Center-bending small-diameter earth pressure shield tunneling machine

Abstract

To provide a center-bending small-diameter mud pressure shield tunneling machine capable of efficiently crushing rock masses contained in mud at the rear of a screw conveyor and discharging excavated earth and sand more smoothly when excavating ground where no rock masses are produced. [Solution] The inner cone rod section 43 of the crushing device 40 is provided inside the cylindrical outer shell 41 so as to be able to advance and retreat between the section directly above the soil discharge opening 41a and a section to the side of the section directly above. When excavating ground that produces rock lumps, the inner cone rod section 43 can be switched between a state in which it is moved to the section directly above the soil discharge opening 41a and a state in which it is moved to the side of the soil discharge opening 41a and retracted when excavating ground that does not produce rock lumps.

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.As a result, it is difficult to properly control the drive of the hydraulic cylinder and oscillating blade buried in the slurry mud 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 new technology that will enable small-diameter shield tunneling machines to crush rock blocks contained in slurry mud fed in via a screw conveyor more efficiently in a stable manner in the rear part of the screw conveyor.

[0008] On the other hand, when a small-diameter earth pressure shield machine is used to continuously excavate a long distance along the planned length of a tunnel, the geology may change, for example, from gravel to sand, or from sand to gravel.For example, when excavating ground that does not contain gravel, if a rock crushing device is placed between the screw conveyor and the soil discharge opening at the rear, there is a risk that the flow of mud from the excavated earth from the screw conveyor to the soil discharge opening will be obstructed, hindering the smooth discharge of the mud.Therefore, when excavating ground that does not contain gravel, for example, it is desirable to ensure that the smooth discharge of the mud is not obstructed.

[0009] The object of the present invention is to provide a center-bending small-diameter mud pressure shield tunneling machine that can more stably and efficiently crush rock blocks contained in slurry mud fed via a screw conveyor using a crushing device at the rear of the screw conveyor, and that, when excavating ground that does not produce rock blocks, does not obstruct the flow of mud from the screw conveyor to the discharge opening, allowing the excavated soil to be discharged more smoothly from the discharge opening. [Means for solving the problem]

[0010] 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 a screw conveyor having screw blades with a blade diameter of 19% or more of the outer diameter of the skin plate, which is installed inside the skin plate. A crushing device is attached to the screw conveyor, which is coaxially joined to the rear end portion of the cylindrical body, and crushes the rock blocks that are taken in. 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 drive unit of the crushing device is mounted in the same position as 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 which is arranged inside the cylindrical outer body of the crushing device, which is arranged axially, and is capable of moving back and forth in the axial direction of the cylindrical outer body, between the part directly above the soil discharge opening formed at the bottom of the cylindrical outer body and a part to the side of the part directly above it, and which can be switched between a state in which the crushing drive unit is moved to the part directly above the soil discharge opening when excavating ground that produces rock blocks, and a state in which the crushing drive unit is moved and retracted to the part to the side of the soil discharge opening when excavating ground that does not produce rock blocks.

[0011] Furthermore, in the articulated small-diameter mud pressure shield tunneling machine of the present invention, it is preferable that the crushing drive unit of the crushing device is capable of moving back and forth in the axial direction of the cylindrical outer body by driving an expansion jack whose one end is connected to a support bracket that is joined to and protrudes outward from the outer periphery of the cylindrical outer body of the crushing device.

[0012] In addition, 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 the 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 part of the cylindrical outer casing and protrudes radially inward, and has an inclined clamping surface that slopes radially inward toward the rear end in the axial direction, and an inner cone rod portion that is the crushing drive portion that is rotatably supported and attached to the cylindrical outer casing, with a tip portion equipped with a clamping and crushing means arranged in the inner region surrounded by the outer cone protrusion.

[0013] Furthermore, in the articulated small-diameter mud pressure shield tunneling machine of the present invention, it is preferable that the inner cone rod portion, which is the crushing drive portion, is connected to a rotary drive device attached to a rear end blocking member that blocks the rear end opening of the cylindrical outer body, and is thereby rotatably supported by the cylindrical outer body.

[0014] Furthermore, in the articulated small-diameter mud pressure shield tunneling machine of the present invention, the rear end blocking member that blocks the rear end opening of the cylindrical outer shell is configured to include an outer annular blocking disk with a slide opening formed in the center and joined and fixed integrally to the rear end surface of the cylindrical outer shell, and a cylindrical sliding blocking section that is slidably mounted so as to fit into the slide opening of the outer annular blocking disk, with a motor support plate attached to the rear end opening surface and a rod support plate with a rotational slide hole attached to the front end opening surface, and a rotation drive device that is supported by the motor support plate part of the cylindrical sliding blocking section and rotates the inner cone rod part is attached integrally with the cylindrical sliding blocking section with a rod joint part protruding inside, and a joint base end part is joined to the rod joint part of the rotation drive device within the hollow interior of the cylindrical sliding blocking section. It is preferable that the inner cone rod portion, which is attached such that its tip end portion equipped with the clamping crushing means protrudes forward from the rod support plate and is inserted into the rotary sliding hole so as to be rotatable and slidable, and that a jack joint plate is provided extending from the rear end of the cylindrical sliding closing portion to the side of the cylindrical outer body, and that one end of the telescopic jack, one end of which is connected to the support bracket joined to the cylindrical outer body, is connected to the other end of the telescopic jack, and that the inner cone rod portion, which is the crushing drive portion of the crushing device, is rotatably supported by the cylindrical outer body in a state where it can advance and retreat in the axial direction between the part directly above the soil discharge opening of the cylindrical outer body and a part to the side retracted from the part directly above the soil discharge opening by extension and contraction of the telescopic jack.

[0015] 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]

[0016] With the articulated small-diameter mud pressure shield tunneling machine of the present invention, rock blocks contained in the slurry mud fed via the screw conveyor can be crushed more stably and efficiently by the crushing device in the rear part of the screw conveyor, and when excavating ground that does not produce rock blocks, the flow of mud from the screw conveyor to the soil discharge opening is not obstructed, allowing the excavated soil to be discharged more smoothly from the soil discharge opening. [Brief explanation of the drawings]

[0017] [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 the screw conveyor, which is swingably joined to the lower end opening of the 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 part of the screw conveyor that is slidably supported by a slide support part erected from the rear body part. [Figure 4] 10 is a side view of the main part of the crushing device, illustrating an inspection window portion formed in the cylindrical outer shell and capable of being opened and closed by an opening / closing lid. FIG. [Figure 5] 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 6] FIG. 5(b) is a cross-sectional view taken along line BB in FIG. 5(a). [Figure 7] FIG. 5(b) is a cross-sectional view taken along CC in FIG. 5(a). [Figure 8] FIG. 5( b ) is a cross-sectional view taken along the line DD in FIG. 5( a ), illustrating the first gate mechanism. [Figure 9] 1A is a cross-sectional view of the main part, FIG. 1B is a schematic cross-sectional view taken along line EE in FIG. 1A, and FIG. 1C is a schematic cross-sectional view taken along line FF in FIG. 1A, which illustrates a second gate mechanism and a rotation mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0018] 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 takes in and fills the earth excavated by the rotary cutter 32 at the tip into the earth pressure chamber 33 behind the rotary cutter 32, stabilizing the face with the earth pressure of the filled excavated earth and discharging the excavated earth 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.

[0019] 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.

[0020] 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, 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 body section 22. Furthermore, the earth pressure shield tunneling machine 10 of this embodiment is able to crush rock blocks at the rear of the screw conveyor 11, making it possible to take in excavated soil containing relatively large boulders into the earth pressure chamber 33 and 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, and also eliminates the need for bit replacement due to wear and prevents the excavation speed from slowing down. It also has the function of enabling rock blocks 50 contained in the slurry mud sent through the screw conveyor 11 to be crushed efficiently in a more stable state at the rear part of the screw conveyor 11, and when excavating ground that does not produce rock blocks, preventing the flow of mud from the screw conveyor 11 to the soil discharge opening 41a from being obstructed, allowing the excavated soil to be discharged more smoothly from the soil discharge opening 41a.

[0021] As shown in Figure 1, 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 of 19% or more of the outer diameter of the skin plate 20 is provided inside the skin plate 20.A crushing device 40 is attached to the screw conveyor 11 and is coaxially joined to the rear end portion of the cylindrical body 12 to crush 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. As shown in Figures 5(a) and (b), the crushing drive unit of the crushing device 40, preferably the inner cone rod unit 43, is arranged inside the cylindrical outer body 41 of the crushing device 40, which is arranged coaxially with the cylinder 12 of the screw conveyor 11, and is capable of moving back and forth in the axial direction of the cylindrical outer body 41 between the part directly above the soil discharge opening 41a formed at the bottom of the cylindrical outer body 41 (see Figure 5(a)) and the part to the side of the part directly above (see Figure 5(b)).When excavating ground that produces rock lumps, the inner cone rod unit 43, which is the crushing drive unit, can be switched between a state in which it is moved to the part directly above the soil discharge opening 41a (see Figure 5(a)), and a state in which it is moved to the side of the soil discharge opening 41a and retracted (see Figure 5(a)) when excavating ground that does not produce rock lumps.

[0022] In addition, in this embodiment, the crushing drive part of the crushing device 40, preferably the inner cone rod part 43, can move back and forth in the axial direction of the cylindrical outer body 41 by driving an expansion jack 47, one end of which is connected to a support bracket 49a that is joined to and protrudes outward from the outer circumferential surface of the cylindrical outer body 41 of the crushing device 40.

[0023] Furthermore, in this embodiment, the crushing device 40 preferably includes a cylindrical outer casing 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 casing 41 in the axial middle portion of the cylindrical outer casing 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 which is a crushing drive unit rotatably supported and attached to the cylindrical outer casing 41, with its tip portion equipped with a clamping crushing means 43a positioned in the inner region surrounded by the outer cone protrusion 42.

[0024] 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 is able to press down on the tunnel face in a balanced manner. Furthermore, the excavated soil, including rock blocks 50 in a fluidized state 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 the 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 the soil discharge hose 14 connected to the soil discharge opening 41a at the bottom of the crushing device 40, preferably via a rotating mechanism 16.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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 attached integrally 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.

[0032] 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.

[0033] The upright support portion 26b is formed by arranging a pair of upright plates (see FIG. 1) with right-angled 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.

[0034] 1 and 5(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. A first gate mechanism 28 that can be opened and closed can be provided behind the rotation drive device 27, interposed 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 the soil discharge hose 14 is connected to a soil discharge opening 41a formed in the lower part of the crushing device 40, and is attached thereto, preferably via a rotation mechanism 16 (see FIG. 1).

[0035] Here, in this embodiment, the first gate mechanism 28 is a left-right opening / closing type gate mechanism that blocks the flow of mud from the screw conveyor 11 to the crushing device 40 by means of a pair of opening / closing plates 28a that can move back and forth along a plane that crosses the connection between the rear end portion 12c of the cylindrical body 12 of the screw conveyor 11 and the cylindrical outer body 41 of the crushing device 40. That is, as shown in FIG. 8, the first gate mechanism 28 is configured to include a pair of hydraulic cylinders 28b arranged parallel to one another across the rear end portion 12c of the cylinder 12 at the connection portion between the rear end portion 12c of the cylinder 12 of the screw conveyor 11 and the cylindrical outer shell 41 of the crushing device 40, for example, a pair of hydraulic cylinders 28b arranged vertically and in parallel across the rear end portion 12c of the cylinder 12, a pair of advancing / retracting rods 28c projecting from each of the hydraulic cylinders 28b so as to be able to advance and retreat on both the left and right sides, connecting rods 28d connecting the tips of the upper and lower advancing / retracting rods 28c on both the left and right sides, and a pair of rectangular opening / closing plates 28a on both the left and right sides whose outer edges are respectively joined to the connecting rods 28d and which slide transversely along slide guide grooves formed across the rear end portion 12c of the cylinder 12 as each pair of upper and lower advancing / retracting rods 28c advance and retreat. Since the first gate mechanism 28 is a left-right opening and closing type gate mechanism, it is easier to secure space for opening and closing the gate in the narrow working space within the rear body portion 22 of the skin plate 20 that constitutes the center-bending small-diameter mud pressure shield tunneling machine 10.

[0036] 5(a) and 5(b), the crushing device 40 is a device for crushing 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 blade 13 into small pieces before being sent to the soil discharge hose 14. As described above, the crushing device 40 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 a crushing drive portion 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.

[0037] 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.

[0038] 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.

[0039] In this embodiment, as shown in FIG. 6 , the outer cone protrusion 42 preferably has multiple cone protrusions 42b extending circumferentially, with multiple spacing portions 42c interposed between them. This allows the excavated soil 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 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.

[0040] 5(a) and 5(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 when excavating ground that produces rock lumps (see FIG. 5(a)), and a state in which the inner cone rod portion 43, which is the crushing drive portion, is moved to the side from the portion immediately above the soil discharge opening 41a of the cylindrical outer shell 41 and retracted (see FIG. 5(b)) when excavating ground that does not produce rock lumps.

[0041] 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 5(a) and 5(b), the extension jack 47 and the support brackets 47a, 49a 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 7).

[0042] In this embodiment, the inner cone rod portion 43, which is the crushing drive portion, is rotatably supported by the cylindrical outer body 41 by being connected to a rotation drive device 45, which is preferably attached to a rear end blocking member 44 that blocks the rear end opening of the cylindrical outer body.

[0043] The rear-end closing portion 44, which closes the rear-end opening of the cylindrical outer shell 41, preferably includes an outer annular closing disk 44a, which 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, which is slidably mounted so as to fit into the slide opening 44b of the outer annular closing disk 44a, and which has a motor support plate 48a attached to its rear-end opening surface and a rod support plate 48b, which has a rotation slide hole 48c, attached to its front-end opening surface. A rotation drive device 45, which 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 its 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 hole 48c so as to be rotatable and slidable.

[0044] 7, 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 support brackets 49a joined integrally to the side ends of 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 a side portion retracted from the portion directly above the soil discharge opening 41a.

[0045] 1, for example, a cylindrical earth discharge port member 41b is attached by being joined integrally with the cylindrical outer shell 41, protruding downward from the opening periphery of the earth discharge opening 41a formed in the lower part of the cylindrical outer shell 41, and the earth discharge hose 14 is rotatably connected to the lower end of the earth discharge port member 41b via a rotation mechanism 16, for example, a rotation joint jig. Also, in this embodiment, the earth discharge port member 41b can be provided with an openable second gate mechanism 29, which is interposed between the earth discharge opening 41a and the rotation mechanism 16, which is a rotation joint jig to which the earth discharge hose 14 is connected, and which blocks the inflow of mud from the crushing device 40 to the earth discharge hose 14 as necessary.

[0046] As shown in Figures 9(a) to 9(c), the rotation mechanism 16 includes a plurality of inverted L-shaped fall prevention hardware 16a, preferably spaced apart circumferentially around the annular flange 41c, which is engaged with the annular flange 41c extending outward from the lower end of the cylindrical earth-discharge port member 41b. The fall prevention hardware 16a is bolted to the fall prevention hardware 16a, for example, to rotatably support the annular flange 41c. The rotation mechanism 16b includes a bearing mechanism and other components. The lower end of the rotation ring 16b is integrally joined to the soil discharge hopper 17 (see Figure 1). The soil discharge hose 14 is connected to the discharge outlet 17a of the soil discharge hopper 17 via a joint hardware 17b (see Figure 1). The soil discharge hose 14 is thus rotatably connected to the soil discharge opening 41a of the earth-discharge port member 41b of the crushing device 40, preferably via the rotation mechanism 16.

[0047] In this embodiment, the second gate mechanism 29 is a one-way sliding gate mechanism that blocks the flow of mud from the crushing device 40 into the soil discharge hose 14, preferably by using a single opening / closing plate 29a that can move back and forth along a plane that crosses the connection between the soil discharge opening 41a and the soil discharge hose 14 (see Figure 1). That is, as shown in Figures 9(a) to (c), the second gate mechanism 29 is configured to include, at the connection portion by the earth unloading port member 41b that protrudes downward from the opening periphery of the earth unloading opening 41a of the cylindrical outer casing 41, a pair of hydraulic cylinders 29b arranged in parallel on both sides of the earth unloading port member 41b, a pair of advancing / retracting rods 29c that protrude forward and backward from one end of each of these hydraulic cylinders 29b, a strip-shaped connecting member 29d that connects the tip ends of the advancing / retracting rods 29c on both the left and right sides, and a rectangular opening / closing plate 29a whose side edge portion is integrally joined to the strip-shaped connecting member 29d and which slides transversely, for example, along a slide guide groove formed across the earth unloading port member 41b as the strip-shaped connecting member 29d moves forward and backward by the pair of advancing / retracting rods 29c. Because the second gate mechanism 29 is a one-way sliding gate mechanism, operations for opening and closing the gate can be performed more smoothly in the narrow working space inside the rear body section 22 of the skin plate 20 that constitutes the center-bending small-diameter mud pressure shield tunneling machine 10.

[0048] In this embodiment, inspection windows 60a, 60b that can be opened and closed by opening and closing lids 61a, 61b are formed in the cylindrical outer shell 41 of the crushing device 40, as shown in Fig. 4. In this embodiment, the inspection windows 60a, 60b are rectangular openings, for example, measuring approximately 200 to 250 mm in length and width, and are preferably formed in two locations, for example, at the top of the cylindrical outer shell 41 in the vicinity of the first gate mechanism 28 and on the side of the axially intermediate portion. The opening and closing covers 61a, 61b are rectangular plate members, each curved in an arc with the same radius of curvature as the outer periphery of the cylindrical outer shell 41, and each one is slightly larger than the inspection windows 60a, 60b, measuring approximately 280 to 330 mm in length and width. The covers slide circumferentially along guide rails (not shown) that extend circumferentially around the outer periphery of the cylindrical outer shell 41, and can be fixed in a predetermined position, allowing the inspection windows 60a, 60b to be closed or opened as needed. This allows for the smooth removal of rock blocks 50 that were not sufficiently crushed at the rear of the screw conveyor 11.

[0049] 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 more stably and efficiently crush rock blocks 50 contained in the slurry mud sent in via the screw conveyor 11 in the rear part of the screw conveyor 11, and when excavating ground that does not produce rock blocks, the flow of mud from the screw conveyor 11 to the soil discharge opening 41a is not obstructed, making it possible to more smoothly discharge the excavated soil from the soil discharge opening 41a.

[0050] 1. In other words, 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, preferably comprises a cylindrical outer casing 41, an outer cone protrusion 42 having an inclined clamping surface 42a that extends circumferentially along the inner surface of the cylindrical outer casing 41 and protrudes radially inward at the axial middle portion of the cylindrical outer casing 41, and an inner cone rod portion 43 that is rotatably supported by the cylindrical outer casing 41. Rock blocks 50 transported to the rear end portion 12c of the cylinder 12 via the screw conveyor 11 are crushed by being clamped between the inclined clamping surface 42a of the outer cone protrusion 42 and the clamping and crushing means 43a of the inner cone rod portion 43 as a result of the rotational drive of the inner cone rod portion 43, and are then discharged together with the mud via the discharge hose 14. This makes it possible to crush rock blocks contained in the slurry mud that has been sent in more stably and efficiently at the rear portion of the screw conveyor.

[0051] In addition, the crushing drive unit of the crushing device 40, preferably the inner cone rod unit 43, is arranged inside the cylindrical outer body 41 of the crushing device 40, between the part directly above the soil discharge opening 41a and the part to the side of the part directly above it, so that it can move back and forth in the axial direction of the cylindrical outer body 41.When excavating ground that does not produce rock lumps, the inner cone rod unit 43 can be moved to the side part of the soil discharge opening 41a and switched to a retracted state.Therefore, when excavating ground that does not produce rock lumps, by retracting the inner cone rod unit 43, which is the crushing drive unit, to the side part of the soil discharge opening 41a, the flow of mud from the screw conveyor 11 to the soil discharge opening 41a is not obstructed, and the excavated soil can be discharged more smoothly from the soil discharge opening 41a.

[0052] 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 configured to include a cylindrical outer shell, an outer cone protrusion extending circumferentially along the inner peripheral surface of the cylindrical outer shell, and an inner cone rod portion having a clamping crushing means at its tip, and the clamping crushing means at the tip of the inner cone rod portion does not necessarily have to be a crushing blade.

[0053] 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 28a Opening and closing plate 28b Hydraulic cylinder 28c Retractable Rod 28d connecting rod 29 Second Gate Mechanism 29a Opening / closing plate 29b Hydraulic cylinder 29c Retractable rod 29d Belt-shaped connecting member 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 50 Rock mass 60a, 60b Inspection window 61a, 61b Opening and closing lid 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 drive unit of the crushing device is provided inside a cylindrical outer shell of the crushing device, which is arranged coaxially with the cylindrical body of the screw conveyor, between a portion directly above the soil discharge opening formed in the lower part of the cylindrical outer shell and a side portion of the directly above portion, so as to be movable back and forth in the axial direction of the cylindrical outer shell, This is a center-bending small-diameter mud pressure shield tunneling machine that can be switched between a state in which the crushing drive unit is moved to the part directly above the soil discharge opening when excavating ground that produces rock lumps, and a state in which the crushing drive unit is moved to the side of the soil discharge opening and retracted when excavating ground that does not produce rock lumps.

2. The crushing drive unit of the crushing device is capable of moving back and forth in the axial direction of the cylindrical outer body by driving an expansion jack whose one end is connected to a support bracket that is joined and protrudes outward from the outer periphery of the cylindrical outer body of the crushing device. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 1.

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

4. A center-bending small-diameter mud pressure shield tunneling machine as described in claim 3, wherein the inner cone rod portion, which is the crushing drive portion, is connected to a rotary drive device attached to a rear end blocking member that blocks the rear end opening of the cylindrical outer body, and is thereby rotatably supported by the cylindrical outer body.

5. The rear end closing member that closes the rear end opening of the cylindrical outer shell is configured to include an outer peripheral annular closing disk that is joined and fixed integrally to the rear end surface of the cylindrical outer shell and has a slide opening formed in its central portion, and a cylindrical slide closing portion that is slidably mounted so as to be fitted into the slide opening of the outer peripheral annular closing disk, and has a motor support plate attached to its rear end opening surface and a rod support disk having a rotation slide hole attached to its front end opening surface, a rotation drive device that is supported by the motor support plate of the cylindrical sliding closing portion and that rotates the inner cone rod portion is integrally attached to the cylindrical sliding closing portion with a rod joint portion that protrudes inside the cylindrical sliding closing portion, the inner cone rod portion, the base end of which is joined to the rod joint portion of the rotation drive device, is attached to the hollow interior of the cylindrical sliding closing portion in a state in which a tip end portion of which is equipped with the clamping and crushing means protrudes forward from the rod support plate and is inserted rotatably and slidably into the rotation sliding hole, A jack joint plate is provided extending from the rear end of the cylindrical sliding closing portion to the side of the cylindrical outer body, and one end of the telescopic jack, one end of which is connected to the support bracket joined to the cylindrical outer body, is connected to a support bracket joined integrally to the jack joint plate, the other end of which is connected to the support bracket joined to the cylindrical outer body, A center-bending small-diameter mud pressure shield tunneling machine as described in claim 4, wherein the inner cone rod portion, which is the crushing drive portion of the crushing device, is rotatably supported by the cylindrical outer body in a state where it can move axially back and forth between the portion directly above the soil discharge opening of the cylindrical outer body and a side portion retracted from the portion directly above the soil discharge opening, by the extension and contraction of the telescopic jack.

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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