreat in the axial direction.

[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 and fluidized as slurry-like 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) and (b), 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, and an earth discharge hose 14 is attached to a soil discharge opening 41a formed in the lower part of the crushing device 40 (see FIG. 1).

[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 includes, as described above, a cylindrical outer shell 41 that is 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 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 is provided so as to extend radially outward from the tip portion of the inner cone rod portion 43.

[0036] The rock blocks 50 transported to the rear end portion 12c of the cylindrical body 12 via the screw conveyor 11 are then 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 slurry mud sent rearward by the spiral blades 13 of the screw conveyor 11.

[0037] In this embodiment, as shown in FIG. 5, the outer cone protrusion 42 preferably has multiple cone protrusions 42b extending circumferentially, with multiple spacing portions 42c interposed between them. This allows the slurry-like mud of excavated earth and sand fed into the crushing device 40 to pass smoothly through the spacing portions 42c while the rock blocks 50 are being crushed by the outer cone protrusions 42, effectively preventing the mud from accumulating inside the cylindrical outer shell 41. Furthermore, by engaging the rock blocks 50 with the corners of the multiple cone protrusions 42b and preventing the rock blocks 50 from rotating together with the inner cone rod portion 43, the rock blocks 50 can be more easily crushed by the clamping and crushing means 43a. The outer cone protrusions 42 may also be provided continuously in the circumferential direction.

[0038] 4(a) and 4(b), the inner cone rod portion 43 is preferably rotatably supported by the cylindrical outer shell 41 in a state in which it can advance and retreat in the axial direction. This makes it possible to switch between a state in which the inner cone rod portion 43, which is the crushing drive portion, is moved to the portion immediately above the soil discharge opening 41a of the cylindrical outer shell 41 (see FIG. 4(a)) when excavating ground that produces rock lumps, and a state in which the inner cone rod portion 43, which is the crushing drive portion, is moved to the side and retracted from the portion immediately above the soil discharge opening 41a of the cylindrical outer shell 41 when excavating ground that does not produce rock lumps.

[0039] That is, in this embodiment, the inner cone rod portion 43 of the crushing device 40 can advance and retreat in the axial direction of the cylindrical outer shell 41, for example, by driving an extension jack 47 having one end connected to a support bracket 47a that is joined to and protrudes outward from the outer circumferential surface of the cylindrical outer shell 41 of the crushing device 40. Note that in Figures 4(a) and 4(b), the extension jack 47 and the support brackets 47a, 47b are depicted as being arranged on the upper part of the cylindrical outer shell 41 for convenience, but these extension jacks 47 and support brackets 47a, 49a are preferably arranged in pairs on both sides of the cylindrical outer shell 41, for example, via a jack joint plate 49 (see Figure 6).

[0040] In this embodiment, the rear-end closing portion 44 that closes the rear-end opening of the cylindrical outer shell 41 includes an outer annular closing disk 44a that is joined and fixed integrally to the rear-end surface of the cylindrical outer shell 41 and has a slide opening 44b formed in its central portion, and a cylindrical sliding closing portion 48 that is slidably mounted so as to fit into the slide opening 44b of the outer annular closing disk 44a, with a motor support plate 48a attached to the rear-end opening surface and a rod support plate 48b that passes through a rotational slide opening 48c attached to the front-end opening surface. A rotation drive device 45 that is supported by the motor support plate 48a of the cylindrical sliding closing portion 48 and rotates the inner cone rod portion 43 is attached integrally to the cylindrical sliding closing portion 48 with a rod joint portion 45a protruding inside the cylindrical sliding closing portion 48. Inside the hollow interior of the cylindrical sliding blocking portion 48, an inner cone rod portion 43, whose base end is joined to the rod joint portion 45a of the rotary drive device 45, is attached so that its tip portion, to which the clamping and crushing means 43a is attached, protrudes forward from the rod support plate 48b and is inserted into the rotary sliding opening 48c so as to be rotatable and slidable.

[0041] 6, in this embodiment, a jack joint plate 49 is provided extending from the rear end of the cylindrical sliding closing portion 48 to the sides of the cylindrical outer shell 41 on both sides. One end of each of the pair of telescopic jacks 47, one of which is connected to a support bracket 47a joined to the cylindrical outer shell 41, is connected to each of the mounting brackets 49a joined integrally to the side ends on both sides of the jack joint plate 49. As a result, by extension and contraction of these telescopic jacks 47, the inner cone rod portion 43, which is the crushing drive portion of the crushing device 40, is rotatably supported by the cylindrical outer shell 41 in a state in which it can advance and retreat in the axial direction between the portion directly above the soil discharge opening 41a of the cylindrical outer shell 41 and the side retracted from the portion directly above the soil discharge opening 41a.

[0042] Furthermore, in this embodiment, as shown in Figure 1, a preferably cylindrical earth discharge port member 41b is attached by being joined as a single unit, protruding downward from the opening periphery of the earth discharge opening 41a formed, for example, at the bottom of the cylindrical outer casing 41, and an earth discharge hose 14 is rotatably connected to the earth discharge opening 41a at the lower end of the earth discharge port member 41b via a rotation mechanism 16, for example, a rotation joining jig.

[0043] In addition, in this embodiment, the soil discharge port member 41b (see Figures 4(a) and (b)) 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 (see Figure 1) consisting of 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.

[0044] 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 rock blocks 50 contained in the slurry mud fed through the screw conveyor 11 more stably and efficiently at the rear of the screw conveyor 11.

[0045] That is, according to the mud pressure shield tunneling machine 10 of this embodiment, the crushing device 40, which is coaxially joined to the rear end portion of the screw conveyor 11, is configured to include a cylindrical outer shell 41, an outer cone protrusion 42 having an inclined clamping surface 42a that extends circumferentially along the inner surface of the cylindrical outer shell 41 and protrudes radially inward at the axial middle portion of the cylindrical outer shell 41, and an inner cone rod portion 43 that is rotatably supported by the cylindrical outer shell 41, and the rock blocks 50 that have been transported to the rear end portion 12c of the cylindrical body 12 via the screw conveyor 11 are crushed by the rotation of the inner cone rod portion 43. The rocks are crushed by being clamped between the inclined clamping surface 42a and the clamping and crushing means 43a of the inner cone rod portion 43, and are then discharged together with the mud through the soil discharge hose 14.Therefore, by simply controlling the rotation of the inner cone rod portion 43 using the rotation drive device 45 inside the cylindrical outer body 41 filled with slurry mud, it is possible to crush the rock lumps contained in the slurry mud that has been sent in more stably and efficiently at the rear of the screw conveyor, compared to using a jaw crusher that crushes the gravel lumps by clamping them between a fixed blade and an oscillating blade using the extension and retraction drive of a hydraulic cylinder.

[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 clamping and crushing means at the tip of the inner cone rod does not necessarily have to be a crushing blade, and the inner cone rod does not necessarily have to be supported by the cylindrical outer shell in a state where it can advance and retreat in the axial direction.

[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 16 Rotating mechanism 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 Soil discharge port member 42 Outer cone protrusion 42a Inclined clamping surface 43 Inner cone rod part 43a Crushing blade (clamping crushing means) 43b Sloped tip edge 44 Posterior end occlusion 44a Outer annular closure 44b Slide opening 45 Rotational drive unit 47 Telescopic Jack 48 Cylindrical sliding closure 48a Motor support plate 48b Rod support plate 48c Rotating sliding opening 49 Jack jointer 49a Support bracket 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 crushing device is a center-bending small-diameter mud pressure shield tunneling machine that includes a cylindrical outer casing that is arranged coaxially with the cylindrical body of the screw conveyor, an outer cone protrusion that extends circumferentially along the inner surface of the cylindrical outer casing at the axial middle portion of the cylindrical outer casing and protrudes radially inward, and has 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.

2. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 1, wherein the inner cone rod portion is rotatably supported by the cylindrical outer body by being connected to a rotary drive device attached to a rear end closure portion that closes the rear end opening of the cylindrical outer body.

3. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 1 or 2, wherein the clamping and crushing means is a crushing blade having an inclined tip edge portion that extends radially outward from the tip portion of the inner cone rod portion and is positioned opposite the inclined clamping surface of the outer cone protrusion.

4. 3. A center-bending type small-diameter mud pressure shield tunneling machine according to claim 1 or 2, wherein the inner cone rod portion is rotatably supported by the cylindrical outer body in a state in which it can advance and retreat in the axial direction.

5. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 1 or 2, wherein the outer cone protrusion is arranged so that multiple cone protrusions are connected together in a circumferential direction by interposing multiple spacing portions between them.

6. 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.

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