Supply part structure of fluidization liquid material in sealed machine
Patent Information
- Application Number
- JP2022170974
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-10-25
- Publication Date
- 2025-02-12
- Estimated Expiration
- 2042-10-25
AI Technical Summary
Existing shield excavators face the challenge of earth and sand entering the gap at the front end of the elastic sleeve member during excavation, leading to potential clogging and environmental contamination from spilled fluidized liquid material.
A structure with multiple liquid material discharge openings, a closed-end discharge cylinder, guide walls, and an elastic sleeve member secured by a nut-like member with an annular skirt, prevents cut earth and sand from entering the gap by guiding the fluidized liquid material effectively.
Prevents cut earth and sand from entering the gap at the front end of the elastic sleeve member, maintaining efficient fluidized liquid material supply and reducing environmental impact during excavation.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to a supply section structure for fluidized liquid material in a shield tunneling machine, and in particular to a supply section structure for supplying fluidized liquid material that generates plastically fluidized mud to a cutter chamber in a mud pressure type shield tunneling machine. [Background technology]
[0002] As a shield tunneling machine, a mud pressure type shield tunneling machine is a machine that excavates the ground at the tunnel face while stabilizing the face by mixing the soil and sand taken into the cutter chamber by cutting the ground at the tunnel face with a rotating cutter with a liquid material that preferably contains a plastic fluidizing agent such as a mud making agent, thereby generating plastic fluidized mud, and filling the cutter chamber with the generated mud, generating mud pressure.
[0003] In addition, in such a mud pressure type shield machine, when the ground is cut by the rotating cutter rotated by the drive unit, a liquid material containing a plastic fluidizer is supplied from a supply unit provided on the rotating cutter toward the ground at the face, so that the excavated soil is mixed together with the liquid material containing the plastic fluidizer in the chamber (see, for example, Patent Document 1). As the ground at the face is excavated, the mud that has been mixed with the liquid material containing the plastic fluidizer and plastically fluidized is discharged to the rear of the shield machine via a screw conveyor, one end of which opens into a partition wall that divides the cutter chamber, while maintaining a state in which mud pressure is generated by the mud filled in the cutter chamber. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] JP 2000-234494 A Summary of the Invention [Problem to be solved by the invention]
[0005] On the other hand, as a structure of a supply section for supplying a fluidized liquid material containing a plastic fluidizer from a rotating cutter toward the ground at the face, for example, as shown in Fig. 6, a structure in which the discharge port for discharging the fluidized liquid material is not clogged by the soil during cutting by the rotating cutter has been proposed. The structure 50 of the fluidized liquid material supply section proposed in Fig. 6 includes a topped cylindrical discharge cylinder 52 having a plurality of liquid material discharge openings 53 on the side surface and a closed tip 54, which is provided in communication with a supply pipe 51 for the fluidized liquid material, and an elastic sleeve member 55 attached in close contact with the side surface of the discharge cylinder 52 to cover the liquid material discharge openings 53. The liquid material discharge openings 53 are covered by the elastic sleeve member 55, so that they are not clogged by the soil during cutting. The elastic sleeve member 55 is positioned so that it does not shift out of position by a nut-shaped member 56 being screwed to the tip of the discharge cylinder 52.
[0006] In the structure 50 of the fluidizing liquid supply section proposed in Figure 6, the fluidizing liquid material pressurized through the supply piping 51 is discharged from the liquid material discharge opening 53, lifting the elastic sleeve member 55 due to the pressure of the fluidizing liquid material, and the discharged fluidizing liquid material is forcefully sprayed out from both ends of the elastic sleeve member 55 through the gap between the lifted elastic sleeve member 55 and the side surface of the discharge cylinder 52. In particular, the fluidizing liquid material sprayed out from the end on the rear side of the excavation direction X of the elastic sleeve member 55 collides with the tapered wall portion 57a of the guide wall portion 57 provided in a ring shape on the outside of the discharge cylinder 52, and is guided by the guide wall portion 57 and sprayed out while diffusing toward the front side in the opposite excavation direction X.
[0007] However, in the structure 50 of the fluidizing liquid supply section proposed in Figure 6, when the shield tunneling machine (see Figure 1) is advanced in the tunneling direction X, while the fluidizing liquid is sprayed and the ground at the face is cut by the rotating cutter, it is thought that there is a risk that the cut soil and sand due to the pressure during tunneling will flow back into the gap at the front end of the elastic sleeve member 55 in the tunneling direction X, which has been turned up by the pumping pressure of the fluidizing liquid, and will cause the gap to become blocked.
[0008] When cut earth and sand gets into the gap at the end of the turned-up elastic sleeve member 55 on the front side in the excavation direction X, it is possible to take measures to remove the trapped earth and sand using hydraulic pressure, but attempting to remove it using hydraulic pressure would result in a considerable amount of oil flowing into the ground, increasing the burden on the environment. For this reason, there is a need for a means to be developed that can effectively prevent cut earth and sand from getting into the gap at the end of the elastic sleeve member on the front side in the excavation direction when the ground at the face is cut by the rotating cutter while the fluidizing liquid material is sprayed while the mud pressure type shield machine is advanced in the excavation direction X.
[0009] The present invention aims to provide a fluidized liquid supply structure in a shield tunneling machine that can effectively prevent cut soil from getting into the gap at the end of the elastic sleeve member on the forward side in the tunneling direction, with a simple configuration, when the mud pressure type shield tunneling machine is advanced in the tunneling direction while jetting fluidized liquid and cutting the ground at the face with a rotating cutter. [Means for solving the problem]
[0010] The present invention relates to a supply section structure for supplying fluidized liquid material to the cutter chamber, which generates plastically fluidized mud, in a mud pressure type shield tunneling machine that cuts the ground with a rotating cutter while stabilizing the face with mud filled in the cutter chamber, the supply section structure comprising a topped cylindrical discharge cylinder body having a closed tip and a plurality of liquid material discharge openings on its side circumferential surface, the discharge cylinder body being connected to a supply pipe for the fluidized liquid material and protruding forward in the tunneling direction from the rotating cutter, a guide wall section being provided in an annular shape at intervals on the outside of the discharge cylinder body, and a guide wall section being attached in a state of closely contacting the side circumferential surface of the discharge cylinder body, covering the plurality of liquid material discharge openings. The above-mentioned object has been achieved by providing a supply structure for fluidized liquid material in a shield tunneling machine, the supply structure being composed of a nut-shaped member having a female thread ridge formed on its inner peripheral surface and a male thread ridge formed on the side peripheral surface of the tip portion of the discharge cylinder, the elastic sleeve member being positioned on the side peripheral surface of the discharge cylinder, the nut-shaped member having a female thread ridge formed on its inner peripheral surface being screwed onto a male thread ridge formed on the side peripheral surface of the tip portion of the discharge cylinder, the nut-shaped member having an annular skirt portion extending rearward in the excavation direction from its outer peripheral edge, the annular skirt portion being arranged so as to cover from the outside the tip portion of the positioned elastic sleeve member on the front side in the excavation direction.
[0011] In the structure of the fluidizing liquid supply section in the shield tunneling machine of the present invention, it is preferable that the guide wall section has a tapered wall surface section that expands forward in the tunneling direction.
[0012] In the fluidizing liquid material supply structure for the shield tunneling machine of the present invention, the elastic sleeve member is preferably made of natural rubber having a hardness of A55 to A75 according to JIS K 6253.
[0013] Furthermore, in the structure of the fluidizing liquid material supply section in the shield tunneling machine of the present invention, the natural rubber preferably has a thickness of 5 to 10 mm.
[0014] Furthermore, it is preferable that the fluidized liquid supply structure in the shield tunneling machine of the present invention is such that the annular skirt portion of the nut-shaped member is attached with its inner surface in close contact with the outer surface of the tip portion of the elastic sleeve member at the front side in the tunneling direction.
[0015] In addition, it is preferable that the supply structure of the fluidized liquid material in the shield tunneling machine of the present invention is such that both end portions are joined to the rotating cutter, and a band-shaped buffer wall member is extended radially from the discharge cylinder and is attached so as to overlap the discharge cylinder when viewed from the front in the tunneling direction, with a gap maintained between its inner surface and the tip of the discharge cylinder. Effect of the Invention
[0016] According to the fluidized liquid supply section structure in the shield tunneling machine of the present invention, when the mud pressure type shield tunneling machine is advanced in the tunneling direction while fluidized liquid is sprayed and the ground at the face is cut with the rotating cutter, the simple configuration effectively prevents the cut soil and sand from getting into the gap at the end of the elastic sleeve member on the forward side in the tunneling direction. [Brief description of the drawings]
[0017] [Figure 1] 1 is a vertical cross-sectional view of a mud pressure type shield tunneling machine that employs a fluidizing liquid material supply structure according to a preferred embodiment of the present invention. [Diagram 2] FIG. 2 is a front view of the mud pressure type shield machine of FIG. 1, as viewed from the front side in the excavation direction. [Diagram 3] FIG. 2 is an enlarged cross-sectional view of part A in FIG. 1, illustrating the structure of a supply section for fluidizing liquid material according to a preferred embodiment of the present invention. [Figure 4] FIG. 2(a) is an enlarged cross-sectional view of a supply structure for fluidizing liquid material according to a preferred embodiment of the present invention, and FIG. 2(b) is an enlarged cross-sectional view of an elastic sleeve member. [Diagram 5] 13(a) and 13(b) are enlarged cross-sectional views illustrating other examples of the structure of the supply portion for the fluidizing liquid material. [Figure 6]FIG. 13 is an enlarged cross-sectional view illustrating the structure of a conventional fluidizing liquid material supply section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] A fluidized liquid supply structure 10 in a shield machine according to a preferred embodiment of the present invention (see Figures 3 and 4(a)) is adopted as a fluidized liquid supply structure for supplying fluidized liquid, preferably containing a mud-making agent, toward the ground at the face 33 in an earth pressure type shield machine 30 shown in Figure 1, for the purpose of plastically fluidizing the excavated soil and sand taken into the cutter chamber 31 and filling it as mud in the cutter chamber 31.
[0019] In other words, the mud pressure type shield machine 30 cuts the ground at the tunnel face 33 with a rotating cutter 32, and the soil and sand taken into the cutter chamber 31 is mixed with a liquid material, preferably containing a plastic fluidizing agent such as a mud working agent, to generate plastically fluidized mud, and the ground at the tunnel face 33 is excavated while stabilizing the tunnel face 33 by the mud pressure generated by filling the cutter chamber 31 with the generated mud.
[0020] In addition, the mud pressure type shield tunneling machine 30 shown in Figure 1 has a structure similar to that of known mud pressure type shield tunneling machines, and cuts the ground at the face 33 with a rotating cutter 32 rotated by a cutter drive unit 34, and when stirring the cut soil taken in in a cutter chamber 31 partitioned at the tip by a partition wall 35, liquid material containing a plastic fluidizing agent is supplied to the ground at the face 33 from two supply parts 32c (see Figure 2) located, for example, on the circular base part 32a of the rotating cutter 32 described below and at the tip of a selected cutting spoke 32b. The mud is mixed and stirred with liquid material containing a plastic fluidizing agent and plastically fluidized. As the shield machine 30 advances, excavating the ground at the face 33, the mud pressure in the cutter chamber 31 keeps the face 33 stable, and the mud is discharged to the rear of the shield machine 30 via a screw conveyor 36, one end of which opens into the partition wall 35.
[0021] Here, as a structure for the supply section 32c for supplying the fluidizing liquid material containing a plastic fluidizing agent from the rotating cutter 32 to the ground at the face 33, a structure has been proposed in which the discharge opening 53 from which the fluidizing liquid material is discharged is covered with an elastic sleeve member 55 as shown in Figure 6 above, thereby preventing the discharge opening 53 from being clogged with the soil and sand being cut by the rotating cutter 32.However, with the structure of the supply section 32c in Figure 6, when the shield tunneling machine 30 is advanced in the excavation direction X, while the fluidizing liquid material is being sprayed and the ground at the face 33 is cut by the rotating cutter 32, it is conceivable that the cut soil and sand will get into the gap at the end of the elastic sleeve member 55 on the forward side in the excavation direction X, causing clogging.
[0022] The fluidized liquid supply structure 10 in the shield tunneling machine of this embodiment has been designed with the intention of solving the technical problems specific to the structure of the supply section 32c, which supplies fluidized liquid containing a plastic fluidizing agent from the rotating cutter 32 to the ground at the face 33.When the mud pressure type shield tunneling machine 30 is advanced in the excavation direction X, fluidized liquid is sprayed while the rotating cutter 32 cuts the ground at the face 33, and the simple structure effectively prevents the cut soil and sand from getting into the gap at the front end of the elastic sleeve member 14 in the excavation direction X.
[0023] The fluidized liquid material supply structure 10 (see Figure 4(a)) in the shield tunneling machine of this embodiment is a supply structure for supplying fluidized liquid material to the cutter chamber 31 to generate plastically fluidized mud in a mud pressure type shield tunneling machine 30 (see Figure 1) which cuts the ground with a rotating cutter 32 while stabilizing the face 33 with mud filled in the cutter chamber 31, and as shown in Figures 3 and 4(a), it is composed of a topped cylindrical discharge cylinder 11 which is connected to the fluidized liquid material supply pipe 20 and protrudes from the rotating cutter 32 forward in the excavation direction X, has a plurality of liquid material discharge openings 12 on its side surface 11a and has a closed tip portion 11b, a guide wall portion 13 which is provided in an annular shape with intervals on the outside of the discharge cylinder 11, and an elastic sleeve member 14 which is attached in a state of close contact with the side surface 11a of the discharge cylinder 11, covering the plurality of liquid material discharge openings 12. The elastic sleeve member 14 is positioned on the side surface 11a of the discharge cylinder 11 by a nut-shaped member 15, which has a female thread ridge (not shown) formed on its inner surface, being screwed onto a male thread ridge (not shown) formed on the side surface 11a of the tip portion of the discharge cylinder 11, and the nut-shaped member 15 has an annular skirt portion 15a extending from its outer peripheral edge to the rear side in the excavation direction X, and this annular skirt portion 15a is arranged so as to cover the front tip portion of the positioned elastic sleeve member 14 in the excavation direction X from the outside.
[0024] In the fluidizing liquid material supply structure 10 of this embodiment, the guide wall portion 13 is provided with a tapered wall surface portion 13a that expands in diameter toward the front side in the excavation direction X.
[0025] In this embodiment, the mud pressure type shield machine 30 is, for example, a bending type machine as shown in Figures 1 and 2, and has the same structure as a known mud pressure type shield machine as described above. The shield machine 30 includes a rotating cutter 32, a bulkhead 35, a cutter chamber 31, a cutter drive unit 34, a front body shell 37a, a rear body shell 37b, a shield jack 38, a bending jack 39, a rotary join 40, an erector 41, etc., and the segments 42 are assembled into a ring shape by the erector 41 inside the rear body shell 37b to sequentially form a primary lining body 43, and the shield jack 38 is extended while receiving a reaction force from the primary lining body 43 formed by the formed segments 42, so that the machine can advance in the excavation direction X while cutting the ground at the face 33 with the rotating cutter 32.
[0026] In this embodiment, the rotating cutter 32 rotates together with the rotating shaft 40b of the rotary join 40 by integrally joining the circular base portion 32a to the tip of the rotating shaft 40b, which is provided extending from the housing portion 40a of the rotary join 40 fixed to the central portion of the surface of the rear body outer body 37b side of the partition wall 35 through the partition wall 35 into the inside of the cutter chamber 31. In this embodiment, four cutting spokes 32b, to which cutting bits 32h are fixed, are attached integrally, extending in a cross shape in all four directions from the circular base portion 32a of the rotating cutter 32, and a center bit 32d is attached integrally, protruding in a mountain shape from the central portion where the circular base portion 32a of the rotating cutter 32 is provided, toward the front side in the excavation direction X. In this embodiment, the fluidized liquid material supply section structure 10 is provided as a structure of the above-mentioned two supply sections 32c (see Figure 2) arranged in a total of two locations, for example, at a position in the central part of the circular base portion 32a of the rotating cutter 32 that partially overlaps with the center bit 32d when viewed from the front side, and at a position in the radially outer end portion of a selected one of the four cutting spokes 32b.
[0027] Furthermore, in this embodiment, the four cutting spokes 32b are extended rearward in the excavation direction X, and the rotating and moving rod section 32e is attached with its rear end joined to the annular rotating rail member 46 of the rotary drive mechanism 45 (see FIG. 1). The annular rotating rail member 46 is engaged with the cutter drive device 34, preferably a hydraulic motor, fixed to the partition wall 35 inside the connection box 47, for example, by a gear mechanism. This makes it possible to transmit the rotational drive force of the cutter drive device 34 to the four cutting spokes 32b via the annular rotating rail member 46 and the rotating and moving rod section 32e, and the rotary cutter 32 is rotated in a stable state with a predetermined torque, so that the cutting of the ground at the face 33 can be efficiently performed by the cutting bit 32h and the center bit 32d.
[0028] In this embodiment, as described above, the fluidized liquid material supply structure 10 is provided as a structure of a fluidized liquid material supply section 32c (see Figure 2) arranged in two locations, for example, the central portion of the circular base portion 32a of the rotating cutter 32 and the tip portion of a selected cutting spoke 32b, and as shown in Figures 3 and 4(a), it comprises a topped cylindrical discharge cylinder 11 having a plurality of liquid material discharge openings 12 on its side surface 11a and a closed tip portion 11b, a guide wall portion 13 provided on the outside of the discharge cylinder 11, an elastic sleeve member 14 attached in a state of close contact with the side surface 11a of the discharge cylinder 11, and a nut-shaped member 15 screwed onto the tip portion of the discharge cylinder 11.
[0029] The discharge cylinder 11 is a cylindrical metal member having an inner diameter of, for example, about φ50 mm, and the discharge hardware 18, which is integrally molded with the guide wall portion 13 via the base portion 17, is fitted into a fitting hole 19 formed in the circular base portion 32a of the rotating cutter 32 or a selected cutting spoke 32b, and the peripheral portion is fixed to the inner surface of the fitting hole 19, for example by welding, so that at least the tip portion 11b of the discharge cylinder 11 protrudes from the surface of the circular base portion 32a or the cutting spokes 32b of the rotating cutter 32 and is attached as a single unit to the rotating cutter 32. The hollow interior of the discharge cylinder 11 communicates with the supply pipe 20 for the fluidized liquid material through the rotary cutter 32 and the rotary shaft 40b of the rotary join 40 via a communication hole 17a formed penetrating the base plate 17, and the discharge cylinder 11 is a cylindrical body with a top, the tip 11b of which is closed by a top plate. On the side peripheral surface 11a of the discharge cylinder 11, a plurality of liquid material discharge openings 12 are formed, for example, circular openings having an inner diameter of about φ20 mm, preferably at four locations spaced at 90 degree intervals in the circumferential direction.
[0030] This allows the fluidizing liquid material, which preferably contains a mud-making agent as a plastic fluidizing agent and is pressure-fed through the supply pipe 20, to be forcefully sprayed in all four directions from the four liquid material discharge openings 12.
[0031] In this embodiment, the elastic sleeve member 14 attached in close contact with the side peripheral surface 11a of the discharge cylindrical body 11 can be formed using natural rubber having a hardness of A55 to A75 based on JIS K 6253 as an elastic material. As shown in FIG. 4(b), the elastic sleeve member 14 is preferably formed into a cylindrical shape using natural rubber having a thickness of about 5 to 10 mm, with an inner diameter equal to or slightly smaller than the outer diameter of the discharge cylindrical body 11, and with a length similar to the length of the discharge cylindrical body 11 excluding the tip portion 11b on which the male thread protrusion is formed. The elastic sleeve member 14 is attached in close contact with the entire side peripheral surface 11a of the discharge cylindrical body 11 while elastically deforming and covering the four liquid material discharge openings 12 formed on the side peripheral surface 11a of the discharge cylindrical body 11 from the outside.
[0032] When the fluidizing liquid material is supplied from the rotary cutter 32 to the face 33, the fluidizing liquid material is discharged from each of the liquid material discharge openings 12 while elastically deforming the elastic sleeve member 14 to lift it due to the pressure of the supply pipe 20, and the discharged fluidizing liquid material is similarly lifted by the pressure of the elastic sleeve member 14, and is pressure-fed toward the front and rear ends of the elastic sleeve member 14 through the gap between the lifted elastic sleeve member 14 and the side peripheral surface 11a of the discharge cylinder 11, and then, in this embodiment, is sprayed mainly from the rear end of the elastic sleeve member 14 by the action of the nut-shaped member 15 described later. The fluidizing liquid material sprayed from the rear end is guided by the guide wall portion 13 provided on the outside of the discharge cylinder 11, changes direction, and is sprayed vigorously toward the face 33 ahead in the excavation direction X.
[0033] The guide wall 13 provided on the outside of the discharge cylinder 11 is a metal part molded integrally with the discharge cylinder 11 as a part of the discharge hardware 18, as described above. The guide wall 13 is provided as an annular part arranged concentrically with the discharge cylinder 11 on the outside of the discharge cylinder 11 by fixing the discharge hardware 18 to the fitting holes 19 formed in the circular base 32a and the cutting spokes 32b of the rotating cutter 32. The guide wall 13 has a function of guiding the fluidizing liquid material sprayed from the rear end of the elastic sleeve member 14 toward the rear in the excavation direction X so as to change direction along the inner circumferential surface including the bottom of the guide wall 13, and spraying the fluidizing liquid material toward the face 33 in the front of the excavation direction X.
[0034] In addition, in this embodiment, the guide wall portion 13 preferably has a tapered wall portion 13a which expands towards the front in the excavation direction X from the base end portion connected to the base plate portion 17 of the discharge portion hardware 18, thereby enabling the fluidized liquid material which is sprayed rearward in the excavation direction X from the rear end portion of the elastic sleeve member 14 and then redirected can be sprayed over a wider area in all directions towards the face portion 33 ahead in the excavation direction X.
[0035] The nut-shaped member 15 screwed to the tip of the discharge cylinder 11 is a metal fitting having a screw opening in the center with a female thread ridge (not shown) formed on the inner circumferential surface. The nut-shaped member 15 also has an annular skirt portion 15a extending from the outer circumferential edge portion to the rear side in the excavation direction X. The female thread ridge on the inner circumferential surface of the screw opening of the nut-shaped member 15 can be screwed to a male thread ridge (not shown) formed on the side circumferential surface 11a of the closed tip portion 11b of the discharge cylinder 11, so that the inner side surface on the rear side in the excavation direction X can be abutted against the tip surface of the elastic sleeve member 14 preferably attached to the side circumferential surface 11a of the discharge cylinder 11. This makes it possible to position the elastic sleeve member 14 so that it does not shift position when the shield machine 30 excavates while rotating the rotating cutter 32.
[0036] Furthermore, when the nut-like member 15 is screwed onto the tip portion 11b of the discharge cylinder 11, the annular skirt portion 15a is arranged so as to cover from the outside the tip portion of the positioned elastic sleeve member 14 on the front side in the excavation direction X. In this embodiment, the annular skirt portion 15a is arranged so as to cover from the outside the tip portion of the elastic sleeve member 14 while maintaining a gap between the annular skirt portion 15a and the outer circumferential surface of the tip portion of the elastic sleeve member 14. The annular skirt portion 15a can also be attached preferably with its inner circumferential surface in intimate contact with the outer circumferential surface of the tip portion of the elastic sleeve member 14 (see Figs. 5(a) and (b)).
[0037] The annular skirt portion 15a of the nut-shaped member 15 is arranged so as to cover the tip portion of the elastic sleeve member 14 attached to the discharge cylinder body 11 from the outside while covering the liquid material discharge opening 12, so that when the shield machine 30 is advanced in the excavation direction X and the fluidized liquid material is sprayed and the ground at the face portion 33 is cut by the rotating cutter 32, the cut earth and sand will not reach the end of the elastic sleeve member 14 on the front side in the excavation direction X unless it moves around the annular skirt portion 15a and moves forward in the excavation direction X. This makes it possible to prevent the cut earth and sand from reaching the gap at the end on the front side in the excavation direction X of the elastic sleeve member 55, which is turned up during discharge, and effectively prevents the cut earth and sand from entering the gap at the end on the front side in the excavation direction X of the elastic sleeve member 55, which is turned up during discharge, and becoming blocked.
[0038] Therefore, according to this embodiment, with a simple configuration in which only the annular skirt portion 15a is provided on the nut-shaped member 15, it is possible to effectively prevent the cut soil from getting into the gap at the end of the elastic sleeve member 14 on the forward side in the excavation direction X when the mud pressure type shield machine 30 is advanced in the excavation direction X, while spraying fluidizing liquid material and cutting the ground at the face portion 33 with the rotating cutter 32.
[0039] Furthermore, if the inner surface of the annular skirt portion 15a of the screwed nut-shaped member 15 is kept in close contact with the outer surface of the tip portion of the elastic sleeve member 14 (see Figures 5(a) and (b)), the cut soil and sand will be blocked from moving around the annular skirt portion 15a and forward in the excavation direction X, making it possible to more effectively prevent the cut soil and sand from getting into the gap at the end of the elastic sleeve member 14 on the forward side in the excavation direction X.
[0040] In this embodiment, the fluidizing liquid material supply structure 10 in the supply section 32c (see FIG. 2) arranged in the center of the circular base section 32a of the rotating cutter 32 is arranged so as to overlap with the center bit 32d as viewed from the front side by protruding the discharge cylinder 11 from the circular base section 32a in the trapezoidal cutout section 32f provided in the rear part of the center bit 32d in the excavation direction X. This allows the center bit 32d to function as a buffer wall member, and effectively relieves the pressure during cutting from being directly applied to the supply structure 10 in the center when the rotating cutter 32 cuts the ground at the face section 33 while the mud pressure type shield machine 30 is advanced in the excavation direction X.
[0041] 2 and 4(a), a belt-shaped buffer wall member 32g can be attached to the fluidizing liquid material supply structure 10 in the supply section 32c where the end portion of the selected cutting spoke 32b is located, by extending it in the radial direction of the discharge cylinder 11 and arranging it so as to overlap with the discharge cylinder 11 as viewed from the front side in the excavation direction X, with a gap being maintained between the inner peripheral surface of the belt-shaped buffer wall member 32g and the tip portion 11b of the discharge cylinder 11. This makes it possible, by the function of the belt-shaped buffer wall member 32g2d, to effectively alleviate the pressure during cutting being directly applied to the supply structure 10 at the end portion of the cutting spoke 32b when the mud pressure type shield machine 30 is advanced in the excavation direction X and the rotating cutter 32 cuts the ground at the face 33.
[0042] Figures 5(a) and (b) illustrate fluidizing liquid material supply structure 10', 10" according to another embodiment of the present invention. In the fluidizing liquid material supply structure 10' shown in Figure 5(a), the elastic sleeve member 14' has a radial two-layer structure, for example, with soft rubber 14a on the inside and hard rubber 14b on the outside, and the difference in the contraction speed of the rubber is used to prevent backflow of soil and sand. In the fluidizing liquid material supply structure 10" shown in Figure 5(b), the elastic sleeve member 14" has an axial three-layer structure, for example, with hard rubber 14c on both ends and soft rubber 14a in the center, and the fluidizing liquid material is ejected from the center to prevent backflow of soil and sand. The other configurations are the same as those of the above embodiment.
[0043] The fluidized liquid material supply structure 10', 10'' using these elastic sleeve members 14', 14'' also provides the same effects as the fluidized liquid material supply structure 10 of the above embodiment.
[0044] The present invention is not limited to the above embodiment and may be modified in various ways. For example, the guide wall does not necessarily have to have a tapered wall surface portion that expands toward the front side in the excavation direction.
[0045] 10,10',10" Fluidizing liquid material supply structure 11 Discharge cylinder 11a Side surface 11b Tip 12 Fluid discharge opening 13 Guide wall 13a Tapered wall 14,14',14" Elastic sleeve member 15 Nut-shaped member 15a Circular skirt 18 Discharge metal fittings 19 Fitting hole 20 Supply pipe 30 Mud pressure type shield tunneling machine 31 Cutter chamber 32 Rotating cutter 32a Circular base 32b Cutting spokes 32c supply section 32g Belt-shaped buffer wall material 33 Face 34 Cutter drive unit 35 Bulkhead X Excavation direction
Claims
1. In a mud pressure type shield machine that cuts the ground with a rotary cutter while stabilizing a face with mud filled in a cutter chamber, a supply unit structure for supplying a fluidizing liquid material that generates plastically fluidized mud to the cutter chamber, the discharge cylinder includes a top-top cylindrical discharge cylinder having a plurality of liquid material discharge openings on its side circumferential surface and a closed tip end, the discharge cylinder being connected to a supply pipe for the fluidized liquid material and protruding forward from the rotating cutter in the excavation direction, a guide wall portion provided in an annular shape at intervals on the outside of the discharge cylinder, and an elastic sleeve member attached in a state of tight contact with the side circumferential surface of the discharge cylinder, covering the plurality of liquid material discharge openings; the elastic sleeve member is positioned on the side circumferential surface of the discharge cylinder by a nut-shaped member having a female thread ridge formed on its inner circumferential surface being screwed onto a male thread ridge formed on the side circumferential surface of the tip portion of the discharge cylinder, The nut-shaped member has an annular skirt portion extending from its outer peripheral edge rearward in the excavation direction, and the annular skirt portion is arranged to cover from the outside the tip portion of the positioned elastic sleeve member on the front side in the excavation direction.This is a supply structure for fluidized liquid material in a shield tunneling machine.
2. 2. A structure of a supply section for fluidizing liquid material in a shield tunneling machine according to claim 1, wherein the guide wall section has a tapered wall surface section whose diameter increases toward the front side in the tunneling direction.
3. 3. A structure for supplying fluidized liquid material in a shield tunneling machine according to claim 1 or 2, wherein the elastic sleeve member is made of natural rubber having a hardness of A55 to A75 based on JIS K 6253.
4. 4. A structure for supplying fluidizing liquid material in a shield tunneling machine according to claim 3, wherein the natural rubber has a thickness of 5 to 10 mm.
5. A supply section structure for fluidized liquid material in a shield tunneling machine as described in claim 1 or 2, wherein the annular skirt portion of the nut-shaped member is attached with its inner surface in close contact with the outer surface of the tip portion of the elastic sleeve member at the front side in the tunneling direction.
6. A supply structure for fluidized liquid material in a shield tunneling machine as described in claim 1 or 2, in which a band-shaped buffer wall member is extended radially from the discharge cylinder by joining both ends to the rotating cutter, and is attached so as to overlap with the discharge cylinder when viewed from the front in the excavation direction, with a gap maintained between its inner surface and the tip of the discharge cylinder.