Shield tunneling machine

Abstract

To provide a shield tunneling machine capable of preventing a tail seal unit from degrading in water-stopping performance.SOLUTION: Multiple sealing members 12Ba and 12Bb placed along the inner circumference of a skin plate 5 of a shield tunneling machine 1 are segmented into sealing members 12Ba1 and 12Bb1 in an upper area Up, and sealing members 12Ba2 and 12Bb2 in a lower area Un. The spring force of the sealing members 12Ba2 and 12Bb2 in the lower area Un is stronger than the spring force of the sealing members 12Ba1 and 12Bb1 in the upper area Up. With this, the water-stopping performance of the tail seal unit of the shield tunneling machine 1 is prevented from degrading.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a shield tunneling machine, and more particularly to tail seal technology for a shield tunneling machine. [Background technology]

[0002] When excavating the ground with a shield machine, a water-stopping structure called a tail seal is provided at the rear end of the shield machine to prevent groundwater and soil from seeping into the shield machine through the gap between the segment at the rear end of the shield machine and the skin plate of the shield machine, or to prevent backfill material pressed into the ground from seeping in.

[0003] This tail seal section has multiple seal members arranged along the inner periphery of the skin plate. Each seal member has, for example, two springy steel plates and a wire brush (a brush-type brush made of a bundle of fine steel wires) arranged between the two steel plates. During shield excavation, the wire brushes of the seal members come into contact with the segments, and a sealing agent such as waterproof grease is supplied to the wire brushes themselves and the contact areas between the wire brushes and the segments, thereby maintaining waterproofing.

[0004] The tail seal portion is described, for example, in Patent Document 1, which discloses a configuration in which the seal member is divided into upper, middle, and lower sections along the circumferential direction of the skin plate, and the thickness of the rubber seal member is different on the upper, middle, and lower sections.

[0005] Furthermore, for example, Patent Document 2 discloses a configuration in which the sealing member is divided into upper, middle and lower sections along the circumferential direction of the skin plate, and the deformation characteristics of the rubber sealing member are different for the upper, middle and lower sections.

[0006] Furthermore, for example, Patent Document 3 discloses a configuration in which the height of the seal member can be adjusted by changing the shape of the wire brush that constitutes the seal member of the tail seal portion between straight and curved. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Jikko No. 54-25300 [Patent Document 2] Jikko No. 54-25301 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-87531 Summary of the Invention [Problem to be solved by the invention]

[0008] In recent years, with the shield tunneling method, tunnels have become longer and longer, and various problems have occurred, such as malfunctions in the segments and abnormal increases in thrust, due to deterioration or damage to the sealing material in the tail seal (deformation of the sealing material itself, or loss or deformation of the wire brushes, etc.). Furthermore, tunnels are becoming deeper, and construction under high water pressure is becoming more common, which has led to problems such as the sealing material in the tail seal being turned over by water pressure. Therefore, with the shield tunneling method, it is important to design tail seals that will prevent the above-mentioned problems from occurring during excavation.

[0009] Based on past field conditions, the inventors' research has revealed that groundwater and other infiltration occurs most frequently in the lower area of ​​the shield tunneling machine. This is thought to be due to higher water pressure, which leads to greater groundwater and other infiltration in the lower area of ​​the shield tunneling machine. Normally, the seal member in the lower area is pressed between the segment and the skin plate by the weight of the segments and trailing bogies. However, due to variations in load conditions depending on the type of segment and construction conditions such as the shield tunneling machine's attitude control, the shield tunneling machine may rise by approximately 10 to 15 mm, widening the clearance between the segment and the skin plate. In this way, the clearance in the lower area repeatedly increases and decreases. If the seal member remains crushed, water may leak between the segment and the skin plate. Therefore, the seal member's resilience must be increased so that it can follow the segment even when the clearance increases.

[0010] The present invention has been made in light of the above-mentioned technical background, and has as its object to prevent a decrease in the watertightness of the tail seal portion of a shield tunneling machine. [Means for solving the problem]

[0011] In order to solve the above problem, the shield tunneling machine of the present invention described in claim 1 comprises a cutter head for excavating the ground, an equipment body for supporting the cutter head in a rotatable state, a skin plate that forms the outer shell of the equipment body, and a tail seal portion provided between the inner periphery of the skin plate and the outer periphery of a segment provided at the rear end of the equipment body, wherein the tail seal portion has a plurality of plate-shaped sealing members provided along the inner periphery of the skin plate, the sealing members having spring properties, and one end side of the sealing members in the front-to-rear direction of the equipment body is fixed to the skin plate, and the other end side of the sealing members in the front-to-rear direction is provided in contact with the outer periphery of the segment, and the plurality of sealing members provided along the inner periphery of the skin plate are divided into sealing members in an upper region and sealing members in a lower region along the inner periphery of the skin plate, and the spring force of the sealing member in the lower region is stronger than the spring force of the sealing member in the upper region.

[0012] The shield tunneling machine of the present invention described in claim 2 is characterized in that, in the invention described in claim 1, the sealing member has a springy steel plate portion fixed in a cantilevered state to the skin plate, and the number of steel plates in the steel plate portion of the sealing member in the lower region is greater than the number of steel plates in the steel plate portion of the sealing member in the upper region.

[0013] The shield tunneling machine of the present invention described in claim 3 is characterized in that, in the invention described in claim 2 above, the steel plate portion of the sealing member in the upper region has a first steel plate portion and a second steel plate portion located inward from the first steel plate portion, the steel plate portion of the sealing member in the lower region has a third steel plate portion and a fourth steel plate portion located inward from the third steel plate portion, and the number of steel plates in the third steel plate portion of the sealing member in the lower region is greater than the number of steel plates in the first steel plate portion of the sealing member in the upper region.

[0014] The shield tunneling machine of the present invention described in claim 4 is characterized in that, in the invention described in claim 3, the steel plate portion of the sealing member in the lower region further has a fifth steel plate portion between the third steel plate portion and the fourth steel plate portion.

[0015] The shield tunneling machine of the present invention described in claim 5 is characterized in that, in the invention described in claim 2 above, the steel plate portion of the sealing member in the upper region has a first steel plate portion and a second steel plate portion provided inward from the first steel plate portion, and the steel plate portion of the sealing member in the lower region has a third steel plate portion, a fourth steel plate portion provided inward from the third steel plate portion, and a fifth steel plate portion provided between the third steel plate portion and the fourth steel plate portion.

[0016] The shield tunneling machine of the present invention described in claim 6 is characterized in that, in the invention described in any one of claims 1 to 5 above, the lower region is set to the lower one-quarter to one-third of the total perimeter of the skin plate, and the remainder is the upper region. [Effects of the Invention]

[0017] According to the present invention, it is possible to prevent a decrease in the watertightness of the tail seal portion of a shield tunneling machine. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram showing the main components of a shield tunneling machine according to an embodiment of the present invention, seen from the side. FIG. [Figure 2] This is a schematic diagram showing the inside of a shield tunneling machine seen from the side. [Figure 3] FIG. 2 is a rear view of the shield tunneling machine of FIG. 1 as seen from the rear. [Figure 4] 4(a) is a side view of the tail seal portion in the upper region of the shield tunneling machine in FIG. 1, and FIG. 4(b) is a front view of the seal member that constitutes the tail seal portion in FIG. 4(a) as seen from the rear of the shield tunneling machine. [Figure 5] FIG. 5 is a side view showing an example of dimensions of the tail seal portion of FIG. 4(a). [Figure 6] 1(a) is a side view of the tail seal portion with the sealant supply pipe added, and FIG. 1(b) is a cross-sectional view taken along line II in FIG. [Figure 7] FIG. 10 is a plan view of a group of essential parts of the tail seal portion. [Figure 8] FIG. 2 is a side view of the tail seal portion in the lower region of the shield machine of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings for explaining the embodiment, the same components are generally designated by the same reference numerals, and repeated description thereof will be omitted.

[0020] First, an example of the configuration of a shield tunneling machine according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a configuration diagram of the main parts of the inside of the shield tunneling machine according to this embodiment, seen through from the side.

[0021] The shield tunneling machine 1 of this embodiment is a mud pressure type shield machine that excavates while ensuring the stability of the face by filling the chamber 4 between the cutter head 2 and the equipment body 3 with mud that is impermeable and has plastic fluidity (the ability to deform and move freely) created by injecting additives into the soil and sand excavated by the cutter head 2 and mixing it, thereby generating mud pressure that counteracts the earth pressure at the face and ensuring the stability of the face.

[0022] The cutter head 2 is a shield cutter machine that excavates the ground, and is installed in front of the tip head of the shield tunneling machine 1 in a state where it can rotate forward and backward along the circumferential direction of the equipment body 3. Although not particularly limited, the diameter of the cutter head 2 is, for example, about 2320 mm.

[0023] A center bit CB, a bit B, and scraper teeth (not shown) are attached to the front surface of the cutter head 2 (the surface facing the working face). The center bit CB and bit B are excavation components that mainly cut away the natural ground, and the scraper teeth are cutting components that mainly cut the natural ground. Note that instead of the bit B, for example, a roller cutter or the like may be attached.

[0024] A copy cutter CC is also installed on the outer periphery of the cutter head 2. The copy cutter CC is responsible for over-excavating when constructing sharp curves and controlling the attitude of the shield machine 1. A plurality of stirring rods SB are attached to the center of the rear surface of the cutter head 2. The stirring rods SB are formed, for example, from cylindrical protruding members, and have the role of stirring and mixing the soil and additives in the chamber 4 when the cutter head 2 rotates. The stirring rods SB are, for example, equipped with a vibration sensor.

[0025] The equipment body 3 is the main component that drives the shield machine 1. The equipment that drives the shield machine 1 is surrounded and protected by a skin plate 5 that forms the outer shell of the equipment body 3. The skin plate 5 has a forward body plate (forward body section) 5a and an aft body plate (aft body section) 5b behind it. The forward body plate 5a and the aft body plate 5b are made of, for example, cylindrical steel plates, and are engaged by inserting a spherical bearing at the tip of the aft body plate 5b into the forward body plate 5a while in contact with the inner circumferential surface.

[0026] The hollow space within the skin plate 5 is divided into a face side and an inboard side by a bulkhead 7 provided inside the front body plate 5a. The chamber 4 described above is provided on the face side (i.e., between the cutter head 2 and the bulkhead 7). Note that earth and sand excavated by the cutter head 2 is taken into the chamber 4 through a through-hole (not shown) that penetrates the front and back surfaces of the cutter head 2.

[0027] Meanwhile, inside the hollow space of the skin plate 5, there are installed a cutter driver 8, a center bending jack 9a, a shield jack 9b, a screw conveyor 10, an erector 11, and a tail seal unit 12. Although not shown, in addition to the above, the main body 3 is also equipped with various other devices, such as an earth pressure detection unit that detects the earth pressure in the chamber 4, and an additive injection unit that injects the additive (earth-making material) into the chamber 4.

[0028] The cutter drivers 8 are motors (drive sources) that rotate the cutter head 2 in forward and reverse directions, and a plurality of them are installed in a line near the outer periphery inside the front of the cutter head 2 along the circumferential direction of the cutter head 2. Note that a periphery support drive system is exemplified here as the cutter drive system.

[0029] The articulating jacks 9a are devices that correct the forward movement direction and attitude of the shield machine 1, and are installed in multiple rows along the circumferential direction of the machine body 3, straddling the boundary between the front and rear plates 5a and 5b so as to connect the front and rear plates 5a and 5b within the machine body 3. By supplying pressure oil to these articulating jacks 9a and advancing the shield machine 1 with the front and rear plates 3a and 3b bent in a predetermined direction and angle, it is possible to control the forward movement direction and attitude of the shield machine 1.

[0030] The shield jack 9b is a device that generates a propulsion force to move the shield tunneling machine 1 forward by receiving a reaction force from the segment SG installed at the rear of the equipment main body 3, and multiple shield jacks 9b are installed in a row along the circumferential direction of the equipment main body 3, straddling the boundary between the front body plate 5a and the rear body plate 5b within the equipment main body 3.

[0031] The screw conveyor 10 is a device for discharging the soil and sand taken into the chamber 4 to the outside of the machine, and is installed so as to extend continuously from the chamber 4 through the partition wall 7 and diagonally upward toward the rear. Note that a ribbon screw conveyor is shown as an example here.

[0032] The erector 11 is an assembly device that grasps the segment SG, rotates it in the direction of the inner circumference of the excavation hole, and transports it to an assembly position in the direction of the inner circumference of the excavation hole, and is installed in the hollow of the rear body plate 5b in a state that allows it to rotate in the direction of the circumference of the excavation hole by a hydraulic motor (not shown) for driving the erector, etc.

[0033] The tail seal portion 12 is provided between the inner circumference of the skin plate 5 and the outer circumference of the segment SG, and is a water-stopping structure that prevents groundwater, soil and backfill material, etc. (hereinafter referred to as groundwater, etc.) from entering the interior of the equipment main body 3 from the outside of the rear end side of the shield tunneling machine 1 during excavation operations, and has two-stage plate-shaped seal members 12Ba, 12Bb with spring properties, and a seal chamber 12R provided between these seal members 12Ba, 12Bb.

[0034] The seal members 12Ba, 12Bb are installed, for example, at two locations on the inner periphery of the rearmost end of the skin plate 5, spaced apart from each other along the fore-and-aft direction of the shield machine 1 (the direction of the central axis of the shield machine 1, the extension direction of the excavation hole), and each seal member 12Ba, 12Bb is installed in a ring-shaped arrangement along the inner periphery of the skin plate 5 so as to surround the outer periphery of the segment SG. The number of seal members installed is not limited to two, and they may be installed at three or more locations along the fore-and-aft direction of the shield machine 1, for example.

[0035] Furthermore, each of the sealing members 12Ba, 12Bb is installed in a cantilevered state on the inner periphery of the skin plate 5. That is, each of the sealing members 12Ba, 12Bb is installed such that one end side in the front-to-rear direction of the device body 3 is fixed to the inner periphery of the skin plate 5, the sealing members 12Ba, 12Bb are bent in an inclined state toward the segment SG between one end side and the other end side in the front-to-rear direction of the device body 3, and the other end side in the front-to-rear direction of the device body 3 is in contact with the outer periphery of the segment SG.

[0036] Additionally, a sealing agent supply pipe 14 is installed on the outer periphery of the rear body plate 5b. The sealing agent supply pipe 14 is a pipe for supplying a sealing agent such as grease to the sealing chamber 12R, and multiple sealing agent supply pipes 14 are installed on the outer periphery of the rear body plate 5b. By filling the sealing chamber 12R with sealing agent through this sealing agent supply pipe 14, the gap between the inner periphery of the skin plate 5 and the outer periphery of the segment SG is sealed, and in combination with sealing members 12Ba and 12Bb, groundwater and the like are prevented from entering the interior of the shield machine 1 during excavation work.

[0037] Furthermore, a backfilling material supply passage (not shown) is installed on the outer wall of the rear body plate 5b. The backfilling material supply passage is a pipe for supplying backfilling material, such as a cement-based hardening or solidifying material, to the gap between the excavation hole behind the skin plate 5 and the segment SG. By filling the gap between the excavation hole and the segment SG with backfilling material, ground subsidence is prevented, and further, the segment SG and the natural ground are integrated, preventing water leakage from the joints of the segment SG.

[0038] Furthermore, the backfilling material supply passages are provided, for example, at two locations on either side of the top of the skin plate 3. While the sealant supply passages 14 are provided at multiple locations on the outer periphery of the skin plate 5, the backfilling material supply passage is only provided near the top of the skin plate 5. This is because the sealant has high viscosity and must be supplied evenly around the inner periphery of the skin plate 5 in order to adhere to the outer periphery of the segment SG, whereas the backfilling material has low viscosity and so if it is supplied near the top of the skin plate 5, it will flow under its own weight to the lower outer periphery of the segment SG.

[0039] The locations and numbers of the sealant supply channels 14 and backfilling material supply channels are not limited to those described above. For example, more sealant supply channels 14 may be provided, and the backfilling material supply channel may be provided at only one location on the top of the skin plate 5 in the axial direction.

[0040] Next, we will explain the issues with shield tunneling and an example configuration that solves them with reference to Figures 2 and 3. Figure 2 is a schematic configuration diagram showing the inside of a shield tunneling machine as seen from the side, and Figure 3 is a rear view of the shield tunneling machine shown in Figure 1 as seen from the rear. Note that the symbols X and Y in Figure 3 represent the X-axis and Y-axis, respectively. For ease of explanation, Figure 3 also shows the symbols for the front-stage sealing members 12Ba1 and 12Ba2 (12Ba).

[0041] Furthermore, the inventors' investigations into past on-site conditions revealed that groundwater and other infiltration is most prevalent in the lower area of ​​the shield machine 50. This is thought to be due to higher water pressure, which leads to greater groundwater and other infiltration in the lower area of ​​the shield machine 50. Normally, the seal member in the lower area is pressed between the segment and the skin plate by the weight of the segments and the following bogies. However, due to variations in load conditions depending on the type of segment and construction conditions such as the attitude control of the shield machine 50, the shield machine 50 may rise by approximately 10 to 15 mm, widening the clearance between the segment and the skin plate. In this way, the clearance in the lower area repeatedly increases and decreases. If the seal member remains crushed, water may leak between the segment and the skin plate. Therefore, the resilience of the seal member must be increased so that it can follow the segment even when the clearance increases.

[0042] Therefore, in this embodiment, as shown in Figure 3, the multiple sealing members 12Ba, 12Bb arranged along the inner circumference of the skin plate 5 are divided into sealing members 12Ba1, 12Bb1 in the upper region Up and sealing members 12Ba2, 12Bb2 in the lower region Un, and the spring force of the sealing members 12Ba2, 12Bb2 in the lower region Un is set to be stronger than the spring force of the sealing members 12Ba1, 12Bb1 in the upper region Up.

[0043] This improves the spring force of the seal members 12Ba2, 12Bb2 in the lower region Un, thereby increasing the restoring force of the seal members 12Ba2, 12Bb2 in the lower region Un and improving their ability to follow the segments. Furthermore, the pressing pressure of the seal members 12Ba2, 12Bb2 in the lower region Un against the segments SG can be improved compared to the pressing pressure of the seal members 12Ba1, 12Bb1 in the upper region Up against the segments SG, thereby suppressing or preventing the intrusion of groundwater or the like from below, where water pressure is high. This makes it possible to prevent a decrease in the watertightness of the tail seal portion 12 of the shield machine 1.

[0044] In this embodiment, the lower region Un is located, for example, in the lower one-quarter to one-third of the overall perimeter of the skin plate 5 that constitutes the shield machine 1. Specifically, for example, when the skin plate 5 is viewed from the rear, the range from 4 o'clock to 8 o'clock is defined as the lower region Un, and the rest is defined as the upper region Up. Furthermore, although not particularly limited, the angle Rx from the X-axis is set to, for example, 29°.

[0045] Next, examples of the configuration of the seal members 12Ba, 12Bb that constitute the tail seal portion 12 of the shield tunneling machine 1 of this embodiment will be described with reference to Figs.

[0046] First, Figure 4(a) is a side view of the tail seal section in the upper region of the shield machine in Figure 1, and Figure 4(b) is a front view of the seal members that make up the tail seal section in Figure 4(a) as seen from the rear of the shield machine. Note that dashed line S1 indicates the outer periphery position when the segments are planned for assembly, and dashed line S2 indicates the outer periphery position when the segments are fully recessed. Furthermore, lengths Lc1 and Lc2 indicate the overlapping allowances of seal members 12Ba and 12Bb on the segments.

[0047] Each of the sealing members 12Ba1, 12Bb1 in the upper region Up has, for example, a steel plate portion (first steel plate portion) P1, a steel plate portion (second steel plate portion) P2 arranged inward and away from the steel plate portion P1, a wire mesh portion M arranged between them, and a brush portion Br arranged between the steel plate portions P1, P2 and the wire mesh portion M.

[0048] Each of the steel plate portions P1, P2 of the sealing members 12Ba1, 12Bb1 in the upper region Up is provided with, for example, a single steel plate acting as a leaf spring. The steel plates of the steel plate portions P1, P2 are made of, for example, carbon tool steel, and each has a thickness of, for example, approximately 1.0 mm. The planar shape of the steel plates of the steel plate portions P1, P2 is, for example, rectangular, as shown in FIG. 4(b). The number, thickness, and planar shape of the steel plates of the steel plate portions P1, P2 are not limited to those described above and can be modified in various ways as long as they satisfy the condition that the spring force of the sealing members 12Ba2, 12Bb2 in the lower region Un is greater than the spring force of the sealing members 12Ba1, 12Bb1 in the upper region Up.

[0049] The wire mesh portion M of the seal members 12Ba1, 12Bb1 in the upper region Up is provided with, for example, two sheet-like wire meshes. The sheet-like wire mesh of the wire mesh portion M is formed by weaving thin wires made of, for example, stainless steel into a mesh shape, and has a thickness of, for example, about 0.5 mm. The planar shape of the sheet-like wire mesh of the wire mesh portion M is formed, for example, into a rectangular shape, which is approximately the same as the planar shape of the steel plates of the steel plate portions P1, P2. The number, thickness, and planar shape of the wire meshes of the wire mesh portion M are not limited to those described above and can be changed in various ways.

[0050] Furthermore, the brush portion Br of the seal members 12Ba1, 12Bb1 in the upper region Up is formed, for example, by a wire brush having spring properties. That is, the brush portion Br is formed by bundling together multiple wires extending in the front-to-rear direction of the shield tunneling machine 1. The wire of the brush portion Br is made, for example, of hard steel wire, and the overall planar shape of the brush portion Br is formed, for example, in a rectangular shape that is approximately the same as the planar shape of the steel plates of the steel plate portions P1, P2. Note that the planar shape of the brush portion Br is not limited to the one described above and can be modified in various ways.

[0051] Next, FIG. 5 is a side view showing an example of dimensions of the tail seal portion of FIG. 4(a).

[0052] The distance Ld between adjacent seal members 12Ba1, 12Bb1 in the upper region Up is, for example, about 187 mm. The length Ls of the fixed portion of each seal member 12Ba1, 12Bb1 is, for example, about 110 mm. The outer tilt angle R1 of each seal member 12Ba1, 12Bb1 is, for example, about 50°, and the inner tilt angle R2 is, for example, about 30°.

[0053] The outer protrusion length Lp1 of the front seal member 12Ba1 is, for example, about 200 mm, and the protrusion length Lp2 of the outer steel plate portion P1 of the seal member 12Ba1 is, for example, about 190 mm. The inner protrusion length Lp3 of the seal member 12Ba1 is, for example, about 120 mm, and the protrusion length Lp4 of the inner steel plate portion P2 of the seal member 12Ba1 is, for example, about 110 mm.

[0054] On the other hand, the outer protrusion length Lp5 of the rear-stage seal member 12Bb1 is, for example, about 250 mm, and the protrusion length Lp6 of the outer steel plate portion P1 of the seal member 12Bb1 is, for example, about 240 mm.Furthermore, the inner protrusion length Lp7 of the seal member 12Bb1 is, for example, about 170 mm, and the protrusion length Lp8 of the inner steel plate portion P2 of the seal member 12Bb1 is, for example, about 160 mm.

[0055] The dimensions and angles of each part of the seal members 12Ba1 and 12Bb1 are not limited to those described above, but can be changed in various ways.

[0056] Next, FIG. 6(a) is a side view of the tail seal portion with the sealant supply pipe added, and FIG. 6(b) is a cross-sectional view taken along line II in FIG. 6(a).

[0057] A communication hole 14h that communicates the sealant supply pipe 14 with the sealing chamber 12R is formed in the skin plate 5 (rear body plate 5b). That is, the sealant supply pipe 14 is connected to the sealing chamber 12R through the communication hole 14h. The sealing agent SL that flows through the sealant supply pipe 14 is supplied into the sealing chamber 12R through the communication hole 14h, as shown by the arrow.

[0058] Next, FIG. 7 is a plan view of a group of essential parts of the tail seal portion.

[0059] A plurality of seal members 12Ba1 are arranged along the inner periphery (vertical direction in FIG. 7) of the skin plate 5 (rear body plate 5b). Adjacent seal members 12Ba1 along the inner periphery of the skin plate 5 are arranged such that both sides of each seal member 12Ba1 in the width direction (circumferential direction of the skin plate 5) partially overlap each other.

[0060] Similarly, a plurality of seal members 12Bb1 are arranged along the inner periphery (vertical direction in FIG. 7) of the skin plate 5 (rear body plate 5b). Adjacent seal members 12Bb1 along the inner periphery of the skin plate 5 are also arranged with portions of both sides of each seal member 12Bb1 in the width direction (circumferential direction of the skin plate 5) overlapping each other.

[0061] The width W1 of the fixing portion of the sealing members 12Ba1, 12Bb1 (the dimension in the circumferential direction of the skin plate 5) is, for example, about 100 mm, and the width W2 of the protruding portion of the sealing members 12Ba1, 12Bb1 is, for example, about 150 mm. Note that the widths W1, W2 of the sealing members 12Ba1, 12Bb1 are not limited to those described above and can be changed in various ways.

[0062] Next, Figure 8 is a side view of the tail seal portion in the lower region of the shield machine in Figure 1. The front view of seal members 12Ba2 and 12Bb2 in the lower region Un is the same as Figure 4(b), so it is not shown.

[0063] The sealing members 12Ba2, 12Bb2 of the lower region Un have, for example, a steel plate portion (third steel plate portion) P3, a steel plate portion (fourth steel plate portion) P4 arranged inward and away from the steel plate portion P3, a wire mesh portion M and a steel plate portion (fifth steel plate portion) P5 arranged between them, and a brush portion Br arranged between the steel plate portions P3, P4 and the wire mesh portion M and steel plate portion P5.

[0064] Each steel plate portion P3 of the sealing members 12Ba2, 12Bb2 in the lower region Un includes, for example, three steel plates that function as leaf springs. In other words, in this embodiment, the number of steel plates in the steel plate portion P3 of the sealing members 12Ba2, 12Bb2 in the lower region Un is two more than the number of steel plates in the steel plate portion P1 of the sealing members 12Ba1, 12Bb1 in the upper region Up shown in FIG. 4(a). The three steel plates in the steel plate portion P3 are made of, for example, carbon tool steel, and each steel plate has a thickness of, for example, approximately 1.0 mm. The planar shape of the steel plate in the steel plate portion P3 is, for example, rectangular, similar to the steel plate in the steel plate portion P1 shown in FIG. 4(b).

[0065] On the other hand, the steel plate portion P4 of the sealing members 12Ba2, 12Bb2 in the lower region Un is provided with, for example, a single steel plate acting as a leaf spring. That is, in this embodiment, the number of steel plates in the steel plate portion P4 of the sealing members 12Ba2, 12Bb2 in the lower region Un is the same as the number of steel plates in the steel plate portion P2 of the sealing members 12Ba1, 12Bb1 in the upper region Up shown in FIG. 4(a). This single steel plate in the steel plate portion P4 is made of, for example, carbon tool steel and has a thickness of, for example, about 1.0 mm. Furthermore, the planar shape of the steel plate in the steel plate portion P4 is formed, for example, rectangular, similar to the steel plate in the steel plate portion P1 shown in FIG. 4(b).

[0066] Furthermore, in this embodiment, a steel plate portion P5 is provided between the steel plate portions P3 and P4. Two steel plates that function as leaf springs are installed in the steel plate portion P5. The two steel plates of the steel plate portion P5 are made of, for example, carbon tool steel, and each steel plate has a thickness of, for example, about 0.5 mm. The planar shape of the steel plate of the steel plate portion P5 is, for example, rectangular, similar to the steel plate of the steel plate portion P1 shown in FIG. 4(b).

[0067] In this embodiment, the number of steel plates of the sealing members 12Ba2 and 12Bb2 in the lower region Un is greater than the number of steel plates of the sealing members 12Ba1 and 12Bb1 in the upper region Up, so that the spring force of the sealing members 12Ba2 and 12Bb2 in the lower region Un is set to be stronger than the spring force of the sealing members 12Ba1 and 12Bb1 in the upper region Up.

[0068] This improves the spring force of the seal members 12Ba2, 12Bb2 in the lower region Un, thereby increasing the restoring force of the seal members 12Ba2, 12Bb2 in the lower region Un and improving their ability to follow the segments. Also, the pressing pressure of the seal members 12Ba2, 12Bb2 in the lower region Un against the segments SG can be made higher than the pressing pressure of the seal members 12Ba1, 12Bb1 in the upper region Up against the segments SG, thereby suppressing or preventing the intrusion of groundwater or the like from below, where water pressure is high.

[0069] Therefore, it is possible to prevent a decrease in the watertightness of the tail seal portion 12 of the shield machine 1. The conformability of the seal members 12Ba2, 12Bb2 in the lower region Un to the segments SG is higher than the conformability of the seal members 12Ba1, 12Bb1 in the upper region Up to the segments SG.

[0070] The wire mesh portions M of the sealing members 12Ba2 and 12Bb2 in the lower region Un are the same as the wire mesh portions M of the sealing members 12Ba1 and 12Bb1 in the upper region Up shown in Fig. 4(a), and therefore will not be described. Also, the brush portions Br of the sealing members 12Ba2 and 12Bb2 in the lower region Un are the same as the brush portions Br of the sealing members 12Ba1 and 12Bb1 in the upper region Up shown in Fig. 4(a), and therefore will not be described.

[0071] The dimensions of each part of the sealing members 12Ba2, 12Bb2 in the lower region Un are the same as those explained in Fig. 5, and therefore illustration and description thereof will be omitted. The sealing agent supply structure that supplies sealing agent to the sealing members 12Ba2, 12Bb2 in the lower region Un is also the same as that explained in Fig. 6, and therefore illustration and description thereof will be omitted. Furthermore, the plan view of the group of sealing members 12Ba2, 12Bb2 in the lower region Un is also the same as that explained in Fig. 7, and therefore illustration and description thereof will be omitted.

[0072] The configuration of the seal members 12Ba2, 12Bb2 in the lower region Un is not limited to the above configuration and can be modified in various ways as long as the spring force thereof is greater than the spring force of the seal members 12Ba1, 12Bb1 in the upper region Up.

[0073] For example, the number of steel plates in the steel plate portion P3 is not limited to three, but may be two or four or more. Furthermore, the steel plate portion P3 may have one steel plate and the steel plate portion P4 may have two or more steel plates. Furthermore, the steel plates in the steel plate portions P3 and P4 may be thicker than the steel plates in the steel plate portions P1 and P2. Furthermore, the steel plates in the steel plate portions P3 and P4 may be made of a different metal material from the steel plates in the steel plate portions P1 and P2 so that the spring force of the steel plates in the steel plate portions P3 and P4 is greater than the spring force of the steel plates in the steel plate portions P1 and P2.

[0074] The number of steel plates in the intermediate steel plate portion P5 is not limited to two, and may be one, three, or more. A wire mesh portion M or a brush portion Br may be interposed between the steel plates in the intermediate steel plate portion P5. The thickness of the steel plate in the intermediate steel plate portion P5 may be the same as the thickness of the steel plates in the steel plate portions P1 to P4. The steel plate in the intermediate steel plate portion P5 may be made of a different metal material than the steel plates in the steel plate portions P1 to P4. If the number of steel plates in the steel plate portions P3 and P4 is greater than the number of steel plates in the steel plate portions P1 and P2, the intermediate steel plate portion P5 may be eliminated. If the intermediate steel plate portion P5 is provided, the number of steel plates in each of the steel plate portions P3 and P4 may be the same as the number of steel plates in each of the steel plate portions P1 and P2.

[0075] Furthermore, in order to make the spring force of the sealing members 12Ba2, 12Bb2 in the lower region Un greater than the spring force of the sealing members 12Ba1, 12Bb1 in the upper region Up, the number of wires constituting the brush portion Br of the sealing members 12Ba2, 12Bb2 in the lower region Un may be greater than the number of wires constituting the brush portion Br of the sealing members 12Ba1, 12Bb1 in the upper region Up.

[0076] The invention made by the inventor has been specifically described above based on the embodiments, but the embodiments disclosed in this specification are illustrative in all respects and are not limited to the disclosed technology. In other words, the technical scope of the present invention should not be interpreted restrictively based on the description of the above embodiments, but should be interpreted solely in accordance with the claims, and includes technologies equivalent to the technologies described in the claims and all modifications that do not deviate from the gist of the claims.

[0077] In the above embodiment, a case where a ribbon screw type screw conveyor is used has been described, but the present invention is not limited to this and various modifications are possible. For example, a screw conveyor that combines a ribbon type and a shaft type may be used. [Industrial Applicability]

[0078] The above explanation has been given of the present invention as applied to a mud pressure shield machine, but it is not limited to this and can also be applied to other shield machines, such as a mud pressure shield machine that has a mechanism for stabilizing the face by applying a predetermined pressure to the mud in a chamber and transporting excavated soil by circulating the mud, or a tunnel boring machine that has the function of moving the body forward using a front gripper, a main gripper, and a thrust jack between them. [Explanation of symbols]

[0079] 1. Shield tunneling machine 2 cutter heads 3. Device body 4 chambers 5 Skin Plate 5a Front fuselage plate 5b Rear fuselage plate 7 Bulkhead 8 Cutter driver 9a Folding jack 9b Shield Jack 10 Screw conveyor 11 Erector 12 Tail seal part 12Ba, 12Bb, 12Ba1, 12Bb1 sealing material 12R seal chamber 14 Sealant supply pipe 14h communication hole CB Center Bit B bit CC copy cutter SB Stirring Bar SG Segment P1,P2 Steel plate part P3,P4 Steel plate part P5 Steel plate part M Wire mesh section Br Brush part

Claims

1. a cutter head for excavating the ground; a device body that rotatably supports the cutter head; a skin plate that forms an outer shell of the device body; a tail seal portion provided between an inner periphery of the skin plate and an outer periphery of a segment provided on the rear end side of the device main body; Equipped with The tail seal portion has a plurality of plate-shaped seal members provided along an inner periphery of the skin plate, the sealing member has spring properties, and one end of the sealing member in the front-rear direction of the device body is fixed to the skin plate, and the other end of the sealing member in the front-rear direction is in contact with the outer periphery of the segment, the plurality of seal members provided along the inner periphery of the skin plate are divided into seal members in an upper region and seal members in a lower region along the inner periphery of the skin plate, A shield tunneling machine characterized in that the spring force of the seal member in the lower region is stronger than the spring force of the seal member in the upper region.

2. The shield tunneling machine described in claim 1, characterized in that the sealing member has a springy steel plate portion fixed in a cantilevered manner to the skin plate, and the number of steel plates in the steel plate portion of the sealing member in the lower region is greater than the number of steel plates in the steel plate portion of the sealing member in the upper region.

3. the steel plate portion of the sealing member in the upper region has a first steel plate portion and a second steel plate portion provided inward from the first steel plate portion, the steel plate portion of the sealing member in the lower region has a third steel plate portion and a fourth steel plate portion provided inward from the third steel plate portion, A shield tunneling machine as described in claim 2, characterized in that the number of steel plates in the third steel plate portion of the sealing member in the lower region is greater than the number of steel plates in the first steel plate portion of the sealing member in the upper region.

4. A shield tunneling machine as described in claim 3, characterized in that the steel plate portion of the sealing member in the lower region further has a fifth steel plate portion between the third steel plate portion and the fourth steel plate portion.

5. the steel plate portion of the sealing member in the upper region has a first steel plate portion and a second steel plate portion provided inward from the first steel plate portion, A shield tunneling machine as described in claim 2, characterized in that the steel plate portion of the sealing member in the lower region has a third steel plate portion, a fourth steel plate portion provided inside the third steel plate portion, and a fifth steel plate portion provided between the third steel plate portion and the fourth steel plate portion.

6. A shield tunneling machine as described in any one of claims 1 to 5, characterized in that the lower region is set to the lower one-quarter to one-third of the total circumference of the skin plate, and the remainder is set to the upper region.

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